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Research on rechargeable ion batteries is in continuous rapid expansion driven by huge international investments in both scientific and industrial sectors. Significant research efforts are focused worldwide on the study and development of durable, reliable, cheap, ecological sustainable materials and energy devices. In this context, advanced analytical imaging, spectroscopic and X-ray diffraction techniques such as those offered by synchrotron facilities, can provide morphological, chemical and structural information not easily accessible by traditional laboratory methods.
“The battery challenge at synchrotrons” workshop is aimed at gathering scientists working on battery innovation and development and highlighting the most recent achievements obtained with synchrotron-based approaches, also providing future perspectives at soft x-ray FELs beamlines. This dissemination initiative is of strategic importance for Elettra-Sincrotrone Trieste as it is intended to both attract new users involved in ion battery research and reinvigorate the impact of our research infrastructure in the development of ion batteries.
This workshop will be hosted by Elettra-ST in the Adriatico Guesthouse, on November 29th and 30th, 2023.
No attendance fee is requested to the participants.
Confirmed invited speakers:
Scientific Committee:
Matteo Amati
Giuliana Aquilanti
Alessandra Gianoncelli
Alessandro Mariani
Jasper Plaisier
Emiliano Principi
Organizing Committee:
Michela Bassanese
Letizia Pierandrei
Mojca Skabar
In the last decades, remarkable industrial and academic research efforts have been focusing on lithium-ion batteries (LIBs) for portable electronics and electric vehicles (EV). Generally speaking, LIBs are more expensive than other battery chemistries, but they provide the highest power and energy densities as well as longer cycle. This technology requires further development in terms of safety and performance to establish itself also in the automotive market. Thus, new materials and chemistries at the positive/negative electrode sides as well as at the electrolyte side are necessary to overcome the state-of-the-art and the commercial benchmarks.
Over-stoichiometric Li-rich layered oxides (LRLO) materials are a family of promising positive electrode materials with large specific capacity and high working potential. The eco-friendly Co-free LRLOs have attracted a lot of attentions, thanks to the improved sustainability, reduced costs and outstanding performance (250 mAh g-1). The crystal structure and cation ordering of LRLO are a matter of controversy. In the literature the structure of these materials is identified as solid solution, with an R3 ̅m crystal structure with partial supercell ordering of lithium ions, or as a nano-mosaic constituted of coexisting solid-solution phases with R3 ̅m and C2/m structures. Overall, extensive defectivities play a key role in the breakdown of the cation ordering in the C2/m lattice that degrades in the R3 ̅m one. This structural ambiguity/instability is at the origin of the capacity and voltage fading in batteries originating from undesired lattice transformations.
The resilience of the LRLO lattice can be finely tuned by a careful optimization of the transition metals blend and overlithiation. This complex balance allows to enhance the electrochemical performance in batteries in parallel with the removal of cobalt.
Renewable energy production is characterised by intermittent power output and requires large-scale applications to improve energy storage capability (currently, less than 1% of the electrical energy production can be stored). Developing low-cost and environmentally friendly electrochemical storage systems characterised by high performance is of fundamental importance for a sustainable energy economy. The currently most mature battery technology is the lithium-ion battery, considered one of the most appealing candidates as a power source for electric vehicle applications. However, the large-scale application of lithium-ion batteries is currently under discussion due to the limited lithium and certain transition metals such as Co and Ni resources. Several other metallic anodic materials such as sodium, potassium, calcium, magnesium and aluminium [1–4], characterised by a higher abundance of lithium, have been considered suitable candidates for electrochemical storage devices in replacing lithium systems. Notably, significant efforts are being devoted to understanding and addressing key challenges in developing these so-called “beyond Li-ion” chemistries, and substantial insights into their storage and failure mechanisms have been obtained over the past few years thanks to advanced characterisation and computation/modelling techniques. An insight into the aluminium graphite dual-ion battery reaction mechanism obtained through advanced operando synchrotron-based techniques will be reported.[5–8]
Acknowledgements
Project funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.3 - Call for tender No. 1561 of 11.10.2022 of Ministero dell’Università e della Ricerca (MUR); funded by the European Union – NextGenerationEU Award Number: Project code PE0000021, Concession Decree No. 1561 of 11.10.2022 adopted by Ministero dell’Università e della Ricerca (MUR), CUP - E13C22001890001, according to attachment E of Decree No. 1561/2022, Project title “Network 4 Energy Sustainable Transition – NEST”
References
[1] G. A. Elia, K. Marquardt, K. Hoeppner, S. Fantini, R. Lin, E. Knipping, W. Peters, J.-F. Drillet, S. Passerini, R. Hahn, Advanced Materials 2016, 28, 7564.
[2] G. A. Elia, K. V. Kravchyk, M. V. Kovalenko, J. Chacón, A. Holland, R. G. A. Wills, J Power Sources 2021, 481, 228870.
[3] G. G. Eshetu, G. A. Elia, M. Armand, M. Forsyth, S. Komaba, T. Rojo, S. Passerini, Adv Energy Mater 2020, 2000093.
[4] I. Hasa, J. Barker, G. Elia, S. Passerini, in Reference Module in Chemistry, Molecular Sciences and Chemical Engineering, Elsevier, 2023.
[5] G. Greco, D. Tatchev, A. Hoell, M. Krumrey, S. Raoux, R. Hahn, G. A. Elia, J Mater Chem A Mater 2018, DOI 10.1039/C8TA08319C.
[6] G. A. Elia, I. Hasa, G. Greco, T. Diemant, K. Marquardt, K. Hoeppner, R. J. Behm, A. Hoell, S. Passerini, R. Hahn, J Mater Chem A Mater 2017, DOI 10.1039/c7ta01018d.
[7] G. A. Elia, G. Greco, P. H. Kamm, F. García‐Moreno, S. Raoux, R. Hahn, Adv Funct Mater 2020, 30, DOI 10.1002/adfm.202003913.
[8] G. Greco, G. A. Elia, D. Hermida‐Merino, R. Hahn, S. Raoux, Small Methods 2023, 7, DOI 10.1002/smtd.202201633.
Operando synchrotron radiation-based characterization techniques applied to energy storage materials are becoming a widespread characterization tool as they allow for non-destructive probing of materials with various depth sensitivities through spectroscopy, scattering, and imaging techniques. Moreover, they allow for faster acquisition rates, variable penetration depths, higher spectral or spatial resolution, or access to techniques that are only possible with a continuous tuneable source over a wide photon energy range. Compatibility between the electrochemical cell designs and the experimental setups may force some specific design features and care must be taken to ensure that these do not perturb the electrochemical response of the materials under investigation. The use of operando techniques has intrinsic advantages, as they enable the detection of metastable intermediates, if any, and ensure characterization under real conditions avoiding the risk of ex situ sample evolution during its preparation. Operando experiments are thus crucial for both the elucidation of redox mechanisms in new technologies and also for understanding of failure and aging processes for already commercial concepts. However, they do not come with the extent of risks. The interaction of the synchrotron radiation with the sample especially in the complex context of an operating electrochemical cell can give rise to abnormal behavior of the sample at the measurement point, compromising the reliability of the experiment. Here we will present a study that aims to assess the beam-induced effects under variable experimental conditions in terms of radiation energy and dose on commercial NMC and LPF electrodes and present a series of measures that can be taken to evaluate and minimize or suppress beam-induced hindrance in battery operando experiments.
Lithium-ion batteries are the state-of-the-art electrochemical energy storage technology and applied in wide range of devices, including inter alia portable electronic devices, power tools, (hybrid) electric vehicles, and stationary storage installations [1–3]. However, this tremendous success also calls for further improvement concerning their energy and power density, sustainability, and cost efficiency. While large improvements have been and will be realized by advanced battery, cell, and electrode designs, the development of new active material candidates is at the forefront of scientific activities. This frequently involves also new charge storage mechanisms that have been unexplored so far, e.g., combined alloying and conversion reactions as well as novel insertion-type processes.
Herein, the important role of hard and soft X-ray absorption spectroscopy will be highlighted to develop an in-depth understanding of these new reaction mechanisms, including the impact of the elemental composition of such materials for the processes occurring in the bulk of these new materials and at the interface with the electrolyte.
References
[1] M. Marinaro, D. Bresser, E. Beyer, P. Faguy, K. Hosoi, H. Li, J. Sakovica, K. Amine, M. Wohlfahrt-Mehrens, S. Passerini, J. Power Sources. 459 (2020) 228073.
[2] M. Armand, P. Axmann, D. Bresser, M. Copley, K. Edström, C. Ekberg, D. Guyomard, B. Lestriez, P. Novák, M. Petranikova, W. Porcher, S. Trabesinger, M. Wohlfahrt-Mehrens, H. Zhang, Journal of Power Sources. 479 (2020) 228708.
[3] B. Dunn, H. Kamath, J.-M. Tarascon, Science. 334 (2011) 928–935.
Batteries are of key importance in the energy transition, i.e. for mobility as well as for a temporary (intermediate) storage of excess energy (e.g. stabilise the grid). Li ion batteries are widely used in applications such as mobile phones and laptops, and will likely be key to future electromobility due to their low weight. Alternatively, more sustainable batteries are essential to enable the significant increase in demand as well as their differing applications and requirements (incl. local and grid storage), while reducing pressure on climate and environment.
Rational design of novel battery chemistries and technologies requires a detailed understanding of the charge, discharge and deactivation mechanisms, preferably quantitative and spatially resolved. X-ray techniques (spectroscopy and scattering (XAS and XRD) are characterisation technique which provide detailed structural and electronic information on the material under investigation, in a time- and spatially resolved manner. These operando spectro-electroechemical investigations [1] provide insights in the type, location and reversibility of the intermediates formed in and on electrodes and/or electrolytes as a function of state-of-charge and position in the battery. Obtained insights in cycling and deactiviation mechanisms for different battery types, i.e. Li-ion and Li-S [1-6] as well as more sustainable battery technologies like Ni-Fe and Fe-air, will be discussed.
[1] Y. Gorlin, A. Siebel, M. Piana, T. Huthwelker, H. Jha, G. Monsch, F. Kraus, H.A. Gasteiger, M. Tromp, J. Electrochem. Soc. 162(7): A1146-A1155, 2015.
[2] Y. Gorlin, M. U. M. Patel, A. Freiberg, Q. He, M. Piana, M. Tromp, H. A. Gasteiger, J. Electrochem. Soc. 2016, 163(6), A930-A939.
[3] J. Wandt, A. Freiberg, R. Thomas, Y. Gorlin, A. Siebel, R. Jung, H. A. Gasteiger, M. Tromp, J. Mater. Chem. A 2016, 4, 18300-18305.
[4] A. T. S. Freiberg, A. Siebel, A. Berger, S. M. Webb, Y. Gorlin, H. A. Gasteiger, M. Tromp, J. Phys. Chem. C 2018, 122, 10, 5303-5316.
[5] A. Berger, A. T. S. Freiberg, R. J. Thomas, M. U. M. Patel, M. Tromp, H. Gasteiger, Y. Gorlin, J. Electrochem. Soc. 2018, 165(7), A1288-A1296.
[6] R. Jung, F. Linsenmann, R. J. Thomas, J. Wandt, S. Solchenbach, F. Maglia, C. Stinner, H. A. Gasteiger, M. Tromp, J. Electrochem. Soc. 2019, 166(2): A378-A389.
Rational exploitation of the energy produced by renewable sources and electromobility, call for the development of efficient and reliable energy storage systems. Batteries are natural candidates for this purpose, and metal-air batteries are expected to gain momentum with respect to Li-ion technologies, because of their potentially higher energy density and sustainability. Among post-Li metal-air systems, Zn-air batteries are especially promising for safety, environmental and cost reasons. Disposable devices are already commercially available, but rechargeable systems are still far from the market, because two key challenges still remain open: on the one hand the optimization of bifunctional catalysts for the reversible air-cathode, that would increase the round-trip efficiency, and, on the other hand, the minimization of anode degradation in both the discharge and charge processes. Even if research is making great efforts in the field, satisfactory grasp of the mechanisms underlying these processes is still lacking. This talk will focus on an approach to the fundamental understanding of a comprehensive range of open issues of Zn-air batteries, based on spectroscopic and imaging methods, with special emphasis on in situ X-ray techniques. Recent results will be expounded, regarding: (i) oxygen catalyst fabrication, operation and degradation, followed by soft-X ray microspectroscopies (SXM) in the direct and Fourier spaces as well as EXAFS; (ii) unstable electrodeposition and dissolution studied in different electrolytes by SXM and photoelectron microspectroscopy; (iii) shape change of Zn anodes investigated by in situ X-ray micro Computed Tomography. This multi-technique approach, combined with mathematical modelling of electrochemical phase formation, opens up new routes for knowledge-based cathode and anode material design and the definition of rational charge/discharge policies.
The goal of the REALSEI project (MSCA-IF-2020) is to visualize for the first time in real-time the Solid Electrolyte Interphase formation at the hard-carbon (HC) anode in a Na-ion battery (NIB). Local electrochemical processes occurring at the solid-liquid interface of Na-ion batteries are currently largely unexplored. To keep global warming around 2.7°C by 2100, the installed global grid energy storage capacity needs to be tripled by 2050. A technological breakthrough is required to meet this challenge: we need a low cost and sustainable alternative to Li-ion batteries. Thanks to recent advances, the so-called ‘beyond-lithium’ batteries (BLB) such as K+ and Na+ based systems could be an everyday reality. Bio-waste mesoporous hard carbon (BHC) is one of the most promising anode materials as a universal ion host for BLBs. The use of BHC as a low-cost and recycled solution in BLBs might provide the breakthrough required and give rise to the next generation of batteries. However, uncontrolled SEI formation limits the large-scale application of BHC in BLBs, in particular for Na-ion batteries (NIBs), the most mature and promising. For NIBs, the SEI is still an unresolved issue that limits its long-term stability.
REALSEI established a comprehensive operando time- and space- resolved characterization methodology to transit from bulk (transmission mode) to surface analytical characterization (grazing incidence mode) based on lab and synchrotron high-resolution X-ray techniques which resulted for the first time in a comprehensive visualization and quantification of the species forming the SEI in real-time on HC. REALSEI will apply principles of physics and electrochemistry and its results have substantial scientific, technological, and societal impact.
Since their discovery, Deep Eutectic Solvents (DES) have been gaining growing attention due to their versatility coupled with good sustainability[1]. Indeed, DES are usually formulated starting from inexpensive, abundant and renewable materials. Initially, they were made by the complexation of choline chloride (ChCl, a quaternary ammonium salt) with a Hydrogen Bond Donor (HBD), which usually was urea, a carboxylic acid, a polyalcohol or a metal salt. Even though more than 15 years have passed since their discovery, fundamental research on these mixtures is still in its infancy. As a matter of fact, scientists mainly focused their efforts on the final application of DES.[2] Indeed, they were successfully employed in metal processing and extraction, as green solvents or gas absorbers and in industrial applications. The replacement of ChCl with metallic salts (e.g. NaCl, ZnCl2…) will enable their exploitation as electrolytes for electrochemical energy storage systems.
Notwithstanding the broad application of DES, a thorough knowledge of the chemical and physical interactions lying behind their formation is necessary, especially when one of the components is liquid at room temperature.[3] In fact, the solubilization of the salt in a liquid HBD could lead to either a DES or a salt-in-solvent system, following on from the intermolecular interactions established.
In this context, a stable hydrogen bond network (HBN) seems to play a pivotal role in the formation of the supramolecular interaction characterizing a DES. Recently, we explored the use of spectroscopy (both IR and Raman) coupled with structural and electrochemical analyses to analyze the HBN of a couple of mixtures of metal salts and glycerol: data analyses, supported by computational calculation, allowed us to determine the eutectic composition unequivocally.[4] However, lab-scale instrumentation usually suffers from low sensibility at lower wavenumber (< 150 cm-1), preventing us from systematically analyzing how the HBD nature influences the energetic contribution of HBN in DES formation. Here, the exploitation of advanced spectroscopic techniques, especially Far-InfraRed, provided at the Elettra synchrotron could allow a dramatic improvement in the fundamental understanding of the HBN in DES. Moreover, the rationalization of the dynamics and the energy of the HBN would be fundamental to designing stable liquid systems as electrolytes in electrochemical storage systems (i.e. batteries and supercapacitors).
Acknowledgements. This research acknowledges support from Project CH4.0 under the MUR program “Dipartimenti di Eccellenza 2023-2027” (CUP D13C22003520001). This study was carried out within the “GENESIS” project – funded by the Ministero dell’Università e della Ricerca – within the PRIN 2022 program (D.D.104 - 02/02/2022).
[1] S. Nejrotti, A. Antenucci, C. Pontremoli, L. Gontrani, N. Barbero, M. Carbone, M. Bonomo, ACS Omega. 7 (2022) 47449–47461. doi:10.1021/acsomega.2c06140.
[2] E.L. Smith, A.P. Abbott, K.S. Ryder, Chem. Rev. 114 (2014) 11060–11082. doi:10.1021/cr300162p.
[3] M. Bonomo, L. Gontrani, A. Capocefalo, A. Sarra, A. Nucara, M. Carbone, P. Postorino, D. Dini, J. Mol. Liq. 319 (2020) 114292. doi:10.1016/j.molliq.2020.114292.
[4] F. Cappelluti, A. Mariani, M. Bonomo, A. Damin, L. Bencivenni, S. Passerini, M. Carbone, L. Gontrani, J. Mol. Liq. 367 (2022) 120443. doi:10.1016/j.molliq.2022.120443.
Phase transitions in electrodes are considered to be the major reason for ageing in lithium/Sodium ion batterie. The electrolyte decomposition, on the other hand, leads to the formation of a protective and insulating layer called the solid electrolyte interphase (SEI) [1,2] that prevents further reduction of the active material interfaces, leading to an operative electrode while its ionic conductivity allows the Li+/Na+ battery operation. [3,4] Depth profiling of the active material and SEI layer starting from the very first monolayers of the structure to a few nanometers below can improve the understanding of the formation and evolution of the battery performance. Different approaches for depth profiling of the active materials and SEI structure, such as Ar+ sputtering, have proven to induce an artificial material gradient, endangering the consolidated picture of the prevalence of inorganic components occupying regions close to the active particles and of organics occupying the external zone. [5] X-ray absorption spectroscopy (XAS), specially in soft regime, is a powerful technique to investigate the evolution of the short-range structure with a tunable probing depth in the range 3–100 nm with minimal destructive effects, preventing the degradation of the components of the active material and SEI layer upon measurement.[6,7] It is also element-specific, targeting the evolution of a desired chemical species in complex systems. X-ray photoemission spectroscopy (XPS), on the other hand, is strongly surface-sensitive and can be used to investigate the SEI superficial layer within the first few atomic monolayers. The combination of the two techniques results in a depth profiling of the active material and SEI layer without invasive structure modification providing a complete image of their structural dynamics.
[1]Peled, E. The Electrochemical Behavior of Alkali and Alkaline Earth Metals in Nonaqueous Battery Systems– The Solid Electrolyte Interphase Model J. Electrochem. Soc. 1979, 126, 2047– 2051
[2]Peled, E.; Golodnitsky, D.; Ardel, G. Advanced Model for Solid Electrolyte Interphase Electrodes in Liquid and Polymer Electrolytes J. Electrochem. Soc. 1997, 144, L208– L210
[3]Verma, P.; Maire, P.; Novak, P. A Review of the Features and Analyses of the Solid Electrolyte Interphase in Li-Ion Batteries Electrochim. Acta 2010, 55, 6332– 6341
[4]Peled, E. Lithium Batteries; Gabano, J. P, Ed.; Academic Press, 1983.
[5]urbach, D.; Zaban, A.; Gofer, Y.; Ely, Y. E.; Weissman, I.; Chusid, O.; Abramson, O. Recent Studies of the Lithium-Liquid Electrolyte Interface Electrochemical, Morphological and Spectral Studies of a Few Important Systems J. Power Sources 1995, 54, 76– 84
[6]Rezvani S. J. , Nobili F, Gunnella R, Ali M, Tossici R, Passerini S, Di Cicco A (2017). SEI Dynamics in Metal Oxide Conversion Electrodes of Li-Ion Batteries. JOURNAL OF PHYSICAL CHEMISTRY. C, vol. 121, p. 26379-26388
[7]Rezvani S. J. , Gunnella R, Witkowska A, Mueller F, Pasqualini M, Nobili F, Passerini S, Di Cicco A (2017). Is the Solid Electrolyte Interphase an Extra Charge Reservoir in Li-Ion Batteries?. ACS APPLIED MATERIALS & INTERFACES, vol. 9, p. 4570-4576,
Niobium-based oxides were recently proposed as new anode materials for advanced Lithium-Ion Batteries (LIBs) [1], due to very high theoretical capacities and high working potential that can prevent the formation of lithium dendrites, increasing the battery safety. Most of them crystallizes in open Wadsley–Roth shear structures, which show large Li-ion diffusion coefficients and promising applications in energy storage systems [2]. The results of the application of in situ Raman Spectroscopy, operando X-Ray Diffraction (Figure 1) and electrochemical techniques to unravel the complex structural and electrochemical features of FeNb11O29 will be discussed [3]. The intrinsic pseudocapacitance shown by the iron niobate is correlated to the large channels of the structure that cause weak Li+-host interactions and very little charge- transfer resistances. The symmetrisation of the octahedral framework that occurs after the reduction of Nb5+ cations, detected for the first time, seems to be the key of the electrochemistry of FeNb11O29, which shows excellent features for advanced high-power density LIBs.
[1] I. Pinus, M. Catti, R. Ruffo, M.M. Salamone, C.M. Mari. Chem. Mater. 2014, 26, 2203. DOI: 10.1021/cm500442j
[2] D. Spada, I. Quinzeni, M. Bini, Electrochimica Acta 2019, 296, 938. DOI: 10.1016/j.electacta.2018.11.047
[3] D. Spada, B. Albini, P. Galinetto, D. Versaci, C. Francia, S. Bodoardo, G. Bais, M. Bini, Electrochim. Acta 2021, 393, 139077. DOI: 10.1016/j.electacta.2021.139077.
Realizing post-lithium-ion batteries, such as Metal-sulfur (Li-S) and metal-air (Li-O2) batteries, could be game-changing due to theoretical specific capacity amongst the highest of all batteries paired with the low cost and sustainability of the active materials. However, the insufficient understanding of the mechanism that reversibly converts the active materials between their lithiated and de-lithiated state slows down the practical realization.
In this talk, I will present the results of employing operando small and wide angle X-ray scattering (SAXS/WAXS) and operando small angle neutron scattering (SANS) to track the growth and dissolution of solid deposits from atomic to sub-micron scales during operating a Li-S battery cell [1]. Machine-learning-assisted stochastic modelling based on the SANS (and SAXS) data allows quantification of the chemical phase evolution during discharge and charge. Combined with complementary data from transmission electron microscopy and Raman spectroscopy, we show that the deposit is comprised of nanocrystalline Li2S and smaller, solid short-chain polysulfide particles. Knowing this has important implications for influencing the reaction mechanism. As a second example, I will show results from operando SAXS/WAXS on Li-O2 battery cathodes, tracking the reversible formation and dissolution of Li2O2 on the nanoscale [2, 3].
The examples on Li-S and Li-O2 batteries demonstrate that structural information on mesoscopic length scales is key to understanding complex transformations in energy materials. Operando SAXS/SANS, (cryo-) electron microscopy, and machine-learning-assisted stochastic modelling combine the advantages of integral time-resolved structural information, local element-specific microscopy, and quantitative data analysis.
References:
[1] C. Prehal, V. Wood et al. Nature Communications 13, 6326 (2022)
[2] C. Prehal, S.A. Freunberger et al. PNAS 118, 14, e2021893118 (2021)
[3] C. Prehal, S.A. Freunberger et al. ACS Energy Letters 7, 9, 3112 (2022)
Lithium-ion batteries (LIBs) represent one of the pillars of the energy transition induced by the climate changes [1]. While the choice of the materials used as electrodes determines the power energy, the voltage window is defined by the thermodynamic stability of the employed organic electrolytes. When cycling the batteries outside the stability window of the electrolyte, it can decompose, and a few Å-thin and chemically inhomogeneous layer called solid-electrolyte interphase is formed on the positive (CEI) and negative (SEI) electrodes. While the SEI is responsible of the initial irreversible capacity lost during the firsts cycles, its electronic insulating character prevents from the short-circuit of the battery and further degradation of the electrolyte upon cycling. It is therefore clear why the understanding of the formation and stability of the SEI is of pivotal importance for improving safety [2], lifespan and power density [3] of the next battery generation. Thanks to its high chemical sensitivity, XPS is the suitable tool to study the heterogeneous and mosaic-like SEI, providing accurate information about its chemical composition. On the other hand, XPS requires UHV environment, and it is extremely surface sensitive, thus ex situ electrodes are heavily manipulated before the XPS analysis to remove the salt excess, inducing significant changes in the SEI [4]. Here we propose two approaches to directly investigate the SEI in the framework of the European Battery Interfaces Genome – Materials Accelerations Platform (BIG-MAP) [5]. First, the solid-liquid interphase is probed through the electrolyte using the dip & pull setup combined with Near Ambient Pressure Photo-electron Spectroscopy (NAP-PES) available at HIPPIE beamline (MAXIV, Lund), where we have investigated the interphase formed on a glassy carbon electrode cycled against metallic lithium as a function of applied voltage [6]. Second, we have studied the formation and stability of the interphase through the solid phase with hard X-rays PES (HAXPES). Therefore, a tailored liquid cell has been designed and developed at GALAXIES beamline (SOLEIL, France), aiming to reproduce realistic electrochemical properties. Preliminary tests showed the feasibility of the HAXPES approach and guided us to optimize the experimental. These two approaches represent a first step towards obtaining crucial information regarding the SEI growth and stability, thus paving the way for future studies on the effect of electrolyte additives and solvent mixtures on battery performances.
[1] O. Gröger, et al., J. of Electrochem. Soc., 2015, 162(14), A2605. DOI:10.1149/2.0211514jes
[2] M. Gauthier, et al., J. Phys. Chem. Lett., 2015, 6(22), 4653-4672. DOI:10.1021/acs.jpclett.5b01727
[3] E. Peled, et al., MRS Online Proceeding Library Archive, 1995, 395.
[4] K. Edström, et al., J. Power Sources, 2006, 153(2), 380-384. DOI:10.1016/j.jpowsour.2005.05.062
[5] D. Atkins, et al., Adv. Energy Mater., 2021, 2102687. DOI:10.1002/aenm.202102687
[6] F. G. Capone et al., Submitted to Energy and Environmental Science, 2023.
Higher energy density materials are being pushed by the research community to make lithium ion batteries a better competitor of chemical fossil fuels for transport applications. This increases potential risk of lithium ion batteries and therefore safety investigations are highly important for application purposes. Operando Computer Tomography provides a non-destructive investigation method of different abuse mechanisms.
Application of X-ray computed tomography (XCT) for studying lithium-ion batteries has gained interest among the research community especially in the past decade [1]. This technique is widely used for ex-situ samples to measure porosity and tortuosity [2], particle size and volume distribution [3] in the graphite anode as well as different cathode materials such as LiCoOx and NiMnCoOx. [4]. In situ measurements of commercial batteries are also often carried out to detect defects induced in a cell by a safety abuse test or manufacturing process [5]. Operando CT of large cells (for example 18650 form factor) is conducted at synchrotron facilities with high flux of high energy photons, however at a cost of details due to the large field of view [6].
Thanks to their high brilliance, synchrotron beam facilitates us to do a full Computed Tomography in a short time. This enables us to measure batteries while being cycled with a reasonable time resolution to record morphological changes. In this poster we illustrate how one can utilize this ability to investigate abuse mechanisms on an actual commercially available lithium ion battery as well as a home made micro cell.
In this work, synchrotron X-ray computed tomography is applied to commercial lithium-ion batteries. It is shown how to find most suitable imaging settings to study available lithium-ion batteries on different size scales, from cell level to particle level. We also demonstrate how to optimize contrast as well as both temporal and spatial resolutions to study in-situ and operando processes in a commercial battery using attenuation and phase contrast SXCT. Manufacturing defects and inconsistencies on cell level as well as the electrode and microstructure on material level are shown in our study.
Using the presented methodic, some abuse conditions are induced and imaged in operando on a commercially available li-ion battery. In this work, deep discharge mechanism is visualized and quantified in detail for the first time in 4 dimensions.
Chemically produced graphene has already been used to increase specific capacity of batteries and maximum rate of charge and discharge; thanks to its affinity with graphite, batteries with graphene-based anodes can be assembled easily by partially exploiting the already established lithium-ion battery (LIB) technology. Moreover, graphene is also a good candidate in composite materials, in conjunction with high capacity lithium-ion cathodes or anodes, as a conductive matrix.
Graphene was synthesized by thermal exfoliation of graphite oxide (TEGO), while hydrogenated TEGO (H-TEGO) was obtained by heating TEGO under hydrogen flux. Lithium half-cells were assembled either to characterize TEGO and H-TEGO or to achieve preformation of the SEI on the graphene-based electrodes before assembling full cells. Preformed graphene-based electrodes were tested in full cells in combination with different cathodes.
Hydrogenated graphene boasts an impressive reversible specific capacity with fast charge/discharge capabilities, exceeding 370 mA h g-1 even at 25 C-rate. Diffusion mechanisms of lithium is characterized at different states of intercalation by means of electrochemical impedance spectroscopy. In addition, a novel combined electrostatic and electrochemical charge storage mechanism of lithium ions in graphene-based electrodes is proposed, based on three-electrode cyclic voltammetry investigation. Furthermore, graphene and hydrogenated graphene anodes are paired with commercial cathode materials, to study the feasibility of their application to full-cells.
Besides the efforts to further increase the overall battery performance, the sustainability aspect is gaining more and more importance. From that perspective, aqueous processed cobalt-free LiNi0.5Mn1.5O4 (LNMO) positive electrodes represent a promising candidate – not least as they enable a higher energy density compared to cobalt-free LFP. As presented in previous publications, there have been already a lot of efforts made to optimize the LNMO active material and its electrochemical performance.[1–3] In the work presented here, we combined the previously optimized LNMO, the specially developed aqueous processing, and an optimized electrolyte composition to achieve the best performing aqueous processed graphite‖LNMO Li-ion Cells reported so far. More specifically, to understand how the applied surface modification and the electrolyte additives protect the LNMO active material during cycling and also storage, soft-XAS is a very powerful technique that enables the simultaneous characterization of the electrode surface (including the cathodeelectrolyte interface, CEI) and the bulk material. The results provide an answer to the question why the protection mechanism differs for the cycling and storage tests, which is rather unexpected, in fact.
[1] G. Gabrielli, P. Axmann, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2016, 163, A470–A476.
[2] M. Kuenzel, D. Bresser, T. Diemant, D. V. Carvalho, G. T. Kim, R. J. Behm, S. Passerini, ChemSusChem 2018, 11, 562–573.
[3] A. Kazzazi, D. Bresser, M. Kuenzel, M. Hekmatfar, J. Schnaidt, Z. Jusys, T. Diemant, R. J. Behm, M. Copley, K. Maranski, J. Cookson, I. de Meatza, P. Axmann, M. Wohlfahrt-Mehrens, S. Passerini, J. Power Sources 2021, 482, 228975.
Li-rich layered oxides (LROs) are amongst the most promising high voltage cathode materials with regards to their practical density and cost, to increase the efficiency of Li-ion batteries (LIBs). LROs are reported to exhibit capacities reaching >250 mAh/g. However, LROs suffer from low initial coulombic efficiencies, voltage decay and low-rate capabilities. The origin of these issues is difficult to interpret, and thereby tackle, due to the inherent complexity of the oxide. These oxides consist of two crystal structures, monoclinic and rhombohedral, the combination of which is still under scrutiny in the scientific community. In this work, LROs are synthesized through sol-gel synthesis; different parameters are varied and their effect on the structure of the material is studied through lab-scale to synchrotron techniques. The study indicates clear distinction in particle size and ordering of monoclinic and rhombohedral phases in local and bulk range. The results of this work illustrate the need for in-depth characterization of LROs to adequately understand and compare LROs synthesized by differing parameters, in order to establish a clear foundation for further work in this growing field.
Asymmetric hybrid supercapacitors (AHSCs) exploit the advantages of both supercapacitors and batteries by storing charges through both capacitive processes and redox reactions. The capacitive electrical double layer is effectively harnessed using graphene electrodes due to its exceptional specific surface area. Meanwhile, redox reactions are introduced by means of transition metal oxide/hydroxide materials, such as Ni(OH)2 which possess a theoretical specific capacity exceeding 1400 C/g in KOH-based aqueous electrolyte [1].The physico-electrochemical properties and the application of both graphene and Ni(OH)2-decorated graphene electrodes in an AHSC are characterized. Reduced graphene, produced via thermal exfoliation of graphite oxide (TEGO), with a specific surface area of 600 m2/g [2], is a good candidate as a supercapacitor electrode, achieving a specific charge of 110 C/g at 10 mV/s. Moreover, owning a great defect amount, TEGO is able of anchoring Ni nanoparticles (NPs). During the early voltammetry cycles in KOH 3.5 M aqueous electrolyte, metal Ni-NPs are converted in Ni(OH)2, enabling the positive electrode to reach a high reversible specific charge of 800 C/g at 10 mV/s. The effective oxidation of Ni-NPs to nickel hydroxide is proved by both powder-XRD and operando Raman spectroscopy. Coupling TEGO with Ni-NPs decorated TEGO, an extended working voltage window of 1.5V has been reached [3].
Commercially available lithium-ion batteries (LIBs) show limitations for future large-scale applications, due to still low energy density, safety, slow charge/discharge rate and limited cycle-life. Battery recycling is also still an open problem, mostly bound to the use of toxic heavy metals. TiO2 is an abundant, low-cost and environmentally friendly electrode material, attractive for large scale energy-storage. However, TiO2 electrodes suffer from low electrical conductivity. Graphene can embed TiO2 nanoparticles, forming a conductive nanocomposite anode material for Li-ion batteries, with improved Li-ion and electron transport. Here, novel gram-scale graphene-based electrodes decorated with titanium dioxide (TiO2) anatase were investigated as anodes for LIBs.
Graphene employed for this work was obtained in large (grams) scale, through a thermal exfoliation of graphite oxide (TEGO) under dynamic vacuum. We managed to decorate TEGO with TiO2 anatase nanocrystals via a novel facile solvothermal synthesis employing titanium tetraisopropoxide as TiO2 precursor. Different stoichiometries of TiO2:TEGO have been synthesized, characterized with powder XRD, Raman and TEM; the electrochemical behavior was studied in half-cell configuration (CR2032 coin cells) via galvanostatic chronopotentiometry. The structural evolution of TiO2 nanocrystals was followed by means of operando synchrotron powder x-ray diffraction.
We found that graphene plays an important role, both as a substrate, favouring the almost pure TiO2 anatase nanocrystal growth, and as an efficient charge collector, thanks to its high electrical conductivity, contrasting the insulating nature of TiO2 and thus improving specific capacity of the electrode. In particular, electrodes with 99:1 TiO2:TEGO composition proved to be the most promising ones, showing a stable and reversible capacity of above 180 mAh/g at C/5 and high charge/discharge capability.
A possible Na-ion batteries (SIB) consists of non-graphitizable carbons for the negative electrode and Na3V2(PO4)2F3 (NVPF) for the positive electrode. (De)intercalation and (de)insertion of Na ions from/into non-graphitizable carbons and NVPF are focus of many recent studies [1]. The mentioned battery is relatively new compared to Li-ion, and the exact mechanism of its operation and degradation is not yet clear [2]. In this study, the physical and electrochemical properties of half-cell corncob derived non-graphitizable carbon prepared at 1400°C [3] and NVPF were established via operando solid-state nuclear magnetic resonance (NMR) spectroscopy.
It is likely that various metastable, intermediate, and/or short-lived phases occur during the electrochemical reactions in the cell are not captured in the ex-situ mode. Therefore, recent research is moving towards operando measurements. In this mode, the battery is not destroyed during operation, but rather non-invasive methods are used to observe the battery in operation and thus provide information on dynamic structural changes and processes in real time. The main reasons that operando NMR method has rarely been used is that it is quite difficult to manipulate samples in a very limited space and in a very strong magnetic field. Also, the sample during the operando NMR measurement is static so the signal peaks are broader and thus the resolution of the measurement is lower compared to ex-situ NMR measurements where the magic angle spinning method can be used [4][5].
By measuring 23Na NMR spectra of non-graphitizable carbon in a half cell configuration, we obtained information about sodium intercalation in the active material, leading to a shift of the NMR peak during the sodiation process, the formation of a solid electrolyte interphase (SEI) on the electrode surface in the form of Na2CO3 and the potential formation of plating and metal sodium dendrites. Additionally, we were also able to observe changes in the chemical environment of the NVPF material during sodiation in half-cell configuration.
This research received financial support from CERIC-ERIC and the Slovenian Research and Innovation Agency (ARIS) under research program P2-0423 and project N2-0266.
[1] X. Chen, Y. Zheng, W. Liu, C. Zhang, S. Li, and J. Li, Nanoscale, Dec. 2019, vol. 11, no. 46, pp. 22196–22205, DOI: 10.1039/C9NR07545C.
[2] C. Bommier, T. W. Surta, M. Dolgos, and X. Ji, Nano Lett., Sep. 2015, vol. 15, no. 9, pp. 5888–5892, DOI: 10.1021/acs.nanolett.5b01969.
[3] B. Tratnik et al., ACS Appl. Energy Mater., Sep. 2022, vol. 5, no. 9, pp. 10667–10679, DOI: 10.1021/acsaem.2c01390.
[4] O. Pecher, J. Carretero-González, K. J. Griffith, and C. P. Grey, Chem. Mater., Jan. 2017, vol. 29, no. 1, pp. 213–242, DOI: 10.1021/acs.chemmater.6b03183.
[5] L. H. B. Nguyen et al., Chem. Mater., Dec. 2019, vol. 31, no. 23, pp. 9759–9768, DOI: 10.1021/acs.chemmater.9b03546.
The increasing popularity of portable electronic devices and the fast development of electric vehicles have greatly spurred the modernization of lithium-ion batteries (LIBs) towards higher energy density, higher power density, and better safety. The currently commercialized graphite anode is limited by its relatively low theoretical and practical capacity (372 mAh g-1), its sluggish lithium-ion diffusivity and the difficulties to meet the growing demand for the next-generation energy storage systems.[1] As superior alternatives to graphite anode, lithium metal anodes display higher theoretical capacities. However, these systems produce dendrite and whisker formations. These, together with volumetric changes, strongly affect the safety and lifetime of the battery.[2]
In this sense, the development of anode-less batteries provides numerous benefits, which can be highlighted as an increased energy density, safety improvement and reduction of costs. Many of the current batteries under the concept of anodes-less or anode free, have an extra reservoir of lithium to compensate the irreversibility of the electrochemical processes. This extra contribution is usually given by the cathode with the use of sacrificial salts; in this case, preconditioning cycles are needed with the subsequent increase in fabrication costs and reduce the energy density. On the other hand, surface modification of the current collector (CC) is one of the most used strategies to improve electrochemical behavior in anode free lithium metal batteries (AFLMB).[3]
In this regard, thermal evaporation is a well-known and very basic technique for coating surfaces and substrates with both organic and inorganic thin layers.[4] This technique is especially suitable for materials with low melting points and high vapor pressure, as for instance lithium with melting point 180ºC.[5]
In this study, a quasi-anode free lithium metal battery is presented. It has been fabricated by using thermal evaporation technique to deposit a lithium thin film onto the Cu current collector. No modifications have been carried out neither any CC treatment. Cell assembly has been done with commercial liquid electrolyte without additives.
This study will show the substantial improvements on the electrochemical performance of lithium batteries when used with lithium thin film deposited on Cu current collector by thermal evaporation.
[1] D. Lin, Y. Liu, and Y. Cui, “Reviving the lithium metal anode for high-energy batteries,” Nat Nanotechnol, vol. 12, no. 3, pp. 194–206, Mar. 2017, doi: 10.1038/nnano.2017.16.
[2] H. Wang, J. Wu, L. Yuan, Z. Li, and Y. Huang, “Stable Lithium Metal Anode Enabled by 3D Soft Host,” ACS Appl Mater Interfaces, vol. 12, no. 25, pp. 28337–28344, Jun. 2020, doi: 10.1021/acsami.0c08029.
[3] C.-J. Huang et al., “Lithium Oxalate as a Lifespan Extender for Anode-Free Lithium Metal Batteries,” ACS Appl Mater Interfaces, vol. 14, no. 23, pp. 26724–26732, Jun. 2022, doi: 10.1021/acsami.2c04693.
[4] T. Nishinaga, “Handbook of Crystal Growth: Thin Films and Epitaxy: Second Edition,” Handbook of Crystal Growth: Thin Films and Epitaxy: Second Edition, vol. 3, pp. 1–1346, Dec. 2014, doi: 10.1016/C2013-0-09792-7.
[5] B. Acebedo et al., “Current Status and Future Perspective on Lithium Metal Anode Production Methods,” Adv Energy Mater, vol. 13, no. 13, Apr. 2023, doi: 10.1002/aenm.202203744.
Quantum Computing (QC) has the potential to revolutionize battery research by not only offering
computational advantages over classical computers but aspiring at a potential paradigm shift in
computational approaches. Potential research applications of high impact are in material
discovery, electrolyte design, reaction kinetics, molecular dynamics, and optimization of charging
algorithms.
This work aims at providing an overview of these applications but focuses on optimisation of
charging algorithms. Optimization of charging algorithms for batteries is an essential aspect of
battery management and energy storage system design. The goal is to maximize the efficiency,
performance, and lifespan of batteries while ensuring safe charging operations. Long term
scientific progress may arise by simulations of the complex physical and chemical processes,
including ion diffusion, electrochemical reactions, and thermal management but also in other
domains such as rapid testing of multiple charging algorithms, safety considerations and grid
integration. The goal of this research is to introduce an application for QC for adaptive charging
where the quantum algorithm could adapt a prohibitively large number of charging parameters in
real-time based on the battery’s current state. For example, if the battery is showing signs of
heating up or increased internal resistance, the algorithm could automatically reduce the charging
rate and voltage to prevent overheating and extend the battery's life. Conversely, when the battery
is in optimal conditions, it could allow faster charging to meet user demands. The preliminary
results point at Quantum Variational Algorithms in specific the Approximate Optimization
Algorithm (QAOA) for approximating the solutions to combinatorial optimization problems.
Quantum annealers, basic Grover's algorithm, and Quantum Adiabatic optimization are also
presented in relation to the problem of adaptive charging.
This work also stresses that QC is still in its early stages, and practical applications are limited by
the current state of quantum hardware, which may not yet offer a significant advantage over
classical computers for many optimization problems. However, as quantum technology continues
to advance, it is expected that quantum optimization algorithms will find broader application in
energy research. In order to illustrate the complexity of such developments, this work also
presents the overview of a state-of-the-art atomic system.
The poster presents a novel Electrochemical Impedance Spectroscopy (EIS) methodology for lithium-ion cells, and a digital model simulating the measurement system. The proposed methodology takes the nonlinear behaviour of the lithium-ion cell into account, modelling the cell as a Volterra system. The digital model is employed to showcase both the strengths and weaknesses of the proposed method and it is hereinafter referred as the Digital Twin (DT).
The EIS methodology is the common approach used to acquire information about electrochemical conditions of the cell, analysing the variations of resistance and reactance in relation to frequency – the Nyquist diagram. The shape of the Nyquist diagram changes as the cell charges and discharges, and the evolving shape over time offer valuable information, primarily related to aging phenomena, State of Charge (SoC), and State of Health (SoH).
Despite its different tasks, the EIS method is almost invariably implemented by subjecting the cell to different tones, as the impedance is calculated by the ratio of the fundamental harmonics of voltage and current at each stimulating frequency.
In contrast, the proposed methodology consists of stimulating the cell with a specific current signal. The current signal is obtained from a deterministic and periodic sampled signal, whose samples have a white uniform distribution. The impedance spectrum for small signal amplitude (i.e., the spectrum of first order Volterra kernel) of the cell is estimated with the Orthogonal Periodic Sequences (OPS) technique, computing the cross-correlation between the output voltage samples and the OPS. The technique is robust towards the higher order Volterra kernels, i.e., towards the cell nonlinear effects. The DT provides a controlled and customizable environment, serving as a reference system for a prior verification of the measurement equipment, before conducting tests on the cell.
Batteries are electrochemical devices that have characterized society and its development in recent decades. Moreover, to improve the use of renewable energy sources and electric vehicles, and with the continuous growth of the demand for portable electronics, the demand for batteries that can meet global needs has increased. Currently, the most widely used type of them is the lithium-ion battery (LIB), which is reliable and provides satisfying electrochemical performances[1]. However, the most used anode in this system is the graphite anode (theoretical capacity of 370 mAh g-1 ), which suffers from aging and becomes unsafe with high currents. So, it is important to investigate other types of materials as possible and promise anode that could give better properties. MAX phase (where M is a transition metal cation, A is a metallic or metalloid element and X is C, N or B) are a class of 3D materials, with layered hexagonal crystal structure (space group P63/mmc) consisting of several layers of MX, alternated with layers of pure A-elements along the c cell parameter[2]. One of the most common of this class of materials is the Ti3AlC2 MAX phase. However, it shows poor energy storage performances as active electrode (capacity of 60 mAh g-1).
One compound well-known as active material is titanium oxide (TiO2). This has been shown to be a well-established and particularly stable material for applications in ion batteries. However, it has a lower capacity than graphite[3].
One interesting material as electrode is tin oxide (SnO2): this is a very promising material due to its high specific capacity, but it suffers from poor stability due to the high volume change it undergoes during charge and discharge cycles[4].
A possible strategy to improve the long-term stability of this oxide is to use the stable titanium oxide with it: is reported that by adding it, making a solid solution of Sn/Ti oxide, the total system achieves less volume change during cycling and so gains a stability improvement.
Here, a promising strategy to obtain a new active electrode material based on the MAX-phase system, combined with titanium/tin oxide to improve its specific capacity, is proposed. First, MAX-phase Ti3Al(1-x)SnxC2 are obtained via spark plasma sintering, with x equal to 0.4, 0.7 and 1. After that, the material is oxidized by a thermal treatment in air to obtain a nanostructured layer based on tin oxide and titanium oxide. To better understand their structure and composition, these materials are investigated by morphological and structural analysis, like x-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. Then, their electrochemical properties are studied, versus lithium in coin cell setup and versus a working positive electrode in pouch cell setup, demonstrating their possible availment as promising negative electrode in LIB.
Sodium-ion batteries have attracted great interest because of the wide range of their potential applications and sodium abundance. To make Na-ion batteries competitive, the research on Na-ion batteries focuses on the development of new electrode materials, offering higher specific charges and voltages to reach higher energy density and performance comparable to or higher than those of state-of-the-art Li-ion batteries [1]. Therefore, we are searching for novel Na-ion Co-free materials with high specific charge, preferably mainly based on earth-abundant elements like Mn. One promising approach to achieve this goal is the substitution of one of the transition metals by lithium, which not only increases energy density due to its low molar mass but also, as an additional positive ion in the structure, leads to the increase of manganese oxidation state. In conventional intercalation cathodes, Na-ions can move in and out of a layered material, with the charge being compensated by reversible reduction and oxidation of the transition metal ions. Since Mn4+ ions are not likely to change their oxidation state in the cycling voltage range, the anionic redox reaction on oxygen is likely to be the only accountable resource for the observed reversible capacity. This can increase the battery’s energy density by storing charge on both the oxygen and manganese, rather than on the transition metal alone.
The aim of this work was to study the influence of the degree on charge compensation mechanism, crystal structure, and gas evolution in Mn-based materials, Na0.6Li0.1Mn0.9O2 and Na0.6Li0.2Mn0.8O2. To achieve this goal, materials have been synthesized using solid-state synthesis approach and characterized using electrochemical methods, operando XRD, Online Electrochemical Mass Spectrometry (OEMS) and X-ray Absorption Spectrometry (Swiss Light Source, SuperXAS beamline).
Na0.6Li0.1Mn0.9O2 showed an excellent initial capacity of 180 mAh/g, and the evolution of oxygen at high voltages during first charge was suspected from the shape of the potential profile. No particular Li ordering has been observed for this material. Na0.6Li0.2Mn0.8O2 had ribbon-type Li ordering [2] and a lower capacity of 140 mAh/g without showing any oxygen evolution characteristics in the potential profile.
The material with lower lithium content exhibited also an irreversible phase transition during first charge as detected by operando XRD. The gas evolution at voltages above 4.2 V suggests that irreversible oxygen redox reactions actually take place in case of Na0.6Li0.1Mn0.9O2. Additionally, XAS measurements revealed rather a peculiar behavior of the Mn oxidation degree upon first charge for this material. The decrease of the oxidation state of the transition metal at voltages seems to correspond well with the irreversible oxidation of O2- ions and loss of oxygen from the structure during the first cycle, which was confirmed by OEMS. Furthermore, the presence of Li-ordering appears to stabilize Na0.6Li0.2Mn0.8O2 both in terms of crystal structure and gas evolution. The influence of different degrees of Li substitution in sodium manganese layered oxides on oxygen redox activity will be discussed.
Acknowledgements: The SCCER HaE network is acknowledged for funding
[1] S. F. Schneider, C. Bauer, P. Novák & E.J. Berg, Sustain. Energy Fuels 3 2019 3061
[2] R. A. House, U. Maitra, M. A. Pérez-Osorio, J.G. Lozano, L. Jin, J. W. Somerville, L.C. Duda, A. Nag, A. Walters, K-J Zhou, M. R. Roberts & P. G. Bruce, Nature 577 2020 502
With the growing need to further enhance the sustainability of lithium-ion batteries (LIBs), the substitution of critical raw materials like cobalt in common positive electrode materials, i.e., layered oxides, by more abundant elements such as nickel and manganese is considered essential [1]. To address the challenging structural instability of such compositions, tuning the stacking order of these layered oxides towards the T2/O2-type structure is known as an effective approach [2]. However, the inherent Li+ deficiency and limited first charge capacity remains a major obstacle for any practical application [2,3].
Within this study, we introduce a new synthesis concept to overcome this limitation by exemplarily increasing the Li+ content in T2-Li0.67Ni0.33Mn0.67O2 obtained by a Na+/Li+ ion-exchange process. Based on a reductive treatment this approach is shown to be capable of significantly enhancing the first charge capacity of such materials and, thus, compensate the Li+ deficiency. Surprisingly, different synthesis environments appear to strongly influence the shape of the first charge voltage profile with a significant impact on the cycling stability. To understand the mechanism of the lithiation process and the nature of additionally incorporated Li+, we performed an in-depth investigation to differentiate between structural and morphological effects, as well as surface and bulk contributions.
In particular, we highlight the capability of ex situ soft-XAS to address such questions regarding the evolution of oxidation states, the composition of surface layers, and the resolution of depth-dependent gradients in the material. Consequently, we present detailed insights into the distinct origin of the increased capacity during the first charge, revealing different underlying redox processes depending on the synthesis conditions.
[1] M. Armand et al., J. Power Sources, 2020, 479, 228708.
[2] D. Eum et al., Nat. Mater., 2020, 19, 419-427.
[3] B. M. de Boisse, J. Electrochem. Soc., 2018, 165, A3630-A3633.
With the purpose of boosting the Circular Economy, the European-funded project “Recyclable Materials development@Analytical Research Infrastructures” (ReMade@ARI) aims at providing a platform of characterization techniques around Europe.
With regular calls dedicated to academic research groups (TNA) and to industries (SME and IND), we offer access to different facilities, probing materials with neutrons, X-rays, magnetic fields, positrons, electrons, light, and ions.
Through the Smart Science Cluster (SSC), composed of Junior Scientists (JS) expert in the different techniques proposed in the ReMade@ARI project, we provide support to the users before, during, and after their experiment. Submitting a pre-proposal to the SSC will allow the discussion of the best-suited technique to investigate the specific problem, while trainings are offered by the JS to help the users with the data analysis when needed.
More information can be found on the website: remade-project.eu
Subpicosecond intense pulses delivered by extreme ultraviolet and soft x-ray free electron lasers (FEL) have been recently found to trigger second harmonic generation (SHG) from surfaces and interfaces in simple materials. Those disruptive pioneering experiments suggest that nonlinear spectroscopies could be a valid approach to monitor the atomic structure of selected interfaces in all solid state ion batteries [1].
An overview on FEL SHG pilot experiments carried out at the FERMI FEL in Trieste (beamline EIS-TIMEX) is presented [2,3], analyzing current limits and promising features of the approach. Theoretical principles are discussed that govern nonlinear optics and explain the potential sensitivity of SHG techniques to nanometer interfaces in multilayered materials.
Synergies between FEL beamlines, theoretical simulation groups and research teams involved in ion batteries development might be established to explore soft x-ray nonlinear spectroscopies and foster their use in battery research.
[1] E. Principi, Journal of Physics: Energy, 2023 (submitted)
[2] Lam R.K. et al., Physical Review Letters, 2018, 120, 023901. DOI: 10.1103/PhysRevLett.120.023901
[3] Schwartz C.P. et al., Physical Review Letters, 2021, 127, 096801. DOI: 10.1103/PhysRevLett.127.096801
Ex-situ and operando battery research play a crucial role in the development and improvement of energy storage technologies. One of the powerful analytical techniques that has gained prominence in this field is Fourier Transform Infrared (FTIR) microspectroscopy. This technique provides valuable insights into the chemical and structural changes occurring within battery materials, enhancing our understanding of their behavior and performance.
Coupling synchrotron radiation with FTIR microspectroscopy (SR-µFTIR) has great potential to study ex-situ and operando battery materials, as the synchrotron infrared source is 100–1000 times brighter than a conventional thermal (e.g. Globar) sources.[1] Moreover, its high brightness (i.e. flux density) allows smaller regions (3–10 µm) to be probed in microscopy using different operation modes like transmission or reflection, suitable for ex-situ and operando battery analysis with an acceptable signal-to-noise ratio.[2]
The material science program at MIRAS end station devoted to Fourier Transform Infrared micro-spectroscopy (µFTIR) has grown significantly at the beamline during the recent years, in particular, in the fields of batteries and electrochemistry [3-6].
The beamline design and the availability of specific detectors with different detection spectral ranges allows optimizing the performance in the Mid-IR and Far-IR regions to cover a broad wavelength range from ∼1μm to ∼100μm [7]. That made the technique particularly a robust tool to probe many of the fundamental spectral features of the organic and inorganic materials used in batteries.
In this participation, we will present an overview of the applications and significance of FTIR microspectroscopy in ex-situ battery research performed so far at MIRAS beamline. It will be demonstrated how SR-FTIR microspectroscopy allows to investigate fundamental processes such as the solid-electrolyte interphase (SEI) formation. By characterizing the chemical composition, surface chemistry, and molecular interactions within battery components. Furthermore, we are at the initial steps of exploring how FTIR microspectroscopy can be employed to monitor and diagnose battery performance under various Operando conditions and cycling protocols.
This contribution will shed some light on the role of FTIR microspectroscopy in battery research performed at MIRAS beamline, highlighting its contributions to the advancement of energy storage systems and the quest for sustainable and high-performance battery solutions.
[1] G. P. Williams et al., Appl. Opt., 1983, 22(18), 2914–2923, DOI: 10.1364/AO.22.002914.
[2] J. A. Reffner, et al., Rev. Sci. Instrum., 1998, 66(2), 1298, DOI: 10.1063/1.1145958.
[3] J. Forero Saboya et al., Energy and Environ.Sci., 13 (2020) 3423, DOI: 10.1039/d0ee02347g
[4] C. Bodin et al., Batteries & Supercaps (2022), DOI.org/10.1002/batt.202200433
[5] A.P. Black et al., Chemical Science 14(2022) 1641, DOI: 10.1039/d2sc04397a
[6] D. Monti et al. ACS Appl. Energy Mater. 6 (2023) 7250, DOI.org/10.1021/acsaem.3c00969
[7] I. Yousef, et al. SRN, Vol. 30, No. 4, (2017), DOI.org/10.1080/08940886.2017.1338410
Higher energy density materials are being pushed by the research community to make lithium-ion batteries a better competitor to chemical fossil fuels for transport applications. This increases potential risk of lithium-ion batteries and therefore safety investigations are highly important for application purposes. Operando Computer Tomography provides a non-destructive investigation method of different abuse mechanisms.
Application of X-ray computed tomography (XCT) for studying lithium-ion batteries has gained interest among the research community especially in the past decade [1]. This technique is widely used for ex-situ samples to measure porosity and tortuosity [2], particle size and volume distribution [3] in the graphite anode as well as different cathode materials such as LiCoOx and NiMnCoOx. [4]. In situ measurements of commercial batteries are also often carried out to detect defects induced in a cell by a safety abuse test or manufacturing process [5]. Operando CT of large cells (for example 18650 form factor) is conducted at synchrotron facilities with high flux of high energy photons, however at a cost of details due to the large field of view [6].
Thanks to their high brilliance, synchrotron beam facilitates us to do a full Computed Tomography in a short time. This enables us to measure batteries while being cycled with a reasonable time resolution to record morphological changes. In this presentation we illustrate how one can utilize this ability to investigate abuse mechanisms on an actual commercially available lithium-ion battery from cell level to electrode level.
In this work, lab-based and synchrotron X-ray computed tomography is applied to commercial lithium-ion batteries. It is shown how to find most suitable imaging settings to study available lithium-ion batteries on different size scales, from cell level to particle level. We also demonstrate how to optimize contrast as well as both temporal and spatial resolutions to study in-situ and operando processes in a commercial battery using attenuation and phase contrast SXCT. Manufacturing defects and inconsistencies on cell level as well as the electrode and microstructure on material level are shown in our study.
Using the presented methodic, some abuse conditions are induced and imaged in operando on a commercially available li-ion battery. In this work, deep discharge mechanism is visualized and quantified in detail for the first time in 4 dimensions.
The reaction processes in Li-ion batteries can be highly heterogeneous at the electrode scale, leading to local deviations in the lithium content or local degradation phenomena. To access the distribution of lithiated phases throughout a high energy density silicon-graphite composite anode, we apply correlative operando small- and wide-angle X-ray scattering (SAXS and WAXS) tomography.
In-plane and out-of-plane inhomogeneities are resolved during cycling at moderate rates, as well as during relaxation steps performed at open circuit voltage (OCV) at given states of charge. Lithium concentration gradients in the silicon phase are formed during cycling, with regions close to the current collector being less lithiated when charging.
In relaxing conditions, the multi-phase and multi-scale heterogeneities vanish to equilibrate the chemical potential. In particular, Li-poor silicon regions pump lithium ions from both lithiated graphite and Li-rich silicon regions.
This charge redistribution between active materials is governed by distinct potential homogenization throughout the electrode and hysteretic behaviours. Such intrinsic concentration gradients and out-of-equilibrium charge dynamics, which depend on electrode and cell state of charge, must be considered to model the durability of high capacity Li-ion batteries.
Li-S batteries are promising candidates for the next generation energy storage systems due to their extremely high theoretical capacity and energy density and their low cost as well. However, Li-S batteries suffer from limited cycle stability due to the formation of different side-products during the cycling. The use of suitable binder material in the production of cathodes for Li-S batteries can be a possible approach to improving the overall electrochemical performance of the battery. Biomass-originated materials, like carrageenan, can suppress the shuttle effect of soluble polysulfides [1]. Carrageenan contains sulfate groups which facilitate a chemical reaction with the polysulfides and reduce their diffusion throughout the separator, leading to improved cycling stability and increased capacity retention. Additionally, the water-solubility of carrageenan eliminates the need for expensive and hazardous solvents in battery manufacturing processes, thus reducing costs and environmental risks. The literature was controversial regarding the functionality of the carrageenan binder [2], [3], however, it is important to understand its role in designing even better batteries. Therefore, X-ray Absorption Spectroscopy measurements have been done at sulfur K-edge to reveal the carrageenan effect on the polysulfide formation during the discharge and charge of the battery, and a comparison with the industrial standard PVDF has been done. The XANES region of the spectra allowed the determination of the different polysulfide species inside the electrochemical in operando cell and the effect of the binder material on the electrochemical reaction was identified.
Acknowledgements: The further development of ASTRA beamline at NSRC SOLARIS for measuring at low photon energies was supported within the EU Horizon2020 program (952148-Sylinda). CERIC-ERIC Consortium, the Slovak Research and Development Agency under the contract No. APVV-20-0138 and the Visegrad Fund under the contract No. 62320092 is acknowledged for the access to experimental facilities and financial support. We would like to express our thanks to MSc. Eng. Marcin Brzyski.
[1] T. Kazda et al., “Carrageenan as an ecological alternative of polyvinylidene difluoride binder for Li-S batteries,” Materials, vol. 14, no. 19, Oct. 2021
[2] D. Blanchard and M. Slagter, “In operando Raman and optical study of lithium polysulfides dissolution in lithium–sulfur cells with carrageenan binder,” JPhys Energy, vol. 3, no. 4, Oct. 2021.
[3] M. Ling et al., “Nucleophilic substitution between polysulfides and binders unexpectedly stabilizing lithium sulfur battery,” Nano Energy, vol. 38, pp. 82–90, Aug. 2017.