Welcome

• Alfonso Franciosi (Elettra - Sincrotrone Trieste S.C.p.A.)

Room: Kastler Hall

Deciphering the complexity of Li-rich layered oxides (LRLO) by synchrotron-based techniques

• Sergio Brutti (Università di Roma La Sapienza)

Room: Kastler Hall 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.

Insights into the aluminium graphite dual-ion battery by synchrotron-based techniques

• Giuseppe Antonio Elia (Politecnico di Torino)

Room: Kastler Hall 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.

Beam damage in synchrotron radiation based operando characterization of battery materials

• Ashley Black (icmab-csic)

Room: Kastler Hall *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.

Hard and soft X-ray absorption spectroscopy as powerful tools to deepen the understanding of the charge storage mechanisms in lithium-ion battery materials

• Dominic Andre Bresser (Karlsruhe Institute of Technology (KIT))

Room: Kastler Hall 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.

The Quest for Sustainable and Circular Battery Technologies - Operando X-ray Techniques probing Dynamic Processes in Batteries

• Moniek Tromp (University of Groningen, Zernike Institute for Advanced Materials)

Room: Kastler Hall 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.

Spectroscopy and imaging of Zn-air batteries

• Benedetto Bozzini (Politecnico di Milano)

Room: Kastler Hall 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.

Analysis of cathodes based Prussian Blue for LiBs and SIBs at synchrotron

• Marco Giorgetti (Università di Bologna)

Room: Kastler Hall

Contribution of large scale facilities to the battery field development

• Robert Dominko (National Institute of Chemistry - Slovenia)

Room: Kastler Hall

REALSEI: opeRando chEmical spAce- and time-resoLved quantification of Solid Electrolyte Interphase in hard carbon anode for sustainable sodium-ion batteries

• Giorgia Greco (La Sapienza University)

Room: Kastler Hall 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.

Vibrational spectroscopies insights on the molecular interactions in Deep Eutectic Solvents: a step forward in the rational design of electrolytes for energy devices

• Matteo Bonomo (University of Turin)

Room: Kastler Hall 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.

Structural dynamics in Li ion batteries via synchrotron non-damaging depth profiling

• Javad Rezvani (university of camerino)

Room: Kastler Hall 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,

Operando XRD as an essential tool to unravel the electrochemical mechanisms of FeNb11O29, anode for LIBs

• Marcella Bini (University of Pavia, Chemistry Department)

Room: Kastler Hall 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.

Nanoscale electrochemical conversion in post-lithium-ion batteries tracked by operando scattering and stochastic modelling

• Christian Prehal (Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Strasse 2a, 5020 Salzburg, Austria)

Room: Kastler Hall 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)

Investigating the SEI formation in Li-ion batteries

• Antonella Iadecola (PHENIX)

Room: Kastler Hall 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.

Probing battery interfaces through free electron laser pulses

• Emiliano Principi (ELETTRA-Sincrotrone Trieste S.C.p.A.)

Room: Kastler Hall 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

IMPRESS: expanding the horizons of TEM towards fully interoperable arrangements

• Regina Ciancio (Area Science Park & CNR IOM Trieste - Italy)

Room: Kastler Hall

The current and future opportunities of battery research activities at MIRAS beamline of ALBA synchrotron light

• Ibraheem Yousef (ALBA Synchrotron)

Room: Kastler Hall 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

4D Synchrotron X-ray Imaging to enhance battery safety

• Shahabeddin Dayani (Bundesanstalt fuer Materialforschung und -pruefung (BAM))

Room: Kastler Hall 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. 1. Le Houx, J. and D. Kramer, X-ray tomography for lithium ion battery electrode characterisation — A review. Energy Reports, 2021. 7: p. 9-14. 2. Eastwood, D.S., et al., The application of phase contrast X-ray techniques for imaging Li-ion battery electrodes. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2014. 324: p. 118-123. 3. Finegan, D.P., et al., Investigating lithium-ion battery materials during overcharge-induced thermal runaway: an operando and multi-scale X-ray CT study. Phys Chem Chem Phys, 2016. 18(45): p. 30912-30919. 4. Ebner, M., et al., Tortuosity Anisotropy in Lithium-Ion Battery Electrodes. Advanced Energy Materials, 2014. 4(5). 5. Patel, D., et al., Thermal Runaway of a Li-Ion Battery Studied by Combined ARC and Multi-Length Scale X-ray CT. Journal of The Electrochemical Society, 2020. 167(9). 6. Finegan, D.P., et al., In-operando high-speed tomography of lithium-ion batteries during thermal runaway. Nat Commun, 2015. 6: p. 6924.

Demystifying mysterious time and space evolution in state-of-the art graphite-silicon composite battery electrodes

• Valentin Vinci

Room: Kastler Hall 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.

Impact of biomass-based multifunctional binders on Li-S battery chemistry - analysis of polysulfide phases by in operando XAS

• Dora Zalka (University Pavol Jozef Šafárik in Košice)

Room: Kastler Hall 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.

LEAPS INNOV Eu project

• Franz Hennies (MAX IV Laboratory)
• Doriana Orbanic (MAX IV Laboratory)

Room: Kastler Hall