| AVS 66th International Symposium & Exhibition | |
| Frontiers of New Light Sources Applied to Materials, Interfaces, and Processing Focus Topic | Thursday Sessions |
| Session LS+AS+SS-ThM |
| Session: | Operando Methods for Unraveling Fundamental Mechanisms in Devices Towards Renewable Energies |
| Presenter: | Natalie Seitzman, Colorado School of Mines |
| Authors: | N. Seitzman, Colorado School of Mines J. Nelson Weker, SLAC National Accelerator Laboratory M. Al-Jassim, National Renewable Energy Laboratory S. Pylypenko, Colorado School of Mines |
| Correspondent: | Click to Email |
Solid state Li ion conductors are next-generation battery technologies that reap the capacitive benefits of Li metal anodes while mechanically resisting the Li interface evolution and thus prolonging lifetime. Additionally, they are not flammable, offering greater safety than liquid counterparts. However, interface evolution and Li protrusions are observed in solid state batteries despite the mechanical resistance.1,2 There is debate as to whether these protrusions nucleate at the Li anode or within the ceramic electrolyte, and there are several factors that affect these protrusions including electrolyte density, pre-existing defects, anode/electrolyte interfacial contact, and imperfect electronic insulation within the electrolyte.3 Understanding the influence of these variables is greatly enhanced by directly imaging the interior of the ceramic at multiple scales in conjunction with electrochemical experiments.
This talk addresses the contribution of electrolyte density and defects, interfacial contact, and conductivity to structural changes in β-Li3PS4 (LPS) ceramic electrolyte in operating cells via 3D X-ray imaging with sub-micron resolution. Cells of Li, LPS, and a blocking contact are constructed and studied in operando at 200 psi and 70˚C. Because electrolyte density and initial defects depend on the composition and synthesis of the ceramic conductor, two syntheses of LPS with different particle sizes are compared. Also, pressure is a key parameter in the quality and stability of interfacial contact while temperature affects both the ionic and electronic conductivity of the ceramic.
Synchrotron micro-tomography is combined with synchrotron transmission x-ray microscopy to study the cells with spatial resolution in the hundreds of nanometers and tens of nanometers. Image analysis of these data has identified sites of Li microstructure growth4 and now isolates variable-dependent trends such as pressure-dependent void formation in the Li anode. Linking structural changes observed in operando to these factors that contribute to Li evolution will guide the design of robust ceramic electrolytes with improved performance and safety.
1. L. Porz, T. Swamy, B. W. Sheldon, D. Rettenwander, T. Frömling, H. L. Thaman, S. Berendts, R. Uecker, W. C. Carter, and Y.-M. Chiang, Adv. Energy Mater., 7, 1701003 (2017).
2. E. J. Cheng, A. Sharafi, and J. Sakamoto, Electrochim. Acta, 223, 85–91 (2017).
3. F. Han, A. S. Westover, J. Yue, X. Fan, F. Wang, M. Chi, D. N. Leonard, N. J. Dudney, H. Wang, and C. Wang, Nat. Energy (2019).
4. N. Seitzman, H. Guthrey, D. B. Sulas, H. A. S. Platt, M. Al-Jassim, and S. Pylypenko, J. Electrochem. Soc., 165, 3732–3737 (2018).