Tape Casting of Thin Electrolyte and Thick Cathode for Halide-Based All-Solid-State Batteries

Journal Article · 09 October 2023 · Journal of the Electrochemical Society

DOI: https://doi.org/10.1149/1945-7111/acfdd1 · OSTI ID:2008392

Shen, Fengyu ; McGahan, Michael; Pietras, John D.; Lau, Grace Y.; Doeff, Marca M.; Battaglia, Vincent S.; Tucker, Michael C.

Most previous studies about halide solid-state electrolytes have used pellets prepared by uniaxial pressing, which is a good approach for materials development but is not suitable for commercialization. Thinner electrolyte layers that can be scaled up to large cell areas are required, and tape casting is a promising approach. It is challenging, however, as halide materials are reactive with most of the conventional solvents used in the process. In this study, solvents with low polarity, such as toluene, are found to be compatible with the Li ₃ YBr ₆ halide material. A wide variety of candidate binders that are soluble in toluene are studied. MSB1–13 binder is preferred, based on the ionic conductivity and mechanical properties of the tape. Electrolyte tapes (<70 μ m) are successfully cast on Al substrates, using 2 wt% binder. The resulting room temperature ionic conductivity is 2 × 10 ⁻⁴ S cm ⁻¹ . Two composite cathodes including active material (LiFePO ₄ or LiNi _0.82 Mn _0.07 Co _0.11 O ₂ ) and 1 to 1.5 wt% MSB1–13 are tape cast as proof-of-concept for a scalable cell fabrication approach. A LiFePO ₄ cell shows good retention at 25 °C. The performance of NMC cells with tape electrolyte or pellet electrolyte is similar. This study demonstrates the feasibility of tape casting halide-based electrolytes and cathodes.

• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: NONE; AC02-05CH11231
• OSTI ID: 2008392
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 10 Vol. 170; ISSN 0013-4651
• Publisher: The Electrochemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English