( Invited ) Accelerating Development of All Solid-State Batteries through Increases In: Electrochemical Test Throughput, Cell Yield, and Cell Capacity

All-solid-state batteries have the potential to significantly improve the energy density of batteries for demanding applications. However, the development of all solid-state batteries has been hindered by researchers using fabrication/testing techniques that are unsuitable for high-throughput production. During this presentation, we will report on NLR/CSM efforts to fabricate and test with methods more relevant for high volume manufacturing/scale-up. A novel automated mechanical “kneader” is used to fabricate high energy density catholytes composed of NMC 811 active material and Li 6 PS 5 Cl solid electrolyte (LPSC). The kneader provides insight into the mechanical properties required to successfully mix and fibrilize poly-tetrafluoroethylene (PTFE) in industrial relevant twin-screw extrusion process. Thin, solid-state separators (~100 micron total) are made using high through-put slurry casting of LPSC/polyisobutylene binder layers combined with a poly-aramid fiber mechanical support. Unlike other thin-film separators, this setup achieves high short tolerance which enabled a 98% success rate across nearly 100 attempted cells. Small area coin cells are tested using 2032 coin-cell hardware combined with a compact and low-cost pressure jig enabling traditional coin cell racks to be converted to all solid-state coin cell racks for high-throughput testing. These reliable/high-throughput methods are used to provide clear understanding into how changes in catholyte carbon type and current collectors affect cell performance. Lastly, this presentation will detail recent efforts to move our solid-state cell testing from a few mAh coin cell to more industrial relevant large area, multi-layer pouch cells (with 100 mAh demonstrated to date and 1 Ah in the coming year). We will provide insight into how mechanical instabilities at larger areas was overcome and the use of a continuous calendaring roll for densification of multiple layers.