Rapid Processing of Uniform, Thin, Robust, and Large-Area Garnet Solid Electrolyte by Atmospheric Plasma Spraying

All-solid-state batteries (ASSBs) are rapidly moving toward commercialization as a promising high-performance energy storage device for portable electronics and electric vehicles. One of the most challenging problems hindering the industrialization of ASSBs is the lack of technologies for cost-effective and large-scale manufacturing of high-quality solid-state electrolytes (SSEs) with about the same thickness as the polymer separators in conventional lithium-ion batteries. Herein, atmospheric plasma spraying (APS) is adopted as a practical route to process large-scale, uniform, and thin SSEs to conduct Li-ions and further to manufacture ASSBs. Garnet-type Li7La3Zr2O12 (LLZO) films with thicknesses ranging from 30 to 300 & mu;m are successfully manufactured with direct APS technique followed with a post annealing treatment. The electrolyte reaches a high Li-ion conductivity of 3.82 x 10(-5) S cm(-1) at room temperature (25 & DEG;C). Additionally, the LLZO film with a thickness of 300 & mu;m shows a flexural strength of 157 MPa. Li/LLZO/Li and Li/LLZO/LiFePO4 cells are assembled with the films, both showing stable cycling performance. The APS method shows scalability in solid-state electrolyte film production, and most importantly, such a process is highly compatible with the current battery industry.