Coatable Li 4 SnS 4 Solid Electrolytes Prepared from Aqueous Solutions for All-Solid-State Lithium-Ion Batteries.

Bulk-type all-solid-state lithium-ion batteries (ASLBs) for large-scale energy-storage applications have emerged as a promising alternative to conventional lithium-ion batteries (LIBs) owing to their superior safety. However, the electrochemical performance of bulk-type ASLBs is critically limited by the low ionic conductivity of solid electrolytes (SEs) and poor ionic contact between the active materials and SEs. Herein, highly conductive (0.14 mS cm ^-1 ) and dry-air-stable SEs (Li ₄ SnS ₄ ) are reported, which are prepared using a scalable aqueous-solution process. An active material (LiCoO ₂ ) coated by solidified Li ₄ SnS ₄ from aqueous solutions results in a significant improvement in the electrochemical performance of ASLBs. Side-effects of the exposure of LiCoO ₂ to aqueous solutions are minimized by using predissolved Li ₄ SnS ₄ solution.
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