A high energy and power all-solid-state lithium battery enabled by modified sulfide electrolyte film

In recent decades, all-solid-state lithium batteries have gained enormous attention due to the improved safety performance and high specific energy. However, the brittle nature of sulfide-based solid electrolytes and poor interface compatibility limit the long-cycle stability and high rate performance of ASSLBs. The utilization of a thick solid electrolyte further reduces the cell-level energy and power. Herein, we prepare a thin sulfide electrolyte film (65 μm) using modified Li6PS5Cl and poly (ethylene oxide) (PEO). Under a high loading of 4.46 mA h cm−2, the assembled cell employing this electrolyte film with LiNi0.7Co0.2Mn0.1O2 cathode and lithium-indium alloy anode maintains a 1000 stable cycles with 74% capacity retention and average 99.85% coulombic efficiency at 60 °C. The cell-level energy and power are increased by an order of magnitude compared with traditionally prepared solid-state batteries. An excellent specific power of 374.7 W kg−1 is delivered at the initial cycle. This modified electrolyte film is expected to be commercially produced in the near future.