Solid polymer electrolyte-based high areal capacity all-solid-state batteries enabled with ceramic interlayers

Solid polymer electrolytes(SPEs)based all-solid-state batteries(ASSBs)have attracted extensive attention as a promising candidate for next-generation energy storage systems.Typical ASSBs require high fabrication pressure to achieve high areal capacity,under which,however,SPEs struggle and risk damage or failure due to their low mechanical strength.There is also a lack of study on complex stress and strain SPEs experience during ASSB cell assembly processes.Here,ceramic solid electrolytes are selected as interlayers to address the stress-strain conditions during assembling.As a result,high areal capacity ASSBs with a LiCoO2 loading of 12 mg·cm^(-2) were assembled with SPE-based composite electrolytes.Around 200 cycles were carried out for these cells at a current density of 1 mA·cm^(-2) under room temperature.The capacity decay of the battery at 200 cycles is observed to be as low as 0.06% per cycle.This work identifies a critical issue for application of SPEs in ASSBs and provides a potential strategy for the design of SPE-based ASSBs with high specific energy and long cycle life.