Self-Sacrificed Interface-Based on the Flexible Composite Electrolyte for High-Performance All-Solid-State Lithium Batteries

Ceramic electrolyte guarantees the commercial application of all-solid-state lithium batteries (ASSLBs) for its high ionic conductivity and wide voltage window. However, the large interfacial impedance between the ceramic and polymeric electrolyte is still tough issue for all-solid-state batteries. Here, a self-sacrifice interface established by a flexible Li1.5Al0.5Ge1.5(PO4)(3) (LAGP)/30% poly(propylene carbonate) (PPC) solid composite electrolyte causes a performance enhancement of the LiFePO4/Li battery with a discharge specific capacity of 151 mA h g (-1) at 0.05 C and a retention of 92.3% for 100 cycles at 55 degrees C without any liquid electrolyte, where the PPC-derived layer swells the Li metal and infiltrates to develop the amorphous state to reduce both interfacial and bulk resistance; while the LAGP with good mechanical strength and the LiF layer provides stability and resists the growth of Li dendrites, which guaranteed the long cycle life and security of batteries. This study demonstrates the complementary advantages of ceramic and polymer, which implies a feasible way to achieve a well-wetted, soft, and stable contact of the electrolyte and electrode to overcome the interface issues in ASSLBs.