High Energy Density Hybrid Solid-State Li-Ion Batteries Enabled by a Gel/Ceramic/Gel Sandwich Electrolyte

In this work, a hierarchical PVDF-HFP gel polymer electrolyte (GPE) membrane is prepared intentionally and placed between the solid electrolyte and the electrodes. The fabricated LiFePO4/GPE/LAGP/GPE/Li hybrid solid-state cell displays superior rate performance and capacity retention. After 300 cycles at 0.5 C, negligible degradation can be observed, and the specific capacity remains as high as 145.6 mA h/g at room temperature. The excellent battery performance is ascribed to the significantly improved interfacial stability of the sandwich-like hybrid electrolyte and the remarkably enhanced charge transfer kinetics across the interface due to the flexibility of GPE.