A flexible three-dimensional composite nanofiber enhanced quasi-solid electrolyte for high-performance lithium metal batteries

Abstract

Solid-state lithium-ion batteries have attracted great attention in recent years due to their remarkable safety and high energy density. However, the ionic conductivities of most solid-state electrolytes (SSE) are still not high enough for practical applications. Herein, we report a high-performance quasi-solid-state electrolyte composed of an electrospinning LATP-PVDF-HFP nanofiber matrix and an in situ formed gel. The prepared quasi-solid gel electrolyte shows a 3D porous network with significantly improved ionic conductivity up to 3.394 mS cm⁻¹. Meanwhile, the quasi-solid-state electrolyte exhibits a wider electrochemical window than the gel electrolyte, due to the synergistic effect between the 3D network fiber and in situ formed gel. The Li|CGE|LiFePO₄ battery with this quasi-solid gel electrolyte shows good rate capability and cycling stability, and the discharge capacity of the cell is 146.6 mA h g⁻¹ at 2C. The capacity retention can still reach 97% after 300 cycles at 0.5C. This work provides a promising strategy for designing high-performance lithium metal batteries.