Interfacial electric field effect of Double-Network composite electrolyte for Ultra-Stable lithium batteries

Abstract

All-solid-state lithium metal batteries (LMBs) with ultra-high energy density are used as a new generation of safe energy storage systems. However, the unstable lithium/electrolyte interface and poor mechanical strength hinder the large-scale application of all-solid-state LMBs. Herein, to address these issues, a kind of double-network composite polymer electrolyte (CPE) with interfacial electric field effect that can availably facilitate the uniform deposition of ions for LMBs is designed using a polyvinylidene fluoride (PVDF) fiber membrane as the matrix. The double-network CPE with a 3D interconnected structure and lithium philophile effect is fabricated by compositing the 3D coral-like oxide electrolyte Li0.3La0.557TiO3 (LLTO) and the PVDF fiber membrane that ZnO grows in situ on the surface. The double-network CPE demonstrates excellent mechanical properties and good ionic conductivity. Specifically, it presents an exceptional tensile strength 23.7 MPa and an ultrahigh lithium-ion transference number of 0.83. More importantly, the electrolyte can achieve stable ion deposition and eliminate the growth of lithium dendrites due to the presence of the interfacial electric field. The symmetrical Li/Li battery with CPE has a long cycle life of 2000 h and ultra-stable performance even at a high current density of 1 mA cm−2. This work offers a prospective strategy to develop applied electrolytes for all-solid-state lithium metal batteries.