High-Voltage Solid-State Lithium Metal Batteries with Stable Anodic and Cathodic Interfaces by a Laminated Solid Polymer Electrolyte

Abstract

Solid polymer electrolyte (SPE) is quite an attractive candidate for constructing high-voltage Li metal batteries (LMBs) with high energy density and excellent safety. However, sim ultaneous achievement of high-voltage stability against the cathode and good compatibility with the Li anode remains challenging for the current SPE technology. Herein, a dual-layered solid electrolyte (DLSE) consisting of an oxidation-resistant poly(acrylonitrile) (PAN) layer facing a high-potential cathode and a reduction-compatible poly(vinylidene fluoride) (PVDF) layer incorporated by Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) nanoparticles and an ionic liquid plasticizer in contact with a Li anode was fabricated. The uniquely designed DLSE holds favorable overall properties in ionic conductivity, Li⁺ transference number, and mechanical strength. Moreover, the combined advantages of two polymer electrolyte layers greatly address the interface issues on both the cathode and anode. Consequently, the high-voltage LMBs employing the DLSE exhibit excellent room-temperature performances including high rate capacity and long cycle life.