An optimizing hybrid interface architecture for unleashing the potential of sulfide-based all-solid-state battery

Abstract

Sulfide-based all-solid-state lithium metal batteries are received tremendous focus due to the potential to deliver high energy density. Nevertheless, extremely unstable lithium/sulfide interface reaction and growth of unfavorable Li dendrites upon cycling remain challenging aspects and not yet fully settled. In this work, a lithophilic and high interfacial-energy hybrid interphase rich in chloride and Li-Ga alloy was in-situ constructed at Li/Li7P3S11 interface to tackle the vexing issue. Benefiting from the high interfacial energy and electronic insulation of LiCl in the hybrid interphase, lithium dendrites were effectively inhibited. In addition, the Li-Ga alloy-rich layer possesses excellent lithiophilicity and low diffusion energy, which can provide a uniform electric field distribution and induce rapid conduction of Li-ions. Consequently, the densification of Li/Li7P3S11 interface is achieved, which contributes to the decrease of interfacial impedance, uniform Li-ion flux and inhibition of continuous side reactions. Exalting, the Li symmetric cells with the Li-Ga alloy/LiCl (LGC) interlayer display high critical current density of 1.5 mA cm−2 and steady cycle for 1000 h at 0.3 mA cm−2 (0.3 mAh cm−2) at room temperature. Furthermore, the modified all-solid-state lithium battery also demonstrates an ultra-stable cycling. This work provides a reasonable design approach for the selection of interface layers in the all-solid-state lithium metal batteries (ASSLMBs) based on theoretical calculations, with the objective of attaining a stable Li/sulfide solid electrolyte interface.