In Situ Generated Li2S–Li3N Dual Component Protective Layers Enable High Stability for High-Temperature Li Metal Batteries

Li metal has been considered as a promising anode for next-generation high-energy-density Li metal batteries. However, the uncontrollable Li dendrite growth, infinite volume change, and unstable solid electrolyte interphase (SEI) layer cause serious safety issues and poor cycling performances, inhibiting its practical application. Herein, N-doped CoS2 needle-like nanoarrays are decorated on carbon cloth. The N-doped CoS2 nanoarrays with a lithiophilic nature can decrease Li nucleation barriers and induce uniform Li deposition. Furthermore, during the prelithiation process, the in situ reaction between Li and N-doped CoS2 has formed stable Li2S and Li3N dual-component protective layers, which efficiently suppresses the dendrite growth and stabilizes the electrolyte-electrode interface. As a result, the N-CoS2@CC electrode shows an excellent rate performance and a long lifespan of 800 h under a 5 mA cm–2/1 mA h cm–2 electrode with a low overpotential (12 mV). When paired with a LiFePO4 (LFP) cathode, the obtained N-CoS2@CC@Li||LFP cell exhibits outstanding electrochemical performances at the high temperature of 60 °C as well as mass loading of 10 mg cm–2. This work provides a rational approach to constructing a 3D lithiophilic host with stable SEI layers toward practical Li metal batteries.