In Situ Topological Interphases Boosting Stable Solid‐State Lithium Metal Batteries

Incompatible interphases resulting from the irreconcilable contradiction between impedance and mechanical strength have become one of the major obstacles to the practical application of solid‐state lithium metal batteries (SSLMBs). With the employment of a decoupling strategy by rational topological design, herein a topological polymer‐reinforced interphase layer is in situ constructed using a synthesized solid polymer electrolyte. As a result, the constructed topological solid electrolyte interphase (SEI) layer harmonizes the enhanced mechanochemical stability and fast diffusion dynamics of Li + , which maintains the integrity and stability of the SEI layer during cycling. In addition, a highly stable and reversible Li nucleation/stripping behaviors exceeding 3000 h and the superior cycling performance of practical LiFePO 4 /Li metal battery beyond 500 cycles can be achieved by virtue of the formation of the topological interphase layer. This design strategy of constructing a topological interphase layer to decouple mechanical strength and the activation energy of Li + transport provides a feasible paradigm for realizing practical SSLMBs.