A Lithiophilic Artificial LiP Interphase with High Li-Ion Conductivity via Solid-State Friction for Lithium Metal Anodes.

Interfacial modification strategies for lithium metal anodes have emerged as a promising method to improve cycling stability, suppress lithium dendrite growth, and increase Coulombic efficiency. However, the reported chemical synthesis methods lead to side reactions and side products, which hinder their electrochemical performance. In this study, we propose a novel and facile red phosphorus-assisted solid-state friction method to in situ fabricate a uniform LiP interphase directly on the surface of lithium metal. Interestingly, the as-formed artificial LiP interphase with high ionic conductivity and lithium affinity features significantly enhanced interfacial stability and electrochemical kinetics. The symmetric cells based on Li@P with the LiP interphase achieved a prolonged lifespan, over 1000 h, at 1 mA/cm with low polarization. When paired with a high-loading LiFePO cathode (10.5 mg/cm), the Li@P||LiFePO full cell retained 88.9% of its capacity after stable cycling for 550 cycles at 2 C and further demonstrated the excellent performance and stability of the Li@P‖LiCoO full pouch cell. This study provides an efficient and scalable strategy for stabilizing lithium metal anodes, expanding new ideas for the development of next-generation high-energy-density batteries.