High‐Areal‐Capacity and Long‐Cycle‐Life All‐Solid‐State Lithium‐Metal Battery by Mixed‐Conduction Interface Layer

Abstract The rapid growth of lithium dendrites has seriously hindered the development and practical application of high‐energy‐density all‐solid‐state lithium metal batteries (ASSLMBs). Herein, a soft carbon (SC)‐nano Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) (with high ionic conductivity and diffusion coefficient) mixed ionic and electronic conducting interface layer is designed to promote the rapid migration of Li⁺ at the interfacial layer, induce the uniform deposition of lithium metal on nanoscale (nano) LLZTO ion‐conducting network inside the interface layer, effectively suppress the growth of lithium dendrites, and significantly improve the electrochemical performance of ASSLMBs. LiZrO₂@LiCoO₂(LZO@LCO)/Li₆PS₅Cl(LPSCl)‐nano LLZTO/Li ASSLMB achieves high current density (12.5 mA cm⁻²), ultra‐high areal capacity (15 mAh cm⁻², corresponding to LZO@LCO mass loadings of 111.11 mg cm⁻²), and ultra‐long cycle life (20 000 cycles). Therefore, the introduction of SC‐nano LLZTO mixed conducting interface layer can greatly improve the interfacial stability between solid‐state electrolyte (SSE) and lithium metal anode to enable dendrite‐free ASSLMBs.