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

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 Li6.4La3Zr1.4Ta0.6O12 (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. Li/SC-nano LLZTO/LPSCl/SC-nano LLZTO/Li symmetric cells achieve a CCD of 20 mA cm-2 and a stable cycling of 2200 h. Furthermore, LZO@LCO/LPSCl/SC-nano LLZTO/Li ASSLMB achieves ultra-high current density (12.5 mA cm-2), ultra-long cycle life (20 000 cycles) and ultra-high areal capacity (15 mAh cm-2). image