Constructing Electronic and Spatial Barriers: A Practical Strategy for High-Performance All-Solid-State Lithium Metal Batteries

Argyrodite-type sulfide electrolytes are promising for all-solid-state lithium metal batteries (ASSLMBs) due to their high ionic conductivity and processability. However, their high electronic conductivity and porous structure promote Li dendrite growth. In this work, a simple, effective, and practical strategy has been developed to simultaneously reduce the electronic conductivity and porosity of the electrolyte membrane by incorporating commercial nanoscale dielectric materials into the electrolyte membrane and further mitigate dendritic growth. The additive can passivate the anode interface and form a uniform distribution of ion transport. In addition, it acts as an electronic barrier blocking the formation metallic Li at the grain boundaries. As a result, the critical current density of the Li symmetric cell is doubled, and its cycling performance is improved by 14 times (1400 h at 1.0 mA cm^-2), surpassing the pure Li₆PS₅Cl for Li metal. The ASSLMB not only exhibits a high initial discharge capacity of 213.3 mAh g^-1 at 0.1 C, high-rate performance at 3 C, and excellent cycling performance of 80.69% capacity retention ratio after 900 cycles. This work delineates a versatile design paradigm for developing dense, electronically insulating composite electrolytes, paving the way for dendrite-free and highly stable ASSLMBs.