A porous tellurium interlayer for high-power and long-cycling garnet-based quasi-solid-state lithium-metal batteries

Li-metal batteries with solid oxide electrolytes have garnered increasing attention as promising technologies that can overcome the safety and energy density limits of lithium-ion batteries (LIBs). However, the less than satisfactory long-term stability of Li-metal batteries—a consequence of Li dendrite formation caused by unstable Li plating/stripping at the interface between the Li metal and solid electrolyte—is hampering their commercialisation. Herein, we propose an negative electrode multilayer consisting of porous Te and carbon-based layers that can suppress Li dendrite formation and significantly lower the degree of capacity decay during long-term cycling. A quasi-all-solid-state Li-metal battery fabricated using Li6.4La3Zr1.7Ta0.3O12 (LLZTO), a Te/Ag-C anodenegative electrode interlayer, and a LiNi0.8Co0.1Al0.1O2 (NCA811) positive electrode impregnated with an ion-conducting liquid demonstrated high capacity retention (80.1% over 4000 cycles) and Coulombic efficiency (99.7%) when operated at a high current density of 2.2 mA/cm2 at 25 °C. Furthermore, we successfully demonstrate 100-mAh-level single cells in a pouch cell configuration using a large-area (36 cm2) LLZTO solid electrolyte and a 3.2-mAh/cm2 LiCoO2 (LCO) positive electrode capable of operating for >400 cycles at a 0.5 C-rate (85 mA/g). Unsatisfactory long-term stability of solid-state Li-metal batteries is hampering their commercialisation despite their potential high energy density. Here, authors employed a rationally designed porous tellurium interlayer and demonstrated high capacity retention for 4000 cycles.