Smart-flame-retarding layered composite Li negative electrode for safe Li metal battery

The high flammability problem of Li metal negative electrode has persistently impeded the safe application of energy-dense Li metal batteries. Conventional flame-retardant mixing strategy also fails in addressing this challenge because of the severe function-destroying corrosion reaction between flame retardant and Li metal. In this work, we propose a layered graphene oxide/flame retardant/lithiophilic ZnO layer/Li metal negative electrode for eliminating the corrosion between Li metal and flame retardant, while smartly releasing the thermal-triggered flame-retarding gases for covering and bonding with Li metal against combustion. This smart-flame-retard layered Li negative electrode afford 2677.78% prolonged battery cycle life than the pure Li negative electrode after 600 °C ignition, and 94.68% suppressed side reaction than conventional flame retardant-Li mixture during regular electrode operation. This resolution on the flammability challenge of Li metal negative electrode presents a meaningful advancement for safe Li metal battery construction. The flammability of the Li electrode impedes its safe application in a battery. Here, the authors develop a layered Li electrode design to eliminate corrosion between Li metal and fire retardant, and smart release fire retardant against Li combustion during heating conditions, enabling a safe Li metal battery.