Enabling High-Voltage Lithium-Metal Batteries under Practical Conditions

High-energy-density Li-metal batteries are promising next-generation energy-storage systems. However, their development is greatly restricted because of the lack of functional electrolytes that can work efficiently on both the reactive Li anode and the aggressive cathodes under practical conditions, where high-voltage, high-loading cathode, thin Li anode and lean electrolyte are all indispensable. Here, we chose ether as the base solvent, which has intrinsic good cathodic but poor anodic stabilities and redesigned the electrolyte in a localized high-concentration electrolyte (LHCE) formulation to build the protective interphases onto both the anode and the cathode, simultaneously. Ether-based LHCE can effectively suppress side reactions, resulting in stable cycling of Li||NMC811 cells under voltages up to 4.5 V and under practical conditions. This electrolyte design provides critical insights for future electrolyte development for practical high-energy-density Li-metal batteries.