Hierarchically porous graphitized carbon membrane for 1-Watt-hour-class rechargeable lithium-oxygen pouch cells

Despite lithium-oxygen batteries (LOBs) achieving energy densities over 500 Watt hours (Wh) kg −1 at the cell level, challenges remain in extending cycle life, high-rate operation, and scalability. A critical limitation lies in designing carbon-based positive electrodes with optimal porosity and stability. Previous efforts with highly porous carbon materials face issues like unoptimized pore structures, excessive microporosity, low stability, and non-scalable fabrication methods, particularly under lean-electrolyte conditions. Here, we report a scalable, cost-effective approach to fabricate self-standing carbon membranes via (1) hard-templated synthesis of mesoporous carbon with reduced microporosity, (2) slurry casting using the doctor-blade method, and (3) non-solvent-induced phase separation (NIPS) to create interconnected macropores for improved oxygen transport. LOB cells employing these hierarchically porous carbon membranes and lean electrolyte demonstrated stable cycling for over 150 cycles at 1.5 mA cm −2 . Additionally, a 1-Wh-class multi-stacked LOB achieved long cycling stability. This report offers a breakthrough in scalable, high-energy-density LOB electrode development.