Hierarchical porous-structured self-standing carbon nanotube electrode for high-power lithium–oxygen batteries

Abstract

The demand for energy storage devices with high energy and power densities has increased, and lithium–oxygen batteries (LOBs) have attracted significant attention owing to their superior theoretical energy density, which exceeds that of conventional lithium-ion batteries. Although recently reported LOBs exhibit cell-level energy densities greater than 500 W h kg⁻¹, their power densities are less than 1.0 mW cm⁻², limiting their widespread use as energy storage devices. In this study, we fabricated a carbon nanotube (CNT)-based self-standing membrane with macro-sized interconnected pores using a nonsolvent-induced phase separation technique and demonstrated its practical application as the positive electrode in high-power-density LOBs. In particular, LOBs equipped with the prepared CNT electrode exhibited power densities greater than 4.0 mW cm⁻², which is the highest performance reported thus far. These results demonstrate the feasible practical implementation of CNT-based membrane electrodes in LOBs with high energy and power densities.