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.