Carbon-black-based self-standing porous electrode for 500 Wh/kg rechargeable lithium-oxygen batteries

Abstract

While lithium-oxygen batteries exhibit high theoretical energy densities that by far exceed those of conventional lithium-ion batteries, there are a limited number of examples that actually demonstrate cells with high energy density. The limitation of the positive electrode with a capacity high enough to sustain repeated discharge/charge cycles under high areal capacity conditions hinders the implementation of the lithium-oxygen batteries with practically high energy density. In this study, we develop a carbon black powder-based self-standing membrane, which exhibits a discharge capacity of ~7,000 mAh/gelectrode even under high current density conditions (>0.4 mA/cm2). Using the developed self-standing carbon membrane as the positive electrode, a 500-Wh/kg class rechargeable lithium-oxygen battery was fabricated and a repeated discharge/charge cycle was demonstrated at 0.1 C-rate. The results obtained in this study provide new material research directions to realize high energy density rechargeable lithium-oxygen batteries and facilitate their future development.