Enhanced Rate Capability of Na-SO2 Rechargeable Battery by Urea-templated Meso/Macroporous Carbon Electrode

Abstract

Sodium rechargeable batteries have garnered intensive attention as alternatives to currently used lithium-ion batteries (LIBs). Among various sodium secondary batteries, a rechargeable Na–SO2 battery deserves to be regarded as one of the most promising sodium battery systems because of its high energy density and safety. Here we report the enhanced rate performance of Na–SO2 battery by introduction of meso/macropores in the carbon electrode using urea as a pore-forming agent. The resulting meso/macroporous carbon electrode leads to much improved rate capability and structural stability of the electrode in a Na–SO2 battery against mechanical stress/strains induced by the formation of large size insulting discharge product (NaCl). We firmly believe that the urea-based cost-effective and scalable process for a meso/macroporous electrode would be one of the most practical ways to improve the performance of Na–SO2 battery to be a candidate for post-LIB systems.