High-Performance Li-CO2 Batteries with α-MnO2/CNT Cathodes

Abstract

A rechargeable Li-CO2 battery has been considered to be a promising battery system due to its high-energy density and the utilization of carbon dioxide (CO2). However, the high overvoltage caused by the discharge product Li2CO3 hinders the development of Li-CO2 batteries. In this work, α-MnO2 nanowires obtained via a redox reaction have been employed as the cathode catalyst in the Li-CO2 battery, which can provide sufficient catalytic sites for CO2 evolution and tune the cathode structure for the uniform distribution of Li2CO3 and C on the cathode. The Li-CO2 battery with an MnO2/carbon nanotube (CNT) cathode exhibits significantly reduced overpotential, and could be operated for 50 cycles with a fixed capacity of 1000 mAh g−1 and 6 cycles of full discharge–charge tests at a current density of 100 mA g−1.