Porous Carbon Foam with Carbon Nanotubes as Cathode for Li-CO2 Batteries

Abstract

With the extensive use of fossil fuels, the ever-increasing greenhouse gas of mainly carbon dioxide emissions will result in global climate change. It is of utmost importance to reduce carbon dioxide emissions and its utilization. Li-CO₂ batteries can convert carbon dioxide into electrochemical energy. However, developing efficient catalysts for the decomposition of Li₂ CO₃ as the discharge product represents a challenge in Li-CO₂ batteries. Herein, we demonstrate a carbon foam composite with growing carbon nanotube by using cobalt as the catalyst, showing the ability to enhance the decomposition rate of Li₂ CO₃ , and thus improve the electrochemical performance of Li-CO₂ batteries. Benefiting from its abundant pore structure and catalytic sites, the as-assembled Li-CO₂ battery exhibits a desirable overpotential of 1.67 V after 50 cycles. Moreover, the overpotentials are 1.05 and 2.38 V at current densities of 0.02 and 0.20 mA cm^-2 , respectively. These results provide a new avenue for the development of efficient catalysts for Li-CO₂ batteries.

Keywords: Li−CO2 battery; carbon nanotubes; cathode; electrochemical performance; porous carbon foam.