Electrochemically Activated CNT Sheet as a Cathode for Zn-CO2 Batteries

Abstract

High demand for electrochemical storage devices is increasing the need for high-performance batteries. A Zn-CO2 battery offers a promising solution for CO2 reduction as well as energy storage applications. For this study, a Zn-CO2 battery was fabricated using a Carbon Nanotube (CNT) sheet as a cathode and a Zn plate as an anode. The electrochemical activation technique was used to increase the surface area of the CNT electrode by roughly 4.5 times. Copper (Cu) as a catalyst was then deposited onto the activated CNT electrode using electrodeposition method and different Cu loadings were investigated to optimize CO2 reduction. The final assembled Zn-CO2 battery has a 1.6 V output voltage at a current density of 0.063 mA/cm2, which is higher than most devices reported in the literature. This study demonstrates the importance of activation process which enabled more catalyst loading on the cathode resulted in additional active sites for electroreduction process. This paper presents the activated CNT sheet as a promising cathode material for Zn-CO2 batteries.