VO2/CNTs thick cathode electrode with multi-dimensional electron transport pathways enabled by rolling for high energy thermal batteries

Abstract

Increasing the thickness of cathode electrodes is a promising strategy for improving the specific energy of thermal batteries. However, this approach also introduces challenges related to electron transfer kinetics and discharge performance due to the extended electron transport distance. In this study, a novel approach combining the rolling process and carbon thermal reduction was employed to construct the VO2/CNTs cathode powders with multi-dimensional electron transport pathways. A quasi-two-dimensional structure inside VO2/CNTs electrode materials is constructed by the rolling process, enabling the formation of additional electronic transmission channels, and enhancing the structural stability during discharge. As a result, VO2/CNTs thick electrodes with 0.4 g have a remarkable specific capacity with 350.96 mAh g−1, which is the highest value in contrast to the thick electrodes with grinding and ball milling. Even the electrode mass is increased to 1.0 g, it still exhibits a high specific capacity with 316.89 mAh g−1. This approach holds promise for the development of low-cost, sustainable thick electrodes with increased specific energy for thermal batteries, and can be extended to other electrode materials.