A Co‐Doped MnO 2 Catalyst for Li‐CO 2 Batteries with Low Overpotential and Ultrahigh Cyclability

Li‐CO 2 batteries can not only capture CO 2 to solve the greenhouse effect but also serve as next‐generation energy storage devices on the merits of economical, environmentally‐friendly, and sustainable aspects. However, these batteries are suffering from two main drawbacks: high overpotential and poor cyclability, severely postponing the acceleration of their applications. Herein, a new Co‐doped alpha‐MnO 2 nanowire catalyst is prepared for rechargeable Li‐CO 2 batteries, which exhibits a high capacity (8160 mA h g −1 at a current density of 100 mA g −1 ), a low overpotential (≈0.73 V), and an ultrahigh cyclability (over 500 cycles at a current density of 100 mA g −1 ), exceeding those of Li‐CO 2 batteries reported so far. The reaction mechanisms are interpreted depending on in situ experimental observations in combination with density functional theory calculations. The outstanding electrochemical properties are mostly associated with a high conductivity, a large fraction of hierarchical channels, and a unique Co interstitial doping, which might be of benefit for the diffusion of CO 2 , the reversibility of Li 2 CO 3 products, and the prohibition of side reactions between electrolyte and electrode. These results shed light on both CO 2 fixation and new Li‐CO 2 batteries for energy storage.