Spherical, flower-like MnCo2O4 with a hollow structure as the cathode for efficient Li-CO2 batteries

Global warming and climate change caused by the emission of carbon dioxide (CO2) have induced unprecedented threats to the natural environment. Efficient utilization of CO2 is a highly desirable approach to neutralizing CO2 emissions. Li-CO2 batteries can store electrochemical energy. They have received considerable attention due to their ability to "fix" and convert CO2. However, their application suffers from poor reversibility as well as short cycle stability without the use of effective catalysts. We demonstrated that a flower-like MnCo2O4 sphere with a hollow structure could be introduced as the cathode to enhance the electrochemical performance of Li-CO2 batteries. The flower-like, hollow, spherical structure could facilitate the transport and accessibility of CO2. Moreover, it could relieve the accumulation of insoluble Li2CO3 on the electrode to further sweep the pathway of CO2. After 100 charge-and-discharge cycles, the corresponding overpotential was similar to 1.41 V at a current density of 100 mA g(-1). MnCo2O4 as a cathode provided an efficient electrocatalytic activity to enhance the reduction and evolution of CO2. These features could promote the development of other binary transition-metal oxides in Li-CO2 batteries.