The high overpotential due to the slow kinetics of the carbon dioxide reduction reaction (CO2RR) and the carbon dioxide evolution reaction (CO2ER) greatly limits the practical application of Li-CO2 batteries. In this study, PVP/Bi2S3 is used as the cathode of a Li-CO2 battery for the first time. The introduction of PVP not only increases the generation of S vacancies, but also improves the electronic conductivity of Bi2S3. The PVP is beneficial to the generation of intermediate lithium oxalate, thereby improving CO2RR and CO2ER kinetics and reducing charge and discharge overpotentials. Therefore, the PVP/Bi2S3-based Li-CO2 battery achieves an ultra-low charging platform of 3.6 V and a high discharge platform of 2.75 V. The proposed PVP/Bi2S3 cathode can also be applied to lithium-oxygen battery systems by efficiently reducing and separating O-2 and O-2(2-) providing important insights into achieving efficient energy conversion of metal-air batteries.

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jilin normal university; Changchun University of Science and Technology