A Li–O2/CO2 battery based on bio-inspired engineering of the Bi2S3/PVP cathode

Abstract

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 O₂ and O₂²⁻ providing important insights into achieving efficient energy conversion of metal–air batteries.