A highly efficient biomass based electrocatalyst for cathodic performance of lithium–oxygen batteries: Yeast derived hydrothermal carbon

In this study, we report a kind of highly efficient and environmentally friendly cathode based on yeast derived hydrothermal carbon. Different hydrothermal conditions are explored in order to obtain the optimal hydrothermal carbon based cathode. Then a kind of one-step synthesis method of yeast based cathode is developed to simplify the experimental scheme. The yeast derived hydrothermal carbon is rich in various atoms including N, P, S, which could provide amounts of active sites for electrochemical reactions in the cathode. Another feature of the hydrothermal carbon based cathode is the mild preparation process in which there is no need of introduction of other surfactants and catalysts. This study is aimed to provide a feasible plan to utilize the biomass derived hydrothermal carbon with unique microstructures, higher heat value, higher carbon content, lower ash content as well as green and inexpensive access. A lithium–oxygen battery with the cathode delivers a high capacity of 21,000 mAh g⁻¹ at 185 mA g⁻¹ in a 1 M LiTFSI/TEGDME electrolyte system. Moreover, the cathode exhibits a good oxygen reduction reaction and oxygen evolution reaction activity. These results suggest that the yeast derived hydrothermal carbon can be efficiently optimized for efficient electrocatalytic reactions in lithium–oxygen batteries.