Electrochemistry of Electrode Materials Containing S-Se Bonds for Rechargeable Batteries

Sulfur (S) and selenium (Se) have been considered as promising high capacity cathode materials for rechargeable batteries. They have differences in their physical properties (e.g., electronic conductivity) but the same number of electrons in their outermost shells, which leads to similarity in their electrochemical behavior in batteries. In recent years, some efforts have been taken to combine them in electrodes in the hope of improved battery performance. The S-Se bonds of these electrode materials lead to unusual properties and intriguing electrochemical behavior, which have attracted increasing interest. In this Minireview, electrode materials containing S-Se bonds are summarized, including inorganic S_x Se_y solid solutions, organic compounds, and organic-inorganic hybrid materials. Our understanding in these materials is still premature, but they have shown unique properties to be electrode materials. We hope this Minireview could provide a new insight into the design, synthesis, and understanding of these materials, which could enable high energy density rechargeable batteries.