N/S co-doped CoSe/C nanocubes as anode materials for Li-ion batteries

The transition metal selenide can be used as a potential material for the negative electrode of lithium-ion batteries (LIBs) owing to its high density and conductivity. Unfortunately, a large volume change occurs in the transition metal selenide during the charging and discharging process, which eventually results in the poor rate performance and rapid capacity decay. In response to this, the N/S co-doped CoSe nanocubes (CoSe/C–NS) can be fabricated where the S-doped cobalt 2-methylimidazole (ZIF-67) as both sacrifice template and cobalt source to directly mix with selenium powder and followed by the annealing process. In the process, the carbon frameworks derived from ZIF-67 can establish a coating layer to protect the structure of materials, and simultaneously the N/S co-doping can enhance the conductivity and broaden the interlayer of frameworks. These can further accelerate the storage capacity and the Li+ insertion and deintercalation process. As a negative electrode material of LIBs, the CoSe/C–NS delivers the high capacity, high rate performance, and long-term cycle stability. This protocol opens up an approvable approach to fabricate efficient anode materials with persistent electrochemical stability in LIBs.