In Situ Synthesis of CuCo2S4@N/S-Doped Graphene Composites with Pseudocapacitive Properties for High-Performance Lithium-Ion Batteries

To satisfy the demand of high power application, lithium-ion batteries (LIBs) with high power density have gained extensive research effort. The pseudocapacitive storage of LIBs is considered to offer high power density through fast faradic surface redox reactions rather than the slow diffusion-controlled intercalation process. In this work, CuCo2S4 anchored on N/S-doped graphene is in situ synthesized and a typical pseudocapacitive storage behavior is demonstrated when applied in the LIB anode. The pseudocapacitive storage and N/S-doped graphene enable the composite to display a capacity of 453 mA h g-1 after 500 cycles at 2 A g-1 and a ultrahigh rate capability of 328 mA h g-1 at 20 A g-1. We believe that this work could further promote the research on pseudocapacitive storage in transition-metal sulfides for LIBs.