Constructing ZnSe/CoSe2/N-doped carbon composite with multiple heterointerfaces using a solvent-assisted strategy to enhance lithium storage

Interface engineering, as an effective strategy for preparing high power density and long-life battery anodes, can promote the electrochemical performance of materials. Herein, metal organic frameworks (MOFs) derived N-doped carbon nanosheets loaded nanoscale ZnSe/CoSe2 particle composite with multiple heterointerfaces is fabricated by solvent assisted strategy. Wherein the content of water in the solvent is a key factor in establishing a homogeneous heterojunction containing cubic phase CoSe2 (c-CoSe2) and orthorhombic phase CoSe2 (o-CoSe2). The built-in electric field generated by the energy band gap difference between ZnSe and CoSe2 or c-CoSe2 and o-CoSe2, and a strong interaction between ZnSe/CoSe2 particles and N-doped carbon nanosheets, can reduce the migration barrier of Li+ at the interface, accelerate charge transfer, and promote the lithium storage kinetic process. In addition, nanoscale ZnSe/CoSe2 particles coupled with N-doped carbon nanosheets can also generate more active sites, reduce volume expansion, and maintain the structural integrity of the anode material. Based on the above structural advantages, the prepared ZnSe/CoSe2-3# exhibits a high reversible capacity (1188 mAh g-1 after 280 cycles at 0.5Ag-1), and excellent long-term cycling stability (788 mAh g-1 at 1Ag-1 over 600 cycles).