Construction of Cu–Ag@MnS–NiS ₂ –Co ₃ S ₄ Composites with Core–Shell Structure for High Energy Density Supercapacitors

To overcome the intrinsic limitations of metal–organic frameworks in energy storage, such as poor conductivity and stability, we designed a unique core–shell heterostructure. This is achieved by in situ growth, conversion of MOFs to layered double hydroxide, and a subsequent sulfidation strategy, which transforms ZIF-67-decorated Cu–Ag nanowires into a robust Cu–Ag@MnS–NiS 2 –Co 3 S 4 (CAMNCS) complex. This rational design results in superior electrochemical performance, including a specific capacity of 295.5 mAh g –1 and excellent cycling stability. Meanwhile, the nitrogen-doped Ginkgo biloba -derived carbon material (NGLC) prepared by the pyrolysis–activation method exhibited a specific capacitance of 277.2 F g –1 under the same test conditions. When paired with a biomass-derived carbon anode, the assembled device achieves an energy density of 109.4 Wh kg –1, validating our material design concept. This research introduces new ideas and methods for the design and preparation of high-performance electrodes.