Fabrication of the Cu₂S@NiMn-LDH@Co₄S₃ Material with Mixed-Dimensional Structures by In Situ Selective Vulcanization for High-Performance Supercapacitors

The development of multicomponent composite electrode materials with mixed-dimensional architectures is essential for improving both the area-specific capacitance and long cycling stability of high-energy-density supercapacitors. Hence, we successfully developed a 1D Cu 2 S nanowire–2D NiMn–LDH nanosheet–0D Co 4 S 3 hierarchical heterostructure through selective sulfidation and a synergistic design strategy involving mixed-dimensional structures. Electrochemical tests show that the resulting electrode achieves an ultrahigh area-specific capacitance of 14.78 F cm –2 at 10 mA cm –2 and an excellent retention capacitance of 80.56% over 5000 cycles. Additionally, the Cu 2 S@NiMn-LDH@Co 4 S 3 //AC asymmetric supercapacitor (ASC) device demonstrates an ultrahigh energy density/power density (2.32 mWh cm –2 /9 mW cm –2 ), with an outstanding retention capacitance of 76.22% at 30 mA cm –2 over 10000 cycles. The selective sulfidation process enables 1D Cu 2 S to provide structural support, 2D NiMn-LDH to offer a large surface area, and 0D Co 4 S 3 nanoparticles to introduce additional active sites. This unique structure demonstrates excellent stability, with synergistic interactions among components accelerating redox reactions and enhancing electron transfer rates.