In situ growth of CoMoO₄@NiO heterojunction on nickel foam with 3D flower-like architecture for high-performance asymmetric supercapacitors

This study employed a stepwise hydrothermal-calcination strategy to in situ construct a three-dimensional nanosheet-like CoMoO_₄@NiO heterojunction on foam nickel, serving as a high-performance pseudocapacitive electrode. This unique hierarchical structure provides abundant active sites and excellent ion transport pathways. The prepared electrode exhibits a high specific capacitance of 1796.8 F g⁻¹ (at 1 A g⁻¹) and outstanding cycling stability (95.7% capacity retention after 5000 cycles). Based on this, the assembled CoMoO_₄@NiO//AC asymmetric supercapacitor device exhibits a wide voltage window of 1.7 V, achieving an energy density of 62.39 Wh kg⁻¹ and a corresponding power density of 6250 W kg⁻¹. It maintains 82.3% of its initial capacity after extended cycling. The significant performance enhancement stems from the synergistic effects between CoMoO_₄ and NiO. This composite structure effectively modulates the interfacial electronic structure, optimizes charge transfer dynamics, and promotes ion diffusion. It provides a modification strategy for next-generation cathode materials.