Interface engineering of nickel molybdenum nitride@nickel cobalt molybdenum layered double hydroxide heterostructure...

The construction of well-defined heterointerfaces represents an efficient strategy for boosting supercapacitor electrode performance. Herein, we fabricated an advanced nickel molybdenum nitride (Ni_0.2Mo_0.8N)@nickel cobalt molybdenum-layered double hydroxide (NiCoMo-LDH) heterostructure by electrodeposition of NiCoMo-LDH on a porous Ni_0.2Mo_0.8N backbone. This heterostructure design integrates Ni_0.2Mo_0.8N and NiCoMo-LDH into an interconnected three-dimensional (3D) nanosheet network, which enhances redox activity, facilitates rapid ion transport, and ensures structural integrity. Density functional theory (DFT) analyses substantiate that the heterointerface engineering between Ni_0.2Mo_0.8N and NiCoMo-LDH induces charge redistribution at the heterointerfaces, improves charge carrier mobility, and enhances hydroxyl ion adsorption capability. The Ni_0.2Mo_0.8N@NiCoMo-LDH heterostructure electrode delivers a specific capacity of 1054.4C g^-1 / 2425.2 mC cm^-2 at 1 A g^-1 while maintaining 95.7% capacity retention after 5000 cycles, outperforming the pristine Ni_0.2Mo_0.8N and NiCoMo-LDH in both capacity and durability. Furthermore, the hybrid supercapacitor (HSC) device based on the Ni_0.2Mo_0.8N@NiCoMo-LDH cathode achieves an energy density of 82.6 Wh kg^-1 at 794.4 W kg^-1, coupled with robust long-term cycling performance (96.0% capacity maintenance over 20,000 cycles). These results validate the effectiveness of rational heterostructure design with complementary constituents for next-generation energy storage applications.