Constructing Rich Crystalline–Amorphous Heterojunction In NiCoMo/Ag Composites for High‐Performance Supercapacitor

In this work, a simple one-step hydrothermal method is utilized to synthesize rich crystalline Ag/amorphous NiCoMo (NCM) heterojunction electrode materials. The amorphous NCM phase provides rich unsaturated coordination sites and a shortened ion diffusion path, while the crystalline Ag ensures efficient electron transfer. The synthesized rich crystalline–amorphous heterojunction interface electrode material optimizes the charge transfer kinetics and improves the electrochemical performance through the synergistic effect of the two phases. The synthesized NCM/Ag₁ (NCM/Ag₁) exhibits an areal capacitance of 9266.67 mF cm⁻² at 2 mA cm⁻² and retains 74.02% capacity after 10 000 cycles. The constructed NCM/Ag₁//activated carbon (AC) attains an energy density of 55.13 Wh kg⁻¹ at 750 W kg⁻¹, and demonstrates outstanding cyclic stability. By connecting two devices in series, an LED bulb is lit and works for 27  min.

The crystalline–amorphous heterojunction (C–AH) has become an important strategy for constructing electrode materials due to the synergistic effect between the high conductivity from the crystalline phase and the fast ion transport capabilities from the amorphous phase. In this work, a NiCoMo/Ag₁ (NCM/Ag₁) electrode material with abundant C–AH interfaces is successfully produced on nickel foam substrates through a facile one-step hydrothermal approach. The optimized NCM/Ag₁ electrode demonstrates good electrochemical performance, delivering an areal capacitance of 9266.7 mF cm⁻² (125.23 mAh g⁻¹) at 2 mA cm⁻² and retaining 84.7% rate capability at 10 mA cm⁻². It is combined with activated carbon to construct an asymmetric supercapacitor, which achieves an energy density of 55.13 Wh kg⁻¹ at a power density of 750 W kg⁻¹, while also demonstrating a capacity retention of 79.7% after 10 000 cycles. This research supplies a theoretical basis for the design of high-performance supercapacitors.

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