NiCoZn-LDH grown with NiMoO4 nanoneedles as a high-performance electrode for supercapacitors

One of the key obstacles in preparing high-performance supercapacitors is designing advanced structures with excellent electrochemical capacitance properties. This paper proposes a simple and fast hydrothermal synthesis method for synthesizing high-performance flower-shaped NiCoZn layered hydroxides (NiCoZn-LDH) on a foam nickel substrate with a heterostructure of NiMoO4 (NMO) nanoneedles, and further forming a heterostructure with NiCoZn-LDH nanoflowers. The electrode material synthesized by this method has significantly improved electrochemical performance. Its specific capacitance reached 3030 mF/cm2 (863C/g) at 4 mA/cm2 and 2317 mF/cm2 (662C/g) at 10 mA/cm2. In addition, an asymmetric supercapacitor (ASC) constructs with NiCoZnLDH@NMO@NF as the positive electrode material and activated carbon as the negative electrode material achieves an energy density of 0.222 mWh/cm2 at a power density of 0.08 W/cm2. Experimental studies shown that the heterostructure of NiCoZn-LDH@NMO plays a crucial role in improving the electrochemical performance of asymmetric supercapacitors. This provides new insights for the design of next-generation ASC active materials and is beneficial for the development of new energy storage devices.