Solvothermal synthesis of nickel cobalt hydroxide nitrate on CuO nanowires via redox reaction between nitrate and ethanol for electrochemical energy storage

Due to high theoretical capacity and good electrochemical stability, nickel-cobalt hydroxide has attracted extensive attention in alkaline energy storage applications. In this work, we coated nickel cobalt hydroxide nitrate nanosheets arrays on CuO nanowires using a simple solvothermal reaction without any alkali sources and additional oxidants. The three-dimensional structure of core-shell nanowire arrays and the synergistic combination of Ni²⁺ and Co²⁺/Co³⁺ resulted in a large specific capacity of 3.76 mAh cm⁻² (43.2 F cm⁻²) under 11.6 mg cm⁻². At the power density of 0.754 kW kg⁻¹, the energy density of as-fabricated nickel-zinc battery can reach 530.1 Wh kg⁻¹, indicating excellent alkaline energy storage performance.