Nickel-cobalt layered double hydroxide nanosheets anchored to the inner wall of wood carbon tracheids by nitrogen-doped atoms for high-performance supercapacitors

In this paper, a novel type of electrode material for high-performance hybrid supercapacitors is designed. The electrode mainly uses nitrogen-doped atoms to anchor the nickel-cobalt layered double hydroxide on the inner wall of wood-derived carbon tracheids from Chinese fir wood scraps. The specific capacity of the composite single electrode is 14.26 mAh cm-2 at 10 mA cm-2. The hybrid supercapacitor with a composite electrode cathode and nitrogen-doped wood-derived monolithic carbon materials as the anode has a high specific capacitance of 4.74F cm-2 at 5 mA cm-2, and the capacitance retention rate is 93.15% after 8000 charge-discharge cycles. The highest energy density and power density reach 1.48 mWh cm-2 and 22.40 mW cm-2, respectively. After doping with nitrogen, the combination with the nickel-cobalt layered double hydroxide is more uniform and stable, and the capacitance and cycling stability are significantly improved.