Carbon-coated nickel oxide nanocomposite material, preparation method therefor and use thereof

A carbon-coated nickel oxide nanocomposite material, comprising carbon-coated nickel oxide nanoparticles having a core-shell structure, with an outer shell being a graphitized carbon film optionally doped with nitrogen and an inner core comprising one or more nickel oxide nanoparticles,

• wherein the nanocomposite material has a carbon content of from greater than 0 wt % to not greater than about 5 wt %, based on the weight of the nanocomposite material, and
• wherein a surface of the nanocomposite material has a carbon element content of about 15-60 mol %, as determined by X-ray photoelectron spectroscopy;
• and/or a ratio of the carbon element mass content in a surface of the nanocomposite material determined by X-ray photoelectron spectroscopy to the carbon element mass content determined by elemental analysis of not less than about 10.