HPC (hierarchical porous carbon) material with high specific surface area as well as low alkali activation preparation method and application of thereof

The invention belongs to the technical field of materials and discloses an HPC (hierarchical porous carbon) material with a high specific surface area as well as a low alkali activation preparation method and an application thereof. The preparation method comprises following steps: biomass is cut into pieces and dried, then the dried biomass is soaked in an alkaline solution, the mass ratio of alkali in the alkaline solution to the biomass is 0.05-1; a homogeneous mixture is formed after ultrasonic mixing and subjected to freeze drying; under the condition of a certain gas atmosphere and temperature, carbonization is performed on the obtained product; and inorganic matter in the carbonized product is removed by use of an acid solution, and the HPC material with the high specific surface area is obtained. The BET specific surface area of the obtained carbon material can be up to 1400-3500 m .g. The obtained carbon material has better performance when used in the fields such as energy storage, gas adsorptio