A novel hydrochar and nickel composite for the electrochemical supercapacitor electrode material

The novel electrochemical supercapacitor anode material hydrochar/nickel composite was prepared from biomass via a facile method in this paper. Hydrochar was synthesized by sulfuric acid hydrolysis solution of rice husk. The nickel, acted as graphitization catalyst, effectively changed the graphitization degree of hydrochar. Then the hydrochar/nickel effectively improved the specific capacity of hydrochar by 149%. Hydrochar/nickel presented a specific capacitance of 174.5 F g− 1, which was higher than the activated carbon/nickel. The electrochemical performance of the hydrochar, activated carbon and their composites was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. The better capacitive behavior of the hydrochar/nickel composite illuminated a promising electrode material for electrochemical supercapacitor.

► Hydrochar/nickel effectively improved the specific capacity of hydrochar by 149%.
► Hydrochar/nickel was prepared from biomass.
► The preparation method can be extended to other metals and hydrochar composites.