Abstract
A method of preparing a soft carbon material for high-voltage supercapacitors includes: providing an initial soft carbon material characterized by: (A) a first carbon layer spacing greater than 0.345 nm but less than 0.360 nm; (B) a crystal plane (002) with a length (Lc) less than 6 nm; (C) a crystal plane (101) with a length (La) less than 6 nm; and (D) an intensity ratio (I(002)/I(101)) of the crystal plane (002) to the crystal plane (101) obtained by XRD analysis being less than 60; performing an alkaline activation on the initial soft carbon material with an alkaline activator to obtain a first processing carbon material; and performing an electrochemical activation on the first processing carbon material with an electrolyte to obtain the soft carbon material for the high-voltage supercapacitors.