Hard carbon is produced by heating carbonaceous precursors to approximately 1000 °C in the absence of oxygen.
Among the precursors for hard carbon are polyvinylidene chloride (PVDC), lignin and sucrose.
Soft carbon can be readily converted to graphite by heating to 3000 °C.
Hard carbon is a low density material, with extremely high microporosity, while soft carbon has little microporosity.
[5][6] Manufacturers of hard carbon include Xiamen Tob New Energy (China), Kuraray (Japan) and Stora Enso (Finland).