1. An asymmetric supercapacitor, comprising: a negative electrode made of a first carbon; a positive electrode made of a treated soft carbon; a separator disposed in between the negative and positive electrodes; and an electrolyte; wherein the treated soft carbon has an activation threshold (AT) larger than 1400, and the activation threshold (AT) is obtained from the following formula: 
 AT= L a *( A a /A c ) L a is an in-plane correlation length of the treated soft carbon, A a is an area of amorphous peak of the treated soft carbon analysed by X-ray diffraction in Gaussian distribution graph, and A c is an area of crystalline peak of the treated soft carbon analysed by X-ray diffraction in Gaussian distribution graph.