Novel cadmium-doped cobalt nanoparticles encapsulated in graphite shell are introduced to be utilized in the electrochemical supercapcitors. Electrochemical characterization for the introduced NPs indicated that the corresponding specific capacitance is 255F/g with good stability. The introduced NPs were synthesized using a simple sol–gel technique. Typically, a sol–gel composed of cadmium acetate, cobalt acetate and poly(vinyl alcohol) was prepared based on the polycondensation property of the acetate anions. The utilized physiochemical characterizations affirmed that drying, grinding and calcination in Ar atmosphere of the prepared gel leads to produce Cd-doped Co nanoparticles encapsulated in a thin graphite layer. Overall, the present study opens a new avenue for the encapsulated bimetallic nanostructures to be used as effective materials in the electrochemical supercapacitors.