Co(CO3)0.5(OH)•0.11H2O/graphene composites are synthesized by a hydrothermal method through altering reaction time. Their capacitive performance is studied. The results show the that the crystallite size of Co(CO3)0.5(OH)•0.11H2O in the composites increases when reaction time prolongs. The morphology of Co(CO3)0.5(OH)•0.11H2O in the composites consists of flake and rod structures and remains unchanged when reaction time prolongs. The specific capacitance of the composites decreases when the composites prepared in long reaction time. Co(CO3)0...
