Influence of Structure on Supercapacitors of Co-Vanadate-Based Electrode Materials

This paper reports the synthesis of different crystalline phase-pure Co-vanadates (CVOs), CoV2O6, Co2V2O7, and Co3V2O8, in the same structure. Electrochemical performance experiments were conducted, and density functional theory calculation was used to study their crystalline properties. This paper finds that the supercapacitor performance of CVOs largely depends on the crystalline structure property and charge storage mechanism. Co2V2O7 has the biggest tunnel size and thus exhibits the best electrochemical performance at a low rate. In the aspect of Co3V2O8, superior crystalline structure properties are attributed to excellent performance at a high rate. We anticipate that this study will make a contribution toward offering theoretical guidance for CVO supercapacitor electrode materials.