Vanadium Compounds As Negative Electrode Materials For Electrochemical Capacitor

According to the fact that the electrochemical capacitors falling short of high capacity negative electrode materials, in this paper, a series of VN negative electrode materials have been designed and prepared. Their electrochemical performances have been studied systematically. First, we used high temperature ammonia reduction method to prepare VN nanoparticles, and proposed that the specific capacity of VN nanoparticle was decided by its specifio surface area for the first time. Following this, we used template and spray drying method to prepare mesoporous VN and spherical porous VN with high specific surface area and high specific capacity. Then we fabricated carbon coated VN/C composite material to improve its rate capability and cycle performance. On the basis of the experimental data, the energy storage mechanism of VN material was discussed and proved:the specific capacity of VN was mainly provided by capacitance produced in redox reaction of the surface vanadium oxide. VN materials were used as negative electrode for electrochemical capacitor. We assembled a VN/NiOx electrochemical hybrid capacitor with good energy density and powder density.