Preparation and discharge performance of porous VB2 anodes for high capacity VB2-air battery

Abstract

VB2 has great potential as an anode material of air batteries due to its high theoretical specific capacity (4060 mAh/g). In present work, the porous anodes for high capacity VB2-air battery were prepared by using powder metallurgy technology, with VB2 as the active materials of anodes, Ni as the conductive agents, and NH4HCO3 as the space-holder. The effect of porosity on the discharge performances of porous anodes was investigated. The results show that the porous anodes exhibit a good discharge performance with specific capacity up to 3216-3463 mAh/g. The discharge capacity, specific capacity, coulombic efficiency, and specific energy all significantly depend on the porosity of the porous anodes. When the addition of space-holder NH4HCO3 is 15wt%, the porous anodes have the porosity of 60.91%, and possess the superior discharge properties with discharge capacity of 7792 mAh, specific capacity of 3463 mAh/g, coulombic efficiency of 85.30%, and specific energy of 2370 mWh/g.