Mechanochemical synthesis and electrochemical characterization of VB x as high capacity anode materials for air batteries

Abstract: A series of VB x (x =0.1, 0.25, 0.5, and 1) are prepared by a mechanochemical reaction of elemental B and V powders and tested as alternative high capacity anodic materials for alkaline air batteries. The VB x (x =0.25, 0.5, and 1) anodes tested can deliver an extraordinary capacity of >2000mAhg−1, twice higher than the theoretical capacity of metallic Zn currently used as high capacity anodes in aqueous primary batteries. The strong discharge capabilities observed from electrochemically inert boron (B) and passive vanadium (V) in the VB x samples are suggested to result from a combined chemical interaction, in which the B atoms are electrochemically activated by bonding with V atoms to partially decrease the covalent stability of elemental B component. At the same time, the electrochemically activated B can alleviate, in turn, the anodic polarization of metallic V element by clamping the electrode potential to a region where elemental V is in active state. [Copyright &y& Elsevier]