Nanoparticle Facilitated Charge Transfer and Voltage of a High Capacity VB2 Anode

Abstract

The storage of multiple electrons per molecule provides opportunities to greatly enhance electrochemical energy capacity. VB2 releases, via electrochemical oxidation, 11 electrons per molecule at a favorable, electrochemical potential. Coupled with an air cathode, this 4060 mAh/g intrinsic capacity anode, has energy capacity greater than that of gasoline. Nanochemical improvements of VB2 are probed to facilitate charge transfer and discharge voltage. Nanoparticle formation is accomplished with a planetary ball mill media (tungsten carbide) with hardness comparable to that of VB2 (8–9 Mohs2). Mechanochemical synthesized, VB2 nanorods, exhibit higher voltage, sustain higher rate, and depth of discharge than macroscopic VB2.