Nano Facilitated Charge Transfer for an 11 Electron Redox Couple for Anodic Charge Storage: VB_2

摘要

The storage of multiple electrons per molecule provides opportunities to greatly enhance electrochemical energy capacity. VB_2 releases, via electrochemical oxidation, 11 electrons per molecule at a favorable, electrochemical potential. Nanochemical improvements of VB_2 are probed to facilitate charge transfer and discharge voltage. Mechanochemical synthesized VB_2 exhibit higher voltage, sustain higher rate, and depth of discharge than macroscopic VB2. Recently, we introduced a synthetic pathway to nanorod VB_2. In addition, here a straightforward synthetic route to nano-VB_2 particles, via planetary ball milling of elemental vanadium and boride in a 1:2 equivalent ratio is presented. Variation of the mechanochemical synthesis milling speed and milling time is used to optimize this nano-VB_2 for use as a high capacity anode material with enhanced charge transfer and increase voltage. Coupled with an air cathode, this 4060 mAh/g intrinsic capacity anode has an energy capacity greater than that of gasoline.