Ag2V4O11: from primary to secondary battery

Ag2V4O11 (silver vanadium oxide, SVO) is the positive electrode in primary lithium/SVO batteries that had known an extraordinary success as a power source in implantable cardiac defibrillators (ICD). However, its use in rechargeable batteries is questioned due to the need of the negative lithium metal electrode that acts as the lithium source and that cannot be safely recharged in standard liquid electrolytes. In this study, a proof of concept of rechargeable graphite/SVO battery is demonstrated. The introduction of 3,4-dihydroxybenzonitrile dilithium salt (Li2DHBN) as a sacrificial lithium source in the positive electrode allows in situ lithiation of the graphite electrode. The cell can further be cycled as a secondary battery. Different parameters have been investigated such as the particle size of Ag2V4O11 synthesized by solid state and hydrothermal processes, especially with regard to peak power delivery. In situ XRD was used to investigate the link between irreversible silver reduction, which allows high electronic conductivity, and amorphization of the SVO structure.