Molten Air - a New Class of Rechargeable Batteries

A new class of high-energy batteries, the molten air battery, is presented. These batteries use a molten electrolyte, are quasi-reversible (rechargeable), and have amongst the highest intrinsic battery storage capacities available.

In today’s society there exists a need for higher energy capacity, cost effective batteries for a range of electronic, transportation and large-scale power storage devices. The molten air battery overcomes these problems. For example, these batteries address the “range anxiety” of electric vehicles as a result of energy density limitations, and offer increased energy storage capacity for the electric grid.

The electron charge transfer chemistry of the molten air battery is demonstrated through three examples. These examples utilize metal, carbon and vanadium diboride as reactive material each containing the respective intrinsic volumetric energy capacities of 10,000 Wh liter^-1 for Fe to Fe(III), 19,000 Wh liter^-1 for C to CO₂^- and 27,000 Wh liter^-1 for VB₂ to B₂O₃ + V₂O₅, compared to 6,200 Wh liter^-1 for the lithium air battery.