Researchers led by Professor John Andrews from the RMIT in Melbourne have demonstrated for the first time a working rechargeable “proton battery” which  is environmentally friendly, used cheap materials and has the potential to store more energy than currently available lithium-ion batteries.

The proton battery uses a carbon electrode as a hydrogen store, coupled with a reversible fuel cell to produce electricity.

During charging, the carbon in the electrode bonds with protons generated by splitting water with the help of electrons from the power supply. The protons are released again and pass back through the reversible fuel cell to form water with oxygen from air to generate power. Unlike fossil fuels, the carbon does not burn or cause emissions in the process.

The researchers have shown that their small proton battery, which has yet to be optimised and has an active inside surface area of only 5.5 square centimetres (smaller than a 20 cent coin), was able to store as much energy per unit mass as commercially-available lithium ion batteries.

The carbon electrode plus protons from water give the proton battery an environmental, energy and potential economic edge