The combination of a carbon electrode with the protons from water gives the cell environmental, energy, and potential economic edge, says lead researcher Professor John Andrews.
“Our latest advance is a crucial step towards cheap, sustainable proton batteries that can help meet our future energy needs without further damaging our already fragile environment,” he said. “The proton battery is one among many potential contributors towards meeting this enormous demand for energy storage.”
“Powering batteries with protons has the potential to be more economical than using lithium ions, which are made from scare resources. Carbon, which is the primary resource used in our proton battery, is abundant and cheap compared to both metal hydrogen-storage alloys, and the lithium needed for rechargeable lithium ion batteries.”
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.
The prototype small proton battery has an active inside surface of 5.5 cm2 and can store as much energy per unit mass as commercially-available lithium ion batteries. The porous activated-carbon electrode made from phenolic resin was able to store around 1 wt% hydrogen in the electrode with a maximum cell voltage was 1.2 volt.
“Future work will now focus on further improving performance and energy density through use of atomically-thin layered carbon-based materials such as graphene, with the target of a proton battery that is truly competitive with lithium ion batteries firmly in sight,” said Andrews.