‘Proton battery’ for EVs and more under development

A “proton battery” that may be developed to power homes, vehicles and devices has been patented by Melbourne’s RMIT University.

The cheap, rechargeable battery uses a carbon electrode to store hydrogen that has been split from water, and then works as a hydrogen fuel cell to produce electricity.

The RMIT team is embarking on a two-year research collaboration with Italian-based international automotive component supplier Eldor Corporation to develop and prototype this technology, both involved with it during the past five years.

Recent design improvements to RMIT’s proton battery means it’s becoming competitive as a carbon-neutral alternative to lithium-ion batteries, says lead researcher professor John Andrews.

“As the world shifts to intermittent renewable energy to achieve net-zero greenhouse emissions, additional storage options that are efficient, cheap, safe and have secure supply chains will be in high demand,” says Andrews from RMIT’s School of Engineering.

“That’s where this proton battery – which is a very equitable and safe technology – could have real value and why we are keen to continue developing it into a viable commercial alternative.

Andrews says there’s no end-of-life environmental challenges with a proton battery.

“All components and materials can be rejuvenated, reused or recycled.”

RMIT has already demonstrated the proton battery can power several small fans and a light for several minutes.

Andrews says their latest battery’s storage capacity of 2.2 weight percentage of hydrogen in its carbon electrode is nearly three times that of RMIT’s 2018 prototype, and more than double other reported electrochemical hydrogen storage systems.

“Our battery has an energy-per-unit mass already comparable with commercially available lithium-ion batteries, while being much safer and better for the planet in terms of taking less resources out of the ground,” he explains.

“Our battery is also potentially capable of very fast charging.”

Andrews says the main resource used in RMIT’s proton battery is carbon – abundant, available in all countries and cheap compared to the resources needed for other types of rechargeable battery such as lithium, cobalt and vanadium.

The planet’s supply of lithium is concentrated in just a few countries, while other metals such as cobalt that go into lithium batteries are becoming increasingly scarce and costly, he adds.

Andrews says the proton battery’s recent performance gains have been achieved by design changes that enhance electrochemical reactions in the battery.

During charging, the RMIT proton battery splits water molecules to generate protons, which bond to a carbon electrode.

Andrews says the proton battery avoids energy-wasting steps of storing hydrogen gas at high pressure, and then splitting these gas molecules again in fuel cells.

“When discharging, protons are released again from the carbon electrode and pass through a membrane to combine with oxygen from the air to form water – this is the reaction that generates power.

“Our proton battery has much lower losses than conventional hydrogen systems, making it directly comparable to lithium-ion batteries in terms of energy efficiency.”

Andrews says the collaboration with Eldor aims is to scale up the system from the watt to the kilowatt and ultimately to the megawatt scale.

The results and analysis of the RMIT team’s work on the proton battery have been published in the Journal of Power Sources.

Funding by the Australian Renewable Energy Agency (ARENA) and the Victorian Government through a VESKI Study Melbourne Research Partnerships grant have supported RMIT’s earlier work on the proton battery.