What has the RMIT team achieved with their latest battery?
The team has demonstrated the proton battery as a working device that can power several small fans and a light for several minutes.
Andrews said their latest battery’s storage capacity of 2.2 wt% hydrogen in its carbon electrode was nearly three times that of their 2018 prototype, and more than double of 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 said.
“Our battery is also potentially capable of very fast charging.
“The main resource used in our proton battery is carbon, which is 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.
The recent performance gains have been achieved by design changes that enhance electrochemical reactions in the battery.
How does the proton battery work?
During charging, the proton battery splits water molecules to generate protons, which bond to a carbon electrode.
Andrews said the proton battery avoided the 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,” he said.
“Our proton battery has much lower losses than conventional hydrogen systems, making it directly comparable to lithium-ion batteries in terms of energy efficiency.”