Researchers at RMIT University in Melbourne have built a working prototype of a rechargeable battery that relies on carbon and water instead of lithium and other rare earth metals. The device, described as the first rechargeable proton battery, could eventually offer a more sustainable way to store electricity for everything from portable electronics to home energy systems.
The concept is straightforward: during charging, an electrical current splits water molecules, releasing protons that bind to a carbon electrode. When the battery discharges, those protons travel through a fuel cell and react with oxygen from the air to produce water and electricity. The team behind the project, led by Professor John Andrews, says the materials involved are both abundant and inexpensive.
“The advantage is we’re going to be storing protons in a carbon-based material, which is abundant, and we are getting protons from water which is readily available,” Andrews told The Guardian.
Lithium-ion batteries, which power most modern devices and electric vehicles, depend on a supply chain concentrated in a handful of countries. Mining lithium and other conductive metals also carries environmental costs, including chemical runoff and land clearing. Processing those materials requires significant energy, much of it still generated from fossil fuels.
By contrast, the proton battery’s main components are carbon and water, both of which are widely available and have minimal environmental impact during production. The primary emissions footprint would come from the electricity used to charge the device, the researchers note.
In laboratory tests, a small prototype with an active surface area of just 5.5 square centimeters (0.85 square inches) achieved an energy density comparable to that of commercial lithium-ion batteries, according to an RMIT press release. That suggests the technology could one day match the performance of existing storage systems while using far cheaper materials.
Why the shift matters for renewable energy
The push for cleaner energy storage comes as demand for batteries is expected to grow sharply, driven by the expansion of solar and wind power. Without effective storage, electricity generated on sunny or windy days cannot be saved for later use. Andrews said the proton battery could eventually compete with systems like Tesla’s Powerwall, and possibly even the large-scale battery installations already operating in Australia.
The RMIT team estimates that a commercially viable version of the proton battery could be available within five to ten years. That timeline, if met, would place the technology in a market that is rapidly evolving as utilities and homeowners seek alternatives to lithium-based storage.
While the prototype demonstrates proof of concept, significant work remains before the battery can be scaled up for real-world applications. The researchers are continuing to refine the design, focusing on improving efficiency and durability.
For now, the proton battery stands as a promising research development rather than a commercial product. But its reliance on common materials and its low environmental footprint during production make it a notable entry in the race to find more sustainable energy storage solutions.
