Performance Enhancements to Experimental Proton Battery Yield Promising Results

Researchers from Australia’s Royal Melbourne Institute of Technology (RMIT) University have developed an improved proton battery that uses a carbon electrode as a hydrogen storage mechanism. 

 

A proton battery developed by Australian researchers powers two small fans for several minutes. Image used courtesy of RMIT University

 

Part of a years-long project, the latest version achieved a hydrogen storage capacity of 2.23 wt% in its carbon electrode – nearly triple that of the earlier proton-exchange membrane (PEM) proton battery the team developed in 2018. It’s also more than twice that of the highest-reported electrochemical hydrogen storage system using an acidic electrolyte. 

With a higher storage capacity, the battery is one step closer to competing with lithium-ion batteries, currently the industry standard. Its potential applications range from storing electricity from solar panels to powering electric vehicles. 

RMIT University has secured an international patent and begun a two-year partnership with Eldor Corporation, an Italy-based automotive component manufacturer, to scale up the prototype. 

 

Energy Storage Capacity and Power Output Improvements

Like other proton batteries, the RMIT invention splits water to generate protons that bond to the carbon electrode. Upon discharge, the protons are released from the carbon electrode and traverse a membrane to combine with oxygen and form water, generating power. The researchers recently demonstrated the battery’s ability to power a light and two small fans for several minutes. 

John Andrews, an RMIT University engineering professor and lead researcher on the project, said the battery has an energy-per-unit mass comparable with existing lithium-ion batteries. After recent performance gains, the battery now provides improved electrochemical reactions. Some changes involved heating the cell to 70 degrees Celsius (158 degrees Fahrenheit) and replacing the oxygen-side gas diffusion layer with a thin titanium-fiber sheet. 

The researchers hypothesized that the source of the major gain in energy storage is an enhanced water formation reaction on the oxygen side via reduced flooding. They found an alternative mode of discharging the battery, enabling direct hydrogen gas generation from the hydrogenated carbon through a reaction similar to a hydrogen pump. 

 

 In a laboratory, RMIT researchers demonstrate the proton battery’s ability to power two fans. Image used courtesy of RMIT University

 

Since the evolved hydrogen gas is high-purity, the storage technology may open up new opportunities in supply chains for hydrogen fuel cell vehicles, according to the study. 

The team plans to scale the prototype from watts and kilowatts to megawatts through ongoing testing in Melbourne and Italy. 

 

Market Implications: Lithium-Ion Battery Alternative

The RMIT University researchers say their proton battery has lower losses than conventional hydrogen systems, making its efficiency comparable to lithium-ion batteries. The proton battery also offers benefits beyond its lifespan since all components and materials can be recovered, reused, or recycled.

The battery’s abundant materials would allow manufacturers to avoid risky and expensive supply chains. The main resource, carbon, is readily available worldwide and cheaper than raw materials used in incumbent rechargeable batteries, such as cobalt, nickel, and lithium. This advantage comes as battery makers and researchers explore alternative chemistries, including sodium-ion and seawater batteries, enabling a more sustainable and cost-effective supply chain. 

Still, the lithium cobalt oxide segment holds the largest share of the lithium-ion battery market today, according to a recent report from MarketsandMarkets. But alternatives are emerging to take their place. Tesla, Ford, and other auto giants have started using lithium-iron-phosphate (LFP) batteries in some models, taking advantage of LFP’s safety and affordability benefits. 

Overall, longer range and high performance are critical for switching to new technologies, spurring a boom in research and development activities aiming to commercialize promising alternatives.