Harvard researchers have developed a fuel cell that utilizes methane gas, a significant breakthrough that promises longer-lasting battery life and a more environmentally friendly power source for mobile devices in the future.

Shriram Ramanathan, a professor at the School of Engineering and Applied Sciences, and his team have developed micro-fuel cells that harness energy from cheap methane gas instead of more expensive hydrogen gas, and do not utilize platinum, a traditional component in fuel cells.

Fuel cells convert the chemical energy of fuels like hydrogen and methane gas into electrical energy, which could be used to power mobile devices.

But in order for this new type of battery to be used in commercial devices, its operating temperature must be significantly reduced, which will require significant additional research.

Solid oxide fuel cells (SOFCs) operate at extremely high temperatures of around 1,000 degrees Celsius. And while the fuel cell developed by Ramanathan and his team operates at 500 degrees Celsius, it is still too high a temperature for consumer products.

Similar technology exists in fuel cell cars, but due to the expensive products involved in the process, they come with a hefty price tag. SOFCs are being researched as a potential alternative energy source that might be used to phase out fossil fuel sources.

Ramanathan’s team is working on fuel cells that can power smaller devices, but he said the temperature of 500 degrees Celsius is ideal for an automobile engine.

His work, however, involves designing miniature power sources that can be integrated into mobile devices or even insect-sized robots, he said, which means the project is not complete.

SOFCs can use a variety of gases for input, but they also utilize a high temperature to enhance the oxidation-reduction reaction. That means the materials used must be strong enough to withstand the heat, according to Ramanathan.

“This is a thermally activated process,” he said, “so the higher the temperature, the better the typical performance metric. You’re sort of competing against temperature.”

Ramanathan’s platinum-free, methane-utilizing fuel cells are able to operate under 500 degrees Celsius, a feat in the overall goal of building highly compact power sources.

“The same line that brings natural gas into your home for heating can also supply your electricity in a cleaner and more efficient manner,” said Kian Kerman—a Ph.D. student who is involved in the project—highlighting the potential practical applications of the team’s findings.

Ramanathan’s research is supported by the National Science Foundation.