Researchers at Purdue University have created electrodes from a species of wild fungus called Tyromyces fissilis. Carbon fibers derived from the sustainable source have been shown to outperform conventional graphite electrodes for lithium-ion batteries.

Microscope images of a type of wild fungus shows that it contains an interconnected network of fibers ideal for battery anodes.
(Purdue University image/ Jialiang Tang)

Vilas Pol, an associate professor in the School of Chemical Engineering and the School of Materials Engineering, and doctoral student Jialiang Tang attached cobalt oxide nanoparticles to the fibers. The hybrid anodes have a stable capacity of 530 milliamp hours per gram, which is one and a half times greater than graphite's capacity.

"Both the carbon fibers and cobalt oxide particles are electrochemically active, so your capacity number goes higher because they both participate," Pol said.

Comparisons with other fungi showed the Tyromyces fissilis was especially abundant in fibers. The fibers are processed under high temperatures in a chamber containing argon gas. The procedure, known as pyrolysis, yields pure carbon in the original shape of the fungus fibers.

The fibers have a disordered arrangement and intertwine, forming a conductive and interconnected network that brings faster electron transport and could result in faster battery charging.


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