The findings suggest that fungus Neurospora crassa present in a red bread mold could be the key to producing more sustainable electrochemical materials for use in rechargeable batteries
"We have made electrochemically active materials using a fungal manganese biomineralisation process," said Geoffrey Gadd from the University of Dundee in Scotland.
The electrochemical properties of the carbonised fungal biomass-mineral composite were tested in a supercapacitor and a lithium-ion battery.
The compound was found to have excellent electrochemical properties. This system, therefore, suggests a novel biotechnological method for the preparation of sustainable electrochemical materials.
Gadd and his colleagues have long studied the ability of fungi to transform metals and minerals in useful and surprising ways.
In earlier studies, they showed that fungi could stabilise toxic lead and uranium.
That led the researchers to wonder whether fungi could offer a useful alternative strategy for the preparation of novel electrochemical materials too.
"We had the idea that the decomposition of such biomineralised carbonates into oxides might provide a novel source of metal oxides that have significant electrochemical properties," Gadd added in a paper published in the Cell Press journal Current Biology.
"We were surprised that the prepared biomass-Mn oxide composite performed so well," he noted.
In comparison to other reported manganese oxides in lithium-ion batteries, the carbonised fungal biomass-mineral composite "showed an excellent cycling stability and more than 90 percent capacity was retained after 200 cycles," the authors noted.
The team will continue to explore the use of fungi in producing various potentially useful metal carbonates.