Fossilised algae may soon power electric vehicles

Inexpensive and energy-efficient lithium-ion batteries from fossilised remains of single-celled algae called diatoms can soon power electric vehicles, a team of researcher has found. Researchers at the University of California - Riverside's Bourns College of Engineering have developed a way to create silicon-based anodes for ultra-high capacity lithium-ion batteries that in future may power not only portable electronics but also electric cars.

In the paper, published in the journal Scientific Reports, the researchers said unlike graphite, which is the material of choice for most anodes, silicon can store about 10 times more energy. But developing a silicon anode as an alternative through the traditional method, called carbothermic reduction, is expensive and energy-intensive.

So to cut down the cost, the team turned to a cheap source of silicon -- diatomaceous earth (DE) -- and a more efficient chemical process called magnesiothermic reduction, which converts this low-cost source of Silicon Dioxide (SiO2) to pure silicon nano-particles. DE is an abundant, silicon-rich sedimentary rock that is composed of the fossilised remains of diatoms deposited over millions of years.

"A significant finding in our research was the preservation of the diatom cell walls -- structures known as frustules -- creating a highly porous anode that allows easy access for the electrolyte," Mihri Ozkan, research lead and professor of electrical engineering, said. To improve the adoption of electric vehicles, we need much better batteries. We believe diatomaceous earth, which is abundant and inexpensive, could be another sustainable source of silicon for battery anodes, added Ozkan.