Lithium-ion batteries have two big hurdles to climb if they're going to power millions of plug-in vehicles – they're too expensive and their reliability has been called to question. For next-gen li-ion batteries to make it, there had better be a cheap and plentiful component. How about rice husks?
Researchers at Chungnam National University in South Korea say there's huge potential for the husks, which make up 20 percent of harvested rice kernels and are produced at a rate of about 80 million metric tons a year. Until now, rice husks were mostly thrown away because their usage has been limited to low-value agriculture functions such as fertilizer additive and bed soil. They have tough and abrasive properties, which severely limits the value. But the Chungnam researchers figured out that silica in the rice husks can be converted into silicon for high-capacity lithium batteries. Silicon is in high demand for batteries that are used in many hybrid and electric vehicles. Perhaps rice husks could make the silicon cheaper and thereby reduce the battery price?
The researchers took several steps to extract the silica. Through acid and heat treatments, they found that the silicon had excellent electrochemical performance when used for anodes, further suggesting the potential of rice husks.
We wonder if Toyota might be game to try out this potential. Aside from its passion for next-gen batteries, the company recently dug up some controversy surrounding with the leveling of a 17th century rice patty. Rice farmers would likely be pleased to see Toyota make restitution by paying for rice husks to support the future of next-gen lithium batteries.