Recycled rice husks could improve battery life

Ars Technica : To improve lithium-ion batteries, used in electric cars and other devices, researchers are working to replace the carbon anodes with ones made of silicon, which would have 10 times the capacity. However, because the silicon expands and contracts as it charges and discharges, the capacity of batteries using silicon decreases precipitously with each cycle. A group of researchers in South Korea may have found a novel solution . They have taken rice-grain husks, which are about 20% silica, and treated them with acid and heat to remove the organic and metallic components. What’s left is 99.9% silica, which is further treated to remove the oxygen and leave just the silicon. The new silicon anode retains the porous structure of the rice grain and thus allows the silicon to expand and contract without deforming. Now the researchers are working to see whether they can recycle the rice husks on a large enough scale to be cost effective.