Beach sand could triple EV battery range
A team of graduates and two professors at the University of California, Riverside’s Bourns College of Engineering made the discovery while investigating ways to improve the performance of batteries in personal electronics and electric vehicles.
Most lithium-ion batteries use graphite for the anode, the negative side, but the material is said to have almost reached its limits and the nanoscale silicon being researched as a replacement is hard to produce in large quantities and degrades quickly in use.
Noting that sand contains high quantities of quartz, in turn made of silicon and oxygen, graduate Zachary milled grains from Cedar Creek Reservoir, near Dallas, and purified it until it turned white. This was then ground with salt and magnesium, both abundant materials, and heated.
The salt absorbed the heat and the magnesium removed the oxygen from the quartz, leaving pure nanoscale silicon with a porous, sponge-like consistency, said to offer greatly improved performance compared to other nano-silicons.
Research so far has produced a coin-sized battery, but the next stage will move up to a pouch-type cell used in mobile phones and could be used in electric vehicles. The increased energy density would triple the range of future lithium-ion batteries and improve durability, yet the production costs are low and the materials are abundant, the university has said.