Researchers at the University of California, Riverside made a lithium-ion battery anode from beach sand. They milled quartz-rich sand to the nanoscale, purified it, and heated it with salt and magnesium. The magnesium stripped oxygen from the quartz, leaving pure silicon, while the salt absorbed heat. The silicon formed a porous, sponge-like 3D structure, which proved key to its performance.
Silicon can store far more lithium than the graphite in today's anodes. The carbon-coated nano-silicon kept a capacity of 1024 mAh/g after 1000 cycles, about three times the industry standard. The work was published in Scientific Reports in 2014.
via Sand-based batteries could soon power your mobile phone | ScienceAlert (archived)
via Using sand to improve battery performance | ScienceDaily