Stanford researchers have found a way to use silicon nanowires to improve the lifespan of lithium-ion batteries by a factor of 10. The nanowires measure one-thousandth the thickness of a sheet of paper. As the nanowires are saturated with lithium, they expand to 4 times their original size and produce 10 times the electricity of today’s batteries. The technology could power laptops for 20 hours, and drastically improve battery life in smaller devices such as mobile phones.