A metal-spiced mineral may lead to cheaper batteries for cellular phones and laptop computers. The new material, which researchers would use to make lithium-ion batteries' positive electrodes, should also be safe enough for building large, lightweight batteries for power-hungry hybrid electric vehicles and power tools.
Lithium-ion batteries, first introduced by Sony over a decade ago, are now widely used as convenient, lightweight, and rechargeable power sources for cell phones, laptops, and some other gadgets. But the batteries' positive electrode, or cathode, is typically made of lithium cobalt oxide, which is expensive and requires electronic circuitry to keep devices from overheating when charged (SN: 12/16/00, p. 399). This risk also limits the size of the batteries.
In 1997, researchers at the University of Texas in Austin proposed a new cathode material, lithium iron phosphate, which is cheaper and safer than lithium cobalt oxide. Yet lithium iron phosphate has h