Colin Wessells, Stanford University Energy In Search of the Ideal Grid Battery
Researchers at Stanford make an electrode that can be recharged 40,000 times without losing much capacity.Tuesday, November 22, 2011 By Prachi Patel
Energy utilities are increasingly looking for batteries that can help stabilize the grid. By quickly storing and delivering charge, batteries could accommodate fluctuations in supply and demand, and help to incorporate variable sources of power such as wind and solar. However, currently available battery technologies are either too expensive or don't last for enough charge cycles to be practical.
Researchers at Stanford University have now demonstrated a high-efficiency new nanomaterial battery electrode that lasts for 40,000 charge cycles without significantly losing its charge-holding capacity. The work was led by Yi Cui, a materials science and engineering professor at Stanford University. Cui says the electrode is a first step toward a new type of low-cost battery suitable for storing large amounts of electricity within the power grid.
Cui's new battery chemistry uses inexpensive, abundant materials. It relies on the same principle employed in lithium-ion batteries—moving sodium or potassium ions between electrodes during charging and discharging—but does it much more cheaply. "For grid storage, the battery can be huge, and using sodium and potassium is very attractive because they are so abundant and cheap," Cui says. These batteries will use water-based electrolytes that are cheaper and easier to use than organic solvent-based electrolytes used in lithium-ion batteries.