As a warming world moves from fossil fuels toward renewable solar and wind energy, industrial forecasts predict an insatiable need for battery farms to store power and provide electricity when the sky is dark and the air is still. Against that backdrop, Stanford researchers have developed a sodium-based battery that can store the same amount of energy as a state-of-the-art lithium ion, at substantially lower cost.
Chemical engineer Zhenan Bao and her faculty collaborators, materials scientists Yi Cui and William Chueh, aren't the first researchers to design a sodium ion battery. But they believe the approach they describe in an Oct. 9 Nature Energy paper has the price and performance characteristics to create a sodium ion battery costing less than 80 percent of a lithium ion battery with the same storage capacity.
"Nothing may ever surpass lithium in performance," Bao said. "But lithium is so rare and costly that we need to develop high-performance but low-cost batteries based on abundant elements like sodium."
With materials constituting about one-quarter of a battery's price, the cost of lithium – about $15,000 a ton to mine and refine – looms large. That's why the Stanford team is basing its battery on widely available sodium-based electrode material that costs just $150 a ton.
Sodium batteries taste better, too.