Researchers develop hybrid flow battery for renewable energy sources

By Olivia Moore May 5, 2013

A team of Stanford researchers recently unveiled a new low-cost, high-capacity, hybrid flow battery that can stabilize fluctuations in wind and solar power to enable greater use of renewable energy sources.

The researchers published their findings in a study co-authored by Associate Professor of Materials Science and Engineering Yi Cui, Yuan Yang M.S. ’10 Ph.D. ’12 and third-year doctoral candidate Wesley Zheng.

Cui, who began teaching at Stanford eight years ago, put together a research team to create innovative methods of energy storage, such as batteries for cellphones, laptops and electrical cars, as well as stationary forms of storage like solar cells and wind farms.

According to Cui, the new hybrid battery differs significantly from the traditional flow battery, which Cui described as “battery electrodes that are liquid and can flow.”

The team’s hybrid battery uses a new cathode with higher energy density and a solid as the negative electrode so that the battery only “half flows,” according to Cui. The researchers also eliminated the need for an ion-selective membrane, which is typically found in flow batteries and can be expensive.

“We potentially have four-times-higher energy compared to the other flow batteries that have already been developed,” Cui said. “[The new battery] stores a lot of charges, which is so important for solar storage to reduce the cost.”

Zheng, Yang and Cui began collaborating on the battery’s creation last year. According to Zheng, the project was born out of a discussion about how to improve lithium-sulfur batteries so that the sulfur would not dissolve into the electrolytes.