A research lab at the University of Houston has developed a new type of material for sodium-ion batteries that could make them more efficient and boost their energy performance.

Led by Pieremanuele Canepa, Robert Welch assistant professor of electrical and computer engineering at UH, the Canepa Research Laboratory is working on a new material called sodium vanadium phosphate, which improves sodium-ion battery performance by increasing the energy density. Energy density is the amount of energy stored per kilogram, and the new material can do so by more than 15 percent. With a higher energy density of 458 watt-hours per kilogram — compared to the 396 watt-hours per kilogram in older sodium-ion batteries — this material brings sodium technology closer to competing with lithium-ion batteries, according to the researchers.

The Canepa Lab used theoretical expertise and computational methods to discover new materials and molecules to help advance clean energy technologies. The team at UH worked with the research groups headed by French researchers Christian Masquelier and Laurence Croguennec from the Laboratoire de Reáctivité et de Chimie des Solides, which is a CNRS laboratory part of the Université de Picardie Jules Verne, in Amiens France, and the Institut de Chimie de la Matière Condensée de Bordeaux, Université de Bordeaux, Bordeaux, France for the experimental work on the project.

The researchers then created a battery prototype using the new materia sodium vanadium phosphate, which demonstrated energy storage improvements. The material is part of a group called “Na superionic conductors” or NaSICONs, which is made to let sodium ions move in and out of the battery during charging and discharging.

“The continuous voltage change is a key feature,” Canepa says in a news release. “It means the battery can perform more efficiently without compromising the electrode stability. That’s a game-changer for sodium-ion technology.”

The synthesis method used to create sodium vanadium phosphate may be applied to other materials with similar chemistries, which could create new opportunities for advanced energy storage. A paper of this work was published in the journal Nature Materials.

"Our goal is to find clean, sustainable solutions for energy storage," Canepa adds. "This material shows that sodium-ion batteries can meet the high-energy demands of modern technology while being cost-effective and environmentally friendly."