Sodium Ion Battery Research to Power Up RE Storage

Longer life and increased capacity for a new technology battery that could be the workhorse of a renewable energy grid.

A team of researchers from the University of Alabama in Huntsville (UAH), led by Dr. George Nelson, associate professor of mechanical and aerospace engineering is studying the effect of charging cycles on the structure of anodes in sodium ion batteries.

Working under a $233,000 grant from the National Science Foundation (NSF), the team will use X-ray diffraction and multiscale X-ray imaging to study changes in the microstructure of the tin-based anodes (negative electrodes) that affect the battery’s longevity and storage capability.

“As with most batteries, there is a desire to increase the capacity of sodium ion batteries. Unfortunately, high capacity battery materials like tin expand a lot when fully charged with sodium,” said Dr. Nelson.

Experiments include electrochemical testing, X-ray diffraction to characterise crystal structure of electrode materials and in operand X-ray tomography. The experimental methods will be coupled with mesoscale computational studies of sodium ion battery electrode microstructures. The research will provide insight into the interactions between microstructure, chemistry and performance in sodium ion batteries.

“We’re using a combination of experiments and numerical models to understand exactly how these changes affect battery performance, so future battery engineers can design the materials and microstructures to make better sodium ion batteries,” he added.

While not ideal for portable applications like mobile electronics or electric vehicles, sodium ion batteries are well matched to stationary applications like storage of electricity produced by solar and wind power.

“If we create an electric vehicle fleet, continue the expansion of mobile electronics and build large grid-scale batteries all based on lithium-ion technology, we could put serious pressure on global lithium supplies. Sodium is Earth-abundant, and sodium ion batteries have energy densities that are well suited for grid-scale storage,” said Nelson.