Sodium ion battery research could power up renewable energy storage

Longer life and increased capacity for a new technology battery that could be the workhorse of a renewable energy grid are the goals of a study of the effect of charging cycles on the structure of anodes in sodium ion batteries.

Under a three-year, $233,000 grant from the National Science Foundation (NSF), a team led by Dr. George Nelson, an associate professor of mechanical and aerospace engineering at The University of Alabama in Huntsville (UAH), will use X-ray diffraction and multiscale X-ray imaging to study changes in the microstructure of the tin-based anodes –also known as 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,” says Dr. Nelson.

“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 says.

Experiments include electrochemical testing, X-ray diffraction to characterize crystal structure of electrode materials and in operando X-ray tomography. These 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.

“In a way, it is a continuation of work that we did on tin-based anodes for lithium ion batteries,” Dr. Nelson says.

Supporting the project are graduate students Hernando Gonzalez and Hosna Sultana.

“Hernando has been in my lab for a couple years, and he is partially supported by the project while he trains Hosna on some of our techniques. Hosna is a new student in my group,” Dr. Nelson says.