Georgia Institute of Technology scientists have developed an anode material that enables sodium-ion batteries to perform at high capacity over hundreds of cycles. Lithium-ion batteries have become essential in everyday technology. But these power sources can explode under certain circumstances and are not ideal for grid-scale energy storage. Sodium-ion batteries are potentially a safer and less expensive alternative, but current versions don’t last long enough yet for practical use.
Sodium Antimony Graphene Anode Activity. Image Credit: American Chemical Society. Click image for the largest view.
Meilin Liu, Chenghao Yang and their colleagues wanted to find an anode material that would give sodium-ion batteries a longer life. The colleagues hail from Georgia Institute of Technology, New Energy Research Institute, School of Environment and Energy, South China University of Technology and Department of Chemistry, National Taiwan Normal University.
For years, scientists have considered sodium-ion batteries a safer and lower-cost candidate for large-scale energy storage than lithium-ion. But so far, sodium-ion batteries have not operated at high capacity for long-term use. Lithium and sodium have similar properties in many ways, but sodium ions are much larger than lithium ions. This size difference leads to the rapid deterioration of a key battery component.
The researchers developed a simple approach to making a high-performance anode material by binding an antimony-based mineral onto sulfur-doped graphene sheets. Incorporating the anode into a sodium-ion battery allowed it to perform at 83 percent capacity over 900 cycles. The researchers say this is the best reported performance for a sodium-ion battery with an antimony-based anode material. To ultimately commercialize their technology, they would need to scale up battery fabrication while maintaining its high performance.
The team’s development is closing in on three years of life with daily charge and discharge cycling. Still in its lab stage of development the technology has lots of work yet to be done. For now the tech is very hopeful, some applications simply can’t tolerate the lithium-ion risk, getting those kinds of devices a higher power lower weight battery is a worthwhile effort, indeed.