Columbia Engineering researchers have developed a novel electrolyte that improves the performance of K-Na/S batteries. The improved K-Na/S batteries could provide a much-needed low-cost option for renewable energy storage.
Published in Nature Communications, the battery utilizes potassium (K) and sodium (Na), readily available elements, with sulfur (S) resulting in a low-cost high-energy battery solution.
“It’s important that we be able to extend the length of time these batteries can operate, and that we can manufacture them easily and cheaply,” said Yuan Yang, associate professor of materials science and engineering at Columbia University. “Making renewable energy more reliable will help stabilize our energy grids, reduce our dependence on fossil fuels, and support a more sustainable energy future for all of us.”
Historically, K-Na/S batteries faced two major challenges. The batteries require high temperatures and complex thermal management to operate while the formation of solid K2S2 and K2S leads to a low capacity. To overcome these challenges, the team developed a novel electrolyte, a solvent of acetamide and ε-caprolactam, to assist in energy storage and release. This solvent is capable of dissolving K2S2 and K2S, enhancing the overall energy density and intermediate temperature of the K-Na/S battery.
“Our approach achieves nearly theoretical discharge capacities and extended cycle life. This is very exciting in the field of intermediate-temperature K/S batteries,” said the study’s co-first author Zhenghao Yang, a PhD student with Yang.