Renewable energy sources such as wind and solar play a vital role in preserving our environment, yet they present a significant issue: they don’t always produce electricity when we need it. To utilize these energy sources effectively, we require efficient and cost-effective storage solutions, ensuring we have power available even in the absence of wind or sunlight.
Renewable energy sources such as wind and solar play a vital role in preserving our environment, yet they present a significant issue: they don’t always produce electricity when we need it. To utilize these energy sources effectively, we require efficient and cost-effective storage solutions, ensuring we have power available even in the absence of wind or sunlight.
Researchers at Columbia Engineering are dedicated to inventing new types of batteries that could revolutionize the storage of renewable energy. In a recent study published on September 5 in Nature Communications, the team explored K-Na/S batteries that integrate low-cost, widely available materials—potassium (K), sodium (Na), and sulfur (S)—to develop an economical, high-energy method for long-term energy storage.
“It is crucial that we increase the operating duration of these batteries and simplify their manufacturing process to keep costs low,” explained Yuan Yang, the team leader and an associate professor of materials science and engineering in the Department of Applied Physics and Mathematics at Columbia Engineering. “Enhancing the reliability of renewable energy will stabilize our power grids, lessen our reliance on fossil fuels, and contribute to a more sustainable energy future for everyone.”
Improved electrolyte enhances K-Na/S battery efficiency
K-Na/S batteries face two significant obstacles: they typically have a low capacity due to the formation of inactive solid K2S2 and K2S, which impede the diffusion process, and they require very high operating temperatures (>250 °C), necessitating complicated thermal management that drives up costs. Earlier research has struggled with solid deposits and limited capacity, urging the search for new methods to enhance these battery types.
Yang’s team has introduced a novel electrolyte comprising acetamide and ε-caprolactam, which aids in energy storage and release. This electrolyte can dissolve both K2S2 and K2S, improving both energy density and power density in intermediate-temperature K/S batteries. Additionally, it allows the battery to function at a significantly lower temperature of about 75°C compared to previous models, while still approaching the maximum energy storage capacity.
“Our approach realizes almost the theoretical discharge capacities and longer cycle life, which is very promising for intermediate-temperature K/S batteries,” remarked Zhenghao Yang, a PhD student and co-first author of the study.
Path to a sustainable energy future
Yang’s research group is connected with the Columbia Electrochemical Energy Center (CEEC), which adopts a comprehensive approach to uncover innovative technologies and hasten their commercial application. CEEC brings together faculty and researchers from across the School of Engineering and Applied Science, focusing on electrochemical energy, spanning from individual electrons to complete systems. Their partnerships with industry facilitate the realization of advancements in electrochemical energy storage and conversion.
Plans for scaling up
While the current focus is on small, coin-sized batteries, the team aims to eventually expand this technology to accommodate large-scale energy storage. Success in this endeavor could ensure a steady and dependable power supply from renewable sources, even during periods of limited sunlight or wind. The researchers are actively working on refining the electrolyte composition.