Renewable energy sources like wind and solar are critical to sustaining our planet, but they arrive with a giant challenge: they do not at all times generate power when it’s needed. To profit from them, we want efficient and reasonably priced ways to store the energy they produce, so we have now power even when the wind is not blowing or the sun is not shining.
Columbia Engineering material scientists have been focused on developing recent sorts of batteries to rework how we store renewable energy. In a brand new study published September 5 by Nature Communications, the team used K-Na/S batteries that mix inexpensive, readily-found elements — potassium (K) and sodium (Na), along with sulfur (S) — to create a low-cost, high-energy solution for long-duration energy storage.
“It is important that we have the opportunity to increase the length of time these batteries can operate, and that we are able to manufacture them easily and cheaply,” said the team’s leader Yuan Yang, associate professor of materials science and engineering within the Department of Applied Physics and Mathematics at Columbia Engineering. “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.”
Recent electrolyte helps K-Na/S batteries store and release energy more efficiently
There are two major challenges with K-Na/S batteries: they’ve a low capability since the formation of inactive solid K2S2 and K2S blocks the diffusion process and their operation requires very high temperatures (>250 oC) that need complex thermal management, thus increasing the fee of the method. Previous studies have struggled with solid precipitates and low capability and the search has been on for a brand new technique to enhance most of these batteries.
Yang’s group developed a brand new electrolyte, a solvent of acetamide and ε-caprolactam, to assist the battery store and release energy. This electrolyte can dissolve K2S2 and K2S, enhancing the energy density and power density of intermediate-temperature K/S batteries. As well as, it enables the battery to operate at a much lower temperature (around 75°C) than previous designs, while still achieving almost the utmost possible energy storage capability.
“Our approach achieves nearly theoretical discharge capacities and prolonged cycle life. This could be very exciting in the sector of intermediate-temperature K/S batteries,” said the study’s co-first creator Zhenghao Yang, a PhD student with Yang.
Pathway to a sustainable energy future
Yang’s group is affiliated with the Columbia Electrochemical Energy Center (CEEC), which takes a multiscale approach to find groundbreaking technology and speed up commercialization. CEEC joins together faculty and researchers from across the School of Engineering and Applied Science who study electrochemical energy with interests starting from electrons to devices to systems. Its industry partnerships enable the belief of breakthroughs in electrochemical energy storage and conversion.
Planning to scale up
While the team is currently focused on small, coin-sized batteries, their goal is to eventually scale up this technology to store large amounts of energy. In the event that they are successful, these recent batteries could provide a stable and reliable power supply from renewable sources, even during times of low sun or wind. The team is now working on optimizing the electrolyte composition.
