Renewable energy sources such as wind and solar are critical for a sustainable future, but their intermittent nature creates a challenge: they do not always supply power when demand is highest. To realize their full potential, efficient and cost-effective energy storage is required to ensure electricity availability when the sun isn’t shining or the wind isn’t blowing.
By creating new battery technology, a group of material scientists from Columbia Engineering are attempting to address this problem. The utilization of potassium-sodium-sulfur (K-Na/S) batteries, which combine the abundant and reasonably priced components potassium, sodium, and sulphur to build a low-cost long-term energy storage option, was examined in a recent study that was published in Nature Communications.
According to Columbia assistant professor of materials science and engineering Yuan Yang, “extending battery operation times and ensuring they can be produced affordably are key to stabilising energy grids and reducing reliance on fossil fuels.” But K-Na/S batteries have two major drawbacks. They need very high operating temperatures (above 250°C), which makes the process costly and complicated, and their capacity is limited by the formation of solid compounds (K2S2 and K2S), which impair the battery’s ability to store energy efficiently.
Yang’s group used acetamide and ε-caprolactam to create a novel electrolyte in order to get around these obstacles. By dissolving the troublesome K2S2 and K2S compounds, this novel approach can increase the energy density and power density of K/S batteries operating at intermediate temperatures. Furthermore, the batteries can operate at a significantly lower temperature roughly 75°C while still reaching near-theoretical energy storage capacity thanks to the novel electrolyte.
The team, which is a component of the Columbia Electrochemical Energy Centre (CEEC), is currently aiming to scale up the technology by improving the electrolyte composition. If they are proven successful, these K-Na/S batteries would provide a dependable and steady energy storage option, enabling the use of renewable energy sources even in times when wind or sunlight are scarce.