Grid-scale energy storage breakthrough? Upgrading vanadium redox batteries
By: SGN Staff
Quick Take:It's still too early to know if the discovery described below can make it out of the laboratory. Many technologies that work well in lab quantities cannot be manufactured at scale or do not perform as well in large settings. But if it does pan out, it could mean a step-change in the cost and capacity of flow batteries, which have great potential for grid-scale storage.
Many observers expect storage breakthroughs to come - if they come at all - from lithium-ion, which is the focus of so much research around the world. Here's a reminder that there are other possibilities, especially for the grid. Grid storage doesn't have to be as compact, as lightweight or operate at the same temperatures as batteries for cars and consumer electronics. - Jesse Berst
Vanadium redox batteries have been thought of as promising for grid-scale energy storage for some time, but their narrow operating temperature range and high cost have sidelined them. However, a fairly simple tweak (simple for scientists anyway) at DOE's Pacific Northwest Regional Laboratory (PNNL) could change all that.
Under lab conditions, the modified flow battery's storage capacity jumped by 70% and its operating temperature was boosted from a range of 50-104 degrees Fahrenheit to between 23 and 122 degrees, making it far better suited for working in colder and warmer temperatures.
"Our small adjustments greatly improve the vanadium redox battery," said PNNL chemist Liyu Li, lead author of a report on the project. "And with just a little more work, the battery could potentially increase the use of wind, solar and other renewable power sources across the electric grid. The adjustments he refers to are adding hydrochloric acid to the sulfuric acid typically used as an electrolyte in the batteries.
In addition to much improved storage capacity and operating temperature range, the batteries are very efficient, generate power quickly and can be idle for long periods without losing capacity. But don't expect to see the new and improved battery on the market anytime soon. Researchers concede that while initial results are promising, more research is necessary.
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