Silicon is cheap and plentiful – but using it in batteries has proved to be quite a vexing task. Researchers at Germany’s Forschungszentrum Jülich haven’t given up on the prospect and have made significant headway.
We first wrote about silicon-air batteries in 2009. Back then it was predicted rechargeable electric car batteries made using silicon would be available within a decade. As it turns out, it may be a little (or perhaps a lot) longer than that.
There has been progress since 2009 and other related developments. For example, University of Waterloo researchers created a lithium-ion battery with a silicon anode last year; but a major and ongoing issue for true silicon air batteries has been short run times.
The best that had previously been achieved was a few hundred hours – but the electrolyte used was expensive.
Researchers at Forschungszentrum Jülich, one of the largest interdisciplinary research institutions in Europe, say they believe they have identified the short run-time culprit. They say the issue has to do with the consumption of active electrolyte through the battery self-discharging.
“If the silicon anode remains in contact with the electrolyte, the battery will continue running,” said Dr. Hermann Tempel from Jülich’s Institute of Energy and Climate Research (IEK), Fundamental Electrochemistry department.
Dr. Tempel says a test battery kept in contact with active electrolyte achieved a running time of over 1,100 hours, or almost 46 days. A pump system was developed to keep the electrolyte fluid, which consisted of potassium hydroxide dissolved in water, fresh and topped up.
Dr. Tempel is confident they are on the right track by tackling the self discharging issue.
“The battery is not yet perfect, but we now know what we have to work on.”
So while we may not see silicon-air batteries in the decade previously predicted; they are still a real possibility at some point.
If such an energy storage solution was achieved and could be mass produced, it would mean smaller, lighter and cheaper battery systems for all sorts of applications – from solar energy storage to electric vehicles and beyond.
