A new design that could “greatly extend” the shelf life of single-use metal-air batteries for a variety of applications has been unveiled by researchers at the Massachusetts Institute of Technology (MIT).
The research team said they have found a way to substantially reduce corrosion in batteries, which could benefit electric vehicles, off-grid storage and other applications.
Metal-air batteries are one of the lightest and most compact types of batteries available, but their major limitation is that, when not in use, they degrade quickly, as corrosion eats away at their metal electrodes, the MIT team said.
“The MIT design overcomes the problem of corrosion in aluminum-air batteries by introducing an oil barrier between the aluminum electrode and the electrolyte — the fluid between the two battery electrodes that eats away at the aluminum when the battery is on standby,” the team said.
“The oil is rapidly pumped away and replaced with electrolyte as soon as the battery is used. As a result, the energy loss is cut to just 0.02% a month— more than a thousand-fold improvement.”
According to the MIT team, the method of corrosion suppression exploits the same property of aluminum that promotes corrosion in conventional systems.
“The result is an aluminum-air prototype with a much longer shelf life than that of conventional aluminum-air batteries.”
The researchers showed that when the battery was repeatedly used and then put on standby for one to two days, the MIT design lasted 24 days, while the conventional design lasted for only three.
“Even when oil and a pumping system are included in scaled-up primary aluminum-air battery packs, they are still five times lighter and twice as compact as rechargeable lithium-ion battery packs for electric vehicles,” the researchers said.
Details of the research are on MIT’s website.
