Published on March 19th, 2013 | by Nicholas Brown3
Silicon Nano Beads Could Improve Li-ion Battery Life
Silicon designs have a track record for extremely high energy density, which is 10 times more than that of conventional lithium-ion batteries that use a graphite anode. This is because silicon can store ten times as many lithium ions as graphite.
How The Beads Were Created
The researchers attached organic molecules which are sometimes used in food flavouring products to carbon nanotubes less than 50 nanometres wide (which have been used to make almost miraculous things). They then surrounded the tubes with a gas which contains silicon. This caused silicon beads to grow on the tubes.
The researchers think this is more reliable than past designs that involved flat silicon coatings because the beads will expand like flexible balloons without cracking.
Past designs involved chunks of silicon, which cracked so quickly that they were not feasible, followed by silicon nanowire batteries in 2007, which also failed, but were attempted again, and another porous silicon anode design in 2012. None of these have been used commercially because of their limitations, but they were still an improvement, and researchers learned from that.
When charging these batteries, the silicon beads absorb lithium ions, causing them to swell, which resembles a balloon being inflated.
When discharging them, the lithium ions are released from the anode, and generate electricity as they travel over to the anode. I wonder if anyone will combine this high-energy-density battery technology with MIT’s fast-charging and -discharging technology.
Electric cars that can charge in 20 seconds, travel several hundred miles per charge, and deliver blistering speed would be a game changer.
Could this battery technology move beyond the lab? We’ll have to wait and see. For more details about it, check out the University of Maryland press release announcing the breakthrough.
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