For years, scientists have been trying to use nanowires to create batteries because of their larger surface area and higher conductivity. This could result in batteries that can be charged twice as many times as present lithium-ion equivalents. However, the scientists at University of California, Irvine (UCI) have stumbled upon a discovery that could result in batteries lasting a lifetime.
As batteries are charged and discharged (cycled), they expand and contract, resulting in the structure being weakened with each cycle. Nanowire-based batteries have never reached the commercial stage because of their extreme fragility, which can lead to the battery’s structure literally cracking into pieces.
Mya Le Thai, a PhD candidate on the team, may have found a way to overcome this issue resulting in nanowire-based batteries that maintain a stable structure and last 20-40 times longer than previous nanowire-based capacitor technology.
She coated a gold nanowire in a manganese dioxide shell and encased it in an electrolyte made of a Plexiglas-like gel called propylene carbonate. The poly-based gel helps maintain structural integrity during expansion and contraction phases, thus resulting in a capacitor that can be used for life.
To put things into perspective, our everyday lithium-ion batteries found in cellphones and laptops cycle between 300 to 1,200 times with degradation along the way. Nanowire capacitors can cycle anywhere between 5,000-7,000 cycles (which is significantly better) but lose structural integrity very quickly.
Le Thai’s discovery could result in the number of cycles being increased to at least 100,000 with almost no energy storage loss.
The team was able to cycle their capacity up to 200,000 times over a 3 month period with the same level of stability they started with.
“Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said Penner, chair of UCI’s chemistry department. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity.”
“That was crazy,” he added, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.”
While this does not solve the problem of battery capacity, at least this could bring some hope of introducing batteries which output their expected storage value without degrading over time, along with the potential of lasting way longer than our devices themselves.
You can read up more via their published paper.