A new material that has its roots in the humble contact lens could suddenly refocus the power storage issue for electric cars of the future.
Dr. Donald Highgate engineered the technology behind the soft contact lens in the 1970s, and now – by sheer fluke – he is using the same type of innovation that could accelerate electric car usage.
Presently, power is stored for electric cars in battery form, but a new supercapacitor is being worked on that could store an electric charge.
Supercapacitors have a longer lifecycle, are more durable and have faster charging times.
Jim Heathcote, CEO of Superdielectrics Ltd, which is behind the supercapacitor material, said it’s cheap to manufacture, doesn’t use raw elements and can’t catch fire, as it is mostly water.
And it appears to have overcome the issue of energy density. The best supercapacitors hold just five percent of the energy per kilogram of a lithium-ion battery.
A fleet of supercapacitor-powered electric buses in Shanghai can charge in less than 30 seconds but need to do so every few stops. That could now change.
Dr. Highgate, now director of research at Superdielectrics, said the discovery came by chance. The contact lens was based on polymer mesh that swelled up when water molecules attached to it, trapping more water within the holes in the net.
By adding different elements to the mix, he was able to give the polymer additional properties. In 2016, the pair were trying to make the polymer matrix more electrically conductive.
But when they tested the new polymer – a thin, light blue square the size of a postage stamp – it had 100 times more capacitance.
They had stumbled on a material with dielectric properties between 1,000 and 10,000 times greater than existing conductors.
Since then, Superdielectrics has been working with researchers at the universities of Bristol and Surrey to determine whether their polymers work in real-world conditions.
Mr. Heathcote said the supercapacitor material can store “remarkable amounts of electricity, far beyond what we’ve seen before.”
THEY HAD STUMBLED ON A MATERIAL WITH DIELECTRIC PROPERTIES BETWEEN 1,000 AND 10,000 TIMES GREATER THAN EXISTING CONDUCTORS.
Scientists have since created small devices that can power a fan or an LED for a few minutes. They claim that with further work the material could reach energy densities of up to 180 watt-hours per kilogram. That would bring supercapacitors in line with lithium-ion batteries.
Instead of charging every other stop, China’s buses could run for 20 or 30 before seeking extra power.
Dr. Jenifer Baxter at the Institution of Mechanical Engineers said:
“If you can decrease the time spent charging and you can maintain or increase the range within that charge, that will certainly reduce people’s anxiety about electric vehicles.”
Issues do remain, not least the power leakage from the supercapacitor, the volume of the unit for a car could be 30 percent more than a battery and the ability to provide electricity as speed.
Mr. Highgate said more research would be conducted but was positive it could be a game changer for the “energy system which underpins our way of life”.
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