Energy in Demand – Sustainable Energy – Rod Janssen

Scientists believe they have achieved a breakthrough in cutting recharging time for electric vehicles. Tom Whipple explains in an article on The Times website.

Electric car scientists use nuclear tech to chase a 10‑minute charge

For all the advantages of electric cars, there is one big disadvantage. If you want to go further than, say, London to Durham, you have to factor in spending 45 minutes at a motorway service station to recharge.

A new technology based on research into nuclear fusion may have found a way to cut that recharging time by two thirds, meaning that electric car users will barely have time to enjoy the facilities at a Welcome Break before they are back on the move.

The British engineers behind the innovation believe that they can achieve this because they have found a way to solve the chief bottleneck on speedy charging. Batteries take a long time to be replenished not because it is hard to get energy in but because it is hard to get a different kind of energy out.

“One of the big problems with charging quickly is that they generate a lot of heat internally,” Jack Nicholas, the cofounder of the Qdot engineering group, said. “And no one’s yet come up with a way of basically taking that heat out fast enough.”

As luck would have it, Dr Nicholas has some experience of dissipating heat in an even more extreme environment than a Tesla engine. He did his PhD at Oxford University on designing the exhaust of fusion reactors. “A fusion reactor is very hot,” he said. “It is five times the centre of the sun.” This means that what comes out needs to undergo a rapid temperature drop. “With the exhaust it is pretty much critical to have a high-performance cooling system.”

The solution he found was to use metal plates drilled with a precise geometry of holes. As well as increasing the surface area for heat loss the pattern, which is a commercial secret, allows heat to keep flowing, and be lost evenly through the plate.

He and his colleagues claim to have shown that the same technique can rapidly speed up the cooling of batteries. Rather than the present technique of placing plates on the outside of the battery, where it takes longer for heat from the inside to reach the exterior, they connect directly to the centre, drawing heat away.

“We’re using them like highways to get the heat out faster,” Tsun Holt Wong, Qdot’s other co-founder, said.

The Faraday Institution, Britain’s battery research collaboration, has backed the team. Ian Ellerington, the institution’s head of technology transfer, said he hoped that the system could be in cars in five years. “This is a device that can take out very large amounts of heat using a very small area,” he said. “If this can drop charging to ten minutes, suddenly it’s equivalent to refilling a petrol car — that’s the goal.”

Dr Wong said that if the technology can be proved its benefits would go beyond faster charging. “There are three main problems that people complain of with electric cars,” he said. “The first is they don’t charge fast enough, the second is they don’t go far enough, the third is they are expensive.

“This directly answers the first. On the second, if you need to go 300 miles you have two options. Either you get a car that can go 300 miles, so you don’t have to stop at all. Or you get one that can go 150 miles and stop once for ten minutes. So you effectively increase your range, and also almost halve the price — as batteries are the main cost.”

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