The time spent re-charging an electric vehicle could be cut by more than two-thirds thanks to fusion-related technology developed by former Culham PhD student Dr Jack Nicholas.
Jack – who worked on the concept of removing intense heat from a tokamak’s divertor (the exhaust region where hot plasma is ejected from the reactor) as part of his PhD, and then subsequently with EUROfusion – is now CEO at a company he founded in 2018, Qdot Technology.
His research of the exhaust heat removal in fusion is relevant to electric vehicles because battery charging takes longer in part because of heat generated internally.
Jack believes the same technology could see the charging-time of an electric car reduced from 45 minutes to 10 minutes – a big difference when it comes to long-haul journeys requiring more than one full charge worth of battery.
The initial research was undertaken in Jack’s PhD at Oxford University – funded by CCFE and Rolls-Royce – and it focused on the design of a fusion reactor’s exhaust system.
Qdot’s concept uses a specific battery cell geometry, combined with its high-performance cooling technology, to allow rapid dissipation of heat generated within the cell.
Larger scale tests
Having carried out tests using this method for a single battery, Qdot, which is based at the Harwell Campus in Oxfordshire, will now test it on a larger scale.
Jack Nicholas said: “During the research I undertook as part of my PhD I designed a ‘heat-sink’ (a device for drawing heat away from a device). The role of this is to take heat out and stop components in the machine from melting.
“I think working on such a challenging thermal problem like fusion has given me the grounding to explore this.
“This technology has been developed further by us – it’s very good at extracting heat out of a small area like a battery for example.
“The type of batteries we are researching are called ‘pouch cells’. Inside each of these cells is a number of layers, stacked together, which are then completely sealed within the unit.
Working on a challenging problem like fusion has given me the grounding to explore this.
“Currently what people do is cool the outer faces of such cells, and so remove the heat out across the layers. The drawback to this approach is that you have poor thermal conductivity due to the number of interfaces, and so you end up with a very large temperature gradient between the inside of the battery cell and the outside.
“This is not ideal, as the hotter regions of the cell will age faster than the colder parts, reducing the overall life of the cell.
“What our prototype does is remove the heat vertically through aluminium and copper plates that make up part of the cell stack. This enables both better cooling performance and extended life due to a more uniform temperature distribution within the cell.
“Not only do we hope it will reduce the charging time, but it could mean it makes electric vehicles cheaper. Approximately 40 per cent of the cost of an electric car is battery cost – that’s big. So if we can charge more quickly, do we need such a big battery pack? Instead of a battery pack which allows you to drive you 400 miles, why not halve the price of the car and have a battery capable of 200 miles but which is able to rapidly charge?”
Benefits to different industries
The work will now see Qdot prove the technology on a more fundamental level as well as potentially tweak the design, Jack added.
“By the end of this year or early next, we would hope to have proven the technology at a modular level (multiple batteries in cells integrated together).
“Longer term we are searching for the best applications for this kind of technology. It might be that standard commercial vehicles are not the most obvious initial market. Rapid charging has the most benefit where there is a need for high availability of your vehicle – for example lorries, taxis, or, buses – things where any downtime is lost profit.
“We are also part of a consortium looking to apply this technology to electric aircraft. The thermal demands in electric aircraft are even more demanding than those in cars, so we think the performance benefits of our system could work well in that context.
“It’s extremely exciting research to be involved in, and something we hope will benefit different industries.”
The work of Qdot is also being backed by the Faraday Institution – the UK’s national institute for electrochemical energy storage science and technology.