Electric vehicle (EV) battery life and charging times are two of the biggest concerns among consumers today. Nobody wants to wait hours for their EV to charge; even 30 minutes can seem unreasonable when it interrupts a long road trip. And while most new EV batteries are covered by a 100,000-mile warranty, imagine the peace of mind that could come if this ran to a million miles. One UK company believes its innovative approach to thermal transfer could provide a step-change in both battery charging and longevity.
Flint Engineering has developed a multi-channel flat heat pipe called IsoMat. Drawing on isothermal principles, it provides a constant temperature across the material. While traditional heat pipe technology transfers heat from point to point in one dimension, IsoMat moves heat in both the x and y dimensions. The sealed structure features an internal network of interconnected cavities and is charged with a calculated amount of saturated fluid. When any part of the IsoMat is exposed to a thermal energy source, the liquid immediately boils, becoming a vapour and quickly absorbing energy. By manipulating thermal energy at the molecular level in this way, IsoMat opens up many new applications.
“If you take this into situations where heat is a problem or could be used elsewhere, you have thousands of potential applications,” says Chief Executive Mark Robinson.
A range of use cases
Over the past ten years, Flint Engineering has been exploring the use of IsoMat in various applications, including building materials and commercial refrigeration. Up next could be EV batteries, where it promises to maintain all battery cells in a pack at a stable temperature, generally about 25 degrees Celsius. “We’ve done a lot of development on EVs, from small cars to big trucks,” Robinson tells Automotive World. “That covers battery systems as small as a couple of feet square to systems 12 times bigger.”
In these applications, the IsoMat acts as a plate on which the individual battery cells sit. “Hundreds of cells may be sitting on one of our plates, and all of them are maintained at exactly the same temperature,” he adds. Cooling manifolds running down the end of the plate enable close thermal management of every individual cell. This means the cells can be worked harder and discharged faster. On EVs, that opens the door to faster charging times, and because all the cells are maintained at a stable unified temperature, their lifetime increases. “You don’t end up with rogue cells starting to fail,” Robinson points out. “That’s one of the key reasons that packs degrade over time.”
In comparison, traditional battery cooling systems deploy a serpentine pipe with coolant running between two pressed plates of aluminium. While the initial cells are cooled very well, the effectiveness can fade as the liquid travels through the pack. The result is inconsistent cooling. “We were able to fix that,” he emphasises. “There is no other way to maintain every cell at the same temperature, depending on the application.”
IsoMat won’t replace current thermal management systems but rather serves as a modification to them. While it has potential in any EV, it really comes into its own for applications within extreme conditions. This includes cold weather regions, where EV range can take a big hit. “IsoMat can heat as well as cool,” says Robinson. A small heating mechanism in the corner of the pack allows for rapid heating of cells to an even temperature, effectively extending range in colder climates.
There’s a similar impact on the opposite end of the environmental spectrum. Heavy autonomous mining trucks working around the clock in Australia’s extreme heat can exhaust a battery quickly. “In these circumstances, thermal management is difficult. These packs should last ten years, but some of the trucks are burning through them in just two. That’s because they don’t have a way of evenly managing the temperature. This is a perfect example where the IsoMat can make a really big win.”
Quantifying the impact
Flint Engineering’s technical development is based at Brunel University in the UK. It previously conducted a four-year development project with US company Allison Transmission, which produces drivetrains for trucks. Since then, Flint has continued to develop the IsoMat and hopes to quantify some of its claims over the coming years.
“The IsoMat is almost unlimited in the amount of energy it can shift,” says Robinson. “The energy is taken from the cells to our condenser sections. Since carrying out the work with Allison, we’ve put all of our development effort into coming up with some really clever and high-performing condenser sections for the IsoMat. We are now going through initial trials with those, with a view to specifying performance.” That trial work will run over the course of 2025, after which time the Flint team may resume development work with Allison.
What we are talking about with IsoMat is mind boggling, ground-breaking core technology
In commercial refrigeration systems, IsoMat can cut energy use by nearly one-third. In EV batteries, it could go even further. “It’s difficult to get the metrics because the EV industry is a bit cloak and dagger when it comes to battery longevity and performance. We know that we can extract two to three times more heat from a battery pack than you can using traditional methods. What that will mean in terms of battery longevity, charge times or range, we don’t yet know. That’s where we really need to engage with application-specific partners.”
While IsoMat promises significant benefits, it will likely weigh in slightly heavier than the pressed aluminium plates currently used and cost “a bit more”. The system should be more robust, however, with generally superior performance. At the end of the day, drivers of all sorts of EVs are looking for extended range, improve safety, reduced charging times and longer lifespans. Because of this, Robinson is optimistic IsoMat could find its way into everything from mining trucks in Australia to family cars in Europe.
“Consumer demand will drive this,” he concludes. “EV owners are frustrated by the promised range not matching what they see every day. There is growing pressure to increase EV mileage and EV adoption…What we are talking about with IsoMat is mind boggling, ground-breaking core technology.”
Commercial production for non-automotive applications launches later in 2025, and development work in automotive is gaining pace. With Flint Engineering reporting strong interest from UK, North American and Middle Eastern markets, this thermal management breakthrough could help to shape the future of electric transportation.
