Automotive

Student team breaks the 4-minute barrier for EV fast-charging

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Students at Eindhoven University of Technology have developed a fast-charging battery solution for a prototype electric racecar that can fully charge in under four minutes
Charlie Acuna/Eindhoven University of Technology
Students at Eindhoven University of Technology have developed a fast-charging battery solution for a prototype electric racecar that can fully charge in under four minutes
Charlie Acuna/Eindhoven University of Technology
The Next Generation Battery Pack technology has been installed in the InMotion team's Revolution electric racecar, part of a development project aiming to compete in a future 24 Hours of Le Mans endurance race
Charlie Acuna/Eindhoven University of Technology
The InMotion team's 29.2-kWh Next Generation Battery Pack is reckoned good for around 290 km per charge
Charlie Acuna/Eindhoven University of Technology
The InMotion battery pack installed in the Revolution electric racecar prototype was recently fast-charged to capacity in 3 minutes and 56 seconds
Charlie Acuna/Eindhoven University of Technology
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It's often the case that technologies developed for racing vehicles trickle down to the wider automotive market. With an endurance race in its sights, a team of more than 30 students at Eindhoven University of Technology (TU/e) in the Netherlands has developed a technology that's allowed a 250-km battery pack to be fast-charged in under four minutes.

A few years ago, 10 students from TU/e joined forces to create the InMotion team, with hopes of building a technologically advanced electric racer that could take part in the 24 Hours of Le Mans endurance competition.

Since then, a number of vehicles have been built – and one or two lap records broken along the way. While developing the recent Revolution prototype, the team managed to get the battery pack to 80% capacity in 12 minutes. But that wasn't fast enough, so InMotion embarked on a two-year quest to significantly reduce plug-in times.

As the fast-charging process generates a lot of heat, the students – which now number more than 30 – had to find a way to stop the battery cells from quickly degrading during the fast-charging process.

"We developed an innovative cooling technology at module level, where cooling plates filled with coolant were placed between the modules containing the cells," said team manager, Julia Niemeijer. "This allowed us to extract a lot of heat from the pack. If you want to extract heat as efficiently as possible from the battery pack, you want to cool as close as possible to the battery cells. Therefore, we have developed a method that enables cooling at the cell level, with actual coolant flowing between each cell."

The Next Generation Battery Pack technology has been installed in the InMotion team's Revolution electric racecar, part of a development project aiming to compete in a future 24 Hours of Le Mans endurance race
Charlie Acuna/Eindhoven University of Technology

A 24-hour test of the setup resulted in minimal degradation of the battery, and a 29.2-kWh pack with a per-charge range of around 250 km (155 miles) was subsequently installed in the LMP3 prototype racecar – which is a special class of vehicle that allows "young drivers and new teams" to enter the Le Mans endurance competition.

The pack is rated for 322-kW fast-charging, and the InMotion crew managed to top it up in 3 minutes and 56 seconds, hopefully paving the way for super-quick pit stops. The vehicle prototype and its fast-charging battery are to undergo more extensive testing in the coming year, with a view to showcasing the technology at a future 24 Hours of Le Mans race. But the cooling architecture could mean big things for the larger EV space.

"Student teams like InMotion are important for pushing boundaries and testing new technologies in practice, triggered by challenging applications such as an electric race car," said Henk Jan Bergveld, part-time professor of Electrical Engineering at TU/e. "Faster battery charging in an electric car is certainly not trivial. It is crucial for faster market acceptance, where innovations such as a battery pack with highly optimized cooling will play a significant role."

Source: InMotion

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9 comments
Username
Nice work. But cooling is not the (long term) answer to overheating. Overheating is due to inefficiency where some of the electricity you are trying to put in the battery is wasted as heat. Fixing that inefficiency is the real key.
vince
Even bigger batteries can be swapped out in 90 seconds or less. So charging isn't the answer. Swapping is. In fact, a firm in China announced a 60 second battery swap station which is a record. Seveeral others have managed 2 minutes or less. One company announced a record 50 second battery swap.
-dphiBbydt
I hope circuits and race car developers are considering on-the-move in-track charging - either inductive or conductive.
Henk Smit
Is it also an idea to install thin tubes through which coolant flows longitudinally in the battery itself? These tubes can be made of plastic or metal. If chosen for metal, this conductive material may also be used to improve the battery itself.....maibe ifthis idee is not to fast canseled
Sergius
Perhaps a good solution would be to develop a bank of capacitors in the charging device and another in the vehicle, providing an instantaneous charge that would later be transferred to the batteries slowly by computational monitoring.
Aross
I agree with Vince. Swapping is the only answer to batteries in EVs. If I could buy an EV with a swappable battery with a range of say 500km even if it took 10 minutes to do so I would buy it today. Since we do a fair bit of long distance driving this would solve the problem with having to be stationary for an overly long time. Secondly it would eliminate the need to buy a new very expensive battery or in some cases a whole new car. Similar to renting propane tanks for barbecues.
jerryd
Rather heavy, low density for a race car and just what does full charging mean as unlikely to charge to 100%?
We've had cells, A123 at 30c, back in 2000 and multiple ones now that could do this, just the rest of the system couldn't handle it. And this only does as a small pack. A 100kwh pack the charger, etc would be huge.
guzmanchinky
Someday we will look back on this and laugh the same way we do those old glass gas filling stations from the early days of driving. Someday soon we will have chargers and battery tech that will be as simple and quick as it is now to fill up a car, except that 80% of the energy won't be lost as heat...
SplineDoctor
Sounds promising.
The only problem is that it's almost impossible to find such a high power charging infrastructure around most roads.
Even the number and charging performance of stations grow much slower than the number and charging capacity of EVs. In Hungary a new charging station could take a year to install because the electricity provider couldn't extend their grid quick enough, and it's also quite expensive.
With the quickly rising temperature average in many countries those chargers also will face to challenges about cooling them.