MAHLE and Allotrope Energy launch new lithium-carbon technology for ultra-fast charging

On September 22, MAHLE Powertrain and Allotrope Energy launched a new battery technology that provides ultra-fast charging and good power density. By combining the advantages of supercapacitors and traditional lithium-ion batteries, this new lithium-carbon technology can achieve fast full charging, which is close to the time it takes to refuel an internal combustion engine-powered car. In addition, lithium-carbon batteries do not contain rare earth metals, are fully recyclable, and are not susceptible to runaway events.

(Photo credit: Mahler)

Dr Mike Bassett, Head of Powertrain Research at MAHLE, said: “Range anxiety is often cited as a major barrier to the uptake of electric vehicles , but if batteries could be charged as quickly as refuelling a conventional internal combustion engine car, much of this concern would disappear.”

Bassett also said: "With the rise of the on-demand economy, gasoline-powered mopeds for urban deliveries such as food delivery have become increasingly common, damaging air quality. Until now, delivery has been difficult to decarbonize without expensive interchangeable battery reserves or switching to larger, heavier, more energy-intensive electric vehicles."

However, in a joint project with Allotrope Energy, MAHLE Powertrain is considering using electric mopeds as urban delivery vehicles by powering them with inexpensive, low-capacity lithium-carbon batteries that can be fully charged between two delivery points in just 90 seconds.

Allotrope Energy's lithium-carbon technology combines the advantages of supercapacitors and traditional lithium-ion batteries to provide a battery that can charge quickly and maintain good energy density. The technology uses a high-rate battery-type anode and a high-capacity electric double-layer capacitor (EDLC)-type cathode, separated by an organic electrolyte.

The battery does not suffer from thermal degradation like traditional lithium-based batteries. It is stable even at high temperatures, allowing high currents and fast charging without the need for complex external cooling or battery management systems.

In addition, its capacitor-type cathode can be cycled more than 100,000 times, far higher than conventional batteries. At the same time, the battery does not require the use of rare earth metals and is fully recyclable, making it more environmentally friendly, both during production and after the battery is used.

As part of the project, MAHLE Powertrain investigated the scenario of a city-based fast food delivery service with an electric moped with a target range of 25 kilometers. It was found that a conventional lithium-ion battery of 500 Wh would need to be charged during a shift, which takes more than 30 minutes even with a fast charger. In addition, regular fast charging will shorten the battery life, so it may need to be replaced every two years. However, the lithium-carbon battery pack can be fully charged in 90 seconds at a power of 20 kW, which means that it can be fully charged when the next delivery is taken.

“With ultra-fast charging, battery size can be optimized to suit different vehicle usage scenarios, reducing weight and costs, further clearing the way for decarbonization,” said Bassett. “The real challenge was designing an electrical architecture that could absorb such high charges. Furthermore, because there were no suitable charging systems on the market that could deliver these charge rates from domestic supplies, we created our own custom design.”

The solution proposed by Bassett’s team uses its own built-in capacitor energy storage to provide ultra-fast charging of up to 20 kW by increasing the power of a typical 7 kW single-phase connection, thereby reducing cost and complexity and thus eliminating the need for expensive grid connection upgrades.