Researchers Tackle EV Fast Charging with Electrode Laser Treatment

The results of this research have yielded a patent-worthy process for increasing the energy density in modern electric vehicle (EV) batteries.

Many lasers are used at LAZ to improve advanced material processing and develop new methods of laser-based production. Image used courtesy of LAZ at Aalen University.

The research project consisted of members of IMFAA, who are known for developing resource-efficient mobility, renewable energy, and machine learning models to improve in manufacturing, characterization, and testing of materials and components.

The team from IMFAA is accompanied by researchers from LAZ, which is a part of the Mechanical Engineering Production and Management course at the Center for Optical Technologies within Aalen University. LAZ researchers typically focus on materials, surface technology, FEM simulation, foundry technology, optical technology, and energy-efficient production.

One example of LAZ’s work involves laser pretreatment of surfaces for joining hybrid material pairings, which is a large part of their collaboration with IMFAA. This project was funded by the Federal Ministry of Economics (BMWi) and features nine corporate partners that include the German Aerospace Center and the Center of Solar Energy and Hydrogen Research.

 

LAZ and IMFAA Laser Experiments Target Lithium-ion Batteries

Impacts from this research are that EVs will require less time at charging stations, giving drivers more time on the road versus at the station. From engineers’ perspective, cell production processes can be shortened by having compact, efficient battery designs that meet demanding specifications such as fast charging capabilities.

“A battery should be as small as possible and still be able to store as much energy as possible,” stated Jonathan Kleefoot and Jens Sandherr, doctoral students of LAZ and IMFAA. “But then you are faced with the next challenge, the battery now contains more energy in a smaller volume and is more difficult to recharge.” The EV market revolves around driving range and cost, and in some fashion, both are influenced by the battery system.

Through several experiments led by the teams of LAZ and IMFAA were able to utilize the laser to roughen and perforate the surface which pierces through and made holes on the electrodes within the battery. This will improve the charging and discharging of the battery due to the increased exchange of lithium ions between electrodes.

IMFAA is a part of the German-wide battery research factory that has recently received 1.25 million euros in funding from the Federal Ministry of Education and Research. Image used courtesy of IMFAA at Aalen University.

 

The laser used by LAZ is a 4kW disk laser equipped with two single-mode fiber lasers that go up to 1kW power. LAZ also utilized their three pulsed solid-state lasers with two pulsed fiber lasers. The research team utilized high-temperature lasers to harden the electrode's surface, the properties of the surface would be altered in a way that would damage the integrity of the electrode. Now the material is prepped for laser perforation. Laser perforation is contactless and is able to generate a high-intensity beam at a fixed repetitive rate. The lens turns each beam into spots on the surface, generating holes.

Lasers helped pave new methods that provide endless possibilities in the overall production of EV batteries. These lasers are able to modify and improve batteries at the electrode level, making them withhold more charging energy within a compact design. This increases the level of comfort for consumers since EVs can continue to improve the experience of short charging times and longer driving ranges. The discussed research is still in the early development stage, however, through the combined effort of researchers from LAZ and IMFAA, they were able to improve the overall charging capacity of lithium-ion batteries with laser-based processes.