Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Electromobility: Laser-Based Processes for Lightweight Battery Packs


By continuing to develop the electrification of powertrains, researchers are looking to the future of mobility in economic and environmental terms: indeed, electric mobility provides valuable solutions for the automotive industry as it implements climate change objectives. Thanks to lightweight materials, the weight of the vehicles can be reduced significantly, thus increasing their operating distance. Within the framework of the joint project »Fraunhofer System Research for Electromobility II«, the Fraunhofer Institute for Laser Technology ILT has developed processes for the production of lightweight battery packs that significantly contribute to the reduction of CO2 emissions.

At the 66th International Motor Show IAA in Frankfurt, Fraunhofer ILT will be presenting the joint project »Fraunhofer System Research for Electromobility II« along with 16 other Fraunhofer institutes from 15 to 18 September 2015. Using the example of a »Lightweight Battery Pack« they will demonstrate to visitors how production technologies for lightweight construction can assist in storing the energy to power vehicles. They will be showing three different and partially complementary process technologies.

Lightweight battery pack: a combination of high-strength steel and fiber reinforced plastic.

© Fraunhofer ILT, Aachen

Battery block with hermetically sealed laser welded battery cells (Type 18650).

© Fraunhofer ILT, Aachen / Klaus D. Wolf

Laser-beam cutting and welding

For the processing of high-strength steel, it is important to avoid excessive thermal influence and, thus, material damage. Since they have such a small heat-affected zone, laser cutting and welding are particularly well suited here. In addition, these processes are economically more efficient than the traditional metal-cutting processes, since no material wear occurs.

“This process is already being used by Volvo. What is new here, however, is the combination of a plastic/metal compound for use in the car body, which we are presenting to the automotive industry for the first time. Thanks to the connection to the plastic, less steel is required in the application. Higher strength is achieved and the battery case is lighter. Through this process, we ensure that the industry can exploit the full potential of lightweight high-strength steel,” explains Dr. Alexander Olowinsky.

Joining plastic and metal

As an alternative to the conventional adhesive bonding of multi-material composites, Fraunhofer ILT will present a laser-based process of connecting simple semi-finished products, organic sheets, with metals such as high-strength steel. This process can, for example, be used in lightweight automotive construction as well as in the fields of mechanics and small components.

In the two-step method, a continuously emitting fiber laser at high speed first generates a microstructure in the metal. The structures have an undercut and are 30 µm wide and about 100 µm deep. In the subsequent joining step, the plastic is pressed against the structure and heated up to the molten phase of the matrix material. The matrix material then flows into the microstructures and locks into the undercut structures. The result: the connection is highly robust and an additive is unnecessary.

Reproducible and safe: oscillation welding for the electrical connection of battery cells

To construct complete battery packs, the Aachen researchers rely on oscillation welding with laser radiation. Here, individual battery cells (type 18650), which are normally used in power tools and notebooks, are welded together with copper contacts, therefore providing an electrical and thermal connection. The remarkable thing is that the joining at the negative pole also takes place from the top of the cell.

In a parallel circuit of 30 cells, a tight space between the battery cells is created by the design of the module and filled with PCM slurry (Phase Change Material, a mixture of paraffin and water). “By using the PCM, we are able to protect the battery cells thermally. This ultimately extends battery life,” says ILT researcher Benjamin Mehlmann. The use of laser-beam oscillation welding leads to a better control of the welding and, thus, a stable process. Moreover, the method is qualified and suitable for industrial mass production, for example, for the production of power tools.

Strengthening the German economy

Together, these three process technologies are especially suitable for the large-scale production of traction batteries for vehicles, for example, as the processes are highly automated and the energy input is easy to control. Since the market for these vehicles is steadily growing, this process development has a very promising future.

“In order to advance the battery production in Germany – currently most components are bought from abroad – our processes have to be automated, robust and less expensive. We are pleased that we can make a decisive contribution towards the production of lightweight battery packs and battery modules in Germany,” said Dr. Olowinsky.

Presentation of the lightweight battery packs at the IAA

What makes the lightweight battery pack special is that it is modular: the so-called traction batteries are suitable for hybrid vehicles as well as for use in electric vehicles with higher operating distances. Fraunhofer ILT is coordinating the subproject »Lightweight Battery Pack« within the »Fraunhofer System Research for Electromobility II«. The Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT is managing the use of the PCM slurry for buffering the thermal energy.

The electric control and the battery management system have been developed by the Fraunhofer Institute for Solar Energy Systems ISE. The assessment of the plastic-metal compounds was carried out by the Fraunhofer Institute for Mechanics of Materials IWM, which used simulation and load tests to examine the mechanical design of the battery case.

First results of the crash tests as well as the entire demonstrator model of the lightweight battery packs will be shown at the joint Fraunhofer stand D33 in Hall 4.1.


Dipl.-Ing. Benjamin Mehlmann
Micro Joining Group
Telephone +49 241 8906-613

Dr. Alexander Olowinsky
Head oft he Micro Joining Group
Telephone +49 241 8906-491

Fraunhofer Institute for Laser Technology ILT
Steinbachstraße 15
52074 Aachen, Germany

Weitere Informationen:

Petra Nolis | Fraunhofer-Institut für Lasertechnik ILT

Further reports about: Electromobility Energy IAA ILT Lasertechnik battery construction oscillation plastic structures technologies vehicles

More articles from Trade Fair News:

nachricht Creating living spaces for people: The »Fraunhofer CityLaboratory« at BAU 2017
14.10.2016 | Fraunhofer-Gesellschaft

nachricht Reducing Weight through Laser-assisted Material Processing in Automobile Construction
13.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Trade Fair News >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

First-time reconstruction of infectious bat influenza viruses

25.10.2016 | Life Sciences

Novel method to benchmark and improve the performance of protein measumeasurement techniques

25.10.2016 | Life Sciences

Amazon rain helps make more rain

25.10.2016 | Life Sciences

More VideoLinks >>>