Lightweight Power Pack
For the housing, a lightweight construction made out of
high-tensile steel, plastic-metal composites and organic sheets
is used. For this, crash simulations at the Fraunhofer IWM
were conducted in order to guarantee a corresponding safety
and, simultaneously, a low weight along with inexpensive
In electromobility, the energy pack constitutes an important
component, which firstly has to have a high energy density
and secondly low weight. Within the scope of the Fraunhofer
project, »Fraunhofer System Research on Electromobility«, the
The development of the power pack and the proof that
Fraunhofer ILT, along with the Fraunhofer Institutes for Solar
individual components can be produced currently stand in
Energy Systems ISE, for Mechanics of Materials IWM, and
the foreground. The components designed from organic
for Environmental, Safety, and Energy Technology UMSICHT,
sheets, reinforcement structures and plastic-metal composites
developed a »lightweight power pack«. This pack consists
are all currently being tested. Positive results have been
of highly integrated and exchangeable energy components
demonstrated by investigations on the wear of the cells with
in the sector of battery packs and of thermo aggregates. It is
a copper alloy concerning the electrical resistance and stability
planned to be used in an all-electric, multi-user vehicle. The
of the connections during thermal cycle.
»lightweight power pack« should distinguish itself from other
batteries through its use of different lightweight technologies
as well as innovative cooling and set-up strategies.
The processes applied to battery technology presented
here can be used in many sectors of electrical contacts and
of lightweight construction. They go far beyond the use in
In the scope of the project, the project partners worked on
three sectors – battery pack, housing/lightweight construction
and cooling.
This project is funded by the internal program of Fraunhofer
Gesellschaft under grant number 826 472.
The work group ‘Battery Pack’ has developed a process
whereby the strings of the battery pack are built out of small-
format cylindrical cells of the type 18650. These cells offer, on
account of their metal housing, possibilities for direct cooling.
Dip.-Ing. Benjamin Mehlmann
By means of laser micro welding, both poles of the cell are
Telephone +49 241 8906-613
contacted on the upper side and the cells are switched in
parallel into units (blocks), which act as individual cells for the
battery management system (Fraunhofer ISE) and the overall
system. To directly cool the individual cells internally, one block
is provided with PCM slurry (Fraunhofer UMSICHT) without
3 CAD model of a unit (without cover).
additional heat conducting structures inside the block.
4 CAD model of a housing (without cover).
Fraunhofer Institute for Laser Technology ILT,
DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01
Subject to alterations in specifications and other technical information. 09/2014.
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