Miba FLEXcooler® – Innovative Thermal Management Technology for Batteries

Authors

Dipl.-Ing. M. Liebl, Miba Friction Holding GmbH, Laakirchen;
Dipl.-Ing. (FH) S. Gaigg, Miba eMobility GmbH, Laakirchen / Voltlabor GmbH, Bad Leonfelden;
T. Haidwagner MSc, Dipl.-Ing. F. Pöhn, Dipl.-Ing. Dr. A. Sonnleitner, Miba eMobility GmbH, Laakirchen

Year

2020

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 813

Summary

Thermal management is a critical success factor for an electric vehicle and its acceptance in the market. A long service life and a short charging time are directly related to the efficient performance of the cooling system.
Traditional battery cooling takes the form of a plate, usually made from aluminum, with embedded channels for the coolant. The battery cells, which are usually surrounded by a metal sleeve, and the cooling plate consist of rigid surfaces. Any direct contact – for example, due to manufacturing tolerances – always leads to an air gap and thereby to poor heat conductivity. By adding thermal interface materials (gap fillers), good thermal coupling can be achieved at this point. However, based on the Miba Design Thinking Process, the cooling plate has been replaced by a flexible heat exchanger, which adjusts its shape to the battery cell. This causes direct thermal contact between the heat exchanger and the battery cell, even without the use of thermally conductive paste.
The flexible heat exchanger can be used in a wide variety of cooling options for extremely different shapes of cells (cylindrical, prismatic, and pouch). A comparison of the different cooling options based on the newly defined cross-system cooling efficiency coefficient and the cell uniformity coefficient shows the superior performance of pole cooling for cylindric cells as used in the Voltlabor battery module.