Some suppliers of phase change materials for thermal management Germany Axiotherm GmbH +49 36691 53 118 www.axiotherm.de Henkel AG & Co. KGAA +49 211 797 0 www.henkel.com Rubitherm Technologies GmbH +49 30 7109622 0 www.rubitherm.eu Hong Kong BOCA-PCM +852 2882 1222 www.pcm-tes.com/boca Italy i-TES +39 011 670 6352 www.i-tes.eu India Promethean Power Systems, Inc +91 77570 66473 www.coolectrica.com South Africa Sasol +27 10 344 5000 www.sasol.com Sweden Azelio - www.azelio.com Switzerland Cowa Thermal Solutions AG +41 41 244 17 00 www.cowa-ts.com United Kingdom Croda Europe Ltd +44 1405 860551 www.croda.com Phase Change Products Pty Ltd (PCP) +44 1733 245511 www.pcmproducts.net USA Advanced Cooling Technologies, Inc. +1 717 295 6061 www.1-act.com Boyd Corporation +1 888 244 6931 www.boydcorp.com KULR Technology Group, Inc. +1 408 675 7002 www.kulrtechnology.com Microtek Laboratories, Inc. +1 937 236 2213 www.microteklabs.com Parker Hannifin Corporation +1 800 272 7537 www.parker.com PureTemp LLC +1 952 941 0306 www.puretemp.com Chemours +1 302 773 1000 www.chemours.com Vietnam PCM Technology +84 931876066 www.pcmtech.vn 42 January/February 2024 | E-Mobility Engineering different systems that have heat that needs to be managed and avoids having many different fluids in the vehicle to manage. The dielectric strength, or the ability to insulate the electronic components from each other electrically as well as thermally is also key to reducing the size of the inverters and modules by allowing components to be closer together. The dielectric is specifically tested for the density of electronics it supports. In some cases there is an opportunity to pressurise the system, but at 50 C it is still a low pressure system at a few psi; less than 10 psi. This minimises the risk of leaks and makes designs easier to develop. The higher boiling temperature is not a problem even for battery packs as it is the hot spots in the pack that cause a lot of the stress. The dual phase boiling point reliably limits any cell to 50 C and avoids the risk of thermal runaway or damage to the cells, particularly with faster charging. Where things start getting really interesting is what comes after lithium ion cells. Solid state batteries for example operate at the higher temperatures; some battery types may have higher temperature operation. The dual phase materials allow more focus on holistic thermal management, using the heat from the battery to heat the car in the winter and providing more effective methods for managing the heat with less radiators rather than just getting rid of the heat. Conclusion There are many types of phase change material used in different areas of an electric vehicle. Some are designed to provide a more efficient thermal interface in power electronics, and the materials are designed to be easy to use in the assembly process, cut into templates and able to be stored for long periods before being assembled. But the real opportunity for PCMs is in the cooling of battery packs. The basic paraffin wax turning from solid to liquid can carry heat away from battery cells. Mixed with other PCMs, the wax can provide more thermal capacity. Adding in graphite or carbon fibres can provide more structural strength and further boost the thermal capacity, but this can cause more abrasion with the rest of the pack. This is a key engineering balance that is still being addressed, as the additives can cause abrasion in the battery pack as the PCM melts and solidifies. The heat can be carried out with passive heat pipes, reducing the complexity of the battery pack design and assembly. Liquid phase change materials can avoid the abrasion issues, but require other components such as a condenser, even if this replaces an existing radiator. The higher latent heat capacity of the liquid phase maintains the temperature even with high charging and discharging rates and boosts the lifetime of the battery pack. There is further discussion on the technology specifically for immersion cooling on page 58 of this issue. Acknowledgments With thanks to Eitam Friedman at Carrar, Brandon Marshall at Chemours and Alexander Budiman at the Research Center for Transportation Technology in Indonesia. Focus | Phase change materials
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