Combining Water and Paraffin to Cool BatteriesCategory: Science & Technology
Posted: July 18, 2012 11:09AM
Ever felt a laptop or phone get warm as the battery heats up from use? Those are small batteries so imagine how hot batteries in an electric vehicle (EV) can get. Unfortunately batteries cannot stand very high heat and those used in EVs prefer to be between 20 ºC and 35 ºC. Reaching 45 ºC will actually cuts its useable lifespan in half. To avoid this, an air cooling system is used, but like computers, a liquid cooling system would be better. Such systems are still in development though and face several hurdles including the limited amount of water that can be stored in a vehicle. In the future though, a different medium being developed at Fraunhofer-Gesellschaft may prove better than water for cooling batteries.
CryoSolplus is a dispersion of water, paraffin, stabilizing tensides, and glycol, an anti-freeze. Paraffin is a phase change material (PCM) that researchers around the globe are looking at as a means to store and regulate thermal energy. When it's hot, paraffin absorbs the heat and melts, but once the temperature drops it releases the heat back to the environment as it solidifies. With the other additives, CryoSolplus has a thermal capacity three times that of regular water, which is huge when considering the limited space within a vehicle.
Having already overcome the issues of the paraffin particles sticking together and the fact it is lighter than water, the researchers are now looking to optimize the dispersion further. The hope is to achieve an even better heat capacity while improving the material's heat transfer and flow capability. Eventually the researchers will also start field testing CryoSolplus in an experimental vehicle.