Nanofluid thermoelectric cooler based advanced battery thermal management system for battery degradation mitigation in real driving cycles

Thermal management systems are utilized to keep the battery temperature below a certain limit for safe and long-life operation in electric vehicles. A detailed look at the issue of battery health is very important. One different small-size thermal management system based on nanofluid and thermoelectric elements is investigated in this work to keep the battery pack temperature below 25°C. The two parameters, lithium-ion loss (LIL) and battery energy capacity fade (BECF) are introduced to assess the extent of battery degradation. The results of the system showed that the Peltier element is at 25°C and with the operation of the fan coil in the cycle and consumes less energy. In the study of the heat transfer coefficient of the battery channel vs the two parameters, the optimum coefficients are achieved 28 and 32 (W/m2·K). In the case of the study of hydraulic diameter for these two parameters, the optimum diameters are achieved d = 0.019 and 0.021 (m). Also, in the case of metal nanoparticles for these two parameters, 5% and 7.5% are obtained and the values ​​of the mentioned parameters are obtained by compromising the desired parameter with the COP of thermoelectric elements. Using the fan coil system, the maximum heat rate decreased by 0.6 W compared with the Peltier cooling device in the vehicle acceleration mode. The degradation, that is, the voltage difference reduction between the two poles of the battery, is about one-tenth of a thousandth of the nominal voltage in each charge and discharge cycle. Finally, the results showed that the battery destruction rate would be almost similar in all three parametric investigations. Parametric assessments showed not only an increase in the battery lifetime but also a clear reduction of the pollution effect. Which is an important outcome of the presented novel thermal management system.