Thermal Simulation of Li-Ion Battery Pack Using ANSYS Fluent
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keep on decreasing with time [4]. Pesaran et al. [5] showed that the optimal temperature range for Li-ion batteries is 15–35 °C. The effect of temperature on efficiency
is studied by Ma et al. [6], and according to his work, the efficiency of the battery is
decreased by 60–70% in some timeline of 10 days and of including various charge–
discharge cycles. For prolonged battery performance, a proper cooling system is
required to reduce the effects of higher temperatures.
3 Different Type of Cooling Method for Li-Ion Battery
Two types of cooling methods are there; the first one is related to modifying internal
parts of the battery and the second is through providing external cooling. In these
two categories, there are several methods available which are mentioned here:
1. By modifying electrode thickness—The thick electrode was found to be highly
resistive while current is flowing through it. A high resistance leads to an increase
in ohmic heat generation, severe capacity loss can be found at higher discharge
rates, and unbalanced heat generation was also increased in a cell. Zhao et al.
[7] suggested that to optimize the thermal and electrochemical performance of
Li-ion battery cells, one way is to reduce the particle size of active material
and thickness of electrode which in turn shorten the distance traveled by ions in
electrodes and active particles.
2. By modifying material of the battery—Various techniques such as doping,
coating, deposition, and additives have been adopted for modification of electrode material. The main purpose behind these modifications is to decrease the
transport distance of electrons so that the overall conductivity and thermal performance can be improved. Reduction in the diffusion distances of lithium ions can
result in better conductivity of Li-ion battery cells, and it is possible by reducing
the particle size of the electrode. Better conductivity will result in improved
thermal performance of the Li-ion battery.
3. Air cooling—Air cooling is cooling just by air. It is only suitable for small battery
packs. According to one research [8], air cooling can cool down the battery around
72 °C, which requires additional cooling methods such as liquid cooling or PCM
cooling.
4. Liquid cooling—It is suitable for large battery packs [9]. The advantages of liquid
cooling are rapid cooling and higher temperature uniformity, but the drawback
is that it is bulkier compared to air cooling and PCM cooling [10].
5. PCM cooling—In this cooling method, a particular material will change its phase
throughout the cooling cycle. So the latent heat of the material can be fully
utilized to reduce the temperature of the battery pack. Paraffin wax is the most
popular for research purposes among researchers, due to its range of phase change
temperature. PCMs are mixed with graphene, carbon fiber in order to increase its
thermal conductivity. Based on one research, this mixture’s thermal conductivity
could reach values near to 40 W/m K [11] which is considered to be very high.
267
keep on decreasing with time [4]. Pesaran et al. [5] showed that the optimal temperature range for Li-ion batteries is 15–35 °C. The effect of temperature on efficiency
is studied by Ma et al. [6], and according to his work, the efficiency of the battery is
decreased by 60–70% in some timeline of 10 days and of including various charge–
discharge cycles. For prolonged battery performance, a proper cooling system is
required to reduce the effects of higher temperatures.
3 Different Type of Cooling Method for Li-Ion Battery
Two types of cooling methods are there; the first one is related to modifying internal
parts of the battery and the second is through providing external cooling. In these
two categories, there are several methods available which are mentioned here:
1. By modifying electrode thickness—The thick electrode was found to be highly
resistive while current is flowing through it. A high resistance leads to an increase
in ohmic heat generation, severe capacity loss can be found at higher discharge
rates, and unbalanced heat generation was also increased in a cell. Zhao et al.
[7] suggested that to optimize the thermal and electrochemical performance of
Li-ion battery cells, one way is to reduce the particle size of active material
and thickness of electrode which in turn shorten the distance traveled by ions in
electrodes and active particles.
2. By modifying material of the battery—Various techniques such as doping,
coating, deposition, and additives have been adopted for modification of electrode material. The main purpose behind these modifications is to decrease the
transport distance of electrons so that the overall conductivity and thermal performance can be improved. Reduction in the diffusion distances of lithium ions can
result in better conductivity of Li-ion battery cells, and it is possible by reducing
the particle size of the electrode. Better conductivity will result in improved
thermal performance of the Li-ion battery.
3. Air cooling—Air cooling is cooling just by air. It is only suitable for small battery
packs. According to one research [8], air cooling can cool down the battery around
72 °C, which requires additional cooling methods such as liquid cooling or PCM
cooling.
4. Liquid cooling—It is suitable for large battery packs [9]. The advantages of liquid
cooling are rapid cooling and higher temperature uniformity, but the drawback
is that it is bulkier compared to air cooling and PCM cooling [10].
5. PCM cooling—In this cooling method, a particular material will change its phase
throughout the cooling cycle. So the latent heat of the material can be fully
utilized to reduce the temperature of the battery pack. Paraffin wax is the most
popular for research purposes among researchers, due to its range of phase change
temperature. PCMs are mixed with graphene, carbon fiber in order to increase its
thermal conductivity. Based on one research, this mixture’s thermal conductivity
could reach values near to 40 W/m K [11] which is considered to be very high.