Battery thermal management is a critical component to an electric vehicles (EVs) operation. Cells need to be kept cool when under load from driving and charging or kept warm during cold ambient conditions. This enables more efficient operation of the batteries and improves safety. This is typically done via a water cold plate at the base of the battery pack or via water coolant channels between the cells. Immersion cooling is often touted as the next-generation thermal management technology, but there are certainly barriers to adoption. Based on IDTechEx’s latest research report, “Thermal Management for Electric Vehicles 2023-2033”, this article looks at the benefits, drawbacks, current market adoption, and potential for the future.
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Benefits
As the name suggests, immersion cooling involves having the battery cells directly immersed in a dielectric fluid. The immediate benefit is the superior thermal contact and homogeneity; the fluid contacts much more of the cell directly than a cold plate or coolant channel would, helping eliminate a non-uniform temperature gradient. Depending on the fluid used, it can act to extinguish a fire in the event of thermal runaway.
Not so obviously, immersion can lead to the removal of several components, such as the cold plate, thermal interface materials, condenser, and chiller.
The more effective thermal management helps enable fast charging, an often publicized factor for selling an EV.
Drawbacks
The initial concern for most is the weight of the fluids. This is certainly true for heavy hydrofluoroether products that often have densities above 1.5g/cm3. However, this can be mitigated somewhat by removing other components (as above) or the use of other types of dielectric fluids like synthetic esters or other oil mixtures with a density below that of water (1g/cm3). The argument is complicated by the need for enough space between the cells for fluid flow; this may not directly impact weight but could reduce the volumetric energy density of the pack.
SOURCE: PR Newswire