IDTechEx’s market forecasts for thermal management materials, fluids, technologies, and strategies
IDTechEx has released its report forecasting thermal management for electric vehicles (EV) for 2025 to 2035 of Li-ion batteries outlining trends for thermal management materials, fluids, technologies, and strategies.
Early market trends mainly centre on the adoption of active cooling for the battery pack. Batteries, motors, and power electronics in EVs keep developing with new cell-to-pack designs, directly oil-cooled motors, and silicon carbide power electronics.
New technologies integrating with the cabin thermal management are just as important, as thermal architectures are becoming more integrated with impending regulations impacting future refrigerant designs.
IDTechEx analysed the EV market and the thermal management strategies used by OEMs and suppliers. The research took advantage of IDTechEx’s electric car database consisting of 650 model variants.
The cabin and drivetrain thermal management components interaction is important to the vehicle. Market trends show greater levels of integration can be expected, with heat pumps and integrated thermal management modules. Heat pumps and integrated thermal management modules are being introduced into systems.
Some OEMs are bringing thermal management and components development in-house to improve overall system efficiency and reduce lead time on supply chains.
Refrigerants, oils, water-glycol, and other fluids are required for operation in an EV. New requirements in EVs result in an ever-evolving fluid requirement, as lower electrical conductivity, copper corrosion performance, and other properties become factors.
The choice between using R134a, R1234yf, R744, and R290 will be limited by regulatory factors.
Cell-to-pack or cell-to-body/chasis designs have increased due to the move towards increasing energy density and reducing costs. Cell-to-pack removes the need for module housing, allowing the cells to stack together. BYD, Tesla, CATL, and other designers have successfully got their designs onto the road, with more expected to join them.
How thermal interface materials (TIMs) are applied going forward will change, in favour of thermally conductive adhesives to make a structural connection rather than the typical gap filler. The report expects demand for TIMs to increase with EV batteries.
Other functions, such as fire protection, are now considerations for suppliers who are tailoring their materials to be fire-resistant. This allows fire protection to be a feature without severely impacting the energy density of the pack. Inter-cell materials that provide compression, thermal insulation, and fire protection are included in this.
Immersion cooling has retained interest within the EV market due to its greater thermal homogeneity proposing benefits such as faster charging and increased safety. It is still early days for this technology in the realm of automotive commercialisation but has seen good success in off-road markets.
In electric motors the magnets in the rotor and windings in the stator must be kept at the optimal operating temperature window to avoid damage or inefficient operation.
Water-glycol used in a jacket around the motor has been the go-to method for thermal management. Recent times have seen a greater uptake in direct oil cooling the motor to provide better thermal performance. In some cases even eliminating the cooling jacket.
Water jackets are not necessarily going away, as they are often used in conjunction with oil cooling. Water-glycol coolant is often used to remove heat from the oil and can integrate with the vehicle's thermal management strategy.
The largest trend for EV power electronics is the adoption of SiC. This has affected how power electronic packages are constructed. Developments are happening across TIMs, wire bonding, and substrate materials. The wider goal is to improve package reliability.
Water-glycol is used to cool most inverter IGBT or SiC Mosfet modules. However, both single-sided and double-sided cooling options are used, each with its own benefits.
Oil to cool power electronics has increased interest in recent years, as it eliminates much of the water-glycol componentry within the electric drive unit. This uses the same oil for the motors and inverters.
IDTechEx has yet to see any adoption of this in the current market; however, their 10-year forecast does see EV inverters using air, water, or oil cooling.
