- TIMs in EV Batteries: Shifting from Modular to Cell-to-Pack Designs
Thermal Interface Materials (TIMs) are essential components used in various applications such as power electronics, sensors, computing processors, and energy storage devices. They are used to fill the gaps between heat sources and heat sinks to enhance heat transfer. TIMs come in different forms such as gap pads, thermal greases, thermally conductive adhesives, and phase change materials. These forms vary depending on the target application areas, cost, and ease of mass deployment. Due to the increasing power demand and heat generation in emerging industries such as data centers, 5G, and advanced driver-assistance systems (ADAS), TIMs are evolving rapidly, leading to significant market oppor tunities and potential for each of the target industries.
Electric vehicles (EVs) are growing at a fast pace. According to IDTechEx, the electric vehicle market across land, sea, and air will generate US$2.6 trillion by 2042 with a double-digit annual growth rate. The battery is an essential component of an EV. As EVs gain more popularity, there is a trend for higher power density, larger battery capacity, and faster charging.
Gap pads, gap fillers, and thermally conductive adhesives (TCAs) are the most commonly used TIM forms in the EV battery industry. There is no one-size-fits-all solution when it comes to TIM form, and the choice is ultimately subject to battery design configuration. Gap filler is the most widely adopted TIM for EV batteries due to their ability to be efficiently dispensed at high volumes. However, as EV batteries transition from modular to cell-to-pack designs to increase energy density and achieve a longer range, the adoption of TIMs is expected to change significantly.
Modular battery designs consist of multiple individual battery modules connected to form a battery pack, each requiring a separate TIM to transfer heat from the cell to the cooling system. On the other hand, cell-to-pack design combines the battery cells into a single, large battery module, eliminating the need for separate module housings and TIMs.
This battery transition reduces TIM usage per vehicle as there are fewer thermal interfaces between the cells and the cooling plate. The elimination of module housings means cells can directly contact the cooling plate, changing the performance requirements of the TIM. The TIM must efficiently transfer heat to avoid hotspots and have good material compatibility with the cold plate. As the TIMs are positioned directly between the cells and the cold plate, an increased adhesion of TIMs is needed to stick the cells and cold plates together. Therefore, IDTechEx forecasts that thermally conductive adhesives will be increasingly adopted due to this battery design transition, and by 2020, the market size of TCA within the EV industry is expected to have a 15-fold increase.
In conclusion, as the EV market grows, the battery design is evolving, and so are the TIM requirements. The shift from modular to cell-to-pack design will significantly impact the adoption of TIMs. While gap fillers are currently the most widely used TIMs for EV batteries, thermally conductive adhesives are expected to become increasingly adopted in the near future. The TIM market is growing rapidly, and there are significant market opportunities for TIM manufacturers in various emerging industries.
