Electric vehicles are developing fast in line with growing demand. However, only by selecting proven, reliable, high-quality products for the effective thermal management and EMI shielding of batteries, is it possible to maximize performance.
Battery heat management
Although electric vehicles represent a greener and cleaner future, they come with a number of technology challenges, including within the battery pack. When large batteries need to provide as much power as possible to supply energy to the car, they generate a considerable amount of heat that must be dissipated. Left unchecked, excessive heat can cause faster battery wear, reduced performance and reduced charge efficiency, not to mention the obvious safety hazards associated with thermal runaway of the battery packs.
Effective thermal management is therefore critical to optimize battery performance and longevity with improved safety and reliability, allowing vehicles to travel greater distances and increasing the achievable run-time on a single charge.
- High volume thermal dispensable gels, such as the THERM-A-GAP GEL family, can be dispensed between the coils and the aluminum chassis of the battery to deliver long-term thermal stability and performance. These gels are particularly suitable in volume markets such as automotive due to the ease of dispensing using robotics or automation, thus reducing cycle times and costs considerably.
- Thermally conductive gap filler pads are an alternate solution depending on the design of the battery packs. Products such as the THERM-A-GAP gap filler pad family are perfect for assemblies that might require some additional support and higher electrical isolation.
In addition to effective thermal management, another technology challenge presented by the growing demand for electric vehicles is the need to shield against electromagnetic interference (EMI). The cables that travel between the battery and engine, as well as the battery and charger, see high current produced at low frequency. This produces a large magnetic field that can negatively affect other electronics within the vehicle. High shielding attenuation is also required to protect the battery and its circuits from any incoming EMI.
Conductive elastomers can be used to overcome these issues. These elastomers, such as the CHO-SEAL family of elastomer gaskets, are filled with conductive particles and connect interfacing components to reduce the air gap and create a Faraday Cage that blocks EMI fields. Oftentimes, batteries also need to be sealed against environmental dust/fluids. Here, it is possible to deploy combined solutions to support EMI and environmental shielding/sealing.
Form-in-place (FIP) conductive gaskets can be used for battery applications which require shielding of the electric traction elements. FIP can be robotically dispensed directly onto castings making it a low cost option.
Electrically conductive plastic, which can replace the metal housing of the battery ECU, can eliminate 35% of the housing weight, and provide cost reductions of up to 65% by eliminating secondary operations. PREMIER PBT-225 is a single pellet electrically conductive polybutylene terephthalate that offers many comparable properties to those of aluminum, along with weight reduction which helps improve the performance of electric vehicles.
Learn more about Parker Chomerics' EMI shielding and thermal management technologies for electric and hybrid vehicles.
This article was contributed by:
Tiberius Recean - sales manager, automotive
David Beresford, marketing and technology manager, Chomerics Division Europe.