Battery cells are the basic unit that produces energy in every battery. Electric vehicle (EV) batteries need to be shock resistant and be able to cope with extreme temperature variations (both high and low).
A battery module contains a stack of battery cells assembled into a frame. The module’s function is to protect the cells from heat and vibration.
Battery packs are constructed by assembling battery modules along with control systems (e.g. battery management system (BMS)) and protection systems (e.g. cooling system).
When batteries are charging they will produce heat and this needs to be removed from the battery. Overheating can cause a battery to lose life and performance.
A solution for effective heat transfer within battery cells, modules and packs are thermal interface components that have been die-cut. Dr. Dietrich Mueller GmbH produces such components (gap pads, phase change and graphite) to overcome heat issues and extend the battery’s life.
Ensuring battery and EV safety can be done within cells and modules by preventing and suppressing thermal runaway propagation. Dr. Dietrich Mueller GmbH conversions include different materials that are both flame proof and meet Underwriter Laboratories (UL) requirements. For example 3M, Flame Barrier and BISCO silicone foams.
Gaskets and Seals
Critical to the operation of battery modules and battery packs are their seals. Upper and lower housings often enclose a battery module or pack. Protection of fragile components against air, dust and water ingress is afforded by a seal between the two housings.
As well as keeping unwanted elements out, the seal also contains any dangerous material if a collision occurs. Seal and gasket materials must be able to withstand extremely high temperatures and often need to have passed vertical and horizontal tests with a flammability rating of UL94 V-0.
Dr. Dietrich Mueller GmbH are able to provide help and assistance in selecting appropriate materials. We have strong and business relationships with raw material suppliers including Koepp, 3M, Zote Foam, Armacell, the Rogers Corporation and others.
PORON urethane and Rogers BISCO silicone have excellent compression and set resistance properties as well as having proven enduring performance under extreme temperature conditions. This makes them ideal materials for the production of EV seals and gaskets.
Double coated tapes such as 3M VHB are suitable for joining and bonding materials and will seal from moisture and dirt ingress.
Dielectric Barriers and Insulators
In order to comply with electrical barrier and insulation safety requirements, flame barriers and materials that have dielectric barrier qualities are integrated into the components of batteries. Often, these materials have a dual function, doubling as heat insulation and barriers.
These materials need to be light, flame retardant and adaptable to meet bespoke application requirements. Dr. Dietrich Mueller GmbH uses such materials (including ITW Formex, Lexan films, polymide films and 3M EMI/EMC materials) to manufacture customized battery components.
Spacers and Compression Pads
A battery module’s spacers and compression pads need to hold the cells in place. They need to be firm enough to achieve this whilst being able to maintain compression with the cell’s expansion and contraction.
Spacers and compression pads also require enduring performance under extreme conditions and temperature ranges. Dr. Dietrich Mueller GmbH is one of the leading converters for various foam materials for compression pads. They include: Rogers PORON polyurethane, Rogers BISCO silicone foam along with foams based on neoprene.
Rogers PORON and BISCO are great solutions for battery cell compression pads due to them offering reliability of stress relaxation performance and compression set resistance over a wide temperature and conditions range. As proven in NVH and BSR testing, foam pads also provide isolation and dampening of noise and vibration that come from operating a vehicle.
Performance of vehicle electronics and batteries can be maximized by providing protection from electromagnetic interference (EMI). The operation of a battery and connecting battery cables can often produce a large EMI field which can affect the vehicle’s other electronics.
Conductive elastomer, seals, foils adhesive components that are sensitive to pressure can assist with EMI shielding. Dr. Dietrich Mueller GmbH uses such products in the manufacture of battery converted parts.