CELLS, PACKS, HOUSING & SAFETY
The electrification of our industry brings challenges but also benefits to sustainability initiatives and opportunities. Sika’s reach to technologies for bonding and sealing in new energy vehicles is founded in our 100+ year heritage, drawing on experience and innovation, as well as our vast product range serving markets around the world. The challenges presented with the new electric powertrain are solved readily with Sika expertise; focused on a specific application, substrates, and functionality requirements of the material used for assembly, but also adding value in vehicle performance and assembly techniques. Sika solutions run deep into the heart of components while also answering the call for specialized assembly and functional needs in the construction of cooled/heated full battery packs and even full drive “Sleds.”
In the Array Modules – Heat Management & Mechanical Performance Improvements
Sika high performing bonding solutions offer thermal-conductivity and electrical isolation for packing the battery cells inside the array modules. Our SikaForce®-32X TC series, a range of 2C-PUR products, are used to enhance the heat transfer between cells and module cooling plates while improving stiffness to make array modules stronger and lighter. They offer thermal conductivity performance from 0.8-2.0 W/m.K as well as high strength and excellent adhesion; without surface pre-treatment to metals. All products perform to the UL94-V0 standard and offer ease of use in application – manual or in standard automated equipment.
Battery Pack Housing Construction
For battery pack housing assembly Sika offers the broadest range of products in the industry drawing on vast experience in basic or advanced sealing and bonding applications. We continue to be creative in developing new bonding solutions that overcome challenges in diverse applications; adhesion on plain metals, plastics, and composites while offering answers to heat and glycol resistance. Accommodation of the constant delta-alpha effects is also solved when joining multi-materials all in cold assembly process conditions. We have a broad pallet to select from based on our global portfolio; one-component, two-component and boosted PUR, silicone, STP, MMA, epoxy, hybrids, hot-melts, and PSA. The same or mixed material requirements are answered readily with all products, also offering flexibility to the manufacturing process and throughput targets.
Answering the Call For Safety
Sikaflex® FR series, Sikasil® FR series, and Sikagard® series fire resistant products are used to stop fire spread in the event of a failure in battery cells, arrays, and even the complete module itself. FR series products are fully tested to conform to standards for fire and smoke spread and are used in assembly and bonding/sealing applications throughout the battery module. Further, Sikagard® intumescent coating products proven throughout industry applications swell when activated by heat serving to contain and delay fire spread by increasing in volume and decreasing in density thus contributing to increased occupant exit time in the event of catastrophic battery failure. They are readily applied as functional surface treatments with standard application equipment.
Bringing it All Together
SikaBiresin® TC-4XX series are used for Thermal conductive gap filling applications and serve as a functional interface to the battery arrays and work interactively in heat transfer (cooling and heating) to engage active temperature control systems in the battery packs. Products are available in both silicone and silicone-free formulations. Performance levels are available in the range of up to 3.0 W/m.K, products are resistant to glycol, perform to the UL94-V0 standard, and are room temperature cured. “On-demand” adjustable curing processes add value to “typical” assembly processes. Additionally, low compression force & viscosity allows for easy assembly while moderate adhesion strength allows for disassembly and serviceability.
Finally, the closing of the battery pack, also called battery lid sealing is a core Sika competency. Already present in the market for several years with our 1C boosted PUR solutions, we are also now taking the path to simplify maintenance operations by providing non-permanent bonding butyl-based sealing systems from our SikaLastomer® range. Sika is well equipped for complete battery system assembly. From cells to arrays to enclosures, to full drive modules, our solutions answer the needs of your toughest and most innovative design and assembly challenges.