Silicone coatings for flexible barrier systems protect battery components during thermal runaway. WACKER also presents newly formulated potting compounds for power electronics thermal management. Taking place from June 9 to 11 in Stuttgart, Germany, the Battery Show features WACKER’s innovative safety solutions for battery electric vehicles (BEV), exhibited at Booth K45 in Hall 1.
A major highlight at WACKER’s booth is ceramic-forming silicone, which significantly enhances the heat resistance and flame retardancy of thermal barrier structures. The company also launches new thermally conductive potting compounds tailored for temperature control of power electronic components. Featuring outstandinganti-sedimentation properties, these products require no complex pre-treatment even after long-term storage and can be processed directly, greatly simplifying manufacturing workflows.
ELASTOSIL® CM TR Ceramic Silicone: Building a Robust Thermal Barrier System for Automotive Batteries
One of the flagship exhibits, ELASTOSIL® CM TR ceramic-forming silicone, is specially developed to optimize thermal barrier systems for pure electric vehicles. It effectively improves the heat resistance and dielectric strength of battery enclosures and automotive protective structures, upgrading the overall safety performance of traction batteries. Integrated into flexible automotive barrier systems, the silicone rapidly forms a protective ceramic layer in the event of battery thermal runaway. This structure insulates high temperatures and blocks flame spread, fully safeguarding core battery components and raising the safety margin of automotive power batteries under extreme conditions.
New Thermally Conductive Potting Formulas: Resolving Industrial Sedimentation Challenges and Optimizing Thermal Management
Another key exhibit is WACKER’s advanced potting compounds for power electronics thermal management, headlined by two premium grades: ELASTOSIL® RT 7616 TC and ELASTOSIL® RT 7624 TC. These filler-added, addition-cure silicone elastomers support room-temperature curing without high-temperature baking, enabling energy-efficient processing of large and heavy components for mass production. ELASTOSIL® RT 7616 TC delivers a thermal conductivity of 1.6 W/mK, while ELASTOSIL® RT 7624 TC reaches 2.4 W/mK. The graded thermal conductivity covers diverse temperature control requirements for automotive applications.
Traditional thermally conductive potting compounds suffer from inherent processing limitations. Formulas balancing high thermal conductivity and low viscosity often experience filler sedimentation and caking after prolonged storage and long-distance transportation. Re-dispersing settled fillers is time-consuming and requires specialized mixing equipment, increasing manufacturers’ production and operational costs.
WACKER’s new potting compounds featureoptimized rheological properties that eliminate filler sedimentation and agglomeration issues. Even if slight sedimentation occurs due to poor transportation or storage conditions, the fillers can be easily re-dispersed using standard mixing equipment without additional specialized machinery, drastically reducing pre-processing time.
Tested in accordance with the DIN 53019 standard, ELASTOSIL® RT 7616 TC and ELASTOSIL® RT 7624 TC exhibit relatively low viscosities of 5,500 mPa•s and 8,000 mPa•s respectively. Their excellent fluidity enables fast, void-free filling of micro gaps measuring hundreds of micrometers for superior encapsulation tightness. With room-temperature curing, heat resistance and low emission characteristics, the two potting compounds serve as long-acting thermal management materials for discrete electronic components such as coils and inductors in EV battery chargers, DC/DC converters and inverters.
Comprehensive Silicone Product Portfolio for E-Mobility Covering Full-Range Battery Applications
Leveraging four core brands including ELASTOSIL®, SEMICOSIL®, SILRES® and WACKER Silgel®, WACKER provides a full-spectrum silicone material solution for e-mobility. A series of specialized automotive functional materials are showcased at the exhibition:
1. SILRES MK Silicone Resin
A condensation-curing methyl silicone resin soluble in various organic solvents, SILRES MK acts as a high-performance binder and impregnant for mechanical protection and thermal barrier structures. Silicone resin laminates reinforced with mica, glass fiber or mineral fiber deliver long-term resistance to extreme temperatures, while maintaining excellent electrical insulation, waterproof performance and mechanical strength, ideal for manufacturing high-temperature resistant composite panels for automotive applications.
2. ELASTOSIL CM 18x Potting Compound Series
Tailored for cell side sealing and top potting of pressure relief vents in batteries, ELASTOSIL CM 18x series cures at room temperature into medium-hard elastomers, with self-adhesive grades available for selection. In top vent potting applications, the compound forms a protective layer without impairing vent pressure relief functions. The cell side seal provides electrical insulation and thermal isolation while offering mechanical support for battery modules. The elastic structure compensates for operational vibration, external impact and thermal expansion of battery cells, preventing mechanical stress and damage to modules and suppressing heat transfer through cell side walls.
3. ELASTOSIL R 531/60 Ceramic Silicone for Busbar Insulation
Developed specifically for high-voltage battery busbar insulation, ELASTOSIL R 531/60 extrudable silicone rubber supports cost-effective mass production while ensuring reliable insulation performance. In fire scenarios and other extreme conditions, the material rapidly ceramicizes to form a dense protective ceramic layer on the busbar surface. The persistent insulating layer prevents high-voltage short circuits and significantly improves the safety level of electric vehicles under extreme operating conditions.
