Recently, BYD (for BYD Co., Ltd.) unveiled its sales figures, revealing a staggering total of 287,454 new cars sold in September 2023. Notably, passenger car sales soared to an impressive 286,903 units, up 42.8% year on year, which has marked an unprecedented pinnacle in the realm of sales.
With the advancement of new energy vehicle consumption, consumers ask more for the safety, power battery heat dissipation, lightweight properties, NVH (noise, vibration, and acoustic roughness), as well as VOC (air detection of organic volatiles in car and interior decoration materials) of the vehicle. In recent years, foamed materials have emerged as the "new favorite" within the realm of new energy due to their exceptional attributes such as to being lightweight, flame retardant, sound-absorbing and cushioning. The Tesla Model 3 battery pack extensively employs silicone foam encapsulation material to safeguard individual cells against heat transfer from the upper section of the battery pack while effectively preventing heat loss.
Have a browse over any silicone foam encapsulation materials being used in the battery against heat loss inside the cars below.
(1) Microporous polyurethane foam and silicone foam
A microporous polyurethane foam, specifically engineered for cushioning soft bags and square lithium-ion battery structures, exhibits exceptional resistance to long-term compression, repeated compression, and possesses high flame retardancy properties between layers of lithium batteries, thereby enhancing the performance and lifespan of soft batteries. Additionally, the organosilicon foam demonstrates outstanding flame retardancy characteristics along with low toxicity, minimal smoke emission, softness and lightweight design, which meets the highest flame retardant rating - UL94V0.
Picture 1 Norseal ® PF Series microporous polyurethane foam
The two types of foam possess the ability to shield the battery against impact and vibration, while simultaneously compensating for design tolerances and thickness variations caused by cell expansion or contraction, thereby ensuring optimal contact between the battery and heat dissipation fins.
(2) Liquid foamed silicon material
The liquid foam silicone material is a remarkable organosilicon foam material that exhibits exceptional resistance to compression permanent deformation. In comparison to conventional carbon foaming materials, the liquid foaming silicon materials showcase outstanding endurance against extreme temperatures (-60-200℃), high flame retardancy (V-0), and remarkably low smoke concentration. Presently, they find extensive applications in the packaging sealing of new energy power battery PACKs, support protection for power battery thermal management systems, insulation materials for power batteries, as well as serving as an insulation buffer for power batteries.
Picture 2 Application of silica gel in lithium battery PACK safety protection and thermal management
(3) Super soft silicone foam
In addition to its lightweight and exceptional flexibility, silicone foam boasts remarkable flame retardancy. When the electric core ignites, superior flame retardant properties of the foam effectively impede fire propagation, prolonging escape time and ensuring heightened safety with minimal smoke emission and low toxicity.
Enhanced with exceptional compression resistance and plasticity, this series of foam surpasses other foam materials by enduring extreme temperatures ranging from -50℃ to -200℃, rendering it an extraordinary solution for battery cell cushioning pads. Currently, numerous enterprises are actively promoting the research and application of heat dissipation and protection materials for new energy vehicle power batteries, eagerly anticipating the remarkable performance of silicone materials in the new energy industry as they play a pivotal role.
