The inconspicuous silicone parts in new energy vehicles

When it comes to new energy vehicles, most people think of batteries, motors, and intelligent cockpits. But there are dozens of inconspicuous silicone parts in a car, which are not very visible, but they really affect the safety, durability, and user experience of the car.

This article brings out these "little characters" to see what they are doing and why liquid silicone has become an increasingly important material in new energy vehicles.

Sealing - the most basic and critical use

There are several sealing requirements for new energy vehicles that are higher than traditional fuel vehicles:

Sealing of battery pack. The outer shell of the battery pack needs to be sealed to prevent water and dust, and IP67 rating is a basic industry requirement. The sealing ring between the battery pack shell and the cover plate is a silicone component. The temperature resistance range (-50 ℃ to over 200 ℃), weather resistance, and compression rebound performance of liquid silicone make it more reliable than ordinary rubber in battery pack sealing scenarios.

The charging interface is sealed. The charging port needs to be repeatedly plugged and unplugged, and the sealing ring needs to withstand thousands of compression rebound cycles without failure. The aging resistance of silicone is crucial here - ordinary rubber begins to harden and lose elasticity within two to three years, while silicone can last longer.

Sealing of cooling pipelines. The thermal management system of new energy vehicles is more complex than that of fuel vehicles, and the sealing components at the coolant pipeline joints need to be both temperature resistant and chemical resistant (the coolant formula varies). Silicone has better resistance to various chemical media than most elastomeric materials.

Glue wrapping - making metal and plastic more 'grounded'

There are many sensors and connectors in new energy vehicles, and their shells or interfaces require a layer of silicone coating, which is used for:

Insulation. The connector in the high-voltage system is wrapped with a layer of silicone insulation, which is more reliable than adding an insulation sleeve separately - it is integrally formed without gaps.

Waterproof The silicone coating on the outside of the sensor probe isolates the electronic components from the outside world, preventing water vapor from entering.

Buffer. The silicone layer outside the collision sensor and pressure sensor acts as a buffer during vehicle vibrations, protecting the internal precision components.

Liquid silicone injection molding is almost standard in these scenarios - high precision, complete encapsulation, and high efficiency of automated mass production.

Shock absorption and sound insulation - invisible roles in NVH

NVH (Noise, Vibration, and Acoustic Roughness) is an important indicator of comfort for new energy vehicles. The high-frequency vibration, road noise, and wind noise of the motor all require the use of damping and sound insulation materials to control.

The applications of silicone in NVH include:

Motor suspension shock pad: The high damping characteristics of silicone are suitable for absorbing high-frequency vibrations Bottom buffer pad of battery pack: balancing shock absorption and heat insulation Door frame sealing strip: dual function of sealing and sound insulation Air conditioning pipeline damping ring: reducing compressor vibration transmission Compared to traditional EPDM or CR rubber, silicone rubber has a slower damping performance degradation in high-temperature environments, which is a tangible advantage for new energy vehicles that operate for long periods of time.

Why is liquid silicone increasingly popular in new energy vehicles?

Several reasons combined:

Wide temperature resistance range. The working temperature range of batteries and motors is wider than that of gasoline car engines, and silicone can work stably from winter temperatures of -30 ℃ to battery conditions above 80 ℃.

Resistant to aging. The design life of new energy vehicles is usually 8-10 years or even longer, and seals and shock absorbers cannot fail midway. The weather resistance and ozone aging resistance of silicone are among the top in elastic materials.

Processing adaptability. Liquid silicone injection molding is suitable for medium to large-scale production, with high automation and good dimensional consistency, matching the large-scale demand of the new energy vehicle supply chain.

Environmental compliance. Silicone does not contain plasticizers (such as phthalates), does not release VOCs, and meets the requirements of in car air quality regulations - which is a plus point in the new energy market that is increasingly concerned about the in car environment.

A small reminder

Although silicone components are widely used in new energy vehicles, the volume of each individual component is often small and the unit price is not high. This also means that they are easily overlooked, and in terms of supplier selection and quality management, it is easy to be "just about the same".

It is precisely these inconspicuous small items that, if there is a problem - such as aging and leaking seals, delamination of the coating layer causing short circuits, or hardening of shock absorbers causing NVH deterioration - the consequences are not insignificant. So when choosing a silicone component supplier, both technical ability and quality system should be considered.