Silicone and Thermal Management

Why Use Silicone Tubing for Thermal Management in EV Batteries

As discussed in our previous post about Electric Vehicles (EVs), the government’s pledge to meet our Net Zero Target in 2050 is driving a technological step-change.  Electric Vehicles are evidently beneficial for this movement, with lower emissions and reducing our reliance on traditional fuels.  Irrespective of the target date, it’s vital that EVs are produced according to strict safety regulation.

Batteries are the powerhouse of electric vehicles. Not only do they supply the energy to run the car, they also provide power for features such as the radio, climate control and USB charging ports. In charging and discharging, the battery generates heat, which must be managed to maintain its quality and safety, therefore thermal management is key:

Battery Efficiency can be significantly reduced if exposed to excessive heat which, in turn, will result in energy loss; working constantly over optimal temperature will cause performance inefficiencies. With the extensive workload expected of a car battery, this will eventually degrade the Battery Life, which has an average life span of 15-20 years, but this could reduce by years if not managed correctly. This inconsistency in heat can translate to the Performance of the car; temperature fluctuations can reduce power output, impact acceleration and even the Range of a vehicle.

The outside temperature of a car also impacts range – with extreme heat leading to faster degradation, and cold weather decreasing battery efficiency. At a consistent temperature, these issues can be mitigated, and a Reliable driving range can be achieved. Above all else, the Safety and integrity of the battery and vehicle could be compromised. Intense heat with improper safety measures can lead to fires – posing risk to the vehicle itself and to its’ user(s).

Unsurprisingly, it’s not as straight forward to resolve these issues as it may seem. Batteries are made up of many components, all of which generate heat at varying rates. This makes maintaining a uniform temperature quite difficult with just one material. Furthermore, electric vehicles are being made with ‘fast charging’, which causes batteries to generate more heat much quicker than regular batteries. This needs to be dissipated quickly to prevent subsequent issues. So not only does the surrounding material need to tolerate high and low temperatures, it also needs to safely dissipate heat and energy, without transferring them to other volatile parts of the car. As well as managing temperatures inside the car, the chosen material needs to resist external climates, be weather resistant, prevent dust, moisture, and heat from getting into the battery, all whilst maintaining the temperature of the battery inside.

Moreover, the battery system is just one component of a car. Manufacturers must consider the weight and size of the system, so as not to impact the vehicle’s overall weight, and to ensure it conforms to the space allowed in the design. If a vehicle weighs too much, it’s performance will suffer, which puts more work on the battery.  A vicious cycle that impacts the whole vehicle.

Silicone Tubing Is The Answer

Automotive manufacturers are turning to silicone tubing; silicone possesses many unique properties which makes it ideal. For example, it is highly heat resistant. It can withstand high and low temperatures, both in air and water. This means it can be used in coolant circulation, where it is used to transport coolant within battery packs and dissipate the heat that the coolant absorbs. Furthermore, the flexibility of silicone tubing allows it to be manipulated into intricate pathways to suit each system.

In being heat resistant, silicone can also act as an insulator, maintaining consistent temperatures which is ideal for use as an insulating layer around battery packs. It can prevent localised overheating and heat transfer between cells, whilst maintaining uniform thermal conditions, as well as providing electrical insulation, counteracting short circuits.

Silicone as a whole is incredibly weather and corrosion resistant, offers excellent dust and moisture ingress, whilst simultaneously being UV and Ozone resistant. Silicone also doesn’t degrade when exposed to cosmic or ionising radiation, corona discharge or oxidisation. The weather resistance also protects internal components from general weather conditions and wear, such as rain and road debris.

Finally, silicone tubing is lightweight in comparison to market alternatives, and performs to high standards consistently whilst adding little weight to the overall build of the car – maximizing output.

Silicone is a versatile and reliable material. It’s varied properties and ability to perform consistently allow it to excel in a range of applications. Use in electric vehicles showcases just a fraction of its capabilities. It is a vital enabler of high-performance and safety and will support the continuing development of new technology in EVs and other industry advancements.

If you have any questions with regards to silicone properties or its applications, please contact our Sales team, who will be happy to provide you with more information.