Composite materials are used in electric vehicle battery packaging shells to alleviate "mileage anxiety"
The Environmental Protection Agency (EPA) says that for every 100 pounds a car loses, fuel economy increases by 1-2%. The electric vehicle (EV) industry is committed to improving energy efficiency and alleviating "mileage anxiety", which undoubtedly brings business opportunities. The battery packaging shell (also known as battery slot, box or shell) of electric vehicle is mainly used to package and protect the battery. They are different in shape and size, and just like other auto parts, they have a variety of choices in terms of materials, and the competition between different materials is fierce. Aluminum and steel are the traditional materials for battery packaging. However, composite materials can provide better alternatives, which will greatly improve the performance of electric vehicles.
difficult problem
At present, the large-scale popularity of electric vehicles is plagued by mileage anxiety, because people worry that the driving distance is not long enough after one charge. In order to alleviate mileage anxiety, there is no doubt that people need safe, light and cost-effective electric vehicles. In order for electric vehicles to achieve this goal in the market, their components must also have these characteristics. If a component can be made of lighter materials without affecting its safety and functionality, it is undoubtedly a wise choice for designers and material screeners of original equipment manufacturers (OEMs) and system suppliers.
In some ways, replacing metal materials with composite materials can not only compare with the functionality of the past, but even surpass the previous performance, because composite materials bring additional advantages. A good example is the battery packaging shell of electric vehicles, because composite materials can reduce weight, improve thermal insulation, reduce noise, reduce vibration, and reduce the roughness of sound and vibration. Let's take a closer look at all aspects of composite features:
Reduce weight
It can be said that the main driving factor for choosing composite materials is to reduce the weight of the car body. If the battery shell is made of 100% composite materials instead of aluminum, the weight of the car body can be reduced by up to 40%. The battery package made of composite materials is light in weight, which has a positive effect on vehicle design. Because the weight of the car body is reduced due to the battery box factor, the required battery and engine size will be reduced when towing a lighter vehicle. This positive spiral effect can reduce vehicle cost and mileage anxiety, and help to promote the large-scale use of electric vehicles.
Heat insulation
In addition to the lightweight nature of the composite material, it also avoids the need for separate insulation systems, which further reduces the weight of the car body and helps streamline the supply chain and value chain. For the metal battery packaging shell, the thermal insulation system should be installed around the material to maintain the working temperature of the battery. Because the composite material has the characteristics of heat insulation, it has a good effect in preventing heat transfer, so there is no need to add more weight-added components in the system.
Noise, vibration and roughness
Although it is not a key factor related to safety, low noise vehicles are more commercially feasible. Noise, vibration and vibro acoustic roughness (NVH) are the results of vibration or noise, which will spread and diverge through sound in the cab. Compared with metal materials, the noise, vibration and acoustic vibration roughness (NVH) of composite materials are smaller because of their inherent damping characteristics. This is true for battery packages and other vehicle components, and the difference between the two may mean that in terms of driving experience, one is more luxurious and comfortable, while the other is less comfortable.
Safety
From the perspective of a larger body, the composite battery shell can be designed as a part of the body structure, which can not only protect the battery, but also protect the passengers in the vehicle. The strength and stiffness properties of composite materials exceed those of aluminum or steel, which can provide better crash safety. This combination will require close cooperation between battery package suppliers and chassis designers, but it is feasible to improve vehicle safety.
Pultrusion molding
Large scale production is very important to reduce the total cost. Continuous manufacturing methods, such as pultrusion, can be used to produce battery pack components for electric vehicles. Compared with other composite manufacturing methods, pultrusion process enables composite manufacturers to fill more fibers in the same cross section, which can produce stronger but lighter parts.
Remember, fiber is the part that carries the load of the material. Working closely with composite manufacturers, the fiber content and arrangement can be precisely designed to achieve the best weight to strength ratio characteristics.
How will it evolve in the future?
If, as predicted by the US Environmental Protection Agency (EPA), original equipment manufacturers (OEMs) can get energy efficiency returns from vehicle lightweight, then composites will undoubtedly play a role. Its function is not only to simply reduce the weight of the vehicle, but also to improve the crash safety, enhance the dynamic performance and driving experience of the vehicle, and improve the overall strength of the vehicle. Mileage anxiety is still one of the key problems that the electric vehicle industry must overcome. Considering the choice of materials other than the traditional battery shell materials is an important step to reduce the weight of the car body and improve the fuel economy.
Source: Jung
