What Material is Used for Electric Vehicle Battery Housings?
3 Answers
Electric vehicle battery housings are made of plastic. Here are specific details about electric vehicle batteries: 1. Types: Electric vehicle batteries can be divided into two main categories: storage batteries and fuel cells. Storage batteries are suitable for pure electric vehicles and can be classified into lead-acid batteries, nickel-based batteries (nickel-metal hydride batteries, nickel-cadmium and nickel-zinc batteries), sodium-based batteries (sodium-sulfur and sodium-nickel chloride batteries), secondary lithium batteries, and air batteries. 2. Composition: An electric vehicle battery pack consists of multiple batteries connected in series and stacked together. A typical battery pack contains about 96 batteries. For lithium-ion batteries charged to 4.2V, such a battery pack can generate a total voltage exceeding 400V.
The material used for electric vehicle battery enclosures is quite particular! I've seen most manufacturers opt for aluminum alloy, with extruded aluminum alloy enclosures being the mainstream choice. It's lightweight, high-strength, and aids in heat dissipation—critical for keeping the battery cool during scorching 40-degree summer temperatures. However, the cost is quite high, so some entry-level models use high-strength engineering plastics, such as glass fiber-reinforced PP. These offer better toughness in crashes but poorer heat dissipation. Some luxury cars go all out with magnesium alloys or carbon fiber composites, which are outrageously expensive but offer unparalleled weight reduction. By the way, I noticed Tesla's 4680 battery uses a glass fiber resin composite enclosure, which resulted in significantly fewer fragments in crash tests. All these materials must pass IP67 waterproof testing before leaving the factory, as water ingress leading to a short circuit would be disastrous.
When it comes to battery casing materials, my neighbor who works at a battery factory shared some insights. Currently, there are three main types: aluminum alloy dominates 60% of the market due to its ease of processing and lightweight properties; plastic casings are used in compact cars, saving up to 30% in costs; and high-end models use composite laminated materials. A special reminder for car owners: it's normal for aluminum alloy casings to feel hot in summer—they have thermal conductive coatings that transfer heat to the vehicle's chassis. Last year, I repaired a car with a deformed casing; plastic casings can still be used even when dented, but metal ones need complete replacement. When choosing a car, don’t just focus on the advertised range—casing materials directly impact battery life, with metal casings lasting about two years longer than plastic ones on average. The latest trend is honeycomb-structured aluminum alloy casings, which reduce weight while increasing stiffness, as seen in the BMW iX.
