Global energy crisis and increasingly serious environmental pollution force human beings to take new measures for the development of the automotive industry. Electric vehicles are recognized as a solution in the world. As the power source carried by the electric vehicle, the battery box of the electric vehicle is the key component of the electric vehicle. Its performance will have a significant impact on the application prospect of the electric vehicle. For a long time, the protective shell of the battery of the electric vehicle has been made of metal boxes that are easy to form. What kind of material should be used to make the protective shell of electric vehicle power battery? Nowadays, battery boxes made of thermoplastic and thermosetting plastics are being developed. Due to the low thermal conductivity of plastics, it is not necessary to use the foam insulation board used in metal boxes. The connector integrated in the battery box can act as a thermal barrier layer to avoid the impact of battery overheating during charging and low temperature in winter. Thermosetting plastic battery box. The protective shell of electric vehicle power battery can carry a battery weighing up to 340kg, with a dead weight of 35kg, which is about 35% lighter than the weight of metal box. The thermosetting battery box can withstand the impact of ten times the acceleration of gravity. Thermosetting plastic SMC composite is the abbreviation of sheet molding compound, namely sheet molding compound. The main raw materials are GF (special yarn), up (unsaturated resin), low shrinkage additives, MD (filler) and various additives. It first appeared in Europe in the early 1960s. Around 1965, the United States and Japan successively developed this technology. In the late 1980s, China introduced foreign advanced SMC production lines and processes. As the most advanced and popular shell manufacturing material in the world, SMC composite has incomparable advantages with other non-metallic materials and metal materials. Thermosetting plastic SMC composites have the following advantages:
What kind of material should be used to make the protective shell of electric vehicle power battery?
1. Good electrical performance the fiber-reinforced polyester Ningbo Huayuan SMC composite used for manufacturing electrical products has the following electrical properties: insulation resistance (immersion in water for 24h): 1.0x10 m Ω arc resistance: 180s resistance to electric leakage and tracking index: ≥ 600V insulation protection and anti creepage index comply with relevant din/vde standards. This material not only has excellent electrical insulation, but also can maintain good dielectric properties at high frequencies. It is not affected by electromagnetic effects and does not reflect electromagnetic waves. These properties are far superior to those of non-metallic materials.
2. The chemical resistant fiber reinforced polyester Ningbo Huayuan SMC composite has good corrosion resistance to acid, dilute alkali, salt, organic solvent and seawater, while the metal material is not resistant to acid and seawater.
3. The specific strength and specific modulus of light weight and high strength are one of the indicators to measure the bearing capacity of materials. The specific modulus of fiber reinforced polyester SMC composites is equivalent to that of steel, but its specific strength can reach 4 times that of steel.
4. Good fatigue resistance the tensile strength of fiber reinforced polyester Ningbo Huayuan SMC composite is slightly better than that of steel. The fatigue resistance limit of steel and most metal materials is 40%-50% of its tensile strength, while the fatigue resistance limit of fiber reinforced composite is generally higher than this value, up to 70%-80%.
5. Notch sensitivity when the component is overloaded and a small amount of fiber is broken, the load is quickly distributed on the undamaged fiber to regain the mechanical balance. This is not comparable to metal components.
6. Low thermal conductivity, small coefficient of expansion, the thermal stress produced by temperature difference is much smaller than that of metal.
7. Excellent UV resistance and aging resistance among non-metallic materials, fiber reinforced polyester SMC composites have excellent aging resistance. The anti-aging performance test shows that the maximum aging thickness of the surface is less than 50 after 20 years in different places and climatic zones μ m。 The minimum thickness of most boxes is 5mm, which is less than 1% of the box thickness, so it has no obvious impact on the mechanical performance of the box. Our company has adopted a special UV resistant surface treatment process to further strengthen its aging resistance.
8. Long service life European service history can prove that its service life is at least 20 years; The simulated aging test shows that its service life is more than 20 years, which is far more than that of traditional materials such as metals.
9. Flame retardant, smokeless and nontoxic this material is a kind of flame retardant material, with a flame retardant grade of fv0 (the highest level of non-metallic materials), a smoke level of 15 (smoke level 1-100) under high temperature ignition, and a non-toxic smoke, with a toxicity level of za1 (quasi safety level 1). The above SMC composite materials have the advantages of electrical insulation performance, mechanical performance, thermal stability, superior corrosion resistance, light weight, easy and flexible engineering design, etc. Therefore, SMC composite materials are one of the materials for the manufacture of electric vehicle battery boxes. The electric vehicle battery box can be manufactured by SMC molding process. After a certain amount of SMC composite materials are installed in the mold, the SMC composite materials flow and fill the mold cavity under a certain temperature and pressure, and cross-linking agglomeration reaction occurs. After a certain period of time, the three-dimensional shape structure is formed to obtain the expected SMC composite product electric vehicle battery box. Ningbo Huayuan provides SMC composite materials and the manufacturing and processing of electric vehicle battery cases. Ningbo Huayuan Group, founded in 1994 and located in Gaoqiao, hometown of Liangzhu, is a FRP professional group company integrating material production, mold making and part forming. The company has long been committed to the production of smc/bmc materials, Smc/bmc molding and processing services for molded parts and BMC injection parts and the composite materials branch of smc/bmc mold design and manufacturing group can provide customers with integrated solutions for smc/bmc composites with strong technical force and strong R & D capability. The annual production capacity of smc/bmc composites reaches 25000 tons. The SMC materials and BMC materials produced by the company have passed UL and SGS certification, The GRP products branch of the group has more than 60 smc/bmc GRP professional forming presses, 100t---2500t, with an annual pressing capacity of 5million pieces. Provide customers with smc/bmc molding products processing services in the fields of smc/bmc electrical, automotive, rail transit, construction and other industries.