Application of New Materials and New Technologies in Low-carbon Design of New Energy Vehicles

The Chinese government proposes to vigorously develop green and low-carbon industries. As one of the development priorities, the new energy vehicle industry has solved the low-carbon problem of power in the process of use. The main reason is that petrochemical energy is replaced by other forms of energy such as solar energy, wind energy and hydropower. However, new energy vehicles still need to carry out further low-carbon reforms in the production process to truly help the carbon peak and carbon neutral strategy. Therefore, excluding the application of power systems, the application of new materials and new technologies in the automobile manufacturing process can make the automobile low energy consumption and low carbon more complete.

1. Application of new materials in low-carbon design of new energy vehicles

As the new energy vehicle manufacturing industry enters a mature stage of development, parts and materials are gradually developing towards lightweight and energy saving, and finally achieve the effect of energy saving, emission reduction and production cost reduction. Among them, the three new materials of spray-free plastics, polydicyclopentadiene engineering plastics and copolyester materials can achieve low-carbon design.

01. Spray-free plastic

Spray-free plastic refers to a material that no longer needs to use traditional spraying technology and can be directly injected into the model to produce colorful appearance effects, and has the advantages of ultra-high gloss, chemical solvent resistance, green environmental protection and lower production costs. The three parts of the substrate, colored pigments and additives make up the spray-free material.
At present, spray-free plastic substrates include PA, PP, PC, HIPS, PC\ABS, ASA, ABS, PMMA, ABS\PMMA, PBT and POM, etc. Colored pigments include copper powder, pearl powder, ceramic powder, fluorescent powder and high-gloss toner, etc. Spray-free materials are mostly used in home appliances, automobiles, 3C and other fields.
In the field of new energy vehicle manufacturing, spray-free plastics are increasingly used for interior and exterior parts. Among them, interior and exterior parts include car navigator panels, car door handles, rearview mirror housings, and column outer guards. And anti-scratch strips, etc. For example, Suzuki's color navigation panel uses spray-free resin, which not only has bright colors, but also has a high-end texture.
Spray-free plastics are in line with the development trend of the automobile manufacturing industry while saving production costs and environmental protection due to their low volatile organic compound content and relatively small odor release. In terms of environmental protection, spray-free plastic has an overwhelming advantage, which is very beneficial to the environment, and it also has great benefits in health management, avoiding the harm of spray paint to the human body.

02. Polydicyclopentadiene engineering plastics
Poly (dicyclopentadiene) (PDCPD) is an environmentally friendly engineering material, which is a polymer with a cross-linked three-dimensional network structure formed by organic metal-catalyzed polymerization of dicyclopentadiene (DCPD). This new engineering material not only has excellent acid and alkali resistance, water resistance, weather resistance, electrical insulation, surface coating and excellent mechanical properties, and its products can be recycled. Polydicyclopentadiene materials also have good application prospects in sports equipment, engineering machinery, automobiles and chemical anti-corrosion fields.

03. Copolyester material
Copolyester material is a transparent plastic composite material formed by polycondensation of three monomers, phthalic acid (PTA), ethylene glycol (EG) and 1,4-cyclohexanedimethanol (CHDM), also known as SKYTRA. According to the study found that copolyester material has high transparency, good toughness and strong corrosion resistance and other properties. Because the copolyester material is added with biological raw materials extracted from corn, it has obvious bioplastic characteristics and becomes a new type of green, low-carbon and environmentally friendly transparent engineering plastic.

2. Application of new technologies in low-carbon design of new energy vehicles

On the basis of traditional automobile manufacturing, new energy vehicles still have many new technology to be developed. In order to promote the development of green and low-carbon, the development direction of automobile processing and manufacturing technology is lightweight and intelligent. Among them, 4D printing technology, integrated die-casting technology and roll-punching composite forming technology have the advantages of effectively reducing fuel consumption, reducing emissions and reducing production costs.

01.4D printing technology

4D printing technology is upgraded on the basis of 3D printing technology, specifically upgrading materials, technology and applications. 4D printing technology has the advantages of low production cost, forming intelligent components and high design freedom. This technology refers to the ability of three-dimensional objects to transform their physical properties through the use of 3D printing technology and "programmable substances" under specially set stimuli. Among them, through programming, the substance that changes its properties is a "programmable substance", and its properties cover shape, color, elasticity, density, and electromagnetic properties.
In the field of automobile manufacturing, 4D printing technology can produce auto parts with transformable shapes to meet the needs of product combination component performance, external shape and internal structure; at the same time, 4D printing technology can well solve the current resource consumption. Large, decreasing space and high carbon emissions.

02. Integrated die casting technology

Integrated die-casting technology is a new type of auto parts manufacturing technology, which uses large die-casting machines to highly integrate complex components of multiple independent and scattered parts to achieve a die-casting molding. This technology was first proposed by Tesla. The concept of "one die-casting" has been realized. The application of integrated die casting technology can greatly reduce the number of parts, save the welding process of parts, and achieve the effect of reducing body weight, reducing production costs and energy saving and emission reduction.

Integrated die casting technology is mainly used in the field of automobile manufacturing, which is an important development trend of automobile body manufacturing technology in the future. In 2019, Tesla formally put forward the concept of "integrated die casting" and took the lead in completing the application of this technology in body manufacturing in 2020. Among them, the rear floor assembly system of ModelY model successfully realized rapid die casting by adopting integrated die casting, and added integrated die casting of front longitudinal beam to the rear floor, reducing the number of parts of the front and rear floor from 171 to 2 and the number of welding spots by more than 1600.

03. Roller composite forming technology
Roll-punching composite forming (chain die forming) is a new lightweight metal forming technology for new energy vehicles, which was proposed by Dr. Sun Yong's research team in 2020. This technology combines the advantages of rolling and stamping related process forming, and has the advantages of saving energy, reducing costs and improving efficiency, especially effectively solving the problem of difficult forming of aluminum alloy new energy automobile parts in China. At present, in the industries of new energy vehicles, construction, electronics and rail transportation, roll-punching composite forming technology is one of the most promising forming technologies for lightweight and variable cross-section parts.

3. Conclusion
Because new materials and new technologies have good performance, lower cost and environmental protection, they can realize lightweight design and low-carbon design of vehicles to meet the development needs of the automotive industry. This paper studies the application of new environmentally friendly low-carbon materials and new environmentally friendly manufacturing technologies in order to promote the rapid, healthy and sustainable development of China's new energy automobile industry.