The main chain of the silicone rubber (SR) raw rubber molecule is composed of Si-O bonds, and the side groups are mainly methyl groups. Depending on the type of silicone rubber, some methyl groups can also be substituted by groups or atoms such as vinyl, phenyl or fluorine. The end groups can be methyl or hydroxyl, and the like.

Liquid silicone rubber (LSR) is an elastomer that is vulcanized and cross-linked in the atmosphere or under heating with a small amount of water as an initiator or platinum as a catalyst. It is divided into one-component and two-component ( According to the type of reaction, it can be divided into condensation type or addition type liquid silicone rubber. Liquid silicone rubber does not contain any stabilizers, plasticizers or accelerators, and as a cross-linking material, it can withstand very high temperatures without thermal aging and can maintain its mechanical properties and elasticity. By altering certain pendant groups on it, modification of the material to meet specific functions or requirements can be achieved. LSR has excellent chemical resistance, oil resistance and weather resistance, can be stable in the temperature range of 50 ℃ to 180 ℃, can be stable at temperatures above 250 ℃ after adding stabilizers, and can be stable at -60 ℃ has low temperature flexibility. LSR is usually transparent, other pigments can be added as required, and it is very easy to color. It is widely used in electronic component sealing, pipe sealing, medical equipment, keyboards and baby related products. The application of liquid silicone rubber in the fields of 3D printing, waterproofing, coating, food contact silicone and wearable parts has great potential for development. Of course, the application in the automotive industry has also achieved a full range of coverage, such as connectors in the automotive industry, electric vehicle battery seals, engine gaskets, headlight seals and shock absorbers, etc. and the material of choice for protecting interior application solutions.

Rapidly changing technology trends in electric vehicle manufacturing are driving silicone manufacturers to take innovative approaches to producing custom products. The solution of liquid silicone rubber in new energy vehicles mainly has four applications: sealing and waterproofing, safety protection, structural heat conduction, and lightweight. Liquid silicone rubber elastomer is the most prominent product segment in the electric vehicle market, and its growth can be attributed to its wide range of applications such as seals, housings and gaskets for thermal insulation of various components such as connector seals, heat sinks etc., form a heat shield around the battery pack to protect the battery cells from excessive heat or cold. Additionally, custom designs can insulate or help dissipate heat to ensure optimal operating temperatures. To fit in demanding spaces, the silicone is designed to withstand severe vibrations. Short circuits and overcurrent are the main causes of battery failure in electric vehicles, and the dielectric properties of silicone rubber protect and isolate critical components, keep batteries and busbars safe from power surges, and help prevent battery fires.

In new energy vehicles, liquid silicone encapsulant is mainly used in the lithium battery pack link, which plays the role of heat dissipation, flame retardant, insulation, waterproof, etc., which greatly improves the power safety of new energy vehicles. Lithium batteries are sensitive to moisture, and the tightness directly affects the working safety of the battery system and the safety of electric vehicles. From the perspective of development history, silicone has undergone product upgrades from single-component cushion-free glue - foam molding sealing ring - online foam silicone in sealing and waterproofing. However, the liquid silicone potting compound has a large proportion, which will increase the weight of the battery pack, reduce the energy ratio per unit volume, and ultimately affect the energy density. How to realize the lightweight of liquid silicone is an urgent problem to be solved by silicone enterprises at present. At present, online foamed silica gel is favored in the new energy automobile industry, and is suitable for application scenarios such as sealing and waterproofing of power batteries, shock absorption protection of soft-packed cells, thermal insulation of battery packs, and lightweight.