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What kind of aerogel does the power battery need?
- Time of issue:2023-02-11 06:49
What kind of aerogel does the power battery need?
The Kirin battery released by Ningde Times has a volume utilization rate of up to 72% and an energy density of up to 255Wh/kg. It has a fast charging function, and its overall efficiency has been greatly improved. Kirin battery has achieved performance improvements such as safer, longer endurance and fast charging by setting up elastic interlayer, changing the structure of water-cooled plate, and intelligently using the bottom space. The change of battery structure is also accompanied by the upgrading and growth of related materials. The upgrading of Kirin battery in the direction of heat insulation, lightweight, insulation, etc. will bring investment opportunities to water cooling plate, heat conduction ball aluminum, LIFSI, polyurethane, aerogel, insulation materials, etc.
Especially aerogel: a leader in the field of thermal insulation materials, which is expected to usher in large-scale application.
Significant advantages in thermal insulation performance and high production technical barriers
Aerogel is a special gel that uses gas to replace the liquid in gel without changing the network structure or volume of gel itself in essence. The International Union of Pure and Applied Chemistry defines aerogel as "microporous solid gel with gas as the dispersion phase". Because of its translucent color and ultra-light weight, it is sometimes called "solid smoke" or "frozen smoke".
The internal structure is unique, and the thermal insulation performance is particularly outstanding. Aerogel materials have the characteristics of low density, large specific surface area, high porosity, and special thermal, optical, electrical, and acoustic properties such as high temperature resistance, low thermal conductivity, low refractive index, and low sound propagation speed. Depending on its unique structure, aerogel has the thermal insulation performance far beyond that of traditional thermal insulation materials such as aluminum silicate and glass wool through no convection effect, infinite shielding effect and infinite loose path effect. As a result, aerogel is an excellent application material in the application field with high thermal insulation requirements, low demand and good stability.
The material system has diversified and developed, and the downstream applications are extensive. According to different materials, aerogels can be divided into four categories: inorganic aerogels, organic aerogels gel, mixed aerogels gel and composite aerogels gel. According to their properties, aerogels correspond to downstream aerospace, industrial equipment, petrochemical, building pipelines and other application fields. Among them, SiO2 gas gel of inorganic gas gel, as a light nano porous amorphous solid material with excellent fire and heat insulation performance, is the most mature product in production technology and commercial application at present. It has excellent properties such as low density, low thermal conductivity, high porosity, high specific surface area, etc., and has broad application prospects in the fields of pipeline heat insulation, heat insulation coating, energy-saving glass, pipeline corrosion prevention, adsorption catalysis, etc.
The solution gel process has become the mainstream process, and drying is the key step. Silica aerogels are usually prepared by the sol gel method: first, select an appropriate silicon source and catalyst, and let the silicon source hydrolyze under the catalyst condition. The hydroxyl groups carried in the hydrolysate undergo condensation reaction to form a sol. The sol particles form particle clusters in a chain structure, and form a wet gel in the container. Finally, remove the water or solvent in the wet gel through the drying process to prepare a dry gel, Also called aerogel. The type of silicon source, the performance of catalyst, and the selection of drying process are all important factors affecting the structure and performance of Silica aerogels.
Selection of silicon source: silicon source can be divided into three categories: single silicon source, composite silicon source and functional silicon source, while single silicon source can be subdivided into two types according to material type: inorganic silicon source (sodium silicate) and organic silicon source (methyl orthosilicate (TMOS) and ethyl orthosilicate (TEOS). Although the cost of organosilicon source represented by methyl orthosilicate and ethyl orthosilicate is relatively high, it has significant advantages of good process adaptability and high product purity, and is the mainstream choice for large-scale production of silica gel at present.
Drying process: the drying process is a key step for the transformation of Silica aerogel from wet gel to dry gel. The drying process requires that the solvent filled in the wet gel network structure should be removed while keeping the network structure intact. At present, supercritical drying technology and atmospheric pressure drying technology are mainly used in industrial production. In general, the supercritical drying technology often selects organic silicon as the silicon source for production. The equipment investment and energy consumption are higher than the atmospheric drying technology, but the product purity is relatively high.
The medium and high-end fields of traditional thermal insulation continue to penetrate,
New energy and construction are expected to form a rapid growth point
The advantages of aerogels are relatively prominent, and they are widely used in high-end engineering, equipment construction and other fields. On the one hand, because of its superior performance and low density, gel has very good applicability in most heat preservation and heat insulation applications. However, gel has relatively high production barriers, relatively large equipment investment, and relatively difficult process control, so the cost of gel is relatively high. Therefore, it is mainly used in projects and equipment that have high requirements for application scenarios, use effects, and other fields.
At present, the downstream demand of aerogel mainly comes from the oil and gas field. Gas gel is mainly used in energy infrastructure in petrochemical industry, including thermal insulation materials for distillation tower, reaction pipeline, storage tank, pump, valve, natural gas and LNG pipeline. Among high-temperature steam, heat transfer oil and process fluid medium pipelines that are critical equipment in the fields of thermoelectricity, oil refining and chemical industry, aerogel pipelines can well reduce the heat loss caused by pipeline exposure. According to ID TechEX prediction, the demand of domestic petrochemical industry will still account for 47% by 2026, and petrochemical industry will still be the main battlefield of downstream demand of aerogel in the future.
With the increasing supply of aerogel enterprises and the continuous improvement of the process, aerogel is expected to achieve the penetration of high-end applications in the existing thermal insulation demand field, so as to continue to drive the improvement and expansion of market demand.
The construction sector is the main force driving the demand for aerogels. Under the strategic background of carbon neutrality, building thermal insulation materials are also developing towards energy conservation, environmental protection and high efficiency. At present, the main building thermal insulation materials in the market, such as rock wool, glass wool and other inorganic fiber cotton, have problems of loose fiber structure and easy moisture absorption, and the thermal insulation performance will be significantly reduced during the service cycle. Organic thermal insulation materials such as polystyrene and polyurethane foam have fire risk. Silica aerogel is light, low in heat conduction, long in life and good in hydrophobic performance, which can meet the needs of thermal insulation, fire prevention, sound insulation and waterproofing in the construction field. At present, the application forms of silica aerogel mainly include aerogel energy-saving glass, aerogel coating, aerogel felt pad, aerogel gel plate, aerogel gel concrete and mortar, roof solar collector, etc.
At present, new energy vehicles mainly use lithium-ion batteries as power batteries, and thermal runaway under extreme conditions is a major safety hazard for new energy vehicle power batteries. In the field of new energy vehicles, aerogel thermal insulation materials are mainly used for thermal insulation and flame retardancy between power battery cells, thermal insulation and shock resistance between modules and shells, and external cold and high temperature insulation layers of battery boxes, so as to better realize the temperature control and electronic control management of batteries and significantly reduce the possibility of thermal runaway of batteries. Compared with the traditional IXPE heat insulation foam, the aerogel heat insulation sheet has obvious advantages in many core indicators such as service temperature, thermal conductivity, flame retardancy, etc.
Battery safety requirements drive the demand for thermal insulation materials to continue to increase. With the further improvement of the safety performance requirements of the battery pack, aerogel, as a more high-end thermal insulation material, can significantly improve the safety performance of the battery, so it continues to penetrate into the battery application. Among them, the ternary battery has higher compaction density and longer endurance mileage. The requirements for safety have led to the gradual selection of more high-end aerogel materials in the production process of related battery packs, and the penetration rate continues to increase, Other lithium iron phosphate power batteries and energy storage batteries have also gradually entered into the field. On the one hand, with the continuous increase of downstream battery shipments, the application of aerogel as PACK thermal insulation material will also increase. At the same time, with the improvement of cost control and permeability, the application proportion of aerogel will further increase. It is expected that new energy batteries will also drive the rapid expansion of demand for aerogel, It has become another potential market in addition to the construction field.