Views: 0 Author: Bin Publish Time: 2024-12-27 Origin: Nasa
Since its invention in the 1931s, aerogel has set 15 "Guinness World Records" and is known as one of the "Ten Magical Materials that Changed the World" for its extremely light, heat-insulating, and lowest dielectric constant.
Aerogel is a highly dispersed solid material composed of colloidal particles or polymer molecules that are mutually aggregated to form a nanoporous network structure, and the pores are filled with gaseous dispersion media. Aerogel is the lightest solid in the world, also known as "solid smoke". It is widely used in aerospace, military equipment, ships and warships, petroleum and petrochemical, urban thermal pipe networks, metallurgical kilns, locomotives, new energy and other fields.
The raw material of aerogel is silica matrix, which is not fatal or poisonous to the human body, but aerogel is irritating to a certain extent. Aerogel powder can irritate the skin, mucous membranes, eyes, respiratory tract and digestive system. Therefore, it is recommended not to directly contact aerogel with the skin, and to wear medical masks/goggles, protective gloves and protective clothing when working.
Aerogel is thin, easy to process and shape, has excellent thermal insulation performance, low thermal conductivity, lightweight, sound insulation and noise reduction, and cushioning and shock absorption.
Why does aerogel insulate? How does aerogel insulate against temperature? I'm going to quote from a NASAarticle that explains why aerogel is such a good insulator.
According to Mary Ann Meador, NASA's official chemical engineer and team leader for aerogel research, "Maintaining the gel structure is paramount." Aerogels provide very effective insulation because they are extremely porous, with pores in the nanometer range. Nanopores are invisible to the human eye. The presence of these pores makes aerogels so good at insulating.
"The pores are so small that the vapor phase conducts heat very poorly," Meador says. "Air molecules can't pass through the aerogel, so the material is very poor at transferring heat."
Aerogel insulation sheets are used for thermal protection between cells of new energy power batteries. When one of the cells experiences thermal runaway, the aerogel insulation sheets between the cells can effectively block the heat from being transferred to the adjacent cells, preventing heat diffusion, thereby avoiding the domino effect of thermal runaway of new energy power battery cells. Aerogel insulation sheets have good compression properties. While providing thermal insulation, they can also be used as a buffer material to offset the expansion and contraction changes of the cells during charging and discharging.
When there is an unexpected collision, the car body will first resist a round of impact. If the car body fails to resist, the battery shell equipped with high-strength steel beams will resist again. Then, the physical relationship between the battery pack, module and battery cell will buffer the impact again. After multiple rounds of decomposition of the impact, even if the battery pack is squeezed and finally catches fire, the thermal insulation barriers such as aerogel fire blankets set between the battery cell and the module, between the module and the battery pack, and between the battery pack and the car body will try their best to seal the fire locally, and the pressure relief valve and quick exhaust channel will quickly discharge the high-temperature gas from the battery pack. The step-by-step decomposition of the collision impact + the step-by-step shielding of the fire have achieved the ceiling-level safety level of electric vehicle batteries!
