Aerogel is a lightweight solid material that is composed of nano-colloidal particles that aggregate to form a nano-skeleton and nano-porous network structure, and the pores are filled with gaseous dispersion medium. Due to its translucent color and ultra-light weight, aerogel appears like smoke in the air and is known as "solid smoke".


In 1931, American chemist Samuel Stephens Kistler prepared the world's first aerogel. He used supercritical technology to dry the gel (similar to jelly, consisting of a network skeleton formed by a solid and a liquid contained in the network), replaced the liquid in the gel with air, and kept the solid network structure in the gel from collapsing, thus obtaining an aerogel. On the contrary, if the gel is dried directly, the capillary force brought by the evaporation of the liquid in the network will usually shrink the network, resulting in a dense rather than porous material. This unique porous and loose structure gives aerogel extremely low density, as well as extremely low thermal conductivity and large specific surface area. Due to these outstanding properties, aerogel is expected to be a "magic material that changes the world."
Aerogel has extremely low density, ultra-high porosity, low thermal conductivity, low acoustic impedance and other characteristics, which are not possessed by general solid materials. These characteristics make it have great application prospects in the fields of thermal insulation, biomedicine, sound insulation, adsorption, etc. As the "insulation king" in the field of materials, aerogel has a wide range of applications in aerospace, automotive batteries, construction and other fields. The Russian "Peace" space station, the US "Mars Pathfinder" probe, my country's "Long March 5" carrier rocket and the "Zhurong" Mars rover have all used aerogel materials as thermal insulation materials. Aerogel is also used for thermal runaway insulation of ternary batteries. Occasionally, electric vehicle batteries will spontaneously combust in life. It often takes only a few seconds from the ignition to the explosion of the entire vehicle. The main reason is that the insulation level inside the battery is not enough, and the thermal runaway of a single battery cell is extended to the entire battery pack. As a fireproof and heat-insulating material, the biggest role of aerogel is to delay or prevent heat diffusion and the spread of flames. Applying it in new energy vehicles can better achieve battery temperature control and electronic control management and improve performance, play a role in heat insulation and fire prevention, and buy more time for users and passengers to escape from the scene and extinguish the fire.
In addition, in low-temperature environments, the mobility of charged electrons in the positive and negative electrode materials of lithium iron phosphate batteries deteriorates, resulting in battery capacity decline and reduced battery life. The excellent thermal insulation performance of aerogel can prevent the cells in lithium iron phosphate batteries from being affected by external low temperatures.
In daily production and life, aerogels are also widely used: functional cellulose aerogels have natural advantages in adsorbing gases such as carbon dioxide and formaldehyde, and removing heavy metal ions, organic dyes, organic solvents and oily sewage from wastewater.
In the future, with the continuous improvement of preparation technology and the continuous development of science and technology, aerogels will gradually be integrated into public life, bringing surprising changes to various fields.