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

In 1931, American chemist Samuel Stephens Kistler prepared the world's first aerogel. He dried the gel (similar to jelly, consisting of a network skeleton formed by a solid and the liquid contained in the network) by supercritical technology, replacing the liquid in the gel with air, while keeping the structure of the solid network in the gel from collapsing, that is, the aerogel. In contrast, if the gel is dried directly, the capillary force caused by the evaporation of the liquid in the network usually causes the network to shrink, resulting in a dense rather than porous material. This unique porous and loose structure gives aerogel very low density, as well as very low thermal conductivity and large specific surface area. Due to these excellent properties, aerogels are expected to be "miracle materials that change the world".

Aerogel has the characteristics of extremely low density, ultra-high porosity, low thermal conductivity and low impedance, which are not possessed by general solid materials. These characteristics make it have great application prospects in thermal insulation, biomedicine, sound insulation, adsorption and other fields.
As the "king of heat insulation" in the field of materials, aerogel has a wide range of applications in aerospace, automotive batteries, construction and other fields. Russia's "Peace" space station, the United States "Mars Pathfinder" probe, China's "Long March 5" carrier rocket and "Zhurong" rover have all used aerogel materials as insulation materials.

Aerogel is also used for thermal runaway insulation of ternary batteries. In life, there will occasionally be spontaneous combustion of electric vehicle batteries, from the fire to the vehicle deflagration is often only a few seconds, the main reason is that the heat insulation level inside the battery is not enough, and the thermal loss of a single cell expands to the entire battery pack. As a fire insulation material, the biggest role of aerogel is to delay or prevent the spread of heat diffusion and flame, and its application in new energy vehicles can better realize the temperature control and electronic control management of the battery and improve the performance, play the role of heat insulation and fire prevention, and win more time for users and passengers to escape the scene and fight the fire.

In addition, lithium iron phosphate batteries at low temperatures, the movement of charged electrons in the positive and negative materials deteriorates, resulting in battery capacity decline and reduced battery life. The excellent thermal insulation performance of aerogel can make the cells in the lithium iron phosphate battery not affected by external low temperature.

In daily production and life, aerogels also have a wide range of applications: functional cellulose aerogels have natural advantages in adsorption of carbon dioxide, formaldehyde and other gases, and removal of heavy metal ions in wastewater, organic dyes, organic solvents and oil sewage.

In the future, with the continuous improvement of the preparation process and the continuous development of the scientific and technological level, aerogels will gradually integrate into public life and bring surprising changes to various fields.