Airgel applications in the battery industry
Battery industry is currently the most widely used is the lithium-ion battery, the appliance market from mobile phones, computers, ipad, to power in the field of new energy vehicles, cruise ships, and then thermal batteries, lithium-ion batteries used in figure weapons-free ubiquitous. However, the lithium ion battery due to its structural characteristics and the nature of the material led to its inevitable safety concerns. For example, the lithium ion battery separator interposed between the positive and negative strength and thermal stability is not ideal, easily lead to internal short circuit of the battery; higher temperatures may occur inside the battery results in a strong exothermic reaction and the temperature of the lithium ion battery internal pressure rise ; lithium ion battery electrolyte and a negative electrode materials are combustible materials. In particular, lithium-ion batteries in the power scenario, the total voltage required due to the high power field, and large operating current of specificity, often require hundreds of thousands of cell groups used, battery safety issues this time becomes more prominent . E.g. Tesla car battery using a lithium-ion battery cell thousands. A large number of cells arranged in a compact sealed space, Ruoyin mechanical damage, thermal shock, internal short circuit, overcharge and other factors, resulting in some of the monomers into thermal runaway, so that the surrounding cell temperature will also rise, in turn thermal runaway spread to the entire battery pack, eventually resulting in the overall combustion, the disastrous consequences of the explosion. On the current level of technology battery materials, the security problem has not been fundamentally resolved completely. Thus the current lithium-ion battery for insulation, fire-retardant, fire protection is an effective means to reduce the thermal runaway of a lithium ion battery harm occurs. Aerogels is the thermal conductivity of the lowest known solid material,insulation mats, insulation panels, thermal insulation properties of paper products up to as much as five times the norm, coupled with excellent fire retardant, soft impact, noise reduction and other functions, in addition to achieve good promotion in industrial energy efficiency, insulation and other civilian areas, but with the development of the industry airgel, airgel is also in the field of battery more and more widely. Single cell airgel insulation thermal runaway protection single cell is the source of the entire thermal runaway of the battery pack, because a single cell when thermal runaway is triggered, heat production will surge, far less than the amount of heat heat production, resulting in heat transfer to the surrounding batteries, then quickly lead to thermal runaway peripheral cell mass, form a security risk. Thus heat is an effective means of protection throughout the thermal runaway of the battery pack to eliminate safety hazards among batteries. ElectricityThermal protection between the core between the batteries is to increase the heat insulation layer, the thermal runaway to block uncontrolled propagation from single cell to the surrounding batteries, to reduce damage to the battery pack and the damage accompanying. Electrically insulating material between the monomers of the core, can effectively delay or as a single cell block thermal runaway A thermal protective material to the mass of the entire battery system, must meet the following conditions:. A flame retardant ( achieve V0 rating) b aging resistance, chemical stability;. c does not generate toxic gases;. d good elasticity, low thermal conductivity, waterproof anti-vibration;.. e lowest thin lightweight insulating material often used in current , advantages and disadvantages of foam, ultrafine Glass wool , high silica cotton, vacuum insulation panel, aerogels, and other insulating materials: having very low thermal conductivity airgel , researchers verified by experiment the protective effect of airgel insulation between the insulation board batteries monomer. 6Ah capacity of the composition by 20mm spacing module enclosure four 200mm insulating material, and increasing the thickness of 1cm airgel insulation panel (Figure 1) between the two monomers thermal runaway propagation experiment shows airgel separator in the single cell gap in the thermal protection of the blocking effect of thermal runaway. Experimental results show that the monomers A thermal runaway, next to the blank group without thermal protection monomer B quickly heated, thermal runaway, and the airgel insulation panel disposed between the monomer B monomers experiment the maximum temperature of only 110 ℃, successfully blocked the thermal runaway 6Ah monomer at 20mm spacing spread, and no uncontrolled cell voltage substantially constant for the single cell of the battery pack explosion threat of thermal runaway play a very good protection. In addition, due to its excellent heat insulating airgel flame retardant properties, it can be further reduced to reduce the distance between the safety monomers. To save even more space and improve overall battery power, airgel company has developed a series of high-performance ultra-thin airgel insulation panels, insulation paper products to cater to safety, high energy density requirements. Occur when the battery pack / protective case integrally lithium-ion battery thermal runaway accident, battery power system related to thermal runaway of the lithium ion battery cells between the guard addition, between the battery module and the battery box and the passenger cabin also required thermal protection provided toImprove the thermal resistance of the heat transfer to the thermal runaway batteries other battery systems, so as to achieve the purpose of hindering the spread of thermal runaway. In addition airgel mats having excellent thermal insulation, fire retardant properties, but also has a soft, performance can be arbitrarily cut, machined. The battery module may be used in various shapes, insulating shield between the passenger compartment and the battery case. Because the battery protection airgel heat discharge current density, long life storage, easily influenced by ambient temperature during operation characteristics, it is widely used in the field of thermal battery arms. From the JAS-39 light fighter life-saving emergency EAP-12188 uses battery power, GPS-9 battery on a remote global positioning artillery, AN on sonar buoys / SSQ-62 C batteries, to all kinds of missiles, you can see the shells the shadow of thermal batteries. The thermal battery operating temperature is generally between 450 \”C ~ 600\” C, the whole process depends on the initial discharge heat \”input\”, and the battery life is dependent on the discharge rate of the battery and the battery cooling freezing temperature. For long battery life hot key issue is to have a good insulating material . Airgel insulation blankets with extremely low thermal conductivity, the maximum temperature can reach 900-1100 ℃, airgel materials using a heat insulation tube as a battery cell thermally insulating layer may be a perfect solution aerospace, weapons areas of the heat battery of high performance, long-life requirements. With the development of industry in China airgel, airgel applications in the form of battery in the field will be more diverse range of applications from the earliest military hot cells spread to more areas of civilian batteries, such as new energy battery, insulation electronic equipment retardant protective lithium-ion batteries, the batteries and so on.