Lithium ion battery applications: Advantages cellulose airgel film have?
With the widespread use of lithium-ion batteries in cell phones, computers and new energy vehicles, the safety of lithium-ion batteries more and more people\’s attention. As an important part the separator of a lithium ion battery, for battery safety have a significant impact. Now the polyolefin material used in the battery separator having high strength, chemical stability, etc., but the presence of the polyolefin separator at a high temperature is easy to shrink, with the disadvantage of poor affinity with the electrolytic solution, it is an important cause of accidents of the lithium ion battery. Zhang Institute of Chemistry Research Group at the largest nature reservesas raw materials, the new green \”ionic liquid\” as the solvent, by regulating the development of regeneration process preparing a transparent, flexible, three-dimensional apertures having adjustable cellulose structure and easy way high porosity aerogels. Based on this work, they use the latest three-dimensional pore structure of the airgel a lithium ion transmission channel, is successfully applied to a lithium-ion battery, its advantages are as follows: ▲ gas cellulose preparing a gel membrane (AmimCl 1-allyl-3-methyl-imidazolium chloride ionic liquid) many hydroxyl groups on the cellulose molecular chains and the capillary effect of the cellulose film nanoporous airgel structure, gas cellulose gel film has a high affinity for the organic electrolytic solution, and can quickly absorb large quantities of organic electrolyte, absorbent rate of 325%; obtained cellulose-based ionic conductivity gel polymer electrolyte up to 2.81 mS / cm, much higher than the commercial membrane; cellulose airgel film assembled lithium ion battery having excellent high rate performance and cycle stability; cellulose unique heat resistance imparting good cellulose-based lithium-ion high temperature battery separator stability, resulting assembled lithium ion battery can still work normally under 120 ℃. ▲ FIG surface morphology is typical of a cellulose airgel film b for FIG fracture surface ▲ FIG as a battery separator LiFePO4 // // Li half-cycle performance of the battery, b in FIG. its rate capability (Celgard 2400 separator is a polyolefin commercial) Further, the presence of three-dimensional pore structure helps to prevent lithium ion batteries self-discharge and a short circuit occurs, inhibit the formation of lithium dendrites. Thus, this natural origin, green cellulose airgel film is high security, high performance lithium ion batteries have potential applications.