Cellulose Aerogel Film for High-safety Lithium-ion Battery Preparation
With the widespread use of lithium-ion batteries in mobile phones, computers, and new energy vehicles, the safety of lithium-ion batteries has received increasing attention. As an important component of lithium-ion batteries, separators have an important impact on the safety performance of batteries. The polyolefin battery separator currently used has the advantages of high strength and good chemical stability, but the polyolefin separator has the disadvantages of being easy to shrink at a high temperature and having poor affinity with an electrolyte, and is an important cause of a safety accident of a lithium ion battery.
Zhang Jun, a researcher from the Institute of Chemistry, Chinese Academy of Sciences, developed a transparent, flexible, and adjustable three-dimensional nanopore by regulating the regeneration process by using the most abundant cellulose in the natural world as a raw material and using a new environmentally friendly "ionic liquid" as a solvent. A convenient method of structure and high porosity cellulose aerogel. Based on this work, they recently used the three-dimensional nanopore structure in aerogel as a lithium ion transport channel to successfully apply the cellulose aerogel membrane to lithium ion batteries. The advantages are as follows:
Preparation of cellulose aerogel film (AmimCl is 1-allyl-3-methylimidazolium chloride ionic liquid)
The capillary effect of a large amount of hydroxyl groups on the molecular chain of cellulose and the nanoporous structure of cellulose aerogel membrane makes the cellulose aerogel membrane have strong affinity to the organic electrolyte, and can quickly absorb a large amount of organic electrolyte, and absorb The liquid rate can reach 325 %; the obtained cellulose-based gel polymer electrolyte can have an ionic conductivity of 2.81 mS/cm, which is much higher than that of a commercial separator;
A lithium ion battery assembled with a cellulose aerogel film has excellent cycle stability and high rate performance;
The unique heat resistance of cellulose gives good stability to the high temperature of cellulose-based lithium-ion battery separators, and the assembled lithium-ion battery can still work normally at 120 °C.
In addition, the presence of the three-dimensional nanopore structure helps prevent self-discharge and short-circuit of the lithium ion battery, and inhibits the formation of lithium dendrites.
Therefore, this natural and environmentally friendly cellulose aerogel membrane has potential applications in high-safety, high-performance lithium-ion batteries.