Ionic Liquids For Battery Additives

In recent years, due to excellent properties of ionic liquids, they have been gradually applied in the field of battery additives. Especially, ionic liquids using for battery additives can significantly improve the safety and electrical properties of batteries.

Applications:

• Electrolyte additive for colloidal battery: As a new kind of technology products, colloidal battery has huge advantages of environmental friendly, long service life, little self-discharge effect and low corrosion. Inside the structure of colloidal battery, the materials of electrolyte of a colloidal battery is colloidal. One unique feature of ionic liquids is that they have excellent ionic conductivity, so they can help improve the Ion exchange efficiency in colloidal batteries. Indeed, the cation of ionic liquid is usually chosen [BMIm]⁺ for its low viscosity, which is worked in colloidal battery electrolyte additives.
• Electrolyte additive for lithium ion battery: Lithium ion battery is high energy and environmental protection battery. Electrolyte has an important impact on the properties of lithium ion battery, such as the capacity, circulation, storage performance and so on. In fact, conventional electrolytes always destroy the structure of the graphite electrode and greatly reduce the battery cycle life. It is new way to add ionic liquid into electrolyte as an additive, which is not only to promote the formation of graphite anode film, but also to improve the safety and cycling performance of lithium battery. In summary, ionic liquids is one of the best choices as the electrolyte additive for lithium ion battery.

Figure 1. Ionic liquid used in lithium ion battery.

• Additive for perovskite solar cells: Perovskite solar cells are resource - saving and environment - friendly energy devices, and the only substance it needed is sunlight. In recent years, many researches have shown that, the preparation process of high quality and low defect perovskite crystal films is the key to obtain high efficiency perovskite battery devices. To keep the high quality of crystal films, ionic liquid additives is added during the preparation process. And by this way, more and more people finally prepare high quality perovskite crystal film, and they document it in details.

For example, the ionic liquid 1-ethylpyridine chloride has low boiling point, which can be used as an additive in the process of perovskite film. Research shows that the morphology of perovskite film can be effectively improved, and the roughness of perovskite film can be reduced. Moreover, the coverage rate of the film can be improved by regulating the content of the additive. Furthermore, the preparation method has the advantages of mild and controllable conditions, simple preparation method and low cost, which are suitable for large-scale commercial production.

Figure 2. Ionic liquid used in perovskite solar cell.

References

• Seckin Akin, Erdi Akman, Savas Sonmezoglu. FAPbI3‐Based Perovskite Solar Cells Employing Hexyl‐Based Ionic Liquid with an Efficiency Over 20% and Excellent Long‐Term Stability [J]. Advanced Functional Materials, 2020.
• Jiaxin Fan, Zhixiong Zhang, Yinhua Liu, Aiye Wang, Li Li and Wenhui Yuan. An excellent rechargeable PP14TFSI ionic liquid dual-ion battery[J]. Chemical Communications, 2017.