Potassium hexafluorophosphate

Description

Potassium hexafluorophosphate, abbreviated as KPF₆, is a associated electrolyte. In battery systems, it acts as an electrolyte additive in anode-less lithium metal batteries, lithium-sulphur batteries and solid-state batteries; by forming a protective shielding effect and modulating the solid-state electrolyte interface, it enhances cycling stability, ionic conductivity and electrochemical performance [1-3]. In perovskite solar cells, KPF₆ is used as an interface modification material; by treating the SnO₂ quantum dot/perovskite interface, it can passivate defects and enhance stable photoconversion efficiency [4].

Chemical Properties

white crystalline powder

Uses

Potassium Hexafluorophosphate is used in preparation of Moxifloxacin derivatives and its application.

Uses

A soluble neutral salt, Potassium hexafluorophosphate can be used for synthesis.

Preparation

Potassium hexafluorophosphate is prepared by reacting phosphorus pentachloride, potassium chloride, and hydrofluoric acid in liquid hydrogen fluoride. The reaction equation is: PCl₅ + KCl + 6HF → KPF₆ + 6HCl.

Hazard

Toxic by ingestion.

Purification Methods

Crystallise it from alkaline aqueous solution, using polyethylene vessels, or from 95% EtOH, and dry it in a vacuum desiccator over KOH. [Kloditz Z Anorg Allgem Chem 284 144 1956, Kwasnik in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 196 1963.]

References

[1] Hagos, T. M., Berhe, G. B., Hagos, T. T., Bezabh, H. K., Abrha, L. H., Beyene, T. T., Huang, C.-J., Yang, Y.-W., Su, W.-N., Dai, H., Hwang, B.-J. (2019). Dual electrolyte additives of potassium hexafluorophosphate and tris (trimethylsilyl) phosphite for anode-free lithium metal batteries. Electrochimica Acta, 316, 52–59. https://doi.org/10.1016/j.electacta.2019.05.061
[2] Li, J., Liu, S., Cui, Y., Zhang, S., Wu, X., Xiang, J., Li, M., Wang, X., Xia, X., Gu, C., Tu, J. (2020). Potassium Hexafluorophosphate Additive Enables Stable Lithium–Sulfur Batteries. ACS Applied Materials & Interfaces, 12(50), 56017–56026. https://doi.org/10.1021/acsami.0c17406
[3] Li, J., Liang, J., Ren, Z., Shi, C., Li, Y., Zhang, L., Zhang, Q., He, C., Ren, X. (2022). Insights of potassium hexafluorophosphate additive in solid polymer electrolyte for realizing high performance all-solid-state lithium metal batteries. Electrochimica Acta, 429, 141061. https://doi.org/10.1016/j.electacta.2022.141061
[4] Wang, Z., Wu, T., Xiao, L., Qin, P., Yu, X., Ma, L., Xiong, L., Li, H., Chen, X., Wang, Z., Wu, T., Xiao, M. L., Qin, P., Yu, D. X., Ma, D. L., Xiong, D. L., Li, D. H., Chen, X. (2021). Multifunctional potassium hexafluorophosphate passivate interface defects for high efficiency perovskite solar cells. Journal of Power Sources, 488, 229451. https://doi.org/10.1016/j.jpowsour.2021.229451