سداسي فلوروفوسفات الليثيوم

سداسي فلوروفوسفات الليثيوم
Lithium hexafluorophosphate.png
الأسماء
اسم أيوپاك
lithium hexafluorophosphate
المُعرِّفات
رقم CAS
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.040.289 Edit this at Wikidata
UNII
الخصائص
الصيغة الجزيئية LiPF6
كتلة مولية 151.905 g/mol
المظهر white powder
الكثافة 2.84 g/cm3
نقطة الانصهار
قابلية الذوبان في الماء soluble
المخاطر
صفحة بيانات السلامة External MSDS
ن.م.ع. مخطط تصويري مصوّر التآكل في النظام المنسق عالمياً لتصنيف وعنونة الكيماويات (GHS)
ن.م.ع. كلمة الاشارة DANGER
H314
P280, P305+P351+P338, P310
نقطة الوميض Non-flammable
مركبات ذا علاقة
Lithium tetrafluoroborate
Sodium hexafluorophosphate
Potassium hexafluorophosphate
Ammonium hexafluorophosphate
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
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مراجع الجدول

Lithium hexafluorophosphate is an inorganic compound with the formula LiPF6. It is a white crystalline powder.

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الانتاج

LiPF6 is manufactured by reacting phosphorus pentachloride with hydrogen fluoride and lithium fluoride[1] [2]

PCl5 + LiF + 5 HF → LiPF6 + 5 HCl

Suppliers include Targray and Morita Chemical Industries Co., Ltd.


الكيمياء

The salt is relatively stable thermally, but loses 50% weight at 200 °C (392 °F). It hydrolyzes near 70 °C (158 °F)[3] according to the following equation forming highly toxic HF gas:

LiPF6 + 4 H2O → LiF + 5 HF + H3PO4

Owing to the Lewis acidity of the Li+ ions, LiPF6 also catalyses the tetrahydropyranylation of tertiary alcohols.[4]

In lithium-ion batteries, LiPF6 reacts with Li2CO3, which may be catalysed by small amounts of HF:[5]

LiPF6 + Li2CO3 → POF3 + CO2 + 3 LiF

Application

The main use of LiPF6 is in commercial secondary batteries, an application that exploits its high solubility in polar aprotic solvents. Specifically, solutions of lithium hexafluorophosphate in carbonate blends of ethylene carbonate, dimethyl carbonate, diethyl carbonate and/or ethyl methyl carbonate, with a small amount of one or many additives such as fluoroethylene carbonate and vinylene carbonate, serve as state-of-the-art electrolytes in lithium-ion batteries.[6][7][8] This application takes advantage of the inertness of the hexafluorophosphate anion toward strong reducing agents, such as lithium metal, as well as of the ability of [PF6-] to passivate the positive aluminium current collector.[9]

References

  1. ^ Dunn, JB; Gaines, L; Barnes, M; Sullivan, J; Wang M (Sep 2014). "Material and Energy Flows in the Materials Production, Assembly, and End-of-Life Stages of the Automotive Lithium-Ion Battery Life Cycle". p. 28. Retrieved 5 December 2020.
  2. ^ O'Leary, Brian (11 May 2011). "High-Volume Manufacturing of LiPF6, A Critical Lithium-ion Battery Material" (PDF). p. 5. Retrieved 5 December 2020.
  3. ^ Xu, Kang (October 2004). "Nonaqueous Liquid Electrolytes for Lithium-Based Rechargeable Batteries". Chemical Reviews. 104 (10): 4303–4418. doi:10.1021/cr030203g. PMID 15669157. S2CID 33074301.
  4. ^ Nao Hamada; Sato Tsuneo (2004). "Lithium Hexafluorophosphate-Catalyzed Efficient Tetrahydropyranylation of Tertiary Alcohols under Mild Reaction Conditions". Synlett (10): 1802–1804. doi:10.1055/s-2004-829550.
  5. ^ Bi, Yujing; Wang, Tao; Liu, Meng; Du, Rui; Yang, Wenchao; Liu, Zixuan; Peng, Zhe; Liu, Yang; Wang, Deyu; Sun, Xueliang (2016). "Stability of Li2CO3 in cathode of lithium ion battery and its influence on electrochemical performance". RSC Advances. 6 (23): 19233–19237. Bibcode:2016RSCAd...619233B. doi:10.1039/C6RA00648E. ISSN 2046-2069.
  6. ^ Goodenough, John B.; Kim, Youngsik (9 February 2010). "Challenges for Rechargeable Li Batteries". Chemistry of Materials. 22 (3): 587–603. doi:10.1021/cm901452z.
  7. ^ Qian, Yunxian; Hu, Shiguang; Zou, Xianshuai; Deng, Zhaohui; Xu, Yuqun; Cao, Zongze; Kang, Yuanyuan; Deng, Yuanfu; Shi, Qiao; Xu, Kang; Deng, Yonghong (2019). "How electrolyte additives work in Li-ion batteries". Energy Storage Materials. 20: 208–215. doi:10.1016/j.ensm.2018.11.015. ISSN 2405-8297. S2CID 139865927.
  8. ^ Jow, T. Richard; Borodin, Oleg; Ue, Makoto; Xu, Kang (2014). Electrolytes for Lithium and Lithium-Ion Batteries. Springer: New York. ISBN 9781493903023.
  9. ^ Corrosion inhibition of aluminum current collector with molybdate conversion coating in commercial LiPF6-esters electrolytes. 2021. Corrosion Sci. 190/11. S.L. Yang, S.M. Li, Y.B. Meng, M. Yu, J.H. Liu, B. Li. doi: 10.1016/j.corsci.2021.109632.

قالب:Hexafluorophosphates