Sunday, 13 October 2019: 09:40
Room 217 (The Hilton Atlanta)
L. Caracciolo (IPREM UMR5254 - E2S UPPA/CNRS), G. Gachot (LRCS - Univ. Picardie, RS2E), V. Gabaudan (ICG-AIME, Université Montpellier 2, RS2E), E. Petit (CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB UMR 5026, RS2E), L. Stievano (Université de Montpellier, UMR CNRS 5253, RS2E), L. Monconduit (ICG-AIME, Université Montpellier 2, RS2E), H. Martinez, and L. Madec (IPREM UMR5254 - E2S UPPA/CNRS, RS2E)
Developing batteries based on Earth abundant elements such as sodium, magnesium or more recently potassium has become a mandatory challenge in the context of renewable energy growth that requires large-scale storage systems for which cost is the dominant factor and lithium supply a possible issue. Due to the beneficial potassium abundance (2.09 wt.% of the Earth’s crust), low standard potential of K
+/K,
1 weaker K
+ Lewis acidity,
2 K-ion batteries (KIBs) are expected to greatly favor both the energy and power density compared to NIB. Numerous new materials for KIBs have thus rapidly been proposed
3 but their performance evaluation still remains greatly limited by the lack of efficient electrolytes and the high reactivity of K metal in half cells.
4 Indeed, the use of KN(SO
2F)
2 (KFSI) instead of KPF
6 have been reported to be beneficial to most of the anode materials
5 while detrimental to some cathode materials,
6 probably due to the corrosion of Al current collector by KFSI at high potential.
In this presentation, the impact of KPF6 and KFSI salts in carbonate- and glyme-based electrolytes is investigated. The reactivity of K metal is first evaluated by its immersion in the different electrolytes. The soluble/gaseous and solid electrolyte degradation species are analyzed using GC/MS and XPS, respectively. A comparison with the reactivity of Li metal in the equivalent Li salts based electrolyte is also performed. Moreover, K//graphite and K//KVPO4F half-cells have also been prepared and stored (no cycling) to investigate interactions between electrodes (i.e. migration of electrolyte degradation species from the K metal to the working electrode) and their impact in solid electrolyte interphases formation and resulting electrochemical performance.
References
- N. Matsuura, K. Umemoto, and Z. Takeuchi, Bull. Chem. Soc. Jpn., 47, 813–817 (1974).
- M. Okoshi, Y. Yamada, S. Komaba, A. Yamada, and H. Nakai, J. Electrochem. Soc., 164, A54–A60 (2017).
- K. Kubota, M. Dahbi, T. Hosaka, S. Kumakura, and S. Komaba, Chem. Rec., 18, 1–22 (2018).
- L. Madec, V. Gabaudan, G. Gachot, L. Stievano, L. Monconduit, and H. Martinez, ACS Appl. Mater. Interfaces, 10, 34116–34122 (2018).
- N. Xiao, W. D. McCulloch, and Y. Wu, J. Am. Chem. Soc., 139, 9475–9478 (2017).
- X. Jiang, T. Zhang, L. Yang, G. Li, and J. Y. Lee, ChemElectroChem, 4, 2237–2242 (2017).
