Simultaneous intercalation of lithium, potassium and strontium into graphite in molten salts medium

Inass El Hajj (1) , Lucie Speyer (1) , Sebastien Cahen (1) , Pascal Berger (2) , Ghouti Medjahdi (1) , Philippe Lagrange (1) , Claire Hérold (1)

1 IJL - Institut Jean Lamour
2 LEEL - UMR 3685 - Laboratoire d'Etudes des Eléments Légers

The LiCl-KCl molten salts method has been used in order to intercalate strontium into graphite. Combination of X-Ray Diffraction (XRD) experiments and ion beam analyses attests the obtaining of a monophasic sample. Its chemical composition corresponds to the Li 0.2 K 0.6 Sr 0.4 C 6 formula, revealing the synthesis of a quaternary Graphite Intercalation Compound (GIC), in agreement with the high repeat distance of 640 pm determined from its 00 l XRD and with the 1D electronic density profile. The very high-quality data obtained by hk 0 diffraction and rotating crystal method lead to a 2D organization of the intercalated sheet described by a large hexagonal unit cell containing 78 carbon atoms. Such quaternary phase including simultaneously alkali and alkaline-earth metals is unique and can only be prepared from molten salts method, opening new perspectives concerning graphite-based two-dimensional materials.

Keywords: Graphite intercalation compound; molten salts; 2D materials; alkaline-earth metal; XRD; nuclear microprobe

Domains: Material chemistry

Inass El Hajj, Lucie Speyer, Sebastien Cahen, Pascal Berger, Ghouti Medjahdi, et al.. Simultaneous intercalation of lithium, potassium and strontium into graphite in molten salts medium. Journal of Solid State Chemistry, 2023, 320, pp.123824. ⟨10.2139/ssrn.4243745⟩. ⟨cea-03874442⟩