Opening mechanism of closed graphitized tips via low-temperature surface fluorination : interest for electrochemical storage

Henri Groult (1) , Tsuyoshi Nakajima (2) , A. Tressaud (3) , Seiko Shibata (2) , Etienne Durand (3) , Laurent Perrigaud (1) , Fabienne Warmont (4)

1 LI2C - Liquides Ioniques et Interfaces Chargées
2 AIT - Aichi Institute of Technology
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
4 CRMD - Centre de Recherche sur la Matière Divisée

When treated at high temperatures, petroleum coke materials exhibit structures which are formed of graphitized closed tips. The external surface of these materials is mostly formed of hemispherical tips similar to those found in carbon nanotubes. By low-temperature fluorination using radio-frequency plasmas, an opening mechanism of the closed tips occurs, thus allowing a drastic increase of possible intercalation into the structure. The interest for storage in Li-ion batteries has been demonstrated by capacity measurements which show an enhancement of the capacity retention into the host materials.

Domaines: Chimie-Physique [physics.chem-ph]

Henri Groult, Tsuyoshi Nakajima, A. Tressaud, Seiko Shibata, Etienne Durand, et al.. Opening mechanism of closed graphitized tips via low-temperature surface fluorination : interest for electrochemical storage. Electrochemical and Solid-State Letters, 2007, 10 (9), pp.A212-A215. ⟨10.1149/1.2752476⟩. ⟨hal-00165347⟩