Self-supported carbon nanofibers as negative electrodes for K-ion batteries: Performance and mechanism

Justine Touja (1, 2) , Vincent Gabaudan (1, 2) , Filippo Farina (1) , Sara Cavaliere (1, 3) , Laure Caracciolo (4, 2) , Lénaïc Madec (4, 2) , Hervé Martinez (4, 5) , Athmane Boulaoued (6) , Joachim Wallenstein (6) , Patrik Johansson (6, 7) , Lorenzo Stievano (8, 5, 7) , Laure Monconduit (8, 5, 7)

1 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 IUF - Institut universitaire de France
4 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
5 RS2E - Réseau sur le stockage électrochimique de l'énergie
6 Chalmers University of Technology [Göteborg]
7 ALISTORE-ERI - Advanced Lithium Energy Storage Systems - ALISTORE-ERI
8 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

Self-standing carbon nanofibers (CNF) were electrospun and tested in K-ion batteries (KIB). The comparison of the electrochemical performance of KIB using potassium bis(fluorosulfonyl)imide (KFSI) and potassium hexafluorophosphate (KPF6) carbonate-based electrolytes revealed that, despite the coulombic efficiency is more readily stabilized with KFSI than with KPF6, the long-term cycling is quite the same, with a specific capacity of 200 mAh.g−1 for the CNF electrode. Post-mortem X-ray photoelectron spectroscopy analysis shows a more stable solid electrolyte interphase (SEI) for KIB employing KFSI. Finally, the K+ ion storage mechanism was investigated by combining cyclic voltammetry and operando Raman spectroscopy, showing a combination of adsorption and intercalation processes.

Domaines: Matériaux

Justine Touja, Vincent Gabaudan, Filippo Farina, Sara Cavaliere, Laure Caracciolo, et al.. Self-supported carbon nanofibers as negative electrodes for K-ion batteries: Performance and mechanism. Electrochimica Acta, 2020, 362, pp.137125. ⟨10.1016/j.electacta.2020.137125⟩. ⟨hal-02956561⟩