Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors

Yohan Dall’agnese (1, 2, 3) , Pierre-Louis Taberna (1, 2) , Yury Gogotsi (3) , Patrice Simon (1, 2)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 Drexel University

Ion capacitors store energy through intercalation of cations into an electrode at a faster rate than in batteries and within a larger potential window. These devices reach a higher energy density compared to electrochemical double layer capacitor. Li-ion capacitors are already produced commercially, but the development of Na-ion capacitors is hindered by lack of materials that would allow fast intercalation of Na-ions. Here we investigated the electrochemical behavior of 2D vanadium carbide, V2C, from the MXene family. We investigated the mechanism of Na intercalation by XRD and achieved capacitance of ∼100 F/g at 0.2 mV/s. We assembled a full cell with hard carbon as negative electrode, a known anode material for Na ion batteries, and achieved capacity of 50 mAh/g with a maximum cell voltage of 3.5 V.

Mots clés: Li-ion capacitor; MXene; Na-ion capacitor; vanadium carbide; XRD

Domaines: Génie chimique; Matériaux; Supraconductivité [cond-mat.supr-con]; Chimie-Physique [physics.chem-ph]

Yohan Dall’agnese, Pierre-Louis Taberna, Yury Gogotsi, Patrice Simon. Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors. Journal of Physical Chemistry Letters, 2015, vol. 6 (n° 12), pp. 2305-2309. ⟨10.1021/acs.jpclett.5b00868⟩. ⟨hal-01447700⟩