Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors.
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.
†Université Paul Sabatier, CIRIMAT UMR CNRS 5085, 118 route de Narbonne, 31062 Toulouse, France.|‡Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 33 rue Saint Leu, 80039 Amiens Cedex, France.|§Department of Materials Science and Engineering and A. J. Drexel Nanomaterials Institute, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
Yohan
Y
Dall'Agnese
†Université Paul Sabatier, CIRIMAT UMR CNRS 5085, 118 route de Narbonne, 31062 Toulouse, France.|‡Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 33 rue Saint Leu, 80039 Amiens Cedex, France.
Pierre-Louis
PL
Taberna
§Department of Materials Science and Engineering and A. J. Drexel Nanomaterials Institute, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
Yury
Y
Gogotsi
†Université Paul Sabatier, CIRIMAT UMR CNRS 5085, 118 route de Narbonne, 31062 Toulouse, France.|‡Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 33 rue Saint Leu, 80039 Amiens Cedex, France.
Patrice
P
Simon
Li-ion capacitor; MXene; Na-ion capacitor; XRD; vanadium carbide