Open AccessFlexible Free‐Standing MoO 3 /Ti 3 C 2 T z MXene Composite Films with High Gravimetric and Volumetric Capacities
Author(s) -
Zheng Wei,
Halim Joseph,
El Ghazaly Ahmed,
Etman Ahmed S.,
Tseng Eric Nestor,
Persson Per O. Å.,
Rosen Johanna,
Barsoum Michel W.
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202003656
Subject(s) - gravimetric analysis , materials science , electrode , electrochemistry , composite number , capacitor , chemical engineering , nanotechnology , energy storage , analytical chemistry (journal) , composite material , voltage , electrical engineering , chemistry , organic chemistry , power (physics) , physics , quantum mechanics , engineering
Enhancing both the energy storage and power capabilities of electrochemical capacitors remains a challenge. Herein, Ti 3 C 2 T z MXene is mixed with MoO 3 nanobelts in various mass ratios and the mixture is used to vacuum filter binder free, open, flexible, and free‐standing films. The conductive Ti 3 C 2 T z flakes bridge the nanobelts, facilitating electron transfer; the randomly oriented, and interconnected, MoO 3 nanobelts, in turn, prevent the restacking of the Ti 3 C 2 T z nanosheets. Benefitting from these advantages, a MoO 3 /Ti 3 C 2 T z film with a 8:2 mass ratio exhibits high gravimetric/volumetric capacities with good cyclability, namely, 837 C g −1 and 1836 C cm −3 at 1 A g −1 for an ≈ 10 µm thick film; and 767 C g −1 and 1664 C cm −3 at 1 A g −1 for ≈ 50 µm thick film. To further increase the energy density, hybrid capacitors are fabricated with MoO 3 /Ti 3 C 2 T z films as the negative electrodes and nitrogen‐doped activated carbon as the positive electrodes. This device delivers maximum gravimetric/volumetric energy densities of 31.2 Wh kg −1 and 39.2 Wh L −1 , respectively. The cycling stability of 94.2% retention ratio after 10 000 continuous charge/discharge cycles is also noteworthy. The high energy density achieved in this work can pave the way for practical applications of MXene‐containing materials in energy storage devices.