| 1. |
- Halim, Joseph, et al.
(författare)
-
Synthesis and Characterization of 2D Molybdenum Carbide (MXene)
- 2016
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 26:18, s. 3118-3127
-
Tidskriftsartikel (refereegranskat)abstract
- Large scale synthesis and delamination of 2D Mo2CTx (where T is a surface termination group) has been achieved by selectively etching gallium from the recently discovered nanolaminated, ternary transition metal carbide Mo2Ga2C. Different synthesis and delamination routes result in different flake morphologies. The resistivity of free-standing Mo2CTx films increases by an order of magnitude as the temperature is reduced from 300 to 10 K, suggesting semiconductor-like behavior of this MXene, in contrast to Ti3C2Tx which exhibits metallic behavior. At 10 K, the magnetoresistance is positive. Additionally, changes in electronic transport are observed upon annealing of the films. When 2 mu m thick films are tested as electrodes in supercapacitors, capacitances as high as 700 F cm(-3) in a 1 M sulfuric acid electrolyte and high capacity retention for at least 10,000 cycles at 10 A g(-1) are obtained. Free-standing Mo2CTx films, with approximate to 8 wt% carbon nanotubes, perform well when tested as an electrode material for Li-ions, especially at high rates. At 20 and 131 C cycling rates, stable reversible capacities of 250 and 76 mAh g(-1), respectively, are achieved for over 1000 cycles.
|
|
| 2. |
- Kalnaus, Sergiy, et al.
(författare)
-
Multifunctional approaches for safe structural batteries
- 2021
-
Ingår i: Journal of Energy Storage. - : Elsevier BV. - 2352-152X. ; 40
-
Forskningsöversikt (refereegranskat)abstract
- Recent advancements in Li and Li-ion based energy storage resulted in development of novel electrode materials for higher energy density which are finding their applications in transportation. There appears to be a limitation in improvement of specific energy of the system based solely on design of material compositions for multivalent intercalation compounds. In addition, higher energy stored by the system implies need for addressing safety concerns especially when it comes to large automotive battery packs. New approaches for improvement of both energy density and safety of batteries are emerging, where multifunctionality of the materials and/or architectures is utilized. This article presents a review for such approaches from multifunctional current collectors to design of batteries capable of supporting mechanical loads and thus possessing ability to be used as a structural component.
|
|
| 3. |
- Yang, Jian, et al.
(författare)
-
Two-Dimensional Nb-Based M4C3 Solid Solutions (MXenes)
- 2016
-
Ingår i: Journal of The American Ceramic Society. - : WILEY-BLACKWELL. - 0002-7820 .- 1551-2916. ; 99:2, s. 660-666
-
Tidskriftsartikel (refereegranskat)abstract
- Herein, two new two-dimensional Nb4C3-based solid solutions (MXenes), (Nb-0.8,Ti-0.2)(4)C3Tx and (Nb-0.8,Zr-0.2)(4)C3Tx (where T is a surface termination) were synthesizedas confirmed by X-ray diffractionfrom their corresponding MAX phase precursors (Nb-0.8,Ti-0.2)(4)AlC3 and (Nb-0.8,Zr-0.2)(4)AlC3. This is the first report on a Zr-containing MXene. Intercalation of Li ions into these two compositions, and Nb4C3Tx was studied to determine the potential of those materials for energy storage applications. Lithiation and delithiation peaks at 2.26 and 2.35 V, respectively, appeared in the case of Nb4C3Tx, but were not present in Nb2CTx. After 20 cycles at a rate of C/4, the specific capacities of (Nb-0.8,Ti-0.2)(4)C3Tx and (Nb-0.8,Zr-0.2)(4)C3Tx were 158 and 132 mAh/g, respectively, both slightly lower than the capacity of Nb4C3Tx.
|
|
