Mott-Schottky MXene@WS2 Heterostructure: Structural and Thermodynamic Insights and Application in Ultra Stable Lithium-Sulfur Batteries.
ChemSusChem
; 16(19): e202300507, 2023 Oct 06.
Article
en En
| MEDLINE
| ID: mdl-37314096
ABSTRACT
Due to the "shuttle effect" and low conversion kinetics of polysulfides, the cycle stability of lithium sulfur (Li-S) battery is unsatisfactory, which hinders its practical application. The Mott-Schottky heterostructures for Li-S batteries not only provide more catalytic/adsorption active sites, but also facilitate electrons transport by a built-in electric field, which are both beneficial for polysulfides conversion and long-term cycle stability. Here, MXene@WS2 heterostructure was constructed by in-situ hydrothermal growth for separator modification. In-depth ultraviolet photoelectron spectroscopy and ultraviolet visible diffuse reflectance spectroscopy analysis reveals that there is an energy band difference between MXene and WS2 , confirming the heterostructure nature of MXene@WS2 . DFT calculations indicate that the Mott-Schottky MXene@WS2 heterostructure can effectively promote electron transfer, improve the multi-step cathodic reaction kinetics, and further enhance polysulfides conversion. The built-in electric field of the heterostructure plays an important role in reducing the energy barrier of polysulfides conversion. Thermodynamic studies reveal the best stability of MXene@WS2 during polysulfides adsorption. As a result, the Li-S battery with MXene@WS2 modified separator exhibits high specific capacity (1613.7â
mAh g-1 at 0.1â
C) and excellent cycling stability (2000 cycles with 0.0286 % decay per cycle at 2â
C). Even at a high sulfur loading of 6.3â
mg cm-2 , the specific capacity could be retained by 60.0 % after 240 cycles at 0.3â
C. This work provides deep structural and thermodynamic insights into MXene@WS2 heterostructure and its promising prospect of application in high performance Li-S batteries.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
ChemSusChem
Asunto de la revista:
QUIMICA
/
TOXICOLOGIA
Año:
2023
Tipo del documento:
Article