Molybdenum carbide nanostructures for electrocatalytic polysulfide conversion in lithium-polysulfide batteries.
Nanoscale Horiz
; 5(3): 501-506, 2020 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-32118217
ABSTRACT
Introduction of appropriate cathode electrocatalysts in lithium-sulfur or lithium-polysulfide batteries can accelerate the polysulfide interconversion and suppress the shuttle effect. However, improvements are often limited especially under high sulfur loading. Herein, we prepare molybdenum carbide nanostructures and investigate their potential as the cathode electrocatalyst for lithium-polysulfide batteries. The product is prepared by the self-polymerization of dopamine in the presence of Mo7O246- ions, followed by high-temperature carburization. It features ultrasmall α-MoC1-x nanoparticles uniformly dispersed on a hierarchical carbonaceous support. Polysulfide adsorption experiments and electrochemical measurements show that this material has a strong surface affinity toward polysulfides, and can greatly enhance their conversion rate, in particular the Li2S4â Li2S2/Li2S conversion. When assessed as the cathode electrocatalyst, it enables lithium-polysulfide batteries with large specific capacity (up to 1400 mA h g-1), impressive rate capability (800 mA h g-1 at 3200 mA g-1) and excellent cycling stability even at high sulfur loading.
Texto completo:
1
Bases de dados:
MEDLINE
Idioma:
En
Revista:
Nanoscale Horiz
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China