Electrochemical Phase Evolution of Metal-Based Pre-Catalysts for High-Rate Polysulfide Conversion.
Angew Chem Int Ed Engl
; 59(23): 9011-9017, 2020 Jun 02.
Article
en En
| MEDLINE
| ID: mdl-32203631
ABSTRACT
Inâ
situ evolution of electrocatalysts is of paramount importance in defining catalytic reactions. Catalysts for aprotic electrochemistry such as lithium-sulfur (Li-S) batteries are the cornerstone to enhance intrinsically sluggish reaction kinetics but the true active phases are often controversial. Herein, we reveal the electrochemical phase evolution of metal-based pre-catalysts (Co4 N) in working Li-S batteries that renders highly active electrocatalysts (CoSx ). Electrochemical cycling induces the transformation from single-crystalline Co4 N to polycrystalline CoSx that are rich in active sites. This transformation propels all-phase polysulfide-involving reactions. Consequently, Co4 N enables stable operation of high-rate (10â
C, 16.7â
mA cm-2 ) and electrolyte-starved (4.7â
µL mgS -1 ) Li-S batteries. The general concept of electrochemically induced sulfurization is verified by thermodynamic energetics for most of low-valence metal compounds.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2020
Tipo del documento:
Article
Pais de publicación:
ALEMANHA
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ALEMANIA
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DE
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DEUSTCHLAND
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GERMANY