Non-negligible Influence of Oxygen in Hard Carbon as an Anode Material for Potassium-Ion Batteries.
ACS Appl Mater Interfaces
; 14(42): 47674-47684, 2022 Oct 26.
Article
en En
| MEDLINE
| ID: mdl-36223510
ABSTRACT
The development of potassium-ion batteries (PIBs) has been impeded by the lack of an appropriate carbon anode material that could accommodate K+ with a large ionic radius. Hard carbon with low cost and larger interlayer spacing is a promising anode material for PIBs. However, the impact of oxygen-containing functional groups in hard carbon (HC) is less reported. Herein, a hypercrosslinked polymer (HCLP) is prepared and used for the synthesis of microporous hard carbons with superior structural stability and abundant oxygen-containing functional groups and defects, in which the crosslinking agent provided copious oxygen atoms. It is found that a large number of CâO groups and micropores provide more storage sites for K+. The surface-controlled process is dominated by the reversible reaction of CâO + K+ + e- â C-O-K, which directly increases the capacity contribution. The HCs obtained at 600 °C exhibit good cycling and rate performance with an initial specific capacity of about 254.3 mAh g-1 and the capacity retention of 83.2% after 200 cycles at 50 mA g-1. The capacity reached up to 121 mAh g-1 at 2 A g-1. A possible capacitive-adsorption mechanism is proposed by kinetic analysis. The redox reaction mechanism between CâO and K+ at the HC is clearly also revealed.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
ACS Appl Mater Interfaces
Asunto de la revista:
BIOTECNOLOGIA
/
ENGENHARIA BIOMEDICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
China