Enhancing the Electrochemical Performance of Sodium-Ion Batteries by Building Optimized NiS2 /NiSe2 Heterostructures.
Small
; 17(45): e2104186, 2021 Nov.
Article
en En
| MEDLINE
| ID: mdl-34622576
ABSTRACT
NiS1.23 Se0.77 nanosheets closely attached to the internal surface of hollow mesoporous carbon sphere (HMCS) to form a NiS1.23 Se0.77 nanosheets embedded in HMCS (NSSNs@HMCS) composite as the anode of sodium ion batteries (SIBs) is reported by a facile synthesis route. The anode exhibits a superior reversible capacity (520 mAh g-1 at 0.1 A g-1 ), impressive coulombic efficiency (CE) of up to 95.3%, a high rate capacity (353 mAh g-1 at 5.0 A g-1 ), excellent capacity retention at high current density (95.6%), and high initial coulombic efficiency (ICE) (95.1%). Firstly, the highest ICE for NiS2 /NiSe2 -based anode can be ascribed to ultrathin layered structure of NiS1.23 Se0.77 nanosheet and highly efficient electron transfer between the active material and HMCS. Secondly, the optimized NiS2 /NiSe2 heterostructure at the nanoscale of the inside HMCS is formed after the first discharge/charge cycles, which can provide rich heterojunction interfaces/boundaries of sulfide/selenides to offer faster Na+ pathways, decrease the Na+ diffusion barriers, increase electronic conductivity, and limit the dissolution of polysulfides or polyselenides in the electrolyte. Finally, the hollow structure of the HMCS accommodates the volume expansion, prevents the pulverization and aggregation issues of composite materials, which can also promote outstanding electrochemical performance.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Small
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2021
Tipo del documento:
Article