Tuning the morphology of sulfur-few layer graphene composites via liquid phase evaporation for battery application.
Nanoscale Adv
; 4(4): 1136-1144, 2022 Feb 15.
Article
em En
| MEDLINE
| ID: mdl-36131758
ABSTRACT
A comparative study on sulfur-based composite electrodes comprising different few-layer graphene contents prepared via a facile evaporation method is presented here. The active material production process employed here, exploring different sulfur-few layer graphene ratios, enabled tuning and optimization of the sample morphology, as confirmed via a scanning electron microscopy study. The results reveal that the graphene content is a crucial parameter yielding an optimized morphology of spherical particles composed of an elemental sulfur inner core covered by the carbonaceous compound. The electrodes are characterized in lithium metal half-cells in terms of cyclic voltammetry, galvanostatic cycling tests, rate capability and electrochemical impedance spectroscopy. Moreover, the lithium-ion diffusion coefficients of each sample are obtained by the Randles-Sevcik equation in order to evaluate the reliability of the electrochemical processes. The lithium metal half-cell with the sulfur carbon composite active material exploiting a spherical particle morphology delivers a high specific capacity of 950 mA h g-1 after 100 cycles at C/4 with a coulombic efficiency of 98%. An optimized sample, tuned in terms of sulfur content and morphology, shows superior performance, exhibiting capacities of 1128 mA h g-1 and 842 mA h g-1 over 80 cycles at C/4 and 2C, respectively.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nanoscale Adv
Ano de publicação:
2022
Tipo de documento:
Article