Preparation of a Si/SiO2 -Ordered-Mesoporous-Carbon Nanocomposite as an Anode for High-Performance Lithium-Ion and Sodium-Ion Batteries.
Chemistry
; 24(19): 4841-4848, 2018 Apr 03.
Article
em En
| MEDLINE
| ID: mdl-29194824
ABSTRACT
In this work, an Si/SiO2 -ordered-mesoporous carbon (Si/SiO2 -OMC) nanocomposite was initially fabricated through a magnesiothermic reduction strategy by using a two-dimensional bicontinuous mesochannel of SiO2 -OMC as a precursor, combined with an NaOH etching process, in which crystal Si/amorphous SiO2 nanoparticles were encapsulated into the OMC matrix. Not only can such unique porous crystal Si/amorphous SiO2 nanoparticles uniformly dispersed in the OMC matrix mitigate the volume change of active materials during the cycling process, but they can also improve electrical conductivity of Si/SiO2 and facilitate the Li+ /Na+ diffusion. When applied as an anode for lithium-ion batteries (LIBs), the Si/SiO2 -OMC composite displayed superior reversible capacity (958â
mA h g-1 at 0.2â
A g-1 after 100â
cycles) and good cycling life (retaining a capacity of 459â
mA h g-1 at 2â
A g-1 after 1000â
cycles). For sodium-ion batteries (SIBs), the composite maintained a high capacity of 423â
mA h g-1 after 100â
cycles at 0.05â
A g-1 and an extremely stable reversible capacity of 190â
mA h g-1 was retained even after 500â
cycles at 1â
A g-1 . This performance is one of the best long-term cycling properties of Si-based SIB anode materials. The Si/SiO2 -OMC composites exhibited great potential as an alternative material for both lithium- and sodium-ion battery anodes.
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MEDLINE
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Ano de publicação:
2018
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Article