Si-decorated graphene: a superior media for lithium-ions storage

Autor: Mahdi Ardjmand, Masoud Darvish Ganji, N. Sharifi, Morteza Ghorbanzadeh Ahangari
Rok vydání: 2012
Předmět:
Zdroj: Structural Chemistry. 24:1473-1483
ISSN: 1572-9001
1040-0400
DOI: 10.1007/s11224-012-0183-z
Popis: The characteristics of lithium adsorption on Si-decorated graphene are investigated using first-principles density functional theory calculations. It is found that the Si atom is strongly adsorbed at the bridge site of the C–C bond with binding energy of about −26.75 kcal/mol. We show that Si decorating turns Si:graphene complex into an electron-deficient system and significantly enhances the Li-storage capacity on the graphene. The obtained results indicate that up to eight Li-ions being adsorbed onto the Si-decorated graphene can form the stable complex. It is found, interestingly, that two Si atoms coated onto double-side of the graphene can strongly adsorb sixteen Li-ions. The analyses of electronic structures show a strong interaction between Li-ions and Si-decorated graphene leading to a high exothermicity. The stability of the sixteen Li-ions adsorbed on the Si:graphene system was evaluated with ab initio molecular dynamics simulation which have been carried out at room temperature. Our first-principles results are relevant to identify the potential applications of Si-decorated graphene as superior media for Li-ions storage.
Databáze: OpenAIRE
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