| DOI | Trouver le DOI : https://doi.org/10.1039/c4ta00993b |
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| Auteur | Rechercher : Kohandehghan, A.1; Rechercher : Cui, K.2; Rechercher : Kupsta, M.2; Rechercher : Memarzadeh, E.1; Rechercher : Kalisvaart, P.2; Rechercher : Mitlin, D.2 |
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| Affiliation | - Conseil national de recherches du Canada. Institut national de nanotechnologie
- Conseil national de recherches du Canada. Technologies de sécurité et de rupture
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| Format | Texte, Article |
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| Résumé | We demonstrate that a thin partially dewetted coating of Sn will improve the cycling performance of silicon nanowire (SiNWs) lithium ion battery (LIB) anodes. The optimum architecture 3Sn/SiNWs (i.e. a Sn layer with an average film thickness of a 3 nm covering the nanowire) maintained a reversible capacity of 1865 mA h g-1 after 100 cycles at a rate of 0.1 C. This is almost double of the baseline uncoated SiNWs, where the reversible capacity after 100 cycles was 1046 mA h g-1 (∼78% improvement). The 1Sn/SiNWs and 3Sn/SiNWs electrodes demonstrated much improved cycling coulombic efficiency, with >99% vs. 94-98% for the baseline. At a high current density of 5 C, these nanocomposite offered 2× the capacity retention of bare SiNWs (∼20 vs. ∼10% of 0.1 C capacity). It is demonstrated that the Sn coating both lithiates and delithiates at a higher voltage than Si and thus imparts a compressive stress around the nanowires. This confines their radial expansion in favor of longitudinal, and reduces the well-known failure mode by lithiation-induced nanowire stranding and fracture. TOF-SIMS analysis on the post-cycled delithiated specimens shows enhanced Li signal near the current collector due to accelerated SEI formation at the interface. FIB demonstrates concurrent en-masse delamination of SEI agglomerated sections of the nanowires from the current collector. Both of these deleterious effects are lessened by the presence of the Sn coatings. © 2014 the Partner Organisations. |
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| Date de publication | 2014-05-28 |
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| Dans | |
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| Langue | anglais |
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| Publications évaluées par des pairs | Oui |
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| Numéro NPARC | 21272311 |
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| Exporter la notice | Exporter en format RIS |
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| Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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| Identificateur de l’enregistrement | 2614f7f3-7c67-4769-a71f-11712ed64bb4 |
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| Enregistrement créé | 2014-07-24 |
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| Enregistrement modifié | 2020-04-22 |
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