| DOI | Resolve DOI: https://doi.org/10.1039/c4ta00993b |
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| Author | Search for: Kohandehghan, A.1; Search for: Cui, K.2; Search for: Kupsta, M.2; Search for: Memarzadeh, E.1; Search for: Kalisvaart, P.2; Search for: Mitlin, D.2 |
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| Affiliation | - National Research Council of Canada. National Institute for Nanotechnology
- National Research Council of Canada. Security and Disruptive Technologies
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| Format | Text, Article |
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| Abstract | 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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| Publication date | 2014-05-28 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 21272311 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 2614f7f3-7c67-4769-a71f-11712ed64bb4 |
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| Record created | 2014-07-24 |
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| Record modified | 2020-04-22 |
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