Tunable Core–Shell Nanowire Active Material for High Capacity Li-Ion Battery Anodes Comprised of PECVD Deposited aSi on Directly Grown Ge Nanowires
| Autor: | Hugh Geaney, Kevin M. Ryan, Wil Boonen, Killian Stokes, Tadhg Kennedy, Dana Borsa |
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| Rok vydání: | 2019 |
| Předmět: |
Battery (electricity)
Amorphous silicon Materials science business.industry Nanowire chemistry.chemical_element High capacity Germanium 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Anode Ion chemistry.chemical_compound chemistry Plasma-enhanced chemical vapor deposition Optoelectronics General Materials Science 0210 nano-technology business |
| Zdroj: | ACS Applied Materials & Interfaces. 11:19372-19380 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.9b03931 |
| Popis: | Herein, we report the formation of core@shell nanowires (NWs) comprised of crystalline germanium NW cores with amorphous silicon shells (Ge@aSi) and their performance as a high capacity Li-ion battery anode material. The Ge NWs were synthesized directly from the current collector in a solvent vapor growth (SVG) system and used as hosts for the deposition of the Si shells via a plasma-enhanced chemical vapor deposition (PECVD) process utilizing an expanding thermal plasma (ETP) source. The secondary deposition allows for the preparation of Ge@aSi core@shell structures with tunable Ge/Si ratios (2:1 and 1:1) and superior gravimetric and areal capacities, relative to pure Ge. The binder-free anodes exhibited discharge capacities of up to 2066 mAh/g and retained capacities of 1455 mAh/g after 150 cycles (for the 1:1 ratio). The 2:1 ratio showed a minimal ∼5% fade in capacity between the 20th and 150th cycles. Ex situ microscopy revealed a complete restructuring of the active material to an interconnected Si |
| Databáze: | OpenAIRE |
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