Carbon dioxide as a green carbon source for the synthesis of carbon cages encapsulating porous silicon as high performance lithium-ion battery anodes
Autor: | Yifan Chen, Yuanhong He, Yu Lei, Ning Du, Deren Yang, J.Z. Jiang, Yangfan Lin, Zhang Yaguang |
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Rok vydání: | 2018 |
Předmět: |
Materials science
02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Magnesium silicide Porous silicon 01 natural sciences Lithium-ion battery 0104 chemical sciences Anode chemistry.chemical_compound chemistry Chemical engineering Electrode General Materials Science 0210 nano-technology Porosity Current density |
Zdroj: | Nanoscale. 10:5626-5633 |
ISSN: | 2040-3372 2040-3364 |
Popis: | Si/C composite is one of the most promising candidate materials for next-generation lithium-ion battery anodes. Herein, we demonstrate the novel structure of carbon cages encapsulating porous Si synthesized by the reaction between magnesium silicide (Mg2Si) and carbon dioxide (CO2) and subsequent acid washing. Benefitting from the in situ deposition through magnesiothermic reduction of CO2, the carbon cage seals the inner Si completely and shows higher graphitization than that obtained from the decomposition of acetylene. After removing MgO, pores are created, which can accommodate the volume change of the Si anode during the charge/discharge process. As the anode material for lithium-ion batteries, the porous Si/C electrode shows a charge capacity of ∼1124 mA h g−1 after 100 cycles with 86.4% capacity retention at the current density of 0.4 A g−1. When the current density increases to 1.6 and 3.2 A g−1, the capacity can still be maintained at ∼860 and ∼460 mA h g−1, respectively. The prominent cycling and rate performance is contributed by the built-in space for Si expansion, static carbon cages that prevent penetration of electrolyte and stabilize the solid electrolyte interface (SEI) outside, and fast charge transport by the novel structure. |
Databáze: | OpenAIRE |
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