SiO<sub><i>x</i></sub>C<sub><i>y</i></sub> Microspheres with Homogeneous Atom Distribution for a High-Performance Li-Ion Battery.

Cui, Shiqiang; Zhang, Jiangjiang; Fan, Shangze; Xing, Xuteng; Deng, Libo; Gong, Yongji · Nano Lett · 2022

basic_science · Level V

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Abstract

The broad application of silicon-based materials is limited by large volume fluctuation, high preparation costs, and complicated preparation processes. Here, we synthesized SiO<sub><i>x</i></sub>C<sub><i>y</i></sub> microspheres on 3D copper foams by a simple chemical vapor deposition method using a low-cost silane coupling agent (KH560) as precursors. The SiO<sub><i>x</i></sub>C<sub><i>y</i></sub> microspheres are available with a large mass loading (>3 mg/cm<sup>2</sup>) on collectors and can be directly used as the electrode without any binders or extra conductive agents. As a result, the as-prepared SiO<sub><i>x</i></sub>C<sub><i>y</i></sub> shows a high reversible capacity of ∼1240 mAh g<sup>-1</sup> and can be cycled more than 1900 times without decay. <i>Ex situ</i> characterizations show that the volume change of the microspheres is only 55% and the spherical morphology as well as the 3D structure remain intact after cycles. Full-cell electrochemical tests paired with LiFePO<sub>4</sub> as cathodes show 87% capacity retention after 500 cycles, better than most reported results, thus showing the commercial potential of the material.