• 한국재료학회지
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• 제34권10호
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• pp.497-505
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• 2024

Silicon-based anode materials have attracted significant interest because of their advantages, including high theoretical specific capacity (~4,200 mAh/g), low working potential (0.4 V vs Li/Li+), and abundant sources. However, their significant initial capacity loss and large volume changes during cycling impede the application of silicon-based anodes in lithium-ion batteries. In this work, we propose a silicon oxide (SiO_x) anode material for lithium-ion batteries produced with a magnesio-thermic reduction (MTR) process adopting Boryeong mud as a starting material. Boryeong mud contains various minerals such as clinochlore [(Mg,Fe)₆(Si,Al)₄O₁₀(OH)₈], anorthite (CaAl₂Si₂O₈), illite [K_0.7Al₂(Si,Al)₄O₁₀(OH)₂], and quartz (SiO₂). The MTR process with Boryeong mud generates a mixture of amorphous silicon oxides (SiO_x and SiO₂), and magnesium aluminate which helps to alleviate the volume expansion of the electrode during charge/discharge. To observe the effects of these oxides, we conducted various analyses including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-Transformation infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and cyclic voltammetry (CV) galvanic cell testing. The amorphous SiO₂ and MgAl₂O₄ suppressed the volume expansion of the silicon-based anode, and excellent cycle performance was achieved as a result.