Polysilane계 전구체 고분자를 사용한 리튬 이온 전지 음극재용 무기물의 제조

Abstract

Two different polysilanes, poly(methyl(phenyl)silane) (PMPS) and poly(methyl(phenyl)silane-co-methyl (vinyl)silane) (PMPS-co-PMVS), were synthesized as precursor polymers to ceramics as anodes in lithium ion batteries. Upon pyrolysis at 1000 oC, the polysilanes yielded ceramics with a Si content of 67−70%. The vinyl group containing PMPS-co-PMVS showed a higher ceramic yield than that containing PMPS due to the thermal crosslinking reactions between the vinyl groups. The ceramic products were characterized using elemental analysis, Fourier transform-infrared spectroscopy, thermogravimetry, X-ray diffractometry, and atomic force microscopy. It was revealed that the ceramics from PMPS-co-PMVS had a higher Si atomic content, had more Si-Si bonds, and a more crystalline structure than those from PMPS. The discharge capacities of the ceramics were less than 200 mAh/g, but they showed excellent cycling performance, maintaining their capacities after 100 charge/discharge cycles.