본 연구에서는 피치가 코팅된 실리콘 시트/흑연 음극복합소재의 전기화학적 특성을 조사하였다. NaCl을 주형으로하여 스토버 법 및 마그네슘 열 환원법을 통해 실리콘 시트를 제조하고, 양친성 물질인 SDBS로 흑연과 결합시켜 실리콘 시트/흑연을 합성하였다. THF를 용매로 석유계 피치가 코팅된 실리콘 시트/흑연 음극복합소재를 제조하였고, 음극복합소재의 물리적 특성은 XRD, SEM, EDS와 TGA를 통해 분석하였다. 전기화학적 특성은 LiPF6 (EC:DMC:EMC=1:1:1 vol%)의 전해액을 사용해 전지를 제조하여, 충·방전 사이클, 율속, 순환전압전류, 전기화학적 임피던스 테스트를 통해 조사하였다. 실리콘 조성이 증가함에 따라 방전 용량이 증가하였고, 장기 안정성은 감소하는 경향을 보였다. 30 wt% 실리콘 조성을 갖는 실리콘 시트/흑연 복합소재에 피치를 코팅한 음극복합소재는 1228.8 mAh/g의 높은 초기방전 용량을 보였으며, 50사이클 이후 용량 유지율은 77%로 실리콘 시트/흑연 복합소재에 비해 안정성이 개선됨을 알 수 있었다.

In this study, the electrochemical properties of pitch coated silicon sheets/graphite anode materials were investigated. Using NaCl as a template, silicon sheets were prepared through the st.ber method and the magnesiothermic reduction methode. In order to synthesize the anode composite, the silicon sheets and graphite were combined with SDBS. The pitch coated silicon sheets/graphite was synthesized using THF as a solvent for the anode material composite. The physical properties of the prepared anode composites were analysed by XRD, SEM, EDS and TGA. The electrochemical performances of the prepared anode composites were performed by the current charge/discharge, rate performance, cyclic voltammetry and EIS tests in the electrolyte LiPF6 dissolved solvents (EC:DMC:EMC=1:1:1 vol%). As the silicon composition of silicon sheets/graphite composite material increased, the discharge capacity also increased, but the cycle stability tended to decrease. The anode material of pitch coated silicon sheets/graphite composite (silicon sheets:graphite=3:7 weight ratio) showed the initial discharge capacity of 1228.8 mAh/g and the capacity retention ratio of 77% after 50 cycles. From these results, it was found that the cycle stability of pitch coated silicon sheets/graphite was improved.

Silicon sheets Pitch Graphite Anode Lithium ion battery

Kim JS, Pfleging W, Kohler R, Seifert HJ, Kim TY, Byun D, Jung HG, Choi WC, Lee JK, J. Power Sources, 279, 13 (2015)
Bao Q, Huang YH, Lan CK, Chen BH, Duh JG, Electrochim. Acta, 173, 82 (2015)
Yang Y, Wang Z, Yang G, Guo H, Wang J, Li X, Zhou Y, Zhou R, Ceram. Int., 43, 8590 (2017)
Lee JH, Moon JH, Korean J. Chem. Eng., 34(12), 3195 (2017)
Liu JH, Liu XW, Adv. Mater., 24(30), 4097 (2012)
Park JM, Cho JH, Ha JH, Kim HS, Kim SW, Lee J, Chung KY, Cho BW, Choi HJ, Nanotechnology, 28, 255401 (2017)
Dou F, Shi L, Chen G, Zhang D, Electrochem. Energy Reviews, 2, 149 (2019)
Chen S, Chen Z, Xu X, Cao C, Xia M, Luo Y, Small, 4(12), 170336 (2018)
Suresh S, Wu ZP, Batrolucci SF, Basu S, Mukherjee R, Gupta T, Hundekar P, Shi Y, Lu TM, Koratkar N, ACS Nano, 11, 5051 (2017)
Lee SH, Lee JD, Korean Chem. Eng. Res., 57(1), 118 (2019)
Han YJ, Hwang JU, Kim KS, Kim JH, Lee JD, Im JS, J. Ind. Eng. Chem., 73, 241 (2019)
Lai J, Guo H, Wang Z, Li X, Zhang X, Wu F, Yue P, J. Alloy. Compd., 530, 30 (2012)
Yoshio M, Wang H, Fukuda K, Angew. Chem.-Int. Edit., 42, 4203 (2003)
Kim WS, Hwa Y, Shin JH, Ynag M, Sohn HJ, Hong SH, Nanoscale, 6, 4297 (2014)
Meng XL, Huo HY, Cui ZH, Guo XX, Dong SM, Electrochim. Acta, 283, 183 (2018)
Jung MZ, Park JY, Lee JD, Korean Chem. Eng. Res., 54(1), 16 (2016)
Lee SH, Lee JD, Korean Chem. Eng. Res., 85(1), 142 (2020)
Jo YJ, Lee JD, Korean Chem. Eng. Res., 57(1), 5 (2019)
Chen HD, Wang ZL, Hou XH, Fu LJ, Wang SF, Hu XQ, Qin HQ, Wu YP, Ru Q, Liu X, Hu SJ, Electrochim. Acta, 249, 113 (2017)
Xie J, Tong L, Su LW, Xu YW, Wang LB, Wang YH, J. Power Sources, 342, 529 (2017)