Korean Chemical Engineering Research, Vol.58, No.1, 142-149, February, 2020
실리카로 코팅된 흑연을 이용한 리튬 이차전지용 흑연/실리콘/피치 복합소재의 전기화학적 특성
Electrochemical Characteristics of Graphite/Silicon/Pitch Anode Composites for Lithium Ion Batteries using Silica-Coated Graphite
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초록
본 연구에서는 인조흑연의 낮은 이론용량을 개선하기 위하여 음극소재로서 흑연/실리콘/피치 복합소재의 전기화학
적 성능을 조사하였다. 구형의 인조 흑연 표면을 polyvinylpyrrolidone (PVP) 양친성 물질로 코팅한 후 실리카를 성장시켜 흑연/실리카 소재를 합성하였으며, 석유계 피치 코팅과 마그네슘 열 환원법을 통해 흑연/실리콘/피치 복합소재를 제조하였다. 흑연/실리콘/피치 복합소재의 전극은 poly(vinylidene fluoride) (PVDF), carboxymethyl cellulose (CMC), polyacrylic acid (PAA) 바인더에 따라 제조하였으며, 다양한 전해액과 첨가제를 이용하여 전지를 조립하였다. 흑연/실리콘/피치 복합소재는 X-ray diffraction (XRD), scanning electron microscope (SEM)와 thermogravimetric analyzer (TGA)를 통해 물리적 특성을 분석하였으며, 전기화학적 특성은 충·방전 사이클, 율속, 순환전압전류, 임피던스 테스트를 통해 조사하였다. 흑연/실리콘/피치 복합소재는 흑연 : 실리카 : 피치 = 1 : 4 : 8일 때 높은 사이클 안정성을 보였다. PAA 바인더를 사용하여 제조된 전극은 높은 용량과 안정성을 보였으며, EC:DMC:EMC 전해액을 사용하였을 때 719 mAh/g의 높은 초기 용량과 우수한 사이클 안정성 나타내었다. 또한 vinylene carbonate (VC) 첨가시에 2 C/0.1 C 일 때 77% 용량 유지율과 0.1 C/0.1 C 일 때 88% 용량 회복을 나타냄을 확인하였다.
In this study, the electrochemical performance of Graphite/Silicon/Pitch composites as anode material was investigated to improve the low theoretical capacity of artificial graphite. Spherical artificial graphite surface was coatedwith polyvinylpyrrolidone (PVP) amphiphiles material to synthesize Graphite/Silica material by silica islands growth. The Graphite/Silicon/Pitch composites were prepared by petroleum pitch coating and magnesiothermic reduction. The Graphite/Silicon/Pitch composite electrodes manufactured using poly(vinylidene fluoride) (PVDF), carboxymethyl cellulose (CMC) and polyacrylic acid (PAA) binders. The coin type half cell was assembled using various electrolytes and additives. The Graphite/Silicon/Pitch composites were analysed by X-ray diffraction (XRD), scanning electron microscope (SEM) and a thermogravimetric analyzer (TGA). The electrochemical characteristics of Graphite/Silicon/Pitch composite were investigated by constant current charge/discharge, rate performance, cyclic voltammetry and electrochemical impedance spectroscopy. The Graphite/Silicon/Pitch composites showed high cycle stability at a graphite/silica/pitch ratio (1:4:8 wt%). When the electrode is prepared using PAA binder, the high capacity and stability is obtained. The coin type half cell assembled using EC: DMC: EMC electrolyte showed high initial capacity (719 mAh/g) and excellent cycle stability. The rate performance has an capacity retention (77%) at 2 C/0.1 C and an capacity recovery (88%) at 0.1 C / 0.1 C when the vinylene carbonate (VC) was added.
- Ko HS, Park HW, Lee JD, Korean Chem. Eng. Res., 56(5), 718 (2018)
- Jo YJ, Lee JD, Korean Chem. Eng. Res., 56(3), 320 (2018)
- Long W, Fang B, Ignaszak A, Wu Z, Wang YJ, Wilkinson D, Chem. Soc. Rev., 46, 7176 (2017)
- Bao Q, Huang YH, Lan CK, Chen BH, Duh JG, Electrochim. Acta, 173, 82 (2015)
- Lee JH, Moon JH, Korean J. Chem. Eng., 34(12), 3195 (2017)
- Wachtler M, Besenhard JO, Winter M, J. Power Sources, 94(2), 189 (2001)
- Wu H, Chan G, Choi JW, Ryu L, Yao Y, McDowell MT, Lee SW, Jackson A, Yang Y, Hu L, Cui Y, Nat. Nanotechnol., 7(5), 310 (2012)
- Antitomaso P, Fraisse B, Stievano L, Biscaglia S, Perrot DA, Girard P, Sougrati MT, Monconduit L, J. Mater. Chem. A, 5, 6546 (2017)
- Sohn M, Kim DS, Park HI, Kim JH, Kim H, Electrochim. Acta, 196, 197 (2016)
- Huang L, Wei HB, Ke FS, Fan XY, Li JT, Sun SG, Electrochim. Acta, 54(10), 2693 (2009)
- Kim H, Seo M, Park MH, Cho J, Angew. Chem.-Int. Edit., 49, 2146 (2010)
- Lee SH, Lee JD, Korean Chem. Eng. Res., 57(1), 118 (2019)
- Jeena MT, Bok T, Kim SH, Park S, Kim JY, Park S, Ryu JH, Nanoscale, 8, 9245 (2016)
- Wang W, Yang S, J. Alloy. Compd., 695, 3249 (2017)
- Cai Y, Allan SM, Sandhage KH, J. Am. Ceram. Soc., 88(7), 2005 (2005)
- Choi S, Kim K, Nam J, Shim SE, Carbon, 60, 254 (2013)
- Lee HY, Lee JD, Korean Chem. Eng. Res., 54(4), 459 (2016)
- Yang Y, Wang Z, Zhou Y, Guo H, Li X, Mater. Lett., 199, 84 (2017)
- Komaba K, Yabuuchi N, Ozeki T, Han ZJ, Shimomura K, Yui H, Katayama Y, Miura T, J. Phys. Chem., 116, 1380 (2012)
- Komaba S, Shimomura K, Yabuuchi N, Ozeki T, Yui H, Konno K, J. Phys. Chem., 115, 13487 (2011)
- Chen LB, Wang K, Xie XH, Xie JY, J. Power Sources, 174(2), 538 (2007)
- Jaumann T, Balach J, Langklotz U, Sauchuk V, Fritsch M, et al., Energy Storage Materials, 6, 26 (2017)