Korean Chemical Engineering Research, Vol.54, No.1, 16-21, February, 2016
CNT를 첨가한 Silicon/Carbon 음극소재의 전기화학적 특성
Electrochemical Characteristics of Silicon/Carbon Composites with CNT for Anode Material
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초록
실리콘의 부피팽창과 낮은 전기전도도를 개선하기 위하여 Silicon/Carbon/CNT 복합체를 제조하였다. Silicon/Carbon/CNT 합성물은 SBA-15를 합성한 후, 마그네슘 열 환원 반응으로 Silicon/MgO를 제조하여 Phenolic resin과 CNT를 첨가하여 탄화하는 과정을 통해 합성하였다. 제조된Silicon/Carbon/CNT 합성물은 XRD, SEM, BET, EDS를 통해 특성을 분석하였다. 본 연구에서는 충방전, 사이클, 순환전압전류, 임피던스 테스트를 통해 CNT 첨가량에 따른 전기화학적 효과를 조사하였다. LiPF6 (EC:DMC:EMC=1 :1 :1 vol%) 전해액에서 Silicon/Carbon/CNT 음극활물질을 사용하여 제조한 코인셀은 CNT 함량이 7 wt% 일 때 1,718 mAh/g으로 높은 용량을 나타내었다. 코인셀의 사이클 성능은 CNT 첨가량이 증가할수록 개선되었다. 11 wt%의 CNT를 첨가한 Silicon/Carbon/CNT 음극은 두 번째 사이클 이후 83%의 높은 용량 보존율을 나타냄을 알 수 있었다.
Silicon/Carbon/CNT composites as anode materials for lithium-ion batteries were synthesized to overcome the large volume change during lithium alloying-de alloying process and low electrical conductivity. Silicon/Carbon/CNT composites were prepared by the fabrication processes including the synthesis of SBA-15, magnesiothermic reduction of SBA-15 to obtain Si/MgO by ball milling, carbonization of phenolic resin with CNT and HCl etching. The prepared Silicon/Carbon/CNT composites were analysed by XRD, SEM, BET and EDS. In this study, the electrochemical effect of CNT content to improve the capacity and cycle performance was investigated by charge/discharge, cycle, cyclic voltammetry and impedance tests. The coin cell using Silicon/Carbon/CNT composite (Si:CNT=93:7 in weight) in the electrolyte of LiPF6 dissolved in organic solvents (EC:DMC:EMC=1:1:1 vol%) has better capacity (1718 mAh/g) than those of other composition coin cells. The cycle performance of coin cell was improved as CNT content was increased. It is found that the coin cell (Si:CNT=89:11 in weight) has best capacity retension (83%) after 2nd cycle.
Keywords:Silicon/Carbon/CNT;Anode material;Carbon nanotube;Magnesiothermic reduction;Lithium ion battery
- Ko HS, Choi JE, Lee JD, Korean Chem. Eng. Res., 52(1), 52 (2014)
- Jeon BJ, Kang SW, Lee JK, Korean J. Chem. Eng., 23(5), 854 (2006)
- Pan LI, Wang H, Gao D, Chen S, Tan L, Li L, Royal Soc. Chem., 50, 5878 (2014)
- Zhou XY, Tang JJ, Yang J, Xie J, Ma LL, Electrochim. Acta, 87, 663 (2013)
- Wen Z, Lu G, Mao S, Kim H, Cui S, Yu K, Huang X, Hurley PT, Mao O, Chen J, Electrochem. Commun., 29, 67 (2013)
- Yim T, Choi SJ, Jo YN, Kim TH, Kim KJ, Jeong G, Kim YJ, Electrochim. Acta, 136, 112 (2014)
- Li H, Lu CX, Zhang BP, Electrochim. Acta, 120, 96 (2014)
- Liu Y, Wen ZY, Wang XY, Hirano A, Imanishi N, Takeda Y, J. Power Sources, 189(1), 733 (2009)
- Cetinkaya T, Guler MO, Akbulut H, Microelectron. Eng., 108, 169 (2013)
- Su MR, Wang ZX, Guo HJ, Li XH, Huang SL, Gan L, Adv. Powder Technol., 24(6), 921 (2013)
- Zhao DY, Feng JL, Huo QS, Melosh N, Fredrickson GH, Chmelka BF, Stucky GD, Science, 279(5350), 548 (1998)
- Wang YG, Zhang FY, Wang YQ, Ren JW, Li CL, Liu XH, Guo Y, Guo YL, Lu GZ, Mater. Chem. Phys., 115(2-3), 649 (2009)
- Park JY, Jung MZ, Lee JD, Appl. Chem. Eng., 26(1), 80 (2015)
- Li HH, Wang JW, Wu XL, Sun HZ, Yang FM, Wang K, Zhang LL, Fan CY, Zhang JP, Royal Soc. Chem., 4, 36218 (2014)