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Improvement of High-Temperature Performance of LiMn2O4 Cathode by Surface Coating

표면코팅을 통한 LiMn2O4 양극의 고온성능 개선

  • Lee, Gil-Won (Department of Chemical and Biological Engineering and Research Center for Energy Conversion & Storage, Seoul National University) ;
  • Lee, Jong-Hwa (Department of Chemical and Biological Engineering and Research Center for Energy Conversion & Storage, Seoul National University) ;
  • Ryu, Ji-Heon (Graduate School of Knowledge-Based Technology and Energy, Korea Polytechnic University) ;
  • Oh, Seung-M. (Department of Chemical and Biological Engineering and Research Center for Energy Conversion & Storage, Seoul National University)
  • 이길원 (서울대학교 화학생물공학부 및 에너지 변환 저장 연구센터) ;
  • 이종화 (서울대학교 화학생물공학부 및 에너지 변환 저장 연구센터) ;
  • 류지헌 (한국산업기술대학교 지식기반기술.에너지대학원) ;
  • 오승모 (서울대학교 화학생물공학부 및 에너지 변환 저장 연구센터)
  • Published : 2009.02.28

Abstract

An indium-tin oxide (ITO) coated spinel manganese oxide (${LiMn_2}{O_4}$, LMO) is prepared and its high-temperature ($55^{\circ}C$) cycle performance and rate capability are examined. A severe electrolyte decomposition and film deposition is observed on the un-coated ${LiMn_2}{O_4}$ cathode, which leads to a significant electrode polarization and capacity fading. Such an electrode polarization is, however, greatly reduced for the ITO-coated (> 2 mol%) LMO cathode, which leads to an improved cycle performance. This can be rationalized by a suppression of electrolyte decomposition, which is in turn indebted to a decrease in the direct contact area between LMO and electrolyte. The suppression of film deposition on the ITO-coated LMO cathode is confirmed by infra-red spectroscopy. The rate capability is also improved by the surface coating, which may be resulted from a suppression of resistive film deposition and high electric conductivity of ITO itself.

리튬 이차전지의 양극 활물질인 스피넬 망간산화물(${LiMn_2}{O_4}$, LMO) 표면에 ITO(indium tin oxide)를 코팅하여, 고온($55^{\circ}C$)에서 사이클 수명과 속도특성을 조사하였다. 정전류 정전압 충방전 실험의 결과, ITO가 코팅되지 않은 LMO 전극의 표면에서 고온 고전압 조건에서 전해질이 분해하여 피막이 형성되고, 이 피막의 저항으로 인하여 분극현상(polarization)이 심하게 발생하였다. 그러나, ITO가 2 mol% 이상 코팅된 LMO의 경우 양극 활물질과 전해질과의 직접적인 접촉 면적이 줄어들어, 전해질의 분해가 감소하였고 내부저항에 의한 분극 현상 또한 현저히 감소하였다. 이러한 결과, ITO가 코팅된 전극의 충방전에 따른 가역성이 코팅되지 않은 LMO에 비해 크게 향상되었다. 적외선 분광기를 이용하여 ITO가 코팅된 LMO 표면에서 피막형성이 감소함을 확인하였다. ITO의 코팅으로 LMO 전극의 속도특성도 크게 향상되었는데, 이는 저항이 큰 피막형성이 억제된다는 점과 ITO의 전기전도도가 크다는 사실로 설명할 수 있다.

Keywords

References

  1. J. Desilvestro and O. Haas, 'Metal Oxide Cathode Materials for Electrochemical Energy Storage: A Review' J. Electrochem. Soc., 137, 5C (1990) https://doi.org/10.1149/1.2086438
  2. S. Megahed and B. Scrosati, 'Lithium-ion Rechargeable Batteries' J. Power Sources, 51, 79 (1994) https://doi.org/10.1016/0378-7753(94)01956-8
  3. C. Sigala, D. Guyomard, A. Vebaere, Y. Piffard, and M. Tourmous, 'Positive Electrode Materials with High Operating Voltage for Lithium Batteries: $LiCr_{y}Mn_{2-y}O_{4}$ (0 ${\leq}$ y ${\leq}$ 1)' Solid State Ionics, 81, 167 (1995) https://doi.org/10.1016/0167-2738(95)00163-Z
  4. R. J. Gummow, A. de Kock, and M. M. Thackeray, 'Improved Capacity Retention in Rechargeable 4 V lithium/lithium manganese oxide (spinel) cells' Solid State Ionics, 69, 59 (1994) https://doi.org/10.1016/0167-2738(94)90450-2
  5. Y. Y. Xia, Y. H. Zhou, and M. Yoshio, 'Capacity Fading on Cycling of 4 V Li/$LiMn_2O_4$ Cells' J. Electrochem. Soc., 144, 2593 (1997) https://doi.org/10.1149/1.1837870
  6. J. M. Tarascon, W. R. Mckinnon, F. Coowar, T. N. Bowmer, G. Amatucci, and D. Guyomard, 'Synthesis Conditions and Oxygen Stoichiometry Effects on Li Insertion into the Spinel $Limn_{2}O_{4}$' J. Electrochem. Soc., 141, 1421 (1994) https://doi.org/10.1149/1.2054941
  7. D. Guyomard and J. M. Tarascon, 'The carbon/$Li_{1+x}Mn_{2}O_{4}$ system' Solid State Ionics, 69, 222 (1994) https://doi.org/10.1016/0167-2738(94)90412-X
  8. Y. Gao and J. R. Dahn, 'Correlation between the growth of the 3.3 V Discharge Plateau and Capacity Fading in $Li_{1+x}Mn_{2}O_{4}$ Materials' Solid State Ionics, 84, 33 (1996) https://doi.org/10.1016/S0167-2738(96)83003-7
  9. Y. Gao and J. R. Dahn, 'Synthesis and Characterization of $Li_{1+x}Mn_{2}O_{4}$ for Li-Ion Battery Applications' J. Electrochem. Soc., 143, 100 (1996) https://doi.org/10.1149/1.1836393
  10. Y. Xia and M. Yoshio, 'An Investigation of Lithium Ion Insertion into Spinel Structure Li-Mn-O compounds' J. Electrochem. Soc., 143, 825 (1996) https://doi.org/10.1149/1.1836544
  11. D. H. Jang, Y. J. Shin, and S. M. Oh, 'Dissolution of Spinel Oxides and Capacity Losses in 4 V $Li/Li_{x}Mn_{2}O_{4}$ cells' J. Electrochem. Soc., 143, 2204 (1996) https://doi.org/10.1149/1.1836981
  12. G. H. Li, H. Ikuta, and T. Uchida, 'The Spinel Phases $LiM_{y}Mn_{2-y}O_{4}$ (M = Co, Cr, Ni) as the Cathode for Rechargeable Lithium Batteries' J. Electrochem. Soc., 143, 178 (1996) https://doi.org/10.1149/1.1836405
  13. S. T. Myung, S. Komaba, and N. Kumagai, 'Enhanced Structural Stability and Cyclability of Al-Doped $LiMn_{2}O_{4}$ Spinel synthesized by the Emulsion Drying Method' J. Electrochem. Soc., 148, A482 (2001) https://doi.org/10.1149/1.1365140
  14. A. M. Kannan, L. Rabenberg, and A. Manthiram, 'Surface/Chemically Modified $LiMn_{2}O_{4}$ Cathodes for Lithium-Ion Batteries' Electrochem. Solid-State Lett., 5, A167 (2002) https://doi.org/10.1149/1.1482198
  15. M. M. Thackeray, C. S. Johnson, J.-S. Kim, K. C. Lauzze, J. T. Vaughey, N. Dietz, D. Abraham, S. A. Hackney, W. A. Zeltner, and M. A. Anderson, '$Zro_{2}-$ and $Li_{2}ZrO_{3}$-stabilized Spinel and Layered Electrodes for Lithium Batteries' Electrochem. Commun., 5, 752 (2003) https://doi.org/10.1016/S1388-2481(03)00179-6
  16. Y. K. Sun, K. J. Hong, and J. Prakash, 'The Effect of ZnO Coating on Electrochemical Cycling Behavior of Spinel $LiMn_{2}O_{4}$ Cathode Materials at Elevated Temperature' J. Electrochem. Soc., 150, A970 (2003) https://doi.org/10.1149/1.1580819
  17. J. P. Cho, T. J. Kim, Y. J. Kim, and B.W. Park, 'Complete Blocking of $Mn^{3+}$ ion Dissolution from a $LiMn_{2}O_{4}$ Spinel Intercalation Compound by $Co_{3}O_{4}$ Coating' Chem. Commun., 12, 1074 (2001)
  18. D. Aurbach, K. Gamolsky, B. Markovsky, G. Salitra, and Y. Gofer, 'The Study of Surface Phenomena Related to Electrochemical Lithium Intercalation into $Li_{x}MO_{y}$ Host Materials (M = Ni, Mn)' J. Electrochem. Soc., 147, 1322 (2000) https://doi.org/10.1149/1.1393357
  19. A. Douglas and F. Skoog, James Holler and Timothy A. Nieman, Principles of Instrumental Analysis, 5th edition, pp. 410, Harcourt Brace College Publishers, USA (1998)
  20. R. Yazami, 'Surface Chemistry and Lithium Storage Capability of the Graphite-Lithium Electrode' Electrochim. Acta, 45, 87 (1999) https://doi.org/10.1016/S0013-4686(99)00195-4