The Electrochemical Characteristics of Surface-modified Carbonaceous Materials by tin Oxides and Copper for Lithium Secondary Batteries

The Electrochemical Characteristics of Surface-modified Carbonaceous Materials by tin Oxides and Copper for Lithium Secondary Batteries

Joong Kee Lee

, D. H. Ryu*, Y. G. Shul*, B. W. Cho and D. Park

Clean Technology Research Center/Battery and Fuel Cell Center

Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul, Korea

*Dept. of Chemical Eng., Yonsei University, Shinchon, Seoul, Korea

♠e-mail: leejk@kist.re.kr

(Received November 28, 2000; accepted January 19, 2001)

Abstract

Lithium intercalated carbon (LIC) are basically employed as an anode for currently commercialized lithium second- ary batteries. However, there are still strong interests in modifying carbon surface of active materials of the anode because the amount of irreversible capacity, charge-discharge capacity and high rate capability are largely determined by the surface conditions of the carbon. In this study, the carbonaceous materials were coated with tin oxide and copper by fluidized-bed chemical vapor deposition (CVD) method and their coating effects on electrochemical characteristics were investigated. The electrode which coated with tin oxides gave the higher capacity than that of raw material. Their capacity decreased with the progress of cycling possibly due to severe volume changes. However, the cyclability was improved by coating with copper on the surface of the tin oxides coated carbonaceous materials, which plays an impor- tant role as an inactive matrix buffering volume changes. An impedance on passivation film was decreased as tin oxides contents and it resulted in the higher capacity.

Keywords : Lithium Secondary Batteries, Fluidized-Bed CVD, Surface Modification.

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Fig. 1. Schematic diagram of fluidized chemical vapor deposi- tion process.

Table 1. Properties of Cu & Sn precursor

Cu(hfac)2 (CH3)4Sn

Solid Liquid

Decomposition at T >400^oC Decomposition at T >400^oC Vapor pressure ~10 torr at 100^oC Vapor pressure 100 torr at 25^oC Melting point at 85~89^oC Melting point at -54^oC Boiling point at 220^oC Boiling point at 78^oC Specific gravity 1.35 Specific gravity 1.31 Formula weight 447.64 Formula weight 178.83

Fig. 2. Schematic diagram of Li secondary batteries.

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Element Analysis Sample preparation method (Fluidized CVD reaction conditions) Cu (wt%) Sn (wt%)

CS0* − − −

SN1 − 1.37 tin oxides coating at Ca. 500^oC for 30 min

SN2 − 0.93 tin oxides coating at Ca. 500^oC for 10 min

CS1 0.14 1.83 tin oxides coating at Ca. 500^oC for 40 min and subsequently copper coating at Ca.

450^oC for 2hrs CS0*: raw MCMB

Fig. 3. SEM photographs of surface-modified MCMB1028 (×100K): (a) CS0 (b) SN1 (c) SN2 (d) CS1.

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(b) corresponding EPMA mapping of Sn.

Fig. 5. (a) SEM photographs of tin oxides and copper coated MCMB and corresponding EPMA mapping of (b) Sn & (c) Cu.

Fig. 6. 1st, 2nd charge/discharge curves of surface-modified MCMB1028. (a) CS0 (b) SN1 (c) SN2 (d) CS1.

Fig. 7. Cyclic voltammograms of surface-modified MCMB1028 with scan rate of 0.1 mV/s (0.0 V : 3.0 V); (a) CS0 (b) SN1 (c) SN2 (d) CS1.

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 peak¢ &V† > ìb–, æ ~öB "C peakòj {

ž† > ®.

6‚  þöBº *~ >w~ Ö"ö ~š Z "Cš

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xLi + 6C  LixC6 (3)

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Fig. 9º C-rate¢ C/5‚ ;*~ þj ê¯~&j ãÖ~

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before and after cycle.

Fig. 9. Cycle performances of surface-modified MCMB1028.

~ ¾*öB jv~ ê~&. âöB š z+B "

CÖzb~ ·š Ã&†>ƒ O* Ïïš Ã&~º ãËj 

š ®æò, N O*b‚ .>ƒ O* Ïï~ Nš& *Ú j r > ®. š©f &N O*öº z+B "CÖzb

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4. Ö †

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C Özb 5 ’Òº cluster ;‚ ê² Òò ‚šöB j v' ¢‚ ª¢ ¾æÚîb–, "CÖzbf 50 nm, ’ Òº 200 nm ;ê~ ’V¢ <º ’;~ ;çj ¾æÚ

®î.

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* ";öB ÒÒ~ Öz 5 "C~ ~öö ~‚ j& >

wf væ² ¾æÒb–, š‚ žš .VÎNö ®ÚB

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Fig. 10. Nyquist plots of surface-modified MCMB1028 at 2th cycle.

Fig. 11. C-rate effect of surface-modified MCMB1028.

{ž† > ®î. ¾ š‚ Қš >«~ 6²¢ š Ö~V *š inactive matrix‚B ’Ò¢ Î&~ Қš

>«j BF~&.

− &N O*öº z+B "CÖzbš ÒÒ" alloying reactionj ¢bÊVö Ϫ‚ *j <² >æò, N O

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− z+B "CÖzb~ ·š Ã&Žö V¢ êšöB~

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impedanceº Ã&ʺ Ö"¢ .¾~&.

^^ò

[1] Murphy, D. W.; Cardies, J. N. J. Electrochem. Soc. 1979, 126, 349.

[2] Lazzari, M.; Scrosati, B. J. Electrochem. Soc. 1980, 127, 773.

[3] Auborn, J. J.; Barberio, Y. L. J. Electrochem. Soc. 1987, 134, 638.

[4] Yang, J.; Winter, M.; Besenhard, J. O. Solid State Ionics 1996, 90, 281.

[5] Besenhard, J. O.; Yang, J.; Winter, M. J. Power Sources 1997, 68, 87.

[6] Brandt, K. J. Power Sources 1995, 54, 151.

[7] Brnadt, K. Solid State Ionics 1994, 69, 173.

[8] Winter, M.; Besenhard, J. O.; Spahr, M. E.; Novak, P. Adv.

Mater. 1998, 10, 725.

[9] Dey, N. J. Electrochem. Soc. 1971, 118, 1547.

[10] Baliga, B. J.; Ghandhi, S. K. J. Electrochem. Soc. 1976, 123, 941.

[11] Chow, T. P.; Ghezzo, M.; Baliga, B. J. J. Electrochem. Soc.

1982, 129, 1040.

[12] Courtney, I. A.; Dahn, J. R. Progress in Batteries and Bat- tery Materials 1997, 16, 214.

[13] Courtney, I. A.; Dahn, J. R. J. Electrochem. Soc. 1997, 144, 2045.

[14] Huggins, R. A. “Handbook of battery Materials”, Part III, ch. 4. ed. Besenhard, J. O. Wiley-VCH, Weinheim, 1999, 359.