Fabrication of Electrodes for PEMFC using Electrodeposition

(Journal of the Korean Institute of Chemical Engineers)

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(1999j 3ú 30¢ 7>, 1999j 9ú 16¢ j)

Fabrication of Electrodes for PEMFC using Electrodeposition

Kyoung Hwan Choi, Young Joon Park*, Han Sung Kim** and Tae Hee Lee**^†

Korea Institute of Energy Research

*KEPCO

**Dept. of Chem. Eng., Yonsei Univ.

(Received 30 March 1999; accepted 16 September 1999)

º £

3 C/cm²¢ r *~&ê 300 mA/cm²(0.7 V)

& &Ë Ö>‚ ªÊ*O *~ï 1.8 C/cm²¢ r 664 W/g Ptb‚ &Ë – 8j &.

Abstract−The low Pt loading electrodes for PEMFC were manufactured using electrodeposition and their cell perfor- mances were measured. Also an optimal electrode fabrication process was determined by comparing Pt dispersion, loading and electrodeposition efficiency in direct current and pulse electrodeposition. Electrodeposition could reduce Pt particle size about 15ç, and enhance dispersion and specific surface area of Pt because of impregnating catalyst on the surface of electrode.

Pulse electrodeposition was better than direct current one in electrodeposition efficiency and Pt dispersion, and it could increase cell performance due to higher Pt loading at same total passed charge. The electrode, which was made by growing Pt nuclei in direct current electrodeposition after creating Pt nuclei in pulse one at pulse charge of 3 C/cm², showed the best per- formance of 300 mA/cm²(0.7 V). At 0.7 V the electrode that Pt dispersion was highest and pulse charge was 1.8 C/cm² had the largest mass activity of 664 W/g Pt.

Key words: PEMFC, Pulse Electrodeposition, Nuclei Creation, Nuclei Growth, Dispersion

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Table 2. Surface concentration of Pt atom for carbon and Pt loading at the various conditions(Total charge: 4 C/cm²)

Charge(C/cm²)

Pt loading (Pt/C)_atom

Pulse Direct

0.6 3.4 0.239 0.128

1.8 2.2 0.295 0.229

3.0 1.0 0.320 0.138

Fig. 8. Electrode performances with total passed charge in direct cur- rent electrodeposition(70^oC, 1 atm).

Fig. 9. Electrode performances with total passed charge in pulse current electrodeposition(70^oC, 1 atm).

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Fig. 10. Performances of electrodes fabricated at the different ratio of pulse and direct current(Total charge: 4 C/cm², 70^oC, 1 atm).