| 초록 |
Performance degradation of direct methanol fuel cell was observed by keeping at a constant current density of 150 mA/cm2 and 55 oC for 435 hours. Maximum power density decreased to 71, 57 and 50 % of initial value after operation for 145, 290 and 435 hours, respectively. In-situ methanol oxidation activity was measured before and after stability test, where activity decrease by 8 % was observed. To separate contributions of each component on the degradation, electrochemical impedance spectroscopy was used. In anode measurement, IR resistance increase was dominant and anode resistance increase was 11 % of total resistance increase. In full cell measurement, we found out that increase of reaction resistance was 30 % of total increase. Therefore, we could conclude that the contribution of each components was in order of IR resistance, cathode resistance and anode resistance. |
