固体高分子形燃料電池における電気化学測定に対する電位掃引速度の影響

Abstract

There is a problem that the sweep speeds do not match among the electrochemical parameters of hydrogen crossover current (i(sub cross)), electrochemical area (ECA), electric double layer charging current (i(sub dl charging)), exchange current density (i(sub 0)), and oxygen reaction reduction specific activity (ORR activity), which causes measurement errors with the conventional method. In this paper, we first investigate the correlation between i(sub cross) and ECA over a wide range of sweep speed, and examine the influencing factors. Then, while quantitatively evaluating the measurement error of the conventional method, an appropriate sweep rate for the measuring electrochemical parameters is shown. As a result, the sweep speed dependence of i(sub cross), ECA, i (sub dl charging), i(sub 0), and ORR activity is confirmed. The measurement accuracy of these parameters could be improved significantly by reducing the sweep speed.