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本文讨论了电化学交流阻抗图中图形旋转的物理意义.电化学体系等效电路中的电容基本上属复数电容,由此推导出在这个假设下的阻抗极坐标公式,及其参数的数学表达式.实际上此表达式与很多电化学体系的实际阻抗谱相符,如:实际测量的理想极化电极的阻抗图并不是平行于虚轴的一条直线,而是其与实轴的交点顺时钟旋转了α角的直线,这时,即双层电容的耗散角;与RC并联电路有关的半圆阻抗图几乎都有同一方向的α角旋转,其值等于相关电容的耗散角.若明确了旋转的物理意义,由电化学阻抗谱拟合得到的参数均可表征体系的性质,这对于寻求某些特殊性能的电池体系将是有用的.
In this paper, we discuss the physical meaning of the rotation of the graph in electrochemical AC impedance diagram.The capacitance in the equivalent circuit of the electrochemical system basically belongs to the complex capacitance, and deduces the formula of impedance polar coordinate under this assumption and the mathematical expression of its parameters In fact, this expression is consistent with the actual impedance spectrum of many electrochemical systems. For example, the impedance diagram of the actual measured ideal polarized electrode is not a straight line parallel to the imaginary axis, but the intersection of its real axis and the clockwise In this case, that is, the dissipation angle of the double-layer capacitor; the semicircular impedance diagram related to the RC parallel circuit has almost the same rotation angle of α, which is equal to the dissipation angle of the relevant capacitor. The physical meaning of rotation, the parameters obtained from the fitting of the electrochemical impedance spectroscopy, characterize the properties of the system, which will be useful for battery systems that seek for some particular properties.