Electrical conductivity relaxation (ECR) is a widely adopted technique for determination of oxygen surface exchange coefficient (k_chem) and chemical oxygen diffusivity (D_chem) of mixed ionic and electronic conductors (MIECs). However, it has been argued that the fitting process of determining two kinetic parameters from a single conductivity relaxation curve inevitably leads to high error in the determined values. In this research, we demonstrate experiment-based analytical approaches to overcome the issue and obtain highly reliable kinetic parameters using ECR for the case of (La_0.6Sr_0.4)_0.95Co_0.2Fe_0.8O_3-δ (LSCF), a representative MIEC. As a baseline, kinetic parameters of a standard LSCF bar sample with the thickness close to the critical thickness are obtained using a conventional ECR method along with error range and sensitivity analysis at oxygen partial pressures of 0.2–3.125 × 10⁻³ atm. D_chem with improved accuracy is obtained by ECR under primarily bulk diffusion-controlled condition, which is achieved by either increasing the thickness or coating porous LSCF on the baseline sample. With the D_chem determined, the baseline data are further refined to obtain k_chem as the sole fitting parameter and the error range is reduced more than 70% of the original value under all test conditions. With the significantly improved accuracy and sensitivity of both k_chem and D_chem, this demonstrated method is proven to be a practical approach to advance the application of ECR.

电导率弛豫（ECR）是一种广泛采用的技术，用于确定混合离子和电子导体（MIEC）的氧表面交换系数（k _chem）和化学氧扩散系数（D _chem）。然而，已经争论了从单个电导率弛豫曲线确定两个动力学参数的拟合过程不可避免地导致确定值的高误差。在这项研究中，我们证明了基于实验的分析方法可以克服该问题，并在（La _0.6 Sr _0.4）_0.95 Co _0.2 Fe _0.8 O3 _-δ的情况下使用ECR获得高度可靠的动力学参数（LSCF），代表性的MIEC。作为基线，使用常规ECR方法以及在0.2–3.125×10 ^-3  atm的氧气分压下的误差范围和灵敏度分析，获得了厚度接近临界厚度的标准LSCF条形样品的动力学参数。通过ECR在主要是本体扩散控制的条件下可获得精度更高的D _chem，这可以通过增加厚度或在基准样品上涂覆多孔LSCF来实现。与d_化学确定的，基线数据被进一步精制以获得ķ_化学作为唯一的拟合参数，并且在所有测试条件下，误差范围均减小至原始值的70％以上。随着k _chem和D _chem的准确性和灵敏度的显着提高，该证明的方法被证明是推进ECR应用的实用方法。