A highly accurate, inexpensive procedure for computing theoretical chronoamperometric current at cylindrical wire electrodes

Cylindrical wire or fiber electrodes are attractive for electro-analytical applications, but the theory of transient methods at such electrodes is complicated, implying that theoretical discussions and experimental data analysis usually rely on various approximations. In particular, a number of approximate expressions has been proposed in the literature to describe the chronoamperometric limiting current at such electrodes. All these expressions have a low accuracy. In the present work a new, highly accurate and computationally inexpensive procedure for computing the current is presented. The procedure relies on local polynomial approximations covering the entire time domain, and provides at least 14–15 significant digits. It can therefore be useful both for theoretical purposes (e.g. as a source of reference values for testing electrochemical digital simulation techniques that are usually less accurate), and for the analysis of the experimental data.