A Controlled-Potential and Controlled-Current Cyclic Voltammeter†

Abstract

An instrument has been designed and constructed to be used primarily for electrochemical investigations in molten salt systems. It operates in either a controlled-potential or controlled-current mode. In the controlled-potential mode it may be used for linear potential sweep voltammetry or chronoamperometry; in the controlled-current mode, for chronopotentiometry with control of the initial potential. Fast electronic switching circuitry permits reversal of the sweep direction or current polarity, or termination of the experiment at preselected electrode potentials. Easily implemented extensions of the basic operating modes are discussed. The potentiostat is designed to deliver 100 mA at ±10 V, but larger transient currents can be accommodated. Accurate, calibrated sweep rates of 0.005 to 500 V/sec make the instrument suitable for kinetics studies. The rapid sweep rates also are used to advantage to minimize the effects of convective mass transport.