Recent advances in electrochemical impedance measurement

Summary form only given as follows: Accurate measurements of electrochemical impedance requires highly sophisticated instrumentation, especially in applications where small stimulating signals are employed. The combination of a frequency response analyser (FRA) and a potentiostat are the most widely utilised for these applications, but have limitations when measuring high impedances, or high frequency (>1 MHz). Some of these may be overcome by using an impedance analyser instead of the traditional FRA/potentiostat arrangement. The authors review the operating principles of AC measurement instrumentation and compare the different techniques available (single-sine, FFT, etc.). The differences between the FRA/potentiostat combination are discussed, and the applications and benefits presented. Finally, a number of experimental techniques are suggested which may enable better impedance measurements to be obtained; these compromise both simple experimental precautions and use of advanced instrumentation functions to obtain improved results