On the use of activated carbon as a quasi-reference electrode in non-aqueous electrolyte solutions

The application of high surface area activated carbon (AC) as a convenient quasi-reference electrode (QRE) in non-aqueous electrolyte solutions is evaluated. By calibration against the ferrocene/ferrocenium ion redox system, the potential of the AC QRE investigated in this work was found to lie close to +3 V vs. Li/Li+ for several non-aqueous electrolyte solutions and to exhibit drifts of less than +1 mV/day at room temperature for certain electrolyte solutions. AC QREs are thus proposed as suitable alternatives to other QREs with the distinct advantages that no additional ionic impurities are introduced into the electrochemical system under investigation, no potential-determining redox system is required and the electrode potential is less influenced by changes in the concentration of redox-active species in the electrolyte solution.