Redox Capacity and DC Electron Conductivity in Electroactive Materials

摘要

The storage and transport of charge in electroactive materials are closely related. We develop the macroscopic concepts of redox capacity, rho, and DC electronic conductivity, sigma subscript e/rho. Their ratio, De = Sigma subscript e/rho, is identified as the electron diffusion coefficient. A microscopic model is developed incorporating interaction among the stored electrons and variation of counterion activity as a function of electrochemical potential. Data obtained for the polymer poly Os(2,2'-bipyridine)2(4-vinylpyridine 2 (C104) x (x = 0-3) are compared with the model. The dependence of the electron diffusion coefficient on electrochemical potential is particularly revealing of discrepancies between the real material and the model, suggesting that this quantity will be a useful parameter for the characterization of a variety of electroactive materials. (Author)