Discharging, of conducting polymers

Electrochemically stimulated conformational relaxation model (ESCR model) — This model [i, ii] describes the relaxation phenomena occurring during the charging and discharging of -> conducting polymers. It assumes that applying an anodic -> overpotential to a neutral conjugated polymer, as a first step, an expansion of the closed polymeric structure occurs. In this way, partial oxidation takes place and counter ions from the solution enter the solid polymer under the influence of an electrical field at those points of the polymer/electrolyte... 

As already mentioned, the principle of electroneutrality must be fulfilled in charged polymers. Consequently, in freshly prepared p-doped polymers, anions must compensate the positive charges within the polymeric chains. However, spectroelectrochemical studies [114], electrochemical quartz microbalance (EQMC) measurements [115], and SIMS and XPS measurements [116] on the mechanism of ion transport during charging and discharging of conducting polymers prove that discharging involves not only the expulsion of... 

The diffusion of dopants into, and out of, conducting polymers is important for possible applications in batteries, and as conductors or semiconductors. For conductors or semiconductors, the chief requirements are that the material can be doped in a reasonable time, but that it will then not lose dopant over periods of years. This is particularly important in determining junction stability in devices. In the case of batteries, on the other hand, rapid and reversible uptake and loss of dopants is needed, since the diffusion rate controls charging and discharging rates. In addition, the accessibility of the structure to oxygen, and other degradants, will be a factor in the stability of the polymer. 

Redox conductivity of conducting polymers involves anion insertion associated to oxidation processes (p-type doping) and cation insertion coupled with reduction ones (n-type doping). Efficient polymer-based electronic devices require lowering of the redox potential of the involved electron transfer processes, and electrochemical reversibility is necessary to allow repetitive charge/discharge processes. In the... 

A new PsC wholly based on electrodes of conducting polymers (both the cathode and the anode) was suggested for energy storage. The cathode was PPy and the anode was a styryl-substituted dialkoxy terthiophene (poly(OC(lO)DASTT)) on Ni/Cu-coated nonwoven polyester. The discharge performance was 94% the specific charge was 39.1 mAh/g. 

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