Solid redox polymerization electrode

SMC-II SMC, low-pressure molding SRPE solid redox polymerization electrode... 

Lampert and coworkers [36] have used a modified amorphous PEO-LiCFaSOs electrolyte for the realization of WO3 laminated windows using several types of counter-electrodes, such as niobium oxide, nickel oxide and a new class of solid redox polymerization electrodes [63]. These latter electrodes have an advantage over inorganic layers in that they can be tailored to the electrochromic material and ion specifically. Figure 8.18 illustrates the optical transmittance of a EW made of WOa/modified a-PEO/ion storage polymer [63]. 

Poly- and copoly(disulfide)s as electroactive materials have been used successfully in the lithium/poly(ethylene oxide)/(solid redox polymerization electrodes) (Li/PEO/SRPE) battery system (96). The high level of performance of these polymeric materials in thin-film Li/PEO batteries demonstrates the versatility of the SRPE and indicates that such batteries may be useful for a wide range of applications. 

Liu M, Viseo SJ, De Jonghe LC (1991) Novel solid redox polymerization electrodes all-solid-state, thin-film, rechargeable lithium batteries. J Electroehem Soc 138(7) 1891-1895... 

The superior mechanical properties of elastomeric electrolytes, combined with the simplicity of fabrication of thin separator films from these materials, has led to very active pursuit of solid state cells based on solid polymeric materials. However, the development of a novel class of solid state or nic positive electrodes which not only operate on an entirely new principle for energy storage, but have demonstrated performances in a number of instances exceeding those for intercalation electrodes in solid state hthium and sodium batteries. These new electrodes have been called solid redox polymerization electrodes (SRPE) and arc based on polysulfide polymers [-S(R) 0 (R) S-] where R is an organic radical such as CH3, QH, CF3, etc. The redox mechanism for the positive electrode is in essence a redox dimeriza-tion/scission reaction which occurs in two steps as... 

The first and very simple solid contact polymeric sensors were proposed in the early 1970s by Cattrall and Freiser and comprised of a metal wire coated with an ion-selective polymeric membrane [94], These coated wire electrodes (CWEs) had similar sensitivity and selectivity and even somewhat better DLs than conventional ISEs, but suffered from severe potential drifts, resulting in poor reproducibility. The origin of the CWE potential instabilities is now believed to be the formation of a thin aqueous layer between membrane and metal [95], The dominating redox process in the layer is likely the reduction of dissolved oxygen, and the potential drift is mainly caused by pH and p02 changes in a sample. Additionally, the ionic composition of this layer may vary as a function of the sample composition, leading to additional potential instabilities. 

Figure 10. Complex impedance plot expected for thin layer redox polymeric film on solid electrode 1 and 2 represent mass transfer controlled region for different thickness of the film. 

An example is shown in Fig. 6.31 for a polymer with a redox couple M /M that is attached to the silicon surface through chemical bonding. On illumination is converted to M. The resulting oxidized surface is then capable of oxidizing a second species B to B. The redox species B is not efficient in capturing holes directly from silicon due to its distance from the valence band. When the Si surface is covered with a polymer, the location of electron transfer is within the polymeric film rather than at the solid interface. " The photocurrent response of derivatized electrode is similar to that of bare silicon surface but the stability is significantly improved. ... 

Garcia et al. [98] conducted coulometric initiation of acrylamide polymerization in oil-continuous AOT-toluene-water microemulsions using platinum/Nafion solid polymer electrodes (SPEs). The SPE served to separate the microemulsion from an aqueous electrolyte phase. Polymerization was initiated at room temperature by constant-potential electrolytic reduction of potassium persulfate initiator solubilized in the microemulsion droplets. Acrylamide monomer behaved as a cosurfactant and was required for the redox process. Latex particles and solid polyacrylamide were obtained. The kinetics of electroinitiated polymerization was slower than observed with UV or thermal initiation. Latex stability results suggest that coalescence is the primary mechanism for particle growth. 

Hashmi and Upadhyaya compared the electrochemical properties of the electrochemically synthesized MnO /PPy composite electrodes, fabricated with different electrolytes, namely polymer electrolyte film (polyvinyl alcohol [PVA]-HjPO aqueous blend), aprotic liquid electrolyte (LiClO -propylene carbonate [PC]), and polymeric gel electrolyte (poly methyl methacrylate [PMMA]-ethylene carbonate [EC]-PC-NaClO ) [60]. The cell with aqueous PVA-H PO showed non-capacitive behavior owing to some reversible chemical reaction of MnO with water, while the MnO / PPy composite was found to be a suitable electrode material for redox supercapacitors with aprotic (non-aqueous) electrolytes. The solid-state supercapacitor based on the MnO /PPy composite electrodes with gel... 

Hashmi SA, Suematsu S, Naoi K (2004) All solid-state redox snpracapacitors based on supramolecular 1,5-diaminoanthraquinone oligomeric electrode and polymeric electrolytes. J Power Sources 137 145-151... 

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