Tipo
Artigos em Conferência
Tipo de Documento
Poster without full or short paper
Título
Monitoring the optical properties and swelling of low temperature synthesized PEDOT:PSS films during redox conversion
Participantes na publicação
Daniel R. Santos (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Jorge F. Zeferino (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Ana S. Viana (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Upul Wijayantha (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Killian Lobato (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Jorge P. Correia (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Resumo
Lithium-ion batteries are, nowadays, the energy storage system with the most widespread use but, at this moment, there are insufficient lithium resources, consequently causing an unbalanced demand for this metal [1]. In terms of availability of raw material resources, sodium-ion batteries appear as a promising alternative. This change implies the design of new cathode materials capable of accommodating a larger ion [2]. The cathodic structure must be chemically stable and extremely light [3] to balance the mass increase of the storage unit, imparted by the lithium replacement by sodium. An electronically conducting polymer with pseudocationic doping character may fulfil these requirements.\nIn this work poly(3,4-ethylenedioxythiophene) doped with poly(styrene-4-sulfonate) (PEDOT:PSS) films were galvanostatically synthesized at 0ºC for different time intervals (10 s – 50 s) on platinum electrodes from aqueous solutions containing the monomer and the polyanion. A proper and uncommon strategy was applied to assess the polymer optical properties and thickness variation as a function of the potential applied, during redox conversion. Therefore, the redox behaviour of films synthesized with different growth charges in aqueous medium, was monitored by cyclic voltammetry at room temperature in NaClO4 containing acetonitrile solution, with simultaneous recording of ellipsometric parameters. The plotting of psi vs. delta of the different films at selected potential values, allowed to simulate the films growth effect on the dielectric constants at different degrees of doping, as a function of their thickness. The optical constants obtained allow accessing the polymer properties imparted by the low temperature synthesis, as well as the swelling/shrinking behaviour related to the pseudocationic character of the doping process. Further support of the adequacy of the model used to compute the relevant ellipsometric information was provided by in-situ UV-Vis reflectance spectrophotometry experiments. \n
Data de Publicação
2022-07
Instituição
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Evento
2nd Chem & BioChem Students Meeting
Identificadores da Publicação
Local
Lisboa, Portugal
Keywords
Sodium-ion batteries
PEDOT:PSS
in-situ Ellipsometry
in-situ UV-Vis Reflectance Spectrophotometry