In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2019-04, No. 3 ( 2019-06-30), p. 157-157
Abstract:
Heterogeneous electron transport (HET) is important in many technologies, including batteries, fuel cells, medical sensors, organic electrochemical synthesis, food analysis, corrosion protection, and thermogalvanic cell. HET takes place at the interface between a solid electrode and a reactant in a liquid electrolyte, and it depends on the type of reactants, electrodes, solvents, and electrolyte. HET has been well studied for metal, semiconductor, metal oxide, carbon electrode. The current passing at the electrode/electrolyte interface is related to the density of electronic states of the electrode, the concentration of reactant and the rate of electron transfer and the electronic level of the reactant in the solution Here, we study the HET between a conducting polymer electrode and a redox electrolyte, and we found that a new phenomenon is observed. Conducting polymers possess a unique combination of properties compared with most of the inorganic electrodes: acid resistance, the absence of surface-insulating oxide, low temperature and solution processability, a high natural abundance of their elements, molecular porosity. Conducting polymers are in-homogeneous conductors composed of ordered and disordered regions through which electronic transport takes place via percolation paths. We studied the heterogeneous electron transport between the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and redox electrolyte ferro/ferricyanide in an aqueous electrolyte. We discovered that the density of percolation paths in the bulk of the material dictates the rate of electron transfer at the electrolyte–polymer electrode interface. This reveals one of the key parameters of designs to achieve efficient electrochemical technologies based on polymer electrodes. We use this finding to optimize the electrical power generated by a thermogalvanic cell (TGC), which is an electrochemical device that converts heat energy into electricity. The power produced by the TGC increased by four orders of magnitude upon changing the morphology and electrical conductivity of the PEDOT electrode. References: Wijeratne K, Vagin M, Brooke R, & Crispin X (2017) Poly(3,4-ethylenedioxythiophene)-tosylate (PEDOT-Tos) electrodes in thermogalvanic J. Mater. Chem. A 5:19619 –19625. Wijeratne K, Ail U, Brooke R, Vagin M, Liu X, Fahlman M, & Crispin X (2018) Bulk electronic transport impacts on electron transfer at conducting polymer electrode-electrolyte interfaces. PNAS, 115:11899 - 11904.
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2019-04/3/157
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2019
detail.hit.zdb_id:
2438749-6
Permalink