Protonic conductivity and fuel cell tests of nanocomposite membranes based on bacterial cellulose
authors Gadim, TDO; Loureiro, FJA; Vilela, C; Rosero-Navarro, N; Silvestre, AJD; Freire, CSR; Figueiredo, FML
nationality International
journal ELECTROCHIMICA ACTA
author keywords Bacterial cellulose; poly(4-styrene sulfonic acid); Nanocomposite membrane; Protonic conductivity; Fuel cell
keywords POLYMER ELECTROLYTE MEMBRANES; THROUGH-PLANE; COMPOSITE MEMBRANES; EXCHANGE MEMBRANES; PEMFCS; TRANSPORT; PROGRESS
abstract The effect of the preferential orientation of supporting bacterial cellulose (BC) nanofibrils on the conductivity of composite proton conducting electrolytes with poly(4-styrene sulfonic acid) (PSSA) is reported. Data obtained by impedance spectroscopy show that the in-plane conductivity at 40% relative humidity (RH) is more than half order of magnitude higher than that measured through-plane, indicating significant discontinuity of proton transport at the PSSA/BC interface. The difference becomes less than 20% in nearly saturated conditions (98% RH), demonstrating the key role of water in ensuring proton transport through those interfaces. The negative impact of the conductivity anisotropy in fuel cell performance is mitigated due to operation in wet conditions and fuel cell tests of PSSA/BC-based membrane electrode assemblies under humidified hydrogen/air gradients at room temperature yield 40 mW cm(-2) at 125 mA cm(-2), which is amongst the highest values reported for a biopolymer-based electrolyte. It also results from the presented investigation that conventional electrode preparation used for thermoplastic polymer electrolytes must be modified in order to ensure proper adhesion to BC-based MEAs and thus to lower polarization losses. (C) 2017 Elsevier Ltd. All rights reserved.
publisher PERGAMON-ELSEVIER SCIENCE LTD
issn 0013-4686
year published 2017
volume 233
beginning page 52
ending page 61
digital object identifier (doi) 10.1016/j.electacta.2017.02.145
web of science category Electrochemistry
subject category Electrochemistry
unique article identifier WOS:000398328000006

Events
Sponsors

1suponsers_list_ciceco.jpg