Investigation Of The Effects Of Speek And Its Clay Composite Membranes On The Performance Of Direct Borohydride Fuel Cell

Autor: Kürşat Can Ata, Ramiz Gültekin Akay, Tuncay Kadıoğlu, Anil Can Turkmen, Cenk Celik
Rok vydání: 2020
Předmět:
Popis: In this study, composite cation exchange membranes (CEM) were developed. With the experience from widely studied proton exchange membrane fuel cells (PEMFC), sulfonated polyether ether ketone (SPEEK) was prepared to be a more effective and cheaper ionomer alternative to the industry standard Nafion (R). SPEEK polymer membrane can reach sufficient ionic conductivities but have some mechanical and chemical stability problems (at a high degree of sulfonations (DS)). Therefore, in order to optimize the membrane, composite mixing with a well-known organic/inorganic clays called Cloisite (R) 15A, Cloisite (R) 308 and MMT were used. Test cells for both single-cell and conductivity were designed and constructed. The ionic conductivity cell was different than the ones used in most studies, measuring conductivity in-plane with 4 probes using EIS. The membranes were characterized for their proton conductivity with electrochemical impedance spectroscopy (EIS), for DS with H NMR, water uptake, and fuel cell performance tests. First results showed that the acidic sulfonic groups of SPEEK interacted with organic/inorganic clays and as a result of partial barrier the ionic conductivity was decreased but power densities were increased. SPEEK-Cloisite (R) 30B composite membrane has given 40 mW/cm(2) power density value which is higher than pure SPEEK membrane (35 mW/cm(2)). The proton conductivities of the final composite membranes were close to bare SPEEK membranes which are 0,065 and 0,075 S/cm for SPEEK-Cloisite (R) 30B and pristine SPEEK, respectively. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Databáze: OpenAIRE