Accession Number : ADA622747


Title :   Mechanical Characterization of Anion Exchange Membranes Under Controlled Environmental Conditions


Descriptive Note : Doctoral thesis


Corporate Author : COLORADO SCHOOL OF MINES GOLDEN


Personal Author(s) : Caire, Benjamin R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a622747.pdf


Report Date : 11 May 2015


Pagination or Media Count : 125


Abstract : While proton exchange membrane (PEM) fuel cells have been the focus of development in the past, anion exchange membranes (AEM) have the potential to dramatically lower the cost of fuel cells by utilizing non-noble catalysts and a variety of fuel sources. Although chemical degradation typically dominates membrane failure pathways in a fuel cell, mechanical breakdown due to humidity cycling is a common occurrence. This thesis aims to understand the mechanical properties of anion exchange membranes under fuel cell operating conditions. A humidity delivery system was developed for the TA Instruments ARES-G2 rheometer to allow for testing at a range of temperatures (30-100 C) and relative humidity conditions (0-95% RH). A modified Sentmanat Extensional Rheometer (SER) was used to perform tensile-like testing using less than 5% of material needed for a traditional tensile tester. These tools established metrics for a robust membrane through mechanical characterization across temperatures and humidities. A pentablock AEM with a balance of stiff and elastic blocks was shown to have adequate conductivity (up to 60 mS/cm at 90 C and 95%RH), low water uptake (25%), and good mechanical integrity under dry and hydrated conditions, showing potential for being durable under hydration and mechanical stresses.


Descriptors :   *FUEL CELLS , *ION EXCHANGE , ABSORPTION , BALANCE , CATALYSTS , CHEMICAL ATTACK(DEGRADATION) , CONDUCTIVITY , COSTS , CYCLES , DELIVERY , ELASTIC PROPERTIES , FAILURE(MECHANICS) , FUELS , HUMIDITY , HYDRATES , HYDRATION , INSTRUMENTATION , MECHANICAL COMPONENTS , MECHANICAL PROPERTIES , MEMBRANES , MOISTURE CONTENT , PRECIOUS METALS , PROTONS , RHEOMETERS , SOURCES , STRESSES , TEMPERATURE , TENSILE TESTERS , THESES , TOOLS , WATER


Subject Categories : Physical Chemistry
      Electrochemical Energy Storage


Distribution Statement : APPROVED FOR PUBLIC RELEASE