Accession Number : ADA581715


Title :   Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes


Descriptive Note : Journal article


Corporate Author : CONNECTICUT UNIV STORRS DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Kiss, Andrew M ; Myles, Timothy D ; Grew, Kyle N ; Peracchio, Aldo A ; Nelson, George J ; Chiu, Wilson K


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a581715.pdf


Report Date : 25 Jun 2013


Pagination or Media Count : 9


Abstract : Anion exchange membranes (AEMs) are being developed for potential use in fuel cell systems which include portable power applications. In a fuel cell, these membranes transport hydroxide ions from the cathode to the anode. If carbon dioxide is present, carbonate and bicarbonate ions can form, displacing the hydroxide ions. Among the challenges this presents, the carbonate and bicarbonate are less mobile than the hydroxide and therefore the ionic conductivity of the membrane suffers. A procedure is outlined to take data from a permeation based water flux experiment and determine diffusion coefficients and the ionic conductivity of the membrane. The water-membrane diffusion coefficients can be measured from a water flux experiment. Using principles from kinetic theory, the water-membrane diffusion coefficient can be converted to an appropriate ion-membrane diffusion coefficient. Finally, an equation derived from the dusty fluid model can be used to calculate the ionic conductivity of the membrane in different counter ion forms. The calculated ionic conductivities have been shown to agree well with reported values for proton and anion exchange membranes.


Descriptors :   *BICARBONATES , *CARBONATES , *ION EXCHANGE , HYDROXIDES , MEMBRANES


Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrochemical Energy Storage


Distribution Statement : APPROVED FOR PUBLIC RELEASE