Layer double hydroxides (LDHs) are defined as a class of lamellar hydroxides with two or more kinds of metallic cations in the main layers and interlayers containing exchangeable hydrated anions.  In an effort to improved membrane performance in fuel cells, this work focuses on the preparation and characterization of layered double hydroxides.  Layered double hydroxides prepared and characterizaed in this work include LiAl₂(OH)₇ •2H₂O, Mg₃Al(OH)₈(NO₃) •2H₂O and Mg₃Al(OH)₉•2H₂O.  These materials were prepared by coprecipitation, anion-exchange or rehydration methods.  They were characterized by, scanning electron microscopy (SEM) with an energy-dispersive spectrometer (EDS), thermogravimetric analysis (TGA), infrared spectroscopy, Raman spectroscopy, powder x-ray diffraction (XRD), and ionic conductivity measurements.  Preliminary results show anion conductivity measurements for MgAl(OH)₈(NO₃) •2H₂O and LiAl₂(OH)₇•2H₂O are 5.2 x 10^-3 S/cm and 3.0 x 10^-2 S/cm, respectively.  The conductivity for LiAl₂(OH)₇•2H₂O is higher than the measured conductivity for commercial anion exchange membranes AHA and FAA (1-2 x 10^-2 S/cm).  This suggests significant promise for the use of layered double hydroxides in fuel cells.  There is continued research on the synthesis and characterization inorganic membranes and inorganic-organic composite membranes containing LDHs.