Abstract
This presentation will describe the development of a new type of radiation-grafted anion-exchange membrane (RG-AEM) made from high-density polyethylene (HDPE) base material, which contains benzyltrimethylammonium cationic head-group chemistry. This RG-AEM has an ion-exchange capacity (IEC) of 2.4 meq g
-1
, and is less than 30 μm in thickness (when fully hydrated) with an ultimate tensile strength of ca. 35 MPa (elongation to break of 280 %). It exhibits a hydroxide conductivity of 214 ± 2 mS cm
-1
at 80 °C in a 100% relative humidity (RH) atmosphere, which decays to 195 mS cm
-1
after 500 h exposure to these same
ex situ
conditions.
Despite exhibiting similar
ex situ
characteristics to a low-density polyethylene (LDPE) analogue RG-AEM (of similar hydrated thickness and IEC), the HDPE-RG-AEM yields significantly higher beginning-of-life H
2
/O
2
-benchmark alkaline membrane fuel cell power densities (see Figure): 2.55 W cm-2 peak power density was achieved at 80 °C with 92% RH H
2
/O
2
gas supplies (no back pressure applied). Internal area specific resistances of < 30 mΩ cm
2
were recorded.
Figure 1