Fabrication of Hydrocarbon Membrane based DMFC MEAs with Low Temperature Decal Method

탄화수소계 전해질막과 저온 전사법을 이용한 DMFC용 MEA 제조

A low temperature decal (LTD) transfer method is tried to fabricated hydrocarbon (HC) membrane based MEA. Sandwiched structures of outer ionomer/catalyst/carbon coating/substrate, which had been developed for Nafion membrane, are used for transfer of catalyst to the HC membrane. Performances of the HC MEA before and after 500hr continuous operation are compared and it is found that a severe delamination occurs at the interface between the HC membrane and the catalyst layer, which is the main reason of the low performance and its degradation. The delamination is due probably to the different nature of HC membrane to the Nafion ionomer. A substitutional method, therefore, is suggested to overcome this. In such a way, the outer ionomer process is removed and the low transfer rate of catalyst by skipping the ionomer process is compensated with optimization of other process variables such as transfer time or temperature. The resulting performance is superior to the original LTD method, which can be explained in terms of low resistive components both in ohmic and kinetic.