초록 ▼

The invention relates to a membrane electrode unit (MEU) for electrochemical apparatuses, in particular for direct methanol fuel cells (DMFC). The membrane electrode unit contains backings (i.e. gas diffusion layers) on the anode side and cathode side, which have a different water tightness (WT). Th

The invention relates to a membrane electrode unit (MEU) for electrochemical apparatuses, in particular for direct methanol fuel cells (DMFC). The membrane electrode unit contains backings (i.e. gas diffusion layers) on the anode side and cathode side, which have a different water tightness (WT). The anode backing must have a lower water tightness (i.e. a higher water permeability) than the cathode backing, where WTAnodeWTCathode. The anode backing preferably has no compensating layer (microlayer), has a lower content of water repellent (from 2 to 10 wt.-%, based on the total weight) and has a higher total pore volume (VTot) than the cathode backing. The membrane electrode units produced have a substantially improved performance in DMFC fuel cells which are operated with aqueous methanol solution.

대표청구항 ▼

1. Membrane electrode unit for direct methanol fuel cells (DMFC), comprising five layers, namely an ion-conducting membrane, at least one anode electrode layer, at least one cathode electrode layer, at least one anode backing and at least one cathode backing, wherein, said ion-conducting membrane is

1. Membrane electrode unit for direct methanol fuel cells (DMFC), comprising five layers, namely an ion-conducting membrane, at least one anode electrode layer, at least one cathode electrode layer, at least one anode backing and at least one cathode backing, wherein, said ion-conducting membrane is in the middle, the two backings are attached on either side of the membrane and the electrode layers are present between the membrane and the respective backings,the anode backing has no compensating layer between a backing surface of the anode backing and the anode electrode layer,the anode backing has a lower water tightness (WT) than the cathode backing, andthe following is applicable: WTAnode