A novel method for the preparation of a self-humidifying MEA used for PEMFC and the optimum conditions for the fabrication are presented. Different from the method involved dispersion of Pt particles through out the m...A novel method for the preparation of a self-humidifying MEA used for PEMFC and the optimum conditions for the fabrication are presented. Different from the method involved dispersion of Pt particles through out the membrane or between two thin membranes. The new type self-humidifying MEA gain self-humidifying operation by asymmetry electrode. The anode with 0.1 mg Pt/cm 2, has super-hydrophilicity by coating the hydrophilic colloid, while the cathode with 0.4 mg Pt/cm 2, has a strong hydrophobic nature by doping PTFE. When the current density is less than 2.3 A/cm 2, the discharge performance of the humidifying gases little excel the self-humidifying operation, but more than 2.3 A/cm 2, the self-humidifying operation do better than humidifying gases operation, and the most power density reaches over 1.5 W/cm 2. Inner resistance of electrochemistry reaction and transportation are studied by the AC impedance method, and validate that the self-humidifying MEA can give a good three-dimension reaction area with dry hydrogen and dry oxygen.展开更多
Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in...Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in the membrane electrode assembly (MEA) of each cell, in which the moisture of the cathode exhaust gas could transfer through the membrane to humidify anode or cathode dry gas. With a simple model, the relative humidity (RH) of the dry air exhaust from a membrane humidifier with 100% RH stream as a counter flow is calculated to be 60.0%, which is very close to the experimental result (62.2%). Fuel cell performances with hydrogen humidifying, air humidifying and no humidifying are compared at 50, 60 and 70°C and the results indicate that humidifying is necessary and the novel design with humidifying zone in MEA is effective to humidify dry reactants. The hydrogen humidifying shows better performance in short term, while water recovered is limited and the stability is not as good as air humidifying. It is recommended that both air and hydrogen should be humidified with proper design of the humidifying zones in MEA and plates.展开更多
文摘A novel method for the preparation of a self-humidifying MEA used for PEMFC and the optimum conditions for the fabrication are presented. Different from the method involved dispersion of Pt particles through out the membrane or between two thin membranes. The new type self-humidifying MEA gain self-humidifying operation by asymmetry electrode. The anode with 0.1 mg Pt/cm 2, has super-hydrophilicity by coating the hydrophilic colloid, while the cathode with 0.4 mg Pt/cm 2, has a strong hydrophobic nature by doping PTFE. When the current density is less than 2.3 A/cm 2, the discharge performance of the humidifying gases little excel the self-humidifying operation, but more than 2.3 A/cm 2, the self-humidifying operation do better than humidifying gases operation, and the most power density reaches over 1.5 W/cm 2. Inner resistance of electrochemistry reaction and transportation are studied by the AC impedance method, and validate that the self-humidifying MEA can give a good three-dimension reaction area with dry hydrogen and dry oxygen.
基金Supported by the National High Technology Research and Development Program of China (2008AA05Z104)
文摘Water management is of great importance to maintain performance and durability of proton exchange membrane fuel cells. This paper presents a novel proton exchange membrane (PEM) fuel cell with a humidification zone in the membrane electrode assembly (MEA) of each cell, in which the moisture of the cathode exhaust gas could transfer through the membrane to humidify anode or cathode dry gas. With a simple model, the relative humidity (RH) of the dry air exhaust from a membrane humidifier with 100% RH stream as a counter flow is calculated to be 60.0%, which is very close to the experimental result (62.2%). Fuel cell performances with hydrogen humidifying, air humidifying and no humidifying are compared at 50, 60 and 70°C and the results indicate that humidifying is necessary and the novel design with humidifying zone in MEA is effective to humidify dry reactants. The hydrogen humidifying shows better performance in short term, while water recovered is limited and the stability is not as good as air humidifying. It is recommended that both air and hydrogen should be humidified with proper design of the humidifying zones in MEA and plates.
