The performance of proton exchange membrane is mainly influenced by water content and distribution in proton exchange membrane for PEM fuel cell, and influence factors of the water content and the distribution in memb...
详细信息
The performance of proton exchange membrane is mainly influenced by water content and distribution in proton exchange membrane for PEM fuel cell, and influence factors of the water content and the distribution in membrane mainly include the pressure, the temperature, the electric current and so on. This text has discussed the influence of pressure to water content and distribution in proton exchange membrane, and we made the ingenious experimental design to measure directly the distribution of water content in membrane. We have got the disciplines of water content and distribution in membrane under pressure. Experiment reveals that the influence of pressure to water content in membrane is small and water distribution among membrane is average, these conclusions do not accord with model completely.
This paper introduced the preparation of zinc oxide whiskers with different morphology. The result of SEM showed that one was multi-needle whiskers, the other was hexagonal rods. The result of the XRD indicated that t...
详细信息
This paper introduced the preparation of zinc oxide whiskers with different morphology. The result of SEM showed that one was multi-needle whiskers, the other was hexagonal rods. The result of the XRD indicated that the production structure was wurtzite, which was mixed with hydrocarbon. The results of SEM indicated that the mixture had an important effect on the the morphology of the whiskers.
In this paper, fuel cell testing process was summarized. From the calibration of test station, parameters record and testing process, we analyzed the process and experiment condition which must be standardized in orde...
详细信息
In this paper, fuel cell testing process was summarized. From the calibration of test station, parameters record and testing process, we analyzed the process and experiment condition which must be standardized in order to obtain repeatable, reproducible and scaleable parameters of the performance and durability. Due to the process of fuel cell working is a complicated balanceable system including mass transfer, electrochemical reaction and thermo transfer etc, the fuel cell testing is consequentially a rigorous testing process. Every tache of it was restricted by the other, and every restricted factor will maybe influence the test results. So, a exhaustive testing protocol must be established.
Nafion/PTFE composite membranes based on different ePTFE were prepared in this work. Porous PTFE was perfectly impregnated by Nafion resin. The differences of mechanical properties such as tensile strengths and dimens...
详细信息
Nafion/PTFE composite membranes based on different ePTFE were prepared in this work. Porous PTFE was perfectly impregnated by Nafion resin. The differences of mechanical properties such as tensile strengths and dimensional changes were analyzed in this paper. From electrochemical and single cell tests, the optimum thickness of porous PTFE for the composite membrane is 15 μm. The performance of the composite membrane based on the 15 μm-thick porous PTFE was 0.664 V at 600 mA/cm2, which was higher than Nafion111 membrane at the same conditions.
The gas diffusion layer (GDL) durability of proton exchange membrane fuel cell (PEMFC) was reviewed. The testing methods and the characterization of the durability of GDL were summarized in this paper. The degradation...
详细信息
The gas diffusion layer (GDL) durability of proton exchange membrane fuel cell (PEMFC) was reviewed. The testing methods and the characterization of the durability of GDL were summarized in this paper. The degradation mechanisms of GDL were analyzed through discussion. The research trends of the GDL were proposed as well.
This paper modeled a single cell with active area of nearly 50 cm2 by the CFD software of Fluent and discussed the influence of cooling water on the temperature distribution of membrane. The results show that most of ...
详细信息
This paper modeled a single cell with active area of nearly 50 cm2 by the CFD software of Fluent and discussed the influence of cooling water on the temperature distribution of membrane. The results show that most of the cooling water's temperature is low, the effect of heat exchange is bad;At the high current density, cooling water with the same flow direction of reactant gas has better effect on improving temperature distribution in the fuel cell. Increasing overall flow velocity and depressing the inlet temperature of cooling water has little effect on improving temperature distribution.
High alumina cement/graphite conductive composites were prepared by mold pressing at room temperature. Electrical conductivity was measured and the composite morphology was investigated by scanning electron microscope...
详细信息
High alumina cement/graphite conductive composites were prepared by mold pressing at room temperature. Electrical conductivity was measured and the composite morphology was investigated by scanning electron microscope (SEM). The heat stability and water content of conductive composites were also studied under proton exchange membrane fuel cell (PEMFC) operating temperature. The test results show that the percolation phenomenon is exist in the composite bipolar plate, the threshold value is 8%-10%;moreover, the composite bipolar plate has excellent heat stability and self- humidification.
Metal-N-H is considered as one of the most-potential hydrogen storage materials as on-board applications for its high gravimetric hydrogen content at relatively gentle condition. The research development of conversion...
详细信息
Metal-N-H is considered as one of the most-potential hydrogen storage materials as on-board applications for its high gravimetric hydrogen content at relatively gentle condition. The research development of conversion from Li-N-H to Mg-N-H is presented, two types of possible reaction mechanisms are discussed and three amide-synthesizing methods are introduced. The unsolved problems of development and application of the Metal-N-H system are also generalized.
Different humidification of proton exchange membrane fuel cells were investigated using PEM module of fluent software. Influence of different humidification degrees on performance of PEM fuel cell was studied, especia...
详细信息
Different humidification of proton exchange membrane fuel cells were investigated using PEM module of fluent software. Influence of different humidification degrees on performance of PEM fuel cell was studied, especially influence of Concentration polarization on PEM fuel cell performance was discussed in the high current density. 0%, 50% and 100% humidification of 80°C cathode gas were contrasted. The results showed that 100% humidification was better at low current density, while at high current density, 50% humidification was better. The relation between the performance of fuel cell and the distribution of O2 and H2O mol concentration on the interface between cathode diffusion layer and catalyst layer were analyzed. The results showed only partial regions of catalyst layer exist concentration polarization. Taking properly humidification can obtain higher performance in different current density.
The α-Fe fibers were prepared successfully by the method of electrodepositing in porous alumina template. The results indicated that the diameter of the fibers was 300 nm and the length of them increased along with t...
详细信息
The α-Fe fibers were prepared successfully by the method of electrodepositing in porous alumina template. The results indicated that the diameter of the fibers was 300 nm and the length of them increased along with the electrodepositing time increasing. The saturation magnetization per m2 of the iron fibers increased with the increasing of the length/diameter ratio, but the coercive field decreased.
暂无评论