Performance of a direct methanol fuel cell

The performance of a direct methanol fuel cell based on a Nafion® solid polymer electrolyte membrane (SPE) is reported. The fuel cell utilizes a vaporized aqueous methanol fuel at a porous Pt–Ru–carbon catalyst anode. The effect of oxygen pressure, methanol/water vapour temperature and methanol concentration on the cell voltage and power output is described. A problem with the operation of the fuel cell with Nafion® proton conducting membranes is that of methanol crossover from the anode to the cathode through the polymer membrane. This causes a mixed potential at the cathode, can result in cathode flooding and represents a loss in fuel efficiency. To evaluate cell performance mathematical models are developed to predict the cell voltage, current density response of the fuel cell.  

纳米复合在光聚合高分子固体电解质中的应用研究

将纳米级陶瓷粉末分散到含有高分子基体预聚物、高氯酸锂及光引发剂的光敏物质中 ,并通过紫外光辐射使其交联固化为导电薄膜锂聚合物电池用电解质材料 ,并对其成膜性、感光性能以及导电性能进行了研究 ;本文还介绍了近年来纳米复合材料在锂聚合物电池中的应用进展情况  

Methanol-tolerant electrocatalysts for oxygen reduction in a polymer electrolyte membrane fuel cell

Heat-treated -oxo-iron(iii) tetramethoxy phenyl porphyrin (Fe-TMPP)2O and iron(iii) tetramethoxy phenyl porphyrin (FeTMPP-Cl) as well as iron(iii) octaethyl porphyrin (FeOEP-Cl) adsorbed on high-area carbons such as deashed and un-deashed RB carbon (Calgon) and Black Pearls-2000 (Cabot) have been found to exhibit stable and very high oxygen reduction rates. Experiments done over a period of 24h showed no performance degradation. Measured performances were very similar to supported platinum (E-Tek), when tested in 85% H3PO4-equilibrated Nafion 117 membrane at 125°C and hydrated-Nafion membrane at 60°C in a minifuel cell. The macrocycle cathodes are insensitive to the presence of methanol whereas the platinum cathodes are very sensitive and show degradation in the oxygen reduction performance.  

An investigation of scale-up on the response of the direct methanol fuel cell under variable load conditions

The electrical response of the direct methanol fuel cell, based on solid polymer electrolyte, to variable load is reported. The dynamic power response of the direct methanol fuel cell is of importance particularly when the cell is used for transportation applications. The study reports the dynamic characteristics of a small-scale cell (active area 9 cm²), a large-scale cell (active area 272 cm²), and a three-cell stack. The effect of operating conditions (i.e., flow rate, cathode pressure and solution concentration) on the voltage response is described and the effect of a change of scale is discussed.  

固体聚合物电解质对质子交换膜燃料电池

燃料电池是一种通过电极催化反应过程将化学能直接转化为电能的发电装置．燃料电池反应器是借助于电极催化反应过程实现化学品一电能共生的新型反应器类型．随着燃料电池技术的不断进步，燃料电池反应器已经成为燃料电池应用研究的一个新方向．  

Gas evolution and power performance in direct methanol fuel cells

The use of acrylic cells and a CCTV camera for visually investigating the carbon dioxide gas evolution process inside an operating direct methanol fuel cell environment is demonstrated. Also, the effect of operating parameters on the system gas management, using a series of tests with different gas diffusion layer supporting materials, flow bed designs, cell sizes and exhaust manifold configurations, is studied. Carbon dioxide gas management is an important issue obstructing progress in viable direct methanol fuel cell systems development. Gas evolution mechanisms and gas management techniques are discussed and analysed with reference to several video picture and performance data. The data demonstrate that Toray carbon paper is not a suitable material for DMFCs due to its poor gas removal properties. A type carbon cloth shows relatively good gas removal behaviour. Increasing the liquid phase inlet flow rate is beneficial for gas removal. Increasing the current density results in higher gas production and in the formation of gas slugs, especially at low flow rates, which can lead to blocking of the channels and hence deterioration in the cell performance. A new flow bed design, based on a heat exchanger concept, is affective for gas management and gives a more uniform flow distribution in the flow bed channels. Using the results of this study, and the modelling techniques developed by our group, will are able to determine suitable operating conditions for our prototype 0.5kW cell DMFC stack.  

新颖离子导电型聚氨酯弹性体

以低聚二氧戊环磺酸盐(SPDXL)为离子源和增塑剂,聚己二酸乙二醇酯聚氨酯弹性体(EGPU)为基质,设计了一种新颖的正离子导电型聚氨酯弹性体,并对其结构、形态及性能进行了研究。结果表明,通过选取适当平均相对分子质量的磺化低聚醚以及通过控制磺化低聚醚的质量分数,可以优化聚氨酯固体电解质体系的离子导电性能。对于EGPU/SPDXL固体电解质体系,采用SPDXL800的样品具有较高的离子导电性能,其室温离子电导率均达到10-6S/cm以上。  

高分子固体电解质研究进展

综述了高分子固体电解质的电性能、离子传导特性以及提高高分子固体电解质性能的途径及近期发展 ,并对其发展前景作了简要的探讨。  

Electrochemical detoxification of waste water without additives using solid polymer electrolyte (SPE) technology

Ion exchange membranes as solid polymer electrolytes (SPE) facilitate the electrochemical detoxification of waste water without addition of supporting electrolyte. Cation exchange membranes as H⁺ ion conductors or anion exchange membranes as OH⁻ ion conductors were used in combination with different electrode materials. A variety of cell configurations were investigated which differ in the direction of the electro-osmotic stream (EOS). This is a characteristical property of SPE technology, caused by the solvation shells of the ions during their migration through the membrane. Dependent on cell configuration mass transfer at the electrodes can be hindered or enhanced by EOS. In the latter case it is appropriate to increase EOS by preparation of Nafion^® membranes in order to decrease energy consumption per m³ waste water. Using a perforated membrane, which operates in this case only as ion conducting solid polymer electrolyte but not as cell separator, flow rates through the cell can be adjusted independent of the EOS and a further decrease of energy consumption is possible. The best results were obtained using anodic oxidation followed by cathodic reduction: 2-chlorophenol as example compound was destroyed almost completely and more than 80% of the chlorine was mineralized to chloride ions. By-products were detected in very low amounts, less than the remaining traces of 2-chlorophenol.