Effect of polymer binders in anode catalyst layer on performance of alkaline direct ethanol fuel cells

In preparing low-temperature fuel cell electrodes, a polymer binder is essential to bind discrete catalyst particles to form a porous catalyst layer that simultaneously facilitates the transfer of ions, electrons, and reactants/products. For two types of polymer binder, namely, an A3-an anion conducting ionomer and a PTFE-a neutral polymer, an investigation is made of the effect of the content of each binder in the anode catalyst layer on the performance of an alkaline direct ethanol fuel cell (DEFC) with an anion-exchange membrane and non-platinum (non-Pt) catalysts. Experiments are performed by feeding either ethanol (C₂H₅OH) solution or ethanol–potassium hydroxide (C₂H₅OH–KOH) solution. The experimental results for the case of feeding C₂H₅OH solution without added KOH indicate that the cell performance varies with the A3 ionomer content in the anode catalyst layer, and a content of 10 wt.% exhibits the best performance. When feeding C₂H₅OH–KOH solution, the results show that: (i) in the region of low current density, the best performance is achieved for a membrane electrode assembly without any binder in the anode catalyst layer; (ii) in the region of high current density, the performance is improved with incorporation of PTFE binder in the anode catalyst layer; (iii) the PTFE binder yields better performance than does the A3 binder.     

Synthesis of Pd-Sn nanoparticles by ultrasonic irradiation and their electrocatalytic activity for oxygen reduction

Nanoparticles of Pd-Sn were prepared under various conditions by applying ultrasonic irradiation, and their electrocatalytic activity for oxygen reduction was evaluated in 0.5 M KOH. The average size of Pd-Sn nanoparticles thus prepared was about 3-5 nm. The Pd in Pd-Sn nanoparticles was found to be mostly in the metallic state. The electrocatalytic activity of the Pd-Sn nanoparticles for the oxygen reduction reaction (ORR) is greater than Pt or Pd nanoparticles in alkaline media. The molar ratio of Pd to Sn metal ions in the synthesizing solution, their initial concentrations, the concentration of ethanol, which increases primary hydrogen radicals during sonolysis, and the concentration of citric acid were found to affect the size distribution of the Pd-Sn nanoparticles, and therefore, those factors controlled the electrocatalytic activity for ORR. Particularly, the concentration of citric acid was found to be important for controlling the surface property on Pd-Sn particles to adjust the electrocatalytic activity for ORR.     

可充碱性锌锰电池进展

本文综合介绍了可充碱锰电池的最新进展,重点论述了目前国际上正在研制开发的两种可充二氧化锰电极,即奥地利kordesch的加压式二氧化锰电极和美国Ford公司的改性二氧化锰电极,对各自的特性进行了分析对比,阐明了可充碱锰电池的发展方向。     

新型镍电极及其在碱性电池中的应用

本文综合报告了我们与匈牙利工业电力研究所在塑料粘结镍电极,泡沫镍电极以及纤维毡镍电极方面的共同研究结果。分析了三种新型镍电极在与烧结式和袋式镍电极的比较中的优越性以及尚未完全克服的缺点。     

可充碱锰电池发展与展望

重点介绍了通过二氧化锰的改性来实现其可逆性的途径,并扼要地介绍了可充碱锰电池的进步与成就,指出存在的问题并展望了前景。     

碱性锌锰电池封口新结构

本文作者研制了一种碱性锌锰电池的封口结构。经过电池的生产和长时间的贮存试验证实此种封口结构可以有效地防止电池泄漏。     

贮氢材料及其电池的发展(上)

本文系统地评述了目前国外贮氢合金材料、电极制备、电池性能、大生产情况以及存在的技术问题和解决的办法。     

碱性电池密封胶塞的防爆

碱性电池密封胶塞的防爆问题实际上是高分子材料的断裂问题。文章引述了分子理论和Griffith理论,从这两个理论角度阐述了胶塞的防爆压力受生产、贮存、温度过程中一系列复杂的物理、化学变化的影响,提出了确保胶塞质量等采取的措施。     

低汞碱锰电池的研制

低汞碱性锌锰电池的技术关键是低汞锌粉加入适当的添加剂,集流体铜芯的表面处理。     

高功率可充碱性锌锰电池的研制

本文对新一代可充碱锰电池即高功率可充碱锰电池(H—R—LR6型)的制作作了详细的研究,确定了电池结构、制造工艺,测试了产品性能,建立了产品的检验方法和检验标准。该电池标称电压1.5V,短路电流可达24.6A,1C率放电容量可放出约70％,循环寿命可达200周,明显优于传统粉环式结构的可充碱锰电池。