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Abstract: The dissolution of nickel oxide cathode in the electrolyte is one of the major technical obstacles to the commercialization of molten carbonate fuel cell (MCFC). To improve the MCFC cathode stability, the alternative cathode material for MCFC was prepared, which was made of Co/Ce-coated on the surface of Ni powder using a polymeric precursor based on the Pechini method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX) were employed in characterization of the alternative cathode materials. The Co/Ce-coated Ni cathode prepared by the tape-casting technique. The solubility of the Co/Ce-coated Ni cathode was about 80% lower when compare to that of pure Ni cathode under CO2:O2 (66.7:33.3%) atmosphere at 650°C. Consequently, the fine Co/Ce-coated Ni powder could be confirmed as a new alternative cathode material for MCFC. [Copyright &y& Elsevier]

In this study, we made a novel alternative cathode material of molten carbonate fuel cell (MCFC) using electroless deposition of Co on the surface of the Ni powder. Using this manufacturing method, we expect that economical and large-scale cathode can be made easily. The cathode prepared by this method formed LiCo1−yNiyO2 phase in molten (Li0.62K0.38)2CO3 at 650 °C under CO2:O2=66.7:33.3% atmosphere, its solubility is 40% lower than that of NiO cathode. In the unit cell test, the performance of the cell composed of Co-coated Ni cathode was same as that of the cell composed of NiO cathode. Thus the cathode made by Co-coated Ni powder used as an alternative cathode can maintain the advantages of NiO cathode and lengthen the lifetime of MCFC. [Copyright &y& Elsevier]

Development of an inexpensive high performance catalyst with low Pt loading remains a great challenge. Herein galvanic exchange-formed ultra-low Pt loaded porous Ag-Pd binary alloy nanotubes (Pt/Ag-Pd) was prepared as a catalyst toward oxygen reduction reaction (ORR). With highly dispersed active but ultra-low Pt atoms (Pt: about 5.8 wt%) on the porous binary alloy surface, the Pt/Ag-Pd catalyst increases mass activity toward ORR by 1.82 times than commercial Pt/C while possessing excellent operation stability. The performance enhancement is mainly attributed to the unique porous Pt shell/Ag-Pd core tubular structure for increased active sites and facilitated interfacial electron transfer rate by a unique Ag-Pd jointly modified electronic structure. This catalyst holds great promise for practical applications in low temperature fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: Organic–inorganic hybrid composite membranes have been prepared and evaluated for polymer electrolyte membrane fuel cells (PEMFCs) at 100–140°C. A series of synthesized poly (fluorinated arylene ether)s was sulfonated by fuming sulfuric acid (20% SO3). The zirconium phosphate composite membrane was prepared by soaking the sulfonated poly (fluorinated arylene ether)s stepwise in 1M zirconyl chloride solution and 1M phosphoric acid solution. The chemical, thermal, and electrochemical properties of the composite membrane were investigated by thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and unit cell test. The cell performance of the zirconium phosphate sulfonated poly (fluorinated arylene ether)s composite membrane was superior to that of the starting membrane at intermediate temperature, 100–140°C. And the cell performance with composite membrane indicated stable behavior during experimentation when operating temperature maintained at 120°C, whereas sulfonated poly (fluorinated arylene ether)s membrane was irreversible degradation under the same condition. [Copyright &y& Elsevier]

Abstract: Layered Li[Ni0.5−x Mn0.5−x Zr2x ]O2 (x =0, 0.025) have been prepared by the mixed hydroxide and molten-salt synthesis method. The individual particles of synthesized materials have a sub-microsize range of 200–500nm, and LiNi0.475Mn0.475Zr0.05O2 has a rougher surface than that of LiNi0.5Mn0.5O2. The Li/Li[Ni0.5−x Mn0.5−x Zr2x ]O2 (x =0, 0.025) electrodes were cycled between 4.5 and 2.0V at a current density of 15mA/g, the discharge capacity of both cells increased during the first ten cycles. The discharge capacity of the Li/LiNi0.475Mn0.475Zr0.05O2 cell increased from 150 to 220mAh/g, which is 50mAh/g larger than that of the Li/LiNi0.5Mn0.5O2 cell. We found that the oxidation of oxygen and the Mn3+ ion concerned this phenomenon from the cyclic voltammetry (CV). Thermal stability of the charged Li[Ni0.5−x Mn0.5−x Zr2x ]O2 (x =0, 0.025) cathode was improved by Zr doping. [Copyright &y& Elsevier]

Abstract: A high-performance LiNi0.8Co0.2O2 cathode was successfully fabricated by a sol–gel coating of CeO2 to the surface of the LiNi0.8Co0.2O2 powder and subsequent heat treatment at 700°C for 5h. The surface-modified and pristine LiNi0.8Co0.2O2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Unlike pristine LiNi0.8Co0.2O2, the CeO2-coated LiNi0.8Co0.2O2 cathode exhibits no decrease in its original specific capacity of 182mAh/g (versus lithium metal) and excellent capacity retention (95% of its initial capacity) between 4.5 and 2.8V after 55 cycles. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Organic–inorganic composite membranes for operation above 100°C in polymer electrolyte membrane fuel cells (PEMFCs) were prepared, characterized and cell-tested. Composite membranes were obtained by mixing organic polymers, which have a SO3H group as a proton conductor with inorganic material, SiO2, using the sol–gel process. Electron probe micro analyser (EPMA) was used to show the homogeneous and uniform distribution of SiO2. The physico-chemical properties of all membranes were investigated regarding their tensile strength, water uptake and thermogravimetric analyzer (TGA). Due to a higher water uptake and thermal stability of composite membranes, the cell performances at high temperatures above 100°C, were improved. In addition, the SiOH group in the composite membrane was shown to play a major role in capturing water strongly and maintaining proton conductivity even at high temperature. Furthermore, the fuel cell performance of organic–inorganic composite membranes was superior to that of the Nafion membrane at high current density over all ranges of temperature. [Copyright &y& Elsevier]

New proton exchange membranes were prepared and evaluated as polymer electrolytes for a proton exchange membrane fuel cell (PEMFC). Two types of fluorinated poly(arylene ether)s (FPAEs) were synthesized by nucleophilic aromatic substitution of decafluorobiphenyl (DFBP) with 4,4′-(hexafluoroisopropylidene)diphenol (HFDP) and bisphenol-A (BPA). The FPAEs so prepared were converted into proton exchange polymers by sulfonation with fuming sulfuric acid (30% SO3). The FPAEs and sulfonated-fluorinated poly(arylene ether)s (S-FPAEs) with various sulfonation levels were characterized using 1H NMR, thermogravimetric analysis (TGA) and back titration, and then successfully evaluated as proton exchange membranes (PEM) with unit cell operation. power output measurements of S-DFBP-HFDP carried out at a cell temperature of 80 °C. They exhibited a maximum power density of 425.5 mW/cm2 at 1150 mA/cm2. [Copyright &y& Elsevier]