Directly meso-meso linked porphyrin dimers were utilized as novel sensitizers of dye-sensitized solar cells. Three dimers were prepared: bis-freebase (FbP1-FbP2a), zinc-freebase (ZnP1-FbP2a), and bis-zinc (ZnP1-ZnP2a), which exhibited maximum energy conversion efficiencies of 1.98%, 3.42% and 2.34%, respectively, even with very thin 5 µm TiO2 films.
Micro-structure of catalyst layer influences performance of direct methanol fuel cell (DMFC). The dry-squeegee method which was a technique proposed for catalyst layer formation, was found to form a dense and uniform catalyst layer. The membrane electrode assembly (MEA) prepared by using the dry-squeegee method (MEA-ds) had a better performance than that prepared by conventional methods including dropper and brush method, since the MEA-ds had a shorter proton path from the catalyst surface to polymer membrane and many active reaction sites than other MEAs.
Titanium tetrachloride vapor was selectively introduced into hexagonally arranged PEO cylinders in PEOm-b-PMA(Az)n ((m, n)=(272, 116), (272, 94), and (114, 67)) thin films by simply exposing the films to the vapor in a glass vessel. TEM images of PEOm-b-PMA(Az)n thin films with m=272 and 114 after the exposure showed hexagonally arranged dark spots with 14-nm diameter and 38-nm distance, and 10-nm diameter and 20-nm distance, respectively. FTIR measurement indicated a change in the peak shape at stretching vibration of C-O-C in the PEO chain as titanium tetrachloride was introduced. The film weight during the vapor process was increased in QCM measurement. XPS analysis was carried out for the films before and after hydrolysis with water vapor. It was found that titanium oxide with some different oxidation states existed in the hydrolysis treatment. FESEM revealed that calcination of the hydrolyzed film gave titanium oxide nanowires with about 10-nm diameter. XRD pattern of the calcined film suggested that the process demonstrated here generated the titanium oxide nanowires consisting of polymorph mixture with brookite, rutile, and anatase.
A polymer electrolyte composite has been prepared with Li3PO4 dispersion in a polyether-cross-linked polymer electrolyte system (PEO-PMA). From DSC measurements, it was confirmed that the glass-transition temperature (Tg) of the polymer electrolyte tends to shift to higher temperature by the addition of Li3PO4. The ionic conductivity was decreased with the addition of Li3PO4, but the cationic mobility, estimated from the DC polarization measurements, was improved at higher temperature. From these results, it was suggested that Li3PO4 work as a carrier site for Li+-transport in the polymer electrolyte. The addition of Li3PO4 also tended to suppress the resistance increase at the interface between Li deposited on a Ni substrate and the polymer electrolyte. Thus, the polymer electrolyte containing Li3PO4 dispersion as a filler has lower interface resistance so that it can provide better performances of a battery system using Li metal negative electrode.
The Fe, Ni-BaCe0.8Y0.2O3−δ, and Pt catalysts and Pt catalysts were used as the anodic materials of an intermediate-temperature Solid Oxide Fuel Cell (SOFC) for direct utilization of dimethylether (DME) gas fuel. A proton conducting oxide BaCe0.8Y0.2O3−δ (BCY20) was used as the electrolyte (thickness 500 µm) and a Pt was used as the cathode. The cell was operated at 600°C. The maximum power density of the cell with the Fe anodic catalyst was 36.4 mW cm−2 at 70 mA cm−2, while the maximum power density of the cell with a Ni-BCY20 and the Pt anode were 5.5 mW cm−2 at 10 mA cm−2 and 8.4 mW cm−2 at 20 mA cm−2, respectively. DME was mainly decomposed to H2, CO and CH4 by Fe anode. In this study, we investigated the process of anodic reactions with H2 and CO fuel.
This paper studies the analysis method of thermal stress generated in the module of SOFC. The module is constructed from variously sized components. For example, cell’s thickness is about 2 mm, and module’s external size is about 500 mm. Therefore, the analysis of SOFC module expends very large computational resources and analysis time. To solve this problem, we tried to apply the technique of zooming analysis. We proposed the method to substitute homogeneous material model for the bundle at the overall module analysis and to use the results of overall module’s analysis for the boundary condition at the bundle’s detail analysis. By the way, the homogeneous material model should simulate the bundle’s mechanical properties. And then we verified the precision of this method by comparing homogeneous material model with original material model. At last, we give examples of reliability-evaluation of SOFC module using this method.
On ionic liquids having functional groups in the side chain of their imidazolium cations, their characterization has been carried out. The ion conduction properties of the lithium salt solutions of these ionic liquids have also been investigated Proton NMR measurement reveals that CmMI cation has a tendency of charge localization than other imidazolium cations. Among the ionic liquids investigated, only the one having CmMI cation exhibit conductivity increase when it dissolves small amount of lithium salt. Raman spectra for the lithium salt solutions indicate that the CmMI-based ionic liquid provides different status of lithium ion compared with EMI-based ionic liquid. Such a difference appears to come from the difference in electronic structure of imidazolium cation.