The solid polymer electrolysis apparatus for natural tritium enrichment had a flow pass to exchange water in the reservoirs of anode and cathode sides. In this study, electrolysis was investigated for tritium water only in the anode side, in which the flow pass was closed. The accompanying water obtained in the cathode side showed a tritium enrichment factor of 1.3, and no tritium enrichment was observed in the anode side. Multi step of this batch electrolysis should be useful to achieve further enrichment of tritium.

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The Li storage in mesoporous titania was investigated with varying the framework and porous structure by changing the calcination temperature. By the calcination at 673 K, the amorphous framework was converted into anatase, which is accompanied with the lost of angle X-ray diffraction peak around 2θ=2.4° and with an increase of mesopore diameter. The crystallite size increased while the specific surface area decreased with the increase of calcination temperature. The amorphous framework structure was further analysed by Raman spectroscopy and transmission microscopy. The charge-discharge curves were measured for all mesoporous titanias analysed. The maximum capacity was 225 mAh g⁻¹, which was recorded for 773 K-calcined mesoporous titania. The distinct plateaux appeared in mesoporous anatase and the voltage gap between the plateaux in charge and discharge processes decreased with the calcination temperature. The electrochemical behavior was discussed in relation with the meso- and microscopic structures of the material.

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In this research, we studied the optimization of a segmented-in-series tubular solid oxide fuel cell using La_0.5Sr_0.5−xCa_xMnO₃ system materials for the cathode. La_0.5Sr_0.25Ca_0.25MnO₃ (LSCM25) was chosen for the cathode to obtain high electric conductivity and prevent the formation of highly resistive second phases with Y₂O₃-stabilized ZrO₂ (YSZ) electrolyte as a result of X-ray diffraction. To obtain lower resistance at the cathode/electrolyte interface, we studied the optimization of the cathode interlayer by changing the LSCM25-YSZ volume ratio and YSZ particle sizes. As a result, the lowest resistance was obtained at 50 vol.% LSCM25 (particle size: 3 µm)+50 vol.% YSZ (2 µm). The area-specific resistance of a tubular cell stack using the LSCM25 cathode and the LSCM25-YSZ interlayer decreased by 17% compared to a stack using only an LSCM25 cathode. We also conducted power-generation tests under pressurization to measure the cell stack performance integrated with micro gas turbines. Judging from the I-V characteristics, an increase of test pressure brought about not only an increase of open circuit voltage but also a decrease of internal resistances. According to our analysis of the internal resistances using the current interruption method, the electrode polarizations decreased as the operating pressure rose.

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