In this review, our results of over ten years of research on the all-solid-state polymer electrolyte lithium secondary cell are introduced. The conductivity of polyethylene oxide (PEO)-based polymer electrolytes, which is the best candidate for polymer electrolyte lithium cells, and the interface resistance between PEO and the electrodes have been improved by the addition of BaTiO₃. New composite anodes of Li_2.6Co_0.4N and metal oxides have been proposed for the polymer electrolyte cells. The composite anode has a high reversible capacity and a low irreversible capacity at the first cycle. A carbon anode for the polymer electrolyte lithium cell has also been developed and mesocarbon micro beads exhibit high electrochemical performance. 4-volt class all-solid-state polymer electrolyte cells with the PEO-Li(CF₃SO₂)₂N-LiPF₆-BaTiO₃ electrolyte have been proposed that have good reversible charge-discharge performance.

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The electrodeposition of the Nb₃Sn alloy film from the Lewis basic NbCl₅-SnCl₂-EMIC melt (50 mol%<EMIC) was investigated. The relationship between melting point or glass transition point and molar fraction of NbCl₅ was constructed for the NbCl₅-EMIC system, which showed a melting point less than room temperature in the range of 10.0 mol%≤molar fraction of NbCl₅≤33.3 mol%. From the results of the cyclic voltammograms, the possibility of electrodeposition of the Nb₃Sn alloy film was suggested from the Lewis basic melt. The Nb₃Sn alloy film was reproducibly obtained from the 19.2 mol% NbCl₅–10.0 mol% SnCl₂–70.8 mol% EMIC bath using a constant current pulse electrodeposition method at 0.1 A cm⁻² with a pulse period of 10 ms, duty ratio of 0.20, and electricity of 50°C cm⁻² at 130°C, although the existence of the metallic Sn simple substance and the Cu-Sn alloy in the film was confirmed by an XRD analysis.

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The cathodic reduction of selenonium salts bearing substituted benzyl, allyl and ethoxycarbonylmethyl group gave the ylides which were confirmed by the Corey-Chaykovsky reaction with benzaldehyde. In the absence of benzaldehyde, the [2,3] Sigmatropic rearrangement, coupling reaction, and olefin or cyclopropane formation via the ylides occurred in good yield. To elucidate the reaction mechanisms of the reactions of selenium ylides from selenium salts bearing allyl group, the theoretical density functional calculations were performed by using B3LYP with the 6–31+G(d) basis set.

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Breakage of beta alumina, that was used as solid electrolyte of sodium-sulfur (NAS) battery, by calcium impurities was evaluated. The Breakage generated from the inner surface of beta alumina tube. A hetero-phase of calcium oxide was observed at the beginning point and the oxide was compound of calcium, sodium and aluminum. The inner surface made oxygen defect part by contacting with sodium and calcium reached this oxygen defect and form the hetero-phase on charging. This caused a deterioration of strength by develop inside the beta alumina and breakage.

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We have developed a new Die-to-Wafer (D2W) bonding process for a 3-D packaging technology called SMAFTI (SMArt chip connection with FeedThrough Interposer), which enables over a thousand parallel interconnects between memory and logic dies. The bonding process achieved metal/adhesive simultaneous bonding between die and wafer. We also characterized the interlaminar horizontal wiring of FTI (Feed Through Interposer) by Sparameter measurement and confirmed its potential for high frequency transmission at over 10 GHz.

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