Publications by authors named "Hidenori Miki"

All-solid-state fluoride-ion batteries (FIBs) have attracted extensive attention as candidates for next-generation energy storage devices; however, promising cathodes with high energy density are still lacking. In this study, CuN is investigated as a cathode material for all-solid-state fluoride-ion batteries, which offers enough anionic vacancies around the 2-fold coordinated Cu center for F intercalation, thereby enabling a multielectron-transferred fluorination process. The contribution of both cationic and anionic redox to charge compensation, in particular, the generation of molecular nitrogen species in highly charged states, has been proved by several synchrotron-radiation-based spectroscopic technologies.

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Structural characteristics on fluoride ion storage and conduction mechanism in LaSrMnO, and its fluoridated materials, LaSrMnOF and LaSrMnOF, for an all-solid-state fluoride ion battery positive electrode with a high volumetric capacity surpassing those of lithium-ion ones have been revealed using the Rietveld method and maximum entropy method. In LaSrMnO, once the F ions are taken into the NaCl slabs in its crystal through the charging process, it forms two stable fluoride compounds, LaSrMnOF and LaSrMnOF, with the help of the Mn oxidation reaction. In these oxyfluorides, thermal vibrations of the F ions inserted are much larger, especially in the - plane, than along the axis.

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Developing electrochemical high-energy storage systems is of crucial importance toward a green and sustainable energy supply. A promising candidate is fluoride-ion batteries (FIBs), which can deliver a much higher volumetric energy density than lithium-ion batteries. However, typical metal fluoride cathodes with conversion-type reactions cause a low-rate capability.

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Developing high-performance solid electrolytes that are operable at room temperature is one of the toughest challenges related to all-solid-state fluoride-ion batteries (FIBs). In this study, tetragonal β-PbSnF, a promising solid electrolyte material for mild-temperature applications, was modified through annealing under various atmospheres using thin-film models. The annealed samples exhibited preferential growth and enhanced ionic conductivities.

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