著者

Daisuke Mori Miho Sato Sou Taminato Nobuyuki Imanishi Kota Suzuki Masaaki Hirayama

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.131, no.10, pp.690-695, 2023-10-01 (Released:2023-10-01)

参考文献数

36

被引用文献数

1

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Li ionic conductors that are stable to lithium metal with high ionic conductivity are required as solid electrolytes for all-solid-state lithium metal batteries with high energy density. Lithium dendrite growth leading to short-circuit is one of the major issues to solve for developing practical batteries using lithium metal electrodes. We have introduced Li3PO4 (LPO) and Li3BO3 (LBO) as a grain boundary phase in the garnet-type lithium ionic conductor, Li6.25Ga0.25La3Zr2O12 (LGLZ), by co-sintering. The lattice parameters, sinterability, elemental distribution, particle morphology, and electrochemical properties have been investigated. The sinterability has decreased with the introduction of LPO and LBO, while no significant change in the ionic conductivity is observed. The LGLZ with LPO was unstable to Li metal and did not exhibit the improvement of Li plating/stripping. Meanwhile, the LBO introduction into the grain boundary as a functional core increased the critical current density of the short circuit. Li dendrite growth could be suppressed by modifying the grain boundaries of the sintered body.

著者

Takumi Yabuzaki Miho Sato Hanseul Kim Kenta Watanabe Naoki Matsui Kota Suzuki Satoshi Hori Kazuhiro Hikima Satoshi Obokata Hiroyuki Muto Atsunori Matsuda Ryoji Kanno Masaaki Hirayama

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.131, no.10, pp.675-684, 2023-10-01 (Released:2023-10-01)

参考文献数

36

被引用文献数

1

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Sulfide-type solid electrolytes for all-solid-state lithium-ion batteries are required to have high ionic conductivity, high (electro) chemical stability, and suitable mechanical properties. Compositing different materials is widely performed in developing multifunctional materials. However, only a few studies have investigated sulfide electrolytes due to the concern of lowering ionic conductivity. In this study, composite electrolytes comprising Li10GeP2S12 (LGPS)-type electrolytes and nanosized Al2O3 are fabricated by a solid-state reaction. Al2O3 particles are mainly located in the voids between LGPS particles, whereas very limited oxygen content is substituted for sulfur in the LGPS structure. LGPS–Al2O3 composites exhibit ionic conductivities of ∼5 mS cm−1 without significant changes by compositing Al2O3. LGPS–Al2O3 composites are softer and have higher atmospheric stability than uncomposed LGPS. All solid-state cells that use air-exposed LGPS–Al2O3 as a separator layer exhibit an improved cycle retention compared with that using air-exposed LGPS. These results demonstrate that electrolyte compositing is an effective means of improving other properties while maintaining high lithium ionic conductivity.

著者

Yohei SAWAYA Miho SATO Masahiro ISHIZAKA Takahiro SHIBA Akira KUBO Tomohiko URANO

出版者

Japanese Society of Physical Therapy

雑誌

Physical Therapy Research (ISSN:21898448)

巻号頁・発行日

vol.25, no.1, pp.35-40, 2022-04-20 (Released:2022-04-20)

参考文献数

26

被引用文献数

8

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Objective: The maximum phonation time (MPT) is used to assess simple respiratory functions and can be performed anywhere without special instruments. We investigated the association between MPT and respiration, considering the future utilization of simple respiratory assessments during home-based physical therapy. Method: This cross-sectional study included 140 older adults enrolled in Japanese long-term care insurance (77 men, 63 women; mean age, 77.9±8.0 years). The participants performed the MPT, followed by spirometry. We analyzed the MPT of the three age groups, relative reliability of the MPT values, and the association between MPT and respiratory function. Results: We found that the MPT of older men requiring long-term care or support was related to age. The intraclass correlation coefficient of MPT was >0.8 for all groups. Only forced vital capacity was associated with MPT in the partial correlation and multiple regression analyses. Conclusion: MPT could be an alternative assessment of respiratory function in home-based physical therapy for older adults requiring long-term care or support.