Development of divalent calcium ion conducting solid electrolytes

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05936
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic industrial materials
• Research Institution: Osaka University
• Principal Investigator: Tamura Shinji 大阪大学, 工学研究科, 准教授 (80379122)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 固体電解質 / ナシコン型構造 / カルシウムイオン

Outline of Final Research Achievements

In this research, I have synthesized the divalent Ca2+ cation conducing solid electrolytes showing high conducting property even in rigid crystal lattice for the purpose of developing the practically applicable divalent cation conducting solids for the next generation batteries. By selecting both the NASICON-type crystal structure having a well-ordered three-dimensional ion conducting pathway and the constituent cations whose valencies are +4 or +5, two kinds of Ca2+ ion conductors, (CaxHf1－x)4/4－2xNb(PO4)3 and Ca(1－x)/2Zr2－xNbx(PO4)3, showing extraordinary high were successfully obtained.
In addition, I have developed a Ni2+ cation conducting solid with NASICON-type structure, and revealed that (NixHf1－x)4/4－2xNb(PO4)3 solids also exhibited high divalent Ni2+ ion conductivity.

Free Research Field

無機材料化学

Academic Significance and Societal Importance of the Research Achievements

これまで電池材料などとして利用可能な高いイオン伝導性を示すCa2+イオン伝導体は開発されていなかった。本研究では実用領域のイオン伝導性には達していないが、従来の材料と比較すると1000倍以上高いCa2+イオン伝導性が実現できたことから、本研究成果は今後の同分野の材料開発に大いに貢献できる成果である。
また、本研究成果を通して実用的な2価カチオン伝導性固体の創成が実現されれば、より優れた二次電池開発につながる。