Elucidation of physical properties of transition metal phosphate cathode in the oxide glass-ceramic-derived all-solid-state battery

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02428
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Nagaoka University of Technology
• Principal Investigator: Honma Tsuyoshi 長岡技術科学大学, 工学研究科, 准教授 (70447647)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 二次電池 / 全固体電池 / ガラス / 結晶化 / レーザープロセス

Outline of Final Research Achievements

We aimed to create new glasses and glass-ceramics and to elucidate the interface formation with the solid electrolyte and the intrinsic properties of the active cathode material based on the all-solid-state sodium battery with oxide and crystallized glasses as the reaction field. The crystallization mechanism of alkaline phosphate glasses containing transition metal ions and the interface formation by the laser process were characterized. It was found that the crystallization of Na2MP2O7 (M=Fe, Ni) glass-ceramics decomposes the liquid electrolyte, but the solid electrolyte with a high potential window has an oxidation peak at 4.8V. In addition, the glass was instantly melted and successfully bonded to the solid electrolyte by irradiating the precursor glass of the active material with laser irradiation.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

全固体電池とって、活物質と固体電解質および助剤との間の堅牢な界面の形成は重要な課題である。本研究では希少金属を用いない酸化物系全固体ナトリウムイオン電池において、レーザー照射による界面形成プロセスの優位性を示すことができた。さらに高い電位窓をもつ固体電解質を用いて、液系電池では達成不可能な4.5Vを超える電気化学的酸化反応を誘起できることを実証した。以上、本研究の成果は酸化物系全固体電池の課題を解決するだけでなく、まだ明らかにされていない材料探求の余地を広げた。