Development of magnesium current collectors with high corrosion resistance at high voltages

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21230
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 36:Inorganic materials chemistry, energy-related chemistry, and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Habazaki Hiroki 北海道大学, 工学研究院, 教授 (50208568)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: マグネシウム / 正極集電体 / リチウムイオン電池 / 不働態皮膜

Outline of Final Research Achievements

In this study, to clarify the possibility of a magnesium cathode current collector in environments containing fluoride ions for lithium-ion batteries, the stability of magnesium in various electrolyte solutions for lithium-ion batteries at high potentials was investigated. As a result, in the LiPF6-based electrolyte, magnesium can be passivated up to about 4 V vs Li+/Li, and is deactivated at higher potentials. Surface analysis suggests that this is due to the inability to form a stable passivation film composed of MgF2 in this environment. On the other hand, when the stability was evaluated using the electrolyte for the fluoride shuttle battery, it was found that no de-passivation occurred up to 10 V.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

研究結果は当初の期待ほどの高いマグネシウムの正極集電体としての安定性を示すものではなかったが，最も軽量な実用金属であり，電池分野においても応用が期待される金属の各種電解液中における安定を評価できた点において一定の学術的意義はあったと思われる。マグネシウムは高活性であるが，安定なMgF2を形成するにはある程度の濃度のフリーのフッ化物が存在する電解液が必要と推察される。