Study of electrodeposition mechanism of Li metal by using a ultra-micro-electrode

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04965
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: National Institute for Materials Science
• Principal Investigator: NISHIKAWA Kei 国立研究開発法人物質・材料研究機構, エネルギー・環境材料研究拠点, 主任研究員 (30457824)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: リチウム金属 / 電析 / 電池 / 結晶成長 / 超微小電極 / 電子顕微鏡観察

Outline of Final Research Achievements

Li metal is a very attractive candidate for next-generation Li batteries because Li metal has huge capacity. In this study, electrodeposition of Li metal was analyzed by using ultra-micro-electrode technique in order to understand the electrodeposition mechanism of Li metal. Three dimensional analysis for the electrodeposited Li metal was conducted by cryogenic focused ion beam (FIB) scanning electron microscope (SEM) system. The electrodeposited Li metal from 1M LiPF6-EC:DEC(1:1) electrolyte has very dense column shape with uniform diameter. The surface layer analysis was also conducted by cryo-STEM-EELS, and LiF rich surface layer with several tens nm is formed on the electrodeposited Li metal. These analysis technique is very important to discuss the relationship between the morphological variation of electrodeposited Li metal and surface layer characteristics.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

持続可能な社会実現のために、高性能二次電池は、エネルギーの高効率利用という意味で、非常に重要である。リチウム金属は、リチウムイオン電池の現行の負極を大きくしのぐ理論容量を有する材料で、実用化されることの意義は大きい。ただし、そのためには安全かつ長期間の利用が出来なければならない。本研究はこの課題解決のために、リチウム金属の基礎的知見を深めるためのものであり、将来のリチウム金属電池実現に資するものである。