Development of novel carbides anode for next-generation batteries with high-cost performance

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05651
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: Yamaguchi University
• Principal Investigator: Kitajou Ayuko 山口大学, 大学院創成科学研究科, 准教授 (50446861)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: Liイオン電池 / 負極材料 / 炭化物

Outline of Final Research Achievements

The high safety and large capacity are required at same for anode material for a large-scale LIB. The Fe-Fe3C/C core shell was investigated as anode material, and its operating voltage was 0.8 V vs. Li+/Li. In addition, this anode martial showed a large delithiated capacity of 500 mAh/g. On the other hand, Fe3C previously was found to store only 1/6 Li per unit (26 mAh/g). However, the Fe3C having low crystallinity showed lithiated capacity of 300 mAh/g and delithiated capacity of 230 mAh/g. In this research, the lithiated/delithiated mechanism of Fe3C was investigated by XRD and XANES measurement. The structure change of Fe3C during lithiated/delithiated reaction was not confirmed, and it clarified that the electric structure also was not change from Fe K-edge XANES spectra. There results suggested that the reaction may be due to the dissolution and precipitation of Li on the surface of Fe3C, etc., rather than the insertion reaction of Li ions to the crystal structure of Fe3C.

Free Research Field

無機化学

Academic Significance and Societal Importance of the Research Achievements

Liイオン電池の高安全性と高容量を同時に達成する新規負極材料として、炭化鉄に着目し検討を進めてきた。その結果、これまで知られている結晶構造へLiイオンの挿入脱離や体積変化が大きい合金化反応による電池反応ではなく、Fe3CはLi金属の溶解析出をスムーズに引き起こすために機能している可能性が示唆された。この反応は、電池分野だけでなく、触媒材料などとしても利用できる可能性を秘めているものと期待できる成果であると考えられる。