Structure and electrochemical performance of LiFePO4 cathode materials modified with carbon coating and metal doping

• Published in: Journal of solid state electrochemistry Vol. 26; no. 8; pp. 1655 - 1665
• Main Authors: Liu, Zhihua, Zhang, Ronglan, Xu, Feifei, Gao, Yan, Zhao, Jianshe
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2022; Springer Nature B.V
• Subjects: Analytical Chemistry; Atomic emission spectroscopy; Carbon; Carbon nanotubes; Cathodes; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Competitive materials; Condensed Matter Physics; Dispersion; Doping; Electrochemical analysis; Electrochemistry; Electrode materials; Electrons; Emission analysis; Energy Storage; Inductively coupled plasma; Ion currents; Lithium; Lithium-ion batteries; Mechanical milling; Metal phthalocyanines; Original Paper; Physical Chemistry; Rechargeable batteries; Van der Waals forces; Lithium-ion battery; LiFePO; cathode material; Metal doping; Carbon coating; Metal phthalocyanine
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-022-05198-8

LiFePO 4 cathode material is considered as a competitive material for lithium-ion battery, but its poor electronic and ionic conductivity hinder its further commercial application. Carbon nanotubes are considered as one of the most promising carbon materials to improve the electrochemical performance of LiFePO 4 . However, they have poor dispersion in solution due to the high van der Waals forces, which makes it impossible to take full advantage of carbon nanotubes. In order to improve the dispersibility, phthalocyanine functionalized carbon nanotubes were prepared and used to improve the electrochemical performance of LiFePO 4 . In this work, four kinds of LiFePO 4 cathode materials modified with phthalocyanine functionalized carbon nanotubes were prepared via mechanical milling method with subsequent calcination. The effect of different metals, carbon contents, structures and modification methods on the properties of LiFePO 4 /C composites was investigated by XRD, ICP-AES, FTIR, SEM, TEM, EIS, CV and charge–discharge tests. In addition, the modification ability of pure carbon nanotubes was compared. The results indicate that metal phthalocyanine functionalized carbon nanotubes can simultaneously achieve carbon coating and ion doping to further improve electrochemical performance of LiFePO 4 .