Effect of different carbon precursors on properties of LiFePO4/C

• Published in: Journal of Central South University Vol. 22; no. 12; pp. 4507 - 4514
• Main Authors: Xiao, Zheng-wei, Zhang, Ying-jie, Hu, Guo-rong
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.12.2015
• Subjects: Engineering; Metallic Materials; charge–discharge test; LiFePO; decomposition; graphite; carbon precursor; lithium ion cell
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-015-2999-3

The anoxic decomposition and influence of carbon precursors on the properties of LiFePO 4 /C prepared by using Fe 2 O 3 were investigated. X-ray powder diffractometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and carbon content and charge–discharge tests were applied to the characterization of the as-synthesized cathodes. Partial carbon is lost in the anaerobic decomposition of organic precursors and a high hydrogen content leads to a high residual carbon rate. Pyromellitic anhydride and citric acid participate in reactions before and in ball-milling. All the chosen carbon precursors are capable of producing LiFePO 4 with high degree of crystallinity and purity. The carbon derived from α - D -glucose, pyromellitic anhydride, soluble starch, citric acid and polyacrylamide has a loose and porous texture in LiFePO 4 /C which forms conduction on and between LiFePO 4 particles. LiFePO 4 /C prepared by using α - D -glucose, pyromellitic anhydride, citric acid and sucrose exhibits appreciable electrochemical performance. Graphite alone is able to enhance the electrochemical performance of LiFePO 4 to a limited extent but incapable of preparing practical cathode.