Synthesis and electrochemical performance of Ti–Fe co-doped LiMnPO4/C as cathode material for lithium-ion batteries. Issue 9 (July 2016)

• Record Type: Journal Article
• Authors: Huang, Qiao-Ying; Wu, Zhi; Su, Jing; Long, Yun-Fei; Lv, Xiao-Yan; Wen, Yan-Xuan
• Is Part Of: Ceramics international. Volume 42:Issue 9(2016)
• Page Start: 11348
• Page End: 11354
• Publication Date: 2016-07
• Subjects: B. Microstructure -- E. Batteries -- E. Electrodes -- Lithium manganese phosphate; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.04.057
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: LiMnPO4 /C, LiMn0.85 Fe0.15 PO4 /C, LiMn0.92 Ti0.08 PO4 /C and Li(Mn0.85 Fe0.15 )0.92 Ti0.08 PO4 /C are prepared by a solid-state reaction route and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and electrochemical tests. All samples are single phase with similar morphologies, particle sizes and carbon contents. Ti 4+ and Fe 2+ co-doping at the Mn-site greatly enhances the performance of LiMnPO4 /C due to the synergistic effect between Ti 4+ and Fe 2+, resulting in an improvement in the dynamic stability of the olivine structure, lithium ion diffusion and electrochemical kinetics. Compared with LiMn0.85 Fe0.15 PO4 /C and LiMn0.92 Ti0.08 PO4 /C, Li(Mn0.85 Fe0.15 )0.92 Ti0.08 PO4 /C shows a much higher discharge capacity and a better rate capability. It delivers a capacity of 144.4 mA h g −1 with a capacity retention ratio of approximately 100% after 50 cycles at 1 C. These results prove that Fe 2+ and aliovalent ion co-doping at the Mn site is an effective way to improve the electrochemical properties of lithium manganese phosphate.