Improvement of the overall performances of LiMn2O4 via surface-modification by polypyrrole. (November 2015)

• Record Type: Journal Article
• Authors: Wang, Ting; Wang, Wan; Zhu, Ding; Huang, Liwu; Chen, Yungui
• Is Part Of: Materials research bulletin. Volume 71(2016)
• Page Start: 91
• Page End: 97
• Publication Date: 2015-11
• Subjects: A. Composite -- A. Surfaces -- D. Electrochemical properties; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2015.06.051
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Polypyrrole(PPy) film has improved the rate performance of LiMn2 O4 efficiently due to its excellent conductivity. PPy@LiMn2 O4 could provide more energy under the higher power than pristine LMO. Highlights: The PPy layer on the surface of LMO particles hasn't been studied in LiMn2 O4 so far. The solvent in the synthesis process of PPy@LMO is absolute ethyl alcohol. The differences of surface-modification between the PPy and PI for LMO. The analyses of rate performances are through specific power. Abstract: Polypyrrole (PPy) is an excellent conductive polymer and the study on its utilization in the surface modification of the LiMn2 O4 (LMO) is few. In this work, the structure, morphology and electrochemical performance of surface-modified LiMn2 O4 composites with PPy and polyimides (PI) were discussed. The crystal structure, chemical bonds and morphology were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Moreover, the specific power and cycling performance were tested at room and high (55 °C) temperature. The PPy@LMO (surface-modified LMO composites with PPy) shows better performances than the pristine LMO. The addition of PPy not only weakens the corrosion caused by electrolyte, but also improves the discharge capacity at higher rates. The charge transfer resistance of the PPy@LMO is much lower than that of the pristine LMO after cycling.