The Mechanism of Capacity Enhancement in LiFePO4 Cathodes Through Polyetheramine Coating
2009 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 156, no 9, A720-A725 p.Article in journal (Refereed) Published
Thispaper addresses the possible mechanisms underlying the capacity enhancement throughpolyetheramine [PEA, glyceryl poly(oxypropylene)triamine] coating on LiFePO4 (Phostech Lithium) particlesurface. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared studieshave confirmed the presence of PEA on the surface bythe appearance of the N 1s peak in the XPSspectra and bands in the 2850–2960 cm−1 wavenumber range of theIR spectra. Potentiostatic measurements in organic electrolytes have shown thatthe discharge capacity is increased ca. 12% compared to theas-received material, i.e., more Fe2+/Fe3+ ions are utilized during theredox process. This is due to better wettability of theelectrolyte to the particle surface, which is indicated by theslower sedimentation of coated particles. Furthermore, cyclic voltammetry has shownthat PEA-coated particles display higher capacity than the as-received materialalso in an aqueous electrolyte, which to some extent canbe explained by the difference in wettability between the materials,but also by the protection of LiFePO4 from spontaneous formationof a Li3PO4 surface layer and Fe3+-containing solids when incontact with water.
Place, publisher, year, edition, pages
The Electrochemical Society , 2009. Vol. 156, no 9, A720-A725 p.
cathodes, electrolytes, Fourier transform spectra, infrared spectra, iron compounds, lithium compounds, oxidation, polymers, sedimentation, voltammetry (chemical analysis), wetting, X-ray photoelectron spectra
Research subject Inorganic Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-120132DOI: 10.1149/1.3155451ISI: 000268405400002OAI: oai:DiVA.org:uu-120132DiVA: diva2:302637