Back Cover:Synthesis of Lithium Iron Phosphate/Carbon Microspheres by Using Polyacrylic Acid Coated Iron Phosphate Nanoparticles Derived from Iron(III) Acrylate (ChemSusChem 6/2015)

Abstract

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA. Lithium iron phosphate/carbon (LiFePO 4 /C) microspheres with high rate and cycling performance are synthesized from iron phosphate/polyacrylic acid (FePO 4 /PAA) nanoparticles. Iron(III) acrylate is used as a precursor for both the iron and carbon sources. FePO 4 nanoparticles are first produced by a coprecipitation reaction. The byproduct, acrylic acid ions, is polymerized in situ to form a uniform PAA layer on the surface of the FePO 4 nanoparticles. The as prepared LiFePO 4 /C microspheres are composed of primary nanoparticles with sizes of 40-50 nm. The nanoparticles are fully coated with a thin, uniform carbon layer derived from the decomposition of the PAA layer. The uniform carbon-coating layer cooperates with interstitial and boundary carbon derived from sucrose successfully to construct an excellent interconnecting conductive network in the microspheres. As a result of the unique structure, the as prepared LiFePO 4 /C microspheres display both high electronic and ionic conductivities, which contribute to their high rate performance (162.9 mAhg -1 at 0.1C and 126.1 mAhg -1 at 5C) and excellent cycling stability (97.1% of capacity retention after 500 cycles at 5C/5C).