title: Synthesis and enhanced electrochemical performance of Li2CoPO4F cathodes under high current cycling.
abstract: Lithium cobalt fluorophosphate, Li(2)CoPO(4)F, is successfully synthesized by a solid state reaction under Ar flow at 700 °C. X-ray diffraction and scanning electron microscopic studies are utilized to analyze the structural and morphological features of the synthesized materials, respectively. The presence of fluorine is also supported by energy-dispersive X-ray spectroscopy. The electrochemical properties are evaluated by means of Li/Li(2)CoPO(4)F half-cell configurations in both potentiostatic and galvanostatic modes. The Li/Li(2)CoPO(4)F cell delivers an initial discharge capacity of 132 mA h g(-1) at a current density of 0.1 mA cm(-2) between 2.0 and 5.1 V at room temperature. Due to the higher operating potential of the Co(2+/3+) couple in the fluorophosphate matrix, this cell shows a capacity retention of only 53% after 20 cycles, still the material delivered 108 mA h g(-1) at a high current rate of 1 C. Cyclic voltammetric studies corroborate the insertion and extraction of Li(+) ions by a single phase reaction mechanism during cycling.
authors: Faculty of Applied Chemical Engineering, Chonnam National University, Gwang-ju 500-757, Korea.
authors: S
authors: S
authors: Amaresh
authors: G J
authors: GJ
authors: Kim
authors: K
authors: K
authors: Karthikeyan
authors: V
authors: V
authors: Aravindan
authors: K Y
authors: KY
authors: Chung
authors: B W
authors: BW
authors: Cho
authors: Y S
authors: YS
authors: Lee