Electrochemical performance of NASICON type carbon coated LiTi2(PO4)3 with a spinel LiMn2O4 cathode

Abstract

NASICON type LiTi₂(PO₄)₃ particles are synthesized by a modified pechini type polymerizable complex method at 1000 °C in an air atmosphere. The synthesized LiTi₂(PO₄)₃ particles are ball milled and subsequently carbon coated from the carbonization of glucose (C–LiTi₂(PO₄)₃). Li-insertion properties are evaluated in half-cell configurations (Li/C–LiTi₂(PO₄)₃) and delivered an initial discharge capacity of 117 mAh g⁻¹ at a current density of 15 mA g⁻¹. Carbon coating alleviates the severe capacity fading of LiTi₂(PO₄)₃ during cycling. A full-cell with an operating potential of 1.5 V is constructed employing C–LiTi₂(PO₄)₃ as the anode with a spinel cathode, LiMn₂O₄, which delivered the first discharge capacity of 103 mAh g⁻¹ at current density of 150 mA g⁻¹. The LiMn₂O₄/C–LiTi₂(PO₄)₃ cell retains 72% of initial discharge capacity after 200 cycles and the results suggest that, the full-cell can be used for miniature applications by replacing other rechargeable systems like lead–acid, Ni–Cd and Ni–MH.