Improved electrochemical performance of LiFe0.65Mn0.35PO4 cathode material by using electrolytic manganese dioxide for lithium-ion battery

Abstract

The olivine-type structure LiFe0.65Mn0.35PO4 materials are respectively synthesized via MnO2 and MnC2O4·2H2O as manganese resources by using solid-state reaction. The compound materials are characterized by scanning electron microscopies (SEM), transmission electron microscopy (TEM), X-ray photoelectronspectroscopy (XPS) and electrochemical test. The experimental results demonstrate that LiFe0.65Mn0.35PO4 prepared by MnO2 as manganese resource exhibits uniform particles with porous structure in SEM and TEM images. XPS data show the coexistence of Mn4+, Mn3+ and Mn2+ cations. Besides, this sample shows better discharge special capacity of 107.46 mA h g–1 at 5 C and capacitance conservation rate about 95.47% after 100 cycles at 1 C. The superior electrochemical capability is attributed to the coexistence of mixed-valence manganese cations in crystal and the uniform particles with porous structure.