The olivine-type structure LiFe_(0.65)Mn_(0.35)PO_4 materials are respectively synthesized via MnO_2 and MnC_2 O_4·2 H_2 O as manganese resources by using solid-state reaction. The compound materials are characte...The olivine-type structure LiFe_(0.65)Mn_(0.35)PO_4 materials are respectively synthesized via MnO_2 and MnC_2 O_4·2 H_2 O 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 LiFe_(0.65)Mn_(0.35)PO_4 prepared by MnO_2 as manganese resource exhibits uniform particles with porous structure in SEM and TEM images. XPS data show the coexistence of Mn^(4+), Mn^(3+) and Mn^(2+) 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 at1 C. The superior electrochemical capability is attributed to the coexistence of mixed-valence manganese cations in crystal and the uniform particles with porous structure.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51364021)the Natural Science Foundation of Yunnan Province(Grant No.2014FA025)+1 种基金Innovative Research Team in University of Ministry of Education of China(Grant No.IRT1250)Academician Free Exploration Project of Yunnan Province(Grant No.14051600)
文摘The olivine-type structure LiFe_(0.65)Mn_(0.35)PO_4 materials are respectively synthesized via MnO_2 and MnC_2 O_4·2 H_2 O 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 LiFe_(0.65)Mn_(0.35)PO_4 prepared by MnO_2 as manganese resource exhibits uniform particles with porous structure in SEM and TEM images. XPS data show the coexistence of Mn^(4+), Mn^(3+) and Mn^(2+) 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 at1 C. The superior electrochemical capability is attributed to the coexistence of mixed-valence manganese cations in crystal and the uniform particles with porous structure.