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Carbon-coated spinel LiMn₂O₄ composite cathode was synthesized by melt impregnating method using LiNO₃, electrolytic manganese (EMD) and as-prepared carbon xerogel as raw material for Li-ion battery. The crystalline structure, morphology and elements of particles were analyzed by X-ray diffraction (XRD), scanning electromicroscopy (SEM) and energy-dispersion X-ray spectroscopy (EDX). The results showed that the material obtained is pure spinel-type phase and the particles of carbon-coated LiMn₂O₄ have no aggregation, the carbon content was 4.53 wt.% in cathode material. The carbon-coated LiMn₂O₄ cathode showed excellent cycling performance at different C rates. The reason was that carbon film coated on the grains ensured a good electronic contact, restraining the dissolving of Mn and polarization on electrode surface during charge-diacharge. The electrochemical AC impedance spectroscopy showed that the electrical conductivity of LiMn₂O₄ cathodes was enhanced and the charge transfer resistance reduced obviously during electrochemical reaction process.LiMn₂O₄ and its carbon-coated materials were synthesized by euecitc self-mixing method using glucose as carbon source. Galvanostatic charge/discharge tests of carbon-coated and uncoated cathode were carried out at 0.2C rate at room temperature, and the initial discharge capacity were 118.2 mAh·g^-1 and 112.2 mAh·g^-1, respectively, the coulomb efficiency were 94.9% and 94%, respectively. Li⁺ diffusion coefficients which were calculated by cyclic voltammetry measurement, were 5.2×10^-13cm²·s^-1 and 1.7×10^-13cm²·s^-1, respectively.LiMn₂O₄/MWCNT composite cathode was prepared by mixing LiMn₂O₄ particles with Multi-Walled Carbon Nanotubes as electric agent. The morphology was analyzed by SEM, LiMn₂O₄ particles were connected by MWCNT to form a three-dimensional network wiring. Electron transport and electrochemical activity were improved effectively by the web wiring structure. Galvanostatic charge/discharge tests at 1C rate showed that the initial discharge capacities were 96.0mAh·g^-, 105.5mAh·g^-1, 114.8mAh·g^-1, respectively when the contents of MWCNT were 2wt%, 5wt%, 8wt% compared to 98.0mAh·g^-1 with 5wt % acetylene black. The electrochemical AC impedance spectroscopy showed that during electrochemical reaction process the charge transfer resistance reduced obviously with the increasing contents of MWCNT. The activation energy of LiMn₂O₄/MWCNT and LiMn₂O₄/acetylene black composite cathodes which were calculated by EIS measurement at different temperatures, were 27.5kJ·mol^-1 and 32.3 kJ·mol^-1, respectively.Spherical MnO₂ was prepared by solution crystallization method and spherical LiMn₂O₄ and carbon-coated materials were synthesized by using as-prepared spherical MnO₂, LiOH·H₂O and carbon xerogel. The galvanostatic charge-discharge measurements of the materials were investigated under a current rate of 0.5 C with the cutoff voltage between 3.2 and 4.3 V. The carbon-coated spherical LiMn₂O₄ exhibited discharge capacity of 122 mAh·g^-1 and 115 mAh·g^-1 at 25℃and 55℃, respectively, remaining111 mAh·g^-1 which corresponding 91% capacity retention at 25℃after 100 cycles and 0.3% capacity loss at 55℃after 50 cycles. As for uncoated material, the initial discharge capacity were 119 mAh·g^-1 and 112 mAh·g^-1 at 25℃and 55℃, respectively. There were 86% capacity retention at 25℃and 0.5% capacity loss compared to the former. From EIS measurement, charge transfer resistance reduced from 45.02 to 16.28Ωafter carbon coating. The diffusion coefficients of Li⁺ were 1.46×10¹³ cm2·s^-1 and 3.62×10^-12 cm2·s^-1 for pristine and carbon-coated LiMn₂O₄, respectively.