LiFePO4 and carbon-doped LiFePO4were prepared by a novel solid-phase synthesis.The samples were characterized by X-ray diffraction,SEM,elemental analysis and electrochemical performances.These test results showed that the reaction conditions favored stabilization of samples as well as offered some control of the product morphology.Carbon-doped LiFePO4 retained olivine structure and had good electrochemical performance.The results of electrochemical evaluation of the doped product showed a lithium insertion plateau around 3.5 V(vs.Li/Li+) together with the initial charge specific capacity of 159.9 mAh·g-1 at 0.1C rate and with little specific capacity decay after 20 cycle at room temperature.
The transfer behavior of Cr(Ⅲ) through the emulsion liquid membrane system of TBP-Span80-atoleine -kerosene was studied.The effects of membrane phase component, pH value in external phase, concentration of H2SO4 in internal phase,ratio of emulsion-water (R ew)and coexisting ions on the transport rate of Cr(Ⅲ) were investigated.The results showed that the transport rate of Cr(Ⅲ)could reach 99.5% under the optimun conditions of 7%TBP, 5%Span80, 4% atoleine, 84%kerosene, 1.0 mol·L -1 H2SO 4 in internal phase and pH 3.5 in external phase.This method was applied to the treatment of Cr(Ⅲ) waste-water, and the residual concentration of Cr(Ⅲ) could be reduced to 1.0 mg·L -1 ,which was below the national standard of waste-water discharge.