Research On Preparation And Electrochemistry Properties Of Li_1.3Ni_0.35Mn_0.65O_2.3 As Cathode Material For Lithium Batteries

The researching of layered cathode material Li[Li1/3-2X/3 Mn2/3-X/3Nix]O2 for lithium-ion batteries is now a focus due to its advantages such as high specific capacity, high voltage, good stability, low-cost and no pollution in comparison with other cathode materials (LiCoO2, LiNiO2, LiMn2O4, LiFePO4). Layered Li1.3Ni0.35Mn0.65O2.3 cathode material is one of the Li[Li1/3-2X/3 Mn2/3-X/3Nix]O2 system.In this paper, Li1.3Ni0.35Mn0.65O2.3 material was studied on its preparation method, synthesis conditions, physical properties and electrochemical properties.Li1.3Ni0.35Mn0.65O2.3 cathode material were synthesized by the high temperature solid method and coprecipitation method and were compared the structure and electrochemical properties.In order to look for the best route of the coprecipitation method of the Li1.3Ni0.35Mn0.65O2.3, we studied the synthesis condition such as calcination temperature, calcination time, different atmosphere, which affect structure of material and electrochemical performance.The Phase and microstructure of Product were charaeterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The physical properties of the synthesized samples were tested by laser particle size analyzer, PH meter, tap density meter and surface area analyzer. The electrochemical Performance was investigated by the charge-discharge testing. The Li/Ni/Mn ratios in the synthetic sample by the coprecipitation method were determined by inductively coupled plasma emission spectrometer(ICP-2000).The results show that:The phase structure, morphology and electrochemical performance of samples obtained by co-precipitation method were better than solid state method. Li1.3Ni0.35Mn0.65O2.3 prepared by co-precipitation method calcined at 800℃for 12h in the oxygen atmosphere, which had the best morphology, structure, physical properties and electrochemical performance. The analysis result of ICP indicated that lithium, nickel, manganese molar ratio of samples obtained by co-precipitation method is 1.31:0.35:0.65. The analysis result of XRD indicated that the samples is standardα-NaFeO2 layered structure and hexagonal. On electrochemistry property aspect, discharging at 0.1C, the reversible capacity reaches 188mAh/g, after 65 loop cycles, it still get to 188mAh/g. Discharge capacity is reduced with the increase of discharge rate.