Synthesis and Properties of Cathode Materials xLi(2)MnO(3)center dot(1-x)LiMn0.3Ni0.4Co0.3O2 for Li-Ion Batteries

The cathode materials xLi(2)MnO(3)center dot(1-x)LiMn0.3Ni0.4Co0.3O2 (x = 0, 0.2) for Li-Ion batteries were prepared with the help of sol-gel method using citric acid as a chelating agent. Its structural and electrochemical properties were investigated using X-ray diffractometry, scanning electron microscopy, galvanostatic charge-discharge test. Differences between electrochemical and chemical activation of the Li2MnO3 component are discussed. The results indicated that xLi(2)MnO(3)center dot(1-x)LiMn0.3Ni0.4Co0.3O2 cathode materials were successfully prepared with typical alpha-NaFeO2 crystal and trigonal (R3m). It was found that the changes in compositional, crystal structure and electrochemical performance depend highly on the different values of x. The (020) reflection at about 21 degrees (2 theta), which is characteristic of the integrated monoclinic Li2MnO3-like component. The LiMn0.3Ni0.4Co0.3O2 peak increases significantly at about 21-24 degrees (2 theta) for 0.2Li(2)MnO(3)center dot 0.8LiMn(0.3)Ni(0.4)Co(0.3)O(2). The particles with a diameter of approximately 500 nm-1 mu m can be seen clearly, the products are octahedron with the smooth surface. The maximum discharge capacity of materials 0.2Li(2)MnO(3)center dot 0.8LiMn(0.3)Ni(0.4)Co(0.3)O(2) was from 253 mAh/g to 234 mAh/g, and the cycling performance was better. After 40 cycles at different current the capacity retention was 83.4%, the product has very good retention capacity.