| The preparation and structure properties of spinel LiMn204 as a positive active material for lithium-ion battery were studied.The preparation of the positive electrode materials was done in the solution at low temperature. On the same conditions, the perfect spinel-structure LiMn2O4 can be synthesized using the citrate complex method, especially by improving technics, the nanometer and sub-micrometer sample was synthesized with fine crystallization, averaging crystal grain and composing, that is hopeful for electrode application.Different techniques, such as XRD, TEM, SEM, have been used to study the kinetics and examine the structure characteristics. The pure sample with spinel structure can be easily prepared by optimizing the processing parameters. The typical product is LiMniO4 with the cell constant a=8.235 and the powder size belongs to nanometer and sub-micrometer.The effects of different conditions on the phase structure have also been investigated. It's obtained that pH=6.5 is a suited pH value for getting ideal product with good properties. The calcinate temperature is the key factors to transform the precursor to a pure product with spinel structure. Calcinate time can obviously influence the size of the sample, the longer of the calcinate time, the more severe of the conglomeration. And the continuous and discontinuous calcinate manners have different influences on the structure of the sample.For improving the cycling property and the volume fading at high temperature, LiMxMn2-xO4 with doping element Co CR Ni Cu (0.05 |
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