Research On Preparation,Characterization And Modification Of LiMn₂O₄ Through Solid-state Reactions In Low Temperature

The precursor of LiMn₂O₄ is synthesized through solid state reaction among the starting material C₆H₈O₇ ·H₂O(A.R.),Mn(CH₃COO)₂·4H₂O(A.R.)and LiOH·H₂O(A.R.) at ambient temperature. The LiMn₂O₄ is prepared by calcining the precursor. The effect of the processing technology is studied and it is found that products made by calcining in two steps have the better quality than the single calcining.The activate energy of growing is 16.26KJ/mol obtained through analysis the relationship of the annealing temperature and the particle size. When the annealing temperature increase from 550°C to 650°C, the average particle size increases from 19.98nm to 29.93nm. the research shows that as the annealing time goes on ,the LiMn/₂O₄ power grows up through the following steps : nucleus formation,harmonious growth ,unconventional growth and homogenization .the relationship of the growth of the LiMn₂O₄ particle size and the annealing time at 550℃ to 650℃ was studied. The process of growth can be divided into the fast growth and the slow growth process, and both of them accord with the G-M model. The kinetics equation is : At 550℃ the v equals 3.71 and 2.23 at the fast and slow growth process; At 650℃ the v equals 3.34 and 2.17 at the fast and slow growth process. So at the fast growth process the body diffusion is the major mechanism of the growth, and at the slow growth process the body diffusion is the major mechanism of the growth.The misconstruction of the LiMn₂O₄ nanopower by element adopting was researched too. The X-ray diffraction and infrared spectrum of LiMn₂O₄ with element Mg, Cd and Li adopting were studied respectively , it can be found adopting elements in kind or quantity...