C.Q. Xu
,
Y.W. Tian
,
Y.C. Zhai
,
Z.J. Guo
,
Z.Q. Huang
金属学报(英文版)
The differential thermal analysis (DTA) curves were measured at different heating rates in flowing air for studying the synthesis of the spinel LiMn2O4 with Li2CO3 and MnO2. The reaction began at about 503K, and finished at about 873K. The apparent activation energy of Kissinger method was about 122.77kJ·mol-1, the reaction order was 1.67, the frequency factor was 7.81×10 9, and therefore the kinetic equation was ＝ Ａ·ｅｘｐ（－）·（1-δ)n = 7.81×10 9 ｅｘｐ（－）·(1-δ)1．６７. Coats-Redfern integral method was used to analyze the DTA curves of the samples at different heating rates, and the calculated apparent activation energy and frequency factor were 112.13kJ·mol-1 and 1.18×10 9, respectively, rather close to that of Kissinger method. X-ray diffraction (XRD) and scanning electron microscope (SEM) results shown that the synthesized LiMn2O4 possesses pure phase, regular shape and normal particle distribution.
关键词:
lithium manganese oxides
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null
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null
M.S. Zhao
,
Y.C. Zhai
,
Y.W. Tian
金属学报(英文版)
The reaction process during synthesis of LiMn2 O4 with LiOH. H2 O and MnO2 was studied by means of DTA in dynamical air atmosphere, and it could be applied as an important theoretical principle for preparing LiMn2 O4. The active energies of four reaction processes were obtained with Doyle-Ozawa method and Kissinger method as follows: 66.299, 72.640, 128.111 and 113.876 kJ. mol-1, respectively. Reaction orders,frequency factors and kinetic equations of each reaction were determined by using Kissinger method. XRD, SEM and TEM showed that the synthesized LiMn2 O4 is a pure phase, with regular appearance and higher ratio-surface.
关键词:
lithium-ion battery
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null
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null
