Synthesis And Characterization Of Cathode Materials LiM_xMn_2-xO₄ For Lithium Ion Batteries

Lithium-ion battery has gradually replaced the tradition batteries as the power source, duing to the excellent advantages.for example high voltage, high capacity, long using lifetime and no pollution. Being no toxicity and abundance of Mn, the spinel LiMn₂O₄ has been a highlight extensively among electrode materials in the battery. In order to resolve the defect of large capacity fade on cycling, the transition and thulium metal were choosed as additives to synthesize LiMn₂O₄, dope and study the performance in the paper.The synthesis temperature and the technology were got, based on experiment; The spinel lithium manganese oxides LiMn₂O₄ and its dopant materials were prepared by solid-state method. Their structures, performance and the electrode process of the active material were investigated by means of XRD, SEM, CV, EIS and the equivalent circuit,It showed that LiMn_2-xCr_xO₄ system has less resistance than that of the LiMn₂O₄ by EIS, So doped Cr ion help Li⁺ intercalate and unintercalate freely and increased the electrochemical performance of the material.The obvious effects of the scan rate on the CV curves were studied in LiMn_2-xCo_xO₄ system; The CV curves were compared with LiMn₂O₄ after cyclics, which showed that doped Co ion increased reversibility of the reaction.It showed that the La stoichiometric number X has obvious impact on the structure and the CV curves; the structure was attected by the synthesis temperature and Nd stoichiometric number X; By the EIS curves of the different potential, it showed that the resistance decreased with the increase of the potential in the doping thulium elements Nd experiment.It showed that doped ion stabilized the structure and help to increase the performance of the material. By the equivalent circuit, the electrode process was analysed and sthdied.