关键词: 锂离子电池, 富锂锰基正极材料, 聚合物热解法, 电化学性能

Abstract:

To meet the current demand for high-specific capacity electrochemical energy storage materials in new energy generation technology, we prepared high-specific capacity layered lithium-rich manganese-based oxide (Li_1.2Ni_0.13Co_0.13Mn_0.54O₂) by optimizing the proportion of metal ions and acrylic acid in the precursor polymerization process using the polymer-pyrolysis method. Based on the polymerization reaction of acrylic acid to achieve uniform dispersion of metal ions, a Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode material was prepared by secondary heating and calcination. By changing the calcination temperature to prepare cathode material samples at different calcination temperatures, we studied the effect of calcination temperature on the microstructure and electrochemical performance. We employed testing techniques such as X-ray diffraction and scanning electron microscopy to observe differences in the microstructure and crystal structures of different material samples, energy dispersive spectroscopy to observe the distribution of elements in the materials, and the Xinwei battery testing system and electrochemical workstation to study the electrochemical performance of the prepared cathode material. The results show that the Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode material prepared at 925 ℃ has high crystallinity, obvious layered structure, low degree of cation mixing, and uniform dispersion of various elements. During the charge-discharge cycle test in the range of 2.0—4.8 V, the first cycle discharge-specific capacity reached 290.3 mAh/g at a rate of 0.1C. The discharge capacity remained at 204.8 mAh/g for 100 cycles at a rate of 0.5C, with a capacity retention rate of 81.9%, demonstrating good cycling stability. The prepared Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode material exhibits good electrochemical performance. This study promotes the application of lithium-rich manganese-based oxide cathode materials and provides an experimental basis for developing high-specific capacity cathode materials.

Key words: lithium ion battery, lithium rich manganese based cathode material, polymer-pyrolysis method, electrochemical performance