李虹, 李豫云, 刘红雷, 向明武, 苏长伟, 刘晓芳, 郭俊明, 李力. 纳米Li1.05Ni0.05Mn1.90O4正极材料的合成及电化学性能[J]. 云南大学学报(自然科学版), 2022, 44(1): 116-125. doi: 10.7540/j.ynu.20210286
引用本文: 李虹, 李豫云, 刘红雷, 向明武, 苏长伟, 刘晓芳, 郭俊明, 李力. 纳米Li1.05Ni0.05Mn1.90O4正极材料的合成及电化学性能[J]. 云南大学学报(自然科学版), 2022, 44(1): 116-125. doi: 10.7540/j.ynu.20210286
LI Hong, LI Yu-yun, LIU Hong-lei, XIANG Ming-wu, SU Chang-wei, LIU Xiao-fang, GUO Jun-ming, LI Li. Synthesis and electrochemical performance of nano Li1.05Ni0.05Mn1.90O4 cathode material[J]. Journal of Yunnan University: Natural Sciences Edition, 2022, 44(1): 116-125. DOI: 10.7540/j.ynu.20210286
Citation: LI Hong, LI Yu-yun, LIU Hong-lei, XIANG Ming-wu, SU Chang-wei, LIU Xiao-fang, GUO Jun-ming, LI Li. Synthesis and electrochemical performance of nano Li1.05Ni0.05Mn1.90O4 cathode material[J]. Journal of Yunnan University: Natural Sciences Edition, 2022, 44(1): 116-125. DOI: 10.7540/j.ynu.20210286

纳米Li1.05Ni0.05Mn1.90O4正极材料的合成及电化学性能

Synthesis and electrochemical performance of nano Li1.05Ni0.05Mn1.90O4 cathode material

  • 摘要: 采用液相无焰燃烧法在500 ℃反应1 h,然后在600 ℃二次焙烧3、6、9 h和12 h制备了尖晶石型Li1.05Ni0.05Mn1.90O4正极材料. 结果表明,不同二次焙烧时间制备的Li−Ni复合共掺材料没有改变LiMn2O4的尖晶石结构,随着焙烧时间的增加,颗粒尺寸增大,结晶性提高. 二次焙烧时间为9 h的Li1.05Ni0.05Mn1.90O4样品的颗粒尺寸约为70~100 nm,具有优异的电化学性能,在1 C(1 C=148 mA·h·g−1)倍率,初始放电比容量为94.8 mA·h·g−1,400次循环后展现出72.15%的容量保持率;在5 C下初始放电比容量可达到89.7 mA·h·g−1,800次循环后,仍能维持70.79%的容量保持率. 并且具有较小的电荷转移电阻和较低的表观活化能. Li−Ni复合掺杂能够有效抑制Jahn-Teller效应和缓解Mn的溶解,稳定晶体结构,提高循环稳定性和倍率性能.

     

    Abstract: Spinel Li1.05Ni0.05Mn1.90O4 cathode material was synthesized via a flameless combustion method at 500 ℃ for 1 h followed by calcination at 600 ℃ for 3, 6, 9 and 12 h, respectively. Results show that Li−Ni co-doping material prepared at different secondary calcination time did not change the spinel structure of LiMn2O4. With the increased calcination time, the particle size was increased and the crystallinity was enhanced. At the secondary calcination time of 9 h, the obtained Li1.05Ni0.05Mn1.90O4 cathode material shows the particle size of 70—100 nm, and exhibits an excellent electrochemical performance with the first-discharge specific capacity of 94.8 mA·h·g−1 and the capacity retention rate of 72.15% after 400 cycles at 1 C(1 C=148 mA·h·g−1). Moreover, an initial discharge capacity of 89.7 mA·h·g−1 with a capacity retention rate of 70.79% can be obtained after 800 cycles at 5 C. The optimized electrode has a low charge transfer resistance and apparent activation energy. The Li−Ni co-doping inhibits the Jahn-Teller effect effectively and alleviates Mn dissolution, hence, stabilizing the crystal structure and enhancing the rate capability and cycle performance.

     

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