鋰離子電池材料lini0.5mn0.3co0.2o2的制備及其摻雜改性

1、 分類號(hào)： 密 級(jí)： 學(xué) 號(hào)： 6120100118 單位代碼： 10407 碩 士 學(xué) 位 論 文 論文題目 論文題目: 鋰離子電池材料 LiNi0.5Mn0.3Co0.2O2 的制備 及其摻雜改性 研 究 方 向 鋰離子電池及相關(guān)材料 專 業(yè) 名 稱 材料學(xué) 研 究 生 姓 名 鐘風(fēng)娣 導(dǎo)師姓名、職稱 鐘盛文（教授） 2013 年 06 月 05 日 江西·贛州II Abstract Laye

2、red cathode materials LiNi0.5Mn0.3Co0.2O2, with synergwastic effect of Ni, Mn and Co, shows a good electrochemical performance. However, its cycle stability, high rate current stability and high voltage stability need to

3、 be improved. In this paper, LiNi0.5Mn0.3Co0.2O2 was synthesized by mixing nickel cobalt manganese hydroxide precursor prepared by co-precipitation with Li2CO3, roasting at high temperature. The influence of synthes cond

4、itions on its performance was discussed by changing factors one by one and optimized the synthes process. Modifying researches on lithium ion battery cathode materials by doping MgO, TiO2, Al(NO3)3 was studied, and the s

5、tructure, morphology, electrochemical performance was tested and analyzed. In this paper, the roasting temperature, lithium ratio and holding time of the LiNi0.5Mn0.3Co0.2O2 cathode material was discussed, and the optim

6、um process parameters as follows: roasting temperature of 920℃, lithium ratio of 1.06, holding time of 15 hours. Materials were synthesized under these conditions and tested at 25℃, 1C rate current between 2.75 and 4.2V,

7、 the results show that the first discharge capacity was 159.2mAh/g, the discharge capacity after 100 times cycles was 141.0mAh/g, the capacity retention rate was 88.6%. The cycling retention capacity after 235 times cycl

8、es was more than 80%, indicating the material has good cycling performance. The discharge capacity of 1C, 2C, 3C, 4C rate under 2.75-4.4V were 174.2mAh/g, 164.1mAh/g, 155.1mAh/g and 140.2mAh/g, respectively. In the exper

9、iments, the cycle performance of Mg2+ doped LiNi0.5Mn0.3Co0.2O2 cathode material at room temperature has been greatly improved. The cycling performance of the cathode materials when doped 3% MgO was the best. The first d

10、ischarge capacity reached 150.6 mAh/g at 1C when charged at 2.75-4.2V. The discharge capacity after 100 and 200 times was 140.6 mAh/g, 135.4 mAh/g, and the capacity retention rate was 93.4%, 89.9%, respectively. The cyc

11、ling stability of Ti doped LiNi0.5Mn0.3Co0.2O2 cathode materials charged at 1C rate between 2.75 and 4.2V were greatly improved. The first discharge capacity of LiNi0.5Mn0.3Co0.2O2 cathode materials doped 3% TiO2 reach t

12、o a maximum of 149.5mAh/g, and the discharge capacity after 200 times was 142.3mAh/g, and the capacity retention rate was 95.2%. The capacity retention rate after 420 times cycle was more than 80%. The cycling stability

13、 was greatly improved of Li[Ni0.5Mn0.3Co0.2]1-xAlxO2 which synthesized by doping Al. The best electrochemical performance of Al doped cathode material was doped with 2% Al(NO3)3 when charged at 1C rate current between 2.

14、75 and 4.2V, which the first discharge capacity was 150.0mAh/g and the capacity was 137.0mAh/g after 200 cycles, the capacity retention rate was 91.3%, and the cycling retention capacity after 400 times cycles was more t