采用溶胶-凝胶包裹法对尖晶石LiMn2O4及其阳离子掺杂LiM0.1Mn1.9O4(M=Li,Ni)正极材料进行了表面改性研究.X射线衍射及电子探针线扫描分析表明,表面改性以后的晶粒仍为尖晶石结构,表面改性离子Co的浓度由表及里逐步减小.电解液溶蚀实验及电化学循环测试表明,表面改性后的正极材料LiM0.1Mn1.9O4的抗溶蚀性明显增强,循环性能优良.性能改善的原因是表面改性以后,尖晶石晶粒表层Mn3+离子浓度降低,Mn4+离子浓度大大增加,减少了Mn3+发生歧化反应的机会.
The grains of LiMn2O4 and LiMxMn2-xO4 (M=Li, Ni) were coated with LiCoO2 by using sol-gel
process. XRD and EPMA studies confirme the presence of a Co-rich spinel LiMn2-xCoxO4 layer on the surface of LixMn2-xO4 grains
and the content of Co decreases gradually from the surface to the core of spinel grains. Furthermore, the amount of Mn3+ in the surface layer is less than in the core, so
the possibility of Mn dissolution decreases. The surface treatment is effective in reducing the rate of Mn dissolution into electrolyte and
improving cyclability of spinel LiMxMn2-xO4 cathode materials. After bulk Ni-doped spinel LiNi0.1Mn1.9O4 coated with
LiCoO2, the cyclability of the material is better than that of pure spinel LiMn2O4and just only cations doped.
参考文献
| [1] | Huang Haitao, Vincent C A, Bruce P G. J. Electrochem. Soc., 1999, 146 (2): 481--485. [2] Dong H Jang, Seung M Oh. J. Electrochem. Soc., 1997, 144 (10): 3342--3347. [3] Arora P, White R E, Doyle M. J. Electrochem. Soc., 1998, 145: 3647--3667. [4] 罗穗莲, 李伟善, 邱仕洲. 电池, 2001, 31 (1): 44--47. [5] Amatucci G G, Blyr A, Sigala C, et al. Solid State Ionics, 1997, 104: 13--25. [6] Pasquier A Du, Orsini F, Gozdz A S, et al. Journal of Power Source, 1999, 81-82: 607--611. [7] Cho Jaephil, Kim Geunbae. Electrochemical and Solid-State Letters, 1999, 2 (6): 253--255. [8] Mladenov M, Stoyanova R, Zhecheva E, et al. Electrochemistry Communications, 2001, 3: 410--416. [9] Ho-Jin Kweon, Dong Gon Park. Electrochemical and Solid-State Letters, 2000, 3 (3): 128--130. [10] Ying Jierong, Wan Chunrong, Jiang Changyin. Journal of Power Source, 2001, 102: 162--166. [11] Kweon Ho-Jin, Kim Sue Joo, Park Dong Gon. Journal of Power Siurces, 2000, 88: 255--261. [12] Gao Yuan, Reimers J N, Dahn J R. Physical Review B, 1996-?Ⅱ, 54 (6): 3878--3883. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%