以Fe2O3为铁源, 用环氧树脂对反应前驱体进行包覆, 通过固相还原法制备了LiFePO4/C复合正极材料. 采用XRD、SEM、循环伏安以及充放电测试等方法对其晶体结构、表观形貌和电化学性能进行了研究. 研究结果表明, 煅烧温度对材料的电化学性能有较大影响, 在700℃煅烧所得产物为单一的橄榄石型晶体结构, 粒径分布较均匀, 且具有良好的电化学性能. 以0.1C倍率进行充放电, 其首次放电容量为150.3mAh/g, 充放电循环20周后, 容量保持率达99.2%; 以1.0、2.0C倍率进行充放电, 其首次放电容量分别为131.4和122.1mAh/g. 其在过充条件下的电性能也佳, 过充后还能继续放电, 但在过放电条件下, 其电性能迅速劣化.
The LiFePO4/C composite cathode materials for lithiumion batteries were synthesized by a solid state reduction method. The crystalline structure, morphology of particles, and electrochemical performance of the sample were investigated by -ray diffraction, scanning electron microscope, charge-discharge test and cyclic voltammetry. The results show that the composite synthesized at 700℃ has a simple pure olivetype phase with small particles, and uniformly distribution of gain sizes, and shows the best electrochemical performances with 1st discharge specific capacity 150.3mAh/g and 20 th discharge specific capacity retention ratio 99.2% at 0.1C rate. It also shows good rate capability with 131.4mAh/g, 122.1mAh/g at the high rate of 1.0C and 2.0C, respectively. With the excellent characteristic to resist overcharge, this composite can retain its microstructure even after long time overcharge, but it is vulnerable to overdischarge.
参考文献
| [1] | 卢俊彪, 唐子龙, 张中太, 等(LU Jun-Biao, et al). 无机材 料学报(Journal of Inorganic Materials), 2005, 20 (3): 666--670. [2] Striebel K, Shim J, Srinivasan V, et al. J. Electrochem. Soc., 2005, 152 (4): A664--A670. [3] Yang S, Song Y, Ngala K, et al. J. Power Sources, 2003, 119: 239--246. [4] Andersson A S, Thomas John O S. J. Power Sources, 2001, 97: 498--502. [5] 文衍宣, 郑绵平, 童张法, 等(WEN Yan-Xuan, et al). 无机 材料学报(Journal of Inorganic Materials), 2006, 21 (1): 115--120. [6] 谢辉, 周震涛(XIE Hui, et al). 无机材料 学报(Journal of Inorganic Materials), 2006, 21 (3): 591--598. [7] Gaberscek M, Dominko R, Bele M, et al. Solid State Ionics, 2005, 176: 1801--1805. [8] 米常焕, 曹高劭, 赵新兵. 无机化学学报, 2005, 4: 557--560. [9] 杨南如, 岳文海. 无机非金属材料图谱手册. 武汉: 武汉工业大学出 版社, 2000. 67--90. [10] 张祖训. 超微电极电化学. 北京: 科学出版社, 1998. 15--35. [11] Barker J, Pynenburg R, Koksbang R, et al. Electrochim. Acta, 1996, 41 (15): 2481--2488. [12] Takahashi M, Tobishima S, Takei K. Solid State Ionics, 2002, 148 (3-4): 283--289. |
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