Full
YANG Mei (1998-), female, Master candidate. E-mail: 1837678628@qq.com
Outline
Spinel LiMn2O4 cathode materials suffer a serious capacity decay and a poor cycle stability during the charge-discharge process due to the Jahn-Teller effect and Mn dissolution. A cathode material of truncated octahedral single crystal LiFe0.12Mn1.88O4 with {111}, {100} and {110} surfaces was prepared by a solid-state combustion method and element doping and single crystal morphology controlling strategies. The results show that the crystal structure of spinel LiMn2O4 is not changed by Fe doping, the Jahn-Teller effect is effectively inhibited, the crystallinity and the selective growth of {400} and {440} diffraction peak crystal planes are promoted, and the material has superior rate performance and capacity retention. The initial discharge specific capacities at 1 C and 5 C at 25 ℃ are 105.2 mA·h/g and 92.4 mA·h/g, and the capacity retentions after 1 000 cycles are 71.1% and 75.2%, respectively. Moreover, the capacity retention reaches 88.4% after 1 000 cycles at 10 C. The initial discharge capacity of the material is 108.6 mA·h/g at 55 ℃ and 1 C, and the capacity retention rate is 79.1% after 150 cycles, and the capacity retention rate is 79.1% after 150 cycles. By using cyclic voltammetry and electrochemical impedance spectroscopy, we found that the Fe-doped sample has superior circulation reversibility and large Li+ diffusion coefficient. The Fe-doped material of truncated octahedral LiMn2O4 inhibits the Jahn-Teller effect, and slows down the Mn dissolution, thus stabilizing the crystal structure, increasing the Li+ migration channel, and improving the electrochemical rate performance and long cycle life.
29
5
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
