Spinel LiMn2O4 with Two-step Nano-Al2O3 Coating as High Performance Positive Materials

• Published in: International journal of electrochemical science 2017-07, Vol.12 (7), p.6853-6862
• Main Authors: Zhang, Yannan, Dong, Peng, Yu, Xiaohua, Xia, Shubiao, Song, Jinjie, Yang, Ruiming, Liang, Huixin, Shi, Zhezhong, Yao, Yao, Li, Xue, Zhang, Yingjie
• Format: Article
• Language: English
• Subjects: LiMn2O4; lithium-ion batteries; positive materials; sol-gel process
• ISSN: 1452-3981; 1452-3981
• DOI: 10.20964/2017.07.56

To study the influence of the uniformity and integrity of amphoteric metal oxide coating layers on the performance of positive materials in Lithium-ion batteries, nano-Al2O3-coated LiMn2O4 positive material were synthesized by using a two-step sol-gel process. The products were characterized by power X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), energy-dispersive X-ray spectrum (EDX), X-ray photoelectron spectroscopy (XPS), galvanostatic charge-discharge test system, and inductively-coupled plasma emission spectrograph (ICP-AES). The results show that the two step method coating can bring with the uniform and glabrous nano-Al2O3 layer tightly coupling with the surface of the LiMn2O4 particles, when being positive material for Lithium-ion batteries, which exhibits capcity losses of only 13.2 % at 60 °C, after 300 cycles, much better than those of the pristine material and the sample synthesized by conventional one step sol-gel method (with the same Al2O3-coating content). Moreover, the ICP-AES tests of Mn2+ reveal that the Al2O3 layers with two step coating layer plays an important role in protecting LiMn2O4 from the electrolyte corrosion.