A novel process for producing synthetic rutile and LiFePO4 cathode material from ilmenite

作者：Wu, Ling; Li, Xinhai^*; Wang, Zhixing; Guo, Huajun; Wang, Xiaojuan; Wu, Feixiang; Fang, Jie; Wang, Zhiguo; Li, Lingjun

来源：Journal of Alloys and Compounds, 2010, 506(1): 271-278.

DOI：10.1016/j.jallcom.2010.07.003

• Ilmenite
• Leaching
• Synthetic rutile
• Cathode material
• LiFePO4

Synthetic rutile and LiFePO4 cathode materials are prepared from the titanium hydrolysate and iron-rich lixivium, respectively. The titanium hydrolysate and iron-rich lixivium are obtained from the ilmenite by mechanical activation and leaching. The purity of synthetic rutile and the electrochemical performance of LiFePO4 are mainly determined by the leaching process. The optimal leaching conditions are as follows: HCI concentration 20 wt.%, reaction temperature 100 degrees C and hydrochloric acid/ilmenite mass ratio of 1.2:1. The synthetic rutile prepared under the optimal conditions contains 90.8% TiO2, 2.21% Fe2O3, 0.052% MnO2 and 0.23% (MgO+CaO), which meet the requirement for the production of titanium dioxide by chlorination. A co-precipitation method is used to synthesize FePO4.xH(2)O precursor from the iron-rich lixivium. ICP and EDS results show that small amounts of Al and Ti exist in the precursor. XRD results indicate that Al-Ti doping does not obviously change the structure of LiFePO4, and all the LiFePO4 samples are pure triphylite phase. The LiFePO4 sample prepared from the lixivium (leaching with 20 wt.% hydrochloric acid) exhibits a first discharge capacity of 151, 140 and 123 mAh g(-1) at 1C, 2C and 5C rate, respectively, and shows excellent cycling performance.

• 出版日期2010-9-10
• 单位中南大学