(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 以钛铁矿为原料，经机械活化−盐酸浸出得到水解钛渣和富铁浸出液；用H2O2将水解钛渣中的Ti配位溶出，得到配位浸出液，并以其为反应物制备纳米级片状的过氧钛化合物；该过氧钛化合物经洗涤、煅烧制备得到纳米级片状的TiO2，其纯度高达99.31%(质量分数)。将过氧钛化合物与Li2CO3混合，球磨后煅烧合成性能优良的锂离子电池负极材料Li4Ti5O12。以富铁浸出液为原料，经选择性沉淀制备含少量Al和Ti的FePO4·xH2O，并以其为前驱体制备了Al-Ti掺杂的LiFePO4。该LiFePO4在1C和2C倍率下的首次放电比容量分别达151.3和140.1 (mA·h)/g，循环100次之后容量无衰减。该方法也可用于钛白粉副产品硫酸亚铁的回收利用，制备性能优异的LiFePO4。
关键字: 钛铁矿；二氧化钛；正极材料；负极材料；磷酸铁锂；钛酸锂
lithium iron phosphate from ilmenite
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Titanium hydrolysate and iron-rich lixivium were obtained from the ilmenite by mechanical activation and hydrochloric acid leaching. By using H2O2 as a coordination agent, titanium was leached from the titanium-slag and a coordination lixivium was obtained. A nano-sized platelike peroxo-titania compound was prepared by heating the coordination lixivium. The peroxo-titania compound was washed and sintered, then a nano-sized platelike TiO2 (99.31%, mass fraction) was obtained. Li4Ti5O12 was synthesized by sintering the mixture of peroxo-titania compound and Li2CO3, the sample shows a good electrochemical performance as an anode material for the lithium-ion batteries. A selective precipitation method was used to synthesize FePO4·xH2O precursor from the iron-rich lixivium. The Ti-Al doped LiFePO4 was prepared using the FePO4·xH2O as the starting material. The as-prepared LiFePO4 exhibits a first discharge capacity of 151.3 and 140.1 (mA·h)/g, respectively, and shows no capacity fading after 100 cycles. Also, this method was used to synthesize the high-performance LiFePO4 from the ferrous sulfate waste slag produced by the titanium dioxide industry.
Key words: ilmenite; titanium dioxide; cathode material; anode material; lithium iron phosphate; lithium titanium oxide
