(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 以鈦鐵礦為原料，經(jīng)機(jī)械活化−鹽酸浸出得到水解鈦渣和富鐵浸出液；用H2O2將水解鈦渣中的Ti配位溶出，得到配位浸出液，并以其為反應(yīng)物制備納米級(jí)片狀的過(guò)氧鈦化合物；該過(guò)氧鈦化合物經(jīng)洗滌、煅燒制備得到納米級(jí)片狀的TiO2，其純度高達(dá)99.31%(質(zhì)量分?jǐn)?shù))。將過(guò)氧鈦化合物與Li2CO3混合，球磨后煅燒合成性能優(yōu)良的鋰離子電池負(fù)極材料Li4Ti5O12。以富鐵浸出液為原料，經(jīng)選擇性沉淀制備含少量Al和Ti的FePO4·xH2O，并以其為前驅(qū)體制備了Al-Ti摻雜的LiFePO4。該LiFePO4在1C和2C倍率下的首次放電比容量分別達(dá)151.3和140.1 (mA·h)/g，循環(huán)100次之后容量無(wú)衰減。該方法也可用于鈦白粉副產(chǎn)品硫酸亞鐵的回收利用，制備性能優(yōu)異的LiFePO4。
關(guān)鍵字: 鈦鐵礦；二氧化鈦；正極材料；負(fù)極材料；磷酸鐵鋰；鈦酸鋰
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
