(中南大學(xué) 冶金科學(xué)與工程學(xué)院, 長沙 410083)
摘 要: 用共沉淀法制備摻鈦前驅(qū)體FePO4·2H2O，對FePO4·2H2O經(jīng)常溫還原插鋰合成LiFePO4的前驅(qū)混合物，后經(jīng)熱處理得橄欖石型LiFePO4；用SEM，XRD和恒流充放電等對樣品進(jìn)行表征，考察Ti摻雜和合成溫度對LiFePO4的物理和電化學(xué)性能的影響。研究結(jié)果表明，在600 ℃時合成的Ti摻雜樣品具有優(yōu)異的電化學(xué)性能，該樣品在0.1C，1C和2C倍率下的首次放電比容量分別為150，130和125 mA∙h/g，循環(huán)40次后的放電比容量均無衰減。
關(guān)鍵字: 鋰離子電池；LiFePO4；共沉淀；常溫還原；鈦摻雜
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Ti-doped precursors (FePO4·2H2O) were prepared by co-precipitation method. Olivine-type LiFePO4 were synthesized by sintering the LiFePO4 precursor-mixtures which were obtained via reduction and lithiation of FePO4·2H2O at room temperature. The samples were characterized by scanning electron microscopy, X-ray diffractometry and electrochemical charge and discharge tests. Effects of Ti-doping and sintering temperature on physical and electrochemical performance of LiFePO4 were investigated. The results show that the Ti-doped sample sintered at 600 ℃ has excellent electrochemical performance. Its initial discharge capacities are 150, 130 and 125 mA∙h/g at 0.1C, 1C and 2C rates, respectively, and no capacity fading is found after 40 cycles.
Key words: lithium ion battery; LiFePO4; co-precipitation; room temperature reduction; Ti-doping
