(中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083)
摘 要: 采用高溫固相法合成鋰離子電池正極材料LiFe0.9Ni0.1PO4，研究了反應(yīng)條件對(duì)合成產(chǎn)物的影響。 利用X射線衍射(XRD)和掃描電鏡(SEM)對(duì)所得樣品的晶體結(jié)構(gòu)、 表面形貌等進(jìn)行了表征。 結(jié)果表明： 反應(yīng)溫度和時(shí)間對(duì)LiFe0.9Ni0.1PO4晶體結(jié)構(gòu)及材料性能均有較大影響，其中650 ℃下焙燒20 h合成出的樣品電化學(xué)性能最佳； 在20 mA/g的電流密度下進(jìn)行恒流充放電時(shí)，首次放電比容量可達(dá)145 mA·h/g， 循環(huán)30次后比容量仍為135 mA·h/g，容量衰減僅為6.9%。
關(guān)鍵字: LiFePO4； 鋰離子電池； 正極材料； 鎳摻雜； 固相反應(yīng)； 電化學(xué)性能
PENG Wen-jie, LIU Feng-ju
（ School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: LiFe0.9Ni0.1PO4 for cathode materials of lithium-ion battery was synthesized by solid-state reaction. The effects of synthesis temperature and reaction time on the electrochemical performance were studied systematically. The crystalline structure and microstructures of resulting specimens were characterized by X-ray diffractometry (XRD) and scanning electromicroscopy (SEM). The results show that the reaction temperature and time have great effect on the structures and electrochemical performance of the obtained samples. Further electrochemical tests indicate that the material synthesized optimally at 650 ℃ for 20 h possesses excellent electrochemical performance. The first discharge capacity of LiFe0.9Ni0.1PO4 on 20 mA/g current density arrives at 145 mA·h/g and after 30 times cycling the discharge capacity is still up to 135 mA·h/g, only with about 6.9% capacity fade.
Key words: lithium iron phosphate; lithium-ion battery; cathode material; Ni-doping; solid-state reaction; electrochemical performance
