(1. 四川大學(xué) 材料科學(xué)與工程學(xué)院，成都 610064；
2. 西南民族大學(xué) 生命科學(xué)與技術(shù)學(xué)院，成都610041)
摘 要: 以鈦白工業(yè)副產(chǎn)物七水硫酸亞鐵為鐵源，用液相沉淀制得無(wú)定形FePO4·xH2O前軀體，然后在多元醇中與鋰源反應(yīng)制得LiFePO4材料，過(guò)程在常壓下進(jìn)行，無(wú)需煅燒與惰性氣體保護(hù)。用XRD、SEM及電化學(xué)分析考察多元醇乙二醇(EG)、二甘醇(DEG)和三甘醇(TEG)對(duì)材料物相和形貌的影響。結(jié)果表明：三甘醇所得樣品的鋰離子擴(kuò)散速率最小；此樣品的晶粒尺寸最小，結(jié)晶最完整，無(wú)明顯雜相生成。在室溫下放電倍率為0.1C、1C和5C時(shí)，該正極材料的首次放電比容量分別達(dá)到148.8、129.3和102.8 mA∙h/g，其碳包覆樣品的首次放電比容量分別達(dá)到155.6、139.9和112.2 mA∙h/g，且循環(huán)性能良好。
關(guān)鍵字: LiFePO4；液相沉淀；多元醇；鋰離子電池；正極材料
（1. School of Materials Science and Engineering, Sichuan University, Chengdu 610064, China;
2. College of Life Science and Technology, Southwest University of Nationalities, Chengdu 610041, China）
Abstract:Amorphous FePO4·xH2O was prepared by liquid precipitation using FeSO4·7H2O by-product of titanium dioxide industry, and LiFePO4 was synthesized by a polyol route under ordinary pressure without further calcinating or inert gas protection. The effects of different polyols of EG, DEG and TEG on the phase composition and morphology were investigated by X-ray diffraction(XRD), scanning electron microscope (SEM) and electrochemical analysis. The results demonstrate that LiFePO4 prepared by TEG shows the smallest diffusion rate of lithium ion, the smallest particle size, the best crystalline integrity and the highest phase purity. The LiFePO4 prepared by TEG has the first discharge specific capacities of 148.8, 129.3 and 102.8 mA∙h/g at 0.1C, 1C and 5C discharge rate and room temperature, respectively. The improved first discharge specific capacity of its carbon-coating sample reaches 155.6, 139.9 and 112.2 mA∙h/g at 0.1C, 1C and 5C, respectively, exhibiting a favorable capacity cycling maintenance.
Key words: LiFePO4; liquid-precipitation; polyol; lithium-ion battery; cathode material
