(昆明理工大學(xué) 真空冶金國(guó)家工程實(shí)驗(yàn)室,昆明 650093)
摘 要: 用濕法球磨−噴霧干燥法制備LiFe0.98Mg0.02PO4/C復(fù)合正極材料;用激光粒度分析儀、X射線衍射儀、掃描電鏡和恒流充放電等對(duì)前驅(qū)體和磷酸鐵鋰樣品進(jìn)行表征;考察不同球磨工藝對(duì)磷酸鐵鋰顆粒形貌、粒度分布、振實(shí)密度和電化學(xué)性能的影響。結(jié)果表明:用濕法球磨−噴霧干燥法可以制得球形顆粒、高振實(shí)密度且電化學(xué)性能優(yōu)良的磷酸鐵鋰正極材料,原料經(jīng)粗磨后再超細(xì)球磨制得的材料性能更佳,振實(shí)密度達(dá)1.67 g/cm3,在0.1 C、0.5 C和1.0 C倍率下的首次放電比容量分別為151、143和132 mA∙h/g。
關(guān)鍵字: 鋰離子電池;LiFePO4;噴霧干燥;電化學(xué)性能
(National Engineering Laboratory of Vacuum Metallurgy,
Kunming University of Science and Technology, Kunming 650093, China)
Abstract:LiFe0.98Mg0.02PO4/C composite cathode material was prepared by wet ball milling-spray drying method. The precursors and LiFePO4 samples were characterized by laser particle size analyzer, XRD, SEM, and electrochemical charge-discharge tests. The effects of different ball milling processes on the morphologies, particle size distribution, tap density and electrochemical performance of LiFePO4 were investigated. The results show that spherical LiFePO4 with high density and good electrochemical performance can be synthesized by wet ball milling–spray drying method, and LiFePO4 prepared by the two-step ball milling has a tap density of 1.67 g/cm3, which presents large reversible discharge capacities of 151, 143 and 132 mA∙h/g at 0.1 C, 0.5 C and 1.0 C rate, respectively.
Key words: lithium ion battery; LiFePO4; spray drying; electrochemical performance


