(School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
摘 要: 以FeSO4·7H2O、H3PO4、H2O2和尿素為原料，采用均勻沉淀法制備LiFePO4的前驅(qū)體FePO4·xH2O，研究表面活性劑PEG對前驅(qū)體FePO4·xH2O形貌的影響。并將獲得的FePO4∙xH2O與Li2CO3及葡萄糖混合后合成LiFePO4/C。利用XRD、SEM、循環(huán)伏安測試、電化學(xué)性能測試、交流阻抗測試等手段對LiFePO4/C進(jìn)行表征。結(jié)果表明：當(dāng)不添加表面活性劑PEG時，F(xiàn)ePO4·xH2O顆粒呈球形，但團聚現(xiàn)象嚴(yán)重；添加PEG后，顆粒較分散，形貌為多面體，合成的LiFePO4/C在0.1C時的首次放電比容量為151.0 mA∙h/g，倍率性能好，振實密度達(dá)1.44 g/cm3。
關(guān)鍵字: 電極材料；FePO4·xH2O; LiFePO4/C; 電化學(xué)性能；均勻沉淀法
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:FePO4·xH2O precursor was synthesized by the homogenous precipitation method from FeSO4·7H2O, H3PO4, H2O2 and urea. The influence of surfactant PEG on the morphology of FePO4·xH2O was studied. The LiFePO4/C composites were synthesized with the as-prepared FePO4∙xH2O, Li2CO3 and glucose as raw materials. The performance of LiFePO4/C was characterized by XRD, SEM, cyclic voltammograms (CV), electrochemical performance and electrochemical impedance spectroscopy (EIS) tests. The results show that FePO4·xH2O synthesized without surfactant PEG has spherical shape, but serious reunion phenomenon. The particles of FePO4·xH2O synthesized with surfactant PEG disperse well and have polyhedron shape, the discharge specific capacity of LiFePO4/C is 151 mA∙h/g at 0.1C, showing good rate performance. The tap density reaches 1.44 g/cm3.
Key words: electrode materials; FePO4·xH2O; LiFePO4/C; electrochemical performance; homogenous precipitation method
