【摘要】 以共沉淀法制备的Fe1-xNixC2O4.2H2O(x=0,0.05,0.10)为铁源,采用高温固相反应法合成锂离子电池正极材料LiFe1-xNixPO4(x=0,0.05,0.10)。应用热重-差热分析探讨材料合成机理、X射线衍射和扫描电镜表征材料的晶体结构和颗粒形貌,充放电仪测试材料的充放电性能。结果表明,所合成的材料结晶完整,为均一橄榄石型结构,仅含少量三价铁杂质;在室温下以0.1C充放电时,比容量较高,达到150 mAh/g左右,当充放电倍率提高到0.4C时,充放电比容量仍达120 mAh/g以上;且掺杂少量Ni2+后,正极材料氧化峰与还原峰电势差仅为0.079 V,明显低于纯相LiFePO4的0.101 V,有利于抑制材料充放电过程中的极化。更多还原

【Abstract】 The LiFe_1-xNi_xPO₄（x=0,0.05,0.10） cathode materials for Li-ion battery were synthesized by high temperature solid-state reaction method with Fe_1-xNi_xC₂O₄·2H₂O（x=0,0.05,0.10）,produced by liquid co-precipitation method,as Fe sources.The crystalline structure and morphology of the cathode materials were characterized by X-ray diffraction and scanning electron microscopy,its composition contents and charge-discharge performances were measured by chemistry analysis and charge-discharge apparatus. XRD patterns showed that the cathode material is well-crystallized,homogeneous olivine-type phase,with only tiny trivalence iron impurities.Charge-discharge test showed that the cathode materials possess excellent charge/discharge capacities,about 150mAh/g at（0.1C） rate and more than 120mAh/g at 0.4C rate.The polarization of cathode in charge-discharge process can be（restrained） effectively,for the potential offset between oxidative peak and reductive peak of doped LiFePO₄ material is only 0.079V,lower than pure LiFePO₄ markedly.更多还原