【摘要】 采用高温固相法合成了锂离子电池正极材料LiFePO4及改性的LiFe0.9Ni0.1PO4和LiFe0.9Ni0.1PO4/C材料。采用X射线衍射仪和扫描电镜分析样品的晶体结构和表面形貌。结果表明:改性后的LiFe0.9Ni0.1PO4和LiFe0.9Ni0.1PO4/C材料与LiFePO4一样均为单一的橄榄石结构。以20 mA/g电流密度充放电,LiFe0.9Ni0.1PO4的首次放电容量为140 mA.h/g,较LiFePO4增加了12%;而复合掺杂得到的含碳量为2.8%的LiFe0.9Ni0.1PO4/C材料,首次放电容量达162 mA.h/g,充放电循环30次后放电电容量仍为147 mA.h/g,容量衰减仅为9%。当充放电电流密度提高到80 mA/g时,LiFePO4、LiFe0.9Ni0.1PO4和LiFe0.9Ni0.1PO4/C的放电容量分别为86、114和140 mA.h/g。改性后的LiFe0.9Ni0.1PO4/C的电化学性能得到了较大的改善。更多还原

【Abstract】 LiFePO₄,LiFe_0.9Ni_0.1PO₄ and LiFe_0.9Ni_0.1PO₄/C were synthesized by solid-state reaction and all samples were characterized by XRD,SEM and electrochemical performance.The results show that LiFe_0.9Ni_0.1PO₄ and LiFe_0.9Ni_0.1PO₄/C are still olivine type with good electrochemical performance.When the cathode materials are（cycled） at 20mA/g,the LiFe_0.9Ni_0.1PO₄ can delivered 140mA·h/g at the first discharge which is 12% higher than that of LiFePO₄,while LiFe_0.9Ni_0.1PO₄/C can reach 162mA·h/g at the first discharge and only lost about 9% （after） 30 cycles.When the discharge current density reaches up to 80mA/g,the capacity of LiFePO₄,LiFe_0.9Ni_0.1-PO₄ and LiFe_0.9Ni_0.1PO₄/C are 86,114 and 140mA·h/g,respectively.更多还原