研究了配料温度对水热法制备磷酸铁锂的影响.通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安(CV)以及元素分析等手段分析了不同温度下制备的前驱体和最终的LiFePO4样品,其结果表明配料温度对磷酸铁锂前驱体颜色和特性有明显影响.通过仔细控制该温度可以制得高纯Li3PO4中间体并抑制前驱体中Fe(OH)3的形成.有利于进一步获得结晶良好不含Fe3+的LiFePO4样品,显著提高了LiFePO4材料的放电比容量.当配料温度为30℃时获得的样品,0.1C倍率下放电比容量达到156 mAh· g-1,0.5C倍率下放电比容量为151 mAh·g-1,10C倍率下放电比容量为127 mAh·g-1,循环20次容量保持率达99％.%We investigated LiFePO4 particles that were prepared by a hydrothermal reaction at different ingredient temperatures. The precursors and final LiFePO4 products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), and elemental analysis. The results show that ingredient temperature had a significant effect on the color and characteristics of the LiFePO4 precursors. High purity Li3PO4 was obtained and the formation of Fe(OH)3 in the precursors was inhibited by controlling the ingredient temperature carefully. In addition well-crystalline and free Fe3* LiFePO4 samples were synthesized, which greatly increased the discharge capacity of the LiFePO4 cathode materials. At an ingredient temperature of 30 °C the discharge specific capacity of the as-prepared sample was found to be 156 mAh · G-1 at 0.1C rate, 151 mAh · G~1 at 0.5C rate and it remained 127 mAh · G~1 even at a rate of 10C while the cycling retention rate was 99% after 20 cycles.
展开▼
