【摘要】 以钛酸四丁酯为掺杂剂,抗坏血酸为碳源,采用溶胶-凝胶法合成Ti⁴⁺掺杂的锂离子电池正极材料Li₂FeSiO₄。通过X线衍射（XRD）、场发射扫描电子显微镜（FESEM）、高频红外碳-硫分析仪、循环伏安及恒电流充放电测试等表征手段分析了Ti元素掺杂对Li₂FeSiO₄结构、形貌、放电容量、循环稳定性的影响。结果表明:掺Ti减小了Li₂FeSiO₄颗粒尺寸,增加了其与电解液间的接触面积,提高了锂离子的迁移率,从而提高了放电容量。在10 mA/g电流密度下,Ti掺杂的试样首次充放电容量分别为206.9 mA·h/g和172 mA·h/g;未掺杂的试样的充放电电容量分别为169.1 mA·h/g和143.7 mA·h/g。更多还原

【Abstract】 Ti-doped cathode material Li₂FeSiO₄ for Li-ion battery was synthesized by a sol-gel method using ingtetrabutyl titanate as a dopant and ascorbic acid as carbon source. The effects of Ti doping on structure,morphology,discharge capacity,and cycling stability were characterized by X-ray diffraction（ XRD）,field emission scanning electron microscope（ FESEM）,cyclic voltammogram,and galvanostatic charge-discharge measurement. Results showed that Ti doping decreased particle size,increased the contact area between particles and electrolyte and enhanced lithium ion mobility,thus improving the discharge capacity of Li₂FeSiO₄. At the current density of 10 mA / g,the initial charge and discharge capacities for the doped sample were 206. 9 mA · h / g and 172 mA · h / g,while the undoped samples were 169. 1 mA·h / g and 143. 7 mA·h / g,respectively.更多还原