二氧化钛溶胶制备的掺钛磷酸亚铁锂正极材料

Titanium Doped Lithium Iron Phosphate Cathode Material Prepared using a Titanium Dioxide Sol Dopant

采用二氧化钛溶胶作为掺杂剂,经过450℃和750℃两段烧结制备得到橄榄石型结构的掺钛磷酸亚铁锂微米样品.研究表明,在30℃下,采用0.1C、2C和10C倍率电流充放电时,掺钛磷酸亚铁锂第一循环的放电容量分别为136、114和98 mAh·g^(-1).掺钛改善磷酸亚铁锂大电流放电性能是由于掺钛引起橄榄石结构的晶胞的收缩而更稳定,导致在电化学体系中掺钛磷酸亚铁锂的电荷传递阻抗减小,锂离子扩散系数明显增大.

A titanium doped lithium iron phosphate cathode material with the micrometers size and olivine-type structure prepared by sintered at 450 ℃ and 750℃ and by using a titanium dioxide sol as the dopant. Experimental result shows that the titanium doped lithium iron phosphate exhibits the initial discharge capacitiesof 136 mAhog^-1（0.1C rate）,114 mAhog-1 （2C rate） and 98 mAh · g^-1（10C rate）, respectively, at 30 ℃. The titanium dopant in the lithium iron phosphate stabilizes its structure, decreases the charge transfer impedance and increases the lithium-ion diffusion coefficient than that of undoped sample.