掺钛尖晶石锂锰氧化物的合成、结构及电化学性能研究

Synthesis, Structure and Electrochemical Performance of Titanium-doped Spinel Lithium Manganese Oxides

以掺钛电解二氧化锰为锰源合成了一系列掺钛尖晶石锂锰氧化物样品 .实验结果表明 ,无论是在新制样品 40次循环的充放电实验中 ,还是在经过 40次循环充放电并在放电状态下贮藏 3个月的再次充放电实验中 ,掺钛样品均具有极好的电化学性能 . 60 0℃掺钛样品在第一循环中的放电容量达到 2 0 6m A· h/g.在放电态贮藏 3个月后 ,再次充放电实验中 ,第一循环的放电容量达到 1 44 m A·h/g.XRD分析表明 ,掺钛样品仍然具有立方结构 .还用红外和拉曼光谱技术研究了钛对尖晶石锂锰氧化物的电化学性能的改善作用 .

A series of titanium|doped lithium manganese oxides spinel samples were synthesized by using titanium-doped electrolytic manganese dioxide sample as the manganese sources. It is shown that the titanium|doped samples possess an excellent electrochemical performance whether for 40-charge-discharge-cycle or for second 40-charge-discharge-cycle with samples which stored in the discharged state for 3 months after 40 charge-discharge cycles. The titanium|doped sample synthesized at 600 ℃ possesses a discharge capacities of 206 mA·h/g in the 1st cycle and that of 144 mA·h/g in the 1st cycle after being stored. X-ray diffraction analysis showed that titanium|doped lithium manganese oxides possesses a cubic structure. The vibrational spectroscopic techniques(i.e. IR, Raman) were employed to investigate why titanium can obviously improve the electrochemical performance of spinel lithium manganese oxides.