摘要:
Spinel LiMn
2O
4 and F, Al-doped spinel LiAl
0.05Mn
1.95O
3.58F
0.02 have been synthesized by a soft chemistry method using adipic acid as the chelating agent. The synthesized spine/materials were characterized by differential thermal analysis (DTA) and thermogravimetery (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), and chargedischarge testing. The results indicate that all the samples have high phase purity, and fluorine is important in controlling the morphology; the doped aluminum enhances the stability of spinel LiMn
2O
4. The charge-discharge tests indicate that LiAl
0.05Mn
1.95O
4 has high capacity retention, which is 92.60% of the initial after 50 cycles. It is found that the novel compound LiAl
0.05Mn
1.95O
3.98F
0.02 with smaller particles can offer much higher capacity, whose initial discharge capacity is 126.5 mAh·g
-1. The cyclic voltammetric experiments disclose the enhanced reversibility of the F, Al
3+-modified spinel as compared with the undoped spinel.