结晶度对尖晶石LiMn_2O_4动力学性质的影响

Influence of Crystallinity on the Kinetics of Li Ion Insertation and Deinsertation in Spinel LiMn_(2)O_(4)

应用溶胶-凝胶法制备两种结晶度尖晶石锂锰氧化物.X射线衍射(XRD)、电感耦合等离子体原子发射光谱(ICP)、扫描电镜(SEM)、恒电流充放电、循环伏安(CV)和交流阻抗谱(EIS)等方法测试表明:以较高温度焙烧制得的L iMn2O4样品结晶度较高,但结晶度较低的样品却具有较高的放电容量和较好的循环稳定性,这主要是结晶度较低的样品具有较快的电荷交换速率和锂离子扩散速率.

Two spinel lithium manganese oxides of different crystallinity were prepared by sol-gel process and were studied by using inducfively coupled plasma, X-ray diffraction, scaning electron micrographs, constant charging and discharging,cyclic voltammetry and electrochemical impedance spectrometry, the results show that the sample treated under 700℃ has higher crystallinity than the sample treated under 500℃, however,the sample with lower crystallinity has higher discharge capacity and better cyclic performance that due to quicker charge exchange speed and quicker diffusion speed of Li-ion.