Bi^(3+)掺杂尖晶石型LiMn_2O_4的合成及性能研究

Synthesis and characterization of Bi^(3+)-doped LiMn_2O_4 spinel cathode materials for lithium-ion batteries

采用固相反应的方法,以Li2CO3、MnO2、Bi(NO3)3.5H2O和柠檬酸为原料,合成了具有尖晶石结构的锂离子电池正极材料LiMn2-xBixO4(x=0、0.03、0.06)。对材料进行了X射线衍射、扫描电镜、红外光谱、充放电等测试。实验结果表明,所合成的LiMn1.97Bi0.03O4材料具有标准的尖晶石结构,较平滑的表面外观,较高的比容量及优异的循环性能。在0.2C放电速率下,首次放电容量为117.8 mAh/g,循环30次后,容量保持率接近100%。

Bi^3＋ -doped spinel lithium manganese oxides LiMn2-x BixO4 （ x= 0, 0,0.03,0.06） were synthesized by solid state reaction using Li2COa ,MnOz ,Bi（NO3）3 · 5H2O and citric acid as starting materials. Testing of X-ray diffraction, SEM, IR spectra and charge-discharge were carried out for LiMn2-xBixO4 cathode materials and the modified materials, Results showed that the doped LiMn1.97 Bi0.03 O4 exhibited standard spinel structure, regular particle morphology, high reversibility of electrochemistry and excellent properties of charge-discharge. The capacity retention of LiMn1. 97Bi0.03O4 is nearly 100% of the first discharge capacity after 30 cycles at the current rate 0.2C.