铋修饰LiMn2O4 锂离子电池正极材料的研究

采用溶胶凝胶法合成了LiMn2O4及其表面Bi修饰材料, 通过聚丙烯酸(PAA)螯合的Bi(NO3)3溶液浸泡LiMn2O4以及煅烧合成了PAA-Bi/LiMn2O4材料. 采用TGA、XRD、SEM、循环伏安和充放电循环研究了3种锂离子电池正极材料的综合性能. 研究表明，Bi修饰的2种LiMn2O4材料电池的循环稳定性均提高. PAA浸泡-煅烧法的优点是避免了杂质Bi2Mn4O10的形成，PAA-Bi/LiMn2O4的首次放电容量损失较少，同时电池的循环稳定性大大提高.

Study on Bismuth Modified LiMn2O4 as Cathode of Lithium Ion Battery

LiMn2O4 and its Bismuth modified materials were synthesized by sol-gel method, PAA-Bi/LiMn2O4 was prepared by calcining the precursor after LiMn2O4 powders were immersed in polyacrylic acid (PAA) chelated Bi(NO3)3 solution. The performance of three samples were studied by thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammograms (CV) and galvanostatic cycle (GC). The cycle stability of both Bi modified samples is improved. The advantage of PAA-immersing-calcining method is to avoid the formation of impure phases as Bi2Mn4O10. The first cycle discharge capacity of PAA-Bi/LiMn2O4 is decreased slightly, and the cycle stability is greatly improved.