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.