Bi2MoO6 Microsphere with Double-Polyaniline Layers toward Ultrastable Lithium Energy Storage by Reinforced Structure.

Given its competitive theoretical capacity, Bi2MoO6 is deemed as a promising anode material for the realization of efficient Li storage. Considering the severe capacity attenuation caused by the lithiation-induced expansion, it is essential to introduce effective modification. Remarkably, in this work, Bi2MoO6 microsphere with double-layered spherical shells are successfully prepared, and the polyaniline are coated on both inner and outer surfaces of double-layered spherical shells, working as buffer layers to strain the volume expansion during electrochemical cycling. Inspiringly, when utilized as anode in LIBs, the specific capacity of Bi2MoO6@PANI is maintained at 656.3 mAh g-1 after 200 cycles at 100 mA g-1, corresponding to a high capacity of 82%. However, the counterpart of individual Bi2MoO6 is only 36%. This result confirms that the polyaniline layer can dramatically promote stable cycling performances. Supported by in situ EIS and ex situ technologies followed by detailed analysis, the enhanced pseudocapacitance-dominated contributions and electron/ion transfer rate, benefiting from the combination with polyaniline, are further proved. This work confirms the significant effect of polyaniline on the ultrastable energy storage, further providing an in-depth sight on the impacts of polyaniline coating to the electrical conductivity as well as the resistances of electron/ion transport.