Zhang Yang, Zhao Ganggang, Ge Peng, Wu Tianjing, Li Lin, Cai Peng, Liu Cheng, Zou Guoqiang, Hou Hongshuai, Ji Xiaobo
College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China.
Inorg Chem. 2019 May 6;58(9):6410-6421. doi: 10.1021/acs.inorgchem.9b00627. Epub 2019 Apr 22.
Given its competitive theoretical capacity, BiMoO 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, BiMoO 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 BiMoO@PANI is maintained at 656.3 mAh g after 200 cycles at 100 mA g, corresponding to a high capacity of 82%. However, the counterpart of individual BiMoO 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.
鉴于其具有竞争力的理论容量，BiMoO被认为是一种有前途的阳极材料，可实现高效的锂存储。考虑到锂化诱导膨胀导致的严重容量衰减，引入有效的改性至关重要。值得注意的是，在这项工作中，成功制备了具有双层球壳的BiMoO微球，并将聚苯胺涂覆在双层球壳的内表面和外表面，作为缓冲层来缓解电化学循环过程中的体积膨胀。令人鼓舞的是，当用作锂离子电池的阳极时，BiMoO@PANI在100 mA g下循环200次后的比容量保持在656.3 mAh g，对应于82%的高容量。然而，单独的BiMoO的对应值仅为36%。这一结果证实聚苯胺层可以显著促进稳定的循环性能。通过原位电化学阻抗谱和详细分析后的非原位技术的支持，进一步证明了与聚苯胺结合所带来的增强的赝电容主导贡献以及电子/离子转移速率。这项工作证实了聚苯胺对超稳定储能的显著影响，进一步深入了解了聚苯胺涂层对电导率以及电子/离子传输电阻的影响。
