Bio-assisted synthesis of mesoporous Li₃V₂(PO₄)₃ for high performance lithium-ion batteries

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• 作者：Wen He ; Xudong Zhang ; Xiaoyong Du ; Yang Zhang ; Yuanzheng Yue ; Jianxing Shen ; Mei Li
• 关键词：MBC-LVP ; mesoporous biocarbon coated Li3V2(PO4)3 ; BWBY ; beer waste brewing yeasts
• 刊名：Electrochimica Acta
• 出版年：1 December, 2013
• 年：2013
• 卷：112
• 期：Complete
• 页码：295-303
• 全文大小：3502 K

文摘

The mesoporous biocarbon coated Li₃V₂(PO₄)₃ (MBC-LVP) cathode material is synthesized by a biotemplate-assisted sol-gel reaction process using low-cost beer waste brewing yeasts (BWBYs) as both structural template and biocarbon source. The structure and electrochemical performances of MBC-LVP were investigated using Raman spectra, thermogravimetric measurements (TGA), adsorption-desorption isotherms and pore-size-distribution curves, X-ray diffraction (XRD), transmission electron microscope (TEM and HRTEM), and electrochemical methods. The results show that the MBC-LVP synthesized at 750 掳C has a hierarchical nanostructure, which consist of Li₃V₂(PO₄)₃ crystal nanoparticles and amorphous biocarbons network (11.5%) with hierarchical mesoporous structures (slit shape mesopores, open wormlike mesopores and plugged mesopores). This hierarchical nanostructure facilitates electron and lithium ion diffusion. The MBC-LVP electrode has high discharge capacity (about 205 mAh g^鈭?) at a current density of 0.2 C in the voltage region of 3.0-4.8 V and the diffusion coefficient of Li⁺-ions determined by CV and EIS is higher than those of olivine LiFePO₄. We have revealed the formation mechanism of MBC-LVP, the possible lithium pathways in the MBC-LVP and established a relation between the structure and the ionic and electronic transport properties.