高容量金属氧化物/介孔碳复合锂电电极材料的设计及性能

The three dimensional hybrids of metal oxide nanoparticles/ordered mesoporous carbon are synthesized via hard template and hydrothermal chemical routes. The chemical composition, size, distribution and content of oxide nanoparticles are well controlled by adjusting the synthesis parameters, such as temperatures, pressure, portion of the precursors, and growth time. The oxide naoparticles can be homogenesouly embeded within the three dimensional orderd mesoporous carbon (OMC). The microstructures including the surface area, pore volume, chemical bonding state, surface morphology, oxide nanoparticle distribution on OMC, pore size and crystal structure of the hybrids are investigated using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), wide- and low-angle x-ray diffraction (XRD) patterns, x-ray photoelectron spectrometer (XPS), X-ray energy dispersive spectrometer (EDS), Raman spectrometer, FTIR spectra. The effects of incrporation of oxide nanoparticles within OMC structure, synergistic effects including surface and interface effects between the oxide and ordered OMC on the charge and discharge capacity of lithium storage, cycle stability, and coulombic efficiency of the hybrid anode electrodes are studied. cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS) techniques are used to study the capacity attenuation mechanism and the transfer kinetics of litium ion on the interface between oxide and the OMC matrix.　The enhancing mechanism of lithium storage capacity and theoretical model of the oxide/OMC hybrid anode are set up based on the experimental results and theoretical analysis. The goal of the research program and proposal is to fabricate oxide/OMC hybrid anode for lithium ion battery with high specific capacity, coulombic efficiency, long term life and high rate performance and high efficiency.

以模版与水热化学合成方法制备三维有序的氧化物与介孔碳复合材料，实现氧化物在介孔碳内组分、尺寸、分布、含量等的有效控制，以SEM、TEM、XRD、XPS、Raman等研究复合材料的比表面、孔体积、孔道结构、化学键合态等微观结构。氧化物与介孔碳所形成的三维网络结构利于锂离子在电极和电解液间的充分扩散与反应，可得到较高可逆容量。以恒流充放电方法研究复合材料的嵌锂与脱锂容量、循环稳定性。深入分析氧化物与介孔碳的协同作用、表界面效应等对复合材料储锂容量、循环稳定性及倍率性能的影响规律。以循环伏安与交流阻抗法探讨锂离子电池的容量衰减机制及改善循环稳定性和倍率性能的措施。理解锂在氧化物-介孔碳三维复合结构中的储存机制和在电极/电解液界面上的传输动力学机制。建立氧化物与介孔碳复合材料增强锂离子电池性能的机制与理论模型。本项目拟研制高容量、倍率性能佳、长寿命和能量效率高的氧化物-介孔碳复合物锂离子电池材料。

以模版与水热化学合成方法制备三维有序的氧化物与介孔碳复合材料，实现氧化物在介孔碳内组分、尺寸、分布、含量等的有效控制，以SEM、TEM、XRD、XPS、Raman 等研究复合材料的比表面、孔体积、孔道结构、化学键合态等微观结构。氧化物与介孔碳所形成的三维网络结构利于锂离子在电极和电解液间的充分扩散与反应，可得到较高可逆容量。以恒流充放电方法研究复合材料的嵌锂与脱锂容量、循环稳定性。深入分析氧化物与介孔碳的协同作用、表界面效应等对复合材料储锂容量、循环稳定性及倍率性能的影响规律。以循环伏安与交流阻抗法探讨锂离子电池的容量衰减机制及改善循环稳定性和倍率性能的措施。理解锂在氧化物-介孔碳三维复合结构中的储存机制和在电极/电解液界面上的传输动力学机制。建立氧化物与介孔碳复合材料增强锂离子电池性能的机制与理论模型。本项目拟研制高容量、倍率性能佳、长寿命和能量效率高的氧化物-介孔碳复合物锂离子电池材料。