Co–MOFs纳米片/碳布复合材料的制备及在锂离子电池中的应用

Synthesis of Co–MOFs Nanosheets/Carbon Cloth Composite for Lithium-ion Battery Applications

采用液相沉积法在导电碳布表面原位生长Co-MOFs纳米片,制得了Co-MOFs/CF复合材料。通过红外光谱、X射线衍射、扫描电子显微镜、恒流充放电、循环伏安、电化学阻抗等手段对材料的组成、结构形貌和电化学性能进行了表征。结果表明:当用作无黏结剂型锂离子电池电极时,在50 mA/g电流密度下,Co-MOFs/CF的首次放电比容量为1 621.3 mA·h/g,100次循环后,其放电比容量仍可达445.1 mA·h/g。相比于纯Co-MOFs,Co-MOFs/CF的首次Coulomb效率和循环性能均有明显改善,主要归因于Co-MOFs的二维片状结构与碳布良好导电性之间的协同作用,Co-MOFs/CF优异的电化学性能使其成为很好的锂离子电池电极候选材料。

Co-MOFs nanosheets were in situ grown on the surface of the pretreated carbon cloth(Co-MOFs/CF) by a facile liquid-phase deposition method. The compositions, structures, morphologies and electrochemical properties of the composite were investigated and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, galvanostatic charge-discharge test, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. As binder-free anodes for lithium ion batteries, the Co-MOFs/CF composite shows a higher initial coulombic efficiency and a better cycling performance, compared with pure Co-MOFs. At a current density of 50 mA/g, Co-MOFs/CF has an initial discharge capacity of 1 621.3 mA·h/g, and becomes 445.1 mA·h/g after 100 charge/discharge cycles. The improved electrochemical performance could be attributed to the synergetic effect betheen the conductive carbon cloth and the two-dimensional nanosheets of Co-MOFs. Co-MOFs/CF could be used as a promising candidate for anode material of lithium ion batteries due to its superior electrochemical performance.