基于有机磷酸类MOFs前驱体制备Ni2P/C复合材料

以镍为金属中心、 对二甲苯二磷酸为有机配体, 构筑了一种有机磷酸类Ni-MOF前驱体, 再经过一步碳化, 原位制备出多孔碳包覆Ni₂P纳米颗粒的复合材料. 该复合材料保留了前驱体的片状形貌, 比表面积可达202 m²/g, 复合材料中的Ni₂P纳米颗粒具有良好的结晶度, 颗粒均匀且无团聚现象. 在锂离子电池性能测试中, 该Ni₂P/C复合结构在缓解材料体积膨胀的同时提高了材料的电子和离子电导率, 进而提高了材料的电化学性能. 在0.2 C的电流密度下, 材料首次充、 放电比容量分别为247和226 mA·h·g^-1, 库仑效率可达91.7%, 循环200圈后, 库仑效率接近100%.

Synthesis of Organodiphosphonate MOFs-derived Ni2P/C Composite†

Ni and organodiphosphonate-based metal organic framework(Ni-MOF) was synthesized under hydrothermal condition using p-xylylenediphosphonate as the organic ligand. Then, Ni-MOF was selected to prepare the amorphous carbon coated Ni₂P composite materials by facile method. The composite material retained the lamellate shape of the precursor, and the BET surface area reached 202 m²/g. The Ni₂P nanoparticles in the composites had good crystallinity, and the particles were homogeneous and had no reunion. In the performance of lithium ion battery, the Ni₂P/C composite structure improved the electron and ion conductivity of the material while reducing the volume expansion of the material, thus improving the electrochemical properties of the material. The first charge and discharge capacity of Ni₂P/C composite material were 247 and 226 mA·h·g^-1, respectively, coulombic efficiency can reach 91.7%, and the coulombic efficiency reaches 100% after 200 cycles.