基于ZIF-8的中空立方体的制备及锂离子电池应用

Synthesis of Zeolitic Imidazolate Framework Cubes for Fabrication of Lithium Ion Battery

材料的结构形貌对其应用起到至关重要的作用,中空结构因其独特的结构特征广泛应用于催化,气体储存,锂离子电池等领域。本文首先通过调控表面活性剂CTAB制备出大小一致的沸石咪哩骨架(ZIF-8)立方体,然后利用TEOS和多巴胺来固定立方体ZIF-8的形貌,接着通过退火以及刻饰的方法获得SiO2@C的中空立方体结构。通过X射线衍射、扫描电镜、透射电镜等一系列表征方法可知,采用模板法制备出的SiO2@C不仅在尺寸上保持大小的高度一致并且具有规则的立方体结构。作为中空结构在实际应用中的典型例子,将SiO2@C作为模板制备出的中空SiO2@C@MoS2结构,具有优异的锂离子储存性能。在100mA/g恒流充放电下循环100次后保持着930mAh/g的放电比容量,且在此过程中充放电循环效率均在95%以上。

The zeolitic imidazolate framework (ZIF-8) hollow cubes, a novel template for fabrication of lithium ion battery, were synthesized via chemical route. The influence of the surfactant CTAB concentration on the micro/ nano-structures and lithium ion storage behaviour of the SiO2@ C@ MoS2 hollow cubes,fabricated with the SiO2@ C template , was investigated with X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electrochemical analysis. The results show that the surfactant CTAB concentration liad a major impact. To be specific ,the SiO2@ C had well-defined cubic structure with a narrow size distribution and the SiO2@ C@ MoS2 Li-ion battery demonstrated excellent Li-ion storage properties. For instance,tested at a constant current of 100 mA/g for 100 charge/discharge cycles,the Li-ion battery,made of newly-developed SiO2@ C@ MoS2 composite cubes, had a spe-cific discharge capacity of 930 mAh/g and a charge/discharge cycling efficiency above 95%.