Yan Yige, Huang Mohan, Wang Yongsheng, He Dawei, He Jiaqi
Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing, 100044, China.
College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing, 100029, China.
Heliyon. 2024 Feb 17;10(5):e25586. doi: 10.1016/j.heliyon.2024.e25586. eCollection 2024 Mar 15.
Metal-organic frameworks (MOF) have been wildly synthesised and studied as electrode materials for supercapacitors, and bimetallic MOF of Ni and Co has been broadly studied to enhance both specific capacitance and stability of supercapacitors. Herein, a best performance (about 320 F/g) of Ni-Co bimetallic MOF was found in a uniform preparation condition by adjusting the ratio of Ni to Co. Then tiny third metal ion was introduced, and we found that the morphology of material has a significant change on the original basis. Furthermore, certain ions (Zn, Fe, Mn) introduced make a huge improvement in capacitance based on Ni-Co MOF of 320 F/g. The result shows that Zn-Ni-Co MOF, Fe-Ni-Co MOF and Mn-Ni-Co MOF perform specific capacitance of 1135 F/g, 870 F/g and 760F/g at 1 A/g, respectively. Meanwhile, the asymmetric supercapacitor (ASC) was constructed by Zn-Ni-Co MOF as positive electrode and active carbon (AC) as negative electrode. The Zn-Ni-Co MOF//AC ASC possesses a energy density of 58 Wh/kg at a power density of 775 W/kg. This research provides a new methods to regulate the morphology of MOF and a novel viewpoint for assembling high-performance, low-price, and eco-friendly green energy storage devices.
金属有机框架材料（MOF）已被广泛合成并作为超级电容器的电极材料进行研究，其中镍钴双金属MOF已被广泛研究以提高超级电容器的比电容和稳定性。在此，通过调整镍与钴的比例，在均匀的制备条件下发现了镍钴双金属MOF的最佳性能（约320F/g）。然后引入微量的第三种金属离子，我们发现材料的形态在原有基础上有显著变化。此外，引入某些离子（锌、铁、锰）后，基于320F/g的镍钴MOF，其电容有了巨大提升。结果表明，锌镍钴MOF、铁镍钴MOF和锰镍钴MOF在1A/g时的比电容分别为1135F/g、870F/g和760F/g。同时，以锌镍钴MOF为正极、活性炭（AC）为负极构建了不对称超级电容器（ASC）。锌镍钴MOF//AC ASC在功率密度为775W/kg时的能量密度为58Wh/kg。该研究为调控MOF的形态提供了新方法，并为组装高性能、低成本且环保的绿色储能器件提供了新观点。
