Cheng Cheng, Zou Yongjin, Xu Fen, Xiang Cuili, Sun Lixian
Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China.
Nanomaterials (Basel). 2023 Jan 31;13(3):581. doi: 10.3390/nano13030581.
Metal organic frameworks (MOFs) are a kind of porous coordination polymer supported by organic ligands with metal ions as connection points. They have a controlled structure and porosity and a significant specific surface area, and can be used as functional linkers or sacrificial templates. However, long diffusion pathways, low conductivity, low cycling stability, and the presence of few exposed active sites limit the direct application of MOFs in energy storage applications. The targeted design of MOFs has the potential to overcome these limitations. This study proposes a facile method to grow and immobilize MOFs on layered double hydroxides through an in situ design. The proposed method imparts not only enhanced conductivity and cycling stability, but also provides additional active sites with excellent specific capacitance properties due to the interconnectivity of MOF nanoparticles and layered double hydroxide (LDH) nanosheets. Due to this favorable heterojunction hook, the NiMo-LDH@NiCo-MOF composite exhibits a large specific capacitance of 1536 F·g at 1 A·g. In addition, the assembled NiMo-LDH@NiCo-MOF//AC asymmetric supercapacitor can achieve a high-energy density value of 60.2 Wh·kg at a power density of 797 W·kg, indicating promising applications.
金属有机框架材料（MOFs）是一类以有机配体为支撑、金属离子为连接点的多孔配位聚合物。它们具有可控的结构和孔隙率以及显著的比表面积，可作为功能连接体或牺牲模板。然而，长扩散路径、低电导率、低循环稳定性以及极少的暴露活性位点限制了MOFs在储能应用中的直接应用。对MOFs进行靶向设计有潜力克服这些限制。本研究提出了一种通过原位设计在层状双氢氧化物上生长并固定MOFs的简便方法。所提出的方法不仅赋予了增强的电导率和循环稳定性，而且由于MOF纳米颗粒与层状双氢氧化物（LDH）纳米片的互连性，还提供了具有优异比电容性能的额外活性位点。由于这种有利的异质结连接，NiMo-LDH@NiCo-MOF复合材料在1 A·g时表现出1536 F·g的大比电容。此外，组装的NiMo-LDH@NiCo-MOF//AC不对称超级电容器在功率密度为797 W·kg时可实现60.2 Wh·kg的高能量密度值，显示出良好的应用前景。
