PEDOT: PSS for Reinforced Performances of Co/Ni-MOF as Flexible Supercapacitor Electrodes

• Published in: Journal of electronic materials 2023-08, Vol.52 (8), p.5543-5553
• Main Authors: Jiang, Wenkun, Han, Yinghui, Yu, Xiaole, Xu, Yanmei, Wang, Lijing, Zhang, Xin, Qin, Xiaodong, Zhu, Yongqi, Zhang, Yuanxun
• Format: Article
• Language: English
• Subjects: Bimetals; Capacitance; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cobalt; Conducting polymers; Electrical resistivity; Electrode materials; Electrodes; Electron microscopes; Electron microscopy; Electronics and Microelectronics; Instrumentation; Low conductivity; Materials Science; Metal oxides; Metal-organic frameworks; Microscopy; Nickel; Optical and Electronic Materials; Original Research Article; Polystyrene resins; Solid State Physics; Supercapacitors; Tensile properties
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-023-10507-6

To overcome the limitations of low conductivity and poor stability of metal–organic framework materials (MOFs) used in flexible supercapacitors, a high-performance flexible electrode material has been prepared by combining the conductive polymer poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with a cobalt and nickel bimetallic organic framework (Co/Ni-MOF). The optimal formula of the fabricated MOF-based electrode material was determined by screening tests of different metal pairwise combinations and the tuning of mutual ratios. The characterizations of x-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDS) indicated that PEDOT:PSS wraps around the surface of Co/Ni-MOF and encapsulates it internally, which helps to increase the electrochemical surface active area between ions/electrons and the electrolyte, consequently forming a high-performance complex called PEDOT:PSS@Co/Ni-MOF in a homogeneous crystal consistent with that of Co/Ni-MOF. In the presence of PEDOT:PSS, the specific capacitance was up to 860.5 F g −1 , which is 366.5 F g −1 higher than that of Co/Ni-MOF without PEDOT:PSS at the same current density of 494 F g −1 . The electrode assembled from PEDOT:PSS@Co/Ni-MOF has a very high energy density of 38.24 Wh kg −1 , while its power density is as high as 402.06 W kg −1 . Broadly, the combination of conductive polymer and MOFs can improve the capacitance performance, electrical conductivity, and tensile properties of the MOFs, which provides a promising new strategy to improve the capacitance performance of metal–organic framework materials, and can be extended to other metallic oxide materials. Graphical Abstract