Metal ion hybrid capacitors combine the advantages of high energy density, high power output, and long cycle life. In recent years, they have become an important development direction for future sustainable development of new types of energy storage systems. Among them, due to the abundance of sodium resources and low prices, The physical and chemical properties of lithium are similar, making sodium-ion batteries and sodium-ion hybrid capacitors as effective substitutes for lithium-ion energy storage systems. The development momentum is rapid. Research reports on various types of new-type sodium-ion hybrid capacitors continue to emerge.
Recently, the research team of Lanzhou Institute of Chemical Physics, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, used the new metal organic framework (MOFs) materials to open up the pore structure, high specific surface area and adjustable structure, from MIL-125 (Ti). In combination with ZIF-8, TiO2/C nanocomposite anode materials with a stable structure and high dynamic surface characteristics, and 3D graded nanoporous carbon ZDPC cathodes with high specific surface area have been successfully prepared, and the NaClO4/EC-PC organic electrolyte system has been successfully prepared. , Successfully constructed a high performance new type of sodium ion hybrid capacitor.
It has been found that MOFs derived TiO2/C nanocomposites have a continuous conductive network formed in situ on the surface of TiO2 nanocrystals formed by the thermal decomposition of organic ligands. This not only helps to improve the conductivity of the material, but also effectively prevents the charge and discharge of the material. The agglomeration and volume expansion of TiO2 nanoparticles during the process greatly improve the cycle stability and rate characteristics of the material. The unique pore structure of micropores and mesopores and the tiny TiO2 nanocrystals can effectively shorten the ion diffusion path and increase the active material. The contact sites with the electrolyte can effectively improve the dynamic behavior of the material. The ZIF-8-derived 3D graded nanoporous carbon positive electrode, due to the in-situ introduction of nitrogen and oxygen heteroatoms into the ligand, effectively improves the conductivity and electrolysis of the material. Liquid wetting, combined with a high specific surface area and a hierarchical porous structure with micropores, mesopores and macropores coexist, this material still exhibits excellent double layer capacitance behavior in organic electrolyte systems, with significantly higher specific capacitance than commercial Activated carbon. Based on this, based on the optimization of the positive and negative electrode mass ratios and dynamic behavior matching, a high energy density and high power output and circulation were successfully constructed. Qualitatively novel energy storage device excellent in TiO2 / C // ZDPC.
The results were recently published online in Advanced Functional Materials (2018, DOI:10.1002/adfm.201800757). This work was supported by the National Natural Science Foundation of China (21573265, 21673263, and 51501208) and the Qingdao City's Independent Innovation Plan Fund ( 16-5-1-42-jch) funding and support.
Sodium ion hybrid capacitor construction schematic diagram and performance display
