Fluorinated pillared-layer metal-organic framework microrods for improved electrochemical cycling stability

• Published in: Chinese chemical letters 2021-12, Vol.32 (12), p.3817-3820
• Main Authors: Zheng, Shasha, Ru, Yue, Xue, Huaiguo, Pang, Huan
• Format: Article
• Language: English
• Subjects: Cyclic stability; Electrochemical energy storage; Fluorinated metal-organic framework; Microrod; Pillar-layer structure; Supercapacitor
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2021.05.010

Developing metal-organic framework (MOF)-based materials with good cyclic stability is the key to their practical application. Fluorinated organic compounds are usually highly chemically stability due to the high electronegativity of fluorine. Also, the pillared-layer structures based on coordination bonds have better structure and thermal stability than those based on hydrogen bonds. Herein, the fluorinated pillared-layer [Ni(2,3,4,5-tetrafluorobenzoic acid)(4,4′-bipyridine)]n MOF ([Ni(TFBA)(Bpy)]n) materials were constructed through a facile room-temperature solution reaction and used as electrode materials for supercapacitors. Surprisingly, the size/morphology of Ni(TFBA)(Bpy)]n MOFs could be adjusted by varying the synthesis time. Benefting from the short ion diffusion length, unique pillar-layer structure, and strong intercomponent synergy of organic ligands, the Ni(TFBA)(Bpy)]n MOF microrods showed a higher electrochemical energy storage capability than bulk MOFs. At the same time, compared to the non-fluorinated [Ni(benzoic acid)(Bpy)]n MOFs (31.5% capacitance decay), the fluorinated Ni(TFBA)(Bpy)]n MOFs have a higher cycle stability with only 2.6% capacitance loss after 5000 cycles at 3 mA/cm2. The fluorinated pillared-layer [Ni(TFBA)(Bpy)]n materials were constructed through a facile room-temperature solution reaction and used as electrode materials for supercapacitors. The fluorinated MOF microrods show remarkable cycling properties after 5000 cycles with 97.4% capacitance retention at 3 mA/cm2, while the non-fluorinated MOFs were only 68.5%. [Display omitted]