A conductive anionic Co-MOF cage with zeolite framework for supercapacitors

• 作 者: Wei Du Yue-Ling Bai Zhen Yang Runlong Li Dan Zhang Zhiheng Ma Anbao Yuan Jiaqiang Xu
• 机 构: College of Science, Shanghai University, Shanghai 200444, China
• 出 处: 中国化学快报（英文版）
• 发表日期: 2020年9期
• 关键词: Metal organic frameworks Supercapacitors Cetyltrimethylammonium bromide In-situ

Conductive MOFs could exhibit full potential as integrated electrode materials for supercapacitors without interference from additional conductive additives. Here we report an anionic Co-MOF cage with zeolite framework, which was balanced by the redox-active guest [Co(H2O)6]2+ and protonated [(CH3)2NH2]2+ ions. Benefit from the unique ion skeleton structure, Co-MOF exhibits a conductivity higher than most of reported MOFs with the value of 1.42 × 10-3 S/cm, which can be directly fabricated as electrode for supercapacitors. A maximum specific capacitance of 236.2 F/g can be achieved at a current density of 1 A/g of Co-MOF. Additionally, the electric performance and morphology of this Co-MOF can be modified by cetyltrimethylammonium bromide (CTAB) and the maximum specific capacitance could increase up to 334 F/g at 1 A/g when the ratio of ligand and CTAB is 1:6 (Co-MOF-6). Furthermore, the specific capacitance can retain at 64.04％and 77.92％of the initial value after 3000 cycles of Co-MOF and Co-CTAB-6, respectively. Obviously, the addition of CTAB further improves both capacitance and cycle stability.