Pyridine-Rich Covalent Organic Frameworks as High-Performance Solid-State Supercapacitors
Pyridine-Rich Covalent Organic Frameworks as High-Performance Solid-State Supercapacitors
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DOI：
10.1021/acsmaterialslett.9b00222
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发表时间：
2019-10-01
影响因子：
11.4
通讯作者：
Vaidhyanathan, Ramanathan
中科院分区：
文献类型：
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作者：
Haldar, Sattwick;Kushwaha, Rinku;Vaidhyanathan, Ramanathan
共价有机骨架（COF），由于其有序的孔和晶体结构，成为电荷存储应用的可设计的聚合物。超级电容器在开发混合能源设备中至关重要。在电容器组件中合并这些高表面积框架可以帮助开发强大的固态超级电容器。在这里，我们提出了三个密切相关的吡啶基-羟基官能化的COFs上绘制的超级电容器。酮烯醇互变异构和羟基单元的氢键能力保证了这种潜在可水解的席夫键合COF的化学稳定性。同时，吡啶基和三嗪基通过与来自酸性电解质的质子可逆地相互作用来确保快速电荷存储。如所预期的，具有最高表面积的COF在酸性溶液中在500 mA/g下产生546 F/g的优异比电容，并且在固态器件中在0.5 mA/cm（2）下产生类似于92 mF/cm（2）的比电容，这是所有COF衍生的固态电容器中最高的，这反映在0.5 mA/cm（2）时98 μ W/cm（2）的高功率密度上，即使在10000次循环后，大部分功率密度仍保持不变。这种高活性来自于有序多孔结构所支持的平滑双电层电容和氧化还原活性官能团参与所辅助的一些赝电容。该研究强调了由设计开发的COF的上级能源/充电设备。
Covalent organic frameworks (COFs), because of their ordered pores and crystalline structure, become designable polymers for charge storage applications. Supercapacitors are critical in developing hybrid energy devices. Amalgamating these high-surfacearea frameworks in the capacitor assembly can aid develop robust solid-state supercapacitors. Here, we present supercapacitors drawn on three closely related pyridyl-hydroxyl functionalized COFs. The ketoenol tautomerism and the hydrogen bonding ability of the hydroxyl units promise added chemical stability in this potentially hydrolyzable Schiff-bonded COF. Meanwhile, the pyridyl and triazine groups ensure rapid charge storage by reversibly interacting with protons from the acidic electrolyte. The COF with the highest surface area, as expected, yields an excellent specific capacitance of 546 F/g at 500 mA/g in acidic solution and similar to 92 mF/cm(2) at 0.5 mA/cm(2) in the solid-state device, which is the highest among all the COF-derived solid-state capacitors, which is reflected by a high power density of 98 mu W/cm(2) at 0.5 mA/cm(2), most of which is retained even after 10 000 cycles. This high activity comes from a smooth electrical-double-layer-capacitance favored by an ordered-porous structure and some pseudo-capacitance assisted by the participation of redox-active functional groups. The study highlights the by-design development of COFs for superior energy/charge devices.