Wang Yingchao, Li Guochang, Zhou Jiachao, Tao Kai, Zhao Wenna, Chen Linli, Han Lei
State Key Laboratory Base of Novel Functional Materials and Preparation Science, School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
School of Biological and Chemical Engineering, Ningbotech University, Ningbo, Zhejiang 315100, China.
Dalton Trans. 2023 Jul 25;52(29):10089-10098. doi: 10.1039/d3dt01484c.
Metal-organic frameworks (MOFs) have been extensively applied in supercapacitors. Unfortunately, metal active sites in MOFs are commonly blocked and saturated by organic ligands, leading to insufficient positions available for the electrochemical reaction. To address this issue, we develop a novel strategy to design and prepare a series of hollow metal sulfide/MOF heterostructures, which simultaneously alleviate the large volume expansion, avoid slow kinetics of metal sulfides and expose more electrochemically active sites of the MOF. Consequently, the optimized CoS/Co-BDC MOF heterostructure presents outstanding electrochemical performance with a high areal specific capacitance of 15.84 F cm at 2 mA cm and a capacitance retention rate of 87.5% after 5000 charge-discharge cycles. The asymmetric supercapacitors based on the heterostructure deliver a high energy density of 0.87 mW h cm and a power density of 19.84 mW cm, as well as long cycling stability. This study provides a new strategy for the rational design and synthesis of metal sulfide/MOF heterostructures for electrochemical applications.
金属有机框架材料（MOFs）已在超级电容器中得到广泛应用。遗憾的是，MOFs中的金属活性位点通常会被有机配体阻塞和饱和，导致可用于电化学反应的位点不足。为了解决这个问题，我们开发了一种新颖的策略来设计和制备一系列中空金属硫化物/MOF异质结构，该结构同时减轻了大体积膨胀，避免了金属硫化物的缓慢动力学，并暴露出更多MOF的电化学活性位点。因此，优化后的CoS/Co-BDC MOF异质结构具有出色的电化学性能，在2 mA cm时具有15.84 F cm的高面积比电容，在5000次充放电循环后电容保持率为87.5%。基于该异质结构的不对称超级电容器具有0.87 mW h cm的高能量密度、19.84 mW cm的功率密度以及长循环稳定性。本研究为合理设计和合成用于电化学应用的金属硫化物/MOF异质结构提供了一种新策略。
