ic0c01157_si_001.pdf (1.76 MB)
Solvent-Controlled Morphology of Amino-Functionalized Bimetal Metal–Organic Frameworks for Asymmetric Supercapacitors
journal contribution
posted on 2020-08-01, 10:13 authored by Jie Sun, Xianbo Yu, Shihang Zhao, Hongmei Chen, Kai Tao, Lei HanThe
composition-tuned, structure-modified, and morphology-controlled nanoscale
metal–organic frameworks (MOFs) are quite important to improve
the electrochemical performances for supercapacitors. In this work,
a solvent-controlled method to prepare amino-functionalized bimetal
MOFs with various morphologies is proposed. Three different morphologies
of NiCo-MOFs, such as nanospheres, nanosheet-assembled hollow spheres
(NSHSs), and rhombus sheets, have been successfully synthesized by
using different solvents. The as-prepared three nanoscale NiCo-MOFs
are comparatively characterized and are endowed a possible mechanism
on nucleation and crystal growth controlling morphology. When used
as electrode materials for supercapacitors, all NiCo-MOFs have excellent
electrochemical properties. Specifically, the NiCo-MOF NSHS owns the
best specific capacitance, which can achieve 1126.7 F g–1 at the current density of 0.5 A g–1 and maintain
93% of its original capacitance at the current density of 10 A g–1 after 3000 charge–discharge cycles. Moreover,
an asymmetric supercapacitor device (NiCo-MOF NSHS//AC) assembled
with NiCo-MOF NSHS as the positive electrode and activated carbon
(AC) as the negative electrode achieves an energy density of 20.94
Wh kg–1 at a power density of 750.84 W kg–1. This work is facile and highly reproducible and can be extended
to prepare other nano-MOFs in energy storage and conversion fields.
In addition, it opens up an effective approach to synthesizing amino-functionalized
MOFs by a solvent-controlled method without any other changes in the
experimental conditions.