1 research outputs found
Functionalized Bimetallic Hydroxides Derived from Metal–Organic Frameworks for High-Performance Hybrid Supercapacitor with Exceptional Cycling Stability
A hybrid
supercapacitor consisting of a battery-type electrode
and a capacitive electrode could exhibit dramatically enhanced energy
density compared with a conventional electrical double-layer capacitor
(EDLCs). However, advantages for EDLCs such as stable cycling performance
will also be impaired with the introduction of transition metal-based
species. Here, we introduce a facile hydrothermal procedure to prepare
highly porous MOF-74-derived double hydroxide (denoted as MDH). The
obtained 65%Ni-35%Co MDH (denoted as 65Ni-MDH) exhibited a high specific
surface area of up to 299 m<sup>2</sup> g<sup>–1</sup>. When
tested in a three-electrode configuration, the 65Ni-MDH (875 C g<sup>–1</sup> at 1 A g<sup>–1</sup>) exhibited excellent
cycling stability (90.1% capacity retention after 5000 cycles at 20
A g<sup>–1</sup>). After being fabricated as a hybrid supercapacitor
with N-doped carbon as the negative electrode, the device could exhibit
not only 81 W h kg<sup>–1</sup> at a power density of 1.9 kW
kg<sup>–1</sup> and 42 W h kg<sup>–1</sup> even at elevated
working power of 11.5 kW kg<sup>–1</sup>, but also encouraging
cycling stability with 95.5% capacitance retention after 5000 cycles
and 91.3% after 10 000 cycles at 13.5 A g<sup>–1</sup>. This enhanced cycling stability for MDH should be associated with
the synergistic effect of hierarchical porous nature as well as the
existence of interlayer functional groups in MDH (proved by Fourier
transform infrared spectroscopy (FTIR) and in situ Raman spectroscopy).
This work also provides a new MOF-as-sacrificial template strategy
to synthesize transition metal-based hydroxides for practical energy
storage applications