Construction of NiCo-Layered Double Hydroxide Microspheres from Ni-MOFs for High-Performance Asymmetric Supercapacitors

Abstract

Layered double hydroxide (LDH) materials, especially metal–organic framework (MOF)-derived LDHs, have attracted much attention in electrochemical capacitor applications. However, the construction of porous three-dimensional microsphere architectures with controlled morphology is highly demanded for high-performance supercapacitor electrodes. Thus, a simple and effective strategy is recommended to design and fabricate the well-defined layered structure of LDHs with high performance. In this study, we demonstrate the synthesis of nickel–cobalt-LDHs (NiCo-LDHs) by in-situ etching of the Ni-MOF template at different hydrolysis times. Based on the different characterization results of the sample, a formation mechanism has been proposed in terms of the proton production rate and etching process. As a result of the disparity in the layered structure and the surface area, the electrochemical behavior of the NiCo-LDHs has been altered. The sample NiCo-LDH/10 (prepared after the 10 h reaction) exhibited a high surface area and the large size of LDH sheets on microspheres, which promoted the rapid electrolyte ion transportation for supercapacitors and displayed a maximum specific capacity of 1272 C g–1 at 2 A g–1. In addition, the assembled asymmetric supercapacitor delivered a remarkable energy density of 36.1 Wh kg–1 with an outstanding cyclic stability (103.9% after 5000 cycles). This work establishes an effective strategy to synthesize a well-defined NiCo-LDH structure from the MOF template toward high-performance asymmetric supercapacitors, which could be extended to large-scale preparation of other transition metal-based LDHs from Ni-MOFs.

Novel Two-Dimensional Siloxene Material for Electrochemical Energy Storage and Sensor Applications

“…Due to the increases in energy consumption and the non-renewable sources decreasing gradually, the development of high-efficiency energy storage devices is highly demanded. Electrochemical or supercapacitors are the perfect choice for high-performance devices as the results of its high-power density and long cyclic lifetime [21]. Compared with the commercial activated carbon-based supercapacitors, the integration of Si-based materials with the current microelectronic technology can lead to higher performance in energy storage devices because of its high theoretical capacity (3579 mA hg −1 ).…”

3D Ultralight Hollow NiCo Compound@MXene Composites for Tunable and High-Efficient Microwave Absorption

“…Compared with pure metal materials, the LDHs own better chemical stability to enlarge their practical applications [ 23 ]. Recently, metal organic frameworks (MOFs) are utilized as a promising self-template to construct LDH materials with hollow or core–shell structure, which normally equip with large surface areas and porous architecture to alleviate the stress and endow their enhanced MA performance [ 24 , 25 ]. However, LDH monomers usually deliver limited local microcurrent networks, which directly result in poor conduction loss.…”

Recent Advances of Asymmetric Supercapacitors

“…The MOFs derivate could inherit the porous microstructure of MOFs and displayed adjustable compositions. [ 44,76,114–123 ] Pristine MOFs were considered as Ramachandran et al. demonstrated the synthesis of NiCo‐LDHs through etching of Ni‐MOF precursor.…”

“…demonstrated the synthesis of NiCo‐LDHs through etching of Ni‐MOF precursor. [ 114 ] Through combining NiCo‐LDHs as cathode and CNT as anode, the hybrid SC was constructed and it showed excellent electrochemical performance with E d of 36.1 Wh kg −1 and 103.9% cycling stability after 5000 cycles. Onion‐like CuCo 2 O 4 hollow spheres (ON‐CCO) were synthesized through bimetal‐organic frameworks derived method and displayed remarkable electrochemical performances.…”