Bimetallic-MOF Derived Accordion-like Ternary Composite for High-Performance Supercapacitors

Abstract

Supercapacitors are regarded to be highly probable candidates for next-generation energy storage devices. Herein, a bimetallic Co/Ni MOF is used as a sacrificial template through an alkaline hydrolysis and selective oxidation process to prepare an accordion-like ternary NiCoO/β-Ni Co(OH)/α-Ni Co(OH) composite, which is composed of Co/Ni(OH) nanosheets with large specific surface as the frame and NiCoO nanoparticles with high conductivity as the insertion, for supercapacitor application. This material exhibits both high specific capacitance (1315 F·g at 5 A·g) and excellent cycle performance (retained 90.7% after 10 000 cycles). This hydrolysis-oxidation process, alkali hydrolysis followed by oxidation with HO, offers a novel approach to fabricate the Ni/Co-based electrode materials with enhanced supercapacitor performance.

Hollow and Hierarchical Cobalt–Metal Organic Framework@CoCr2O4 Microplate Array as a Battery‐Type Electrode for High‐Performance Hybrid Supercapacitors

“…The resulting products can inherit the inherent structural characteristics of parent MOFs, and own rich porous structures and high specific surface areas applying in electrochemical energy storage. Furthermore, the easy tuning of metal ions in MOFs could endow their derivatives with multiple compositions, which can enhance the specific capacitance, rate capability and cycling stability of electrode materials . However, to the best of our knowledge, MOF‐directed synthesis of hierarchically structured CoCr 2 O 4 ‐based arrays has never been reported.…”

Metal–Organic Framework Derived Bimetallic Materials for Electrochemical Energy Storage

“…[60] In sharp contrast, the ternary NiCo 2 O 4 /b-Ni x Co 1Àx (OH) 2 / a-Ni x Co 1Àx (OH) 2 material retained 90.7 %o fi ts specific capacitance after 10 4 charge-discharge cycles at ac urrent density of 5Ag À1 (Figure 11 b), which is considerably better than the stability of Ni 0.25 Co 0.75 (OH) 2 .T he increase in the diffusion path length and the electrolyte migration rate observed in the fast charge-discharge cycles was attributed to the well-designed accordion-like structure of the Ni x Co 1Àx -(OH) 2 nanosheets. [60] Them orphology of the hierarchical structure was apparently protected during the charge-discharge cycling assessment owing to the volume provided by the voids and channels between nearby nanosheets.A dditionally,the NiCo 2 O 4 component played two significant roles. It served as ascaffold supporting the accordion-like structure and also contributed to facilitating electron migration.…”

“HOT” Alkaline Hydrolysis of Amorphous MOF Microspheres to Produce Ultrastable Bimetal Hydroxide Electrode with Boosted Cycling Stability

“…Unlike Ni/Co(OH) 2 nanomaterials produced through the widely utilized self‐assembly strategy usually having loose stacked structures, the Ni/Co(OH) 2 nanomaterials obtained through hydrolysis of metal‐organic framework (MOF) templates perform dense stacking of hydroxide nanoflakes, which is expected to have robust structure . However, the MOF residuals are always an issue to consider because the residuals may influence the structure stability.…”