Pillar-Coordinated Strategy to Modulate Phase Transfer of alpha-Ni(OH)(2) for Enhanced Supercapacitor Application

• Key Words:METAL-ORGANIC FRAMEWORK; ELECTRODE MATERIALS; NANOSHEET ARRAYS; RATE CAPABILITY; ENERGY-STORAGE; HIGH-POWER; PERFORMANCE; NANOPARTICLES; NI(OH)(2); COMPOSITE
• Abstract:Modulating the phase property of electrode materials is of intrinsic importance for enhanced energy storage performance. Here, through a pillar-coordinated strategy, a series of metaborate pillar-coordinated hierarchical alpha-Ni(OH)(2) (Ni(BO2-)-LDH) are fabricated via Ni-MOF precursor etching process. During the etching process, the coordinated organic ligand is gradually substituted by inorganic anions (OH- and BO2-) with small size and the BO2-anions are effectively coordinated on the surface of as-formed alpha-Ni(OH)(2) layer to fabricate a pillar-coordinated alpha-Ni(OH)(2) structure. The physical morphology of MOFs parent is successfully maintained, which provides rich pores and channels for fast diffusion of electrolyte. Meanwhile, the unique pillar-supported alpha-Ni(OH)(2) structure is robust to avoid the phase-transfer reaction from the alpha-phase to beta-phase during the charge/discharge process in strong alkaline electrolyte, which can provide a deep and durable Faraday reaction. Therefore, the optimized Ni-(BO2-)-LDH-4 shows a capacity value of 244.4 mAh g(-1) (1760 F g(-1)) at 1 A g(-1) and an outstanding cycle performance of keeping approximately 82.1% of its initial capacitance after 10 000 cycles at 5 A g(-1). Furthermore, a hybrid supercapacitor with the Ni(BO2-)-LDH-4 and three-dimensional reduced graphene oxide (3D-RGO) as electrodes presents a high energy density of 56.5 W h kg(-1) at 0.111 kW kg(-1).
• Volume:3
• Issue:6
• Translation or Not:no