Morphology-controlled and low-temperature synthesis of hierarchical nickel carbonate hydroxide architectures for supercapacitor applications

초록

Redox-type materials with superior charge storage capability are crucial for developing high-energy density hybrid supercapacitors (HySCs). Herein, a simple and scalable synthesis of three-dimensional hierarchical flower-like nickel carbonate hydroxide (NCH) nanosheet@nanowire hybrid architectured electrode material was synthesized by a low-temperature-assisted hydrothermal process. Different time intervals were explored to assess their impact on the morphological, physical, and electrochemical characteristics of the prepared NCH materials. The heterostructured NCH composed of nanoflower and nanowire morphologies provides a large surface area and increases the rate of redox reactions, leading to enhanced electrochemical performances. Specifically, the optimized NCH electrode delivers a remarkable specific capacity of 568 C/g at a current density of 2 mA/cm2 and maintains 81% of its capacity even at 40 mA/cm2. Furthermore, HySC is designed using heterostructured NCH and activated carbon, which exhibits high energy and power densities of 27.1 Wh/Kg and 5825 W/kg, respectively, with high capacitance retention of 71.2% and coulombic efficiency of 94.3% over 5000 GCD cycles. Benefiting from superior energy storage performance, the HySCs can power up portable bulbs and motor fans for a long time, indicating the NCH-based HySCs for real-time applications. These features make it as a promising electrode material for high performance battery-type energy storage.

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