Core-shell Ni1.5Sn@Ni(OH)2 nanoflowers as battery-type supercapacitor electrodes with high rate and capacitance

Poor conductivity and aggregation of two-dimensional Ni(OH)(2) nanosheets hinder their extensive applications in supercapacitors. In the current study, a core-shell nanoflower composite is successfully synthesized using a high conductivity Ni1.5Sn alloy and Ni(OH)(2) nanosheets via a facile two-step hydrothermal reaction. The alloy material enhances the conductivity of the sample and promotes electron transport for Ni(OH)(2). The as-prepared core-shell structure effectively restrains the clustering of nanosheets and improves the specific surface area of active materials. The optimized NS@NL-3 displays an outstanding specific capacitance (1002.2C g(-1)at 1 A g(-1)) and satisfactory capacitance retention rate (80.63% at 20 A g(-1)) by adjusting the coating amount of Ni(OH)(2) nanosheets, which is significantly higher compared with the performance of pure Ni(OH)(2) (609.6C g(-1) at 1 A g(-1) and 55.64% at 20 A g(-1)). The all-solid-state hybrid supercapacitor (HSC) is fabricated with activated carbon (AC) as the negative electrode and NS@NL-3 as the positive electrode, which shows a high energy density of 57.4 Wh kg(-1) at 803.6 W kg(-1) as well as a superior cycling stability (88.45 % after 10,000 cycles). Experiment shows that 42 LEDs are effortlessly lit by two series-wound solid-state HSC devices, which indicates its high potential for practical applications. (C) 2022 Published by Elsevier Inc.

Automated summary

A core-shell nanoflower composite consisting of high conductivity Ni1.5Sn alloy and Ni(OH)2 nanosheets was successfully synthesized, which improved the conductivity and specific surface area of the sample. The resulting sample exhibited outstanding specific capacitance and capacitance retention rate in supercapacitors, and demonstrated high energy density and superior cycling stability in experiments, suggesting its potential for practical applications.