Hierarchical Ni2P@Ni(OH)2 architectures supported on carbon cloth as battery-type electrodes for hybrid supercapacitors with boosting specific capacitance and cycle stability

Abstract

In this work, a novel binder-free electrode, in which three-dimensional porous Ni2P@Ni(OH)2 nanosheet arrays were in-situ grown on carbon cloth (CC), is rationally designed for supercapacitor applications. In comparison with Ni2P@CC, the Ni2P@Ni(OH)2@CC electrode represents superior electrochemical characteristics: the gravimetric capacitance and areal capacitance are boosted to be 632 C g -1 and 0.73 C cm -2 at 1 mA cm -2 , about 2 and 2.7 times larger than those of Ni2P@CC (321 C g -1 and 0.27 C cm -2 ), respectively; the rate capability is improved to be 63.3% from 1 to 2 10 mA cm -2 , about 1.5 times larger than Ni2P@CC (42.9%); the cycle stability is enhanced to be 81.4% after cycles, about 1.6 times larger than Ni2P/CC (51.8%).The assembly Ni2P@Ni(OH)2@CC//AC hybrid supercapacitor device shows high energy density of 23.5 Wh kg -1 at a power density of 1158.0 W kg -1 and good cycling stability of 75.2% maintenance after 5000 cycles. Benefiting from the combined advantages of high electronic conductivity and large specific capacitance of Ni2P, superior anion exchanging/intercalating capacity of Ni(OH)2, excellent flexibility of carbon cloth and special hierarchical architecture with large surface area, the Ni2P@Ni(OH)2@CC electrode is promised to be a good candidate for supercapacitors.

Rational design of CoP@Ni(OH)2 bilayer nanosheets for high-performance supercapacitors

“…The Ragone plot (Fig. 6e) and Table S4 (ESI†) showed that the CoP@Ni(OH) 2 //AC had a greater energy density than CoP@Ni(OH) 2 ·0.75H 2 O//AC, 34 NiCoP@C@ Ni(OH) 2 //AC, 35 Ni 2 P@Ni(OH) 2 //AC, 36 and Mn 3 O 4 /Ni(OH) 2 //AC. 37 The long charging/discharging curves, over 10 000 GCD cycles at 5 A g −1 , disclosed that the CoP@Ni(OH) 2 //AC demonstrated superior cycling stability, with only a 1.4% decrease in capacitance compared to the initial specific capacitance (Fig.…”