Microwave hydrothermal synthesis of La decorated Ni(OH)2 nanosheets for performance-enhanced hybrid supercapacitor

Rational design and rapid synthesis of an electrode material with high power is of significance for a supercapacitor which has a potential application as a power supply. Herein, the La-decorated Ni(OH)2 nanosheets (La-Ni(OH)2) were fabricated via a one-pot microwave hydrothermal method. The electrochemical behavior of the La-Ni(OH)2 electrode material could be modulated by expediently adjusting the amount of La precursor in the preparation process. The La-Ni(OH)2–0.3 electrode material with 0.3 mmol of the La precursor has the best electrochemical property, possessing a specific capacity of 209.8 mA h g−1 (1510.7F g−1) at 1 A g−1, which is 2.1 times as much as that of Ni(OH)2 electrode material and superior to most investigated counterparts. The assembled La-Ni(OH)2–0.3//active carbon (AC) hybrid supercapacitor (HSC) delivers the supreme energy density of 47.5 W h k g−1 at 375.0 W kg−1 and excellent stability (89.3%) for 2000 cycles. The prominent electrochemical performance of La-Ni(OH)2–0.3 is mainly thanks to its high surface area, large amount of mesopores and enhanced conductivity induced by La introduction. The robust performance of the hybrid supercapacitor in this work shows a dependable feasibility for facile development of supercapacitive materials.