Mesoporous NiCoP microflowers as a superior electrode material for supercapacitors

In this study, mesoporous NiCoP microflowers are fabricated by a simple direct low-temperature phosphorization of the hydrothermal-prepared Ni0.5Co0.5(OH)(2) microflower precursors. The resultant NiCoP material possesses a unique three-dimensional flower-like architecture with high specifc surface area (56.6 m(2) g(-1)) and large pore volume (0.432 cm(3) g(-1)). Utilized as the supercapacitor electrodes, mesoporous NiCoP microflowers outperform the monometallic phosphides (CoxP and Ni2P microflowers) with excellent charge-discharge rate properties (e.g., specific capacity of 1153 and 715 F g(-1) at 1 and 30 A g(-1), respectively) and superior cycling performance. The specific capacitance of 883 F g(-1) can remain stable at 20 A g(-1) after 7000 cycles. More importantly, as-prepared NiCoP microflower electrode is able to deliver high energy densities of 48.4 Wh kg(-1) and 30 Wh kg(-1) at the power densities of 275 W kg(-1) and 8.2 kW kg(-1), respectively. The enhanced pseudocapacitive performance is mainly attributed to the mesoporous microflower structure and the synergistic combination of different metal elements (Ni and Co) for electrochemical reactions. (C) 2018 Elsevier B.V. All rights reserved.