Hierarchical 3D Zn-Ni-P nanosheet arrays as an advanced electrode for high-performance all-solid-state asymmetric supercapacitors

摘要

High-performance all-solid-state supercapacitors (SCs) have potential applications in modern electronics, such as portable and flexible electronics; however, their low specific capacity and operating voltage window limit their industrial applications. Herein, we developed a new type of zinc nickel phosphide nanosheet (Zn-Ni-P NS) arrays via a simple, scalable, and cost-effective hydrothermal and subsequent effective phosphorization technique to enhance the electrochemical performance of SCs. The hierarchical Zn-Ni-P NS array electrode exhibits an ultra-high specific capacity of similar to 384 mA h g(-1) at a current density of 2 mA cm(-2) with excellent rate capability (79.43% of capacity retention at 50 mA cm(-2)), and outstanding cycling stability (similar to 96.45% of capacity retention after 10 000 cycles). Furthermore, the Zn-Ni-P NS//Fe2O3@NG all-solid-state asymmetric SC (ASC) delivers an ultra-high volumetric capacity of similar to 1.99 mA h cm(-3), excellent energy density of similar to 90.12 W h kg(-1) at a power density of 611 W kg(-1), and extraordinary cycling stability (93.05% of initial capacity after 20 000 cycles at a high current density of 15 mA cm(-2)). Such enhanced electrochemical performances are ascribed to the 3D hierarchical nanostructures, porous nanonetworks, improved conductivity, and synergistic interaction between the active components of Zn-Ni-P NS arrays.