One-step microwave-assisted solvothermal nano-manufacturing of Ni2P nanosphere as high-performance supercapacitors

Abstract

Ni2P nanospheres were prepared by an ultrafast (120 s), easy, and energy-efficient one-step microwave method. By controlling the reaction conditions and feed ratio, Ni2P nanospheres with novel nanostructures and ultra-high electrochemical properties were prepared. These nanospheres demonstrated a high specific capacitance of 404.2 F g−1 at 1 A g−1 and high cycling durability. They maintain 81% of their initial capacity after 2000 cycles at 6 A g−1. The optimum device based on Ni2P//AC showed an outstanding energy density of 27.2 Wh kg−1 and power density of 375 W kg−1. A method that is much faster and much more energy-efficient than other approaches was developed to produce transition metal phosphates without atmosphere protection. Graphical abstract

High-rate transition metal-based cathode materials for battery-supercapacitor hybrid devices

“…Transition metal phosphides have excellent electrical conductivity and redox activity due to the lower electronegativity of phosphorus, as mentioned before. 42,44,45,162 Chen et al in situ grew dense NiCo(HPO 4 ) 2 –3H 2 O nanosheet arrays on porous CuO nanowires, referred to as Cu/p-CuO/NiCo-P, and the corresponding schematic diagram is shown in Fig. 8d .…”

Metal−Organic Precursors for Transition‐Metal‐Doped Ni2P via Pyrolysis for Efficient Overall Water Splitting and Supercapacitance

“…[8] The colloidal route hitherto employed dual or multiple precursors, which were tedious for forming phase pure and compositionally controlled Ni 2 P. The use of metal-organic compounds today as single-source precursors has bypassed the challenges associated with the use of multiple precursors. [1b,9] Materials chemists have employed single-source precursors in colloidal routes such as the heat-up [10] and hot-injection, [1] phosphorization of pre-formed nickel or nickel phosphide particles [11] and microwave decomposition to form Ni 2 P. [12] The strengths of the single source precursors over the multiple ones lie in their simplicity and ease as well as the potential to synthesize different complexes, which in turn can lead to the formation of diverse materials. A few metal-organic compounds including dithiophosphinates, [13] dithiophosphonates [1,8] and phosphines [8,14] have been explored to prepare Ni 2 P. It is interesting to note that the single-source precursor route to dinickel phosphide formation is less explored in comparison to nickel chalcogenides.…”