Abstract Ni 2 P nanospheres were prepared by an ultrafast (120 s), easy, and energy-efficient one-step microwave method. By controlling the reaction conditions feed ratio, with novel nanostructures ultra-high electrochemical properties prepared. These demonstrated a high specific capacitance of 404.2 F g ?1 at 1 A cycling durability. They maintain 81% their initial capacity after 2000 cycles 6 ...