Controllable synthesis of hydrangea-like NixSy hollow microflower all-solid-state asymmetric supercapacitor electrodes with enhanced performance by the synergistic effect of multiphase nickel

In this work, through controlling the urea content in the synthesis system, the nucleation rate of Ni_xS_y can be adjusted, and a series of Ni_xS_y with multiphase nickel and various sizes and surface morphologies can be achieved.