Bimetallic Ni‐Co Silicate Hollow Spheres with Controllable Morphology for the Application on Supercapacitor

Abstract A facile and one‐step synthetic method is developed to produce the layered bimetallic Ni−Co silicate with the controllable morphology and porous microstructure by using the silica as the sacrifice template at the moderate reaction conditions. The bimetallic Ni−Co silicate core‐shell and hollow spheres were obtained under 140 °C for 6 h and 12 h, respectively. The pore size and the content of metal ions of the bimetallic Ni−Co silicate could be affected by the different structure. The final product shows good dispersivity, which is benefit to the homogeneity as an active material in the electrode. The as‐prepared Ni−Co silicate hollow spheres exhibit good electrochemical performance with high specific capacitance and rate capability, good charge‐discharge stability and long cycle life. The capacitance retention of the hollow structure can reach 58.69% at the current density of 10 A/g and 86.38% after 5000 cycle. The good electrochemical performance can be attributed to the different size of the pores and layer architecture. Bimetallic Ni−Co silicate hollow spheres show better electrochemical properties than the monometallic Ni or Co, which attribute to the synergistic effect.