Remarkable electrochemical properties of novel LaNi0.5Co0.5O3/0.333Co3O4 hollow spheres with a mesoporous shell†
An atomization route incorporating colloidal silica as a template was employed to synthesize LaNi0.5Co0.5O3/0.333Co3O4 (LNCO/CO) hollow spheres with a highly mesoporous shell. XRD and FESEM and HRTEM were used to characterize the crystalline phases and micro-morphology, respectively. The mesoporous shell showed a high specific surface area of 247 m2 g−1 as well as a mean pore size of about 2.53 nm as determined from N2 adsorption–desorption isotherms. The as-obtained spherical hollow spheres exhibited remarkable electrochemical performance as a battery-type electrode material with a maximum specific capacity of 498C g−1 at a current density of 2 A g−1 and ultra-long charge–discharge stability for 50 000 cycles in a three-electrode system. Additionally, a hybrid supercapacitor assembled with LNCO/CO hollow spheres as the positive electrode and N-doped mesoporous carbon as the negative electrode showed a high specific capacitance of 113.2 F g−1 at 1 A g−1 and a very high energy density of 42.8 Wh kg−1 at a power density of 424 W kg−1. The hybrid supercapacitor also exhibited a long-term cycle life of up to 30 000 cycles with a specific capacitance retention of 90.4%, and these properties meet the growing demands of long-life energy-related devices.