Synergistic effect of ZnO@Bi/C sphere for rechargeable Zn-Ni battery with high specific capacity

ZnO@Bi/C sphere with a distinctive core-shell construct is designed and fabricated by using solvothermal method, which is applied as a novel electrode material of Zn-Ni battery for the first time. The analytical results manifest that the core of the ZnO@Bi/C sphere coated with carbon layer consists of a large number of ZnO nanoparticles (NPs), and in situ modified metal Bi is embedded in the amorphous carbon layer and ZnO NP core uniformly, thereby forming a unique core-shell construct. Unlike pure ZnO anode, the ZnO@Bi/C sphere shows more remarkable specific capacity and cycling stability: that is, after cycling 180 times at 1 C, the discharge specific capacity remains at 630.7 mAh g(-1). The excellent electrochemical properties are attributed to the synergistic effect of carbon and metal Bi in the ZnO@Bi/C sphere, which is conducive to decreasing the voltage polarization and promoting the battery reversibility.