Construction of highly ordered ZnO microrod@SnO₂ nanowire heterojunction hybrid with a test-tube brush-like structure for high performance lithium-ion batteries: experimental and theoretical study

ZnO@SnO₂ heterojunction hybrid with a novel test-tube brush-like structure is fabricated successfully through a facile hydrothermal approach. Sixfold symmetric epitaxial growth of SnO₂ nanowires on non-polarized planes of ZnO microrods is realized via the approach. The synthesized ZnO@SnO₂ with the unique structure as a lithium-ion battery anode material exhibits enhanced electrochemical properties when compared with the single-phase ZnO microrod and SnO₂ nanowire electrode. The existence of heterostructure on the influence of lithium storage performance is studied by using first-principles calculations through density functional theory method. Experimental and theoretical calculation results demonstrate that the excellent electrochemical performance of the heterojunction hybrid is ascribed to the synergistic effect of the respective components. The construction of ZnO@SnO₂ heterojunctions can not only provide facile Li⁺ kinetics and enhanced ion diffusion, but also improve the mobility rate of electrons and holes by means of the presence of internal electric field.