Template-free synthesis of mesoporous nanoring-like Zn-Co mixed oxides with high lithium storage performance.

Mesoporous nanoring-like Zn-Co mixed oxides are synthesized via a simple template-free solvothermal method with a subsequent annealing process. The ring-like nanostructures with hollow interiors are formed under the complexing effects of potassium sodium tartrate. Numerous mesopores are generated after the precursor is annealed at 500 °C. When applied as anode materials, the mesoporous nanoring-like Zn-Co mixed oxides can deliver a high discharge capacity of 1102 mAh g −1 after 200 cycles at 500 mA g −1 . Even when the current density is increased to 2 A g −1 , the mixed oxides can still retain a reversible capacity of 761 mAh g −1 . Such high cycling stability and rate capability are mainly derived from the unique mesoporous ring-like nanostructures and the synergistic effects between Zn and Co based oxides. [ABSTRACT FROM AUTHOR]