220 / 2022-02-15 11:30:13

Prussian blue analogue-derived ZnO/ZnFe2O4 core–shell nanospheres as high-performance anode materials for alkali-ion batteries

volume expansion; Prussian blue analogue; core–shell; self-sacrifice template method; ZnO/ZnFe2O4;

Mineral Materials and Advanced Energy Materials > 8. New Energy Materials

The transition metal oxides (TMOs) have been intensively researched for alkali-ion batteries because of the high theoretical specific capacity. However, TMOs have the problems of rapid specific capacity attenuation owing to the volume change during the cycles. For a long time, researchers have designed a variety of reasonable nanostructures to solve the volume expansion problem to improve the commercial application of TMOs. In this work, the core-shell nanostructures of ZnO/ZnFe₂O₄ through self-sacrifice template method with Prussian blue analogue (Zn₃[Fe(CN)₆]₂ ) as precursor were successfully synthesized by controlling the annealing temperatures and rates. The formation mechanism of the core–shell nanostructures is explored through the morphology transformation at different annealing temperatures and rates. Annealed at 450° at 5 ℃ min⁻¹, the obtained sample shows the core-double shell nanostructure. Benefiting from the unique core-double shell nanostructure and the synergistic effect of the ZnO and ZnFe₂O₄, the obtained ZnO/ZnFe₂O₄ composite material shows excellent cycling performance as LIBs (1310 mAh g⁻¹ at 100 mA g⁻¹ after 50 cycles) and PIBs (112 mAh g⁻¹ at 100 mA g⁻¹ after 100 cycles). The results prove that the strategy of designing nanostructures can significantly relieve the volume expansion of TMOs and improve the electrochemical performance of TMOs for alkali-ion batteries.