Rational construction of hollow nanoboxes for long cycle life alkali metal ion batteries

Hollow nanostructures are extremely attractive in energy storage and show broad application prospects. But the preparation method is accompanied by a complicated process. In this article, the CoZn–based hollow nanoboxes with electrochemical synergy are prepared in a simple way. This structure can effectively shorten the transmission distance of ions and electrons, and alleviate the volume expansion during the cycle. In particular, bimetallic oxides are rich in oxygen vacancies, providing more active sites for electrochemical reactions. In addition, the stepwise oxidation–reduction reaction can also improve the volume change of the electrode material. According to the kinetic analysis and density functional theory (DFT) calculation, it is confirmed that the synergistic effect of the bimetallic oxide can accelerate the reaction kinetics. Based on these characteristics, the electrode exhibits stable cycle performance and long cycle life in alkali metal ion batteries, and can provide reversible capacities of 302.1 (LIBs, 2000 cycles), 172.5 (SIBs, 10000 cycles) and 109.6 (PIBs, 5000 cycles) mA h g^–1 at a current density of 1.0 A g^–1, respectively. In addition, by assembling (LiCoO₂//CoZn–O₂) and (Na₃V₂(PO₄)₃//CoZn–O₂) full–cells, the practical application value is demonstrated. The sharing of this work introduces a simple way to synthesize hollow nanoboxes, and shows excellent electrochemical performance, which can also be expanded in other areas.