Hollow ZIF-67-C/LDO core/shell heterostructure as a high-performance anode material for sodium ion batteries

The rapid development of novel renewable energy storage systems promotes the evolution of sodium ion batteries. Among various anode materials, the conversion-type material with high sodium storage capacity suffers from large irreversible volume change during charge–discharge, which eventually results in inferior cycling performance. Herein, heterostructure hollow ZIF-67-C/layered double oxides (LDO) nanoparticles as an anode material are constructed to realize high sodium storage performance. The hollow ZIF-67-C/LDO anode with high electrical conductivity and specific surface area endows electrodes with fast electron/ion transport and reduced voltage hysteresis. As a consequence, the ZIF-67-C/LDO with calcination under 350 °C possesses a high sodium storage capacity of 341 mAh g−1 at 0.1 A g−1 and superior rate performance with a capacity of around 200 mAh g−1 at 2 A g−1. The hollow core/shell structure can not only improve the specific surface area but also alleviate the stress during the electrochemical reactions, leading to enhanced capacity and improved structural stability of the electrode material.