Mesocrystalline effect boosts the alloying reaction kinetics of Sb2O4 anode in half/full sodium-ion batteries

Abstract

Mesocrystalline materials are reported to show great advantages in improving electrochemical performance. However, there are no reports about mesocrystalline Sb₂O₄ anode, and the structure advantage in reaction kinetics is unclear. In this work, we have prepared a mesocrystalline Sb₂O₄ structure (M−Sb₂O₄) in a facile hydrothermal process and further explored the structure effect on reaction kinetics. The exploration results show that the micro-flower mesocrystalline M−Sb₂O₄ consists of oriented nanowires with (110) crystal faces showing large surface area and high porosity. This structure can increase the contact area between electrode and electrolyte, provide fast Na⁺ transfer channels, and shorten the charge transport path, exhibiting excellent alloying reaction kinetics. The excellent reaction kinetics improves rate performance with a capacity of 432 mA h g^-1 at 5 A g^-1. Furthermore, it exhibits a high power density of 1700 W kg⁻¹ in the full cell. Compared to the other reported various structured Sb-based anodes, M−Sb₂O₄ exhibits a great performance advantage. This work demonstrates that the mesocrystalline effect can effectively enhance alloying reaction kinetics, providing a new strategy for performance optimization of other alloy-based anodes.