Ion-exchange induced statically activated zinc-containing hydroxyapatite interface toward stable zinc metal anodes

Abstract

Zinc (Zn) metal has garnered substantial interest as an anode material in aqueous zinc-ion batteries (AZIBs) due to its cost-effectiveness and high theoretical capacity. However, its commercial viability is impeded by critical issues such as dendritic growth and parasitic side reactions. This study presents the construction of the Zn-induce static activation for hydroxyapatite layer (Z-HAP) on the zinc anode, which exhibits enhanced interface stability. The Z-HAP layer, rich in zinc-affinitive sites, facilitates preferential adsorption and ion exchange with calcium, thereby enabling controlled and uniform zinc ion transport and directing zinc growth and deposition along the hydroxyapatite structure. As a result, the Z-HAP@Zn symmetric cell demonstrates over 1800 h at 1 mA cm⁻² with a cumulative capacity of 1 mAh cm⁻², maintaining a low polarization voltage. Moreover, the Z-HAP@ZnǁMnO₂ battery achieves exceptional cycling stability, with a capacity of 157.5mAh g⁻¹ after 1000 cycles at 2 A g⁻¹. This work reports on a statically activated hydroxyapatite layer that is effectively constructed on the zinc anode surface, providing valuable insights for the advancement of interface layer technologies in zinc anode applications.