Double‐Shelled Open Hollow Metal‐Organic Frameworks for Efficient Aqueous Zn‐Ion Batteries

Abstract

Abstract Multi‐shelled hollow metal‐organic frameworks (MH‐MOFs) are highly promising as electrode materials due to their impressive surface area and efficient mass transfer capabilities. However, the fabrication of MH‐MOFs has remained a formidable challenge. In this study, two types of double‐shelled open hollow Prussian blue analogues, one with divalent iron (DHPBA‐Fe(II)) and the other with trivalent iron (DHPBA‐Fe(III)), through an innovative inner‐outer growth strategy are successfully developed. The growth mechanism is found to involve lattice matching growth and ligand exchange processes. Subsequently, DHPBA‐Fe(II) and DHPBA‐Fe(III) are employed as cathodes in aqueous Zn‐ion batteries. Significantly, DHPBA‐Fe(II) demonstrated exceptional performance, exhibiting a capacity of 92.5 mAh g −1 at 1 A g −1 , and maintaining remarkable stability over an astounding 10 000 cycles. This research is poised to catalyze further exploration into the fabrication techniques of MH‐MOFs and offer fresh insights into the intricate interplay between electronic structure and battery performance.