Suppression of Vanadium Oxide Dissolution via Cation Metathesis within a Coordination Supramolecular Network for...

Aqueous zinc metal batteries (ZMBs) are a promising sustainable technology for large-scale energy storage applications. However, the water is often associated with problematic parasitic reactions on both anode and cathode, leading to the low durability and reliability of ZMBs. Here, a multifunctional separator for the Zn-V₂ O₅ batteries by growing the coordination supramolecular network (CSN:Zn-MBA, MBA = 2-mercaptobenzoic acid) on the conventional non-woven fabrics (NWF) is developed. CSN tends to form a stronger coordination bond as a softer cation, enabling a thermodynamically preferred Zn²⁺ to VO₂ ⁺ substitution in the network, leading to the formation of VO₂ -MBA interface, that strongly obstructs the VO₂ (OH)₂ ^- penetration but simultaneously allows Zn²⁺ transfer. Moreover, Zn-MBA molecules can adsorb the OTF^- and distribute the interfacial Zn²⁺ homogeneous, which facilitate a dendrite-free Zn deposition. The Zn-V₂ O₅ cells with Zn-MBA@NWF separator realize high capacity of 567 mAh g^-1 at 0.2 A g^-1 , and excellent cyclability over 2000 cycles with capacity retention of 82.2% at 5 A g^-1 . This work combines the original advantages of the template and new function of metals via cation metathesis within a CSN, provides a new strategy for inhibiting vanadium oxide dissolution.