Suppression of Vanadium Oxide Dissolution via Cation Metathesis within a Coordination Supramolecular Network for Durable Aqueous Zn-V 2 O 5 Batteries.

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-V 2 O 5 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 Zn 2+ to VO 2 + substitution in the network, leading to the formation of VO 2 -MBA interface, that strongly obstructs the VO 2 (OH) 2 - penetration but simultaneously allows Zn 2+ transfer. Moreover, Zn-MBA molecules can adsorb the OTF - and distribute the interfacial Zn 2+ homogeneous, which facilitate a dendrite-free Zn deposition. The Zn-V 2 O 5 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.