Continuous multivariate conversion processes for stabilized anode in aqueous zinc-ion battery

The performance of aqueous zinc-ion batteries (AZIBs) is often hindered by issues at the electrode/electrolyte interface, such as dendrite growth and unwanted byproducts. In this study, we applied pyridoxine (PN) electrolyte and used in situ UV‒vis spectroscopy to observe its multistep transformation. The pristine protonated pyridoxine (PN + ) gradually lost a proton connecting to the N atom and became PN due to the applying voltage bias. Then PN kept lost a proton that connected to the O atom, changing to a higher electronegativity variant named PN - . The final variant maintained its state and possibly coordinated with zinc ion, and bonded to H + . Relying on the continuous multivariate conversion processes, these transformed PN variants can release H + ions to maintain pH balance at the interface and interact strongly with zinc ions, improving the zinc ion solvation structure and reducing hydrogen evolution reaction (HER). Additionally, as-generated higher electronegativity variants formed an electrostatic shielding layer on the Zn electrode, promoting uniform zinc deposition and enhancing the plating/stripping process. As proof of continuous multivariate conversion processes, Zn||Zn symmetric batteries operated stably for 7000 hours at 1 mA cm –2 and 1 mAh cm –2 , and Zn||NH 4 V 4 O 10 (NVO) full batteries showed excellent stability over 1500 cycles. These results significantly outperformed those using the ZnSO 4 (ZS) electrolyte and previously reported systems. This work suggests a promising approach for advancing various metal batteries towards commercialization, not limited to AZIBs.