Interfacial Regulation via Configuration Screening of Disodium Naphthalenedisulfonate Additive Enabled High-Performance Wide-pH Zn-based Batteries

Abstract

The structure design principles of organic additives for high-performance anode over wide-pH electrolytes are elusive, which are critical barriers to the practical application of aqueous zinc-metal batteries (AZMBs). Herein, this work takes disodium naphthalenedisulfonate (NADS) as an example to examine the structure-activity relationship of additives in AZMBs. The pair of –SO3- groups within the 26 NADS molecules fully exerted double-end capturing function to achieve single-molecule regulation facilitated by the distal-most substituent site, effectively minimising the electrostatic repulsion of the homo-charged solvated structure. The highly symmetric and electronegative 26 NADS molecule tended to form a molecular-layer on the surface of electrode retarded the concentration polarisation and accelerated the deposition kinetics of Zn2+ in acidic-neutral electrolytes, even preventing [Zn(OH)4]2- excessive localised saturation in alkaline electrolyte, ultimately suppressing the dendrites and side reactions of the Zn anode in wide-pH electrolytes. Consequently, the Zn-symmetrical battery retained long-term cycling stability in acidic, near neutral and strong alkaline electrolytes. Importantly, the Zn || MnO2 full batteries and Zn || activated carbon capacitor also deliver excellent reversibility in wide-pH electrolytes. Even better, a 0.19 Ah pouch battery with high performance, further confirms its fundamental guidance for the molecular design of multifunctional additives for practical aqueous metal batteries.