Interfacial regulation via configuration screening of a disodium naphthalenedisulfonate additive enabled high-performance wide-pH Zn-based batteries

Abstract

The structure design principles of organic additives for high-performance anodes 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 a 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 the electrode, which reduced the concentration polarisation and accelerated the deposition kinetics of Zn²⁺ in acidic-neutral electrolytes, even preventing excessive [Zn(OH)₄]²⁻ localised saturation in alkaline electrolytes, 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 exhibit excellent reversibility in wide-pH electrolytes. Furthermore, a 0.19 A h pouch battery with high performance provided guidance for the molecular design of multifunctional additives for practical aqueous metal batteries.