Despite these attractive merits, the performance is largely limited by unstable Zn chemistry in aqueous electrolyte with mildly acidic environment. [4][5][6] The produced hydrated [Zn(H 2 O) x ] 2+ ion complex species and the free water outside the Zn 2+ -solvation sheath induce severe interfacial side reactions, including Zn corrosion and H 2 evolution, along with aggravation of nonuniform Zn deposition. [7][8][9] This inevitably results in low Coulombic efficiency (CE) and can ultimately compromise safety (e.g., battery swelling and explosion, shortcircuit failure). [10] To circumvent the problems, many attempts have been made, including Zn alloying, [11] surface modification, [12,13] structure optimization of Zn host, [14,15] adoption of Zn 2+ intercalation anode material, [16,17] and compositional design of electrolyte. [18][19][20] Among them, electrolyte design is the most expedient solution with the potential to scale up from lab to practical application, owing to its superior repeatability and diversity. Recently, super-concentrated electrolytes are explored to interrupt original solvated balance and improve Zn reversibility. [21][22][23][24] The most representative example was proposed by Wang et al., where the Zn 2+ is surrounded by bis(trifluoromethanesulfonyl) imide (TFSI -) instead of water molecules due to the formation of copious [Zn(TFSI)] + ionic pairs with close coordination. [25][26][27][28] However, a high concentration of reaction-unrelated salt or flammable organic species in the electrolyte may induce safety and reaction kinetic issues with occurring costs, going against the initial rationale behind using AZIBs. [29] As such, investigations now are focusing on developing electrolyte additives on Zn 2+ -solvation structure in dilute solutions, such as methanol, [30] polyhydric alcohols, [31,32] dimethyl sulfoxide, [33,34] and polyacrylamide. [35] Although the Zn deposition behavior is optimized, many organic additives are still plagued by limited alleviation of side reactions. [10] Meanwhile, most of them hugely increase the polarization voltage while improving the cycling stability, leading to inferior electrochemical performance under practical conditions with high current density and areal capacity. Currently, rationally developing a class of advanced multifunctional additives remains challenging and a general additive design principle is accordingly of great significance for aqueous Zn chemistry.Carbonyl-containing liquid organics, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and acetoneThe benefits of Zn, despite many of its performance advantages (e.g., high theoretical capacity and low redox potential), are compromised by severe side reactions and Zn dendrite growth in aqueous electrolytes, due to the coordinated H 2 O within the Zn 2+ -solvation sheath and reactive free water in the bulk electrolyte. Unlike most efforts focused on costly super-concentrated electrolytes and single additive species, a universal strategy is proposed to boost Zn reversibility in dil...
