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The practical application of aqueous Zn‐ion batteries is still greatly hindered by the unstable Zn anode with severe Zn dendrites growth and side reactions. As it is accessible and economical, the exploitation of electrolyte additives is one of the most promising strategies to stabilize the Zn electrode/electrolyte interface. Herein, the penta‐potassium triphosphate (KTPP) as a novel trifunctional electrolyte additive is introduced to tune the electrode/electrolyte interface. First, the KTPP additive can induce an ion‐conducting and mechanically robust solid electrolyte interphase film to stabilize the Zn anode. Second, the KTPP can complex with Zn2+ ions to reconstitute the dissolution sheath structure of the Zn2+ ion. Finally, the K+ cations in KTPP adsorb on the tips of the Zn anode surface as a shielding film to regulate Zn2+ ion flux. As a result, Zn//Zn symmetric cells can achieve significantly prolonged cycling stability (e.g., from 1077 to 3800 h at 1 mA cm−2/1 mAh cm−2, from 256 to 2500 h at 2 mA cm−2/2 mAh cm−2), and ultrahigh cumulative capacity of 6400/7200 mAh cm−2 at high current density (40/20 mA cm−2). A four‐layer Zn–MnO2 pouch full cell with a high capacity of 9 mAh can be constructed, showing impressive practical application potential. [ABSTRACT FROM AUTHOR]

The serious dendrite growth and H 2 O-induced side reactions on the Zn electrode lead to a significant fading in the cycling performance, hindering the development of commercial applications of aqueous Zn-ion batteries (AZIBs). Herein, a novel bifunctional network coating of dynamically cross-linking sodium alginate with trehalose has been rationally constructed on the Zn anode (Zn@AT). Firstly, the AT coating possesses abundant zinophilic oxygen-containing functional groups, which are able to induce uniform Zn 2+ ion flux. Secondly, the AT coating as a solid barrier can effectively inhibit H 2 O-induced side reactions by lowering the activity of H 2 O molecules. More specially, based on the dynamic cross-linking, AT network coating is endowed with self-healing capacity during cycling for durable battery operation. Consequentially, Zn@AT anodes in symmetric cells can cycle stably for 2787 h at 2 mA cm -2 /2 mAh cm -2 , and even achieve a significantly long cycle performance of 1087 h at large charge/discharge depths of 10 mA cm -2 /10 mAh cm -2 . Moreover, the Zn@AT//MnO 2 full cell shows excellent specific capacity of 175 mAh g -1 after 400 cycles. This study lights an effective strategy to enhance the durability of Zn electrodes in AZIBs., (© 2024 Wiley-VCH GmbH.)