Synergistic Effect Enables Aqueous Zinc‐Ion Batteries to Operate at High Temperatures

Abstract The performance of aqueous zinc‐ion batteries (AZIBs) at high temperatures (HT) is severely compromised by active water corrosion, parasitic reactions, and dendrite growth. Herein, zinc trifluoroacetate is introduced at a low concentration (0.2 m ), dissolved in triethyl phosphate (TEP) and H 2 O. The active water is suppressed due to the reconstructed original hydrogen bond network, which helps inhibit parasitic reactions and severe corrosion. Meanwhile, a solid electrolyte interphase (SEI) formed on the zinc anode due to the decomposition of the introduced zinc salt. The high‐tolerance SEI physically separates the electrolyte and anode, reducing the corrosion caused by active water. Moreover, TEP, as a prevalent fire‐retardant cosolvent, can preferentially anchor on the zinc sheet, serving as a shielding buffer layer. TEP is not only reconstructing the structure of the electric double layer (EDL), decreasing the content of active water, but also accelerating the prompt formation of SEI further. As proof of this synergistic effect, the assembled symmetric Zn‖Zn cells sustain to 700 h under the condition of 0.5 mA cm −2 , and the Zn‖NH 4 V 4 O 10 (NVO) full cells achieve 1400 cycles at 1 A g −1 at 60 °C. This work offers a promising solution to prompt the commercialization of AZIBs at HT.