Shuyun Wang1,Shengmei Chen1,Yiran Ying2,Gang Li3,Haipeng Wang4,Ka Kiu Keith Cheung1,Qingjun Meng5,Haitao Huang2,Longtao Ma6,Juan Antonio Zapien1
City University of Hong Kong1,The Hong Kong Polytechnic University2,Northwestern Polytechnical University3,Yantai University4,Shaanxi University of Science and Technology5,South China University of Technology6
Shuyun Wang1,Shengmei Chen1,Yiran Ying2,Gang Li3,Haipeng Wang4,Ka Kiu Keith Cheung1,Qingjun Meng5,Haitao Huang2,Longtao Ma6,Juan Antonio Zapien1
City University of Hong Kong1,The Hong Kong Polytechnic University2,Northwestern Polytechnical University3,Yantai University4,Shaanxi University of Science and Technology5,South China University of Technology6
Although rechargeable aqueous zinc batteries are cost effectiveness, intrinsic safety, and high activity, they are also known for bringing rampant hydrogen evolution reaction and corrosion. While eutectic electrolytes can effectively eliminate these issues, its high viscosity severely reduces the mobility of Zn<sup>2+</sup> ions and exhibits poor temperature adaptability. Here, we infuse acetamide molecules with Lewis base and hydrogen bond donors into a solvated shell of Zn[(H<sub>2</sub>O)<sub>6</sub>]<sup>2+ </sup>to create Zn(H<sub>2</sub>O)<sub>3</sub>(ace)(BF<sub>4</sub>)<sub>2</sub>. The viscosity of 1ace-1H<sub>2</sub>O is 0.032 Pa s, significantly lower than that of 1ace-0H<sub>2</sub>O (995.6 Pa s), which improves ionic conductivity (9.56 mS cm<sup>-1</sup>) and shows lower freezing point of -45 , as opposed to 1ace-0H<sub>2</sub>O of 4.04 mS cm<sup>-1</sup> and 12 , respectively. The acidity of 1ace-1H<sub>2</sub>O is ~2.8, higher than 0ace-1H<sub>2</sub>O at ~0.76, making side reactions less likely. Furthermore, benefiting from the ZnCO<sub>3</sub>/ZnF<sub>2</sub>-rich organic/inorganic solid electrolyte interface, the Zn||Zn cells cycle more than 1300 hours at 1 mA cm<sup>-2</sup>, and the Zn||Cu operate over 1800 cycles with an average Coulomb efficiency of ~99.8%. The Zn||PANI cell cycles over 8500 cycles, with a specific capacity of 99.8 mAh g<sup>-1</sup> at 5 A g<sup>-1 </sup>at room temperature, and operated at -40 with a capacity of 66.8 mAh g<sup>-1</sup>.