Succinonitrile Electrolyte Additive for Stabilizing Aqueous\nZinc Metal\nBatteries

The utilization of water electrolytes in zinc-ion batteries\noffers\nthe advantages of enhanced safety, reduced cost, and improved environmental\nfriendliness, rendering them an optimal choice for replacing lithium-ion\nbatteries. Nevertheless, the conventional zinc sulfate electrolyte\nfails to meet stringent requirements. Therefore, developing electrolytes\nis crucial for addressing the low cycle life of zinc ions and suppressing\nthe growth of zinc dendrites. So we proposed a strategy for engineering\ndilution of aqueous Zn(OTf)<sub>2</sub> solution with succinonitrile\n(SN) network electrolytes. The introduction of SN also disrupts the\noriginal hydrogen bonding network within the system and mitigates\nissues related to side reactions. Additionally, the inclusion of SN\nadditives significantly diminishes the reactivity of water molecules\nand smoothing zinc deposition to form favorable two-component Zn<sub>3</sub>N<sub>2</sub>/ZnF<sub>2</sub> SEI. The results indicate that\nsymmetric cells exhibit a remarkable cycling performance (877 h at\ncurrent density and capacity of 1 mA cm<sup>–2</sup> and 1\nmAh cm<sup>–2</sup>, respectively). Furthermore, after 2000\ncycles at a current density of 5 A g<sup>–1</sup>, the full\nbattery demonstrates an impressive capacity of 151.2 mAh g<sup>–1</sup>. These results show that the electrolyte structure project provides\na promising direction for the design of aqueous zinc–metal\nbatteries, aiming to achieve high reversibility and long cycle life.