A Dynamically Ion-Sieved Electrolyte towards Ultralong-Lifespan Zn-Ion Batteries

The practical deployment of Zn-ion batteries faces challenges such as dendrite growth, side reactions and cathode dissolution in traditional electrolytes. Here, we develop a highly conductive and dynamically ion-sieved electrolyte to simultaneously enhance the Zn metal reversibility and suppress the cathode dissolution. The dynamic ion screen at the electrode/electrolyte interface is achieved by numerous pyrane rings with a radius of 3.69 Å, which can selectively facilitate the plating/stripping and insertion/extraction process of [Zn(H₂O)₆]²⁺ and Zn²⁺ on the anode and cathode surfaces. As a proof of concept, Zn//Zn symmetric cells deliver exceptional cyclic stability for over 6,800 h and ultrahigh cumulative plated capacity of 1.95 Ah cm^-2. Zn//Na₂Mn₃O₇ cells exhibit satisfactory cycling performance with capacity retention of 82.7 % after 4,000 cycles, and the assembled pouch cells achieve excellent stability and durability. This work provides valuable insights into the development of electrolytes aimed at enhancing the interface stability of aqueous batteries.