“Tube-Sieve” Effect from Polymer Electrolyte Additive Enables Highly Reversible Zn Anodes at High Current Densities

The side reactions and dendrite growth caused by the kinetic mismatch between slow mass transfer and rapid reduction reaction of Zn2+ restrict the practical application of aqueous zinc-ion batteries. Inspired by the “pipe-sieve” effect in pipeline transportation, we designed an amphiphilic polymer additive PACMA to regulate the above kinetics of Zn2+. First, the side chain groups of PACMA construct ion channels (“ion guide tube”) through strong coordination with Zn2+, promoting the rapid migration of Zn2+. Second, PACMA preferentially adsorbs on the zinc anode to form an interface “sieve”, effectively intercepting free water molecules and slowing down the rapid reduction process of Zn2+. Consequently, the Zn||Zn symmetric cell operates steadily for over 2000 h at 5 mA cm–2. Even under severe conditions of 10 mA cm–2 and 20 mA cm–2, the cell can stably cycle for more than 6000 cycles. Notably, the Zn||NVO full cells deliver a capacity of 186.14 mAh g–1 and retain 97.02% after 8000 cycles at 5A g–1. This work offers a novel approach as an effective reference for enhancing the performance of AZIBs under high current density conditions.