Regulating Zn2+ Migration‐Diffusion Behavior by Spontaneous Cascade Optimization Strategy for Long‐Life and Low N/P Ratio Zinc Ion Batteries

Parasitic side reactions and dendrite growth on zinc anodes are formidable issues causing limited lifetime of aqueous zinc ion batteries (ZIBs). Herein, a spontaneous cascade optimization strategy is first proposed to regulate Zn2+ migration‐diffusion behavior. Specifically, PAPE@Zn layer with separation‐reconstruction properties is constructed in situ on Zn anode. In this layer, well‐soluble poly(ethylene oxide) (PEO) can spontaneously separation to bulk electrolyte and weaken the preferential coordination between H2O and Zn2+ to achieve primary optimization. Meanwhile, poor‐soluble polymerized‐4‐acryloylmorpholine (PACMO) is reconstructed on Zn anode as hydrophobic flower‐like arrays with abundant zincophilic sites, further guiding the de‐solvation and homogeneous diffusion of Zn2+ to achieve the secondary optimization. Cascade optimization effectively regulates Zn2+ migration‐diffusion behavior, dendrite growth and side reactions of Zn anode are negligible, and the stability is significantly improved. Consequently, symmetrical cells exhibit stability over 4000 h (1 mA cm−2). PAPE@Zn//NH4+−V2O5 full cells with a high current density of 15 A g−1 maintains 72.2 % capacity retention for 12000 cycles. Even better, the full cell demonstrates excellent performance of cumulative capacity of 2.33 Ah cm−2 at ultra‐low negative/positive (N/P) ratio of 0.6 and a high mass‐loading (~17 mg cm−2). The spontaneous cascade optimization strategy provides novel path to achieve high‐performance and practical ZIBs. A spontaneous cascade optimization strategy is reported firstly to regulate Zn2+ migration‐diffusion behavior. A separation‐reconstruction layer is constructed on the Zn anode. The soluble components can be separated into the electrolyte for primary optimization, and the poor‐soluble components are reconstructed into flower‐like arrays for secondary optimization. This strategy realizes the overall improvement of Zn ion battery performance.