Regulating Zn<sup>2+</sup> Migration‐Diffusion Behavior by Spontaneous Cascade Optimization Strategy for Long‐Life and Low N/P Ratio Zinc Ion Batteries
Jie Feng, Xinyang Li, Yuxin Ouyang, Hongyang Zhao, Hongyang Zhao, Na Li, Kai Xi, Junyan Liang, Shujiang Ding
Abstract
Abstract 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 Zn 2+ 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 H 2 O and Zn 2+ 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 Zn 2+ to achieve the secondary optimization. Cascade optimization effectively regulates Zn 2+ 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//NH 4 + −V 2 O 5 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.