Ultra-stable and long-life zinc anodes enabled by porous cyclodextrin-based polymer coatings

Aqueous zinc ion batteries are considered to have a broad application prospect in the future due to their advantages of high safety, low cost, abundant sources, etc. Nevertheless, zinc-ion batteries are limited by their inherent defects of zinc anode, such as uncontrollable dendrite growth and irreversible side reactions. In this work, porous cyclodextrin-based polymers (CD-Si) are successfully constructed and applied as artificial coatings of zinc anode. The porous polymer framework of CD-Si provides abundant zincophilic sites and organized transport channels for zinc-ion transport, thus it could well regulate the uniform deposition of Zn. The Zn anode protected by α -CD-Si exhibited an excellent zinc-ion migration number of 0.92. The assembled α -CD-Si@Zn// α -CD-Si@Zn symmetric battery could achieve a long cycle life of 2000 h at a current density of 0.5 mA cm −2 . Furthermore, the α -CD-Si@Zn//Cu asymmetric battery achieved a low nucleation overpotential of 25 mV. The assembled α -CD-Si@Zn//NH 4 V 4 O 10 full battery was able to cycle stably for 4300 cycles with capacity retention rate of 91 % at a current density of 5 A g −1 . This work provides a satisfactory idea to improve the stability of aqueous zinc ion batteries.