A semi-interpenetrating network polymer coating for dendrite-free Zn anodes

Abstract

Zn metal has been proved to be a promising anode material in aqueous secondary Zn-ion batteries. However, the uncontrollable dendrite growth on Zn anode deriving from uneven Zn deposition during cycling seriously impairs its reliability and limits the service life. Achieving uniform Zn deposition is the key to overcoming the dendritic issue and accelerating the commercial application of aqueous Zn-ion batteries. Herein, a polymer coating with semi-interpenetrating network (s-IPN) structure is designed for the protection of Zn anode in aqueous Zn-ion batteries. Benefiting from the hydrophilic and robust polymer network, uniform Zn deposition and excellent dendrite growth resistance could be realized for the s-IPN polymer coated Zn (s-IPN@Zn) anode. As a consequence, the symmetric cell with s-IPN@Zn shows an ultra-long cycle life of 2370 h at 0.5 mA cm−2, which exhibits significant improvement compared with the unmodified bare Zn anode. Furthermore, the Zn//MnO2 rechargeable aqueous battery with s-IPN@Zn anode shows more excellent long-cycle stability compared with bare Zn, revealing the effectiveness of this unique s-IPN polymer coating design.