摘要
Aqueous zinc-ion batteries encounter enormous challenges such as Zn dendrites and parasitic reactions.Separator modification is a highly effective strategy to address these issues.With the advantages of low cost,nontoxicity,biodegradability,good film-forming ability,superior hydro phi licity,and rich functional groups,chitosan is an ideal matrix for constructing separators.However,the presence of positive charges within chitosan in weakly acidic electrolytes is unfavorable for dendrite inhibition.Herein,Schiff base reaction is introduced to modify chitosan matrix,transforming its charge polarity from positive to negative.Additionally,NbN with excellent zincophilicity is coated onto chitosan matrix,forming a Janus separator with low thickness of 19μm and considerably improved mechanical properties.The resultant separator can promote the transport of Zn^(2+)ions while triggering a repulsive shielding effect against anions,therefore dramatically enhancing Zn^(2+)ion transfer number from 0.28 to 0.49.This separator can also facilitate desolvation process,improve exchange current density,restrict two-dimensional Zn^(2+)ion diffusion,and enhance electrochemical kinetics,contributing to significantly inhibited dendrite growth,by-product formation,and hydrogen evolution.Consequently,stable and reversible Zn stripping/plating process is enabled for over 2500 h at 2 mA cm^(-2)and 2 mAh cm^(-2).And great rate capability and excellent cyclability can be achieved for full batteries even under harsh conditions.This work provides new insights into separator design for Zn-based batteries.
基金
the financial support from the Natural Science Foundation of Jiangsu Province(BK20231292)
the Jiangsu Agricultural Science and Technology Innovation Fund(CX(24)3091)
the National Natural Science Foundation of China(12464032)
the Natural Science Foundation of Jiangxi Province(20232BAB201032)
supported by the high performance computing university-level public platform of Jinggangshan University.
作者简介
Jiaqi Yu,contributed equally to this work;Bo Liu,contributed equally to this work;Corresponding author:Jizhang Chen,E-mail address:chenjizhang@njfu.edu.cn.
