A rational design of multi-functional separator for uniform zinc deposition and suppressed side reaction towards zinc–nickel batteries with superior cycling life and shelf life

With the development of electrochemical energy storage systems with intrinsic safety, zinc–nickel batteries (ZNBs) have attracted widespread attention. However, the poor cycling life and shelf life restrict their further application. Herein, a porous-structured "multifunctional layered conductive" (MLC) separator was developed to comprehensively address problems of ZNB. MLC separator was prepared by a simple and effective strategy, in which various polymer and inorganic compositions can be easily integrated to functionalize the separator. MLC separator can effectively suppress dendrites and deformation of the anode, while avoiding the anode collapse under the extended conductive network for an excellent cycling life of ZNB. Furthermore, the side reactions and electrolyte loss have been mitigated to improve the shelf life of ZNB. Consequently, MLC separator enables an impressive cycling life of ZNB for 1672 h at a high current density of 55.3 mA cm−2. Besides, ZNB can be stored and floating charged for more than 440 h and 580 h, respectively, under a high temperature of 60℃. This strategy has great potential for replication and large scale impact, which represents a milestone in preparation of functional separators for ZNB.