Preparation of an organic-copper composite modified layer via displacement reaction on zinc anode

A bilayer Cu-BTC@Zn interlayer was in-situ grown on Zn anode via exchange reaction. • The upper layer, rich in carboxyl, promotes the ordered deposition of zinc ions. • The bottom layer of zincophilic Cu clusters forms dense physical protection. • Cu-BTC@Zn symmetric cell cycles over 4000 h at 3 mA cm −2 and 2000 h at 10 mA cm −2 . Aqueous zinc-ion batteries face severe challenges in practical cycling, mainly including irregular zinc dendrite growth and unstable interfacial reactions, which greatly degrade the cycling performance. Herein, via a facile immersion method relying on a one-step in-situ spontaneous displacement reaction, an organic-inorganic composite layer composed of organic components and copper nanoparticles are fabricated on the surface of the zinc metal anode. The upper layer is enriched with carboxyl groups and Cu 2+ , constructing the upper layer by coordination interactions. Acting as migration sites and transport pathways for Zn 2+ , the as-formed SEI layer induces the uniform and ordered deposition of zinc. The bottom layer is composed of zincophilic copper clusters, which can form a compact physical shielding layer on the zinc anode surface and effectively inhibit interfacial corrosion. Benefiting from the synergistic effect, the symmetric cell achieves an ultra-long cycle life of over 4000 h at 3 mA cm −2 , and still maintains a cycle life exceeding 2000 h even at a high current density of 10 mA cm −2 . Meanwhile, the Cu-BTC@Zn//MVO full battery exhibits a 57% increase in capacity retention compared with bare Zn anode after 700 cycles. Meanwhile, this work reveals the synergistic regulation mechanism of the organic-inorganic composite layer toward Zn deposition, and provides a facile and practical strategy to construct stable artificial SEI layers for high performance zinc-metal anodes. The organic copper composite interface layers with a unique bilayer structure, fabricated on the zinc anode surface via a one-step in-situ spontaneous displacement reaction. The bilayer structured SEI facilitates orderly zinc ion deposition and inhibits zinc dendrite growth. This approach offers a novel strategy for designing highly stable and durable anodes for aqueous zinc-ion batteries. Download: Download high-res image (91KB) Download: Download full-size image