Suppressing dendrite growth and side reactions on Zn metal anode via guiding interfacial anion/cation/H2O distribution by artificial multi-functional interface layer

Abstract

Introducing artificial interface layer is a cost-effective strategy to inhibit parasitic reactions and dendritic growth on the zinc anode. However, boosting cation transfer while blocking anions and active water molecules through the interface layer is still a formidable challenge at current stage. Here, a zeolitic imidazolate framework (ZIF) based multi-functional interface layer is fabricated to prevent active water molecules reaching the deposition sites while increasing the cation concentration at the interface based on the coordinative self-concentration mechanism and electrokinetic effects, thus effectively inhibiting parasitic reactions and dendrite growth. Specifically, a super-saturated interfacial electrolyte layer is formed in the ZIF-11 layer because a large amount of water and large solvated molecule are removed in advance, eventually inhibiting the generation of hydrogen and basic zinc sulfate. Simultaneously, a thin electric double layer on the wall of the channel inside the interface layer can be formed due to the intense adsorption of zinc ions by the abundant zincophilic nitrogen-containing functional groups in the interface layer, leading to smooth electrokinetic surface conduction and stable deionization shock in the channel. These electrokinetic effects will jointly guide the distribution of zinc ions, thereby forming a uniform shock electrodeposition on the anode surface. Accordingly, the ZIF-11@Cu-Zn based symmetric cells can operate stably for 1800 h, nearly 18 times longer than that of Cu-Zn based symmetric cells at 0.5 mA cm−2. And the ZIF-11@Cu-Zn based aqueous Zn-ions hybrid supercapacitors (AC||ZIF-11@Cu-Zn ZHCs) exhibit a reversible capacity of 58.6 mA h g−1 and the capacity retention is about 96.23% after 5000 cycles. Moreover, AC||ZIF-11@Cu-Zn ZHCs can still run effectively for 5000 cycles even paired with the cathode with commercial-grade loading of 23.3 mg cm−2.