A Functional Organic Zinc-Chelate Formation with Nanoscaled Granular Structure Enabling Long-Term and Dendrite-Free Zn Anodes

Abstract

Aqueous Zn metal batteries suffer from rapid cycling deterioration due to the severe water corrosion and dendrite growth o n Z n a n o d e s . H e r e i n , a h i g h l y a n t i w a t e r Z n xdiethylenetriaminepenta(methylene-phosphonic acid) interface layer with good zinc affinity and special nanoscaled 3D granular structure is designed on Zn metal to address these problems. Experimental results combined with theoretical analysis and COMSOL simulations reveal that the hydrophobic groups in such Zn-based organic complex are the decisive factor in preventing H 2 O from damaging Zn anode surface. The massive Zn 2+ attractive sites formed by interaction of methylene-phosphonic acid groups and Zn cause ion channel for fast zinc-ion adsorption and migration. And the developed nano granular architecture on the surface induces redistributed Zn 2+ ion flux to realize homogenization with smooth and compact surface deposition. Under the synergism, such modified anodes exhibit long cycling lifespan over 1300 h with a relatively low polarization voltage at 5 mA cm −2 . Also, the assembled full cells (including Zn//V 2 O 5 and Zn//MnO 2 cell) based on this anode are also demonstrated. The work provides a simple, low cost, and efficient pathway by combining the two concepts of structural design and constructing protective layers on the surface to prepare high-performance Zn anodes toward prospering aqueous zinc−metal batteries.

Kinetics‐Boosted Effect Enabled by Zwitterionic Hydrogel Electrolyte for Highly Reversible Zinc Anode in Zinc‐Ion Hybrid Micro‐Supercapacitors

“…[10,11] In turn, baneful parasitic reactions drive by-product formation and flagrant dendrite growth. [12] Especially, such issues are serious in conventional liquid electrolytes (LEs) due to the uncontrolled irregular ion migration and high-activity free water. [13,14] The undesired dendrite growth and parasitic reactions degenerate Zn plating/stripping reversibility, thus reducing the coulombic efficiency (CE) and lifespan of ZHMSCs.…”

A flexible and stable zinc-ion hybrid capacitor with polysaccharide-reinforced cross-linked hydrogel electrolyte and binder-free carbon cathode

“…LSV curves show that the current density of the PAM/CMC/XG/Zn(CF 3 SO 3 ) 2 hydrogel electrolyte prominently lowers relative to LE, suggesting the suppressed HER in the former. 40 Then, we assembled transparent Zn//Zn symmetric cells with different electrolytes to in situ monitor the morphological change in Zn surface during electrodeposition (Fig. 2c and d).…”

Manipulating Deposition Behavior by Polymer Hydrogel Electrolyte Enables Dendrite‐Free Zinc Anode for Zinc‐Ion Hybrid Capacitors

“…[7,51] From linear scanning voltammetry (LSV) curves (Figure 3c), it is found that the Zn electrode in CGPPHE compared to LE has a smaller current density, and the onset potential of HER increases by ≈70 mV, indicative of the suppressed HER in CGPPHE. [11,27] Profiting from the promotion effect of CGPPHE on confining dendrite growth and parasitic reactions, Zn anodes may possess good electrochemical durability, which is verified by galvanostatic cycling of the symmetric Zn|CGPPHE|Zn cell. As expected, the Zn|CGPPHE|Zn cell can be stably circulated for Small Methods 2023, 7, 2201398 more than 350 h at a current density of 1 mA cm −2 with an area capacity of 1 mAh cm −2 (Figure 3d).…”

“…[8,9] More problematically, baneful interfacial side reactions, including hydrogen evolution reaction (HER) and corrosion caused by high-water-activity aqueous solution, exacerbate the dendrite issue. [10,11] At present, Rechargeable aqueous zinc-ion hybrid capacitors (ZHCs) have aroused unprecedented attention because of their high safety, cost effectiveness, and environmental compatibility. However, the intractable issues of dendrite growth and side reactions at the electrode-electrolyte interface deteriorate durability and reversibility of Zn anodes, deeply encumbering the large-scale application of ZHCs.…”