Sacrificial Anode Research Articles

Integrated Trap‐Adsorption‐Catalysis Nanoreactor for Shuttle‐Free Aqueous Zinc‐Iodide Batteries

AbstractAqueous zinc‐iodine batteries (AZIBs) are very promising energy storage systems owing to their safety, reliability, large specific capacity, and durable lifespan. However, the sluggish iodine redox kinetics and polyiodides shuttle effect severely impedes their wider application. Addressing these challenges, this study develops a new multifunctional nanoreactor integrating “Trap‐Adsorption‐Catalysis” advantages, which features the electron‐rich cobalt (Co) nanoparticles embedded in porous activated carbon (AC). Benefiting from the integrated advantages of trap‐adsorption‐catalysis behavior in the nanoreactor, this novel system enables the fast iodine (I2/I‐) conversion by enhanced kinetics, achieving high utilization of iodine and corrosion‐free zinc anode without producing polyiodides. In situ UV–vis spectroscopy, theoretical calculation combined with electrochemical analysis demonstrates that the Co@AC nanoreactor reduces the adsorption energy and conversion energy barrier of iodine species, and accelerates the conversion of polyiodides to improve the electrochemical properties. Notably, the Co@AC/I2 cathode delivers an outstanding rate capability of 221.1 and 102.5 mA h g−1 at the current density of 0.5 and 25C with high CE over >99.9%, respectively, low self‐discharge rate over 96h and high energy efficiency (EE) of 89.2% at 5.0C over 1000 cycles. These self‐discharge and EE properties are the best among AZIBs systems with Co‐based host cathodes ever reported.

Numerical analysis of cathodic protection of a Q355ND frame in a shallow water subsea Christmas tree

Abstract This study develops a 3D model of a Christmas tree using cathodic protection technology and conducts numerical simulations on the Q355ND framework of a shallow Christmas tree. The boundary element method is employed for modeling, examining the distribution of protection potentials under varying corrosion layer breakage rates, anode numbers, and positions. The influence of sacrificial anode parameters on the cathodic protection effect of the Christmas tree is also investigated. The findings reveal that when the breakage rate of the anticorrosion layer reaches 35 % during Christmas tree operation, the sacrificial anode fails to provide complete protection. However, if the coating breakage rate is 10 %, reducing the number of anodes by six can still achieve a protection potential of −850 mV. Thus, it is imperative for Christmas trees to maintain a corrosion protection layer breakage rate below 35 %. Beyond this threshold, sacrificial anodes exhibit minimal effectiveness in preserving their integrity.

Constructing Dynamic Cross-Linking Networks as Durable Bifunctional Coating for Highly Stable Zinc Anodes.

The serious dendrite growth and H2O-induced side reactions on the Zn electrode lead to a significant fading in the cycling performance, hindering the development of commercial applications of aqueous Zn-ion batteries (AZIBs). Herein, a novel bifunctional network coating of dynamically cross-linking sodium alginate with trehalose has been rationally constructed on the Zn anode (Zn@AT). Firstly, the AT coating possesses abundant zinophilic oxygen-containing functional groups, which are able to induce uniform Zn2+ ion flux. Secondly, the AT coating as a solid barrier can effectively inhibit H2O-induced side reactions by lowering the activity of H2O molecules. More specially, based on the dynamic cross-linking, AT network coating is endowed with self-healing capacity during cycling for durable battery operation. Consequentially, Zn@AT anodes in symmetric cells can cycle stably for 2787 h at 2 mA cm-2/2 mAh cm-2, and even achieve a significantly long cycle performance of 1087 h at large charge/discharge depths of 10 mA cm-2/10 mAh cm-2. Moreover, the Zn@AT//MnO2 full cell shows excellent specific capacity of 175 mAh g-1 after 400 cycles. This study lights an effective strategy to enhance the durability of Zn electrodes in AZIBs.

In Situ Assembly of Metal‐Organic Coordination Polymer Layers Enables Highly Reversible Zn Anodes with a Long Cycle Life of over 6900 h

AbstractZn anodes in aqueous zinc‐ion batteries chronically suffer from pernicious side reactions and ineluctable dendrite growth, resulting in inadequate reversibility and suboptimal Coulombic efficiency (CE) and impeding commercialization. Herein, a multifunctional metal–organic coordination polymer layer (FAZ) is constructed on the zinc anode surface (FAZ@Zn) utilizing a simple self‐assembly strategy. The zincophilic FAZ interfacial layer with a high Zn2+ transfer number and low nucleation barrier effectively facilitates the de‐solvation process, supports the rapid transport of zinc ions, and contributes to the preferential growth of Zn (002) crystal planes, enabling dendrite‐free Zn deposition. Furthermore, the FAZ layer, as an interfacial pH regulating layer, effectively inhibits the direct contact between Zn and active water molecules, lowering the severity of side reactions. Consequently, the FAZ@Zn anode furnishes an eminent cycle stability over 6900 h, with a low polarization voltage at 1 mA cm−2 and 1 mA h cm−2 and a boosted CE of 99.88% over 4100 cycles. More encouragingly, when coupled with Na2V6O16·3H2O, the FAZ@Zn anode enables the full cell to deliver satisfactory rate performance and a 97% capacity retention over 1600 cycles. This work provides a simple strategy for the effective preparation of highly reversible zinc anodes for high‐performance aqueous zinc‐ion batteries.

Utilization of Sodium Polyacrylate Hydrogels in the Sacrificial Anode Cathodic Protection Method for Steel Members at the Atmospheric Environment

Utilization of Sodium Polyacrylate Hydrogels in the Sacrificial Anode Cathodic Protection Method for Steel Members at the Atmospheric Environment

Harnessing Ion‐Dipole Interactions for Water‐Lean Solvation Chemistry: Achieving High‐Stability Zn Anodes in Aqueous Zinc‐Ion Batteries

AbstractThe reversibility and stability of aqueous zinc‐ion batteries (AZIBs) are largely limited by water‐induced interfacial parasitic reactions. Here, dimethyl(3,3‐difluoro‐2‐oxoheptyl)phosphonate (DP) is introduced to tailor primary solvation sheath and inner‐Helmholtz configurations for robust zinc anode. Informed by theoretical guidance on solvation process, DP with high permanent dipole moments can effectively substitute the coordination of H2O with charge carriers through relatively strong ion‐dipolar interactions, resulting in a water‐lean environment of solvated Zn2+. Thus, interfacial side reactions can be suppressed through a shielding effect. Meanwhile, lone‐pair electrons of oxygen and fluorinated features of DP also reinforce the interfacial affinity of metallic zinc, associated with exclusion of neighboring water to facilitate reversible zinc planarized deposition. Thus, these merits endow the Zn anode with a high‐stability performance exceeds 3800 hours at 0.5 mA cm−2 and 0.5 mAh cm−2 for Zn||Zn batteries and a high average Coulombic efficiency of 99.8 % at 4 mA cm−2 and 1 mAh cm−2 for Zn||Cu batteries. Benefiting from the stable zinc anode, the Zn||NH4V4O10 cell maintains 80.3 % of initial discharge capacity after 3000 cycles at 5 A g−1 and exhibits a high retention rate of 99.4 % against to the initial capacity during the self‐discharge characterizations.

Recovery and utilization of zinc dross for sacrificial anode cathodic protection of steel structures

Zinc dross is highly zinc-rich industrial waste produced during galvanization of steel. It is a byproduct of the reaction between molten zinc and loose iron particles in a molten zinc bath. Generally, 10–20% of galvanized zinc is converted into zinc dross. This work proposes a unique way of recycling of dross into a high value sustainable resource material leading to development of sacrificial anode used in cathodic protection of steel. The electrochemical behavior was studied in 3.5 wt% NaCl solution. The anode performance test was performed as per the standard DNV-RP-B401 in an artificial seawater solution. The performance parameters, (closed circuit potential (CCP), anode efficiency, and consumption rate) of the recovered zinc anode from dross, are close to the commercial zinc anodes. It satisfies the required anode criteria. Hence, the recovered zinc anode from dross could be used as a sacrificial anode for the cathodic protection of steel structures.

Ultrathin Zn(002) textured zinc anodes for dendrite-free and hydrogen evolution-inhibited zinc batteries

For practical rechargeable aqueous zinc-ion batteries, the long-term cycling stability of the zinc anode remains significantly constrained by its low utilization efficiency and the persistent challenge of hydrogen evolution. This study demonstrates the fabrication of ultrathin zinc electrodes with a robust Zn (002) texture while ensuring an adequate supply of zinc metal for use as an anode material. This approach effectively suppresses the tendency of zinc atoms to undergo deposition transformation due to dislocation-induced phenomena. Compared to zinc foils with higher deposition amount, the ultrathin Zn anode exhibits enhanced resistance to dendrite growth and interfacial side reactions. Assembled symmetrical cells based on this ultra-thin Zn anode show a cycle life of 1750 h (1 mAcm−2, 0.5 mAhcm−2), maintaining stable cycling for over 100h even at a high depth of discharge (DOD) of 46.23%. Additionally, the full cell couple with V10O24 exhibits a high initial capacity of 429.6 mAh g−1 and a capacity retention of 75.8% after 1000 cycles.

A Crystalline-Water Electrolyte Enabled High Depth-of-Discharge Anodes in Aqueous Zinc Metal Batteries.

Aqueous zinc metal batteries are regarded as a promising energy storage solution for a green and sustainable society in the future. However, the practical application of metallic zinc anode is plagued by the thermodynamic instability issue of water molecules in conventional electrolytes, which leads to severe dendrite growth and side reactions. In this work, an ultra-thin and high areal capacity metallic zinc anode is achieved by utilizing crystalline water with a stable stoichiometric ratio. Unlike conventional electrolytes, the designed electrolyte can effectively suppress the reactivity of water molecules and diminish the detrimental corrosion on the metallic zinc anode, while preserving the inherent advantages of water molecules, including great kinetic performance in electrolytes and H+ capacity contribution in cathodes. Based on the comprehensive performance of the designed electrolyte, the 10µm Zn||10µm Zn symmetric cell stably ran for 1000h at the current density of 1mAcm-2, and the areal capacity of 1mAhcm-2, whose depth-of-discharge is over 17.1%. The electrochemical performance of the 10µm Zn||9.3mgcm-2polyaniline (PANI) full-cell demonstrates the feasibility of the designed electrolyte. This work provides a crucial understanding of balancing activity of water molecules in aqueous zinc metal batteries.

In Situ Polymerization of a Self-Healing Polyacrylamide-Based Eutectogel as an Electrolyte for Zinc-Ion Batteries.

Gel electrolytes have attracted extensive attention in flexible batteries. However, the traditional hydrogel electrolyte is not enough to solve the fundamental problems of zinc anodes, such as dendrite growth, side reactions, and freezing failure at temperatures below zero, which seriously restricts the development of zinc-ion batteries. As a flexible energy storage device, the zinc-ion battery inevitably undergoes multiple stretches, bends, folds, or twists in daily use. Here, a self-healing and stretchable eutectogel, designated as deep eutectic solvent-acrylamide eutectic gel (DA-ETG), was developed as a solid-state electrolyte for zinc-ion batteries. This gel was prepared by immobilizing a high-concentration ZnCl2 deep eutectic solvent (DES) into a polyacrylamide matrix through in situ polymerization under ultraviolet light. The eutectogel electrolyte showed exceptional mechanical properties with a maximum fracture strength of 0.6 MPa and a high ionic conductivity of 6.4 × 10-4 S cm-1. The in situ polymerization of the DA-ETG electrolyte in the assembly of a full solid-state zinc-ion battery increased the electrode-electrolyte interface area contact, reduced the ion transport distance between the electrode and electrolyte, minimized the internal resistance, and enhanced the battery's long-term cycling stability. Using the DA-ETG electrolyte, a remarkably high capacity of 580 mAh g-1 at 0.1 A g-1 was achieved by the zinc-ion battery, and a considerable capacity of 234 mAh g-1 was maintained even at 5 A g-1, showing exceptional rate performance. After 2000 cycles at 2 A g-1, the cell with the eutectogel retained a capacity of 85% with a cycling efficiency close to 98%, which demonstrated excellent cycling stability. The self-healing function enabled the prepared soft battery to be reused multiple times, with full contact between the electrode and electrolyte interface, and without device failures.

Construction of an anti-anionic-depletion layer to mitigate the tip deposition effect for dendrite-free zinc anode

Rechargeable aqueous zinc-ion batteries have been plagued by the well-known problem of zinc dendrite formation. This issue mainly arises from the inherent depletion of anions in the vicinity of the zinc anode during deposition process, leading to a strong spatial electric field that influences Zn2+ cations deposition and triggers dendrite growth. Herein, the anti-anionic-depletion strategy is proposed that involves anions anchored in the surface region of zinc anode to mitigate the adverse effects of the spatial electric field and inhibit dendrite growth. By theoretical calculations and experimental verification, layered double hydroxides (LDHs) materials were selected to immobilize SO42- anions and construct a protective coating layer against anion depletion (anti-anionic-depletion layer). Furthermore, the deposition flux of Zn2+ cations was also regulated by in-situ growing LDH nanosheets. Benefiting from these modifications, the in-situ grown ZnAl-LDH modified electrode (Zn@ZnAl) exhibits outstanding stability (5500 cycles at 40 mA cm−2), and shows negligible capacity degradation in both Zn-Mn full cells and zinc hybrid capacitors.

Energetic aqueous zinc-sulfur battery achieved via co-solvent and redox mediator synergistic regulation

Aqueous Zn–S batteries (AZSBs) have received significant attention due to the outstanding energy density, low cost, and high safety. However, the slow kinetics and poor reversibility of the sulfur conversion reaction, coupled with the formation of dendrites in zinc anode and hydrogen evolution reaction (HER), hinder the practical applications of AZSBs. In this paper, we developed a novel co-solvent electrolyte that utilizes N-methylpyridine (NMP) and KI as additives to regulate the cathode reversibility and anode stability synergistically. Firstly, the electrophilic group of NMP (–CO–NR2-) effectively activates the oxidation of I− to form I3−. The resulting I3−/I− redox mediator participates in the sulfur conversion reaction and lowers its energy barrier, thus enhancing the reaction kinetics of ZnS ↔ S and inhibiting the formation of irreversible by-products. Secondly, NMP alters the solvation structure of Zn(H2O)62+, achieving uniform deposition of Zn2+ and inhibiting the growth of zinc dendrites. Thirdly, NMP forms a dense solid-electrolyte-interphase layer between the zinc metal and H2O during cycling, inhibiting HER. Under the synergistic effect from solvent and redox mediator, AZSBs exhibit an impressive capacity of 775 mAh g−1 at 5 A g−1 (10 C) with 77.5 % capacity retention after 300 cycles.

Ion confinement effect enabled by carboxymethyl cellulose/tannic acid hybrid hydrogel electrolyte toward stable zinc anode

Zinc metal batteries have garnered considerable attention ascribing to its cost effectiveness, intrinsic safety, and eco-friendliness. Nevertheless, zinc metal batteries yet are confronted with service life issue arising from dendrite and side reactions. Here, a highly ionic confined and hydrogen bond-enhanced tannic acid-modified carboxymethyl cellulose-based hybrid hydrogel electrolyte is designed for regulating structure of Zn2+ solvent and inhibiting dendrites growth, and simultaneously remaining operational under severe condition like low temperature. The phenolic hydroxyl group in tannic acid and the carboxyl group in carboxymethyl cellulose can respectively engage in chelation and coordination with Zn2+ to regulate Zn2+ transportation channel for guiding uniform zinc plating/stripping. Simultaneously, the enhanced ion confinement effect changes the solvation structure of Zn2+ to reduce H2O activity, effectively alleviating corrosion and hydrogen evolution reaction induced by H2O. Based on the principles of thermodynamics and reaction kinetics combined with theoretical calculations and experimental findings, the mechanism underlying its pivotal role in attenuating hydrogen evolution and fostering zinc deposition is elucidated systematically. The carboxymethyl cellulose/tannic acid hydrogel electrolyte endows exceptional cycling longevity (2, 100 h at 0.5 mA cm−2/0.25 mAh cm−2) for Zn||Zn battery, as well as high Coulombic efficiency for Zn||Cu battery (averagely 98.31 % within 500 cycles at 1 mA cm−2/mAh cm−2. Moreover, the assembled Zn||Zn battery, Zn||NH4V4O10 battery and Zn||NH4V4O10 pouch battery utilizing carboxymethyl cellulose/tannic acid hydrogel electrolyte can even function normally under severe conditions like low temperature and bending. This study provides valuable reference to develop hydrogel electrolytes with the ability to withstand low temperature and stabilize zinc anode.

Hydrous Molybdenum Oxide Coating of Zinc Metal Anode via the Facile Electrodeposition Strategy and Its Performance Improvement Mechanisms for Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (ZIBs) are widely recognized as highly promising energy storage devices because of their inherent characteristics, including superior safety, affordability, eco-friendliness, and various other benefits. However, the significant corrosion of the zinc metal anode, side reactions occurring between the anode and electrolyte, and the formation of zinc dendrites significantly hinder the practical utilization of ZIBs. Herein, we utilized an electrodeposition method to apply a unique hydrous molybdenum oxide (HMoOx) layer onto the surface of the zinc metal anode, aiming to mitigate its corrosion and side reactions during the process of zinc deposition and stripping. In addition, the HMoOx layer not only improved the hydrophilicity of the zinc anode, but also adjusted the migration of Zn2+, thus facilitating the uniform deposition of Zn2+ to reduce dendrite formation. A symmetrical cell with the HMoOx-Zn anode displayed reduced-voltage hysteresis (80 mV at 2.5 mA/cm2) and outstanding cycle stability after 3000 cycles, surpassing the performance of the uncoated Zn anode. Moreover, the HMoOx-Zn anode coupled with a γ-MnO2 cathode created a considerably more stable rechargeable full battery compared to the bare Zn anode. The HMoOx-Zn||γ-MnO2 full cell also displayed excellent cycling stability with a charge/discharge-specific capacity of 129/133 mAh g-1 after 300 cycles. In summary, this research offers a straightforward and advantageous approach that can significantly contribute to the future advancements in rechargeable ZIBs.

Construction of a Composite Sn‐DLC Artificial Protective Layer with Hierarchical Interfacial Coupling Based on Gradient Coating Technology Toward Robust Anodes for Zn Metal Batteries

AbstractDeveloping a robust zinc (Zn) anode, free from Zn dendrites and unwanted side reactions, relies on designing a durable and efficient interfacial protection layer. In this study, gradient coating technology is employed to construct a hierarchically structured composite of Sn with diamond‐like carbon (DLC/Sn‐DLC) as an artificial protective layer. The DLC framework endows DLC/Sn‐DLC layer with high stability and adaptability, achieving long‐term stability of the anode–electrolyte interface. The gradual‐composite Sn, with its Sn─O─C interface chemical bonds, facilitates rapid charge transfer and offers ample zincophilic sites at the base, promoting uniform Zn2+ reduction reaction and deposition. Additionally, the DLC/Sn‐DLC composite exhibits a “lotus effect” and favorable hydrophobic properties, preventing water‐reduced side reactions. Leveraging this structural design and the synergistic cooperation of DLC and Sn, the DLC/Sn‐DLC@Zn electrode demonstrates remarkable Zn plating/stripping reversibility, eliminating Zn dendrites and side reactions. Notably, under a high current density of 10 mA cm−2, the DLC/Sn‐DLC@Zn anode‐based symmetrical cell exhibits stable operation for over 1550 h, with a low nucleation overpotential of 101 mV. The DLC/Sn‐DLC@Zn||Mn3O4‐CNTs full battery delivers a high capacity of 109.8 mAh cm−2 after 5800 cycles at 2 A g−1, and the pouch cell shows potential for energy storage applications.

Highly efficient corrosion inhibitor for low charge voltage and long lifespan rechargeable aqueous zinc-air battery

Hydrogen evolution, passivation and dendrite growth problems faced by zinc anodes of aqueous zinc-air batteries greatly reduce their cycle life and hinder their application in energy storage devices. Herein, a reversible, corrosion-resistant, and long-term stable cycle-life zinc anode is achieved by introducing zinc acetate and zinc gluconate into an alkaline electrolyte as corrosion inhibitors. Zinc acetate adsorbed on the surface of the zinc anode could be able to regulate the anode/electrolyte interface and thus inhibit the growth of dendrites, and zinc gluconate can reduce the charge voltage on the cathode to regulate the oxidation reaction and then prolong the cycle life, which eventually inhibit zinc anode corrosion. The additive package of zinc acetate and zinc gluconate provides a better performance. With addition of corrosion inhibitors, Zn||Cu cells show a high average coulombic efficiency about 94 %, and zinc-air batteries achieve a cycling lifespan of 297 h and low charge voltage of 1.7 V. This work provides a simple but practical guideline for high-performance zinc-air batteries.

Improving the Oxygen Evolution Reaction Kinetics in Zn-Air Battery by Iodide Oxidation Reaction.

Zinc-air batteries (ZABs) have garnered considerable attention as a highly promising contender in the field of energy storage and conversion. Nevertheless, their performance is considerably impeded by the proliferation of dendrites on the Zinc anode and the slow kinetics of the redox reaction on the air cathode. Herein, taking Ag30%@LaCoO3 (Ag30%@LCO) heterojunction catalyst as the cathode, it is demonstrated that adding KI additives to the alkaline electrolyte can not only enhance the oxygen electrocatalytic reaction but also inhibit the formation of zinc anode dendrites, thereby achieving a comprehensive improvement in the performance of ZABs. Under the action of the KI additive, the optimized Ag30%@LCO catalyst shows a decreased overpotential from 460 to 220mV at j = 10mA cm-2, while the assembled ZAB shows reduced charging potential (1.8V), and long cycle stability (180h). Furthermore, the morphology characterization results indicate a reduction in dendrites on the Zn anode. Both experimental and calculated results indicate that the presence of I- as a reaction modifier alters the trajectory of the conventional oxygen evolution reaction, resulting in a more thermodynamically favorable pathway. The introduction of KI additives as electrolytes provides a straightforward approach to developing comprehensively improved ZABs.

In situ preparation of MOF-74 for compact zincophilic surfaces enhancing the stability of aqueous zinc-ion battery anodes

Zinc-ion batteries (ZIBs), while celebrated for their environmental friendliness, abundant material availability, and inherent safety, face significant challenges that curtail their performance and lifecycle. These challenges include the formation of zinc dendrites, susceptibility to electrolyte corrosion, and the propensity for hydrogen evolution reactions. Addressing these critical issues, our research introduces an innovative surface modification strategy for zinc anode of ZIB with mild electrolyte, by the in-situ synthesis of Metal-Organic Framework (MOF-74) facilitated by the mild acidity of a 2,5-dihydroxyterephthalic acid (DHTA) methanol solution. The zincophilic sites and pore structure introduced by MOF-74 to substantially enhance the surface properties of zinc anodes and accelerate the solvation process, enabling uniform zinc deposition, inhibiting dendrite growth, and significantly bolstering corrosion resistance and electrochemical stability. Combination of physical and electrochemical characterization techniques are employed to validate the successful implementation of MOF-74 on the zinc anode surface and its resultant benefits. When tested in full cell setups with α-MnO2 as the cathode, the MOF-74 modified zinc anodes displayed exceptional cyclic stability and rate performance, surpassing those of unmodified counterparts. This investigation highlights the potential of MOF materials to address the electrochemical challenges facing zinc anodes, offering a straightforward yet efficacious strategy to enhance the performance and longevity of ZIBs.

Suppressed Dissolution of Fluorine-Rich SEI Enables Highly Reversible Zinc Metal Anode for Stable Aqueous Zinc-Ion Batteries.

The instability of the solid electrolyte interface (SEI) is a critical challenge for the zinc metal anodes, leading to an erratic electrode/electrolyte interface and hydrogen evolution reaction (HER), ultimately resulting in anode failure. This study uncovers that the fluorine species dissolution is the root cause of SEI instability. To effectively suppress the F- dissolution, an introduction of a low-polarity molecule, 1,4-thioxane (TX), is proposed, which reinforces the stability of the fluorine-rich SEI. Moreover, the TX molecule has a strong affinity for coordinating with Zn2+ and adsorbing at the electrode/electrolyte interface, thereby diminishing the activity of local water and consequently impeding SEI dissolution. The robust fluorine-rich SEI layer promotes the high durability of the zinc anode in repeated plating/stripping cycles, while concurrently suppressing HER and enhancing Coulombic efficiency. Notably, the symmetric cell with TX demonstrates exceptional electrochemical performance, sustaining over 500 hours at 20 mA cm-2 with 10 mAh cm-2. Furthermore, the Zn||KVOH full cell exhibits excellent capacity retention, averaging 6.8 mAh cm-2 with 98 % retention after 400 cycles, even at high loading with a lean electrolyte. This work offers a novel perspective on SEI dissolution as a key factor in anode failure, providing valuable insights for the electrolyte design in energy storage devices.

Suppressed Dissolution of Fluorine‐Rich SEI Enables Highly Reversible Zinc Metal Anode for Stable Aqueous Zinc‐Ion Batteries

AbstractThe instability of the solid electrolyte interface (SEI) is a critical challenge for the zinc metal anodes, leading to an erratic electrode/electrolyte interface and hydrogen evolution reaction (HER), ultimately resulting in anode failure. This study uncovers that the fluorine species dissolution is the root cause of SEI instability. To effectively suppress the F− dissolution, an introduction of a low‐polarity molecule, 1,4‐thioxane (TX), is proposed, which reinforces the stability of the fluorine‐rich SEI. Moreover, the TX molecule has a strong affinity for coordinating with Zn2+ and adsorbing at the electrode/electrolyte interface, thereby diminishing the activity of local water and consequently impeding SEI dissolution. The robust fluorine‐rich SEI layer promotes the high durability of the zinc anode in repeated plating/stripping cycles, while concurrently suppressing HER and enhancing Coulombic efficiency. Notably, the symmetric cell with TX demonstrates exceptional electrochemical performance, sustaining over 500 hours at 20 mA cm−2 with 10 mAh cm−2. Furthermore, the Zn||KVOH full cell exhibits excellent capacity retention, averaging 6.8 mAh cm−2 with 98 % retention after 400 cycles, even at high loading with a lean electrolyte. This work offers a novel perspective on SEI dissolution as a key factor in anode failure, providing valuable insights for the electrolyte design in energy storage devices.