Zinc-ion Batteries Research Articles

Production of eco-friendly cathode materials from cellulose skeleton induced manganese dioxide to produce zinc ion battery: Physicochemical, morphological, and electrochemical study

Energy security is a universal issue since modern civilization cannot be imagined for a single moment without energy. Though lean fossil fuels are fighting against the current energy demand principally, these are linked to adverse environmental effects. Various energy storage technologies can resolve this issue in a sustainable eco-friendly manner. Rechargeable Zn-ion batteries (ZIBs) are emerging as potential candidates to meet the growing commercial demand with several advantages. As a part of this, the cellulose skeleton-induced manganese dioxide-based electroactive cathode materials have been prepared by an innovative route and characterized using UV–vis-NIR, FTIR, FESEM, EDS, and XRD analysis. Results suggested that the newly produced eco-friendly cathode materials have possessed outstanding physicochemical, morphological, and structural properties. While the finished product namely the coin cell of ZIBs has shown a good CV profile along with minimal charge transfer resistance in PEIS. Noteworthy that the newly prepared cathode materials have also been shown a significant capacity of 29 mAhg-1 at a 5 mA constant current charge-discharge rate. Thus, the method could be beneficially used in energy storage devices for its eco-friendly nature though some drawbacks have been noticed. The cyclic stabilities were somewhat low which can be increased in further studies.

The host-guest effect of D-xylose constructs the weak-synergistic sheath structure of Zn2+ to achieve high performance of aqueous zinc ion batteries at the low temperature

Aqueous zinc ion batteries (AZIBs) have been widely concerned because of their low cost and high safety. However, zinc anodes are affected by active H2O, which promotes side reactions, and performs poorly at low temperatures. Herein, a weak-synergistic solvated sheath structure of Zn2+ is implemented by constructing a host–guest solvation modulation effect with the addition of D-xylose. As the host, D-xylose can replace the guest H2O in the solvated shell of Zn2+, weaken the interaction of Zn2+ with the guest H2O and SO42−, and destroy the original hydrogen bond network of the guest H2O-H2O. This electrolyte can greatly reduce side reactions induced by reactive H2O and lower the freezing point. Consequently, the electrolyte containing D-xylose has a high ionic conductivity of 21.2 mS cm−1 at −10 °C. The Zn||Zn battery can run stably for more than 2000 h at 25 °C (1 mA cm−2) and −10 °C (0.5 mA cm−2). Furthermore, the Zn||PANI battery displays promising capacity and sustained stability over 1000 cycles at −10 °C with an average CE of up to 100 %. This study highlights a new electrochemical perspective to achieve a weak-synergistic structure around Zn2+, providing new insights into the application of AZIBs at low temperatures.

CeO2 anchored in VO2@C rambutan-like microsphere achieving advanced zinc storage

Low-cost and high-safety aqueous zinc ion batteries (AZIBs) show great potential in energy storage for the grid. We propose a strategy to construct the self-assembled microspheres with the cerium oxide nanocrystals anchored on B-phase vanadium dioxide nanobelts, which are encapsulated by carbon (CVC), as cathode for high capacity and cycle stability of AZIBs. The rambutan-like structure with large specific surface area provides more active sites for the overall improvement of reaction kinetics; the carbon layer relieves vanadium dioxide from dissolving in the electrolyte while enhancing electron transfer rate; and electrocatalytic activity of cerium oxide accelerates redox reaction to enhance the performance of the cells. Consequently, the CVC electrode exhibits excellent electrochemical properties, including a reversible specific capacity (490 mAh g−1 at 0.1 A g−1), incredible cycle (84 % capacity retention after 1000 cycles at 5 A g−1). The excellent performance demonstrates the correctness of the combined internal and external modification strategy, while the simple hydrothermal method and inexpensive raw materials point to a new direction for the large-scale preparation of high-performance aqueous zinc ion batteries.

Modified structure of vanadium oxide via cadmium doping and in-situ activation for high-performance aqueous zinc ion storage

Vanadium oxides are promising cathode materials for aqueous zinc-ion batteries, but they suffer from severe crystal collapse and poor electrical/ionic conductivity. Herein, we successfully synthesized the designed cadmium-doped, carbon-coated vanadium oxide precursor with abundant oxygen vacancies (Cd0.015V2O3-x@C) using a straightforward one-pot thermal reduction method, followed by in-situ activation to form a high-performance cathode material, Cd0.004V2O5-y·nH2O@C. We find that the interlayered water dramatically reduces the electrostatic force between zinc ions and V2O5-y layers, meanwhile, abundant oxygen vacancies and cadmium doping alter the material’s band structure, resulting in enhanced electronic and ionic conductivities. Leveraging these advantages, the phase transitioned Cd0.004V2O5-y·nH2O@C cathode delivers a remarkably high capacity of 420 mAh/g (0.2 A/g), an excellent rate capability of 198 mAh/g (20.0 A/g), and an outstanding capacity retention of 78.5 % after 3500 cycles (20 A/g). This synergistic structure modification strategy of elemental doping and in-situ activation offers a novel approach to design high-performance vanadium oxide-based cathodes for advanced aqueous batteries.

Direct ink writing of engineered MOF-based hybrid composite empowering dendrite free zinc ion battery anode

The relationship between morphology and electrochemical performance of zinc-ion battery (ZIB) anodes is crucial. Optimizing zinc-ion intercalation efficiency, suppressing dendrite formation, and mitigating shape changes are achievable through thoughtful anode architecture design. Herein, we have engineered a hybrid composite by coordinating a metal-organic framework with phenolic formaldehyde resin using a direct ink writing approach to rationally design a gridline-patterned 3DP-UiON-PHC@Zn. This anode in a symmetrical cell shows exceptional stability with a low voltage hysteresis of 15 mV at 0.1 mA cm−2 over 2375 h and 67 mV at 0.5 mA cm−2 over 4470 h. When paired with a 3DP-VOC@Al cathode in a full cell, it achieves a remarkable areal capacity of 85.1 mAh cm2 (94.8 %) and maintains a capacity retention of 122 mAh g−1 (88.6 %) over 900 cycles at 0.1 A g−1. It also offers a power density of 69.1 W kg−1 and an energy density of 34.6 Wh kg−1. Kinetic analysis reveals that the charge storage mechanism is primarily capacitive (94.7 %). This study concludes that DIW significantly improves anode performance by minimizing dendrite growth and improving electrochemical stability, while the 3D-printed hybrid composite ensures robust mechanical stability and a porous structure.

Toward the Rechargeable Aqueous Zinc Ion Batteries with Improved Overall Performance: Electrolyte with Surface Adsorptive Additive.

Aqueous zinc-ion batteries (AZIBs) with slightly acidic electrolytes process advantages such as high safety, competitive cost, and satisfactory electrochemical performance. However, the failure behaviors of both electrodes, regarding zinc dendrite growth, interfacial parasitic reactions, and the collapse of cathode materials hinder the practical application of ZIBs. To alleviate the issues of both anode and cathode at the same time, D-xylose (DX) is introduced to the electrolyte as a multifunctional additive. As a result, the side reaction of the anode is suppressed and the metallic deposition behavior is regulated due to the hydrogen bonding network reconstruction and preferential surface adsorption of DX; for the MnO2 cathode, the DX adsorption can help the interfacial charge transfer and increase the reactive sites. Benefiting from these merits, DX-optimized Zn//Zn battery displays reveal a prolonged lifespan of 6912h and an ultra-high cumulative capacity of 17.28Ahcm-2 at 5mAcm-2. With the function of water reactivity suppression, the Coulombic efficiency reaches 99.91% at 2mAcm-2; the Zn||MnO2 full batteries exhibit excellent cyclability over 2000 cycles at 5C with an increased capacity of 118.9mAhg-1, indicating the dual functions to both of the electrodes for AZIBs.

Advancing Zinc Anodes: Strategies for Enhanced Performance in Aqueous Zinc-Ion Batteries.

The promising features of aqueous zinc ion batteries (AZIBs), including their inherent safety, environmental friendliness, abundant raw materials, cost-effectiveness, and simple manufacturing process, position them as strong candidates for large-scale energy storage. However, their practical application faces significant challenges, such as uncontrolled dendritic growth, undesirable side reactions, and hydrogen evolution reactions (HER), which undermine the efficiency and longevity of the system. To address these issues, extensive research has been conducted to improve these batteries' energy density and lifespan. This comprehensive review explores the fundamental mechanisms of zinc dendrite formation, its properties, and the interfacial chemistry between the electrode and electrolyte. It also delves into strategies for protecting the zinc anode, with a focus on the modulation of zinc ion deposition dynamics at the electrolyte interface. The discussion concludes with an evaluation of the current challenges and future prospects of AZIB, aiming to enhance their viability for grid-scale energy storage solutions.

Synergizing Proton‐Dominated Storage and Electron Transfer for High‐Loading, Fast‐Rate Organic Anode in Metal‐Free Aqueous Zinc‐Ion Batteries

AbstractDeveloping suitable anode materials to fabricate metal‐free Zinc ion battery is a promising strategy to solve the issues of Zn metal anode, such as dendrite growth and side reactions. However, the reported anode materials face shortcomings such as unsatisfactory rate performance, low mass loading, etc. Herein, featuring synergetic proton‐dominated storage and electron transfer, a conjugated polyimide nanocomposite trapped by multi‐walled carbon nanotubes (PPN‐MWCNT) is developed for high‐loading, fast‐rate organic anode materials in metal‐free Zinc ion battery. Specifically, abundant hydrophilic active sites and nonplaner conjunctional structure in PPN achieve proton‐dominated storage with two steps four electrons mechanism, leading to fast ion diffusion, and the intimate contact between the polymer and MWCNT via in situ polymerization ensures the excellent charge transfer and robust structure. Thus, the PPN‐MWCNT electrode delivers low redox potential, ultrahigh rate performance (50 A g−1), superior loading capability (≈40 mg cm−2) and exceptional long‐term cyclability (over 12 000 cycles). More importantly, the full batteries assembled with PPN‐MWCNT anode and different cathodes deliver a high energy density of 106.4 Wh kg−1 (PPN‐MWCNT//MnO2) and 83.7 Wh kg−1 (PPN‐MWCNT//active carbon‐I2), exceeding the most reported metal‐free Zinc ion batteries.

Disodium Malate Electrolyte Additive Facilitates Dendrite-Free Zinc Anode: Deposition Kinetics and Interface Regulation.

Due to the presence of H2O within the solvated sheath of [Zn(H2O)6]2+ as well as reactive free water in the electrolyte bulk phase, the extended cycling of aqueous zinc-ion batteries (AZIBs) is significantly affected by detrimental side reactions and the growth of Zn dendrites. This study significantly enhances the long-term cycling stability of AZIBs by introducing a small amount of disodium malate (DM) into a 2m ZnSO4 electrolyte solution. DM involvement in the solvation sheath of Zn2+ reduces the desolvation energy of Zn2+, thereby mitigating the corrosion and hydrogen evolution reaction (HER) of the negative electrode surface by [Zn(H2O)6]2+ ions. Additionally, DM adsorption on the zinc surface retards the reduction kinetics of Zn2+ at anode, promoting uniform distribution and predominant deposition on the flat (002) crystal plane, thus reducing dendrite formation. The assembled Zn||Zn symmetric cell exhibits stable cycling for over 500 h at 10mA cm-2 and 5 mAh cm-2. The Zn||VO2 full cells with DM additive exhibits an ultralong cycling lifespan without capacity loss.

Zwitterion Modified Polyacrylonitrile Fiber Separator for Long‐Life Zinc‐Ion Batteries

AbstractThe major challenges of aqueous zinc‐ion batteries (ZIBs) are the dendrite formation and the passivation of zinc metal anode, which restrict their practical applications. Herein, polyacrylonitrile (PAN) and zwitterionic surfactant (Sulfobetaine methacrylate, SBMA) are combined as a precursor to design a modified PAN nanofiber separator by electrospinning. SBMA with sulfonate group [SO3−] can alter the physical property of the precursor solution and electrostatic field during the electrospinning process. Besides, it can regulate the zinc ions crossing and homogenize the electric field by minimizing the zinc ion concentration polarization on the zinc foil surface due to the polar group. As a result, Zn symmetric cells with PAN@SBMA separators show long‐term stability (up to 1700 h), which outdistances the cell with GF‐D (only up to 50 h) under current density at 1 mA cm−2. Meanwhile, the Zn//PAN@SBMA//NH4V4O10 full cells have high specific capacity (236 mAh g−1) and excellent long‐term durability with 84.2% capacity retention after 2000 cycles at 5 A g−1. This work illustrates an easy and effective way to design a high ion transference number and functional PAN‐based separator for regulating Zn2+ deposition for the development of high‐performance ZIBs.

Spatially Confined Engineering Toward Deep Eutectic Electrolyte in Metal-Organic Framework Enabling Solid-State Zinc-Ion Batteries.

Uncontrollable interfacial side reactions generated from common aqueous electrolytes, just like the hydrogen evolution reaction (HER) and dendrite growth, have severely prevented the practical application of zinc-ion batteries (ZIBs). Solid-state ZIBs are considered to be an efficient strategy by adopting high-quality solid-state electrolytes (SSEs). Here, by confining deep eutectic electrolyte (DEE) into the nanochannels of metal-organic framework (MOF)-PCN-222, a stable DEE@PCN-222 SSE with internal Zn2+ transport channels was obtained. A distinctive ion-transport network composed of DEE and PCN-222 in the interior of DEE@PCN-222 realizes the efficient Zn2+ conduction, contributing to high ionic conductivity of 3.13×10-4 S cm-1 at room temperature, low activation energy of 0.12 eV, and a high Zn2+ transference number of 0.74. Furthermore, experimental and theoretical investigations demonstrate that DEE@PCN-222 with its unique channel structure could homogeneously regulate the Zn2+ distribution and effectively alleviate the side reactions. Highly reversible Zn plating/stripping performance of 2476 h can be realized by the SSE. The solid-state ZIBs show a specific capacity of 306 mAh g-1 and display cycling stability of 517 cycles. This unique design concept provides a new perspective in realizing the high-safety and high-performance ZIBs.

Construction of VO2@V2C MXene heterostructure toward superior-rate rechargeable aqueous zinc batteries

V2C MXene delivers excellent metallic properties and robust mechanical stability. However, its low capacity, easy volume expansion during charge/discharge and relatively short cycle life limits its further development. It is an effective strategy to build Van der Waals heterostructures that can shield the monolithic materials from defects and integrate the advantages of the monolithic materials. Herein, via a one-step hydrothermal method, a VO2@V2C heterostructure is successfully constructed by the controllable oxidation of V2C, which allows for shorter ion diffusion distances, faster ion transport and enhancement of hydrophilic properties of the material. The VO2@V2C heterostructures have incredible reversibility (440.9 mAh/g at 0.2 A/g), remarkable cycling stability (142.7 mAh/g at 1.0 A/g after 900 cycles) and superior-rate capacity (255.3 mAh/g at 6.0 A/g). Density functional theory (DFT) calculations revealed that VO2@V2C possesses excellent adsorption capacity for zinc ions and outstanding electrical conductivity. The heterogeneous interface between the two materials is conducive to the increase of the embedding sites of zinc ions, which promotes the homogeneous distribution and rapid diffusion of zinc ions in the materials, and consequently enhances the capacity and cycling reliability of the electrodes. It provides a new idea for the selection of cathode electrodes for aqueous zinc ion batteries (ZIBs) in present study.

Interfacial space confinement engineering toward ultrastable all-climate aqueous zinc ion batteries

The interfacial instability, particularly uncontrollable Zn nucleation and deposition, significantly impeding the commercialization of aqueous zinc ion batteries (ZIBs). Herein, we propose an interfacial space confinement strategy to enable the dendrite-free anode, specifically through constructing a zincophilic buffer layer based on hollow Sn@C. The porous Sn@C contributes to modify the electrical double layer structure, which greatly alleviates the concentration polarization during high-rate plating. In-situ experimental results demonstrate the inhibited H2O-mediated parasitic side reactions and the absence of dendrite deposition morphology. Based on the improved thermodynamics and kinetics, zincophilic buffer layers can deliver low nucleation overpotential (20 mV), ultrastable cycle life (> 5000 h), and excellent zinc utilization rate (62.4%). Importantly, the full batteries with zincophilic buffer layer exhibit excellent electrochemical stability over -40 to 70 °C, pushing forward the construction of advanced all-climate ZIBs.

Charged organic ligands inserting/supporting the nanolayer spacing of vanadium oxides for high-stability/efficiency zinc-ion batteries.

Given their high safety, environmental friendliness and low cost, aqueous zinc-ion batteries (AZIBs) have the potential for high-performance energy storage. However, issues with the structural stability and electrochemical kinetics during discharge/charge limit the development of AZIBs. In this study, vanadium oxide electrodes with organic molecular intercalation were designed based on intercalating 11 kinds of charged organic carboxylic acid ligands between 2D layers to regulate the interlayer spacing. The negatively charged carboxylic acid group can neutralize Zn2+, reduce electrostatic repulsion and enhance electrochemical kinetics. The intercalated organic molecules increased the interlayer spacing. Among them, the 0.028EDTA · 0.28NH4 + · V2O5 · 0.069H2O was employed as the cathode with a high specific capacity (464.6mAhg-1 at 0.5Ag-1) and excellent rate performance (324.4mAhg-1 at 10Ag-1). Even at a current density of 20Ag-1, the specific capacity after 2000 charge/discharge cycles was 215.2mAhg-1 (capacity retention of 78%). The results of this study demonstrate that modulation of the electrostatic repulsion and interlayer spacing through the intercalation of organic ligands can enhance the properties of vanadium-based materials.

Facile Synthesis of Monoclinic (NH4)2V4O9 Nanosheets for Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) are increasingly popular due to their low cost and high safety. However, the quest for cathode materials with robust internal structures and efficient ion transport pathways remains critical. In this study, we introduce a simple hydrothermal method to synthesize monoclinic (NH4)2V4O9 nanosheets, serving as a advanced cathode for ZIBs. This material demonstrates outstanding electrochemical properties, with a high specific capacity of 389 mAh g−1 at 0.1 A g−1, and retains 78.9% capacity after 3000 cycles at 1 A g−1 and 77.3% after 15000 cycles at 5 A g−1. Additionally, it achieves an energy density of 325 Wh kg−1 at 101 W kg−1. In-depth electrochemical analysis reveals the structural stability during reversible Zn2+ ion intercalation/de-intercalation, underscoring the potential of (NH4)2V4O9 as a high-performance material for ZIBs.

Development and characterization of zinc ion conducting biopolymer electrolytes based on cellulose acetate for primary zinc ion batteries

Development and characterization of zinc ion conducting biopolymer electrolytes based on cellulose acetate for primary zinc ion batteries

Manipulating the d-band center of bimetallic molybdenum vanadate for high performance aqueous zinc-ion battery

Vanadium-based oxides have good application prospects in aqueous zinc ion batteries (AZIBs) due to their structures suitable for zinc ion extraction and intercalation. However, their poor conductivity limits their further development. The d-band center plays a key role in promoting adsorption of ions, which promotes the development of electrode materials. Here, a series of MoV2O8 compounds with oxygen defect (Od-MoV2O8) were synthesized by a simple hydrothermal process and a subsequent vacuum calcination process through strict control of the deoxidation time. Theoretical calculations reveal that the abundant oxygen vacancies in MoV2O8 effectively regulate the d-band center of the zinc ion adsorption site. This precise control of the d-band center enhances the zinc ion adsorption energy of MoV2O8, lowers the migration energy barrier for zinc ions, and ultimately significantly boosts zinc storage performance. The specific capacity is as high as 282.4 mAh/g after 100 cycles at 0.1 A/g, and it also shows excellent performance and outstanding cycle life. In addition, the maximum energy density of Od-MVO-0.5 (MoV2O8 sample deoxidized for 0.5 h) is 343.3 Wh kg−1. Importantly, the mechanism of Zn2+ storage in Od-MoV2O8 was revealed by the combination of in situ and ex situ characterization techniques.

Achieving Dendrite-Free Zinc Deposition by Large-Size Anion-Reinforced Solvated Structures for Highly Reversible Zinc Anode

The electrochemical instability of zinc anode caused by surface side reactions and irregular zinc deposition severely hinders the practical application of aqueous zinc ion batteries (AZIBs). In this work, diethylenetriaminepentaacetic acid, pentasodium salt (DTPA) was used as a novel electrolyte additive to modulate the electrochemical stability of Zn anode. The DTPA anion can strongly coordinate with Zn2+, thus enabling the formation of a unique large-size anion-enhanced solvation structure of electrolyte. In this, not only the generation of by-products on Zn anode can be effectively inhibited, but more importantly, the deposition kinetics of Zn2+ can be well regulated to induce even and stable zinc deposition. In addition, DTPA is more prone to chemically adsorbed on the surface of Zn anode than H2O, contributing to the resistance of electrochemical corrosion. Synergistically, the Zn anode demonstrates excellent cycling stability (3850 h at 1 mA cm−2, 1 mAh cm−2, and 500 h at 10 mA cm−2, 10 mAh cm−2), enhanced coulombic efficiency (99.83% upon 3500 cycles at 5 mA cm−2, 1 mAh cm−2), and high reversibility of 1050 h even at a stringent discharge depth of 80%. Particularly, the full cell assembled with NaV3O8·1.5H2O (NaVO) cathode can also operate stably for 1800 cycles at 2 A g−1 with a high capacity retain of 90.8%. This work may pave a new route to achieve high-performance AZIBs by regulating the deposition process of Zn2+ based on large-size anion-enhanced solvation structure of electrolyte.

Zwitterion Intercalated Manganese Dioxide Nanosheets as High-Performance Cathode Materials for Aqueous Zinc Ion Batteries.

In this study, a novel approach is introduced to address the challenges associated with structural instability and sluggish reaction kinetics of δ-MnO2 in aqueous zinc ion batteries. By leveraging zwitterionic betaine (Bet) for intercalation, a departure from traditional cation intercalation methods, Bet-intercalated MnO2 (MnO2-Bet) is synthesized. The positively charged quaternary ammonium groups in Bet form strong electrostatic interactions with the negatively charged oxygen atoms in the δ-MnO2 layers, enhancing structural stability and preventing layer collapse. Concurrently, the negatively charged carboxylate groups in Bet facilitate the rapid diffusion of H+/Zn2+ ions through their interactions, thus improving reaction kinetics. The resulting MnO2-Bet cathode demonstrates high specific capacity, excellent rate capability, fast reaction kinetics, and extended cycle life. This dual-function intercalation strategy significantly optimizes the electrochemical performance of δ-MnO2, establishing it as a promising cathode material for advanced aqueous zinc ion batteries.

Comparison of gas-sensitive properties of Pb, Pd and Pt metal-doped Ti3C2X2 for aqueous zinc ion battery H2 gas

This work aims to provide early warning of uncontrolled reactions in aqueous zinc-ion batteries by timely and effectively detecting H2 gas. The large specific surface area and rich pore structure of Ti3C2X2 (X = F, O, and OH) make it a good gas-sensitive sensing material, and the gas-sensitive properties of the material can be improved by metal doping. Therefore, in this paper, the gas-sensitive response properties of Pb, Pd and Pt metal-doped Ti3C2X2 (M-Ti3C2X2) to H2 are compared based on density functional theory (DFT) calculations. The adsorption mechanism was analyzed by structure optimization, density of states, frontier molecular orbital theory and differential charge density, and the results were in high agreement. Doping of three metals, Pb, Pd and Pt, improved the adsorption capacity of Ti3C2X2 for H2 gas to different degrees. The simulation results show that the energy gap of Pb-Ti3C2(OH)2 adsorbed gas changes most obviously, and the maximum change value of energy gap (Eg) is 297.56 %. And Pt-Ti3C2F2 and Pt-Ti3C2O2 adsorbed H2 with large adsorption energies and large charge transfers indicating that they can be used as H2 removers. The energy gaps after the adsorption of H2 by M-Ti3C2O2 are 0.109 eV, 0.163 eV, and 0.082 eV, and the change of Eg is 24.77 %, 16.56 %, and 67.07 %, respectively. The change of Eg for the adsorption of H2 by Pt-Ti3C2O2 adsorbed H2 with a resistivity change of 67.07 %. This is caused by the irreversibility of adsorption due to too strong adsorption resulting in elongation of Pt-O bond length after adsorption. For the detection of H2, the properties of several doped materials were ranked as follows: Pb-Ti3C2(OH)2 > Pt-Ti3C2O2 > Pb-Ti3C2F2 > Pb-Ti3C2O2 > Pd-Ti3C2O2 > Pd-Ti3C2(OH)2 > Pt-Ti3C2F2 > Pt-Ti3C2(OH)2 > Pd-Ti3C2F2. In summary, it is shown that Ti3C2X2 doped with Pb, Pd and Pt metals is a potential H2 gas-sensitive material that can be a new material for online monitoring of fault gas content in aqueous zinc-metal energy storage batteries.