Aqueous Zinc-ion Batteries Research Articles

Seed-Assisted Reversible Dissolution/Deposition of MnO2 for Long-Cyclic and Green Aqueous Zinc-Ion Batteries.

Manganese oxide (MnO2) based aqueous zinc-ion batteries (AZIBs) are considered to be a promising battery for grid-scale energy storage. However, they usually suffer from the great challenge of capacity attenuation due to Mn dissolution and irreversible structural transformation. Herein, full use of the shortcomings is made to design high-performance cathode-free AZIBs. Manganese-based Prussian blue analog (Mn-PBA) is selected as a seed layer to provide a stable MnO2 electrodeposition surface. Thanks to the large specific surface area and manganophilic nature of Mn-PBA, the deposition/dissolution kinetics between Mn2+ and MnO2 are significantly enhanced. Systematic studies revealed the mechanism of MnO2 deposition-dissolution related to the reversible transformation of manganese oxide hydroxide and zinc hydroxide sulfate hydrate. Based on this, the developed cathode-free AZIBs exhibit outstanding rate performance (with a specific capacity of 273.7 mAh g-1 at 1 A g-1) and extraordinary cycle stability (maintaining a specific capacity of 52.3 mAh g-1 after 50000 cycles at 20 A g-1). Furthermore, the AZIBs with non-toxic, biocompatible materials can be directly discarded after use, without causing pollution to the environment, which is expected to help achieve the sustainable development goals.

Electroplating of zinc onto polyelectrolyte complex membranes as anode for aqueous zinc-ion batteries

Conventionally, the anode of a primary Aqueous zinc-ion batteries (ZIBs) is metallic and rigid, which made it difficult to integrate into flexible designs. In this research, a composite polyelectrolyte complex (PEC) with cationic poly(diallyldimethylammonium chloride), anionic poly(sodium-4-styrenesulfonate) and carbon black (CB) as conductive filler (PEC-CB) was developed as an anode substrate for zinc deposition via electroplating technique. The Zinc-electroplated PEC-CB (Zn-PEC-CB) anode was characterized using electron microscopy and X-Ray diffraction analysis to verify the successful zinc coating. The Zn-PEC-CB was then assembled with PEC-CB-MnO cathodes in an ZIB setup. The results demonstrated the potential of PEC-based electrodes as a promising alternative to conventional materials in ZIBs, encouraging further exploration in energy storage applications.

Fully Conjugated Anthraquinone‐Quinoxaline Derivative Cathode Enabling a Superior Zn‐Ion Storage at Extremely Low Temperature −50 °C

AbstractSmall molecule organic materials have been considered promising candidates as cathodes in aqueous zinc‐ion batteries (AZIBs) because of their low cost, environmental friendliness, and sustainable production. However, the rapid capacity fading and sluggish kinetics restrict their practical applications, especially under extremely low temperatures (−50 °C). Here, by the condensation of hexaketocyclohexane octahydrate (HKCO) and 1, 2‐diaminoanthraquinone (DQ), a fully conjugated organic molecule, anthraquinone‐quinoxaline derivative (HATAN) is prepared. With the fully conjugated structure, HATAN possesses enhanced π‐electron delocalization and strong intermolecular interaction, which ensure superior electronic conductivity and physicochemical/electrochemical stability. Additionally, the introduction of multiple redox‐active sites (C═O and C═N) can increase the theoretical capacity of HATAN. Consequently, the HATAN cathode for AZIBs exhibits remarkable capacity, long lifespan, and high‐rate capability. Even at −50 C, an exceptional capacity of 75.4 mAh g−1 and 98% capacity retention over 1500 cycles can be preserved. This study presents valuable insights into the structure design of small molecule organic cathodes for advanced AZIBs which can efficiently operate at −50 °C.

Anti‐freezing electrolyte modification strategies toward low‐temperature aqueous zinc‐ion batteries

AbstractDue to the availability of zinc resources, and reduced security risks, aqueous zinc‐ion batteries (AZIBs) are potential contenders for next‐generation energy storage systems. With the multi‐scene application of AZIBs, the temperature adaptation of electrolytes poses a great challenge. However, the aqueous electrolyte is prone to freezing in sub‐zero environments, which leads to undesirable problems such as undesirable ion transfer and poor electrode/electrolyte interface, resulting in a sharp deterioration of the electrochemical properties of AZIBs in cold conditions and limited practical use of AZIBs. Antifreeze electrolyte modification strategies have gained popularity as effective ways to optimise the low‐temperature behaviour of AZIB. The results of recent studies of electrolyte modification strategies are systematically summarised for low‐temperature AZIBs, focusing on the modification methods, principles, and effects achieved. Firstly, the authors describe the mechanism of failure of AZIBs at low temperatures. Subsequently, the modification strategies of antifreeze electrolytes are summarised, including the utilisation of high salt content, the design of organic electrolytes, the adoption of antifreeze electrolyte additives, and the building of hydrogel electrolytes. Finally, the issues faced by electrolytes at low temperatures are further indicated and suggestions are provided for their future development.

Performances of MnO2 and SnO2 Coated MnO2 as Cathode Materials for Aqueous Rechargeable Zinc-ion Batteries

In this study, the micro-emulsion method was used to create the manganese-based cathode materials MnO2 and MnO2@SnO2. For the use as cathode materials in rechargeable zinc-ion batteries, MnO2 and SnO2 coated MnO2@SnO2 were synthesized. FT-IR, Powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), and UV-visible Spectroscopy were used to characterize the as-prepared materials. Electrochemical impedance spectroscopy (EIS), battery charge-discharge (BCD), and cyclic voltammetry (CV) techniques were used to investigate the electrochemical properties of the prepared cathode materials for aqueous rechargeable zinc-ion batteries (ARZIBs). The CV profiles were measured in the potential range of 2.1-1.0 V at a scan rate of 20 mV/s. A pair of redox peaks can be seen in the cycle of CV curves. Charge/discharge cycles of SnO2 coated MnO2@SnO2 electrodes are higher than those of pristine MnO2. SnO2 coated MnO2@SnO2 electrodes have better initial charge/discharge capacities than pristine MnO2 electrodes, which is a factor to take into account. In the first cycle, SnO2 coated MnO2@SnO2 electrode has a 26% higher charge capacity than the bare MnO2 electrode. The SnO2 coating on MnO2 may be the cause of the enhanced charge and discharge capabilities of MnO2@SnO2. J. of Sci. and Tech. Res. 5(1): 83-92, 2023

Stable Zn metal anode enabled via ferroelectric nanotube arrays

Aqueous zinc-ion batteries are receiving increasing attention owing to their markedly high safety and low cost. However, the uncontrolled zinc dendrite growth and the side reactions at Zn-electrolyte interfaces hinder the practical application of aqueous rechargeable zinc-based batteries. Therefore, regulating the electrode/electrolyte interface to achieve dense zinc deposition is crucial for improving the electrochemical performance of zinc-ion batteries. Herein, ferroelectric composite nanotube arrays (BaTiO3 modified TiO2 nanotubes, TiO2@BaTiO3) are designed and fabricated as the three-dimensional current collector for Zn metal anode. Abundant zincophilic sites on the surface of BaTiO3 induce zinc nucleation, enabling a compact and horizontally-aligned Zn morphology. At external electric field, the depolarization field produced the ferroelectric BaTiO3 layer on the electrode surface can accelerate the dissociation of ZnSO4 and regulate the Zn-ion desolvation process at the interfaces, leading to dendrite-free Zn deposition and less byproducts. As a result, the TiO2@BaTiO3/Zn anode achieves reversible Zn plating/stripping with low overpotential for over 3000 h at 3 mA cm−2 in symmetric cells, and the assembled full battery exhibits a significantly enhanced cycling stability over 1800 cycles at 1 A g−1. Ferroelectric nanotube arrays brings new opportunities for next-generation aqueous zinc-ion batteries.

Understanding the hydrogen and halogen bonds of ionic liquids in regulating ion solvation and dynamic behaviors of aqueous zinc electrolytes

Despite their low cost and intrinsic safety, aqueous rechargeable zinc-ion batteries suffer from rapid performance deterioration originating from parasitic reactions and inhomogeneous deposition on the Zn anode. Halogen bonds share similarities with hydrogen bonds, yet their unique directionality, strength tunability, and hydrophobicity provide a promising approach for enhancing the reversibility of Zn anodes. Herein, a systematic comparison of ionic liquids with different anions, acetate (Ac−) and chloride (Cl−), is performed to explore the non-covalent interactions in regulating ion solvation and dynamic behaviors of electrolytes. Different from the Ac− possessing a strong capacity to form hydrogen bonds with water, the Cl−-water halogen bonds not only enable the structural diffusion of Zn2+ with better diffusion efficiency but also reduce the Zn2+ de-solvation energy barrier to promote uniform Zn nucleation. Consequently, the accelerated ions diffusion and homogeneous Zn deposition work in synergy to ensure high reversibility of Zn anode. These fundamental insights highlight the importance of hydrogen and halogen bonds in determining the dynamics and electrochemical behavior of electrolytes, providing theoretical guidance for the rational design of high-performance electrolytes.

Design and construction of V6O13/C nanorods as high-performance cathode material for aqueous zinc-ion batteries

As a candidate for commercial cathode material of aqueous zinc ion batteries (AZIBs), vanadium-based materials have attracted wide attention due to their unique layered structure and high specific capacity. However, the insertion/extraction process of Zn2+ can easily lead to the volume expansion of vanadium-based materials, resulting in battery failure. In addition, the inherent low conductivity and low diffusion kinetics of vanadium-based materials limiting their further development into high-performance cathode materials. Herein, a novel V6O13/N, O co-doped carbon (V6O13/C) nanorod electrode material has been successfully fabricated as a cathode for AZIBs. The N, O co-doped carbon can significantly improve the conductivity of materials and alleviate the volume change. The nanorod-like structure could enhance the structural stability during the Zn2+ insertion/extraction processes. Moreover, with N, O doped, the electrode can expose more reactive sites which is beneficial for promoting electrochemical processes. With the synergistic effort of the above optimization strategy, the as-obtained electrode delivers excellent long-term cycle stability of 151.7 mAh g−1 at 1 A g−1 after 1000 cycles.

Multifunctional zinc-nickel alloy enabling high-performance aqueous zinc ion batteries

Aqueous zinc ion batteries are considered to be the new type of secondary batteries that have the potential to replace lithium-ion batteries as the most widely used in the future due to their green environment, high specific capacity and abundant zinc resources. However, due to the contact between the zinc anode and electrolyte, the generation of by-products and corrosion phenomena are not completely avoided, which can easily lead to problems such as short cycle life and poor electrochemical performance of the battery. In this study, uniform zinc-nickel alloy (ZnNi) was prepared by melting method. The element nickel has excellent corrosion resistance and is widely used to improve the corrosion resistance of metal alloys, so the introduction of nickel effectively enhances the corrosion resistance of ZnNi alloys. In addition, metallic nickel shows strong attraction to Zn2+, which can promote the uniform distribution and deposition of Zn2+ and inhibit the dendrites growth to prolong the battery life. Notably, the ZnNi-assembled symmetric cell exhibited excellent cycling performance compared with the Zn//Zn cell (100 h), with a cycle life of up to 1000 h at 2 mA cm−2. In addition, the capacity retention rate of the ZnNi//MnO2 full cell was still as high as 90.6 % after 1000 cycles. The preparation of the ZnNi alloy anode may provide a new idea for future alloying strategies.

Trace alcohol ether electrolytes with dual-site hydrogen bonds and modulated solvation structures for ultralong-life zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) are highly regarded for their affordability, stability, safety, and eco-friendliness. Nevertheless, their practical application is hindered by severe side reactions and the formation of zinc (Zn) dendrites on the Zn metal anode surface. In this study, we employ tetrahydrofuran alcohol (THFA), an efficient and cost-effective alcohol ether electrolyte, to mitigate these issues and achieve ultralong-life AZIBs. Theoretical calculations and experimental findings demonstrate that THFA acts as both a hydrogen bonding donor and acceptor, effectively anchoring H2O molecules through dual-site hydrogen bonding. This mechanism restricts the activity of free water molecules. Moreover, the two oxygen (O) atoms in THFA serve as dual solvation sites, enhancing the desolvation kinetics of [Zn(H2O)6]2+ and improving the deposition dynamics of Zn2+ ions. As a result, even trace amounts of THFA significantly suppress adverse reactions and the formation of Zn dendrites, enabling highly reversible Zn metal anodes for ultralong-life AZIBs. Specifically, a Zn-based symmetric cell containing 2 % THFA achieves an ultralong cycle life of 8,800 h at 0.5 mA cm−2/0.5 mAh cm−2, while a Zn//VO2 full cell containing 2 % THFA maintains a remarkable 80.03 % capacity retention rate at 5 A g−1 over 2,000 cycles. This study presents a practical strategy to develop dendrite-free, cost-effective, and highly efficient aqueous energy storage systems by leveraging alcohol ether compounds with dual-site hydrogen bonding capabilities.

Enhancing aqueous zinc-ion energy storage performance with ion-mediating carbon quantum dots-modified separators regulating zinc deposition behavior

Aqueous zinc-ion batteries (AZIBs) hold promising applications owing to their safety, cost-effectiveness, and competitive capacity. However, issues such as zinc dendritic formation and side reactions severely impede their practical viability. Utilizing carbon quantum dots (CQDs) to modify cheap, tenacious, and highly hydrophilic filter paper (FP) as separator effectively improves the electrochemical performance of zinc ion energy storage systems. The structured arrangement of CQDs redistributes zinc ion transport and induces uniform zinc icon deposition, thereby improving zinc ion reaction kinetics. Moreover, the rich functional groups on the surface of CQDs readily form hydrogen bonds with active H2O, further inhibiting corrosion reactions. With the assistance of CQDs, the FP-CQDs separator maintains high ionic conductivity and a high zinc-ion transference number, ensuring dendrite-free and corrosion-resistant operation with high coulombic efficiency and a prolonged lifespan of 1200 h at 1 mA cm−2. Zn//AC hybrid capacitors incorporating FP-CQDs separator demonstrate superior capacity retention compared to those using FP separator alone, with a high capacity retention after 600 cycles at 1 A/g, while Zn//V2O5 full batteries also exhibit excellent cycling stability. Given these findings, this study presents a new composite separator for advanced aqueous zinc-ion energy storage systems.

Inorganic-organic hybrid heterogeneous membrane for zinc protective layers in high-performance aqueous zinc ion batteries

Aqueous zinc-ion Batteries (AZIBs) suffer from stability and performance limitations due to challenges related to the zinc (Zn) metal anode, including hydrogen evolution reaction (HER), metal corrosion, and Zn dendrite formation. To mitigate these issues, researchers are developing innovative coatings and protective layers for Zn anodes, focusing on enhancing ion conductivity, electrochemical inertness, mechanical strength, and processability. Hybrid organic-inorganic heterostructure coating materials with silver nanowires (Ag NWs) encapsulated with Polypyrrole (Ag/PPy) have shown promise in addressing these challenges. The Zn anode coated with Ag/PPy layers and paired with an α-MnO2 cathode, achieved an impressive initial capacity of 302 mAh/g at a current density of 0.5 A/g. Remarkably, it retained a substantial capacity of 283 mAh/g after 300 cycles at a current density of 0.5 A/g, demonstrating a 94 % capacity retention rate. Moreover, the symmetry cell using this anode maintains stable Zn deposition/stripping overpotentials even at a high current density (a rate of 10C) for over 175 h. These findings highlight the potential of Ag/PPy coatings as a viable approach for enhancing the surface chemistry and physical properties of the Zn metal anode, paving the way for a wider use of AZIBs.

Polyaniline/graphene oxide nanocomposite as an innovative cathode for high energy density aqueous zinc-ion batteries

In order to resolve hard processability, poor conductive and lower capacity of polyaniline(PANI), We design and obtain a nanofiber network polyaniline/graphene oxide(PGO) and polyaniline/graphene oxide/manganese dioxide(PMGO) composite cathode. They are synthesized by electrochemical in-situ intercalative polymerization on oxidized graphite paper and assembled with the zinc anode into aqueous Zn-ion batteries(AZIBs). The initial discharged specific capacity of the PGO cathode is 224 mAh·g-1, and it is lower than that of the PMGO electrode when it discharges at 200mA·g-1. However, the capacity can reach 345 mAh·g-1 with better stability and reversibility compared to the PMGO under the same discharge/charge conditions. Characterization analysis and electrochemical studies show that the PGO composite cathode provides a large specific surface and charge/discharge channel, which optimizes the electrochemical performance of the battery. We also propose a new energy storage mechanism for intercalating PANI into graphene oxide(GO) layers to construct a nano-three-dimensional(3D) network for AZIBs and a proton pool with a hydrogen bond network of the PGO electrode. It is profitable for hindering the polarization, facilitating the electrode reaction, and enhancing the capacity and stability. For these reasons, the storage performance of the PGO electrode is superior to the polyaniline cathode reported at present.

Polypyrrole functionalized cellulose/polypropylene composite membrane with zinc inducing and dendrite resistance for robust zinc-ion batteries

Dendrite growth and subsequent membrane puncture stemming from uneven deposition of zinc ions pose a significant challenge for aqueous zinc ion batteries (AZIBs). Herein a polypyrrole functionalized cellulose/polypropylene (PPy-cellulose/PP) composite membrane with promising zinc inducing and dendrite resistance was rationally designed through an in-situ polymerization strategy to enable robust zinc-ion batteries. Experimental data and theoretical simulations reveal that a continuous conducting network, constructed by PPy nanoparticles, could homogenize the electric field and reduce the interfacial resistance of zinc anode. Moreover, the zincophilic nitrogen-containing functional groups in PPy induced the migration and deposition of zinc ions uniformly. The combination of polypropylene laminate enhanced the puncture resistance and mechanical strength of the composite membranes. Consequently, Zn||Zn symmetric cell assembled with the PPy-cellulose/PP composite membrane exhibited stable cycling performance over 2000 h at 0.5 mA cm−2/0.5 mAh cm−2. Further verification was conducted on the practical application of PPy-cellulose/PP membranes in Zn||MnO2 full cells and Zn||AC capacitors. Notably, a high capacity retention of 89.6 % was achieved for the Zn||AC capacitor after 10,000 cycles at 1 A g−1. The new design of PPy functionalized cellulose/polypropylene membranes provides a valuable protocol to stabilize zinc anodes for zinc-ion batteries.

Converting a low-cost industrial polymer into organic cathodes for high mass-loading aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) using organic cathodes have emerged as a sustainable energy storage technology benefitting from high safety, low cost, and abundant feedstocks. However, most organic cathodes are n-type polyaromatic compounds and conjugated polymers, which require sophisticated synthesis, provide a low operational voltage and slow Zn2+ diffusion kinetics. Herein, we report access to p-type radical polymer cathodes from a commercially available poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) polymer. The modification of poly(MVE-alt-MA) with 4-amino-TEMPO produces radical polymers (PTEMPO) that are easily scalable to tens of grams. The corresponding polymer AZIBs deliver a capacity of 92 mAh g-1 at 10 C with 95 % capacity retention over 1000 cycles. Importantly, the electrode composites and battery assembly procedure are optimised so that no fluoro-containing electrolytes and binders are needed, and cheap carbon additives can be used. We assemble the Swagelok batteries, small pouch, and large pouch batteries with a high mass-loading of 7.8 to 50 mg cm-2, demonstrating nearly 100 % Coulombic efficiency. The pouch battery with 0.8–0.9 g of active polymer displayed a 60-mAh capacity with 1.5 V operational voltage. This work paves the way for simple and practical implementation of polymer AZIBs for real-world applications.

Fe doping 1T phase MoS2 with enhanced zinc-ion storage ability and durability for high-performance aqueous zinc-ion batteries

Fe doping 1T phase MoS2 with enhanced zinc-ion storage ability and durability for high-performance aqueous zinc-ion batteries

Introducing PANI into a Manganese-Based Cathode Material to Improve the Energy Storage Performance of Aqueous Zinc-Ion Batteries by Generating Dual Redox Reactions

Introducing PANI into a Manganese-Based Cathode Material to Improve the Energy Storage Performance of Aqueous Zinc-Ion Batteries by Generating Dual Redox Reactions

Zn-doped MnCO3 as cathode material for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs), known for their high discharge capacity, low cost, and relatively low environmental impact, are a promising alternative for advanced energy storage. The exploration of novel electrode materials and the reaction mechanisms in AZIBs have garnered considerable attention. MnCO3, as an electrode material, is known for its safety, nontoxic nature, and widespread availability as a raw material. Nevertheless several constraints limit the use of MnCO3 cathodes, including short lifespan and reduced electrical conductivity. To resolve these shortcomings, compounds containing Zn, Co and Ni elements were added to improve the properties of the MnCO3 material. The Zn doped MnCO3 (MnCO3–Zn-0.0015 M) was successful synthesized by solvothermal, which presents a special microstructure of spherical shell. Not only does the spherical microstructure of the shell enhance the packing density, but the pore configuration within the shell layer also facilitates the insertion and extraction of Zn2+. The MnCO3–Zn-0.0015 M material, operating at a current density of 0.1 A g−1, exhibited an impressive discharge capacity of 120.4 mAh∙g−1 along with remarkable rate performance. The cathode sustained 75.29 % of its capacity following 1000th cycles at current density of 1.0 A g−1. Considering these results, the MnCO3–Zn-0.0015 M material developed in this study opens a novel avenue for optimizing the use of manganese compounds in aqueous zinc-ion batteries.

Mn2+-Modified Ammonium Vanadate as High Rate and Long Cycle Life Cathode for Aqueous Zinc Ion Batteries

Mn²⁺-Modified Ammonium Vanadate as High Rate and Long Cycle Life Cathode for Aqueous Zinc Ion Batteries

Highly reversible Zn anode by guiding uniform Zn deposition through LiF protective layer

Deep-seated issues such as ineluctable dendrite deposition and parasitic reaction of Zn anode pose a major obstacle to the commercialization of aqueous zinc ion batteries (AZIBs). Herein, we proposed LiF as a solid-electrolyte interphase for highly reversible Zn anode. Combining experimental analyses and theoretical simulation calculations, the electronegative fluorine atoms could provide uniform zincophilic nucleation sites to regulate Zn deposition behavior. Additionally, a ZnF2 layer with outstanding Zn2+ conductive can be formed insitu thus further shielding bulk water molecules and expediting the Zn2+ transfer kinetics. Therefore, the LiF@Zn symmetric cells manifest long-cycling stability with 650 h at 1.0 mA/cm2 and 1.0 mAh/cm2 and 1000 h at 2.0 mA/cm2 and 1.0 mAh/cm2. Meanwhile, the rate performance of Zn//MnO2 and Zn//NH4V4O10 full cells are also enhanced by the LiF coating. This work provides a horizon for the design of artificial protective layer and promotes the large-scale practical development of AZIBs.