High-performance Zinc-ion Batteries Research Articles

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 the deep eutectic electrolyte (DEE) into the nanochannels of the 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 a high ionic conductivity of 3.13 × 10-4 S cm-1 at room temperature, a low activation energy of 0.12 eV, and a high Zn2+ transference number of 0.76. 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.

High Performance Aqueous Zinc-Ion Batteries Developed by PANI Intercalation Strategy and Separator Engineering.

Aqueous zinc-ion batteries (ZIBs) have attracted burgeoning attention and emerged as prospective alternatives for scalable energy storage applications due to their unique merits such as high volumetric capacity, low cost, environmentally friendly, and reliable safety. Nevertheless, current ZIBs still suffer from some thorny issues, including low intrinsic electron conductivity, poor reversibility, zinc anode dendrites, and side reactions. Herein, conductive polyaniline (PANI) is intercalated as a pillar into the hydrated V2O5 (PAVO) to stabilize the structure of the cathode material. Meanwhile, graphene oxide (GO) was modified onto the glass fiber (GF) membrane through simple electrospinning and laser reduction methods to inhibit dendrite growth. As a result, the prepared cells present excellent electrochemical performance with enhanced specific capacity (362 mAh g-1 at 0.1 A g-1), significant rate capability (280 mAh g-1 at 10 A g-1), and admirable cycling stability (74% capacity retention after 4800 cycles at 5 A g-1). These findings provide key insights into the development of high-performance zinc-ion batteries.

High-performance zinc-ion hydrogel electrolytes based on molecular-level hybridization of PVA with polymer quantum dots

Aqueous zinc ion batteries have received widespread attention. However, the growth of zinc dendrites and hydrogen evolution reaction generation seriously hinder the practical application of zinc ion batteries. Herein, it is reported that a multifunctional dendrites-free low-temperature PVA-based gel electrolyte by introducing negatively charged polymer carbon quantum dots (QDs) and the organic antifreeze dimethyl sulfoxide (DMSO) into it. The QDs carrying a large number of functional groups on the surface can effectively adsorb Zn2+, eliminating the “tip effect”, and inducing the uniform deposition of Zn2+ and the formation of a dendrites-free structure. Meanwhile, the solvation structure of adsorbed Zn2+ can be controlled by charged groups to reduce the generation of side reactions, thus obtaining high-performance zinc ion batteries. The Zn/polyaniline (PANi) full battery can be stably cycled more than 1000 times at –20 °C, and the design of this gel electrolyte can provide good feasibility for safe, stable, and flexible energy storage devices.

Ammonium vanadate doped by transition bivalent metal ions for high-performance zinc-ion batteries

Vanadium-based materials are considered as promising cathode materials in aqueous zinc-ion (Zn2+) batteries (AZIBs) because of their abundant valence states and adjustable ion diffusion channels. However, the slow kinetics of the Zn2+ intercalation and the instability of the layered structure during long cycle are the bottlenecks restricting their further development. In this paper, the transition bivalent manganese ions (Mn2+) are introduced into ammonium vanadate (NH4V4O10) to partly replace the NH4+ ions to prepare a high-performance AZIB cathode. After doping transition bivalent Mn2+, the interlayer spacing of NH4V4O10 is enlarged, providing a broadened channel for the diffusion of Zn2+ accordingly. The results reveal that the electrode with the optimal doping quantity has a very high discharge capacity (539.4 mAh/g at 0.2 A/g) and excellent cyclic stability (85.3 % retention of the initial capacity after 3000 cycles at 5 A/g). A highly competitive energy density of 378 Wh kg−1 at 362 W kg−1 is delivered by the corresponding AZIB. Moreover, this method is a general and effective strategy for developing high-performance AZIB cathode materials, as demonstrated by the consistent crystal structure and stable cycling properties for NH4V4O10 doped with other transition bivalent metal cations

Regulation of Zn2+ solvation shell by a novel N-methylacetamide based eutectic electrolyte toward high-performance zinc-ion batteries

Aqueous Zn-ion batteries (AZIBs) have been regarded as promising alternatives to Li-ion batteries due to their advantages, such as low cost, high safety, and environmental friendliness. However, AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling. To address these issues, a new eutectic electrolyte based on Zn(ClO4)2·6H2O-N-methylacetamide (ZN) is proposed in this work. Compared with aqueous electrolyte, the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn2+, effectively suppressing zinc dendrite growth and side reactions. As a result, the Zn//NH4V4O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g−1. Therefore, this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn2+ solvation structure on the cycle stability, contributing to the exploration of novel electrolytes for high-performance AZIBs.

Room temperature synthesis of the Co-doped δ-MnO2 cathode for high-performance zinc-ion batteries

Manganese oxide (MnO2) is considered as one of the most hopeful cathode materials for aqueous zinc ion batteries (ZIBs) thanks to its nontoxicity, high voltage, and low cost. However, its practical application in ZIBs is hindered by its slow reaction kinetics and poor structural stability. The heteroatom-doped δ-MnO2 prepared by hydrothermal reaction can overcome the inherent defects of δ-MnO2 and significantly improve the performance of ZIBs. Nevertheless, hydrothermal method requires high temperature and high pressure processes, which will increase production costs and energy consumption. To address this issue, herein, the Co-doped δ-MnO2 (Co-δ-MnO2) cathode is synthesized by a one-step route through stirring the solution of MnCl2, CoCl2, and H2O2 in the presence of tetramethylammonium cations at room temperature. The Co-δ-MnO2 cathode displays outstanding zinc ion storage performance with a high specific capacity of 408.9 mAh g−1 at the current density of 0.1 A g−1, a superior rate capability of 232.7 mAh g−1 at 3.0 A g−1, a high energy density of 554.9 Wh kg−1 at 135.2 W kg−1, and good cyclability with a capacity retention rate of 77.8 % after 1000 cycles. Ex-situ tests reveal that the charge storage mechanism of the Co-δ-MnO2 cathode is H+/Zn2+ co-insertion/extraction.

Green proton reservoirs of PANI for disposable high-performance zinc-ion batteries

Rechargeable batteries are widely used to power various electronic devices. However, their toxic components cause serious environmental pollution when discarded. To date, the toxicity characteristics of rechargeable batteries do not meet the requirements for implantable medical devices. Herein, we report an organic cathode using tannin-protonated polyaniline (Tannin-PANI). As “green proton reservoirs”, plant-derived tannins continuously supply H+ to maintain high electrochemical activity and excellent reversibility of Tannin-PANI. Hence, the Tannin-PANI-based cathode exhibited a capacity of 92.8 mAh g−1 after 1500 cycles at 10.0 A g−1. Moreover, it demonstrated long-term stability for more than 10,000 cycles in bacterial cellulose-based gel electrolyte. Further, the Tannin-PANI-based cathode showed excellent in vitro biocompatibility, and a pouch cell composed of the Tannin-PANI electrode had no significant impact on plant growth. This study provides further insights into the design of implantable batteries with high stability, excellent biocompatibility, and high environmental compatibility.

Ethylene Glycol-Choline Chloride Based Hydrated Deep Eutectic Electrolytes Enabled High-Performance Zinc-Ion Battery.

Aqueous rechargeable zinc-ion batteries (ARZIBs) are considered as an emerging energy storage technology owing to their low cost, inherent safety, and reasonable energy density. However, significant challenges associated with electrodes, and aqueous electrolytes restrict their rapid development. Herein, ethylene glycol-choline chloride (Eg-ChCl) based hydrated deep-eutectic electrolytes (HDEEs) are proposed for RZIBs. Also, a novel V10O24·nH2O@rGO composite is prepared and investigated in combination with HDEEs. The formulated HDEEs, particularly the composition of 1ml of EG, 0.5g of ChCl, 4ml of H2O, and 2M ZnTFS (1-0.5-4-2 HDEE), not only exhibit the lowest viscosity, highest Zn2+ conductivity (20.38mScm-1), and the highest zinc (Zn) transference number (t+ = 0.937), but also provide a wide electrochemical stability window (>3.2V vs ZnǁZn2+) and enabledendrite-free Zn stripping/plating cycling over 1000 hours. The resulting ZnǁV10O24·nH2O@rGO cellwith 1-0.5-4-2 HDEE manifests high reversible capacity of ≈365mAhg-1 at 0.1Ag-1, high rate-performance (delivered ≈365/223mAhg-1 at 0.1/10mAg-1) and enhanced cycling performance (≈63.10% capacity retention in the 4000th cycle at 10Ag-1). Furthermore, 1-0.5-4-2 HDEE support feasible Zn-ion storage performance across a wide temperature range (0-80°C) FInally, a ZnǁV10O24·nH2O@rGO pouch-cell prototype fabricated with 1-0.5-4-2 HDEE demonstrates good flexibility, safety, and durability.

Stable Zinc Anode Facilitated by Regenerated Silk Fibroin-modified Hydrogel Protective Layer.

Inherent dendrite growth and side reactions of zinc anode caused by its unstable interface in aqueous electrolytes severely limit the practical applications of zinc-ion batteries (ZIBs). To overcome these challenges, a protective layer for Zn anode inspired by cytomembrane structure is developed with PVA as framework and silk fibroin gel suspension (SFs) as modifier. This PVA/SFs gel-like layer exerts similar to the solid electrolyte interphase, optimizing the anode-electrolyte interface and Zn2+ solvation structure. Through interface improvement, controlled Zn2+ migration/diffusion, and desolvation, this buffer layer effectively inhibits dendrite growth and side reactions. The additional SFs provide functional improvement and better interaction with PVA by abundant functional groups, achieving a robust and durable Zn anode with high reversibility. Thus, the PVA/SFs@Zn symmetric cell exhibits an ultra-long lifespan of 3150 h compared to bare Zn (182 h) at 1.0 mAh cm-2-1.0 mAh cm-2, and excellent reversibility with an average Coulombic efficiency of 99.04% under a large plating capacity for 800 cycles. Moreover, the PVA/SFs@Zn||PANI/CC full cells maintain over 20 000 cycles with over 80% capacity retention under harsh conditions at 5 and 10 A g-1. This SF-modified protective layer for Zn anode suggests a promising strategy for reliable and high-performance ZIBs.

One-Stone-for-Two-Birds Strategy for VSe2 to Enable High Capacity and Long-Life Zinc Storage.

Based on a specific zinc storage mechanism and excellent electronic conductivity, transition metal dichalcogenides, represented by vanadium diselenide, are widely used in aqueous zinc-ion battery (AZIB) energy storage systems. However, most vanadium diselenide cathode materials are presently limited by low specific capacity and poor cycling life. Herein, a simple hydrothermal process has been proposed for obtaining a vanadium diselenide cathode for an AZIB. The interaction of defects and crystal planes enhances zinc storage capacity and reduces the migration energy barrier. Moreover, abundant lamellar structure greatly increases reaction sites and alleviates volume expansion during the electrochemical process. Thus, the as-obtained vanadium diselenide AZIB exhibits an excellent reversible specific capacity of 377 mAh g-1 at 1 A g-1, and ultralong cycle stability of 291 mAh g-1 after 3200 cycles, with a nearly negligible capacity loss. This one-stone-for-two-birds strategy would be expected to be applied to large-scale synthesis of a high-performance zinc-ion battery cathode in the future.

Metal ions and organic molecule co-intercalated vanadium oxide cathode for high-performance zinc-ion batteries

Vanadium oxide is a highly promising cathode material for zinc-ion batteries due to its unique layered structure and high theoretical capacity. However, the material dissolution and structural collapse severely limit the development of zinc-ion batteries. Herein, inorganic metal ions (Mg2+) and organic polymer molecules (PANI) were introduced into the hydrated vanadium oxide interlayer in this paper. Mg2+ ions enhance the conductivity of the cathode and widen the interlayer spacing. Meanwhile, PANI serves to cushion the structural expansion resulting from ion embedding and stabilize the layered structure. Additionally, PANI actively participates in the charging and discharging process, thereby enhancing the diffusion rate of Zn2+. Thanks to the synergistic effect of Mg2+ and PANI, the MgVOH/PANI cathode exhibits a discharge capacity of 412 mAh·g−1 at 0.1 A g−1 and retains 93% of its capacity after 1000 cycles at a current density of 2A·g−1. This synergistic strategy of combining organic molecules and inorganic ions can provide a reference for improving the kinetic and structural stability of other aqueous battery cathodes.

In Situ Constructing Metal-Organic Complex Interface Layer Using Biomolecule Enabling Stabilize Zn Anode.

Aqueous zinc-ion batteries (ZIBs) are considered as a promising candidate for next-generation large-scale energy storage due to their high safety, low cost, and eco-friendliness. Unfortunately, commercialization of ZIBs is severely hindered owing to rampant dendrite growth and detrimental side reactions on the Zn anode. Herein, inspired by the metal-organic complex interphase strategy, the authors apply adenosine triphosphate (ATP) to in situ construct a multifunctional film on the metal Zn surface (marked as ATP@Zn) by a facile etching method. The ATP-induced interfacial layer enhances lipophilicity, promoting uniform Zn2+ flux and further homogenizing Zn deposition. Meanwhile, the functional interlayer improves the anticorrosion ability of the Zn anode, effectively suppressing corrosion and hydrogen evolution. Consequently, the as-prepared ATP@Zn anode in the symmetric cell exhibits eminent plating/stripping reversibility for over 2800h at 5.0mA cm-2 and 1 mAh cm-2. Furthermore, the assembled ATP@Zn||MnO2 full cells are investigated to evaluate practical feasibilities. This work provides an efficient and simple strategy to prepare stabilized Zn anode toward high-performance ZIBs.

Polypyrrole pre-intercalation engineering-induced NH4+ removal in tunnel ammonium vanadate toward high-performance zinc ion batteries

Ammonium vanadate with stable bi-layered structure and superior mass-specific capacity have emerged as competitive cathode materials for aqueous rechargeable zinc-ion batteries (AZIBs). Nevertheless, fragile NH…O bonds and too strong electrostatic interaction by virtue of excessive NH4+ will lead to sluggish Zn2+ ion mobility, further largely affects the electro-chemical performance of ammonium vanadate in AZIBs. The present work incorporates polypyrrole (PPy) to partially replace NH4+ in NH4V4O10 (NVO), resulting in the significantly enlarged interlayers (from 10.1 to 11.9 Å), remarkable electronic conductivity, increased oxygen vacancies and reinforced layered structure. The partial removal of NH4+ will alleviate the irreversible deammoniation to protect the laminate structures from collapse during ion insertion/extraction. The expanded interlayer spacing and the increased oxygen vacancies by the virtue of the introduction of polypyrrole improve the ionic diffusion, enabling exceptional rate performance of NH4V4O10. As expected, the resulting polypyrrole intercalated ammonium vanadate (NVOY) presents a superior discharge capacity of 431.9 mAh g−1 at 0.5 A g−1 and remarkable cycling stability of 219.1 mAh g−1 at 20 A g−1 with 78 % capacity retention after 1500 cycles. The in-situ electrochemical impedance spectroscopy (EIS), in-situ X-ray diffraction (XRD), ex-situ X-ray photoelectron spectroscopy (XPS) and ex-situ high resolution transmission electron microscopy (HR-TEM) analysis investigate a highly reversible intercalation Zn-storage mechanism, and the enhanced the redox kinetics are related to the combined effect of interlayer regulation, high electronic conductivity and oxygen defect engineering by partial substitution NH4+ of PPy incorporation.

Three-dimensional Ordered Macroporous Flexible Electrode Design toward High-Performance Zinc-Ion Batteries.

Flexible zinc-ion batteries (ZIBs) have been considered to have huge potential in portable and wearable electronics due to their high safety, cost efficiency, and considerable energy density. Therein, the design and construction of flexible electrodes significantly determine the performance and lifespan of flexible battery devices. In this work, an ultrathin flexible three-dimensional ordered macroporous (3DOM) Sn@Zn anode (60 μm in thickness) is presented to relieve dendrite growth and expand the lifespan of flexible ZIBs. The 3DOM structure can ensure uniform electric field distribution, guide oriented zinc plating/stripping, and extend the lifespan of anodes. The rich zincophilic Sn sites on the electrode surface significantly facilitate Zn nucleation. Accordingly, a lowered nucleation overpotential of 8.9 mV and an ultralong cycling performance of 2400 h at 0.1 mA cm-2 and 0.1 mAh cm-2 are achieved in symmetric cells, and the 3DOM Sn@Zn anode can also operate in deep cycling for over 200 h at 10 mA cm-2 and 5 mAh cm-2. A flexible 3DOM MnO2/Ni cathode with a high structural stability and a high mass-specific capacity is fabricated to match with the anode to form a flexible ZIB with a total thickness of 200 μm. The flexible device delivers a high volumetric energy density of 11.76 mWh cm-3 at 100 mA gMnO2-1 and a high average open-circuit voltage of 1.5 V and exhibits high-performance power supply under deformation in practical application scenarios. This work may shed some light on the design and fabrication of flexible energy-storage devices.

Steering in-situ low-voltage phase transition from spinel to layered cathode for high-performance zinc-ion batteries

ZnV2O4, as a ternary transition metal oxides (TOMs), has garnered significant attention as a high-performance cathode for zinc-ion batteries (ZIBs) primarily due to its high theoretical capacity and abundance. However, its densely-packed lattice structure and strong coulomb interactions with the guest Zn2+ severely restrict the exposure of active sites and impede the diffusion kinetics. Herein, we propose an innovative in-situ low-voltage phase transition strategy and successfully trigger thorough phase transition of spinel-structured ZnV2O4 to layered-structured Zn3(OH)2V2O7⋅2H2O (ZnVOHNSs). In-depth mechanism analysis reveals that a thorough and efficient transition reaction necessitates meticulous control of the external driving force, reaction kinetics, and the reactant. The activated ZnVOHNSs with large lattice spacing and abundant oxygen vacancies provides an unobstructed pathway for accelerated ion diffusion and abundant exposed active sites for ions storage. Moreover, the inherent structure stability of ZnVOHNSs ensures exceptional reaction stability and reversibility during the Zn2+ intercalation/deintercalation process. Benefiting from these merits, the activated ZnVOHNSs cathode exhibits high reversible capacity and extraordinary rate capability (achieving 369 and 233 mAh g−1 at 0.1 and 20 A g−1, respectively), which exceeds most reported cathode materials in ZIBs. This work unveils the critical phase transition mechanism and offers insight into electrode design for advanced batteries.

Fast and efficient in-situ construction of low crystalline PEDOT-intercalated V2O5 nanosheets for high-performance zinc-ion battery

Layered vanadium oxides have recently emerged as ideal cathode materials for aqueous zinc-ion batteries (ZIBs) due to their high theoretical capacity and low cost. However, their inherent shortages of narrow interlayer distance and poor electric conductivity cause sluggish reaction kinetics and low structure stability, leading to battery performance deterioration. Herein, we developed a novel strategy to simultaneously realize the intercalation of conductive polymer into V2O5 polyhedrons and exfoliation of the V2O5 into ultrathin nanosheets. The strategy is realized by in-situ polymerization of 3,4-ethylene-dioxythiophene (EDOT) monomers in the interlayer of the V2O5 polyhedrons that were derived from the annealing of vanadium-based metal–organic frameworks (MIL-100(V)) in air. The MIL-100-derived V2O5 polyhedrons assembled into porous microspheres (PVO) with abundant porosity and small particle size, which facilitates the penetration of EDOT molecules into the interior of the PVO during in-situ intercalation and polymerization processes, ultimately leading to the V2O5 polyhedrons exfoliating into ultrathin nanosheets. The uniform poly(3,4-ethylene-dioxythiophene) (PEDOT) layer and abundant oxygen vacancies in PVO@PEDOT nanosheets can accelerate the diffusion of electrons and zinc ions, which are evidenced by dynamic analysis, ex-situ characterizations, and density functional theory (DFT) calculations, revealing the synergetic effect of PEDOT and oxygen vacancies. Therefore, the PVO@PEDOT cathode exhibits high specific capacity (403.7 mAh g-1 at 0.2 A g-1), superior rate capability (312.8 mAh g-1 at 10 A g-1), and long-term stability (92.8% of the initial capacity remained after 3000 cycles), which is superior to the majority of ion intercalation improved V2O5.

Recent Advances in Graphene-Based Materials for Zinc-Ion Batteries.

Zinc-ion batteries (ZIBs) are a promising alternative for large-scale energy storage due to their advantages of environmental protection, low cost, and intrinsic safety. However, the utilization of their full potential is still hindered by the sluggish electrode reaction kinetics, poor structural stability, severe Zn dendrite growth, and narrow electrochemical stability window of the whole battery. Graphene-based materials with excellent physicochemical properties hold great promise for addressing the above challenges foe ZIBs. In this review, the energy storage mechanisms and challenges faced by ZIBs are first discussed. Key issues and recent progress in design strategies for graphene-based materials in optimizing the electrochemical performance of ZIBs (anode, cathode, electrolyte, separator and current collector) are then discussed. Finally, some potential challenges and future research directions of graphene-based materials in high-performance ZIBs are proposed for practical applications.

In situ prepared amorphous VOH-Polyaniline@Carbon cloth as cathodes for high performance zinc ion batteries

Vanadium-based compounds are promising cathode materials for aqueous zinc ion batteries (AZIBs) while suffering from notorious poor conductivity and structural instability, leading to severe performance degradation.Herein, we grew polyaniline intercalated VOH nanoarrays on conductive carbon cloth (VOH-PANI@CC) via one-step electrochemical deposition route. Owing to the advantageous nature of amorphous structure of VOH, good conductivity of PANI and the strong synergistic effect between two components, the VOH-PANI@CC free-standing electrodes showed abundant ion diffusion paths, plentiful ion storage sites and high conductivity. The electrode thus achieves an initial charging capacity up to 500 mAh g−1 at 0.1 A g−1 and can still maintain 117.4 mAh g−1 for 500 cycles at 0.5 A g−1. Furthermore, ex-situ XRD and XPS studies revealed the zinc storage process of VOH-PANI@CC and underlying mechanism of the enhanced performance. This work provides a universality design strategy for designing advanced high-performance V-based cathodes for AZIBs.

Constructing ultra-stable and high-performance zinc-ion batteries through Mn doped vanadium oxide nanobelt cathode

In this study, analysis of density functional theory calculations shows that the Mn2+ doping between VO6 layers functions as a “structural pillar,” and Mn2+ in the layer can boost the conductivity of VO2·0.2H2O and hold high specific capacity.

An integrated Janus hydrogel with different hydrophilicities and gradient pore structures for high-performance zinc-ion batteries

A pioneering achievement is made in developing integrated Janus hydrogel electrolytes featuring gradient pores in cross-section and varying hydrophilicities on surfaces. This novel hydrogel enables Zn-ion batteries to exhibit excellent performance.