氧化锰纳米球的合成方法及水系锌电性能；高锰酸钾和柠檬酸制氧化锰纳米球

Zinc ion stabilized MnO2 nanospheres with a flower-like morphology and mesoporous texture are prepared, and they show high specific capacity and superior cycling stability for Zn-ion batteries.

… Manganese-based materials are widely employed as electrode materials for batteries, with … The MnO 2 nanospheres with a tunnel structure (α-MnO 2 NSs) were synthesized through a …

… Manganese-based oxides (MNO) are commonly employed as cathodes in aqueous zinc-ion batteries (AZIBs) … However, the Jahn–Teller (JT) effect of high-spin Mn 3+ can induce Mn 2+ …

… prepared by a simple synthesis to overcome manganese dissolution during electrochemical reaction with zinc and thereby improve the cycling properties of aqueous zinc-ion batteries. …

… The development of zinc-ion storage cathode materials for aqueous zinc-ion batteries (AZIBs) … Iron-doped alpha-manganese dioxide (α-MnO 2 ) nanocomposites were achieved in this …

Aqueous zinc‐ion batteries (AZIBs) are regarded as promising electrochemical energy storage devices owing to its low cost, intrinsic safety, abundant zinc reserves, and ideal specific capacity. Compared with other cathode materials, manganese dioxide with high voltage, environmental protection, and high theoretical specific capacity receives considerable attention. However, the problems of structural instability, manganese dissolution, and poor electrical conductivity make the exploration of high‐performance manganese dioxide still a great challenge and impede its practical applications. Besides, zinc storage mechanisms involved are complex and somewhat controversial. To address these issues, tremendous efforts, such as surface engineering, heteroatoms doping, defect engineering, electrolyte modification, and some advanced characterization technologies, have been devoted to improving its electrochemical performance and illustrating zinc storage mechanism. In this review, we particularly focus on the classification of manganese dioxide based on crystal structures, zinc ions storage mechanisms, the existing challenges, and corresponding optimization strategies as well as structure–performance relationship. In the final section, the application perspectives of manganese oxide cathode materials in AZIBs are prospected.

Abstract Aqueous rechargeable zinc-manganese dioxide batteries have attracted extensive attention due to their high energy density, low cost, and environmental friendliness. However, the crystalline MnO2 polymorphs suffer from substantial phase changes upon cycling, leading to structural collapse and poor long-term cycling performance. Here, a highly reversible amorphous manganese dioxide with structural defects is reported as the cathode for aqueous rechargeable zinc-ion batteries (ARZIBs). Because of the existence of the abundant structural defects and intrinsic isotropic nature, the A-MnO2-δ exhibits significant pseudocapacitive contribution and facilitated reaction kinetics. As expected, the A-MnO2-δ delivers a high specific capacity of 301 mAh g−1 at 100 mA g−1 and long cycle-life with a capacity retention of 78% over 1000 cycles at 1 A g−1, which is better than its crystalline counterparts. In addition, a reversible H+ and Zn2+ two-step insertion storage mechanism of the A-MnO2-δ electrode is demonstrated. This study not only suggests that amorphous manganese dioxide can serve as a stable cathode for ARZIBs but also provides significant guidance to realize other high-capacity and long-lifespan aqueous batteries by using the amorphous materials.

… ionic diffusion and manganese dissolution, leading to … battery performances. A binder-free cathode featuring nitrogen-doped carbon (NC) encapsulated manganese oxide nanoparticles …

… and Mn distribute on the short nanorods and nanoparticles and … Apart from manganese dioxide, other manganese oxides may … Recently, some manganese oxides have been reported to …

… Aqueous zinc-ion batteries have been regarded as owning substantial potential for … However, the long-term service lifespan and high-capacity retention of aqueous zinc-ion batteries are …

Manganese (Mn) oxides are promising cathode materials for rechargeable aqueous Zn‐ion batteries. However, the Mn dissolution in weakly acidic electrolytes always hinders the development of better aqueous Zn–Mn batteries. Herein, a hydroxylated manganese oxide cathode material (H‐MnO2) is fabricated using an electrochemical method for stable aqueous Zn–Mn batteries without relying on the Mn2+ electrolyte additives. The partial hydroxylation of the oxides leads to charge redistribution of the material, changing the reaction thermodynamics and kinetics. Theoretical simulation suggests that the hydroxylation of manganese oxide promotes both Zn2+ adsorption thermodynamics and diffusion kinetics on the surface of H‐MnO2 but weakens the interaction between H+ and the electrode. Therefore, Zn2+ ions can be more reactive with the hydroxylated manganese oxide than H+ ions. Experimental results show that the Zn2+ insertion mechanism dominates the charge storage process of H‐MnO2, and the H+‐induced Mn dissolution reaction is effectively alleviated. Importantly, H‐MnO2 exhibits good cycling stability with 95% capacity retention over 5000 cycles at the current density of 3.8 A g−1 in the ZnSO4 electrolyte, outperforming the state‐of‐the‐art aqueous Zn–Mn batteries, even those with Mn2+ electrolyte additives. The findings provide new insights for designing stable manganese oxide cathodes in aqueous Zn–Mn batteries.

… (AZIBs… permanganate (KMnO 4 ), and different molar amounts (0.5, 1, 2) of copper nitrate (Cu(NO 3 ) 2 ) were dissolved in 70 mL deionized water. Subsequently, 3 mL of 0.1M citric acid …

Flowerlike manganese oxide microspheres and cryptomelane-type manganese oxide nanobelts were selectively synthesized by a simple decomposition of KMnO4 under mild hydrothermal conditions without using template or cross-linking reagents. The effect of varying the hydrothermal times and temperatures on the nanostructure, morphology, compositional, and electrochemical properties of the obtained manganese oxides was investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies showed that the flowerlike manganese oxide microspheres could be obtained at relatively low hydrothermal temperatures, while high hydrothermal temperatures were favorable for the formation of cryptomelane-type manganese oxide nanobelts. A morphology and crystalline evolution of the nanostructures was observed as the hydrothermal temperature was increased from 180 to 240 °C. On the basis of changing the temperatures and hydrothermal reaction times, the formation mechanism of cryptomelane-type manganese oxide nanobelts is discussed. Cyclic voltammetry (CV) was used to evaluate the electrochemical properties of the obtained manganese oxide nanostructures, and the results show that the electrochemical properties depend on their shape and crystalline structure. This easily controllable, template-free, and environmentally friendly method has the potential for being used in syntheses of manganese oxide nanomaterials with uniform morphologies and crystal structures.

… the electrochemical properties, especially for electrocatalytic reduction characteristics. Full … surface area on the electrochemical properties of manganese oxides with different structures …

… In the battery manufacturing process, owing to its suitable electrochemical properties, manganese dioxide (MnO 2 ) is progressively used. It could take up the role of an oxidant as well …

… This work provides a comprehensive understanding on manganese oxide re-crystallization process, and present phase tuning tools to obtain pure manganese oxide phase with …

… -β-MnO₂) nanospheres are synthesized via a hydrothermal … into amorphous-like nanospheres with a significantly … Therefore, as a cathode material for aqueous zinc-ion battery…

… (named as HMS) and evaluate its potential as a cathode material for ZIBs. The three-dimensional (… This work provides a novel approach for developing high-performance aqueous ZIBs. …

Rechargeable aqueous zinc‐ion batteries (AZIBs) have attracted extensive attention and are considered to be promising energy storage devices, owing to their low cost, eco‐friendliness, and high security. However, insufficient energy density has become the bottleneck for practical applications, which is greatly influenced by their cathodes and makes the exploration of high‐performance cathodes still a great challenge. This review underscores the recent advances in the rational design of advanced cathodes for AZIBs. The review starts with a brief summary and evaluation of cathode material systems, as well as the introduction of proposed storage mechanisms. Then, fundamental problems associated with ion and electron transport behaviors inside the electrode will be pointed out and followed by potential solutions, aiming to reveal the correlation between cathode architecture design and efficient transport kinetics through structural engineering. Afterward, the structural engineering for designing advanced cathodes, including interlayer intercalation, doping effects, defect engineering, surface coatings, composite formation, and morphology control, are summarized and discussed from the view of experimental and theoretical results. Finally, the critical research challenges and future perspectives on advanced cathode materials as well as the potential developing directions of AZIBs are also given.

Aqueous zinc ion batteries (AZIBs) are regarded as promising candidates for large‐scale energy storage due to their intrinsic safety, environmental friendliness, and high energy density. However, their practical deployment is hindered by several challenges, including dendrite growth on the anode, dissolution and structural degradation of cathode materials, and the limitations of conventional separators. To address these issues, various materials have been explored. Among them, electrospun nanofibers have emerged as a particularly attractive solution owing to their controllable nanostructures, large specific surface area, and tunable porosity. Although the application of electrospun nanofibers in AZIBs has expanded rapidly in recent years, a systematic review focusing on this topic remains lacking. To fill this gap, this review comprehensively summarizes the recent progress in leveraging electrospun nanofibers to overcome key limitations in AZIBs. Beginning with the fundamentals and structural design strategies of electrospinning, it highlights advances in their integration into cathodes, anode, and separators. Special emphasis is placed on elucidating the working mechanisms of the nanofibers and the structure–performance correlations between their microstructure and electrochemical properties. Finally, the review outlines future directions and remaining challenges in this field, aiming to offer valuable insights for the rational design of electrospun nanofiber architectures toward more efficient AZIBs.

Aqueous zinc-ion batteries (AZIBs) have recently attracted worldwide attention due to the natural abundance of Zn, low cost, high safety, and environmental benignity. Up to the present, several kinds of cathode materials have been employed for aqueous zinc-ion batteries, including manganese-based, vanadium-based, organic electrode materials, Prussian Blues, and their analogues, etc. Among all the cathode materials, manganese (Mn)-based oxide cathode materials possess the advantages of low cost, high theoretical specific capacity, and abundance of reserves, making them the most promising cathode materials for commercialization. However, several critical issues, including intrinsically poor conductivity, sluggish diffusion kinetics of Zn2+, Jahn–Teller effect, and Mn dissolution, hinder their practical applications. This Review provides an overview of the development history, research status, and scientific challenges of manganese-based oxide cathode materials for aqueous zinc-ion batteries. In addition, the failure mechanisms of manganese-based oxide materials are also discussed. To address the issues facing manganese-based oxide cathode materials, various strategies, including pre-intercalation, defect engineering, interface modification, morphology regulation, electrolyte optimization, composite construction, and activation of dissolution/deposition mechanism, are summarized. Finally, based on the analysis above, we provide future guidelines for designing Mn-based oxide cathode materials for aqueous zinc-ion batteries.

Abstract Mn3O4 is regarded as one of the potential cathode materials for neutral zinc-ion battery, due to its high discharge capacity, low cost, and environmental benignity. Unfortunately, the bulk Mn3O4 presents an inferior electrochemical performance resulting from its poor electrochemical activity. In this paper, cube-like Mn3O4@C material with interconnected pores and carbon layers is synthesized by one-step hydrothermal method followed by calcination. Owing to the high specific surface area, enhanced conductivity and protection of carbon layers, the porous cube-like Mn3O4@C cathode presents excellent electrochemical performances, compared with pure Mn3O4 cathode. Our elaborate zinc-ion battery owns an operating voltage of 1.33 V, an energy density of 429.8 W h kg−1 (based on cathode) at 100 mA g−1, and achievable capacity of 102.3 mAh g−1 at a quite high rate of 2000 mA g−1, as well as maintains a capacity retention of 77.1% over 200 cycles at 500 mA g−1. Our findings enable Mn3O4 as a promising cathode candidate in low-cost neutral zinc-ion battery for large-scale energy storage.

This review highlights the recent developments of cathode materials for aqueous zinc-ion batteries, which are cost effective and have good safety.

MnO2, a prominent manganese‐based cathode material, has been used extensively in aqueous zinc‐ion batteries (ZIBs). However, Zn2+ intercalation in MnO2 faces multiple obstacles, primarily due to the electrostatic interaction between Zn2+ and the skeleton, the coverage of by‐product Zn4SO4 (OH)6·xH2O (ZSH) on the cathode, and the preferential occupation by H+ of the active sites. Here, we introduce MnOOH into K+‐doped α‐MnO2 (KMO) to produce an ultrahigh‐capacity KMO‐MnOOH cathode. The MnOOH can transform into the active material β‐MnO2 via the in situ release of protons. The β‐MnO2 with the 1*1 tunnel structure shows the strong adsorption for H+ and unique tunnels that allow for rapid migration of H+, resulting in the diversion of protons originally intercalated into KMO. This “proton diversion effect” leads to sufficient active sites in KMO that accelerate Zn2+ transport kinetics. The released protons from MnOOH can reduce the by‐products ZSH, facilitating rapid Zn2+ migration and deep Zn2+ intercalation. Accordingly, the KMO‐MnOOH cathode exhibits an ultrahigh specific capacity (645.6 mA h g−1 at 0.3 A g−1) and an excellent cycling stability (239.3 mA h g−1 at 2 A g−1 after 950 cycles). This work provides new insights into the regulation of H+/Zn2+ intercalation for high‐performance Zn//MnO2 batteries.

Abstract The growing demand for energy storage devices leads to great interest in advanced batteries researches. Among them, aqueous rechargeable zinc ion batteries (ARZIBs) has attracted wide attention due to their low cost, simple manufacturing process and environmental friendliness. Here, we prepared a composite material, namely MnO2 particles grown on the surface of N-doped hollow porous carbon nanospheres, that is, combining hollow carbon material with metal oxides, and employed it as the cathode of ARZIBs. Owing to the synergistic merits of desirable structural features of manganese oxides and hollow porous carbon nanospheres, the composite material exhibited excellent performance for the storage of zinc ions, including high capacity of 206 mA h g−1 at 100 mA g−1, impressive rate capability of 103 mA h g−1 at 500 mA g−1 and superior cycling stability with the coulombic efficiency (capacity retention) of 98.3% over 650 cycles. The distinguished electrochemical behavior is attributed to the synergistic effects of desirable structural features of manganese oxides and hollow porous carbon nanospheres, which can be summed up as larger electron modified interface, high mass loading, and stable carbon-layer structure. These results demonstrate that the composite material could satisfy the criteria for applying in advanced ARZIBs.

In-situ formation of ultrafine ZnMn2O4-MnOOH composite nanoparticles embedded into porous carbon nanospheres for stable aqueous zinc-ion batteries - ScienceDirect …

The use of MnO2 as a promising cathode material for aqueous zinc ion batteries (AZIBs) remains challenging, because its inherent poor electrical conductivity and huge volume changes lead to a fast capacity decay, short cycle life, and sluggish electrode kinetics. In this study, ultrathin MnO2 nanoflakes grown on N-doped hollow carbon spheres (defined as MnO2–NHCSs) were prepared via a simple solution-phase route and subsequent hydrothermal process, and then evaluated for their potential as a cathode for AZIBs. Ultrathin MnO2 nanoflakes decorated on NHCSs endow the overall electrode with abundant exposed active sites and excellent electrical conductivity, which could buffer the volumetric expansion and facilitate the charge-transfer kinetics. Owing to these favorable structural characteristics, the as-synthesized MnO2–NHCS composite can display a high discharge capacity of 349 mA h g−1 at 0.1 A g−1 after 80 cycles. Significantly, ultra-stable long-term cycling performance of 100 mA h g−1 with a superior capacity retention of 78.7% is achieved after 2000 cycles at 2.0 A g−1. Such notable electrochemical properties of MnO2–NHCSs are demonstrated to be superior to that of pure MnO2 hollow spheres (MnO2-HSs) and other previously reported manganese-based oxide cathodes, which is promising for practical applications.

Abstract For manganese-based oxides to be used as one of the most promising aqueous zinc-ion batteries (ZIBs) cathode materials, improvements in cycling stability are required. In this work, manganese oxides (MnOx) hierarchical microspheres, including MnO, γ-MnO2 (MnO2), Mn2O3 and Mn3O4, are prepared, and their electrochemical performances are systematically investigated as cathode materials for aqueous ZIBs. The MnOx hierarchical structures can effectively shorten the diffusion pathway of Zn2+, tolerate the structural stress caused by Zn2+ insertion/extraction and restrain the self-aggregation of nanomaterials. Among MnOx, MnO hierarchical microspheres displays a high reversible capacity of 376.7 mAh g−1, good rate capability and excellent cycling stability with capacity retention of 99.37% over 1000 cycles. Finally, the zinc ion storage mechanism of MnO cathode is revealed. The results show that the remarkable electrochemical performance of MnO cathode is attributed to layered-type MnO2 structure formed during the initial few cycles, which is conducive to the insertion/extraction of zinc ions. This work is expected to deepen the understanding of the energy storage mechanism of MnO and helped to choose the ideal manganese-based cathode materials for aqueous ZIBs.

… Therefore, it is urgent and necessary to develop a facile strategy for the preparation of manganese oxide nanoparticles confined in carbon matrix with effective electron transport “bridges…

… manganese-based cathodes for aqueous zinc-ion batteries (… of inorganic Zn single bond Mn oxide residues. This thermal … oxide precursor into a carbon-supported Zn single bond Mn …

Abstract Manganese oxides are promising cathode materials for aqueous zinc‐ion batteries (ZIBs) due to their high energy density and low cost. However, in their discharging processes, the Jahn–Teller effect and Mn 3+ disproportionation often lead to irreversible structural transformation and Mn 2+ dissolution, deteriorating the cycling stability of ZIBs. Herein, ZnMn 2 O 4 quantum dots (ZMO QDs) were introduced into a porous carbon framework by in‐situ electrochemically inducing Mn‐MIL‐100‐derived Mn 3 O 4 quantum dots and the carbon composite. In such ZMO QDs and carbon composite, the quantum dot structure endows ZnMn 2 O 4 with a shorter ion diffusion route and more active sites for Zn 2+ . The conductive carbon framework is beneficial to the fast transport of electrons. Furthermore, at the interface between the ZMO QDs and the carbon matrix, the Mn−O−C bonds are formed. They can effectively suppress the Jahn–Teller effect and manganese dissolution of discharge products. Therefore, Zn/ZMO QD@C batteries display remarkably enhanced electrochemical performance.

Considering the high safety, low-cost and high capacity, aqueous zinc ion batteries have been a potential candidate for energy storage ensuring smooth electricity supply. Herein, we …

… Aqueous zinc-ion batteries (AZIBs) have gained a lot of interest as a potential alternative … 3D macroscopic interlayer to enhance the zinc anode stability for future AZIBs application. …

Zinc‐ion batteries (ZIBs) have gained considerable attention as sustainable energy storage systems, offering advantages in capacity, safety, and cost. However, issues such as dendrite growth and side reactions hinder their practical adoption. Cellulose‐based gel electrolytes (CGEs) have recently emerged as promising materials to mitigate these challenges. By inhibiting zinc dendrite formation and enhancing interfacial stability, CGEs improve cycling longevity and safety in ZIBs. This review begins by classifying gel electrolytes and outlining the distinctive benefits of CGEs prepared via crosslinking and non‐crosslinking strategies. It then systematically examines recent developments in CGEs for use with various cathode materials and in multifunctional ZIBs configurations. Finally, the environmental merits and compelling electrochemical properties of CGEs are highlighted, together with a forward‐looking discussion on their role in next‐generation ZIBs and related future research directions. This work provides a timely and comprehensive resource that integrates materials design with electrochemical insights, offering valuable guidance for the rational development of CGEs.

Aqueous zinc-ion batteries (AZIBs) have emerged as a promising alternative to lithium-ion batteries owing to their abundant zinc resources, low cost, environmental friendliness, and impressive theoretical specific capacity of 820 mAh g-1. However, zinc anodes face significant challenges, including short cycle lifetimes and poor reversibility, primarily due to rampant dendrite growth and the inevitable hydrogen evolution reaction (HER). To address these issues, an artificial protective layer of Ca-doped LaCrO3 (denoted as LCCO2) was coated onto zinc foil utilizing a facile doctor blade casting method. Experimental results demonstrate that the dense and uniform LCCO2 coating effectively suppresses side reactions, regulates the electric field at the zinc anode interface, and facilitates rapid ion migration coupled uniform zinc deposition, thereby enhancing anode stability. Remarkably, symmetrical cells with LCCO2 coating exhibit a stable cycle lifespan of 1500 h at 5 mA cm-2, along with highly reversible zinc plating/stripping behavior. Furthermore, the LCCO2@Zn||MnO2 full cell also delivers a high reversible capacity of 174 mAh g-1 after 500 cycles at 1 A g-1, underscoring the advantages of the LCCO2 protective layer in achieving highly reversible Zn anodes.

Summary of MOF-based aqueous zinc-ion battery electrode materials design strategies.

… surface properties and electrochemical properties were studied elaborately and discussed in detail. The stability of these nanoparticles was also investigated. The synthesis conditions …

… Up to now, many manganese oxides with various structures and morphologies have been fabricated via electrochemical and chemical routes, and their electrochemical properties have …

We report here an efficient single step combined sonochemical and solvothermal synthesis process to obtain bulk quantities of nanospherical particles of cubic Mn2O3 and characterized its pseudocapacitive characteristics in relevance to electrochemical capacitors for the first time. It has been found that quantitative determination of specific capacitance yielded a value of capacitance of ∼100 Fg-1 within 0-0.4 V (versus SCE) potential range in a 6 M KOH alkaline electrolyte. The as-prepared nanopowders after being subjected to heat treatment at 400°C were characterized by using XRD which shows a typical cubic single-phase structure (space group Ia-3), the broad crystalline peaks indicating the presence of explicit nanostructure. Electron microscopic studies (FE-SEM and TEM) revealed that the synthesized powders exhibit nanospherical morphology with uniform sphere-like grains of ∼10-15nm range. Two heat-treated samples were studied in the context of crystallinity versus electrochemical capacitance using rate-dependent cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode system. The excellent well-refined redox behavior corroborates with EIS measurements. The presence of near symmetric redox couple observed in CV has been attributed to pronounced one-electron-transfer process owing to the presence of facileMn redox centere facilitating the reversible one-electron transfer that accounts for its pseudocapacitance.

… surging method for synthesizing manganese oxides with different … Moreover, their electrochemical properties depending on … Mesoporous manganese oxide nanoparticles for the …

… The electrochemical properties of the AMONTF electrodes were … and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere …

… An electrochemical electrode, based on dual-morphology manganese-oxide nanoparticles, … This combinatorial effect increases the charge storage performance of the manganese-oxide…

… Polyhedron structured sphere-like lithium manganese oxide (LiMn 2 O 4 ) is successfully synthesized from β-MnO 2 nanorod precursor via a solid state reaction at a temperature of 800 …

Abstract The present work addresses the important need of new materials to improve energy storage materials. The synthesis of MnCo2O4 nanospheres by employing solvothermal method at different incubation times was carried out. The effects of reaction time on structural, morphological, and electrochemical studies were briefly investigated. The X-ray diffraction result unveils the formation of cubic-structured MnCo2O4 nanospheres with Fd3m (2 2 7) space group. The appearance of two Raman peaks at 480 and 662 cm−1 was greatly attributed to the stretching vibration mode of M–O (M = Mn, Co), and substantiates the formation of MnCo2O4. The presence of functional group and characteristics group was analyzed by Fourier-transform infrared spectroscopy. The scanning electron microscope image clearly indicated different sizes of nanoparticles due to the effect of solvothermal reaction period. The energy storage behavior of MnCo2O4 nanospheres was studied by employing the cyclic voltammetric and charge–discharge cycles. The results confirmed the pseudocapacitive nature of MnCo2O4 nanoparticles (RF3) with porous, spherical nanostructure with larger radius than others and contribute to better specific capacitance of 252 F g−1 at current density of 1 A g−1 which could be considered as a potential candidate for pseudocapacitive electrode for energy storage devices.

… Manganese oxide) nanoflakes were synthesized for use as electrode material in electrochemical … contents (δ), and the electrochemical supercapacitive properties of the MnO 2+δ …

… formation of manganese oxide occur simultaneously, forming a manganese-oxide/graphite … In this sandwich structure, the electrochemical properties of Mn 3 O 4 and MnO can be …

… ], [27], [28], [29], electrochemical deposition method [30], [31], [32], … The values of specific capacitance of manganese oxide film … the electrochemical properties of manganese oxide films …

Abstract Objectives of this study are to probe the effect of reducing agents on physicochemical and electrochemical properties of manganese oxide. Manganese oxide is synthesized by chemical reduction of KMnO4 at room temperature using ethylene glycol, hydrazine hydrate, Na2S2O3, potassium iodide, formic acid, citric acid, and NaBH4. All as-prepared manganese oxide samples are analysed by powder XRD, FE-SEM and FT-IR. It is found that manganese oxide prepared using formic acid and sodium thiosulphate have nanorod or nanowire type morphology as confirmed by FE-SEM analysis. Electrochemical properties of samples are studied in aqueous medium (1 M Na2SO4) by cyclic voltammetry and galvanostatic charge-discharge techniques. Due to the rod type structure formic acid sample shows high surface area (117 m2g−1) and high porosity (0.1331 cc g−1), which results into high specific capacitance of 155 Fg−1 at 0.64 Ag−1.

… synthesized CuMn 2 O 4 nanoparticles structure, morphology, optical and electrochemical properties … The rice-like morphology formation of CuMn 2 O 4 nanoparticles prepared at 160 C …

Vanadium oxide nanospheres encapsulated in N-doped carbon nanofibers with morphology and defect dual-engineering toward advanced aqueous zinc-ion batteries - ScienceDirect …

Abstract The emerging aqueous zinc ion batteries (ZIBs) are one of the alternatives to lithium ion batteries (LIBs) because zinc electrode possesses low equilibrium potential, high exchange current density and high hydrogen evolution overpotential. Nevertheless, they are still challenging on improving the cycle stability and compatibility with electrolytes. Herein, we report VO2-5@ PPy hollow nanospheres consisting of many nanosheets as cathode materials for ZIBs. The spaces between nanospheres facilitate transmission of Zn ions and make electrode tolerate high volume change. The as-obtained material delivers a specific capacity of 440 mAh g−1 at 0.1 A g−1. Also, they remain a reversible capacity of 143 mAh g−1 after 860 cycles at 1 A g−1.

Abstract Vanadium pentoxides (V2O5) show potential in aqueous zinc ion batteries (AZIBs) originating from their layered structure and high theoretical capacity. However, most of the reported V2O5 cathodes suffer from rapid capacity decay and sluggish Zn2+ diffusion kinetics. Herein, hollow V2O5 nanospheres with a diameter of about 450 nm and shell thickness of 50 nm were constructed via a template-free solvothermal method combined with subsequent calcination treatment. The nano-sized hollow structure can not only alleviate the structural stress upon cycling, but also provide shortened ion and electron transport paths, and enhance the surface capacitive behavior. When applied as cathode for AZIBs, it delivers ultrahigh reversible capacity (327 mAh g−1 at 0.1 A g−1), superior rate performance (146 mAh g−1 at 20 A g−1), and excellent cyclic performance (147 mAh g−1 after 6000 cycles at 10 A g−1; 122 mAh g−1 after 10,000 cycles at 15 A g−1), showing clear superiority over commercial V2O5 with irregular appearance. Such attractive capabilities demonstrate that hollow V2O5 nanospheres are a prospective cathode material for AZIBs.

Vanadium dioxide (VO2) is a very promising cathode material for aqueous zinc ion batteries (AZIBs) because of its high reversible specific capacity, excellent rate performance and fast diffusion kinetics. However, its long-term cycle stability and compatibility with electrolytes have not met expectations. In this study, another metastable phase of vanadium dioxide-monoclinic VO2(D)-is demonstrated to be a better choice as a cathode for AZIBs. Electrochemical results revealed that the as-prepared VO2(D) hollow nanospheres delivered high reversible discharge capacity (up to 408 mA h g-1 at 0.1 A g-1), exceptional rate performance (200 mA h g-1 at 20 A g-1), and long cyclic endurance stability (cycling for 30 000 cycles with a low capacity fading rate of 0.0023% per cycle) in inexpensive 3 M ZnSO4 electrolyte. Furthermore, the electrochemical reaction mechanism was corroborated using ex situ XRD, HRTEM and XPS, showing that an interesting electrochemically induced phase transition from VO2(D) to V2O5·xH2O occured with the insertion/extraction of zinc ions. Finally, the prototype batteries assembled with our as-prepared VO2(D) hollow nanospheres and the impressive performance of this electrode under high active material mass loading further reveal its high potential in practical applications.

Recently, vanadium dioxide (VO2) has been recognized as one of the most prospective cathodes for aqueous zinc ion batteries (AZIBs) for its high reversible specific capacity; nevertheless, its Zn2+ diffusion kinetics and cycling stability have not yet met expectations. Herein, Mo ions are introduced into VO2 to optimize the intrinsic electronic structure and micromorphology of VO2, achieving significantly enhanced zinc-ion storage. It is found that the substitution of Mo for V narrows the band gap of VO2 and thus enhances the conductivity of the material, while VO2 nanorods are transformed into VO2 nanoflowers which are self-assembled from ultra-thin nanosheets after the introduction of Mo, exposing much more active sites to enhance the migration kinetics of Zn2+. Consequently, the Mo-substituted VO2 (0.5-Mo-VO2) exhibits excellent electrochemical properties, presenting a high initial capacity of 494.5 mAh/g at 0.5 A/g, excellent rate capability of 336 mA h g-1 at 10 A/g and brilliant cycling stability with the capacity retention of 82% over 2000 cycles at 10 A/g. This work provides significant guidance for the design of advanced cathodes for AZIBs by optimizing the electronic structure and tailoring morphology of V-based materials.

… At present, research on aqueous ion batteries is progressing … of high-performance aqueous zinc-ion batteries (AZIBs). … Herein, a cathode material of self-assembled nanospheres …

In the pursuit of efficient energy storage solutions for renewable energy, aqueous zinc-ion batteries (ZIBs) have emerged as promising contenders, offering high capacity and …

… for use as cathode materials in zinc-ion batteries include … design a series of V2O3 nanospheres embedded in nitrogen-… tions, different V2O3 nanosphere morphologies were synthesized…

… Rechargeable aqueous zinc ion hybrid … cathode candidates with satisfactory capacity and excellent cycling stability. Herein, we developed dual-doped carbon hollow nanospheres (PN-…