Cathode For Aqueous Zinc-ion Batteries Research Articles

Harnessing oxygen vacancy in V2O5 as high performing aqueous zinc-ion battery cathode

Abstract Rechargeable aqueous zinc-ion batteries (ZIBs) have attracted considerable attention for large-scale energy storage systems due to their high energy density, low cost, and inherent safety. However, ZIBs suffer from limited cyclic stability with the use of the current cathode materials (such as V2O5) due to the strong electrostatic ion–lattice interactions with the diffusing divalent Zn2+, usually leading to a limited cyclic duration (

Sandwich-Like Heterostructures of MoS2 /Graphene with Enlarged Interlayer Spacing and Enhanced Hydrophilicity as High-Performance Cathodes for Aqueous Zinc-Ion Batteries.

Layered materials have great potential as cathodes for aqueous zinc-ion batteries (AZIBs) because of their facile 2D Zn2+ transport channels; however, either low capacity or poor cycling stability limits their practical applications. Herein, two classical layered materials are innovatively combined by intercalating graphene into MoS2 gallery, which results in significantly enlarged MoS2 interlayers (from 0.62 to 1.16nm) and enhanced hydrophilicity. The sandwich-structured MoS2 /graphene nanosheets self-assemble into a flower-like architecture that facilitates Zn-ion diffusion, promotes electrolyte infiltration, and ensures high structural stability. Therefore, this novel MoS2 /graphene nanocomposite exhibits exceptional high-rate capability (285.4mA h g-1 at 0.05 A g-1 with 141.6mA h g-1 at 5 A g-1 ) and long-term cycling stability (88.2% capacity retention after 1800 cycles). The superior Zn2+ migration kinetics and desirable pseudocapacitive behaviors are confirmed by electrochemical measurements and density functional theory computations. The energy storage mechanism regarding the highly reversible phase transition between 2H- and 1T-MoS2 upon Zn-ion insertion/extraction is elucidated through ex situ investigations. As a proof of concept, a flexible quasi-solid-state zinc-ion battery employing the MoS2 /graphene cathode demonstrates great stability under different bending conditions. This study paves a new direction for the design and on-going development of 2D materials as high-performance cathodes for AZIBs.

Three-dimensional networked Na3V2(PO4)3/C composite as high-performance cathode for aqueous zinc-ion battery

Na3V2(PO[Formula: see text] (NVP) as one typical Na[Formula: see text] super ionic conductor (NASICON) is recognized as an ideal cathode material for ZIBs owing to its promising structural stability that facilitates long cycle, rich vacancies and channels facilitate storing metal ions, high operating potentials to ensure high energy density. However, it still faces poor cyclability and high-rate capacity. Here, three-dimensional networked Na3V2(PO[Formula: see text]/C composite is synthesized by a microemulsion strategy with cetyltrimethyl ammonium bromide (CTAB) as the soft template, and the effect of aging temperature of microemulsion on their morphology and electrochemical performance is investigated. The Na3V2(PO[Formula: see text]/C composite derived from the precursor reacted at 70[Formula: see text]C shows micrometer-size particles assembled by three-dimensional networked nanoplates, facilitating for ions transport and delivers the best electrochemical performance. It displays a high first capacity of 102.2 mAh g[Formula: see text] with 42.3 mAh g[Formula: see text] remained after 5000 stable cycles (capacity retention of 41.4%) at 5 C, a high capacity of 83.2 mAh g[Formula: see text] even the current density is as high as 20 C, which is better than most of the reports.

Flower-like W/WO3 as a novel cathode for aqueous zinc-ion batteries.

Aqueous zinc-ion batteries (ZIBs) with exceptional safety and cost-effective features have captured researchers' attention, but the cathode materials available still need to be further explored. Herein, a flower-like W/WO3 hybrid is developed as a cathode of ZIBs. Impressively, the W/WO3-ZIBs exhibit extraordinary rate performance (158 mA h g-1 under 0.1 A g-1) and remarkable cycling performance (96% over 1000 cycles). Additionally, an electrochemical mechanism based on reversible Zn2+ insertion/extraction in W/WO3 is firstly demonstrated, and the impressive flexibility and excellent capabilities of the soft-packaged batteries are also realized. Therefore, this research will pave a novel consideration of metal/metal oxide hybrids in designing cathodes of ZIBs with high electrochemical performance.

Two-dimensional hierarchical Mn2O3@graphene as a high rate and ultrastable cathode for aqueous zinc-ion batteries

There has been increasing interest in aqueous Zn-ion batteries (ZIBs) because of their absolute safety, but it remains challenging to develop cathode materials with a high rate capability and cycling stability.

Vanadium-based cathodes for aqueous zinc-ion batteries: from crystal structures, diffusion channels to storage mechanisms

The developments, challenges and solutions of vanadium-based aqueous zinc ion battery cathodes are reviewed, focusing on the intrinsic connections of ion diffusion channels, mechanisms, and battery performances.

Construction of molybdenum vanadium oxide/nitride hybrid nanoplate arrays for aqueous zinc-ion batteries and reliable insights into the reaction mechanism

Unique CC@a-MVO/MVN HNPAs have been synthesized as an additive- and binder-free cathode for aqueous zinc-ion batteries. Moreover, the reversible formation/decomposition of two different kinds of zinc-containing byproducts is evidently discovered.

Investigating Na3V2(PO4)3 @C/CNF Hybrid Cathode in Aqueous Zinc-Ion Battery

With the rapid development of new energy storage technologies, aqueous zinc-ion batteries (AZIBs) gaining significant attention as one of the most promising candidate due to its lower cost and enhanced safety aspects. The key to the development of full batteries lies in suitable high-performance electrode materials. A NASICON type material, Na3V2(PO4)3 (NVP) has a high ion conductivity and an open three-dimensional structure, which can accommodate zinc-ion intercalation, reversibly. Here, we developed a hybridcarbon coated NVP interconnected with carbon nanofibers (NVP@C/CNF) as cathode in AZIBs. The cyclic voltammogram analysis shows that after adding CNF, electrode material owns higher diffusion coefficient of Zn2+ with lower electrochemical polarization. The as-prepared NVP@C/CNF composite exhibits discharge capacity of 95.1 mAhg-1 at 1 C, larger than that of the NVP@C composite (77.3 mAhg-1 at 1 C). The capacity retention of NVP@C/CNF is 75.6 % after 100 cycles, superior to NVP@C without incorporation of CNF (63.1 %). The uniform carbon layer on the surface of NVP alleviates the vanadium dissolution during cycling, while the CNF network further improves the electrical conductivity and structural stability of the hybrid, which can effectively suppress material expansion caused by insertion and extraction of Zn2+. As verified, NVP@/C/CNF is expected to be a great potential electrode in safer ZIBs.

Synergistic nanostructure and heterointerface design propelled ultra-efficient in-situ self-transformation of zinc-ion battery cathodes with favorable kinetics

Abstract In-situ self-transformation is proved to be an effective strategy to design high-performance cathodes for aqueous zinc-ion batteries (ZIBs). However, the inferior transformation efficiencies during phase transition limit its further application. Herein, a 3D spongy VO2-graphene (VO2-rG) precursor has been designed for achieving the ultra-efficient in-situ self-transformation process from VO2-rG into multifaceted V2O5·nH2O-graphene composite (VOH-rG). Benefiting from the highly conductive heterointerfaces, rich reaction sites and numerous ions diffusion channels of VO2-rG, almost 100% VO2 nanobelts are converted into VOH during the first charging with few side reactions, indicating a highly efficient transformation kinetics. This strategy enables structural modulation from micro-nano level to molecular level by integrating pre-inserted H2O molecules and constructing 3D porous heterogeneous architecture into the VOH-rG cathode simultaneously, leading to fast and enduring Zn2+ (de)intercalation kinetics. Consequently, the VOH-rG cathode exhibits high capacity of 466 mA h g−1 at 0.1 A g−1, superior rate performance (190 mA h g−1 even at 20 A g−1) and excellent cycling stability with 100% capacity retention over 5000 cycles. Moreover, the assembled VOH-rG//Zn flexible quasi-solid-state batteries also present impressive performance. Such an ultra-efficient in-situ self-transformation strategy would pave a new way to explore promising electrode materials for advanced energy storage.

Cu-MOF-derived and porous Cu0.26V2O5@C composite cathode for aqueous zinc-ion batteries

One fundamental issue for developing high-performance Zn-ion batteries (ZIBs) is the exploration of stable and efficient cathode materials that can reversibly intercalate zinc ions at a high capacity and potential. Layered vanadium oxides have been regarded as a suitable candidate for this purpose due to their high zinc-ion storage capacity. However, the sluggish kinetics of zinc-ion intercalation/deintercalation and the poor conductivity of vanadium oxides are still the bottle bottlenecks that impede the further enhancement of their performance for ZIBs. Addressing this issue, we herein demonstrate a direct impregnation and conversion strategy to prepare a Cu-doped V2O5 and hierarchical porous carbon (Cu0.26V2O5@C) composite as the cathode for ZIBs. In this protocol, the Cu doping can promote the zinc-ion migration by broadening and stabilizing the layered structure of V2O5, the hierarchical porosity can enlarge the contact between the active material and the electrolyte to achieve efficient infiltration of the electrolyte into the material, while the carbon host can improve the electronic conductivity. The combination of these merits thus delivers a high specific capacity (328.8 mAh g−1 at 0.2 A g−1), high rate performance (163.8 mAh g−1 at 2 A g−1), and excellent long-term cyclic stability with 93.5% capacity retention after 500 cycles.

Free-standing three-dimensional carbon nanotubes/amorphous MnO2 cathodes for aqueous zinc-ion batteries with superior rate performance

Rechargeable aqueous zinc-ion batteries (ZIBs) have gained particular attention in recent years because of their low cost and high safety. However, most of their performances are limited by unsatisfied architecture of cathodes. In addition, the degree of crystallinity of active materials also plays an important role in their electrochemical performance. Herein, we fabricated free-standing composite films with amorphous MnO2 (a-MnO2) and carbon nanotubes (CNTs) by an in situ deposition method. The free-standing a-MnO2@CNTs composite films can directly serve as the cathodes of ZIBs without binder and current collector. The resultant cathode exhibits highly electrical conductivity and fast ion-diffusion because of the corporation of interconnected three-dimensional CNTs architectures and ultra-thin a-MnO2 nanosheets. As a result, the resultant ZIB displays high energy and power density, as well as stable cycling performance. Moreover, based on composite films, flexible ZIBs were constructed, and they could remain stable electrochemical performance under different bending states, which have great potential for the application in flexible and wearable electronics.

Tunable oxygen vacancy concentration in vanadium oxide as mass-produced cathode for aqueous zinc-ion batteries

Oxygen vacancy (Vo) is important in the modification of electrode for rechargeable batteries. However, due to the scarcity of suitable preparation strategy with controllable Vo incorporation, the impact of Vo concentration on the electrochemical performances remains unclear. Thus, in this work, Vo-V2O5-PEDOT (VoVP) with tunable Vo concentration is achieved via a spontaneous polymerization strategy, with the capability of mass-production. The introduction of poly(2,3-dihydrothieno-1,4-dioxin) (PEDOT) not only leads to the formation of Vo in V2O5, but it also results in a larger interlayer spacing. The as-prepared Vo-V2O5-PEDOT-20.3% with Vo concentration of 20.3% (denoted as VoVP-20) is able to exhibit high capacity of 449 mAh·g−1 at current density of 0.2 A·g−1, with excellent cyclic performance of 94.3% after 6,000 cycles. It is shown in the theoretical calculations that excessive Vo in V2O5 will lead to an increase in the band gap, which inhibits the electrochemical kinetics and charge conductivity. This is further demonstrated in the experimental results as the electrochemical performance starts to decline when Vo concentration increases beyond 20.3%. Thus, based on this work, scalable fabrication of high-performance electrode with tunable Vo concentration can be achieved with the proposed strategy.

VS2 nanosheets vertically grown on graphene as high-performance cathodes for aqueous zinc-ion batteries

Aqueous rechargeable zinc-ion batteries (ZIBs) have been considered as potential grid-scale energy storage devices owing to their low cost, high safety, and environmental friendliness. However, the cathode materials of ZIBs usually show poor cycling stability and inferior rate performance. Here, a new 2D hierarchical composite comprised of ultrathin VS2 nanosheets perpendicularly grown on graphene sheets (rGO-VS2) is prepared through a one-step solvothermal strategy. Benefiting from the unique hierarchical structure and synergistic merits between the VS2 and graphene nanosheets, the rGO-VS2 composite exhibits excellent performance as new cathode materials for ZIBs. Specifically, it not only can deliver a high capacity of 238 mAh g−1 at 0.1 A g−1, but also maintains a capacity of 190 mAh g−1 at a quite high rate of 5 A g−1 with a capacity retention over 93% after 1000 cycles. This work highlights the great promise of rational designing high-performance rechargeable aqueous ZIBs.

Promise and challenge of vanadium-based cathodes for aqueous zinc-ion batteries

Abstract Aqueous zinc-ion batteries (ZIBs) have got wide attention with the increasing demands for energy resource recently. It has a number of merits compared with lithium-ion batteries, such as enhanced safety, low cost and environmental friendliness. Vanadium-based materials have been developed to serve as the cathodes of ZIBs for many years. But there are also some challenges to construct high performance ZIBs in the future. Herein, we reviewed the research progress of vanadium-based cathodes and discussed the energy storage mechanisms in ZIBs. In addition, we summarized the major challenges faced by vanadium-based cathodes and the corresponding ways to improve electrochemical performance of ZIBs. Finally, some excellent vanadium-based cathodes are summarized to pave the way for future research in ZIBs.

Graphene-Wrapped MnO/C Composites by MOFs-Derived as Cathode Material for Aqueous Zinc ion Batteries

ABSTRACT Aqueous zinc ion batteries (AZIBs) show tremendous application prospect in the fields of energy storage for smart grid and electric tools because of their high safety, environmental benignity and low cost. However, the sluggish zinc ion diffusion kinetics and the serious manganese dissolution issue seem to impede its practical application. Herein, the MnO/C@rGO composites are fabricated via an in situ strategy of one-step MOFs-derived solvothermal method, combined with a calcination step at 570 °C under Ar for 2 h. As further evaluated as a cathode for AZIBs, it can maintain a discharge capacity of 170.6 mAh g-1 after 300 cycles at 500 mA g-1. Importantly, even as the current density reaches up to 2.0 A g-1, it still delivers a reversible capacity as high as 110.1 mAh g-1. The excellent cycleability, superior rate capability and smaller self-discharge phenomenon are ascribed to the inhibition of manganese dissolution and the conductivity improvement. Therefore, this work may give a new insight into improving the comprehensive electrochemcial performances of manganese-based cathode materials for AZIBs with large power densities and long cycle life.

Appropriately hydrophilic/hydrophobic cathode enables high-performance aqueous zinc-ion batteries

Organic batteries with improved electrode wettability will exhibit a better electrochemical performance. How about the relationship between electrode wettability and battery performance in aqueous batteries? Here the effect of cathode wettability in aqueous zinc-ion batteries (AZIBs) on the zinc-ion diffusion and charge transfer based on a research platform of cellulose nanowhiskers (CNWs)/graphene/MnO2 wire-in-scroll nanowires with water contact angles turning from 64.70 ​± ​3.72° to 115.85 ​± ​3.36° as cathodes for AZIBs has been investigated, where the corresponding battery performance shows a parabola trend with the peak in 103.04 ​± ​2.91°. The cathode achieves a high capacity of 384 ​mAh g−1 at 1 ​C and features an ultra-long lifetime of over 5000 cycles at 20 ​C, representing excellent Zn storage performance. A combination of experimental measurements and density functional theory calculations suggests that increased cathode hydrophobicity forces hydrated Zn2+ desolvation at electrode-electrolyte interface, facilitating zinc-ion insertion into host materials, yet extremely hydrophobic cathode leads to sluggish electrochemical kinetics. This study opens a new idea in the design of promising candidates for developing low cost and long lifespan batteries for aqueous systems.

Cobalt-Doped Layered MnO2 Thin Film Electrochemically Grown on Nitrogen-Doped Carbon Cloth for Aqueous Zinc-Ion Batteries

The layered manganese dioxide (δ-type MnO2) film electrodeposited on carbon cloth (CC) functioned as a cathode in aqueous zinc-ion batteries. Battery performance was notably improved by doping MnO2...

A novel organic-inorganic hybrid V2O5@polyaniline as high-performance cathode for aqueous zinc-ion batteries

Aqueous Zn-ion batteries (ZIBs) have received increasing attention because of their high safety, low cost and environmental benignity. However, the development of high-performance cathode materials using for zinc-ion de/intercalation is still a challenge. In this work, V2O5@polyaniline (V2O5@PANI) nanocomposites were synthesized by the polymerization of aniline and V2O5. Due to the organic-inorganic compatibility, V2O5@PANI exhibits a good electrochemical performance serving as cathode material for ZIBs, which displays a high specific capacity (361 mAh g−1 at 0.1 A g−1) and an excellent cycling stability (93.8% capacity retention after 1000 cycles).

Amorphous Bimetallic Oxides Fe-V-O with Tunable Compositions toward Rechargeable Zn-Ion Batteries with Excellent Low-Temperature Performance.

Vanadium oxides have been considered as promising cathode candidates for zinc-ion batteries (ZIBs) because of their high theoretical specific capacity. However, the poor rate performance and the unsatisfactory cycle life resulting from the sluggish electrode kinetics seriously impede their practical implementation. Herein, we report the rational design of amorphous Fe-V-O bimetallic oxides with tunable compositions as cathodes for aqueous ZIBs. The bimetallic Fe-V-O oxides show improved composition-dependent Zn2+ storage performance and superior structural integrity during cycling. The enhanced electrode kinetics is attributed to the superior electronic conductivity of Fe-V-O oxides than pristine V2O5 owing to the introduction of the Fe element and an amorphous crystalline structure, which can provide reduced diffusion paths and more free volume for Zn2+ insertion. As a result, the as-prepared Fe-V-O exhibits outstanding rate capability and impressive cycling stability. Particularly, a stable reversible capacity of 70 mA h g-1 can be still maintained after 2500 cycles at 5 A g-1, corresponding to the high capacity retention of 95%.

H+ -Insertion Boosted α-MnO2 for an Aqueous Zn-Ion Battery.

Rechargeable Zn/MnO2 batteries using mild aqueous electrolytes are attracting extensive attention due to their low cost, high safety, and environmental friendliness. However, the charge-storage mechanism involved remains a topic of controversy so far. Also, the practical energy density and cycling stability are still major issues for their applications. Herein, a free-standing α-MnO2 cathode for aqueous zinc-ion batteries (ZIBs) is directly constructed with ultralong nanowires, leading to a rather high energy density of 384 mWh g-1 for the entire electrode. Greatly, the H+ /Zn2+ coinsertion mechanism of α-MnO2 cathode for aqueous ZIBs is confirmed by a combined analysis of in situ X-ray diffractometry, ex situ transmission electron microscopy, and electrochemical methods. More interestingly, the Zn2+ -insertion is found to be less reversible than H+ -insertion in view of the dramatic capacity fading occurring in the Zn2+ -insertion step, which is further evidenced by the discovery of an irreversible ZnMn2 O4 layer at the surface of α-MnO2 . Hence, the H+ -insertion process actually plays a crucial role in maintaining the cycling performance of the aqueous Zn/α-MnO2 battery. This work is believed to provide an insight into the charge-storage mechanism of α-MnO2 in aqueous systems and paves the way for designing aqueous ZIBs with high energy density and long-term cycling ability.