Aqueous zinc‐ion batteries (ZIBs) are considered promising energy storage devices for large‐scale energy storage systems as a consequence of their safety benefits and low cost. In recent years, ...various vanadium‐based compounds have been widely developed to serve as the cathodes of aqueous ZIBs because of their low cost and high theoretical capacity. Furthermore, different energy storage mechanisms are observed in ZIBs based on vanadium‐based cathodes. In this Minireview, we present a comprehensive overview of the energy storage mechanisms and structural features of various vanadium‐based cathodes in ZIBs. Furthermore, we discuss strategies for improving the electrochemical performance of vanadium‐based cathodes; including, insertion of metal ions, adjustment of structural water, selection of conductive additives, and optimization of electrolytes. Finally, this Minireview offers insight into potential future directions in the design of innovative vanadium‐based electrode materials.
Vanadium‐based compounds are widely implemented as cathodes for aqueous zinc‐ion batteries (ZIBs) because of their low cost and high theoretical capacity. This Minireview presents a comprehensive overview of the energy storage mechanisms and structural features of various vanadium‐based cathodes in ZIBs. Strategies for improving the electrochemical performance of vanadium‐based cathodes are discussed.
Capping agents are frequently used in colloidal synthesis to inhibit nanoparticle overgrowth and aggregation as well as to control the structural characteristics of the resulted nanoparticles in a ...precise manner. Study of the effect of the residual capping agents on particle surface has unveiled various adverse and favorable behaviors in catalytic applications. In essence, while the capping agents usually act as a physical barrier to restrict the free access of reactants to catalytic nanoparticles, they can also be utilized to promote catalytic performance of nanocrystals. Due to the complexity of these effects, a general survey of capping agents in nanocatalysis is therefore necessary. This short review starts from a brief introduction of common capping agents in nanoparticle synthesis and their adverse impact on heterogeneous catalysis. Next, representative progresses in capping agent removal and surfactant-free synthesis for obtaining surface-clean nanocatalysts are summarized. Lastly, we discuss the recent advance in utilizing the capping agent effect including chiral modification, molecular recognition, adsorption regulation, surface crowding, and charge transfer at the metal–organic interface and so on to improve the catalytic performance of nanocatalysts.
Self-charging power systems integrating energy harvesting technologies and batteries are attracting extensive attention in energy technologies. However, the conventional integrated systems are highly ...dependent on the availability of the energy sources and generally possess complicated configuration. Herein, we develop chemically self-charging aqueous zinc-ion batteries with a simplified two-electrode configuration based on CaV
O
·3H
O electrode. Such system possesses the capability of energy harvesting, conversion and storage simultaneously. It can be chemically self-recharged by the spontaneous redox reaction between the discharged cathode and oxygen from the ambient environment. Chemically self-recharged zinc-ion batteries display an initial open-circuit voltage of about 1.05 V and a considerable discharge capacity of about 239 mAh g
, indicating the excellent self-rechargeability. Impressively, such chemically self-charging zinc-ion batteries can also work well at chemical or/and galvanostatic charging hybrid modes. This work not only provides a route to design chemically self-charging energy storage, but also broadens the horizons of aqueous zinc-ion batteries.
Rechargeable aqueous zinc‐ion batteries (ZIBs) have garnered tremendous attention in the field of next energy storage devices due to their high safety, low cost, abundant resources, and ...eco‐friendliness. As an important component of the zinc‐ion battery, the electrolyte plays a vital role in the electrochemical properties, since it will provide a pathway for the migrations of the zinc ions between the cathode and anode, and determine the ionic conductivity, electrochemically stable potential window, and reaction mechanism. In this Minireview, a brief introduction of electrochemical principles of the aqueous ZIBs is discussed and the recent advances of various aqueous electrolytes for ZIBs, including liquid, gel, and multifunctional hydrogel electrolytes are also summarized. Furthermore, the remaining challenges and future directions of electrolytes in aqueous ZIBs are also discussed, which could provide clues for the following development.
Zinc about it: Electrolytes play a vital role in the electrochemical properties of zinc‐ion batteries (ZIBs). This Minireview focuses on the electrochemical principles of the aqueous ZIBs and the recent advances of various aqueous electrolytes for ZIBs, including liquid, gel, and multifunctional hydrogel electrolytes. In addition, this Minireview also discusses the remaining challenges and future directions of electrolytes in aqueous ZIBs.
Lithium-sulfur (Li-S) batteries are attracting much attention due to their high energy densities. However, Li-S batteries often suffer from low Coulombic efficiency, severe degradation of cyclic ...capacity, and low utilization of active sulfur material because of the low electrical conductivity of sulfur and the severe shuttle effect. To solve these issues, various nanostructured carbon-based materials have been developed to serve as the sulfur host materials, modify separators and protect lithium (Li) anode due to their good conductivity, large surface area, and electrochemical stability. In this review, a brief introduction of electrochemical principles and prospects of the Li-S batteries are discussed firstly. Then the recent achievements and challenges of nanostructured carbon-based materials in Li-S batteries are summarized. The nanostructured carbon-based materials focus on active carbon, carbon nanotubes, graphene and their composites. The role of these carbon-based materials in Li-S batteries emphasize on the design of sulfur host materials, the modification of functional separators as well as the protection of the Li anode. Furthermore, various flexible Li-S batteries based on freestanding nanostructured carbon/sulfur electrodes are also presented. Finally, the further developments and prospects in this field are also discussed.
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The surface and interfaces of heterogeneous catalysts are essential to their performance as they are often considered to be active sites for catalytic reactions. With the development of nanoscience, ...the ability to tune surface and interface of nanostructures has provided a versatile tool for the development and optimization of a heterogeneous catalyst. In this Review, we present the surface and interface control of nanoparticle catalysts in the context of oxygen reduction reaction (ORR), electrochemical CO2 reduction reaction (CO2 RR), and tandem catalysis in three sections. In the first section, we start with the activity of ORR on the nanoscale surface and then focus on the approaches to optimize the performance of Pt-based catalyst including using alloying, core–shell structure, and high surface area open structures. In the section of CO2 RR, where the surface composition of the catalysts plays a dominant role, we cover its reaction fundamentals and the performance of different nanosized metal catalysts. For tandem catalysis, where adjacent catalytic interfaces in a single nanostructure catalyze sequential reactions, we describe its concept and principle, catalyst synthesis methodology, and application in different reactions.
Aqueous rechargeable metal batteries are intrinsically safe due to the utilization of low-cost and non-flammable water-based electrolyte solutions. However, the discharge voltages of these ...electrochemical energy storage systems are often limited, thus, resulting in unsatisfactory energy density. Therefore, it is of paramount importance to investigate alternative aqueous metal battery systems to improve the discharge voltage. Herein, we report reversible manganese-ion intercalation chemistry in an aqueous electrolyte solution, where inorganic and organic compounds act as positive electrode active materials for Mn
storage when coupled with a Mn/carbon composite negative electrode. In one case, the layered Mn
V
O
·nH
O inorganic cathode demonstrates fast and reversible Mn
insertion/extraction due to the large lattice spacing, thus, enabling adequate power performances and stable cycling behavior. In the other case, the tetrachloro-1,4-benzoquinone organic cathode molecules undergo enolization during charge/discharge processes, thus, contributing to achieving a stable cell discharge plateau at about 1.37 V. Interestingly, the low redox potential of the Mn/Mn
redox couple vs. standard hydrogen electrode (i.e., -1.19 V) enables the production of aqueous manganese metal cells with operational voltages higher than their zinc metal counterparts.
Metallic zinc is a promising anode candidate of aqueous zinc‐ion batteries owing to its high theoretical capacity and low redox potential. However, Zn anodes usually suffer from dendrite and side ...reactions, which will degrade their cycle stability and reversibility. Herein, we developed an in situ spontaneously reducing/assembling strategy to assemble a ultrathin and uniform MXene layer on the surface of Zn anodes. The MXene layer endows the Zn anode with a lower Zn nucleation energy barrier and a more uniformly distributed electric field through the favorable charge redistribution effect in comparison with pure Zn. Therefore, MXene‐integrated Zn anode exhibits obviously low voltage hysteresis and excellent cycling stability with dendrite‐free behaviors, ensuring the high capacity retention and low polarization potential in zinc‐ion batteries.
A MXene‐coated Zn (MZn) anode was fabricated by an in situ spontaneously reducing/assembling strategy, which effectively decreases the Zn nucleation energy barrier and uniformizes electric field distribution. The dendrite‐free zinc anode not only exhibits prolonged cycle life and lower voltage hysteresis, but also endows Zn/MnO2 batteries with the excellent electrochemical performance.
Sodium ion battery is a potential sustainable energy storage system due to its abundance and low cost. To date, some Na-storage anode materials have achieved long life span, but the rate performance ...still remains insufficient. Herein, we show that in some linear ether-based electrolytes, graphite can not only render unprecedented cyclability (∼6000 cycles), but also exhibit ultrahigh rate capability (up to 10 A g−1), along with a reversible capacity of ∼110 mAh g−1. By combining electrochemical measurements and structural analysis (e.g. in situ Raman and ex situ XRD measurements), we reveal that graphite undergoes a stage-evolution mechanism induced by the insertion of solvated sodium ions. Furthermore, kinetic studies have shown that this process accompanies with an intercalation pseudocapacitive behavior, which should be responsible for the obtained superior electrode properties.
•Sodium storage performance of graphite in ether-based electrolytes is evaluated.•Unprecedented cyclability and ultrahigh rate capability are obtained.•Solvated-Na co-intercalated into graphite via a stage-evolution process.•Kinetic studies reveal an intercalation pseudocapacitive behavior.•A full cell based on graphite and Na3V2(PO4)3@C are successfully fabricated.
Rechargeable aqueous zinc-ion batteries are promising energy storage devices due to their high safety and low cost. However, they remain in their infancy because of the limited choice of positive ...electrodes with high capacity and satisfactory cycling performance. Furthermore, their energy storage mechanisms are not well established yet. Here we report a highly reversible zinc/sodium vanadate system, where sodium vanadate hydrate nanobelts serve as positive electrode and zinc sulfate aqueous solution with sodium sulfate additive is used as electrolyte. Different from conventional energy release/storage in zinc-ion batteries with only zinc-ion insertion/extraction, zinc/sodium vanadate hydrate batteries possess a simultaneous proton, and zinc-ion insertion/extraction process that is mainly responsible for their excellent performance, such as a high reversible capacity of 380 mAh g
and capacity retention of 82% over 1000 cycles. Moreover, the quasi-solid-state zinc/sodium vanadate hydrate battery is also a good candidate for flexible energy storage device.
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