Vanadium‐Based Materials as Positive Electrode for Aqueous Zinc‐Ion Batteries

Abstract

development, but these energy sources have geographical limitations and instability, so it is difficult to achieve a wide range of applications. As an important part of sustainable energy development, electrochemical energy storage has become an area of active research in recent decades. [7-10] In the current energy market, lithium ion batteries (LIBs) are dominant in the automobile, medical equipment, and portable wearable device industries, among others, which can be attributed to their outstanding energy density and environmental protection performance. [11,12] However, the use of organic solvent-based electrolytes may raise safety issues and increase costs. [13-19] Therefore, the creation of an efficient battery system is very important. Compared with nonaqueous batteries, aqueous rechargeable batteries have the characteristics of low cost, nontoxicity, and incombustibility, and are more economically competitive than lithium technology in terms of largescale deployment. [20-22] Therefore, the most important task at present is to develop an ideal battery device with low cost, acceptable safety, long cycle performance, and environmental friendliness as a substitute for LIBs. [23-25] For the past few years, ion batteries with polyvalent metals as the negative electrodes have attracted much attention. Polyvalent cations (Zn 2+ , Mg 2+ , Al 3+) transfer twice or even three times as many electrons into the main material as monovalent cations (Li + , Na +), and each polyvalent positive ion can be inserted into the main compound. [26-32] Theoretically, the capacity of the host material depends on the number of transferred electrons coexisting with the intercalated ions, such that multivalent positive ions have higher weight capacity and energy density. [33] Notably, the element zinc (Zn) has become a common choice for a negative electrode material, owing to its ample sources, low price, low redox potential (−0.76 V vs standard hydrogen electrode), and high surface capacity. [34,35] The mixture of aqueous solution and/or aqueous solution and organic-based electrolyte has emerged as a new research field. Therefore, aqueous zinc ion batteries (ZIBs) have been widely considered for their advantages of high safety, low price, ecological friendliness, and high theoretical capacity. [36] Typically, aqueous ZIBs consist of a Zn metal negative electrode, an aqueous electrolyte that accounts for a majority of the battery material, and a positive electrode containing Zn 2+ ions. [37] A survey has revealed that the conventional With the increasing dependence on high power equipment, there is an urgent need to develop advanced and sustainable energy systems. As one of the main energy storage devices, battery research should make great efforts to implement the sustainable development strategies on ecological, clean and environmentally friendly energy. Currently, aqueous zinc ion batteries (ZIBs) have gained much attention owing to their cheapness, abundant resources, high safety, and ecological friendliness. Nevertheless, ZIBs als...

Understanding the Dissolution and Phase Transformation Mechanisms in Aqueous Zn/α-V2O5 Batteries

“…Rechargeable aqueous Zn-ion batteries (ZIBs) with a Zn metal anode have attracted significant interest from academia, research institutions, and industries alike due to their potential to be a viable energy storage technology to address the need for large-scale stationary “energy buffering” applications. − Anhydrous orthorhombic α-V 2 O 5 was the first class of cathodes studied for rechargeable ZIBs, mainly due to its layered structure and high theoretical capacity (588.4 mA h g –1 based on V 3+ /V 5+ redox). ,− Generally, the intercalation of a foreign ion into α-V 2 O 5 takes place on the a – b plane in sixfold coordination with oxygen. Unfortunately, due to the compact gallery space of the a – b plane (4.37 Å), in which single V–O layers composed of VO 5 square pyramids are tightly stacked, the intercalation and diffusion of Zn 2+ are rather difficult. , However, previous studies have surprisingly shown a good charge capacity and rate capability of α-V 2 O 5 . − Another trend observed in Zn/α-V 2 O 5 batteries was the capacity increasing with cycling in the initial cycles, which was proposed to derive from in situ phase transformation of α-V 2 O 5 to hydrated zinc pyrovanadate (Zn 3 (OH) 2 V 2 O 7 ·2H 2 O or ZVO), into which a reversible Zn 2+ /H + intercalation/extraction takes place in the subsequent cycles .…”

Ammonium vanadate cathode materials with enhanced Zn storage by the optimization of electrolytes

“…Thus far, some potential electrode materials, including Prussian blue, manganese-based materials, vanadium-based materials, organic materials, polyanionic compounds and so on, have been reported. [17][18][19][20][21][22][23][24][25][26] Among them, ternary vanadate shows potential applications because of its high theoretical capacity. For instance, Li et al designed a kind of layered K 2 V 3 O 8 nanostructure as an electrode.…”

Layer-by-layer stacked vanadium nitride nanocrystals/N-doped carbon hybrid nanosheets toward high-performance aqueous zinc-ion batteries

“…Vanadium-based compounds are highly promising anode materials for AZIBs due to safety, high theoretical capacity, and rich resources. In addition, tunnel and layered types of vanadium-based anode materials, [18][19][20][21] O, exhibit an open skeleton and high specific surface areas owing to the various valence states of vanadium (V 2+ to V 5+ ).…”