High‐Voltage Electrolytes for Aqueous Energy Storage Devices

Abstract

Aqueous energy storage devices have been considered as one of the most promising candidates for large-scale energy storage owing to their high safety and low cost. However, the narrow stability voltage window of electrolytes originating from the decomposition of water limits their energy density. In this Minireview, we discuss the limited energy density of aqueous energy storage devices in detail, and then the water decom-position mechanism and corresponding key factors. Furthermore, we present the comprehensive overview of the strategies for increasing the stability of aqueous electrolytes, including redox-active additives, pH regulation of electrolytes, utilization of water-in-salt electrolytes, and selection of highly stable electrolyte salts. Finally, this Minireview also offers insights in the design of high-voltage aqueous electrolytes. The Limited Energy Density of Aqueous Energy Storage DevicesThe common aqueous energy storage devices are supercapacitors and batteries. The two systems are quite different on [a] Dr.

Design Strategies for High‐Performance Aqueous Zn/Organic Batteries

“…With the increased concerns about natural resources and environmental issues,i ti sh ighly desired to develop renewable electrode materials of aqueous ZIBs.C ompared with inorganic counterparts,organic cathode materials are mainly made up of C, H, O, Nand Selements,which are abundant on the earth. Importantly,t hey can be obtained by artificial synthesis or from abundant biomass resources.Inthe artificial synthesis,m ost reactants can be achieved from the natural resources directly.F or example, p-aminobenzoic acid is an essential precursor for the synthesis of calix [4]quinone (C4Q), which can be prepared from wheat bran. [32] Furthermore, some redox-active organic molecules even exit in biomass resource.F or instance,r iboflavin (RF) that can act as the electrode material of aqueous ZIBs is widely distributed in our food, such as eggs,m ilk and fruit.…”

“…Rechargeable aqueous zinc-ion batteries (ZIBs) are attracting tremendous attention because the Zn anode possesses intrinsic merits such as high specific capacity (820 mAh g À1 and 5855 mAh cm À3 ), low redox potential (À0.76 Vv s. standard hydrogen electrode (SHE)), dramatic stability in water and low cost. [1] Recently,the development of aqueous ZIBs mainly focuses on design of cathode materials, [2,3] optimization of electrolytes, [4] and modification of Zn anode. [5,6] Among them, the design of cathode materials plays ac ritical role in enhancing the electrochemical performance of aqueous ZIBs.V arious cathode materials of aqueous ZIBs have been developed, such as transition-metal oxides or sulfides (based on manganese, [7][8][9][10] vanadium [11][12][13][14][15][16] and molybdenum [17] ), Prussian blue analogues, [18] V-based NASI-CONs [19] and organic compounds.…”

Thermal‐Gated Polymer Electrolytes for Smart Zinc‐Ion Batteries

“…[7] Therefore, the design of the separator with a thermal-responsive porous structure is a promising strategy for controlling the migration of conductive ions and achieving the self-protection of the ZIBs at high temperature. [8] The poly(N-isopropylacrylamide) (PNIPAM) based hydrogel is a class of thermal-responsive polymers with porous networks that shrink at temperatures beyond its volume phase transition temperature (VPTT) because of the formation of intramolecular hydrogen bonds in PNIPAM chains. [9] More impressively, when cooled, its porous network structure recovers.…”

Flexible and Wearable Power Sources for Next‐Generation Wearable Electronics

“…[81] In this case, aqueous-based electrolytes are promising ionic conducting media with no flammable tendency. [83,84] Moreover, the use of semi-solid polymer electrolytes is an effective strategy to solve this problem. For example, hydrogel polymer electrolyte possesses a three-dimensional polymeric network within which the water is trapped primarily through surface tension to address leakage issues.…”