Charge Carriers for Aqueous Dual‐Ion Batteries

Abstract

Environmental and safety concerns of energy storage systems call for application of aqueous battery systems which have advantages of low cost, environmental benignity, safety, and easy assembling. Among the aqueous battery systems, aqueous dual‐ion batteries (ADIBs) provide high possibility for achieving excellent battery performance. Compared with the “rocking chair” batteries with only one type of carrier involved in the charging and discharging, ADIBs with both cations and anions as charge carriers possess diverse selections of electrodes and electrolytes. Charge carriers are the basis of the configuration of ADIBs. In this Review, cations and anions that could be applied in ADIBs are demonstrated with corresponding electrode materials and favorable electrolytes. Some insertion mechanisms are emphasized to provide insights for the possibilities to enhance the practical performances of ADIBs.

Anion-hosting cathodes for current and late-stage dual-ion batteries

“…Theoretically, the anode materials that are used in most non-aqueous metal-ion batteries, such as LIBs, may also be used in DIBs [52][53][54][55][56]. However, unlike anode materials, the cathode materials of DIBs need to store large-size anions (such as PF 6 -, BF 4 -, FSI -, FTFS -, TFSI -, and ClO 4 -) [57][58][59], which show slower ion-diffusion rates than those of alkali metal ions, resulting in inferior electrochemical properties [3,60].…”

Reverse Dual‐Ion Battery Enabled by Reversing the Cation/Anion Storage Mechanism in an Aqueous ZnCl2 Water‐in‐Salt Electrolyte

“…[12][13][14][15][16][17][18][19] However, DIBs with multivalent charge carrier-electrolytes have demonstrated higher energy density in comparison to univalent charge carrier-electrolytes. [20][21][22] Additionally, electrode materials such as molecular organic framework (MOF), MXenes, organic materials, graphite etc., [23][24] have been explored as ion-hosts in DIBs, with graphite-based cathode electrodes being a preferred choice for anion storage in conventional DIBs. [4] Nevertheless, Challenges such as the dissolution of anode electrode materials, and electrolyte decomposition pose major concerns, limiting the freedom of material choices for DIB systems.…”