Intrinsic Structure Modification of Electrode Materials for Aqueous Metal‐Ion and Metal‐Air Batteries

Abstract

In consideration of low cost, simple operation, safe reliability, and environmental benignity, aqueous rechargeable batteries (ARBs) have attracted great interest among portable electronic devices, energy storage, and power source batteries. As the key components of ARBs, the electrode materials lead to a crucial effect for the overall battery properties, such as working voltage, electrocatalytic activity, capacity, and cycling stability. However, owing to the highly reactive aqueous environment, the electrode materials typically demonstrate a series of issues, including active material dissolution, structural instability, and poor catalytic activity, restricting their application. So far, several researchers have devoted much effort to improve the properties of electrode materials for ARBs. In particular, intrinsic structure modification in terms of vacancy regulation, interlayer engineering, and element doping have been applied to optimize the electronic and phase structure of electrode materials, contributing to elevated ion diffusion, fast charge transfer, and adequate active sites for electrochemical reaction. In this review, recent reports are demonstrated about the intrinsic structure modification of electrode materials in aqueous metal‐ion and metal‐air batteries, focusing on various regulation strategies and functional mechanisms. Finally, a brief conclusion and perspective is presented to demonstrate constructive suggestions and opinions for further research.

Ultrafast Rechargeable Aqueous Zinc‐Ion Batteries Based on Stable Radical Chemistry

“…[ 2–4 ] Compared with the ionic conductivities of organic electrolytes (1–10 mS cm −1 ), those of water‐based electrolytes are up to 1 S cm −1 in favor of high rate capabilities. [ 5 ] Among the emerging aqueous rechargeable battery systems, aqueous zinc‐ion batteries (ZIBs) have attracted extensive attentions for fast charge storage. [ 6–8 ]…”

Supramolecular Gel‐Derived Highly Efficient Bifunctional Catalysts for Omnidirectionally Stretchable Zn–Air Batteries with Extreme Environmental Adaptability

“…The ultrahigh bifunctional catalytic activity and remarkable stability of the rationally designed NiFe/B,N-CNFs are expected to ensure good electrochemical performance for ZABs under extreme working conditions. [51] Based on the concept design proposed in Scheme 1, an omnidirectionally stretchable ZAB was assembled. The structure and fabrication of the stretchable ZAB are schematically shown in Figure 3a and Video S1, Supporting Information.…”

“…The ultrahigh bifunctional catalytic activity and remarkable stability of the rationally designed NiFe/B,N‐CNFs are expected to ensure good electrochemical performance for ZABs under extreme working conditions. [ 51 ]…”

Insight into the Active Contribution of N-Coordinated Cobalt Phosphate Nanocrystals Coupled with Carbon Nanotubes for Oxygen Electrochemistry

“…Rechargeable zinc–air batteries, benefiting from their impressive rechargeable efficiency and outstanding theoretical energy density (1086 Wh kg –1 ), are emerging as one of the most attractive technologies for sustainable energy conversion and storage. − In principle, the overall efficiency of the zinc–air battery highly relies on the performance of the oxygen cathode, wherein the commutative oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) occur during the discharge process and charge process, respectively. − Both the OER and ORR are the typical multiple proton-coupled electron transfer reactions, and their sluggish reaction kinetics always results in enlarged cathodic overpotentials and inferior overall battery efficiency, impairing the commercial applications of zinc–air batteries. , Usually, noble metal materials, for instance, Pt-based catalysts and IrO 2 /RuO 2 catalysts, exhibit excellent ORR or OER electrocatalytic activities, whereas their high cost, scarce crustal abundance, poor durability, and poor bifunctional activity retard the large-scale implementation severely. , From these considerations, it is highly urgent and necessary to develop efficient and robust bifunctional electrocatalysts from earth abundant elements and investigate their actual zinc–air battery performance.…”