Aqueous Zn‐based rechargeable batteries: Recent progress and future perspectives

Abstract

Benefiting from the advantageous features of high safety, abundant reserves, low cost, and high energy density, aqueous Zn‐based rechargeable batteries (AZBs) have received extensive attention as promising candidates for energy storage. To achieve high‐performance AZBs with high reversibility and energy density, great efforts have been devoted to overcoming their drawbacks by focusing on the modification of electrode materials and electrolytes. Based on different cathode materials and aqueous electrolytes, the development of aqueous AZBs with different redox mechanisms are discussed in this review, including insertion/extraction chemistries (e.g., Zn2+, alkali metal ion, H+, NH4+, and so forth) dissolution/deposition reactions (e.g., MnO2/Mn2+), redox couples in flow batteries (e.g., I3−/3I−, Br2/Br−, and so forth), oxygen electrochemistry (e.g., O2/OH−, O2/O22−), and carbon dioxide electrochemistry (e.g., CO2/CO, CO2/HCOOH). In particular, the basic reaction mechanisms, issues with the Zn electrode, aqueous electrolytes, and cathode materials as well as their design strategies are systematically reviewed. Finally, the remaining challenges faced by AZBs are summarized, and perspectives for further investigations are proposed.

A Functional Organic Zinc-Chelate Formation with Nanoscaled Granular Structure Enabling Long-Term and Dendrite-Free Zn Anodes

“…Zn metal batteries (ZMBs) with high safety and abundant resources have been widely studies in mild aqueous electrolytes because of the appealing merits of Zn anode, comprising high theoretical capacity (820 mAh g –1 , 5854 mAh L –1 ) and low electrochemical potential (−0.76 V vs SHE). − Nevertheless, the direct contact between the water-based electrolyte and zinc together with the lower redox potential of Zn 2+ /Zn than H + /H 2 (0 V vs SHE) would cause baneful interfacial parasitic reactions including chemical corrosion and H 2 evolution, thereby leading to severe byproduct accumulation and electrode passivation. − Such behaviors in turn accelerate nonuniform formation and dendrite growth, eventually bringing about undesirable electrolyte consumption, low coulombic efficiency (CE), and short cycling lifespan. − Thus, feasible and efficient strategies to inhibit side reactions and Zn dendrites are urgent for stable zinc anodes for large scale applications.…”

A universal spray printing strategy to prepare gradient hybrid architectures

“…Vanadium oxides are the promising electrode materials of energy storage devices due to their multiple valence states, diverse crystallographic structures, and convenient structural regulation. [21][22][23][24][25][26][27][28][29] Owing to their excellent mechanical properties and gradient conductive paths, free-standing V 2 O 5 / CNTs GCFs are able to be directly used as the electrodes of energy storage devices, avoiding the use of binder agents and current collector. Among various energy storage devices, aqueous zinc-ion batteries (ZIBs) are attracting more attention due to their high safety, environmental friendliness, and low cost.…”

“…As a result, they will have potential applications in many fields, such as energy storage and conversion, energy harvesting, environmental remediation, and photoelectric devices. Vanadium oxides are the promising electrode materials of energy storage devices due to their multiple valence states, diverse crystallographic structures, and convenient structural regulation 21–29 . Owing to their excellent mechanical properties and gradient conductive paths, free‐standing V 2 O 5 /CNTs GCFs are able to be directly used as the electrodes of energy storage devices, avoiding the use of binder agents and current collector.…”

Towards the practical application of Zn metal anodes for mild aqueous rechargeable Zn batteries

“…Owing to the high theoretical specic capacity of Zn anodes and multi-charge intercalation chemistry of Zn 2+ , mildly acidic aqueous Zn batteries are expected to deliver high gravimetric energy density and have attracted surging interest in the research community. [66][67][68] In practice, the achievable energy density of aqueous Zn batteries should be carefully considered for the use of many inactive components (carbon additives, current collectors, separators, cell package, etc.) and extra Zn metal anodes.…”