Recent Advances in Materials and Design of Electrochemically Rechargeable Zinc–Air Batteries

Abstract

The century-old zinc-air (Zn-air) battery concept has been revived in the last decade due to its high theoretical energy density, environmental-friendliness, affordability, and safety. Particularly, electrically rechargeable Zn-air battery technologies are of great importance for bulk applications like electric vehicles, grid management, and portable electronic devices. Nevertheless, Zn-air batteries are still not competitive enough to realize widespread practical adoption because of issues in efficiency, durability, and cycle life. Here, following an introduction to the fundamentals and performance testing techniques, the latest research progress related to electrically rechargeable Zn-air batteries is compiled, particularly new key findings in the last five years (2013-2018). The strategies concerning the development of Zn and air electrodes are in focus. The design of other battery components, namely electrolytes and separators are also discussed. Poor performance of O electrocatalysts and the lack of the long-term stability of Zn electrodes and electrolytes remain major challenges. Finally, recommendations regarding the testing routines and materials design are provided. It is hoped that this up-to-date account will help to shape the future research activities toward the development of practical electrically rechargeable Zn-air batteries with extended lifetime and superior performance.

Synthesis of Porous Carbon‐coated Cobalt Catalyst through Pyrolyzing Metal–Organic Framework and their Bifunctional OER/ORR Catalytic Activity for Zn‐Air Rechargeable Batteries

“…In light of this, several studies have been conducted to investigate catalysts that show higher catalytic activity for both OER and ORR while using simpler techniques. Through these studies, transition metals such as Co and Ni and their oxides, as well as perovskites, are most widely studied …”

Recent Advances in Carbon‐Based Bifunctional Oxygen Catalysts for Zinc‐Air Batteries

“…However, Li‐ion batteries face a number of challenges, especially the safety issues and the uprising cost of battery materials . To avoid these problems, the development of alternative electrochemical energy storage and conversion technologies (e. g., sodium‐ion batteries, lithium‐metal batteries, lithium and nonlithium metal‐sulfur batteries, fuel cells, and metal‐air batteries) has led to intensive research activity. Among them, metal‐air batteries have gained special research interests due to their very high energy density, low cost, and environment‐friendly operation.…”

“…Amongst, carbon materials are the most popular candidates to construct efficient bifunctional oxygen catalysts for ZABs, due to their high electrical conductivity, high chemical stability, versatile porous nanostructure, tunable physical and chemical properties, and low cost . Remarkably, the electronic structure of carbon materials can be facilely modified via multiple regulation strategies (e. g., heteroatom doping, defect engineering, surface engineering, etc .)…”

A Composite Bifunctional Oxygen Electrocatalyst for High‐Performance Rechargeable Zinc–Air Batteries

“…Typically, a rechargeable zinc–air battery is constructed from a zinc metal anode, an air cathode, and an aqueous alkaline electrolyte together with zinc salts . The anode process involves the reversible plating/stripping of zinc whereas the cathode reactions are the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) during charge and discharge, respectively .…”

“…Typically,ar echargeable zinc-airb attery is constructed from az inc metal anode, an air cathode, anda na queous alkaline electrolyte togetherw ith zinc salts. [11] The anode process involves the reversible plating/stripping of zinc whereas the cathoder eactions are the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) during charge and discharge,r espectively. [12] Both ORR and OER are multi-electron reactionso ccurring at multi-phase boundaries and thus are heavily sluggish in kinetics, which renders large voltage gaps, [13] reduced energyefficiency, [14] andlimited cycling stability.…”