Rechargeable Zinc–Air Batteries: Advances, Challenges, and Prospects

Abstract

Rechargeable zinc–air batteries (Re‐ZABs) are one of the most promising next‐generation batteries that can hold more energy while being cost‐effective and safer than existing devices. Nevertheless, zinc dendrites, non‐portability, and limited charge–discharge cycles have long been obstacles to the commercialization of Re‐ZABs. Over the past 30 years, milestone breakthroughs have been made in technical indicators (safety, high energy density, and long battery life), battery components (air cathode, zinc anode, and gas diffusion layer), and battery configurations (flexibility and portability), however, a comprehensive review on advanced design strategies for Re‐ZABs system from multiple angles is still lacking. This review underscores the progress and strategies proposed so far to pursuit the high‐efficiency Re‐ZABs system, including the aspects of rechargeability (from primary to rechargeable), air cathode (from unifunctional to bifunctional), zinc anode (from dendritic to stable), electrolytes (from aqueous to non‐aqueous), battery configurations (from non‐portable to portable), and industrialization progress (from laboratorial to practical). Critical appraisals of the advanced modification approaches (such as surface/interface modulation, nanoconfinement catalysis, defect electrochemistry, synergistic electrocatalysis, etc.) are highlighted for cost‐effective flexible Re‐ZABs with good sustainability and high energy density. Finally, insights are further rendered properly for the future research directions of advanced zinc–air batteries.

Synergistic Pore Structure and Active Site Modulation in Co–N–C Catalysts Enabling Stable Zinc–Air Batteries

“…6 In particular, transition metals (Fe, Co, Mn) and N-doped carbon-based hybrids (M− N−C), which are optimal bifunctional oxygen catalysts, are essential for cathodic oxygen electrodes of ZABs. 12,13 On the one hand, in addition to providing plentiful reactive sites and smooth transport pathways for the OER/ORR, porous nanocarbons have excellent stability and conductivity, which helps to speed up chemical reactions. On the other hand, by combining heteroatoms with transition-metal active substances (including monometallic, multimetallic atoms, nanoparticles (NPs) (alloys and oxides)), the carbon skeleton can be used as a really good electron donor or acceptor in electrochemical reactions, thus improving the performance and energy conversion efficiency of M−N−C hybrid materials.…”

“…In the past few years, many nonprecious metal-based catalysts, including transition-metal oxides, sulfides, nitrides, phosphates, carbides, and carbon-based nanomaterials and their composites, have been developed for the catalytic processes of ORR and/or OER . In particular, transition metals (Fe, Co, Mn) and N-doped carbon-based hybrids (M–N–C), which are optimal bifunctional oxygen catalysts, are essential for cathodic oxygen electrodes of ZABs. , On the one hand, in addition to providing plentiful reactive sites and smooth transport pathways for the OER/ORR, porous nanocarbons have excellent stability and conductivity, which helps to speed up chemical reactions. On the other hand, by combining heteroatoms with transition-metal active substances (including monometallic, multimetallic atoms, nanoparticles (NPs) (alloys and oxides)), the carbon skeleton can be used as a really good electron donor or acceptor in electrochemical reactions, thus improving the performance and energy conversion efficiency of M–N–C hybrid materials. ,− For example, Li and co-workers developed a combined polymer coating, wet chemistry adsorption, ammonia treatment, and pyrolysis approach to construct a single-atom Fe catalyst over a mesoporous nitrogen-doped carbon catalyst (Fe SAs/NC).…”

Graphitic Carbocatalysts with Pentagon Defects Synthesized from Polyperylene for Electrocatalytic Oxygen Reduction and Flexible Zinc-Air Batteries

“…However, the sluggish cathode reaction, namely electrochemical oxygen reduction reaction (ORR), which is an important part of such battery systems, suffers from a serious bottleneck of slow reaction kinetics, greatly impeding the commercialization of these batteries. Although platinum-based precious metal catalysts possess excellent ORR activity, their high cost, rarity, and poor stability still cannot meet the large-scale application …”

“…Although platinum-based precious metal catalysts possess excellent ORR activity, their high cost, rarity, and poor stability still cannot meet the large-scale application. 4 To tackle these issues, carbocatalysts have garnered significant researchers' attention and emerged as a potential alternative, considering their relatively low cost and better stability. 5−7 Typically, the fabrication of functional carbocatalysts can be achieved through methods such as doping, activating, or etching various carbon substrates at the nanoscale, 2,8 collectively referred to as post-treatment techniques.…”

Aqueous Rechargeable Zinc–Metal Batteries: A Critical Analysis

“…Past research on a Zn anode (10–40% DOD) with low charge/discharge utilization for RAA batteries has reported a poor energy efficiency due to surplus or unreacted Zn–metal anodes, which determines the energy density. Similar with RAM batteries, achieving a long cycle life with a DOD Zn of 100% for Zn–air batteries is practically very difficult due to high Zn passivation. − …”