Proton storage chemistry in aqueous zinc‐organic batteries: A review

Abstract

Benefiting from the advantageous features of structural diversity and resource renewability, organic electroactive compounds are considered as attractive cathode materials for aqueous Zn-ion batteries (ZIBs). In this review, we discuss the recent developments of organic electrode materials for aqueous ZIBs. Although the proton (H + ) storage chemistry in aqueous Zn-organic batteries has triggered an overwhelming literature surge in recent years, this topic remains controversial. Therefore, our review focuses on this significant issue and summarizes the reported electrochemical mechanisms, including pure Zn 2+ intercalation, pure H + storage, and H + /Zn 2+ co-storage. Moreover, the impact of H + storage on the electrochemical performance of aqueous ZIBs is discussed systematically. Given the significance of H + storage, we also highlight the relevant characterization methods employed. Finally, perspectives and directions on further understanding the charge storage mechanisms of organic materials are outlined. We hope that this review will stimulate more attention on the H + storage chemistry of organic electrode materials to advance our understanding and further its application.

Advances in organic cathode materials for aqueous multivalent metal-ion storage

“…18,33,71,[96][97][98][99][100][101] Protons (H + ) are considered as attractive charge carriers due to their merits of small radius and light atomic mass. 102,103 The Grotthuss mechanism, a special proton hopping process that takes place in aqueous environments, gives protons unparalleled ion mobility to consequently realize the fast H + (de)sorption kinetics. NH 4 + as a potential charge carrier can take action in weakly acidic and neutral environments with the safety, non-toxicity, and ecofriendliness advantages, which is beneficial for future grid-scale energy storage.…”

High-Voltage and Stable Manganese Hexacyanoferrate/Zinc Batteries Using Gel Electrolytes

“…The development of AZIB cathode materials is mainly focusing on vanadium-based compounds, manganese-based compounds, Prussian blue and its analogues (PBAs), and organics-based compounds. − Most materials have acceptable specific capacity, but the output voltages are generally low, such as 1.2–1.4 V for Mn-based compounds, 0.6–0.9 V for V-based compounds, and about 1 V for organic compounds. − Considering the demands on high energy density and power density, PBAs are better choices as the cathode candidates because they have the highest voltage (>1.5 V).…”

Covalent Organic Frameworks as Promising Electrode Materials for High-Valent Ion Rechargeable Batteries

“…With the explosive growth of demand on lithium-ion batteries (LIBs) with high energy density in portable electronic products, the prices of key raw materials for LIBs such as lithium, cobalt, and nickel continue to rise. , At the same time, battery safety is becoming increasingly crucial in the pursuit of extensive and efficient energy storage. , Designing low-cost, safe, high-energy-density, and environment-friendly energy storage systems is an important guarantee for the sustainable development of human beings. , To fully leverage the advantages of wind and solar power generation, high-valent metal-ion batteries with low energy storage cost and high theoretical volume energy density show potential broad application prospects in large-scale power grids. − Rechargeable high-valent metal-ion batteries (HMIBs) mainly include zinc-ion batteries (ZIBs), magnesium-ion batteries (MIBs), calcium-ion batteries (CIBs), and aluminum-ion batteries (AIBs). Based on the benefits of high natural abundance of high-valent metals, low activity in air, and high-electron redox reaction, HMIBs are considered as potential replacements for LIBs (Figure a).…”