Design Strategies for High‐Performance Aqueous Zn/Organic Batteries

Abstract

Organic electroactive compounds are attractive to serve as the cathode materials of aqueous zinc‐ion batteries (ZIBs) because of their resource renewability, environmentally friendliness and structural diversity. Up to now, various organic electrode materials have been developed and different redox mechanisms are observed in aqueous Zn/organic battery systems. In this Minireview, we present the recent developments in the energy storage mechanisms and design of the organic electrode materials of aqueous ZIBs, including carbonyl compounds, imine compounds, conductive polymers, nitronyl nitroxides, organosulfur polymers and triphenylamine derivatives. Furthermore, we highlight the design strategies to improve their electrochemical performance in the aspects of specific capacity, output voltage, cycle life and rate capability. Finally, we discuss the challenges and future perspectives of aqueous Zn/organic batteries.

Electrochemical Zinc Ion Capacitors: Fundamentals, Materials, and Systems

“…[ 108–110 ] Meanwhile, extra pseudocapacitance can also be obtained by grafting redox materials. [ 117,235 ] The low conductivity of redox materials can be enhanced by compositing high‐conductive advanced materials like MXenes or graphene.…”

“…According to their charge storage mechanism, redox organic materials can be classified into n, p, and bipolar types. [ 117 ] N‐type redox organic materials undergo reduction reactions with cation adsorption during the discharge process ( Figure 8 a). In contrast, p‐type redox organic materials go through oxidation reactions with anion adsorption during the discharge process (Figure 8b).…”

“…Reproduced with permission. [ 117 ] Copyright 2020, Wiley‐VCH. c) Schematic illustrating the charging and discharge process of Zn//poly(3,3′‐DHB)/AC ZIC.…”

A Polymer/Graphene Composite Cathode with Active Carbonyls and Secondary Amine Moieties for High‐Performance Aqueous Zn‐Organic Batteries Involving Dual‐Ion Mechanism

“…Therefore, they are almost insoluble in the aqueous electrolytes with a relatively large molecular weight. [8,37] Furthermore, conductive polymers usually show stable redox behaviors via anion delocalization, providing higher working voltage. [38][39][40][41][42] For example, in the case of Zn/polyaniline (PANI) batteries, the deposition/dissolution of Zn 2+ /Zn occurs in the anode side, while the counter anions will participate in the reaction between the NH +  and NH moieties in the cathode side during charge/discharge processes, which is regarded as dual-ion mechanism.…”

Construction of a Poly(anthraquinone Sulfide)/Carbon Nanotube Composite with Enhanced Li‐ion Storage Capacity

“…By contrast, organic compounds have received great attention as active materials for rechargeable battery electrodes due to their advantages such as structural diversity, reproducibility, low cost, light weight, and environmental friendliness. [2][3][4] Moreover, organic electrode materials are usually not limited by counterion selection and will, therefore, have a wider application range than that inorganic electrode materials. [5] In particular, carbonyl compounds, and especially quinone compounds, have emerged among the most promising candidate organic energy storage materials due to their advanta-geously high theoretical energy density, fast speed, and good reaction reversibility .…”