Molecular Engineering of Aromatic Imides for Organic Secondary Batteries

Abstract

Aromatic imides are a class of attractive organic materials with inherently electroactive groups and large π electron‐deficient scaffolds, which hold potential as electrode materials for organic secondary batteries (OSBs). However, the undecorated aromatic imides are usually plagued by low capacity, high solubility in electrolyte, and poor electronic/ionic conductivity. Molecular engineering has been demonstrated to be an effective strategy to address unsatisfying characteristics of the aromatic imides, thereby expanding their scope for applications in OSBs. In this review, the recent research progress in modulation of the capacity, dissolution, and electronic/ionic conductivity of aromatic imides for organic lithium batteries, organic sodium batteries, and redox flow batteries are summarized. In addition, the challenge and prospective of aromatic imides in organic secondary battery applications are also discussed.

Optimization of Monomer Molecular Structure for Polymer Electrodes Fabricated through in‐situ Electro‐Polymerization Strategy

“…Nonetheless, they often suffer from severe dissolution in organic electrolytes and low electrical conductivity, leading to fast capacity fading and inferior rate performance [8,9] . To date, many methods have been adopted to alleviate the dissolution problem, including (1) the surface coating (Al 2 O 3 ) via atomic layer deposition, [10] (2) adding selectively permeable membrane, [11–13] (3) using solid‐state or high‐concentration electrolytes, [14,15] (4) encapsulating the active materials into microporous carbon scaffold (such as CMK‐3), [16] (5) using reasonable molecular design, [17] salification, [18] or polymerization, [19–22] and so on [23,24] . Among them, constructing polymers containing redox‐active units have been proved to be an effective approach, which could efficaciously inhibit the dissolution of redox‐active small molecules.…”

Extending π‐Conjugation and Integrating Multi‐Redox Centers into One Molecule for High‐Capacity Organic Cathodes

“…Organic electrode materials for rechargeable batteries have attracted much attention for their designable structures, eco‐sustainability, and cost‐effectiveness [1–7] . Scientists have discovered many types of redox‐active organic compounds suitable for energy storage, such as nitroxides, [8–11] imines, [12,13] quinones, [14–16] and imides [17,18] . However, due to the low specific capacity and dissolution in electrolytes, we need continuous effort to develop high‐capacity organic materials comparable to inorganic materials.…”

Immobilizing Redox‐Active Tricycloquinazoline into a 2D Conductive Metal–Organic Framework for Lithium Storage

“…Owing to their abundant resource, environmental friendliness, flexible structure designability and high theoretical capacity, organic electrode materials have inspired numerous interests in LIBs [3] . Among various organic electrode materials, heteroaromatic‐conjugated aromatic molecules with multi‐electron redox activity for Li + storage [4] originated from the redox‐active group like C=N, [5] C≡N, [6] and N=N [7] can ensure a high specific capacity, thus they are now drawing increasing research interest for high‐energy‐density LIBs electrodes [8] . Despite their advantages, the development of organic electrodes based on heteroaromatic‐conjugated aromatic molecules is challenged by their easy dissolution in organic electrolytes, low electronic conductivity and sluggish reaction kinetics [9] .…”

“…[3] Among various organic electrode materials, heteroaromatic-conjugated aromatic molecules with multi-electron redox activity for Li + storage [4] originated from the redox-active group like C=N, [5] C N, [6] and N = N [7] can ensure a high specific capacity, thus they are now drawing increasing research interest for highenergy-density LIBs electrodes. [8] Despite their advantages, the development of organic electrodes based on heteroaromatic-conjugated aromatic molecules is challenged by their easy dissolution in organic electrolytes, low electronic conductivity and sluggish reaction kinetics. [9] Building such redox-active molecules into polymeric structures, like metal-organic frameworks (MOFs) which are constructed by functional molecular building blocks and metal nodes, [10] have witnessed numerous successes in resisting the solubility in organic electrolytes to ensure a robust electrode.…”