Thionin as a Bipolar Organic Cathode Material for Aqueous Rechargeable Zinc Batteries

Abstract

Organic cathode materials (OCMs) have been widely applied in aqueous rechargeable zinc batteries (ARZBs), but there are still many novel structures to be explored for better electrochemical performance and clearer mechanism. Herein, we have studied an organic biological dye, namely thionin (Thn‐CH3COO), as a bipolar‐type OCM for ARZBs based on its electroactive phenothiazine unit. In the optimal electrolyte of 2 M Zn(CF3SO3)2, Thn‐CH3COO exhibited the lowest solubility and thus the highest cycling stability (94 % capacity retention after 100 cycles), with a reversible capacity of 162 mAh g−1 (the theoretical value is 186 mAh g−1) and a discharge plateau at ∼0.8 V vs. Zn2+/Zn. Various characterization and DFT calculations have revealed that both CH3COO− and CF3SO3− anions and H+ cations participated the p‐type and n‐type reactions, respectively. In brief, the novel structure, competitive performance, and exhaustive mechanism investigation will facilitate the further development of ARZBs based on OCMs.

A High‐Potential Bipolar Phenothiazine Derivative Cathode for Aqueous Zinc Batteries

“…The authors have cited additional references within the Supporting Information. [43][44][45][46][47][48][49][50][51][52][53][54][55]…”

Recent advance and design strategies of chalcogenides for high-performance aqueous zinc-ion batteries

“…Significant advancements have been made in enhancing the electrochemical performance of cathode materials, such as manganese-based oxides [18][19][20], vanadium-based oxides [21][22][23], Prussian blue analogues [24][25][26], and organic compounds [27][28][29]. These materials possess either a tunneltype structure with ion channels or a layered-type structure with large interlayer spacing (figure 1).…”

“…Organic compounds have found comprehensive application in AZIBs due to their lightweight nature, multiple electron reactions, low toxicity, sustainability, cost-effectiveness, and controllable synthesis. However, their high dissolubility and low electron conductivity impede their electrochemical properties [28].…”

Carboxyl‐Substituted Organic Molecule Assembled with MXene Nanosheets for Boosting Aqueous Na+ Storage

“…[7,8] More importantly, the use of aqueous electrolytes can eliminate the risk of flammability caused by organic electrolytes, allowing the aqueous alkali-ion batteries to avoid severe safety hazards. [9][10][11] Unfortunately, the limited potential window of water raises the difficulties of selecting electrode materials, hence the exploration of suitable electrode materials that are capable of inserting alkali-ions is of tremendous significance for developing high-performance aqueous alkali-ion batteries.…”