(Digital Presentation) Ionic Liquid-Based Electrolytes for Evaluation of Anthraquinone Derivative As Cathode in Zinc Ion Battery

Abstract

Aqueous zinc ion batteries are a very promisingly emerging class of energy storage devices. They are brought to the attention of the researchers owing to the abundant resourcefulness, user and environmental friendliness, and excellent water compatibility unlike the alkaline and alkaline earth metals. Unfortunately, their research and development are still in the unmatured stage. Few of the inorganic materials, such as oxides of manganese, vanadium, Prussian blue, etc., are some of the inorganic materials evaluated as cathode for zinc batteries. Even though inorganic materials offer high energy density which directly affects the size of the battery, they face some serious constraints of being used for real practical applications. They undergo irreversible structural lattice changes during the cycling process which ultimately deteriorate the battery performance over prolonged cycling. In addition, they face serious dissolution problems, lack of resourcefulness, and environmental non-benignity. In this regard, organic cathodes are interesting candidates because of their flexibility, simple charge storage mechanism, numerous choices of molecular engineering, and high resourcefulness. Herein, we studied the anthraquinone derivative as an organic cathode in ionic liquid electrolytes. Even though aqueous electrolytes are user-friendly, excessive water evaporation occurs with subsequent salt crystallization on the electrode which deteriorates the battery performance. We previously reported on addressing the restriction of water evaporation by choosing ethylene glycol as an electrolyte additive. Since ionic liquid exists as a liquid at room temperature, we selected different types of ILs, ie., imidazole containing different types of alkyl and functionalized alkyl chains as shown in the figure.This work essentially emphasizes the aqueous zinc battery performance using functionalized ionic liquids as electrolytes with a newly designed anthraquinone-based organic cathode. It has been observed that the zwitterionic electrolyte exhibited comparatively good capacity performance of 156.2 mAhg-1 at 50 mAg-1 current density. The cycling stability, as well as coulombic efficiency, were also found to be much promising. On the whole, user-friendly organic-based electrolyte, as well as organic cathode, converge a new integrated electrode-electrolyte system for zinc ion battery. The detailed battery performance and post-mortem analysis have also been performed which reinvigorate the battery research, for zinc-like multivalent ion-based batteries in particular. Figure 1