Thiosalicylic Acid Modified Graphene Aerogel as Efficient Electrode Material for Ionic Liquid Electrolyte-Based Supercapacitors

Abstract

Balancing energy density and power density of supercapacitors is highly desired to extend their application range. The development of new electrode materials with efficient electron/ion migration channels and large surface area accessible by the ionic liquid (IL) electrolyte with high stable potential window is a critical way to construct the high-performances of supercapacitors. In this work, a thiosalicylic acid modified graphene aerogel (TGA) was prepared by hydrothermal treatment of a graphene oxide precursor using thiosalicylic acid (TSA) as reductant, sulfur-dopant, and modifier. As-prepared TGA material has hierarchically porous texture with wide pore size distribution range and large accessible surface area by IL electrolytes, which is beneficial to the rapid diffusion and adsorption of IL electrolyte ions with larger ion sizes and high viscosity. Therefore, the TGA material possesses high specific capacitance and rate capability. Using 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmim][Tf 2 N]) IL electrolyte, the assembled symmetric TGA-based supercapacitor can deliver energy densities of 115−28 Wh kg −1 within power densities of 946−11586 W kg −1 . The current work provides a feasible avenue to accomplish the balance between energy density and power density of supercapacitors via the design and synthesis of hierarchically porous graphene aerogels containing doped-heteroatoms and matching with IL electrolyte.

Experimental and Theoretical Indagation of Binder-Free N-Graphene Coupling Vanadium Tetrasulfide Aerogel Cathode for Promoting Aqueous Zn-Ion Storage

“…To achieve this, the construction of three-dimensional (3D) free-standing graphene aerogel is a feasible strategy. The graphene aerogel contains interconnected 2D sheets with rich pores and ultralow density and flexibility, while the restacking of sheets can be effectively inhibited. − Benefiting from its structure advantages, the 3D architecture can provide higher electrical conductivity for rapid ion/electron transport, a larger electrode/electrolyte interfacial area, and greater mechanical integrity than that of graphene-based films or powders. In addition, conventional cathodes generally contain inert addition agents like plastering agent, which always block electron transport and possess deficient ion permeation .…”