Star-Shaped Block Copolymers: Effective Polymer Gelators of High-Performance Gel Electrolytes for Electrochemical Devices

Abstract

Ion gels composed of copolymers and ionic liquids (ILs) have attracted great interest as polymer gel electrolytes for various electrochemical applications. Here, we present highly robust ion gels based on a six-arm star-shaped block copolymer of (poly(methyl methacrylate)-b-polystyrene) 6 ((MS) 6 ) and an ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([EMI][TFSI]). Compared to typical ion gels based on linear polystyrene-bpoly(methyl methacrylate)-b-polystyrene (SMS), the (MS) 6based gels show mechanical moduli of more than twice under various strains (e.g., stretching, compression, and shear). In addition, the outstanding mechanical property is maintained even up to 180 °C without a gel−sol transition. To demonstrate that (MS) 6 -based ion gels can serve as effective gel electrolytes for electrochemical applications, tris(2,2′bipyridyl)ruthenium(II) (Ru(bpy) 3 2+ ), a representative electrochemiluminescent (ECL) luminophore, is incorporated into the gels. In particular, flexible ECL devices based on (MS) 6 gels exhibit high durability against bending deformation compared to devices with gels based on linear SMS having a similar molecular weight and a composition. This result implies that star-shaped block copolymers are effective gelators for achieving flexible/wearable electrochemical electronics.

From Cellulose, Shrimp and Crab Shells to Energy Storage EDLC Cells: The Study of Structural and Electrochemical Properties of Proton Conducting Chitosan-Based Biopolymer Blend Electrolytes

“…The reduced ion mobility in SPE matrices has led numerous research groups to develop different approaches that have improved the ambient conductivity. Two common approaches which are widely addressed are the blending of two polymers and using a variety of salts [ 8 , 9 , 10 , 11 , 12 , 13 ]. Polymer blending is regarded as a promising technique to upgrade the properties of individual polymer constituents.…”

Structural, Impedance and Electrochemical Characteristics of Electrical Double Layer Capacitor Devices Based on Chitosan: Dextran Biopolymer Blend Electrolytes

“…To allow low-voltage operation and fast response of electrochemical devices, high ionic conductivity has to be achieved. These properties can largely be manipulated by decisive selection of the polymer gelators [19][20][21][22][23][24]. These have been known to possess excellent film-forming capability because of enrichment in many oxygen functional groups in the dextran structure.…”

Structure Code for Advanced Polymer Electrolyte in Lithium‐Ion Batteries

“…Reproduced with permission. [ 130 ] Copyright 2019, American Chemical Society. c) Synthesis of hb PPEGMA m ‐ s ‐PS n hyperstar polymers.…”

“…This new electrolyte material exhibited high conductivity (1.54 × 10 −6 S cm −1 ) at room temperature, and considerably improved elastic modulus and thermal stability than its linear analog with similar molecular weight (Figure 6b). [ 130 ]…”