Zwitterionic semi-IPN electrolyte with high ionic conductivity and high modulus achieving flexible 2.4 V aqueous supercapacitors

Abstract

Polymer electrolytes (PEs) have the widespread interest for solid-state supercapacitors. As an ideal PEs, it is requested to possess high ionic conductivity, high electrolyte content, and excellent mechanical properties. Here, we present the zwitterionic semi-interpenetrating polymeric network electrolytes (ZSIPNEs) that enable achieving ultra-high ionic conductivity and excellent mechanical properties. ZSIPNEs are synthesis by interpenetrating various content of poly(sulfobetaine methacrylate) (pSBMA) into zwitterionic polymer (ZP) matrix, being simply prepared by 17 m NaClO4(aq) intake. At content of pSBMA of 0.1%, ZS-0.1 possesses the ultra-high ionic conductivity of 135.2 mScm−1 at 25 °C. In addition, ZS-0.1 shows excellent mechanical properties, including the compressive strength of 0.36 MPa, compressive strain of 74.5%, compressive modulus of 33.7 kPa, and toughness of 4.329 Jm−3. Furthermore, the electrochemical performances of electrolytes are studied using carbon-based supercapacitors which are assembled with 17 m NaClO4(aq) (C-aq), ZS-0 (C-ZPE), and ZS-0.1 (C-ZSIPNE), being evaluated by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge. C-ZSIPNE shows the wide electrochemical window of 2.4 V and the superior electrochemical performance by delivering high energy density of 83.6Whkg−1, and high power density of 19.1kWkg−1. Under bending angles of 90°, the capacitance of C-ZSIPNE keeps at almost 100%, being potential application in flexible supercapacitors. 3 brief informative subheadingsZwitterionic polymer electrolyte, Semi-interpenetrating polymeric network, High performance supercapacitors BackgroundPolymer electrolytes (PEs) have the widespread interest for solid-state supercapacitors. As an ideal PEs, it is requested to possess high ionic conductivity, high electrolyte content, and excellent mechanical properties. MethodsThe ionic conductivity of PE was evaluated by electrochemical impedance spectroscopy. The mechanical properties of PE were evaluated by compressive strain-stress curve. The electrochemical properties of PE were evaluated by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge. Significant FindingsZSIPNEs enable achieving ultra-high ionic conductivity of 135.2 mScm−1 and excellent mechanical properties (compressive modulus of 33.7 kPa). C-ZSIPNE shows the wide electrochemical window of 2.4 V and the superior electrochemical performance by delivering high energy density of 83.6Whkg−1, and high power density of 19.1kWkg−1. Under bending angles of 90°, the capacitance of C-ZSIPNE keeps at almost 100%, being potential application in flexible supercapacitors.