Structural Changes and Electrochemical Stability of Ionogel Incorporating Tetraethyl Orthosilicate and PVDF-HFP

¹ Faculty of Engineering and Science, Department of Mechanical Engineering, Curtin University, Malaysia
² Energy and Resources Institute, College of Engineering, Information Technology and Environment, Charles Darwin University, Darwin, Northern Territory 0909, Australia
³ Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan BE1410, Brunei Darussalam

Corresponding author: s_jiwei@postgrad.curtin.edu.my ; naveenkumar.elumalai@cdu.edu.au; d.sujan@curtin.edu.my; mubarak.yaseen@gmail.com

Abstract

Ionogels are emerging hybrid materials and are widely studied due to the combination of thermophysical properties from ionic liquid and mechanical integrity from the polymer matrix. Ionic liquid has received wide attention due to its promising properties, high ionic conductivity, and thermal stability. The liquid nature of ionic liquid has restricted its application. Thus, the confinement of ionic liquid within a polymer matrix has allowed ionogel to be applied in strain sensors and lithium-ion batteries. Nevertheless, the compatibility between the polymer matrix and ionic liquid is crucial for ionogel. Incompatibility between polymer host and ionic liquid results in low ionic conductivity, poor mechanical strength, and undesired for practical application. The interaction between polymer matrix and ionic liquid is studied in this study through optical microscopy. The addition of ionic liquid resulted in the disappearance of the polymer matrix’s highly porous nature, as evidenced by the optical microscopy images. This disappearance of the porous nature suggests the compatibility of the polymer matrix with ionogel. Furthermore, the electrochemical stability of the ionogel is also examined through linear sweep voltammetry technique and achieved 2.3V.