ABSTRACT
In this study, electrolyte materials were synthesized by mixing a highly conducting salt (K2CO3) with the poly(vinyl alcohol) (PVA) in different proportions (from 10 to 50 wt.%). The synthesized electrolyte was characterized using Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for their functional groups, morphology, thermal stability, glass transition temperature (Tg), ionic conductivity, and potential window, respectively. Characterization results show that the complex formation between PVA and K2CO3 salt has been established by FTIR spectroscopic study, which indicates the detailed interaction between PVA and the salts in PVA-K2CO3 composites while the amorphous nature of the electrolyte after incorporation of the salts has been confirmed by FESEM analysis. Similarly, TGA and DSC analysis revealed that both decomposition temperature and Tg of the synthesized electrolytes decrease with the addition of K2CO3 due to the strong plasticizing effect of the salt. The results confirm that the electrolytes have sufficient thermal stability for supercapacitor operation, as well as an amorphous phase to effectively deliver high ionic conductivity. The highest ionic conductivity of 4.53 × 10−3 S cm−1 at 373 K and potential window of 2.7 V was exhibited by PK30 (30 wt.% K2CO3), which can be considered as high value for solid-state electrolytes which are superior to those electrolytes from PVA salts earlier reported. The results similarly show that the prepared electrolyte is temperature-dependent as conductivity increase with increase in temperature. Based on these properties, it can be imply that the PVA-K2CO3 gel polymer electrolyte (GPE) could be a promising electrolyte candidate for EDLC applications. The results indicate that the PVA-K2CO3 as a new electrolyte material has great potential in practical applications of portable energy-storage devices.
Graphical abstract
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Acknowledgments
The authors are grateful to the Universiti Teknologi PETRONAS for providing research facilities and graduate assistantship.
Additional information
Notes on contributors
Bashir Abubakar Abdulkadir
B. A. Abdulkadir is a PhD. student with the Department of Fundamental & Applied Sciences, Universiti Teknologi PETRONAS (UTP), Malaysia. He received his B.Sc. degree (Hons.) in Chemistry from Gombe State University, Gombe, Nigeria, in 2010, and the M.Sc. degree in Industrial Chemistry from Universiti Teknologi PETRONAS Malaysia, in 2015. Since 2012, he has been a Chemistry Lecturer with Gombe State University, Gombe, Nigeria. His research interests include the development and characterization of polymer and polymer electrolytes as a source of energy for use in various electrochemical devices.
John Ojur Dennis
J. O. Dennis was born in Malakal, South Sudan in 1959. He received the Bachelor of Education (Science) degree in mathematics and physics from the University of Juba, Juba, South Sudan, in 1982, and the Ph.D. degree in applied physics from Universiti Teknologi Malaysia, Malaysia, in 2001. In 2003, he joined the Electrical and Electronic Engineering Department, Universiti Teknologi PETRONAS, as a Senior Lecturer. He is currently an Associate Professor with the Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS. His current focus of research is in microelectromechanical systems design, simulation, and fabrication.
Muhammad Fadhlullah Bin Abd. Shukur
M. F. Shukur is a senior lecturer at the Department of Fundamental & Applied Sciences, Universiti Teknologi PETRONAS (UTP), Malaysia. He received his B.Sc. (Physics) from the University of Malaya, Malaysia, in 2011 and Ph.D. degree in Physics (Advanced Materials) from the same university in 2015. He has been with UTP since 2016. His research interests include the development and characterization of polymer and polymer electrolytes as a source of energy for use in various electrochemical devices.
Mohamed Mahmoud Elsayed Nasef
Dr. Mohamed Mahmoud Nasef is currently a Professor at Chemical Engineering Department Universiti Teknologi Petronas (UTP), Malaysia. He is also a visiting professor at Malaysia-Japan International Institute of Technology (UTM). Dr. Nasef holds a Master and PhD in Chem. Eng. from UTM and obtained his BSc in Chemistry from Minoufiyya University (Egypt). He is one the panel of experts in the International Atomic Energy Agency (IAEA) in the field of radiation processing of polymers since 2007. Dr. Nasef authored more than 150 research articles and comprehensive reviews in renowned journals in addition to 100 presentations and various book chapters. His H-Index stands at 35. Dr. Nasef is an active member in various professional societies such as American Chemical Society, Institute of Chemical Engineers and Electrochemical Society. Dr. Nasef research interests include but not limited to development of the ionic and functional polymeric materials for renewable energy and environmental applications. He makes especial emphasis on the development of new polymer electrolyte membranes for fuel cells, redox flow batteries and supercapacitors in addition to modified membranes for separation/purification technologies.
Fahad Usman
Fahad Usman was born in Kankara-Katsina, Nigeria in 1987. He received the B.Sc. degree (Hons.) in physics from Usmanu Danfodiyo University, Sokoto, Nigeria, in 2012, and the M.Sc. degree in medical physics from Universiti Sains Malaysia, in 2015. He is currently pursuing the Ph.D. degree in applied physics (medical biosensors) with Universiti Teknologi PETRONAS, Malaysia. Since 2016, he has been a Physics Lecturer with Al-Qalam University, Katsina, Nigeria. His area of focus is mainly in the application of physics in medicine that includes areas, such as medical imaging, medical devices, radiation physics, and breathe analysis.