Original scientific paper
https://doi.org/https://doi.org/10.5599/jese.2351
Strategy on enhancing ionic conductivity of biocompatible hydroxypropyl methyl cellulose/polyethylene glycol polymer blend electrolyte with TiO2 nanofillers and LiNO3 ionic salt
Mohan Srinivas
; Department of Physics, Karnatak University, Dharwad 580003, Karnataka, India
Rajashekhar Bhajantri
; Department of Physics, Karnatak University, Dharwad 580003, Karnataka, India
Abstract
A biocompatible and biodegradable polymer in the fabrication of solid polymer electrolytes for high energy density rechargeable batteries is gaining interest owing to their safety, compatibility and flexibility. In this study, a polymer electrolyte based on hydroxypropyl methylcellulose (HPMC)/polyethylene glycol (PEG) biopolymers, incorporating TiO2 nanofillers and LiNO3 as a lithium source, was fabricated using the solution casting method. Mixed-phase TiO2 nanofillers were synthesized via hydrolysis of titanium tetraisopropoxide. The crystal structure, phase morphology, and electrochemical impedance spectra of the films and nanofillers were investigated. X-ray diffraction analysis confirmed the amorphous nature of the polymer electrolyte and crystalline nature of nanofiller. In addition, it was noted that the amorphous phase of the polymer blend remained unaltered despite the incorporation of TiO2 and LiNO3. Thermogravimetric analysis and differential thermal analysis confirmed that the pure blend exhibited a melting point of around 60°C and complete degradation of around 340 °C, while the blend electrolyte with additives demonstrated thermal stability with a broad melting point. The blend containing 5 wt.% TiO2 fillers and 10 wt.% LiNO3ionic salt exhibited the highest ionic conductivity of 0.213 mS cm-1 at room temperature. The polymer blend electrolyte displayed a narrow electrochemical stability window of 2.85 V, with the highest cationic transfer number of 0.323. The temperature-dependent ionic conductivity of the prepared polymer blend electrolyte followed Arrhenius behaviour, with an activation energy of 0.1 eV. The study examined and reported the effect of aging on the interfacial resistance of polymer blend electrolyte. The mechanical properties of the optimized HPMC/PEG/TiO2/LiNO3 polymer blend electrolyte were investigated and reported. Thus, this research elucidated the role of nanofillers and ionic salt in enhancing the performance of biocompatible polymer electrolytes.
Keywords
Mixed polymer; polymer composite; Arrhenius behaviour; cationic transference number; electrochemical stability
Hrčak ID:
319753
URI
Publication date:
23.7.2024.
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