Crosslinked thermoelectric hydro-ionogels:A new class of highly conductive thermoelectric materials

Sajid, I.H. and Sabri, M.F.M. and Said, S.M. and Salleh, M.F.M. and Ghazali, N.N.N. and Saidur, R. and Subramaniam, B. and Hasan, S.W. and Jaffery, H.A. (2019) Crosslinked thermoelectric hydro-ionogels:A new class of highly conductive thermoelectric materials. Energy Conversion and Management, 198. ISSN 0196-8904

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Abstract

In this work, a new class of highly-conductive chemically cross-linked gel has been synthesized by the confinement of water and IL N, N, N triethyl octyl ammonium bromide ([N2228] Br) in polyethylene glycol dimethacrylate (PEGDMA) matrix, using in situ thermally initiated radical polymerization loaded with 1 wt% free radical initiator azobisisobutyronitrile (AIBN). This novel gel was named as hydro-ionogel (HIG). The thermoelectric properties of HIG such as ionic conductivity, Seebeck coefficient, and thermal conductivity were measured and owing to its high thermoelectric performance, we referred to this as crosslinked thermoelectric hydro-ionogel, henceforth will be denoted by X-TEHIG. For all the measurements, coin cells were fabricated using commercial LIR 2032 stainless steel battery casings with X-TEHIG sandwiched between the two graphene electrodes. The ionic conductivity of X-TEHIG was examined via AC impedance spectroscopy technique by using a Gamry apparatus. Remarkably, the ionic conductivity of X-TEHIG was higher than that of neat [N2228] Br. A linear increase in ionic conductivity of X-TEHIG as a function of temperature was recorded that showed a considerably higher value of 74 mScm−1 at 70 °C. The origin of this high conductivity is attributed to interactions between PEGDMA monomers and cations and anions of the IL and formation of hydrogen bonds between water and Br− anion, OH⋯Br−. X-TEHIG demonstrated a higher Seebeck coefficient of 1.38 mVK−1. The Fourier transform infrared (FTIR) spectroscopy results revealed the successful polymerization of X-TEHIG by the disappearance of CC peak of methacrylate group in the spectrum of PEGDMA. These results suggest that X-TEHIG may be a potential candidate for thermoelectric applications owing to their high values of ionic conductivity and Seebeck coefficient.

Item Type:
Journal Article
Journal or Publication Title:
Energy Conversion and Management
Additional Information:
This is the author’s version of a work that was accepted for publication in Energy Conversion and Management . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Energy Conversion and Management, 198, 2019 DOI: 10.1016/j.enconman.2019.111813
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2100/2105
Subjects:
ID Code:
136021
Deposited By:
Deposited On:
09 Aug 2019 10:50
Refereed?:
Yes
Published?:
Published
Last Modified:
16 Nov 2020 09:24