Gel-Polymer Electrolytes for Sodium Batteries - Raman and Electrochemical Impedance Spectroscopic Studies

2021 ◽  
Vol 1023 ◽  
pp. 21-26
Author(s):  
Gnanasubramaniam Menisha ◽  
J.H.T. Bandara Jayamaha ◽  
K. Vignarooban ◽  
Ganeshalingam Sashikesh ◽  
Kugamurthy Velauthamurthy ◽  
...  

Sodium-ion batteries (SIBs) as low-cost alternatives to expensive lithium-ion batteries become a hot R&D topic in the recent days due to the natural abundancy of sodium in the Earth’s crust and also in the oceans. As far as solid electrolytes for SIBs are concerned, larger size of Na+ ions compared to that of Li+ ions hinders the ionic mobility resulting to insufficient ionic conductivity for practical applications. Development of quasi-solid state gel-polymer electrolytes (GPEs) would be a feasible solution to overcome this challenge. In this work, we developed Poly (methyl methacrylate) (PMMA) based GPEs with six different compositions dissolved in EC:PC (ethylene carbonate and propylene carbonate, 1:1 wt%) mixture. Among six different GPE samples investigated by Electrochemical Impedance Spectroscopic and Raman Spectroscopic techniques, the best ambient temperature ionic conductivity of 4.2 mS cm-1 was obtained for 9PMMA:9NaPF6:41EC:41PC (wt%). Variation of ionic conductivity with inverse temperature showed Arrhenius behavior with almost constant activation energies. The best conducting GPE showed an activation energy of 0.14 eV. In the Raman spectra, very sharp crystalline peaks (400-850 cm-1 wave number range) of NaPF6 disappear in the gel state of the electrolytes confirming the non-crystalline nature of the GPEs. Boson modes remain almost constant in intensity for all the six different compositions. The best conducting GPE seems to be highly suitable for practical applications in SIBs as it has sufficient ambient temperature ionic conductivity.

2013 ◽  
Vol 334-335 ◽  
pp. 137-142 ◽  
Author(s):  
Lisani Othman ◽  
Khairul Bahiyah Md. Isa ◽  
Zurina Osman ◽  
Rosiyah Yahya

The gel polymer electrolytes (GPEs) composed of polymethylmethacrylate (PMMA) with lithium trifluoromethanesulfonate (LiCF3SO3) salt dissolved in a binary mixture of ethylene carbonate (EC) and propylene carbonate (PC) organic solvents have been prepared by the solution casting technique. The samples are prepared by varying the salt concentrations from 5 wt.% to 30 wt.%. Impedance spectroscopy measurement has been carried out to determine the ionic conductivity of the samples. The sample containing 25 wt.% of LiCF3SO3salt exhibits the highest room temperature ionic conductivity of 2.56 x 10-3S cm-1. The conductivity of the GPEs has been found to depend on the salt concentration added to the sample, while at higher salt concentration reveals a decrease in the ionic conductivity due to ions association. The temperature dependence of conductivity from 303 K to 373 K is found to obey the Arrhenius law. The ionic transference number,tiof GPEs has been estimated by the DC polarization method and the value is found to be 0.98, 0.93, and 0.97 for the sample containing 25 wt.%, 5 wt.% and 30 wt.% respectively. This result is consistent with the conductivity studies.


2021 ◽  
Vol 12 (5) ◽  
pp. 6114-6123

Solid polymer electrolytes (SPEs) based carboxymethyl cellulose (CMC) with lithium perchlorate (LiClO4) were prepared via solution drop-cast technique. The CMC host is complexed by different concentrations of LiClO4 salt. SPEs were characterized by Electrochemical Impedance Spectroscopy (EIS) and Linear Sweep Voltammetry (LSV) in coin cells with lithium metal electrodes. EIS performed unique results based on various ionic conductivity values and dielectric properties. The higher ionic conductivity (1.32 × 10-5 S/cm) was obtained by SPEs 2 following by short-range ionic transport results based on dielectric properties depending on frequency. SPEs with LiClO4 addition are electrochemically stable over 2 V in lithium battery coin cells from LSV results.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4115 ◽  
Author(s):  
Aimi Mahirah Zulkifli ◽  
Nur Izzah Aqilah Mat Said ◽  
Shujahadeen Bakr Aziz ◽  
Elham Mohammed Ali Dannoun ◽  
Shameer Hisham ◽  
...  

In the present work, phthaloyl chitosan (PhCh)-based gel polymer electrolytes (GPEs) were prepared using dimethylformamide (DMF) as a solvent, ethyl carbonate (EC) as a co-solvent, and a set of five quaternaries of potassium iodide (KI) as a doping salt, which is a mixed composition of iodine (I2). The prepared GPEs were applied to dye-sensitized solar cells (DSSC) to observe the effectiveness of the electrolyte, using mesoporous TiO2, which was sensitized with N3 dye as the sensitizer. The incorporation of the potassium iodide-based redox couple in a polymer electrolyte is fabricated for dye-sensitized solar cells (DSSCs). The number of compositions was based on the chemical equation, which is 1:1 for KI:I2. The electrical performance of prepared GPE systems have been assessed using electrical impedance spectroscopy (EIS), and dielectric permittivity. The improvement in the ionic conductivity of PhCh-based GPE was observed with the rise of salt concentration, and the maximum ionic conductivity (4.94 × 10−2 S cm−1) was achieved for the 0.0012 mol of KI:I2. The study of dielectric permittivity displays that ions with a high dielectric constant are associated with a high concentration of added ions. Furthermore, the gel polymer electrolyte samples were applied to DSSCs to detect the conversion effectiveness of the electrolytes. For electrolytes containing various content of KI:I2 the highest conversion efficiency (η%) of DSSC obtained was 3.57% with a short circuit current density (Jsc) of 20.33 mA cm−2, open-circuit voltage (Voc) of 0.37 V, fill factor (FF) of 0.47, as well as a conductivity of 2.08 × 10−2 S cm−1.


2020 ◽  
Vol 32 (2) ◽  
pp. 208-219
Author(s):  
CP Singh ◽  
PK Shukla ◽  
SL Agrawal

Ion conducting gel polymer electrolytes (GPEs) are being intensively studied for their potential applications in various electrochemical devices. The poly(vinyl alcohol)-based GPE films containing ammonium acetate (NH4CH3COO) salt have been studied for various concentrations of salt. The gel electrolyte films (GPEs) have been prepared using solution casting technique. Structural characterization carried out using X-ray diffraction reveals an increase in the amorphous nature of the samples on increasing salt concentration up to 70 wt%. The complexation of polymer and salt has been studied by Fourier-transform infrared analysis. Ionic conductivity of the GPEs has been found to increase with salt concentration and reaches an optimum for an intermediate concentration. The room temperature conductivity isotherm exhibits a maximum in conductivity of 2.64 × 10−4 Scm−1 for 65 wt% salt concentration. The temperature dependence of ionic conductivity exhibits a combination of Arrhenius and Vogel–Tamman–Fulcher behavior. Ion transport in the electrolyte system has been explored using dielectric response of the material and the observed variation in conductivity is suitably correlated to the change in charge carrier concentration and mobility of charge carriers.


2017 ◽  
Vol 19 (22) ◽  
pp. 14615-14624 ◽  
Author(s):  
Nimai Bar ◽  
Pratyay Basak ◽  
Yoed Tsur

Semi-interpenetrating polymer networks with significant ionic conductivity (10−4 S cm−1 at ambient temperature) were studied by vibrational and impedance spectroscopies coupled with advanced analysis procedures.


2012 ◽  
Vol 501 ◽  
pp. 44-48 ◽  
Author(s):  
Azizan Ahmad ◽  
Shwu Ping Low ◽  
Fadwa Saad Addaokali Almakhzoom ◽  
Mohd Yusri Abdul Rahman

The effect of plasticizer (PC) on the conductivity and chemical interaction of polymer electrolyte of MG49–PC–LiClO4–TiO2 has been investigated. The electrolyte films were successfully prepared by solution casting technique. Alternating current electrochemical impedance spectroscopy was employed to investigate the ionic conductivity of the electrolyte films at 25 °C, and the analysis showed that the addition of propylene carbonate (PC) plasticizer has increased the ionic conductivity of the electrolyte up to its optimum level. The highest conductivity of 2.54×10−4 Scm−1 was obtained at 30 wt.% of PC. Fourier transform infrared spectroscopy measurement was employed to study the interactions between lithium ions and oxygen atoms that occurred at carbonyl (C=O) and ether (C-O-C) groups. XRD pattern showed that the crystallinity phase was reduced at the highest conductivity.


2013 ◽  
Vol 33 (8) ◽  
pp. 713-719 ◽  
Author(s):  
Pei Ling Cheang ◽  
Yee Ling Yap ◽  
Lay Lian Teo ◽  
Eng Kiong Wong ◽  
Ah Heng You ◽  
...  

Abstract A Monte Carlo (MC) model to incorporate the effect of Al2O3 with different particle sizes in enhancing the ionic conductivity of composite polymer electrolytes consisting of polyethylene oxide (PEO), lithium trifluoromethanesulfonate (LiCF3SO3), and ethylene carbonate (EC), is proposed. The simulated ionic conductivity in our MC model is validated by the results of electrochemical impedance spectroscopy, which determined the room temperature ionic conductivity of various composite electrolyte samples differing from the size of the Al2O3 prepared via the solution cast method. With the simulated current density and recurrence relation, cation transference numbers, t+si of composite polymer electrolytes were derived using the steady-state current method proposed by Bruce et al. Addition of Al2O3 (≤10 μm) in micron size greatly enhances the ionic conductivity to a magnitude of two orders, i.e., from 2.9025×10-7 S/cm to 2.970×10-5 S/cm and doubles the cation transference number from 0.230 to 0.465. However, the addition of Al2O3 (<50 nm) in nano size decreases both the ionic conductivity and the cation transference number. The smaller size of Al2O3 in the nano range is responsible for the congestion on the conducting pathways that traps some of the Li+ in PEO electrolytes.


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