scholarly journals On The Proton Conduction Mechanism And The Effect of Steam on The Ionic Conductivity and Polarizability of MEAS Based on High Temperature Polymer Electrolytes

2013 ◽  
Vol 850-851 ◽  
pp. 300-303
Author(s):  
Guan Min Li

As part of the weak electrolyte, Multiphase Composite System’s structure is more complex. So the conductive electrolyte ion transport has some difficulty to understanding the mechanism. And the present study has not yet reached a consensus, but through the ion conduction mechanism in-depth research on polymer electrolytes Preparation of important guiding significance. Current theories include ionic conductivity effective medium theory (EMT), MN law, WFL equation, NE equation, dynamic bonding penetration model.


2015 ◽  
Vol 719-720 ◽  
pp. 114-118 ◽  
Author(s):  
M.I.N. Isa ◽  
Noor Azniza Mohd Noor

A conducting solid biodegradable polymer electrolytes based carboxymethyl cellulose (CMC) doped ammonium thiocyanate (NH4SCN) system with concentration in the range 0 – 25 wt.% of NH4SCN have been prepared via solution casting method. The impedance study of CMC-NH4SCN system was measured via Electrical Impedance Spectroscopy (EIS) in the temperature range 303 K – 353 K. The highest ionic conductivity at room temperature (303 K) is 6.48 x 10-5Scm-1for sample containing 25 wt.% NH4SCN. The temperature dependence of CMC-NH4SCN system was found to obey the Arrhenius behaviour where the ionic conductivity increases with increase of temperature. Dielectric data were analyzed using complex permittivity, Ɛifor sample with the highest ionic conductivity at various temperatures and found was non Debye behavior. The conduction mechanism of the charge carrier of CMC-NH4SCN system can be presented by quantum mechanical tunneling (QMT) model.


2008 ◽  
Vol 73 (12) ◽  
pp. 1777-1798 ◽  
Author(s):  
Olt E. Geiculescu ◽  
Rama V. Rajagopal ◽  
Emilia C. Mladin ◽  
Stephen E. Creager ◽  
Darryl D. Desmarteau

The present work consists of a series of studies with regard to the structure and charge transport in solid polymer electrolytes (SPE) prepared using various new bis(trifluoromethanesulfonyl)imide (TFSI)-based dianionic dilithium salts in crosslinked low-molecular-weight poly(ethylene glycol). Some of the thermal properties (glass transition temperature, differential molar heat capacity) and ionic conductivities were determined for both diluted (EO/Li = 30:1) and concentrated (EO/Li = 10:1) SPEs. Trends in ionic conductivity of the new SPEs with respect to anion structure revealed that while for the dilute electrolytes ionic conductivity is generally rising with increased length of the perfluoroalkylene linking group in the dianions, for the concentrated electrolytes the trend is reversed with respect to dianion length. This behavior could be the result of a combination of two factors: on one hand a decrease in dianion basicity that results in diminished ion pairing and an enhancement in the number of charge carriers with increasing fluorine anion content, thereby increasing ionic conductivity while on the other hand the increasing anion size and concentration produce an increase in the friction/entanglements of the polymeric segments which lowers even more the reduced segmental motion of the crosslinked polymer and decrease the dianion contribution to the overall ionic conductivity. DFT modeling of the same TFSI-based dianionic dilithium salts reveals that the reason for the trend observed is due to the variation in ion dissociation enthalpy, derived from minimum-energy structures, with respect to perfluoroalkylene chain length.


2020 ◽  
pp. 152808372097062
Author(s):  
Muhammad Yameen Solangi ◽  
Umair Aftab ◽  
Muhammad Ishaque ◽  
Aqeel Bhutto ◽  
Ayman Nafady ◽  
...  

Solid polymer electrolytes (SPEs) are the best choice to replace liquid electrolytes in supercapacitors, fuel cells, solar cells and batteries. The main challenge in this filed is the ionic conductivity and thermal stability of SPEs which is still not up to mark, therefore more investigations are needed to address these issues. In this study, PVA/salt based SPEs was fabricated using both solution cast and electro-spinning methods to probe the effect of different salts such as (NaCl, KCl and KI) and their concentrations on the ionic conductivity. Scanning electron microscopy (SEM) x and Fourier Transform Infra-Red (FTIR) have been employed to study the morphology as well as the different functional groups of SPEs, respectively. It was noted that small addition of NaCl, KCl and KI salts in SPEs dramatically increased the ionic conductivity to 5.95×10−6, 5.31×10−6 and 4.83×10−6 S/cm, respectively. Importantly, the SPEs obtained with NaCl via electro-spinning have higher ionic conductivity (5.95×10−6 S/cm) than their casted SPEs (1.87×10−6 S/cm). Thermal stability was also studied at two different temperatures i.e. 80 °C and 100 °C. The weight loss percentage of electrospun SPEs have zero percent weight loss than the solution based SPEs. The combined results clearly indicated that the nature of salt, concentration and fabrication process play a vital role in the ionic conductivity. Also, the NaCl salt with low molecular weight at low concentrations shows an enhanced ionic conductivity.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
Zul Hazrin Z. Abidin

Solid polymer electrolytes based on chitosan NaCF3SO3 have been prepared by the solution cast technique. X-ray diffraction shows that the crystalline phase of the pure chitosan membrane has been partially disrupted. The fourier transform infrared (FTIR) results reveal the complexation between the chitosan polymer and the sodium triflate (NaTf) salt. The dielectric constant and DC conductivity follow the same trend with NaTf salt concentration. The increase in dielectric constant at different temperatures indicates an increase in DC conductivity. The ion conduction mechanism follows the Arrhenius behavior. The dependence of DC conductivity on both temperature and dielectric constant (σdc(T,ε′)=σ0e−Ea/KBT) is also demonstrated.


RSC Advances ◽  
2017 ◽  
Vol 7 (40) ◽  
pp. 24856-24863 ◽  
Author(s):  
Yue Lin ◽  
Yun Cheng ◽  
Jie Li ◽  
Jan D. Miller ◽  
Jin Liu ◽  
...  

Wheat flour modified solid polymer electrolytes were synthesized and used in high safety and long cycling lithium batteries.


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