The Effect of Ethylene Carbonate and Salt Concentration on the Conductivity of Propylene Carbonate∣Lithium Perchlorate Electrolytes

2000 ◽  
Vol 147 (2) ◽  
pp. 399 ◽  
Author(s):  
H. P. Chen ◽  
J. W. Fergus ◽  
B. Z. Jang
Keyword(s):  
Propylene Carbonate ◽  
Salt Concentration ◽  
Ethylene Carbonate ◽  
Lithium Perchlorate

New Insight into Electrochemical Differences in Cycling Behaviors of a Lithium-ion Battery Cell Between the Ethylene Carbonate- and Propylene Carbonate-Based Electrolytes

2011 ◽  
Vol 1313 ◽  
Author(s):  
Ken Tasaki ◽  
Alexander Goldberg ◽  
Jian-Jie Liang ◽  
Martin Winter
Keyword(s):  
Dft Calculations ◽  
Lithium Ion Battery ◽  
Propylene Carbonate ◽  
Salt Concentration ◽  
Density Functional ◽  
Ethylene Carbonate ◽  
Lithium Ion ◽  
Md Simulations ◽  
High Salt ◽  
Insight Into

ABSTRACTDensity functional theory (DFT) calculations and classical molecular dynamics (MD) simulations have been performed to gain insight into the difference in cycling behaviors between the ethylene carbonate (EC)-based and the propylene carbonate (PC)-based electrolytes in lithium-ion battery cells. DFT calculations for the ternary graphite intercalation compounds (Li+(S)iCn: S=EC or PC), in which the solvated lithium ion Li+(S)i (i=1~3) was inserted into a graphite cell, suggested that Li+(EC)iCn was more stable than Li+(PC)iCn in general. Furthermore, Li+(PC)3Cn was found to be energetically unfavorable, while Li+(PC)2Cn was stable, relative to their corresponding Li+(PC)i in the bulk electrolyte. The calculations also revealed severe structural distortions of the PC molecule in Li+(PC)3Cn, suggesting a rapid kinetic effect on PC decomposition reactions, as compared to decompositions of EC. In addition, MD simulations were carried out to examine the solvation structures at a high salt concentration: 2.45 mo kg-1. The results showed that the solvation structure was significantly interrupted by the counter anions, having a smaller solvation number than that at a lower salt concentration (0.83 mol kg-1). We propose that at high salt concentrations, the lithium desolvation may be facilitated due to the increased contact ion pairs, so that a stable ternary GIC with less solvent molecules can be formed without the destruction of graphite particles, followed by solid-electrolyte-interface film formation reactions. The results from both DFT calculations and MD simulations are consistent with the recent experimental observations.

Ionic Conductivity, Morphology and Transport Number of Lithium Ions in PMMA Based Gel Polymer Electrolytes

2013 ◽  
Vol 334-335 ◽  
pp. 137-142 ◽  
Author(s):  
Lisani Othman ◽  
Khairul Bahiyah Md. Isa ◽  
Zurina Osman ◽  
Rosiyah Yahya
Keyword(s):  
Ionic Conductivity ◽  
Salt Concentration ◽  
Polymer Electrolytes ◽  
Ethylene Carbonate ◽  
Transference Number ◽  
Gel Polymer Electrolytes ◽  
Casting Technique ◽  
Ionic Transference Number ◽  
Temperature Dependence Of Conductivity ◽  
Solution Casting Technique

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.

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