Gas Solubility and Vapor Pressure of Electrolytes Based on Alkylcarbonates Containing Litfsi, Lifap, and LiPF6 Lithium Salt: Measurement and Prediction

Most liquid electrolytes used in commercial lithium-ion batteries are composed by alkylcarbonate mixture containing lithium salt. The decomposition of these solvents by oxidation or reduction during cycling of the cell, induce generation of gases (CO2, CH4, C2H4, CO …) increasing of pressure in the sealed cell, which causes a safety problem [1]. The prior understanding of parameters, such as structure and nature of salt, temperature pressure, concentration, salting effects and solvation parameters, which influence gas solubility and vapor pressure of electrolytes is required to formulate safer and suitable electrolytes especially at high temperature.

We present in this work the CO2, CH4, C2H4, CO solubility in different pure alkyl-carbonate solvents (PC, DMC, EMC, DEC) and their binary or ternary mixtures as well as the effect of temperature and lithium salt LiX (X = LiPF6, LiTFSI or LiFAP) structure and concentration on these properties. Furthermore, in order to understand parameters that influence the choice of the structure of the solvents and their ability to dissolve gas through the addition of a salt, we firstly analyzed experimentally the transport properties (Self diffusion coefficient (D), fluidity (h-1), and conductivity (s) and lithium transport number (tLi) using the Stock-Einstein, and extended Jones-Dole equations [2]. Furthermore, measured data for the of CO2, C2H4, CH4 and CO solubility in pure alkylcarbonates and their mixtures containing LiPF6; LiFAP; LiTFSI salt, are reported as a function of temperature and concentration in salt. Based on experimental solubility data, the Henry’s law constant of gases in these solvents and electrolytes was then deduced and compared with values predicted by using COSMO-RS methodology within COSMOthermX software. From these results, the molar thermodynamic functions of dissolution such as the standard Gibbs energy, the enthalpy, and the entropy, as well as the mixing enthalpy of the solvents and electrolytes with the gases in its hypothetical liquid state were calculated and discussed [3]. Finally, the analysis of the CO2 solubility variations with the salt addition was then evaluated by determining specific ion parameters Hi by using the Setchenov coefficients in solution. This study showed that the gas solubility is entropy driven and can been influenced by the shape, charge density, and size of the anions in lithium salt.

References

[1] S.A. Freunberger, Y. Chen, Z. Peng, J.M. Griffin, L.J. Hardwick, F. Bardé, P. Novák, P.G. Bruce, Journal of the American Chemical Society 133 (2011) 8040-8047.

[2] P. Porion, Y.R. Dougassa, C. Tessier, L. El Ouatani, J. Jacquemin, M. Anouti, Electrochimica Acta 114 (2013) 95-104.

[3] Y.R. Dougassa, C. Tessier, L. El Ouatani, M. Anouti, J. Jacquemin, The Journal of Chemical Thermodynamics 61 (2013) 32-44.

South Carolina economic outlook

Since 2008, the South Carolina Department of Commerce has published the Economic Outlook, a monthly snapshot of key state economic indicators on income, employment, and real estate.

Report of the University of South Carolina

The bulletin presents a report of the work of the University of South Carolina for the session of 1930-1931 and also a financial statement by the Treasurer of receipts and expenditures from January 1, 1931, to December 31, 1931.

Mosquito Bite Prevention in South Carolina

This sheet gives tips on repelling mosquitoes including: what you wear is important, buying the right repellent and using it correctly and using special care when applying repellents to children and babies.

KEY PARTNERS: SOUTH CAROLINA ZIKA CONTROL

This chart shows ways in which local and state governments in South Carolina can help each other in preventing and controlling the Zika virus.

South Carolina COPD Strategic Plan

Chronic obstructive pulmonary disease is the third leading cause of death in South Carolina and affects approximately 15 percent of the adult population. Although tobacco cessation and avoidance are slowly advancing in South Carolina, 20 percent of COPD occurs in non-smokers, and this percentage will likely increase in the coming years. Therefore, a strategic plan must include other initiatives in addition to smoking cessation. This document was developed by a multidisciplinary group of health care providers, public health practitioners, and patients, as such a combined approach is imperative to target this disease.

University of South Carolina Aiken Annual Accountability Report Fiscal Year 1994-1995

The University of South Carolina Aiken reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

University of South Carolina Aiken Annual Accountability Report Fiscal Year 1995-1996

The University of South Carolina Aiken reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

University of South Carolina Aiken Annual Accountability Report Fiscal Year 1997-1998

The University of South Carolina Aiken reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

University of South Carolina Beaufort Annual Report Fiscal Year 1994-1995

The University of South Carolina Beaufort reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

University of South Carolina Beaufort Annual Report Fiscal Year 1995-1996

The University of South Carolina Beaufort reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

University of South Carolina Beaufort Annual Accountability Report Fiscal Year 1997-1998

The University of South Carolina Beaufort reports to the Office of State Budget its annual accountability report that includes an executive summary, a description of the leadership system, customer focus and satisfaction and other performance criteria, mission, and program descriptions and budgets.

UNIVERSITY OF SOUTH CAROLINA BEAUFORT ANNUAL REPORT 2006-2007 Progress Through Partnerships

The annual report highlights events, projects, and financing.

New South Carolina state documents - May 2016

The monthly New South Carolina State Documents publication by the State Library provides a list of state documents published by state agencies that have been cataloged and added to the South Carolina State Documents Depository. Included is the title, author and/or agency, description, thumbnail, link to access full-text file, and OCLC number.

More : the newsletter for South Carolina libraries 

This June 2016 newsletter from the South Carolina State Library, volume 48, issue 6, features news and updates for South Carolina libraries.