Transport properties of a high molecular weight poly(propylene oxide)-LiCF{sub 3}SO{sub 3} system
- Lawrence Berkeley National Lab., CA (United States)
- Royal Inst. of Tech., Stockholm (Sweden)
Conductivities ({sigma}), salt diffusion coefficients (D{sub s}), and cationic transference numbers (t{sub +}{sup 0}) are reported for a high molecular weight polypropylene oxide (Parel{trademark})-LiCF{sub 3}SO{sub 3} polymer electrolyte system at 85 C. Transference numbers were determined as a function of salt concentration using a recently described electrochemical method based on concentrated solution theory. For the Parel-LiCF{sub 3}SO{sub 3} system, t{sub +}{sup 0} is slightly positive for electrolytes with O:Li ratios of 15 or 12:1 but decreases to negative values for more concentrated solutions. This implies that negatively charged ionic aggregates such as triplets are more mobile than free cations in this concentration range. Such behavior is commonly seen in binary salt/polymer electrolytes, which typically exhibit a high degree of nonideality. The nonunity transference numbers and microphase separation in the Parel-LiCF{sub 3}SO{sub 3} system strongly suggest that salt precipitation or phase separation in operating cells containing these electrolytes due to the development of large concentration gradients during passage of current.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 680015
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 6 Vol. 146; ISSN JESOAN; ISSN 0013-4651
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Effects of Lithium Triflate (LiCF{sub 3}SO{sub 3}) on the PMMA-based Solid Polymer Electrolytes
The measurement of a complete set of transport properties for a concentrated solid polymer electrolyte solution