Organic Electrolyte Permselective Membranes.
Rept. no. 4 (Final), 1 Apr 68-15 Sep 70,
CALIFORNIA UNIV BERKELEY SEA WATER CONVERSION LAB
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Experiments were performed to assess the value of various commercial and specially-prepared membranes as separators in batteries containing electrolytes dissolved in propylene carbonate PC. Specifically, these membranes should prevent self-discharge of lithium-copper halide cells. Since literature data suggest that self-discharge is caused by transport of anionic copper complexes to the lithium electrode, the separators selected were primarily cation-exchange membranes, which are known to exclude anions in aqueous solutions. Selective permeability for anions was tested by a variety of electrolyte diffusion, interdiffusion and transport number measurements. It was established that most commercial cation-exchange membranes have high resistances in PC, but three membranes with resistances less than 250 ohms sq cm in 0.50 M LiClO4PC at 25 C were found, viz. C-322 American Machine and Foundry Co., Stamford, Conn. - 117 ohm sq cm, UM-05 Amicon Corp., Lexington, Mass. - 230 ohm sq cm and 7930 Porous Glass Corning Glass Works, Corning, N.Y. - 75 ohms sq cm. In order to combine the advantages of cation selectivity with low resistance, laminated membranes consisting of thin layers of phenolsulfonic acid-formaldehyde cation-exchange membranes on porous inert supports were prepared and tested. The data indicate that anion-barrier membranes of low resistance can be prepared by further developing this method. Author
- Physical Chemistry
- Electrochemical Energy Storage