LONG CYCLE-LIFE SECONDARY LITHIUM CELLS UTILIZING TETRAHYDROFURAN

Abraham and Goldman (1983) have found that a use of tetrahydrofuran(THF)/LiAsF6 electrolyte solution in ambient temperature rechargeable lithium cells is highly desirable. Unsaturated organic additives such as 2, methyl-furan (2Me-F) were found to enable high efficiency Li cycling in THF/LiAsF6. The employment of the high rate, low temperature mixed solution, 50:50 THF:2Me-THF/LiAsF6(1.5M), in 5 A-hr Li/TiS2 cells made it possible to achieve, for the first time, more than 200 cycles of 60 percent depth-of-discharge (d.o.d.). The Li anode cycling efficiency in these 5 A-hr cells exceeded 97 percent. It is now believed that this mixed electrolyte is significantly better than 2Me-THF/LiAsF6 for use in ambient temperature secondary Li cells. The relevant data which form the basis for this conclusion are presented. 12 references.