Xm. Wang et al., Electrochemical behavior of lithium imide/cyclic ether electrolytes for 4 V lithium metal rechargeable batteries, J ELCHEM SO, 146(11), 1999, pp. 3992-3998
To develop organic electrolytes for 4 V lithium metal rechargeable batterie
s, LiN(SO2CF3)(2) electrolytes with five-, six-, and seven-membered cyclic
ether solvents were characterized. Among these examined electrolytes, LiN(S
O2CF3)(2)/tetrahydropyran (THP) electrolyte was found to possess the most a
dvantages, such as high cycling efficiency, good oxidation stability, and h
igh boiling point. Furthermore, lithium cycling efficiency and conductivity
were improved by mixing 50% ethylene carbonate (EC) in 1 mol/dm(3) LiN(SO2
CF3)(2)/THP electrolyte. By using LiN(SO2C2F5)(2) solute as an alternative
to LiN(SO2CF3)(2) in EC + THP(1:1) electrolyte, corrosion of the aluminum c
urrent collector was inhibited and therefore, excellent cycling performance
of a Li/LiMn2O4 coin cell was realized. It was also found that lithium cyc
ling efficiency increased with decreasing deposition current density or inc
reasing dissolution current density. Especially at deposition/dissolution c
urrent densities of 0.2/0.6 mA/cm(2), the observed lithium cycling efficien
cy in 1 mol/dm(3) LiN(SO2C2F5)(2)/EC + THP (1:1) electrolyte was above 99%.
Thermal tests further disclosed that this mixed electrolyte has good therm
al stability even in the presence of lithium metal or cathode materials. (C
) 1999 The Electrochemical Society. S0013-4651(99)03-060-8. All rights rese
rved.