Use of Organic Esters as Cosolvents in Electrolytes for Lithium-Ion Batteries with Improved Low Temperature Performance

The electrolyte composition plays a strong role in determining the low temperature performance of lithium-ion cells, both in terms of ionic mobility in the electrolyte solution, as well as forming suitable surface films on the electrode surfaces A series of ester solvents was chosen for incorporation into multicomponent electrolyte formulations due to their favorable physiochemical properties (i.e., low viscosity, low melting point, and high permittivity), as well as good compatibility with carbonaceous anodes and mixed metal cathodes (i.e LiCoO 2 and LiNiCoO 2 ). In addition to determining the relative facility of lithium intercalation and deintercalation in Li-carbon cells as a function of temperature, a number of conventional electrochemical methods were employed to further enhance the understanding of the nature of the electrode surface films in these ester-based electrolytes, including do polarization and ac impedance measurements A distinct trend was observed with respect to the stability of the surface films formed. In solutions containing low molecular weight cosolvents (i.e., methyl acetate and ethyl acetate) the surface films appear resistive and inadequately protective, whereas electrolytes containing higher molecular weight esters resulted in surface films with more desirable attributes. Promising electrolyte formulations were further evaluated in prototype lithium-ion cells (AA-size) and fully characterized in terms of their low temperature discharge performance.

[1]  H. Lim,et al.  Performance of Li-ion cells with new electrolytes conceived for low-temperature applications , 2000 .

[2]  B. Ratnakumar,et al.  Irreversible Capacities of Graphite in Low‐Temperature Electrolytes for Lithium‐Ion Batteries , 1999 .

[3]  B. Ratnakumar,et al.  Electrolytes for low-temperature lithium batteries based on ternary mixtures of aliphatic carbonates , 1999 .

[4]  B. Ratnakumar,et al.  Lithium ion batteries for Mars exploration missions , 1999, Fourteenth Annual Battery Conference on Applications and Advances. Proceedings of the Conference (Cat. No.99TH8371).

[5]  Minoru Inaba,et al.  Impedance Study on the Electrochemical Lithium Intercalation into Natural Graphite Powder , 1998 .

[6]  E. Plichta,et al.  Conductivity of lithium imide in mixed aprotic solvents for lithium cells , 1997 .

[7]  Minoru Inaba,et al.  A.c. impedance analysis of electrochemical lithium intercalation into highly oriented pyrolytic graphite , 1997 .

[8]  M. Broussely,et al.  Chemical passivation of lithiated graphitized mesocarbon fibers , 1997 .

[9]  Subbarao Surampudi,et al.  Development of advanced lithium-ion rechargeable cells with improved low temperature performance , 1997, IECEC-97 Proceedings of the Thirty-Second Intersociety Energy Conversion Engineering Conference (Cat. No.97CH6203).

[10]  Yair Ein-Eli,et al.  Li‐Ion Battery Electrolyte Formulated for Low‐Temperature Applications , 1997 .

[11]  M. Wagner.  Difference of the electrochemical surface behaviour of lithium/carbon intercalation electrodes in different charge/discharge cycles , 1997 .

[12]  Yair Ein-Eli,et al.  New Electrolyte System for Li‐Ion Battery , 1996 .

[13]  J. Yamaki,et al.  Ethylene carbonate-based ternary mixed solvent electrolytes for rechargeable lithium batteries , 1995 .

[14]  A. Ohta,et al.  Relationship between carbonaceous materials and electrolyte in secondary lithium-ion batteries , 1995 .

[15]  M. Odziemkowski,et al.  Raman spectroscopic and electrochemical studies of lithium battery components , 1995 .

[16]  E. Takeuchi,et al.  Low temperature electrolytes for lithium/silver vanadium oxide cells , 1991 .

[17]  B. Boukamp.  A Nonlinear Least Squares Fit procedure for analysis of immittance data of electrochemical systems , 1986 .