Secondary lithium battery electrolyte and secondary lithium battery including the same

#This application claims the benefit of Korean Patent Application No. 10-2008-0124290, filed Dec. 8, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

#1. Field

#Exemplary embodiments relate to a secondary lithium battery electrolyte and a secondary lithium battery including the secondary lithium battery electrolyte that can improve the cycle and high temperature retention characteristics of a battery using the secondary lithium battery electrolyte.

#These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

#FIG. 1 illustrates a solid electrolyte interface (SEI) membrane formed on a surface of a cathode when a polar organic solvent is used as a conventional electrolytic solution;

#FIG. 2 illustrates an SEI membrane formed on a surface of a cathode when a secondary lithium battery electrolyte additive is added to an electrolyte, according to an exemplary embodiment;

#Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain aspects of the present invention by referring to the figures. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “formed on” or “disposed on” another element, it can be disposed directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being “formed directly on” or “disposed directly on” another element, there are no intervening elements present.

#Unless there is any specific contrary description in this specification, when the term “substitution” is used, it means that a material is substituted by a halogen, a hydroxyl group, an alkyl group, an alkoxyl group, or a combination thereof. Unless there is any specific contrary description in this specification, the term “alkoxy” is indicated by “—OR”; the term “ester” is indicated by “—COOR”; the term “carbonate” is indicated by “—OCO(OR)”; and the term “carbonyl” is indicated by “—COR”. In addition, “R” is an unsubstituted or substituted alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted cycloalkyl group, an unsubstituted or substituted alkenyl group, an unsubstituted or substituted alkynyl group, or a combination thereof. Unless there is any specific contrary description in this specification, the term “alkyl” is C1-C20 alkyl, for example, a C1-C12 alkyl; the term “aryl” is C6-C30 aryl, for example, a C6-C18 aryl; the term “cycloalkyl” is C3-C30 cycloalkyl, for example, a C3-C18 cycloalkyl; “alkenyl” is C2-C20 alkenyl, for example, a C2-C12 alkenyl; and the term “alkynyl” is C2-C20 alkynyl, for example, a C2-C12 alkynyl.

#According to an embodiment, a secondary lithium battery electrolyte includes a lithium salt, a nonaqueous organic solvent, and an electrolyte additive represented by Formula 1: