ELECTROLYTE FOR LITHIUM SECONDARY BATTERIES, AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

• Main Authors: CHOI YOUNG GEUN, LEE CHUL HAENG, YOON YOU RIM, YOON SEUNG JAE, JUNG JONG MO, CHAE JONG HYUN, CHOI YOUNG CHEOL, CHUNG GEUN CHANG
• Format: Patent
• Language: English; Japanese
• Published: 08.06.2017
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide: an electrolyte for lithium secondary batteries, which is small in viscosity and high in ion conductivity, and which decreases the internal resistance of a lithium secondary battery, and further enhances the rate characteristics and output characteristics; and a lithium secondary battery including the electrolyte.SOLUTION: An electrolyte for lithium secondary batteries and a lithium secondary battery including the electrolyte are disclosed. The electrolyte comprises 10-90 wt% of an ester-based solvent and 10-90 wt% of carbonate-based solvent relative to the total weight of a nonaqueous solvent. The carbonate-based solvent is at least one cyclic carbonate of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, and 2,3-pentylene carbonate. The electrolyte does not contain a sulfur compound.SELECTED DRAWING: Figure 2 【課題】粘度が小さく、イオン伝導度が高く、リチウム二次電池の内部抵抗を減少し、レート特性及び出力特性がより向上するリチウム二次電池用電解液及びそれを含むリチウム二次電池の提供。【解決手段】非水系溶媒の全重量に対して１０〜９０重量％のエステル系溶媒及び１０〜９０重量％のカーボネート系溶媒を含み、カーボネート系溶媒は、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、１，２−ブチレンカーボネート、２，３−ブチレンカーボネート、１，２−ペンチレンカーボネート、及び２，３−ペンチレンカーボネートのうちの１つ以上の環状カーボネートであり、電解液は、硫黄化合物を含まない、リチウム二次電池用電解液及びそれを含むリチウム二次電池。【選択図】図２