Nonaqueous electrolyte solution and lithium secondary battery using same

Abstract

Disclosed is a nonaqueous electrolyte solution suitable for a lithium secondary battery having high energy density wherein capacity decrease due to charge / discharge cycles is extremely small and no gas is generated during the charging / storing period. Specifically disclosed is a nonaqueous electrolyte solution wherein a nonaqueous solvent contains a fluorinated solvent composed of a chain fluorinated carbonate (a1) and a fluorinated ethylene carbonate (a2) in such an amount that the total amount of the fluorinated solvent in the nonaqueous solvent is within a range of 50-100 wt%.

Description

Non-aqueous electrolytic solution and lithium secondary battery using the same technical field The present invention relates to an electrolytic solution used for a high-energy-density lithium secondary battery with little capacity drop accompanying charge-discharge cycles. Background technique Lithium batteries are widely used as power sources for consumer electronics due to their high voltage, high energy density, and high reliability such as storage stability. A lithium ion secondary battery is mentioned as a representative example of a lithium battery. It is a battery composed of a negative electrode using a carbon material capable of absorbing and releasing lithium as an active material, a positive electrode using a composite oxide of lithium and a transition metal as an active material, and a non-aqueous electrolyte. Here, the non-aqueous electrolyte plays a role of transferring ions between the positive electrode and the negative electrode. In order to improve th...

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Problems solved by technology

However, in the technical solutions and examples for solving the problems of the invention, there is no specific example about fluorinated chain carbonates, and there is no description about improving the charge-discharge cycle characteristics of lithium-ion batteries.

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