Nonaqueous electrolyte secondary battery

Abstract

A nonaqueous electrolyte secondary battery includes a positive electrode having a positive electrode active material layer provided on a positive electrode collector, a negative electrode having a negative electrode active material layer provided on a negative electrode collector, and a nonaqueous electrolyte. The nonaqueous electrolyte contains at least one member selected from the group consisting of sulfone compounds represented by the following formulae (1) and (2); and an inorganic phosphorus compound represented by the following formula (3) exists on the surface of a positive electrode active material: R1 represents CmH2m-n1Xn2; X represents a halogen; m represents an integer of from 2 to 7; each of n1 and n2 independently represents an integer of from 0 to 2m; R2 represents CjH2j-k1Zk2; Z represents a halogen; j represents an integer of from 2 to 7; each of k1 and k2 independently represents an integer of from 0 to 2j; each of R3, R4 and R5 independently represents H or OH; and a is 0 or 1.

Description

References to related applications The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2009-046651 filed in the Japan Patent Office on Feb. 27, 2009, the entire content of which is hereby incorporated by reference. technical field The present invention relates to a nonaqueous electrolyte secondary battery. Background technique Among nonaqueous electrolyte batteries, lithium ion secondary batteries are rapidly developing as power sources for portable electronic devices such as mobile phones and portable personal computers. In power sources for such portable electronic devices, energy density, that is, energy storage capacity per unit volume, is the most necessary characteristic, and attention is paid to how long the portable device can be used. JP-A-2004-22336 discloses an electrolytic solution in which sulfonic anhydride is contained in an aprotic organic solvent to obtain lithium disulfide having not only...

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Problems solved by technology

However, although the adverse effect on the anode due to the dissolution of Co can be avoided, the cathode resistance also increases due to the change in the cathode structure, and the capacity is deteriorated.

That is, unless the dissolution of Co itself is suppressed, a battery with high reliability cannot be obtained

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