Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2016036051-A1
Application number	US-201414772341-A
Country	US
Kind code	A1
Filing date	Mar 4, 2014
Priority date	Mar 5, 2013
Publication date	Feb 4, 2016
Grant date	—

Abstract

The present invention relates to a lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 162 to 166 eV are present in XPS analysis of sulfur (S2p) of a positive electrode surface, and P169/P164 is in the range of 0.7 to 2.0 wherein the P 169/P 164 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 162 to 166 eV (P164). The present invention can provide a lithium secondary battery having excellent cycle characteristics.

First claim

1 . A lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 162 to 166 eV are present in XPS analysis of sulfur (S2p) of a positive electrode surface, and P169/P164 is in the range of 0.7 to 2.0 wherein the P169/P164 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 162 to 166 eV (P164).

2 . The lithium secondary battery according to claim 1 , wherein a positive electrode active material included in the positive electrode comprises sulfur in the range of 100 to 400 ppm.

3 . The lithium secondary battery according to claim 1 , further comprising an electrolyte solution comprising a sulfur compound as an additive.

4 . The lithium secondary battery according to claim 3 , wherein the sulfur compound is at least one selected from compounds represented by the following formula (1) or formula (2):

wherein Q represents an oxygen atom, methylene group, or a C—S single bond; A represents substituted or unsubstituted alkylene group having 1 to 5 carbon atoms; carbonyl group; sulfinyl group; substituted or unsubstituted fluoroalkylene group having 1 to 6 carbon atoms; or divalent group having 2 to 6 carbon atoms in which a plurality of alkylene units, a plurality of fluoroalkylene units, or an alkylene unit and a fluoroalkylene unit are bonded through an ether bond; and B represents substituted or unsubstituted alkylene group; substituted or unsubstituted fluoroalkylene group; or an oxygen atom;

wherein n represents an integer of 0 or more and 2 or less; and R 1 to R 6 each independently represent a hydrogen atom, alkyl group having 1 or more and 12 or less carbon atoms, cycloalkyl group having 3 or more and 6 or less carbon atoms, or aryl group having 6 or more and 12 or less carbon atoms.

5 . A method for producing a lithium secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution comprising a sulfur compound, comprising:
a step of producing an electrode element by arranging the positive electrode comprising a positive electrode active material comprising sulfur in the range of 100 to 400 ppm, and the negative electrode to face each other; and a step of encapsulating the electrode element, and the electrolyte solution comprising an additive comprising the sulfur compound and a non-aqueous electrolytic solvent in an outer package, and performing charging; whereby a peak at 167 to 171 eV and a peak at 162 to 166 eV are present in XPS analysis of sulfur (S2p) of the positive electrode surface, and P169/P164 is in the range of 0.7 to 2.0 wherein the P169/P164 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 162 to 166 eV (P164).

6 . The method of producing a lithium secondary battery according to claim 5 , wherein the charging is performed at a temperature of 39° C. or more.

7 . The method of producing a lithium secondary battery according to claim 5 , wherein the sulfur compound is at least one selected from compounds represented by the formula (1) or formula (2).

Assignees

• Nec Corp

Inventors

• Iriyama Jiro

Classifications

• H01M4/38 Primary

  of elements or alloys · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title