Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2016226100-A1
Application number	US-201415024415-A
Country	US
Kind code	A1
Filing date	Sep 25, 2014
Priority date	Sep 25, 2013
Publication date	Aug 4, 2016
Grant date	—

Abstract

To improve battery characteristics by an optimum combination of an electrolytic solution and a negative electrode active material. An electrolytic solution of a nonaqueous electrolyte secondary battery contains a metal salt, and an organic solvent having a heteroatom and satisfying, regarding an intensity of a peak derived from the organic solvent in a vibrational spectroscopy spectrum, Is>Io, when an intensity of an original peak of the organic solvent is represented as Io and an intensity of a peak resulting from shifting of the original peak is represented as Is. As a negative electrode, any of the following (1) to (5) is used: (1) a graphite whose G/D ratio, which is a ratio of G-band and D-band peaks in a Raman spectrum, is not lower than 3.5; (2) a carbon material whose crystallite size, calculated from a half width of a peak appearing at 2θ=20 degrees to 30 degrees in a X-ray diffraction profile measured by X-ray diffraction method, is not larger than 20 nm; (3) silicon element and/or tin element; (4) a metal oxide configured to occlude and release lithium ions; or (5) a graphite whose ratio (long axis/short axis) of long axis to short axis is 1 to 5.

First claim

1 .- 23 . (canceled)

24 . A nonaqueous electrolyte secondary battery comprising a negative electrode and an electrolytic solution, wherein
the electrolytic solution contains a salt whose cation is an alkali metal, an alkaline earth metal, or aluminum, and an organic solvent having a heteroelement, regarding an intensity of a peak derived from the organic solvent in a vibrational spectroscopy spectrum of the electrolytic solution, Is>Io is satisfied when an intensity of an original peak of the organic solvent is represented as Io and an intensity of a peak resulting from shifting of the original peak is represented as Is, or d/c obtained by dividing a density d (g/cm 3 ) of the electrolytic solution by a salt concentration c (mol/L) of the electrolytic solution is within a range of 0.15≦d/c≦0.71, and at least one of the following conditions 1 to 5 is satisfied. Condition 1: The negative electrode includes, in a negative electrode active material, a graphite whose G/D ratio, which is a ratio of G-band and D-band peaks in a Raman spectrum, is not lower than 3.5. Condition 2: The negative electrode includes, in a negative electrode active material, a carbon material whose crystallite size, calculated from a half width of a peak appearing at 2θ=20 degrees to 30 degrees in a X-ray diffraction profile measured by X-ray diffraction method, is not larger than 20 nm. Condition 3: The negative electrode includes, in a negative electrode active material, silicon element and/or tin element. Condition 4: The negative electrode includes, as a negative electrode active material, a metal oxide configured to occlude and release lithium ions. Condition 5: The negative electrode includes, in a negative electrode active material, a graphite whose ratio (long axis/short axis) of long axis to short axis is 1 to 5.

25 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 1 is satisfied, and the G/D ratio is not lower than 10.

26 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 2 is satisfied, and the crystallite size is not larger than 5 nm.

27 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 3 is satisfied, and the negative electrode active material includes silicon element.

28 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 3 is satisfied, and the negative electrode active material includes silicon element, and oxygen element and/or carbon element.

29 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 4 is satisfied, and the metal oxide includes, as a main component, at least one type selected from titanium oxides, lithium titanium oxides, tungsten oxides, amorphous tin oxides, and tin silicon oxides.

30 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 4 is satisfied, and the metal oxide includes, as a main component, a lithium titanium oxide represented by Li 4+x Ti 5+y O 12 (x and y respectively satisfy −1≦x≦4 and −1≦y≦1).

31 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein
the condition 5 is satisfied, and I(110)/I(004) of particles of the graphite measured through X-ray diffraction is in a range of 0.03 to 1.

32 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein the cation of the salt in the electrolytic solution is lithium.

33 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein a chemical structure of an anion of the salt in the electrolytic solution includes at least one element selected from a halogen, boron, nitrogen, oxygen, sulfur, or carbon.

34 . The nonaqueous electrolyte secondary battery according to claim 24 , wherein a chemical structure of an anion of the salt in the electrolytic solution is represented by general formula (1), general formula (2), or general formula (3) below:
(R 1 X 1 )(R 2 X 2 )N  General Formula (1)
(R 1 is selected from: hydrogen; a halogen; an alkyl group optionally substituted with a substituent group; a cycloalkyl group optionally substituted with a substituent group; an unsaturated alkyl group optionally substituted with a substituent group; an unsaturated cycloalkyl group optionally substituted with a substituent group; an aromatic group optionally substituted with a substituent group; a heterocyclic group optionally substituted with a substituent group; an alkoxy group optionally substituted with a substituent group; an unsaturated alkoxy group optionally substituted with a substituent group; a thioalkoxy group optionally substituted with a substituent group; an unsaturated thioalkoxy group optionally substituted with a substituent group; CN; SCN; or OCN. R 2 is selected from: hydrogen; a halogen; an alkyl group optionally substituted with a substituent group; a cycloalkyl group optionally substituted with a substituent group; an unsaturated alkyl group optionally substituted with a substituent group; an unsaturated cycloalkyl group optionally substituted with a substituent group; an aromatic group optionally substituted with a substituent group; a heterocyclic group optionally substituted with a substituent group; an alkoxy group optionally substituted with a substituent group; an unsaturated alkoxy group optionally substituted with a substituent group; a thioalkoxy group optionally substituted with a substituent group; an unsaturated thioalkoxy group optionally substituted with a substituent group; CN; SCN; or OCN. R 1 and R 2 optionally bind with each other to form a ring. X 1 is selected from SO 2 , C═O, C═S, R a P═O, R b P═S, S═O, or Si═O. X 2 is selected from SO 2 , C═O, C═S, R c P═O, R d P═S, S═O, or Si═O. R a , R b , R c , and R d are each independently selected from: hydrogen; a halogen; an alkyl group optionally substituted with a substituent group; a cycloalkyl group optionally substituted with a substituent group; an unsaturated alkyl group optionally substituted with a substituent group; an unsaturated cycloalkyl group optionally substituted with a substituent group; an aromatic group optionally substituted with a substituent group; a heterocyclic group optionally substituted with a substituent group; an alkoxy group optionally substituted with a substituent group; an unsaturated alkoxy group optionally substituted with a substituent group; a thioalkoxy group optionally substituted with a substituent group; an unsaturated thioalkoxy group optionally substituted with a substituent group; OH; SH; CN; SCN; or OCN. R a , R b , R c , and R d each optionally bind with R 1 or R 2 to form a ring.);
R 3 X 3 Y  General Formula (2)

(R 3 is selected from: hydrogen; a halogen; an alkyl group optionally substituted with a substituent group; a cycloalkyl group optionally substituted with a substituent group; an unsaturated alkyl group optionally substituted with a substituent group; an unsaturated cycloalkyl group optionally substituted with a substituent group; an aromatic group optionally substituted with a substituent group; a heterocyclic group optionally substituted with a substituent group; an alkoxy group optionally substituted with a substituent group; an unsaturated alkoxy group optionally substituted with a substituent group; a thioalkoxy group optionally substituted with a substituent group; an unsaturated thioalkoxy group optionally substituted with a substituent group; CN; SCN; or OCN. X 3 is selected from SO 2 , C═O, C═S, R e P═O, R f P═S, S═O, or Si═O. R e and R f are each independently selected from: hydrogen; a halogen; an alkyl gr

Assignees

• Univ Tokyo

Inventors

• Yamada Atsuo
• Yamada Yuki
• Nakagaki Yoshihiro
• Kawai Tomoyuki
• Hasegawa Yuki
• Mase Kohei
• Goda Nobuhiro

Classifications

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M10/0568 Primary

  characterised by the solutes · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0569

  characterised by the solvents · CPC title