Secondary battery

Patent metadata

Field	Value
Publication number	US-2023137208-A1
Application number	US-202218090947-A
Country	US
Kind code	A1
Filing date	Dec 29, 2022
Priority date	Sep 17, 2020
Publication date	May 4, 2023
Grant date	—

Abstract

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-nickel composite oxide. The negative electrode includes a lithium-titanium composite oxide. The electrolytic solution includes a carboxylic acid ester. The carboxylic acid ester includes at least one of ethyl acetate, propyl acetate, ethyl propionate, or propyl propionate. A first oxygen spectrum and a second oxygen spectrum are detectable by a surface analysis of the positive electrode by X-ray photoelectron spectroscopy. The first oxygen spectrum has a peak within a range of binding energy that is greater than or equal to 528 eV and less than or equal to 531 eV. The second oxygen spectrum has a peak within a range of binding energy that is greater than 531 eV and less than or equal to 535 eV. A ratio of an intensity of the first oxygen spectrum to an intensity of the second oxygen spectrum is greater than or equal to 0.30 and less than or equal to 0.80. A third oxygen spectrum and a fourth oxygen spectrum are detectable by a surface analysis of the negative electrode by the X-ray photoelectron spectroscopy. The third oxygen spectrum has a peak within a range of binding energy that is greater than or equal to 528 eV and less than or equal to 531 eV. The fourth oxygen spectrum has a peak within a range of binding energy that is greater than 531 eV and less than or equal to 535 eV. A ratio of an intensity of the third oxygen spectrum to an intensity of the fourth oxygen spectrum is greater than or equal to 0.82 and less than or equal to 1.35.

First claim

1 . A secondary battery comprising:
a positive electrode including a lithium-nickel composite oxide; a negative electrode including a lithium-titanium composite oxide; and an electrolytic solution including a carboxylic acid ester, wherein the carboxylic acid ester includes at least one of ethyl acetate, propyl acetate, ethyl propionate, or propyl propionate, a first oxygen spectrum and a second oxygen spectrum are detectable by a surface analysis of the positive electrode by X-ray photoelectron spectroscopy, the first oxygen spectrum having a peak within a range of binding energy that is greater than or equal to 528 electron volts and less than or equal to 531 electron volts, the second oxygen spectrum having a peak within a range of binding energy that is greater than 531 electron volts and less than or equal to 535 electron volts, a ratio of an intensity of the first oxygen spectrum to an intensity of the second oxygen spectrum is greater than or equal to 0.30 and less than or equal to 0.80, a third oxygen spectrum and a fourth oxygen spectrum are detectable by a surface analysis of the negative electrode by the X-ray photoelectron spectroscopy, the third oxygen spectrum having a peak within a range of binding energy that is greater than or equal to 528 electron volts and less than or equal to 531 electron volts, the fourth oxygen spectrum having a peak within a range of binding energy that is greater than 531 electron volts and less than or equal to 535 electron volts, and a ratio of an intensity of the third oxygen spectrum to an intensity of the fourth oxygen spectrum is greater than or equal to 0.82 and less than or equal to 1.35.

2 . The secondary battery according to claim 1 , wherein the lithium-nickel composite oxide includes a compound represented by Formula (1) below,
Li x Ni (1-y) M1 y O 2   (1)
where M1 is at least one of elements belonging to groups 2 to 15 in a long period periodic table of elements excluding Ni, and x and y satisfy 0.8≤x≤1.2 and 0≤y<1.0.

3 . The secondary battery according to claim 2 , wherein a proportion of a number of moles of Ni to a sum of the number of moles of Ni and a number of moles of M1 is greater than or equal to 80 percent.

4 . The secondary battery according to claim 1 , wherein
the electrolytic solution includes a solvent and an electrolyte salt, the solvent includes the carboxylic acid ester, and a content of the carboxylic acid ester in the solvent is greater than or equal to 50 weight percent and less than or equal to 90 weight percent.

5 . The secondary battery according to claim 4 , wherein the solvent further includes a cyclic carbonic acid ester.

6 . The secondary battery according to claim 1 , wherein
the positive electrode includes
a positive electrode active material layer including the lithium-nickel composite oxide, and
a positive electrode film provided on a surface of the positive electrode active material layer, the positive electrode film including oxygen as a constituent element, and
the surface analysis of the positive electrode by the X-ray photoelectron spectroscopy comprises an analysis of the positive electrode film.

7 . The secondary battery according to claim 1 , wherein the lithium-titanium composite oxide includes at least one of respective compounds represented by Formula (2), Formula (3), and Formula (4) below,
Li[Li x M2 (1-3x)/2 Ti (3+x)/2 ]O 4   (2)
where M2 is at least one of Mg, Ca, Cu, Zn, or Sr, and x satisfies 0≤x≤⅓,
Li[Li y M3 1-3y Ti 1+2y ]O 4   (3)

where M3 is at least one of Al, Sc, Cr, Mn, Fe, Ga, or Y, and y satisfies 0≤y≤⅓,
Li[Li 1/3 M4 z Ti (5/3)-z ]O 4   (4)

where M4 is at least one of V, Zr, or Nb, and z satisfies 0≤z≤⅔.

8 . The secondary battery according to claim 1 , wherein
the negative electrode includes
a negative electrode active material layer including the lithium-titanium composite oxide, and
a negative electrode film provided on a surface of the negative electrode active material layer, the negative electrode film including oxygen as a constituent element, and
the surface analysis of the negative electrode by the X-ray photoelectron spectroscopy comprises an analysis of the negative electrode film.

9 . The secondary battery according to claim 1 , further comprising an outer package member having flexibility and containing the positive electrode, the negative electrode, and the electrolytic solution.

10 . The secondary battery according to claim 1 , wherein the secondary battery comprises a lithium-ion secondary battery.

Assignees

• Murata Manufacturing Co

Inventors

• Munaoka Takatoshi
• Katayama Shinichi
• Ouki Atsushi
• Kuratsuka Masaki
• Fujikawa Takashige
• Shima Yousuke

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title