Secondary battery

Patent metadata

Field	Value
Publication number	US-2023025122-A1
Application number	US-202217955830-A
Country	US
Kind code	A1
Filing date	Sep 29, 2022
Priority date	Mar 31, 2020
Publication date	Jan 26, 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 dinitrile compound and a carboxylic acid ester. A ratio of a capacity per unit area of the positive electrode to a capacity per unit area of the negative electrode is greater than or equal to 100% and less than or equal to 120%. A ratio of a number of moles of the dinitrile compound to a number of moles of the carboxylic acid ester is greater than or equal to 1% and less than or equal to 4%.

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 dinitrile compound and a carboxylic acid ester, wherein a ratio of a capacity per unit area of the positive electrode to a capacity per unit area of the negative electrode is greater than or equal to 100 percent and less than or equal to 120 percent, and a ratio of a number of moles of the dinitrile compound to a number of moles of the carboxylic acid ester is greater than or equal to 1 percent and less than or equal to 4 percent.

2 . The secondary battery according to claim 1 , wherein
the lithium-nickel composite oxide includes lithium, nickel, and another element as constituent elements, the other element being at least one of elements belonging to groups 2 to 15 in the long period periodic table of elements, excluding nickel, and a ratio of a number of moles of the nickel to a sum of the number of moles of the nickel and a number of moles of the other element is 80 percent or greater.

3 . The secondary battery according to claim 1 , wherein the lithium-titanium composite oxide includes at least one of a compound represented by Formula (1) below, a compound represented by Formula (2) below, or a compound represented by Formula (3) below,
Li[Li x M1 (1-3x)/2 Ti (3+x)/2 ]O 4   (1)
where M1 is at least one of Mg, Ca, Cu, Zn, or Sr, and x satisfies 0≤x≤⅓,
Li[Li y M2 1-3y Ti 1+2y ]O 4   (2)

where M2 is at least one of Al, Sc, Cr, Mn, Fe, Ga, or Y, and y satisfies 0≤y≤⅓,
Li[Li 1/3 M3 z Ti (5/3)-z ]O 4   (3)

where M3 is at least one of V, Zr, or Nb, and z satisfies 0≤z≤⅔.

4 . The secondary battery according to claim 1 , wherein
the dinitrile compound includes at least one of succinonitrile, glutaronitrile, or adiponitrile, and the carboxylic acid ester includes ethyl propionate, propyl propionate, or both.

5 . The secondary battery according to claim 1 , wherein
the electrolytic solution includes a solvent, 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.

6 . The secondary battery according to claim 1 , further comprising a separator interposed between the positive electrode and the negative electrode, wherein
the positive electrode and the negative electrode are alternately stacked with the separator interposed therebetween.

7 . 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.

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

Assignees

• Murata Manufacturing Co

Inventors

• Munaoka Takatoshi
• Miyamoto Masahiro
• Sakuma Tomomi
• Hashimoto Takuju

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/525 Primary

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

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/0569

  characterised by the solvents · CPC title