Lithium ion secondary battery and production method thereof

Patent metadata

Field	Value
Publication number	US-2022085377-A1
Application number	US-202117447228-A
Country	US
Kind code	A1
Filing date	Sep 9, 2021
Priority date	Sep 17, 2020
Publication date	Mar 17, 2022
Grant date	—

Abstract

A lithium ion secondary battery includes: a positive electrode having a positive electrode active material layer on a surface of a positive electrode collector; a negative electrode a having a negative electrode active material layer on a surface of a negative electrode collector; and a nonaqueous electrolyte. The positive electrode, the negative electrode, and the nonaqueous electrolyte are accommodated in a battery case. The nonaqueous electrolyte contains γ-butyrolactone as a main component of a nonaqueous solvent. A monoalkyl sulfate ion-derived coat is formed on the surface of the positive electrode active material layer. A VC-derived coat is formed on the surface of the negative electrode active material layer.

First claim

1 . A lithium ion secondary battery comprising: a positive electrode having a positive electrode active material layer on a surface of a positive electrode collector; a negative electrode having a negative electrode active material layer on a surface of a negative electrode collector; a nonaqueous electrolyte, the positive electrode, the negative electrode, and the nonaqueous electrolyte being accommodated in a battery case,
the nonaqueous electrolyte containing γ-butyrolactone as a main component of a nonaqueous solvent; a coat containing a component derived from vinylene carbonate, on a surface of the negative electrode active material layer; and a coat containing a component derived from monoalkyl sulfate ions, on a surface of the positive electrode active material layer.

2 . The lithium ion secondary battery of claim 1 , wherein
a coat containing components each derived from the vinylene carbonate or from the monoalkyl sulfate ions is formed on the surface of the negative electrode active material layer.

3 . The lithium ion secondary battery of claim 1 , wherein
a coat containing components each derived from the monoalkyl sulfate ions or from bis(oxalate)borate ions is formed on the surface of the positive electrode active material layer.

4 . The lithium ion secondary battery of claim 1 , wherein
the positive electrode contains lithium iron phosphate having an olivine crystal structure as a positive electrode active material.

5 . The lithium ion secondary battery of claim 1 , wherein
the negative electrode contains a carbon material as a negative electrode active material.

6 . The lithium ion secondary battery of claim 1 , wherein
the nonaqueous electrolyte contains, as the nonaqueous solvent, dibutyl carbonate in addition to the γ-butyrolactone.

7 . A production method of a lithium ion secondary battery that includes: a positive electrode having a positive electrode active material layer on a surface of a positive electrode collector; a negative electrode having a negative electrode active material layer on a surface of a negative electrode collector; and a nonaqueous electrolyte, the positive electrode, the negative electrode, and the nonaqueous electrolyte being accommodated in a battery case, the production method comprising:
accommodating the positive electrode and the negative electrode in the battery case and further encapsulating the nonaqueous electrolyte into the battery case and sealing the battery case, thereby obtaining a battery assembly, the nonaqueous electrolyte being obtained by dissolving a lithium salt in a nonaqueous solvent containing γ-butyrolactone as a main component and containing vinylene carbonate and lithium monoalkyl sulfate, and subjecting the battery assembly to an initial charge process, thereby forming a coat containing a component derived from the vinylene carbonate on the surface of the negative electrode active material layer and forming, on the surface of the positive electrode active material layer, a coat containing a component derived from monoalkyl sulfate ions generated by ionization of the lithium monoalkyl sulfate.

8 . The production method of claim 7 , wherein
the nonaqueous electrolyte is obtained by dissolving a lithium salt in a nonaqueous solvent containing γ-butyrolactone as a main component and containing vinylene carbonate, lithium monoalkyl sulfate, and lithium bis(oxalate)borate, and a coat containing components each derived from bis(oxalate)borate ions generated by ionization of the lithium bis(oxalate)borate or from the monoalkyl sulfate ions generated by ionization of the lithium monoalkyl sulfate is formed on the surface of the positive electrode active material layer.

Assignees

• Mazda Motor

Inventors

• Shimamoto Kei
• Fukunaga Takao
• Sugiyama Hideyuki
• Masuda Wataru
• Fujita Hiroki
• Higuchi munetaka

Classifications

• H01M2220/20

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

• H01M2004/028

  Positive electrodes · 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