Lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2017331145-A1
Application number	US-201515528040-A
Country	US
Kind code	A1
Filing date	Nov 18, 2015
Priority date	Nov 19, 2014
Publication date	Nov 16, 2017
Grant date	—

Abstract

A lithium-ion battery with high safety is provided. A lithium-ion battery 20 includes an electrode group 6 , an electrolyte, and a battery container 5 that contains the electrode group 6 and the electrolyte. The electrode group 6 is formed by stacking a positive electrode and a negative electrode via a separator. The positive electrode contains a composite oxide of lithium, nickel, manganese, and cobalt as a main positive active material. The negative electrode contains amorphous carbon as a main negative active material. The lithium-ion battery 20 has a discharge capacity of 20 Ah or more. The ratio (the value of Y/X) of a volume Y occupied by the electrolyte to a volume X of a void space in the battery container 5 is 0.65 or more.

First claim

1 . A lithium-ion battery comprising an electrode group, an electrolyte, and a battery container that contains the electrode group and the electrolyte, the electrode group being formed by stacking a positive electrode and a negative electrode via a separator, the positive electrode containing a composite oxide of lithium, nickel, manganese, and cobalt as a main positive active material, the negative electrode containing amorphous carbon as a main negative active material, and the lithium-ion battery having a discharge capacity of 20 Ah or more, wherein
a ratio (a value of Y/X) of a volume Y occupied by the electrolyte to a volume X of a void space in the battery container, with the electrode group being placed in the battery container, is 0.65 or more.

2 . The lithium-ion battery according to claim 1 , wherein
the value of Y/X is 0.8 or more.

3 . The lithium-ion battery according to claim 1 , wherein
the value of Y/X is 0.9 or more.

4 . The lithium-ion battery according to claim 1 , wherein
the composite oxide of lithium, nickel, manganese, and cobalt is a layered composite oxide of lithium, nickel, manganese, and cobalt.

5 . The lithium-ion battery according to claim 1 , wherein
the amorphous carbon is easily graphitizable carbon.

6 . The lithium-ion battery according to claim 1 , wherein
the electrolyte is prepared by dissolving lithium hexafluorophosphate in a mixed solution prepared by mixing ethylene carbonate, dimethyl carbonate, and ethylmethyl carbonate.

7 . The lithium-ion battery according to claim 1 , wherein
the discharge capacity is 20 Ah or more and less than 99 Ah.

8 . The lithium-ion battery according to claim 1 , wherein
the electrode group is a wound electrode group.

Assignees

• Hitachi Chemical Co Ltd

Inventors

• Itoh Shingo
• Ochida Manabu
• Kajimoto Takanori
• Itoh Youhei
• Yoshiura Tadashi

Classifications

• H01M10/0525 Primary

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

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/0587

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