Lithium-ion secondary battery and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-10340527-B2
Application number	US-201615563183-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2015
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

A lithium-ion secondary battery that includes a positive electrode including a sulfur-based positive active material containing at least sulfur and a negative electrode including a silicon-based negative active material containing at least silicon or a tin-based negative active material containing tin, in which lithium ions are easily implanted and moved. A positive electrode includes a positive current collector and a sulfur-based positive active material containing at least sulfur (S). A negative electrode includes a negative current collector and a silicon-based negative active material containing at least silicon (Si) or a tin-based negative active material containing tin (Sn). The positive current collector is made of an aluminum foil having a plurality of through holes. The negative current collector is made of a copper foil having a plurality of through holes. The positive electrode and the negative electrode are stacked via a separator to form an electrode group.

First claim

The invention claimed is:

1. A lithium-ion secondary battery comprising:
a positive electrode including a positive current collector and a sulfur-based positive active material containing at least sulfur (S);
a negative electrode including a negative current collector and a silicon-based negative active material containing at least silicon (Si) or a tin-based negative active material containing tin (Sn); and
a separator, wherein:
the positive current collector is made of an aluminum perforated foil having a plurality of through holes formed to pierce the foil from a front surface to a back surface thereof;
the negative current collector is made of a copper foil having a plurality of through holes; and
the positive electrode and the negative electrode are stacked via the separator;
the through holes formed in the aluminum perforated foil and the through holes formed in the copper foil each have a density of 1×10 4 holes/m 2 or more and a hole opening rate of 3 to 50%; and
when the respective average inside diameters of the through holes formed in the aluminum perforated foil and the through holes formed in the copper foil are defined as R (μm), the respective hole opening rates of the aluminum perforated foil and the copper foil are indicated by the following expression:

hole
⁢

⁢
opening
⁢

⁢
rate
⁢

⁢

(
%
)

=

π
⁢

⁢

R
2

4

×

10

-
12

×

density
⁡

(

holes
/

m
2

)

×
100.

[

Expression
⁢

⁢
1

]

2. The lithium-ion secondary battery according to claim 1 , wherein:
the aluminum perforated foil has a foil thickness of 50 μm or less;
the through holes formed in the aluminum perforated foil have an average inside diameter of 2 μm to 500 μm;
the copper foil has a foil thickness of 50 μm or less; and
the through holes formed in the copper foil have an average inside diameter of 30 μm to 500 μm.

3. The lithium-ion secondary battery according to claim 2 , wherein
the aluminum perforated foil has a hole opening rate of 5 to 30%.

4. The lithium-ion secondary battery according to claim 2 , wherein
the through holes formed in the copper foil have an average inside diameter of 50 μm to 300 μm.

5. The lithium-ion secondary battery according to claim 3 , wherein
the through holes formed in the copper foil have an average inside diameter of 50 μm to 300 μm.

Assignees

• Hitachi Chemical Co Ltd

Inventors

• Hama Yoshiki
• Sekiya Masaaki

Classifications

• H01M4/66

  Selection of materials · CPC title

• H01M10/0585

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

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/70

  characterised by shape or form · CPC title

• H01M10/052

  Li-accumulators · CPC title