Alkaline storage battery

• US 20020025472A1
• Filed: 04/24/2001
• Published: 02/28/2002
• Est. Priority Date: 04/27/2000
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Takahashi, Yasuhiro, Sato, Naoto, Ito, Takashi, Taniguchi, Akihiro, Ikoma, Munehisa, Komori, Katsunori
• Granted Patent: US 6,777,129 B2
• Time in Patent Office: Days
• US Class Current: 429/118
• CPC Class Codes: H01M 10/28 Construction or manufacture
• CPC Class Codes: H01M 10/34 Gastight accumulators
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 50/414 Synthetic resins, e.g. thermoplastics or thermosetting resins
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

An alkaline storage battery having excellent self-discharge characteristics even after a number of charge-discharge cycles is provided. The alkaline storage battery is provided with a case and an electrode group enclosed in the case, and a separator that is included in the electrode group retains at least 15 mg/cm² of an electrolyte at least in a period after assembling the battery, from the time the separator is impregnated with the electrolyte to the time the battery is activated.

Claims

1. An alkaline storage battery comprising:

a case; and

a positive electrode, a negative electrode, a separator and an electrolyte that are provided in the case;

wherein an amount of the electrolyte retained in the separator is at least 15 mg/cm² in a period, after assembling the battery, from a time the separator is impregnated with the electrolyte to the time the battery is activated.

2. The alkaline storage battery according to claim 1, wherein the separator is formed of sulfonated polypropylene, and sulfur atoms and carbon atoms in the separator satisfy a relationship of (the number of the sulfur atoms)/(the number of the carbon atoms)=A, where 2.0×

10<sup>−

3</sup>≦

A≦

5.5×

10<sup>−

3.</sup>

3. The alkaline storage battery according to claim 1, wherein the electrolyte is poured into the case in a vacuum atmosphere.

4. The alkaline storage battery according to claim 1, wherein the separator has a specific surface area ranging from 0.6 m²/g to 0.9 m²/g.

5. The alkaline storage battery according to claim 1, wherein the separator has a median pore diameter of not larger than 30 μ

m on a volume basis when pores are measured in a range of 0.1 μ

to 360 μ

m with a mercury porosimeter.

6. The alkaline storage battery according to claim 1, wherein the separator has a weight per unit area ranging from 60 g/m² to 85 g/m^2.

7. An alkaline storage battery comprising:

a case; and

a positive electrode, a negative electrode, a separator and an electrolyte that are provided in the case;

wherein a total area X (cm²) of the separator and an amount Y (mg) of the electrolyte satisfy a relationship of Y/X≧

20 in a period, after assembling the battery, from a time the separator is impregnated with the electrolyte to the time the battery is activated.

8. The alkaline storage battery according to claim 7, wherein the separator is formed of sulfonated polypropylene, and sulfur atoms and carbon atoms in the separator satisfy a relationship of (the number of the sulfur atoms)/(the number of the carbon atoms)=A, where 2.0×

10<sup>−

3</sup>≦

A≦

5.5×

10<sup>−

3.</sup>

9. The alkaline storage battery according to claim 7, wherein the electrolyte is poured into the case in a vacuum atmosphere.

10. The alkaline storage battery according to claim 7, wherein the separator has a specific surface area ranging from 0.6 m²/g to 0.9 m²/g.

11. The alkaline storage battery according to claim 7, wherein the separator has a median pore diameter of not larger than 30 μ

m on a volume basis when pores are measured in a range of 0.1 μ

m to 360 μ

m with a mercury porosimeter.

12. The alkaline storage battery according to claim 7, wherein the separator has a weight per unit area ranging from 60 g/m² to 85 g/m².

14. The alkaline storage battery according to claim 13, wherein the negative electrode contains a hydrogen absorbing alloy, the hydrogen absorbing alloy containing misch metal and manganese in a composition ratio of 1:

B, where 0.2≦

B≦

0.5.

15. The alkaline storage battery according to claim 13, wherein the electrolyte contains a manganese ion.

13. An alkaline storage battery comprising:

a case; and

a positive electrode, a negative electrode, a separator and an electrolyte that are provided in the case;

wherein a chemical compound containing manganese is deposited on a surface of the separator.