ELECTRODE UNIT FOR PRISMATIC BATTERY, PRISMATIC BATTERY, AND METHOD OF MANUFACTURING ELECTRODE UNIT FOR PRISMATIC BATTERY

• US 20070092792A1
• Filed: 10/25/2006
• Published: 04/26/2007
• Est. Priority Date: 10/26/2005
• Status: Active Grant

• Current Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Original Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Inventors: Hayashi, Kiyoshi, Kasahara, Hideki
• Granted Patent: US 8,039,143 B2
• Time in Patent Office: Days
• US Class Current: 429/161
• CPC Class Codes: H01M 10/0413 Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/058 Construction or manufacture
• CPC Class Codes: H01M 10/281 Large cells or batteries with stacks of plate-like electrodes
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/533 characterised by the shape of the leads or tabs
• CPC Class Codes: H01M 50/536 characterised by the method of fixing the leads to the electrodes, e.g. by welding
• 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
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

To provide an electrode unit for a prismatic battery capable of increasing the output of the battery while suppressing the battery internal resistance value and improving the degree of freedom of the size of the electrode plate. An electrode unit for a prismatic battery including an electrode group in which positive electrode plates and negative electrode plates in an almost rectangular shape are alternately stacked with separators interposed therebetween. In each of the positive electrode plate and the negative electrode plate, core material exposed portions are formed at least on two side edges. The positive electrode plates and the negative electrode plate are stacked such that their core material exposed portions are directed not to overlap each other in the stack direction. The electrode unit for a prismatic battery includes a positive current collector having a shape capable of joining to all of the core material exposed portions of the positive electrode plates constituting the electrode group, and a negative current collector capable of joining to all of the core material exposed portions of the negative electrode plates constituting the electrode group, not in contact with the positive current collector.

Claims

1. An electrode unit for a prismatic battery comprising an electrode group in which positive electrode plates and negative electrode plates in an almost rectangular shape are alternately stacked with separators interposed therebetween,

wherein core material exposed portions are formed at least on two side edges in each of said positive electrode plates and negative electrode plates, and

wherein said positive electrode plates and negative electrode plate are stacked such that the core material exposed portions thereof are directed not to overlap each other in the stack direction,

said electrode unit further comprising:

a positive current collector having a shape capable of joining to the core material exposed portions of said positive electrode plates; and

a negative current collector having a shape capable of joining to the core material exposed portions of said negative electrode plates, not in contact with said positive current collector.

2. The electrode unit for a prismatic battery according to claim 1,

wherein said electrode group is fixed by fixing said positive current collector to the core material exposed portions of said positive electrode plates, and fixing said negative current collector to the core material exposed portions of said negative electrode plates.

3. The electrode unit for a prismatic battery according to claim 1,

wherein the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates are formed on two side edges along a pair of opposite sides on each of said positive electrode plates and said negative electrode plates.

4. The electrode unit for a prismatic battery according to claim 1,

wherein the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates are formed on two adjacent side edges on each of said positive electrode plates and said negative electrode plates.

5. The electrode unit for a prismatic battery according to claim 1,

wherein the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates are formed on three adjacent side edges on each of said positive electrode plates and said negative electrode plates, and

wherein lengths of the core material exposed portions formed on two side edges located on opposite sides of the three side edges are shorter than respective entire lengths of the two side edges.

6. The electrode unit for a prismatic battery according to claim 3,

wherein said positive current collector and said negative current collector have shapes along the side edges comprising the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates, and

wherein connecting terminal portions protrude from edges or corners of said positive current collector and said negative current collector.

7. The electrode unit for a prismatic battery according to claim 4,

wherein said positive current collector and said negative current collector have shapes along the side edges comprising the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates, and

wherein connecting terminal portions protrude from edges or corners of said positive current collector and said negative current collector.

8. The electrode unit for a prismatic battery according to claim 5,

wherein said positive current collector and said negative current collector have shapes along the side edges comprising the core material exposed portions formed in each of said positive electrode plates and said negative electrode plates, and

wherein connecting terminal portions protrude from edges or corners of said positive current collector and said negative current collector.

9. The electrode unit for a prismatic battery according to claim 3,

wherein said positive electrode plates and said negative electrode plates are stacked such that the two side edges of said positive electrode plate where the core material exposed portions are formed and the two side edges of said negative electrode plate where the core material exposed portions are formed are arranged in directions to form right angles with each other.

10. The electrode unit for a prismatic battery according to claim 9,

wherein both of said positive current collector and said negative current collector are formed having a cross section in a C-shape,

wherein two opposite side plate portions of said positive current collector are joined to a pair of core material exposed portions of each of said positive electrode plates, and

wherein two opposite side plate portions of said negative current collector are joined to a pair of core material exposed portions of each of said negative electrode plates.

11. The electrode unit for a prismatic battery according to claim 1,

wherein said positive current collector and said negative current collector are joined to respective core material exposed portions by any of laser beam welding, electron beam welding or resistance heating welding.

12. The electrode unit for a prismatic battery according to claim 1,

wherein an active material of said positive electrode plate contains nickel hydroxide as a main component, and an active material of said negative electrode plate contains a hydrogen absorbing alloy as a main component.

13. The electrode unit for a prismatic battery according to claim 1,

wherein an active material of said positive electrode plate contains a lithium-containing metal compound as a main component, and an active material of said negative electrode plate contains a carbon material as a main component.

14. A prismatic battery comprising:

the electrode unit for a prismatic battery according to claim 1;

a casing for housing the electrode unit for a prismatic battery;

a positive electrode terminal electrically connected to a positive current collector of the electrode unit for a prismatic battery and attached to said casing, and

a negative electrode terminal electrically connected to a negative current collector of the electrode unit for a prismatic battery and attached to said casing.

15. A method of manufacturing an electrode unit for a prismatic battery, comprising:

an active material filling step of filling active materials in a positive electrode core material forming a positive electrode plate and a negative electrode core material forming a negative electrode plate;

a core material exposed portion forming step of forming core material exposed portions at least on two side edges in each of the positive electrode plate and the negative electrode plate fabricated in an almost rectangular shape;

a rolling step of rolling the positive electrode plate and the negative electrode plate into a predetermined thickness;

a stacking step of stacking the positive electrode plates and the negative electrode plates with separators interposed therebetween such that the respective core material exposed portions are directed not to overlap each other in the stack direction and the respective active material filled portions are opposed to each other;

a positive current collector joining step of joining, to the core material exposed portions, a positive current collector formed in a shape in contact with all of the core material exposed portions located in the positive electrode plates; and

a negative current collector joining step of joining, to the core material exposed portions, a negative current collector formed in a shape in contact with all of the core material exposed portions located in the negative electrode plates but not in contact with the positive current collector.

16. The method of manufacturing an electrode unit for a prismatic battery according to claim 15,

wherein in said core material exposed portion forming step, the core material exposed portion is formed by an ultrasonic removing method or stripping method.

17. The method of manufacturing an electrode unit for a prismatic battery according to claim 15,

wherein the positive current collector and the core material exposed portions corresponding thereto are joined in said positive current collector joining step, and the negative current collector and the core material exposed portions corresponding thereto are joined in said negative current collector joining step, by any of laser beam welding, electron beam welding or resistance heating welding.