JP2005142026A - Secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery in which the current collector plate can be steadily jointed to an electrode body, even when the output is increased, as compared to conventional systems, at welding of the strip-shaped current collector plate to the electrode edge of the electrode body. <P>SOLUTION: Belt-shape current collector plates 3, 30 covering the electrode edges 28, 29 are respectively installed at a pair of positive and negative electrode edges 28, 29 which protrude at both ends of a winding electrode body 2, which is flat in the vertical direction to the winding axis in a secondary battery. Both the current collector plates 3, 30 have a belt-shape flat plate part 31, and a pair of ribs 32, 32 which protrude toward the electrode edge are formed at both ends of the flat plate part 31, and the rib 32 has an opening angle of 120 degrees to the rear face of the flat plate part 31 facing the electrode edge. The electrode edges 28, 29 are jointed respectively to the current collector plates 3, 30 in a state of being bundled between the both ribs 32, 32 and the current collector plates 3, 30 are respectively coupled to electrode terminal mechanisms 4, 40 via reed members 5, 50. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a secondary battery in which an electrode body serving as a secondary battery element is accommodated in a battery can and power generated by the electrode body can be taken out from a pair of electrode terminal portions provided in the battery can.

  In recent years, lithium ion secondary batteries with high energy density (Wh / Kg) have been developed as power sources for portable electronic devices, electric vehicles, etc. Among them, rectangular secondary batteries with high volume energy density (Wh / l) have been developed. Batteries are attracting attention.

As shown in FIG. 1, the prismatic secondary battery has a rectangular parallelepiped can body (11) and a battery can (1) formed by a sealing body (12) covering the opening of the can body (11). A winding electrode body (2) serving as a power generation element is accommodated, and a pair of positive and negative electrode terminal mechanisms (4), (40) are provided on the sealing body (12). The winding electrode body (2) is accommodated horizontally in the can body (1) and has a flat shape in a direction perpendicular to the winding axis as shown in FIG.
Band-shaped current collector plates (8) and (80) are joined to both electrode edges (28) and (29) of the wound electrode body (2), respectively, and the current collector plates (8) and (80) are shown in FIG. It is connected to the electrode terminal mechanism (4) (40) shown, and it is possible to take out the electric power generated by the winding electrode body (2) from the electrode terminal mechanism (4) (40).

As shown in FIG. 9, the current collector plates (8) and (80) are formed by a band member (81) covering the electrode edges (28) and (29) of the winding electrode body (2). ), A plurality of arc-shaped protrusions (82) extending between the left and right side portions of the belt member (81) project toward the electrode edges (28) and (29).
In the step of joining the current collector plate (8) on the positive electrode side to the electrode edge (28) on the positive electrode side, first, the current collector plate (8) is pressed against the electrode edge (28), and the ridge (82) Bite into the electrode edge (28). As a result, a joining portion formed of a cylindrical surface is formed between the protrusion (82) and the electrode edge (28). Next, laser welding is performed on the joint surface, so that the protrusion (82) and the electrode edge (28) are joined with a large contact area.

By the way, in order to reduce the internal resistance of the battery, it is effective to reduce the electric resistance of the welded joint. For this purpose, it is conceivable to increase the output when performing welding.
A current collecting structure shown in FIG. 10 has been proposed as an improvement in weldability. In this structure, the shape of the current collector plate is U-shaped, thereby suppressing the expansion of both ends of the electrode group. However, in this structure, the electrode cores forming the electrode edges (28) and (29) of the take-up electrode body (2) are thin, and the distance between adjacent core bodies is as large as before. When laser welding was performed with a large output, the weld joint was melted and the laser output could not be increased.
Japanese Patent Laid-Open No. 2001-266828 [H01M10 / 04]

By the way, in order to reduce the internal resistance of the battery, it is effective to reduce the electric resistance of the welded joint. For this purpose, it is conceivable to increase the output when welding is performed.
However, in the current collecting structure shown in FIG. 10, when the electrode cores forming the electrode edges (28) and (29) of the take-up electrode body (2) are thin and the distance between adjacent core bodies is large However, when laser welding is performed with a larger output than before, there is a possibility that the welded joint is melted.
Therefore, an object of the present invention is to provide a secondary that can reliably join the current collector plate to the electrode body even when the output when the current collector plate is welded to the electrode edge of the electrode body is increased as compared with the conventional case. It is to provide a battery.

In the secondary battery according to the present invention, an electrode body in which a separator (22) is interposed between a strip-like positive electrode (21) and a negative electrode (23) is accommodated in the battery can (1), The power generated by the body can be taken out from a pair of positive and negative electrode terminal mechanisms (4) and (40) provided on the battery can (1).
The electrode body has a flat shape in the lamination direction of both electrodes, and a pair of positive and negative electrode edges (28) (29) projecting at both ends of the electrode body includes the electrode edge (28) ( Current collecting plates (3) and (30) covering 29) are respectively installed. The current collector plates (3) and (30) include a flat plate portion (31) having a width equal to or less than the thickness of the electrode body in the stacking direction. A pair of ribs (32) and (32) projecting at a predetermined opening angle toward the edges (28) and (29) are formed along the both ends, and both electrode edges (28) and (29) are respectively These are joined to the current collector plates (3) and (30) in a state of being bundled between the ribs (32) and (32). The current collector plates (3) and (30) are connected to the electrode terminal mechanisms (4) and (40) through lead members (5) and (50), respectively.

  In a specific configuration, both the ribs (32) and (32) have an opening angle of more than 90 degrees and less than 180 degrees with respect to the flat plate portion (31).

  In the secondary battery according to the present invention, a pair of ribs (32) and (32) are formed at both ends in the width direction of the flat plate portion (31) of the current collector plates (3) and (30). The rigidity of the electric plates (3) and (30) increases. Accordingly, even when the current collector plate (3) (30) is pressed against the electrode body in the assembly process, the current collector plate (3) is pressed by the pressing force pressing the current collector plate (3) (30) against the electrode body. ) (30) is not likely to be deformed.

Further, in the assembly process, a pair of positive and negative current collector plates (3) and (30) are pressed against the electrode edges (28) and (29), respectively, so that the flat plate portion (31) of the current collector plates (3) and (30). A pair of ribs (32) and (32) projecting on both sides of the two lead the plurality of core body end portions of the electrode body between the ribs (32) and (32). Accordingly, the current collector plates (3) and (30) are positioned with respect to the electrode edges (28) and (29), respectively, and the positions of the current collector plates (3) and (30) are wound up. There is no deviation in the stacking direction of the electrode body (2).
The plurality of core end portions are gathered together and bundled toward the center portion of the flat plate portion (31) by a pair of ribs. The electrode edges (28) and (29) are joined to the current collector plates (3) and (30) in a state where the ends of the plurality of core bodies are tightly bundled. When welding is performed by irradiating a laser beam or electron beam on the welding joint, fusing may occur at the welded joint even if the output is increased and welding heat is generated at the welded joint. Rather, both current collector plates (3) and (30) are securely joined to the electrode edges (28) and (29).

  In a specific configuration, the flat plate portion (31) of the current collector plates (3) and (30) has a plurality of ridge portions (33) extending in a direction intersecting with the pair of ribs (32) and (32). It protrudes toward the electrode edge (28) (29).

In the specific configuration, since the plurality of ridges (33) exhibit a large resistance to bending deformation in a plane including the ridges (33), the current collector plate (3) ( The rigidity of 30) is further increased, and there is no possibility that the current collector plates (3) and (30) are deformed even when a large pressing force is applied in the assembly process.
Accordingly, in the assembling process, both the current collector plates (3) and (30) are pressed against the electrode edges (28) and (29), respectively, so that the protruding portions (33) of the current collector plates (3) and (30) are pressed. ) Each bite uniformly into the electrode edges (28) and (29), and by welding the contact portions between the convex strips (33) and the electrode edges (28) and (29), The protrusion (33) and the electrode edge (28) (29) are joined with a large contact area.

  In another specific configuration, one or a plurality of through holes (34) are formed in the flat plate portion (31) of the current collector plates (3) and (30). Thus, a passage for the electrolytic solution when the electrode body is impregnated with the electrolytic solution in the assembly process is secured.

  In still another specific configuration, the flat plate portion (31) of the current collector plates (3) and (30) has a pair of cut and raised pieces (32) (32) protruding toward the electrode edges (28) and (29). 32) is formed. Both the cut and raised pieces (35) and (35) are cut and raised at an angle range of less than 90 degrees with respect to the flat plate portion (31), and the cut and raised pieces (35) on one rib (32) side are The electrode edge is bundled together with one rib (32), and the cut and raised piece (35) on the other rib (32) side bundles the electrode edge together with the other rib (32).

In the specific configuration, in the assembly process, a pair of positive and negative current collector plates (3) and (30) are pressed against the electrode edges (28) and (29), respectively, so that the current collector plates (3) and (30) are pressed. A pair of ribs (32) and (32) and a pair of cut and raised pieces (35 and 35) are arranged between one rib (32) and the cut and raised pieces (35) on the rib (32) side. The plurality of core end portions are introduced, and the plurality of core end portions are introduced between the other rib (32) and the cut-and-raised piece (35) on the rib (32) side. As a result, the end portions of the plurality of cores are gathered together toward the center of the flat plate portion (31) located between the rib (32) and the cut and raised piece (35) and bundled into two. It is done. As a result, the electrode edges (28) and (29) are joined to the current collector plates (3) and (30) in a state where the ends of the plurality of core bodies are tightly bundled.
Further, since the opening (36) is opened in the flat plate portion (31) with the formation of the cut and raised piece (35), the opening (36) allows the electrode body to be impregnated with the electrolytic solution in the assembly process. A passage for the electrolyte is secured.

  According to the secondary battery of the present invention, even when the output when welding the belt-shaped current collector plate to the electrode edge of the electrode body is increased as compared with the conventional case, the current collector plate is securely joined to the electrode body. I can do it.

Hereinafter, the embodiment in which the present invention is applied to a prismatic secondary battery will be specifically described with reference to the drawings.
First Embodiment In the prismatic secondary battery of the present embodiment, as shown in FIG. 1, an aluminum sealing plate (12) is welded to the opening of an aluminum rectangular parallelepiped can body (11). A rectangular parallelepiped battery can (1) is formed. A winding electrode body (2) is accommodated in the battery can (1). The wound electrode body (2) has an outer dimension of, for example, 17 mm × 50 mm × 90 mm.

The positive electrode and the negative electrode of the wound electrode body (2) are connected to a pair of positive and negative electrode terminal mechanisms (4) and (40), and electric power can be taken out from these electrode terminal mechanisms (4) and (40). is there.
In addition, the sealing plate (12) of the battery can (1) includes a gas discharge valve (13) to be operated when the internal pressure of the battery can (1) rises, and the battery can (1) in the assembly process. An injection plug (14) for closing the injection hole for injecting the electrolyte is attached.

  As shown in FIG. 3, the wound electrode body (2) is formed by interposing a strip-shaped separator (22) between a strip-shaped positive electrode (21) and a negative electrode (23) and winding them in a spiral shape. Has been. The positive electrode (21) is formed by applying a positive electrode active material (24) made of lithium cobaltate on both surfaces of a strip-shaped core (25) made of an aluminum foil having a thickness of 15 μm, and the negative electrode (23) has a thickness of 10 μm. The negative electrode active material (26) made of graphite is applied to both surfaces of a strip-like core (27) made of copper foil. The separator (22) is a microporous membrane made of ion-permeable polypropylene, and the separator (22) is impregnated with a non-aqueous electrolyte.

The positive electrode (21) is formed with a coated portion where the positive electrode active material (24) is applied and an uncoated portion where the positive electrode active material (24) is not applied. The negative electrode (23) is also formed with a coated portion where the negative electrode active material (26) is applied and a non-coated portion where the negative electrode active material is not applied.
The positive electrode (21) and the negative electrode (23) are respectively shifted and overlapped on the separator (22) in the width direction, and the non-coated portions of the positive electrode (21) and the negative electrode (23) are separated from both end edges of the separator (22). Each protrudes outward. And after winding these in a spiral shape, the wound electrode body (2) which exhibits a flat shape in a direction perpendicular to the winding axis is formed by compressing the outer peripheral surface of the electrode body from both sides. A central hole (210) penetrating both ends is formed in the central portion of the winding electrode body (2).

At one end of the wound electrode body (2), the edge of the core body (25) of the plurality of positive electrodes (21) protrudes to form the electrode edge (28) on the positive electrode side, and the other The edge of the core body (27) of the plurality of negative electrodes (23) protrudes from the end of the negative electrode (29) to form an electrode edge (29) on the negative electrode side. As shown in FIG. 2, a pair of positive and negative current collector plates (3) and (30) are joined to each other.
Each of the positive and negative current collecting plates (3) and (30) includes a strip-shaped flat plate portion (31) having a width slightly smaller than the thickness of the winding electrode body (2), and the width direction of the flat plate portion (31). A pair of ribs (32) and (32) projecting toward the electrode end edges (28) and (29) are formed along the both end portions. The current collecting plates 3 and 30 have a thickness of 0.5 mm, the flat plate portion 31 has an outer dimension of 14 mm × 50 mm, and the rib 32 has an outer dimension of 2 mm × 50 mm.
Both ribs (32) and (32) have an opening angle of 120 degrees with respect to the back surface of the flat plate portion (31) that faces the electrode edges (28) and (29) of the winding electrode body (2). Have. The flat plate portion (31) has a plurality of (three in this embodiment) ridges (33) extending in a direction crossing the pair of ribs (32) and (32), and the electrode edge (28) ( 29) and a plurality of (three in this embodiment) through holes (34) are formed between the adjacent ridges (33).
The positive current collector plate (3) is made of aluminum, and the negative current collector plate (30) is made of nickel.

  As shown in FIG. 4, the current collector plates (3), (30) and the surface of the flat plate portion (31) of the current collector plates (3), (30) joined to both ends of the winding electrode body (2) A polypropylene insulating tape (6) for electrical insulation between the can bodies (11) is attached, and the insulating tape (6) is a plurality of current collector plates (3) (30). An opening (61) is formed at a position facing the through hole (34).

The take-up electrode body (2) with the current collector plates (3) and (30) joined to both ends is accommodated in the can body (11) in such a posture that its outer peripheral surface is along the bottom surface of the can body (11). Is done.
Further, at both ends of the winding electrode body (2), strip-shaped lead members (5) and (50) having arc-shaped bent portions are installed, and one end portion of the lead members (5) and (50) is provided. While being welded to the back surface of the flat plate portion (31) of the current collector plates (3) and (30), the other end portion of the lead members (5) and (50) is the base end of the electrode terminal mechanism (4) and (40). It is caulked and fixed to the part.
The lead member (5) on the positive electrode side is made of aluminum, and the lead member (50) on the negative electrode side is made of nickel.

As shown in FIG. 6, the electrode terminal mechanism (4) on the positive electrode side has a flange portion (42) on the sealing plate (12) via the first insulating member (44) and the second insulating member (45). An aluminum terminal member (41) is riveted, and a first insulating member (44) and a second insulating member (between the flange portion (42) and the caulking portion (43) of the terminal member (41) ( 42) is clamped, and the one end of the lead member (5) is clamped by the caulking portion (43) and the first insulating member (44).
The electrode terminal mechanism (40) on the negative electrode side has the same structure except that the terminal member (41) is made of nickel.

In assembling the prismatic secondary battery of the above embodiment, first, a can body (11), a sealing plate (12), and a winding electrode body (2) shown in FIG. Electroplates (3) and (30) are prepared.
Next, the current collector plates (3) and (30) are pressed against the electrode edges (28) and (29) protruding from both ends of the wound electrode body (2). Here, the rigidity of the current collector plates (3) and (30) is large due to the pair of ribs (32) and (32) and the ridges (33) formed by pressing. (3) There is no possibility that the flat plate portion (31) of the current collector plates (3) and (30) is deformed by the pressing force pressing the electrode edges (28) and (29).
Accordingly, by pressing the current collector plates (3) and (30) against the electrode edges (28) and (29), respectively, the protruding portions (33) of the current collector plates (3) and (30) are moved to the electrode edge ( 28) (29) bite into each of them uniformly, and a joint portion formed of a cylindrical surface is formed between each ridge (33) and the electrode edge (28) (29).

  Further, as shown in FIG. 5, a plurality of core end portions of the winding electrode body (2) are formed by a pair of ribs (32) and (32) so that the flat plate portion (31) of the current collector plates (3) and (30). They are gathered and bundled toward the center. Accordingly, the current collector plates (3) and (30) are positioned with respect to the electrode edges (28) and (29), respectively, and the positions of the current collector plates (3) and (30) are wound up. There is no deviation in the thickness direction of the electrode body (2).

  In this way, the current collector plates (3) and (30) are pressed against the electrode edges (28) and (29) of the winding electrode body (2), and are directed toward the inner peripheral surface of each protrusion (33). The laser beam is irradiated and laser welding is performed. At this time, the electrode edges (28) and (29) are in contact with the current collector plates (3) and (30) in a state in which the end portions of the plurality of core bodies are more tightly bundled than in the prior art. Even when welding is performed with a large output and a large welding heat is generated in the welded joint, the welded joint does not melt, and both current collector plates (3) and (30) have their respective electrode edges. (28) It is securely joined to (29).

Then, as shown in FIG. 6, a pair of positive and negative electrode terminal mechanisms (4) and (40) are assembled to the sealing plate (12), and the other end of the pair of lead members (5) and (50) is connected to the electrode. Secure to the crimping part (43) of the terminal mechanism (4) (40).
Thereafter, the one end of each of the lead members (5) and (50) is welded to the back surface of the flat plate portion (31) of the current collector plates (3) and (30).

  Next, as shown in FIG. 4, after attaching an insulating tape (6) to the surface of the flat plate portion (31) of both current collector plates (3) and (30), the winding electrode body (2) is attached to the can body ( 11), the sealing plate (12) is placed on the opening of the can body (11), and the sealing plate (12) is welded to the can body (11).

Thereafter, an electrolytic solution is injected from the injection hole of the sealing plate (12) in the dry box. At this time, the electrolytic solution is supplied to the inside of the winding electrode body (2) from the through hole (34) of the current collector plates (3) and (30) through the opening (61) of the insulating tape (6). The time for impregnating the winding electrode body (2) with the electrolytic solution is greatly shortened, whereby the time for injecting the electrolytic solution into the battery can (1) is greatly shortened. In this example, the injection time was shortened by 40% compared to the secondary battery having the conventional current collecting structure shown in FIG.
Incidentally, the electrolyte, a volume ratio of ethylene carbonate and diethyl carbonate 1: mixed solvent 1, in which LiPF ₆ was dissolved at a rate of 1 mol / l.
Finally, the liquid injection hole is sealed with a liquid injection stopper (14), and the assembly of the battery is completed.

  In the prismatic secondary battery of the above embodiment, the ends of the plurality of cores forming the electrode edges (28) and (29) are the current collector plates (3) and (30) covering the electrode edges (28) and (29). ) Are tightly bundled by a pair of ribs (32) and (32), so that even when laser welding is performed with a larger output than in the past, fusing does not occur at the weld joint. Therefore, the projections (33) of the current collector plates (3) (30) and the electrode edges (28) (29) are securely welded, thereby reducing the internal resistance, Battery performance is improved. In this example, the internal resistance was reduced by 20% compared with the secondary battery having the conventional current collecting structure shown in FIG.

Second Embodiment The prismatic secondary battery of this embodiment shown in FIGS. 7 and 8 is different from the first embodiment in the structure of the current collector plates (3) and (30), but the other structure is the first embodiment. Therefore, only the structure of the current collector plates (3) and (30) will be described, and the other structures will be denoted by the same reference numerals and will not be described.

  As shown in FIG. 7, in the prismatic secondary battery of the present embodiment, the winding electrode body (2) is disposed between the adjacent protruding strips (33) and (33) of the current collector plates (3) and (30), respectively. A pair of cut and raised pieces (35) and (35) projecting toward the electrode edges (28) and (29) are formed. Both the cut and raised pieces (35) and (35) extend in the longitudinal direction of the flat plate portion (31) and are about 120 degrees with respect to the surface facing the electrode edges (28) and (29) of the flat plate portion (31). Has an opening angle. The opening (36) formed in the flat plate portion (31) as the cut and raised pieces (35) and (35) are cut and raised impregnates the winding electrode body (2) with the electrolytic solution in the assembly process described later. It becomes a passage when letting go.

  In the assembly of the prismatic secondary battery of the present embodiment, when the current collector plates (3) and (30) are pressed against the electrode edges (28) and (29) of the winding electrode body (2), respectively, as shown in FIG. As described above, a plurality of core body end portions of the wound electrode body (2) are introduced between the rib (32) and the cut and raised piece (35). As a result, the plurality of core end portions are gathered together toward the flat plate portion (31) between the rib (32) and the cut and raised piece (35) and bundled into two. Accordingly, the current collector plates (3) and (30) are positioned with respect to the electrode edges (28) and (29), respectively, and the positions of the current collector plates (3) and (30) are changed. There is no deviation in the thickness direction of the winding electrode body (2).

  Further, the protruding strips (33) of the current collector plates (3) and (30) shown in FIG. 7 bite into the electrode edges (28) and (29) of the take-up electrode body (2) to form the protruding strips (33). Between the electrode edge (28) and the electrode edge (29), a joint portion having a cylindrical surface is formed. Here, the rigidity of the current collector plates (3) and (30) is such that the pair of ribs (32) and (32), the pair of cut and raised pieces (35) and (35), and the protrusion (33) formed by pressing. ), The flat plate portion (31) is not deformed even when the flat plate portion (31) is pressed against the electrode edges (28) (29) of the take-up electrode body (2). The contact area between each protrusion (33) and the electrode edges (28) (29) is uniform.

  Thus, in the state where the flat plate portion (31) of the current collector plates (3) and (30) is pressed against the electrode edges (28) and (29) of the winding electrode body (2), each protrusion (33) A laser beam is irradiated toward the inner peripheral surface of the substrate to perform laser welding. At this time, the electrode edges (28) and (29) are in contact with the current collector plates (3) and (30) in a state in which the end portions of the plurality of core bodies are more tightly bundled than in the prior art. Even when welding is performed with a large output and large welding heat is generated in the welded joint, the fusing does not occur in the joint, and the current collector plates (3) and (30) are respectively connected to the electrode edges ( 28) It will be securely joined to (29).

  And after accommodating the winding electrode body (2) which joined current collecting plates (3) and (30) in the inside of battery can (1), it electrolyzes from the injection hole of sealing plate (12) in a dry box. Inject liquid. At this time, since the electrolytic solution is supplied into the winding electrode body (2) from the opening (36) formed in the cut and raised portion (37) of the current collector plates (3) and (30), the winding electrode The time for impregnating the body (2) with the electrolytic solution is greatly shortened, and thereby the time for injecting the electrolytic solution into the battery can (1) is significantly shortened. In this example, the injection time was 40% shorter than that of the secondary battery having the conventional current collecting structure shown in FIG.

  In the prismatic secondary battery of the above embodiment, the ends of the plurality of cores forming the electrode edges (28) and (29) are the current collector plates (3) and (30) covering the electrode edges (28) and (29). ) Are tightly bundled by the ribs (32) and the cut and raised pieces (35), so that even when laser welding is performed with a larger output than before, no fusing occurs in the welded joint. Therefore, the projections (33) of the current collector plates (3) (30) and the electrode edges (28) (29) are securely welded, thereby reducing the internal resistance, Battery performance is improved. In this example, the internal resistance was reduced by 25% compared to the secondary battery having the current collecting structure shown in FIG.

  In addition, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim. For example, the current collector plates (3) and (30) of this embodiment are joined to the electrode edge of a laminated electrode body formed by interposing a sheet-like separator between a sheet-like positive electrode and a negative electrode In this case, the same effect as in the above embodiment can be obtained.

1 is a perspective view showing an appearance of a prismatic secondary battery according to a first embodiment of the present invention. It is a perspective view of a winding electrode body and a current collector plate. It is a perspective view which expands and shows a winding electrode body. It is a disassembled perspective view of this square type secondary battery. It is a partially broken side view which shows the junction part of a winding electrode body and a current collecting plate. It is a partially broken front view which shows the connection part of an electrode terminal mechanism and a winding electrode body. It is a perspective view of the winding electrode body and current collector plate of the square secondary battery of 2nd Example which concerns on this invention. It is a partially broken side view which shows the junction part of a winding electrode body and a current collecting plate. It is a perspective view of the winding electrode body and current collecting plate of the conventional square secondary battery. It is a perspective view of the winding electrode body and current collector plate of the other conventional square secondary battery.

Explanation of symbols

(1) Battery can
(11) Can body
(12) Sealing plate
(2) Winding electrode body
(28) Electrode edge
(29) Electrode edge
(3) Current collector
(30) Current collector
(31) Flat plate
(32) Ribs
(33) Convex section
(34) Through hole
(35) Cut and raised pieces
(36) Opening
(4) Electrode terminal mechanism
(40) Electrode terminal mechanism
(5) Lead material
(50) Lead material
(6) Insulation tape
(210) Winding core

Claims (5)

Inside the battery can (1), an electrode body laminated with a separator (22) interposed between a strip-like positive electrode (21) and a negative electrode (23) is accommodated, and the electric power generated by the electrode body is stored in the battery can ( In the secondary battery that can be taken out from the pair of positive and negative electrode terminal mechanisms (4) and (40) provided in 1),
The electrode body has a flat shape in the lamination direction of both electrodes, and a pair of positive and negative electrode edges (28) (29) projecting at both ends of the electrode body includes the electrode edge (28) ( Current collecting plates (3) and (30) covering 29) are installed, and the current collecting plates (3) and (30) are flat plate portions (31) having a width equal to or less than the thickness in the stacking direction of the electrode bodies. A pair of ribs (32) (32) projecting at a predetermined opening angle toward the electrode edge (28) (29) at both ends in the width direction of the flat plate portion (31). The electrode edges (28) and (29) are joined to the current collector plates (3) and (30) in a state of being bundled between the ribs (32) and (32), Both current collector plates (3) and (30) are connected to electrode terminal mechanisms (4) and (40) through lead members (5) and (50), respectively, and the secondary battery.   The secondary battery according to claim 1, wherein both the ribs (32), (32) have an opening angle of more than 90 degrees and less than 180 degrees with respect to the flat plate portion (31).   The flat plate portion (31) of the current collector plates (3) and (30) has a plurality of ridges (33) extending in a direction intersecting with the pair of ribs (32) and (32), and the electrode edge (28) ( 29. The secondary battery according to claim 1, wherein the secondary battery projects toward 29).   The secondary battery according to any one of claims 1 to 3, wherein one or a plurality of through holes (34) are formed in the flat plate portion (31) of the current collecting plates (3) and (30). The flat plate portion (31) of the current collector plates (3) and (30) is formed with a pair of cut and raised pieces (35) and (35) protruding toward the electrode edges (28) and (29). Both the cut and raised pieces (35) and (35) are cut and raised at an angle range of less than 90 degrees with respect to the flat plate portion (31), and the cut and raised pieces (35) on one rib (32) side are The electrode edge is bundled together with one rib (32), and the cut-and-raised piece (35) on the other rib (32) side bundles the electrode edge together with the other rib (32). Item 5. The secondary battery according to any one of Items 4.

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