JP2002175797A - Secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the following rotation of an electrode terminal member 5 together with an electrode terminal mechanism 4 when the electrode terminal mechanism 4 is fixed to a lid body 12 in a secondary battery capable of taking out the electric power generated by a wound electrode body 2 stored inside a battery can 1 from the electrode terminal mechanism 4. SOLUTION: The electrode terminal mechanism 4 of the secondary battery has the electrode terminal member 5 piercing through the lid body 12 constituting the battery can 1, an insulating seal member 6 disposed between the inner surface of a center hole of the lid body 12 and the outer surface of a screw shaft part 52 of the electrode terminal member 5, and a nut 7 engaged with the screw shaft part 52 of the electrode terminal member 5 projecting to the outside of the battery can 1. The lid body 12 and the insulating seal member 6, as well as the insulating seal member 6 and a flange part 51 of the electrode terminal member 5, are engaged with each other in such a way that they are not rotatable relative to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery can in which an electrode body serving as a secondary battery element is housed, and electric power generated by the electrode body is taken out from a pair of electrode terminals provided on the battery can. The present invention relates to a secondary battery that can be used.

[0002]

2. Description of the Related Art In recent years, lithium ion secondary batteries with high energy density have been attracting attention as power sources for portable electronic devices, electric vehicles and the like. For example, a relatively large capacity cylindrical lithium-ion secondary battery used for electric vehicles,
As shown in FIG. 6, a winding electrode body (2) is housed inside a cylindrical battery can (1) in which lids (12) and (12) are fixed to both ends of a cylindrical body (11). It is configured. A pair of positive and negative electrode terminal mechanisms (40) and (40) are attached to both lids (12) and (12), respectively, and both electrodes of the winding electrode body (2) and both electrode terminal mechanisms (40).
(40) are connected to each other so that the electric power generated by the winding electrode body (2) can be taken out from the pair of electrode terminal mechanisms (40) and (40). A screw plug (14) for closing a screw hole (18) for injecting the electrolyte into the battery can (1) is screwed into each lid (12), and a gas discharge hole (17) is inserted.
A gas discharge valve (13) is installed to block the gas.

[0003] The winding electrode body (2) is, as shown in FIG.
A band-shaped separator (22) is interposed between the band-shaped positive electrode (21) and the band-shaped negative electrode (23), and these are spirally wound. The positive electrode (21) is formed by applying a positive electrode active material (24) made of a lithium composite oxide to both sides of a band-shaped core (25) made of aluminum foil, and the negative electrode (23) is made of a band-shaped core made of copper foil. Negative electrode active material (26) containing a carbon material on both sides of the body (27)
Is applied. The non-aqueous electrolyte is impregnated in the separator (22). Further, a non-coated portion on which the positive electrode active material (24) is not applied is formed on the positive electrode (21), and the base ends of a plurality of current collecting tabs (3) are joined to the non-coated portion. ing. Similarly, on the negative electrode (23), a non-coated portion on which the negative electrode active material (26) is not applied is formed, and the base end portions of the plurality of current collecting tabs (3) are joined to the non-coated portion. ing.

[0006] As shown in FIG. 6, tips of a plurality of current collecting tabs (3) having the same polarity are connected to one electrode terminal mechanism (40). Note that FIG. 6 shows a state in which the tip of a part of the current collecting tab is connected to the electrode terminal mechanism (40) for convenience, and the tip of the other current collecting tab is connected to the electrode terminal mechanism (40). ) Is not shown.

The electrode terminal mechanism (40) is a cover (1) for the battery can (1).
2) comprising an electrode terminal member (9) attached through
The electrode terminal member (9) has a screw shaft (9) penetrating the lid (12).
At the base end of 2), a flange (91) projecting into the battery can (1)
And a prism (93) at its tip. A cylindrical insulating seal member is provided in the through hole of the lid (12).
(8) is mounted, a disc-shaped insulating seal member (81) is provided on the surface of the lid (12), and a cylindrical insulating seal member (8) and an electrode terminal member (9) are further mounted. Between the surface facing the flange portion (91), and the cylindrical insulating seal member (8) and the lid (12)
O-rings (82) and (83) are interposed between the surfaces facing
Electrical insulation and sealing are provided between (12) and the electrode terminal member (9). The insulating seal members (8) and (81) are made of polypropylene.

A washer (71) and a spring washer (72) are fitted to the screw shaft portion (92) of the electrode terminal member (9) from the outside of the lid (12), and a nut (7) is screwed thereto. The nut (7) is tightened and the flange (9) of the electrode terminal member (9) is tightened.
By sealing the insulating seal members (8) and (81) and the O-rings (82) and (83) between 1) and the washer (71), the sealing performance is improved.

A tab connecting screw member (41) is screwed into the flange portion (91) of the electrode terminal member (9), so that a gap between the flange portion (91) and the tab connecting screw member (41) is provided. Further, the distal ends of a plurality of current collecting tabs (3) extending from the winding electrode body (2) are sandwiched.

[0008]

However, in the above-mentioned conventional cylindrical secondary battery, the battery can
After assembling the electrode terminal mechanism (40) to the lid (12) that constitutes (1), screwing the nut (7) causes the electrode terminal member (9) to rotate with the rotation of the nut (7). There was something to do.
For this reason, there was a problem that the nut (7) could not be tightened with sufficient strength and the contact resistance increased.

Before fixing the lid (12) to the cylinder (11), the lid
According to the step of attaching the electrode terminal mechanism (40) to (12), the flange portion (91) of the electrode terminal member (9) is held in a non-rotatable manner with a tool to prevent the electrode terminal member (9) from rotating. It is possible to prevent the current collecting tab 3 from being damaged. However, for example, in a cylindrical secondary battery used for an electric vehicle, the nut (7) may become loose due to the influence of vibration. In this case, it is necessary to retighten the nut (7). There is a problem that the member (9) rotates.

Therefore, a secondary battery in which an electrode terminal mechanism and a lid are fixed to each other using a rotation stopping pin (Japanese Patent Application Laid-Open No. 9-92238)
However, in this case, a new insulating member is required to electrically insulate the rotation stop pin and the electrode terminal mechanism from each other, and there is a problem that the number of components increases. Further, since it is necessary to fix the detent pin and the lid together by welding, there is a problem that the number of manufacturing steps is increased and the cost is increased.

An object of the present invention is to prevent the electrode terminal member from rotating around when the electrode terminal mechanism is fixed to the lid, and of course, the number of parts and the number of manufacturing steps are not increased. It is to provide.

[0012]

In the secondary battery according to the present invention, an electrode body (2) serving as a secondary battery element is accommodated in a battery can (1), and the electrode body (2) is The generated power can be taken out from the pair of electrode terminals. Here, at least one of the electrode terminals is a battery can (1).
Formed by the electrode terminal mechanism (4) attached to the
The electrode terminal mechanism (4) has a central hole formed in the battery can (1).
(19) An electrode terminal member provided with a flange portion (51) protruding inside the battery can (1) and a screw shaft portion (52) protruding outside the battery can (1). (5) and the battery can (1) interposed between the inner peripheral surface of the central hole (19) of the battery can (1) and the outer peripheral surface of the screw shaft portion (52) of the electrode terminal member (5). And electrode terminal members
(5) Insulation seal member for electrical insulation and sealing during
(6) and a nut (7) screwed from the outside of the battery can (1) to the screw shaft (52) of the electrode terminal member (5), and the battery can (1) and the insulating sealing member (6) In addition, the insulating seal member (6) and the flange portion (51) of the electrode terminal member (5) are engaged with each other so that they cannot rotate relative to each other.

In the above secondary battery of the present invention, the battery can
With the electrode terminal mechanism (4) attached to (1), tighten the nut
By rotating (7) and screwing into the screw shaft portion (52) of the electrode terminal member (5), the insulating seal member (6) is connected to the flange portion (51) of the electrode terminal member (5) and the nut (7). And the electrode terminal mechanism (4) is fixed to the battery can (1), and the insulating seal member (6) exhibits a sufficient sealing property.
In the operation of rotating the nut (7), the rotational force of the nut (7) is transmitted to the electrode terminal member (5), and the electrode terminal member (5) is rotated.
Receives rotational force, but the flange portion of the electrode terminal member (5)
(51) is engaged with the insulating seal member (6) so as not to rotate relatively,
Since the insulating seal member (6) is engaged with the battery can (1) so as not to rotate relatively, the rotational force acting on the electrode terminal member (5) is received by the battery can (1). Therefore, the electrode terminal member (5) does not rotate.

Since no special member is required to prevent the electrode terminal member (5) from rotating around, the number of parts does not increase.
The structure is simple. Further, the insulating seal member (6) can be easily manufactured by integral molding of a resin similarly to the conventional insulating seal member, and as a matter of course, the number of assembling steps is the same and the manufacturing process is simple.

Specifically, the battery can (1) and the insulating sealing member
(6), and a pair of engaging portions which are engaged with the insulating seal member (6) and the flange portion (51) of the electrode terminal member (5) so that they cannot rotate relative to each other. A surface is formed. According to the specific configuration, a conventionally existing battery can
(1) Since the three members of the electrode terminal member (5) and the insulating seal member (6) are provided with a structure for preventing entrainment, the present invention can be realized with the same component configuration as the conventional one. I can do it.

Specifically, the insulating seal member (6) has a central hole through which the screw shaft portion (52) of the electrode terminal member (5) passes.
(64) is opened, and around the central hole (64), two peripheral walls whose radial distance around the central hole (64) changes in the circumferential direction are formed, and the battery can (1) is formed in the battery can (1). Is formed with a peripheral wall on which one peripheral wall of the insulating sealing member (6) is engaged so as to be relatively non-rotatable, and the other peripheral wall of the insulating sealing member (6) is provided on the flange portion (51) of the electrode terminal member (5). Is formed with a peripheral wall that engages with the rotor so that it cannot rotate relatively. According to the specific configuration, the one peripheral wall of the insulating seal member (6) and the peripheral wall of the battery can (1) form a pair of engagement surfaces that cannot rotate relative to each other, and the insulating seal member (6). ) And the peripheral wall of the flange portion (51) of the electrode terminal member (5) form a pair of engagement surfaces that cannot rotate relative to each other.

More specifically, the insulating seal member (6) has a plate-shaped main body (60), and the outer peripheral wall of the main body (60) has one or more corners formed by crossing planes. A part is formed, and the one peripheral wall is formed by the outer peripheral wall. In this specific configuration, the corner formed on the main body (60) of the insulating seal member (6) is sharply engaged with the peripheral wall of the battery can (1), so that the insulating seal member (6) for the battery can (1) is formed. The relative rotation of 6) is reliably prevented. Further, since the distance between the two peripheral walls of the insulating seal member (6) can be increased, the strength of the insulating seal member (6) increases, and the electrode terminal member ( The follow-stopping force against 5) increases.

In a specific configuration, the electrode terminal member
The outer peripheral wall of the flange portion (51) of (5) has a shape in which a part of the cylindrical surface is replaced by a plane, and the insulating seal member (6) has a flange portion (51) of the electrode terminal member (5). ) Are formed so that the outer peripheral wall of the engagement recess (62) engages with the relative rotation impossible.
The other peripheral wall is formed by the inner peripheral wall of 2).
According to the specific configuration, the flange portion of the electrode terminal member (5)
(51) and the engagement recess (62) of the insulating seal member (6) can be easily processed, and the encircling of the electrode terminal member (5) when fixing the electrode terminal member (5) can be ensured. Can be blocked.

Further, in a specific configuration, the outer peripheral wall of the flange portion (51) of the electrode terminal member (5) has one or more corners where planes intersect with each other, and the insulating seal member ( 6), an engagement recess (62) is formed in which the outer peripheral wall of the flange portion (51) of the electrode terminal member (5) engages in a relatively non-rotatable manner, and is formed by the inner peripheral wall of the engagement recess (62). The other peripheral wall is formed. According to this specific configuration, the corners formed on the flange portion (51) of the electrode terminal member (5) are sharply engaged with the engagement recesses (62) of the insulating seal member (6), so that the insulating seal is formed. The relative rotation of the electrode terminal member (5) with respect to the member (6) is reliably prevented, and as a result, the rotation of the electrode terminal member (5) when the electrode terminal member (5) is fixed can be reliably prevented. I can do it.

[0020]

According to the secondary battery of the present invention, it is possible to prevent the rotation of the electrode terminal member when the electrode terminal mechanism is fixed to the cover without increasing the number of parts and the number of manufacturing steps. I can do it.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied to a cylindrical lithium ion secondary battery will be specifically described with reference to the drawings. As shown in FIG. 1, a cylindrical lithium ion secondary battery according to the present invention has a cylindrical aluminum battery can (1) formed by welding and fixing lids (12) to both openings of a cylindrical body (11). ) Accommodates the wound electrode body (2). The outer diameter of the battery can (1) is 57 mm and the length is 220
mm. Note that the configuration of the winding electrode body (2) is the same as the conventional configuration shown in FIG.

An electrode terminal mechanism (4) is attached to each lid (12) constituting the battery can (1). Also, each lid (12)
In the same manner as before, a screw plug (14) is screwed into a screw hole (18) for injecting the electrolyte into the battery can (1), and a gas discharge valve closing the gas discharge hole (17). (13) is attached.

The electrode terminal mechanism (4) has a winding electrode body.
The tips of a plurality of current collecting tabs (3) extending from (2) and having the same polarity are connected. FIG. 1 shows a state in which the tip of a part of the current collecting tab is connected to the electrode terminal mechanism (4) for convenience, and the tip of the other current collecting tab is connected to the electrode terminal mechanism (4). ) Is not shown.

As shown in FIGS. 1 and 2, the electrode terminal mechanism (4) includes an electrode terminal member (5) mounted through a central hole (19) of the lid (12). The member (5) is a lid
At the base end of the screw shaft (52) passing through the center hole (19) of (12),
It has a flange (51) projecting into the battery can (1), and has a prism (5) at the tip protruding outside the battery can (1).
It has 3). A cylindrical insulating seal member (6) is attached to a central hole (19) of the lid (12), and a disc-shaped insulating seal member (61) is provided at an opening edge of the central hole (19). Installed between the cylindrical insulating seal member (6) and the flange portion (51) of the electrode terminal member (5), and between the cylindrical insulating seal member (6) and the lid (12). The O-ring (82) (8
3) is interposed, and electrical insulation and sealing are provided between the lid (12) and the electrode terminal member (5). The electrode terminal member (5) of the electrode terminal mechanism (4) on the positive electrode side is made of aluminum,
The electrode terminal member (5) of the electrode terminal mechanism (4) on the negative electrode side is made of nickel. Also, in any electrode terminal mechanism (4),
The insulating seal members (6) and (61) are made of polypropylene,
The rings (82) and (83) are made of fluororesin.

A washer (71) and a spring washer (72) are fitted to the screw shaft (52) of the electrode terminal member (5) from the outside of the lid (12), and a nut (7) is screwed thereto. The nut (7) is tightened and the flange (5) of the electrode terminal member (5) is tightened.
By sealing the insulating seal members (6) (61) and the O-rings (82) and (83) between 1) and the washer (71), the sealing performance is improved.

A tab connecting screw member (41) is screwed into the flange portion (51) of the electrode terminal member (5), so that a gap between the flange portion (51) and the tab connecting screw member (41) is provided. Further, the distal ends of a plurality of current collecting tabs (3) extending from the winding electrode body (2) are sandwiched.

In the electrode terminal mechanism (4), the insulating sealing member (6) has a cylindrical portion (63) having a central hole (64) at the center of the rectangular plate-shaped main body (60) as shown in FIG. An oblong engagement recess (62) having an inner peripheral surface in which a part of a cylindrical surface is replaced with a flat surface is formed on the back surface of the rectangular plate-shaped main body (60) by projecting upward.
Are formed. On the other hand, the back of the lid (12) has a central hole
A rectangular engaging concave portion (16) with which the square plate-shaped main body (60) of the insulating seal member (6) can be engaged is formed around (19). Further, the flange portion (51) of the electrode terminal member (5) has an elliptical shape which can be engaged with an engagement concave portion (62) formed in the square plate-shaped main body (60) of the insulating seal member (6). It has an outer shape.

Therefore, as shown in FIG. 1, after the electrode terminal mechanism (4) is assembled to the lid (12), the nut (7) is rotated and tightened by rotating the nut (7).
(5), the flange portion of the electrode terminal member (5)
(51) non-rotatably engages with the insulating seal member (6) and the insulating seal member (6) engages with the lid (12) so as not to rotate relative to the electrode terminal member (5). Is prevented from rotating. In this way, the electrode terminal member accompanying the tightening of the nut (7)
Since the rotation of (5) is prevented, a sufficient tightening torque can be applied to the nut (7), and the contact resistance can be reduced.

Further, in the cylindrical lithium ion secondary battery according to the present invention, the lid (12), the insulating seal member (8) and the insulating seal member provided in the conventional cylindrical lithium ion secondary battery shown in FIG. Instead of the electrode terminal member (9), the lid (12), the insulating seal member (6) and the electrode terminal member (5) shown in FIGS.
In the present invention, a rectangular engaging recess (16) is provided on the lid (12), and an elliptical flange (5) is provided on the electrode terminal member (5).
1) is inserted into the insulating sealing member (6) with the square plate-shaped main body (60) and the engaging recess.
By forming (62), the rotation of the electrode terminal member (5) is prevented, so that the number of parts and the number of manufacturing steps do not increase. Needless to say, the cylindrical lithium secondary battery according to the present invention can be easily assembled through exactly the same steps as those in the related art.

The engagement structure of the lid (12), the insulating seal member (6) and the electrode terminal member (5) is not limited to the structure shown in FIG. 3, but may be, for example, the structure shown in FIG. It is. In the engagement structure shown in FIG.
Is formed by projecting a cylindrical portion (63) having a central hole (64) upward at the center of the square plate-shaped main body (60), and the square plate-shaped main body (60)
A rectangular engaging concave portion (62) is formed on the back surface of the.
The flange portion (51) of the electrode terminal member (5) is provided with an engagement recess (6) formed in the square plate-shaped main body (60) of the insulating seal member (6).
It has a square plate outer shape that can be engaged with 2). According to the engagement structure, similarly to the engagement structure shown in FIG. 3, an effect of preventing the electrode terminal member (5) from rotating around can be obtained.

In order to confirm the effect of the electrode terminal mechanism (4) of the present invention for preventing entrainment of the electrode terminal member (5), FIG.
And the conventional battery shown in FIG.
In the battery of the present invention shown in FIG. 1, the nut (7) is tightened with a torque of 80 kgf · cm using a torque wrench, while in the conventional battery shown in FIG.
The nut (7) was tightened with a torque wrench until (9) started to rotate, and the battery was assembled. The final tightening torque of the conventional battery was 40 kgf · cm.

Then, using the battery of the present invention and the conventional battery, a module battery composed of four unit cells (10) was assembled as shown in FIG. The four cells (10) are connected between the spring washer (72) and the nut (7).
By pinching the connection part of (15), they were connected in series with each other. Then, the resistance values of the module battery of the present invention and the conventional module battery were measured by a 1 kHz AC resistance meter. As a result, the resistance value of the module battery of the present invention was 9.3 mΩ, whereas the resistance value of the conventional module battery was 15.6 mΩ.

In the battery of the present invention, the electrode terminal member
Since the (5) and the lid (12) are engaged with each other so that they cannot rotate relative to each other, a sufficient tightening torque can be given, thereby reducing the contact resistance. A sufficient tightening torque cannot be given because the electrode terminal member (9) rotates, and the contact resistance increases.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, it is possible to employ a sheet-like seal packing instead of the O-rings (82) and (83).
The engagement structure between the lid (12) and the insulating seal member (6) and the engagement structure between the insulating seal member (6) and the electrode terminal member (5) are rectangular as shown in FIGS. It is not limited to an engagement structure using an oval or an ellipse, but may be an engagement structure using engagement surfaces having various shapes as long as it is an engagement structure using a pair of engagement surfaces that cannot rotate relative to each other.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of a cylindrical lithium ion secondary battery according to the present invention.

FIG. 2 is an exploded front view showing a part of the electrode terminal mechanism in a cutaway manner.

FIG. 3 is an exploded perspective view of a lid, an insulating seal member, and an electrode terminal member.

FIG. 4 is an exploded perspective view of a lid, an insulating seal member, and an electrode terminal member according to another embodiment.

FIG. 5 is a perspective view of a module battery.

FIG. 6 is a cross-sectional view illustrating a main part of a conventional cylindrical lithium ion secondary battery.

FIG. 7 is a partially developed perspective view of a wound electrode body.

[Explanation of symbols]

 (1) Battery can (11) Cylindrical body (12) Lid (16) Engaging recess (2) Winding electrode body (3) Current collecting tab (4) Electrode terminal mechanism (5) Electrode terminal member (51) Flange Part (52) Screw shaft part (6) Insulation seal member (60) Square plate body (62) Engagement concave part (7) Nut (71) Washer (72) Spring washer (82) O-ring (83) O-ring ( 41) Screw member for tab connection

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiyuki Noma 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Ikuo Yonezu 2-chome Keihanhondori, Moriguchi-shi, Osaka No.5-5 Sanyo Electric Co., Ltd. F-term (reference) 5H011 AA01 AA17 EE01 EE04 FF04 GG02 HH02 5H022 AA09 BB03 CC03 CC08 CC12 5H029 AJ11 AJ15 BJ02 DJ05

Claims (6)

[Claims] An electrode body (2) serving as a secondary battery element is housed inside a battery can (1), and electric power generated by the electrode body (2) is taken out from a pair of electrode terminals to the outside. In the secondary battery, at least one of the electrode terminal portions is formed by an electrode terminal mechanism (4) attached to the battery can (1), and the electrode terminal mechanism (4) includes the battery can (1). A flange portion (51) installed through the central hole (19) opened in the battery can (1) and projecting inside the battery can (1), and a screw shaft portion (52) projecting outside the battery can (1). An electrode terminal member (5) provided with: an inner peripheral surface of a central hole (19) of the battery can (1) and an outer peripheral surface of a screw shaft portion (52) of the electrode terminal member (5). An insulating seal member (6) for electrically insulating and sealing between the battery can (1) and the electrode terminal member (5); and a screw shaft portion of the electrode terminal member (5) from outside the battery can (1). 52)
A battery can (1) and an insulating sealing member (6), and an insulating sealing member (6) and an electrode terminal member.
The secondary battery characterized in that the flange portion (51) of (5) is engaged with each other so as not to rotate relative to each other. An engaging portion between the battery can (1) and the insulating seal member (6) and an engaging portion between the insulating seal member (6) and the flange portion (51) of the electrode terminal member (5) are provided. The secondary battery according to claim 1, wherein a pair of engagement surfaces that engage with each other so as to rotate relative to each other are formed. 3. The insulating seal member (6) includes an electrode terminal member.
A central hole (64) through which the screw shaft portion (52) of (5) penetrates is opened, and a radial distance around the central hole (64) is set around the central hole (64) in the circumferential direction. Two peripheral walls that change are formed, and a peripheral wall is formed on the battery can (1) so that one of the peripheral walls of the insulating seal member (6) is relatively non-rotatably engaged, and a flange portion (5) of the electrode terminal member (5) is formed. 51) Insulation sealing member (6)
3. The secondary battery according to claim 1, wherein a peripheral wall that engages with the other peripheral wall so as to be relatively non-rotatable is formed. 4. 4. The insulating seal member (6) has a plate-shaped main body (60), and one or more corners formed by intersecting planes are formed on an outer peripheral wall of the main body (60). 4. The secondary battery according to claim 3, wherein said one peripheral wall is formed by said outer peripheral wall. 5. An outer peripheral wall of a flange portion (51) of an electrode terminal member (5) has a shape in which a part of a cylindrical surface is replaced by a plane,
The insulating seal member (6) has an engaging recess (6) with which the outer peripheral wall of the flange portion (51) of the electrode terminal member (5) engages in a relatively unrotatable manner.
5. The secondary battery according to claim 3, wherein 2) is formed, and the other peripheral wall is formed by an inner peripheral wall of the engagement concave portion. 6. An outer peripheral wall of a flange portion (51) of an electrode terminal member (5) has one or more corners where planes intersect with each other. An engaging recess (62) is formed in which the outer peripheral wall of the flange portion (51) of the electrode terminal member (5) is relatively non-rotatably engaged, and the other peripheral wall is formed by the inner peripheral wall of the engaging recess (62). The secondary battery according to claim 3 or 4, wherein