JP2014078521A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery capable of having a large contact area and stabilizing resistance in the case where a connection board is connected to an electrode terminal, to thereby charge and discharge a large current.SOLUTION: The present invention relates to a battery 20 in which an electrode terminal 10 connected by a power generation element and a current collecting plate 3 in a battery case projects from a hole arranged at the battery case. The electrode terminal 10 includes; a columnar portion 2 that is arranged sequentially in a projection direction; and a plate-shaped part 1 that is connected by welding at an end portion of the columnar portion 2 projecting to the outer side of the battery case, and has a plane direction orthogonal to the projection direction and a cross-sectional area having an area larger than the columnar portion 2. Further, concave portions 1a and 1d are arranged at a position overlapping to the end portion of columnar portion 2 at a surface in the projection direction side o the plate-shaped part 1, and a welding portion of the columnar portion 2 and the plate-shaped part 1 is in the concave portions 1a and 1d.

Description

  The present invention relates to a battery in which electrode terminals protrude from a battery case.

  When you want to charge or discharge a large current from the battery, such as when driving a motor or charging the battery quickly, in order to reduce the current collection resistance from the electrode terminals, cables or connection plates (hereinafter collectively referred to as “connection plates”) It is necessary to make sufficient contact between the electrode terminal and the electrode terminal. Therefore, conventional electrode terminals are threaded and tightened with nuts to energize the connection plates and the like through the nuts and washers. However, there is a problem that the contact resistance is not stable because the nut is screwed into a screw thread provided around the electrode terminal and makes a current collecting contact at the screw portion.

  In view of this, a method is employed in which the electrode terminal is threaded to the middle of the terminal height, and the upper surface of the side surface that is not threaded is planarized to attach a connection plate or the like. In this case, in order to ensure a sufficient contact area, it is possible to increase the contact area of the connecting plate etc. by increasing the diameter of the columnar part of the electrode terminal, but it is connected to the current collector plate of the power generating element. Since it is necessary to assemble the electrode terminal that has been passed through a terminal hole provided in the battery case (lid), there is a restriction in increasing the diameter of the columnar portion of the electrode terminal.

  The present invention has been made in view of the above problems, and can increase the contact area when connecting a connection plate or the like to an electrode terminal, stabilize the resistance, and can charge and discharge a large current. One object is to provide a simple battery.

In the battery in which the electrode terminal connected by the power generation element and the current collector in the battery case protrudes from the hole provided in the battery case,
The electrode terminal is a plate-like portion that is connected by welding to a columnar portion that is continuous in the protruding direction, and a tip portion of the columnar portion that protrudes to the outside of the battery case, and whose planar direction is perpendicular to the protruding direction and is disconnected. A plate-like portion having an area larger than the cross-sectional area of the columnar portion;
A concave portion is formed at a position overlapping the leading end portion of the columnar portion in the protruding direction on the surface on the protruding direction side of the plate-like portion, and a welded portion between the columnar portion and the plate-like portion is in the region of the concave portion.

  According to such a configuration, the head of the electrode terminal (tip portion on the protruding direction side) can be widened, and a sufficient contact area with the connection plate or the like can be secured when the connection plate or the like is attached to the electrode terminal. it can. For this reason, a large current can be supplied to the power generation element from the outside through the electrode terminal, or a large current can be discharged to the outside from the power generation element, and as a result, the battery can be rapidly charged and discharged.

  Moreover, by welding the plate-like portion and the columnar portion so that the welded portion is formed in the region by providing the recess, the welded portion protrudes (swells) from the surface on the protruding direction side of the plate-like portion. Is prevented. As a result, when the connection plate or the like is attached to the surface of the plate-like portion on the protruding direction side, the protruding (swelled) welded portion comes into contact with the connection plate or the like so that the gap between the plate-like portion and the connection plate or the like It is possible to prevent a gap from occurring (that is, mutual surface contact is hindered).

The plate-like portion has a through hole into which the tip of the columnar portion is fitted,
In the region of the recess, it is preferable that the boundary between the side surface of the columnar portion and the inner peripheral surface defining the through hole is welded.

  In this way, the welded portion between the plate-like portion and the columnar portion is formed from the surface of the plate-like portion on the protruding direction side by a simple configuration in which the tip of the columnar portion is fitted into the through hole provided in the plate-like portion. A recess having a depth that does not protrude can be easily formed.

in this case,
There may be a fixed position between the electrode terminal and the member connected to be energized at a position eccentric in the plane direction from the columnar part in the plate-like part.

  Thus, when a fixed position is provided at a position eccentric in the plane direction, the plate-like portion intersects the plane direction when a force is applied to the plate-like portion from the connected member in the plane direction. Try to tilt in the direction. At this time, as in the above-described configuration, the portion is welded in a state where the side surface (circumferential surface) of the columnar portion and the inner peripheral surface of the plate-shaped portion (inner peripheral surface surrounding the side surface in the circumferential direction) are in surface contact. By this, compared with the case where the front end surface of a columnar part and the surface on the opposite side to the protrusion direction of a plate-shaped part are welded, the intensity | strength with respect to the said inclination is obtained.

  In a state where the columnar part is fitted in the through-hole of the plate-like part, the side area of the columnar part in contact with the plate-like part is preferably equal to or larger than the cross-sectional area of the columnar part.

  According to such a configuration, a sufficient contact area between the plate-like portion and the columnar portion is ensured, whereby a large current is reliably supplied from the outside through the electrode terminal from the battery to the power generating element or from the power generating element. Can be more reliably released from the outside.

  Further, the lower end of the columnar part is connected to the current collector plate by welding, the upper end of the columnar part protrudes from the hole through the gasket to the outside of the battery case, and the nut fitted into the columnar part protruding to the outside of the battery case The gasket may be compressed by tightening.

  Further, in the battery in which the electrode terminal connected by the power generation element and the current collector in the battery case protrudes from the hole provided in the battery case, the electrode terminal includes a columnar portion continuous in the protruding direction, and the columnar portion of the columnar portion. It has a plate-like portion that is fitted into the upper end, the plane direction is orthogonal to the projecting direction, and the cross-sectional area is larger than the cross-sectional area of the columnar portion, and the lower end of the columnar portion is connected to the current collector plate by welding to form a columnar shape The gasket may be compressed by projecting the upper end of the portion from the hole to the outside of the battery case through the gasket and fitting the plate-like portion of the electrode terminal toward the lower end of the columnar portion.

  In this case, the battery is hermetically sealed by disposing a gasket between the lower end of the electrode terminal and the lid and compressing the gasket. It is important to stabilize the compression size of the gasket without changing with time. Therefore, the plate-like portion is fixed at a position where the gasket is compressed. This eliminates the need for tightening parts such as nuts when compressing the gasket, allowing the gasket to be compressed and the plate-like portion to be attached simultaneously, facilitating the work process.

  Moreover, since the compression dimension of the gasket can be made constant by defining the dimensions of each part of the plate-like part, the compression accuracy of the gasket can be increased, and the plate-like part is securely fixed to the columnar part by welding or the like. Therefore, the temporal stability of the gasket compression dimension can be improved. Therefore, since the airtightness of the battery by the gasket is kept constant, a battery with stable quality can be provided.

  The electrode terminal may be provided so that the columnar portion does not protrude from the plate-like portion. In this way, by arranging the head of the columnar part at a position lower than the upper surface of the plate-like part, the projecting part does not become an obstacle when attaching a connection plate etc. to the upper surface of the plate-like part. A board etc. can be attached easily and the contact area of an electrode terminal and a connection board etc. can be taken large reliably.

  Moreover, you may weld at least one part of the contact part of a columnar part and a plate-shaped part. As a result, the resistance is reduced by welding compared to the case where the current is collected by screwing with a screw, and a large current can be taken out.

  Furthermore, it is preferable that the plate-like portion of the electrode terminal has at least one through hole around it. Thereby, the terminal of a some battery can be connected by passing a connection board etc. to the upper surface of the plate-shaped part of an adjacent battery, and connecting using a through-hole. Here, the through hole may be provided with a screw groove on the inner wall. Thereby, since the screwing method can be used for the connection between the electrode terminal and the connection plate or the like, it is easy to ensure the connection, which is preferable.

  The battery according to the present invention is provided with a plate-like portion that is wider than the columnar portion at the end of the electrode terminal, so that a large contact area can be obtained when connecting a connection plate or the like to the electrode terminal. .

The principal part sectional drawing of the battery which concerns on 1st embodiment is shown. The whole battery perspective view of FIG. 1 is shown. The perspective view at the time of connecting two or more batteries of FIG. 2 is shown. The principal part sectional drawing of the battery which concerns on 2nd embodiment is shown. The principal part sectional view of the battery concerning a third embodiment is shown.

<First embodiment>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 relates to a first embodiment of the present invention, and is a cross-sectional view of a main part of a battery in which a gasket is compressed by a nut method and the vicinity of an electrode terminal is sealed, and shows either a positive electrode or a negative electrode. Yes.

  First, the columnar portion 2 of the electrode terminal is attached to the upper surface of the current collector plate 3 connected to the power generation element inside the battery case. The columnar part 2 has a minimum cross-sectional area diameter of 14 mm. Then, a resin gasket 7 is disposed from the lower end of the periphery where the columnar portion 2 and the current collector plate 3 are in contact, and a resin pressing plate 6 is disposed so as to sandwich the battery lid portion 20b. . Further, the nut 4 is fitted on the upper surface of the presser plate 6 via the washer 5. Then, the nut 4 is tightened by a thread groove formed around the columnar portion 2 to compress the gasket 7.

  Next, the plate-like portion 1 having a flat upper portion is attached to the upper end of the electrode terminal 2. The plate-like portion 1 has a concave portion 1a on the upper surface, and a concave portion (not shown) into which the head of the columnar portion 2 is fitted is formed on the opposite surface. The head of the columnar part 2 is fitted into the plate-like part 1 and is welded twice on a concentric circle from the upper surface of the concave part 1a. By this welding, the members of the plate-like portion 1 and the columnar portion 2 are melted, and both members can be joined. Reference numeral 12 represents a welding site. For welding, various types of welding such as arc welding, gas welding, and laser welding can be used. In particular, it is preferable to employ electron beam welding.

  In this way, the electrode terminal 10 composed of the plate-like portion 1 and the columnar portion 2 can be attached. FIG. 2 is an overall perspective view of the battery shown in FIG. In addition, about the part which is the same as that of FIG. 1, or equivalent, attaches | subjects the same code | symbol and abbreviate | omits description.

  As shown in FIG. 2, the exterior body of the battery 20 is composed of a case body 20a of the housing and a lid portion 20b that closes the mouth portion. At both ends of the lid portion 20b, there are terminal holes (not shown) for projecting the columnar portions 2 of the positive electrode or the negative electrode, and further, a safety valve 40 for venting gas and an electrolyte solution are injected. The inlet 30 is provided.

  In order to assemble the battery 20, first, the lid 20 b in which the power generating element and the electrode terminal 10 are fixed together is fitted into the case body 20 a and the periphery is welded. Subsequently, an electrolytic solution is injected from the injection hole 30, and after the injection, the tip portion is welded and closed.

  Next, FIG. 3 shows a perspective view when a plurality of unit cells of FIG. 2 are connected. The plate-like portion 1 constituting the electrode terminal 10 has, for example, a substantially rectangular shape, and is provided with four through holes 1b,. A plurality of batteries 20 are adjacent to each other, and the connection plate 50 is placed on the upper surface of the adjacent plate-like portion 1. The connection plate 50 is provided with a through hole (not shown) communicating with the through holes 1b, and can be fixed by tightening a screw 51.

  As described above, the battery according to the first embodiment was fixed by welding the wide plate-like portion 1 to the tip of the columnar portion 2 from the upper surface. With such a configuration, when the connection plate 50 is attached to the electrode terminal, a large contact area with the electrode terminal can be taken. Moreover, by welding the joint part of the columnar part 2 and the plate-shaped part 1, contact resistance becomes smaller than the case where it screws, and a large electric current can be charged / discharged. Here, the battery capable of charging and discharging a large current of the present invention specifically refers to a battery having a nominal capacity of 5 Ah or more. The welding is performed two times concentrically from the upper surface of the concave portion 1a. However, this is only an example, and the welding may be performed in any manner as long as the plate-like portion 1 and the columnar portion 2 can be joined.

  In the first embodiment, the attachment of the electrode terminal columnar part to the current collector plate 3 was performed by welding. Conventionally, the caulking method is generally used for attaching this portion. However, in the caulking method, in the current path from the power generation element to the electrode terminal, the lower part of the electrode columnar part formed by caulking, the current collector plate, Therefore, in a battery that needs to be charged and discharged with a large current like the battery according to the present invention, it is preferable to perform attachment by welding.

  The plate-like portion 1 used in the first embodiment has a rectangular shape with a side of 28 mm, a thickness of 5 mm, and a depth of the opening 1a of 1 mm. The cross-sectional area of the columnar part was 154 mm2.

<Second embodiment>
FIG. 4 relates to the second embodiment of the present invention, and in a battery in which the gasket is compressed by a nut method and the vicinity of the electrode terminal is sealed, the electrode terminal columnar portion is attached to the current collector plate by a caulking method. 2 is a cross-sectional view of the main part of the battery, and shows either the positive electrode or the negative electrode. In addition, about the part which is the same as that of FIG. 1, or equivalent, attaches | subjects the same code | symbol and abbreviate | omits description.

  As shown in the figure, the columnar portion 2 ″ has a flange portion 2a ″ formed at the lower end, and a caulking projection 2b ″ protruding from the lower end surface of the flange portion 2a ″. First, the upper surface of the flange portion 2a "is fixed by screwing the nut 4 around the columnar portion 2" via the inter-cell connection plate 9. Then, the columnar portion 2 "is inserted into the lid portion 20b sandwiched between the gaskets 7 and 7 and the opening (not shown) of the current collector plate 3, and the caulking projection 2b" is caulked to fix the connection. Is done. FIG. 4 shows the shape after caulking for the caulking projection 2b ″. Note that the attachment of the plate-like portion 1 is the same as in the first embodiment, and the description thereof will be omitted. With such a configuration, it is possible to increase the contact area with the electrode terminal when attaching the connection plate 50 to the electrode terminal, and by screwing the joint portion between the columnar portion 2 and the plate-like portion 1 by welding. The contact resistance is smaller than the case, and a large current can be charged and discharged.

  As described above, the battery according to the second embodiment is provided with the caulking protrusion 2b "at the lower end of the columnar portion 2", and is pressed with a press or the like from the lower end to deform the protrusion 2b "to be fixed to the current collector plate 3. Since the compression accuracy of the gaskets 7 and 7 can be maintained, the current collector plate is in contact with the lower part of the electrode columnar portion formed by caulking in the current path from the power generation element to the electrode terminal. The first embodiment is superior to a battery that needs to be charged and discharged with a large current, such as the battery according to the present invention.

  In the second embodiment described above, the battery in which the vicinity of the terminal is sealed using a gasket has been described. However, a battery in which the vicinity of the terminal is sealed without using a gasket, for example, the vicinity of the terminal is sealed by a glass welding system. You may apply to the battery of a system.

<Third embodiment>
FIG. 5 relates to the third embodiment of the present invention, and forms the plate-like portion on the terminal columnar portion, and simultaneously compresses the gasket by the step of forming the plate-like portion. FIG. 5A is a cross-sectional view of a main part of a battery in which the vicinity of an electrode terminal is sealed. FIG. 5A is a view before compressing the gasket, and FIG. 5B is a view after compressing and fixing the gasket. The battery in FIG. 5 shows either the positive electrode or the negative electrode, and the same or equivalent parts as in FIG.

First, as shown in FIG. 5A, the columnar portion 2 ′ has a flange 2a formed at the lower end thereof. First, the insulating plate 8 is disposed from the lower end around the column portion 2 ′ and the current collector plate 3 are in contact with each other. Subsequently, the gasket 7 is disposed on the shoulder portion of the flange portion 2a, and the battery lid portion 20b is disposed thereon. The holding plate 6 is arranged so as to sandwich it. Finally, the plate-like portion 1 is fitted into the tip of the columnar portion 2. The plate-like portion 1 has an inner peripheral diameter capable of penetrating the columnar portion 2 ′ and an opening 1d having an upper portion whose diameter is wider than the inner peripheral diameter. Therefore, when the head of the columnar part 2 ′ is fitted into the plate-like part 1, a step part 1c is formed. And according to the compression amount of the gasket 7, the height of the level | step-difference part 1c is set, and the amount of the height of the said level | step-difference part 1c is compressed using a jig from the upper surface of the plate-shaped part 1a. For example, if a 2 mm gasket is compressed to 1 mm, the stepped portion 1c is set to 1 mm.

  Subsequently, as shown in FIG. 5B, after the compression amount (step portion 1c) set in advance is compressed from the upper surface of the plate-like portion 1 with a jig, the columnar portion 2 ′ and the opening 1a are in contact with each other. The part 12 is welded.

  As described above, according to the third embodiment, there are further effects described below. That is, since the battery according to the third embodiment is integrally formed by compressing with a jig from the upper surface of the plate-like portion 1 through the gasket 7, the seal of the electrode terminal 10 and the attachment of the plate-like portion 1 are formed. At the same time, shortening the work process and improving productivity. Further, the compression distance can be made constant, the positioning of the members such as the holding plate 6 and the lid 20b arranged around the electrode terminal 10 is facilitated, and the compression accuracy of the gasket 7 can be maintained. . That is, in the case of compressing the gasket by tightening screws with the nut method, there is a problem that the screw thread is deformed due to the repulsive force of compression and the compression accuracy cannot be maintained, but according to the third embodiment, The possibility that such a problem will occur can be greatly reduced. In particular, in a non-aqueous electrolyte battery such as a lithium ion battery, a metal having a low strength such as aluminum or copper must be used for the terminal. Therefore, the above configuration is effective when applied to a non-aqueous electrolyte battery. Furthermore, since a fastening member such as a nut or a caulking member is not necessary, the weight of the battery can be reduced and the height dimension of the electrode terminal 10 can be reduced.

  In the third embodiment, the step portion 1c is provided in the opening 1d of the plate-like portion 1 so that the compression amount can be easily set. However, similarly, the step portion 1c is not provided. It is possible to implement.

  Further, in the electrode terminal 10 described above, the columnar portion 2 ′ is disposed at a lower position than the upper surface of the plate-like portion 1, and this is because the junction between the columnar portion 2 ′ and the plate-like portion 1 is formed by an electron beam. This is to prevent welding from protruding from the upper surface of the plate-like portion 1 when welding. Therefore, it is only necessary that the upper surface of the plate-like portion 1 and the upper end of the columnar portion 2 ′ are flush with each other after welding and the upper end of the columnar portion 2 ′ is lower than the upper surface of the plate-like portion 1. With such a configuration, the connection plate 50 for connecting the electrode terminals of the adjacent batteries 20 can be easily attached to the upper surface of the plate-like portion, and the contact area between the electrode terminal and the connection plate 50 is ensured. Can take a great deal.

  In addition, as an example of the plate-like portion 1 of the present invention, a rectangular shape in plan view is taken up in FIG. 2, but if the periphery of the plate-like portion 1 does not protrude from the periphery of the lid portion 20b, It is not limited to a rectangular shape. As other shapes of the plate-like portion 1, various shapes such as a polygon, a circle, an ellipse, and a rhombus can be adopted, for example. Furthermore, the amount of current that can be extracted can be increased by increasing the surface area and thickness of the plate-like portion 1.

  The number of through holes 1b formed in the plate-like portion 1 is four as an example in FIG. 2, but the number of holes is not limited to four, and it is sufficient that at least one hole is provided.

  The battery of the present invention can be implemented in various batteries such as a primary battery, a secondary battery, a fuel cell, and a solar cell. Furthermore, the battery can be implemented in various shapes such as a rectangular shape, a cylindrical shape, and a flat shape.

  Thus, the battery of this invention can have the effect of the said invention by making the area of the plate-shaped part of an electrode terminal larger than the cross-sectional area of a columnar part. If the area of the plate-shaped portion is too large, there is a risk of causing problems such as contact between terminals when a plurality of batteries are arranged adjacent to each other. When viewed, it is preferable to select a dimension and shape so that the plate-like portion does not protrude from the battery. Although depending on the size (nominal capacity) of the battery, for example, when assuming a battery of 10 to 100 Ah, the area of the plate-like portion is set to 1000 mm 2 or less.

  If the minimum cross-sectional area of the columnar part is too small, in principle, a large current cannot flow, but unless it is extremely thin, it will not melt by a large current and a large current can flow. is there. However, when the configuration of the terminal portion is not optimal, the terminal portion may generate heat due to a large current. For example, when the attachment of the electrode terminal columnar part to the current collector plate 3 is performed by caulking, the lower part of the electrode columnar part formed by caulking and the current collector plate in the current path from the power generation element to the electrode terminal In many cases, heat is generated.

  The inventors of the present invention are necessary for flowing the current so that the heat generation is below the reference when the battery terminal is in a state of 125 A current (corresponding to a case where a battery having a nominal capacity of 25 Ah is energized at a rate of 5 ItA). The cross-sectional area of the terminal columnar part was examined. The terminal material was aluminum or copper. Further, the connection between the power generation element for supplying current and the terminal columnar portion was a caulking method or a welding method. As a result, the necessary minimum cross-sectional area of the terminal columnar portion for the temperature rise when the current of 125 A was continuously supplied was 5 ° C. or less was as shown in Table 1.

  From Table 1, the current collection cross-sectional area required to suppress the temperature rise when flowing a large current to 5 ° C. or less was 78.2 mm 2 in the case of aluminum and 50.0 mm 2 in the case of copper. It was. On the other hand, in the caulking method, it was 568.2 mm 2 in the case of aluminum and 357.1 mm 2 in the case of copper. In the caulking method, the reason why a considerably large current collecting cross-sectional area is required is that the current is taken out at the contact portion b where the caulking projection 2b "and the current collecting plate 3 are in contact. Since the portion of the caulking projection 2b "is deformed by the press and brought into contact with the current collector plate, the current collection becomes unstable due to the deformed state.

  From the above results, in order to suppress the temperature rise to 5 ° C. or less under the above conditions, the welding method is preferable for the connection between the current collector plate and the terminal columnar part of the power generation element, and the minimum cross-sectional area of the columnar part in that case is aluminum It can be seen that 78.2 mm 2 or more in the case of 5 and 50.0 mm 2 or more in the case of copper are sufficient.

  If the minimum cross-sectional area of the columnar part is too large, the degree of freedom of the battery case size is lowered, and in the case of sealing the vicinity of the terminal with a gasket, the peripheral dimension of the gasket increases, which is not preferable.

  From the above viewpoint, the cross-sectional area of the columnar part is preferably 80 mm 2 or more, and more preferably 100 mm 2 or more. Further, it is preferably 600 mm 2 or less, and more preferably 300 mm 2 or less.

  In forming the plate-like portion at the end of the columnar portion of the electrode terminal, when the plate-like member brought into contact with the columnar portion is joined by welding, in the first embodiment and the second embodiment, before the attachment The plate-like portion does not have a through-hole in the central portion where the columnar portion contacts, and in the third embodiment, the plate-like portion before attachment has a through-hole in the center.

  When the plate-like part before attachment does not have a through hole in the central part that contacts the columnar part as in the first embodiment or the second embodiment, the upper surface of the columnar part head is the plate-like part. Therefore, welding can be performed with an electron beam or the like from above the contact portion. At this time, it is easy to make the electron conduction between the columnar part and the plate-like part sufficient by adjusting the width of the welding beam and the welding length (in the first embodiment, two rounds are welded). .

  On the other hand, when the plate-like portion before attachment has a through-hole that can penetrate the columnar portion as in the third embodiment, the plate-like portion is columnar as shown in FIG. It will contact only the side of the part. Here, it is preferable that the side area of the columnar part in contact with the plate-shaped part is not less than the cross-sectional area of the columnar part, and as described above, the cross-sectional area of the columnar part is preferably not less than 80 mm2, The thickness of the plate-like part is preferably 2.5 mm or more. Further, for the same reason, it is more preferable to adjust the welding beam so that the depth of the side surface portion of the columnar part melted by welding (the distance indicated by a in FIG. 5B) is 2.5 mm or more.

DESCRIPTION OF SYMBOLS 1 ... Plate-shaped part 1a ... Recessed part 1b ... Through-hole 1c ... Step part 1d ... Opening part 2 ... Columnar part 3 ... Current collecting plate 10 ... Electrode terminal

Claims (4)

In the battery in which the electrode terminal connected by the power generation element and the current collector in the battery case protrudes from the hole provided in the battery case,
The electrode terminal is a columnar portion that is continuous in a protruding direction, and a plate-shaped portion that is connected by welding to a tip end portion of the columnar portion that protrudes outside the battery case, and the planar direction thereof is the protruding direction. A plate-like part that is orthogonal and has a cross-sectional area larger than the cross-sectional area of the columnar part,
A concave portion is formed at a position overlapping the leading end portion of the columnar portion in the projecting direction on the surface of the plate-shaped portion on the projecting direction side, and a welding site between the columnar portion and the plate-shaped portion is within the region of the concave portion. A battery characterized by being. The plate-like part has a through-hole into which a tip part of the columnar part is fitted,
The battery according to claim 1, wherein a boundary between a side surface of the columnar portion and an inner peripheral surface defining the through hole is welded in the region of the concave portion.   3. The battery according to claim 2, wherein a fixed position between the electrode terminal and a member to be energized is located at a position eccentric in the planar direction from the columnar part in the plate-like part.   The side area of the said columnar part which contacts the said plate-shaped part in the state by which the said columnar part was engage | inserted in the through-hole of the said plate-shaped part is more than the cross-sectional area of this columnar part. Battery.

Images