JP5546997B2 - Welding method, battery manufacturing method, and battery - Google Patents

Description

  The present invention relates to a welding method, a battery manufacturing method, and a battery. More specifically, the present invention relates to a welding method, a battery manufacturing method, and a battery that are characteristic of welding of electrode plates (positive and negative plates) and current collector plates.

  Batteries are used in various fields such as electronic devices such as mobile phones and personal computers, vehicles such as hybrid vehicles and electric vehicles. Such a battery includes a positive electrode plate, a negative electrode plate, and an electrolyte. Further, in order to insulate the positive electrode plate and the negative electrode plate, it is common to provide a separator between them. In many cases, a laminated electrode body in which positive plates and negative plates are alternately arranged and a separator is sandwiched between them is used. This is to improve the volume energy density.

  In such a laminated electrode body, a positive current collector is bonded to a positive electrode substrate, and a negative current collector is bonded to a negative electrode substrate. In order to perform a suitable current collection, it is preferable to perform this joining reliably. This is because if the joint at the joint location is insufficient, the electrical resistance at that location is high. If the junction itself is not made, these parts are of course not conducting. Therefore, no current flows at that point.

  Therefore, a technique for suitably joining the electrode plate substrate and the current collector plate has been developed. For example, Patent Document 1 discloses a technique of laser welding a substrate of an electrode plate and a current collector plate. As a result, it is possible to perform bonding without performing complicated processes such as processing and fixing of leads. Patent Document 2 discloses a technique of beam welding a substrate of an electrode plate and a current collector plate in a vacuum. Thereby, it can be said that it can join without producing the influence by heat in other parts other than a joining location.

JP 2002-042769 A JP 2004-006407 A

  However, when the laser is continuously scanned as in Patent Document 1, sputtering is likely to occur. If spatter enters the electrode body, an internal short circuit may occur. Further, since the energy density of the laser is high, the electrode plate may be melted too much. In this case, a large amount of heat is transmitted to the separator and the separator is burnt.

  On the other hand, when beam welding is performed in vacuum as in Patent Document 2, it is necessary to perform welding in vacuum. In order to realize this vacuum state, many processes such as a decompression process and a decompression process are required. And it takes time to perform these steps. That is, the cycle time becomes long. Furthermore, it is necessary to provide equipment for creating a vacuum.

  The present invention has been made to solve the above-described problems of the prior art. That is, it is an object of the present invention to provide a welding method, a battery manufacturing method, and a battery that can suitably perform welding of the electrode plate substrate and the current collector plate.

The welding method according to one aspect of the present invention for solving this problem is a welding method in which an electrode body in which a positive electrode plate and a negative electrode plate are alternately arranged with a separator interposed therebetween is welded to a current collector. is there. Then, when welding the positive electrode plate and the negative electrode plate to at least one current collector, the irradiation diameter Φ, which is an irradiation region having an intensity significantly higher than the background level, has the following relationship: ΦT / Φ ≧ 0.9
.PHI.T: fulfills diameter <br/> irradiation zone is the intensity of more than 10% of the maximum intensity, the following relation 4 × D1 ≦ Φ ≦ 7 × D1
D1: Perform using a laser that satisfies the target welding width. In such a welding method, the amount of heat applied to the vicinity of the center of the laser irradiation diameter is not so much. For this reason, there is almost no generation of holes in the current collector plate or spatter. Also, the separator does not burn. The current collector plate can be welded to the laminated electrode body with a welding width aimed at.

According to another aspect of the present invention, there is provided a method for producing a battery comprising: a positive electrode plate comprising a positive electrode plate reaction part that causes an electrode reaction in an electrolyte; and a positive electrode plate non-reaction part that does not cause an electrode reaction in the electrolyte; A negative electrode plate having a negative electrode plate reaction part that causes an electrode reaction in the liquid and a negative electrode plate non-reaction part that does not cause an electrode reaction in the electrolyte, and a separator, and the positive electrode plate and the negative electrode while alternating the positive electrode plate and the negative electrode plate A laminated electrode body in which a separator is interposed between plates and at least a part of the positive electrode plate non-reacting part and at least a part of the negative electrode plate non-reacting part are laminated so as to protrude in opposite directions. a work made step, the welding the positive electrode current collector plate to the positive electrode plate unreactive portion projecting from the laminated electrode body, welding body by welding a negative electrode current collector plate to the negative electrode plate unreactive portion projecting from the laminated electrode body Current collector plate welder When, and a battery assembly process for sealing the battery container after injecting the electrolyte solution is inserted a welding body in the battery container. In the current collector plate welding process, the irradiation diameter Φ, which is an irradiation region having an intensity significantly larger than the background level, is expressed by the following relationship ΦT / Φ ≧ 0.9.
.PHI.T: fulfills diameter <br/> irradiation zone is the intensity of more than 10% of the maximum intensity, the following relation 4 × D1 ≦ Φ ≦ 7 × D1
D1: A laser satisfying a target welding width is used, and the laser is applied to the positive electrode plate non-reactive part at one end of the laminated electrode body or from the position of the negative electrode non-reactive part at the other end. Alternatively, scanning is performed in the stacking direction up to the negative electrode plate non-reacting portion. In such a battery manufacturing method, the amount of heat applied to the vicinity of the center of the laser irradiation diameter is not so much. For this reason, there is almost no generation of holes in the current collector plate or spatter. Also, the separator does not burn. The current collector plate can be welded to the laminated electrode body with a welding width aimed at.

  In the battery manufacturing method described above, at least one of the positive electrode current collector plate and the negative electrode current collector plate is used in which bent portions are formed at both ends in the stacking direction. The laser may be irradiated to the inside of the bent portion and the laser may be scanned within 1 mm inside the stacking direction of both ends of the laser irradiation region or within 1 mm outside the stacking direction of both ends. This is because, in the vicinity of the bent portion where the temperature does not rise easily, it is possible to hardly cause a bonding failure in which the current collector plate and the laminated electrode body are not bonded.

  In the battery manufacturing method described above, at least one of the positive electrode current collector plate and the negative electrode current collector plate has a thin portion where the thickness of the region welded in the current collector plate welding step is thinner than the thickness of the other region. In the current collector plate welding process, the positive plate non-reactive portion or the negative plate non-reactive portion is preferably welded to the thin portion. This is because welding can be performed without a shortage of the welding width even when a laser with low energy is used.

A battery according to still another aspect of the present invention includes a positive electrode plate having a positive electrode plate reaction part that causes an electrode reaction in an electrolytic solution and a positive electrode plate non-reacting part that does not cause an electrode reaction in the electrolytic solution; A negative electrode plate having a negative electrode plate reaction part that causes an electrode reaction and a negative electrode plate non-reacting part that does not cause an electrode reaction in an electrolyte, and a separator are disposed between the positive electrode plate and the negative electrode plate while alternating the positive electrode plate and the negative electrode plate. A laminated electrode body that is disposed with a separator interposed therebetween, and is laminated with at least a part of the positive electrode plate non-reacting part and at least a part of the negative electrode plate non-reacting part protruding in opposite directions; It has a positive electrode plate non-reacting portion protruding and a welded positive electrode current collector plate, and a negative electrode plate non-reactive portion protruding from the laminated electrode body and a welded negative electrode current collector plate. Then, at least one of the welded portion of the welded portion of the welded portion and the negative electrode current collector plate and the negative electrode plate unreactive portion of the positive current collector plate and the positive plate nonreactive portion of the unreacted portion of the corresponding electrode plates tip The corresponding current collector plate is joined to the part, and the width of the heat-affected zone during welding on the opposite side of the non-reactive part of the current collector plate is the non-reactive part side of the corresponding current collector plate. It is 4 to 7 times the weld width in the surface . In such a battery, there is almost no possibility that spatter is mixed in the laminated electrode body. Moreover, almost no separator burn occurred. And welding is performed with the required welding width.

The battery in the above embodiment, the at least the one welding portion of the weld between the weld and the negative electrode current collector plate and the negative electrode plate unreactive portion of the positive electrode current collector plate and the positive electrode plate unreactive unit, during welding As the heat-affected zone , the stacking-direction heat-affected zone extending from one end to the other end in the stacking direction of the stacked electrode body, and the first end that is at least in contact with the stacking-direction heat-affected zone on the one end side. And a second contact heat affected zone that is at least in contact with the stacking direction heat affected zone on the other end side. In such a battery, there is almost no defective bonding between the current collector plate and the laminated electrode body at locations located at both ends of the laminated electrode body in the lamination direction.

  In the battery described above, it is preferable that at least one of the positive electrode current collector plate and the negative electrode current collector plate has a thin portion formed in at least a part of the heat affected zone. This is because the possibility that spatter is mixed in the laminated electrode body is even lower.

  ADVANTAGE OF THE INVENTION According to this invention, the welding method and battery manufacturing method and battery which can perform the welding of the board | substrate of an electrode plate and a current collector plate suitably are provided.

It is a partially broken perspective view for demonstrating the battery which concerns on embodiment. It is sectional drawing for demonstrating the structure of the welded body which welded the current collecting plate to the laminated electrode body of the battery which concerns on embodiment. It is a figure for demonstrating intensity distribution of the laser used for the manufacturing method of the battery concerning an embodiment. It is sectional drawing for demonstrating the scanning method of the laser in the manufacturing method of the battery which concerns on 1st Embodiment. It is sectional drawing for demonstrating the laser welding in the manufacturing method of the battery which concerns on embodiment. It is a perspective view which shows the welding area | region of the laser welding in the manufacturing method of the battery which concerns on 1st Embodiment. It is a graph (the 1) for demonstrating the suitability of the laser welding by the combination of the laser output and irradiation diameter in the manufacturing method of the battery which concerns on 1st Embodiment. It is a graph (the 2) for demonstrating the suitability of the laser welding by the combination of the laser output and irradiation diameter in the manufacturing method of the battery which concerns on 1st Embodiment. It is a perspective view for demonstrating the conventional keyhole type laser welding. It is sectional drawing for demonstrating the method of welding the current collecting plate in which the recessed part was formed in the manufacturing method of the battery which concerns on 1st Embodiment. It is sectional drawing for demonstrating the welding failure location in the welding body manufactured by the manufacturing method of the conventional battery. It is a top view for demonstrating the scanning method of the laser in the manufacturing method of the battery which concerns on 2nd Embodiment. It is a top view for demonstrating the heat affected zone by welding of the current collecting plate in the battery which concerns on 2nd Embodiment. It is a top view for demonstrating the length which scans the laser in the manufacturing method of the conventional battery, and the length which irradiates a laser. It is a top view (the 1) for demonstrating the shape of the welding area | region of another battery which concerns on 2nd Embodiment. It is a top view for demonstrating the shape of the welding area | region of another battery which concerns on 2nd Embodiment (the 2). It is a top view (the 3) for demonstrating the shape of the welding area | region of another battery which concerns on 2nd Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. The present embodiment embodies the present invention regarding a nickel metal hydride battery and a method for manufacturing the same.

(First embodiment)
1. Battery A nickel metal hydride battery according to the present embodiment will be described. FIG. 1 is a partially broken perspective view of a battery cell 10 of the present embodiment. As shown in FIG. 1, the battery cell 10 includes a battery container 11, a sealing plate 12, a safety valve 13, and a laminated electrode body 100. The battery container 11 is a case in which the laminated electrode body 100 is inserted and the electrolytic solution is accommodated therein. The sealing plate 12 is for sealing the battery cell 10. The safety valve 13 is a valve that opens when the internal pressure of the battery cell 10 increases too much. As will be described later, the positive electrode current collector plate and the negative electrode current collector plate are joined to the laminated electrode body 100. These are in a position that cannot be seen from the broken portion in FIG.

  FIG. 2 is a cross-sectional view illustrating the welded body 200 extracted from the battery cell 10. Here, the welded body 200 is obtained by joining the positive electrode current collector plate 110 and the negative electrode current collector plate 120 to the laminated electrode body 100. As shown in FIG. 2, the laminated electrode body 100 includes a positive electrode plate P, a negative electrode plate N, and a separator S. The separator S is always laminated between the positive electrode plate P and the negative electrode plate N so as to be disposed therebetween. This is because the positive electrode plate P and the negative electrode plate N are insulated. Here, the direction indicated by the arrow F in FIG. 2 is the same as the direction indicated by the arrow A in FIG. 1, and is the stacking direction of these members.

  The positive electrode plate P is obtained by filling a part of the positive electrode substrate with a positive electrode active material. The positive electrode plate P includes a positive electrode filling part P1 and a positive electrode non-filling part P2. The positive electrode filling portion P1 is located between the separators S as shown in FIG. As shown in FIG. 2, the positive electrode unfilled portion P <b> 2 is in a position where it is not sandwiched between the separators S. The positive electrode filling part P1 is a positive electrode plate reaction part in which a positive electrode substrate is filled with a positive electrode active material. On the other hand, the positive electrode unfilled portion P2 is a positive plate non-reacting portion in which the positive electrode substrate is not filled with the positive electrode active material. The positive electrode plate reaction part is a part where an electrode reaction occurs on the surface thereof and a part that actually contributes to power generation. Here, the positive electrode substrate is, for example, foamed nickel. The positive electrode active material is, for example, nickel hydroxide. Note that the positive electrode active material does not appear in FIG. This is because the surface of the nickel foam is only slightly formed.

  The negative electrode plate N includes a negative electrode filling part N1 (negative electrode plate reaction part) and a negative electrode non-filling part N2 (negative electrode plate non-reaction part) in which a negative electrode substrate is filled with a negative electrode active material. The negative electrode filling portion N1 is located between the separators S as shown in FIG. The negative electrode non-filling portion N2 is in a position not sandwiched between the separators S as shown in FIG. Here, the negative electrode substrate is, for example, nickel punching metal. The negative electrode active material is, for example, a hydrogen storage alloy.

  Further, as shown in FIG. 2, the positive electrode filling portion P1 and the negative electrode filling portion N1 are stacked in contact with the separator S. A part of the positive electrode unfilled portion P <b> 2 protrudes to one side of the laminated electrode body 100. The tip end portion PX of the positive electrode unfilled portion P <b> 2 is joined to the positive electrode current collector plate 110. That is, the positive electrode substrate and the positive electrode current collector plate 110 are electrically connected. A part of the negative electrode non-filling portion N <b> 2 protrudes to the other side of the laminated electrode body 100. The protruding direction is opposite to the protruding direction of the positive electrode unfilled portion P2. The leading end NX of the negative electrode non-filling portion N2 is joined to the negative electrode current collector plate 120. That is, the negative electrode substrate and the negative electrode current collector plate 120 are electrically connected. Here, the thickness of each current collecting plate 110, 120 is about 0.4 to 1 mm. The thickness of the electrode plates P and N is about 50 to 200 μm.

  As shown in FIG. 2, bent portions 111 are formed at both ends of the positive electrode current collector plate 110. An end surface 111 a is formed on the bent portion 111. The end surface 111a is perpendicular to the electrode plates P and N. Similarly, bent portions 121 are formed at both ends of the negative electrode current collector plate 120.

2. 2. Method of welding electrode plate and current collector plate 2-1. Laser intensity distribution to be used The welding method of this embodiment will be described. This embodiment is characterized by the type of laser used for laser welding. Therefore, first, the type of laser used in this embodiment will be described. FIG. 3 shows the intensity distribution of the laser used in this embodiment. In FIG. 3, the horizontal axis is the distance from the center. The vertical axis represents the laser intensity. The solid line shows the intensity distribution of the top-hat type laser. The broken line shows the intensity distribution of the Gaussian laser. In this embodiment, a top hat type laser as shown in FIG. 3 is used.

  In FIG. 3, a top hat type laser (solid line) and a Gaussian type laser (dashed line) having a common irradiation diameter Φ are depicted. Here, the irradiation diameter Φ refers to the diameter of the irradiation region having an intensity significantly greater than the background level. For example, it refers to the diameter of the irradiated region that is 1% or more of the maximum laser intensity.

  Let M be the maximum intensity of the laser. Let 0.9M partial intensity irradiation diameter be ΦQ. The 0.9M partial intensity irradiation diameter refers to the diameter of the irradiation region having an intensity of 10% or more of the maximum value M of the laser intensity distribution.

The top hat type laser in this embodiment can be defined by the ratio between the irradiation diameter Φ and the 0.9M partial intensity irradiation diameter ΦQ. That is, the top-hat type laser is
ΦQ / Φ ≧ 0.9
A laser that satisfies the relational expression. What is a Gaussian laser?
ΦQ / Φ <0.8
A laser that satisfies the relational expression. FIG. 3 shows typical examples of a top hat type laser and a Gaussian type laser.

In FIG. 3, the maximum intensity of the top hat type laser is MT. Then, 0.9MT partial intensity irradiation diameter ΦT is
ΦT / Φ ≧ 0.9 (1)
Meet. In FIG. 3, the maximum intensity of the Gaussian laser is MG. Then, 0.9MG partial intensity irradiation diameter ΦG is
ΦG / Φ <0.8 (2)
Meet.

  Thus, as the partial intensity irradiation diameter ΦQ is closer to the irradiation diameter Φ, the vicinity of the maximum value of the laser intensity distribution is flat. This is a feature of the top hat type laser. The flat region near the maximum value of the laser intensity distribution disappears as the partial intensity irradiation diameter ΦQ becomes a value sufficiently smaller than the irradiation diameter Φ. This is a feature of the Gaussian laser.

  As shown in FIG. 3, when the output is the same and the irradiation diameter Φ is the same, there are the following features. The intensity of the top hat type laser is weaker than the intensity of the Gaussian laser in the region close to the laser irradiation center, and higher than the intensity of the Gaussian laser in the region far from the laser irradiation center. That is, when a top-hat type laser is used, the amount of heat applied to the vicinity of the center of the laser irradiation region is less than when a Gaussian type laser is used. Therefore, the occurrence of spatter is suppressed.

  Note that the top-hat type laser can be irradiated by using a light shield (see paragraph [0024] of FIGS. 1 and 3 of JP-A-10-109186). Moreover, it can also irradiate by using a rear mirror (refer paragraph [0034] of Unexamined-Japanese-Patent No. 9-70681, FIG.5, FIG.9, FIG.10).

2-2. Next, the welding method using the top hat type laser will be described. FIG. 4 is a diagram for explaining the laser welding method of this embodiment. When performing laser welding, the laminated electrode body 100 is pressurized in the left-right direction (arrow E) in FIG. The pressurizing jig 1000 is a jig for reducing the thickness of the laminated electrode body 100 in the laminating direction (direction of arrow F in FIG. 2). This is because welding in such a manner can be accommodated in the battery container 11 and the volume energy density of the battery can be increased. The pressure jig 1000 is only used for the welding process and does not remain in the battery cell 10.

  The bent portion 111 of the positive electrode current collector plate 110 is supported by the upper surface 1001 of the pressure jig 1000. The end surface 111 a faces the upper surface 1001 and is in contact with the pressing jig 1000. At this time, the tip portion PX of the positive electrode plate P is in contact with the positive electrode current collector plate 110.

  Subsequently, the laser is scanned in the direction of arrow B in FIG. 4 while irradiating the positive electrode current collector plate 110 with the laser. Here, the scanning speed of the laser is, for example, 65 mm / sec. Of course, other scanning speeds may be used. The direction of arrow B in FIG. 4 is parallel to the direction of arrow F shown in FIG. Thereby, the laser irradiation spot in the positive electrode current collector plate 110 is heated and melted. FIG. 5 shows an irradiation spot 112 of this laser. FIG. 5 is a cross-sectional view showing a position corresponding to the LL cross section of FIG. However, FIG. 2 shows a welded body 200 after welding, whereas FIG. 5 shows a state during welding. FIG. 5 shows a laser irradiation spot 112 and a melted portion 113 melted by the laser irradiation. As shown in FIG. 5, the melted portion 113 is formed over the thickness direction of the positive electrode current collector plate 110.

  Then, a part of the melted portion 113 wets and spreads on the tip portion PX while being in contact with the tip portion PX of the positive electrode plate P. At this stage, the positive electrode current collector plate 110 and the tip end portion PX of the positive electrode plate P are electrically connected. After the laser irradiation to the melted portion 113 is completed, the melted portion 113 is cooled and solidified. Thereby, the front-end | tip part PX of the positive electrode plate P is joined to the positive electrode current collecting plate 110. The welding width D at that time is shown in FIG. The weld width D is the width of the melted portion 113 on the back side of the positive electrode current collector plate 110.

  Since the laser is scanned in the direction of the arrow B in FIG. 4, the positive electrode current collector plate 110 is welded to a plurality of positive electrode plates P extending in the stacking direction of the stacked electrode body 100, that is, in the left-right direction in FIG. The welding region R to be welded is shown in FIG. The welding region R is a portion that becomes a heat affected zone that is once melted and solidified again by being irradiated with a laser. The laser is scanned along the direction of arrow Q in FIG. Note that HAZ in FIG. 5 indicates the width of the heat-affected zone on the front side of the positive electrode current collector plate 110.

Here, the laser irradiation diameter Φ and the target welding width D1 satisfy the following relationship.
4 x D1 ≤ Φ ≤ 7 x D1
This is because the width HAZ of the heat affected zone on the front side of the positive electrode current collector plate 110 is 4 to 7 times the welding width D.

Similarly, the negative electrode current collector plate 120 is welded to the tip portion NX of the negative electrode plate N of the laminated electrode body 100. Thus, the welding body 200 positive electrode current collector plate 110 and the negative electrode terminal plate 120 is welded to the laminated electrode body 100 is made of work. The welded body 200 is as shown in FIG.

  The width HAZ on the welded region R shown in FIG. 6, that is, the surface 110a side of the heat affected zone, is almost equal to the laser irradiation diameter Φ. That is, in the battery cell welded body 200 according to this embodiment, the heat affected zone having a width 4 to 7 times the welding width D of the current collector plates 110 and 120 is formed on the surface of the current collector plates 110 and 120. . It can be said that the battery cell 10 having the welded body 200 is suitably welded. In other words, almost no welding defects occurred. Further, the current collector plates 110 and 120 are not perforated, and there is almost no possibility that spatter enters the laminated electrode body 100. Also, no separator burn occurred.

2-3. Relationship between Laser Irradiation Diameter Φ and Good Product Conditions Here, the relationship between the laser irradiation diameter Φ and good product conditions will be described. FIG. 7 is a graph showing whether or not welding defects such as insufficient welding width D or burnt separator occur when welding is performed using lasers having different laser irradiation diameters and laser outputs. The horizontal axis is the laser output. The vertical axis represents the laser irradiation diameter Φ. Note that the laser used here is a top-hat type laser that satisfies Equation (1).

The results shown in FIG. 7 and FIG. 8 to be described later are obtained by welding under the following conditions.
Thickness t of current collecting plates 110 and 120: 0.4 mm
Target welding width D1: 0.5 mm
Laser scanning speed: 65 mm / sec

  In FIG. 7, “x” marks indicate that the current collector plate is perforated or sputtered during welding. The diamond mark indicates that the separator is burnt. The triangle mark indicates that the welding width D is insufficient. The “◯” mark indicates that none of the above problems have occurred. That is, it indicates that the product is non-defective.

  In FIG. 7, there are four regions U, V, W, and X. The region U is a region showing a case where a top hat type laser having an irradiation diameter Φ of less than 1.5 mm is used. In the region U, as shown in FIG. 7, the current collector plate is perforated and sputtered. In the region U, since the laser irradiation diameter is small, the laser penetrates the positive electrode current collector plate 110 as shown in FIG. That is, the positive electrode current collector plate 110 has a hole. In the region U, the weld width is further insufficient. In other words, welding that satisfies the quality cannot be performed.

  When the irradiation diameter Φ is 2 mm or more (4 times or more of D1), there are regions V, W, and X. Regions V, X, and W are in ascending order of laser output. The region V is a region on the left side of the line connecting the triangle marks in FIG. The region W is a region on the right side of the line connecting the diamond marks in FIG. The region X is in the middle between the region V and the region W.

In the region V where the laser output is low, the welding width is insufficient. On the contrary, in the region W where the laser output is high, the separator burns. In the region X, the welding body 200 to satisfy the good quality is made work. That is, the welded body 200 is free from problems such as perforations, spatter, burnt separator, and insufficient weld width.

  As described above, if the laser irradiation diameter Φ is set to be four times or more the target coating width D1, and the laser output is appropriately selected, suitable laser welding can be performed. On the other hand, when the laser irradiation diameter Φ exceeds 7 times the target welding width D1, the energy density of the laser becomes low. Therefore, in order to secure the welding width D, it is necessary to increase the laser output. The total amount of heat input at this time is large. In this case, the separator is likely to burn.

2-4. Next, a case where a Gaussian laser is used instead of the top hat laser of this embodiment will be described. FIG. 8 is a graph showing the results using a Gaussian laser. The target welding width at this time is a width equal to or greater than the plate thickness t of the current collector plates 110 and 120. Therefore, the welding width is set to 0.5 mm as in the case of using the top hat type laser of FIG. The laser used in FIG. 8 is a Gaussian laser that satisfies Equation (2).

  Also in the case of FIG. 8, similarly to the case shown in FIG. 7, by selecting an appropriate laser irradiation diameter and laser output, a welded body 200 that satisfies the quality of the non-defective product was obtained. However, in FIG. 8, the region of the combination of the laser irradiation diameter and the laser output that satisfies the quality of the non-defective product is narrower than the region shown in FIG. In other words, the Gaussian type laser has a narrower area where welding can be suitably performed. Conversely, the top hat type laser has a wider area in which welding can be suitably performed. In such a thin T-shaped butt welding, which suppresses spatter scattering and avoids separator burn, a top hat type laser is preferable.

  As described above, as shown in FIG. 7, when a top hat type laser is used, a laser having an irradiation diameter Φ of 2.0 to 3.5 mm may be selected. However, this is the case where the target welding width D1 is 0.5 mm. The irradiation diameter at this time is 4 to 7 times the target welding width D1. When the target welding width D1 is not 0.5 mm, the irradiation diameter Φ suitable for welding is different from that shown in FIG. Even in that case, a laser whose irradiation diameter is 4 to 7 times the welding width may be used.

  As shown in FIG. 8, when a Gaussian laser is used, a laser having an irradiation diameter Φ of 2.5 to 3.5 mm may be selected. However, this is the case where the target welding width D1 is 0.5 mm. The irradiation diameter at this time is 4 to 7 times the target welding width D1. When the target welding width D1 is not 0.5 mm, the irradiation diameter Φ suitable for welding is different from that shown in FIG. Even in that case, a laser whose irradiation diameter is 4 to 7 times the welding width may be used.

  Even if current collector plates 110 and 120 having a plate thickness different from that of the present embodiment are used, a top hat type laser having an irradiation diameter of 4 to 7 times the welding width can be used. This is because suitable welding can be performed by changing the output of the laser.

  The plate thickness t of the current collecting plates 110 and 120 is not limited to the above. For example, it may be about 0.4 to 1 mm. Of course, other values may be used. The target welding width D1 is preferably equal to or greater than the plate thickness t of the current collector plates 110 and 120. This is to maintain the welding strength and not to increase the electrical resistance.

3. Battery Manufacturing Method The battery manufacturing method according to the present embodiment is characterized in that the above-described laminated electrode body 100 and the positive electrode current collector plate 110 or the negative electrode current collector plate 120 are welded.

3-1. Electrode plates work made steps positive plate P is created made by filling a positive electrode active material in the positive electrode substrate. Here, the portion of the positive electrode substrate filled with the positive electrode active material becomes the positive electrode filling portion P1. A portion of the positive electrode substrate that is not filled with the positive electrode active material is a positive electrode unfilled portion P2. Negative electrode plate N is created made by coating wears an anode active material on the negative electrode substrate. Here, the portion filled with the negative electrode active material in the negative electrode substrate becomes the negative electrode filling portion N1. A portion of the negative electrode substrate that is not filled with the negative electrode active material is a negative electrode non-filled portion N2.

3-2. Following step made laminated electrode body work, stacking the positive electrode plate P, negative electrode plate N, the separator S. At that time, the positive plates P and the negative plates N are alternately arranged. Then, the separator S is necessarily laminated between the positive electrode plate P and the negative electrode plate N. At that time, the positive electrode plate P is stacked so that the positive electrode unfilled portion P2 protrudes from one side and the negative electrode unfilled portion N2 of the negative electrode plate N protrudes to the opposite side. Thus, the laminated electrode body 100 is made of work.

3-3. Current collector plate welding step Next, the positive electrode current collector plate 110 and the negative electrode current collector plate 120 are welded to the laminated electrode body 100. FIG. 4 shows the laminated electrode body 100 and the positive electrode current collector plate 110 before welding. Here, as described above, the positive electrode current collector plate 110 is welded to the tip portion PX of the positive electrode unfilled portion P2 by using a laser having an irradiation diameter of 4 to 7 times the target welding width. Similarly, the negative electrode current collector plate 120 is welded to the tip portion NX of the negative electrode unfilled portion N2. The order of these joinings may be either.

3-4. Battery Assembly Process Subsequently, the laminated electrode body 100 is inserted into the battery container 11. Then, an electrolytic solution is injected into the battery container 11. Thereby, the laminated electrode body 100 is immersed in the electrolytic solution. Subsequently, the sealing plate 12 is joined to the battery container 11. Thereby, the battery cell 10 of this embodiment is assembled. After this, various inspection processes may be performed. Through the above steps, the battery cell 10 of this embodiment is manufactured.

4). Modification A modification of this embodiment is shown in FIG. As shown in FIG. 10, the positive electrode current collector plate 210 has a recess 211. The thickness of the concave portion 211 in the positive electrode current collector plate 210 is about half the thickness of the other portions. That is, the recessed part 211 is a thin part. The width of the recess 211 is about the same as the target welding width D1. The recess 210 is formed on the side opposite to the side to be welded with the positive electrode plate P.

  In welding, it is preferable to use a laser having an irradiation diameter slightly larger than the welding width D1, which is aimed at the irradiation diameter of the laser, that is, the width of the recess 211. Since the thickness of the recess 211 is thin, the laser energy can be made smaller. Thereby, generation | occurrence | production of a sputter | spatter can be suppressed. In addition, the recessed part 211 can be formed by performing a press process partially on the area | region which welds. The width D2 of the recess 211 is slightly smaller than the irradiation diameter Φ.

5. Summary As described above in detail, the battery according to the present embodiment is manufactured using a top hat type laser when welding the positive electrode current collector plate 110 to the tip portion PX of the positive electrode unfilled portion P2. Is. The same applies when the negative electrode current collector plate 120 is welded to the tip NX of the negative electrode unfilled portion N2. Therefore, welding with a sufficient welding width can be performed. Moreover, almost no burnt of the separator occurs in the laminated electrode body 100. Further, almost no spatter is contained in the laminated electrode body 100. As a result, a battery that hardly causes an internal short circuit is realized.

  In the battery manufacturing method according to this embodiment, a top hat type laser is used for welding. Therefore, almost no spatter is generated during welding. Moreover, there is almost no possibility that the positive electrode substrate or the negative electrode substrate is melted too much. Therefore, the separator S is hardly melted. That is, it is possible to manufacture a battery that hardly causes an internal short circuit. Furthermore, it is not necessary to use a vacuum state as in beam welding. Laser welding using a top-hat type laser according to this embodiment has a wider area in which welding can be performed more appropriately than laser welding using a Gaussian laser.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, it is not limited to a nickel metal hydride battery. The present invention can also be applied to a lithium ion battery. Even in this case, it has a positive electrode plate having a positive electrode plate reaction part and a positive electrode plate non-reaction part, and a negative electrode plate having a negative electrode plate reaction part and a negative electrode plate non-reaction part. What is necessary is just to weld to an electric plate. In addition, it is applicable to any battery in which the tip PX of the positive electrode unfilled portion P2 is welded to the positive electrode current collector plate 110 or the tip NX of the negative electrode unfilled portion N2 is welded to the negative electrode current collector plate 120 Can do.

  Further, in this embodiment, the positive electrode current collector plate 110 and the tip portion PX of the positive electrode plate P are already in contact with each other during welding. However, there may be a slight gap between them. This is because welding can be performed.

(Second Embodiment)
A second embodiment will be described. In this embodiment, a top hat type laser is used as in the first embodiment. The difference from the first embodiment is a scanning method for scanning a laser. Therefore, the laser scanning method will be mainly described.

  As described in the first embodiment, bent portions 111 are formed at both ends of the positive electrode current collector plate 110 of the welded body 200 shown in FIG. The thickness of the bent portion 111 is thicker than the thickness of the other portions. Therefore, the temperature is less likely to increase in the vicinity of the end of the stacked electrode body 100 in the stacking direction (arrow F in FIG. 2), that is, in the vicinity of the bent portion 111, as compared with other welded portions. This is because the heat of the laser irradiation portion escapes toward the bent portion 111. Therefore, as shown in FIG. 11, poor bonding is likely to occur near the bent portion 111. The same applies to the negative electrode side.

  In order to prevent a bonding failure from occurring in the vicinity of the bent portion 111, more heat may be applied to the portion around the bent portion 111 than the other portions. Therefore, the present embodiment is characterized in that a laser is irradiated to a portion around the bent portion 111 other than that indicated by the welding region R in FIG.

1. Welding Method A laser scanning method in laser welding of this embodiment will be described. A laser scanning method is shown in FIG. FIG. 12 is a view seen from the direction of arrow C in FIG. As shown in FIG. 12, the region to be welded is a region from point Y to point Z. The point Y and the point Z are located immediately inside the place where the bent portion 111 is formed. The welding width is 0.5 mm. In this embodiment, the laser is irradiated three times as shown in FIG.

  In the first laser scanning, the laser is scanned in the direction of arrow I from point Y1 to point Y2. The direction of arrow I is a direction perpendicular to the stacking direction of stacked electrode body 100 (the direction of arrow F in FIG. 2). The direction of the arrow I is parallel to the direction in which the bent portion 111 is formed. The scanning region from the point Y1 to the point Y2 includes a point Y that is an end of the region to be welded.

  In the second laser scanning, the laser is scanned from point Y to point Z in the direction of arrow J. The direction of arrow J is a direction parallel to the stacking direction of stacked electrode body 100 (the direction of arrow F in FIG. 2). The direction of the arrow J is a direction perpendicular to the direction of the arrow I. The area where the second laser is scanned is an area to be welded.

  In the third laser scanning, the laser is scanned in the direction of arrow K from point Z1 to point Z2. The direction of the arrow K is a direction perpendicular to the stacking direction of the stacked electrode body 100 (the direction of the arrow F in FIG. 2). The direction of the arrow K is parallel to the direction of the arrow I and is perpendicular to the direction of the arrow J. The direction of the arrow K is parallel to the direction in which the bent portion 111 is formed. The scanning region from the point Z1 to the point Z2 includes a point Z that is an end of the region to be welded.

  Thereby, reliable welding can be performed over the lamination direction of the laminated electrode body 100. Further, the distance between the first end point and the second start point Y is relatively short. This distance is a distance by which the laser irradiation point is moved from the end of the first laser irradiation to the start of the second laser irradiation. Therefore, the time required from the end of the first laser irradiation to the start of the second laser irradiation is short. For example, it is about 10 milliseconds (10 msec). Therefore, when the second laser is irradiated, the temperature at the starting point is not so different from the temperature when the first laser is heated. Therefore, at the point Y, a sufficient amount of heat is given for welding. And there is almost no loss of heat.

  The distance between the second end point Z and the third start point is also relatively short. Therefore, when the third laser irradiates the point Z, the temperature at the point Z is not so different from the temperature when the second laser is heated. Also, there is almost no loss of heat.

  Here, the moving distance of the laser from the point Y1 to the point Y2 is about 1 mm. The moving distance of the laser from the point Z1 to the point Z2 is also about 1 mm. This scanning step is sufficient because it is a step performed to heat a portion where heating by the laser is likely to be insufficient. However, this distance is an example and may be changed as appropriate. In addition, the amount of heat applied to the periphery of the bent portion 111 can be adjusted by changing the scanning speed of the first and third lasers.

  Further, at the point Y and the point Z, the laser is scanned twice for convenience. Therefore, the point Y and the point Z are given more heat than other regions extending from the point Y to the point Z.

  As described above, the welding from the point Y to the point Z is performed, and the front end portion PX of the positive electrode plate P of the laminated electrode body 100 is welded to the positive electrode current collector plate 110, and also sufficiently around the bent portion 111. Is given heat. In this embodiment, the laser is irradiated twice at the points Y and Z that are both ends of the welding range. As a result, reliable welding is performed.

  The state of the surface on the front side of the positive electrode current collector plate 110 after welding will be described with reference to FIG. Here, the front side is a side that is not welded to the laminated electrode body 100 by welding. A back side is a side welded with the laminated electrode body 100 by welding. An I-shaped heat-affected zone is formed on the front surface of the positive electrode current collector plate 110. A heat affected zone HAZ2 is formed from the point Y to the point Z. While including the point Y, the heat affected zone HAZ <b> 1 is formed perpendicular to the stacking direction of the stacked electrode body 100. While including the point Z, the heat affected zone HAZ3 is formed perpendicular to the stacking direction of the stacked electrode body 100.

  The heat-affected zone HAZ1, the heat-affected zone HAZ2, and the heat-affected zone HAZ3 are welding marks formed by the laser scanned at the first time, the laser scanned at the second time, and the laser scanned at the third time, respectively. The heat affected zone HAZ1, the heat affected zone HAZ2, and the heat affected zone HAZ3 are in contact with each other. Therefore, these boundaries are not clear. The heat affected zone HAZ2 is a stacking direction heat affected zone formed in the stacking direction. The heat affected zone HAZ1 is a first contact heat affected zone. The heat affected zone HAZ3 is a second contact heat affected zone.

2. Comparison with Conventional Laser Scanning Method Here, a case where the first scan indicated by arrow I and the third scan indicated by arrow K in FIG. In that case, it becomes as shown in FIG. The end 114 of the positive current collector 110 is thick. In other words, the heat capacity is large. Therefore, the temperature hardly rises in the vicinity of the end portion 114. The same applies to the vicinity of the end portion 115. Therefore, in order to heat the periphery of the end portion 114 and the periphery of the end portion 115 excessively, the laser is scanned from the end portion 114 to the end portion 115.

  When the end 114 or the end 115 is irradiated with laser, half of the laser irradiation region is irradiated to the positive electrode current collector 110 and the other half is irradiated to the upper surface 1001 of the pressing jig 1000. In that case, the pressing jig 1000 may be damaged. Even in this case, as shown in FIG. 11, there is a possibility that poor welding may occur at a location immediately inside the end portions 114 and 115.

  On the other hand, when the laser irradiation area is from point Y to point Z, as shown in FIG. As described above, the present embodiment can solve the problem of preventing welding failure from occurring in the vicinity of the end portion of the stacked electrode body 100 in the stacking direction (arrow F in FIG. 2).

3. Battery Manufacturing Method The battery manufacturing method of this embodiment uses the above-described welding method. The battery manufacturing process other than the welding method is as described in the first embodiment.

4). Battery The external shape of the battery of this embodiment is the same as that shown in the partially broken perspective view of the battery cell 10 shown in FIG. The difference from the first embodiment is the heat affected zone remaining on the positive electrode current collector plate 110 and the negative electrode current collector plate 120. In the battery cell of this embodiment, a heat-affected zone having a primary shape as shown in FIG. 13 is formed. That is, a heat affected zone is formed from the point Y to the point Z in the stacking direction of the stacked electrode body 100 (the direction of the arrow F in FIG. 2). Further, a heat affected zone passing through the point Y is formed in parallel with the plate surface direction of the electrode plates (the positive electrode plate P and the negative electrode plate N) of the laminated electrode body 100. And the heat affected zone which passes along the point Z in parallel with the plate | board surface direction of the electrode plate of the laminated electrode body 100 is formed.

  As described above, the battery cell of this embodiment has almost no welding failure. Therefore, current can also be suitably collected from the positive electrode plate P and the negative electrode plate N arranged at both ends in the stacking direction of the stacked electrode body 100.

5. Modified example 5-1. Laser scanning order In addition, the laser scanning order may be changed. For example, after scanning the laser from the point Y to the point Z in the direction of arrow J in the first laser scanning, the second laser scanning scans from the point Y1 to the point Y2, and then the third laser scanning. Thus, scanning from the point Z1 to the point Z2 may be performed.

5-2. In this embodiment, as shown in FIG. 12, the first laser is irradiated in the direction of arrow I, the second laser is irradiated in the direction of arrow J, and the third laser is irradiated in the direction of arrow K. . However, the direction of irradiation with this laser may be reversed. Further, laser scanning from the point Y to the point Z may be performed for the first time or the third time. However, the time from when the laser is first scanned at the point Y to when the laser is scanned at the next point Y should be short. This is because the thermal efficiency is good. The same applies to the point Z.

5-3. Heat-affected zone of laser welding In this embodiment, the first laser (arrow I in FIG. 12) and the third laser (arrow K in FIG. 12) are the plate surface directions of the electrode plates (positive plate P and negative plate N). It was decided to scan in parallel. However, it is not always necessary to scan the first laser and the second laser in parallel to the plate surface direction of the electrode plates (the positive plate P and the negative plate N). For example, as shown in FIG. 15, scanning may be performed in a direction shifted from a direction parallel to the plate surface direction of the electrode plate. Even if it does in this way, it is because it does not change that the heat is given to the point Y and the point Z excessively. In the case of FIG. 15 as well, the heat affected zone HAZ5 is in contact with the heat affected zones HAZ4 and HAZ6.

  Further, it is not always necessary to scan the first laser and the third laser so as to pass through the point Y and the point Z. This is because, as shown in FIGS. 16 and 17, the laser may be scanned around the points Y and Z. In FIG. 16, the heat affected zones HAZ7 and HAZ9 intersect the heat affected zone HAZ8. That is, the heat affected zone HAZ8 is at least in contact with the heat affected zones HAZ7 and HAZ9.

  The heat affected zone HAZ7 is formed by scanning a laser aiming at a point within 1 mm inside from the point Y in the stacking direction. The heat affected zone HAZ9 is formed by scanning a laser aiming at a point within 1 mm inside the stacking direction from the point Z. That is, it is formed by scanning the laser within the range within 4 times the target welding width D1 from the points Y and Z in the stacking direction.

  In FIG. 17, the heat affected zone HAZ11 is at least in contact with the heat affected zone HAZ10 and the heat affected zone HAZ12. The heat affected zone HAZ10 is formed by scanning a laser aiming at a point within 1 mm on the outer side in the stacking direction from the point Y. The heat affected zone HAZ12 is formed by scanning a laser aiming at a point within 1 mm outside the point Z from the point Z. In other words, it is formed by scanning the laser within the range within four times the target welding width D1 from the points Y and Z in the stacking direction.

5-4. Type of Laser In this embodiment, laser welding is performed using a top hat type laser as in the first embodiment. However, even when a laser different from the top hat type is used, the temperature does not easily increase in the vicinity of the bent portion 111. Therefore, even when a laser different from the top hat type is used, the laser scanning method of this embodiment can be used. The same applies to beam welding and other welding.

5-5. As described in the first embodiment, the collector plate 110, 120 may have a recess formed in the collector plate 110, 120 as described in the first embodiment.

6). Summary As described above in detail, the battery according to the present embodiment is manufactured using a top hat type laser when welding the positive electrode current collector plate 110 to the tip portion PX of the positive electrode unfilled portion P2. Is. The same applies when the negative electrode current collector plate 120 is welded to the tip NX of the negative electrode unfilled portion N2. Therefore, almost no burnt of the separator occurs in the laminated electrode body 100. Further, almost no spatter is contained in the laminated electrode body 100. As a result, a battery that hardly causes an internal short circuit is realized.

  In the battery manufacturing method according to this embodiment, a top hat type laser is used for welding. Therefore, almost no spatter is generated during welding. Moreover, there is almost no possibility that the positive electrode substrate or the negative electrode substrate is melted too much. Therefore, the separator S is hardly melted. That is, it is possible to manufacture a battery that hardly causes an internal short circuit. Furthermore, it is not necessary to use a vacuum state as in beam welding.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, it is not limited to a nickel metal hydride battery. The present invention can also be applied to a lithium ion battery. Even in this case, it has a positive electrode plate having a positive electrode plate reaction part and a positive electrode plate non-reaction part, and a negative electrode plate having a negative electrode plate reaction part and a negative electrode plate non-reaction part. What is necessary is just to weld to an electric plate. In addition, it is applicable to any battery in which the tip PX of the positive electrode unfilled portion P2 is welded to the positive electrode current collector plate 110 or the tip NX of the negative electrode unfilled portion N2 is welded to the negative electrode current collector plate 120 Can do.

DESCRIPTION OF SYMBOLS 10 ... Battery cell 100 ... Laminated electrode body 110, 210 ... Positive electrode collector plate 111, 121 ... Bending part 120 ... Negative electrode collector plate 200 ... Welded body 211 ... Concave P ... Positive electrode plate P1 ... Positive electrode filling part P2 ... Positive electrode non-filling Part PX ... Tip N ... Negative electrode plate N1 ... Negative electrode filling part N2 ... Negative electrode unfilled part NX ... Tip S ... Separator D ... Welding width D1 ... Target welding width

Claims (7)

In a welding method in which an electrode body in which a positive electrode plate and a negative electrode plate are alternately arranged with a separator interposed therebetween is welded to a current collector,
Welding at least one of the positive electrode plate and the negative electrode plate to the current collector,
The irradiation diameter Φ, which is an irradiation region having an intensity significantly larger than the background level, has the following relationship ΦT / Φ ≧ 0.9
.PHI.T: fulfills diameter <br/> irradiation zone is the intensity of more than 10% of the maximum intensity, the following relation 4 × D1 ≦ Φ ≦ 7 × D1
D1: A welding method characterized by performing using a laser that satisfies a target welding width. In a positive electrode plate having a positive electrode plate reaction part that causes an electrode reaction in an electrolytic solution and a positive electrode plate non-reactive part that does not cause an electrode reaction in the electrolytic solution, and in a negative electrode plate reaction part and an electrolytic solution that cause an electrode reaction in the electrolytic solution A negative electrode plate having a negative electrode plate non-reacting portion that does not cause an electrode reaction, and a separator, with the separator sandwiched between the positive electrode plate and the negative electrode plate while alternating the positive electrode plate and the negative electrode plate, the positive electrode plate unreactive portion of at least a portion between the negative electrode plate unreactive portion of at least a portion laminated with the so as to protrude in opposite directions and stacked electrode assembly stacked electrode assembly work made process,
A positive electrode current collector plate is welded to the positive electrode plate non-reacting portion protruding from the laminated electrode body, and a negative electrode current collector plate is welded to the negative electrode plate non-reactive portion protruding from the laminated electrode body. Current collector plate welding process,
In a battery manufacturing method including a battery assembly step of sealing the battery container after inserting the welded body into the battery container and injecting an electrolyte solution,
In the current collector plate welding process,
The irradiation diameter Φ, which is an irradiation region having an intensity significantly larger than the background level, has the following relationship ΦT / Φ ≧ 0.9
.PHI.T: fulfills diameter <br/> irradiation zone is the intensity of more than 10% of the maximum intensity, the following relation 4 × D1 ≦ Φ ≦ 7 × D1
D1: Use a laser that satisfies the target welding width,
The laser is applied to the positive electrode plate non-reactive part or the negative electrode plate non-reactive part at one end of the laminated electrode body from the positive electrode plate non-reactive part or the negative electrode plate non-reactive part at the other end. Until the stacking direction is scanned. In the manufacturing method of the battery according to claim 2,
As at least one of the positive electrode current collector plate and the negative electrode current collector plate, one having bent portions formed at both ends in the stacking direction,
In the current collector plate welding process,
The laser in the laminating direction is irradiated on the inside of the bent portion, and the laser is scanned within 1 mm inside the laminating direction at both ends of the laser irradiation region or within 1 mm outside the laminating direction at both ends. A battery manufacturing method characterized by the above. In the manufacturing method of the battery of Claim 2 or Claim 3,
Using at least one of the positive electrode current collector plate and the negative electrode current collector plate having a thin portion where the thickness of the region welded in the current collector plate welding step is thinner than the thickness of the other region,
In the current collector plate welding process,
A method of manufacturing a battery, comprising welding the positive electrode plate non-reactive portion or the negative electrode plate non-reactive portion to the thin portion. In a positive electrode plate having a positive electrode plate reaction part that causes an electrode reaction in an electrolytic solution and a positive electrode plate non-reactive part that does not cause an electrode reaction in the electrolytic solution, and in a negative electrode plate reaction part and an electrolytic solution that cause an electrode reaction in the electrolytic solution A negative electrode plate having a negative electrode plate non-reacting portion that does not cause an electrode reaction and a separator, with the positive electrode plate and the negative electrode plate being alternately arranged with the separator sandwiched between the positive electrode plate and the negative electrode plate, A laminated electrode body laminated in a state in which at least a part of the positive electrode plate non-reacting part and at least a part of the negative electrode plate non-reacting part protrude in opposite directions;
A positive electrode current collector plate welded to the positive electrode plate non-reacting portion protruding from the laminated electrode body;
In the battery having the negative electrode plate non-reactive portion protruding from the laminated electrode body and the welded negative electrode current collector plate,
Wherein at least one of the welded portion of the welded portion between the positive electrode current collector plate wherein the positive electrode plate unreactive portion and the welding portion and the negative electrode current collector plate and the negative electrode plate unreactive portion,
The corresponding current collector plate is bonded to the tip of the non-reactive part of the corresponding electrode plate,
The width of the heat-affected zone at the time of welding on the surface opposite to the non-reacting portion of the current collector plate is
The battery characterized by being 4-7 times the welding width in the said non-reaction part side surface in an applicable current collecting plate. The battery according to claim 5 , wherein
Wherein the at least the one welding portion of the welding portion of the positive electrode current collector plate wherein the positive electrode plate unreactive portion and the welding portion and the negative electrode current collector plate and the negative electrode plate unreactive unit, the heat affected zone during the welding As
A heat-affected zone in the stacking direction extending from one end to the other end in the stacking direction of the stacked electrode body; and
A first contact heat affected zone at least in contact with the stacking direction heat affected zone on the one end side;
A battery comprising a second contact heat-affected zone that is at least in contact with the stacking direction heat-affected zone on the other end side. The battery according to claim 5 or claim 6 ,
At least one of the positive current collector and the negative current collector,
A battery, wherein a thin-walled portion is formed in at least a part of the heat-affected zone.

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