JP6665413B2 - Manufacturing method of electrode assembly - Google Patents

Description

The present invention relates to a method for producing an electrode assembly accommodated in the power storage device.

  Patent Literature 1 discloses a secondary battery that is a power storage device having an electrode assembly. The electrode assembly is formed by alternately stacking a positive electrode plate unit in which a positive electrode plate is covered with a thin film separator, and a negative electrode plate.

  When manufacturing an electrode assembly, the positive electrode plate unit and the negative electrode plate may be dropped and stacked in a dedicated housing unit in an upright state. Since the negative electrode plate is not covered with the separator, when it is dropped, its own outer edge is directly received by the wall surface of the housing unit.

JP 2007-27027 A

  When the negative electrode plate is received by the housing unit, the impact may cause the coated active material to fall off around the outer edge of the negative electrode plate. In addition, the impact may cause the periphery of the outer edge of the negative electrode plate to be bent. Note that the term “powder drop” means that a part of a coating material such as an active material applied to an electrode plate peels off and falls.

  An object of the present invention is to prevent a coating substance from falling off an electrode plate when the electrode plate is dropped and stacked in an upright state, and to prevent the electrode plate from being bent.

  In order to solve the above problems, the present invention employs the following means.

  A first aspect of the present invention is a power storage device having an electrode assembly and a case for housing the electrode assembly. The electrode assembly includes a first electrode plate in which a first active material layer is formed on a substantially rectangular first metal plate, and a second active material having a polarity different from that of the first active material layer on a substantially rectangular second metal plate. The second electrode plate on which the layers are formed is alternately stacked with a separator interposed therebetween. The first electrode plate has a first tab portion protruding from an upper side, which is a first side of a substantially rectangular shape, and a periphery of a bottom side facing the upper side and at least one of the remaining left side and right side. Has a first active material layer non-formation region where the first active material layer is not formed. Then, a reinforcing material layer having a higher peel strength than the first active material layer is formed in the first active material layer non-formation region, and the first active material layer non-formation region is reinforced.

  According to a second aspect of the present invention, in the power storage device according to the first aspect, the reinforcing material layer includes a first surface of the first metal plate and a first surface of the first metal plate in a region where the first active material layer is not formed. It is formed on both sides of the second surface opposite to the surface.

  A third invention of the present invention is the power storage device according to the second invention, wherein the reinforcing material layer is provided on the first surface and the second surface of the first metal plate in the region where the first active material layer is not formed. Are also formed on the end surface which is a surface that intersects with the first metal plate and that corresponds to the thickness of the first metal plate.

  A fourth invention of the present invention is a method for manufacturing an electrode assembly in which first electrode plates and second electrode plates are alternately stacked with a separator interposed therebetween. In this method of manufacturing an electrode assembly, the first electrode plate has the first active material layer formed on the substantially rectangular first metal plate and has the first tab portion protruding from the upper side which is the first side of the substantially rectangular shape. , A first active material layer non-formation region where the first active material layer is not formed is formed around a bottom side facing the top side and at least one of the remaining left side and right side. In addition, a second active material layer having a polarity different from that of the first active material layer is formed on a substantially rectangular second metal plate, and a second tab portion having a second tab portion protruding from an upper side that is a first side of the substantially rectangular shape. The second electrode plate and the separator are integrated by covering the first surface of the two-electrode plate and the second surface opposite to the first surface with a separator having a larger area than the second metal plate. The electrode plate unit is formed. Then, each of the bottom side of the first electrode plate and the bottom side facing the top side of the electrode plate unit is set as a first reference side, and the first reference side of the first electrode plate and the first reference side of the electrode plate unit are set. And a housing unit having a first reference plane which is a plane corresponding to the first electrode plate and the electrode plate unit such that the first reference side hits the first reference plane in the housing unit. The first electrode plate and the electrode plate unit are alternately arranged and positioned alternately.

  A fifth aspect of the present invention is a method for manufacturing the electrode assembly according to the fourth aspect. In this method for manufacturing an electrode assembly, the first active material layer non-formation region in the first electrode plate is formed around the bottom and around one of the left side or the right side, and the first electrode plate is formed. Of the active material non-formation side, which is one of the left side and the right side, and the side where the first active material layer non-formation region is formed, and the side corresponding to the active material non-formation side in the electrode plate unit. Is set as the second reference side. In the method for manufacturing an electrode assembly, the housing having the first reference surface and the second reference surface which is a surface corresponding to the second reference side of the first electrode plate and the second reference side of the electrode plate unit is provided. Use a unit. The housing unit makes the first reference plane and the second reference plane perpendicular to each other, inclines a boundary line where the first reference plane and the second reference plane intersect at a predetermined angle with respect to the horizontal direction, and It arrange | positions so that both a surface and a 2nd reference plane can be seen from above. Then, when the first electrode plate and the electrode plate unit are alternately dropped, the first electrode plate and the electrode plate unit are dropped such that the first reference side hits the first reference surface and the second reference side hits the second reference surface.

  A sixth aspect of the present invention is a method for manufacturing the electrode assembly according to the fourth aspect. In this method of manufacturing an electrode assembly, the first active material layer non-formation region of the first electrode plate is formed around the bottom side and around both the left side and the right side, and the first electrode plate is formed. An active material non-forming side which is a left side and a right side where the first active material layer non-forming region is formed, and an active material non-forming side which is a side corresponding to the active material non-forming side in the electrode plate unit. Each of the corresponding sides is set as a second reference side. In the method for manufacturing an electrode assembly, the first reference plane and the two second reference planes corresponding to the second reference side of the first electrode plate and the second reference side of the electrode plate unit are formed. Use the containing unit. The accommodating unit is configured so that the first reference plane and one of the second reference planes are orthogonal to each other, the first reference plane is orthogonal to the other second reference plane, and the second reference planes are opposed to each other in the horizontal direction. The first reference planes are arranged in parallel with each other and are inclined at a predetermined angle with respect to the horizontal direction. Then, when the first electrode plate and the electrode plate unit are alternately dropped, the first reference side hits the first reference surface, and the second reference sides, that is, the left side and the right side, are the respective second reference sides. 2Drop it so as to hit the reference plane.

  A seventh aspect of the present invention is a method for manufacturing an electrode assembly according to any one of the fourth to sixth aspects. In this method of manufacturing an electrode assembly, after the first active material layer non-formation region in the first electrode plate is reinforced with a reinforcing material layer having a higher peel strength than the first active material layer, the first electrode plate is removed. Drop into the storage unit.

  In manufacturing the electrode assembly, for example, the first electrode plate and the second electrode plate covered with the separator may be dropped and stacked in an upright state. The dropped first electrode plate has its bottom edge and outer edges such as one side or both sides received by the surface of the dedicated housing unit. In the first invention of the present invention, instead of the first active material layer, a reinforcing material layer having a higher peel strength than the first active material layer is formed around the outer edge of the first electrode plate. Therefore, when the first electrode plate is received by the housing unit, the impact does not cause the negative electrode active material (coating material) to fall off from the periphery of the outer periphery of the electrode plate, and the reinforcing material layer is formed of the second material. Since the peel strength is higher than that of one active material, the reinforcing material (coating material) is prevented from being powdered from around the outer edge of the electrode plate. In addition, the reinforcing effect of the reinforcing material layer prevents the first electrode plate from being bent around the outer edge of the first electrode plate by an impact when received by the housing unit.

  In the second invention of the present invention, the reinforcing material layers are formed on both the front and back surfaces of the first metal plate. Therefore, the reinforcement around the outer edge of the first electrode plate is reinforced. This prevents the periphery of the outer edge of the first electrode plate from being bent when the electrode plate is received by the housing unit.

  According to the third aspect of the present invention, the reinforcing material layer is also formed on the end face of the first metal plate. Therefore, when the first electrode plate is received by the housing unit, the reinforcing material layer formed on the end face comes into contact with the housing unit, and the end face, and further around the outer edge corresponding to the end face, Shock is reduced. This prevents the periphery of the outer edge of the first electrode plate from being bent when the electrode plate is received by the housing unit.

  In the fourth aspect of the present invention, the dropped first electrode plate is received on the first reference surface of the housing unit by the bottom side. In the fourth aspect, since the periphery of the bottom of the first electrode plate is the region where the first active material layer is not formed, when the first electrode plate is received by the housing unit, the impact of the first electrode plate causes the bottom of the first electrode plate to fall. This prevents the first active material (coating material) from falling off from the surroundings.

  In the fifth invention of the present invention, the dropped first electrode plate is received on the first reference surface and the second reference surface of the housing unit by the bottom side and one side. In the fifth aspect, since the periphery of the bottom side and one side of the first electrode plate is a region where the first active material layer is not formed, when the first electrode plate is received by the housing unit, the impact may be generated. This prevents the first active material (coating material) from falling off from the periphery of the bottom side and one side of the electrode plate.

  In the sixth invention of the present invention, the dropped first electrode plate is received by the first reference surface and the second reference surface of the housing unit by the bottom side and both side sides. In the sixth aspect, since the first active material layer is not formed around the bottom and both sides of the first electrode plate, when the first electrode plate is received by the housing unit, the impact is caused by the impact. The first active material (coating material) is prevented from falling off from around the bottom and both sides of the electrode plate.

  According to the seventh aspect of the present invention, after the first active material layer non-formed region formed around the outer edge of the first electrode plate is reinforced with a reinforcing material layer having a higher peel strength than the first active material layer. Then, the first electrode plate is dropped on the housing unit. Since the peel strength of the reinforcing material layer is higher than that of the first active material layer, the reinforcing material (coating material) of the first electrode plate when received by the housing unit may fall off around the outer edge thereof. Is prevented. Moreover, the periphery of the outer periphery of the first electrode plate when received by the housing unit is prevented from being bent by the reinforcing effect of the reinforcing material layer.

FIG. 3 is a perspective view of the power storage device with a part broken. It is a perspective view of a negative electrode plate and a positive electrode plate unit. It is a perspective view of a negative electrode plate. FIG. 4 is a sectional view taken in the direction of arrows IV-IV in FIG. 2. It is the perspective view showing the positive electrode plate unit in the disassembled state. It is explanatory drawing showing the manufacturing process of the negative electrode plate. It is the perspective view showing the mode that the negative electrode plate and the positive electrode plate unit are laminated | stacked. FIG. 8 is a side view showing how the negative electrode plate and the positive electrode plate unit are stacked, as viewed from the direction of arrow VIII in FIG. 7. FIG. 9 is a front view showing how the negative electrode plate and the positive electrode plate unit are stacked, as viewed from the direction of arrow IX in FIG. 7. It is a front view of the negative electrode plate concerning a 2nd embodiment. It is a perspective view of the negative electrode plate concerning a 2nd embodiment. It is the perspective view showing signs that the negative electrode plate and the positive electrode plate unit concerning a 2nd embodiment are laminated. FIG. 13 is a side view of the storage unit according to the second embodiment when viewed from a direction XIII in FIG. 12. FIG. 14 is a front view illustrating a state in which the negative electrode plate and the positive electrode plate unit according to the second embodiment are stacked, as viewed from the XIV direction in FIG. It is sectional drawing showing the negative electrode plate which concerns on other embodiment corresponding to FIG. It is sectional drawing showing the negative electrode plate which concerns on other embodiment corresponding to FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS.

● [Overall configuration of power storage device 10 (FIGS. 1 and 2)]
As shown in FIG. 1, an electrode assembly 20 and an electrolyte (not shown) are housed inside a power storage device 10 that is a lithium ion secondary battery. The power storage device 10 supplies power to the outside during discharging and power from the outside during charging through the external connection terminals 14 and 16 penetrating the upper surface of the case 12.

  The electrode assembly 20 is formed by alternately stacking the negative electrode plate 30 (first electrode plate) and the positive electrode plate unit 60 (electrode plate unit) shown in FIG. In addition, the negative electrode plate 30 is arranged at both ends in the stacking direction of the electrode assembly 20.

● [Configuration of negative electrode plate 30 (FIGS. 2 to 4)]
The negative electrode plate 30 has a negative electrode metal plate 32 (first metal plate) as shown in FIGS. The negative electrode metal plate 32 has a substantially rectangular shape and is made of, for example, a metal foil such as a copper foil. The negative electrode plate 30 has a negative electrode tab portion 30T (first tab portion) protruding from an upper side 30a that is the first side of the negative electrode plate 30. The negative electrode tab portion 30T is a negative electrode active material layer non-formation region 36 described later. As shown in FIG. 1, the negative electrode tab portions 30T of each of the negative electrode plates 30 are united and directly or indirectly connected to one external connection terminal 16.

  A negative electrode active material layer 34 (first active material layer) is formed on a first surface 32A (see FIG. 4) of the negative electrode metal plate 32 and a second surface 32B opposite to the first surface 32A. . The negative electrode active material layer 34 is formed by applying a negative electrode active material such as carbon to the negative electrode metal plate 32. As shown in FIGS. 2 and 3, the negative electrode active material layer 34 is formed over substantially the entire center of the negative electrode metal plate 32. The area of the region where the negative electrode active material layer 34 is formed is larger than the area of the positive electrode active material layer 74 in the positive electrode plate 70 described later. The negative electrode active material layer 34 is formed in substantially the same region on the first surface 32A and the second surface 32B of the negative electrode metal plate 32.

  As shown in FIGS. 2 to 4, the periphery of each of the bottom side 30 b, the left side 30 c, and the right side 30 d of the negative electrode plate 30 has a negative electrode active material layer non-formed area 36 (a second area) where the negative electrode active material layer 34 is not formed. 1 active material layer non-forming region). In these negative electrode active material layer non-forming regions 36, a reinforcing material layer 38 is formed. The reinforcing material layer 38 is formed by applying a reinforcing material such as a ceramic to the negative electrode metal plate 32. The type of ceramic is alumina oxide, zirconia oxide, titanium oxide, or the like. The reinforcing material layer 38 has higher peel strength than the negative electrode active material layer 34. Further, the reinforcing material layer 38 reinforces the strength of the negative electrode active material layer non-formed region 36 in the negative electrode plate 30.

  The negative electrode active material layer 34 includes, for example, a binder obtained by mixing styrene-butadiene rubber (SBR) and sodium methylcellulose (CMC). The negative electrode active material layer 34 is bonded to the negative electrode metal plate 32 by the binder. The mass ratio of the binder in the negative electrode active material layer 34 (the ratio of the weight of the binder to the total weight of the negative electrode active material and the binder) is, for example, about 2%. When the binder (SBR and CMC) is included at this mass ratio, the peel strength of the negative electrode active material layer 34 is, for example, 0.12 N / cm. The type and mass ratio of the binder and the peel strength of the negative electrode active material layer 34 are not limited to those described above.

  The reinforcing material layer 38 includes, for example, a binder obtained by mixing polyvinyl alcohol (PVA) and styrene acrylic resin (AS resin). The reinforcing material layer 38 is bonded to the negative electrode metal plate 32 by the binder. The mass ratio of the binder in the reinforcing material layer 38 (the ratio of the weight of the binder to the total weight of the reinforcing material and the binder) is, for example, about 11%. When the binder (PVA and AS resin) is included at this mass ratio, the peel strength of the reinforcing material layer 38 is, for example, 1.6 N / cm. The type and mass ratio of the binder and the peel strength of the reinforcing material layer 38 are not limited to those described above.

  As shown in FIG. 4, the reinforcing material layer 38 is formed on both the first surface 32A and the second surface 32B of the negative electrode metal plate 32 and is formed up to a position beyond the end surface E of the negative electrode metal plate 32. ing. Also on the left side 30c and the right side 30d of the negative electrode plate 30, the reinforcing material layers 38 are formed on both the first surface 32A and the second surface 32B of the negative electrode metal plate 32, and the end surfaces of the negative electrode metal plate 32 It is formed up to the position beyond. The end surface is a surface that intersects the first surface A and the second surface A of the negative electrode metal plate 32 and that corresponds to the thickness of the negative electrode metal plate 32.

● [Configuration of positive electrode unit 60 (Figs. 2 and 5)]
As shown in FIGS. 2 and 5, the positive electrode plate unit 60 has a structure in which a positive electrode plate 70 (second electrode plate) and a separator 80 are integrated. The positive electrode plate 70 has a positive electrode metal plate 72 (second metal plate) as shown in FIG. The positive electrode metal plate 72 has a substantially rectangular shape slightly smaller than the negative electrode metal plate 32, and is made of, for example, a metal foil such as an aluminum foil. The positive electrode plate 70 has a positive electrode tab portion 70T (second tab portion) protruding from an upper side 70a which is a first side of the positive electrode plate 70. The positive electrode active material layer 74 described below is not formed on the positive electrode tab portion 70T.

  The positive electrode active material layer 74 (over the entire surface) of the first surface (the front surface side in FIG. 5) of the positive electrode metal plate 72 and the second surface (the rear surface side in FIG. 5) opposite to the first surface. (A second active material layer). The positive electrode active material layer 74 is formed by applying a positive electrode active material such as a lithium-containing metal oxide to the positive electrode metal plate 72.

  Both surfaces of the positive electrode plate 70 are covered with a separator 80 as shown in FIGS. As shown in FIG. 5, the separator 80 is folded in two, and is separated into a first separator 82 and a second separator 84 at the fold. Both the first separator 82 and the second separator 84 have a larger area than the positive electrode plate 70.

  The positive electrode plate 70 is sandwiched between a first separator 82 and a second separator 84, as shown in FIGS. That is, the first separator 82 covers the first surface of the positive electrode plate 70, and the second separator 84 covers the second surface of the positive electrode plate 70. The margins of the first separator 82 and the second separator 84 are welded to each other. Thus, the positive electrode plate 70 is integrated with the separator 80. In addition, the positive electrode tab portion 70T is exposed to the outside of the separator 80 from the opening 80a located at the fold of the separator 80. As shown in FIG. 1, the positive electrode tab portions 70 </ b> T of each positive electrode plate 70 are united and connected directly or indirectly to one external connection terminal 14.

  Note that the first separator 82 and the second separator 84 may be manufactured as individual separators, and the first surface and the second surface of the positive electrode plate 70 may be covered with the respective separators. Also in this case, by welding the margins of both separators to each other, a positive electrode plate unit in which the positive electrode plate 70 and the separator are integrated is formed.

  As described above, the positive electrode plate unit 60 has a configuration in which both surfaces of the positive electrode plate 70 are covered with the separators 80. Therefore, in the electrode assembly 20 shown in FIG. 1, the positive electrode plate 70 and the negative electrode plate 30 are alternately stacked with the separator 80 interposed therebetween. The outer dimensions of the positive electrode plate unit 60 are substantially the same as the outer dimensions of the negative electrode plate 30.

  As shown in FIGS. 2 and 5, the positive electrode plate 70 has an upper side 70a, a bottom side 70b facing the upper side 70a, and a left side 70c and a right side 70d as the remaining two sides. These sides 70a, 70b, 70c, 70d correspond to the top side 60a, bottom side 60b, left side 60c, and right side 60d of the positive electrode plate unit 60, respectively. Naturally, each side 60 a, 60 b, 60 c, 60 d of the positive electrode plate unit 60 is constituted by the separator 80.

Subsequently, a manufacturing process of the electrode assembly 20 of FIG. 1 will be described.
● [Manufacturing process of negative electrode plate 30 (FIG. 6)]
First, the manufacturing process of the negative electrode plate 30 will be described. In this manufacturing process, the long strip-shaped negative electrode metal plate 32 is continuously unwound from the roll body 130.

  In the active material coating step S1, the negative electrode active material is coated on both surfaces of the unwound negative metal plate 32. In this coating, two active material coating rolls 304 are used. The amphoteric material coating rolls 304 are arranged to face each other across the negative electrode metal plate 32. Then, the both active material coating rolls 304 rotate while being in contact with the respective surfaces of the negative electrode metal plate 32.

  When the amphoteric material coating roll 304 rotates, the negative electrode active material containing the binder (for example, SBR and CMC) described above is applied to each peripheral surface in a substantially rectangular shape at predetermined intervals in the circumferential direction. Has become. Then, the applied negative electrode active material is applied (transferred) to the negative electrode metal plate 32 in accordance with the rotation of each active material application roll 304. Thus, the negative electrode active material layers 34 are formed on both surfaces of the negative electrode metal plate 32 in a substantially rectangular shape at predetermined intervals.

  At the stage when the active material coating step S1 has been completed, the four sides of each of the negative electrode active material layers 34 are all the negative electrode active material layer non-formed regions 36. The negative electrode active material layer non-forming region 36 between the adjacent negative electrode active material layers 34 is a negative electrode active material layer non-forming region corresponding to the periphery of both sides 30c and 30d of the negative electrode plate 30 formed in the final cutting step S4 described later. 36. The negative electrode active material layer non-formation regions 36 located on both sides in the width direction of the negative electrode metal plate 32 correspond to the negative electrode active material layer non-formation regions 36 where the negative electrode tab portions 30T are formed and the bottom 30b of the negative electrode plate 30. This is the region 36 where the negative electrode active material layer is not formed.

  After the active material coating step S1, a reinforcing material coating step S2 is performed. In the reinforcing material applying step S2, two reinforcing material applying rolls 308 are used. The two reinforcing material coating rolls 308 are arranged to face each other across the negative electrode metal plate 32. Then, both reinforcing substance coating rolls 308 rotate while being in contact with the respective surfaces of the negative electrode metal plate 32.

  When the two reinforcing material coating rolls 308 rotate, the reinforcing material containing the binder (for example, PVA and AS resin) described above is continuously applied in a predetermined shape to the respective peripheral surfaces in the circumferential direction. I have. Then, the applied reinforcing substance is applied (transferred) to the negative electrode metal plate 32 in accordance with the rotation of each reinforcing substance applying roll 308. More specifically, the reinforcing material is applied (transferred) to the negative electrode active material layer non-formation region 36 (see FIG. 3) corresponding to the bottom 30b and both sides 30c, 30d of the negative electrode plate 30 formed in the final cutting step S4. You. Thereby, the reinforcing material layer 38 is formed in the negative electrode active material layer non-formed region 36 around the bottom 30b and both sides 30c, 30d of the negative electrode plate 30.

  After the reinforcing material application step S2, a tab forming step S3 is performed. In the tab forming step S3, the negative electrode active material layer non-formation region 36 located outside the upper side 30a of the negative electrode plate 30 formed in the final cutting step S4 is cut into a substantially rectangular shape by a cutter device (not shown). As a result, a negative electrode tab portion 30T protruding in a substantially rectangular shape from the upper side 30a is formed.

  Thereafter, a final cutting step S4 is performed. In the final cutting step S4, the negative electrode metal plate 32 is cut between adjacent negative electrode active material layers 34 by a cutter device (not shown). Thus, a substantially rectangular negative electrode plate 30 (see FIG. 3) is manufactured. As described above, the negative electrode plate 30 is not formed around the bottom 30b, the left side 30c, and the right side 30d, not the negative electrode active material layer 34, but the reinforcing material layer 38 having a higher peel strength than the negative electrode active material layer 34. Having.

● [Manufacturing process of positive electrode plate unit 60 (FIG. 5)]
In a step different from the production of the negative electrode plate 30, the positive electrode plate unit 60 is produced as follows. First, in the same steps as the active material coating step S1, the tab forming step S3, and the final cutting step S4 in the manufacturing process of the negative electrode plate 30, the positive electrode active material layers 74 are formed on both surfaces of the substantially rectangular positive metal plate 72. The positive electrode plate 70 (see FIG. 5) on which is formed is manufactured. Thereafter, in a separation wrapping step, the positive electrode plate 70 is sandwiched between, for example, two-folded separators 80, and the entire area of both surfaces of the positive electrode plate 70 is covered with the first separator 82 having a larger area than the positive electrode metal plate 72. And the second separator 84. Thereafter, in a welding step, the blank portions of the first separator 82 and the second separator 84 are welded to each other to form the positive electrode plate unit 60 in which the positive electrode plate 70 and the separator 80 are integrated. Note that the positive electrode tab portion 70T is exposed to the outside of the separator 80 from the opening 80a of the separator 80.

● [Lamination process of negative electrode plate 30 and positive electrode plate unit 60 (FIGS. 7 to 9)]
The electrode assembly 20 shown in FIG. 1 is manufactured by alternately stacking the negative electrode plates 30 and the positive electrode plate units 60. In the laminating step, the bottom sides 30b, 60b of the negative electrode plate 30 and the positive electrode plate unit 60 are set to the first reference side F1, as shown in FIG. Also, the active material non-forming side, which is the left side 30c and the right side 30d of the negative electrode plate 30 and the side on which the negative electrode active material layer non-forming region 36 (see FIG. 3) is formed, is a second reference side F2. Is set to In the positive electrode plate unit 60, the left side 60c and the right side 60d, which are sides corresponding to the active material non-formed side of the negative electrode plate 30, are respectively set to the second reference side F2.

  In the lamination of the negative electrode plate 30 and the positive electrode plate unit 60, as shown in FIG. 7, an accommodation unit 200 is used. The storage unit 200 is configured in a box shape. More specifically, the housing unit 200 includes a substantially rectangular bottom surface 200a (first reference surface), a front surface 200b, a rear surface 200c, and a left side surface 200d (second reference surface) rising from the bottom surface 200a in a direction orthogonal to the bottom surface 200a. Surface) and a right side surface 200e (second reference surface).

  As will be described later in detail, the bottom surface 200a as the first reference surface is a surface that receives the first reference side F1 of the negative electrode plate 30 and the positive electrode plate unit 60. The left side surface 200d and the right side surface 200e, which are the second reference surfaces, are surfaces that receive the second reference side F2 of the negative electrode plate 30 and the positive electrode plate unit 60, respectively.

  As shown in FIGS. 7 and 8, the accommodation unit 200 is arranged such that the rear surface 200c is lifted up with respect to the front surface 200b. That is, the housing unit 200 is arranged such that the bottom surface 200a is inclined at the predetermined angle θ1 with respect to the horizontal plane W. The left side face 200d and the right side face 200e face in the horizontal direction. Note that the left side surface 200d and the right side surface 200e have guide plates G that are continuous along the respective upper edges. The guide plate G is inclined with respect to each of the side surfaces 200d and 200e so as to open outward from the housing unit 200. The guide plate G functions to guide the negative electrode plate 30 and the positive electrode plate unit 60 that are dropped into the housing unit 200.

  The negative electrode plate 30 and the positive electrode plate unit 60 are alternately dropped into the accommodation unit 200 described above. As shown in FIGS. 7 to 9, the negative electrode plate 30 and the positive electrode plate unit 60 are dropped with their respective bases 30 b and 60 b facing downward.

  The drop of the negative electrode plate 30 and the positive electrode plate unit 60 will be described in detail. In the negative electrode plate 30 and the positive electrode plate unit 60, the respective bottom sides 30b and 60b correspond to the bottom surface 200a of the housing unit 200, the respective left sides 30c and 60c correspond to the left side surface 200d of the housing unit 200, and the respective right sides 30d and 60d. The storage unit 200 is dropped onto the storage unit 200 so as to hit the right side surface 200e of the storage unit 200.

  As shown in FIGS. 8 and 9, the negative electrode plate 30 and the positive electrode plate unit 60 dropped into the housing unit 200 have the bottom sides 30b and 60b, the left sides 30c and 60c, and the right sides 30d and 60d. Are received by the corresponding surfaces 200a, 200d, and 200e, and are positioned in an upright state in the storage unit 200. Then, the negative electrode plate 30 and the positive electrode plate unit 60 move toward the front surface 200b while standing up, and are sequentially stacked on the front surface 200b. The lamination of the negative electrode plate 30 and the positive electrode plate unit 60 starts at the negative electrode plate 30 and ends at the negative electrode plate 30.

  In the positive electrode plate unit 60, since the positive electrode plate 70 is covered with the separator 80, when the positive electrode plate unit 60 is received by the housing unit 200, the bottom side 70b of the positive electrode plate 70 (see FIGS. ), Powder of the positive electrode active material from around the left side 70c and the right side 70d is prevented. Further, since the positive electrode plate 70 is received by the housing unit 200 via the separator 80, it is possible to prevent the bottom plate 70b, the left side 70c, and the right side 70d of the positive electrode plate 70 from being bent by an impact when received. Is done.

  The negative electrode plate 30 is not covered with the separator. However, the periphery of the bottom side 30b, the left side 30c, and the right side 30d of the negative electrode plate 30 is a negative electrode active material layer non-formed region 36 (see FIG. 3). Therefore, when the bottom side 30b, the left side 30c, and the right side 30d are received by the corresponding surfaces 200a, 200d, 200e of the corresponding housing unit 200, the negative electrode plate 30 receives the bottom 30b, the left side 30c, Also, the powder of the negative electrode active material (coating material) from around the right side 30d is prevented. The reinforcing material layer 38 formed around the bottom side 30b, the left side 30c, and the right side 30d of the negative electrode plate 30 which is the negative electrode active material layer non-formed region 36 has higher peel strength than the negative electrode active material layer 34. Therefore, when the bottom side 30b, the left side 30c, and the right side 30d of the negative electrode plate 30 are received by the housing unit 200, the impact causes the reinforcing substance (coating material) from around the bottom side 30b, the left side 30c, and the right side 30d. ) Is prevented from falling off. In addition, the reinforcing effect of the reinforcing material layer 38 prevents the negative electrode plate 30 from being bent around the bottom 30b, the left side 30c, and the right side 30d of the negative electrode plate 30 due to the impact when received by the housing unit 200. Is done.

  The reinforcing material layer 38 is formed on both front and back surfaces of the negative electrode metal plate 32 as shown in FIG. Therefore, reinforcement around the bottom side 30b and both sides 30c and 30d of the negative electrode plate 30 is reinforced. Thereby, the periphery of the bottom side 30 b and both sides 30 c and 30 d of the negative electrode plate 30 is further prevented from being bent when received by the housing unit 200.

  Further, the reinforcing material layer 38 is formed on the bottom side 30 b and both sides 30 c and 30 d of the negative electrode plate 30 to a position beyond the end face of the negative electrode metal plate 32. Therefore, when the negative electrode plate 30 is received by the housing unit 200, the reinforcing material layer 38 formed at a position beyond the end face on each side 30b, 30c, 30d has the respective surfaces 200a, 200d, 200e of the housing unit 200. , And the impact on the end faces corresponding to the sides 30b, 30c, 30d and further around the end faces is reduced. Thereby, the periphery of the bottom side 30 b and both sides 30 c and 30 d of the negative electrode plate 30 is further prevented from being bent when received by the housing unit 200.

  Subsequently, a second embodiment of the present invention will be described mainly with reference to FIGS. In the following, only the parts different from the first embodiment will be described. In FIGS. 10 to 14, portions having the same or equivalent configurations and functions as those in FIGS. 1 to 9 are denoted by the same reference numerals, and redundant description will be omitted.

  As shown in FIGS. 10 and 11, in the negative electrode plate 31, a negative electrode active material layer non-forming region 36 is formed around the bottom 30b and the right side 30d. A reinforcing material layer 38 is formed.

  As shown in FIG. 12, in the step of laminating the negative electrode plate 31 and the positive electrode plate unit 60, the bottom sides 30b and 60b of the negative electrode plate 31 and the positive electrode plate unit 60 are respectively set to the first reference side F1. The active material non-forming side, which is the right side 30d of the negative electrode plate 31 and the side where the negative electrode active material layer non-forming region 36 (see FIG. 11) is formed, is set to the second reference side F2. In the positive electrode plate unit 60, the right side 60d, which is the side corresponding to the active material non-forming side of the negative electrode plate 31 corresponding to the active material non-forming side, is set to the second reference side F2.

  When stacking the negative electrode plate 31 and the positive electrode plate unit 60, a housing unit 220 shown in FIGS. The storage unit 220 has a first rectangular receiving surface 220a (first reference surface) and a second rectangular receiving surface 220b (second reference surface), which are orthogonal to each other, and is provided on both sides of both receiving surfaces 220a and 220b. It has a triangular first closing surface 220c and a second closing surface 220d that respectively close the formed V-shaped ends.

  As will be described in detail later, the first receiving surface 220a, which is the first reference surface, is a surface that receives the first reference side F1 of the negative electrode plate 31 and the positive electrode plate unit 60. The second receiving surface 220b, which is the second reference surface, is a surface that receives the second reference side F2 of the negative electrode plate 31 and the positive electrode plate unit 60.

  The accommodation unit 220 is arranged such that the first receiving surface 220a and the second receiving surface 220b open upward from each other, and both the receiving surfaces 220c and 220d are visible from above. Further, the housing unit 220 is arranged such that the second closing surface 220d is lifted with respect to the first closing surface 220c. Therefore, the boundary 220k between the first receiving surface 220a and the second receiving surface 220b is inclined at a predetermined angle θ2 with respect to the horizontal plane W.

  The negative electrode plate 31 and the positive electrode plate unit 60 are alternately dropped onto the housing unit 220. As shown in FIGS. 12 and 14, the negative electrode plate 31 and the positive electrode plate unit 60 are dropped with their bottom sides 30b, 60b and right sides 30d, 60d facing downward. In the inclined standing state, the vertices of the bottom sides 30b, 60b and the right sides 30d, 60d of the negative electrode plate 31 and the positive electrode plate unit 60 are located at the lowermost end.

  The drop of the negative electrode plate 31 and the positive electrode plate unit 60 will be described in detail. The negative electrode plate 31 and the positive electrode plate unit 60 are accommodated such that the bottom sides 30b and 60b correspond to the first receiving surface 220a of the accommodation unit 220, and the right sides 30d and 60d correspond to the second receiving surface 220b of the accommodation unit 220. The unit 220 is dropped.

  As shown in FIGS. 12 and 14, the negative electrode plate 31 and the positive electrode plate unit 60 dropped into the housing unit 220 have their respective bottom sides 30b, 60b and right sides 30d, 60d corresponding to the corresponding surfaces 220a, It is received at 220b and positioned in the inclined upright state in the storage unit 220. Then, the negative electrode plate 31 and the positive electrode plate unit 60 move toward the first closing surface 220c while being tilted upright, and are sequentially stacked on the first closing surface 220c. The lamination of the negative electrode plate 31 and the positive electrode plate unit 60 starts at the negative electrode plate 31 and ends at the negative electrode plate 31.

  The negative electrode plate 31 is not covered with the separator. However, the periphery of the bottom side 30b and the right side 30d of the negative electrode plate 31 is a negative electrode active material layer non-formed region 36 (see FIG. 11). Therefore, when the bottom 30b and the right side 30d are received by the corresponding surfaces 220a and 220b of the corresponding housing unit 220, the negative electrode plate 31 receives the negative electrode active material (coating) from the periphery of the bottom 30b and the right side 30d by the impact. Powder) is prevented from falling off. The reinforcing material layer 38 formed around the bottom side 30 b and the right side 30 d of the negative electrode plate 31, which is the negative electrode active material layer non-formation region 36, has higher peel strength than the negative electrode active material layer 34. Therefore, when the bottom 30b and the right side 30d of the negative electrode plate 31 are received by the housing unit 220, the impact prevents the reinforcing substance (coating substance) from falling around the bottom 30b and the right side 30d. . In addition, the reinforcing effect of the reinforcing material layer 38 prevents the negative electrode plate 31 from being bent around the bottom side 30b and the right side 30d of the negative electrode plate 31 due to the impact when the negative electrode plate 31 is received by the housing unit 220.

  Note that the negative electrode active material layer non-formed region may be formed around the left side instead of the right side of the negative electrode plate, and the reinforcing material layer may be formed around the left side. In this case, the bottom side of the negative electrode plate is set as the first reference side, and the left side of the negative electrode plate is set as the second reference side. Further, the left side of the positive electrode plate unit is set as the second reference side in correspondence with the negative electrode plate. Then, the negative electrode plate and the positive electrode plate unit are dropped in an inverted inclined upright state in which the bottom side and the left side face downward, that is, the state in which the apex of each bottom side and the left side is located at the lowermost end. The housing unit 220 (see FIGS. 12 to 14) has a first reference side of the negative electrode plate and the positive electrode plate unit as the second receiving surface 220 b (first reference surface), and a second reference side as the first receiving surface 220 a (second reference surface). On the reference plane).

  Although two embodiments for carrying out the present invention have been described above with reference to the drawings, the present invention can be implemented in other embodiments. The reinforcing material layer 38 may be formed on the end face E of the negative electrode metal plate 32 so as to be continuous from the first surface 32A and the second surface 32B of the negative electrode metal plate 32, as shown in FIG. In the example shown in FIG. 15, the reinforcing material layer 38 is formed on the end surface E of the negative electrode metal plate 32 corresponding to the bottom side 30 b of the negative electrode plate 30, but naturally corresponds to the left side 32 c and the right side 32 d of the negative electrode plate 30. The reinforcing material layer 38 may be formed on the end surface of the negative electrode metal plate 32. In FIG. 15, portions having the same or equivalent configurations and functions as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

  If the reinforcing material layer 38 is formed on the end face of the negative electrode metal plate 32, when the negative electrode plate 30 is received by the housing unit 200, the reinforcing material layer 38 formed on the end face comes into contact with the housing unit 200. Thus, the impact on the end face and the periphery of the side corresponding to the end face is reduced. Accordingly, the periphery of the side corresponding to the end face on which the reinforcing material layer 38 is formed is prevented from being bent when received by the housing unit 200.

  The reinforcing material layer 38 may be formed on only one surface of the negative electrode metal plate 32 as shown in FIG. Further, the reinforcing material layer 38 may be formed so as to be continuous from one surface of the negative electrode metal plate 32 to the end surface. Further, as shown in FIG. 16, the thickness H2 of the reinforcing material layer 38 may be formed larger than the thickness H1 of the negative electrode active material layer 34. The same applies to the left side 30c and the right side 30d of the negative electrode plate 30. Note that in FIG. 16, portions having the same or equivalent configurations and functions as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

  In the above embodiment, the negative electrode plate is described as the first electrode plate and the positive electrode plate is described as the second electrode plate. However, the positive electrode plate may be replaced with the first electrode plate, and the negative electrode plate may be replaced with the second electrode plate. In this case, the positive electrode metal plate becomes the first metal plate, the positive electrode tab portion becomes the first tab portion, and the positive electrode active material layer becomes the first active material layer. Then, a positive electrode active material layer non-forming region (a first active material layer non-forming region) in which the positive electrode active material layer is not formed around the bottom and both sides of the positive electrode plate, or around the bottom and one side. The reinforcing material layer is formed in the region where the positive electrode active material layer is not formed. In the negative electrode plate, the negative electrode plate metal plate becomes the second metal plate, the negative electrode tab portion becomes the second tab portion, and the negative electrode active material layer becomes the second active material layer. Then, both surfaces of the negative electrode plate are covered with a separator having an area larger than that of the negative electrode plate to form a negative electrode plate unit (electrode plate unit) in which the negative electrode plate and the separator are integrated.

Reference Signs List 10 power storage device 12 case 20 electrode assembly 30, 31 negative electrode plate (first electrode plate)
30T negative electrode tab (first tab)
30a Top side 30b Bottom side 30c Left side (active material non-formed side)
30d right side (active material non-formed side)
32 Negative electrode metal plate (first metal plate)
32A first surface 32B second surface 34 Negative electrode active material layer (first active material layer)
36 Negative electrode active material layer non-formed area (first active material layer non-formed area)
38 Reinforcement material layer 60 Positive electrode plate unit (electrode plate unit)
60a Top side 60b Bottom side 60c Left side (side corresponding to non-active material forming side)
60d Right side (side corresponding to the side where no active material is formed)
70 Positive electrode plate (second electrode plate)
70T positive electrode tab (second tab)
72 Positive metal plate (second metal plate)
74 Positive electrode active material layer (second active material layer)
80 Separator 200, 220 Housing unit 200a Bottom surface (first reference surface)
200d left side surface (second reference plane)
200e Right side (second reference plane)
220a First receiving surface (first reference surface)
220b Second receiving surface (second reference surface)
220k Boundary line E End face F1 First reference side F2 Second reference side W Horizontal plane θ1, θ2 Predetermined angle

Claims (3)

A method for manufacturing an electrode assembly in which first electrode plates and second electrode plates are alternately stacked with a separator interposed therebetween,
In the first electrode plate having a first active material layer formed on a substantially rectangular first metal plate and having a first tab portion protruding from an upper side which is a substantially rectangular first side, a bottom side opposed to the upper side Forming a first active material layer non-forming region where the first active material layer is not formed around at least one of the remaining left side and right side; The formation region is reinforced with a reinforcing material layer having a higher peel strength than the first active material layer,
A second active material layer having a different polarity from the first active material layer is formed on a substantially rectangular second metal plate, and the second metal plate has a second tab portion protruding from an upper side which is a first side of the substantially rectangular shape. A first surface of the two-electrode plate and a second surface opposite to the first surface are respectively covered with the separator having an area larger than the second metal plate, and an area larger than the second metal plate is provided. In the separator that covers the first surface and the separator that covers the second surface, a bottom portion facing the upper side, and a blank portion protruding from the second metal plate at the remaining left side and right side. Are welded to each other to form an electrode plate unit in which the second electrode plate and the separator are integrated,
Setting each of the bottom side of the first electrode plate and a bottom side facing the top side of the electrode plate unit as a first reference side;
Using a housing unit having a first reference surface that is a surface corresponding to the first reference side of the first electrode plate and the first reference side of the electrode plate unit;
The first electrode plate and the electrode plate unit are alternately dropped into the housing unit so that the first reference side hits the first reference surface, and the first electrode plate and the electrode plate unit are dropped. Are positioned alternately and positioned,
A method for manufacturing an electrode assembly. It is a manufacturing method of the electrode assembly of Claim 1, Comprising:
Forming the first active material layer non-forming region in the first electrode plate around the bottom and around one of the left side or the right side;
An active material non-forming side, which is one of the left side and the right side of the first electrode plate and is a side on which the first active material layer non-forming region is formed, and the electrode plate unit Setting each of the sides corresponding to the active material non-forming side corresponding to the active material non-forming side as a second reference side,
Using the housing unit having the first reference surface, and a second reference surface that is a surface corresponding to the second reference side of the first electrode plate and the second reference side of the electrode plate unit,
The first reference plane and the second reference plane are orthogonal to each other, and a boundary line at which the first reference plane and the second reference plane intersect is inclined at a predetermined angle with respect to a horizontal direction; Arranged so that both the reference plane and the second reference plane can be seen from above,
When the first electrode plate and the electrode plate unit are alternately dropped, the first reference side falls on the first reference plane and the second reference side falls on the second reference plane. Let
A method for manufacturing an electrode assembly. It is a manufacturing method of the electrode assembly of Claim 1, Comprising:
Forming the first active material layer non-formation region in the first electrode plate around the bottom and around both the left side and the right side;
An active material non-forming side which is the left side and the right side of the first electrode plate and on which the first active material layer non-forming region is formed, and the active material non-forming side in the electrode plate unit Each of the sides corresponding to the active material non-formation side, which are sides corresponding to, is set as a second reference side,
The housing unit having the first reference plane and two second reference planes corresponding to the second reference side of the first electrode plate and the second reference side of the electrode plate unit is used. ,
The first reference plane is orthogonal to one of the second reference planes, the first reference plane is orthogonal to the other second reference plane, and the second reference planes are opposed to each other in a horizontal direction. Are arranged in parallel with each other, and the first reference plane is arranged to be inclined at a predetermined angle with respect to the horizontal direction,
When the first electrode plate and the electrode plate unit are alternately dropped, the first reference side hits the first reference surface, and the second reference side is the left side and the right side. Dropped so that the sides hit the respective second reference planes,
A method for manufacturing an electrode assembly.

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