JP2016167416A - Separator housing type electrode body of power storage device, electrode assembly of power storage device, and manufacturing apparatus of power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate bending of a melted portion by providing a soft region becoming a fold of the melted portion, at each melted portion between respective electrode plates in a separator covering a plurality of electrode plates (positive electrode plates or negative electrode plates).SOLUTION: A positive electrode assembly 30 has a plurality of positive electrode plates 80, and a separator 40 covering the plurality of electrode plates. The separator has a first separator 50 covering the first surface of the plurality of positive electrode plates arranged in one row at predetermined intervals, a second separator 60 covering the second surface, and a melted portion 70 extending between the adjacent positive electrode plates, and where the first separator and second separator are melted. The melted portion has a pair of welded regions F1 extending between the adjacent positive electrode plates, and where the first separator and second separator are welded, and a molten region F2 where the first separator and second separator are melted between the pair of welded regions, but the melting amount is smaller than that in the welded region and softer than the welded region.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a separator-housing electrode body in which one of a positive electrode and a negative electrode used in a power storage device is housed in a separator, and an electrode constituted by the separator-housing electrode body and the other electrode plate of the positive electrode or the negative electrode The present invention relates to an assembly and an apparatus for manufacturing a power storage device.

  Applications of power storage devices are diverse, and in recent years, especially secondary batteries are installed in portable electronic devices such as digital cameras, and in recent years, electric vehicles such as electric vehicles, and function as a power supply source for these. To do. In the secondary battery disclosed in Patent Document 1, a plurality of positive plates and negative plates are alternately stacked via thin film separators. In this secondary battery, a positive electrode plate and a negative electrode plate are laminated in the next step. First, a plurality of positive electrode plates are arranged in a row and covered with separators from the upper and lower surfaces, and the upper and lower separators are thermally melted and welded between the positive electrode plates. The separator is then folded between adjacent positive plates, and the negative plates are sandwiched between individual folded portions.

JP-A-7-57716

  At the time of the above-described zigzag folding, the welded portion between the positive plates is folded. In general, since the welded portion is hard, folding the welded portion requires a work of making a crease in advance with a guide member or the like, which is troublesome.

  Then, the subject of this invention is providing the soft area | region which becomes the crease | fold of this fusion | melting part in the fusion | melting part between each electrode plate in the separator which covers several electrode plates (positive electrode plate or negative electrode plate), and bend | folds this fusion | melting part. To make it easier.

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

  1st invention of this invention is the separator accommodation type electrode body of an electrical storage apparatus. This separator accommodation type electrode body has a plurality of electrode plates which consist of one of a positive electrode or a negative electrode, and a separator which covers these electrode plates. The separator includes a first separator that covers the first surfaces of the plurality of electrode plates arranged in a line at a predetermined interval, and a second separator that covers the second surface opposite to the first surfaces of the plurality of electrode plates; , And a melted portion that extends between adjacent electrode plates and in which the first separator and the second separator are melted. The fusion part extends along between the adjacent electrode plates, and the first separator and the second separator are melted between the pair of welded areas where the first separator and the second separator are welded. However, it has a small melting region having a smaller melting amount than the welding region.

  In the separator-accommodating electrode body according to the first aspect of the present invention, in the melted portion between the electrode plates, a small melt area having a smaller melt amount than the weld areas is provided between the pair of weld areas. The small melting region is softer than the welding region because the melting amount is small. Therefore, for example, when the separator-housing electrode body is folded in a zigzag manner across each electrode plate, each melting portion can be easily folded using this soft small melting region as a fold. Therefore, in the separator housing type electrode body, it is not necessary to make a crease in advance by a guide member or the like when the separator is folded, and the folding work is made smooth.

  According to a second aspect of the present invention, there is provided a separator-housing electrode body for a power storage device according to the first aspect, wherein the first separator has a thickness of the first separator other than the melting portion. The second separator has a second separator thickness at a portion other than the melting portion. The weld region has a first melt thickness that is thinner than the sum of the first separator thickness and the second separator thickness. The small melt region has a second melt thickness that is greater than the first melt thickness.

  In the separator-housing electrode body according to the second aspect of the invention, the small melting region is thicker than the welding region. For example, at the time of melting, the amount of heating in the welding region is increased, and the amount of heating in the small melting region is decreased with respect to the welding region, whereby the welding region and the small melting region can be appropriately formed.

  According to a third aspect of the present invention, there is provided the separator-housing electrode body of the power storage device according to the first or second aspect, wherein the welding region and the low melting region are adjacent to each other in the adjacent electrode plates. It extends along the entire length of the first side that is the side facing the mating electrode plate.

  In the separator-housing electrode body according to the third aspect of the invention, the welding region and the low melting region extend along the entire length of the first side that is the side facing the adjacent electrode plate in the electrode plate, For example, when the separator-housing electrode body is folded in a zigzag manner between the electrode plates, the small melting region can be easily and reliably folded along the first side of the electrode plates. Thereby, for example, when the electrode plate constituting the separator-housing electrode body is a positive electrode plate, the stacking misalignment between the positive electrode plates due to the melting portion being inclined and bent with respect to the first side of the positive electrode plate is prevented. The Further, for example, when the negative electrode plate is sandwiched between the positive electrode plates with respect to the separator-accommodating electrode body folded in a zigzag state, if the negative electrode plate is rectangular, the negative electrode plate is bent at a position between the positive electrode plates. By inserting one small melting region and positioning one side along the small melting region, the positioned one side of the negative electrode plate is arranged parallel to the first side of the positive electrode plate along the small melting region. As a result, the positive electrode plate and the negative electrode plate are prevented from being obliquely displaced and stacked.

  According to a fourth aspect of the present invention, there is provided an electrode assembly for a power storage device including the separator-housing electrode body for the power storage device according to any one of the first to third aspects. In this electrode assembly, each of the small melting regions in the separator-accommodating electrode body is alternately folded and folded, and the separator-accommodating electrode body is formed in a zigzag folded state, and each electrode plate is opposed to each other. The other electrode plate of the positive electrode or the negative electrode is sandwiched between the gaps.

  In the electrode assembly according to the fourth aspect of the present invention, the other electrode plate of the positive electrode or the negative electrode is sandwiched between the gaps facing each electrode plate with respect to the separator-housing electrode body folded in a zigzag folded state. Therefore, a plurality of positive plates and negative plates are alternately laminated in order, and a current can flow efficiently.

  According to a fifth aspect of the present invention, there is provided a power storage device manufacturing apparatus for forming a melting portion in the separator-housing electrode body of the power storage device according to the first aspect. The manufacturing apparatus includes a first melting tool pressed from the first separator side and a second melting tool pressed from the second separator side, and the heated first melting tool and second melting tool. A melting part is formed by sandwiching the separator with the tool. And the surface pressed against the 1st separator in a 1st melting tool is a pair of welding part formation surfaces which extend along between a pair of adjacent electrode plates in order to form a pair of welding region, and a small melting region. And a small melted portion forming concave portion extending between adjacent electrode plates and recessed with respect to the welded portion forming surface.

  In the manufacturing apparatus according to the fifth aspect of the present invention, a pair of welding regions are formed between adjacent electrode plates by the welding portion forming surface of the first melting tool by pressing the first melting tool and the second melting tool against the separator in a heated state. Since the small melting region can be formed between the pair of welded portion forming surfaces by the small melted portion forming concave portion, the manufacturing region can surely form the welded region and the small melted region.

  A sixth invention of the present invention is the power storage device manufacturing apparatus according to the fifth invention. In this manufacturing apparatus, the shape of the first melting tool and the shape of the second melting tool are columnar, and the axis of the columnar first melting tool and the second melting tool is parallel to the direction along the adjacent electrode plates. It is set to be. And the welding part formation surface and the small fusion part formation recessed part are provided in the outer peripheral surface of the 1st melting tool.

  In the manufacturing apparatus of the sixth invention, the first melting tool and the second melting tool are formed in a columnar shape, and the axes of the two melting tools are arranged in parallel in the direction between the adjacent electrode plates, and Since the welded portion forming surface and the small melted portion forming concave portion are provided on the outer peripheral surface of the first melting tool, both the melting tools are attached to the separator that is continuously conveyed while both the melting tools are heated. By rotating while pressing each other, a welding region and a small melting region can be sequentially formed in the separator.

  A seventh invention of the present invention is the power storage device manufacturing apparatus according to the fifth invention. In the manufacturing apparatus, the electrode plate has a rectangular shape, and the weld portion forming surface has a flat shape. And the 1st fusion tool is along the full length of the 1st side which is the side which counters the adjacent electrode plate in an electrode plate, and the 1st side part in which the welding part formation surface and the small fusion part formation recessed part were formed, A second side welded portion formed so as to be along the entire length of the second side which is one side orthogonal to the first side of the electrode plate from one end of the first side and to be flush with the welded portion forming surface. The second side portion on which the formation surface is formed, and the entire length of the third side, which is the other side orthogonal to the first side of the electrode plate, from the other end of the first side portion and the same plane as the weld portion formation surface And a third side part formed with a third side part welded part forming surface, and has a substantially U-shaped shape.

  In the manufacturing apparatus according to the seventh aspect of the invention, the first melting tool is a first side part having a weld part forming surface and a small melt part forming concave part, and one side perpendicular to the first side of the electrode plate. A second side having a second side welded portion forming surface along two sides and a third side welded portion forming surface along the third side which is the other side orthogonal to the first side of the electrode plate. If the first melter is pressed against the separator in a heated state, the second electrode plate is formed in parallel with the formation of the welded region and the small melt region between the adjacent electrode plates. The part along the side and the third side can be melted, and the melting operation of the separator can be made efficient.

It is an external appearance perspective view showing the electrode assembly accommodated in the electrical storage apparatus. It is sectional drawing showing the electrode assembly. It is sectional drawing which represented the electrode assembly in the decomposition | disassembly state. It is the front view represented in the state which expanded the positive electrode assembly. It is sectional drawing of the VV arrow direction of FIG. It is explanatory drawing showing the manufacturing process of the electrode assembly. It is a perspective view showing a melting tool. It is sectional drawing showing the use condition of the melting tool of FIG. It is sectional drawing which expanded and represented the part of the virtual line IX of FIG. It is a perspective view showing the fusion tool concerning other embodiments. It is sectional drawing showing the use condition of the melting tool of FIG. It is sectional drawing showing the modification of the small fusion part formation recessed part in a melting tool. It is sectional drawing showing the modification of the small fusion part formation recessed part in a melting tool.

● [Entire configuration of power storage device 10 (FIG. 1)]
Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present embodiment, the power storage device 10 is a lithium ion secondary battery. An electrode assembly 20 and an electrolytic solution (not shown) are accommodated inside the power storage device 10 that is a lithium ion secondary battery. The power storage device 10 supplies power to the outside at the time of discharging through the external connection terminals 14 and 16 penetrating the upper surface of the case 12, and power is supplied from the outside at the time of charging.

● [Schematic configuration of electrode assembly 20 (FIGS. 1 to 3)]
In power storage device 10 that is a lithium ion secondary battery, the separator-housing electrode body is positive electrode assembly 30 that includes a positive electrode. The electrode assembly 20 includes a positive electrode assembly 30 and a negative electrode plate 90. As shown in FIG. 3, the positive electrode assembly 30 includes a plurality of positive electrode plates 80 and separators 40. Specifically, the plurality of positive electrode plates 80 are covered with the separators 40 from both sides, and The plurality of positive electrode plates 80 are connected to each other by the separator 40. The positive electrode assembly 30 is folded between adjacent positive electrode plates 80, and the negative electrode plate 90 is sandwiched between the individual folded portions. Thus, as shown in FIG. 2, the electrode assembly 20 forms a laminated structure in which a plurality of (for example, about 50 or more) positive electrode plates 80 and negative electrode plates 90 are laminated to face each other with the separator 40 interposed therebetween. doing. The positive electrode assembly 30 will be described in detail later.

  As shown in FIGS. 2 and 3, the positive electrode plate 80 has a metal foil (for example, aluminum foil) as a base material 80a, and a positive electrode active material (for example, lithium-containing metal oxide) layer 80b is coated on both surfaces of the base material 80a. (Applied). The negative electrode plate 90 has a metal foil (for example, copper foil) as a base material 90a, and a negative electrode active material (for example, carbon) layer 90b is coated (applied) on both surfaces of the base material 90a. The positive electrode plate 80 and the negative electrode plate 90 are extremely thin (for example, about 100 μm), and are both rectangular as shown in FIG. The outer peripheral dimension of the negative electrode plate 90 is slightly larger than the outer peripheral dimension of the positive electrode plate 80. This is a well-known design that is employed for the purpose of suppressing lithium deposition, which is a problem of lithium ion secondary batteries, although details are omitted.

  As shown in FIG. 1, the positive electrode plate 80 and the negative electrode plate 90 each have a current collecting tab T on one side facing the external connection terminals 14 and 16 of the power storage device 10. The current collecting tab T of the positive electrode plate 80 is exposed outward from the separator 40 as shown in FIGS. The current collecting tabs T of the respective positive electrode plates 80 are combined into one, and are directly or indirectly connected to one external connection terminal 14. Further, the current collecting tabs T of the respective negative electrode plates 90 are combined into one and directly or indirectly connected to the other external connection terminal 16. Note that neither the current collecting tab T of the positive electrode plate 80 nor the current collecting tab T of the negative electrode plate 90 is formed with an active material layer.

● [Configuration of positive electrode assembly 30 (FIGS. 4 and 5)]
As shown in FIGS. 4 and 5, the separator 40 constituting the positive electrode assembly 30 includes a strip-shaped first separator 50 and a second separator 60. The first separator 50 and the second separator 60 cover a plurality of positive electrode plates 80 arranged in a line at a predetermined interval from both sides. The first separator 50 and the second separator 60 are made of, for example, an insulating and porous resin material and are extremely thin (for example, about 20 μm).

  As shown in FIGS. 4 and 5, the separator 40 has a melting portion 70 that extends between adjacent positive electrode plates 80 and in which the first separator 50 and the second separator 60 are melted. The melting part 70 partitions the positive electrode plates 80.

  As shown in FIGS. 4 and 5, the melting part 70 includes a pair of welding regions F <b> 1 (regions indicated by hatching in FIG. 4) extending continuously between the adjacent positive electrode plates 80, A small melting region F2 extending continuously between the welding regions F1. In the welding region F1, the first separator 50 and the second separator 60 are welded (strongly). On the other hand, in the small melting region F2, the amount of melting is smaller than in the welding region F1. In the low melting region F2, the first separator 50 and the second separator 60 may or may not be welded, but in the present embodiment, they are not substantially welded. Since the melting amount is small, the small melting region F2 is softer than the welding region F1. The welding region F1 and the small melting region F2 continuously extend along the entire length of the first side A1 of the adjacent (close position) positive electrode plate 80. The first side A <b> 1 of the positive electrode plate 80 is a side facing the adjacent positive electrode plate 80.

  As shown in FIG. 5, the first melt thickness S <b> 1 that is the thickness of the welding region F <b> 1 includes a first separator thickness T <b> 1 that is the thickness of the first separator 50 and a second separator thickness T <b> 2 that is the thickness of the second separator 60. Thinner than the added thickness. In the example shown in FIG. 5, the second melt thickness S2, which is the thickness of the small melt region F2, is thinner than the sum of the first separator thickness T1 and the second separator thickness T2, and the first melt thickness. Thicker than S1. The second melt thickness S2 only needs to be formed thicker than the first melt thickness S1, and the second melt thickness S2 is greater than the thickness obtained by adding the first separator thickness T1 and the second separator thickness T2. It does not have to be thin.

  2 and 3, the positive electrode assembly 30 in the zigzag folded state is formed by alternately repeating mountain folds and valley folds at each melting portion 70 with the small melting region F2 as a fold. In addition, the negative electrode plate 90 is sandwiched between the positive electrode assembly 30 that is folded in a zigzag manner in which the positive electrode plates 80 of the positive electrode assembly 30 face each other. Thereby, the electrode assembly 20 is formed. The negative electrode plate 90 sandwiched between the positive electrode plates 80 is inserted inward to the small melting region F2, and one side is positioned in the small melting region F2.

  By the way, as shown in FIG. 4, the 1st separator 50 and the 2nd separator 60 are along those full length also in 2nd edge | side A2 and 3rd edge | side A3 which are orthogonal to 1st edge | side A1 in the positive electrode plate 80. It is welded. A current collecting tab T is provided on the second side A2. The tab side welding region F3 which is a welding region along the second side A2 and the tab opposing side welding region F4 which is a welding region along the third side A3 are firmly welded as in the above-described welding region F1. . In other words, the first separator 50 and the second separator 60 are firmly welded around the peripheral edges of the four sides of the positive electrode plate 80, and each positive electrode plate 80 is bonded to the first separator 50 and the second separator by this welding. Between 60 and 60. As a result, each positive electrode plate 80 is prevented from being displaced.

● [Production Process of Positive Electrode Assembly 30 and Electrode Assembly 20 (FIG. 6)]
Next, the manufacturing process of the electrode assembly 20 will be described. Now, it is assumed that a plurality of positive electrode plates 80 are conveyed in a line at predetermined intervals. In the positive electrode separator packaging step R1, the conveyed positive electrode plate 80 is covered with the first separator 50 and the second separator 60 from both the upper and lower surfaces. The first separator 50 and the second separator 60 are individually unwound from the wound body 302 and pressed against the positive electrode plate 80 by the roll body 304. The upper surface of the positive electrode plate 80 corresponds to the first surface, and the lower surface of the positive electrode plate 80 corresponds to the second surface (the surface opposite to the first surface).

  Thereafter, the first separator 50 and the second separator 60 are melted in the melting step R2. Here, a melting tool 100 described later is used. In this melting step R2, a melting portion 70 is formed between adjacent positive electrode plates 80. Further, the tab side welding region F3 and the tab opposite side welding region F4 are also formed in this melting step R2, and the positive electrode assembly 30 (see FIGS. 3 and 4) is manufactured.

  Thereafter, in the spelling step R3, the melting part 70 is bent by, for example, a mountain folding jig 306 and a valley folding jig 308. And the negative electrode plate 90 is inserted toward each fusion | melting part 70 by negative electrode plate insertion process R4. Thus, the negative electrode plate 90 is sandwiched between the positive electrode plates 80, and the electrode assembly 20 is manufactured.

● [Production device for melting in the melting step R2 for forming the melting portion 70 (FIGS. 7 to 9)]
The apparatus for manufacturing the power storage device 10 of the present invention has a melting tool 100 shown in FIG. Using the melting tool 100, the above-described melting step R2 is performed.

  As shown in FIG. 7, the melting tool 100 includes a first melting tool 102 and a second melting tool 104. Both melting tools 102 and 104 are formed in a U-shaped block shape and have the same dimensions. Both melting tools 102 and 104 are used by being pressed against the separator 40 as shown in FIG. The first melting tool 102 is pressed against the first separator 50, and the second melting tool 104 is pressed against the second separator 60.

  As shown in FIG. 7, the first melting tool 102 includes a first side portion 110 that extends linearly, a second side portion 120 that extends substantially perpendicularly from one end of the first side portion 110, and a first side portion. And a third side portion 130 extending substantially at a right angle from the other end of 110. The first side portion 110 has a length corresponding to the width H of the separator 40 (see FIG. 4). And the 1st edge part 110 is arrange | positioned along the full length of 1st edge | side A1 (refer FIG. 4) of the positive electrode plate 80 between the adjacent positive electrode plates 80 in the pressing operation with respect to the separator 40, and the fusion | melting shown in FIG. Part 70 is formed. The pressing operation against the separator 40 will be described in detail later. The second side portion 120 has a length corresponding to the entire length of the second side A2 (see FIG. 4) of the positive electrode plate 80. The second side 120 is arranged along the entire length of the second side A2 at the outer edge of the second side A2 of the positive electrode plate 80 in the pressing operation against the separator 40, and the tab side welding region F3 shown in FIG. Form. The third side portion 130 has a length corresponding to the entire length of the third side A3 (see FIG. 4) of the positive electrode plate 80. The third side portion 130 is arranged along the entire length of the third side A3 at the outer edge of the third side A3 of the positive electrode plate 80 in the pressing operation against the separator 40, and the tab facing side welding region F4 shown in FIG. Form. The first side 110, the second side 120, and the third side 130 have a continuous pressing surface M that is pressed against the first separator 50.

  As shown in FIG. 7, the pressing surface M of the first side portion 110 has a first side between a pair of welded portion forming surfaces P1 extending over the entire length of the first side portion 110 and both welded portion forming surfaces P1. It extends over the entire length of the portion 110 and has a small melted portion forming recess P2 that is recessed with respect to both welded portion forming surfaces P1. Further, the pressing surface M of the second side portion 120 is a second side welded portion forming surface P3 that forms the same plane as the welded portion forming surface P1. The pressing surface M of the third side portion 130 is a third side welded portion forming surface P4 that forms the same plane as the welded portion forming surface P1. The functions of the welded portion forming surfaces P1, P3, P4 and the small melted portion forming concave portion P2 will be described later. In addition, the small melting part formation recessed part P2 is dented in U shape over the full length of the 1st edge part 110 (refer FIG. 8).

  The second melting tool 104 has a configuration in which the small melt part forming recess P <b> 2 of the first side part 110 in the first melting tool 102 is omitted. And in the 1st edge part 110 of the 2nd melting tool 104, the pressing surface M is comprised flush. In the second melting tool 104, portions having the same or equivalent configuration / function as the first melting tool 102 are denoted by the same reference numerals, and redundant description is omitted.

  The two melting tools 102 and 104 configured as described above are arranged up and down, for example, as shown in FIG. 8 with the separator 40 being conveyed in between, and approach and leave in synchronization at the predetermined arrangement location. Is set to Both the melting tools 102 and 104 are arranged such that the first side 110, the second side 120, and the third side 130 face each other. The two melting tools 102 and 104 are set so that the first side portions 110 are pressed against each other at a location corresponding to the melting portion 70 of the separator 40. Both melting tools 102 and 104 are heated to a temperature at which the separator 40 can be welded.

  As shown in FIG. 8, when both the melting tools 102 and 104 are pressed against the separator 40, the melting portion 70 is formed between the adjacent positive electrode plates 80 by the first side portions 110 of the both melting tools 102 and 104. . Specifically, both welded portion forming surfaces P <b> 1 of the first melting tool 102 form a pair of welded regions F <b> 1 extending along the adjacent positive electrode plates 80. Moreover, the small melt part formation recessed part P2 of the 1st melting tool 102 forms the small melt area | region F2 extended along between the adjacent positive electrode plates 80 between a pair of welding area | regions F1.

  In the pressing operation of both the melting tools 102 and 104, as shown in FIG. 9, the welding portion forming surface P1 of the first melting tool 102 and the welding area F1 are brought into contact with each other, and the small melting portion forming concave portion P2 of the first melting tool 102 is contacted. A gap S may be formed between the small melting region F2 and the small melting region F2. Thereby, the amount of heating from the first melting tool 102 is smaller in the small melting region F2 than in the welding region F1. By reducing the heating amount in this way, the amount of melting in the small melting region F2 is reduced as compared with the welding region F1, and the first separator 50 and the second separator 60 are welded in the small melting region F2. And can be easily melted.

  As a method for forming the small melting region F2, in addition to changing the heating amount, the force applied to the small melting region F2 when the two melting tools 102 and 104 are pressed is weakened compared to the welding region F1, or the small melting region It is also possible to shorten the time for heating F2.

  When both the melting tools 102 and 104 are pressed against the separator 40, the second sides 120 of the both melting tools 102 and 104 are pressed against each other with the separator 40 interposed therebetween. Thereby, the 2nd edge part welding part formation surface P3 of both the melting tools 102 and 104 forms the tab edge welding area | region F3 shown in FIG. Further, when both the melting tools 102 and 104 shown in FIG. 7 are pressed against the separator 40, the third sides 130 of both the melting tools 102 and 104 are pressed against each other with the separator 40 interposed therebetween. Thereby, the 3rd edge part welding part formation surface P4 of both the melting tools 102 and 104 forms the tab opposing edge welding area | region F4 shown in FIG.

  As described above, in both the melting tools 102 and 104 shown in FIGS. 7 to 9, the second region of the positive electrode plate 80 is formed in parallel with the formation of the welding region F <b> 1 and the small melting region F <b> 2 between the adjacent positive electrode plates 80. The tab side welding region F3 along the side and the tab opposing side welding region F4 along the third side of the positive electrode plate 80 can be formed, and the melting operation of the separator 40 can be made efficient. If the pressing and separation of these melting blocks 102 and 104 are repeated with respect to the separator 40 that is continuously conveyed, the peripheral edges of the four sides of the positive electrode plate 80 are continuously melted. The positive electrode plate 80 can be positioned in a packaged state.

  In addition, the 2nd edge part 120 may be abbreviate | omitted in both fusion | melting blocks 102 and 104, and the tab edge welding area | region F3 may not be formed.

  The first embodiment of the present invention is configured as described above. In the positive electrode assembly 30, in the fusion | melting part 70 between each positive electrode plate 80, the small melting area | region F2 softer than those welding area | regions F1 is provided between a pair of welding area | regions F1 (FIGS. 4 and 5). Therefore, when the positive electrode assembly 30 is folded in a zigzag manner across the positive electrode plates 80, the melting portions 70 can be easily bent using the soft low melting region F2 as a fold. Therefore, in the positive electrode assembly 80, the folding operation is not required by the guide member or the like when the folding is performed, and the folding operation is made smooth.

  Note that when only bending is considered, it is conceivable to provide a complete non-welded region instead of a small melting region. However, in the case where the non-welding region is provided close to the welding region, the width of the non-welding region cannot be set so narrow in terms of design in consideration of variations in temperature at the time of melting. In that case, the folding becomes easy, but the position of the crease tends to vary. Regardless of the presence or absence of welding between the separators as a small melting region, if the amount of melting is controlled, the width can be set narrow and the variation in the position of the crease can be suppressed.

  Further, in the positive electrode assembly 30, the welding region F1 and the small melting region F2 extend along the entire length of the first side A1 that is a side between the adjacent positive electrode plates 80 (see FIG. 4). When the positive electrode assembly 30 is folded in a zigzag shape, the small melting region F <b> 2 can be bent along the first side A <b> 1 of the positive electrode plate 80 easily and reliably. Thereby, the lamination | stacking shift | offset | difference of positive electrode plates 80 resulting from the bending part 70 inclining with respect to 1st edge | side A1 of the positive electrode plate 80 and bending between each positive electrode plate 80 is prevented. Further, the negative electrode plate 90 sandwiched between the positive electrode plates 80 with respect to the positive electrode assembly 30 folded in a zigzag state is inserted into the small melting region F2 which is a bent portion between the positive electrode plates 80. Since one side is positioned along the small melting region F2, the positioned one side is arranged in parallel with the first side A1 of the positive electrode plate 80 along the small melting region F2. As a result, Further, the positive electrode plate 80 and the negative electrode plate 90 are prevented from being stacked obliquely.

● [Other configurations of the melting tool used in the melting process (FIGS. 10 and 11)]
In the melting step R2 shown in FIG. 6, the melting tool 200 shown in FIGS. 10 and 11 may be used instead of the melting tool 100 shown in FIGS.

  A melting tool 200 shown in FIG. 10 has a first melting roll 202 and a second melting roll 204. Both the melting rolls 202 and 204 are configured in a columnar shape having the same dimensions, and both have a length corresponding to the width H (see FIG. 4) of the separator 40 in the axial direction. These two melting tools 202 and 204 are used by being pressed against the separator 40 as shown in FIG. The first melting tool 202 is pressed against the first separator 50, and the second melting tool 104 is pressed against the second separator 60.

  The 1st melting tool 202 has the heating protrusion 210 covering the full length of the axial line 202J direction of this 1st melting tool 202 in the outer periphery. Further, the first melting tool 202 has a heating disk portion 220 having a diameter larger than that of the main portion 230 of the first melting tool 202 at both edges in the axis 202J direction. The surface in the protruding direction of the heating protrusion 210 and the outer peripheral surface of both heating disk portions 220 form a continuous pressing surface M that is pressed against the first separator 50. In addition, the heating protrusion 210 is arrange | positioned along the full length of 1st edge | side A1 of the positive electrode plate 80 between the adjacent positive electrode plates 80 in the pressing operation demonstrated later.

  As shown in FIG. 10, the pressing surface M of the heating protrusion 210 is between a pair of welded portion forming surfaces P1 extending over the entire length in the axis 202J direction of the first melting tool 202 and the two welded portion forming surfaces P1. The first melting tool 202 has a small melted part forming recess P2 that extends over the entire length in the direction of the axis 202J and is recessed with respect to both welded part forming surfaces P1. The small melt part forming recess P2 is recessed in a U shape over the entire length of the heating protrusion 210. Functions of the welded portion forming surface P1 and the small melted portion forming recess P2 will be described later.

  The second melting tool 204 has a configuration in which the small melting portion forming recess P2 of the heating projection 210 in the first melting tool 202 is omitted. And in the heating protrusion 210 of the 2nd melting tool 204, the pressing surface M is comprised flush. In the second melting tool 204, portions having the same or equivalent configuration / function as those of the first melting tool 202 are denoted by the same reference numerals, and redundant description is omitted.

  The two melting tools 202 and 204 configured as described above are disposed so as to face each other vertically as shown in FIG. 11, for example, with the separator 40 to be conveyed interposed therebetween. , 204J is set to rotate. In addition, the axis lines 202J and 204J of both the melting tools 202 and 204 are set so as to be parallel to the direction along the adjacent positive electrode plates 80. In addition, both the melting tools 202 and 204 rotate in the opposite direction in synchronism with the separator 40 sandwiched between them. During this rotation, the heating protrusions 210 of both the melting tools 202 and 204 are pressed against each other at a location corresponding to the melting part 70 of the separator 40. Further, the heating disk portions 220 of both the melting tools 202 and 204 are pressed against each other at both edges in the width direction of the separator 40. Both melting tools 202 and 204 are heated to a temperature at which the separator 40 can be welded. The main part 230 of both the melting tools 202 and 204 does not contact the separator 40.

  As shown in FIG. 11, when both the melting tools 202 and 204 rotate with the separator 40 interposed therebetween, the melting portion 70 is formed between the adjacent positive electrode plates 80 by the heating protrusions 210 of both the melting tools 202 and 204. . Specifically, both welded portion forming surfaces P1 of the first melting tool 202 form a pair of welded regions F1 extending between adjacent positive electrode plates 80. Moreover, the small melt part formation recessed part P2 of the 1st melting tool 202 forms the small melt area | region F2 extended along between the adjacent positive electrode plates 80 between a pair of welding area | regions F1.

  In addition, when both the melting tools 202 and 204 rotate, the heating disk portion 220 presses with the separator 40 sandwiched between the both edges of the both melting rolls 202 and 204. Thereby, the tab side welding area | region F3 shown in FIG. 4 and the tab opposing side welding area | region F4 are formed in the both edges of the width direction of the separator 40. As shown in FIG.

  As described above, in both the melting tools 202 and 204 shown in FIGS. 10 and 11, by rotating them, the welding region F <b> 1 and the small melting region F <b> 2 can be formed between the adjacent positive electrode plates 80, and the positive electrode plate 80. The tab side welding region F3 along the second side A2 and the tab opposing side welding region F4 along the third side A3 of the positive electrode plate 80 can be formed, and the efficiency of the melting operation of the separator 40 is good. And if these both melting tools 202 and 204 are continuously rotated with respect to the separator 40 conveyed continuously, the peripheral edges of the four sides of the positive electrode plate 80 will be continuously melted. The positive electrode plate 80 can be positioned in a packaged state.

  In both melting tools 202 and 204, the heating disk portion 220 corresponding to the tab side welding region F3 may be omitted, and the tab side welding region F3 may not be formed.

  Although the embodiment for carrying out the present invention has been described above with reference to the drawings, the present invention can be implemented in other embodiments. The shape of the small melt part forming recess P2 in the first melting tool 102, 202 is not limited to the above-described U-shape. For example, as shown in FIG. 12, the small melt portion forming recess P2 may be a substantially V-shaped recess inclined so as to spread from the center toward the melt portion forming surface P1 on both sides. Further, as shown in FIG. 13, the small melt part forming recess P <b> 2 may be a substantially arc-shaped or substantially U-shaped recess curved so as to spread from the center toward the melt part forming surface P <b> 1 on both sides.

  In the above-described embodiment, the first melting tool 102, 202 and the second melting tool 202, 204 are both heated for the melting tool 100, 200 (see FIGS. 7 and 10). It is also possible to form the melted portion 70 by heating only one of the second melting tools 202 and 204. 7 and 8, the first melting tool 102 and the second melting tool 104 are both formed in a U-shape, but the melting tool on the heating side (for example, the first melting tool) is used. 102) may be a U-shape, and the melting tool on the non-heated side may be configured such that the pressing surface thereof is, for example, a rectangular plane that does not form a U-shape. Further, in the melting tool 200 shown in FIGS. 10 and 11, both the first melting tool 202 and the second melting tool 204 are provided with the heating protrusions 210, but the melting tool on the heating side (for example, the first melting tool 202). ) May be provided only with a heating projection 210 protruding from the main portion 230, and the melting tool on the non-heated side may be configured in a simple columnar shape without unevenness. Further, with respect to melting by the melting tools 100, 200, the portion overlapping the current collecting tab T of the positive electrode plate 80 may not be welded.

  Further, in the above-described embodiment, the melting tool 100, 200 has the small melt portion forming recess P2 that is the recess corresponding to the small melt region F2, but it may be composed of two or more members. For example, the small melt part formation recessed part P2 may be formed between both by arrange | positioning the two members which have a convex-shaped side in parallel.

  In the above-described embodiment, an example of the power storage device is a lithium ion secondary battery, and the separator housing electrode body is a positive electrode assembly. However, the power storage device is not limited to the lithium ion secondary battery. The separator-housing electrode body is not limited to the positive electrode assembly. The separator housing electrode body may house the negative electrode, and the power storage device may be another battery such as a nickel metal hydride battery.

DESCRIPTION OF SYMBOLS 10 Power storage device 20 Electrode assembly 30 Positive electrode assembly 40 Separator 50 1st separator 60 2nd separator 70 Melting | fusion part 80 Positive electrode plate 90 Negative electrode plate 100,200 Melting tool 110 1st edge part 120 2nd edge part 130 3rd edge part 210 Heating projection A1 First side A2 Second side A3 Third side F1 Welding area F2 Small melting area P1 Welding part forming surface P2 Small melting part forming concave part P3 Second side welding part forming surface P4 Third side part welding part Forming surface S1 First melt thickness S2 Second melt thickness T1 First separator thickness T2 Second separator thickness

Claims (7)

A separator housing electrode body of a power storage device,
A plurality of electrode plates made of one of a positive electrode and a negative electrode, and a separator that covers the plurality of electrode plates;
The separator covers a first separator that covers the first surfaces of the plurality of electrode plates arranged in a line at a predetermined interval, and a second surface opposite to the first surface of the plurality of electrode plates. A second separator, and a melted portion that extends between the adjacent electrode plates and in which the first separator and the second separator are melted,
The melted portion extends between adjacent electrode plates, and a pair of welded areas where the first separator and the second separator are welded, and the first separator and the first between the pair of welded areas. 2. A separator-housing electrode body for a power storage device, comprising: a two-separator melted area, but a low-melting area having a smaller melting amount than the welding area. It is a separator accommodation type electrode body of the electrical storage device according to claim 1,
The first separator has a first separator thickness at a portion other than the melting portion,
The second separator has a second separator thickness at a portion other than the melting portion,
The welding region has a first melt thickness that is thinner than the thickness of the first separator thickness and the second separator thickness,
The small melting region is a separator-housing electrode body of a power storage device having a second melting thickness that is thicker than the first melting thickness. A separator-housing electrode body for a power storage device according to claim 1 or 2,
The welding region and the low melting region are separator storage type electrode bodies of a power storage device that extend along the entire length of the first side that is the side facing the adjacent electrode plate in the adjacent electrode plates.   Each of the said small melting area | region in the separator accommodation-type electrode body of the electrical storage apparatus as described in any one of Claims 1-3 repeats a mountain fold and a valley fold alternately, and the said separator accommodation-type electrode body is folded in a zigzag manner. An electrode assembly of a power storage device in which the other electrode plate of the positive electrode or the negative electrode is sandwiched in each gap formed in a state where the electrode plates face each other. A power storage device manufacturing apparatus for forming the melting portion in the separator-housing electrode body of the power storage device according to claim 1,
The manufacturing apparatus includes a first melting tool pressed from the first separator side and a second melting tool pressed from the second separator side, and the heated first heating tool. Sandwiching the separator with the second melting tool to form the melting portion;
The surface pressed against the first separator in the first melting tool forms a pair of welding portion forming surfaces extending between the adjacent electrode plates to form the pair of welding regions, and the small melting region. Therefore, an apparatus for manufacturing a power storage device, comprising: a small melted portion forming recess that extends along between the adjacent electrode plates between the pair of welded portion forming surfaces and is recessed with respect to the welded portion forming surface. The power storage device manufacturing apparatus according to claim 5,
The shape of the first melting tool and the shape of the second melting tool are cylindrical, and the axis of the cylindrical first melting tool and the second melting tool is parallel to the direction along the adjacent electrode plates. Is set to be
An apparatus for manufacturing a power storage device, wherein the weld portion forming surface and the small melt portion forming recess are provided on an outer peripheral surface of the first melting tool. The power storage device manufacturing apparatus according to claim 5,
The electrode plate is rectangular,
The welded portion forming surface is planar.
The first melting tool extends along the entire length of the first side that is the side facing the adjacent electrode plate in the electrode plate, and the first side on which the welded portion forming surface and the small melted portion forming concave portion are formed. And along the entire length of the second side which is one side of the electrode plate perpendicular to the first side from the one end of the first side part, and is flush with the welded portion forming surface. The second side part where the second side part welded part forming surface is formed and the entire length of the third side which is the other side orthogonal to the first side of the electrode plate from the other end of the first side part. And a third side part formed with a third side part welded part forming surface formed so as to be flush with the welded part forming surface and having a substantially U-shaped shape A manufacturing device for a power storage device.

Images