JP2010232145A - Laminated-type battery and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated-type battery capable of fixing a laminated electrode body firmly without shifts, while suppressing reduction in the battery capacity. <P>SOLUTION: In a laminated electrode body 10 of a laminated-type battery, in a low activity region N1 that deviates from an active region H1 that is apt to be utilized in an electrode reaction substantially, through-parts 31, 32 for preventing the shift in a lamination, penetrating through a positive electrode plate 1 and a negative electrode plate 2 in the direction of lamination are provided, and the laminated electrode body 10 is fixed by the through-parts 31, 32, and thereby, the low active region N1 that is not utilized sufficiently in an electrode reaction is made to be utilized effectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a large-capacity laminated battery having a high rate characteristic and used for robots, electric vehicles and the like. In particular, the number of laminated sheets is large, a large number of positive and negative electrode plates are required to be laminated, and vibration is easily applied to the battery. The present invention relates to a lithium-ion battery for power.
The present invention also relates to a method for manufacturing a stacked battery, and more particularly to a method for positioning and stacking a stacked electrode body easily and accurately.

  For example, power supplies for robots and electric vehicles are required to have a large capacity and high rate characteristics. In recent years, lithium ion batteries having a high energy density have attracted attention as satisfying such demands. As a structure of this lithium ion battery, there is a so-called stacked battery in which a laminated electrode body in which positive and negative electrode plates are alternately laminated via a separator is accommodated in an exterior body.

  The laminated battery for power that requires charging and discharging at a high rate with a large capacity as described above is likely to cause misalignment due to vibration. Therefore, a laminated electrode body in which a large number of positive and negative electrode plates and separators are laminated is firmly formed. Need to be fixed. Although the periphery of the laminated electrode body is also fixed with a tape, in this method, the adhesive of the tape is liable to be lost when it comes into contact with the electrolytic solution, so the laminated electrode body is securely fixed. There is a problem in maintaining the state, and there is a problem that the appearance of the tape appears on the surface of the exterior body made of a laminate, and the appearance is easily impaired. Also, in the stage of manufacturing the battery, it is necessary to accurately align the laminated electrode bodies and laminate them without any deviation, but this operation is difficult and troublesome.

  Therefore, in Patent Documents 1 and 2, a through-hole is formed in the laminated electrode body, and the electrode body is fixed by disposing a cylindrical through-member or pin through the through-hole. .

  Moreover, in patent document 3, the peripheral part of a separator is projected outside an electrode plate, and the electrode body is fixed by fixing the peripheral parts to each other.

JP 2000-340265 A JP 2002-246007 A JP-A-10-64506

  However, in Patent Document 1 and Patent Document 2, the position where the penetrating member or pin penetrates is the central portion (Patent Document 1) of the electrode body or the end portion close to the current collecting terminal (Patent Document 2). The active material at these positions is used at a high rate for the charge / discharge reaction, and if the penetrating member or pin is penetrated at such a position, the active material does not exist at the site, and therefore, the electrode The capacity will be reduced.

  On the other hand, in Patent Document 3, since the separators are fixed to each other, a penetrating member and a pin are unnecessary, but the peripheral edge of the separator is projected outward from the electrode plate. Becomes a small size, and the electrode plate does not exist in a portion corresponding to the fixing portion of the separator, and accordingly, the battery capacity is reduced accordingly.

  Therefore, an object of the present invention is to provide a laminated battery capable of firmly fixing a laminated electrode body without displacement while suppressing a decrease in battery capacity.

  Further, the present invention provides a laminated battery that can position and laminate the laminated electrode body easily and accurately, and can firmly fix the laminated electrode body without displacement while suppressing a decrease in battery capacity. It aims at providing the manufacturing method of.

In order to achieve the above object, the laminated battery according to the present invention is:
A laminated battery comprising a laminated electrode body in which a positive electrode plate and a negative electrode plate are alternately laminated via separators,
In the laminated electrode body, a through-hole for preventing misalignment is provided in a region deviating from an active region that is substantially easily used for electrode reaction, and the through-hole for preventing misalignment through the positive electrode plate and the negative electrode plate is provided. The laminated electrode body is fixed.

  In the present invention, the “active region that is substantially easily used for electrode reaction” (hereinafter, also simply referred to as “active region”) means that the active material is substantially used for electrode reaction in the laminated electrode body and current flows. Thus, even if an active material is used for an electrode reaction and a current flows, the amount of current remains at about 1/10 or less of the maximum amount of current flowing through the active region. Such a region corresponds to a region deviating from the active region (hereinafter also referred to as “low active region”).

  In addition to the through hole, the “penetrating portion” implies not only a notch obtained by cutting out the positive electrode plate and the negative electrode plate from the edge, but also a corner drop portion obtained by cutting off the corners of the positive electrode plate and the negative electrode plate.

  According to the above configuration, in the positive electrode plate and the negative electrode plate, even if there is no active material corresponding to the area occupied by the through portion due to the formation of the through portion, the formation position of the through portion deviates from the active region. Since it is in the region, that is, the low active region, the electrode reaction is not substantially affected. In other words, the penetrating portion is provided by effectively using the low active region that is rarely used for the electrode reaction. Therefore, by fixing the laminated electrode body at this through portion, the laminated electrode body can be firmly fixed without displacement while suppressing a decrease in battery capacity.

  It is desirable that the stacked battery is charged and discharged at a high rate with a current value of 6.0 It or more.

  For example, when the battery is operated, that is, charged and discharged at a low rate of a current value of about 1.0 It, the area of the part that is substantially used for the electrode reaction in the laminated electrode body is relatively large, and therefore low There are relatively few active areas. On the other hand, the higher the current value is about 6.0 It or higher, the more the current tends to flow from the positive electrode terminal to the negative electrode terminal in the shortest distance in the laminated electrode body. As the area becomes narrower, the low active area will expand. Therefore, the present invention in which the through portion is provided in the low active region is particularly preferably applied. Further, since the low active region becomes large, a region suitable for the formation of the penetrating portion is secured so much that the penetrating portion is easily formed.

  It is good also as a structure by which the said penetration part penetrates a separator with a positive electrode plate and a negative electrode plate in the lamination direction, and arrange | positions so that the penetration member which consists of a non-conductor may be penetrated to this penetration part, and the laminated electrode body is being fixed. .

  According to the said structure, a laminated electrode body can be fixed easily and reliably by simple structure. In addition, since the through portion penetrates not only the positive electrode plate and the negative electrode plate but also the separator in the laminating direction, the positive electrode plate, the negative electrode plate and the separator are inserted so as to insert a positioning boss or the like into the through portion. It becomes possible to easily and accurately align and laminate.

  It is good also as a structure by which the laminated electrode body is being fixed by welding the separator which is located so that the said penetration part may not penetrate the separator, and may pinch | interpose this penetration part in this penetration part.

  According to the above configuration, since the separator itself becomes the fixing means, there is no need to prepare a penetrating member or the like as the fixing means, and the configuration can be simplified by reducing the number of parts accordingly. If a separate fixing means is used, this fixing means protrudes somewhat in the thickness direction (stacking direction) and appears on the surface of the exterior body made of laminate. On the other hand, if the separators are welded together in the penetrating portion as described above, they do not protrude even if they are recessed in the thickness direction, so that they appear on the surface of the exterior body made of laminate. Therefore, the appearance and the fit are not impaired.

In addition, the manufacturing method of the stacked battery according to the present invention includes:
A method for producing a laminated battery comprising a laminated electrode body in which a positive electrode plate and a negative electrode plate are alternately laminated via separators,
Each of the positive electrode plate, the negative electrode plate, and the separator is for preventing misalignment of the positive electrode plate, the negative electrode plate, and the separator that penetrates in the stacking direction in a region that deviates from an active region that is substantially easily used for electrode reaction. Each of the through portions is provided, and the positive electrode plate, the negative electrode plate, and the separator are aligned and laminated so that the positioning boss is inserted into the through portion.

  In the present invention, the “positioning boss” is a protrusion that is inserted into the through-hole of the laminated member (positive electrode plate, negative electrode plate and separator) and regulates to align each other, and its shape is Anything that can be inserted into the penetrating portion is implied, and for example, any of a columnar shape, a cylindrical shape, a pin shape, a piece shape and the like is included.

  In the production of a laminated battery, when laminating positive and negative electrodes alternately via separators in the lamination process of the laminated electrode body, these laminated members are accurately aligned so as not to deviate from each other. However, it has been difficult to stack the layers, requiring time and labor, and in the past, positioning was performed while being controlled by a computer. On the other hand, the positioning boss was inserted into the through-hole for preventing stacking deviation as described above. Thus, the positive electrode plate, the negative electrode plate, and the separator can be easily aligned accurately and stacked so as not to be displaced without requiring a large-scale device or jig. .

  According to the multilayer battery of the present invention, the through electrode for preventing misalignment is provided in the low active region of the laminated electrode body, and the laminated electrode body is fixed by this through part, thereby suppressing the decrease in battery capacity. On the other hand, it is possible to obtain a laminated battery capable of firmly fixing the laminated electrode body without deviation.

  Further, according to the method for manufacturing a laminated battery of the present invention, the positioning plate is inserted into the above-described through-hole for preventing misalignment, and the positive electrode plate is obtained by simple alignment means. A negative electrode plate and a separator can be easily and accurately aligned and stacked, and thus a stacked battery that can firmly fix a stacked electrode body without displacement while suppressing a decrease in battery capacity is easily obtained. It can be produced efficiently.

It is a figure which shows a part of laminated battery of this invention, Comprising: The figure (a) is a top view of a positive electrode, The figure (b) is a perspective view of a separator, The figure (c) is a positive electrode arrange | positioned inside. It is a top view which shows the bag-shaped separator. It is a top view of the negative electrode plate used for the laminated battery of this invention. It is a disassembled perspective view of the laminated electrode body used for the laminated battery of this invention. It is a schematic fragmentary sectional view which shows the condition which fixed the laminated electrode body used for the laminated battery of this invention by the penetration part. It is a top view of the laminated electrode body used for the laminated battery of this invention. It is a top view which shows the state which welded the positive / negative electrode tab and the positive / negative electrode current collection terminal. It is a perspective view of the state which inserted the laminated electrode body of FIG. 6 in the exterior body used for the laminated battery of this invention. It is a conceptual diagram which shows the electric current distribution at the time of repeating charging / discharging at a high rate using the laminated battery of this invention. It is a top view of the laminated electrode body used for the laminated battery of the comparative example. It is a perspective view which shows the condition which laminates | stacks the laminated electrode body which concerns on 2nd Example. It is a schematic fragmentary sectional view which shows the condition which fixed the laminated electrode body of FIG. 10 by the penetration part. It is a conceptual diagram which shows the electric current distribution at the time of repeating charging / discharging at a high rate using the laminated battery which concerns on another example. It is a fragmentary top view which shows the other example of arrangement | positioning of a positive / negative electrode tab and a penetration part. It is a top view which shows the condition which fixed the laminated electrode body which concerns on another example with the penetration part. It is CC sectional view taken on the line of FIG.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to the following best modes, and can be implemented with appropriate modifications without departing from the spirit of the present invention. It is a thing.

[Production of positive electrode]
90% by mass of LiCoO ₂ as a positive electrode active material, 5% by mass of carbon black as a conductive agent, 5% by mass of polyvinylidene fluoride as a binder, N-methyl-2-pyrrolidone as a solvent ( NMP) solution was mixed to prepare a positive electrode slurry, and this positive electrode slurry was applied to both surfaces of an aluminum foil (thickness: 15 μm) as a positive electrode current collector. Then, after drying the solvent and compressing it to a thickness of 0.1 mm with a roller, as shown in FIG. 1A, it is cut into a rectangular shape having a width L1 = 95 mm and a height L2 = 115 mm. A positive electrode plate 1 having a positive electrode active material layer 1a on both sides was produced. At this time, a rectangular shape having a width L3 = 30 mm and a height L4 = 20 mm from one end portion (the left end portion in FIG. 1A) of one short side (the upper side in FIG. 1A) of the positive electrode plate 1. The active material uncoated portion was extended to form a positive electrode tab 11.

(Production of negative electrode)
A negative electrode slurry was prepared by mixing 95% by mass of graphite powder as a negative electrode active material, 5% by mass of polyvinylidene fluoride as a binder, and an NMP solution as a solvent. It apply | coated to both surfaces of the copper foil (thickness: 10 micrometers) as a negative electrode collector. Then, after drying the solvent and compressing to a thickness of 0.08 mm with a roller, as shown in FIG. 2, cut into a rectangular shape having a width L7 = 100 mm and a height L8 = 120 mm, A negative electrode plate 2 having a negative electrode active material layer 2a was produced. At this time, a rectangular active material uncoated portion having a width L9 = 30 mm and a height L10 = 20 mm from one end portion (right end portion in FIG. 2) of one short side (upper side in FIG. 2) of the negative electrode plate 2. The negative electrode tab 12 was extended.

(Formation of penetration part)
As shown in FIG. 1 (a), in the positive electrode plate 1, the inner part (that is, FIG. 1 (a) slightly closer to the center than the opposite ends of the short side (lower side in FIG. 1) opposite to the short side of the positive electrode tab 11 formation side. More specifically, the inner part of each of the lower right and lower left corners)), more specifically, the distance D1 = 5 mm from the short side, and the distance D2 = 5 mm from both long sides is 5 mm in diameter. A through-hole 31 was formed by drilling holes.

  Further, as shown in FIG. 2, in the negative electrode plate 2, the inner part (that is, lower right in FIG. 2) slightly closer to the center than both ends of the short side (lower side in FIG. 2) opposite to the short side on the negative electrode tab 12 formation side. And, more specifically, a hole having a diameter of 5 mm centered on a position with a distance D3 = 7.5 mm from the short side and a distance D4 = 7.5 mm from both long sides. The penetrating part 32 was formed by drilling each of these.

[Production of bag-shaped separator with positive electrode plate arranged inside]
After arranging the positive electrode plate 1 between two rectangular polypropylene (PP) separators 3a (thickness 30 μm) having a width L5 = 100 mm and a height L6 = 120 mm as shown in FIG. As shown in FIG. 1 (c), the peripheral part of the separator 3a was thermally welded by the fusion part 4 to produce a bag-like separator 3 in which the positive electrode plate 1 was housed and arranged.

(Production of laminated electrode body)
50 bag-shaped separators 3 and 51 negative electrode plates 2 each having the positive electrode plate 1 disposed therein were prepared, and the bag-shaped separators 3 and the negative electrode plates 2 were alternately laminated as shown in FIG. At that time, the negative electrode plate 2 is positioned at both end surface portions, and the same shape as that of the separator 3a is provided on the outer side (the uppermost end surface portion and the lowermost end surface portion in FIG. 3) of the negative electrode plate 2 disposed on both end surface portions. One polypropylene sheet 3b having the same dimensions was disposed. Next, FIG. 4 shows only a few sheets in the center of the laminate in the stacking direction, and the other parts are omitted, and as schematically shown, a bag-like separator 3 and a polypropylene sheet 3b (shown in FIG. 4). Are omitted from each other in the through holes 31 and 32 of the positive electrode plate 1 and the negative electrode plate 2 and bonded to each other so that the laminate is fixed at the positions of the through holes 31 and 32. Thus, the laminated electrode body 10 shown in FIG. 5 was obtained.

[Welding of current collector terminal]
As shown in FIG. 6, the positive electrode current collector terminal 15 made of an aluminum plate having a width of 30 mm and a thickness of 0.5 mm and a width of 30 mm and a thickness of 0. The negative electrode current collecting terminals 16 made of a 5 mm copper plate were joined by ultrasonic welding.

[Encapsulation in exterior body]
As shown in FIG. 7, the laminated electrode body 10 is inserted into an exterior body 18 composed of two laminate films 17 formed so that the electrode body can be installed in advance, and a positive current collecting terminal 15 and a negative current collecting terminal The sides where the positive electrode current collecting terminal 15 and the negative electrode current collecting terminal 16 are thermally fused so that only 16 protrudes from the exterior body 18 and two of the remaining three sides are thermally fused.

[Encapsulation and sealing of electrolyte]
LiPF ₆ is 1M (moles) in a mixed solvent in which ethylene carbonate (EC) and methyl ethyl carbonate (MEC) are mixed at a volume ratio of 30:70 from one side where the outer package 18 is not thermally welded. The laminated electrolyte was manufactured by injecting an electrolytic solution dissolved at a ratio of 1 / liter) and finally thermally welding one side that was not thermally welded.

[Use test of stacked battery]
After repeating 1000 cycles of charging and discharging at a low rate of 1.0 It (10A) using the above-mentioned laminated battery, this laminated battery was disassembled and the surface states of the positive electrode plate 1 and the negative electrode plate 2 were observed. Similarly, after repeating 1000 cycles of charging and discharging at a high rate of 6.0 It (60 A) using the above laminated battery, the laminated battery was disassembled and the positive electrode plate 1 and the negative electrode plate 2 were The surface condition was observed. As a result, in both cases of the low rate and the high rate, discoloration occurs due to the active material being used for the electrode reaction in the positive electrode plate 1 and the negative electrode plate 2, but the entire surface of the positive electrode plate 1 and the negative electrode plate 2. However, it was recognized that the degree of discoloration differs depending on the region, that is, unevenness occurs. At this time, it was recognized that the unevenness of discoloration was larger when charging / discharging was performed at a high rate of a current value of 6.0 It. From this discoloration situation, it is considered that the current distribution when charging / discharging is repeated at a high rate of 6.0 It is approximately as shown in the conceptual diagram of FIG.

  As shown in the figure, on the positive electrode plate 1 and the negative electrode plate 2, the current path is a straight line connecting the positive electrode tab 11 at the upper left end and the negative electrode tab 12 at the upper right end (that is, the positive electrode in the positive electrode plate 1 and the negative electrode plate 2). From the current path R1 along the tab 11 to the negative electrode tab 12 formation side short side), it gradually spreads in a wave shape to the side opposite to the positive and negative electrode tabs 11 and 12 formation side (the lower side in FIG. 8). It is considered that the current path R2 extends from the positive electrode tab 11 to the negative electrode tab 12 through the center on the opposite side of the positive and negative electrode tabs 11 and 12 to the negative electrode tab 12 while curving in a substantially semicircular shape. Boundary line B1 extending substantially along a short side (lower side in FIG. 8) opposite to the short side of the positive and negative electrode tabs 11 and 12 on the rectangular positive electrode plate 1 or negative electrode plate 2 and a semicircle inscribed in the long sides on both sides. Outside the position (ie FIG. 8 Definitive bottom left and corner of the lower right), the current amount is believed to be significantly reduced. In other words, the region having a substantially U-shaped outer shape on the entire inner side (positive and negative electrode tabs 11 and 12 side) of the boundary line B1 is that the active material in the laminated electrode body 10 is substantially used for the electrode reaction. It is considered that the active region H1 is easy to be activated so as to flow, and the outside of the boundary line B1 is a low active region N1 that deviates from the active region H1. The amount of current flowing through the low active region N1 is considered to be about 1/10 or less of the maximum amount of current flowing through the active region.

[First embodiment]
Example 1
As the stacked battery of Example 1, a battery manufactured in the same manner as the stacked battery described in the embodiment for carrying out the invention was used.
The laminated battery thus produced is hereinafter referred to as the present invention battery A1.

(Example 2)
In the battery A1 of the present invention, in the step of producing the laminated electrode body 10, while confirming the positions of the through portions 31 and 32 of the positive electrode plate 1 and the negative electrode plate 2 with an image processing apparatus, the negative electrode plate 2, the bag-like separator 3 and A laminated battery was produced in the same manner except that the polypropylene sheet 3b was aligned and laminated.
The stacked battery thus produced is hereinafter referred to as the present invention battery A2.

(Comparative Example 1)
In the present invention battery A1, as shown in FIG. 9, the positions of the through holes 33 of the positive electrode plate and the negative electrode plate (here, the through hole of the positive electrode plate and the through hole of the negative electrode plate are collectively referred to) A laminated battery was fabricated in the same manner except that the laminated electrode body 20 was constructed by changing the position to the left and slightly to the right.
The stacked battery thus produced is hereinafter referred to as a comparative battery Z1.

[Consideration of the first embodiment]
The batteries A1 and A2 of the present invention are laminated electrodes that penetrate the positive electrode plate 1 and the negative electrode plate 2 in the laminating direction in the low active region N1 that deviates from the active region H1 that is substantially easily used for electrode reaction. Through-holes 31 and 32 for preventing misalignment are provided, and the laminated electrode body 10 is fixed by the through-holes 31 and 32. Accordingly, in the positive electrode plate 1 and the negative electrode plate 2, the penetration portions 31 and 32 are formed. There is no active material corresponding to the area occupied by the penetrating portions 31 and 32, but the formation positions of the penetrating portions 31 and 32 are in a region deviating from the active region H1, that is, the low active region N1, so that the electrode reaction substantially does not occur. It does not affect. In other words, the through portions 31 and 32 are provided by effectively using the low active region N1 that is rarely used for electrode reactions. Therefore, since the laminated electrode body 10 is fixed by the through portions 31 and 32, the laminated electrode body 10 is firmly fixed without deviation while suppressing a decrease in battery capacity.

  Further, the penetrating portions 31 and 32 are close to both corners (lower left corner and lower right corner in FIG. 8) at positions symmetrical to the formation positions of the positive electrode tab 11 and the negative electrode tab 12 in the low active region N1. Is formed. That is, the width 10 mm and the height 10 mm (15 mm width in the negative electrode plate 2) corresponding to approximately one-tenth of the widths L 1 and L 7 and the heights L 2 and L 8 of the positive electrode plate 1 or the negative electrode plate 2 positioned so as to be aligned at both the corners. The through-holes 31 and 32, which are through-holes having a diameter of 5 mm, are formed so as to fit within (center of) a square region having a height of 15 mm. Therefore, it is considered that the low active region N1 is least used for the electrode reaction, and the through portions 31 and 32 are formed at positions where the laminated electrode body 10 can be fixed most stably and surely. As a result, misalignment of the laminated electrode body 10 is effectively prevented. At this time, paying attention to each of the positive electrode plate 1 and the negative electrode plate 2, the positive electrode tab 11 or the negative electrode tab 12 and the two through portions 31 and 32 in total, that is, three corners (upper left or upper right corner). Part, lower left corner, and lower right corner).

  Further, as is apparent from the results of the use test, when the battery is charged / discharged at a low rate of 1.0 It, the portion of the laminated electrode body 10 that is substantially used for the electrode reaction. Although it is considered that the area is relatively large and therefore there are relatively few low active regions, at a high rate of current value 6.0 It, a low active region N1 extending outside the boundary line B1 is formed. Therefore, the batteries A1 and A2 of the present invention in which the through portions 31 and 32 are provided in the low active region N1 are particularly suitable when charging and discharging at such a high rate.

  At this time, for example, when the current value is increased from 6.0 It, the tendency that the current tends to flow from the positive electrode tab 11 to the negative electrode tab 12 in the laminated electrode body 10 becomes stronger. As the active region is narrowed, the low active region is expanded. That is, the outermost current path R2 shown in the conceptual diagram of FIG. 8 is deflated so as to approach the current path R1 through which the current flows through the shortest distance, and accordingly, the boundary line B1 between the active region H1 and the low active region N1 However, it moves to the positive and negative electrode tabs 11 and 12 side (upper side in FIG. 8) while maintaining the semicircular shape in outline. As the low active area becomes larger in this way, the area suitable for the formation of the penetrating portion increases, and the arrangement of the penetrating portion becomes easy. However, even in the case where the low active region is enlarged in this way, from the viewpoint of stably and surely fixing the laminated electrode body 10, the position where the positive electrode tab 11 and the negative electrode tab 12 are formed is the same as described above. It is desirable to form the penetrating portion at a position as close as possible to both corners.

  Moreover, as shown in FIG. 4, the penetration part 31, 32 does not penetrate the bag-like separator 3 and the polypropylene sheet 3b, and the bag-like separator 3 (and the polypropylene sheet) positioned so as to sandwich the penetration parts 31, 32. 3b) Since the laminated electrode body 10 is fixed by welding each other in the through-portions 31 and 32, the bag-like separator 3 and the polypropylene sheet 3b itself become fixing means. The laminated electrode body 10 is fixed without using the like, and the number of parts is reduced accordingly, and the configuration is simplified. In addition, when a separate fixing means is used, depending on the shape of the fixing means, it may slightly protrude in the thickness direction (stacking direction), and the appearance and fit may be inferior. In A1 and A2, since the laminated electrode body 10 is fixed by welding the bag-like separators 3 (and the polypropylene sheet 3b) in the through portions 31 and 32, there is no protrusion in the thickness direction, and thus the appearance is good. It is well maintained without losing its fit.

  As shown in FIG. 9, in the comparative battery Z1, the penetration part 33 is provided in the center part of the positive electrode plate and the negative electrode plate of the laminated electrode body 20 with respect to the inventive batteries A1 and A2. That is, the penetrating portion 33 is provided in the active region H1, and particularly in the active region H1 at a position near the center. Therefore, the loss of the active material corresponding to the area occupied by the penetrating portion 33 causes a reduction in battery capacity.

[Second Embodiment]
Example 3
In the present invention battery A1, as shown in FIG. 10, the bag-like separator 3 and the polypropylene sheet 3b are also provided with through portions 34 corresponding to the through portions 31, 32 of the positive electrode plate 1 and the negative electrode plate 2. In addition, the positive electrode plate 1 and the negative electrode plate 2 are formed on a board surface portion 35 having a width and height larger than the width and height of the multilayer electrode body 10 and having a rectangular outer shape that can enclose the multilayer electrode body 10 with a margin. A diameter having a length larger than the thickness of the laminated electrode body 10 from the position of two points corresponding to the through portions 31 and 32 (that is, the position of two points having an interval equal to the interval between the two through portions 31 and 32). A positioning board 37 is produced by providing a positioning boss 36 having a cylindrical shape of 5 mm and having a ridge angle portion at the periphery of the tip end surface tapered so as to protrude, and using this positioning board 37, The bag-shaped separator 3, the polypropylene sheet 3 b, and the negative electrode plate 2 are alternately stacked while the positioning boss 36 is inserted through the through portions 31, 32, and 34. Thereafter, the laminated body is removed from the positioning board 37, and as shown in FIG. 11, the penetrating member 38 is inserted into the penetrating parts 31, 32, 34 and fastened, whereby the laminated body is attached to the penetrating parts 31, 32. , 34 to obtain a laminated electrode body 30. The penetrating member 38 is formed of polypropylene, and includes a first divided body 38A having a shape in which a cylindrical shaft 382 having a diameter of 5 mm projects from the center of a disk-shaped flange 381 having a diameter of 8 mm, and the first divided body 38A. When the first divided body 38A and the second divided body 38B are press-fitted into the through-holes 31, 32, 34 from both sides, the first divided body 38A has a shape substantially the same as the body 38A. The tip of the shaft 382 of the body 38A is inserted into the tip of the shaft 383 of the second divided body 38B in a “tenon shape” and is elastically (snap-shaped) engaged to be fastened and fixed. Further, in the positive electrode plate 1 and the negative electrode plate 2, no active material was applied in a circular region having a diameter of 8 mm corresponding to the flange 381 of the penetrating member 38 (not shown).
Except for the above, a laminated battery was fabricated in the same manner as in the case of the battery A1 of the present invention.
The laminated battery thus produced is hereinafter referred to as the present invention battery A3.

[Consideration of the second embodiment]
In the battery A3 of the present invention, the through portions 31, 32, and 34 penetrate the bag-like separator 3 and the polypropylene sheet 3b together with the positive electrode plate 1 and the negative electrode plate 2 in the laminating direction. Since the laminated electrode body 30 is fixed by being arranged so as to penetrate the penetrating member 38 made of polypropylene which is a non-conductor, the laminated electrode body 30 can be fixed easily and reliably with a simple configuration. It has become. Moreover, since the penetration parts 31, 32, and 34 penetrate not only the positive electrode plate 1 and the negative electrode plate 2 but also the bag-like separator 3 and the polypropylene sheet 3b, the penetration parts 31, 32, The positive electrode plate 1, the negative electrode plate 2, the bag-like separator 3, and the polypropylene sheet 3 b can be easily and accurately aligned and stacked so that the positioning boss 36 is inserted into the plate 34.

  In the production of the battery A3 of the present invention, each of the positive electrode plate 1, the negative electrode plate 2, the bag-like separator 3 and the polypropylene sheet 3b has a low deviating from the active region H1 that is substantially easily used for electrode reaction. In the active region N1, there are provided through portions 31, 32, 34 for preventing misalignment that penetrate the positive electrode plate 1, the negative electrode plate 2, the bag-like separator 3 and the polypropylene sheet 3b in the laminating direction. 34, the positive electrode plate 1, the negative electrode plate 2, the bag-like separator 3 and the polypropylene sheet 3b are aligned and laminated so that the positioning boss 36 is inserted, so that a large-scale device or jig may be required. The positive electrode plate 1, the negative electrode plate 2, and the bag shape can be obtained simply by using the positioning board 37 having a simple configuration in which the positioning boss 36 is projected on the board surface portion 35. Comparator 3 and a polypropylene sheet 3b easily and so that the can be stacked precisely aligned so as not to shift.

[Other matters]
(1) In the laminated electrode bodies 10 and 30 of the present invention batteries A1, A2 and A3, all are from the same side (the upper side in FIGS. 1A and 2) of the rectangular positive electrode plate 1 and the negative electrode plate 2. The positive electrode tab 11 and the negative electrode tab 12 are configured to extend. For example, as illustrated in FIG. 12, the positive electrode tab 41 and the negative electrode tab 42 extend from different sides of the positive electrode plate and the negative electrode plate. The laminated electrode body 40 may be used. In the laminated electrode body 40 shown in the same figure, the position of the positive electrode tab 41 is the same as that of the positive electrode tab 11 in the laminated electrode bodies 10 and 30 of the batteries A1, A2 and A3 of the present invention. Is the one end (the left end in FIG. 12) of the negative electrode tab 42, but the position of the negative electrode tab 42 is the other end of the short side (the lower side in FIG. 12) opposite to the positive side of the positive electrode tab 41 formation side. Part (right end part in FIG. 12). That is, the positive electrode tab 41 and the negative electrode tab 42 are respectively opposite to each other (upper and lower in FIG. 12) from a pair of diagonal corners (upper left and lower right corners in FIG. 12) in the positive electrode plate and the negative electrode plate. It is configured to extend downward).

  In the case of the configuration of the laminated electrode body 40, the current path is a current path R11 along a straight line connecting the upper left positive electrode tab 41 and the lower right negative electrode tab 42 at a substantially shortest distance on the positive electrode plate and the negative electrode plate. As the center, it gradually spreads in a wavy shape on both sides, and as a whole, it has a shape extending in a generally spindle shape from the positive electrode tab 41 to the negative electrode tab 42, and one short side of the rectangular positive electrode plate or negative electrode plate (in FIG. 12) In a circle inscribed in the upper side or the lower side) and in the circle inscribed on the long sides on both sides, it is a partial circle that forms a quarter that is close to the diagonal part where the positive and negative electrode tabs 41 and 42 are not formed (that is, the lower left and upper right corners in FIG. 12). It is considered that current hardly flows at positions outside the boundary line B11 extending substantially along (that is, the lower left and upper right corners in FIG. 12). That is, the inside of the boundary line B11 is the active region H11, and the outside is the low active region N11.

  Therefore, in this case, as shown in the figure, the low active region N11 formed at the corner where the positive and negative electrode tabs 41 and 42 are not formed (that is, the lower left and upper right corners in FIG. 12) In this case, as in the case of the batteries A1, A2, and A3 of the present invention, the width and height of the positive electrode plate or the negative electrode plate positioned so as to be aligned at both corners. It is desirable to provide each of the through portions 39 so as to be within (in the center of) a rectangular region having a width and height corresponding to approximately 1/10 of the height.

  When the positive electrode tab 41 and the negative electrode tab 42 are configured to extend in the opposite directions from the positive electrode plate or the negative electrode plate as described above, the respective widths of the positive electrode tab 41 and the negative electrode tab 42 are set to the positive electrode plate or the negative electrode plate. It is considered that the wider the active area, the wider the active region and the lower the resistance, which is desirable in terms of the characteristics of the terminal. Therefore, it is necessary to leave enough room to enable sealing of the exterior body. Therefore, since it is inevitable that the low active region is formed as described above, the present invention is preferably applied.

(2) In the above example, the positive electrode tab and the negative electrode tab are arranged and formed close to one end of one side of the positive electrode plate and the negative electrode plate. For example, as shown in FIG. 13, the positive electrode tab 511 and the negative electrode tab 512 are arranged. Are arranged at a distance D5 from one end of one side (same side; upper side in FIG. 13) of the positive electrode plate 51 to the negative electrode plate 52, respectively, from the positions of the positive electrode tab 511 and the negative electrode tab 512. The low active regions N21 extending along both sides with a width W1 equal to the distance D5 are formed on the outside. Therefore, when the width W1 of the low active region N21 is greater than or equal to the extent that a through portion can be formed, the through portion may be formed in the low active region N21. In the example shown in the figure, through portions 43 are provided at the end portions close to the positive and negative electrode tabs 511 and 512 in the low active regions N21 on both sides, that is, at the corners located on both sides of the positive electrode tab 511 and the negative electrode tab 512, respectively. Therefore, the positive electrode plate 51 and the negative electrode plate 52 are fixed by the through portions at the four corners together with the through portions (not shown) provided at the opposite ends of the positive and negative electrode tabs 511 and 512 on the opposite side. It has become. In this configuration, each of the positive electrode plate 51 and the negative electrode plate 52 is supported and fixed at four corners other than the positive electrode tab 511 to the negative electrode tab 512.

(3) In the present invention batteries A1, A2, and A3, the positive electrode active material layer 1a and the negative electrode active material layer 2a were formed on the entire surfaces of the positive electrode plate 1 and the negative electrode plate 2, respectively. The positive electrode active material layer and the negative electrode active material layer may not be formed in the active region N1. Since the active material in the low active region N1 is hardly used for the electrode reaction, if this is removed, the usage amount of the active material can be saved without substantially reducing the battery capacity. Thus, the material cost can be reduced and the weight energy density of the battery can be improved.

(4) In the above example, the through portion is a circular through hole. However, as the through portion, in addition to the through hole, for example, the positive electrode plate and the negative electrode plate are arc-shaped, rectangular, triangular, etc. from the edge. It may be a notch cut out in an arbitrary shape, a corner drop portion in which corners of the positive electrode plate and the negative electrode plate are cut into an arbitrary shape such as an arc shape, a saddle shape, or a hypotenuse shape. 14 and 15 are diagrams showing an example in which the laminated electrode body is fixed with the penetrating portion as a corner drop portion. In the example shown in the figure, at both ends of the positive electrode plate 61 and the negative electrode plate 62 opposite to the side where the positive and negative electrode tabs 611 and 612 are formed, outside the boundary line B12 similar to the case of the present invention batteries A1, A2 and A3. In the low active region N31 formed in FIG. 14, through portions 44 are formed so that both corners (lower right corner and lower left corner in FIG. 14) are cut into oblique sides so as to drop the corners. The laminated electrode body 50 is fixed by thermally welding the corners of the separator 63 with the portion 44. In FIG. 15, for the sake of clarity, the number of laminated members (positive electrode plate 61, negative electrode plate 62, and separator 63) constituting the laminated electrode body 50 is schematically shown by being significantly smaller than the actual number. Yes. According to this configuration, not only the active material in the low active region N31 but also the positive electrode plate 61 and the negative electrode plate 62 are removed in a wider range of portions that are hardly used as power generation elements. Therefore, the weight of the battery can be further reduced.

(5) In the battery A3 of the present invention of the second embodiment, the penetrating member 38 is made of polypropylene. However, the material of the penetrating member is hardly soluble in the electrolyte as in the case of the separator. What is necessary is just to have insulation, For example, polyolefin resins, such as polyethylene other than a polypropylene, Fluorine-type resin, such as polytetrafluoroethylene (Teflon (trademark)), etc. are mentioned.
In addition, the structure of the penetrating member does not need to be firmly fastened to the laminated electrode body, and may be any structure as long as it can be reliably held without falling off while being inserted into the penetrating portion.

(6) The batteries A1, A2 and A3 of the present invention have a configuration in which the laminated electrode body 10 is inserted into the exterior body 18 composed of the laminate film 17, and such a laminate type is used as the exterior body. For example, a metal battery can or the like may be used. However, since the laminate-type exterior body is more likely to transmit vibration and external force to the laminated electrode body, and more likely to cause misalignment, the effect of the present invention is further exhibited.

(7) The positive electrode active material is not limited to the above-described lithium cobalt oxide, and lithium composite oxide containing cobalt such as cobalt-nickel-manganese, aluminum-nickel-manganese, aluminum-nickel-cobalt, nickel, or manganese. Or a spinel type lithium manganate may be used.

(8) As the negative electrode active material, in addition to graphite such as natural graphite and artificial graphite, graphite, coke, tin oxide, lithium metal, silicon, and a mixture thereof can be used to insert and desorb lithium ions. It doesn't matter.

(9) The electrolyte solution is not particularly limited to that shown in the present embodiment, and examples of the lithium salt include LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiPF _6-x (C _n F _{2n + 1} ) _x [where 1 <x <6, n = 1 or 2] and the like can be used, and one or more of these can be used in combination. The concentration of the supporting salt is not particularly limited, but is preferably 0.8 to 1.8 mol per liter of the electrolyte. In addition to the above EC and MEC, the solvent species include carbonate solvents such as propylene carbonate (PC), γ-butyrolactone (GBL), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). More preferably, a combination of a cyclic carbonate and a chain carbonate is desirable.

  The present invention can be suitably applied to a power source for high output applications such as for power mounted on a robot or an electric vehicle, for example.

10 Laminated electrode body 1/2 Positive electrode plate / Negative electrode plate 31, 32 Through portion H 1 Active region N 1 Low active region

Claims (5)

A laminated battery comprising a laminated electrode body in which a positive electrode plate and a negative electrode plate are alternately laminated via separators,
In the laminated electrode body, a through-hole for preventing misalignment is provided in a region deviating from an active region that is substantially easily used for electrode reaction, and the through-hole for preventing misalignment through the positive electrode plate and the negative electrode plate is provided. A laminated battery, wherein the laminated electrode body is fixed.   The stacked battery according to claim 1, wherein the current value is charged and discharged at a high rate of 6.0 It or more.   The laminated electrode body is fixed by arranging the penetrating portion so as to penetrate the separator in the laminating direction together with the positive electrode plate and the negative electrode plate, and penetrating a penetrating member made of a nonconductor through the penetrating portion. Alternatively, the stacked battery according to claim 2.   The laminated electrode body is fixed by welding the separators positioned so as not to penetrate the separator and sandwiching the through part in the through part. Stacked battery. A method for producing a laminated battery comprising a laminated electrode body in which a positive electrode plate and a negative electrode plate are alternately laminated via separators,
Each of the positive electrode plate, the negative electrode plate, and the separator is for preventing misalignment of the positive electrode plate, the negative electrode plate, and the separator that penetrates in the stacking direction in a region that deviates from an active region that is substantially easily used for electrode reaction. A method for manufacturing a stacked battery, comprising: providing a through portion; and positioning and stacking the positive electrode plate, the negative electrode plate, and the separator so that a positioning boss is inserted through the through portion.

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