JP2003257406A - Square spiral electrode group and square nonaqueous electrolyte battery using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a square spiral electrode group in which the distance between current collecting leads is constant and the specified relative position relation is kept even when sizes are varied, and a core is not extended to a degree exceeding the necessary length. <P>SOLUTION: Current collecting leads 9, 10 for positive and negative electrodes are arranged at the constant distance K in the width direction of a flat square shape. In one electrode plate 12 positioned on winding outside, when the number of turning up repetitions is an even number, the current collecting lead 10 is installed in a position apart to a winding start end side only the half distance of the constant distance K from the middle point c of a first semicircle part at the start of winding, and when the number of turning up repetitions is an odd number, the current collecting lead 10 is installed in a position apart in the opposite direction to the winding start end side only the half distance of the constant distance K from the middle point c. In the other electrode plate 11 positioned on winding inside, the current collecting lead 9 is installed in a position keeping a constant distance K to the current collecting lead 10 of one electrode plate of the core 11a protruded from the final turning up part, independent of the number of turning up repetitions. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a rectangular cross-section having a flat cross section by spirally winding a strip-shaped positive electrode plate and a negative electrode plate with a separator interposed therebetween. The present invention relates to a prismatic spiral electrode group having a shape and a prismatic nonaqueous electrolyte battery such as a prismatic lithium secondary battery, which is configured by using the electrode group.

[0002]

2. Description of the Related Art In recent years, portable and cordless AV equipment or electric equipment such as personal computers and portable communication equipment have been rapidly promoted. Conventionally, nickel-cadmium batteries and nickel-hydrogen batteries have been mainly used as power sources for driving these electric devices, but in recent years, rapid charging is possible, and both volume energy density and weight energy density are high, resulting in high safety. Non-aqueous electrolyte batteries typified by lithium secondary batteries are becoming mainstream.

In the above non-aqueous electrolyte battery, it has been promoted that the non-aqueous electrolyte battery is a sealed type which is excellent in high energy density and load characteristics, and is also a flat prismatic shape which is suitable for thinning equipment and has a high space use effect. Further, these batteries are required to have higher voltages and higher capacities as the performance and functionality of portable electric devices are advanced. 2. Description of the Related Art A rectangular nonaqueous electrolyte battery configured by using a rectangular spiral electrode group formed by spirally winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween is widely used.

FIG. 8 (a) shows positive and negative electrode plates 1 and 2 and a pair of separators, which are constituent elements of a prismatic spiral electrode group used in a prismatic lithium secondary battery having such a high capacity. 3A and 3B are plan views schematically showing the relative positional relationship before winding, and FIG. 3B is a partially cutaway side view of FIG. The positive electrode plate 1 has the positive electrode active material layers 1b formed on both sides of the strip-shaped positive electrode core material 1a, and the negative electrode plate 2 has the negative electrode active material layers 2b formed on both sides of the strip-shaped negative electrode core material 2a. The bipolar plates 1 and 2 have a pair of winding cores 4A and 4B in a state in which the negative electrode plate 2 is positioned on the inner side in the winding direction shown by the arrow and the separators 3A and 3B are interposed between the negative plates 2 and 1A. Are wound by sandwiching the respective starting ends of both separators 3A and 3B from both sides and rotating in the winding direction to form a rectangular spiral electrode group having a flat rectangular cross-sectional shape. In this electrode group, the negative electrode current collector lead 8 is attached to the negative electrode core material 2a protruding from the winding start end of the negative electrode plate 2, and the positive electrode current collector lead 8 is attached to the positive electrode core material 1a protruding from the positive electrode plate 1 at the winding end end. 7 is attached. In addition, R1 shown in FIG.
R13 indicates the center position of the portion that is folded back at the rounded portion on the outer end side of both winding cores 4A and 4B and the winding order thereof.

The prismatic spiral electrode group constructed as described above can constitute a prismatic non-aqueous electrolyte battery with improved weight energy density and volume energy density. That is, the active material layer-unformed portion 2c in which the negative electrode core material 2a is exposed is provided on the inner surface side of the portion of the negative electrode plate 2 on the winding start side, and the portion of the positive electrode plate 1 on the winding end side of the one circle. An active material layer-unformed portion 1c in which the positive electrode core material 1a is exposed on the outer surface side
Is provided. These active material layer-unformed portions 1c and 2c
The opposite polarity active material layers 2b and 1b for chemical reaction do not exist on the sides facing each other with the separators 3A and 3B interposed therebetween. Therefore, in the spiral electrode group, the unnecessary active material layers 1b and 2b that do not participate in charging and discharging are reduced, and the length of the bipolar plates 1 and 2 is increased by the thickness of the reduced unnecessary active material layers 1b and 2b. The length can be increased or the active material layers 1b and 2b can be thickened to increase the capacity, and both the weight energy density and the volume energy density of the battery can be improved.

In the spiral electrode group, the winding start end and the winding end end of the two separators 3A and 3B are aligned at the same position. This is because at the end of the winding process of the electrode group, the two separators 3A and 3B are overlapped with each other under tension and cut at the same position with a cutter, and the two separators 3A are cut in the next winding process. ，
Negative electrode core material 2 provided with winding start portions where the same cut points of 3B are aligned and the negative electrode current collecting lead 8 of the negative electrode plate 2
This is because it is possible to surely align a with a and start winding.

By the way, in the above-mentioned non-aqueous electrolyte battery, the battery case is generally made of aluminum and used as the positive electrode of the battery. This is because the nickel-plated iron battery case has been used in non-aqueous electrolyte batteries for a long time, but during long-term storage, the iron component of the battery case dissolves into iron ions and this dissolution reaction continues. This is because there is a drawback that there are corrosion holes in some parts. On the other hand, aluminum is less likely to be dissolved in a non-aqueous electrolyte than nickel-plated iron, and therefore corrosion can be prevented. Moreover, since its specific gravity is small, the weight energy of the battery as a weight is reduced. There is an advantage that the density can be improved. Aluminum is used as the material of the positive electrode core material 1a because the weight energy density can be improved as the weight is reduced.

Therefore, the positive electrode core material 1a exposed in the active material layer-unformed portion 1c located at the outermost periphery of the positive electrode plate 1 in the spiral electrode group is made of the same metal and the same positive electrode as the battery case. Not only will there be no inconvenience caused by contact with the inner peripheral surface, but conversely, if one cycle of the positive electrode core material 1a is brought into contact with the inner peripheral surface of the battery case, the contact area at the positive electrode terminal portion will be remarkably increased. Because it gets bigger and you can get good electrical connection,
It is possible to obtain an efficient current collecting effect and improve the discharge characteristics.

However, in the above spiral electrode group, it is necessary to align the ends of the two separators 3A and 3B at the same position, and the positive electrode is placed between the outermost peripheral portions of the separators 3A and 3B. Since the plate 1 is interposed and the active material layer 2a of the negative electrode plate 2 is present on the inner side, the end points of both separators 3A and 3B are set to positions beyond the end of the positive electrode plate 1 without stopping. ing. Therefore, in the prismatic battery using the above electrode group, the positive electrode core material 1a of the active material layer-unformed portion 1c is used.
Since it is not possible to make contact with the inner peripheral surface of the battery case, current collection on the positive electrode side must be performed only by the electrical connection between the positive electrode current collecting lead 7 and the sealing plate, and the current collecting efficiency cannot be improved. Therefore, sufficient discharge characteristics cannot be obtained. Moreover,
One or more rounds of the outermost periphery of the outer separator 3B is completely unnecessary and does not function as a battery, which causes a decrease in the volume energy density of the battery.

Therefore, for the purpose of solving the above problem, a spiral electrode group as shown in FIG.
In this electrode group, the positive electrode plate 11 is arranged on the winding inner side and the negative electrode plate 12 is arranged on the winding outer side, and the positive electrode active material layer 11b and the negative electrode active material layer 12b are arranged.
It is configured to be wound so as to be covered with. This allows
Particularly, in a lithium secondary battery in which an aluminum battery case serves as a positive electrode, the occurrence of a short circuit due to the generation of lithium dendrites during discharge is prevented.

In the positive electrode plate 11, the active material is provided on the inner surface side of the positive electrode core material 11a for at least one winding start and on the outer surface side of the positive electrode core material 11a for at least one winding on the winding end side. Active material layer unformed portions 11c and 11d in which the positive electrode core material 11a is exposed without forming the layer 11b are provided. The negative electrode plate 12 has a length terminating at a position that is shorter than the positive electrode plate 11 by at least one turn.
The active material layer 12 is formed on the entire surface except for a half turn at the beginning of winding in a.
b is formed. Pair of separators 13A, 13B
Are set to have the same length as each other, with the terminal ends at substantially the same positions as the terminal ends of the negative electrode plate 12. Further, the negative electrode plate 12 has a negative electrode core material 1 protruding from the starting end portion of the active material layer 12b.
The negative electrode collector lead 10 is attached to 2a, and the positive electrode plate 1
1, the positive electrode current collector lead 9 is attached to the positive electrode core material 11a protruding from the end of the active material layer unformed portion 11d.

Since the outermost circumference of the spiral electrode group is formed by the active material layer-unformed portion 11d of the positive electrode plate 11, it generally constitutes a positive electrode in a non-aqueous electrolyte battery such as a lithium secondary battery. An extremely good electrical connection can be obtained by bringing the positive electrode core material 11a of the active material layer-unformed portion 11d into contact with the inner peripheral surface of the aluminum battery case to improve the current collection efficiency and obtain sufficient discharge characteristics. be able to. Based on this configuration, as shown in FIG.
Since the pair of separators 13A and 13B can be shortened by about one turn with respect to the positive electrode plate 11, the pair of separators 13A and 13B that need to be cut at the same position due to manufacturing restrictions have the configuration of FIG. The total length can be shortened by 2 turns as compared with, and the thickness or length of the active material layers 11b and 12b can be set larger by the shortened amount.
Further, the active material layer-unformed portions 11c and 11d are defined as the locations where the negative electrode active material layer 12b for the chemical reaction does not exist at the facing portions of the positive electrode plate 11. Therefore, this electrode group can form a battery having improved weight energy density and volume energy density.

[0013]

Since the prismatic non-aqueous electrolyte battery such as a lithium secondary battery has the above-mentioned remarkable features, the demand as a power source for driving various electric devices is increasing. Therefore, along with this, a large number of types of prismatic spiral electrode groups are housed in prismatic battery cases of various sizes with different lengths (heights) and cross-sectional shapes, which are different in width and thickness of flat prisms. It is expected to appear. For example, for a rectangular non-aqueous electrolyte battery, the length, width and thickness are (50, 34, 3.
6), (48,30,4.3), (48,30,5.
3), (50,33,6.3), (50,34,10.
It is planned to put the prismatic battery case of 0) into a series for practical use or practical use. The unit of the length, width and thickness is mm.

However, at the present time, each time the size of the non-aqueous electrolyte battery is different, a dedicated production facility for manufacturing those batteries is manufactured, so that the number of types increases and the amount of waste increases. There is a problem that the manufacturing cost is high. The above-mentioned production equipment includes an electrode group forming machine for winding the electrode group, an electrode group inserting machine for inserting the electrode group into the battery case, and connecting the leads 9 and 10 with the sealing plate by welding or the like. A connection machine and a liquid injection machine for injecting electrolyte into the battery case.

The above production equipment cannot be shared because the rectangular spiral electrode group of the prismatic nonaqueous electrolyte battery has a space K between the positive and negative electrode current collecting leads 9 and 10 shown in FIG. This is because the relationship has various configurations corresponding to the difference in the width and thickness of the electrode group. That is, for example, using the same connecting device, the positive and negative electrode current collecting leads 9 and 1
When 0 is connected to a sealing plate or the like, a short circuit may occur due to contact between the positive and negative electrode current collecting leads 9 and 10 in which the interval K is not constant. , 10 are not arranged at a fixed relative position, the connection position between the positive and negative electrode current collecting leads 9 and 10 and the sealing plate is deviated, and a reliable connection state cannot be obtained. Therefore, the prismatic non-aqueous electrolyte battery is required to be manufactured in a plurality of series-sized ones while reducing the manufacturing cost by standardizing the equipment mounting design and sharing the production equipment.

On the other hand, as shown in FIGS. 7 (a) and 7 (b),
When the positive and negative electrode plates 11 and 12 and the separators 13A and 13B having different lengths are wound to form a rectangular spiral electrode group having different sizes, the number of turns is slightly less than that of the electrode group of (a). In the electrode group of (b), in order to match the pattern of the winding end end with the electrode group of (a), when the positive electrode current collecting lead 9 is provided at the position shown by the chain double-dashed line, The current collecting lead 9 is arranged at the position shown by the chain double-dashed line in FIG. 7C, and is not arranged at a predetermined distance K and relative position with respect to the negative electrode current collecting lead 10. Therefore, at present, as shown by the solid line in (b), the end of the positive electrode core material 11a is connected to the active material layer unformed portion 11d.
Of the positive electrode current collector lead 9 at the end portion of the positive electrode core material 11a by extending it to a position where the length from the end of the positive electrode core member 11a is longer than that of the electrode group having the length (a). The current collecting lead 9 is arranged at a predetermined relative position with respect to the negative electrode current collecting lead 10 at a predetermined relative position at a position shown by a solid line in FIG.

However, although FIG. 7 is a schematic illustration in which the lengths of the half circumferences between the two adjacent folding parts are all the same, the number of turns is large in the lengths of the respective half circumferences. Therefore, in the case of the above configuration, the length of the half circumference of the positive electrode core material 11a extended from the longest final winding portion is relatively long. In this way, the long positive electrode core material 11a is provided in the final winding portion.
When it is present, it is difficult to finish winding the electrode group smoothly, and it is easy to cause winding deviation in the thickness direction of the electrode group after winding, and the desired effect cannot be obtained when it functions as a battery. A serious problem arises for the electrode group. In addition, since the above-mentioned longer than necessary positive electrode core material 11a is useless because it does not participate in the function of the battery, the volume energy density of the battery is reduced accordingly.

Therefore, the present invention has been made in view of the above-described conventional problems, and even when the cross-sectional shape is formed into a flat rectangular shape having various widths and thicknesses, the current collectors for the positive and negative electrodes are formed. A rectangular spiral electrode group and a prism using the electrode group, in which the leads are arranged at regular intervals and have a predetermined relative positional relationship, and the core material does not extend longer than necessary at the final winding portion. It is intended to provide a non-aqueous electrolyte battery.

[0019]

In order to achieve the above object, a prismatic spiral electrode group according to the present invention has a positive electrode active material layer formed on both surfaces of a strip-shaped positive electrode core material and has a positive electrode current collector lead. A positive electrode plate to which the negative electrode active material layer is formed on both surfaces of a strip-shaped negative electrode core material, and a negative electrode current collector lead attached to the negative electrode plate, and a separator is interposed therebetween to form a spiral. When the cross-sectional shape is formed into a flat rectangular shape by winding in a rectangular shape, both the positive and negative electrode current collecting leads are formed in the width direction of the flat rectangular shape regardless of whether the number of turns is even or odd. When the number of turns is an even number, the one electrode plate, which is arranged at a constant interval and is located on the outer side of the winding, starts at a distance half the constant interval from the midpoint of the first half circumferential portion of the winding start. Current collecting leads are provided at positions spaced apart from each other And when the number of turns is odd, a current collecting lead is provided at a position separated from the midpoint in the direction opposite to the starting end side by a distance of half the constant interval, and is located on the winding inner side. The other electrode plate, at any of the even number and the odd number of folding back, is located at a position that is at the constant interval with respect to the current collecting lead of the one electrode plate in the core material that is projected from the final folding portion. It is characterized in that a current collecting lead is provided.

In this rectangular spiral electrode group, the distance between the positive and negative electrode current collecting leads is always set to be constant, and the relative positional relationship between the positive and negative electrode current collecting leads is changed regardless of the number of folding back. The numbers are always the same depending on whether the numbers are even or odd. Therefore, if one of the electrode groups with an even or odd number of turns is rotated 180 °,
Since the positive and negative electrode current collecting leads have the same relative positional relationship as the other electrode group as well as the spacing, various rectangular spiral electrode groups of different sizes can be shared by the same electrode group forming machine. The prismatic spiral electrode group for various prismatic batteries to be manufactured can be manufactured at low cost. In addition, the current collecting lead provided at the winding start portion of one electrode plate is provided at different mounting positions depending on whether the number of turns is an even number or an odd number. Regardless of whether the number of turns is even or odd, the core material to be used can always be the same length with the required length, so there is no winding slippage in the thickness direction, and the desired core material is obtained. It is possible to surely obtain the function of and to improve the volume energy density.

In the above invention, the straight line portion excluding the curved portions on both sides is set to a length determined by the desired width and thickness to be formed, and the positive and negative current collecting leads are the straight line portion. It is preferable that the positive and negative electrodes are attached to the central portion of the positive electrode plate at regular intervals.

According to this structure, when a plurality of types of prismatic batteries each having a rectangular flat cross-sectional shape different in width and thickness are manufactured in series, the prismatic spiral shape used for each prismatic battery is produced. Since the thickness of the electrode group is equal to the diameter of each curved portion on both sides in the width direction regardless of the difference in size, the length of the linear portion existing between the curved portions on both sides is required. It can be easily obtained by subtracting a value obtained by adding the diameter of the curved portion, that is, the length of the radius of each curved portion on both sides, from the length of the width of the oblate shape. Further, since both the positive and negative current collecting leads are provided at regular intervals in the central portion of the straight line portion, the mounting positions of the both current collecting leads to the corresponding positive and negative electrode plates are the straight line portion. It can be easily calculated based on the length of.

In the above invention, one of the electrode plates is
An active material layer-unformed portion, in which the active material layer is not formed and the core material is exposed, is provided on the inner surface side of the core material having a length of one round from the first folded portion, and the active material layer is not formed. A current collecting lead is attached to the core material protruding from the starting end of the forming portion, and the other electrode plate is provided in such a position that the starting end is positioned at the third folded portion, and the active material layer is formed from the starting end. At the same time, on the outer surface side with respect to the core member extended for one round from a position facing the end of the one electrode plate,
An active material layer-unformed portion, in which the active material layer is not formed and the core material is exposed, is provided, and a current collector lead is attached to the core material further protruding from the end of the active material layer-unformed portion,
It is preferable that the pair of separators have an end at substantially the same position as the end of one of the electrode plates and have the same length.

Thus, in each of the positive electrode plate and the negative electrode plate, a portion where no active material layer of opposite polarity for chemically reacting with each other through the separator exists is an active material layer-unformed portion. The volume energy density and the weight energy density of the battery can be improved. In addition to this, the active material layer-unformed portion of one electrode plate is present only in the portion corresponding to one turn from the first turn portion to the third turn portion, and each active material layer of both electrode plates is present. However, since the pair of separators and the active material layer-unformed portion of one of the electrode plates are wound from the third turn-back portion after one and a half turns, each active material layer of both electrode plates is Since it is wound from the third folded portion that has a relatively large radius of curvature after the winding of one and a half turns, it can be smoothly wound without bulging outward, and it has an extremely excellent volumetric efficiency. .

Further, in the above invention, the number of turns is set corresponding to the difference in width and thickness in the flat cross-sectional shape of the battery case, and the excess or deficiency with respect to the width and thickness is the active material of the electrode plate. It can be configured to have an outer shape that can be compensated by adjusting the coating thickness of the layer and can be inserted into the battery case in a fitted state. This allows
It is possible to obtain a rectangular spiral electrode group with a high volume energy density even when the sizes are different, and a rectangular spiral electrode group for a rectangular battery with a slightly different width and thickness for each rectangular battery to be made into a series. Then, it can be easily manufactured using the same manufacturing method.

In the above invention, the other electrode plate may be a positive electrode plate in which a positive electrode active material layer is formed on both surfaces of a positive electrode core material made of aluminum. As a result, this prismatic spiral electrode group can be suitably used for a prismatic nonaqueous electrolyte battery such as a lithium secondary battery.

The prismatic non-aqueous electrolyte battery of the present invention is a prismatic spirally wound electrode group having an even or odd number of folding backs, out of the prismatic spirally wound electrode group manufactured by the manufacturing method according to any one of the above inventions. Is inserted into the battery case as a reference for the arrangement, and the other prismatic spiral electrode group is rotated by 180 ° and then inserted into the battery case.
One of the one and the other current collecting leads is connected to the sealing plate, and the other is connected to the electrode terminal.

In this prismatic non-aqueous electrolyte battery, a prismatic spiral electrode group in which the distance and relative positional relationship between the positive and negative electrode current collecting leads are always constant regardless of the difference in width and thickness is housed in a prismatic battery case. Therefore, even when the shape of the rectangular spiral electrode group differs depending on the size of the battery case during assembly, the same spiral electrode group can be shared by the same electrode group insertion machine. Even if the positive and negative electrode current collecting leads are connected to the sealing plate and the electrode terminal by inserting the battery into the battery case and sharing the same connecting device, short circuit due to contact between the positive and negative electrode current collecting leads Positive,
It is possible to surely prevent the displacement of the negative electrode current collecting lead and the sealing plate and the electrode terminal, and to perform the connection. Therefore, a large number of series-shaped cross-sectional shapes having various widths and thicknesses can be constructed inexpensively as the manufacturing cost is reduced.

The prismatic lithium secondary battery of the present invention is
The prismatic spiral electrode group manufactured by the manufacturing method according to any one of the above-mentioned inventions using the positive electrode plate having the positive electrode core material made of aluminum foil as the other electrode plate is housed in a rectangular battery case made of aluminum, and the positive electrode plate Of the positive electrode core material and / or the positive electrode core material to which the positive electrode current collector lead is attached in an exposed state in the active material layer-unformed portion located on the outermost periphery of the battery case is in contact with the inner peripheral surface of the battery case. Is characterized by.

In this prismatic lithium secondary battery, the aluminum positive electrode core material in the active material layer-unformed portion of the positive electrode plate forming one outermost circumference of the rectangular spiral electrode group on the inner peripheral surface of the aluminum battery case, Since the exposed positive electrode core material can be brought into contact with each other, extremely good electrical connection can be obtained, current collection efficiency can be improved, and sufficient discharge characteristics can be obtained. Further, in this prismatic lithium secondary battery, the active material layer is not present at a location where a reverse polarity active material layer for chemical reaction is present on opposite sides of the positive and negative electrode plates of the prismatic spiral electrode group through the separator. The layer core is not formed and the positive electrode core material that is exposed at the end and protrudes to attach the positive electrode current collecting lead in the positive electrode plate is not extended longer than necessary, so both volume energy density and weight energy density are improved. To do. Further, in the spiral electrode group, the positive electrode plate is arranged on the winding inner side and the negative electrode plate is arranged on the winding outer side, and the positive electrode active material layer is wound so as to be covered with the negative electrode active material layer. Therefore, it is possible to prevent the occurrence of a short circuit due to the generation of lithium dendrites during discharge.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1 (a) and 2 (a) are plan views each schematically showing a relative positional relationship before winding of each component in the rectangular spiral electrode group 14 according to the embodiment of the present invention. 1 (b) and 2 (b) are schematic plan views showing the outer shape of the electrode group 14 formed by winding the respective constituent elements of FIG. 1 (a).

In FIGS. 1 and 2, the same or equivalent parts to those in FIG. 7, which are similar in basic technical idea to this embodiment, are designated by the same reference numerals. In addition, FIG.
And R0 to R17 attached to FIG. 2 (a) are a pair of winding cores 4.
3 shows the winding order of the folded-back portion at the time of winding by A and 4B. Between each of the folded portions, the length of a half circumference when winding is shown, and the length of this half circumference gradually becomes longer as the number of turns increases,
In FIG. 1A and FIG. 2A, the same length is shown for convenience of illustration. The setting of the length for each half circumference will be described later.

FIG. 1 shows that each time the winding cores 4A, 4B rotate half a turn (180 ° rotation) in the winding process of the pair of winding cores 4A, 4B, the components in the stacked state are wound while being folded back. FIG. 2 shows the rectangular spiral electrode group 14 when the number of turns is an even number (16 in the figure is an example), and FIG. 2 shows an odd number in which the number of turns is one less than that in FIG. Shows the case of the rectangular spiral electrode group 14 in the case of 15 times).

That is, the prismatic spiral electrode group of this embodiment is determined from the size of the prismatic battery case shown in FIG.
(B) and desired widths L1 to L4 and thickness T in FIG. 2 (b)
1 to T4, the width L1 to L4 and the thickness T1 are obtained when the rectangular spiral electrode group 14 having a rectangular cross section is obtained.
Based on T4, the number of turns is determined to be an even number or an odd number. If the determined number of turns causes excess or deficiency with respect to the desired widths L1 to L4 and thicknesses T1 to T4, the active material layers 11b and 12b of the positive and negative electrode plates 11 and 12 are formed.
Make fine adjustments by changing the coating thickness of. Thereby, when the width and the thickness are slightly different from those of the prismatic non-aqueous electrolyte battery to be made into a series, the same manufacturing method can be used.

In this embodiment, the prismatic spiral electrode group 14 constituting the prismatic lithium secondary battery is exemplified. Therefore, the battery case to be accommodated in the prismatic spiral electrode group 14 is a non-aqueous electrolyte solution. It is made of aluminum that has excellent corrosion resistance and is easy to handle. The positive electrode plate 11 is formed by using a strip-shaped positive electrode core material 11a made of aluminum foil, which is the same metal as the battery case, and applying a positive electrode active material to both surfaces of the positive electrode core material 11a, followed by rolling and drying. The active material layer 11b is formed. Negative electrode plate 12
Is formed by forming a negative electrode active material layer 12b formed by applying a negative electrode active material on both surfaces of a strip-shaped negative electrode core material 12a made of a copper foil, and then rolling and drying. Separator 1
3A and 13B are formed, for example, by using a microporous polyethylene film as a band. This square spiral electrode group 1
4 is configured such that the positive electrode plate 11 is arranged on the winding inner side and the negative electrode plate 12 is arranged on the winding outer side, and the positive electrode active material layer 11b is wound so as to be covered with the negative electrode active material layer 12b. It

In the above-mentioned rectangular spiral electrode group 14, FIG.
As is clear from the comparison between (a) and FIG. 2 (a), the half-circumferential portion from the winding start end R0 to the first turn-back portion R1 is distinguished depending on whether the number of turns is even or odd. By changing the mounting position of the negative electrode current collecting lead 10 mounted on the negative electrode plate 12, the shape and relative positional relationship of each of the positive and negative electrode plates 11 and 12 and the pair of separators 13A and 13B at the winding start portion and the winding end portion. Are set to be the same and wound regardless of the difference in the number of turns.

More specifically, the positive electrode active material layer 11b is formed on the positive electrode plate 11 on the outer surface side of the portion corresponding to one winding on the winding end side regardless of whether the number of turns is even or odd. However, the active material layer-unformed portion 11e in which the positive electrode core material 11a is exposed is provided. The negative electrode plate 12 includes a first folded portion R1 to a third folded portion R.
The negative electrode active material layer 1 is provided on the inner surface side of the portion corresponding to one round up to 3.
An active material layer-unformed portion 12c in which the negative electrode core material 12a is exposed without forming 2b is provided.

In the positive electrode plate 11, the positive electrode core member 11a is protruded by about half a turn from the end of the active material layer unformed portion 11e on the winding end side regardless of whether the number of turns is an even number or an odd number. The current collecting lead 9 is attached, and unlike the positive electrode plate 11 of FIG. 7B, the positive electrode core material 11a does not extend excessively. On the other hand, in the negative electrode plate 12, the negative electrode current collector lead 10 is attached to the negative electrode core material 12a which is projected from the starting end of the active material layer unformed portion 12c on the winding start side to the winding start side. The protruding length of the core material 12a, that is, the attachment position of the negative electrode current collector lead 10 differs depending on whether the number of turns is even or odd, as described above. Details of this will be described later.

The positive and negative electrode plates 11 and 12 shown in FIGS. 1A and 2A have separators 13A and 13B between them.
In a state of being laminated with the interposing of the separators, the pair of winding cores 4A and 4B are connected to the winding start ends of the separators 13A and 13B and the negative electrode plate 1.
The negative electrode core material 12a of the negative electrode current collector lead 10 in FIG. 2 is sandwiched and rotated in the direction of the arrow in the drawing, so that the negative electrode core material 12a is spirally wound, and as shown in FIGS. The rectangular spiral electrode group 14 having a rectangular cross-sectional shape is formed. FIG. 3 shows a rectangular spiral electrode group 14 in the case where the number of turns is an even number in FIG. 1, and FIG.
The rectangular spiral electrode group 14 when the number of turns is odd is shown. At the time of winding, the pair of winding cores 4A, 4B
Are rotated in a displaced position, and are displaced in a direction in which they are close to each other after the configuration of the electrode group 14 is completed and are overlapped with each other.
It can be easily removed from.

3 and 4 show a rectangular spiral electrode group 14
It is a schematic illustration for easy understanding of the structure of only the winding start portion and the winding end portion. That is, in the positive electrode plate 11, the active material layer 11b is shown by two parallel solid lines at relatively wide intervals, and the active material layer-unformed portion 11 is shown.
e is shown by two parallel solid lines at relatively narrow intervals, and the positive electrode core material 11a is shown by one solid line. In the negative electrode plate 12, the active material layer 12b is illustrated by two parallel broken lines, the active material layer unformed portion 12c is illustrated by parallel solid lines and broken lines, and the negative electrode core material 12a is illustrated by one solid line. There is.

The negative electrode current collecting lead 10 is covered and protected by a lead protection tape 18. In the positive electrode core material 11a exposed on the terminal end side of the positive electrode plate 11, the terminal portion beyond the attachment position of the positive electrode current collector lead 9 has an active material layer-unformed portion 1
The group fixing tape 17 is attached to the positive electrode core material 11a exposed to 1e.
And the rectangular spiral electrode group 14 is held in a wound state without slack.

The rectangular spiral electrode group 14 shown in FIGS. 3 and 4 has an opposite polarity activity for chemically reacting with the opposite sides of the positive and negative electrode plates 11 and 12 with the separators 13A and 13B interposed therebetween. Since the portions where the material layers 12b and 11b do not exist are the active material layer-unformed portions 11e and 12c, the volume energy density and the weight energy density of the battery can be improved.

Furthermore, the prismatic spiral electrode group 14 has a very excellent volumetric efficiency. That is, in this rectangular spiral electrode group 14, the first turn-back portion R1
From the negative electrode plate 1 to the third turn-back portion R3
2 only the active material layer unformed portion 12c exists,
Active material layers 11b and 12b of the positive and negative plates 11 and 12, respectively
However, the pair of separators 13A and 13B and the active material layer-unformed portion 12c of the negative electrode plate 12 are wound from the third folded portion R3, which has been wound around one and a half turns. Therefore, positive,
The active material layers 11b and 12b of the negative electrode plates 11 and 12 are
Since the winding is performed while curving from the third turn-back portion R3 having a relatively large radius of curvature after one and a half turns, the winding can be performed smoothly without bulging outward.
On the other hand, in the rectangular spiral electrode group of FIG. 7, the active material layer unformed portion 11c of the positive electrode plate 11 and the active material layer 12b of the negative electrode plate 11 are wound from the first folded portion R1 so as to be folded back with a small radius of curvature. As it does, it swells outward and is difficult to wind smoothly.

In the prismatic spiral electrode group 14 shown in FIG.
In the case where the widths L1 to L4 and the thicknesses T1 to T4 are variously changed according to the difference in the size of the battery cases, as indicated by solid lines and two-dot chain lines in (b) and FIG. 2 (b), respectively. Also, the positive and negative electrode current collector leads 9 and 10 are wound such that the distance K between the electrode groups 14 in the width direction is set to be always constant. Details of this will be described later.

If the number of turns is an even number,
When the positive and negative electrode current collecting leads 9 and 10 are always arranged at predetermined relative positions shown by a solid line and a two-dot chain line in FIG. 1B, respectively, and the number of turns is odd, the positive and negative electrode current collecting leads 9 and 10 are collected. The electric leads 9 and 10 are always arranged at predetermined relative positions shown by a solid line and a two-dot chain line in FIG. Specifically, as shown in FIGS. 3 and 4, the positive electrode plate 11 includes a negative electrode plate 12 and a pair of separators 13A and 1A.
Since 3B is wound once and a half turns and the number of turns is the third time, the positive electrode plate 11 is wound when the number of turns is an even number including the number of turns of 3 times.
The positive electrode current collecting lead 9 attached to the terminal end of the electrode group 14 is arranged at a position further wound by about half a turn from the winding start side (left side in the drawing) on the outer circumference of the electrode group 14, while the above-mentioned 3
When the winding is performed with an odd number of turns including the number of turns, the positive electrode current collector lead 9 attached to the end portion of the positive electrode plate 11 is wound to the winding start side on the outer periphery of the electrode group 14. It will be placed in a different place.

On the other hand, when the number of turns is an even number, the negative electrode plate 12 is displaced at a position displaced by a predetermined distance described later from the midpoint of the half circumference of the winding start (between R0 and R1) toward the starting end side. When the current collecting lead 10 is attached and the number of turns is odd, the negative electrode current collecting lead is displaced from the midpoint of the half circumference of the winding start in a direction opposite to the starting end side by a predetermined distance described later. 10 is attached. As a result, the positive and negative electrode current-collecting leads 9 and 10 have the relative positional relationship shown in FIG. 1B when the number of turns is even, and the number of turns is odd, regardless of the difference in the number of turns. In this case, the relative positional relationship shown in FIG.

When a plurality of types of prismatic non-aqueous electrolyte batteries using battery cases having different widths and thicknesses in the rectangular flat cross-sectional shape are produced in series, the prismatic spiral electrode group 14 used for them is used. Then, first, the length L of the linear portion existing between the curved portions on both sides in the width direction (the left-right direction in the drawing) is set corresponding to the length in the width direction of the battery case. The length L of this straight line portion is equal to the length of the pair of winding cores 4.
It is set by the distance between the outer ends of A and 4B, and is set by changing the distance between the cores 4A and 4B or replacing the cores with the corresponding cores 4A and 4B.

The prismatic spiral electrode group used for each prismatic battery described above has a thickness T1 regardless of the size difference.
In any case, since T4 has a shape equal to the diameter of each curved portion on both sides in the width direction, the length L of the linear portion existing between the curved portions on both sides is set to a desired width to be set. It is easily obtained by subtracting the thickness (in other words, the value obtained by adding the radii of the curved portions on both sides) from the length of the.
Further, since both the positive and negative current collecting leads 9 and 10 are arranged at a constant interval K in the central portion of the straight line portion, the corresponding positive and negative electrode plates 11 and 11 of the both current collecting leads 9 and 10 are provided. The attachment position to 12 can be easily obtained based on the length L of the straight line portion.

That is, in the negative electrode current collector lead 10, when the number of turns is even, the midpoint c of the length L of the straight line portion is described.
On the other hand, when the number of turns is odd, the length L of the straight line portion is provided at a position closer to the winding start end by K / 2.
It is provided at a position near the center point c on the side opposite to the winding start end by K / 2. Since the mounting position of the negative electrode current collecting lead 10 is set at the half circumference of the winding start, if the length L of the straight line portion is determined, it can be accurately and easily obtained.

On the other hand, the mounting position of the positive electrode current collecting lead 9 is
It is set at a position with a constant distance K with respect to the negative electrode current collecting lead 10. The distance from the end of the active material layer-unformed portion 11e of the positive electrode current collecting lead 9 depends on the number of folds or a positive value. , The thickness of each part of the negative electrode plates 11 and 12 and the thickness of each of the separators 13A and 13B, etc., which varies depending on various conditions. Next, this point will be described.

First, the number of turns is determined from the desired widths L1 to L4 and thicknesses T1 to T4 of the electrode group 14 determined based on the size of the battery case. Once the number of turns is determined, the thickness of each part of the positive and negative electrode plates 11 and 12 and the separator 13 can be determined whether the number of turns is an even number or an odd number.
Based on the thickness of A, 13B, etc., the positive and negative electrode plates 11, 1
It is possible to set the total length in 2 and the length of each part.

Now, as shown in FIG. 1A, the thickness of the separators 13A and 13B is t ₁ , the thickness of the active material layer 11b of the positive electrode plate 11 is t ₂ , and the active material layer unformed portion 1 of the positive electrode plate 11 is 1.
1e thickness of t _3, the positive electrode current collector 11a thickness of t ₄ of t ₅ the thickness of the active material layer 12b of negative electrode 12, t ₆ the thickness of the active material layer non-formation portion 12c of the negative electrode plate 12, negative electrode core The thickness of the material 12a is t ₇ . Further, the length of the linear portion of the electrode group 14 is set to L as described above. Let S be the distance between the winding start ends of the positive and negative plates.

Next, the total length A of the positive electrode plate 11 and the positive electrode plate 11
The protruding length B of the positive electrode core material 11a from the active material layer unmolded portion 11e, the length C from the end of the active material layer 11b of the positive electrode plate 11 to the end of the positive electrode core material 11a, the total length D of the negative electrode plate 12, the negative electrode Negative electrode core material 12a from active material layer-unformed portion 12c of plate 12
The projection length E and the length F from the starting end of the negative electrode plate 12 to the starting end of the active material layer 12b are shown below for the cases of the even number and the odd number of folding, respectively. In the following mathematical formula, n is an integer, i
Is (1, 2, 3 ...).

In the positive electrode plate 11 when the folding number is set to an odd number, the above A, B and C are calculated from the following [Equation 1] to [Equation 3].

[0055]

[Equation 1]

[Equation 2] B = 1 / 2π [(6n + 4) t ₁ (3n-6) t ₂ +
_{(3n-4) t 5 +} 3t 3 + 3t 6 ] + L [Equation 3] C = B + 2L + π _{[4nt 1 +2 (n-2)} t 2 + (2
n-3) t ₅ + 2t ₆ ] In the negative electrode plate 12 when the number of folding is set to an odd number, the above D, E and F are calculated from the following [Equation 4] to [Equation 6].

[0057]

[Equation 4]

[Equation 5] E = L / 2 [Equation 6] F = (5L) / 2 + 4t ₁ π In the positive electrode plate 11 when the folding number is set to an even number, the above A, B and C are changed to the following [ It is calculated from [Equation 7] to [Equation 9].

[0059]

[Equation 7]

[Equation 8] B = 1 / 2π [(6n + 4) t ₁ (3n-6) t ₂ +3
_{(N-1) t 5 +} 3t 3 + 3t 6 ] + L [Equation 9] C = B + 2L + π _{[4nt 1 +2 (n-2)} t 2 + (2
n-3) t ₅ + 2t ₆ ] In the negative electrode plate 12 when the number of turns is set to an even number, the above D, E and F are expressed by the following [Equation 10] to [Equation 1].
2].

[0061]

[Equation 10]

[Equation 11] E = L / 2 + K [Equation 12] F = (5/2) L + K + 4t ₁ π where α is the buckling due to expansion of the active material when the battery is used. In order to prevent this, the width for making a gap in advance by allowing for the expansion of the active material,
It is set to a value within the range of 0.1 mm to 2.0 mm depending on the material of the active material.

After obtaining the lengths A to F of the positive and negative electrode plates 11 and 12 from the above-mentioned mathematical expressions, the mounting position of the positive electrode current collecting lead 9 is determined with respect to the negative electrode current collecting lead 10. Interval K
To be set. As a result, the relative positions of the positive and negative electrode current collector leads 9 and 10 are, as described above, irrespective of the difference in the number of turns, when the number of turns is an even number.
The solid line and the two-dot chain line show in (b), and the solid line and the two-dot chain line show in FIG. 2 (b) when the number of turns is odd.

Therefore, if the rectangular spiral electrode group 14 having either an even number or an odd number of turns is rotated by 180 degrees in the winding direction of the constituent elements, the arrangement is changed.
The relative positions of the positive and negative electrode plates 11 and 12 are the same as those of the other rectangular spiral electrode group 14. For example, if the rectangular spiral electrode group 14 of FIG. 2 (b) is rotated 180 ° in any direction from the position shown, it becomes the same as the rectangular spiral electrode group 14 shown in FIG. 1 (b). In other words, the rectangular spiral electrode group 14
Is positive, regardless of whether the number of turns is even or odd.
The interval K and the relative positional relationship between the negative electrode plates 11 and 12 are the same.

As a result, this rectangular spiral electrode group 14
Can be configured by sharing the same electrode group forming machine regardless of whether the number of turns is even or odd. For example, when the device is set on the basis of the case where the number of turns is an odd number, when the number of turns is an even number, the lead protection tape 18 is rotated when the number of turns is half a turn more than when it is an odd number at the beginning and end of winding. The group fixing tape 17 may be set to be attached.

In the above embodiment, the prismatic spiral electrode group 14 for forming the prismatic lithium secondary battery by inserting it into the aluminum battery case has been described, but the battery case is made of iron, for example. When constructing the negative electrode, the positive electrode plate 11 and the negative electrode plate 1 shown in FIGS. 1 and 2 are used.
If the configuration and the arrangement of each of 2 are replaced,
It goes without saying that the same effect as described above can be obtained.

FIGS. 5 (a) and 5 (b) are a plan view and a vertical sectional view taken along a cutting line in the width direction showing a prismatic lithium secondary battery constructed by using the prismatic spiral electrode group 14. In this prismatic lithium secondary battery, the prismatic spiral electrode group 14 manufactured as described above is accommodated in the accommodating portion of the power generation element in the flat prismatic aluminum battery case 19. A sealing plate 20 is provided on the inner peripheral edge of the opening of the battery case 19.
The prismatic battery case 19 and the sealing plate 20 are liquid-tightly and airtightly sealed by integrating the fitting portions 21 by laser welding or the like.

A positive electrode terminal 19a is bulged on the bottom surface of the battery case 19. The sealing plate 20 is formed in such a manner that its central portion is recessed inward, and a through hole 22 is formed. A synthetic resin gasket 23, which is made of a mixture of blown asphalt and mineral oil and coated with a sealing agent and which is resistant to electrolytic solution and electrically insulating, is integrally attached to the through hole 22.

A negative electrode terminal 24 made of nickel or nickel-plated steel rivet, which also serves as a negative electrode terminal, is fixed to the gasket 23. The negative electrode terminal 24 is inserted into the center of the gasket 23,
With the washer 27 fitted to the lower portion, the tip portion is fixed by being caulked, and is tightly attached to the gasket 23 in a liquid-tight and air-tight manner.

A substantially elliptical exhaust hole 28 is provided between the negative electrode terminal 24 which also serves as the negative electrode terminal and the outer edge on the long side of the sealing plate 20. The exhaust hole 28 is provided in the sealing plate 20.
The aluminum foil 29 is closed by an aluminum foil 29 that is pressure-bonded to and integrated with the inner surface of the aluminum foil 29. The aluminum foil 29 forms an explosion-proof safety valve that breaks when the internal pressure of the battery rises and releases gas to the outside. The sealing plate 20 has a liquid injection hole 3
0 is provided, and a predetermined amount of organic electrolytic solution is injected from this liquid injection hole 30. After that, the injection hole 30 is sealed with a plug 31.
Is inserted and blocked.

The positive electrode current collecting lead 9 of the electrode group 14 is connected to the inner surface of the sealing plate 20 by spot welding with a laser beam, and the negative electrode current collecting lead 10 is connected to the washer 27 by resistance welding. For this connection, it goes without saying that other joining means such as ultrasonic welding can be adopted. FIG. 6A shows the positive and negative electrode current collecting leads 9 and 1.
0 is welded and connected to the sealing plate 20 and the washer 27, respectively. Sealing plate 20, gasket 2
3, the negative electrode terminal 24 and the washer 27 are shown in FIG.
The assembly sealing body is pre-assembled into the configuration shown in FIG. 7B, and the sealing plate 20 and the washer 27 of the assembly sealing body are led out from the rectangular spiral electrode group 14 through the opening of the battery case 19. The negative electrode current collecting leads 9 and 10 were welded and connected by a connecting machine (not shown), and then the positive and negative electrode current collecting leads 9 and 10 were bent as shown in FIG. In the state, the sealing plate 20 is the battery case 19
Is fitted into the opening of the.

When the positive and negative electrode current collecting leads 9 and 10 are connected to the sealing plate 20 and the washer 27, the positive and negative electrode current collecting leads 9 and 10 are shown relative to the connecting device as shown in FIG. Assuming that they are installed and connected in an arrangement, the rectangular spiral electrode group 14 having an odd number of turns is inserted into the battery case 19 with the arrangement shown in FIGS. 2B and 4, and the number of turns is FIG. 1 shows an even numbered rectangular spiral electrode group 14.
It is inserted into the battery case 19 in a state of being rotated by 180 ° from the arrangement shown in (b) and FIG. 3 to change the arrangement. As a result, the arrangement of the positive and negative electrode current collecting leads 9 and 10 of the rectangular spiral electrode group 14 inserted in the battery case 19 is the same as that in FIG. 5A regardless of whether the number of turns is even or odd. Relative position. Further, as described above, the widthwise interval K between the positive and negative electrode current collector leads 9 and 10 is always constant regardless of the difference in the number of turns.

Therefore, when assembling the prismatic lithium secondary battery, even if the prismatic spiral electrode group 14 has various shapes depending on the size of the battery case 19, the same electrode group inserting machine is shared. The rectangular spiral electrode group 14 is inserted into the battery case 19, and the positive and negative electrode current collecting leads 9 and 10 and the sealing plate 20 are shared by the same connecting device.
Even if the positive and negative electrode current collecting leads 9 and 10 are brought into contact with each other and the positive and negative electrode current collecting leads 9 and 10 are connected, even if the positive and negative electrode current collecting leads 9 and 10 are displaced from the sealing plate 20 and the washer 27. It is possible to connect while surely preventing. In addition, as described above, the rectangular spiral electrode group 1
No. 4 can be manufactured at low cost by sharing the same electrode group constituting machine regardless of the difference in the number of folding back and whether the number of folding back is even or odd. Therefore, when a prismatic lithium secondary battery is formed using the spiral electrode group 14 manufactured by the manufacturing method of the above-described embodiment, a series of multiple kinds of prismatic lithium secondary batteries can be manufactured at a reduced manufacturing cost. It can be manufactured while trying.

In the prismatic lithium secondary battery, the positive electrode plate forming the outermost circumference of the prismatic spiral electrode group 14 on the inner peripheral surface of the aluminum battery case 19 as shown in FIGS. 3 and 4. Since the positive electrode core material 11a made of aluminum and the exposed positive electrode core material 11a of the active material layer-unformed portion 11e in 11 are brought into contact with each other, extremely good electrical connection can be obtained, and thus the current collection efficiency is improved. And sufficient discharge characteristics can be obtained.

Further, this prismatic lithium secondary battery has an opposite polarity activity for chemically reacting with the opposite sides of the positive and negative electrode plates 11 and 12 of the spiral electrode group 14 with the separators 13A and 13B interposed therebetween. The portions where the material layers 12b and 11b do not exist are the active material layer-unformed portions 11e and 12c, and the positive electrode core material 11a is exposed at the end for attaching the positive electrode current collector lead 9 in the positive electrode plate 11.
Is not extended longer than necessary, so that both the volume energy density and the weight energy density are improved.

Further, in the prismatic spiral electrode group 14, the positive electrode plate 11 is arranged on the winding inner side and the negative electrode plate 12 is arranged on the winding outer side, and the positive electrode active material layer 11b is formed on the negative electrode active material layer. Since the prismatic lithium secondary battery is wound so as to be covered with the layer 12b, this prismatic lithium secondary battery can prevent occurrence of a short circuit due to generation of dendrite of lithium during discharging.

[0077]

As described above, according to the prismatic spiral electrode group of the present invention, the interval between the positive and negative electrode current collecting leads is always set to a constant value regardless of the difference in the number of turns.
The relative positional relationship of the negative electrode current collecting leads is always the same depending on whether the number of turns is even or odd. Therefore, if one of the electrode groups having an even number or an odd number of turns is rotated by 180 °, the positive and negative electrode current collector leads will have the same relative positional relationship as the other electrode group as well as the interval. Various rectangular spiral electrode groups having different sizes can be manufactured by sharing the same electrode group constituting machine, and the rectangular spiral electrode groups for various prismatic batteries to be series can be manufactured at low cost. Further, the current collecting lead provided at the winding start portion of one of the electrode plates is provided at different mounting positions depending on whether the number of turns is even or odd.
The core material to be protruded for attaching the current collecting lead of the other electrode plate is irrespective of whether the number of turns is even or odd,
Since the length can always be the same, there is no winding deviation especially in the thickness direction, the desired function can be reliably obtained when the battery is made, and the volume energy density is improved. Can be achieved.

Further, according to the prismatic non-aqueous electrolyte battery of the present invention, a prismatic spiral electrode group in which the interval and relative positional relationship between the positive and negative electrode current collecting leads are always constant regardless of the difference in width and thickness is provided. Since it is housed in a prismatic battery case, the same electrode group insertion machine can be shared when assembling even if the shape of the prismatic spiral electrode group differs depending on the size of the battery case. Even if the rectangular spiral electrode group is inserted into the battery case and the positive and negative electrode current collecting leads are connected to the sealing plate and the electrode terminal by sharing the same connector, the positive and negative electrode current collecting electrodes are connected. It is possible to surely prevent the occurrence of a short circuit due to contact of the leads and a positional deviation between the positive and negative electrode current collecting leads and the sealing plate and the electrode terminal. Therefore, a large number of series-shaped cross-sectional shapes having various widths and thicknesses can be constructed inexpensively as the manufacturing cost is reduced.

[Brief description of drawings]

FIG. 1A is a plan view schematically showing the relative positional relationship of each constituent element before winding in a spiral electrode group according to an embodiment of the present invention, and FIG. 1B is a plan view after winding. FIG. 3 is a schematic plan view showing an outer shape of an electrode group.

FIG. 2A is a plan view schematically showing a relative positional relationship of each constituent element before winding in a spirally wound electrode group having different sizes according to the above embodiment, and FIG. FIG. 3 is a schematic plan view showing the outer shape of the electrode group of FIG.

FIG. 3 is a schematic plan view schematically showing a spiral electrode group formed by winding the respective constituent elements of FIG.

FIG. 4 is a schematic plan view schematically showing a spiral electrode group formed by winding the respective constituent elements of FIG.

5 (a) and 5 (b) are a plan view and a vertical cross-sectional view taken along a cutting line in a width direction showing a prismatic lithium secondary battery configured by using the above spiral electrode group.

6 (a) and 6 (b) are vertical cross-sectional views taken along the widthwise cutting line showing the manufacturing process of the prismatic lithium secondary battery in the same order.

7 (a) and 7 (b) are plan views schematically showing the relative positional relationship of each constituent element before winding in a conventional spirally wound electrode group, and FIG. 7 (c) shows the electrode group after winding. The top view which showed schematic outline.

FIG. 8A is a plan view schematically showing the relative positional relationship of each constituent element before winding in another conventional spiral electrode group, and FIG. 8B is a partially broken side view of FIG. 8A. Fig.

[Explanation of symbols]

9 Positive Electrode Current Collection Lead 10 Negative Current Collection Lead 11 Positive Electrode Plate (Other Electrode Plate) 11a Positive Electrode Core Material 11b Positive Electrode Active Material Layer 11e Positive Material Active Material Layer Unformed Part 12 Negative Electrode Plate (One Electrode Plate) 12a Negative electrode core material 12b Negative electrode active material layer 12c Active material layer non-formed portion 13A, 13B of negative electrode plate Separator 14 Square spiral electrode group 19 Battery case 20 Sealing plate 24 Negative electrode terminal (electrode terminal) R1 to R17 Folded portion K Lead interval L1 to L4 widths T1 to T4 thickness L lengths of linear portions t ₂ and t ₅ coating thickness c of active material layer c midpoint of linear portions

Claims (7)

[Claims] 1. A positive electrode plate on which positive electrode active material layers are formed on both sides of a strip-shaped positive electrode core material, and a negative electrode active material layer is formed on both sides of a positive electrode plate on which positive electrode current collecting leads are attached. , And a negative electrode plate to which a negative electrode current collecting lead is attached, and by spirally winding with a separator interposed therebetween, in a rectangular spiral electrode group having a flat cross section. The positive and negative current collecting leads are arranged at regular intervals in the width direction of the flat prism regardless of whether the number of turns is an even number or an odd number, and the one electrode plate located on the outer side of the winding. Is a case where the number of turns is an even number, a current collecting lead is provided at a position spaced from the midpoint of the first half of the winding start portion to the starting end side by a distance of half the constant interval, and the number of turns is an odd number. To
A current collecting lead is provided at a position separated from the middle point by a distance of half the constant distance in a direction opposite to the starting end side, and the other electrode plate located on the winding inner side has an even number of turns. In both cases of odd number and odd number, a current collecting lead is provided at a position that is at the constant interval with respect to the current collecting lead of the one electrode plate of the core material that is projected from the final folded portion. And a rectangular spiral electrode group. 2. A straight line portion excluding curved portions on both sides is set to a length determined from a desired width and thickness to be formed,
The prismatic spiral electrode group according to claim 1, wherein both the positive and negative electrode current collecting leads are attached to the positive and negative electrode plates at a constant interval in the central portion of the straight line portion. 3. One of the electrode plates has an active material layer not formed on the inner surface side with respect to the core material having a length of one turn from the first folded portion and the active material layer is exposed, and the active material layer is not formed. Part is provided, and a current collecting lead is attached to the core material projecting from the starting end of the active material layer-unformed part, and the other electrode plate is provided with the starting end positioned at the third folded portion. The active material layer is formed from the starting end, and the active material layer is not formed on the outer surface side with respect to the core member extended by one round from the position facing the end of the one electrode plate. An active material layer-unformed portion in which the core material is exposed is provided, and a current collecting lead is attached to the core material further protruding from the end of the active material layer-unformed portion. The end is located at almost the same position as the end of the And prismatic wound electrode group according to claim 1 or 2. 4. The number of folds is set corresponding to the difference in width and thickness in the flat cross-sectional shape of the battery case, and the excess and deficiency with respect to the width and thickness are applied to the active material layer of the electrode plate. 4. The prismatic spiral electrode group according to claim 1, wherein the prismatic spiral electrode group has an outer shape which is compensated by adjusting a thickness and can be inserted into the battery case in a fitted state. 5. The prismatic spiral electrode group according to claim 1, wherein the other electrode plate is a positive electrode plate in which a positive electrode active material layer is formed on both surfaces of a positive electrode core material made of aluminum. 6. The prismatic spiral electrode group according to claim 1, wherein the prismatic spiral electrode group having an even number or an odd number of folding is arranged in a battery case as a reference for arrangement. After being inserted into the battery case after the other of the rectangular spiral electrode groups is rotated by 180 °, one of the positive and negative current collecting leads is inserted into the sealing plate, and the other is inserted into the battery case. A prismatic non-aqueous electrolyte battery characterized by being connected to an electrode terminal. 7. The prismatic spiral electrode group according to claim 1, wherein a positive electrode plate having a positive electrode core material made of aluminum foil is used as the other electrode plate, and the rectangular spiral electrode group is housed in a rectangular battery case made of aluminum. The positive electrode core material with the exposed positive electrode core material and / or the positive electrode current collector lead in the active material layer-unformed portion located at the outermost periphery of the positive electrode plate is attached to the inner peripheral surface of the battery case. A prismatic lithium secondary battery characterized by being contacted.