JP2013109858A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a short-circuit failure that occurs between an uncoated part of a foil-shaped positive electrode plate and a foil-shaped negative electrode plate of a battery as much as possible.SOLUTION: In this battery, a power generating element 3 having a foil-shaped positive electrode plate and a foil-shaped negative electrode plate on which an active material layer is formed are laminated with a separator held between them is provided; non-formation portions 3a, 3b where the active material layer is not formed on the foil-shaped positive electrode plate and the foil-shaped negative electrode plate are disposed at the end part of the power generating element 3 in the set direction thereof; and the non-formation portion 3a of the foil-shaped positive electrode plate and the non-formation portion 3b of the foil-shaped negative electrode plate are located on the mutually opposite sides in the set direction, and are disposed while projecting from the separator and the facing foil-shaped negative electrode plate or the foil-shaped positive electrode plate in the set direction. In the separator disposed from a first end part located on the non-formation portion 3a side of the foil-shaped positive electrode to a second end part located on the non-formation portion 3b side of the foil-shaped negative electrode plate, pressing means PS for causing the first end part to be pressed more strongly than the second end part is.

Description

  The present invention is provided with a power generation element in which a foil-like positive electrode plate and a foil-like negative electrode plate each having an active material layer formed thereon are stacked with a separator interposed therebetween, and at the end in the setting direction of the power generation element, the foil shape An unformed portion where the active material layer is not formed is disposed on the positive electrode plate and the foil-like negative electrode plate, and the unformed portion of the foil-like positive electrode plate and the unformed portion of the foil-like negative electrode plate are The present invention relates to a battery that is located on the opposite side in the setting direction and that is disposed in a state of projecting in the setting direction with respect to the separator and the foil-like negative electrode plate or the foil-like positive electrode plate facing each other.

A power generation element of such a battery is formed by laminating a foil-like positive electrode plate and a foil-like negative electrode plate each having an active material layer sandwiched between separators. Electrical insulation between the plates and movement of ions, etc. are ensured.
In order to draw out the electrical wiring from the power generation element having such a configuration, an unformed portion where no active material layer is formed is disposed on the foil-like positive electrode plate or the like.
As what performs the electrical wiring with respect to an electric power generation element in such a format, as what is described in the following patent document 1, the foil-shaped positive electrode plate etc. which were formed in the elongate belt shape were wound and laminated | stacked, and what is called winding type Power generation elements are generally well known.
In a battery having a wound-type power generation element, the widthwise ends of the foil-like positive electrode plate and the foil-like negative electrode plate are used as uncoated portions (corresponding to the unformed portions) where no active material is applied. In many cases, the positive electrode and the negative electrode are protruded to the opposite side in the width direction and taken out as electrodes for the positive electrode and the negative electrode.

When the power generation element is configured as described above, it is considered that the separator contracts due to heat generated for some reason, and the uncoated portion of the foil-like positive electrode plate and the foil-like negative electrode plate come into contact with each other.
The active material of the other foil-shaped negative electrode plate with which the uncoated portion of the foil-shaped positive electrode plate comes into contact has a lower resistance than the active material applied to the foil-shaped positive electrode plate, and the uncoated portion of the foil-shaped positive electrode plate If the foil and the foil-like negative electrode plate come into contact with each other, a large current flows to generate heat.
As a technique for avoiding such contact between the uncoated portion of the foil-shaped positive electrode plate and the foil-shaped negative electrode plate, for example, as described in Patent Document 2, high resistance is applied to the uncoated portion of the foil-shaped positive electrode plate. A method of preventing current from flowing as much as possible even when contacting with the foil-like negative electrode plate by applying a protective layer is also conceivable.

JP 2009-105075 A JP 2007-95656 A

However, the method of separately forming a high-resistance layer on the uncoated portion of the foil-like positive electrode plate described above has a disadvantage that the manufacturing process becomes complicated and the manufacturing cost increases.
This invention is made | formed in view of this situation, The objective is to suppress the heat_generation | fever of a battery, suppressing the raise of manufacturing cost.

  1st invention of this application is provided with the electric power generation element which laminated | stacked the foil-shaped positive electrode plate and foil-shaped negative electrode plate which each formed the active material layer in the state which pinched | interposed the separator, The edge part of the setting direction in the said power generation element The foil-shaped positive electrode plate and the foil-shaped negative electrode plate are provided with an unformed portion where the active material layer is not formed, and the foil-shaped positive electrode plate and the foil-shaped negative electrode plate are not formed. The battery is disposed on the opposite side in the setting direction and arranged in a state of protruding in the setting direction from the separator and the foil-like negative electrode plate or the foil-like positive electrode plate facing the separator. In the separator disposed from the first end located on the unformed part side of the electrode plate to the second end located on the unformed part side of the foil-like negative electrode plate, 1 end is pressed more strongly than the second end Pressing means are provided to.

That is, the end of the foil-shaped negative electrode plate on the non-formed part side (the second end) of the separator with respect to the end of the foil-shaped positive electrode plate on the non-formed part side (the first end). By applying a stronger pressing force than the end portion of the separator, the separator is pressed down by the pressing force when the separator is to be shrunk by heat, and is not easily shrunk on the unformed portion side of the foil-like positive electrode plate, On the unformed part side of the foil-shaped negative electrode plate, it becomes easy to shrink.
For this reason, a short circuit occurs in advance on the unformed part side of the foil-like negative electrode plate.
This short circuit is caused by contact between the active material layer forming region of the foil-like positive electrode plate and the active material layer forming region of the foil-like negative electrode plate or the above-mentioned unformed portion of the foil-like negative electrode plate. Since the active material layer formed on the plate has a relatively high resistance, the current flowing due to the short-circuit failure is not as great as the short-circuit failure in the unformed part on the positive electrode side.
Accordingly, the battery gradually fails without heat generation due to excessive current due to a short circuit on the unformed portion side of the foil-shaped negative electrode plate.

According to a second invention of the present application, in addition to the configuration of the first invention, the pressing means includes a first end portion of the separator in an internal space of the battery housing that houses the power generation element. Is set to be narrower than the storage width with respect to the second end portion.
That is, the end of the foil-shaped negative electrode plate on the non-formed part side (the second end part) with respect to the end of the foil-shaped positive electrode plate on the non-formed part side (the first end). The shape of the battery housing is set so that a stronger pressing force is applied.

In addition to the configuration of the first invention, the third invention of the present application is arranged such that the pressing means is disposed between an inner wall of a battery housing that houses the power generation element and the power generation element. It is comprised by the press member which presses the said electric power generation element.
That is, the end of the foil-shaped negative electrode plate on the non-formed part side (the second end part) with respect to the end of the foil-shaped positive electrode plate on the non-formed part side (the first end). In the battery casing, a pressing member that presses the power generation element is disposed between the inner wall of the battery casing and the power generation element so that a stronger pressing force is applied.

According to a fourth invention of the present application, in addition to the configuration of the third invention, the pressing member connects a pair of pressing plates facing each other in a substantially parallel posture and ends of the pair of pressing plates. The pair of pressing plates are arranged in a posture that sandwiches and presses the power generation element.
That is, the power generation element is sandwiched and pressed by a pressing member configured by connecting a pair of pressing plates by a connecting portion.

According to a fifth aspect of the present application, in addition to the configuration of the fourth aspect, at least a part of the pressing member is a pair of battery casings positioned on both sides of the power generation element in the setting direction. It touches the inner wall.
That is, the position of the pressing member is restricted by the pair of inner walls of the battery casing at both ends in the setting direction, and the pressing member is arranged like a pulling member between the pair of inner walls, so that vibration and impact are applied to the battery casing. In this case, the displacement of the power generation element can be suppressed.

According to a sixth aspect of the present application, in addition to the configuration of the fifth aspect, the internal space of the battery casing is formed in a substantially rectangular parallelepiped shape, and the pair of pressing plates in the battery casing are in contact with each other. It arrange | positions in the state in which the said connection part of the said press member contact | connects the inner wall orthogonal to both the inner wall and said pair of inner walls which contact.
That is, since the connecting portion of the pressing member is also arranged in contact with the inner wall of the battery casing, the power generation element can be supported more stably in the battery casing.

According to a seventh invention of the present application, in addition to the configuration of the third invention, the pressing member is constituted by a belt-like member wound around the outer periphery of the power generating element.
That is, the belt-shaped member is wound around the outer periphery of the power generation element to press the power generation element.

According to an eighth aspect of the present application, in addition to the configuration of the first aspect, the pressing means presses the first end of the separator of the power generation element from the outside of the battery casing. Is configured to do.
That is, the end of the foil-shaped negative electrode plate on the non-formed part side (the second end part) with respect to the end of the foil-shaped positive electrode plate on the non-formed part side (the first end). ) Press from the outside of the battery housing to apply a stronger pressing force.
In many cases, the battery casing is formed of a thin plate material, and is pressed from outside the battery casing to deform the battery casing and indirectly press the power generation element.

According to a ninth invention of the present application, in addition to the configuration of the eighth invention, the pressing means is configured by a spacer arranged between the batteries in a battery module configured by arranging a plurality of batteries. ing.
That is, when a plurality of batteries are connected to form a battery module, a spacer is arranged between the batteries, and the plurality of batteries and the spacers between the batteries are integrated to apply tight pressure.
The shape of the spacer is such that the end of the foil-shaped negative electrode plate on the side of the unformed part (the first end) is the end of the foil-shaped negative electrode plate (the first end). The shape is such that a pressing force stronger than that of the second end portion is applied.

In addition to the configuration of any one of the first to ninth inventions, the tenth invention of the present application is characterized in that the power generating element has a long strip shape with the foil-like positive electrode plate formed in a long strip shape. The foil-shaped negative electrode plate formed is wound around a winding axis with the setting direction as a winding axis direction, with the separator formed in a long strip shape interposed therebetween, and The unformed portion is formed at the widthwise ends of the foil-shaped positive electrode plate and the foil-shaped negative electrode plate, and the unformed portion of the foil-shaped positive electrode plate and the unformed portion of the foil-shaped negative electrode plate are the width It is located on the opposite side in the direction, and is disposed in a state of projecting in the width direction with respect to the separator and the opposing foil-like negative electrode plate or foil-like positive electrode plate.
That is, the power generation element is configured as a so-called wound-type power generation element, and in the wound-type power generation element, when the separator contracts by heat, the foil-shaped negative electrode plate precedes from the unformed portion side. A short circuit occurs at the unformed portion side of the foil-like negative electrode plate, and the failure occurs gradually without accompanying heat generation due to an excessive current.

According to the first aspect of the invention, a short circuit occurs in advance with the foil-shaped positive electrode plate on which the active material layer having a high resistance is formed on the unformed portion side of the foil-shaped negative electrode plate. Since it gradually fails without heat generation, short circuit failure that occurs between the unformed part of the foil-shaped positive electrode plate and the foil-shaped negative electrode plate is suppressed as much as possible to prevent excessive heat generation. be able to.
Therefore, the process of forming the high resistance layer on the foil-like positive electrode plate is not required, or even if the high resistance layer is provided, the battery can be simplified while suppressing the increase in manufacturing cost. The heat generation can be suppressed.
In addition, according to the second aspect of the present invention, it is possible to apply an appropriate pressing force to the power generation element only by setting the shape of the battery casing, so that excessive heat generation of the battery can be prevented while suppressing an increase in device cost. it can.
Furthermore, since the power generation element is pressed by the battery casing, the power generation element can be stably supported.
In addition, according to the third aspect of the present invention, an appropriate pressing force can be applied to the power generation element simply by placing a pressing member that presses the power generation element between the inner wall of the battery casing and the power generation element. In addition, excessive heat generation of the battery can be prevented.
Furthermore, since the power generation element is pressed by the pressing member disposed between the inner wall of the battery casing and the power generation element, the power generation element can be stably supported.

According to the fourth aspect of the invention, since the power generation element is sandwiched and pressed by the pressing member constituted by connecting the pair of pressing plates by the connecting portion, the pressing member can be assembled by a simple operation.
In addition, according to the fifth aspect, the pressing member for preventing excessive heat generation of the battery can be used for suppressing the displacement of the power generation element, so that the function of the battery is improved while suppressing the cost increase. Can be achieved.
Further, according to the sixth invention, since the connecting portion of the pressing member is also disposed in contact with the inner wall of the battery casing, the power generation element can be supported more stably in the battery casing, and further The function of the battery can be improved.

Moreover, according to the said 7th invention, since a strip | belt-shaped member is wound around the outer periphery of a power generation element, and a power generation element is pressed, a power generation element can be pressed reliably.
According to the eighth aspect of the invention, since the battery casing is deformed by pressing from the outside of the battery casing and the power generation element is indirectly pressed, the configuration of the battery casing or the battery casing is changed. Without adding, it is possible to easily prevent excessive heat generation of the battery.
Furthermore, since the power generation element is pressed by deforming the battery casing, the power generation element can be stably supported.
According to the ninth aspect of the invention, since the spacer used in the battery module is also used for pressing the power generation element, excessive heat generation of the battery is suppressed while suppressing an increase in device cost as much as possible. Can be suppressed.
According to the tenth aspect of the invention, in a battery having a wound-type power generation element, a short-circuit failure occurring between the unformed portion of the foil-like positive electrode plate and the foil-like negative electrode plate is suppressed as much as possible. Thus, excessive heat generation can be prevented.

1 is an external perspective view of a battery according to an embodiment of the present invention. The perspective view which shows the internal structure of the battery concerning 1st Embodiment of this invention. The perspective view and top view of the battery housing | casing concerning 1st Embodiment of this invention. The perspective view of the electric power generation element concerning embodiment of this invention The top view which shows other embodiment relevant to 1st Embodiment of this invention. The perspective view which shows the internal structure of the battery concerning 2nd Embodiment of this invention. The perspective view which shows the internal structure of the battery of other embodiment relevant to 2nd Embodiment of this invention. The perspective view which shows the internal structure of the battery of other embodiment relevant to 2nd Embodiment of this invention. The perspective view which shows the internal structure of the battery of other embodiment relevant to 2nd Embodiment of this invention. The perspective view which shows the internal structure of the battery of other embodiment relevant to 2nd Embodiment of this invention. External perspective view of a battery according to a third embodiment of the present invention. The top view of the battery module concerning 3rd Embodiment of this invention. The perspective view of the battery housing | casing concerning other embodiment of this invention, and schematic sectional drawing of the battery by planar view External perspective view of a battery according to another embodiment of the present invention. The schematic sectional drawing of the battery by planar view concerning other embodiment of this invention The figure which shows schematic shape of the press means concerning other embodiment of this invention.

Hereinafter, embodiments of the battery of the present invention will be described with reference to the drawings.
In the present embodiment, a non-aqueous electrolyte secondary battery (more specifically, a lithium ion battery) which is an example of a secondary battery will be described as an example.

[First Embodiment]
As shown in the perspective view of FIG. 1, the non-aqueous electrolyte secondary battery RB of the first embodiment includes a battery casing BC (hereinafter referred to as “welded”) that covers the open surface of the can 1 and covers the lid 2. In this case, the device is simply referred to as “casing BC”. The lid portion 2 is formed of a strip-shaped rectangular plate material, and a terminal bolt 5 that is a positive electrode terminal and a terminal bolt 7 that is a negative electrode terminal are attached to a surface on the outer side of the casing BC. It has been.
The can 1 is a flat rectangular parallelepiped in accordance with the shape of the lid portion 2, and thus has a flat and substantially rectangular parallelepiped shape as a whole of the casing BC, and the internal space of the casing BC also has a substantially rectangular parallelepiped shape. ing.

On the inner side of the casing BC, the power generation element 3 and current collectors 4 and 6 indicated by a two-dot chain line in FIG. 2 are housed and arranged in a state of being partially immersed in the electrolyte. FIG. 2 shows the inner side of the casing BC as a perspective view looking up from the lower side with the can 1 removed.
The current collectors 4 and 6 are members for electrically connecting the power generation element 3 and the terminal bolts 5 and 7, and both are formed of a conductor.
The current collector 4 and the current collector 6 have a relationship in which substantially the same shape is arranged symmetrically, but the materials are different, and the current collector 4 on the positive electrode side is mainly composed of aluminum. The current collector 6 on the negative electrode side is formed of a material mainly composed of copper.

  The schematic shape of the current collectors 4 and 6 is such that the above-described metal material plate-like member is bent and formed in a posture along the side surface on the short side of the casing BC to have a substantially L shape. A portion extending along the surface of the lid portion 2 that is an arrangement surface of the lid portion, and a vertical posture portion that is bent 90 degrees downward near the longitudinal end portion of the lid portion 2 and extends in the normal direction of the lid portion 2. It has a continuous shape. In the vertical posture portions of the current collectors 4, 6, connection portions 4 a, 6 a for being bent further toward the power generation element 3 side and connected to the power generation element 3 are formed.

As shown in FIG. 4, the power generating element 3 includes a pair of electrode plates 31, 32 each composed of a foil-like positive electrode plate 31 formed in a long strip shape and a foil-like negative electrode plate 32 formed in a long strip shape. The active material layer is formed by coating, and is formed as a so-called wound-type power generation element in which the active material layers are stacked in a state of being wound around the same long strip-shaped separator 33. The foil-like positive electrode plate 31 and the like are wound around a flat winding axis, and the wound one has a flat shape in accordance with the shape of the battery casing BC.
In FIG. 4, the application area | region of the active material is shown with the double diagonal line.

The formation state of the active material layer in the foil-like positive electrode plate 31 and the foil-like negative electrode plate 32 forms unformed portions 3a and 3b in which the active material layer is not formed at the respective end portions in the width direction. In other words, the winding axis direction of the power generation element 3 is set as the setting direction, and the non-formed portions 3a and 3b are arranged at the ends in the setting direction.
In the first embodiment and each of the following embodiments, the case where the active material layer is formed by coating is illustrated. Therefore, in the following description, the “unformed portions 3a and 3b” are generally referred to as “unformed”. The coating parts 3a and 3b "will be referred to.
The uncoated portion 3a of the foil-shaped positive electrode plate 31 and the uncoated portion 3b of the foil-shaped negative electrode plate 32 are the width direction of the foil-shaped positive electrode plate 31 or the like (the set direction, that is, the winding axis of the power generating element 3). The uncoated portion 3a of the foil-like positive electrode plate 31 is located in the width direction above the edges of the foil-like negative electrode plate 32 and the separator 33. The uncoated portion 3 b of the foil-like negative electrode plate 32 protrudes in the width direction from the edges of the foil-like positive electrode plate 31 and the separator 33. Moreover, the length of the separator 33 in the width direction is set to be slightly wider than the active material application width of the foil-like positive electrode plate 31 and the foil-like negative electrode plate 32, and the uncoated portion of the foil-like positive electrode plate 31. It arrange | positions ranging from the edge part (2nd edge part) located in the uncoated part 3b side of the foil-shaped negative electrode plate 32 from the edge part (1st edge part) located in 3a side.
Therefore, in the state where the foil-like positive electrode plate 31, the foil-like negative electrode plate 32 and the separator 33 are wound, the uncoated portions 3a and 3b are located at both ends in the winding axis direction as shown in FIG.
The arrangement posture of the power generation element 3 in the can 1 is such that the winding axis of the foil-like positive electrode plate 31 and the like is parallel to the longitudinal direction of the lid 2, and the power generation element 3 is arranged as the current collectors 4, 6. In the state where the connecting portion 4a of the current collector 4 is inserted into the gap between the uncoated portions 3a of the foil-like positive electrode plate 31, the bundled uncoated portion 3a and the connecting portion 4a are joined together. Welding is performed, and the bundled uncoated portions 3b and the connecting portions 6a are welded in a state where the connecting portions 6a of the current collector 6 are inserted into the gaps between the uncoated portions 3b of the foil-like negative electrode plate 32. In addition, as a connection aspect of the connection parts 4a and 6a of the collectors 4 and 6 and the uncoated parts 3a and 3b, as a positional relationship in which the connection parts 4a and 6a are located outside the uncoated parts 3a and 3b. Both may be welded.

As described above, the terminal bolt 5 on the positive electrode side attached to the lid portion 2 made of metal (specifically, metal mainly composed of aluminum) is electrically connected to the current collector 4 on the positive electrode side. The negative terminal bolt 7 is electrically connected to the negative current collector 6.
The current collector 4 on the positive electrode side is electrically connected to the terminal bolt 5 via a rivet 8 integrally formed on the head side of the terminal bolt 5, and the rivet 8 includes the current collector 4, the current collector 4, and the current collector 4. Lower gasket 12 for electrical insulation between rivet 8 and lid 2, upper gasket 11 for electrical insulation between lid 2 and terminal bolt 5 including lid 2 and rivet 8 and lid 2 In this state, the current collector 4 is caulked at the inner end portion of the casing BC, thereby fixing the current collector 4 to the lid portion 2.
The negative electrode side has the same configuration, and the negative electrode side current collector 6 is electrically connected to the terminal bolt 7 via a rivet 15 integrally formed on the head side of the terminal bolt 7. The electrical current between the terminal 6 including the electrical current 6, the current collector 6 and the lower gasket 18 for electrical insulation between the rivet 15 and the lid 2, the lid 2 and the rivet 15 and the lid 2 The current collector 6 is fixed to the lid portion 2 by being caulked at the inner end of the casing BC in a state of passing through the upper gasket 17 for insulation.

The can 1 constituting the casing BC is made of metal (more specifically, made of metal containing aluminum as a main component), and has a bottomed cylindrical shape (more specifically, as shown in FIG. 3). 3 (b) showing the can body 1 in plan view, the inner wall of the can body 1 has a step at a symmetrical position with the arrangement space for the power generating element 3 in between. A convex portion 1a is formed.
Due to the presence of the convex portion 1a, the housing width of the power generating element 3 in the internal space of the can 1 is partially narrowed.
In the horizontal direction (in the direction of the winding axis of the power generating element 3 indicated by the arrow C), the projecting portion 1a is formed by inserting the power generating element 3 assembled to the lid portion 2 into the can body 1 in FIG. When positioned at the position indicated by the two-dot chain line, from the end (the first end) on the uncoated portion 3a side of the foil-like positive electrode plate 31 in the separator 33 indicated by the arrow A in FIG. It is located in the range that reaches the set position near the center in the width direction. Moreover, the formation position of the convex part 1a in the vertical direction is a range that covers substantially the entire flat surface of the outer periphery of the power generation element 3.
The width of the power generation element 3 in the thickness direction (the normal direction of the flat surface) is such that, in the state where no external pressure is applied to the power generation element 3 joined to the current collectors 4 and 6, It is set so as to substantially match the width in the short side direction (the width indicated by “W” in FIG. 3B) in the region where the convex portion 1a is not formed, and the pair of convex portions 1a. Since the storage width of the power generation element 3 is narrow in the formation range, the convex portion 1 a presses the power generation element 3.
Therefore, in the internal space of the battery casing BC that houses the power generating element 3, the storage width of the separator 33 with respect to the end portion (the second end portion) of the foil-like positive electrode plate 31 on the uncoated part 3a side is foil-like. By setting the width of the negative electrode plate 32 to be narrower than the storage width with respect to the end portion on the uncoated portion 3b side, the end portion on the uncoated portion 3a side of the foil-like positive electrode plate 31 in the separator 33 of the power generation element 3 is The pressing means PS is configured to be pressed more strongly than the end of the foil-shaped negative electrode plate 32 on the uncoated part 3b side.

When the power generation element 3 is overheated for some reason after being assembled as the secondary battery RB, the separator 33 contracts due to the heat, but as described above, the convex portion 1a formed on the inner wall of the can body 1 Since the range from the end on the uncoated portion 3a side of the foil-shaped positive electrode plate 31 in the separator 33 to the set position near the center in the width direction is pressed, the uncoated foil-shaped negative electrode plate 32 in the separator 33 The end (the position indicated by the arrow B in FIG. 4) on the construction part 3b side is shrunk in advance.
As a result, the active material application portion of the foil-like positive electrode plate 31 and the foil-like negative electrode plate 32 are short-circuited. The active material applied to the foil-like positive electrode plate 31 has a higher resistance than the active material applied to the foil-like negative electrode plate 32, and heat is generated by the short-circuit current flowing through this short circuit, but the degree of heat generation is small, and the state is The secondary battery RB gradually fails while maintaining.

Therefore, it is not always necessary to include the edge of the separator 33 as the detailed position of the end of the foil-like positive electrode plate 31 in the separator 33 on the uncoated portion 3a side pressed by the pressing means PS.
As described above, the pressing position on the separator 33 by the pressing means PS is such that the separator 33 is contracted in such a manner that a short circuit between the active material application portion of the foil-shaped positive electrode plate 31 and the foil-shaped negative electrode plate 32 occurs in advance. It only has to be set so as to be.

As the specific shape of the convex portion 1a formed on the inner wall of the can body 1, various shapes other than those illustrated in FIG. 3 can be considered, and FIG. 5 (a) is shown in a plan view similar to FIG. 3 (b). -It is good also as a shape like FIG.5 (c).
FIG. 5A shows the end of the step of the convex portion 1a having a tapered shape, and FIG. 5B shows the wall thickness of the can 1 for forming the step of the convex portion 1a. The wall surface of the can body 1 is protruded inward of the can body 1 by pressing or the like.
Further, FIG. 5C shows a shape in which the convex portion 1a is formed by aligning hemispherical or semi-cylindrical projections, not the shape of the convex portion 1a.

[Second Embodiment]
Next, a second embodiment will be described.
The second embodiment is different from the first embodiment in that the end of the foil-like positive electrode plate 31 on the uncoated part 3a side in the separator 33 of the power generation element 3 is the uncoated part of the foil-like negative electrode plate 32. The specific configuration of the pressing means PS that is pressed more strongly than the end portion on the 3b side is different.
In the said 1st Embodiment, although the convex part 1a is formed in the inner wall of the can 1, and the electric power generation element 3 is pressed, in this 2nd Embodiment, each inner wall of the can 1 is a substantially uniform plane. The power generating element 3 is pressed by sandwiching a pressing member 13 as shown in FIG. 6 between the inner wall of the can 1 and the power generating element 3 as the pressing means PS. Except for not forming the convex portion 1a on the inner wall, the can body 1 of the second embodiment has the same configuration as the can body 1 of the first embodiment, and has a shape such as a bottomed rectangular tube shape or a metal shape. The same applies to the material.

  The structure of the assembly on the side of the lid 2 in which the terminal bolts 5 and 7, the current collectors 4 and 6, and the power generation element 3 are assembled to the lid 2 shown in FIG. 2 is the same as that of the second embodiment and the above. The configuration of the power generation element 3 shown in FIG. 4 is completely the same as that of the first embodiment, and the configuration of the power generation element 3 shown in FIG. .

FIG. 6 is shown corresponding to FIG. 2, and the can body 1 is removed and the power generation element 3 is shown by a two-dot chain line as a perspective view from the lower side.
The pressing member 13 shown in FIG. 6 has a shape in which a rectangular plate is bent into a U shape so as to conform to the outer peripheral shape of the power generating element 3, and a pair of pressing plates facing each other in a substantially parallel posture. 13a and 13b, and the shape which has the connection part 13c which connects the edge parts of the pair of press plates 13a and 13b.
At a position near the end of the foil-like positive electrode plate 31 on the uncoated portion 3a side in the power generation element 3, the power generation element 3 is disposed in a state of being sandwiched from the lower side, and the pair of pressing plates 13a and 13b holds the power generation element 3 in between. It is sandwiched and pressed.
What is necessary is just to comprise the material of the press member 13 with resin, for example.
The more precise position of the pressing member 13 is the foil shape in the separator 33 indicated by the arrow A in FIG. 4 in the winding axis direction of the power generating element 3 indicated by the arrow C (the direction indicated by the arrow C in FIG. 6). It is located in a range from the end of the positive electrode plate 31 on the uncoated portion 3a side to a set position closer to the center in the width direction. In addition, the range in which the pressing member 13 exists in the vertical direction covers substantially the entire flat surface of the outer periphery of the power generation element 3, and the lower end side is in contact with the can bottom of the can body 1. The pressing member 13 is disposed between the lower end and the bottom of the can body 1, and the pressing member 13 prevents the power generating element 3 from moving downward when vibration or impact is applied to the secondary battery RB. .
The width of the power generation element 3 in the thickness direction (the normal direction of the flat surface) is short in the internal space of the can 1 in the state where no external pressure is applied to the power generation element 3 joined to the current collectors 4 and 6. Since it is set so as to substantially match the width in the side direction, the pressing member 13 exists between the outer peripheral surface of the power generation element 3 and the inner wall of the can 1, so that the pressing member 13 generates power. The element 3 will be pressed.

When the power generating element 3 is overheated for some reason after being assembled as the secondary battery RB, the separator 33 contracts due to the heat. As described above, the pressing member 13 of the foil-like positive electrode plate 31 in the separator 33 is compressed. Since the range from the end portion on the uncoated portion 3a side to the set position near the center in the width direction is pressed, the end portion on the uncoated portion 3b side of the foil-like negative electrode plate 32 in the separator 33 (FIG. 4). The position indicated by the arrow B in FIG.
As a result, the active material application portion of the foil-like positive electrode plate 31 and the foil-like negative electrode plate 32 are short-circuited. The active material applied to the foil-like positive electrode plate 31 has high resistance, and heat is generated by a short-circuit current that flows due to this short circuit, but the degree of heat generation is small, and the secondary battery RB gradually fails while maintaining that state. go.

The specific shape of the pressing member 13 can be various shapes other than the shape shown in FIG.
Specific examples thereof will be described. First, as shown in FIG. 7, which is a perspective view from the lower side corresponding to FIG. 6, the winding axis direction of the power generating element 3 (the direction indicated by the arrow C in FIG. 7). The presence width of the pressing member 13 is not limited to the set width of the end of the foil-like positive electrode plate 31 on the uncoated part 3a side, and may be set so as to cover the substantially entire width of the separator 33. Even in this case, there is a difference in the thickness of the pressing member 13 between the uncoated portion 3a side of the foil-like positive electrode plate 31 and the uncoated portion 3b side of the foil-like negative electrode plate 32. If the uncoated portion 3a side is set thick, the power generating element 3 is pressed more strongly on the uncoated portion 3a side of the foil-shaped positive electrode plate 31, and the separator 33 is not coated with the foil-shaped negative electrode plate 32. It shrinks from the part 3b side.

Further, as shown in FIG. 8 corresponding to FIG. 6, the basic is a U-shaped bent shape similar to that shown in FIG. 6, and further, a part of the pressing member 13, more specifically, the pressing member. It is good also as a structure provided with the extension part 21 which extended the lower end part of 13 to the winding axis center direction of the electric power generation element 3 to the both sides to the position where a front-end | tip contacts the inner wall of the can 1. FIG. By setting the existence width of the extension part 21 in this way, the distal ends on both sides of the extension part 21 are a pair of inner walls (vertical posture of the current collectors 4, 6) perpendicular to the winding axis of the power generation element 3. The position is restricted to the inner wall where the part is close. The point that the lower end side of the connecting portion 13c is in contact with the bottom of the can 1 is the same as the configuration shown in FIG.
When the extension portion 21 is regulated in position by a pair of inner walls orthogonal to the winding axis of the power generation element 3, the winding axis of the power generation element 3 is applied when vibration or impact is applied to the secondary battery RB. In the direction, the movement of the pressing member 13 is prevented. Since the pressing member 13 presses the power generation element 3 in a sandwiched state, as a result, the displacement of the power generation element 3 is suppressed.
Further, the pressing member 13 is attached to the bottom of the can, which is an inner wall orthogonal to both the pair of inner walls that restrict the positions of the ends of the extending portions 21 and the pair of inner walls that are in contact with the pair of pressing plates 13a and 13b. Since the connecting portion 13c is in contact with the pressing member 13, displacement is suppressed from each direction, and as a result, the power generation element 3 when vibration or impact is applied to the secondary battery RB. The displacement suppression effect is also increased.
The effect of the pressing member 13 pressing the power generation element 3 is the same as that described with reference to FIG.

As another specific example of the pressing member 13, as shown in FIG. 9 corresponding to FIG. 6, a belt-like member wound around the outer periphery of the power generation element 3 around the winding axis of the power generation element 3 may be used.
In the configuration shown in FIG. 9, the pressing member 13 is located in the winding axis direction of the power generating element 3 indicated by the arrow C, and the foil-like positive electrode plate 31 in the separator 33 indicated by the arrow A in FIG. It is located in the range from the end on the part 3a side to the set position closer to the center in the width direction. Moreover, the point that the lower end of the pressing member 13 is in contact with the can bottom of the can body 1 is the same as the other specific example of the pressing member 13 described above, and the lower end of the power generation element 3 and the can bottom of the can body 1 When the pressing member 13 is disposed between the two and the secondary battery RB is subjected to vibration or impact, the pressing member 13 prevents the power generation element 3 from moving downward.
Even in the configuration shown in FIG. 9, the width of the power generation element 3 in the thickness direction (the normal direction of the flat surface) The pressing member 13 is present between the outer peripheral surface of the power generation element 3 and the inner wall of the can body 1 because it is set so as to substantially match the width in the short side direction in the internal space of the body 1. Thus, the pressing member 13 presses the power generation element 3.
As a specific method of making the pressing member 13 into a strip shape as shown in FIG. 9, for example, a method of thickly winding a resin tape made of an electrically insulating material around the outer periphery of the power generation element 3 may be used. A technique of resin molding in a strip shape may be used.

  Further, as a further specific example of the pressing member 13, as shown in FIG. 10A corresponding to FIG. 6, a rectangular plate material is bent into a U-shape, and the positive electrode side current collector 4 is formed. It is good also as a structure arrange | positioned so that the collector 4 and the uncoated part 3a side of the electric power generation element 3 may be pinched | interposed from the back side (opposite side where the electric power generation element 3 exists). That is, the configuration itself of the pressing member 13 is a connection that connects a pair of pressing plates 13a and 13b that face each other in a substantially parallel posture and ends of the pair of pressing plates 13a and 13b, as shown in FIG. However, the direction in which the pair of pressing plates 13a and 13b sandwich the power generating element 3 is different.

Also when comprised in this way, a pair of opposing surface in the press member 13 is the uncoated part of the foil-like positive electrode plate 31 in the separator 33 pointed by the arrow A in FIG. A range from the end on the 3a side to the set position near the center in the width direction is sandwiched, and in the vertical direction, substantially the entire flat surface on the outer periphery of the power generation element 3 is sandwiched.
Also in the specific example shown in FIG. 10A, the width of the power generation element 3 in the thickness direction (normal direction of the flat surface) is such that no external pressure is applied to the power generation element 3 joined to the current collectors 4 and 6. By setting the pressing member 13 between the outer periphery of the power generation element 3 and the inner wall of the can body 1, it is set so as to substantially match the width in the short side direction in the internal space of the can body 1. The pressing member 13 presses the power generation element 3.
Furthermore, as shown in FIG. 10 (b), as a pressing member 13 having the same arrangement form as shown in FIG. 10 (a) in addition to the U-shaped shape shown in FIG. It may be formed in a U-shape, or as shown in FIG. 10C, it may have a shape in which an arc-shaped portion and a parallel plate portion are combined in a plan view.

[Third Embodiment]
Next, a third embodiment will be described.
The third embodiment is different from the first embodiment in that the end of the foil-like positive electrode plate 31 on the uncoated part 3a side in the separator 33 of the power generation element 3 is the uncoated part of the foil-like negative electrode plate 32. The specific configuration of the pressing means PS that is pressed more strongly than the end portion on the 3b side is different.
While the pressing means PS in the first embodiment and the second embodiment are incorporated in the battery casing BC, the pressing means PS in the third embodiment is used in the separator 33 of the power generation element 3. The end of the foil-like positive electrode plate 31 on the uncoated part 3a side is configured to be pressed from the outside of the battery casing BC.
That is, the power generation element 3 is indirectly pressed by pressing from the outside of the can body 1 and bending the wall surface of the can body 1.
Therefore, it is not necessary to form the convex portion 1a on the inner wall as in the first embodiment, but the can body 1 of the third embodiment is the same as the first embodiment except that the convex portion 1a is not formed. This is the same configuration as the can body 1 and is also common to the shape of a bottomed rectangular tube and the material made of metal.

  The structure of the assembly on the lid 2 side in which the terminal bolts 5 and 7, the current collectors 4 and 6, and the power generation element 3 are assembled to the lid 2 shown in FIG. 2 is the same as that of the third embodiment and the above. The configuration of the power generation element 3 shown in FIG. 4 is completely the same as that of the first embodiment, and the configuration of the power generation element 3 shown in FIG. 4 is completely the same between the third embodiment and the first embodiment. To do.

As shown in FIGS. 11 and 12, the secondary battery RB of the third embodiment constitutes a battery module BM including a plurality of secondary batteries RB arranged in the battery module BM. The power generation element 3 is indirectly pressed from the outside of the can 1 using the spacer 41 arranged between the secondary batteries RB. That is, the pressing means PS is constituted by the spacer 41.
As shown in FIG. 11 showing the positional relationship between the secondary battery RB and the spacer 41 and FIG. 12 showing the state in which the secondary battery RB is housed in the case 42 together with the spacer 41 in the battery module BM, The spacers 41 are in close contact with each other with the spacers 41 sandwiched between the RBs, and are stored in the internal space of the rectangular parallelepiped case 42.
Although illustration is omitted, the case 42 has a pair of side walls facing each other in the direction in which the secondary batteries RB are arranged in the approaching direction, thereby moving the secondary battery RB to the stored secondary battery RB. A mechanism for applying a set pressing force in the arrangement direction is incorporated, and so-called tight pressure is applied to the arrangement of the secondary batteries RB in a state where the secondary batteries RB are housed in the case 42.

The spacer 41 is formed by forming a convex portion 41a that protrudes in a rectangular plateau shape on a plate material having an area corresponding to the flat surface of the secondary battery RB. In a state where the battery RB and the spacer 41 are overlapped with each other in the posture shown in FIGS. 11 and 12, the secondary portion in which the convex portion 41a contacts in the lateral direction (in the winding axis direction of the power generating element 3 indicated by the arrow C). In the power generation element 3 in the battery RB, the separator 33 is located in a range from the end of the foil-like positive electrode plate 31 on the uncoated portion 3a side to the set position near the center of the separator 33 in the width direction. Further, in the vertical direction, the power generation element 3 has a range that covers substantially the entire flat surface on the outer periphery of the power generation element 3.
Further, the protruding height of the convex portion 41a is such that the wall surface of the can 1 of the secondary battery RB due to the presence of the convex portion 41a in a state where the secondary battery RB is housed in the case 42 and tightly pressed as shown in FIG. When it is concavely curved, it is set to a height that fits within the curved concave space. As a result, the portion of the spacer 41 where the convex portion 41a is not formed also comes into contact with the surface of the can 1 of the secondary battery RB, and the entire secondary battery RB can be pressed in a stable posture.

11 and 12 exemplify a case where the directions of the positive electrode and the negative electrode of the secondary battery RB arranged side by side are the same, and the convex portion 41a of the spacer 41 shown in FIG. The surface of the spacer 41 is formed symmetrically with respect to the plate surface of the spacer 41.
In the case where the positive electrode and negative electrode directions of the secondary battery RB are alternately arranged and arranged, the convex portions 41 a are arranged on the front and back sides of the spacer 41 at positions opposite to the ends on the opposite side.
Although not shown, the pair of side plates of the case 42 that abuts the flat surface of the secondary battery RB also has a protrusion having the same shape as the protrusion 41a of the spacer 41. It is formed at a position corresponding to the formation position. Therefore, strictly speaking, the case 42 also constitutes a part of the pressing means PS.

The width of the power generation element 3 in the thickness direction (the normal direction of the flat surface) is short in the internal space of the can 1 in the state where no external pressure is applied to the power generation element 3 joined to the current collectors 4 and 6. Since it is set so as to substantially match the width in the side direction, as described above, the convex portion 41a of the spacer 41 presses the side surface of the can body 1 of the secondary battery RB from both sides to bend toward the retraction side. Then, the power generation element 3 is pressed from both sides by deformation of the side surface of the can body 1.
After the secondary battery RB is assembled as a battery module BM as shown in FIG. 12, if the power generating element 3 is overheated for some reason, the separator 33 contracts due to the heat. However, as described above, the protrusion 41a Is pressing the range from the end of the uncoated portion 3a side of the foil-shaped positive electrode plate 31 in the separator 33 to the set position closer to the center in the width direction via the side plate of the can body 1, The end of the separator 33 on the uncoated part 3b side of the foil-shaped negative electrode plate 32 (the position indicated by the arrow B in FIG. 4) is shrunk in advance.
As a result, the active material application portion of the foil-like positive electrode plate 31 and the foil-like negative electrode plate 32 are short-circuited. The active material applied to the foil-like positive electrode plate 31 has high resistance, and heat is generated by a short-circuit current that flows due to this short circuit, but the degree of heat generation is small, and the secondary battery RB gradually fails while maintaining that state. go.

[Other Embodiments]
Hereinafter, other embodiments of the present invention will be listed.
(1) In each of the above embodiments, the case where the shape of the power generation element 3 and the battery casing BC storing the power generation element 3 is a flat shape is illustrated, but the flat shape is not necessarily required. In this case, the present invention can be applied.
(2) In each of the above-described embodiments, the wound power generation element 3 in which the long strip-like foil-like positive electrode plate 31 and the like coated with the active material are wound is illustrated. The present invention can also be applied to the case where the negative electrode plate and the separator are both formed into a flat sheet shape and stacked to form a power generation element.

(3) In each of the above embodiments, the pressing range of the pressing means PS in the set direction (the direction of the winding axis of the power generating element 3 in each of the above examples) is the foil-like positive electrode plate 31 in the separator 33 of the power generating element 3. From the end of the uncoated portion 3a to the set position near the center of the separator 33 in the width direction, but on the uncoated portion 3a side of the foil-like positive electrode plate 31 in the separator 33 of the power generation element 3 It may be a range from the end to the set position on the near side of the end of the foil-like negative electrode plate 32 on the uncoated part 3b side beyond the center position in the width direction of the separator 33. The pressing force applied to the separator 33 near the end of the foil-shaped negative electrode plate 32 on the uncoated portion 3b side is greater than the pressing force applied to the separator 33 near the end of the foil-shaped positive electrode plate 31 on the uncoated portion 3a side. Small is good.

As a specific example, as shown in FIG. 13A in which the front side surface of the can body 1 is partially cut away, both the inner wall surfaces forming the flat surfaces of the can body 1 are arranged in the height direction of the can body 1. It is good also as a structure which arrange | positions the convex part 51 formed as the extending | stretching strip | belt-shaped level | step difference along with the winding axis direction of the electric power generation element 3 shown by the arrow C. As shown in FIG. The belt-like convex part 51 partially narrows the storage width of the power generation element 3 and partially presses the power generation element 3 by the can body 1 like the convex part 1a in the first embodiment. .
A relative positional relationship between the convex portion 51 and the constituent members of the power generation element 3 will be described with reference to FIG.
FIG. 13 (b) schematically shows a cross section of the secondary battery RB in plan view, and a foil-like positive electrode plate is shown for easy understanding of the positional relationship between the convex portion 51 and the constituent members of the power generating element 3. 31 and the positive electrode active material layer 31a applied to the foil-like positive electrode plate 31, the foil-like negative electrode plate 32, the negative electrode active material layer 32a applied to the foil-like negative electrode plate 32, and the thickness of the separator 33 are exaggerated. It is shown. In FIG. 13B, the hatched lines indicating the cross section are not shown for easy viewing of the drawing.
Convex portions 51 arranged in the direction of the winding axis of the power generation element 3 indicated by the arrow C are located on the end of the positive electrode uncoated portion 3a side (the left end in FIG. 13B). The positional relationship is such that the uncoated portion 3a side end of the positive electrode is pressed.

On the other hand, the convex portion 51 located at the end of the negative electrode uncoated portion 3b side (the right end in FIG. 13B) is located slightly inward of the separator 33 at the negative electrode uncoated portion 3b side end. It is the positional relationship which presses.
Therefore, the end of the separator 33 on the uncoated portion 3a side of the foil-shaped positive electrode plate 31 (the first end) is the end of the separator 33 on the uncoated portion 3b side of the foil-shaped negative electrode plate 32. When the separator 33 contracts due to overheating of the secondary battery RB, a short circuit occurs in advance on the negative electrode side, resulting in excessive pressure. The secondary battery RB slowly fails without increasing the temperature.

As still another specific example, as shown in FIG. 14 corresponding to FIG. 11 in the third embodiment, a spacer disposed between the secondary batteries RB in a battery module composed of a plurality of secondary batteries RB. Even in the configuration in which the power generation element 3 is pressed indirectly from the outside of the can body 1 using 61, the convex portions 61a formed on the front and back surfaces of the spacer 61 are formed on the inner wall surface of the can body 1 in FIG. It is good also as a shape and arrangement | positioning similar to the convex part 51 to form.
FIG. 15 shows a relative positional relationship between the convex portion 61a and the constituent members of the power generation element 3.
FIG. 15 schematically shows a cross section of the secondary battery RB in a state sandwiched between the spacers 61 in the same manner as in FIG. 13B, and the configuration of the convex portion 61 a and the power generation element 3. In order to show the positional relationship with the members in an easy-to-understand manner, the foil-like positive electrode plate 31 and the positive electrode active material layer 31a applied to the foil-like positive electrode plate 31, the foil-like negative electrode plate 32, and the negative electrode active material applied to the foil-like negative electrode plate 32 The thickness of the material layer 32a and the separator 33 are exaggerated. In FIG. 15, the hatched lines indicating the cross section are not shown for easy understanding of the drawing.

The convex portions 61a arranged in the winding axis direction of the power generating element 3 indicated by the arrow C are arranged such that the convex portion 61a located at the end of the positive electrode uncoated portion 3a side (left end in FIG. 15) is the positive electrode of the separator 33. The positional relationship is such that the uncoated portion 3a side end is pressed.
On the other hand, the convex portion 61a located at the end of the negative electrode on the uncoated portion 3b side (the right end in FIG. 15) slightly presses the inner side position of the separator 33 relative to the end of the negative electrode on the uncoated portion 3b side. It is a positional relationship.
Therefore, the end of the separator 33 on the uncoated portion 3a side of the foil-shaped positive electrode plate 31 (the first end) is the end of the separator 33 on the uncoated portion 3b side of the foil-shaped negative electrode plate 32. When the separator 33 contracts due to overheating of the secondary battery RB, a short circuit occurs in advance on the negative electrode side, resulting in excessive pressure. The secondary battery RB slowly fails without increasing the temperature.
Furthermore, about the specific example shown in FIG.13 and FIG.14, the specific shape of the convex part 51a formed in the convex part 51 formed in the inner wall surface of the can 1 and the spacer 61 can be changed suitably, for example, As shown in FIG. 16, the convex portions 71 may be arranged in an island shape.

(4) In each of the above embodiments, the case where the present invention is applied to a lithium ion battery is illustrated, but the present invention can also be applied to a secondary battery other than a lithium ion battery, and further to a primary battery.
(5) In the third embodiment, the battery module BM configured by arranging a plurality of secondary batteries RB side by side is illustrated, and the power generation element 3 is indirectly connected from the outside of the battery casing BC by the pressing means PS. Although the case of pressing is illustrated, the battery casing BC of the secondary battery RB is not a battery module BM but a member such as the spacer 41 in the third embodiment with respect to a single secondary battery RB. You may make it press.

DESCRIPTION OF SYMBOLS 3 Power generation element 3a, 3b Uncoated part 13 Press member 13a, 13b Press plate 13c Connection part 31 Foil-like positive electrode plate 32 Foil-like negative electrode plate 33 Separator 41 Spacer BC Battery housing BM Battery module PS Press means

Claims (10)

A power generation element is provided in which a foil-like positive electrode plate and a foil-like negative electrode plate each having an active material layer formed thereon are stacked with a separator interposed therebetween,
In the end portion in the setting direction of the power generation element, an unformed portion where the active material layer is not formed is disposed on the foil-like positive electrode plate and the foil-like negative electrode plate,
The unformed part of the foil-like positive electrode plate and the unformed part of the foil-like negative electrode plate are located on the opposite side in the setting direction, and the separator and the foil-like negative electrode plate or the foil-like facing each other. The battery is arranged in a state protruding from the positive electrode plate in the setting direction,
In the separator disposed from the first end located on the unformed part side of the foil-like positive electrode plate to the second end located on the unformed part side of the foil-like negative electrode plate, A battery provided with pressing means for pressing the first end more strongly than the second end.   In the internal space of the battery housing that houses the power generation element, the pressing means sets a storage width for the first end of the separator to be narrower than a storage width for the second end. The battery according to claim 1, comprising:   The battery according to claim 1, wherein the pressing means is configured by a pressing member that is disposed between an inner wall of a battery housing that houses the power generation element and the power generation element, and presses the power generation element. The pressing member is formed in a shape having a pair of pressing plates opposed in a substantially parallel posture, and a connecting portion that connects ends of the pair of pressing plates.
The battery according to claim 3, wherein the pair of pressing plates are arranged in a posture to sandwich and press the power generation element.   The battery according to claim 4, wherein at least a part of the pressing member is in contact with a pair of inner walls of the battery casing located on both sides of the power generation element in the setting direction. The internal space of the battery casing is formed in a substantially rectangular parallelepiped shape,
6. The battery casing is disposed in a state in which the connecting portion of the pressing member is in contact with an inner wall orthogonal to both the inner wall with which the pair of pressing plates abut and the pair of inner walls. The battery described.   The battery according to claim 3, wherein the pressing member is constituted by a belt-like member wound around the outer periphery of the power generation element.   The battery according to claim 1, wherein the pressing means is configured to press the first end portion of the separator of the power generation element from the outside of the battery casing.   The battery according to claim 8, wherein the pressing means is configured by a spacer disposed between the batteries in a battery module configured by arranging a plurality of batteries. The power generation element is configured such that the foil-shaped positive electrode plate formed in a long strip shape and the foil-shaped negative electrode plate formed in a long strip shape are sandwiched between the separators formed in a long strip shape. Constructed by winding around the winding axis with the direction as the winding axis direction,
The unformed part is formed at the end in the width direction of the foil-like positive electrode plate and the foil-like negative electrode plate,
The unformed part of the foil-shaped positive electrode plate and the unformed part of the foil-shaped negative electrode plate are located on the opposite side in the width direction, and are opposed to the separator and the foil-shaped negative electrode plate or the foil-shaped electrode. The battery according to any one of claims 1 to 9, wherein the battery is disposed so as to protrude in the width direction from the positive electrode plate.

Images