JP2021180173A - Electrochemical cell and manufacturing method for electrochemical cell - Google Patents

Abstract

To provide an electrochemical cell that enables a positive electrode and a negative electrode to be wound in a state in which the electrodes are kept in an appropriate relative positional relation so as to interpose a separator therebetween and has improved work reliability.SOLUTION: An electrochemical cell is provided which includes: an electrode body 2 that includes a separator 30, a positive electrode 10, and a negative electrode 20 and is wound to make the positive electrode and the negative electrode be superimposed on each other so as to interpose the separator therebetween; and an exterior body that stores the electrode body inside. At least either of the positive electrode and the negative electrode has a relative position with respect to the separator at the time of starting winding, the relative position positioned by a positioning part 100.SELECTED DRAWING: Figure 4

Description

The present invention relates to an electrochemical cell and a method for manufacturing an electrochemical cell.

Conventionally, electrochemical cells such as lithium ion secondary batteries and electrochemical capacitors have been widely used as power sources for small devices such as wristwatches, smart watches, smartphones, headsets, wearable devices, and hearing aids.
In recent years, as a need for this kind of electrochemical cell, the demand for miniaturization and thinning has become stronger. One of the reasons for this is that ICs (integrated circuits) in various electronic devices on which electrochemical cells are mounted are equipped with unprecedented high-spec functions as ICs (integrated circuits) become extremely fine and have higher performance due to lower power consumption. This is because electronic devices are beginning to be proposed.

In this type of electrochemical cell, as an exterior body for accommodating the electrode body inside, for example, one using a metal case, one using a laminated film, and the like are known.
The metal case is provided with, for example, a bottomed cylindrical case body and a sealing case in which the opening of the case body is sealed by caulking or the like via a gasket, and is configured as a coin shape, a button shape, a cylinder shape, etc. as a whole. Often done. On the other hand, when the laminated film is used as the exterior body, the degree of freedom in shape can be increased, so that it is easy to lead to miniaturization and high capacity of the electrochemical cell itself.

Various structures are known as the electrode body, and for example, one of them is a winding structure formed by flatly winding a positive electrode and a negative electrode via a separator. For example, in Patent Document 1 below, the positive electrode and the negative electrode are each formed in a band shape in which a plurality of laminated surfaces are connected by a connecting piece, and the positive electrode and the negative electrode are wound flat so as to be folded back by each connecting piece. Therefore, a secondary battery including an electrode body in which each laminated surface of a positive electrode and each laminated surface of a negative electrode are alternately laminated via a separator is disclosed.

International Publication No. 02/13305

In the secondary battery provided with the conventional revolving electrode body, for example, in order to secure a predetermined battery capacity, each laminated surface of the positive electrode and each laminated surface of the negative electrode face each other with high accuracy via a separator. It is required to be arranged so that they can interact with each other.
However, in the above-mentioned secondary battery, when the electrode body is wound, the position of the negative electrode may be displaced with respect to the positive electrode, and so-called winding deviation may occur. In this case, it becomes difficult to wind each laminated surface of the positive electrode and each laminated surface of the negative electrode in a state of accurately facing each other via the separator. Therefore, there is a possibility that it may lead to a decrease in operation reliability, and there is room for improvement.

The present invention has been made in consideration of such circumstances, and an object thereof is that the positive electrode and the negative electrode can be wound while maintaining an appropriate relative positional relationship with the separator sandwiched between them. It is an object of the present invention to provide an electrochemical cell provided with an electrode body having improved operational reliability, and a method for manufacturing the electrochemical cell.

(1) The electrochemical cell according to the present invention has a separator, a positive electrode, and a negative electrode, and is an electrode body in which the positive electrode and the negative electrode are overlapped with the separator sandwiched by being wound, and the above. An exterior body that houses the electrode body inside is provided, and at least one of the positive electrode and the negative electrode is positioned relative to the separator at the start of winding by a positioning portion. It is characterized by that.

According to the electrochemical cell according to the present invention, the positioning portion can be used to position the relative position at the start of winding of at least one of the positive electrode and the negative electrode with respect to the separator. Therefore, when the positive electrode and the negative electrode which are overlapped with each other across the separator are wound to form an electrode body, the relative positional relationship between the positive electrode and the negative electrode is deviated by sandwiching the separator, that is, so-called unwinding. It is possible to suppress the occurrence. As a result, the positive electrode and the negative electrode can be formed into an electrode body in which the positive electrode and the negative electrode are accurately superposed with the separator interposed therebetween, and an electrochemical cell having improved operational reliability can be obtained.

(2) The electrode body is wound flat so that the positive electrode and the negative electrode are alternately laminated so as to sandwich the separator, and the positive electrode is arranged along the stacking direction of the electrode body. A plurality of positive electrode bodies and a plurality of positive electrode connecting pieces for connecting the plurality of positive electrode bodies are provided, and the negative electrode electrodes include a plurality of negative electrode bodies arranged along the stacking direction of the electrode bodies and a plurality of negative electrode bodies. A plurality of negative electrode connecting pieces for connecting the negative electrode bodies to each other, and the electrode body is wound so as to fold back the positive electrode connecting piece and the negative electrode connecting piece, thereby sandwiching the separator and the positive electrode. The main body and the negative electrode main body are formed so as to be arranged in a state of alternately facing each other in the stacking direction, and the positioning portion is a first negative electrode main body located on the winding start side among the plurality of the negative electrode main bodies. A negative electrode positioning portion is provided between the separator and the separator to position the first negative electrode body with respect to the separator, and the negative electrode positioning portion sandwiches the separator among the first negative electrode bodies. Ions that are arranged so as to be at least located between the outer end portion facing the positive electrode connection piece and the separator, and move from the positive electrode connection piece toward the outer end portion through the separator during charging and discharging. The ion conductivity of the ion may be lower than that of the ion moving between the positive electrode body and the negative electrode body through the separator.

In this case, since the negative electrode positioning portion can be used to position the first negative electrode body with respect to the separator, the plurality of positive electrode bodies and the plurality of negative electrode bodies are accurately opposed to each other with the separator interposed therebetween. The electrode bodies can be laminated alternately in the stacking direction. This makes it possible to obtain an electrochemical cell with improved operational reliability.
In addition, since the negative electrode positioning portion is arranged so as to be located at least between the outer end portion of the first negative electrode body and the separator, it is as if the negative electrode current collector exposed to the outside at the outer end portion is protected. It is arranged to do. Then, the negative electrode positioning portion is directed from the positive electrode connection piece to the outer end portion through the separator rather than the ionic conductivity of ions (for example, lithium ion) that move between the positive electrode body and the negative electrode body through the separator during charging / discharging. It plays a role in reducing the ionic conductivity of moving ions. Therefore, it is possible to suppress the movement of ions to the exposed portion of the negative electrode current collector during charging and discharging, and it is difficult to cause inconveniences such as ion precipitation on the negative electrode current collector in the form of needles. can. Therefore, this also makes it possible to further improve the operation reliability.

(3) The negative electrode positioning portion is fixed to at least one of the first negative electrode body and the separator, and is an insulator that comes into contact with the first negative electrode body and the separator, and is attached to the separator. The formed ion permeation holes may be closed.

In this case, since the negative electrode positioning portion is fixed to at least one of the first negative electrode body and the separator, the positioning of the first negative electrode body with respect to the separator can be reliably performed, and the positive electrode and the negative electrode are used during winding. It is possible to effectively suppress the occurrence of unwinding between the two. Further, since the negative electrode positioning portion is an insulator and the ion transmission hole can be closed by contacting the first negative electrode body and the separator, the first negative electrode main body is connected to the positive electrode connection piece through the separator during charging and discharging. It is possible to effectively suppress the movement of ions toward the outer end portion of the above, that is, the portion where the negative electrode current collector is exposed. Therefore, the operation reliability can be further improved.

(4) The negative electrode positioning portion may be an insulating adhesive member that adheres the first negative electrode body and the separator to each other, and may also block the ion transmission holes formed in the separator.

In this case, since an adhesive member such as an insulating adhesive layer or an insulating adhesive tape can be used as the negative electrode positioning portion which is an insulator, it is easy to simplify the configuration and reduce the cost. In particular, since the ion permeation hole formed in the separator can be closed by the adhesive member, the outer end portion of the first negative electrode body, that is, the portion where the negative electrode current collector is exposed from the positive electrode connection piece through the separator during charging / discharging. It is possible to effectively suppress the movement of ions toward. Therefore, the operation reliability can be further improved.

(5) The negative electrode positioning portion may be a welding portion in which the first negative electrode main body and the separator are welded to each other, and the ion permeation holes formed in the separator by the welding may be closed.

In this case, since the welded portion in which the first negative electrode body and the separator are welded to each other functions as the negative electrode positioning portion, the positioning of the first negative electrode body with respect to the separator can be reliably performed, and the positive electrode and the positive electrode are used during winding. It is possible to effectively suppress the occurrence of winding misalignment with the negative electrode. Further, it is possible to partially melt the separator by welding the welded portion and surely close the ion permeation pores. Therefore, it is possible to effectively suppress the movement of ions from the positive electrode connection piece through the separator toward the outer end portion of the first negative electrode body, that is, the portion where the negative electrode current collector is exposed during charging / discharging. Therefore, the operation reliability can be further improved.

(6) The negative electrode positioning portion is a separator welding portion in which a part of the separator is partially double welded in advance, and at the same time, the ion permeation hole formed in the separator by the welding is closed to form the first. 1 The negative electrode body may be positioned with respect to the separator by contact of the outer end portion with the separator welded portion.

In this case, the separator welded portion in which a part of the separator is partially double welded in advance can function as the negative electrode positioning portion, and the outer end portion with respect to the separator welded portion when the electrode body is wound. The first negative electrode body can be positioned with respect to the separator. Therefore, it is possible to suppress the occurrence of unwinding between the positive electrode and the negative electrode during winding. Further, it is possible to partially melt the separator by welding the separator welding portion to surely close the ion permeation pores. Therefore, it is possible to effectively suppress the movement of ions from the positive electrode connection piece through the separator toward the outer end portion of the first negative electrode body, that is, the portion where the negative electrode current collector is exposed during charging / discharging. Therefore, the operation reliability can be further improved.

(7) The negative electrode positioning portion is a blank winding portion in which a part of the separator is preliminarily wound, and the first negative electrode main body is the separator due to contact of the outer end portion with the blank winding portion. It may be positioned with respect to.

In this case, the idle winding portion in which a part of the separator is wound in advance can function as the negative electrode positioning portion, and when the electrode body is wound, the outer end portion is brought into contact with the empty winding portion. , The first negative electrode body can be positioned with respect to the separator. Therefore, it is possible to suppress the occurrence of unwinding between the positive electrode and the negative electrode during winding. Further, since it is possible to make it difficult for ions to pass by the amount of idle winding, ions are emitted from the positive electrode connection piece through the separator toward the outer end portion of the first negative electrode body, that is, the portion where the negative electrode current collector is exposed during charging and discharging. Can be effectively suppressed from moving. Therefore, the operation reliability can be further improved.

(8) The positioning portion is provided between the positive electrode and the separator, and positions the first positive electrode body located on the winding start side of the plurality of positive electrode bodies with respect to the separator. A part may be provided.

In this case, since the positive electrode positioning portion can be used to position the first positive electrode body with respect to the separator, the first positive electrode body located on the winding start side of the positive electrode during winding and the negative electrode electrode. The first negative electrode located on the winding start side of the above can be accurately aligned with the separator sandwiched between them. Therefore, it is possible to more effectively suppress the occurrence of winding misalignment between the positive electrode and the negative electrode by sandwiching the separator during winding.

(9) The exterior body may be formed of a metal layer and a laminated film having a resin layer covering both sides of the metal layer.

In this case, since the exterior body is formed of a laminated film having a metal layer and a resin layer, it can be a so-called laminated type electrochemical cell having an excellent degree of freedom in shape, and can be used for various purposes. easy. Furthermore, it is easy to seal the electrode body with high sealing performance, it is easy to prevent the intrusion of dust and moisture from the outside, it is easy to suppress the leaching of the contents inside the battery for a long period of time, and the operation reliability is further improved. It can be an electrochemical cell.

(10) A strut portion housed inside the exterior body and arranged along the battery axis direction is provided, and the electrode body is wound around the strut portion to sandwich the separator and the positive electrode and the positive electrode. The negative electrode electrodes are wound around the central axis of the support column in a state of being overlapped with each other, the positioning portion includes a fixing portion for fixing the support column portion and the separator, and the positive electrode and the negative electrode are the same. The relative position with respect to the separator may be positioned by being positioned on the support column portion with reference to the fixing portion.

In this case, the electrode body is wound around the strut portion to be a wound electrode wound around the central axis of the strut portion in a state where the positive electrode and the negative electrode are overlapped with each other sandwiching the separator. In particular, when the electrode body is wound by using the strut portion, the strut portion and the separator can be fixed by using the fixing portion, and the separator can be positioned with respect to the strut portion. Therefore, at the time of winding, the positive electrode and the negative electrode are positioned on the support column with the fixed portion as a reference, so that the relative positions with respect to the separator can be positioned. Therefore, it is possible to suppress the occurrence of so-called winding misalignment, in which the relative positional relationship between the positive electrode and the negative electrode is displaced across the separator. As a result, the positive electrode and the negative electrode can be formed into an electrode body in which the positive electrode and the negative electrode are accurately superposed with the separator interposed therebetween, and an electrochemical cell having improved operational reliability can be obtained.
Further, since the winding core for winding the electrode body can be used as the strut portion, the electrode body can be housed inside the exterior body together with the strut portion after the electrode body is formed by winding. Therefore, the assembly work can be performed efficiently, which can lead to the improvement of productivity.

(11) The exterior body has a bottom wall portion and a peripheral wall portion, and is welded to the metal container body formed in a bottomed tubular shape and the container body so as to close the opening of the container body. A metal sealing plate for accommodating the electrode body is provided between the container body and the container body, and a current collecting plate whose at least a part is exposed to the outside is insulating on the sealing plate or the bottom wall portion. Welded via a sealing material, the support column supports the sealing plate by having a first end contacting the current collecting plate and a second end contacting the sealing plate or the bottom wall portion. One of the positive electrode and the negative electrode may be conductive to the current collector plate, and the other electrode may be conductive to the container body.

In this case, since the exterior body is formed of a metal container body and a sealing plate, it can be a so-called metal can type electrochemical cell.
In particular, the strut portion is arranged so as to be sandwiched between the sealing plate and the bottom wall portion in the battery axis direction, the first end portion directly or indirectly contacts the current collector plate, and the second end portion is used. The portion is in direct or indirect contact with the sealing plate or the bottom wall portion of the container body.
As a result, for example, the first end portion of the strut portion contacts the current collector plate welded to the sealing plate via the sealing material, and the second end portion of the strut portion contacts the bottom wall portion of the container body. If this is the case, the stanchion can be used to support the sealing plate. Unlike this, for example, the first end of the strut is in contact with the current collector plate welded to the bottom wall via the sealing material, and the second end of the strut is in contact with the sealing plate. Even if it is, the sealing plate can be supported by using the support column portion.
In any case, the sealing plate can be supported by using the support column portion.

Therefore, even if the entire exterior body including the sealing plate is formed to be thin, it is possible to suppress unintended deformation such as bending of the sealing plate before the welding joint between the container body and the sealing plate. Therefore, the welding work can be performed in a state where the misalignment of the sealing plate with respect to the container body is suppressed, the work efficiency can be improved, and the productivity can be improved. Further, the container body and the sealing plate can be welded accurately and appropriately, and a reliable sealing property can be obtained. Therefore, it is possible to obtain a high-quality electrochemical cell with high operation reliability. Since one of the positive electrode and the negative electrode conducts to the current collector plate and the other electrode conducts to the container body, the current collector plate and the container body can be used as an external connection terminal. ..

(12) The method for manufacturing an electrochemical cell according to the present invention has a positive electrode and a negative electrode which are overlapped with each other with a separator interposed therebetween, and is wound flat so as to sandwich the separator and the positive electrode and the negative electrode. A plurality of positive electrode bodies in which negative electrode bodies are alternately laminated and an exterior body that houses the electrode bodies are provided, and the positive electrode bodies are arranged along the stacking direction of the electrode bodies. A plurality of positive electrode connecting pieces for connecting a plurality of the positive electrode bodies are provided, and the negative electrode electrodes connect the plurality of negative electrode bodies arranged along the stacking direction of the electrode bodies and the plurality of the negative electrode bodies to each other. It is a method of manufacturing an electrochemical cell including a plurality of negative electrode connection pieces, and by winding the positive electrode connection piece and the negative electrode connection piece so as to be folded back, the positive electrode main body and the negative electrode are sandwiched between the separators. The electrode body forming step of forming the electrode body is provided so that the main body is arranged in a state of alternately facing each other in the stacking direction, and during the electrode body forming step, winding of a plurality of the negative electrode bodies is started. By providing a negative electrode positioning portion between the first negative electrode body located on the side and the separator, a positioning step of positioning the first negative electrode body with respect to the separator is performed, and during the positioning step, the first In the negative electrode body, the negative electrode positioning portion is provided so as to be at least located between the outer end portion facing the positive electrode connection piece with the separator sandwiched between the separator and the negative electrode positioning portion, and the negative electrode positioning portion is the separator. It is characterized in that the ion conductivity of ions moving from the positive electrode connection piece to the outer end portion through the separator is lower than the ion conductivity of ions moving between the positive electrode body and the negative electrode body through the separator. And.

According to the method for manufacturing an electrochemical cell according to the present invention, the negative electrode positioning portion can be used to position the first negative electrode body with respect to the separator. Therefore, when the electrode body is formed, the separator is sandwiched between the positive electrode and the positive electrode. It is possible to suppress the occurrence of so-called winding misalignment, in which the relative positional relationship with the negative electrode is displaced. Therefore, it is possible to form an electrode body in which a plurality of positive electrode bodies and a plurality of negative electrode bodies are alternately laminated in the stacking direction while accurately facing each other with a separator sandwiched between them, and an electrochemical cell with improved operation reliability can be manufactured. can do.
Further, since the negative electrode positioning portion is arranged so as to be located at least between the outer end portion of the first negative electrode body and the separator, it is possible to protect the negative electrode current collector exposed to the outside at the outer end portion. .. Moreover, the negative electrode positioning portion is not the ion conductivity of the ions moving between the positive electrode body and the negative electrode body through the separator during charging / discharging, but the ion conductivity of the ions moving from the positive electrode connection piece to the outer end portion through the separator. Plays a role in lowering. Therefore, it is possible to suppress the movement of ions to the exposed portion of the negative electrode current collector during charging and discharging, and it is difficult to cause inconveniences such as needle-like precipitation of ions on the negative electrode current collector. can.

(13) An insulating adhesive member is used as the negative electrode positioning portion, and during the positioning step, the adhesive member is used as the outer end portion of the first negative electrode body or the outer end portion of the first negative electrode body. After coating on the surface of the separator facing the surface of the separator, at least a part of the coated adhesive member is solidified or moistened, and then the outer end portion of the first negative electrode body and the separator are bonded to each other. Positioning may be performed.

In this case, in addition to using an insulating adhesive member as the negative electrode positioning portion, at least a part of the adhesive member after coating is solidified or treated in an appropriate wet state. Thereby, when the first negative electrode main body and the separator are brought into contact with each other, the slip between the first negative electrode main body and the separator can be effectively reduced. Therefore, in addition to the above-mentioned action and effect, it is possible to effectively suppress unwinding when forming the electrode body by winding the positive electrode and the negative electrode which are overlapped with each other across the separator, and the operation reliability is improved. The improved electrochemical cell can be manufactured more efficiently.

According to the present invention, it is possible to rotate the positive electrode and the negative electrode in a state where the positive electrode and the negative electrode are maintained in an appropriate relative positional relationship by sandwiching the separator, and the electrochemical cell is provided with an electrode body having improved operation reliability. can do.

It is a perspective view which shows the 1st Embodiment of the secondary battery (electrochemical cell) which concerns on this invention. It is a vertical sectional view of the secondary battery along the line AA shown in FIG. It is a top view of the electrode body shown in FIG. It is a vertical sectional view of the electrode body along the line BB shown in FIG. It is a vertical sectional view of the secondary battery which enlarged the part surrounded by the virtual circle C shown in FIG. FIG. 3 is an enlarged vertical sectional view of an electrode body in which a portion surrounded by a virtual circle D shown in FIG. 4 is enlarged. It is a development view before winding of the positive electrode shown in FIG. It is a development view before winding of the negative electrode shown in FIG. It is a figure which shows an example which the positive electrode and the negative electrode shown in FIGS. 7 and 8 have started to rotate. It is a figure which shows another example which has started to wind the positive electrode and the negative electrode shown in FIGS. 7 and 8. It is a figure which shows an example of the case where the positive electrode and the negative electrode shown in FIGS. 7 and 8 are wound by using a winding machine. It is a figure which shows an example of the case where the outer end portion of the inner peripheral side negative electrode main body and the separator are combined by using an adhesive. It is a figure which shows another example of the case where the outer end portion of the inner peripheral side negative electrode main body and the separator are combined by using an adhesive. It is a figure which shows an example of the case where the outer end portion of the inner peripheral side negative electrode body and the separator are combined by welding. It is a figure which shows an example of the case where the outer end portion of the inner peripheral side negative electrode body is combined after welding a part of a separator in advance. It is a vertical sectional view of the electrode body formed by using the separator shown in FIG. It is a figure which shows an example of the case where the outer end portion of the inner peripheral side positive electrode body and the separator are combined by welding. It is a figure which shows an example of the case where the outer end portion of the inner peripheral side negative electrode main body is combined with the separator shown in FIG. 17 by using an adhesive. It is a vertical cross-sectional view of the electrode body in the case where the outer end portion of the inner peripheral side negative electrode body and the separator are combined by using the empty winding portion of the separator. It is a perspective view which shows the modification of the secondary battery which concerns on this invention. It is a vertical sectional view which shows the modification of the electrode body which concerns on this invention. It is a vertical sectional view which shows the 2nd Embodiment of the secondary battery (electrochemical cell) which concerns on this invention. It is a vertical sectional view of the secondary battery along the line EE shown in FIG. 22. It is sectional drawing of the secondary battery along the line EE shown in FIG. 22. It is one process diagram in the case of winding the electrode body shown in FIG. 23 around a support column portion, and is the figure which shows the state which the separator is fixed to the outer peripheral surface of the support column part. It is a figure which shows the state which the support column is rotated from the state shown in FIG. 25, and the separator is wound around the support column in advance. It is a figure which shows the state which the support column part is further rotated from the state shown in FIG. 26, and the negative electrode electrode is wound around the support column part in advance together with a separator. It is a vertical sectional view which shows the 3rd Embodiment of the secondary battery (electrochemical cell) which concerns on this invention. FIG. 28 is a diagram showing a state in which the negative electrode terminal tab of the negative electrode in the electrode body shown in FIG. 28 is connected to the outer peripheral surface of the support column portion. FIG. 28 is a diagram showing a state in which the negative electrode terminal tab of the negative electrode in the electrode body shown in FIG. 28 and the separator are connected to the outer peripheral surface of the support column portion. FIG. 28 is a diagram showing a state in which the negative electrode terminal tab of the negative electrode in the electrode body shown in FIG. 28 is inserted into the slit groove of the support column. FIG. 28 is a diagram showing a state in which the negative electrode terminal tab of the negative electrode in the electrode body shown in FIG. 28 is inserted into the support column and the separator is connected to the outer peripheral surface of the support column. It is a vertical sectional view which shows the modification of the secondary battery of 3rd Embodiment. It is a vertical sectional view which shows the 4th Embodiment of the secondary battery (electrochemical cell) which concerns on this invention.

(First Embodiment)
Hereinafter, the first embodiment of the electrochemical cell according to the present invention will be described with reference to the drawings. In the present embodiment, as the electrochemical cell, a lithium ion secondary battery (hereinafter, simply referred to as a secondary battery), which is a kind of non-aqueous electrolyte secondary battery, will be described as an example. Further, in the present embodiment, a so-called laminated type secondary battery in which the exterior body is formed of a laminated film will be described as an example.

As shown in FIGS. 1 and 2, the secondary battery 1 of the present embodiment is a so-called coin-type (button-type) battery, and a plurality of electrodes laminated to each other in the stacking direction Z, that is, a positive electrode 10 and a negative electrode. It mainly includes an electrode body 2 having an electrode 20 and an exterior body 3 accommodating the electrode body 2 inside. In each drawing, the electrode body 2 is shown in a simplified manner as appropriate.

As shown in FIGS. 3 and 4, the electrode body 2 includes a positive electrode 10, a negative electrode 20, and a separator 30. The electrode body 2 is a laminated electrode having a wound structure and is wound flat with the positive electrode 10 and the negative electrode 20 overlapped with the separator 30 interposed therebetween. As a result, the positive electrode 10 and the negative electrode 20 are arranged in a state of being alternately laminated in the stacking direction Z with the separator 30 interposed therebetween.

The electrode body 2 is formed so that the outer shape is circular in a plan view. However, the outer shape of the electrode body 2 is not limited to this case, and may be another shape such as an elliptical shape, an oval shape, a diamond shape, or the like, and may be appropriately changed.
The structure of the electrode body 2 will be described in detail later.

In the present embodiment, a case where the positive electrode 10 and the negative electrode 20 are laminated in the vertical direction so that the stacking direction Z is in the vertical direction will be described as an example. Further, the axis extending through the center of the electrode body 2 and along the stacking direction Z is called the battery shaft O1, and the direction intersecting the battery shaft O1 in the plan view from the battery shaft O1 direction is the radial direction and the circumference of the battery shaft O1. The direction of rotation is called the circumferential direction.

(Exterior body)
As shown in FIGS. 1, 2 and 5, the exterior body 3 is formed of a laminated film.
The exterior body 3 includes a first laminated member 40 and a second laminated member 50 that are laminated in the stacking direction Z with the electrode body 2 sandwiched between them. As a result, the exterior body 3 accommodates the electrode body 2 in a sealed state between the first laminated member 40 and the second laminated member 50. An electrolyte solution (electrolyte solution) (not shown) is filled between the first laminating member 40 and the second laminating member 50.

The first laminated member 40 is a member that covers the electrode body 2 from above, and has a metal layer 41, and an inner resin layer 42 and an outer resin layer 43 that cover both sides of the metal layer 41. The inner resin layer 42 and the outer resin layer 43 are closely bonded to both sides of the metal layer 41 via a bonding layer (not shown), for example, by heat fusion or adhesion. In each drawing except FIG. 5, the metal layer 41, the inner resin layer 42, and the outer resin layer 43 are not shown.

The metal layer 41 is made of a metal material suitable for blocking outside air and water vapor, such as stainless steel and aluminum.
The inner resin layer 42 functions as an inner layer in the exterior body 3, and is formed by using a thermoplastic resin such as polyethylene or polypropylene, which is a polyolefin. Examples of the polyolefin include high-pressure low-density polyethylene (LDPE), low-pressure high-density polyethylene (HDPE), inflation polypropylene (IPP) film, unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, and linear chain. Any material of short-chain branched polyethylene (L-LDPE, metallocene catalyst specification) can be used. In particular, a polypropylene resin is preferable.
The outer resin layer 43 functions as an outer layer in the exterior body 3, and is formed by using, for example, the above-mentioned polyolefin, polyester such as polyethylene terephthalate, nylon, or the like.

The first laminating member 40 includes a ridged cylinder-shaped accommodating portion 45 and a first sealing cylinder portion 46, and is arranged coaxially with the battery shaft O1. The accommodating portion 45 includes a tubular peripheral wall portion 47 that surrounds the electrode body 2 from the outside in the radial direction, and a top wall portion 48 that closes the upper end opening of the peripheral wall portion 47 and covers the electrode body 2 from above.
The first sealing cylinder portion 46 is formed in a cylindrical shape that surrounds the peripheral wall portion 47 from the outside in the radial direction. The lower end of the first sealing cylinder 46 is formed so as to be integrally connected to the lower end of the peripheral wall 47. That is, the first sealing cylinder portion 46 is formed by folding back the peripheral wall portion 47 upward.

The second laminated member 50 is a member that covers the electrode body 2 from below, and has a metal layer 51, an inner resin layer 52 and an outer resin layer 53 that overlap both sides of the metal layer 51. The inner resin layer 52 and the outer resin layer 53 are closely bonded to both sides of the metal layer 51 via a bonding layer (not shown), for example, by heat fusion or adhesion.
The materials of the metal layer 51, the inner resin layer 52, and the outer resin layer 53 are the same as those of the metal layer 41, the inner resin layer 42, and the outer resin layer 43 in the first laminating member 40. Further, in each drawing except FIG. 5, the metal layer 51, the inner resin layer 52, and the outer resin layer 53 are not shown.

The second laminated member 50 closes the tubular second sealing cylinder portion 56 that further surrounds the first sealing cylinder portion 46 from the outside in the radial direction and the lower end opening of the second sealing cylinder portion 56, and also has an electrode. It is formed in a bottomed cylindrical shape including a bottom wall portion 57 that covers the body 2 from below, and is arranged coaxially with the battery shaft O1.

In the first laminated member 40 and the second laminated member 50 configured as described above, the electrode body 2 and the electrolyte are formed by heat-welding the first sealing cylinder portion 46 and the second sealing cylinder portion 56 to each other. The solutions are combined in a sealed state. Specifically, the inner resin layer 42 in the first sealing cylinder portion 46 and the inner resin layer 52 in the second sealing cylinder portion 56 are heat-welded to each other.

Further, as shown in FIG. 2, the secondary battery 1 of the present embodiment includes a first electrode plate 60 and a second electrode plate 61, a first electrode terminal plate 62 and a second electrode terminal plate 63, and a first sealant film. 64 and a second sealant film 65 are provided.
The first electrode plate 60, the second electrode plate 61, the first electrode terminal plate 62, the second electrode terminal plate 63, the first sealant film 64, and the second sealant film 65 are inside the exterior body 3 together with the electrode body 2. It is contained.

The first electrode plate 60, the first electrode terminal plate 62, and the first sealant film 64 are arranged between the electrode body 2 and the top wall portion 48 of the first laminated member 40. The second electrode plate 61, the second electrode terminal plate 63, and the second sealant film 65 are arranged between the electrode body 2 and the bottom wall portion 57 of the second laminated member 50.

The first electrode plate 60 is formed, for example, in a circular shape in a plan view, and is electrically connected to the positive electrode 10 in the electrode body 2. The first electrode plate 60 is formed of a metal material such as aluminum or stainless steel with a diameter smaller than that of the electrode body 2, and is arranged coaxially with the battery shaft O1.
A positive electrode terminal tab 15 described later in the positive electrode 10 is joined to the lower surface of the first electrode plate 60 by, for example, ultrasonic welding. As a result, the first electrode plate 60 is electrically connected to the positive electrode 10.

The first electrode terminal plate 62 is formed of a metal material such as nickel into a circular shape in a plan view having a diameter smaller than that of the first electrode plate 60, and the upper surface of the first electrode plate 60 facing the first laminated member 40 side. It is placed on top of each other. The first electrode terminal plate 62 is integrally joined to the upper surface of the first electrode plate 60 by, for example, ultrasonic welding or resistance welding.
As a result, the first electrode plate 60 and the first electrode terminal plate 62 are electrically connected to each other. Further, the first electrode terminal plate 62 may be made of a metal material such as copper having nickel formed on its surface. In this case, for example, the first electrode terminal plate 62 can be manufactured by subjecting it to nickel plating or the like. Further, the first electrode terminal plate 62 may be partially formed on the first electrode plate 60 by nickel plating, thermal spraying, or the like.
The first electrode terminal plate 62 functions as an external connection terminal for the positive electrode 10.

The top wall portion 48 of the first laminated member 40 is formed with a first through hole 48a for exposing the first electrode terminal plate 62 to the outside. The first through hole 48a is formed in a circular shape in a plan view so as to vertically penetrate the central portion of the top wall portion 48, and is formed coaxially with the battery shaft O1.

The first sealant film 64 is formed in an annular shape that surrounds the first electrode terminal plate 62 from the outside in the radial direction, and in a state of surrounding the first electrode terminal plate 62, the first electrode terminal plate 62 and the top wall of the first laminated member 40 are formed. It is arranged coaxially with the battery shaft O1 between the portion 48 and the battery shaft O1.
The first sealant film 64 is heat-welded to the inner resin layer 42 of the top wall portion 48 of the first laminated member 40 and the upper surface of the first electrode plate 60, respectively. As a result, the first electrode plate 60 is heat-welded to the top wall portion 48 of the first laminated member 40 via the first sealant film 64.

The first sealant film 64 is made of a thermoplastic resin made of a polyolefin such as polyethylene or polypropylene or a copolymer of a plurality of types of polyolefins, and contains a non-woven fabric made of polypropylene or the like. It is also possible to form the first sealant film 64 by using a material in which these thermoplastic resins and a non-woven fabric are composited.

Since the first electrode plate 60, the first electrode terminal plate 62, and the first sealant film 64 are formed as described above, the entire surface of the first electrode terminal plate 62 is exposed upward through the first through hole 48a. ..

The second electrode plate 61, the second electrode terminal plate 63, and the second sealant film 65 are formed and arranged in the same manner as the first electrode plate 60, the first electrode terminal plate 62, and the first sealant film 64 described above. ing.

The second electrode plate 61 is formed in a circular shape in a plan view and is electrically connected to the negative electrode 20 in the electrode body 2. The second electrode plate 61 is formed of a metal material such as copper and has a diameter smaller than that of the electrode body 2, and is arranged coaxially with the battery shaft O1. The negative electrode terminal tab 25 described later in the negative electrode 20 is joined to the upper surface of the second electrode plate 61 by, for example, ultrasonic welding. As a result, the second electrode plate 61 is electrically connected to the negative electrode 20.

The second electrode terminal plate 63 is formed of a metal material such as nickel into a circular shape in a plan view having a diameter smaller than that of the second electrode plate 61, and the lower surface of the second electrode plate 61 facing the second laminated member 50 side. It is placed on top. The second electrode terminal plate 63 is integrally joined to the lower surface of the second electrode plate 61 by, for example, ultrasonic welding or resistance welding.
As a result, the second electrode plate 61 and the second electrode terminal plate 63 are electrically connected to each other. Further, the second electrode terminal board 63 may be made of a metal material such as copper having nickel formed on its surface. In this case, the second electrode terminal board 63 can be manufactured, for example, by subjecting it to nickel plating or the like. Further, the second electrode terminal plate 63 may be partially formed on the second electrode plate 61 by nickel plating, thermal spraying, or the like.
The second electrode terminal board 63 functions as an external connection terminal for the negative electrode.

A second through hole 57a for exposing the second electrode terminal plate 63 to the outside is formed in the bottom wall portion 57 of the second laminated member 50. The second through hole 57a is formed in a circular shape in a plan view so as to vertically penetrate the central portion of the bottom wall portion 57, and is formed coaxially with the battery shaft O1.

The second sealant film 65 is formed in an annular shape that surrounds the second electrode terminal plate 63 from the outside in the radial direction, and in a state of surrounding the second electrode terminal plate 63, the bottom wall of the second electrode terminal plate 63 and the second laminated member 50. It is arranged coaxially with the battery shaft O1 between the unit 57 and the battery shaft O1.
The second sealant film 65 is heat-welded to the inner resin layer 52 of the bottom wall portion 57 of the second laminated member 50 and the lower surface of the second electrode plate 61, respectively. As a result, the second electrode plate 61 is heat-welded to the bottom wall portion 57 of the second laminated member 50 via the second sealant film 65.

Similar to the first sealant film 64, the second sealant film 65 is made of a thermoplastic resin made of a polyolefin such as polyethylene or polypropylene or a copolymer of a plurality of types of polyolefins, and contains a non-woven fabric made of polypropylene or the like. ing. It is also possible to form the second sealant film 65 by using a material in which these thermoplastic resins and the non-woven fabric are composited.

Since the second electrode plate 61, the second electrode terminal plate 63, and the second sealant film 65 are formed as described above, the entire surface of the second electrode terminal plate 63 is exposed downward through the second through hole 57a. ..

(Electrode body)
The electrode body 2 will be described in detail.
As shown in FIGS. 3, 4 and 6, the electrode body 2 is formed by being flatly wound in a state where the positive electrode 10 and the negative electrode 20 are overlapped with each other via the separator 30. Therefore, the positive electrode 10 and the negative electrode 20 are wound around the winding axis O2 together with the separator 30.
As shown in FIG. 3, the electrode body 2 is wound around the winding axis O2 intersecting with the battery shaft O1 and is housed inside the exterior body 3 while maintaining this state.

As shown in FIG. 7, the positive electrode electrode 10 includes a positive electrode current collector 11 (positive electrode current collector foil) formed in a band shape extending along the first direction L1 in the unfolded state before winding, and a positive electrode current collector. It is formed in the form of a single sheet provided with a positive electrode active material layer 12 (see FIG. 6) formed on both sides of 11 by coating or the like.
Note that FIG. 7 omits the illustration of the positive electrode active material layer 12.

The positive electrode current collector 11 is made of a metal material such as aluminum or stainless steel and is formed in the form of a thin sheet. The positive electrode active material layer 12 is formed on both sides of the positive electrode current collector 11 except for the positive electrode terminal tab 15, which will be described later. The positive electrode active material layer 12 contains a positive electrode active material, a conductive auxiliary agent, a binder, a thickener and the like.
As the positive electrode active material, for example, lithium cobalt oxide (LCO), nickel-manganese-lithium cobalt oxide (NMC), or the like can be used.

Examples of the conductive auxiliary agent include carbon blacks, carbon materials, metal fibers, metal fine powder and the like. Examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR) and polytetrafluoroethylene (PTFE). Examples of the thickener include resin materials such as carboxymethyl cellulose (CMC).

The positive electrode 10 includes a plurality of positive electrode bodies 13 and a plurality of positive electrode connection pieces 14.
The positive electrode main body 13 is formed in a disk shape in the expanded state of the positive electrode electrode 10, and is arranged at intervals so as to be lined up in a row in the first direction L1. In the illustrated example, the number of the positive electrode main body 13 is 10. However, the number of the positive electrode main body 13 is not limited to 10, and may be changed as appropriate.
The positive electrode main body 13 is a portion that is overlapped with the negative electrode main body 23, which will be described later, so as to face the stacking direction Z via the separator 30.

The positive electrode connection piece 14 is arranged between the positive electrode main bodies 13 adjacent to the first direction L1 in the expanded state of the positive electrode electrodes 10, and connects the adjacent positive electrode main bodies 13 to each other. Therefore, in the illustrated example, the number of the positive electrode connection pieces 14 is nine.
The positive electrode connection piece 14 is a portion that is folded back on the side portion of the electrode body 2 by winding. Further, the positive electrode connection piece 14 is formed so that the width along the second direction L2 orthogonal to the first direction L1 in a plan view is shorter than the width along the second direction L2 of the positive electrode main body 13.
In particular, the dimension of each positive electrode connection piece 14 along the first direction L1 is as large as that of the positive electrode connection piece 14 arranged on the outer peripheral side of the electrode body 2 in the wound state. As a result, the distance between the positive electrode bodies 13 adjacent to each other in the first direction L1 in the unfolded state becomes larger as they are located on the outer peripheral side in the wound state.

Of the plurality of positive electrode bodies 13, the positive electrode body 13 arranged on the innermost peripheral side in the electrode body 2 in the wound state is referred to as the inner peripheral side positive electrode body (first positive electrode body according to the present invention) 13A, and is the outermost peripheral side. The positive electrode body 13 arranged on the side is referred to as an outer peripheral side positive electrode body 13B. Therefore, the inner peripheral side positive electrode body 13A corresponds to the positive electrode body 13 located on the winding start side.

Further, the positive electrode terminal tab 15 is formed on the outer peripheral side positive electrode main body 13B so as to further extend toward the outside of the first direction L1 in the expanded state of the positive electrode 10. As described above, the positive electrode terminal tab 15 does not have the positive electrode active material layer 12 formed on both sides thereof, and is electrically connected to the lower surface of the first electrode plate 60.
The positive electrode terminal tab 15 is electrically connected to the first electrode plate 60 in a folded state with the connection portion with the outer peripheral side positive electrode main body 13B as a base point.

As shown in FIG. 8, the negative electrode electrodes 20 are a negative electrode current collector 21 (negative electrode current collector foil) formed in a band shape extending along the first direction L1 in the unfolded state before winding, and a negative electrode current collector. It is formed in the form of a single sheet provided with a negative electrode active material layer 22 (see FIG. 6) formed on both sides of 21 by coating or the like.
Note that FIG. 8 omits the illustration of the negative electrode active material layer 22.

The negative electrode current collector 21 is made of a metal material such as copper, nickel, and stainless steel, and is formed in the form of a thin sheet. The negative electrode active material layer 22 is formed on both sides of the negative electrode current collector 21 except for the negative electrode terminal tab 25, which will be described later. The negative electrode active material layer 22 contains a negative electrode active material, a conductive auxiliary agent, a binder, a thickener, and the like, and is formed of a carbon material such as natural or artificial graphite.

Examples of the conductive auxiliary agent include carbon blacks, carbon materials, metal fibers, metal fine powder and the like. Examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR) and polytetrafluoroethylene (PTFE). Examples of the thickener include resin materials such as carboxymethyl cellulose (CMC).

The negative electrode electrode 20 includes a plurality of negative electrode main bodies 23 and a plurality of negative electrode connection pieces 24.
The negative electrode main body 23 is formed in a disk shape like the positive electrode main body 13 in the deployed state of the negative electrode main body 20, and is arranged at intervals so as to be lined up in a row in the first direction L1. In the illustrated example, the number of the negative electrode main body 23 is 10 corresponding to the number of the positive electrode main body 13. However, the number of the negative electrode main body 23 is not limited to 10, and may be appropriately changed according to the number of the positive electrode main body 13.

The negative electrode connection piece 24 is arranged between the negative electrode main bodies 23 adjacent to the first direction L1 in the deployed state of the negative electrode electrodes 20, and connects the adjacent negative electrode main bodies 23 to each other. Therefore, in the illustrated example, the number of the negative electrode connection pieces 24 is nine.
The negative electrode connection piece 24 is a portion that is folded back on the side portion of the electrode body 2 by winding. Further, the negative electrode connection piece 24 is formed so that the width along the second direction L2 orthogonal to the first direction L1 in a plan view is shorter than the width along the second direction L2 of the negative electrode main body 23.

In particular, the dimension of each negative electrode connection piece 24 along the first direction L1 is larger than that of the negative electrode connection piece 24 arranged on the outer peripheral side of the electrode body 2 in the wound state. As a result, the distance between the negative electrode bodies 23 adjacent to each other in the first direction L1 in the unfolded state becomes larger as they are located on the outer peripheral side in the wound state.

Of the plurality of negative electrode bodies 23, the negative electrode body 23 arranged on the innermost peripheral side in the electrode body 2 in the wound state is referred to as the inner peripheral side negative electrode body (first negative electrode body) 23A, and the outermost peripheral side. The negative electrode main body 23 arranged on the side is referred to as an outer peripheral side negative electrode main body 23B. Therefore, the inner peripheral side negative electrode main body 23A corresponds to the negative electrode main body 23 located on the winding start side.

Further, the negative electrode terminal main body 23B on the outer peripheral side is formed with a negative electrode terminal tab 25 so as to extend further toward the outside of the first direction L1 in the deployed state of the negative electrode electrode 20. As described above, the negative electrode terminal tab 25 does not have the negative electrode active material layer 22 formed on both sides thereof, and is electrically connected to the upper surface of the second electrode plate 61.
The negative electrode terminal tab 25 is electrically connected to the second electrode plate 61 in a folded state with the connection portion with the outer peripheral side negative electrode main body 23B as a base point.

The negative electrode 20 configured as described above has an outer shape similar to the outer shape of the positive electrode 10 described above. However, the outer size of the positive electrode 10 is formed to be slightly smaller (one size smaller) than the outer size of the negative electrode 20.

The separator 30 shown in FIG. 4 is formed of, for example, a microporous film made of a resin such as polyolefin, a non-woven fabric made of glass or resin, a laminate of fibers such as cellulose fibers, and lithium ions are transmitted through ion permeation holes (not shown). It is possible to pass it.
The separator 30 is arranged in the entire layer between the positive electrode 10 and the negative electrode 20, and insulates between the positive electrode 10 and the negative electrode 20. Therefore, the separator 30 is arranged so as to be interposed between the positive electrode 10 and the negative electrode 20 at least in the entire region where the positive electrode 10 and the negative electrode 20 face each other.

The separator 30 is formed in a sheet shape wider than, for example, the positive electrode 10 and the negative electrode 20 in the state before the electrode body 2 is wound, and the positive electrode 10 is formed by cutting or the like after winding. And is formed in a shape corresponding to the negative electrode 20.

As shown in FIG. 4, the positive electrode 10 and the negative electrode 20 configured as described above are alternately laminated by being wound with the separator 30 sandwiched between them. An example of the step of forming the electrode body 2 in which the positive electrode 10 and the negative electrode 20 are laminated (the electrode body forming step) will be described below.
For example, the positive electrode 10 and the negative electrode 20 are arranged along the first direction L1 so that the positive electrode terminal tab 15 and the negative electrode terminal tab 25 are arranged on opposite sides of each other, and the inner peripheral side with the separator 30 interposed therebetween. The positive electrode 10 and the negative electrode 20 are combined so that the positive electrode body 13A and the negative electrode body 23A on the inner peripheral side overlap each other. Next, as shown in FIG. 9, the positive electrode 10 and the negative electrode 20 are repeatedly wound in the same direction, starting from the inner peripheral side positive electrode main body 13A and the inner peripheral side negative electrode main body 23A that are overlapped with each other. Note that the separator 30 is not shown in FIG.
As a result, the positive electrode main body 13 and the negative electrode main body 23 can be laminated in the stacking direction Z so as to be alternately overlapped with each other, and the electrode body 2 shown in FIG. 4 can be obtained.

The positive electrode terminal tab 15 and the negative electrode terminal tab 25 may be arranged in opposite directions when the positive electrode electrode 10 and the negative electrode electrode 20 are wound to form the electrode body 2, and the positive electrode terminal tab 15 and the negative electrode terminal tab 25 may be arranged in opposite directions as described above. It does not necessarily have to be arranged in opposite directions at the start of the round. For example, as shown in FIG. 10, with the positive electrode terminal tab 15 and the negative electrode terminal tab 25 facing in the same direction, the positive electrode 10 and the negative electrode 20 are overlapped with the separator 30 interposed therebetween, and then winding is started. It doesn't matter. Note that the separator 30 is not shown in FIG.

Further, as shown in FIG. 11, a winding machine 70 having a winding core 71 may be used to wind the positive electrode 10, the negative electrode 20, and the separator 30 to form the electrode body 2.
The winding machine 70 mainly includes a winding core 71 and a pair of touch rolls 72. The winding core 71 is formed in a flat plate shape extending along the winding axis O2 with a predetermined width, and is rotatable around the winding axis O2. A slit groove 71a is formed in the winding core 71 along the winding axis O2. The pair of touch rolls 72 are arranged on opposite sides of the winding core 71, and are arranged so as to be close to and separated from the winding axis O2.

When winding using the winding machine 70 configured as described above, the winding core 71 is first rotated about half a turn with the strip-shaped separator sheet 31 passed through the slit groove 71a of the winding core 71. Let me. As a result, the separator sheet 31 is wound on both sides of the winding core 71 sandwiching the slit groove 71a, and the separator sheet 31 can be arranged in a Z shape when viewed from the direction along the winding axis O2.
The separator sheet 31 is a sheet that later functions as a separator 30.

Next, the positive electrode 10 and the negative electrode 20 are arranged on both sides of the winding core 71. At this time, the inner peripheral side positive electrode main body 13A of the positive electrode 10 is set so as to be overlapped with the separator sheet 31, and the inner peripheral side negative electrode main body 23A of the negative electrode electrode 20 is overlapped with the separator sheet 31. Set to. Then, by rotating the winding core 71 around the winding axis O2 in this state, the positive electrode 10, the negative electrode 20, and the separator sheet 31 are wound flat around the winding axis O2 while being wound around the winding core 71. Can be turned.

As a result, the plurality of positive electrode main bodies 13 and the plurality of negative electrode main bodies 23 are arranged in parallel with the winding core 71, and the plurality of positive electrode connecting pieces 14 and the plurality of negative electrode connecting pieces 24 are respectively along the side edges of the winding core 71. It is possible to obtain a rolled body that has been folded back. During winding, the pair of touch rolls 72 are in constant contact with the wound body, thereby enabling dense winding of the positive electrode 10, the negative electrode 20, and the separator sheet 31.
Finally, the electrode body 2 shown in FIG. 4 can be formed by pulling out the winding core 71 from the winding body in the winding axis O2 direction and then cutting an unnecessary portion of the separator sheet 31.

By the way, in the present embodiment, as shown in FIG. 6, a positioning unit 100 for positioning a relative position at the start of winding of at least one of the positive electrode 10 and the negative electrode 20 is provided with respect to the separator 30.
Specifically, in the electrode body 2 in the wound state, the positioning unit 100 is located between the inner peripheral side negative electrode body 23A located on the winding start side among the plurality of negative electrode bodies 23 constituting the negative electrode electrode 20 and the separator 30. Is provided with a negative electrode positioning portion for positioning the inner peripheral side negative electrode body 23A with respect to the separator 30.
The negative electrode positioning portion is an insulating adhesive layer (adhesive member according to the present invention) 80 that adheres the inner peripheral side negative electrode main body 23A and the separator 30 to each other. Since the adhesive layer 80 is provided between the inner peripheral side negative electrode main body 23A and the separator 30, it is possible to integrally combine the inner peripheral side negative electrode main body 23A with the separator 30 for positioning. ..

In particular, the adhesive layer 80 is provided so as to be located between the separator 30 and the outer end portion of the inner peripheral side negative electrode main body 23A facing the positive electrode connecting piece 14 with the separator 30 interposed therebetween.
At the outer end of the inner peripheral side negative electrode main body 23A, the negative electrode current collector 21 is exposed in a state of facing the separator 30 side due to the winding of the positive electrode 10 and the negative electrode 20. In this regard, as described above, since the adhesive layer 80 is arranged between the outer end portion of the inner peripheral side negative electrode main body 23A and the separator 30, it is as if the negative electrode current collector 21 in which the adhesive layer 80 is exposed to the outside is exposed. Covered to protect.

Moreover, since the adhesive layer 80 covers the surface of the separator 30, it closes the ion permeation holes formed in the separator 30. As a result, the adhesive layer 80 moves from the positive electrode connection piece 14 through the separator 30 toward the outer end of the inner peripheral side negative electrode main body 23A as shown by the arrow F1 shown in FIG. 6 when the secondary battery 1 is charged and discharged. Ion conductivity of lithium ions (that is, lithium ions that inherently contribute to charge and discharge) that move between the positive electrode body 13 and the negative electrode body 23 as shown by the arrow F2 shown in FIG. 6 through the separator 30. It is possible to lower it than.

The adhesive layer 80 is previously attached to the inner peripheral side negative electrode body 23A, as shown in FIG. 12, for example, when winding the positive electrode 10, the negative electrode 20, and the separator 30, that is, when performing the electrode body forming step. It can be formed by applying the adhesive 81 to the outer end portion. Note that FIG. 12 shows only the separator 30 and the negative electrode 20. This makes it possible to perform a positioning step of positioning the outer end portion of the inner peripheral side negative electrode main body 23A with respect to the separator 30.
However, the present invention is not limited to this case, and for example, as shown in FIG. 13, an adhesive 81 is previously applied to the separator 30 side, and the outer end of the inner peripheral side negative electrode main body 23A is applied via the adhesive 81. The adhesive layer 80 may be formed by adhering the portions to the separator 30.

The adhesive 81 may have at least an insulating property and is not limited to a specific one, but for example, it has a characteristic of having little swelling property with respect to an electrolyte solution (electrolyte solution) and with respect to a metal. It is preferable that the properties have excellent adhesion, flexibility against winding, wide potential window, stable material properties against oxidation and reduction potentials, and the like.
Specifically, as the adhesive 81, a polyacrylic acid-based resin, a polyacrylic acid ester-based resin, or the like can be preferably adopted. Furthermore, it is also possible to suitably use a copolymer in which a part of the skeleton of these resins is replaced with styrene as the adhesive 81. More specifically, "Polysol L300 (registered trademark)" manufactured by Showa Denko KK can be used as the adhesive 81.

In the positioning step described above, after the adhesive 81 is applied to the outer end portion of the inner peripheral side negative electrode main body 23A, when the negative electrode 20 is contact-arranged with the separator 30, the surface or the inside of the adhesive 81 is previously applied. It is preferable to solidify it or treat it so that it becomes an appropriate wet state.
When the adhesive 81 is the above-mentioned resin, as a method of solidifying, for example, a method of volatilizing the solvent by heating or the like to dry it, or a method of chemically polymerizing it by heat treatment or irradiation with ultraviolet rays (UV) can be used. ..

Further, the appropriate wet state means a state in which the adhesive 81 suppresses the amount of the solvent contained, although it does not solidify by volatilizing the solvent by the above-mentioned method. By using such an adhesive layer 80, it is possible to reduce slippage between the negative electrode electrode 20 and the separator 30 when the negative electrode electrode 20 is placed in contact with the separator 30. This makes it possible to effectively suppress unwinding, which will be described later, when the electrode body 2 is subsequently formed.

As the material of the adhesive layer 80, in addition to the above-mentioned adhesive 81, polyvinylidene fluoride (PVDF), a copolymer such as vinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), and a resin such as polyimide are used. Can be used.
When these materials are used, they are diluted with a solvent in advance and gelled, and then coated on the outer end of the inner peripheral side negative electrode body 23A and completely dried or semi-dried to solidify. Alternatively, the electrode body 2 may be formed after the treatment is performed so as to obtain an appropriate wet state.
Among these materials, N-methylpyrrolidone (NMP) or the like can be used as a solvent in PVDF. Further, in PVDF-HFP, acetone or the like can be used as a solvent. These solvents are dried before assembling the cell (secondary battery 1). When polyimide is used, its precursor, polyamic acid or the like, can be applied to the outer end portion of the inner peripheral side negative electrode main body 23A and polymerized by heating or the like.

(Action of secondary battery)
According to the secondary battery 1 configured as described above, as shown in FIG. 2, the first electrode terminal plate 62 electrically connected to the first electrode plate 60 is exposed to the outside, and the second electrode is exposed. Since the second electrode terminal plate 63 electrically connected to the plate 61 is exposed to the outside, the first electrode terminal plate 62 and the second electrode terminal plate 63 can each function as external connection terminals. ..
This makes it possible to use the secondary battery 1 by using the first electrode terminal board 62 and the second electrode terminal board 63.

In particular, according to the secondary battery 1 of the present embodiment, since the electrode body 2 is formed by winding the positive electrode 10 and the negative electrode 20, the electrode body 2 is wound into a flat shape without a protrusion. In the rotated state, it can be housed inside the exterior body 3 at a high density. Therefore, the degree of freedom in shape can be improved, the volume ratio occupied by the electrode body 2 to the total volume of the secondary battery 1 can be improved, and the volumetric efficiency of the laminated type secondary battery 1 can be improved. can do.

Further, as shown in FIG. 6, a positioning unit 100 including an adhesive layer 80 that functions as a negative electrode positioning unit is provided. In particular, the adhesive layer 80 can be used to position the inner peripheral side negative electrode body 23A with respect to the separator 30. Therefore, when the positive electrode 10 and the negative electrode 20 that are overlapped with each other with the separator 30 interposed therebetween are wound to form the electrode body 2, the relative positional relationship between the positive electrode 10 and the negative electrode 20 is displaced with the separator 30 interposed therebetween. It is possible to suppress the occurrence of so-called winding misalignment.
As a result, as shown in FIG. 4, the plurality of positive electrode bodies 13 and the plurality of negative electrode bodies 23 can be alternately laminated in the stacking direction Z while accurately facing each other with the separator 30 interposed therebetween. can. Therefore, the secondary battery 1 with improved operation reliability can be obtained.

In addition, as shown in FIG. 6, the adhesive layer 80 is arranged so as to be located between the outer end portion of the inner peripheral side negative electrode main body 23A and the separator 30, so that the adhesive layer 80 is exposed to the outside at the outer end portion. The negative electrode current collector 21 is arranged so as to protect it. In addition, the adhesive layer 80 closes the ion transmission holes in the separator 30, so that the separator 30 is more than the ion conductivity of lithium ions that move between the positive electrode body 13 and the negative electrode body 23 through the separator 30 during charging and discharging. It plays a role of lowering the ionic conductivity of lithium ions moving from the positive electrode connection piece 14 toward the outer end portion through the positive electrode connection piece 14.

Therefore, it is possible to suppress the movement of lithium ions to the exposed portion of the negative electrode current collector 21 during charging / discharging, and for example, lithium ions are deposited in a needle shape (dendrite growth) on the negative electrode current collector 21. It can be made less likely to cause inconvenience. Therefore, this also makes it possible to further improve the operational reliability of the secondary battery 1.

As described above, according to the secondary battery 1 of the present embodiment, it is possible to wind the positive electrode 10 and the negative electrode 20 in a state of maintaining an appropriate relative positional relationship with the separator 30 interposed therebetween. It is possible to use a laminated type battery provided with the electrode body 2 having improved operation reliability.
Further, since the adhesive layer 80 can function as the negative electrode positioning portion, it is easy to simplify the configuration and reduce the cost.

(First modification)
In the first embodiment, the case where the adhesive layer 80 is used as the negative electrode positioning portion has been described as an example, but the present invention is not limited to this case. For example, instead of the adhesive layer 80, an adhesive tape having an insulating property (adhesive member according to the present invention) may be used. Even in this case, the same effect can be achieved.

(Second modification)
Further, the negative electrode positioning portion is not limited to the case where the adhesive layer 80 or the adhesive member such as the adhesive tape described above is used. For example, the inner peripheral side negative electrode body 23A may be positioned with respect to the separator 30 by welding.

Specifically, as shown in FIG. 14, the welded portion 85 formed by welding the outer end portion of the inner peripheral side negative electrode main body 23A and the separator 30 to each other may function as the negative electrode positioning portion. Note that FIG. 14 shows only the negative electrode 20 and the separator 30.
In this case, when winding the positive electrode 10, the negative electrode 20, and the separator 30, it is possible to form the welded portion 85 by performing welding at the initial stage of winding. As the welding, for example, high frequency welding, heat welding, ultrasonic welding and the like can be used.

As described above, even when the welded portion 85 is used, the same effect as that of the above embodiment can be achieved. In particular, by welding the outer end portion of the inner peripheral side negative electrode main body 23A and the separator 30 to each other, the separator 30 can be partially melted and the ion permeation holes can be reliably closed. Therefore, the ionic conductivity of lithium ions moving from the positive electrode connection piece 14 to the outer end portion of the inner peripheral side negative electrode main body 23A through the separator 30 can be effectively reduced. Thereby, the operation reliability of the secondary battery 1 can be further improved.

Further, the case of welding is not limited to the case where the outer end portion of the inner peripheral side negative electrode main body 23A and the separator 30 are welded to each other, and as shown in FIG. 15, a part of the separator 30 is preliminarily formed. A separator welded portion 86 may be formed by double welding, and the separator welded portion 86 may function as a negative electrode positioning portion. Note that FIG. 15 shows only the negative electrode 20 and the separator 30.
In this case, when winding the positive electrode 10, the negative electrode 20, and the separator 30, the separator 30 on which the separator welding portion 86 is formed is prepared in advance. Then, at the stage of the start of winding, the negative electrode 20 is combined with the separator 30 so that the outer end portion of the inner peripheral side negative electrode body 23A comes into contact with the separator welding portion 86 as shown by the arrow shown in FIG. After that, you can turn it around.

As a result, the inner peripheral side negative electrode body 23A can be positioned with respect to the separator 30, so that it is possible to suppress the occurrence of unwinding between the positive electrode 10 and the negative electrode 20 during winding. Further, even in this case, as shown in FIG. 16, since the separator 30 can be partially melted and the ion permeation holes can be reliably closed by the separator welding portion 86, the separator 30 can be reliably closed from the positive electrode connection piece 14. The ionic conductivity of lithium ions moving toward the outer end of the inner peripheral side negative electrode body 23A can be effectively reduced, and the operational reliability of the secondary battery 1 can be further improved.

(Third modification example)
Further, in the first embodiment, as shown in FIG. 17, a positioning portion 100 is provided between the positive electrode electrode 10 and the separator 30, and a positive electrode positioning portion for positioning the inner peripheral side positive electrode body 13A with respect to the separator 30. May be provided.
In the illustrated example, the upper and lower surfaces of the inner peripheral side positive electrode body 13A are mainly wrapped with the separator 30, and then the upper and lower surfaces of the separator 30 are welded along the positive electrode connection piece 14 connected to the inner peripheral side positive electrode body 13A. By forming the positive electrode side welded portion 87, the positive electrode side welded portion 87 functions as a positive electrode positioning portion.
Note that FIG. 17 shows only the positive electrode 10 and the separator 30.

This makes it possible to position the inner peripheral side positive electrode body 13A with respect to the separator 30 by using the positive electrode side welding portion 87. Then, as shown in FIG. 18, the adhesive layer 80 is formed by adhering the outer end portion of the inner peripheral side negative electrode body 23A and the separator 30 to each other using the adhesive 81, as in the above embodiment. As a result, the inner peripheral side negative electrode body 23A is positioned with respect to the separator 30.
At this time, the separator 30 and the negative electrode 20 are combined by using the adhesive layer 80 so that the outer end portion of the inner peripheral side negative electrode main body 23A overlaps the positive electrode side welded portion 87.

By doing so as described above, the inner peripheral side positive electrode body 13A located on the winding start side of the positive electrode electrode 10 and the inner peripheral side negative electrode body 13A located on the winding start side of the negative electrode electrode 20 at the time of subsequent winding. The 23A and the separator 30 can be aligned with each other with high accuracy. Therefore, it is possible to more effectively suppress the occurrence of winding misalignment between the positive electrode 10 and the negative electrode 20 with the separator 30 sandwiched in the middle of winding.

The positive electrode side welded portion 87 is not limited to the case where the upper and lower surfaces of the separator 30 are welded together along the positive electrode connecting piece 14. For example, the upper and lower surfaces of the separator 30 may be partially welded so as to sandwich the positive electrode connection piece 14.

(Fourth modification)
Further, as the negative electrode positioning portion, as shown in FIG. 19, a blank winding portion 88 in which a part of the separator 30 is pre-wound may be used.
In this case, for example, when winding using the winding machine 70 shown in FIG. 11, the winding core 71 is rotated about the winding axis O2 a predetermined number of times in advance, and only the separator 30 is idlely wound. It's fine. Thereby, when the negative electrode 20 is combined with the separator 30, the negative electrode 20 can be combined with the empty winding portion 88 as a reference. That is, the negative electrode 20 can be combined with the separator 30 so that the outer end portion of the inner peripheral side negative electrode body 23A comes into contact with the empty winding portion 88 at the stage of the start of winding.

As a result, the inner peripheral side negative electrode body 23A can be positioned with respect to the separator 30, so that it is possible to suppress the occurrence of unwinding between the positive electrode 10 and the negative electrode 20 during winding.
Further, even in this case, it is possible to make it difficult for lithium ions to pass from the positive electrode connection piece 14 toward the outer end portion of the inner peripheral side negative electrode main body 23A by the amount of idle winding, so that lithium ion ions are similarly formed. The conductivity can be reduced.

(Fifth modification)
In the first embodiment, the second electrode plate 61 is made of copper, but may be made of nickel, for example. In this case, it is possible to omit the second electrode terminal plate 63. That is, on the negative electrode side, the electrode terminal board is not always indispensable and may not be provided. In this case, the second electrode plate 61 itself can function as an external connection terminal on the negative electrode side.

(6th modification)
Further, in the first embodiment, the secondary battery 1 having a circular shape in a plan view has been described as an example, but the shape of the secondary battery 1 may be changed as appropriate. For example, an oval-shaped secondary battery in which a straight portion and a semicircular portion are combined in a plan view may be used. In this case, the shape of the electrode body 2 may be formed into an oval shape in a plan view corresponding to the outer shape of the secondary battery.

(7th modification)
Further, in the first embodiment, the peripheral wall portion 47 of the first laminated member 40 is made to function as the accommodating portion 45, but the present invention is not limited to this case.
For example, as shown in FIG. 20, the second laminated member 50 is formed so as to have the peripheral wall portion 58, and the peripheral wall portion 58 and the peripheral wall portion 47 of the first laminated member 40 form the peripheral wall portion of the accommodating portion 45. The secondary battery 90 may be configured as described above.
In this case, the sealing portion composed of the first sealing cylinder portion 46 and the second sealing cylinder portion 56 surrounds the peripheral wall portion 47 of the first laminated member 40 from the outside in the radial direction to the entire circumference. It may be formed as follows. Even in the case of the secondary battery 90 configured in this way, the same effect can be achieved.

(8th modification)
Further, in the first embodiment, as shown in FIG. 21, the negative electrode connection piece 24 connected to the inner peripheral side negative electrode main body 23A is folded back to the inner peripheral side negative electrode main body 23A and the inner peripheral side negative electrode main body 23A. On the other hand, the negative electrode main body 23 adjacent to each other in the expanded state may be overlapped in advance in the stacking direction Z via the separator 30.
In this case, the electrode body 2 has a positional relationship in which the outer end portion of the inner peripheral side negative electrode body 23A and the negative electrode connecting piece 24 face each other via the separator 30, so that the positive electrode 10 side to the inner peripheral side negative electrode during charging and discharging. It is possible to prevent the lithium ions from moving toward the outer end portion of the main body 23A.

(9th modification)
Further, in the first embodiment, it is not necessary that the entire exterior body 3 is formed of a laminated film, and at least a part thereof may be formed of a laminated film.
Furthermore, the case is not limited to the case where the exterior body 3 is made of a laminated film, and a metal casing may be used. In this case, the electrochemical cell according to the present invention can be a so-called button-type battery made of metal, and can be used as a battery having high versatility.
An example of the case where the exterior body is made of metal will be described in the second embodiment below.

(Second Embodiment)
Next, a second embodiment of the electrochemical cell according to the present invention will be described with reference to the drawings.
As shown in FIGS. 22 to 24, the secondary battery 110 of the present embodiment is a so-called button (coin) type battery, and has a metal exterior body 112 and a power generation element housed inside the exterior body 112. It includes 113 and a support column 114.

The exterior body 112 is welded and joined to the container body 120 formed in a bottomed tubular shape and the container body 120 so as to close the opening of the container body 120, and the accommodation space 115 is formed between the container body 120 and the container body 120. A metal lid member (sealing plate according to the present invention) 130 for forming the above is provided.
The power generation element 113 includes an electrode body 140 having a positive electrode 142 and a negative electrode 143 arranged with the separator 141 interposed therebetween, and also contains an electrolytic solution (electrolyte solution) (not shown) inside the exterior body 112. It is housed in the formed storage space 115.

In the present embodiment, the axis extending in the vertical direction through the center of the exterior body 112 is referred to as a battery shaft O1. Further, in a plan view from the direction of the battery shaft O1, the direction intersecting the battery shaft O1 is referred to as the radial direction, and the direction rotating around the battery shaft O1 is referred to as the circumferential direction. Further, the direction from the bottom wall portion 121 of the container body 120 toward the lid member 130 along the battery shaft O1 is referred to as an upper direction, and the opposite is referred to as a lower direction.

(Exterior body)
The exterior body 112 will be described in detail.
The container body 120 is connected to the bottom wall portion 121 formed in a circular shape in a plan view over the entire circumference of the outer peripheral edge portion of the bottom wall portion 121, and the peripheral wall portion extending upward from the bottom wall portion 121. 122, and is formed in a bottomed cylindrical shape.
However, the shape of the container body 120 is not limited to the bottomed cylindrical shape, and may be formed so that the outer shape is an elliptical shape, a quadrangular shape, or a polygonal shape in a plan view, for example.

The container body 120 is made of metal and functions as an external connection terminal for the positive electrode or an external connection terminal for the negative electrode that conducts to the electrode body 140. The thickness of the container body 120 is, for example, about 0.01 mm to 0.30 mm, and is a thin metal container. However, in each drawing, the thickness of the container body 120 is exaggerated to make it easier to see.

The specific metal material of the container body 120 varies depending on whether the container body 120 functions as an external connection terminal for the positive electrode or an external connection terminal for the negative electrode, but for example, aluminum, aluminum alloy, copper, etc. Copper alloys, stainless steels, and clad materials (highly functional metal materials) formed by crimping metals of the same type or different types can be used. However, it is not limited to these cases.
Examples of the stainless steel include ferrite stainless steels such as SUS430 and SUS444 and austenite ferrite two-phase stainless steels such as SUS329J4L.

Examples of the clad material include a three-layer clad material of Cu (inner layer) / Fe (middle layer) / Ni (outer layer), a three-layer clad material of Ni (inner layer) / Fe (middle layer) / Ni (outer layer), and Al ( Examples thereof include a three-layer clad material of (inner layer) / SUS (middle layer) / Ni (outer layer). However, the clad material is not limited to three layers, and may be formed by pressure-bonding other metals to each other in multiple layers.

When Cu is used as the clad material, the thermal conductivity can be enhanced, so that the heat dissipation during welding can be improved. Therefore, it is preferable to use Cu for the inner layer of the clad material because it can protect the electrode body 140.

Further, it is preferable to perform a plating treatment on either one of the inner surface and the outer surface of the clad material, or both the inner surface and the outer surface to form a metal plating film. By forming a metal plating film on the inner surface of the container body 120, it can be chemically stabilized and the resistance to an electrolytic solution or the like can be improved. Further, by forming a metal plating film on the outer surface of the container body 120, functions such as a rust preventive function can be added and electrical resistance can be reduced, so that electrical connectivity with an external terminal can be achieved. Can be improved.

As the specific metal plating film, for example, a Ni plating film, an alloy plating film such as Ni, or the like can be adopted, and it is particularly preferable to use an alloy plating film made of a eutectic metal material. When an alloy plating film made of a eutectic metal material is adopted, for example, the melting point can be lowered when performing resistance welding, and the temperature at the time of welding can be lowered.
In addition, Au—Ni alloy plating film, Ni—P alloy plating film, Ni—B alloy plating film, and the like can also be suitably adopted.

Further, for example, when the secondary battery 110 of the present embodiment is used for a timepiece, it is preferable that the metal material of the container body 120 is non-magnetic in addition to corrosion resistance. Specifically, in addition to the above-mentioned aluminum, aluminum alloy, copper, and copper alloy, examples of stainless steel include various austenitic stainless steels such as SUS201, SUS202, SUS303, SUS304, SUS305, SUS316, SUS317, SUS321, and SUS347. be able to.
Further, as the container body 120, a material in which a resin layer is formed on the surface of various metals described above may be adopted. For example, a laminated film in which a metal layer made of stainless steel and a film-shaped resin layer are laminated may be used. Can be used. In this case, the opening of the container body 120 can be closed by joining the metal lid member 130 and the metal layer of the container body 120. As the resin layer, for example, a resin material used for the sealant film 150 described later can be used.

As shown in FIGS. 23 and 24, the lid member 130 is formed in a circular shape in a plan view, and is arranged so as to face the battery shaft O1 direction with the electrode body 140 interposed therebetween with respect to the bottom wall portion 121 of the container body 120. An ecstatic cylindrical shape including a top wall portion 131 and an inner peripheral wall portion 132 that is continuously provided over the entire circumference of the outer peripheral edge portion of the top wall portion 131 and extends upward from the top wall portion 131. It is formed.

The shape of the lid member 130 may correspond to the shape of the container body 120, and the outer shape may be an elliptical shape, a quadrangular shape, or a polygonal shape in a plan view, for example, corresponding to the shape of the container body 120. It may be formed. The thickness of the lid member 130 is, for example, about 0.01 mm to 0.30 mm, as in the case of the container body 120, and is thin. However, in each drawing, the thickness of the lid member 130 is exaggerated to make it easier to see.

In the lid member 130, the top wall portion 131 is located below the upper end opening edge of the peripheral wall portion 122 in the container body 120, and the upper end opening edge of the peripheral wall portion 122 and the upper end opening edge of the inner peripheral wall portion 132 are flush with each other. It is arranged inside the peripheral wall portion 122 so as to be. As a result, the inner peripheral wall portion 132 is welded and joined to the inside of the peripheral wall portion 122 of the container body 120 in a state of being double overlapped in the radial direction.

The peripheral wall portion 122 and the inner peripheral wall portion 132 are firmly joined by welding over the entire circumference. As a result, the opening of the container body 120 can be closed by using the lid member 130, and a storage space 115 (sealed space) for accommodating the support column 114 and the power generation element 113 is formed between the lid member 130 and the container body 120. There is.

The welding method between the container body 120 and the lid member 130 is not particularly limited, but for example, resistance welding such as laser welding, ultrasonic joining, seam welding, friction stir welding (FSW), etc. Can be adopted.
At the time of these welding, the so-called work move method may be used in which welding is performed while moving the exterior body 112 side, which is the work to be welded, with the welder side (not shown) fixed, or the exterior body, which is the work to be welded. Welding may be performed by fixing the 112 side and moving the welder side, that is, a so-called head move method. For example, when laser welding is performed by a head move method, a galvanoscanning type laser welder or the like can be adopted.

In the central portion of the lid member 130, a through hole 133 that penetrates the lid member 130 in the vertical direction is formed coaxially with the battery shaft O1. The shape of the through hole 133 is not particularly limited, but is formed, for example, in a circular shape in a plan view.

The lid member 130 configured in this way is made of metal. As a specific metal material of the lid member 130, for example, a metal material of the same type as or different from that of the container body 120 can be adopted. As the metal material of the lid member 130, for example, when a metal material different from that of the container body 120 is used, it is preferable to use a metal material having a coefficient of thermal expansion close to that of the container body 120.
Further, it is preferable that the lid member 130 is also plated on either the inner surface or the outer surface or both the inner surface and the outer surface to form a metal plating film, similarly to the container body 120. As the metal plating film, the metal plating film described above can be adopted.

(Current collector plate)
As shown in FIGS. 22 to 24, the lid member 130 configured as described above is heat-welded (welded) via a sealant film (insulating sealing material according to the present invention) 150, and at least a part thereof is welded. A current collector plate 151 exposed to the outside (upper side) is provided.
Specifically, the sealant film 150 and the current collector plate 151 are arranged on the upper surface side of the top wall portion 131 of the lid member 130 facing opposite to the accommodation space 115 in the battery shaft O1 direction. The current collector plate 151 is heat-welded to the upper surface of the top wall portion 131 via the sealant film 150, and is exposed upward over the entire surface.

The sealant film 150 is formed in an annular shape surrounding the through hole 133 formed in the top wall portion 131, and is arranged so as to overlap the upper surface of the top wall portion 131 in a state of being coaxially arranged with the battery shaft O1. In the illustrated example, the sealant film 150 is formed with an inner diameter smaller than the diameter of the through hole 133.
However, the present invention is not limited to this case, and the inner diameter of the sealant film 150 may be formed to be equal to or larger than the diameter of the through hole 133.

The sealant film 150 is made of, for example, a thermoplastic resin made of poreolefin or an engineering plastic such as polyphenylene sulfide (PPS). Examples of the polyolefin include polyethylene, polypropylene, polybutene and the like.
Further, as the sealant film 150, a composite such as a copolymer or blend polymer of each of the above-mentioned polyolefins or polypropylene reinforced with a non-woven fabric may be used. Further, a plurality of sealant films 150 having different dimensions, shapes, or thicknesses may be stacked and used.

The current collector plate 151 is a metal plate and functions as an external connection terminal for a positive electrode or an external connection terminal for a negative electrode that conducts to the electrode body 140. In the illustrated example, the current collector plate 151 is formed in a circular shape in a plan view with a diameter smaller than the outer diameter of the sealant film 150, and overlaps the upper surface of the sealant film 150 in a state of being coaxially arranged with the battery shaft O1. It is arranged like this. As a result, the current collector plate 151 closes the through hole 133 from above.

The material of the current collector plate 151 is not particularly limited, but nickel or the like can be preferably used. Further, a metal made of a good electrical material such as gold or nickel, or an alloy plating film containing these metals may be formed on the externally connectable surface of the current collector plate 151.

The sealant film 150 described above is heat-welded to the upper surface of the top wall portion 131 and the lower surface of the current collector plate 151, respectively. As a result, the current collector plate 151 is heat-sealed to the upper surface of the top wall portion 131 via the sealant film 150, and the through hole 133 is airtightly sealed from above while maintaining insulation between the current collector plate 151 and the lid member 130. doing. In particular, the current collector plate 151 is integrally combined with the lid member 130 via the sealant film 150.

Here, the sealant film 150 insulates the current collector plate 151 and the container body 120. In the secondary battery 110 of the present embodiment, the current collector plate 151 and the container body 120 come into contact with a pressure contact terminal, a holder, or the like of an electronic device (not shown), so that the positive electrode side terminal and the negative electrode side terminal of the electronic device are contacted with each other. It can be electrically connected to any of these terminals. Further, a metal terminal may be further welded to at least one of the current collector plate 151 and the container body 120, and then electrically connected to an electronic device by soldering, welding, or the like.

(Strut part)
As shown in FIGS. 23 and 24, in the accommodation space 115 in the exterior body 112, the support column 114 is accommodated together with the power generation element 113.
The support column 114 is formed in a shaft shape extending in the vertical direction along the battery shaft O1 and is arranged coaxially with the battery shaft O1. In the illustrated example, the strut 114 is formed in a hollow cylindrical shape, the outer diameter thereof being smaller than the diameter of the through hole 133 and the inner diameter of the sealant film 150. As a result, the upper end portion (first end portion according to the present invention) of the support column portion 114 comes into contact with the current collector plate 151 from below through the through hole 133, and the lower end portion (second end portion according to the present invention). Is arranged so as to come into contact with the bottom wall portion 121 of the container body 120 from above. Therefore, the support column 114 supports the current collector plate 151 integrally combined with the lid member 130 from below. That is, the support column 114 supports the lid member 130 from below via the current collector plate 151.

The strut portion 114 of the present embodiment is formed of an inorganic material such as ceramic or an insulating material such as a synthetic resin material. When the support column 114 is made of synthetic resin, for example, a thermoplastic resin having a melting point equivalent to that of the separator 141 can be preferably used. Specifically, materials such as synthetic resins such as PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), and PBT (polybutylene terephthalate) can be adopted. Furthermore, copolymers of these synthetic resins, blended polymers and the like can also be used.
As a result, the container body 120 and the current collector plate 151 are electrically connected to each other through the support column 114, the current collector plate 151 and the electrode body 140 are electrically connected to each other, and the container body 120 and the electrode body 140 are connected to each other. Electrical connection etc. are suppressed.

(Power generation element)
As shown in FIGS. 23 and 24, the power generation element 113 contains an electrode body 140 and an electrolytic solution (not shown), and is housed in a sealed state in a storage space 115 inside the exterior body 112 together with the support column 114 described above.
As the electrolytic solution, for example, a liquid in which a supporting salt is dissolved in a non-aqueous solvent can be preferably used. As the supporting salt, for example, lithium fluorophosphate (LiPF6) or the like can be used. As the solvent, for example, a low boiling point solvent can be used together with ethylene carbonate (EC).

However, as the power generation element 113, an electrode body 140 using an electrolyte such as a solid electrolyte, a polymer electrolyte, or a gel electrolyte may be adopted instead of the electrolytic solution. Examples of the polymer electrolyte include polyethylene oxide (PEO), polypropylene oxide (PPO), blend polymers containing them, polyacrylic acid ester, polymethacrylic acid ester, polysiloxane, polyphosphazene and the like. Further, a gel electrolyte containing poly (vinylidene fluoride-co-hexafluoropropylene, PVdF-HFP) in the electrolytic solution may be used.

(Electrode body)
As shown in FIG. 23, the electrode body 140 has a positive electrode 142 and a negative electrode 143 arranged with the separator 141 interposed therebetween, and is a wound electrode that is multiplely wound around the battery shaft O1. Specifically, the electrode body 140 is wound around the support column 114, and the support column portion 114 is arranged coaxially with the battery shaft O1 in a state where the positive electrode 142 and the negative electrode electrode 143 are overlapped with the separator 141 interposed therebetween. It is configured to be wound multiple times in the radial direction around the central axis C (see FIG. 4). Therefore, the strut portion 114 also functions as a winding core when winding the electrode body 140.

The electrode body 140 is wound in a plurality of spirals around the battery shaft O1 (center axis C of the support column 114) in a plan view from the direction of the battery shaft O1. In the present embodiment, the negative electrode 143, the separator 141, the positive electrode 142, and the separator 141 are directed from the innermost layer located on the support column 114 side of the electrode body 140 to the outermost layer located on the peripheral wall portion 122 side of the container body 120. , Negative electrode 143, separator 141, and positive electrode 142 are wound so as to be repeatedly arranged in this order.
The electrode body 140 may be, for example, a so-called pellet type electrode body 140 having a positive electrode 142 and a negative electrode 143 on both sides of the separator 141. Further, in each drawing other than FIG. 23, the illustration of the electrode body 140 is simplified.

As shown in FIG. 25, the positive electrode electrode 142 is a long positive electrode current collector (positive electrode current collector foil) 142a formed so as to extend in a strip shape with a constant width in the unfolded state before winding the electrode body 140. And the positive electrode active material layer 142b formed by coating or the like on one side or both sides of the positive electrode current collector 142a, the positive electrode current collector 142a is formed in the form of one sheet.

The positive electrode current collector 142a is made of a metal material such as aluminum, an aluminum alloy, or stainless steel, and is formed in a thin sheet shape (metal foil). The thickness of the positive electrode current collector 142a is, for example, about several μm to several μm. The positive electrode active material layer 142b is formed in a portion of the positive electrode current collector 142a excluding the positive electrode terminal tab 142c described later.
As the positive electrode current collector 142a, in addition to the metal foil, for example, an etching foil, a punching metal, a sintered metal body, or a foamed metal body can be used.

As the material for forming the positive electrode active material layer 142b, in addition to the positive electrode active material, any conductive auxiliary agent (for example, carbon black, graphite, etc.), binder (for example, polyvinylidene fluoride, etc.), solvent (for example, N-methylpyrrolidone, etc.) can be used. The solvent) can be mixed to prepare a slurry for a positive electrode. The coating liquid containing the constituent material for forming the positive electrode active material layer 142b can be referred to as a “positive electrode slurry”. The positive electrode active material layer 142b can be formed by applying this positive electrode slurry to the positive electrode current collector 142a and drying it.
Examples of the positive electrode active material include lithium-manganese-lithium cobalt oxide (NMC), nickel-cobalt-lithium aluminate (NCA), lithium titanate (LTO), lithium manganate (LMO), and the like. Examples include composite oxides containing metals.

A positive electrode terminal tab 142c is formed at one end of both ends of the positive electrode current collector 142a, which is located on the side away from the support column 114. As described above, the positive electrode terminal tab 142c does not have the positive electrode active material layer 142b formed therein, and is electrically connectable to other parts. The positive electrode terminal tab 142c is arranged on the outer layer side of the electrode body 140 when the electrode body 140 is wound.

As shown in FIG. 25, the negative electrode electrode 143 is a long negative electrode current collector (negative electrode current collector foil) 143a formed so as to extend in a strip shape with a constant width in the unfolded state before winding the electrode body 140. And the negative electrode active material layer 143b formed by coating or the like on one side or both sides of the negative electrode current collector 143a, and the negative electrode active material layer 143b is formed in the form of one sheet.

The negative electrode current collector 143a is made of a metal material such as copper, copper alloy, nickel, and stainless steel, and is formed in a thin sheet shape (metal foil). The thickness of the negative electrode current collector 143a is, for example, about several μm to several several μm. The negative electrode active material layer 143b is formed in a portion of the negative electrode current collector 143a excluding the negative electrode terminal tab 143c described later.
As the negative electrode current collector 143a, in addition to the metal foil, for example, an etching foil, a punching metal, a sintered metal body, or a foamed metal body can be used.

As a material for forming the negative electrode active material layer 143b, in addition to the negative electrode active material, a conductive auxiliary agent (for example, carbon black, graphite, etc.), a binder (for example, a dispersion of styrene-butadiene rubber (SBR), etc.), a thickener (for example, a thickener (for example) For example, a cellulose nanofiber (CNF: Cellulose Nano Fiber), carboxymethyl cellulose, etc.) and a solvent (for example, an arbitrary solvent such as pure water) can be mixed to prepare a slurry for a negative electrode. The coating liquid containing the constituent material for forming the negative electrode active material layer 143b can be referred to as a “negative electrode slurry”. The negative electrode active material layer 143b can be formed by applying this negative electrode slurry to the negative electrode current collector 143a and drying it.
Examples of the negative electrode active material include simple substances or mixtures of silicon, silicon oxide, graphite, hard carbon, lithium titanate (LTO), LiAl and the like.

Negative electrode terminal tabs 143c are formed at one end of both ends of the negative electrode current collector 143a, which is located on the side away from the support column 114. As described above, the negative electrode terminal tab 143c does not have the negative electrode active material layer 143b formed therein, and can be electrically connected to other parts. The negative electrode terminal tab 143c is arranged on the outer layer side of the electrode body 140 when the electrode body 140 is wound.

The separator 141 shown in FIG. 25 is formed of, for example, a microporous film made of a resin such as polyolefin, a non-woven fabric made of glass or resin, a laminate of fibers such as cellulose fibers, and lithium ions are transmitted through ion permeation holes (not shown). It is possible to pass it. Further, as the separator 141, for example, a porous body capable of holding the electrolytic solution in the pores, a resin layer having lithium ion conductivity, or the like can be adopted.

The separator 141 is arranged in the entire layers between the positive electrode 142 and the negative electrode 143, and insulates between the positive electrode 142 and the negative electrode 143. Therefore, the separator 141 is arranged so as to be interposed between the positive electrode 142 and the negative electrode 143 in at least the entire region where the positive electrode 142 and the negative electrode 143 face each other.

As shown in FIG. 23, the electrode body 140 configured as described above is wound around the strut portion 114 so as to be wound around the strut portion 114 so as to be integrally combined with the strut portion 114 and the central axis of the strut portion 114. The positive electrode 142 and the negative electrode 143 are wound around C so as to be laminated in multiple radial directions with the separator 141 sandwiched between them.

In the electrode body 140 housed together with the support column 114 in the accommodation space 115 of the exterior body 112, one of the positive electrode 142 and the negative electrode 143 conducts (electrically connects) to the current collector plate 151. The other electrode is conductive (electrically connected) to the container body 120. The electrical connection includes, for example, contact via a carbon-based material, welding between metals, contact between metals, and the like.

In the present embodiment, the negative electrode electrode 143 is conducted to conduct the current collector plate 151, and the positive electrode 142 is conducted to conduct the container body 120. As a result, the current collector plate 151 can function as an external connection terminal for the negative electrode, and the container body 120 can function as an external connection terminal for the positive electrode. However, the present invention is not limited to this case, and by conducting the negative electrode electrode 143 to the container body 120, the container body 120 functions as an external connection terminal for the negative electrode, and the positive electrode electrode 142 is conducted to conduct the current collector plate 151. Therefore, the current collector plate 151 may function as an external connection terminal for the positive electrode.

When conducting the negative electrode electrode 143 to the current collector plate 151, for example, the negative electrode terminal tab 143c may be directly electrically connected to the current collector plate 151, or through a conductor corresponding to a lead wire (not shown). The negative electrode terminal tab 143c and the current collector plate 151 may be electrically connected.
Similarly, when conducting the positive electrode 142 to the container 120, for example, the positive electrode terminal tab 142c may be directly electrically connected to the container 120, or a conductor corresponding to a lead wire (not shown) may be provided. The positive electrode terminal tab 142c and the container body 120 may be electrically connected via the method.

By the way, the secondary battery 110 of the present embodiment includes a positioning unit 155 that positions the relative position at the start of winding of at least one of the positive electrode 142 and the negative electrode 143 with respect to the separator 141 shown in FIG. 25.
Specifically, the positioning portion 155 includes a welding portion (fixing portion according to the present invention) 156 for fixing the support column portion 114 and the separator 141. The positive electrode 142 and the negative electrode 143 are positioned on the support column 114 with reference to the welded portion 156, so that the relative positions with respect to the separator 141 are positioned.

(Formation of electrode body)
In connection with the above-mentioned positioning, a case where the support column 114 is used as a winding core to form the electrode body 140 will be described below.
First, as shown in FIG. 25, after preparing the separator 141, the positive electrode 142, and the negative electrode 143, respectively, the separator 141 is welded to the outer peripheral surface of the support column 114. As a result, the welded portion 156 formed by welding the outer peripheral surface of the strut portion 114 and the separator 141 to each other can be used as the positioning portion 155, and the separator 141 can be positioned with respect to the strut portion 114.

When the length of the separator 141 is determined in advance, the portion shifted toward the region R1 on which the positive electrode electrodes 142 are overlapped from the central portion in the length direction of the separator 141 is formed on the outer peripheral surface of the support column 114. Weld. As a result, it is possible to secure a larger area R2 in which the negative electrode electrodes 143 are overlapped than the area R1 in which the positive electrode 142 is overlapped in the separator 141.

Next, as shown by the arrow M in FIG. 25, the support column 114 is rotated around the central axis C. At this time, the support column 114 is rotated so that the region R2 of the separator 141 on which the negative electrode electrode 143 is overlapped is wound around the support column 114 in advance.
Next, as shown in FIG. 26, the separator 141 and the negative electrode electrode 143 are overlapped with each other so that the negative electrode electrode 143 is inserted between the separator 141 wound in advance of the support column 114 and the support column 114. At this time, as shown by the arrow S in FIG. 26, the negative electrode electrode 143 is inserted until it hits the welded portion 156. As a result, the negative electrode electrode 143 can be positioned on the support column 114 with reference to the welded portion 156. Then, in this state, as shown in FIG. 27, the support column 114 is further rotated. As a result, the negative electrode electrode 143 can be wound around the strut portion 114 in advance, and the innermost layer as the electrode body 140 can be formed by the negative electrode electrode 143.

Further, after inserting the negative electrode electrode 143 described above, the positive electrode 142 is also superposed on the separator 141 so as to abut against the welded portion 156. As a result, the positive electrode 142 can be positioned on the support column 114 with reference to the welded portion 156. After that, the column portion 114 is continuously rotated and wound so as to wind the separator 141, the positive electrode 142, and the negative electrode 143. Thereby, the winding can be performed while positioning the relative positions of the positive electrode 142 and the negative electrode 143 with respect to the separator 141.
As a result, as shown in FIG. 23, it is possible to manufacture the electrode body 140 wound so as to be wound around the support column 114. Since the negative electrode 143 is wound around the support column 114 in advance, it is preferable to form the negative electrode 143 so as to be longer than the positive electrode 142.

(Action of secondary battery)
According to the secondary battery 110 of the present embodiment configured as described above, as shown in FIGS. 22 to 24, the current collector plate 151 that functions as an external connection terminal for the negative electrode is exposed to the outside and is used for the positive electrode. Since the container body 120 that functions as the external connection terminal of the above is exposed to the outside, the secondary battery 110 can be used by using the current collector plate 151 and the container body 120.

In particular, according to the secondary battery 110 of the present embodiment, the support column 114 is accommodated in the accommodation space 115 in addition to the electrode body 140. The support column 114 is arranged so that the upper end thereof contacts the current collector plate 151 from below through the through hole 133 and the lower end portion contacts the bottom wall portion 121 of the container body 120 from above. Thereby, the current collector plate 151 can be supported from below by using the support column 114. Moreover, since the current collector plate 151 is welded to the lid member 130 via the sealant film 150, it is integrally combined with the lid member 130. Therefore, the support column 114 can support the lid member 130 from below via the current collector plate 151.

Therefore, even if the entire exterior body 112 including the lid member 130 is formed to be thin, for example, the lid member 130 may be deformed unintentionally before the welding joint between the container body 120 and the lid member 130. It can be suppressed. Therefore, the welding work can be performed in a state where the displacement of the lid member 130 with respect to the container body 120 is suppressed, the work efficiency can be improved, and the productivity can be improved. Further, the container body 120 and the lid member 130 can be welded accurately and appropriately, and a reliable sealing property can be obtained. Therefore, it is possible to obtain a high-quality secondary battery 110 with high operational reliability.

Further, the electrode body 140 is wound around the support column 114, so that the positive electrode 142 and the negative electrode 143 are overlapped with each other with the separator 141 interposed therebetween, and the wound electrode is wound around the central axis C of the support column 114. Become. That is, since the winding core when winding the electrode body 140 is used as the strut portion 114, after the electrode body 140 is formed by winding, the electrode body 140 together with the strut portion 114 is housed in the container body 120. be able to. Therefore, the assembly work can be performed efficiently, and in this respect as well, it is possible to improve the productivity.

Further, when the electrode body 140 is wound by using the support column 114, the support column 114 and the separator 141 can be fixed by using the welding portion 156, and the separator 141 is positioned with respect to the support column 114. In addition, since the positive electrode 142 and the negative electrode 143 are positioned on the support column 114 via the welding portion 156, the relative positional relationship between the positive electrode 142 and the negative electrode 143 shifts with the separator 141 interposed therebetween. , So-called unwinding can be suppressed. As a result, the positive electrode 142 and the negative electrode 143 can be formed into an electrode body 140 in which the positive electrode 142 and the negative electrode 143 are accurately superposed with the separator 141 interposed therebetween, and the secondary battery 110 having improved operational reliability can be obtained.

As described above, according to the secondary battery 110 of the present embodiment, it is possible to wind the positive electrode 142 and the negative electrode 143 in a state of maintaining an appropriate relative positional relationship with the separator 141 interposed therebetween. It is possible to use a metal case type battery provided with the electrode body 140 having improved operation reliability.
Further, even if the exterior body 112 is made thin, it is possible to obtain a reliable sealing property and to improve the productivity. Further, since the current collector plate 151 is arranged on the upper surface side of the lid member 130, the current collector plate 151 can be largely exposed over the entire surface. Therefore, the current collector plate 151 can be effectively used as an external connection terminal for the negative electrode, and can be a secondary battery 110 that is easy to use and has excellent mountability.

Further, in the secondary battery 110 of the present embodiment, when the container body 120 and the lid member 130 are formed of the clad material or the like described above, or when the container body 120 and the lid member 130 are plated or the like. For example, when the internal pressure rises due to the secondary battery 110 generating heat due to some factor, it is possible to take a fail-safe measure such as peeling off the metal interface to release the internal pressure to the outside.

(Modified example of the second embodiment)
In the second embodiment, when the electrode body 140 is wound around the strut portion 114, as shown in FIG. 25, the separator 141 is welded to the outer peripheral surface of the strut portion 114 to form the welded portion 156, whereby the strut portion 114 is formed. However, the displacement of the separator 141 with respect to the welded portion 141 was prevented, but the position is not limited to the welded portion 156. For example, the adhesive may be used to bond and fix the separator 141 to the outer peripheral surface of the support column 114 to form an adhesive portion, thereby preventing the separator 141 from being displaced with respect to the support column 114. In this case, the adhesive portion functions as the fixing portion in the present invention.

(Third Embodiment)
Next, a third embodiment of the electrochemical cell according to the present invention will be described with reference to the drawings. In the third embodiment, the same parts as the components in the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 28, in the secondary battery (electrochemical cell according to the present invention) 160 of the present embodiment, the support column 114 is a conductor. Specifically, the support column 114 has a metal cylindrical shape. The material of the support column 114 is not particularly limited, but nickel or the like can be preferably used as in the case of the current collector plate 151, for example.

The electrode body 140 is conducting to the current collector plate 151 through the support column 114 in relation to the support column 114 being a conductor. Specifically, the electrode body 140 is wound around the support column 114 in a state where the negative electrode electrode 143 is conducting to the support column 114. As a result, the negative electrode electrode 143 is electrically connected to the current collector plate 151 through the support column 114.

Further, in relation to the support column 114 being a conductor, an insulation that insulates between the support column 114 and the bottom wall portion 121 between the lower end portion of the support column 114 and the bottom wall portion 121 of the container body 120. Body 161 is formed.
In the illustrated example, the insulator 161 is formed over the entire upper surface of the bottom wall portion 121 of the container body 120. This makes it possible to electrically insulate between the lower end portion of the support column 114 and the bottom wall portion 121 by using the insulator 161.

The insulator 161 does not have to be formed over the entire upper surface of the bottom wall portion 121, and is formed at least in a region of the upper surface of the bottom wall portion 121 where the lower end portion of the column portion 114 contacts. Just do it. Further, the insulator 161 may be continuously formed not only on the upper surface of the bottom wall portion 121 but also on the inner surface side of the peripheral wall portion 122.
Further, the insulator 161 does not have to be formed on the bottom wall portion 121 side, and may be formed on the lower end surface of the support column portion 114. Further, an insulator 161 may be formed on each of the upper surface of the bottom wall portion 121 and the lower end surface of the support column portion 114.

The insulator 161 is not limited to a specific one, but for example, an insulating synthetic resin film may be adopted. Further, an insulating tape made of synthetic resin having excellent insulating properties (for example, a tape made of polyimide, a tape made of polyphenylene sulfide (PPS), a tape made of polyethylene terephthalate (PET)) may be adopted as the insulator 161. Further, an insulating film using an insulating paint may be adopted as the insulator 161.

The conduction between the support column 114 and the negative electrode electrode 143 is not limited to a specific method, but as shown in FIGS. 29 and 30, for example, the separator 141 is fixed by using the welded portion 156. The negative electrode terminal tab 143c of the negative electrode electrode 143 may be joined to the outer peripheral surface of the support column 114 via the joint portion 157 by welding or the like while suppressing the positional deviation of the separator 141 with respect to the support column portion 114. At this time, by forming the joint portion 157 with reference to the position of the welded portion 156, the relative position of the negative electrode electrode 143 with respect to the separator 141 can be positioned.

Therefore, by rotating the support column 114, the separator 141 and the negative electrode electrode 143 can be wound while the positional deviation is suppressed. Further, the separator 141 and the negative electrode electrode 143 are wound around the support column 114 in advance, and then the positive electrode 142 is wound together. As a result, the separator 141, the negative electrode electrode 143, and the positive electrode 142 can be wound while the positional deviation is suppressed, and the electrode body 140 wound around the support column 114 can be formed.

Regarding the positive electrode 142, as in the second embodiment, the positive electrode terminal tab 142c is directly electrically connected to the container body 120, or the positive electrode terminal is connected via a conductor (corresponding to a lead wire) (not shown). The tab 142c and the container body 120 may be electrically connected.

(Action of secondary battery)
Even the secondary battery 160 of the present embodiment configured as described above can achieve the same effects as those of the second embodiment.
In addition, since the negative electrode 143 can be electrically connected to the current collector plate 151 through the support column 114, a conductor (corresponding to a lead wire) or the like becomes unnecessary, and the electric resistance can be easily reduced. Therefore, it is easy to improve the battery performance. Further, with respect to the negative electrode electrode 143, the support column 114 and the current collector plate 151 can be brought into contact with each other for electrical connection, so that the assembly work can be performed more efficiently.

(Modified example of the third embodiment)
In the third embodiment, the negative electrode terminal tab 143c is joined to the outer peripheral surface of the support column 114 by the joining portion 157, but the present invention is not limited to this case. For example, as shown in FIGS. 31 and 32, a slit groove 158 is formed in the support column 114, and the negative electrode terminal tab 143c is inserted into the slit groove 158 to position the negative electrode electrode 143 with respect to the support column 114. It doesn't matter.
The slit groove 158 is formed in a vertically long slit shape along the axial direction of the strut portion 114, and is formed so as to penetrate the strut portion 114 in the radial direction.

(Modified example of the third embodiment)
In the third embodiment, the support column 114 itself is made of a metal material to function as a conductor, but the present invention is not limited to this case, and the support column is made of, for example, a conductive synthetic resin (conductive resin). The portion 114 may be formed.
As this type of synthetic resin, engineering plastics are preferably used from the viewpoint of considering mechanical strength and heat resistance, for example, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polyetheretherketone (PEEK), and the like. Perfluoroalkoxy alkane resin (PFA) or the like can be used.

Further, the support column 114 may be formed by forming the material of the support column 114 with an insulating synthetic resin and then forming a metal film on the outer surface of the material. Even in this case, since the metal film can be used for electrical connection, the support column 114 can function as a conductor. When forming a metal film, for example, the plating treatment can be performed by performing a metal spraying treatment or the like.

(Modified example of the third embodiment)
Further, in the third embodiment, the negative electrode 143 of the electrode body 140 is conducted to the current collector plate 151 through the support column 114, but as shown in FIG. 33, for example, the electrode body 140 is connected to the container body 120 through the support column 114. A conductive secondary battery (electrochemical cell according to the present invention) 170 may be used.

In this case, an insulator 171 that insulates between the support column 114 and the current collector plate 151 is formed between the upper end portion of the support column 114 and the current collector plate 151. The insulator 171 may be formed in a region of the lower surface of the current collector plate 151 where the upper end of the support column 114 comes into contact. This makes it possible to electrically insulate between the support column 114 and the current collector plate 151 by using the insulator 171.
The insulator 171 may be formed on the upper end surface of the support column 114, or may be formed on the lower surface of the current collector plate 151 and the upper end surface of the support column 114, respectively.

Regarding the positive electrode 142, the positive electrode terminal tab 142c and the current collector plate 151 are directly electrically connected to the current collector plate 151, or via a conductor (corresponding to a lead wire) (not shown). And should be electrically connected.

In the case of the secondary battery 170 configured as described above, the current collector plate 151 can function as an external connection terminal for the positive electrode, and the container body 120 can function as the external connection terminal for the negative electrode. .. Therefore, the secondary battery 170 can be used by using the container body 120 and the current collector plate 151.

When the electrode body 140 is wound around the support column 114, it is not necessary to conduct the negative electrode 143 to the support column 114, and the positive electrode 142 may be conducted. In this case, the positive electrode 142 and the container body 120 can be electrically connected to each other through the support column 114. Regarding the negative electrode electrode 143, the negative electrode terminal tab 143c is directly electrically connected to the current collector plate 151, or the negative electrode terminal tab 143c and the current collector plate 151 are connected via a conductor (corresponding to a lead wire) (not shown). All you have to do is make an electrical connection.
As a result, the current collector plate 151 can function as an external connection terminal for the negative electrode, and the container body 120 can function as an external connection terminal for the positive electrode.

(Fourth Embodiment)
Next, a fourth embodiment of the electrochemical cell according to the present invention will be described with reference to the drawings. In the fourth embodiment, the same parts as the components in the second embodiment are designated by the same reference numerals and the description thereof will be omitted.
In the second embodiment and the third embodiment, the current collector plate 151 is welded to the lid member 130 via the sealant film 150, the upper end portion of the support column 114 is brought into contact with the current collector plate 151, and the support column portion is formed. The configuration in which the support column 114 is arranged in the accommodation space 115 in a state where the lower end portion of the 114 is in contact with the bottom wall portion 121 of the container body 120 has been described as an example. On the other hand, in the present embodiment, the current collector plate 151 is welded to the bottom wall portion 121 of the container body 120 via the sealant film 150.

As shown in FIG. 34, the secondary battery (electrochemical cell according to the present invention) 180 of the present embodiment penetrates the bottom wall portion 121 in the central portion of the container body 120 in the vertical direction. The through hole 181 is formed coaxially with the battery shaft O1. The shape of the through hole 181 is not particularly limited, but is formed, for example, in a circular shape in a plan view.

A current collector plate 151 is heat-welded to the bottom wall portion 121 in which the through hole 181 is formed via the sealant film 150. Specifically, the current collector plate 151 is heat-welded to the lower surface of the bottom wall portion 121 via the sealant film 150, and is exposed downward over the entire surface.
The sealant film 150 is formed in an annular shape surrounding the through hole 181 formed in the bottom wall portion 121, and is arranged so as to overlap the lower surface of the bottom wall portion 121 in a state of being coaxially arranged with the battery shaft O1. In the illustrated example, the inner peripheral edge portion 150a of the sealant film 150 is folded upward to protect the inner peripheral surface of the through hole 181 formed in the bottom wall portion 121 over the entire circumference.

The current collector plate 151 has a diameter smaller than the outer diameter of the sealant film 150 and is formed in a circular shape in a plan view, and is arranged so as to overlap the lower surface of the sealant film 150 in a state of being arranged coaxially with the battery shaft O1. There is. As a result, the current collector plate 151 closes the through hole 181 from below.

The lid member 185 of the present embodiment is formed in the shape of a flat plate overlapping the peripheral wall portion 122 of the container body 120 from above. As a result, the lid member 185 is welded and joined in a state of being overlapped from above over the entire circumference with respect to the upper end opening end of the peripheral wall portion 122. In the illustrated example, a step 185a is provided on the outer peripheral edge portion of the lid member 185 at a position overlapping the upper end opening end of the peripheral wall portion 122. As a result, the accommodation space 115 is sealed with high airtightness by utilizing the step 185a.

The strut portion 114 is housed together with the power generation element 113 in the accommodation space 115 in the exterior body 112. The support column 114 is formed in a shaft shape extending in the vertical direction along the battery shaft O1 and is arranged coaxially with the battery shaft O1. In the illustrated example, the strut 114 is formed in a hollow cylindrical shape, the outer diameter thereof being smaller than the diameter of the through hole 181 and the inner diameter of the sealant film 150.
As a result, the lower end portion (first end portion according to the present invention) of the support column portion 114 comes into contact with the current collector plate 151 from above through the through hole 181 and the upper end portion (second end portion according to the present invention). Is arranged so as to come into contact with the lid member 185 from below. Therefore, the support column 114 supports the lid member 185 from below while being supported by the current collector plate 151 integrally combined with the bottom wall portion 121 of the container body 120.

(Action of secondary battery)
Even in the secondary battery 180 of the present embodiment configured as described above, since the lid member 185 can be supported from below by using the support column 114, the entire exterior body 112 including the lid member 185 can be supported. For example, even if it is formed to be thin, it is possible to suppress unintended deformation such as bending of the lid member 185 before the welding joint between the container body 120 and the lid member 185. Therefore, the welding work can be performed in a state where the displacement of the lid member 185 with respect to the container body 120 is suppressed, the work efficiency can be improved, and the productivity can be improved. Further, it is possible to obtain a reliable sealing property, and it is possible to obtain a high-quality secondary battery 180 with high operation reliability.

Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Examples of embodiments and variations thereof include those easily conceivable by those skilled in the art, substantially the same, and those having an equal range.

For example, in each of the above embodiments, a secondary battery has been described as an example of an electrochemical cell, but the present invention is not limited to this case, and other electrochemical cells using an electrode capable of occluding lithium ions may be used. Can also be applied. Specifically, for example, it may be applied to various power storage devices such as electric double layer capacitors and lithium ion capacitors.

When the electrochemical cell is applied to an electric double layer capacitor, the positive electrode and the negative electrode may be used as a pair of polarizable electrodes. Examples of the polarizable electrode in this case include one in which powdered activated carbon obtained by activation treatment is mixed with a conductive auxiliary agent and a binder and rolled or press-molded. Examples of the electrolytic solution include those obtained by dissolving a supporting salt such as a quaternary ammonium salt in a non-aqueous solvent.
When the electrochemical cell is applied to a lithium ion capacitor, only one of the positive electrode and the negative electrode should be the above-mentioned polarizable electrode, and the other electrode should be an electrode for a lithium ion battery. Can be done. As the electrolytic solution, the same one as that of the lithium ion battery can be used.

Further, in the first embodiment, lithium ion is taken as an example as an ion that moves between the positive electrode body and the negative electrode body through the separator during charging and discharging, but the present invention is not limited to this case, and for example, sodium ion and potassium. Ions of metals having a low potential such as ions and magnesium ions may be used.

Further, in the second embodiment and the third embodiment, the current collector plate is arranged on the upper surface side of the top wall portion of the lid member, but the present invention is not limited to this case and is not limited to this case. You may place it. In this case, since the current collector plate can be arranged on the lower surface side of the lid member, the entire current collector plate and the lid member can be supported from below by using the support column portion. Therefore, unintended bending of the lid member can be effectively suppressed.

Further, in the second embodiment and the third embodiment, the case where a cylindrical strut portion is used has been described as an example, but the shape of the strut portion is not limited to the cylindrical shape and may be appropriately changed. I do not care. As the support column, it can be used as a winding core when winding the electrode body, and when it is set in the accommodation space together with the electrode body, the upper end portion is in contact with the current collector plate and the lower end portion is in contact with the bottom wall portion. As long as the lid member can be supported from below, the outer shape may be arbitrarily changed.

Further, in the case of a hollow strut portion, as the internal shape, for example, a quadrangular shape, a polygonal shape, a star shape, a cross shape, a slit shape or the like may be adopted in a plan view from the direction of the central axis. .. In particular, when such an internal shape is adopted, it is preferable because it becomes easy to apply rotational torque to the strut portion.

Z ... Lamination direction 1, 90, 110, 160, 170, 180 ... Secondary battery (electrochemical cell)
2,140 ... Electrode body 3,112 ... Exterior body 10,142 ... Positive electrode 13 ... Positive electrode body 14 ... Positive electrode connection piece 20,143 ... Negative electrode 21 ... Negative electrode collector 23 ... Negative electrode body 23A ... Inner peripheral side negative electrode body (First negative electrode body)
24 ... Negative electrode connection piece 30, 141 ... Separator 41, 51 ... Metal layer 42, 52 ... Inner resin layer (resin layer)
43, 53 ... Outer resin layer (resin layer)
80 ... Adhesive layer (adhesive member, negative electrode positioning part)
85 ... Welding part (negative electrode positioning part)
86 ... Separator welding part (negative electrode positioning part)
88 ... Empty winding part (negative electrode positioning part)
87 ... Welding part on the positive electrode side (Positive electrode positioning part)
100, 155 ... Positioning part 114 ... Support part 115 ... Accommodation space 120 ... Container body 121 ... Bottom wall part 122 ... Peripheral wall part 130, 185 ... Lid member (sealing plate)
131 ... Top wall 133 ... Through hole 150 ... Sealant film (sealing material)
151 ... Current collector plate 156 ... Welded part (fixed part)

Claims (13)

An electrode body having a separator, a positive electrode, and a negative electrode, and the positive electrode and the negative electrode are overlapped with the separator sandwiched by being wound.
An exterior body that houses the electrode body inside is provided.
An electrochemical cell characterized in that at least one of the positive electrode and the negative electrode is positioned at a relative position at the start of winding with respect to the separator by a positioning portion. In the electrochemical cell according to claim 1,
The electrode body is wound flat so that the positive electrode and the negative electrode are alternately laminated so as to sandwich the separator.
The positive electrode includes a plurality of positive electrode bodies arranged along the stacking direction of the electrode bodies, and a plurality of positive electrode connection pieces connecting the plurality of positive electrode bodies to each other.
The negative electrode electrode includes a plurality of negative electrode bodies arranged along the stacking direction of the electrode bodies, and a plurality of negative electrode connection pieces connecting the plurality of the negative electrode bodies to each other.
The electrode body is wound so as to fold back the positive electrode connection piece and the negative electrode connection piece, so that the positive electrode main body and the negative electrode main body alternately face each other in the stacking direction with the separator interposed therebetween. Formed to be placed in
The positioning unit is provided between the first negative electrode body located on the winding start side of the plurality of negative electrode bodies and the separator, and is a negative electrode positioning unit that positions the first negative electrode body with respect to the separator. Equipped with
The negative electrode positioning portion is
The first negative electrode body is arranged so as to be at least located between the separator and the outer end portion facing the positive electrode connection piece with the separator interposed therebetween, and is said to pass through the separator during charging and discharging. An electrochemical cell that reduces the ionic conductivity of ions moving from a positive electrode connection piece toward the outer end portion to be lower than the ionic conductivity of ions moving between a positive electrode body and a negative electrode body through the separator. In the electrochemical cell according to claim 2,
The negative electrode positioning portion is fixed to at least one of the first negative electrode body and the separator, and is an insulator that comes into contact with the first negative electrode body and the separator, and is formed on the separator. An electrochemical cell that closes the ion transmission hole. In the electrochemical cell according to claim 3,
The negative electrode positioning portion is an insulating adhesive member that adheres the first negative electrode body and the separator to each other, and is an electrochemical cell that closes an ion transmission hole formed in the separator. In the electrochemical cell according to claim 2,
The negative electrode positioning portion is an electrochemical cell in which the first negative electrode body and the separator are welded to each other and the ion permeation holes formed in the separator by the welding are closed. In the electrochemical cell according to claim 2,
The negative electrode positioning portion is a separator welding portion in which a part of the separator is partially double welded in advance, and at the same time, the ion permeation hole formed in the separator by the welding is closed.
The first negative electrode body is an electrochemical cell positioned with respect to the separator by contact of the outer end portion with the separator welded portion. In the electrochemical cell according to claim 2,
The negative electrode positioning portion is a blank winding portion in which a part of the separator is preliminarily wound.
The first negative electrode body is an electrochemical cell positioned with respect to the separator by contact of the outer end portion with respect to the blank winding portion. In the electrochemical cell according to any one of claims 2 to 7.
The positioning unit is provided between the positive electrode and the separator, and includes a positive electrode positioning unit that positions the first positive electrode body located on the winding start side of the plurality of positive electrode bodies with respect to the separator. The electrochemical cell. In the electrochemical cell according to any one of claims 2 to 8.
The exterior body is an electrochemical cell formed of a metal layer and a laminated film having a resin layer covering both sides of the metal layer. In the electrochemical cell according to claim 1,
It is housed inside the exterior body and has a support column arranged along the battery axis direction.
By being wound around the strut portion, the electrode body is wound around the central axis of the strut portion in a state where the positive electrode and the negative electrode are superposed with the separator interposed therebetween.
The positioning portion includes a fixing portion for fixing the support column portion and the separator portion.
An electrochemical cell in which the positive electrode and the negative electrode are positioned relative to the separator by being positioned on the support column with reference to the fixed portion. In the electrochemical cell according to claim 10,
The exterior body is
A metal container body having a bottom wall portion and a peripheral wall portion and formed in a bottomed cylindrical shape,
A metal sealing plate, which is welded and joined to the container body so as to close the opening of the container body and accommodates the electrode body, is provided between the container body and the container body.
A current collector plate whose at least a part is exposed to the outside is welded to the sealing plate or the bottom wall portion via an insulating sealing material.
The strut portion supports the sealing plate by having a first end portion in contact with the current collector plate and a second end portion in contact with the sealing plate or the bottom wall portion.
An electrochemical cell in which one of the positive electrode and the negative electrode conducts to the current collector plate, and the other electrode conducts to the container body. An electrode body having a positive electrode and a negative electrode stacked on top of each other with a separator sandwiched between them, and by being wound flat so that the positive electrode and the negative electrode are alternately laminated with the separator sandwiched between them.
An exterior body that houses the electrode body inside is provided.
The positive electrode includes a plurality of positive electrode bodies arranged along the stacking direction of the electrode bodies, and a plurality of positive electrode connection pieces connecting the plurality of positive electrode bodies to each other.
A method for manufacturing an electrochemical cell, wherein the negative electrode electrode includes a plurality of negative electrode bodies arranged along the stacking direction of the electrode bodies, and a plurality of negative electrode connection pieces connecting the plurality of the negative electrode bodies to each other. ,
By winding the positive electrode connection piece and the negative electrode connection piece so as to be folded back, the positive electrode main body and the negative electrode main body are arranged in a state of alternately facing each other in the stacking direction with the separator interposed therebetween. The electrode body forming step for forming the electrode body is provided.
During the electrode body forming step,
A positioning step of positioning the first negative electrode body with respect to the separator by providing a negative electrode positioning portion between the first negative electrode body located on the winding start side of the plurality of negative electrode bodies and the separator is performed. Do,
During the positioning step, the negative electrode positioning portion is provided so as to be at least located between the outer end portion of the first negative electrode body that faces the positive electrode connecting piece with the separator sandwiched between the separator and the separator.
The negative electrode positioning portion transfers ion conductivity of ions moving from the positive electrode connection piece toward the outer end portion through the separator, and ion conductivity of ions moving between the positive electrode body and the negative electrode body through the separator. A method for producing an electrochemical cell, which is characterized by lowering the sex rather than the sex. In the method for manufacturing an electrochemical cell according to claim 12,
An insulating adhesive member is used as the negative electrode positioning portion, and an insulating adhesive member is used.
During the positioning process,
After applying the adhesive member to the outer end portion of the first negative electrode body or the surface of the separator facing the outer end portion of the first negative electrode body, at least a part of the applied adhesive member is applied. A method for manufacturing an electrochemical cell, in which positioning is performed by adhering the outer end portion of the first negative electrode body and the separator to each other after being in a solidified or wet state.

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