JP2012230865A - Power generation element and power generation element termination processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation element which is surely fixed using a winding stop tape and a power generation element termination processing method for sure fixing, by considering a condition of a separator surface, with a simple configuration.SOLUTION: An electrode body 2 includes a sheet-like positive electrode 2a, a sheet-like negative electrode 2b, and sheet-like separators 2c and 2c' facing at least one of the sheet-like positive electrode and the sheet-like negative electrode, being wound in lamination. The separators 2c and 2c' include at least, in a part of them, a surface layer A whose peeling strength is high and a surface layer B whose peeling strength is lower than the surface layer A. The termination part of the separators is fixed by a winding stop tape S having an adhesive layer on at least one side. A surface on the outer peripheral side including the termination part of the separator 2c or 2c' being wound is the surface layer A.

Description

  The present invention relates to a power generation element and a power generation element termination method, and particularly to a power generation element used in a nonaqueous electrolyte secondary battery, a nickel cadmium battery, a nickel hydrogen battery, or the like, and a power generation element termination method. Here, the “power generation element” refers to an electrode (or electrode body) in which a sheet-like positive electrode and negative electrode are wound or laminated with a separator interposed therebetween.

  Non-aqueous electrolyte secondary batteries, nickel cadmium batteries, or nickel metal hydride batteries are widely used as power sources for portable electronic devices such as mobile phones, personal computers, and video cameras, taking advantage of their small size, light weight, and high energy density. It is popular. Recently, there has been an increasing trend to increase the size of these batteries and apply them to industrial large electric devices such as electric vehicles. In such a battery, a wound type power generation element in which a strip electrode is wound through a separator, or a stacked type power generation element in which a plate-like electrode is stacked through a separator is accommodated in a battery case, and hermetically sealed with a battery lid. A terminal and a negative electrode terminal are attached to the outside of the battery.

  For example, as a battery using a wound power generation element, a nonaqueous electrolyte secondary battery including an electrode group 102 having a structure in which a positive electrode and a negative electrode are wound in a flat shape through a separator 105 as shown in FIG. Has been proposed (see, for example, Patent Document 1). Here, the active material-containing layer 103b is supported on one side of the positive electrode current collector 103a (hereinafter referred to as a single-sided region) for one round after the beginning of rolling of the positive electrode 103, and thereafter both sides of the positive electrode current collector 103a. The active material-containing layer 103b is supported on the surface (hereinafter referred to as a double-sided region), and the end of the winding is formed only from the positive electrode current collector 103a. The separator 105 is disposed outside the single-sided region of the positive electrode 103, and the negative electrode 104 having the active material-containing layer 104b supported on both surfaces of the current collector 104a is disposed outside the separator 105. Furthermore, the double-sided region of the positive electrode 103 is disposed outside the negative electrode 104 via the separator 105. The outermost periphery of the electrode group 102 includes a positive electrode current collector 103 a of the positive electrode 103. Therefore, in the negative electrode 104 facing the positive electrode current collector 103a with the separator 105 interposed therebetween, the active material-containing layer 104a is formed only on one surface of the current collector 104a. The winding tape 119 prevents the winding deviation by fixing the winding end of the positive electrode current collector 103a to the outermost peripheral surface of the electrode group 102 (see paragraphs 0017 to 0020 of Patent Document 1). Here, 110 is a positive electrode tab, 111 is a negative electrode tab, and 117 and 118 are reinforcing tapes.

  In such secondary batteries, a microporous film mainly made of a resin such as polyolefin is used as a separator for insulating the positive electrode and the negative electrode. This microporous film is excellent in electrolyte retention and ion permeability, but easily deforms at high temperatures. Therefore, a porous heat-resistant layer containing magnesium oxide or alumina on the separator surface (hereinafter referred to as “inorganic layer”). Even when high heat is generated and the separator is melted, the positive electrode and the negative electrode are prevented from coming into direct contact with each other.

JP-A-2005-116186

However, the wound electrode body using the separator having such an inorganic layer has the following problems when the termination treatment is performed on the wound portion using the above-described winding stopper tape. That is, the adhesion function of the winding tape is weaker than that of the microporous film alone with respect to the inorganic layer, and the winding tape may peel from the inorganic layer. Further, at this time, the winding tape may be peeled off together with a part of the inorganic layer. Furthermore, together with the adhering anti-winding tape, the outermost inorganic layer may peel off from the separator substrate.
On the other hand, even in the case of a wound electrode body having a separator that does not contain an inorganic layer, if the surface layer of the separator is subjected to a surface treatment such as heat resistance or insulation reinforcement, the anti-winding tape is also adhered to the surface layer. The function was weak, and there were cases where sufficient termination was not possible.
Thus, in a power generation element such as a conventional wound electrode body, depending on the surface state of the separator, it cannot be said that the winding tape is sufficiently attached to the surface of the power generation element. There was a fear that it was not fixed securely.

  The present invention has been made in view of the above circumstances, and its purpose is to take into consideration the state of the surface of the separator, and with a simple configuration, the power generation element that is securely fixed by the winding tape and can be reliably fixed. It is to provide a method for terminating a power generation element.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the following power generation element and power generation element termination method, and have completed the present invention. It was.

The first aspect of the present invention is:
A sheet-shaped positive electrode wound in a laminated state, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode,
The separator has a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
A power generation element in which the terminal portion of the separator is fixed by a winding tape having an adhesive layer on at least one side,
The outermost surface including the terminal portion of the outermost separator in the wound state is the surface layer A.
It is a power generation element.

The second aspect of the present invention is
The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The first sub-separator and the second sub-separator each have the surface layer A and the surface layer B,
The outermost separator is the second sub-separator;
It is an electric power generation element of the 1st side of the present invention.

The third aspect of the present invention is
The surface layer A and the surface layer B are included only in all or part of the outermost separator,
It is an electric power generation element of the 1st or 2nd side surface of this invention.

The fourth aspect of the present invention is
The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The outermost separator is the first sub-separator;
It is an electric power generation element of the 1st side of the present invention.

The fifth aspect of the present invention provides
The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The outermost separator is the first sub-separator;
The outer peripheral side of the second sub-separator is in contact with the inner peripheral side of the outermost separator,
It is an electric power generation element of the 1st side of the present invention.

The sixth aspect of the present invention provides
A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state;
In the wound state, the positive electrode, the negative electrode or any one of the separators located on the outermost periphery, further provided with an insulating tape having a predetermined adhesive force provided over the outer periphery,
The separator has a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
The terminal portion of the insulating tape was fixed by a first winding tape having an adhesive layer on at least one side,
It is a power generation element.

The seventh aspect of the present invention is
The first winding tape is provided on the outer peripheral side of the insulating tape,
It is an electric power generation element of the 6th side surface of this invention.

The eighth aspect of the present invention provides
The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The inner peripheral side or outer peripheral side of the insulating tape and the surface of the terminal portion of the first sub-separator or the second sub-separator were fixed by a second winding tape,
It is an electric power generation element of the 6th or 7th side surface of this invention.

The ninth aspect of the present invention provides
The surface on the outer peripheral side of the terminal portion of the second sub-separator in the wound state is the surface layer B,
The surface of the terminal portion of the first sub-separator or the second sub-separator fixed by the second winding tape is the surface layer A.
It is an electric power generation element of the 8th side surface of this invention.

The tenth aspect of the present invention provides
In the wound state, the separator is located on the outermost periphery of the positive electrode, the negative electrode or the separator.
It is an electric power generation element of the 6th thru | or 9th side surface of this invention.

The eleventh aspect of the present invention is
The end portions of the insulating tape, the first sub-separator and the second sub-separator extend from the end portions of the positive electrode and the negative electrode,
Inside of the first sub-separator or the second sub-separator located on the outermost periphery by wrapping around the ends of the end portions of the first sub-separator and the second sub-separator from the surface of the insulating tape Having a third winding tape adhering to the circumferential side,
The inner peripheral side of the first separator or the second sub-separator is the surface layer A.
It is an electric power generation element of the 10th side surface of this invention.

The twelfth aspect of the present invention is
A sheet-like positive electrode wound in a stacked state, a sheet-like negative electrode, and a sheet-like separator facing at least one of the sheet-like positive electrode and the negative electrode,
The sheet-shaped separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
A power generation element in which a terminal portion of the first sub-separator or the second sub-separator is fixed by an insulating winding tape having an adhesive layer on at least one side;
The first sub-separator and the second sub-separator each have a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
One end of the insulating winding tape is attached to the inner peripheral side around the tip of the terminal end from the outer peripheral side of the first sub-separator or the second sub-separator located on the outermost side,
The other end of the insulating winding tape is connected to the first sub-separator in the gap formed by the terminal portions of the first sub-separator and the second sub-separator, and the terminal portions of the positive electrode and the negative electrode. Attached to the surface of the separator or the second sub-separator,
The first sub-separator or second sub-separator to which one end of the insulating winding tape adheres and the first sub-separator or second to which the other end of the insulating winding tape adheres Each of the surfaces of the sub-separator is the surface layer A.
It is a power generation element.

The thirteenth aspect of the present invention provides
The surface layer A is composed of resin equipment, and the surface layer B is composed of an inorganic layer.
1 is a power generation element according to any one of the first to twelfth aspects of the present invention.

The fourteenth aspect of the present invention provides
A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) When the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) when the outer peripheral side of the terminal end portion of the separator is the surface layer B of the second sub-separator by the winding step, the first sub-separator is located immediately below the second sub-separator. The sub-separator is wound so as to cover at least the end portion of the second sub-separator, and the adhesive layer surface of the winding tape is further wound on the end portion of the second sub-separator and the outermost end of the second sub-separator. A process of adhering across the outer peripheral surface,
This is a power generation element termination method.

The fifteenth aspect of the present invention provides
A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) If the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the surface of the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) if the outer peripheral side of the terminal end of the separator is the surface layer B of the second sub-separator by the winding step, the outer periphery of the second sub-separator including the terminal end Winding the insulating tape having a predetermined adhesive force one or more times, and fixing the wound end portion of the insulating tape with a winding tape having an adhesive layer on at least one side;
This is a power generation element termination method.

The sixteenth aspect of the present invention provides
A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) If the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) When the outer peripheral side of the end portion of the separator is the surface layer B of the second sub-separator by the winding step,
Extending the end portions of the first sub-separator and the second sub-separator from the end portions of the positive electrode and the negative electrode,
One end of the insulating winding tape is attached to the inner peripheral side around the tip of the terminal end from the outer peripheral side of the second sub-separator located on the outermost periphery,
The other end of the insulating tape is connected to the first sub-separator in the gap formed by the terminal portions of the first sub-separator and the second sub-separator, and the terminal portions of the positive electrode and the negative electrode. Attaching to the surface of the separator or the second sub-separator,
In (b), the first sub-separator or the first sub-separator to which the inner peripheral side of the second sub-separator to which one end of the insulating winding tape is attached and the other end of the insulating winding tape are attached. The surface of each of the two sub-separators is defined on the surface layer A.
This is a power generation element termination method.

Further, the present invention may be configured as follows. That is, the power generation element according to the present invention includes a separator in which a sheet-like positive electrode and a negative electrode are composed of two or more layers having different peel strengths, including a surface layer A having a high peel strength and a surface layer B having a low peel strength. And the outermost periphery is wound by the separator, and the terminal end of the outermost separator is fixed by a winding tape having an adhesive layer on one side,
(A) When the outermost peripheral surface of the separator is constituted by the surface layer A Configuration in which the adhesive layer surface of the winding tape is attached to the surface layer A of the outermost peripheral surface and the surface layer A of the terminal end of the separator (b ) When the outermost peripheral surface of the separator is constituted by the surface layer B (b-1) The outer peripheral surface of one inner peripheral separator from the outermost outer periphery is constituted by the surface layer A, and further includes one or more inner peripheral separators. The outermost peripheral surface is constituted by the surface layer A of the inner peripheral separator, and the adhesive layer surface of the winding tape is the outermost surface A of the outermost peripheral surface and the surface layer A of the end portion of the inner peripheral separator. Configuration attached to, or
(B-2) The adhesive layer of the winding tape and the insulating tape capable of being adhered are wound around one or more outer circumferences from the outermost terminal portion of the separator to the terminal portion, and the adhesive layer surface of the winding tape is It has the structure attached to the one end part and other end part of the insulating tape, It is characterized by the above-mentioned.

  In the power generation element, the termination of the wound separator is important for the stability of the electrode function. If the end of the separator is not fixed, rewinding occurs, the electrode and the separator are loosened, and the outer dimensions of the power generation element are increased, making it difficult to accommodate in the container. Further, since the distance between the positive electrode and the negative electrode becomes non-uniform, the battery performance may be deteriorated. In addition, the surface layer of the separator that has been subjected to a treatment for improving the efficiency, such as the insulating function between the positive electrode and the negative electrode and the holding function of the electrolyte, may weaken the function of attaching the winding tape. In the present invention, even when the surface layer having such a weak adhesion function (low peel strength) is the outermost peripheral surface, both end portions of the adhesive layer surface of the winding tape are utilized by utilizing the surface layer having a high peel strength of the separator. However, by forming a structure that always adheres to a surface layer having a high peel strength, it is possible to configure a power generation element that is securely fixed by a winding tape. Specifically, in the wound separator, if there is a separator whose outer peripheral surface has a surface layer with high peel strength, use this, and if there is no such separator, use an adhesive tape that can be adhered, With a simple configuration, it is possible to form a state where the winding tape can be used. The “outermost circumference” or “outermost circumference surface” means the first layer from the outside of the power generation element. Further, the “outermost separator” refers to a separator for one turn from the terminal end of the separator, and a negative electrode or a positive electrode may be wound around the outer periphery thereof.

Moreover, the present invention is the power generation element described above, wherein in (b-2), the adhesive layer surface of the winding tape is attached to one end and the other end of the insulating tape, and the end of the separator You may have the structure adhered to the inner surface of the part or the surface layer A of inner periphery.
The winding of one end and the other end of the circulating insulating tape sufficiently fixes the power generation element, but does not fix the insulating tape to the power generation element, so it cannot be said that the insulation tape itself is completely fixed. The present invention makes it possible to configure a power generating element having an insulating tape fixed with the same winding tape using the inner surface or inner surface A of the end portion of the separator.

Moreover, this invention is said electric power generation element, Comprising: In said (b-2), the said winding tape is made into two or more, and the adhesion layer surface of a 1st winding tape is the one end part and other end part of this insulating tape. Or the one end portion and the surface layer A of the inner surface of the terminal end portion of the separator, and the adhesive layer surface of the second winding tape is in the former, and the other end portion of the insulating tape and the terminal end portion of the separator The surface layer A of the inner surface of the separator may be attached to the surface layer A of the inner surface of the other end portion and one end portion or the end portion of the separator.
Since the terminal portion is formed of a positive electrode, a negative electrode, and two separators, it has a predetermined height. Therefore, when the insulating tape is fixed with one winding tape, there is a possibility that the attached portion is in the air and the tensile strength is weakened. In the present invention, as a reinforcement of such a fixing portion, in addition to one fastening tape for fixing both ends of the insulating tape, another fastening tape for fixing the insulating tape and the separator is used to securely fix the fixing portion. It was possible to configure the generated power generation element.

Moreover, this invention is said electric power generation element, Comprising: In said (b-2), it replaces with the said insulating tape and the said anti-winding tape, adhesive layer Sb on one side of one end part, and this one side or other side of an other end part Using an insulating winding tape S having an adhesive layer Sc on one side, the adhesive layer Sb of the one end is attached to the inner surface of the terminal end of the separator or the surface layer A of the inner periphery, and the outermost periphery of the separator The adhesive layer Sc at the other end may be configured to be attached to the inner surface of the terminal end of the separator or the surface layer A on the inner periphery.
As described above, in order to fix the wound insulating tape with the winding tape, it is necessary to attach three or more places. The present invention uses an insulating winding tape, and by setting the arrangement of the adhesive layer that can use the surface layer A on the inner surface of the terminal portion of the separator, the termination treatment with only the winding tape with a simple configuration. It was possible to configure the generated power generation element.

Moreover, the present invention is the power generation element described above, wherein the surface layer A is made of a resin base material, and the surface layer B is made of an inorganic layer.
In order to improve the efficiency of the positive electrode and negative electrode insulation functions, electrolyte retention function, etc., the separator is made of a resin base material and is subjected to a process of coating an inorganic material such as alumina on the surface layer. Preferred (inorganic layer). The resin base material has high adhesion strength with the adhesive layer (surface layer A). On the other hand, since such an inorganic layer is easily peeled off from the adhesive layer, it is difficult to use a winding tape (surface layer B). The present invention makes it possible to configure a power generation element that is terminated with only a winding tape with a simple configuration without impairing the functions and characteristics of the separator.

The power generation element termination method according to the present invention is a separator in which a sheet-like positive electrode and negative electrode are composed of two or more layers having different peel strengths, including a surface layer A having a high peel strength and a surface layer B having a low peel strength. In a power generation element configured to be wound via
(1) A sheet-like positive electrode and negative electrode are stacked and wound so that a separator is interposed between them.
(2) It winds so that the outermost periphery of the said electric power generation element may be comprised with the said separator.
And in the termination processing of the winding part,
(3) When the outermost peripheral surface of the separator is constituted by the surface layer A, the adhesive layer surface of the winding tape is attached to the surface layer A of the outermost peripheral surface and the surface layer A of the terminal portion of the separator.
(4) When the outermost peripheral surface of the separator is constituted by the surface layer B (4-1) The outer peripheral surface of one inner peripheral separator from the outermost outer periphery is constituted by the surface layer A, and the inner peripheral separator is further The outermost peripheral surface of the power generation element is constituted by the surface layer A of the inner peripheral separator, and the adhesive layer surface of the winding tape is formed between the outermost surface A and the inner peripheral separator. It adheres to the surface layer A of the terminal part. Or
(4-2) The adhesive layer of the anti-winding tape and the insulating tape capable of adhering are made to circulate one or more outer circumferences from the outermost end portion of the separator to the end portion, and the adhesive layer surface of the anti-winding tape is The insulating tape is attached to one end and the other end. Or
(4-3) A winding tape having an adhesive layer Ta on one side a of one end and an adhesive layer Tb on one side a or the other side b of the other end is used. By adhering to the surface layer A on the inner surface of the terminal end, rotating the outermost periphery of the separator one or more times, and attaching the adhesive layer Tb on the other end to the surface layer A on the inner surface of the terminal end of the separator, A terminal portion of the separator is processed.
Even if the surface layer with a weak adhesion function (high peel strength) becomes the outermost peripheral surface by the treatment method of the terminal portion, the adhesive layer surface of the winding tape is used by utilizing the surface layer with the low peel strength of the separator. By forming a structure in which both ends of the film are always attached to the surface layer having a low peel strength, it is possible to configure a power generating element that is securely fixed by a winding tape.

  The present invention as described above can provide a power generation element that is securely fixed by a winding tape and a power generation element termination method that can be reliably fixed with a simple configuration in consideration of the state of the separator surface. Has an effect.

Schematic illustrating the configuration of a battery using a power generation element according to the present invention. Schematic illustrating the basic configuration of the power generation element according to the present invention Schematic which shows the example of a basic composition of the termination process part of the power generation element concerning the present invention Schematic which shows the 2nd, 3rd structural example of the termination process part of the electric power generation element which concerns on this invention Schematic which shows the 4th structural example of the termination process part of the electric power generation element which concerns on this invention Schematic which shows the 5th structural example of the termination process part of the electric power generation element which concerns on this invention Schematic which shows the structural example of the electrode group of the battery using the winding type electric power generation element which concerns on a prior art.

  The power generating element according to the present invention (hereinafter referred to as “the present electrode body”) has a sheet-like positive electrode and a negative electrode including a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A. It is wound with a separator composed of the above layers, the outermost periphery is wound by the separator, and the terminal end of the outermost separator is fixed by a winding tape having an adhesive layer on one side. It has the structure made. The present electrode body is housed in a container having a predetermined volume, and constitutes a battery (hereinafter referred to as “the present battery”) sealed by a lid disposed at the opening of the container. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Configuration example of the battery>
An outline of a configuration example of the battery is shown in FIG. The battery includes a container 1 having a predetermined volume, a main electrode body 2 formed by winding a sheet-like positive electrode and a negative electrode with a separator interposed therebetween, and a lid body disposed in the opening 1 a of the container 1. 3. By interposing a non-aqueous electrolyte between the sheet-like positive electrode and negative electrode, a highly efficient and compact main electrode body can be formed. The container 1 is sealed by sealing the opening 1a and the peripheral end of the lid 3 in a state where the main electrode body 2 fixed to the lid 3 is accommodated.

  As the container 1, a molded body made of strong aluminum or aluminum alloy is used as a casing (hereinafter referred to as “aluminum container”). In particular, it is a suitable material for secondary batteries that are easy to mold and require weight reduction. When corrosiveness or insulation is required, surface treatment such as oxidation or nitridation can be performed, which can contribute to preventing damage to the container 1 against high-temperature gas. The sealing method usually employs a method of welding the peripheral end portion, but is not limited to this, and an adhesive method using an adhesive or a convex shape so as to sandwich the peripheral end portion of the opening 1a. A crimping method for crimping the peripheral portion of the lid 3 on which the body is formed can be used.

  Electrode terminal portions 3a and 3b for positive electrode and negative electrode are attached to the lid 3. The electrode terminal portions 3a and 3b are formed so that a connection object (not shown) such as a cable or a bus bar can be electrically connected thereto.

<Basic configuration example of the electrode body>
As illustrated in FIG. 2A, the electrode body 2 is configured by winding a sheet-like positive electrode 2a and a negative electrode 2b with two kinds of separators 2c and 2c ′ serving as separators interposed therebetween. Here, as can be seen from the drawing, the separator 2c is a separator positioned between the positive electrode 2a and the negative electrode 2b in the planar laminated state where the winding is unwound, and corresponds to the first sub-separator of the present invention. To do. The separator 2c ′ is a separator located further outside the positive electrode 2a, and corresponds to the second sub-separator of the present invention. The separators 2c and 2c ′ may be independent separators, or may be configured to be one part and the other part when one separator is divided into two by folding or the like. In addition, the positive electrode end 2d is provided on one end side in the winding axis direction of the positive electrode 2a, and the negative electrode end 2e is provided on the other end side in the winding axis direction of the negative electrode 2b. The take-out part is formed. The positive electrode end 2d and the negative electrode end 2e are connected to one end of a current collector (not shown), and are connected to the electrode terminal portions 2a and 2b via the other end of the current collector. The negative electrode is taken out.

  The positive electrode 2a is configured, for example, by supporting a positive electrode active material on the surface of a strip-shaped aluminum foil, and the negative electrode 2b is configured, for example, by supporting a negative electrode active material on the surface of a strip-shaped copper foil. In the present electrode body 2, the positive electrode 2 a and the negative electrode 2 b are each provided with an uncoated portion where no active material is applied on one side end of the belt, and the positive electrode end 2 d and negative electrode The example which forms the electrode end 2e is shown. The positive electrode 2a and the negative electrode 2b are shifted in the opposite directions along the winding axis when the power generating element 2 is wound, so that one end surface of the long cylindrical shape has a side end portion of the positive electrode 2a. Only the aluminum foil (positive electrode end 2d) protrudes, and only the copper foil (negative electrode end 2e) at the side end of the negative electrode 2b protrudes from the other end face.

  The separator 2 c and the separator 2 c ′ have the same configuration except for the positional relationship in the power generation element 2. Hereinafter, the configuration of the separator 2c will be described as an example, but the same applies to the separator 2c '. The separator 2c includes a porous base layer having electrical insulation and an inorganic layer formed on the porous base layer. As the porous base layer, it is preferable to use a porous film, a nonwoven fabric, or the like that exhibits high dischargeability and electrolyte retention. Specific examples of the material constituting the porous base layer include polyacrylate, polyolefin resin typified by polyethylene, polyester resin typified by polyethylene terephthalate, fluorine resin such as polyvinylidene fluoride, polyimide (PI ), Polyamideimide (PAI), polyetheretherketone (PEEK), cellulose and the like. Of these, polyolefin resins such as polyethylene and polypropylene are preferable from the viewpoints of resistance to electrolytic solution and durability. Moreover, said compound may be used independently for a porous base layer, and 2 or more types may be mixed or laminated | stacked and used. For example, a separator in which a polypropylene microporous film is formed on the surface can improve electrolyte retention characteristics.

  The inorganic layer contains inorganic fillers and polymers. Specific examples of inorganic fillers include metal oxides such as silicon oxide, titanium oxide, aluminum oxide, magnesium oxide, zirconium oxide, zinc oxide, and iron oxide, nitrides such as silicon nitride, titanium nitride, and boron nitride, Silicon carbide, calcium carbonate, aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate And metal carbonates such as magnesium silicate and magnesium carbonate. Examples of the polymers include polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, polymethyl methacrylate, and the like. One of these inorganic fillers or polymers may be used alone, or two or more thereof may be mixed and used. The inorganic filler preferably includes at least one of silicon oxide, titanium oxide, and aluminum oxide, and the polymer is preferably an acrylic resin made of acrylic acid ester, methacrylic acid ester, or the like. By forming such an inorganic layer containing inorganic fillers on the surface of the separator 2c, it is possible to increase the efficiency of the insulating function between the positive electrode and the negative electrode, the function of holding the electrolyte, and the like.

  In the separator 2c thus surface-treated, the peel strength differs between the porous base layer and the inorganic layer. As illustrated in FIG. 2B, the porous base layer of the separator 2c forms a surface layer A having a high peel strength, and the inorganic layer forms a surface layer B having a lower peel strength. Alternatively, when different surface treatments are performed on both surfaces, two surface layers having different peel strengths may be formed with a porous base layer interposed, as illustrated in FIG. In this specification, in the separator 2c having both surfaces having different peel strengths, the surface layer having a high peel strength is defined as surface layer A, and the surface layer having a low peel strength is defined as surface layer B.

Here, the peel strength of the surface layer A is based on JIS 6854-2, the 180 degree peel strength measured using a 3M mending tape (width 15 mm) is preferably 50 gf or more, and 100 gf or more. Is more preferable. The peel strength of the surface layer B is preferably 3 gf or more, preferably 180 g peel strength measured using a 3M mending tape (width 15 mm) based on JIS 6854-2. More preferred. If the peel strengths of the surface layer A and the surface layer B are lower than the above values, the surface layer may be peeled off during production or use of the battery. In addition, when the peel strength of the surface layer A is extremely higher than the peel strength of the surface layer B, the surface layer A does not peel even if the 180 degree peel strength test is performed, and peels at the interface between the surface layer B and the surface layer A or the porous base layer. May occur. The peel strength of the surface layer A in this case substitutes the maximum load value of the measuring device.
Further, the ratio of the peel strength between the surface layer A and the surface layer B is preferably 2 or more, more preferably 5 or more, and still more preferably 10 or more. The ratio of the peel strength between the surface layer A and the surface layer B was determined in the same manner as the 180-degree peel strength value of the surface layer A measured with a 3M-made mending tape (width: 15 mm) based on JIS 6854-2. Calculated by dividing by B 180 degree peel strength value.
The peel strength of the surface layer A and the surface layer B is determined by conducting a 180 degree peel strength test based on JIS 6854-2 for the battery disassembled, the separator taken out, washed with an organic solvent such as dimethyl carbonate and dried. It is also possible to measure.

  Further, in order to ensure the insulation between the electrodes in the wound state, the end portions of the separators 2c and 2c ′ are formed to extend from the end portions of the positive electrode 2a and the positive electrode 2b. Due to the difference in length, at the end of the winding part of the entire electrode body 2, there are gaps due to the surfaces of the separators 2c ′ and 2c and the tip of the positive electrode 2a, and the surfaces of the separators 2c and 2c ′ and the tip of the negative electrode 2b. Is formed. This is common in the following configuration examples.

<Configuration of termination part of this electrode body>
The electrode body 2 is characterized in that different termination treatment parts are formed by the peel strength of the outer peripheral surface (outermost peripheral surface) of the separator 2c ′, which is the outermost peripheral separator. Basically, as illustrated in FIGS. 3A to 3C, the outermost periphery is wound by the separator 2 c ′, and the terminal portion 2 f of the outermost separator 2 c ′ is formed on the adhesive layer Sa on one side. Is fixed to the outermost peripheral surface of the separator 2c ′ (first configuration example). Hereinafter, the configuration of the electrode body 2 having the termination portion will be described in detail.

(A) When outermost peripheral surface of separator is constituted by surface layer A having low peel strength As shown in FIGS. 3 (A) and 3 (B), adhesive layer Sa of winding tape S is the outermost surface layer. A is attached to the surface layer A of the end portion 2f of A and the separator 2c ′. FIG. 3A shows a case where the outer peripheral surfaces of the two separators 2c and 2c ′ are both composed of the surface layer A at this time. On the other hand, the outermost peripheral surface of the outermost separator 2c ′ is constituted by the surface layer A, and the outer peripheral surface of one inner peripheral separator 2c from the outermost separator 2c ′ is constituted by the surface layer B in FIG. Shown in B). Both can be attached by the winding tape S using the surface layer A of the outermost separator 2c ′ and the surface layer A of the terminal end 2f.

(B) When the outermost peripheral surface of the separator is constituted by the surface layer B As shown in FIG. 3C, (b-1) the outer peripheral surface of the separator 2c that is one inner circumference from the outermost periphery is constituted by the surface layer A. Then, the outer peripheral separator 2c is further rotated around the outer periphery (represented as a separator 2g), whereby the surface layer B which is the inner peripheral surface of the separator 2g is the outer layer B which is the outer peripheral side of the separator 2c ′. As a result, the outermost peripheral surface of the electrode body 2 can be constituted by the surface layer A of the separator 2g. Here, the adhesive layer Sa surface of the winding tape S is attached to the surface layer A of the outermost peripheral surface and the surface layer A of the terminal portion 2h of the separator 2g, whereby the terminal portion 2h of the separator 2g is fixed. The main electrode body 2 can be configured.

  Here, it is preferable that the winding tape S has heat resistance and insulating properties, has predetermined extensibility, and has high bondability with an adhesive. The material of the winding tape S is not particularly limited as long as it is stably present even when exposed to an electrolyte or the like inside the battery, and can maintain adhesiveness. A tape based on a polyolefin-based resin or a tape based on a resin having heat resistance such as polyimide can be used. Specifically, polyethylene (PE), polypropylene (PP), polyphenyl sulfide, polyester, polyimide, Teflon (TM), or the like can be used as the substrate. As the adhesive layer, acrylic resin, vinyl acetate, synthetic rubber, epoxy resin, silicon resin, or the like can be used.

[Termination method for this electrode body]
The present electrode body 2 includes (1) a sheet-like positive electrode 2a and a negative electrode 2b that are stacked so that most of the intermediate portion except for the terminal portion of the separator 2c is interposed therebetween, and the separator 2c ′ is adjacent to the positive electrode 2a side. (2) The outermost periphery of the wound main electrode body 2 is manufactured so as to be the separator 2c ′, and the outermost peripheral surface is configured as follows. As described above, termination processing of the winding portion is performed.
(3) When the outermost peripheral surface of the separator 2c ′ is constituted by the surface layer A, the adhesive layer Sa surface of the winding tape S is attached to the surface layer A of the outermost peripheral surface and the surface layer A of the end portion 2f of the separator 2c ′. Let
(4) When the outermost peripheral surface of the separator 2c ′ is constituted by the surface layer B, the outer peripheral surface of one inner peripheral separator 2c is constituted by the surface layer A from the outermost separator 2c ′, and the inner peripheral separator 2c ( 2g) is further circulated around the outer periphery by one or more rounds, the outermost peripheral surface of the electrode body 2 is constituted by the surface layer A of the separator 2g, and the adhesive layer Sa surface of the winding tape S is formed by the surface layer A of the outermost peripheral surface. And it adheres over the surface layer A of the terminal part of the separator 2g.

  However, the present invention is not limited to the above configuration example. In the above description, each of the separators 2c and 2c ′ is the surface layer A or the surface layer B, but the portion other than the outermost peripheral portion to which the winding tape S adheres, More preferably, the portion other than the end portion may not be the surface layer A and the surface layer B. For example, both surfaces may be the surface layer B. In this case, while ensuring the strength required for the attachment of the winding tape S, the surface unrelated to the winding tape S can be an inorganic layer, and the heat resistance of the electrode body 2 can be further improved.

  In the above description, the outermost peripheral side of the electrode body 2 is the separator 2c '. However, the separator 2c' may be further wound around the negative electrode 2b. 3A and 3B, the negative electrode 2b is positioned on the outer peripheral side of the outermost separator 2c 'and directly below the winding tape S. In the case of FIG. 3C, the separator The negative electrode 2b is sandwiched between 2g and the separator 2c ′. Further, the separator 2c may be wound around the outer periphery thereof. With these configurations, it is possible to flexibly cope with the case potential setting. In this case, the separator 2c 'and the separator 2c correspond to the third sub-separator of the present invention. Needless to say, in the present electrode body 2, the arrangement of the positive electrode 2a and the negative electrode 2b may be reversed.

<Other structural examples of the electrode assembly>
The present electrode body 2 is (b) in the case where the outermost peripheral surface of the separator is constituted by the surface layer B, instead of extending a part of the separator 2c as in the first configuration example, the adhesive of the winding tape S Using the insulating tape T that can be adhered to the layer Sa, several terminal-treated main electrode bodies 2 can be formed as described below.

  Here, the insulating tape T is preferably made of a material having insulating properties and heat resistance. This is because it is preferable to maintain insulation even when the temperature of the main electrode body 2 increases due to the operation of the battery. Specifically, a polyimide film or a PPS (polyphenylene sulfide) film can be used.

[Second configuration example]
As illustrated in FIGS. 4 (A) and 4 (B), the electrode body 2 has one or more circumferences of the insulating tape T extending from the outermost end portion 2f of the separator 2c ′ to the end portion 2f. The adhesive layer Sa surface of the winding tape S can be configured to be attached to one end Ta and the other end Ta of the insulating tape T (second configuration example). 4A shows a configuration in which the outer peripheral surface of one inner peripheral separator 2c is the surface layer A from the outermost separator 2c ′, and FIG. 4B is one inner side from the outermost separator 2c ′. A configuration in which the outer peripheral surface of the peripheral separator 2c is the surface layer B is shown.

  One end Ta of the insulating tape T is disposed at a position corresponding to the outermost end portion 2f of the separator 2c ', and the insulating tape T is circulated along the outermost periphery of the separator 2c', and in the vicinity of the outermost end portion 2f. By disposing the other end portion Tb, the entire circumference of the electrode body 2 can be covered without damaging the surface layer B on which the inorganic layer or the like of the separator 2c ′ is formed. Here, by attaching the one end Ta and the other end Tb of the insulating tape T with the winding tape S, the separator 2c can be fixed via the insulating tape T. At this time, one end portion Ta of the insulating tape T is disposed at a position corresponding to the outermost end portion 2f of the separator 2c ′, and by attaching the adhesive layer Sa surface of the winding tape S to the outermost peripheral surface thereof, A predetermined step is formed at the end portion 2f. Such a step forms an inclination of the winding tape S and creates a function of locking the slip of the insulating tape T. Therefore, the insulating tape T can be securely fixed, and the separator 2c ′ is interposed via the insulating tape T. Can be fixed.

  Termination treatment of the electrode body 2 uses an adhesive layer Sa of the winding tape S and an insulative adhesive tape T, and the insulating tape T is moved from the outermost peripheral end portion 2f of the outermost peripheral separator 2c ′ to the terminal end portion 2f ( 1 or more around the periphery), and the adhesive layer Sa surface of the winding tape S can be attached to one end Ta and the other end Tb of the insulating tape T.

In the above description, the outermost peripheral side of the electrode body 2 is the separator 2c ′. However, the separator 2c ′ may be further wound around the negative electrode 2b. In that case, the negative electrode 2b exists immediately below the insulating tape T in FIGS. 4 (A) and 4 (B). Further, the separator 2c may be wound around the outer periphery thereof. Needless to say, in the present electrode body 2, the arrangement of the positive electrode 2a and the negative electrode 2b may be reversed.
Further, the insulating tape T has no problem as long as it has approximately the same width as the winding tape, but may have approximately the same width as the separator 2c or 2c ′. If the width of the insulating tape T and the separator 2c or 2c ′ is substantially equal, the active material is not easily dropped off because the insulating tape T protects the negative electrode 2b or the positive electrode 2a around the outermost periphery. There is an advantage.

[Third configuration example]
As illustrated in FIGS. 4C to 4E, the electrode body 2 has the adhesive layer Sa surface of the winding tape S attached to one end Ta and the other end Tb of the insulating tape T, A configuration may be adopted in which the inner surface of the terminal end 2f of the separator 2c ′ or the outermost separator 2c ′ is attached to the surface layer A of the inner separator 2c (third configuration example). FIG. 4C shows a configuration having a surface layer A on the outer peripheral surface of one inner peripheral separator 2c from the outermost separator 2c ′, and FIGS. 4D and 4E show the outermost separator 2c ′. The structure which has the surface layer B in the outer peripheral surface of the separator 2c of one inner periphery is shown.

  4 (C) and 4 (D) show the separators 2c, 2c ′, the positive electrode 2a, the negative electrode 2b, and the above-described separators 2c, 2c ′, in addition to the winding of the one end and the other end of the insulating tape that circulates in the second configuration example. Using the inner surface of the outermost separator 2c ′ as the inner wall of the gap formed by the difference in the length of the end portion of the gap, that is, the surface layer A formed on the inner circumference side in the wound state, The structure to fix is shown. Similarly, FIG. 4E shows a configuration in which the winding tape S is fixed using the surface layer A formed on the inner surface of one inner peripheral separator 2c from the outermost peripheral separator 2c '. By such fixing, the insulating tape T can be more reliably fixed, and the separator 2c 'can be more securely fixed via the insulating tape T. In addition to the same operation as in the second configuration example, the termination treatment of the electrode body 2 can be performed by adding an operation of fixing the winding tape S to the surface layer A formed on the inner surface of the outermost separator 2c ′. it can.

  In the above description, the outermost peripheral side of the electrode body 2 is the separator 2c '. However, the separator 2c' may be further wound around the negative electrode 2b. In that case, the negative electrode 2b exists immediately below the insulating tape T in FIGS. 4 (A) and 4 (B). Further, the separator 2c may be wound around the outer periphery thereof. Needless to say, in the present electrode body 2, the arrangement of the positive electrode 2a and the negative electrode 2b may be reversed. Further, the insulating tape T has no problem as long as it has approximately the same width as the winding tape, but may have approximately the same width as the separator 2c or 2c '. If the width of the insulating tape T and the separator 2c or 2c ′ is substantially equal, the active material is not easily dropped off because the insulating tape T protects the negative electrode 2b or the positive electrode 2a around the outermost periphery. There is an advantage.

[Fourth configuration example]
As illustrated in FIGS. 5A to 5F, the electrode body 2 includes a plurality of winding tapes S, and the adhesive layer Sa1 surface of the first winding tape S1 is one end Ta of the insulating tape T. And the other end Tb, or one end Ta and the surface layer A on the inner surface of the end portion 2f of the outermost separator 2c ′, and the adhesive layer Sa2 surface of the second winding tape S2 is in the former The other end portion Tb of the insulating tape T and the surface layer A on the inner surface of the end portion 2f of the outermost peripheral separator 2c ′, the other end portion Tb and one end portion Ta or one inner peripheral portion from the outermost peripheral separator 2c ′. It can be set as the structure attached to the surface layer A of the inner surface of the termination | terminus part 2f of the separator 2c (4th structural example). Here, FIGS. 5 (A) to 5 (D) show a configuration having the surface layer A on the outer peripheral surface of one inner peripheral separator 2c from the outermost peripheral separator 2c ′, and FIGS. The structure which has the surface layer B in the outer peripheral surface of the separator 2c of 1 inner periphery from the separator 2c 'of the outermost periphery is shown.

FIG. 5A shows that the adhesive layer Sa1 surface of the first winding tape S1 is attached to one end Ta and the other end Tb of the insulating tape T, and the adhesive layer Sa2 of the second winding tape S2. The structure is shown in which the surface is attached to the surface layer A on the inner surface of the other end Tb of the insulating tape T and the terminal end 2f of the outermost separator 2c ′.
FIG. 5B shows that the adhesive layer Sa1 surface of the first winding tape S1 is attached to one end Ta and the other end Tb of the insulating tape T and the second winding tape S2 is adhesive. A structure in which the surface of the layer Sa2 is attached to the surface layer A on the outer peripheral surface of the terminal end 2f of the inner peripheral separator 2c from the other end Tb of the insulating tape T and the outermost peripheral separator 2c ′ is shown.
FIG. 5E shows that the adhesive layer Sa1 surface of the first winding tape S1 is attached to one end Ta and the other end Tb of the insulating tape T, and the second winding tape S2 is adhesive. The structure in which the surface of the layer Sa2 is attached to the surface layer A on the inner surface of the other end Tb of the insulating tape T and the terminal end 2f of the outermost separator 2c ′ is shown.
FIG. 5F shows that the adhesive layer Sa1 surface of the first winding tape S1 is attached to one end Ta and the other end Tb of the insulating tape T, and the second winding tape S2 is adhesive. A structure in which the surface of the layer Sa2 is attached to the surface layer A on the inner surface of the terminal end 2f of the inner peripheral separator 2c from the other end Tb of the insulating tape T and the outermost separator 2c ′ is shown.
5B shows a configuration in which the first winding tape S1 and the second winding tape S2 are both attached to the same surface of the insulating tape T at the other end Tb. 5A, 5E, and 5F show a configuration in which the first winding tape S1 and the second winding tape S2 are respectively attached to both surfaces of the insulating tape T at the other end Tb.

In FIG. 5C, the first winding tape S1 wraps around the tip including the outermost separator 2c ′ from the one end portion Ta of the insulating tape T and reaches the inner peripheral side of the outermost separator 2c ′. Thus, the surface of the adhesive layer Sa1 of the first winding tape S1 is attached to the surface layer A on the inner surface of the one end portion Ta of the insulating tape T and the end portion 2f of the outermost separator 2c ′, and the second winding The structure is shown in which the adhesive layer Sa2 surface of the stop tape S2 is attached to the surface layer A on the inner surface of the other end portion Tb of the insulating tape T and the end portion 2f of the outermost separator 2c ′.
Further, in FIG. 5D, as in FIG. 5C, when the first winding tape S1 wraps around the end of the terminal portion, the surface of the adhesive layer Sa1 of the first winding tape S1 becomes the insulating tape. One end portion Ta of T and the surface layer A on the inner surface of the end portion 2f of the outermost separator 2c ′ are attached to the surface layer A2 of the second winding tape S2 and the other end portion Tb of the insulating tape T. The structure attached to the one end part Ta is shown. The configurations shown in FIGS. 5C and 5D can also be applied to a configuration having the surface layer B on the outer peripheral surface of one inner peripheral separator 2c from the outermost peripheral separator 2c ′.

  In any configuration, in order to reinforce the fixing portion of the insulating tape T, in addition to one winding tape S1 for fixing both ends Ta and Tb of the insulating tape T, the insulating tape T and the outermost separator 2c ′ are fixed. By using the other anti-winding tape S2, the insulating tape T can be reliably fixed, and the electrode body 2 securely fixed can be configured through the insulating tape T.

  Further, the terminal treatment of the electrode body 2 is performed in the same manner as in the second configuration example, except for the configuration shown in FIG. 5C, and the one end Ta or the other end Tb of the insulating tape T and the outermost separator. It can be performed by adding an operation of fixing the winding tape S to the surface layer A formed on the inner surface of 2c ′. In the configuration shown in FIG. 5C, the surface of the adhesive layer Sa1 of the first winding tape S1 is attached to the surface layer A formed on the inner surface of the outermost separator 2c ′ and one end portion Ta of the insulating tape T. The end treatment may be performed by attaching the surface of the adhesive layer Sa2 of the second winding tape S2 to the surface layer A formed on the inner surface of the outermost separator 2c ′ and the other end Tb of the insulating tape T. it can. In the above configuration, the first winding tape S1 shown in FIGS. 5A, 5B, 5E, and 5F corresponds to the first winding tape of the present invention. The winding tape S2 corresponds to the second winding tape of the present invention. Further, the first winding tape S1 shown in FIGS. 5C and 5D corresponds to the first winding tape of the present invention, and the second winding tape S2 is the third winding tape of the present invention. Corresponds to a stop tape.

  However, the present invention is not limited to the above configuration example. In the above description, the separators 2 c and 2 c ′ are both the surface layer A or the surface layer B, but may not be the surface layer A and the surface layer B. For example, both surfaces may be the surface layer B. In the present invention, since the entire outer periphery of the electrode body 2 is covered with the insulating tape T that is fixed to the winding tape S with a constant adhesive force, the surface state of the separators 2c and 2c ′ is determined. Regardless, it is possible to realize reliable fixing with the winding tape S. In this case, for example, both sides of the separators 2c and 2c 'can be formed as inorganic layers, and the heat resistance of the electrode body 2 can be further improved.

  In the above description, the outermost peripheral side of the electrode body 2 is the separator 2c '. However, the separator 2c' may be further wound around the negative electrode 2b. 4A to 4E and FIGS. 5A to 5F, the negative electrode 2b is positioned between the insulating tape T and the outermost separator 2c '. Similar to the first to third configuration examples, these configurations can flexibly cope with the case potential setting. In this case, the separator 2c 'and the separator 2c correspond to the third sub-separator of the present invention. Needless to say, in the present electrode body 2, the arrangement of the positive electrode 2a and the negative electrode 2b may be reversed. Further, the insulating tape T has no problem as long as it has approximately the same width as the winding tape, but may have approximately the same width as the separator 2c or 2c '. If the width of the insulating tape T and the separator 2c or 2c ′ is substantially equal, the active material is not easily dropped off because the insulating tape T protects the negative electrode 2b or the positive electrode 2a around the outermost periphery. There is an advantage.

[Fifth configuration example]
As illustrated in FIGS. 6A to 6D, the electrode body 2 has an adhesive layer Sb on one side b at one end and an adhesive layer Sc on one side b or the other side c at the other end. The anti-winding tape S is used. With the adhesive layer Sb at one end of the winding tape S attached to the inner surface of the terminal end 2f of the outermost separator 2c ′ or the inner surface layer A, the winding tape S of the outermost separator 2c ′ Further, one or more spirals are wound around the outer periphery, and the adhesive layer Sc at the other end is formed on the inner surface of the terminal portion 2f of the outermost separator 2c ′ or one of the inner peripheral separators 2c from the outermost separator 2c ′. It can be set as the structure adhered to the surface layer A of an outer peripheral surface (5th structural example). 6A to 6C show a configuration in which the outer peripheral surface of one inner peripheral separator 2c is the surface layer A from the outermost peripheral separator 2c ', and FIG. 6D is a separator located on the outermost peripheral. A configuration in which the outer peripheral surface of the separator 2c that is one inner periphery from 2c ′ is the surface layer B is shown. The outer peripheral surface of the separator 2c ′ located on the outermost peripheral side in the state where each electrode and the separator are wound is constituted by the surface layer B by using the winding tape S having the adhesive layer only at the portions necessary for adhesion at both ends. Even in such a case, it is possible to securely fix the terminal end at the shortest distance using the minimum unit member.

Specifically, FIGS. 6A and 6B illustrate a configuration using a winding tape S having adhesive layers Sb and Sc at both ends on the same side b.
In FIG. 6A, the adhesive layer Sb at one end of the winding tape S is attached to the surface layer A on the outer peripheral surface of the inner periphery of the terminal portion 2f of the inner peripheral separator 2c from the outermost separator 2c ′. The outer periphery of the outermost separator 2c ′ goes around the tip of the separator 2c ′ so that the outer periphery of the separator 2c ′ is further spirally wound around one or more times, and the adhesive layer Sc at the other end is connected to the end portion 2f of the outermost separator 2c ′. The structure attached to the surface layer A of the inner surface of is shown.
6B, conversely, the adhesive layer Sb at one end of the winding tape S is attached to the surface layer A on the inner surface of the end portion 2f of the outermost separator 2c ′, and the adhesive layer Sc at the other end is The structure attached to the surface layer A of the outer peripheral surface of the inner periphery of the termination | terminus part 2f of one inner peripheral separator 2c from the outermost separator 2c 'is shown.

6 (C) and 6 (D), a winding tape S having an adhesive layer Sb on one side b of one end and an adhesive layer Sc on one side c of the other end opposite to the one side b is used. The configuration is illustrated.
FIG. 6C shows that the adhesive layer Sb at one end is attached to the outer peripheral surface A of the inner surface of the terminal portion 2f of the outermost separator 2c ′, and the outer periphery of the outermost separator 2c ′ is spirally formed. The adhesive layer Sc at the other end is also attached to the surface layer A on the inner surface of the terminal end 2f of the outermost separator 2c ′. This configuration can also be applied to the case where the outer peripheral surface of one inner peripheral separator 2c is the surface layer B from the outermost peripheral separator 2c '.
In FIG. 6D, the adhesive layer Sb at one end is attached to the inner surface layer A of the terminal end 2f of the outermost separator 2c ′, and the adhesive layer Sc at the other end is attached from the outermost separator 2c ′. The structure attached to the surface layer A of the inner surface of the terminal end 2f of one inner peripheral separator 2c is shown. Here, conversely, the adhesive layer Sb at one end is attached to the surface layer A on the inner surface of the terminal end 2f of the inner peripheral separator 2c from the outermost separator 2c ′, and the adhesive layer Sc at the other end is attached to the outermost separator 2c ′. It is also possible to adopt a configuration in which the outer layer separator 2c ′ is attached to the inner surface layer A of the terminal portion 2f (not shown).
Note that the winding tape S referring to FIGS. 6A to 6D corresponds to the insulating winding tape of the present invention.

  However, the present invention is not limited to this configuration example. In the above description, the outermost peripheral side of the electrode body 2 is the separator 2c '. However, the separator 2c' may be further wound around the negative electrode 2b. In this case, the negative electrode 2b is positioned on the outer peripheral side of the outermost separator 2c 'and directly below the winding tape S. With this configuration, it is possible to flexibly cope with the case potential setting. Needless to say, in the present electrode body 2, the arrangement of the positive electrode 2a and the negative electrode 2b may be reversed. In addition, the winding tape S is sufficient if it has a width that has the effect of winding, but it may have a width substantially equal to that of the separator 2c or 2c '. If the widths of the winding tape S and the separator 2c or 2c ′ are substantially equal, the active material may fall off because it is protected by the insulating tape T even if the negative electrode 2b or the positive electrode 2a is wound around the outermost periphery. There is an advantage that it is difficult.

  As mentioned above, although the structural example of five different forms was shown, this invention is not limited to these structural examples, Furthermore, the structure using the winding tape S which has a double-sided adhesive layer in both ends, for example In addition, various configurations applying the basic configuration of the electrode body 2 such as a configuration in which the end portion of the separator 2c is shifted from the end portion of the outermost periphery and the end portion of one inner layer to reduce the protrusion of the winding stop portion. It is possible to apply to the form of.

  The present invention as described above can provide a power generation element that is securely fixed by a winding tape and a method for terminating a power generation element that can be reliably fixed with a simple configuration in consideration of the state of the surface of the separator. And is useful in secondary batteries and the like.

DESCRIPTION OF SYMBOLS 1 Container 1a Opening part 2 This electrode body 2a Positive electrode 2b Negative electrode 2c, 2c ', 2g Separator 2d Positive electrode end 2e Negative electrode end 2f, 2h Termination part 3 Lid 3a, 3b Electrode terminal part A, B Surface layer S, S1, S2 Winding tape Sa, Sb, Sc, Sa1, Sa2 Adhesive layer T Insulating tape Ta One end Tb The other end

Claims (16)

A sheet-shaped positive electrode wound in a laminated state, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode,
The separator has a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
A power generation element in which the terminal portion of the separator is fixed by a winding tape having an adhesive layer on at least one side,
The outermost surface including the terminal portion of the outermost separator in the wound state is the surface layer A.
Power generation element. The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The first sub-separator and the second sub-separator each have the surface layer A and the surface layer B,
The outermost separator is the second sub-separator;
The power generation element according to claim 1. The surface layer A and the surface layer B are included only in all or part of the outermost separator,
The power generation element according to claim 1 or 2. The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The outermost separator is the first sub-separator;
The power generation element according to claim 1. The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The outermost separator is the first sub-separator;
The outer peripheral side of the second sub-separator is in contact with the inner peripheral side of the outermost separator,
The power generation element according to claim 1. A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state;
In the wound state, the positive electrode, the negative electrode or any one of the separators located on the outermost periphery, further provided with an insulating tape having a predetermined adhesive force provided over the outer periphery,
The separator has a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
The terminal portion of the insulating tape was fixed by a first winding tape having an adhesive layer on at least one side,
Power generation element. The first winding tape is provided on the outer peripheral side of the insulating tape,
The power generation element according to claim 6. The sheet-like separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
The inner peripheral side or outer peripheral side of the insulating tape and the surface of the terminal portion of the first sub-separator or the second sub-separator were fixed by a second winding tape,
The power generation element according to claim 6 or 7. The surface on the outer peripheral side of the terminal portion of the second sub-separator in the wound state is the surface layer B,
The surface of the terminal portion of the first sub-separator or the second sub-separator fixed by the second winding tape is the surface layer A.
The power generation element according to claim 8. In the wound state, the separator is located on the outermost periphery of the positive electrode, the negative electrode or the separator.
The power generation element according to any one of claims 6 to 9. The end portions of the insulating tape, the first sub-separator and the second sub-separator extend from the end portions of the positive electrode and the negative electrode,
Inside of the first sub-separator or the second sub-separator located on the outermost periphery by wrapping around the ends of the end portions of the first sub-separator and the second sub-separator from the surface of the insulating tape Having a third winding tape adhering to the circumferential side,
The inner peripheral side of the first separator or the second sub-separator is the surface layer A.
The power generation element according to claim 10. A sheet-like positive electrode wound in a stacked state, a sheet-like negative electrode, and a sheet-like separator facing at least one of the sheet-like positive electrode and the negative electrode,
The sheet-shaped separator has a first sub-separator positioned between the positive electrode and the negative electrode in a state where the winding is unwound, and a second sub-separator facing either the positive electrode or the negative electrode. And
A power generation element in which a terminal portion of the first sub-separator or the second sub-separator is fixed by an insulating winding tape having an adhesive layer on at least one side;
The first sub-separator and the second sub-separator each have a surface layer A having a high peel strength and a surface layer B having a peel strength lower than the surface layer A in at least a part thereof,
One end of the insulating winding tape is attached to the inner peripheral side around the tip of the terminal end from the outer peripheral side of the first sub-separator or the second sub-separator located on the outermost side,
The other end of the insulating winding tape is connected to the first sub-separator in the gap formed by the terminal portions of the first sub-separator and the second sub-separator, and the terminal portions of the positive electrode and the negative electrode. Attached to the surface of the separator or the second sub-separator,
The first sub-separator or second sub-separator to which one end of the insulating winding tape adheres and the first sub-separator or second to which the other end of the insulating winding tape adheres Each of the surfaces of the sub-separator is the surface layer A.
Power generation element. The surface layer A is composed of resin equipment, and the surface layer B is composed of an inorganic layer.
The power generation element according to any one of claims 1 to 12. A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) When the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) when the outer peripheral side of the terminal end portion of the separator is the surface layer B of the second sub-separator by the winding step, the first sub-separator is located immediately below the second sub-separator. The sub-separator is wound so as to cover at least the end portion of the second sub-separator, and the adhesive layer surface of the winding tape is further wound on the end portion of the second sub-separator and the outermost end of the second sub-separator. A process of adhering across the outer peripheral surface,
A power generation element termination method. A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) If the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the surface of the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) if the outer peripheral side of the terminal end of the separator is the surface layer B of the second sub-separator by the winding step, the outer periphery of the second sub-separator including the terminal end Winding the insulating tape having a predetermined adhesive force one or more times, and fixing the wound end portion of the insulating tape with a winding tape having an adhesive layer on at least one side;
A power generation element termination method. A sheet-shaped positive electrode, a sheet-shaped negative electrode, and a sheet-shaped separator facing at least one of the sheet-shaped positive electrode and the negative electrode, wound in a stacked state, and the separator has a high peel strength A and a surface layer B having a peel strength lower than that of the surface layer A at least in part, and the sheet-like separator is a first subposition located between the positive electrode and the negative electrode in a state where the winding is unwound. A power generation element termination method comprising a separator and a second sub-separator facing either the positive electrode or the negative electrode,
The second sub-separator is disposed in a state where the first sub-separator is disposed between the positive electrode and the negative electrode, and the second sub-separator is disposed so as to face either the positive electrode or the negative electrode. Winding these so that the outer peripheral side,
Fixing the terminal portion of the separator with a winding tape having an adhesive layer on at least one side,
The fixing step includes
(A) If the outer peripheral side of the end portion of the separator is the surface layer A of the second sub-separator by the winding step, the surface of the adhesive layer of the winding tape is placed on the second sub-separator. A process of adhering across the terminal end of the separator and the outermost peripheral surface;
Or (b) When the outer peripheral side of the end portion of the separator is the surface layer B of the second sub-separator by the winding step,
Extending the end portions of the first sub-separator and the second sub-separator from the end portions of the positive electrode and the negative electrode,
One end of the insulating winding tape is attached to the inner peripheral side around the tip of the terminal end from the outer peripheral side of the second sub-separator located on the outermost periphery,
The other end of the insulating tape is connected to the first sub-separator in the gap formed by the terminal portions of the first sub-separator and the second sub-separator, and the terminal portions of the positive electrode and the negative electrode. Attaching to the surface of the separator or the second sub-separator,
In (b), the first sub-separator or the first sub-separator to which the inner peripheral side of the second sub-separator to which one end of the insulating winding tape is attached and the other end of the insulating winding tape are attached. The surface of each of the two sub-separators is defined on the surface layer A.
Termination method for power generation elements.

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