JP6330253B2 - Storage element, power supply module, and storage element manufacturing method - Google Patents

Description

  The present invention relates to a storage element such as a secondary battery or other batteries, a method for manufacturing the same, and the like.

  Secondary batteries are widely used as power sources for electronic devices such as mobile phones and IT devices, as well as for replacing primary batteries. In particular, since non-aqueous electrolyte secondary batteries represented by lithium ion batteries have high energy density, they are also being applied to industrial large electric devices such as electric vehicles.

  Such a non-aqueous electrolyte secondary battery has an electrode body having an electrode member of a positive electrode member and a negative electrode member and a pair of separators. In the case of the winding type, the electrode member and the separator have a band shape, and the electrode body has a flat and long cylindrical outer shape by being laminated and wound. Positive and negative leads are exposed at both ends of such an electrode body, and the lead is connected to an electrode terminal provided outside the storage container via a current collector to constitute a battery.

JP 2011-216299 A

  However, the above conventional techniques have the following problems.

  That is, in the conventional wound electrode body, when the positive and negative electrode members and the separator are wound in a stacked state, the separator is interposed between the positive electrode member and the negative electrode member so as to prevent a short circuit between the electrode members. It is in an intervening state.

  However, in the winding process, if a displacement occurs between the separator and the electrode member, the electrode member may come into contact and cause a short circuit, or the separator or electrode member may be wound with wrinkles and distorted in shape. May occur. In particular, due to the increase in the number of windings and the length of the member accompanying the improvement in performance of the electrode body, the influence of the positional deviation cannot be ignored. Also in the laminated electrode body, the positive and negative electrode members and the separator may be placed in a wound state during the manufacturing process, and in this case also, the influence of the positional deviation cannot be ignored.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power storage device having an electrode body that is configured with high accuracy while preventing positional deviation between separators and electrode members, a method for manufacturing the same, and the like. To do.

In order to achieve the above object, the first aspect of the present invention provides:
A winding type electrode body having a pair of separators, a positive electrode member and a negative electrode member;
The pair of separators is at least
The periphery of at least any one of a pair of short sides parallel to a winding axis of the positive electrode member or the negative electrode member and any one of a pair of long sides intersecting the winding axis is joined.
It is a power storage element.

The second aspect of the present invention is
All or a part of the joining location of the pair of separators is located inside the edge of each separator,
It is an electrical storage element of the 1st side surface of this invention.

The third aspect of the present invention is
In the pair of separators, the one side of the pair of short sides parallel to the winding axis and the one side of the pair of long sides intersecting the winding axis are joined in a continuous state,
One end of the one side of the short side that is not coupled to the one side of the long side is joined to the edge of the pair of separators,
It is an electrical storage element of the 1st or 2nd side surface of this invention.

The fourth aspect of the present invention is
The pair of separators is
It is further joined at a position along the direction away from the positive electrode member or the negative electrode member from the edge where the one end is joined.
It is an electrical storage element of the 3rd side surface of this invention.

The fifth aspect of the present invention is
The pair of separators is
It is joined only at a position closer to the winding axis from the positive electrode member or the negative electrode member,
It is an electrical storage element of the 4th side surface of this invention.

The sixth aspect of the present invention is
The pair of separators is
The positive electrode member or the negative electrode member, both the pair of short sides parallel to the winding axis and the periphery of any one of the pair of long sides intersecting the winding axis are joined,
All or part of the distance between the pair of short sides is:
One of a pair of long sides intersecting the winding axis is smaller as it is away from the one side,
It is an electrical storage element of the 1st to 5th side surface of this invention.

The seventh aspect of the present invention is
The positive electrode member or the negative electrode member to which the pair of separators are bonded, the pair of long sides intersecting with the winding axis, which are joined in a continuous state, and parallel to the winding axis. At least one of the pair of short sides is curved in whole or in part.
It is an electrical storage element of the 1st to 6th side surface of this invention.

The eighth aspect of the present invention is
The positive electrode member or the negative electrode member to which the pair of separators are bonded, the pair of long sides intersecting with the winding axis, which are joined in a continuous state, and parallel to the winding axis. The width of all or a part of at least one of the pair of short sides is:
One of a pair of long sides intersecting the winding axis is smaller as it is away from the one side,
It is an electrical storage element of the 1st to 7th side surface of this invention.

The ninth aspect of the present invention is
The positive electrode member or the negative electrode member to which the pair of separators are bonded, the pair of long sides intersecting with the winding axis, which are joined in a continuous state, and parallel to the winding axis. The width of all or a part of at least one of the pair of short sides is:
One of a pair of long sides intersecting the winding axis is larger as it is away from the one side,
It is an electrical storage element of the 1st to 8th side surface of this invention.

The tenth aspect of the present invention provides
Edges parallel to the winding axis on the winding end side of the electrode body of the pair of separators are longer on the outer side than those on the inner side of the winding,
It is an electrical storage element of the 1st thru | or 9th side surface of this invention.

The eleventh aspect of the present invention is
A pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member, wherein the positive electrode member and the negative electrode member are interposed via one of the pair of separators, and the pair of separators are the positive electrode member And a storage element comprising an electrode body formed by winding or further stacking a stacked body that is stacked via any one of the negative electrode members,
At least a part of the positive electrode member or the negative electrode member sandwiched between the pair of separators protrudes between the pair of separators,
At least a part of the periphery of the other part of the positive electrode member or the negative electrode member is sealed by joining the pair of separators at a position inside each edge of the pair of separators. Yes,
It is a power storage element.

The twelfth aspect of the present invention is
A plurality of power storage elements, at least one of the power storage elements is a power storage element according to any one of the first to eleventh aspects of the present invention;
It is a power supply module.

The thirteenth aspect of the present invention provides
As a process of creating an electrode body,
A pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member, wherein the positive electrode member and the negative electrode member are interposed via one of the pair of separators, and the pair of separators are the positive electrode member And a step of superimposing via any one of the negative electrode members,
Bonding a part of any one of the pair of long sides adjacent to the pair of short sides of the pair of separators;
Bonding at least one side of the pair of short sides of the pair of separators;
Winding a pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member from the pair of short sides of the pair of separators,
Synchronizing with the winding step, and adjoining the one side of the pair of short sides of the pair of separators, joining the remaining part of any one of the pair of long sides,
The whole or a part of the joining location of the pair of separators in each step of the joining is determined at a position inside at least one of the edge of each of the one of the pair of short sides and the pair of long sides. Yes,
It is a manufacturing method of an electrical storage element.

  According to the present invention as described above, there is an effect that it is possible to obtain an electrode body configured with high accuracy by preventing the positional deviation between the separator and the electrode member in the electricity storage element.

The principal part disassembled perspective view which shows the structure of the nonaqueous electrolyte secondary battery which concerns on Embodiment 1 of this invention. The principal part disassembled perspective view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 1 of this invention. (A) The figure for demonstrating the manufacturing method of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 1 of this invention (b) The electrode of the nonaqueous electrolyte secondary battery which concerns on Embodiment 1 of this invention The figure which shows the flowchart of the manufacturing method of a body 1 is a schematic plan view showing a configuration of an electrode body of a nonaqueous electrolyte secondary battery according to Embodiment 1 of the present invention. (A) Schematic sectional view showing the configuration of the electrode body along the line AA in FIG. 4 (b) Schematic sectional view showing the configuration of the electrode body along the line BB in FIG. Typical top view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 2 of this invention. Typical top view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 3 of this invention. Typical top view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 4 of this invention. Typical top view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 5 of this invention. Typical top view which shows the structure of the electrode body of the nonaqueous electrolyte secondary battery which concerns on Embodiment 6 of this invention. Schematic top view which shows the other structural example of the electrode body of the nonaqueous electrolyte secondary battery which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view of a nonaqueous electrolyte secondary battery 100 according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the nonaqueous electrolyte secondary battery 100 is a hexahedral battery made up of an open box-shaped container body 110 having an opening 110 x and a plate-shaped lid 120, each made of aluminum. A container is provided as an exterior.

  The electrode body 111 has a configuration in which a positive electrode member and a negative electrode member, which are band-shaped electrode plates, are wound into a long cylindrical shape via a separator. In the wound state, the positive electrode member and the negative electrode member are arranged with their positions shifted in different directions at both ends of the winding shaft, and protrude from the separator with a predetermined width at both ends of the electrode body 111, respectively. Furthermore, the active material is not carried on the protruding portion of each electrode member, and the metal foil as the base material is exposed as a lead.

  The positive electrode side metal foil portion 111 a and the negative electrode side metal foil portion 111 a ′ that protrude from both ends of the electrode body 111 are electrically conductive metal plates, that is, a positive electrode side current collector 112 and a negative electrode side current collector 112. 'Is connected to each other.

  A through-hole 112 a is formed at one end of the current collector 112, and the other end is sandwiched by a metal-carrying plate 114 made of metal such as aluminum together with a wound positive electrode-side metal foil portion 111 a exposed on the side surface of the electrode body 111. Connected and fixed by ultrasonic welding. The current collector 112 'on the negative electrode side has the same configuration, but the metal material is copper or the like. Further, at both ends of the lid portion 120, through holes for guiding electrode terminals 130 described later to the inside of the storage container are opened. In the drawing, only the through hole 120a on the positive electrode side is shown.

  An insulating sealing material 113 having a through hole 113a between the lid portion 120 and the current collector 112 is insulated with a through hole 121b penetrating the cylindrical portion 121c in the vicinity of the end portion on the short side of the lid portion 120. The sealing material 121 is located, and the electrode terminal 130 is disposed so as to cover the main surface of the insulating sealing material 121.

  The electrode terminal 130 includes a planar electrode member 130a made of aluminum or aluminum alloy or other conductive metal, and a connecting member 130b protruding from the surface of the electrode member 130a. The connecting member 130b penetrates the current collector 112. When the tip is caulked while being passed through the hole 112a, the electrode terminal 130 and the current collector 112 are electrically connected, and the lid 120 and the electrode body 111 are mechanically coupled.

  Further, a through hole 122 is opened on the surface of the lid 120, and communicates with the internal space of the container body 110 whose opening 110 x is closed by laser welding by the lid 120 after the electrode body 111 is stored. . After the electrolyte is injected into the container body 110 through the through hole 122, a metal sealing plug 123 is fitted into the through hole 122, and the periphery of the sealing plug 123 is laser welded to the surface of the lid portion 120. Thus, the non-aqueous electrolyte secondary battery 100 is completed.

  Although omitted in FIG. 1, the current collectors 112, 112 ′ and the electrode body 111 are wrapped with an insulating film made of synthetic resin such as polyethylene and insulated from the container body 110. Is stored in the container body 110.

  Next, FIG. 2 is an essential part exploded view showing a schematic configuration of the electrode body 111 of the nonaqueous electrolyte secondary battery 100 according to the first embodiment.

  As shown in FIG. 2, the electrode body 111 is based on a sheet-like negative electrode member 20 laminated in order from the innermost periphery to the outer periphery, a porous film or a non-woven fabric that exhibits high discharge performance and electrolyte retention. Each member of the separator 21, the positive electrode member 22, and the separator 23 made of the same material as the separator 21 is wound, and the cross-sectional shape orthogonal to the winding axis is formed into a long cylindrical shape.

  The negative electrode member 20 is configured, for example, by supporting a negative electrode active material on the surface of a strip-shaped copper foil, and the positive electrode member 22 is configured, for example, by supporting a positive electrode active material on the surface of a strip-shaped aluminum foil. In the electrode body 111, coating portions 20a and 22a coated with an active material are formed on the negative electrode member 20 and the positive electrode member 22 up to one edge in the short direction of the belt, and the other edge is formed on the other edge. Uncoated portions 20b and 22b to which no active material is applied are respectively provided.

  In the figure, the boundaries between the coated portions 20a and 22a and the uncoated portions 20b and 22b are indicated by alternate long and short dash lines. The same applies to each drawing referred to in the following description. Further, in the drawing, for the sake of explanation, the tip of the negative electrode member 20 is shown in a state where it is separated from other members.

  The negative electrode member 20 and the positive electrode member 22 are shifted from each other in the direction of the end surface during winding, so that the uncoated portion 22b is formed on one end surface of the long cylindrical shape as the positive electrode side metal foil portion 111a in FIG. The uncoated portion 20b protrudes from the other end face as the negative electrode side metal foil portion 111a 'in FIG.

  Further, in the state where the positive electrode member 22 is located between the pair of separators 21 and 23, the separators 21 and 22 are bonded to each other at a joint portion 24 indicated by hatching in the drawing, and in the integrated state, the negative electrode member 20 is wound together.

  In the above configuration, the nonaqueous electrolyte secondary battery 1 corresponds to the electricity storage element of the present invention, the electrode body 111 corresponds to the electrode body of the present invention, the negative electrode member 20 corresponds to the negative electrode member of the present invention, and the positive electrode member 22 It corresponds to the positive electrode member of the present invention. The separators 21 and 23 correspond to a pair of separators of the present invention. Further, the joining portion 24 corresponds to a portion where the pair of separators of the present invention are joined and a joining location.

  Hereinafter, with reference to FIG. 3 and FIG. 4, the configuration of the electrode body 111 will be described in more detail, and an embodiment of the method for manufacturing a power storage device of the present invention will be described. However, FIG. 3A is a diagram schematically showing an apparatus for executing the manufacturing process of the electrode body 111, and FIG. 3B is a diagram showing a flowchart of the manufacturing process. FIG. 4 is a schematic plan view showing the laminated body 10 in which the electrode body 111 in a completed state is virtually developed to have a planar shape in order to explain the configuration of the electrode body 111.

  As shown in FIG. 3A, the separator 21 is wound around the bobbin 31, the positive electrode member 22 is wound around the bobbin 32, the separator 23 is wound around the bobbin 33, and the negative electrode member 20 is wound around the bobbin 34. The separator and the electrode member delivered from each bobbin are prepared in the electrode body 111 by being wound around an oval bobbin 35 having a cross-sectional shape that rotates in synchronization with each bobbin in the stacked state shown in FIG. Note that the rotation axis 35 a of the bobbin 35 coincides with the winding axis of the electrode body 111.

  In the present embodiment, in addition to the above basic steps, the bobbin is superposed on the negative electrode member 20 in a state where the separator 21, the positive electrode member 22 and the separator 23 drawn from each bobbin are superposed. Before being wound on 34, it is introduced into the crimping device 30.

  The pressure bonding device 30 includes one or a plurality of pressure rollers 30a composed of a pair of opposed heat rollers, and the pressure roller 30a is a separator while the introduced separators 21 and 23 sandwich the positive electrode member 22 therebetween. The specific portions 21 and 23 to be described later are heated and pressurized from both main surfaces. The joint portion 24 composed of the separator 21 and the separator 23 is formed by heat-sealing the specific portion with the pressure roller 30a, and the separator 21, the positive electrode member 22, and the separator 23 are sandwiched between the positive electrode member 22 and the separator 21 and 23. As a laminated body 40 that is maintained, it is wound around the bobbin 35 in a state of being overlaid on the negative electrode member 20.

  Here, with reference to FIG. 4, the joining part 24 formed by the crimping | compression-bonding apparatus 30 is demonstrated. In the laminated body 10 in which the electrode body 111 is developed, the positive electrode member 22 is overlaid on the lowermost layer, that is, the separator 23 disposed at the outermost periphery in the wound state, and the positive electrode member 22 is stacked on the positive electrode member 22. The separator 21 is overlaid, and the negative electrode member 20 is overlaid on the separator 21, that is, the uppermost layer and the innermost periphery in the wound state.

  The separators 21 and 23 have the same width in the lateral direction parallel to the winding axis, and the separator 23 has a longer configuration than the separator 21 in the longitudinal direction along the development direction. Further, the separator 21 and the separator 23 are arranged so that the winding start end portion Ea of the laminate 10 and the edge ends Ec and Ed of the separator in the short direction coincide with each other. It becomes the end Eb of the laminated body 10.

  Next, the positive electrode member 22 is formed in the longitudinal direction of the separators 21 and 23 so that a part of the uncoated part 22b that becomes the positive electrode side metal foil part 111a is exposed from the edge Ed of the separator in the completed electrode body 111. The center line is shifted in parallel to the center line. Thereby, the positive electrode member 22 is placed in a state in which the coating portion 22a is surrounded by the separators 21 and 23 in a plane.

  Further, the negative electrode member 20 includes the positive electrode member 22 and the positive electrode member 22 so that a part of the uncoated portion 20b that becomes the negative electrode side metal foil portion 111a ′ is exposed from the edge Ec of the separators 21 and 23 in the completed electrode body 111. Are arranged shifted in the opposite direction.

  The electrode body 111 according to the first embodiment is such that the periphery of the separators 21 and 23 sandwiching the positive electrode member 22 is heat-sealed at positions inside the edges Ea, Eb, and Ec in the laminated body 10. Thus, at least the coating part 22a of the positive electrode member 22 is sealed in a space formed by a pair of separators.

  That is, as shown in the schematic cross-sectional views taken along the line AA in FIG. 4 and FIG. 5A, both sides in the short direction of the positive electrode member 22 are separated from each other at the initial winding position of the laminate 10. 21 and 23 are sealed by the joint portion 24a, and the laminate 10 is sealed by the joint portion 24c of the separators 21 and 23 at the winding end position.

  Furthermore, as shown in the schematic cross-sectional view by the BB straight line of FIG. 4 and FIG.5 (b), the edge of the side included in the coating part 22a of the longitudinal direction of the positive electrode member 22 is as follows. It is sealed with a joint portion 24b of the separators 21 and 23 formed continuously with the joint portions 24a and 24c.

  Further, as shown in FIGS. 5A and 5B, the joint portions 24a to 24c and the edge edges Ea to Ed of the separators 21 and 23 are separated from each other, and these edge edges Ea to Ed and the joint portions 24a to 24a are separated. A separation portion 25 having a constant width in which the separators 21 and 23 are separated from each other is formed in a region between the separators 24c.

  In addition, in each figure of FIG. 5, although the junction parts 24a-24c were shown as having a thickness, this is exaggerated for description of the position, and is actually joined by thermal fusion. Therefore, the separators 21 and 23 are in close contact with the inclusions 24a to 24c without inclusions. Similarly, in FIG. 4, the bonding portion 24 a is shown as being seen through the negative electrode member 20 stacked on the separator 21 for the purpose of explaining the position. The same applies to each figure corresponding to FIG. 4 referred to in the following description.

  Next, the process of forming the joint portion 24 in the laminate 10 will be described with reference to FIG. First, in a state where the stacked separator 21, positive electrode member 22, and separator 23 are introduced from the edge Ea of the separator into the pressure bonding device 30, the bonding portion 24b shown as a region α in the drawing along the longitudinal direction by the pressure roller 30a. After joining a part of the predetermined length (step 101), the region β in the short direction near the edge Ea is joined to complete the joined portion 24a (step 102). The part of is sealed. The predetermined length of the region α is preferably the same as or shorter than that of the joint portion 24a.

  Next, the remaining region γ of the joint portion 24b is joined in synchronization with the winding of the bobbin 35 (step 103), and finally, heat fusion is performed in the short direction in the region δ before the edge Eb. The joining portion 24c is completed (step 104), and the laminate 25 is sent out from the crimping device 30.

  As described above, the electrode body 111 of the nonaqueous electrolyte secondary battery 100 of the first embodiment surrounds the separators 21 and 23 from both the longitudinal direction and the lateral direction of the coating portion 22a of the positive electrode member 22. In addition, the negative electrode member 20 is superposed on the negative electrode member 20 in a state where the negative electrode member 20 is joined thereto. Thereby, it becomes possible to obtain a highly accurate electrode body by suppressing the positional deviation between the electrode member and the separator during winding.

  Further, in the electrode body 111, by providing the separation portion 25 between the edge ends Ea to Ed of the separators 21 and 23 and the joint portions 24a to 24c, the following effects are obtained. That is, when the separators 21 and 23 are joined at the edges Ea to Ed, a deviation occurs between the introduction direction of the separators 21 and 23 and the direction of heat fusion by the pressure roller 30a in the pressure bonding device 30. There is a possibility that an imbalance occurs in the width of the joining portion 24, which causes separation of the separator, or causes wrinkles on the surface of the separator at the time of overlapping with the positive electrode member 22 or winding around the bobbin 35.

  On the other hand, in the present embodiment, the separators 25 are joined from the edges Ea to Ed via the separating portion 25, whereby the introduction direction of the separators 21 and 23 and the heat fusion by the pressure roller 30a are performed. Even when a deviation occurs between the directions, the separation portion 25 is used as a buffer for the deviation in a region for forming a bonding surface. Therefore, the width of the joining portion 24 is maintained in a predetermined constant state, and it is possible to reduce the risk of the separator peeling or turning.

  Furthermore, in the electrode body 111, the separators 21 and 23 provide the following effects by providing the joint portion 24 that surrounds the coating portion 20 a of the positive electrode member 22 from both the longitudinal direction and the lateral direction. . That is, the positive electrode member 22 and the negative electrode member 20 are bonded to each other at both ends of the separators 21 and 23 by the bonding portions 24a and 24c in the shape viewed from the longitudinal direction of the laminate 10 shown in FIG. Thus, in the short direction, the separators 21 are separated from each other without gaps.

  Further, in the shape viewed from the short side of the laminate 10 shown in FIG. 5 (b), one end of the separators 21 and 23 is joined by the joining portion 24b, so that the negative electrode member 20 is not seen in the longitudinal direction. The metal layer 20 y corresponding to the coating part 20 b and the boundary between the metal layer 20 y and the active material layer 20 x corresponding to the coating part 20 a and the positive electrode member 22 are separated from each other in a state of being blocked by the separator 21.

  In other words, the portion including the coating portion 20a of the positive electrode member 20 is laminated on the negative electrode member 20 in a state of being accommodated in the separators 21 and 23 that are formed into a bag shape by being joined by the joint portion 24. Thus, both the positive and negative electrode members are separated from each other via the separator 21 or 23 in the state of being wound as the electrode body 111. This prevents contamination that occurs when the metal layers 22y and 20y as the positive and negative electrode leads are ultrasonically welded to the current collectors 112 and 112 'from moving between the electrode members across the separator. it can.

  When contamination such as a metal piece or metal powder generated from one polarity electrode member reaches the other polarity electrode member, an electrochemical reaction occurs on the surface of the electrode member, and the separator is damaged, Causes a short circuit. By providing the configuration of the first embodiment, it is possible to obtain an electrode body in which the contamination generated from the positive and negative electrode members is prevented from reaching the electrode member of a different polarity and the risk of short circuit is reduced.

  Furthermore, in the electrode body 111, the separator 23 is longer than the separator 21 on the winding end side, so that the outermost surface in the wound state covers the other electrode member and the separator 21. It becomes a hidden state. Thereby, the long cylindrical external shape of the electrode body 111 can be maintained satisfactorily, and the risk of contact with the inside of the container main body 110 can be reduced. However, like the other edges of the separators, the separators 21 and 23 may have the same length, and the above-described effect of reducing displacement and sealing is not impaired. Even on the winding start side, the effect of the present invention is not impaired even if the separator 23 precedes the separator 21 for reasons such as facility design.

  As described above, the nonaqueous electrolyte secondary battery 100 according to the first embodiment includes the separators 21 and 23 and includes portions other than the portion corresponding to the positive electrode side metal foil portion 111a of the positive electrode member 22 including the coating portion 20a. By providing the electrode body 111 wound around in a sealed state, it is possible to prevent positional displacement between the separator and the electrode member, and to obtain a highly reliable electrode body configured with high accuracy. It becomes possible.

  In the above description, the joining portions 24a and 24b are both extended from the joining portion 24b and joined to the edge Ed of the separators 21 and 23, but do not reach the edge Ed and are stretched halfway. It is good also as what to do. In this case, it is preferable that the length is at least the same as that of the coating portion 22a because the effect of preventing the movement of contamination due to the coating portion 22a can be maintained.

  Furthermore, it is good also as what extends | stretches to the same length as the coating part 20a of the negative electrode member 20 on the separators 21 and 23. FIG. In this case, the effect which prevents the movement of the contamination resulting from the coating part 20a can be hold | maintained, and it is suitable.

(Embodiment 2)
FIG. 6 is a schematic plan view showing the configuration of the laminated body 11 in which the completed electrode body is virtually developed and planarized in the nonaqueous electrolyte secondary battery according to Embodiment 2 of the present invention. However, the same or corresponding components as those in FIG. 4 are denoted by the same reference numerals and detailed description thereof is omitted. The same applies to the following embodiments.

  The electrode body in the second embodiment is parallel to the joint 24b from the joint 24a reaching the edge Ed of the separators 21 and 23 in the configuration of the laminate 10 of the first embodiment, A joint 24d extended toward the edge Ea on the side is further provided.

  By setting it as the structure which joined the separators 21 and 23 further in the junction part 24d, the laminated body 11 will be in the state by which the junction part was provided in the both ends of the winding axis | shaft at the beginning of winding. Thereby, the cross-sectional shape around the winding axis can be adjusted to a shape approximated at both ends of the winding axis, and it becomes possible to obtain a highly accurate electrode body with reduced distortion.

  Further, in the laminate 11, both ends in the short direction of the separators 21 and 23 are fixed in order by the joint 24d and the joint 24b. Thus, in the winding direction, that is, in the direction from the crimping device 30 to the bobbin 35, only the vicinity of one edge Ec of the separators 21 and 23 is crimped in order to form the joint 24b. It is possible to suppress wrinkling and distortion.

  In the above description, the joint 24d extends from the joint 24a on the winding start side of the laminate 11 toward the edge Ea. However, the joint 24d extends from the joint 24c on the winding end side to the edge. You may provide so that it may extend | stretch toward Eb. In this case, it is possible to reduce the distortion of the surface shape of the electrode body in which the winding end portion, that is, the winding state is completed. Further, it may be provided on both sides of the start and end of winding.

(Embodiment 3)
FIG. 7 is a schematic plan view showing a configuration of a laminated body 12 in which a completed electrode body is virtually developed and planarized in the nonaqueous electrolyte secondary battery according to Embodiment 3 of the present invention.

  In the electrode body according to the third embodiment, the short-side joining portions 24a1 and 24c1 bent from the joining portion 24b formed along one longitudinal side of the separators 21 and 23 are acute angles with respect to the joining portion 24b, respectively. In this state, it is configured to extend toward the edge Ed on the short side.

  This produces the following effects. That is, when the vicinity of one edge Ec of the separators 21 and 23 is joined as the joining portion 24b, the separators 21 and 23 may contract or harden before and after joining depending on a specific joining method such as heat fusion. This may cause distortion along the winding direction between the edge Ec and the edge Ed. This distortion causes wrinkles on the separator surface and uneven adhesion with the positive electrode member 22 during lamination.

  Therefore, in the present third embodiment, by providing the short-side joint portions 24a1 and 24c1 bent from the joint portion 24b, the joint portion 24a1 at the edge Ed where the entire length S1 of the joint portion 24b before contraction is opposed. And 24c1 are set to be larger than the interval S2. Thereby, after the formation of the joining portion 24b, the total length S1 and the interval S2 are made uniform, and the generation of wrinkles on the separator surface and the occurrence of uneven adhesion with the positive electrode member 22 at the time of lamination are suppressed. A high electrode body can be obtained.

  In the above description, each of the joint portions 24a1 and 24c1 has an acute angle with respect to the joint portion 24b, but only one of them has an acute angle, and the other is the same as in the first embodiment. It may be orthogonal. In short, the angle formed by the joints 24a1 and 24c1 is arbitrary as long as the total length S1 of the joint 24b before contraction is larger than the distance S2 between the joints 24a1 and 24c1 at the opposite edge Ed. It's okay.

(Embodiment 4)
FIG. 8 is a schematic plan view showing a configuration of a laminated body 13 in which a completed electrode body is virtually developed and planarized in the nonaqueous electrolyte secondary battery according to Embodiment 4 of the present invention.

  The electrode body in the present fourth embodiment has a short-side joint 24a2 extending from the joint 24b formed along one long side of the separators 21 and 23 toward the edge Ed on the other long side. And 24c2 are each configured to be curved toward the center of the separator.

  In the first embodiment, when the short side edges Ea and Eb in the vicinity of the separators 21 and 23 are joined as linear joining portions 24a and 24c, depending on a specific joining method such as heat fusion, Before and after, the separators 21 and 23 contract in the short direction, and there is a risk of causing distortion along the direction of the winding axis in the vicinity of the edge Ea and the edge Eb. This distortion causes wrinkles on the separator surface and uneven contact with the positive electrode member 22 during lamination.

  Therefore, in the fourth embodiment, the joints 24a2 and 24c2 on the short side extending from the joint 24b are curved so that the shrinkage accompanying the formation of the joint is directly reflected on the edges Ea and Eb. To prevent you from doing. Thereby, after the formation of the joint portions 24a2 and 24c2, distortion in the vicinity of the edge Ea and the edge Eb is reduced, generation of wrinkles on the separator surface, and uneven adhesion between the positive electrode member 22 at the time of stacking. Generation | occurrence | production can be suppressed and it becomes possible to obtain a highly accurate electrode body.

  Furthermore, in the fourth embodiment, the position where the curvature of the joint portions 24a2 and 24c2 is the largest is determined closer to the edge Ed than the center line Lc of the stacked body 13. Thereby, the total length S1 of the joint part 24b before contraction is larger than the facing distance S3 of the joint parts 24a2 and 24c2 close to the edge Ed, and the longitudinal direction of the laminate 13 is the same as in the third embodiment. It is possible to reduce the distortion between the edge Ec and the edge Ed.

  In the above description, the joints 24a2 and 24c2 are curved so as to be symmetric with respect to the center of the separator. However, the degree of curvature may be different at each joint. Further, the joint portions 24a2 and 24c2 are all curved, but only a part thereof may be curved.

(Embodiment 5)
FIG. 9 is a schematic plan view showing a configuration of a laminated body 14 in which a completed electrode body is virtually developed into a planar shape in the nonaqueous electrolyte secondary battery according to Embodiment 5 of the present invention.

  The electrode body in the fifth embodiment includes a short-side joint portion 24a3 extending from a joint portion 24b formed along one long side of the separators 21 and 23 toward an edge Ed on the other long side, and 24c3 has a configuration in which the width is gradually narrowed from the joint 24b to the edge Ed. Specifically, the joints 24a3 and 24c3 have a width W1 larger than the joints 24a and 24c of the first embodiment at the boundary with the joint 24b, and are implemented at the edge Ed of the separators 21 and 23. The width W2 is smaller than the joint portions 24a and 24c of the first embodiment.

  By adopting such a configuration, it is possible to improve the adhesion at the corners on both sides of the positive electrode member 20 sandwiched between the separators 21 and 23, and to more effectively suppress the displacement during winding. . Further, since the surface areas of the joint portions 24a3 and 24c3 are suppressed to the same extent as the joint portions 24a and 24c of the first embodiment as a whole, the influence of strain due to shrinkage can also be suppressed.

(Embodiment 6)
FIG. 10 is a schematic plan view showing a configuration of a laminated body 15 in which a completed electrode body is virtually developed and planarized in the nonaqueous electrolyte secondary battery according to Embodiment 6 of the present invention.

  The electrode body in the sixth embodiment includes a short-side joint 24a4 extending from the joint 24b formed along one long side of the separators 21 and 23 toward the edge Ed on the other long side, and 24c4 is configured such that the width is gradually increased from the joint 24b to the edge Ed. Specifically, the joints 24a4 and 24c4 have a width W3 that is smaller than the joints 24a and 24c of the first embodiment at the boundary with the joint 24b, and are implemented at the edge Ed of the separators 21 and 23. The width W4 is larger than the joint portions 24a and 24c of the first embodiment.

  By adopting such a configuration, it is possible to increase the surface area of the joint portion on the edge Ed side, and based on the same action as in the third embodiment, the longitudinal direction of the laminate 13 caused by contraction at the time of crimping It is possible to reduce the distortion between the edge Ec and the edge Ed. Further, since the surface areas of the joint portions 24a4 and 24c4 are suppressed to the same extent as the joint portions 24a and 24c of the first embodiment as a whole, the influence of strain due to shrinkage can also be suppressed.

  As described above, according to the nonaqueous electrolyte secondary battery 100 of the embodiment of the present invention, in the electrode body 111, the periphery of the portion corresponding to the positive electrode side metal foil portion 111a of the positive electrode member 22 is sealed. With the configuration wound around, it is possible to prevent the positional deviation between the separator and the electrode member, and to obtain a highly reliable electrode body configured with high accuracy.

  However, the present invention is not limited to the above embodiments.

  In the above description, the periphery of the separators 21 and 23 sandwiching the positive electrode member 22 is heat-sealed at both the edge Ec perpendicular to the winding axis and the edge Ea and Eb parallel to the winding axis. Although at least the coating part 22a of the positive electrode member 22 is sealed in the space formed by the pair of separators by being surrounded by the joint part 24, the pair of separators 21 and 23 are parallel to the winding axis. A joining portion may be formed by either one of the edges Ea or Eb and the edge Ec.

  FIG. 11 shows the laminate 16 having joints 24a and 24b formed by heat-sealing the edge Ea side and the edge Ec side near the winding axis. Even in such a configuration, the electrode member can be sealed in the space formed by the orthogonal joining portion, and the displacement of the separator and the electrode member can be prevented.

  Further, in the above description, the joint portion 24 is formed so as to be located on the inner side from the edge ends Ea, Eb, and Ec of the separators 21 and 23 via the separation portion 25. 24 may be formed so that all or a part thereof coincides with the edges Ea, Eb, and Ec, that is, the edge of each separator is not provided through the separation portion 25.

  As an example, the laminated body 16 of FIG. 11 has a configuration in which the edge Ea near the winding axis and the joining portion 24a coincide. The one end 24b1 on the winding end side of the joining portion 24b is located on the inner side of the edge of the separator 21 via the separation portion 25, but may be made to coincide with the edge 21. In short, the effect of the present invention can be sufficiently obtained if the separating portion 25 is provided only in a portion where it is required to secure at least a sufficient width of the joint portion 24.

  Moreover, the structure which forms a junction part in any one side of the edge Ea or Eb parallel to a winding axis | shaft illustrated in FIG. 11, and the edge Ec side, and a part of junction 24 is a isolation | separation part. The configuration of joining up to the edge of each separator without using 25 may be implemented in any combination with the above-described second to sixth embodiments.

  In the above description, the bonding between the separators 21 and 23 using the pressure bonding apparatus 30 is performed by heat fusion, but the present invention is not limited to a specific method for bonding the separators. Therefore, joining by ultrasonic welding, joining by an adhesive or tape, mechanical caulking, or any other technical means may be used.

  In the above description, the electrode body of the present invention is a wound type. However, a plurality of laminates 10 to 16 corresponding to the laminate of the present invention are laminated and uncoated parts of the same polarity It may be realized as a laminated electrode body constituted by connecting.

  In the above description, the storage element of the present invention is a non-aqueous electrolyte secondary battery 100 typified by a lithium ion secondary battery. However, if the battery can be charged and discharged by an electrochemical reaction, Nickel metal hydride batteries and other various secondary batteries may be used. Moreover, a primary battery may be sufficient. Furthermore, it may be an element that directly stores electricity as electric charges, such as an electric double layer capacitor. In short, the power storage element of the present invention is not limited by its specific method as long as it can store electricity.

  Therefore, the electrode body 110 is a lithium ion secondary battery non-aqueous electrolyte secondary battery as an example, and as shown in each figure, the negative electrode member 20 is located inside the winding, and the positive electrode member 22 is located outside. The area of the portion 20a is made larger by the coating portion 22a, and the coating portion 20a is configured to face the entire surface of the coating portion 22a. However, depending on the type of the power generation element, the wound state or the stacked state In the electrode body, the arrangement of the positive electrode member and the negative electrode member and the correspondence between the coating portions of the electrodes may be interchanged.

  Although the container body 110 and the lid 120 are made of aluminum, there is no problem even if the exterior of the electricity storage device of the present invention is made of a member made of a material such as stainless steel, iron, or an aluminum laminate film. The materials of these members do not limit the effects of the present invention. Moreover, although the positive electrode member 22 and the negative electrode member 20 illustrated what applied the positive electrode active material to the aluminum foil, and the negative electrode active material to copper foil, respectively, the positive electrode member and negative electrode member of this invention are the polarity of an electrode body. It is specified, and is not limited by the type of foil for constituting each electrode. Therefore, the specific configuration of the electrode portion does not limit the effect of the present invention.

  Laser welding was used for joining the container body 110 and the lid 120, and joining the lid portion 120 and the sealing plug 123, but mechanical welding, electric welding such as TIG welding, and other technical joining methods are also possible. Good.

  In the above description, the single nonaqueous electrolyte secondary battery 100 is taken as an example. However, the present invention provides a power supply comprising a power storage element of the present invention in at least one power storage element among a plurality of power storage elements. It may be realized as a module.

  In short, the present invention may be implemented by adding various modifications to the above-described embodiment, including those described above, as long as they do not depart from the spirit of the present invention.

  The present invention as described above has an effect that it is possible to obtain an electrode body that is configured with high accuracy by preventing the displacement of separators and electrode members in a power storage element. Useful in devices.

DESCRIPTION OF SYMBOLS 10 Laminated body 20 Negative electrode member 20a, 22a Coating part 20b, 22b Uncoated part 21, 23 Separator 22 Positive electrode member 20x, 22x Active material layer 20y, 22y Metal layer 24, 24a, 24b, 24c Joining part 25 Separating part 30 Crimping device 100 Nonaqueous electrolyte secondary battery 111 Electrode body 111a Positive electrode side metal foil part 111a ′ Negative electrode side metal foil part

Claims (3)

A pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member, wherein the positive electrode member and the negative electrode member are interposed via one of the pair of separators, and the pair of separators are the positive electrode member And a storage element comprising an electrode body formed by winding or further stacking a stacked body that is stacked via any one of the negative electrode members,
At least a portion of the positive electrode member sandwiched between the pair of separators protrudes between the pair of separators;
At least a part of the periphery of the other part of the positive electrode member is sealed by joining the pair of separators at a position inside each edge of the pair of separators,
The joint portion formed by joining the pair of separators is disposed outside the portion where the negative electrode active material in the negative electrode member is coated,
Power storage element. A plurality of power storage elements, wherein at least one of the power storage elements is the power storage element according to claim 1 .
Power supply module. As a process of creating an electrode body,
A pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member, wherein the positive electrode member and the negative electrode member are interposed via one of the pair of separators, and the pair of separators are the positive electrode member And a step of superimposing via any one of the negative electrode members,
Bonding a part of any one of the pair of long sides adjacent to the pair of short sides of the pair of separators;
Bonding at least one side of the pair of short sides of the pair of separators;
Winding a pair of sheet-like separators, a sheet-like positive electrode member, and a sheet-like negative electrode member from the pair of short sides of the pair of separators,
Synchronizing with the winding step, and adjoining the one side of the pair of short sides of the pair of separators, joining the remaining part of any one of the pair of long sides,
The whole or a part of the joining location of the pair of separators in each step of the joining is determined at a position inside at least one of the edge of each of the one of the pair of short sides and the pair of long sides. Yes,
A method for manufacturing a storage element.

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