JP6476746B2 - STORAGE DEVICE, POWER SUPPLY MODULE, AND METHOD FOR MANUFACTURING STORAGE DEVICE - Google Patents

Description

  The present invention relates to, for example, a storage element such as a battery or a capacitor, a method of manufacturing the same, and a power supply module.

  Batteries are widely used as power sources of electronic devices such as mobile phones and IT devices. Furthermore, in recent years, non-aqueous electrolyte secondary batteries represented by lithium ion secondary batteries have high energy density, and their application to industrial large-sized electric devices such as electric vehicles is also promoted.

  A non-aqueous electrolyte secondary battery generally comprises an electrode body formed by superposing positive and negative electrode plates separated by a microporous membrane separator inside a metal storage container, and an electrode terminal provided outside the storage container. And a current collector electrically connecting the electrode body to the electrode body, and a non-aqueous electrolyte solution.

  In such non-aqueous electrolyte secondary batteries, ultrasonic welding is widely used as a technique for joining the electrode body and the current collector, and in order to cope with the increase in output of the battery, the improvement of productivity, etc. Conventionally, bonding by resistance welding, which is widely used, has been proposed (see, for example, Patent Document 1, (0005) to (0010), etc.).

Patent No. 5100281

  However, using resistance welding for joining the current collector and the electrode assembly has the following problems. That is, in order to firmly bond the current collector and the electrode body, it is necessary to increase the area (cross-sectional area at the bonding surface) of the bonding portion (hereinafter referred to as nugget). Along with the spattering (hereinafter referred to as "sputtering"), the expansion of the area of the nugget increases the amount of spattering, which affects the quality of the electrode body.

  The present invention has been made in view of the above problems, and provides a storage element capable of achieving good bonding between an electrode body and a current collector by reducing the influence of sputtering, and a power supply module using the same. And it aims at providing the manufacturing method of an electrical storage element.

In order to achieve the above object, the first aspect of the present invention is
Electrode body,
And a current collector joined to the electrode body by welding.
The position of the bonding portion between the current collector and the electrode body is eccentric to the end face of the electrode body from the central axis of the current collector on the surface of the current collector facing the electrode body. It is a storage element.

The second aspect of the present invention is
The bonding portion has a shape extending in a direction along a long side of the facing surface of the current collector to the electrode body.
It is an electrical storage element of the 1st side of this invention.

The third aspect of the present invention is
The plurality of junctions are arranged along the opposing surface to the electrode body.
It is a storage element of the 1st or 2nd side of the present invention.

The fourth aspect of the present invention is
The plurality of arranged junctions are eccentrically disposed near the end of the electrode body from the center to both ends,
It is a storage element of the 3rd side of the present invention.

The fifth aspect of the present invention is
Electrode body,
And a current collector joined to the electrode body by welding.
A protrusion is formed at a junction of the current collector with the electrode body,
The tip of the protrusion is an electric storage element which is eccentric from the central axis of the surface of the current collector facing the electrode body to the end of the electrode body.

The sixth aspect of the present invention is
The center of the bottom surface of the protrusion is located on the central axis of the surface of the current collector facing the electrode body.
It is a storage element of the 5th side of the present invention.

The seventh aspect of the present invention is
The protrusion forms a ridge along the opposing surface of the current collector with the electrode body.
It is an electrical storage element of the 5th or 6th side of this invention.

The eighth aspect of the present invention is
And a protective member joined to the electrode body on the side opposite to the current collector of the electrode body.
It is a storage element according to any one of the first to seventh aspects of the present invention.

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

The tenth aspect of the present invention is
A method of manufacturing a storage element, comprising the step of joining a current collector to an electrode body by welding.
In the bonding step, the position of the bonding surface of the current collector and the electrode assembly is the end surface of the electrode assembly from the central axis of the current collector on the surface of the current collector facing the electrode assembly. By making it eccentric to
It is a manufacturing method of an electrical storage element.

  The present invention as described above has an effect that it becomes possible to reduce the influence of sputtering and to achieve good bonding of the electrode body and the current collector.

An exploded perspective view showing a configuration of a secondary battery according to Embodiment 1 of the present invention A side view showing a configuration of a secondary battery according to Embodiment 1 of the present invention Front view showing the main parts of the secondary battery according to Embodiment 1 of the present invention The figure for demonstrating the joining method of the electrode body and collector in the secondary battery which concerns on Embodiment 1 of this invention. Sectional view for illustrating a bonding state of an electrode body and a current collector in a secondary battery according to Embodiment 1 of the present invention A plan view for explaining a bonding state of an electrode body and a current collector in a secondary battery according to Embodiment 1 of the present invention The figure for demonstrating the other structural example of the secondary battery which concerns on Embodiment 1 of this invention. The figure for demonstrating the other structural example of the secondary battery which concerns on Embodiment 1 of this invention. The figure for demonstrating the joining of the electrode body and collector in the secondary battery concerning Embodiment 2 of this invention. A diagram for describing a configuration example of a secondary battery according to a second embodiment of the present invention The figure for demonstrating the other structural example of the secondary battery which concerns on Embodiment 2 of this invention. The figure which shows the other structural example of the secondary battery which concerns on embodiment of this invention.

  Hereinafter, the present invention will be described by taking a non-aqueous electrolyte secondary battery as an example. First, Embodiment 1 will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a perspective view schematically showing the configuration of the non-aqueous electrolyte secondary battery 1 according to Embodiment 1 of the present invention in a partially disassembled state, and FIG. 2 is a non-aqueous electrolyte secondary battery 1 It is a side view showing the inside of.

  As shown in FIGS. 1 and 2, the non-aqueous electrolyte secondary battery 1 is a plate made of the same material as the container body, which seals the opening box-shaped container body 10 made of aluminum and the opening 10x of the container body 10. A storage container having a hexahedral outer shape configured by the lid portion 20 of the present invention is provided as an outer package.

  Each side of the storage container is positioned parallel to the X axis, the Y axis, and the Z axis which make orthogonal coordinates shown in FIG. Next, in order to explain the internal configuration of the non-aqueous electrolyte secondary battery 1, the container main body 10 is shown only by a broken line in FIG. For the same reason, the container main body 10 and the lid portion 20 are shown in FIG. 2 as principal part sectional views cut in a plane parallel to the Z-X plane in the drawing.

  An electrode body 11 is disposed in the internal space 10z of the container body 10. The electrode body 11 has a configuration in which a positive electrode plate and a negative electrode plate, which are strip-like electrode plates, are wound in an elongated cylindrical shape with an axis parallel to the Y axis in the figure as a winding axis via a separator. The outermost periphery is covered with the separator by winding only the separator even after the positive and negative electrode plates have been wound. Each positive and negative electrode plate uses a metal foil as a base material, and on the surface thereof, a mixture layer containing an active material is formed.

  The negative electrode plate is formed, for example, by forming a mixture layer containing a negative electrode active material on the surface of a strip-shaped copper foil. The positive electrode plate is configured, for example, by forming a mixture layer containing a positive electrode active material on the surface of a strip-like aluminum foil. The positive electrode plate and the negative electrode plate are arranged in the winding axial direction at different positions in different directions in the winding axis direction, and protrude from the separator 112 c with a predetermined width at each end of the electrode body 11. ing. Furthermore, the mixture layer is not formed in the protruding portion of each electrode, and the metal foil as the substrate is exposed.

  In other words, the electrode body 11 was exposed in a state in which the metal foils of the positive electrode plate were overlapped alone at one end in the winding axis direction, and the metal foils of the negative electrode were overlapped alone at the other end It is exposed in the state, and is located at both ends as the electrode plate lamination part 111 respectively. Hereinafter, a portion of the electrode plate lamination portion 111 as viewed in the Y-axis direction in the drawing is defined as the end surface 11 c of the electrode body 11.

  In addition, in FIG. 1, although only the structure which attached | subjected the metal foil of the negative electrode side exposed as the electrode plate laminated part 111 is attached and demonstrated a code | symbol, the electrode plate laminated part 111 at the positive electrode side is also the same except metal material. The structure of Further, for the purpose of explanation, the electrode body 11 is shown as being separated from the lid portion 20 and partially extracted from the container main body 10.

  The electrode plate laminate portion 111 is connected to the current collector 12. The current collector 12 is made of the same metal material as the base metal of the positive electrode plate and the negative electrode plate, and is fixed to the back surface 20y of the lid 20. The flat rectangular base portion 12a having a rectangular shape and the base portion 12a And a pair of flat plate-like legs 12b extending toward the inner bottom 10y of the container main body 10 along the Z-axis direction. . A through hole 12a1 into which a connection rod 22b of an outer packing 21a and an electrode terminal 22 described later is inserted is opened in the base portion 12a. The connecting rod 22b is shown in FIG. The pair of leg portions 12 b is disposed so as to sandwich the electrode plate laminated portion 111 of the electrode body 11, and is joined to the electrode body 11 by resistance welding described later.

  More specifically, the electrode plate laminate portion 111, which is a portion where metal foils overlap, is divided in half in the thickness direction (X direction) of the electrode body 11 from the winding center of the electrode body 11, and one of the divided ones is a pair The other divided part is joined to the other of the pair of legs 12b.

  A cover 13 which is a metallic plate-like component of the same type as the current collector 12 is disposed at a position facing the leg portion 12b with the electrode plate laminated portion 111 divided in the thickness direction of the electrode body 11 interposed therebetween. It is joined to the electrode body 11 by resistance welding. The metal foil constituting the electrode plate laminated portion 111 is easily damaged because the thickness is extremely thin, and the cover 13 has a function of protecting the surface of the electrode plate laminated portion 111.

  On the other hand, as shown in FIG. 3, an electrode terminal 22 for external connection is provided on the surface 20 x side of the lid 20. The electrode terminal 22 has a rectangular relay plate 22a whose surface is exposed, and a cylindrical connecting rod 22b extending from the back surface of the relay plate 22a toward the inner bottom 10y of the container body 10 along the Z-axis direction in the drawing. And a metal member having

  The connection rod 22b of the electrode terminal 22 is electrically and mechanically connected to the current collector 12 by being joined to the base 12a of the current collector 12 by known technical means such as caulking or pressure bonding. . In the first embodiment, the connection rod 22b is fixed by caulking as an example, and the tip end of the connecting rod 22b forms a caulking end 22x and is in pressure contact with the base portion 12a. Thus, electricity is extracted from the electrode body 11 to the outside of the storage container.

  Although the relay plate 22a and the connecting rod 22b in the electrode terminal 22 are shown as being integrated in the figure, they are formed as an integrally molded component on the positive electrode side and each is independent on the negative electrode side. The relay plate 22a and the connecting rod 22b as the members may be formed as a combined component by means such as press fitting.

  The electrode terminal 22 and the base portion 12a of the current collector 12 are insulated from the storage container by an outer packing 21a and an inner packing 21b made of synthetic resin material which is an insulator. The outer packing 21 a is disposed on the surface 20 x of the lid 20 and insulates the lid 20 from the electrode terminal 22. The inner packing 21 b is disposed on the back surface 20 y of the lid 20 and insulates the lid 20 from the base 12 a of the current collector 12.

  The lid portion 20 is provided with an injection port for injecting an electrolytic solution after being sealed with the container body 10 by laser welding or the like, and sealed by a sealing plug 23 after the electrolytic solution is injected.

  Next, the configuration of the current collector 12, the outer packing 21a and the inner packing 21b, and the vicinity of the electrode terminal 22 in the non-aqueous electrolyte secondary battery 1 will be described with further reference to the enlarged view of the main part in FIG.

  The outer packing 21a is sandwiched between the lid portion 20 and the relay plate 22a of the electrode terminal 22, and has a cylindrical shape partially surrounding the connection rod 22b of the electrode terminal 22 corresponding to the outer shape of the electrode terminal 22. . The inner packing 21b is coaxial with the through hole 12a1 of the base portion 12a, and is sandwiched between the lid portion 20 and the base portion 12a of the current collector 12, and the cylindrical portion of the outer packing 21a It has a through hole through which the connecting rod 22b passes.

  As a result, the outer packing 21a and the inner packing 21b are fastened together by the current collector 12 and the electrode terminal 22 in an integrally combined state to insulate the conductive path from the storage container, and the conductive path and the storage container The space between them and the gap are closed to prevent leakage of the electrolyte from inside the storage container. In addition, in FIG. 3, the cover part 20, the outer packing 21a, and the inner packing 21b were shown as sectional drawing, and the electrode terminal 22 was shown as what was seen through.

  Next, as shown in FIG. 1, the pair of leg portions 12 b of the current collector 12 is disposed so as to sandwich both side surfaces of the electrode plate laminated portion 111 of the electrode body 11 having an outer shape elongated cylindrical shape. In the electrode plate laminate portion 111, the surfaces sandwiched between and in contact with the legs 12b are formed as a pair of flat surfaces parallel to the pair of legs 12b.

  Furthermore, as shown in FIG. 3, the pair of leg portions 12b is joined to the electrode body 11 by welding so as to form a nugget N1 by resistance welding on the surface F facing the electrode plate laminated portion 111. . Joining of the cover 13 and the electrode plate laminated portion 111 is also performed in the same manner as in the case of the leg portion 12b, and the cover 13 is disposed along the flat surface inside the electrode plate laminated portion 111 which becomes the dead angle in the figure. The electrode plate laminated portion 111 is resistance-welded on the opposing surface corresponding to the opposing surface F of FIG.

  At this time, as an actual operation, joining of the leg portion 12b, the electrode plate laminated portion 111 and the cover 13 is performed simultaneously. In addition, since the opposing surface F and the nugget N1 become a dead angle in FIG. 3, the outline was schematically shown by a dotted line. The same applies to the following description.

  In the above configuration, the non-aqueous electrolyte secondary battery 1 corresponds to the storage element of the present invention, and the electrode assembly 11 corresponds to the electrode assembly of the present invention. The current collector 12 corresponds to the current collector of the present invention. The cover 13 corresponds to the protection member of the present invention. The nugget N1 corresponds to the joint of the present invention. The facing surface F corresponds to the facing surface of the present invention.

  In the non-aqueous electrolyte secondary battery 1 according to Embodiment 1 having such a configuration, the nugget N1 includes the leg 12b in the joint by resistance welding between the current collector 12 and the electrode plate laminated portion 111 of the electrode body 11. It is characterized in that it is formed at a position eccentric to the end face 11c side of the electrode body 11 from the center in the width direction of the facing face F.

  FIG. 4 is a schematic cross-sectional view of the region R of FIG. 2 taken along the line A-A, and shows the electrode plate laminate portion 111 of the current collector 12 and the electrode body 11 in the non-aqueous electrolyte secondary battery 1 of the first embodiment. It is a figure explaining the joining process with. Hereinafter, while demonstrating with reference to FIG. 4, while demonstrating one Embodiment of the manufacturing method of the electrical storage element of this invention by this, it demonstrates.

  As shown in FIG. 4, the long cylindrical electrode body 11 does not have a mixture layer of positive and negative electrodes and is formed with an electrode plate laminated portion 111 formed by laminating metal foils as a base material of a positive electrode plate or a negative electrode plate. , And an electrode body main part 112 which causes a battery reaction. The electrode body main portion 112 has a positive electrode main body portion 112a in which the positive electrode mixture layer 112a1 is formed on the positive electrode side base material, and a negative electrode main body portion 112b in which the negative electrode mixture layer 112b1 is formed on the negative electrode side base material. It laminates in the state which intervened separator 112c.

  In addition, although the electrode plate lamination | stacking part 111 was shown as what has a clearance gap between each electrode plate in the figure, this is a schematic display for the facilities of description, and in what reflects an actual condition correctly Absent.

  The leg portion 12 b of the current collector 12 is disposed on the outermost circumferential surface of the electrode plate lamination portion 111, and the cover 13 is disposed on the innermost circumferential surface of the electrode plate lamination portion 111. The dimension of the cover 13 in the Y-axis direction in the drawing is the same as that of the leg 12b, and the electrode plate laminated portion 111 is held between the cover 13 and the leg 12b. The arrangement position of the cover 13 in the winding axial direction (Y direction) is the same as that of the leg 12 b.

  Next, welding electrode 100a is abutted against leg 12b along the direction of the arrow in the figure, and welding electrode 100b is abutted against cover 13 along the direction of the arrow in the figure, and leg 12b and Resistance welding is performed by passing an electric current between the welding electrodes in a state where the cover 13 presses the electrode plate laminated portion 111.

  In the first embodiment, as shown in FIG. 4, welding electrodes 100a and 100b are shifted from the center in the width direction (Y direction) of leg 12b and cover 13 toward end face 11c of electrode body 11. By abutting along the position Cn, at the position Cn, the leg portion 12b is offset closer to the end face 11c of the electrode body 11 than the center line C in the width direction of the facing surface F with the electrode plate laminated portion 111. It is made to be resistance welded. Similarly, the cover 13 is resistance-welded at a position Cn eccentric to the end face 11 c of the electrode body 11 with respect to the center line C of the surface facing the electrode plate laminated portion 111.

  Thereby, as shown in FIG. 5, the nugget N1 formed after resistance welding is formed on the position Cn near the end face 11c from the center line C on the facing face F, that is, near the end face 11c of the electrode body 11. It becomes. In the above description, the central line C corresponds to the central axis of the present invention.

  This produces the following effects. That is, as shown in FIG. 6, conventionally, bonding of the electrode body 11 and the leg portion 12b of the current collector 12 is performed on the center line C of the facing surface F, as in the nugget N0 in FIG. The welding is performed to form a substantially circular nugget that isotropically spreads from the origin O on the facing surface F.

  However, in order to improve the bonding strength between the electrode body 11 and the current collector 12, it is necessary to enlarge the area of the nugget on the facing surface F, while spattering occurs at the time of welding like resistance welding. In welding, the width of the nugget on the side of the electrode body 11, that is, the enlargement of the dimension in the Y-axis direction in the drawing leads to an increase in the amount of spatter scattering, which may deteriorate the quality of the electrode body 11 such as internal short circuit.

  In the first embodiment, welding is performed near the end face 11c from the center line C of the facing surface F so as to form the nugget N1 shown in FIG. The influence on the electrode body 11 is reduced.

  That is, although sputtering occurs isotropically from the peripheral edge of the nugget according to the formation of the nugget, among these, the electrode body main part 112 side which is the central part of the electrode body 11 shown by the white arrow d1 in FIG. In the case of splashing, the distance from the position of the nugget, which is the path to the electrode body portion 112, to the edge of the facing surface F is enlarged relative to the spattering distance. Furthermore, since the spatter scattering path is included in the facing surface F, a part of the spatter is collected in the space in the facing surface F, so the ratio of those reaching the electrode body portion 112 is reduced. .

  The end portion of the electrode body portion 112 communicates with the layer of the electrode plate laminated portion 111 as shown in FIGS. 4 and 5, so that sputtering is likely to intrude between the layers of the electrode body portion 112. . Therefore, it is possible to effectively prevent the quality deterioration of the electrode body 11 by suppressing the scattering to the electrode body main part 112, in particular, for the spatter scattering in each direction as described above.

  On the other hand, with regard to the spatter scattering toward the end face 11c opposite to the electrode body main part 112, as indicated by the white arrow d2 in the figure, there are many falling off from the electrode body 11, which substantially affects the manufacture of the battery. I will not give. Furthermore, as for the spatters scattered in the vertical direction orthogonal to the facing surface F, that is, along the white arrows d3 and d4 along the Z-axis direction in the figure, both in the facing surface F, in the electrode plate lamination portion 111 The effect on the electrode body portion 112 is minor.

  As a result, resistance welding can be performed while reducing the influence of spattering on the electrode body 11 due to the expansion of the area of the nugget N1, and good joining of the electrode body 11 and the leg portion 12b of the current collector 12 is possible. Become.

  In the above description, the bonding of the leg portion 12b of the current collector and the electrode body 11 was mainly described, but also in the bonding of the cover 13 and the electrode plate laminated portion 111, the position of the nugget on the opposing surface The resistance welding direction of the spatter is controlled by resistance-welding so that Ec is eccentric from the central axis. Therefore, the influence of the spatter on the electrode body portion 112 due to the expansion of the nugget is reduced, and good bonding between the electrode body 11 and the cover 13 is possible.

  Furthermore, the first embodiment is characterized in that the nugget N1 has a substantially oval shape along the external surface of the facing surface F and along the Z-axis direction in the drawing. This makes it possible to enlarge the area of the nugget while suppressing the scattering of the spatter to the electrode body portion 112 side, and further firm bonding of the electrode body 11 and the leg portion 12b of the current collector 12 becomes possible. .

  In the above description, the planar shape of the nugget N1, that is, the outer shape on the facing surface F is a substantially oval shape along the outer shape of the facing surface F, but the flat shape along the extending direction of the facing surface F If the shape is the same, the same effect can be obtained. Therefore, the planar shape of the nugget N1 may be rectangular or the like, and if the facing surface F is rectangular, it is desirable that the nugget N1 extend in the direction along the long side. In this case, the planar shape of the nugget N1 can be adjusted by a method such as scanning the welding electrode continuously or changing the planar shape of the welding electrode.

  Furthermore, as shown in FIG. 7, it may be configured to have an arc-like planar shape like nugget N2. In this case, the nugget N2 has a flat shape along the extending direction of the facing surface F (the Z-axis direction in the figure), and both ends are curved toward the end face 11c. In the figure, it has a spread in the Y-axis direction), and the distance from the nugget N2 to the electrode body portion 112 with respect to the spattering distance is further enlarged.

  As a result, it is possible to further improve the strength of the bonding portion between the electrode body 11 and the current collector 12 and to suppress the spattering of the electrode body portion 112 more efficiently.

  Furthermore, although the plane shape of the nugget N2 is shown as arc shape, ie, a curved aspect in FIG. 7, it may be a curved aspect such as a V shape. In short, the same effect as described above can be obtained as long as the shape is such that it is deformed closer to the end face 11c of the electrode body 11 as it moves away from the center of the nugget in the extension direction (Z axis direction) in the leg portion 12b.

  In the above description, the nugget N1 has a substantially oval planar shape along the outer shape of the facing surface F. However, the nugget N1 may have a circular planar shape like the conventional nugget N0. In this case, it is more preferable to arrange a plurality of nuggets along the extension direction of the facing surface F, whereby the total area of the nuggets can be increased as in the nugget N1, and the electrode body 11 and the current collector are collected. A more rigid connection of the legs 12b of the body 12 is possible.

  Furthermore, as shown in FIG. 8, when resistance welding is performed such that a plurality of nuggets N3a to N3g arranged along the extension direction of the opposing surface F are formed, the nugget N3a located at the center of the array is the most opposite For each set of nuggets N3b and N3c, nuggets N3d and N3e, and nuggets N3f and N3g adjacent to the centerline C of the plane F and continuing from the center to both ends of the array, the distance from the centerline C is gradually increased It may be arranged eccentrically near the end face 11c.

  In this case, the plurality of nuggets N3a to N3g are arranged in a square shape as a whole, and the total area of the nuggets is increased to provide the same effect as the nugget N2 of FIG. Furthermore, joining can be performed by a process of welding simpler than in the case of nugget N2, and hence it becomes possible to produce a battery at low cost.

  The configurations shown in FIGS. 7 and 8 have been described taking the leg portion 12b of the current collector 12 as an example, but the cover 13 side is also the same.

Second Embodiment
The non-aqueous electrolyte secondary battery according to the second embodiment of the present invention has the same configuration as that of the first embodiment except for the current collector 12. Therefore, the description will be appropriately referred to with reference to FIGS. 1 and 2 and the same or corresponding components will be denoted by the same reference symbols and detailed description thereof will be omitted.

  FIG. 9 is a view for explaining a bonding process of the current collector 12 and the electrode plate laminated portion 111 of the electrode body 11 in the non-aqueous electrolyte secondary battery 1 of the second embodiment. As shown in FIG. 9, in the leg portion 12b of the current collector 12 joined to the electrode plate laminated portion 111 of the long cylindrical electrode body 11 corresponding to the region R in FIG. 12b1 is formed, and similarly, a protrusion 13a is formed on the surface of the cover 13.

  The protrusions 12b1 and 13a are portions where current concentrates in resistance welding, and are strong even when the electrical resistance of each part of the current collector 12, the cover 13 and the electrode plate laminated portion 111 is low or when the thermal conductivity is high. Bonding can be realized.

  In the second embodiment, the center of the bottom of the protrusion 12b1 is made to coincide with the center line C in the width direction of the surface F of the electrode body 11 facing the electrode plate laminated portion 111, while the tip 12s is It is provided on a position Cs eccentrically located near the end face 11c, and is eccentric from the center of the bottom surface. Thereby, the shape of the projection 12b1 forms a curved surface in which the right side in the drawing is deformed more sharply than the left side with the line indicated by the position Cs interposed therebetween.

  The arrangement of the projections 13a of the cover 13 coincides with the center line C, similarly to the arrangement of the projections 12b1, and the tip 13s of the projection 13a is on the position Cs passing the projection 12b1 so as to face the tip 12s of the projection 12b1. Provided.

  When resistance welding is performed by the leg portion 12b and the cover 13, the nugget N4 formed thereby is formed around the tip 12s. As a result, the nugget N4 is formed eccentrically closer to the end face 11c than the center line C of the facing face F. Resistance welding between the cover 13 and the back surface 11 b 2 of the electrode plate laminated portion 111 is also performed at the same position. In FIG. 9, the nugget N4 is schematically shown in a state where it is not virtually joined to the leg portion 12b and the cover 13 for the convenience of description.

  According to the second embodiment, as in the first embodiment, the resistance welding is performed such that the nugget N4 is formed at a position eccentric to the end face 11c of the electrode body 11. Therefore, the scattering direction of the spatter generated at the time of welding is controlled to suppress the scattering of the spatter to the electrode body portion 112 side, and the influence of the spatter is reduced, and the electrode body 11 and the leg portion 12b of the current collector 12 Good bonding is possible.

  Furthermore, in the present embodiment, the positions of the centers of the bottom surfaces of the protrusions 12b1 and 13a are set on the center line C of the facing surface F, so that the welding electrodes 100a and 100b are opposed as in the conventional resistance welding. The welding can be performed by positioning so as to coincide with the center line C of the face F. Thereby, the positioning of the welding electrode is facilitated, and the present invention can be implemented without complicating the manufacturing process.

  In addition, about the planar shape on the opposing surface F of protrusion 12b1, arbitrary shapes and number can be taken. As an example, what is shown in FIG. 10 is an example which provided several protrusion 12b1 arranged along the extending | stretching direction of the opposing surface F on the leg part 12b. On the facing surface F, the protrusion 12b1 has a circular bottom, the center 12o of the bottom is located on the center line C of the facing surface F, and the tip 12s of the protrusion 12b1 is on the facing surface F of the electrode body 11 It is provided on a position Cs eccentric to the end face 11c. The projections 13a provided on the cover 13 which is a blind spot in the drawing have the same configuration.

  In this configuration, the arrangement of the nuggets formed by the projections 12b1 is closer to the end face 11c on the facing surface F, and the total area of the nuggets is increased, thereby suppressing the spatter from scattering to the electrode body portion 112. At the same time, it is possible to increase the bonding strength of the electrode body 11 and the current collector 12. In FIG. 10, the shape of the bottom of the protrusion 12b1 is shown, and the illustration of the nugget is omitted.

  Furthermore, the configuration example shown in FIG. 11 is an example in which a protrusion 12b1 extending along the extension direction of the facing surface F is provided on the leg 12b. The bottom shape of the protrusion 12b1 on the facing surface F is an oval shape, and the longitudinal center line is located on the center line C of the facing surface F, while the ridge 12t shown as a protrusion in FIG. It is formed extending in parallel to C, and is provided on a position Cs eccentric to the end face 11 c of the electrode body 11. The projections 13a provided on the cover 13 which is a blind spot in the drawing have the same configuration.

  Also in this configuration, while the nugget formed by the protrusion 12b 1 expands the area, the arrangement becomes closer to the end face 11c on the opposing surface F, thereby suppressing the scattering of the sputter to the electrode body main part 112 side. It is possible to increase the strength of bonding between the current collector 11 and the current collector 12. Furthermore, by forming the nugget alone without gaps, the bonding strength can be further enhanced than the configuration shown in FIG. FIG. 11 shows the shape of the bottom of the protrusion 12b1, and the nugget is not shown.

  In the above description, the shape of the protrusion 12b1 is a cross-sectional shape having a vertex, but as shown in FIG. 12 (a), the tip 12s is formed as a flat surface, and the electrode plate laminated portion It may be configured to be in surface contact with 111. If the shape of the protrusion 12b1 is deformed so as to decrease from the bottom to the tip 12s, the effect of current concentration in resistance welding can be maintained, and the tip is closer to the electrode assembly 11 than the center line C of the facing surface F. If it is located near the end face 11c of the present invention, the effect of the present invention is exhibited. Furthermore, when the tip 12s is in surface contact, it is possible to suppress the positional deviation between the electrode plate laminated portion 111 and the leg 12b when the welding electrode 100a abuts.

  Furthermore, in the above description, the shape of the protrusion 12b1 is a curved surface whose surface is curved in a convex shape, but as shown in FIG. 12B, the surface may be a curved surface having a concave surface. Thereby, during welding, the increase of the cross-sectional area especially in the vicinity of the tip 12s is suppressed, and concentration of the current in the vicinity of the tip 12s is maintained, and the nugget can be accurately positioned and welding can be performed efficiently. .

  In the above description, the protrusion 12b1 on the leg 12b side of the current collector 12 and the protrusion 13a of the cover 13 have the same bottom shape and the same height (the dimension in the X-axis direction in the figure) of the tip 12s or 13s. However, the shape and size of the protrusion may be different between the leg 12 b and the cover 13.

  As explained above, according to the non-aqueous electrolyte secondary battery of each embodiment of the present invention, the influence of sputtering is reduced, the area of the nugget is enlarged, and good bonding between the electrode body and the current collector is achieved. It becomes possible.

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

  In the second embodiment, the projections 12b1 and 13a are formed on both the cover 13 and the leg 12b, but the projections may be formed on only one of the leg 12b or the cover 13.

  Furthermore, in bonding the electrode body 11 and the current collector 12, the cover 13 may be omitted to practice the present invention. The cover 13 can be omitted if problems such as damage do not occur in the electrode plate lamination portion 111.

  Furthermore, the present invention may be realized as a combination of the above-described embodiments. Specifically, as shown in FIG. 12C, the center of the bottom surface of the protrusion 12b1 is eccentric to a position Cp closer to the end surface 11c of the electrode body 11 than the center line C of the opposing surface F, and the tip 12s of the protrusion 12b1 Is further brought closer to the end face 11c side. As a result, the scattering of the sputter to the electrode body portion 112 can be further efficiently suppressed, and a good bonding between the electrode body 11 and the current collector 12 can be achieved. 12 (a)-12 (c), the internal structure of the electrode body main part 112 was abbreviate | omitted and shown.

  Furthermore, in the above description, the electrode body 11 has an elongated cylindrical outer shape formed as a tubular electrode plate laminated portion 111 at both ends, and the current collector 12 has an electrode whose leg 12 b is a cylindrical surface. Although the electrode assembly 11 is to be joined to the electrode assembly 11 from the side of the plate laminate portion 111, the electrode assembly and the current collector of the present invention, and their junctions are not limited by the specific configuration. Therefore, the electrode body may have a laminated structure in which a plurality of positive electrode plates and negative electrode plates are stacked with a separator interposed therebetween, and the current collector holds the electrode plate laminated portion of the electrode body from the front and the back. Etc. may be joined in any manner. Furthermore, although the opposing surface of the leg portion 12b on which the nugget as the bonding portion between the electrode body 11 and the current collector 12 is formed is the surface facing the flat surface of the electrode body 11, the electrode body 11 It may be a surface opposite to the curved portion in the long cylindrical shape.

  Furthermore, although the current collector is composed of the base 12a fixed to the lid 20 and the leg 12b joined to the electrode body 11, the current collector of the present invention is joined to the electrode body by welding. It may have any configuration as long as it

  Furthermore, in the above description, the connection between the electrode body 11 and the current collector 12 is resistance welding, but in the case of welding accompanied by the occurrence of spatter, the present invention relates to laser welding, arc welding, etc. You may implement in the well-known welding method.

  Furthermore, in the above description, the storage element of the present invention is a non-aqueous electrolyte secondary battery represented by a lithium ion secondary battery, but in the case of a battery that can be charged and discharged by an electrochemical reaction, nickel A hydrogen battery or any other secondary battery may be used. Also, it may be a primary battery. Furthermore, an electric double layer capacitor or various other capacitors may be used. In short, the storage element of the present invention is not limited by a specific method for generating an electromotive force as long as it is an element capable of storing electricity formed by sealing an electrode body and an electrolytic solution in a storage container. .

  Furthermore, although a single non-aqueous electrolyte secondary battery has been taken as an example in the above description, the present invention relates to a power supply module including a plurality of storage elements and the storage element of the present invention in at least one storage element. It may be realized as

  In short, the present invention may be implemented as various modifications to the above-described embodiment, including those described above, as long as the scope of the present invention is not deviated.

  The present invention as described above has the effect that it is possible to reduce the influence of sputtering and achieve a good bonding between the electrode body and the current collector, and is useful, for example, in a storage element such as a secondary battery. is there.

DESCRIPTION OF SYMBOLS 1 nonaqueous electrolyte secondary battery 10 container body 10 x opening 10 y inner bottom 10 z inner space 11 electrode body 11 c end face 12 current collector 12 a base 12 b leg 12 o center 13 cover 20 lid 21 a outer packing 21 b inner packing 22 electrode terminal 22a relay plate 22b connecting rod 22x caulking end 23 sealing plug 100a, 100b welding electrode 111 electrode plate laminated portion 112 electrode body main portion 112a positive electrode main portion 112b negative electrode main portion 112a1 positive electrode mixture layer 112b1 negative electrode mixture layer 112c separator N1 nugget

Claims (9)

Electrode body,
And a current collector joined to the electrode body by welding.
The electrode body has an electrode body main portion in which electrode plates overlap via a mixture layer, and an electrode plate laminated portion joined to the current collector.
Position of the junction between the collector and the electrode plate laminate unit Oite the opposing surfaces of the electrode plates laminated portion of the current collector, is eccentric to the side away from the electrode body part,
A plurality of the bonding portions are arranged along the facing surface to the electrode plate laminated portion.
Storage element. The bonding portion has a shape extending in a direction along a long side of the facing surface of the current collector to the electrode body.
The storage element according to claim 1. Each of the plurality of the joint portions arranged in, Oite the opposing surfaces of the electrode plates laminated portion of the current collector is disposed eccentrically on the side away from the electrode body portion toward both ends from the center Yes,
The storage element according to claim 1. Electrode body,
And a current collector joined to the electrode body by welding.
The electrode body has an electrode body main portion in which electrode plates overlap via a mixture layer, and an electrode plate laminated portion joined to the current collector.
A protrusion is formed at a joint portion between the electrode plate laminated portion and the electrode body,
Tips of said projections, Oite the opposing surfaces of the electrode plates laminated portion of the current collector is eccentric to the side away from the electrode body part, the electric storage device. Center of the bottom surface of said projections, Oite the opposing surfaces of the electrode plates laminated portion of the current collector is positioned on the center line bisecting the width of the current collector,
The storage element according to claim 4. The protrusion forms a ridge along the opposing surface of the current collector with the electrode body.
The storage element according to claim 4 or 5. And a protective member joined to the electrode body on the side opposite to the current collector of the electrode body.
The storage element according to any one of claims 1 to 6. A plurality of storage elements including at least one storage element according to any one of claims 1 to 7,
Power supply module. A method of manufacturing a storage element, comprising the step of joining a current collector to an electrode body by welding.
The electrode body has an electrode body main portion in which electrode plates overlap via a mixture layer, and an electrode plate laminated portion to which the current collector is joined,
The process of the joining, the position of the joint surface of the electrode plates laminated portion and the current collector, the current collector, Oite the opposing surfaces of the electrode plate laminate portion, the side away from the electrode body portion By decentering the
The plurality of junctions are arranged along the opposing surface to the electrode body.
Method of manufacturing a storage element.

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