BATTERY AND BATTERY PACK

Abstract

Battery, including: an outer sleeve comprising a side wall and a bottom wall and including an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode group housed in the outer sleeve such that a winding axis direction of the wound electrode group intersects the side wall, wherein the wound electrode group comprises a current collection extension wound in several layers, the current collection extension being arranged at at least one end of the wound electrode group; a first line which clamps the current collection unit, which is wound in several layers; a second line that is electrically connected to the first line; and a metallic cover attached to the opening of the outer sleeve and comprising a connection, where the first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collection attachment, wound in several layers, inserted between them; and a connecting plate section connecting the terminal plate section and the cover plate section, facing at least one end of the wound electrode group. the second conductor comprises: a substrate electrically connected to the terminal; and a leg section extending in a direction perpendicular to the winding axis direction of the wound electrode group, the leg section being electrically connected to the terminal plate section, The cover plate section comprises the following: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises the following: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected side and the non-connected side. wherein the second plate section includes a projection defined by an outer edge encompassing the unconnected side and the opposite side, the projection projecting relative to the first plate section along a direction in which the leg section extends, and the unconnected side and part of the opposite side are bent at the projection towards at least one end of the wound electrode group.

Description

AREA OF TECHNOLOGY

[0001] The embodiments described herein generally relate to a battery and a battery pack. BACKGROUND

[0002] Because lithium-ion batteries have high energy densities, they are expected to be used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), electric motorcycles, forklifts, and the like. To obtain an electrical power source with a larger capacity, a battery module has been developed, formed by electrically connecting a large number of batteries.

[0003] A battery, for example, includes a metallic outer casing, a wound electrode assembly housed within the outer casing, leads, and a metallic cover attached to an opening in the outer casing. For example, the cover may be welded to the opening of the outer casing. The wound electrode assembly includes a positive electrode current collector at one end, running parallel to the winding axis, and a negative electrode current collector at the other end, running parallel to the winding axis. The positive electrode current collector is connected to a positive electrode lead, and the negative electrode current collector is connected to a negative electrode lead. The cover is provided with a positive electrode terminal and a negative electrode terminal.These terminals are attached to the cover, for example, by crimping, with a seal inserted between them, thus insulating the terminals from the cover and the outer sleeve. The positive and negative electrode leads, which are connected to the current collector terminals, are each electrically connected to the terminals of the positive and negative electrodes, respectively.

[0004] In a structure where a multi-layered attachment is connected to a conductor element by ultrasonic waves or similar means to extract current to the outside, a backup conductor is used to bundle the attachment. In the section where the multi-layered attachment is bundled by the backup conductor and subjected to ultrasonic connection, the layers of the attachment are in close contact with each other. This reduces the penetration of an electrolytic solution. That is, in the section where the multi-layered attachment is bundled by the backup conductor, it is less likely that an electrolytic solution will penetrate in a direction parallel to the winding axis. COUNTERPOINT LIST PATENT LITERATURE

[0005] PATENT LITERATURE 1: Jpn. Pat. Anmldng. KOKAI Publication No. JP 2011 - 49 065 A SUMMARY OF THE TECHNICAL PROBLEM

[0006] One objective of the present disclosure is to provide a battery that exhibits excellent impregnation properties of an electrolytic solution. SOLUTION TO THE PROBLEM

[0007] According to one embodiment, a battery is provided. The battery includes: an outer sleeve comprising a side wall and a bottom wall, and an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode assembly housed within the outer sleeve such that one winding axis of the wound electrode assembly intersects the side wall, and comprising a current collection attachment wound in multiple layers, arranged at at least one end of the wound electrode assembly; a first lead clamping the multi-layered current collection attachment; a second lead electrically connected to the first lead; and a metallic cover attached to the opening of the outer sleeve, comprising a terminal.The first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collector, wound in multiple layers, inserted between them; and a connecting plate section that joins the terminal plate section and the cover plate section and faces at least one end of the wound electrode group. The second conductor comprises a substrate electrically connected to the terminal and a leg section extending in a direction perpendicular to the winding axis of the wound electrode group, the leg section being electrically connected to the terminal plate section.The cover plate section comprises: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected and non-connected sides. The second plate section includes a projection that extends relative to the first plate section along a direction in which the leg section extends.The unconnected side and part of the opposite side at the projection are bent in the direction of at least one end of the wound electrode group.

[0008] According to another embodiment, a battery pack is provided. The battery pack includes the non-aqueous electrolyte battery according to the embodiment. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of the exterior of a battery according to one embodiment. Fig. Figure 2 is an unfolded perspective view of the battery, which is located in Fig. 1 is shown. Fig. Figure 3 is an unfolded perspective view of a cap body contained within the battery that is in Fig. 1 is shown. Fig. Figure 4 is an unfolded view of a wound electrode assembly contained in the battery that is in Fig. 1 is shown. Fig. 5 is a front view of the battery, which is located in Fig. 1 is shown. Fig. Figure 6 is an enlarged view of the front and side of a circumference of a negative electrode backup lead of an example of the battery according to the embodiment. Fig. Figure 7 is a perspective view showing an example of the negative electrode backup line according to the embodiment. Fig. Figure 8 is a front view of the negative electrode backup line, which is located in Fig. Figure 7 shows the view from the side. Fig. Figure 9 is a top view of the negative electrode backup line, which is located in Fig. Figure 7 shows the view from the top. Fig. Figure 10 is a front view of the negative electrode backup line, which Fig. Figure 7 shows the product in its unfolded state. Fig. Figure 11 is a diagram that schematically shows an example of the flow of an electrolytic solution in the battery, which is in Fig. 6 is shown. Fig. Figure 12 is a diagram that schematically shows an example of the flow of an electrolytic solution in a battery according to a reference example. Fig. Figure 13 is an enlarged view of the front and side of a circumference of a negative electrode backup line of another example of the battery according to the embodiment. Fig. Figure 14 is a perspective view showing another example of the negative electrode backup line according to the embodiment. Fig. Figure 15 is a front view of the negative electrode backup line, which is located in Fig. Figure 14 shows the view from the side. Fig. Figure 16 is a front view of the negative electrode backup line, which is located in Fig. Figure 14 shows the product in its unfolded state. Fig. Figure 17 is a perspective view showing yet another example of the negative electrode backup line according to the embodiment. Fig. Figure 18 is a front view of the negative electrode backup line, which is located in Fig. Figure 17 shows the view from the side. Fig. Figure 19 is a perspective view showing yet another example of the negative electrode backup line according to the embodiment. Fig. Figure 20 is a front view of the negative electrode backup line, which is located in Fig. Figure 19 shows the view from the side. Fig. Figure 21 is an expanded perspective view showing an example of a battery pack according to one embodiment. Fig. Figure 22 is a block diagram showing an example of an electrical circuit of the battery pack that is in Fig. 21 is shown. DETAILED DESCRIPTION (First embodiment)

[0009] According to a first embodiment, a battery is provided. The battery comprises: an outer sleeve, which includes a side wall and a bottom wall and has an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode assembly housed in the outer sleeve such that one winding axis of the wound electrode assembly intersects the side wall, and comprising a current collection attachment wound in multiple layers, which is arranged at at least one end of the wound electrode assembly; a first lead clamping the current collection attachment wound in multiple layers; a second lead electrically connected to the first lead; and a metallic cover attached to the opening of the outer sleeve and comprising a terminal.The first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collector, wound in multiple layers, inserted between them; and a connecting plate section that joins the terminal plate section and the cover plate section and faces at least one end of the wound electrode group. The second conductor comprises a substrate electrically connected to the terminal and a leg section extending in a direction perpendicular to the winding axis of the wound electrode group, the leg section being electrically connected to the terminal plate section.The cover plate section comprises: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected and non-connected sides. The second plate section includes a projection that extends relative to the first plate section along a direction in which the leg section extends.The unconnected side and part of the opposite side at the projection are bent in the direction of at least one end of the wound electrode group.

[0010] The following describes embodiments with reference to the drawings.

[0011] As an example of a battery, Fig. 1 an exterior of a non-aqueous electrolyte battery 100, and shows Fig. Figure 2 shows an unfolded perspective view of the non-aqueous electrolyte battery. The battery 100 comprises an outer sleeve 1, a flat-wound electrode assembly 2, a positive electrode lead 3 (second positive electrode lead), a negative electrode lead 4 (second negative electrode lead), a cover 5, a positive electrode terminal 6, a negative electrode terminal 7, a positive electrode backup lead 8 (first positive electrode lead), a negative electrode backup lead 9 (first negative electrode lead), a positive electrode insulating cover 10, a negative electrode insulating cover 11, a positive electrode seal 12, a negative electrode seal 13, a safety valve 14, a cover 15 for an electrolyte injection port, and an electrolyte solution (not shown). Preferably, the electrolyte solution is present in and fills the outer sleeve 1.

[0012] The outer sleeve 1 has a rectangular tubular shape with a base. The outer sleeve 1 includes a side wall and a base wall, and has an opening on the opposite side of the base wall. The outer sleeve 1 is made of a metal such as aluminum, an aluminum alloy, iron, or stainless steel. The wound electrode assembly 2 is housed within the outer sleeve 1 such that one winding axis of the wound electrode assembly 2 intersects the side wall of the outer sleeve 1.

[0013] The wound electrode group 2 includes: a positive electrode current collector 20a wound in several layers, arranged at one end in the direction of the winding axis; and a negative electrode current collector 22a wound in several layers, arranged at the other end in the direction of the winding axis. Fig. Figure 4 shows an unfolded view of the wound electrode assembly 2. A positive electrode 20 comprises a strip-shaped positive electrode current collector 20c, made, for example, of a metal foil, and a positive electrode active material layer 20b formed on one or both surfaces of the positive electrode current collector 20c. The positive electrode active material layer 20b is formed on the strip-shaped positive electrode current collector 20c such that a region (uncoated section) of a certain width remains on one end face along a longitudinal direction of the positive electrode current collector 20c. The uncoated section is where the positive electrode current collector 20c is exposed and serves as the positive electrode current collector attachment 20a.Similarly, a negative electrode 22 includes a strip-shaped negative electrode current collector 22c, which is made, for example, of a metal foil, and a negative electrode active material layer 22b, which is formed on one or both surfaces of the negative electrode current collector 22c. The negative electrode active material layer 22b is formed on the strip-shaped negative electrode current collector 22c such that a region (uncoated section) of a certain width remains at the other end (the side opposite one end of the positive electrode 20) along a longitudinal direction of the negative electrode current collector 22c. The uncoated section is a section in which the negative electrode current collector 22c is exposed and serves as the negative electrode current collector attachment 22a.

[0014] The positive electrode 20 and the negative electrode 22 are stacked alternately with a strip-shaped separator 21. For example, two separators, a separator 21a and a separator 21b, are used for the separator 21. In this case, the positive electrode current collector 20a is arranged at one end in the winding axis direction, and the negative electrode current collector 22a is arranged at the other end in the winding axis direction. The separator 21a, which is stacked below the negative electrode 22, is arranged such that one end of the separator 21a is positioned along its longitudinal direction on an inner side with respect to the end of the negative electrode 22, which is positioned on the side of the negative electrode current collector.Thus, the negative electrode current collector 22a protrudes from the positive electrode active material-containing layer 20b, the negative electrode active material-containing layer 22b, and the separator 21a, which constitute the wound electrode group 2. The separator 21a is also arranged such that its other end is positioned along its longitudinal direction on an outside surface relative to the other end of the negative electrode 22. The separator 21b, which is inserted between the positive electrode 20 and the negative electrode 22, is arranged such that one end of the separator 21b is positioned along its longitudinal direction on an inside surface relative to the end of the positive electrode 20, which is located on the side of the positive electrode current collector 22.Thus, the positive electrode current collection point 20a protrudes from the layer 20b containing the positive electrode active material, the layer 22b containing the negative electrode active material, and the separator 21b, which constitute the wound electrode group 2. The separator 21b is also arranged such that its other end is positioned along its longitudinal direction on an outer surface relative to the other end of the positive electrode 20.

[0015] The stacked separator 21a, the negative electrode 22, the separator 21b and the positive electrode 20 are wound and then pressed to form the flat wound electrode group 2.

[0016] For example, as in Fig. As shown in Figure 2, the wound electrode group 2 is secured with an insulating tape 40. The insulating tape 40 covers the outermost circumference of the wound electrode group 2, except for the current collection point, in order to insulate the outermost circumference except for the current collection point. The insulating tape 40 can be wound once or several times.

[0017] Fig. Figure 3 shows an unfolded perspective view of an example of a cap body 50. The cap body 50 is formed, for example, from a cover 5, an insulator 18, a positive electrode lead 3 (second positive electrode lead), a negative electrode lead 4 (second negative electrode lead), a positive electrode connection 6, a negative electrode connection 7, a positive electrode seal 12 (first positive electrode seal 12), a second positive electrode seal 16, a negative electrode seal 13 (first negative electrode seal 13) and a second negative electrode seal 17.

[0018] The lid 5 is a shaped element made of metal or alloy such as aluminum, an aluminum alloy, iron or stainless steel.

[0019] The positive electrode lead 3, as a second positive electrode lead, is a conductive element that connects the positive electrode terminal 6 and the positive electrode backup lead 8, as a first positive electrode lead, which is in Fig. 2 is shown, electrically connects, etc. The positive electrode lead 3 is a conductive element such as aluminum or an aluminum alloy.

[0020] The negative electrode lead 4, as a second negative electrode lead, is a conductive element that connects the negative electrode terminal 7 and the negative electrode backup lead 9, as a first negative electrode lead, which is in Fig. 2 is shown, electrically connects, etc. The negative electrode lead 4 is a conductive element such as aluminum or an aluminum alloy.

[0021] The positive electrode terminal 6 is an electrode connection for the positive electrode of the battery, which is provided on the cover 5. The positive electrode terminal 6 is formed from a conductive element such as aluminum or an aluminum alloy. The positive electrode terminal 6 is attached to the cover 5, with the insulating first positive electrode seal 12 and the insulating second positive electrode seal 16 inserted between them. The positive electrode terminal 6 is electrically connected to the positive electrode 20 via the positive electrode lead 3 and the positive electrode backup lead 8.

[0022] The negative electrode terminal 7 is an electrode connection for the negative electrode of the battery, which is provided on the cover 5. The negative electrode terminal 7 is formed from a conductive element such as aluminum or an aluminum alloy. The negative electrode terminal 7 is attached to the cover 5, with the insulating first negative electrode seal 13 and the insulating second negative electrode seal 17 inserted between them. The negative electrode terminal 7 is electrically connected to the negative electrode 22 via the negative electrode lead 4 and the negative electrode backup lead 9.

[0023] The positive electrode insulating cover 10, which is in Fig. The positive electrode insulating cover 10, as shown in Figure 2, etc., is an insulating element that covers the positive electrode lead 3 and the positive electrode backup lead 8. The positive electrode insulating cover 10 engages one end of the wound electrode assembly 2, including the positive electrode current collector 20a. The positive electrode insulating cover 10 is preferably an insulating and heat-resistant element. The positive electrode insulating cover 10 is preferably a resin-molded body, a molded body made of a material consisting mainly of paper, an element obtained by coating a molded body made of a material consisting mainly of paper with a resin, or the like. A polyethylene resin or a fluorinated resin is preferably used as the resin.By using the positive electrode insulating cover 10, the positive electrode 20 and the outer sleeve 1 are insulated from each other, and the current collection region (current collection point, lead, backup lead) can be protected from external influence.

[0024] The negative electrode insulating cover 11, which is in Fig. Figure 2, etc., is an insulating element that covers the negative electrode lead 4 and the negative electrode backup lead 9. The negative electrode insulating cover 11 engages one end of the wound electrode group 2, including the negative electrode current collector attachment 22a. The material, shape, and the like of the negative electrode insulating cover 11 are the same as those of the positive electrode insulating cover 10. Descriptions common to both the positive electrode insulating cover 10 and the negative electrode insulating cover 11 have been omitted.

[0025] The first positive electrode seal 12 and the second positive electrode seal 16 are elements that insulate the positive electrode terminal 6 from the outer sleeve 1. The positive electrode seal is preferably a resin-molded body that exhibits solvent resistance and flame retardancy. For example, a polyethylene resin, a fluorinated resin, or the like is used for the positive electrode seal.

[0026] The first negative electrode seal 13 and the second negative electrode seal 17 are elements that insulate the negative electrode terminal 7 from the outer sleeve 1. The negative electrode seal is preferably a resin-molded body that exhibits solvent resistance and flame retardancy. For example, a polyethylene resin, a fluorinated resin, or the like is used for the negative electrode seal.

[0027] The safety valve 14 is an element provided with the cover 5 and functions as a pressure-reducing valve, reducing the internal pressure of the outer sleeve 1 when the internal pressure of the outer sleeve 1 increases. The safety valve 14 is preferably provided, but may be omitted depending on the requirements of the battery protection mechanism, the electrode material, and the like.

[0028] The cover 15 for an electrolyte injection port seals a hole for injecting an electrolytic solution. The cover 15 for an electrolyte injection port is made of a metal such as aluminum, an aluminum alloy, iron, or stainless steel.

[0029] The metallic cover 5 is attached in an airtight manner to the opening of the outer sleeve 1, which is located in Fig. Figure 1 shows, for example, a welding process. The positive electrode terminal 6 is attached to the cover 5 by upsetting, with the first positive electrode seal 12 and the second positive electrode seal 16 inserted between them. The negative electrode terminal 7 is attached to the cover 5 by upsetting, with the first negative electrode seal 13 and the second negative electrode seal 17 inserted between them. The positive electrode terminal 6 and the negative electrode terminal 7 protrude from the rear surface of the cover 5 into the inside of the outer sleeve 1.

[0030] As in Fig. As shown in Figure 3, the positive electrode lead 3 comprises a substrate 3a electrically connected to the positive electrode terminal 6, a through-hole 3b open in the substrate 3a, and a leg section 3c extending from the substrate 3a in a direction perpendicular to the direction in which the substrate 3a extends. The substrate 3a is in contact with the rear surface of the cover 5, with the insulator 18 inserted between them. The positive electrode terminal 6, which projects from the rear surface of the cover 5, is attached to the through-hole 3b by compression.

[0031] As in Fig. As shown in Figure 2, leg section 3c of the positive electrode lead 3 is electrically connected at least to the positive electrode backup lead 8. Leg section 3c of the positive electrode lead 3 may include a section in direct contact with the positive electrode current collector 20a. The positive electrode backup lead 8 and leg section 3c of the positive electrode lead are connected, for example, by ultrasonic bonding. A more specific connection method is described below.

[0032] In a similar manner to the positive electrode lead 3, the negative electrode lead 4 comprises a substrate 4a electrically connected to the negative electrode terminal 7, a through-hole 4b open in the substrate 4a, and a leg section 4c extending from the substrate 4a in a direction perpendicular to the direction in which the substrate 4a extends. The substrate 4a is in contact with the rear surface of the cover 5, with the insulator 18 inserted between them. The negative electrode terminal 7, which projects from the rear surface of the cover 5, is attached to the through-hole 4b by compression.

[0033] As in Fig. As shown in Figure 2, leg section 4c of the negative electrode lead 4 is electrically connected at least to the negative electrode backup lead 9. Leg section 4c of the negative electrode lead 4 may include a section in direct contact with the negative electrode current collector 22a. The negative electrode backup lead 9 and leg section 4c of the negative electrode lead 4 are connected, for example, by ultrasonic bonding. A more specific connection method is described below.

[0034] Fig. Figure 5 is a front view of a state in which the wound electrode assembly 2, the cap body 50, the positive electrode insulating cover 10, and the negative electrode insulating cover 11 are removed from the battery 100. The negative electrode current collector 22a, which is wound in multiple layers, is clamped and bundled by the negative electrode backup line 9. The negative electrode current collector 22a is clamped by the negative electrode backup line 9, for example, in a direction parallel to the winding axis of the wound electrode assembly 2. Although not shown in the figure, the positive electrode current collector 20a, which is wound in multiple layers, is clamped and bundled by the positive electrode backup line 8. The positive electrode current collection connection 20a is clamped by the positive electrode backup line 8, for example in a direction parallel to the winding axis direction of the wound electrode group 2.

[0035] As in Fig. As shown in Figure 5, the leg section 3c of the positive electrode lead 3 extends in a direction perpendicular to the winding axis direction of the wound electrode group 2. Although in Fig. Not shown in Figure 5, leg section 3c is electrically connected to the positive electrode backup line 8. Leg section 4c of the negative electrode line 4 extends in a direction perpendicular to the winding axis direction of the wound electrode group 2. The direction D in which leg section 4c extends is shown in Figure 5. Fig. 5 shown. The direction D in which the leg section 4c extends is, for example, a direction perpendicular to the winding axis direction of the wound electrode group 2. The direction D in which the leg section 4c extends is also shown in Fig. 2 shown. Although in Fig. Not shown in Figure 5, leg section 4c is electrically connected to the negative electrode backup line 9. Thus, the wound electrode group 2 and the cap body 50 are electrically connected to each other.

[0036] Next, the positive electrode backup line 8 and the negative electrode backup line 9 will be described in detail with reference to Fig. 6 to 20 described. Since the positive electrode backup line 8 has the same shape as that of the negative electrode backup line 9, the illustration of the positive electrode backup line 8 in Fig. Numbers 6 to 20 were omitted.

[0037] In the battery according to the embodiment, the positive electrode backup line 8 and the negative electrode backup line 9 may not have the same shape. However, at least one of the positive electrode backup line 8 or the negative electrode backup line 9 has a shape as described below.

[0038] Fig. Figure 6 is an enlarged view of the front and side of a circumference of a negative electrode backup lead of an example of the battery according to the embodiment. Fig. Figure 7 is a perspective view showing an example of the negative electrode backup line 9 according to the embodiment. Fig. Figure 8 is a front view of the negative electrode backup line 9, which is located in Fig. Figure 7 shows the view from the side. Fig. Figure 9 is a top view of the negative electrode backup line 9, which is located in Fig. Figure 7 shows the view from the top. Fig. Figure 10 is a front view of the negative electrode backup line 9, which Fig. Figure 7 shows the product in its unfolded state.

[0039] The negative electrode backup lead 9 (first negative electrode lead) comprises a terminal plate section 91, a cover plate section 92, and a connecting plate section 93. The terminal plate section 91 is electrically connected to the negative electrode lead 4 (second negative electrode lead). The cover plate section 92 is opposite the terminal plate section 91, with the negative electrode current collector 22a wound in several layers inserted between them. The connecting plate section 93 connects the terminal plate section 91 and the cover plate section 92 and faces one end of the wound electrode group 2.

[0040] The cover plate section 92 is adjacent to the connecting plate section 93. The cover plate section 92 comprises: a first plate section 92a, which forms part of the cover plate section 92; and a second plate section 92b, which extends continuously from the first plate section 92a and forms another part of the cover plate section 92. Each of the connecting plate section 91, the first plate section 92a, the second plate section 92b, and the connecting plate section 93, for example, has a rectangular plate shape.If each of the terminal plate section 91, the first plate section 92a, the second plate section 92b, and the connecting plate section 93 has a rectangular shape, and if the negative electrode current collector 22a, which is wound in several layers, is to be bundled, the negative electrode current collector 22a can be clamped by the high-strength negative electrode backup line 9, even if the width of the negative electrode current collector 22a in the winding axis direction of the wound electrode group 2 is small. In other words, since the width of the negative electrode current collector 22a in the winding axis direction of the wound electrode group 2 can be reduced, the width of the layer containing the negative electrode active material (coated section) in the winding axis direction of the wound electrode group 2 can be increased. As a result, the battery capacity can be increased.

[0041] As in Fig. As shown in Figures 6 to 10, etc., the second plate section 92b includes an upper projection 920 and a lower projection 921, which project relative to the first plate section 92a along a direction in which the leg section 4c of the negative electrode lead 4 extends. The second plate section 92b can include only one of the upper projection 920 or the lower projection 921. That is to say, the second plate section 92b includes at least one of the upper projection 920 or the lower projection 921.

[0042] This describes a case in which the second plate section 92b includes both the upper projection 920 and the lower projection 921. As in Fig. As shown in Figure 8, the second plate section 92b includes: a connected side 922, which is connected to the first plate section 92a; and an upper unconnected side 920a and a lower unconnected side 921a, which are continuous with the connected side 922 and not connected to the first plate section 92a. The second plate section 92b further includes a counter side 923, which is positioned on the opposite side of the connected side 922, the upper unconnected side 920a, and the lower unconnected side 921a.

[0043] The upper projection 920 of the second plate section 92b is a section defined by an outer edge comprising the upper non-connected side 920a, an upper opposite side 920b that is part of the opposite side 923, and an upper side 920c perpendicular to the upper non-connected side 920a and the upper opposite side 920b. The upper opposite side 920b refers to a side of a section of the opposite side 923 that is opposite the upper non-connected side 920a. The outer edge of the upper projection 920 further comprises: a corner section 920d at which the upper non-connected side 920a and the upper side 920c intersect; and a corner section 920e at which the upper opposite side 920b and the upper side 920c intersect.

[0044] The lower projection 921 of the second plate section 92b is a section defined by an outer edge that includes the lower unconnected side 921a, a lower opposite side 921b that is part of the opposite side 923, and a lower side 921c perpendicular to the lower unconnected side 921a and the lower opposite side 921b. The lower opposite side 921b refers to a side of a section of the opposite side 923 that is opposite the lower unconnected side 921a. The outer edge of the lower projection 921 further includes: a corner section 921d at which the lower unconnected side 921a and the lower side 921c intersect; and a corner section 921e at which the lower opposite side 921b and the lower side 921c intersect.

[0045] The cover plate section 92, the negative electrode current collector section 22a, which is wound in several layers, the terminal plate section 91, and the leg section 4c of the negative electrode lead 4 are connected in this order to connected sections J1, J2, and J3. Each of the connected sections J1 to J3 can be formed by an ultrasonic joining process, which will be described later. The battery according to the embodiment can include one or more connected sections between the negative electrode backup lead 9 and the negative electrode current collector section 22a, but preferably includes three or more connected sections.If there are three or more connected sections, the negative electrode backup lead 9 is less likely to become detached from the wound electrode group 2 and the negative electrode lead 4, even if the battery is shaken, and the electrical resistance across the connected sections can be reduced. The shape of the connected sections J1 to J3 is not particularly restricted. The connected sections J1 to J3 are arranged in a line along the direction in which leg section 4c of the negative electrode lead 4 extends.

[0046] In Fig. In section 6, the connected section J2 is positioned in the center along the longitudinal direction of the second plate section 92b. The connected sections J1 and J3 are positioned symmetrically with respect to the longitudinal direction of the second plate section 92b, with the connected section J2 as the center of symmetry. The connected sections J1 and J3 can be positioned either close to or farther away from the connected section J2. This means that the connected sections J1 to J3 may not be located at regular intervals.

[0047] For example, the positions of the connected sections J1 to J3 along the longitudinal direction of the second plate section 92b can vary while maintaining the positional relationship of the uniform interval. The positions of the connected sections J1 to J3 can be closer to the upper projection 920 or closer to the lower projection 921. For example, the positions of the connected sections J1 to J3 are preferably closer to the upper projection 920 along the longitudinal direction of the second plate section 92b while maintaining the positional relationship of the uniform interval. This allows the electrical path from the negative electrode current collector 22a to the negative electrode terminal 7 to be shortened, resulting in a low-resistance battery, which is advantageous.

[0048] As in Fig. As shown in Figure 6, the upper unconnected side 920a and the upper opposite side 920b, contained in the upper projection 920, are bent towards one of their two ends along the winding axis direction of the wound electrode group 2, which includes the negative electrode current collector 22a wound in several layers. Likewise, the lower unconnected side 921a and the lower opposite side 921b, contained in the lower projection 921, are bent towards one of their two ends along the winding axis direction of the wound electrode group 2, which includes the negative electrode current collector 22a wound in several layers. For simplicity, we show Fig. However, Figures 7 to 10 describe the case in which the upper projection 920 and the lower projection 921 of the negative electrode backup line 9 are not bent. A method for bending the upper unconnected side 920a and the upper opposite side 920b, which are contained in the outer edge of the upper projection 920, and the lower unconnected side 921a and the lower opposite side 921b, which are contained in the outer edge of the lower projection 921, is described later.

[0049] If the upper opposite side 920b and the lower opposite side 921b are bent towards one end of the wound electrode group 2 as described above, the impregnation properties of the electrolytic solution near the winding axis of the wound electrode group 2 are improved compared to the case where they are not bent. In the wound electrode group 2, a boundary 220 is provided between the negative electrode active material-containing layer (coated section) 22b and the negative electrode current collection point (uncoated section) 22a, for example, along a direction perpendicular to the winding axis direction of the wound electrode group 2.If the direction of the boundary 220 is parallel to the upper opposite side 920b or the lower opposite side 921b, the movement of the electrolytic solution attempting to penetrate into the coated section in the direction along the winding axis direction tends to be prevented because the negative electrode backup line 9 clamps the negative electrode current collection attachment 22a with sufficient contact strength.

[0050] Fig. Figure 11 is a diagram that schematically shows an example of the flow of an electrolytic solution in the battery, which is in Fig. 6 is shown. Fig. Figure 11 shows a flow E1 and a flow E2 of the electrolytic solution. For example, the electrolytic solution penetrates the gaps between the layers of the negative electrode current collector 22a and then penetrates towards the coated section. On this occasion, when the upper opposite side 920b, which is contained in the outer edge of the upper projection 920, is bent towards one end of the wound electrode group 2, the electrolytic solution, which passes near the negative electrode backup line 9, simply penetrates towards the vicinity of the winding axis of the wound electrode group 2. Therefore, the battery according to the embodiment exhibits excellent charging and discharging characteristics.Likewise, if the lower opposite side 921b, which is contained in the outer edge of the lower projection 921, is bent in the direction of one end of the wound electrode group 2, the electrolytic solution passing in the vicinity of the negative electrode backup line 9 simply penetrates in the direction of the vicinity of the winding axis of the wound electrode group 2.

[0051] Fig. Figure 12 shows an example of the flow of an electrolytic solution in a battery according to a reference example. The battery, which is in Fig. Figure 12 shows the same structure as the battery shown in Fig. Figure 6 is shown, except that the upper opposite side 920b and the upper unconnected side 920a, and the lower opposite side 921b and the lower unconnected side 921a are not bent. For example, the electrolytic solution penetrates parallel to a direction perpendicular to the direction along the boundary 220 between the negative electrode active material-containing layer (coated section) 22b and the negative electrode current collection point (uncoated section) 22a, i.e., parallel to the winding axis direction. Fig. Figure 12 shows the flow of the electrolytic solution in this case as E3 and E4. In this case, it is likely that the amount of electrolytic solution penetrating near the winding axis decreases because the negative electrode backup line 9 clamps the negative electrode current collector connection 22a with sufficient contact strength. As a result, the charging and discharging efficiency tends to be worse than that of the battery according to the embodiment.

[0052] Furthermore, the battery, which is in Fig. As shown in Figure 6, the corner section 920d, where the upper unconnected side 920a and the upper side 920c intersect, is positioned between an extension line of the connected side 922, which connects the first plate section 92a and the second plate section 92b, and an end face of the wound electrode group 2 (side of the connecting plate section 93). Therefore, the negative electrode backup line 9 does not interfere with the installation of the negative electrode insulating cover and does not negatively affect the housing of the wound electrode group 2 in the outer sleeve 1.

[0053] The battery according to the embodiment which is in Fig. As shown in Figure 6, excellent impregnation properties of the electrolytic solution and good storability can be achieved, for example, without changing the area of ​​the cover plate section 92, for example compared with the battery according to the reference example shown in Figure 6. Fig. Figure 12 shows that the electrode group, with its excellent storability, can be housed in a smaller outer sleeve to achieve high capacity.

[0054] In the negative electrode backup line 9, which is in Fig. As shown in Figures 6 to 10, etc., the upper opposite side 920b is bent towards one end of the wound electrode group 2 at an angle of, for example, 1° to 30°, preferably 1° to 16°, with respect to the direction in which the leg section 4c of the negative electrode lead 4 extends. Excessive curvature of the upper opposite side 920b tends to lead to excessive curvature of the upper unconnected side 920a. For example, in this case, an adverse situation may arise in which the upper unconnected side 920a and the corner section 920d project relative to the connecting plate section 93 in a direction parallel to the winding axis direction, and the negative electrode insulating cover 11 is damaged.

[0055] In a manner similar to the upper opposite side 920b, the upper unconnected side 920a is also bent towards an end of the wound electrode group 2 at an angle of, for example, 1° to 30°, preferably 1° to 16° in a direction in which the leg section 4c of the negative electrode lead 4 extends.

[0056] The lower opposite side 921b is bent towards one end of the wound electrode group 2 at an angle of, for example, 1° to 30°, preferably 1° to 16°, with respect to the direction in which the leg section 4c of the negative electrode lead 4 extends. Excessive curvature of the lower opposite side 921b tends to lead to excessive curvature of the lower unconnected side 921a. For example, in this case, an adverse situation may arise in which the lower unconnected side 921a and the corner section 921d project relative to the connecting plate section 93 in a direction parallel to the winding axis direction, and the negative electrode insulating cover 11 is damaged.

[0057] In a manner similar to the lower opposite side 921b, the lower unconnected side 921a is also bent towards an end of the wound electrode group 2 at an angle of, for example, 1° to 30°, preferably 1° to 16° in a direction in which the leg section 4c of the negative electrode lead 4 extends.

[0058] Fig. Figure 13 is an enlarged view of the front and side circumference of a negative electrode backup lead of another example of the battery according to the embodiment. The battery has the same configuration as the one shown in Fig. Figure 6 shows, except that the ends of the upper projection 920 and the lower projection 921 of the negative electrode backup line 9 are turned upwards in a direction away from the negative electrode current collector extension 22a. In this case, the corner section 920d is not excessively pressed into the negative electrode current collector extension 22a, which is wound in several layers. Thus, it is less likely that the negative electrode current collector extension 22a will break. Accordingly, the battery, which has the configuration shown in Figure 6, demonstrates this. Fig. As shown in 13, excellent safety.

[0059] All of the corner sections of the negative electrode backup lead 9 may or may not be chamfered. For example, the corner sections of the terminal plate section 91 and the second plate section 92b may be chamfered, as shown in Fig. 6 to 10 etc. shown. Alternatively, the corner sections of the negative electrode backup line 9 can have an “R” shape.

[0060] Another aspect of the battery according to the embodiment will be discussed with reference to Fig. Described in sections 14 to 16. Fig. Figure 14 is a perspective view showing another example of the negative electrode backup line that may be included in the battery of the embodiment. Fig. Figure 15 is a front view of the negative electrode backup line, which is located in Fig. Figure 14 shows the view from the side. Fig. Figure 16 is a front view of the negative electrode backup line, which Fig. Figure 14 shows the figure in its unfolded state. As in the unfolded view from Fig. As shown in Figure 16, the terminal plate section 91 of the negative electrode backup line 9 can include: a third plate section 91a adjacent to the connecting plate section 93 and forming part of the terminal plate section 91; and a fourth plate section 91b extending continuously from the third plate section and forming another part of the terminal plate section 91.

[0061] The fourth plate section 91b includes an upper projection 910 and a lower projection 911, which project relative to the third plate section 91a along the direction in which the leg section 4c of the negative electrode lead 4 extends. The fourth plate section 91b may include at least one of the upper projection 910 or the lower projection 911.

[0062] How best to Fig. As shown in Figure 16, the fourth plate section 91b includes: a connected side 912, which is connected to the third plate section 91a; and an upper unconnected side 910a and a lower unconnected side 911a, which are continuous with the connected side 912 and not connected to the third plate section 91a. The fourth plate section 91b further includes a counter side 913, which is positioned on the opposite side of the connected side 912, the upper unconnected side 910a, and the lower unconnected side 911a.

[0063] If the fourth plate section 91b includes the upper projection 910, the upper projection 910 is defined by an outer edge comprising the upper non-connected side 910a, an upper opposite side 910b which is part of the opposite side 913, and an upper side 910c perpendicular to the upper non-connected side 910a and the upper opposite side 910b. The upper opposite side 910b refers to a side of a section of the opposite side 913 that is opposite the upper non-connected side 910a. The outer edge of the upper projection 910 further comprises: a corner section 910d at which the upper non-connected side 910a and the upper side 910c intersect; and a corner section 910e at which the upper opposite side 910b and the upper side 910c intersect.

[0064] If the fourth plate section 91b includes the lower projection 911, the lower projection 911 is defined by an outer edge comprising the lower unconnected side 911a, a lower opposite side 911b which is part of the opposite side 913, and a lower side 911c perpendicular to the lower unconnected side 911a and the lower opposite side 911b. The lower opposite side 911b refers to a side of a section of the opposite side 913 that is opposite the lower unconnected side 911a. The outer edge of the lower projection 911 further comprises: a corner section 911d at which the lower unconnected side 911a and the lower side 911c intersect; and a corner section 911e at which the lower opposite side 911b and the lower side 911c intersect.

[0065] Although not shown in the figure, the upper unconnected side 910a and the upper opposite side 910b of the fourth plate section 91b can be bent in the direction of one of the two ends along the winding axis of the wound electrode group 2, which includes the negative electrode current collector extension 22a wound in several layers. In this case, as in the case where the upper projection 920 and the lower projection 921 of the cover plate section 92 are bent, the impregnation properties of the electrolytic solution are improved near the winding axis of the wound electrode group 2.In this case, the corner section 910d, where the upper unconnected side 910a and the upper side 910c, contained in the fourth plate section 91b, intersect, is positioned between an extension line of the connected side 912, which connects the third plate section 91a and the fourth plate section 91b, and an end face of the wound electrode group 2 (side of the connecting plate section 93). Therefore, the negative electrode backup line 9 does not interfere with the application of the negative electrode insulating cover and does not negatively affect the housing of the wound electrode group 2 in the outer sleeve 1. This means that good storage capacity can be achieved, allowing the electrode group to be housed in a smaller outer sleeve, resulting in high capacity.

[0066] The lower unconnected side 911a and the lower opposite side 911b, contained in the fourth plate section 91b, are bent in the direction of one of the two ends along the winding axis of the wound electrode group 2, which includes the negative electrode current collector 22a wound in several layers. In this case, the same effects can be obtained as in the case where the upper unconnected side 910a and the upper side 910c are bent.

[0067] If not only the upper projection 920 and / or the lower projection 921 of the cover plate section 92, but also the upper projection 910 and / or the lower projection 911 of the terminal plate section 91 are bent towards one end of the wound electrode group 2, as shown in Fig. As shown in Figures 14 to 16, a battery with better impregnation properties of the electrolytic solution and lower resistance can be obtained.

[0068] Next, a method for bending the upper projection 920 and / or the lower projection 921 of the cover plate section 92 towards one end of the wound electrode group 2 is described. An example of the bending method is ultrasonic bonding, which is performed when the negative electrode current collector attachment 22a, wound in multiple layers, is clamped by the negative electrode backup line 9. That is, by performing ultrasonic bonding, the upper opposite side 920b and the upper unconnected side 920a of the upper projection 920, and the lower opposite side 921b and the lower unconnected side 921a of the lower projection 921 can be bent towards one end of the wound electrode group 2.By ultrasonic bonding, the upper projection 910 and / or the lower projection 911 of the connection plate section 91 can also be bent towards one end of the wound electrode group 2.

[0069] Instead of performing ultrasonic joining at the negative electrode current collector connection 22a and the negative electrode backup line 9, bending at the negative electrode backup line 9 can be performed beforehand. In this case as well, the upper projection 920 and / or the lower projection 921 of the cover plate section 92 and the upper projection 910 and / or the lower projection 911 of the terminal plate section 91 can be bent towards one end of the wound electrode group 2.

[0070] Ultrasonic joining can also produce a structure in which the ends of the upper projection 920 and the lower projection 921 of the negative electrode backup line 9 are turned upwards in a direction away from the negative electrode current collector attachment 22a. The structure can also be produced by bending the negative electrode backup line 9 either before or after joining.

[0071] When ultrasonic joining is performed, the negative electrode current collector tip 22a of the wound electrode group 2 is first clamped by the terminal plate section 91 and the cover plate section 92 of the negative electrode backup lead 9. At this time, the negative electrode backup lead 9 is positioned so that the terminal plate section 93 covers one end face of the wound electrode group 2. Next, the leg section 4c of the negative electrode lead 4 is placed on a receiving table (anvil). The terminal plate section 91 of the negative electrode backup lead 9, the negative electrode current collector tip 22a, which is wound in multiple layers, and the cover plate section 92 of the negative electrode backup lead 9 are arranged to be stacked onto the leg section 4c in that order.At this time, the terminal plate section 91, the negative electrode current collector attachment 22a, and the cover plate section 92 are positioned so that the leg section 4c of the negative electrode lead 4 and the terminal plate section 91 of the negative electrode backup lead 9 come into contact with each other. Next, a suitable ultrasonic resonator (horn) is pressed vertically against the anvil from the side of the cover plate section 92, and ultrasonic waves are emitted for a predetermined time. Thus, the ultrasonic connection is completed, and the connected sections J1 to J3 are formed, which, for example, are shown in... Fig. Figure 6 shows that by appropriately adjusting the shape of the horn, the load (pressure), the amplitude, the time, and the pressure quantity, it is possible to control the degree of curvature of the upper projection 920 and / or the lower projection 921 of the cover plate section 92 and of the upper projection 910 and / or the lower projection 911 of the connection plate section 91.

[0072] In the battery according to the embodiment, each of the positive electrode lead 3 and the negative electrode lead 4 includes a leg segment. Since the positive electrode lead and the negative electrode lead each include a leg segment, either the positive electrode current collection loop, which is wound in multiple layers, or the negative electrode current collection loop, which is wound in multiple layers, is clamped by a single backup lead. That is, the positive electrode backup lead clamps the positive electrode current collection loop, which is wound in multiple layers, collectively, and the negative electrode backup lead clamps the negative electrode current collection loop, which is wound in multiple layers, collectively.

[0073] In the case of collective clamping of the current collection approach with many layers using a single backup conductor, the amount of pressure exerted by the horn must be increased to achieve sufficient connection strength. However, the width of the tab near the center of the winding axis (the width parallel to the winding axis direction) is the same as the width of the tab near the outer circumference of the winding axis. Therefore, the tab near the outer circumference of the winding axis is excessively pulled by the horn's downward movement during ultrasonic joining and is easily broken by the propagation of ultrasonic vibration energy. To suppress such breaking, the position where ultrasonic joining is performed is preferably closer to the side of the coated section than to an end (end face) of the wound electrode group 2.

[0074] The connected position between the negative electrode backup lead 9 and the negative electrode current collector 22a, which is wound in multiple layers, is preferably closer to the layer 22b containing the negative electrode active material (coated section) than the center of the width of the negative electrode current collector 22a. Similarly, with respect to the positive electrode current collector 20a, the connected position between the positive electrode backup lead 8 and the positive electrode current collector 20a, which is wound in multiple layers, is preferably closer to the layer 20b containing the positive electrode active material (coated section) than the center of the width of the positive electrode current collector 20a. The following advantages are gained when the connected position between the backup lead (first lead) and the current collector is closer to the side of the coated section in each electrode.Specifically, since breakage of the current collector can be suppressed, a short circuit caused by a broken current collector coming into contact with the outer sleeve 1 and the other electrode can be suppressed. Furthermore, since an increase in the density of the current flowing through the unbroken current collector can be prevented, excessive load on the electrode can be avoided. Because no large tensile force is exerted on the current collector, breakage of the current collector is more easily suppressed if physical action occurs while the battery is being moved or used.

[0075] As with reference to Fig. As described in sections 6 to 10, etc., the second plate section 92b of the negative electrode backup line 9 includes the upper projection 920 and / or the lower projection 921, which project relative to the first plate section 92a along the direction in which the leg section 4c of the negative electrode line 4 extends. Therefore, the width of the second plate section 92b in the longitudinal direction is greater than the width of the first plate section 92a in the longitudinal direction. Here, the longitudinal direction is a direction parallel to the direction in which the leg section 4c of the negative electrode line 4 extends. Therefore, the width of the second plate section 92b in the longitudinal direction is the maximum length of the second plate section 92b in the direction in which the leg section 4c extends.The width of the first plate section 92a in the longitudinal direction is the maximum length of the first plate section 92a in the direction in which the leg section 4c extends. The width of the connecting plate section 91 in the longitudinal direction is the maximum length of the connecting plate section 91 in the direction in which the leg section 4c extends.

[0076] The width of the second plate section 92b in the longitudinal direction can be the same as the width of the terminal plate section 91 in the longitudinal direction, as in the case of the negative electrode backup line 9, which is, for example, in Fig. Figures 6 to 10 show that the width of the second plate section 92b in the longitudinal direction can be smaller or larger than the width of the connecting plate section 91 in the longitudinal direction. Preferably, the width of the second plate section 92b in the longitudinal direction is less than the width of the connecting plate section 91 in the longitudinal direction. An example of this case is shown in Figure 6. Fig. 17 and Fig. 18 shown. The negative electrode backup line 9, which is in Fig. 17 and Fig. Figure 18 shows the same structure as that of the negative electrode backup line 9, which was described above with reference to Fig. 7 to 10 is described, with the exception that the width of the second plate section 92b in the longitudinal direction is less than the width of the connecting plate section 91 in the longitudinal direction.

[0077] If the longitudinal length of the second plate section 92b is less than the longitudinal width of the connecting plate section 91, it is possible to prevent the upper opposite side 920b and the upper unconnected side 920a, which are contained in the outer edge of the upper projection 920 of the second plate section 92b, from being excessively bent during ultrasonic joining. It is also possible to prevent the lower opposite side 921b and the lower unconnected side 921a, which are contained in the outer edge of the lower projection 921 of the second plate section 92b, from being excessively bent. In this case, it is possible to prevent the ends of the upper projection 920 and the lower projection 921 of the negative electrode backup lead 9 from being excessively rotated upwards in a direction away from the negative electrode current collector attachment 22a.Therefore, if the width of the second plate section 92b in the longitudinal direction is smaller than the width of the connection plate section 91 in the longitudinal direction, it is possible to maintain the effects of improving battery safety and assembleability, as well as improving battery capacity.

[0078] The width of the connecting plate section 93 in the longitudinal direction is greater than the width of the first plate section 92a in the longitudinal direction, as for example in the case of the negative electrode backup line 9, which is in Fig. Figures 6 to 10 show that the width of the connecting plate section 93 in the longitudinal direction is the same as the width of the terminal plate section 91 in the longitudinal direction, as is the case, for example, with the negative electrode backup line 9, which is shown in Fig. Figures 6 to 10 show the following. The width of the connecting plate section 93 in the longitudinal direction can be smaller or larger than the width of the connecting plate section 91 in the longitudinal direction. The width of the connecting plate section 93 in the longitudinal direction is the maximum length of the connecting plate section 93 in the direction in which the leg section 4c extends.

[0079] The width of the connecting plate section 93 in the longitudinal direction is preferably greater than the width of the first plate section 92a in the longitudinal direction, as for example in Fig. Figures 6 to 10 show that the contact area between the negative electrode backup lead 9 and one end (end face) of the wound electrode group 2 is increased, thus enabling a further reduction in electrical resistance. Furthermore, in this case, the backup lead is easily attached to the current collection section of the wound electrode group using a clamping device when ultrasonic bonding is performed, resulting in a reduced likelihood of positional deviation.

[0080] The widths of the connection plate section 91, the cover plate section 92 and the connecting plate section 93 in the direction of the shorter side are not particularly limited, as long as the negative electrode backup line 9 can be connected to the negative electrode current collector 22a with sufficient connection strength.

[0081] Fig. 19 and Fig. Figure 20 are diagrams that schematically show another example of the backup line included in the battery according to the embodiment. In the negative electrode backup line 9, which is in Fig. 19 and Fig. As shown in Figure 20, the connecting plate section 93 has a substantially rectangular plate shape. The connecting plate section 93 is curved to surround one end of the wound electrode group 2. That is, the connecting plate section 93 has an “R” shape, bent in an arc along the direction of the shorter side of the connecting plate section 93, such that one side is recessed opposite one end of the wound electrode group 2. Apart from this, the negative electrode backup line 9, which is shown in Figure 20, has a substantially rectangular plate shape. Fig. 19 and Fig. Figure 20 shows the same structure as that of the negative electrode backup line 9, which is described with reference to Fig. 17 and Fig. As described in section 18, if the connecting plate section 93 has a substantially rectangular plate shape and is curved to surround one end of the wound electrode group 2, the entire connecting plate section 93 simply comes into contact with the end face of the wound electrode group 2, resulting in a favorable situation in which electrical resistance is reduced. Furthermore, because the end of the connecting plate section 93 is less likely to deform longitudinally away from one end of the wound electrode group 2, a favorable situation arises in which the negative electrode insulating cover 11 is less likely to be damaged.

[0082] A positive electrode, a negative electrode, a separator and a non-aqueous electrolyte of the battery according to the embodiment are described in detail below. (1) Positive electrode

[0083] The positive electrode can, for example, include a positive electrode current collector, a layer containing positive electrode active material that is carried on the positive electrode current collector, and a positive electrode current collector attachment. The layer containing positive electrode active material can, for example, include a positive electrode active material, a conductive medium, and a binder.

[0084] For example, an oxide or a sulfide can be used as the active material of the positive electrode. Examples of oxides and sulfides include manganese dioxide (MnO2) for the insertion of lithium, iron oxide, copper oxide, nickel oxide, and lithium-manganese compound oxides (e.g., Li₂O₃). x Mn2O4 or Li x MnO2), lithium nickel composite oxide (e.g. Li x NiO2), lithium-cobalt composite oxide (e.g. Li x CoO2), lithium nickel cobalt composite oxide (e.g. LiNi 1-y Co y O2), lithium-manganese-cobalt composite oxide (e.g. Li xMn y Co 1-y O2), lithium manganese nickel composite oxide with a spinel structure (e.g. Li x Mn 2-y Ni y O4), lithium phosphorus oxide with an olivine structure (e.g. Li x FePO4, Li x Fe 1-y Mn y PO4 and Li x CoPO4), iron sulfate (Fe2(SO4)3), vanadium oxide (e.g., V2O5), and lithium-nickel-cobalt-manganese compound oxide. In the formulas above, 0 < x ≤ 1 and 0 < y ≤ 1. These compounds can be used alone or in combination as the active material.

[0085] The binder is added to bind the active material and the current collector. Examples of binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and fluorinated gum.

[0086] The conductive agent is added to improve current collection performance and suppress contact resistance between the active material and the current collector. Examples of conductive agents include carbon-containing materials such as acetylene black, carbon black, and graphite.

[0087] In the layer containing the positive electrode active material, the positive electrode active material and the binder are preferably mixed in proportions of 80 wt% to 98 wt% and 2 wt% to 20 wt%, respectively.

[0088] If the binder content is 2% by mass or more, sufficient electrode thickness can be achieved. If the binder content is 20% by mass or less, the insulating material content of the electrode can be reduced, as can the internal resistance.

[0089] When the conductive agent is added, the positive electrode active material, the binder, and the conductive agent are preferably mixed in proportions of 77 wt% to 95 wt%, 2 wt% to 20 wt%, and 3 wt% to 15 wt%, respectively. If the amount of conductive agent is 3 wt% or more, the effects described above can be achieved. If the amount of conductive agent is 15 wt% or less, decomposition of the non-aqueous electrolyte on the surface of the conductive positive electrode agent during high-temperature storage can be reduced.

[0090] The positive electrode current collector is preferably an aluminum foil or an aluminum alloy foil containing at least one element selected from Mg, Ti, Zn, Ni, Cr, Mn, Fe, Cu and Si.

[0091] The positive electrode current collector is preferably integrated into the positive electrode current collector assembly. Alternatively, the positive electrode current collector can be separate from the positive electrode current collector assembly. (2) Negative electrode

[0092] The negative electrode can, for example, include a negative electrode current collector, a layer containing negative electrode active material that is carried on the negative electrode current collector, and a negative electrode current collector attachment. The layer containing negative electrode active material can, for example, include a negative electrode active material, a conductive agent, and a binder.

[0093] For example, a metal oxide, a metal nitride, an alloy, carbon, or the like, which allows lithium ions to be inserted and extracted, can be used as the negative electrode active material. A material that allows lithium ions to be inserted at a high potential of 0.4 V or more (vs. Li / Li) is suitable. + ) inserted and extracted, is preferably used as the negative electrode active material.

[0094] The conductive agent is added to improve current collection performance and to suppress the contact resistance between the negative electrode active material and the current collector. Examples of conductive agents include carbon-containing materials such as acetylene black, carbon black, and graphite.

[0095] The binder is added to fill gaps beneath the dispersed negative electrode active material and also to bind the negative electrode active material and the current collector. Examples of binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorinated rubber, and styrene-butadiene rubber.

[0096] The active material, the conductive agent, and the binder in the negative electrode active material-containing layer are preferably mixed in proportions of 68 wt% to 96 wt%, 2 wt% to 30 wt%, and 2 wt% to 30 wt%, respectively. If the amount of conductive agent is 2 wt% or more, the current collection performance of the negative electrode active material-containing layer can be improved. If the amount of binder is 2 wt% or more, the bond between the negative electrode active material-containing layer and the current collector can be sufficiently strong, and excellent cycling characteristics can be expected. Conversely, from a standpoint of increased capacity, the amount of each of the conductive agent and the binder is preferably 28 wt% or less.

[0097] The current collector is made of a material that is electrochemically stable during lithium insertion and extraction potential testing of the negative electrode active material. The current collector is preferably made of copper, nickel, stainless steel, aluminum, or an aluminum alloy containing at least one element selected from Mg, Ti, Zn, Mn, Fe, Cu, and Si. The thickness of the current collector is preferably in the range of 5 to 20 µm. A current collector of this thickness can maintain a balance between the strength and weight reduction of the negative electrode.

[0098] The negative electrode current collector is preferably integrated into the negative electrode current collector assembly. Alternatively, the negative electrode current collector can be separate from the negative electrode current collector assembly.

[0099] The negative electrode is produced, for example, by suspending the negative electrode active material, the binder, and the conductive material in a commonly used solvent to prepare a slag, applying the slag to the current collector, and allowing the slag to dry to form the negative electrode active material layer. The negative electrode layer is then pressed into place. Alternatively, the negative electrode can be produced by forming the negative electrode active material, the binder, and the conductive material into pellets to form the negative electrode active material layer, and then applying this layer to the current collector. (3) Separator

[0100] The separator can be made, for example, from a porous film or a synthetic nonwoven resin containing polyethylene, polypropylene, cellulose, or polyvinylidene fluoride (PVdF). In particular, a porous film made of polyethylene or polypropylene melts at a specific temperature and is able to interrupt an electric current, resulting in improved safety. (4) Electrolytic solution

[0101] For example, a non-aqueous electrolyte can be used as the electrolytic solution.

[0102] The non-aqueous electrolyte can be, for example, a liquid non-aqueous electrolyte produced by dissolving an electrolyte in an organic solvent, or a non-aqueous gel electrolyte obtained by combining a liquid electrolyte and a polymer material.

[0103] The liquid non-aqueous electrolyte is preferably an electrolyte dissolved in an organic solvent at a concentration of 0.5 mol / l to 2.5 mol / l.

[0104] Examples of electrolytes dissolved in an organic solvent include lithium salts such as lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsene (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), and lithium bistrifluoromethylsulfonylimide (LiN(CF3SO2)2), and mixtures thereof. The electrolyte is preferably resistant to oxidation even at high potentials, with LiPF6 being the most preferred.

[0105] Examples of organic solvents include: cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), and vinylene carbonate; chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC); cyclic ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), and dioxolane (DOX); chain ethers such as dimethoxyethane (DME) and diethoxyethane (DEE); and γ-butyrolactone (GBL), acetonitrile (AN), and sulfolane (SL). These organic solvents can be used either alone or as a mixed solvent.

[0106] Examples of the polymer material include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), and polyethylene oxide (PEO).

[0107] Alternatively, a room temperature melting salt (ionic melt) containing lithium ions, a solid polymer electrolyte, an inorganic solid electrolyte, or the like can be used as the non-aqueous electrolyte.

[0108] Room temperature melting salts (ionic melts) refer to compounds that can exist as liquids at room temperature (15°C to 25°C) and are organic salts formed from combinations of organic cations and anions. Room temperature melting salts include those that exist as liquids on their own, those that become liquids when mixed with an electrolyte, and those that become liquids when dissolved in an organic solvent. Generally, the melting point of room temperature melting salts used in non-aqueous electrolyte batteries is 25°C or less. Furthermore, the organic cations generally possess a quaternary ammonium framework.

[0109] The battery according to the first embodiment comprises: an outer sleeve comprising a side wall and a bottom wall and an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode assembly housed in the outer sleeve such that one winding axis of the wound electrode assembly intersects the side wall, and comprising a current collection attachment wound in multiple layers, arranged at at least one end of the wound electrode assembly; a first conductor clamping the current collection attachment wound in multiple layers; a second conductor electrically connected to the first conductor; and a metallic cover attached to the opening of the outer sleeve and comprising a terminal.The first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collector, wound in multiple layers, inserted between them; and a connecting plate section that joins the terminal plate section and the cover plate section and faces at least one end of the wound electrode group. The second conductor comprises a substrate electrically connected to the terminal and a leg section extending in a direction perpendicular to the winding axis of the wound electrode group, the leg section being electrically connected to the terminal plate section.The cover plate section comprises: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected and non-connected sides. The second plate section includes a projection that extends relative to the first plate section along a direction in which the leg section extends.The unconnected side and part of the opposite side of the projection are bent towards at least one end of the wound electrode group. The battery exhibits excellent impregnation properties for an electrolytic solution. (Second embodiment)

[0110] According to a second embodiment, a battery pack is provided. The battery pack includes the battery according to the first embodiment.

[0111] The battery pack according to the second embodiment can contain a plurality of batteries. The plurality of batteries can be electrically connected in series or in parallel. Alternatively, the plurality of batteries can be connected in a combination of series and parallel connections.

[0112] The battery pack according to the second embodiment can, for example, contain five batteries. These batteries can be connected in series. The batteries connected in series can also form a battery module. This means that the battery pack according to the second embodiment can contain a battery module.

[0113] The battery pack according to the second embodiment can comprise a plurality of battery modules. The plurality of battery modules can be connected in series, in parallel, or in a combination of series and parallel connections.

[0114] An example of the battery pack according to the second embodiment is described below with reference to Fig. 21 and Fig. 22 described. Fig. Figure 21 is an expanded perspective view of an example of the battery pack according to the second embodiment. Fig. Figure 22 is a block diagram showing an example of an electrical circuit of the battery pack that is in Fig. 21 is shown.

[0115] A 200-cell battery pack that is in Fig. 21 and Fig. Figure 22 shows a battery module 23 formed from a plurality of unit cells 39. The unit cell 39 can be an example of the battery according to the first embodiment, which is described with reference to Fig. 1 to 5 are described.

[0116] As in Fig. As shown in Figure 22, the multitude of unit cells 39 are electrically connected in series.

[0117] A printed circuit board 24 is arranged to face the side surface from which a positive electrode side lead 28 and a negative electrode side lead 30 of the battery module 23 extend. As shown in Fig. As shown in Figure 22, the printed circuit board 24 is provided with a thermistor 25, a protection circuit 26, and a terminal 27 for energizing an external device. An insulating plate (not shown) is attached to the surface of the printed circuit board 24 facing the battery module 23 to avoid unnecessary contact with the wiring of the battery module 23.

[0118] A distal end of the positive electrode side lead 28 is inserted into a positive electrode side connector 29 of the printed circuit board 24 and electrically connected to it. A distal end of the negative electrode side lead 30 is inserted into a negative electrode side connector 31 of the printed circuit board 24 and electrically connected to it. These connectors 29 and 31 are connected to the protective circuit 26 by wires 32 and 33 formed on the printed circuit board 24.

[0119] The thermistor 25 detects the temperature of the unit cells 39, and the detection signals are transmitted to the protection circuit 26. Under a predetermined condition, the protection circuit 26 can disconnect a positive-side wire 34a and a negative-side wire 34b between the protection circuit 26 and the terminal 27 to activate an external device. An example of a predetermined condition is when the temperature detected by the thermistor 25 becomes equal to or higher than a predetermined temperature. Another example of a predetermined condition is when an overcharge, over-discharge, overcurrent, or similar condition of the unit cell 39 is detected. Overcharge detection is performed for individual unit cells 39 or for the entire battery module 23. In the case of detection for individual unit cells 39, a battery voltage or a positive or negative electrode potential can be detected.In the latter case, a lithium electrode, used as a reference electrode, is inserted into each unit cell 39. In the battery pack 200, which is in . Fig. 21 and Fig. As shown in Figure 22, a wire 35 for voltage detection is connected to each of the unit cells 39. Detection signals are transmitted via the wires 35 to the protection circuit 26.

[0120] Protective covers 36, made of rubber or resin, are arranged on three side surfaces of the battery module 23, except for the side surface from which the positive electrode side lead 28 and the negative electrode side lead 30 protrude.

[0121] The battery module 23 is housed in a housing container 37 together with each protective cover 36 and the printed circuit board 24. That is, the protective covers 36 are arranged on both of the inner surfaces in the long direction and on one of the inner surfaces in the short direction of the housing container 37, and the printed circuit board 24 is arranged on the other inner surface in the short direction. The battery module 23 is positioned in a space enclosed by the protective covers 36 and the printed circuit board 24. A lid 38 is attached to an upper surface of the housing container 37.

[0122] Instead of adhesive tape 19, a heat-shrinkable tape can be used to secure the battery module 23. In this case, protective sleeves are placed on both of the side surfaces of the battery module, and the heat-shrinkable tape is wrapped around the battery module and then thermally contracted to bind the battery module.

[0123] Fig. 21 and Fig. Figure 22 shows the configuration in which the unit cells 39 are connected in series; however, the unit cells 39 can also be connected in parallel to increase the battery capacity. Furthermore, assembled battery packs can be connected in series and / or parallel.

[0124] The configuration of the battery pack according to the second embodiment is modified as appropriate depending on the application. The battery pack according to the second embodiment is preferably used in applications where cycle power with high current output is desired. Specific applications include power supplies for digital cameras and in-vehicle applications for two- or four-wheeled electric hybrid vehicles, two- or four-wheeled electric vehicles, e-bikes, and the like. The battery pack according to the second embodiment is particularly suitable for use in in-vehicle applications.

[0125] The battery pack according to the second embodiment includes the battery according to the first embodiment. Therefore, the battery pack according to the second embodiment exhibits excellent impregnation properties of the electrolytic solution.

[0126] According to at least one embodiment described above, a battery is provided. The battery comprises: an outer sleeve including a side wall and a bottom wall and an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode assembly housed in the outer sleeve such that one winding axis of the wound electrode assembly intersects the side wall, and comprising a current collection attachment wound in multiple layers, arranged at at least one end of the wound electrode assembly; a first lead clamping the multi-layered current collection attachment; a second lead electrically connected to the first lead; and a metallic cover attached to the opening of the outer sleeve and comprising a terminal.The first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collector, wound in multiple layers, inserted between them; and a connecting plate section that joins the terminal plate section and the cover plate section and faces at least one end of the wound electrode assembly. The second conductor comprises a substrate electrically connected to the terminal and a leg section extending in a direction perpendicular to the winding axis of the wound electrode assembly, the leg section being electrically connected to the terminal plate section.The cover plate section comprises: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected and non-connected sides. The second plate section includes a projection that extends relative to the first plate section along a direction in which the leg section extends.The unconnected side and part of the opposite side of the projection are bent towards at least one end of the wound electrode group. The battery exhibits excellent impregnation properties for an electrolytic solution.

[0127] While certain embodiments have been described, these embodiments are presented only as examples and are not intended to limit the scope of the inventions. In fact, the new embodiments described herein may be embodied in a multitude of other forms; furthermore, various omissions, substitutions, and modifications in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as if they fell within the scope and spirit of the inventions. REFERENCE MARK LIST 1 outer sleeve 2. Wound electrode group 3 Positive electrode leads (second positive electrode leads) 3a Substrat 3b Through hole 3c thigh section 4 Negative electrode leads (second negative electrode leads) 4a Substrat 4b Through hole 4c thigh section 5 lids 6 Positive electrode connection 7 Negative electrode connection 8 Positive electrode backup leads (first positive electrode lead) 9 Negative electrode backup lead (first negative electrode lead) 10 Positive electrode insulating cover 11 Negative electrode insulating cover 12 First positive electrode seal 12 Positive electrode seal 13 Negative electrode seal 13 First negative electrode seal 14 Safety valve 15 Caps for electrolyte injection port 16 Second positive electrode seal 17 Second negative electrode seal 18 Insulator 19 adhesive tape 20 positive electrode 20a Positive electrode current collection approach 20b layer containing positive electrode active material 20c Positive electrode current collector 21 separators 21a Separator 21b Separator 22 Negative electrode 22a Negative electrode current collection approach 22b Layer containing negative electrode active material 22c negative electrode current collector 23 Battery module 24 Printed circuit board 25 Thermistor 26 Protection circuit 27 Power distribution connection 28 Positive electrode side leads 29 Positive electrode side connectors 30 Negative electrode side leads 31 Negative electrode side connectors 32 wire 33 wire 34a Positive side wire 34b Negative side wire 35 wire 36 Protective cover 37 Housing containers 38 lids 39 unit cells 40 insulating tape 50 cap bodies 91 Connection plate section 92 Cover plate section 92a First plate section 92b Second plate section 93 Connecting plate section 100 batteries 200 battery pack 220 limit 910 Upper Lead 910a Upper unconnected side 910b Upper opposite side 910c Top side 910d corner section 910e Corner section 911 Lower Lead 911a Lower unconnected side 911b Lower opposite side 911c Bottom side 911d Corner section 911e Corner section 912 Related Pages 913 Opposite side 920 Upper Lead 920a Upper unconnected side 920b Upper opposite side 920c Top side 920d corner section 920e corner section 921 Lower Lead 921a Lower unconnected side 921b Lower opposite side 921c Bottom side 921d Corner section 921e Corner section 922 related pages 923 Opposite side

Claims

[1] Battery, comprising: an outer sleeve comprising a side wall and a bottom wall and including an opening on the opposite side of the bottom wall; an electrolytic solution; a wound electrode group housed in the outer sleeve such that a winding axis direction of the wound electrode group intersects the side wall, wherein the wound electrode group comprises a current collection extension wound in several layers, the current collection extension being arranged at at least one end of the wound electrode group; a first line which clamps the current collection unit, which is wound in several layers; a second line that is electrically connected to the first line; and a metallic cover attached to the opening of the outer sleeve and comprising a connection, where the first conductor comprises: a terminal plate section electrically connected to the second conductor; a cover plate section opposite the terminal plate section, with the current collection attachment, wound in several layers, inserted between them; and a connecting plate section connecting the terminal plate section and the cover plate section, facing at least one end of the wound electrode group. the second conductor comprises: a substrate electrically connected to the terminal; and a leg section extending in a direction perpendicular to the winding axis direction of the wound electrode group, the leg section being electrically connected to the terminal plate section, The cover plate section comprises the following: a first plate section adjacent to the connecting plate section and forming part of the cover plate section; and a second plate section extending continuously from the first plate section and forming another part of the cover plate section. The second plate section comprises the following: a connected side that is joined to the first plate section; a non-connected side that extends along a direction in which the connected side extends and is not connected to the first plate section; and a counter-side that is positioned on a side opposite the connected side and the non-connected side. wherein the second plate section includes a projection defined by an outer edge encompassing the unconnected side and the opposite side, the projection projecting relative to the first plate section along a direction in which the leg section extends, and the unconnected side and part of the opposite side are bent at the projection towards at least one end of the wound electrode group. [2] Battery according to claim 1, wherein The projection comprises the following: an upper projection that extends relative to the first plate section towards the substrate of the second conduit along the direction in which the leg section extends; and a lower projection that extends relative to the first plate section in one direction opposite to the upper projection along the direction in which the leg section extends, and the upper projection is defined by an outer edge comprising an upper non-connected side and an upper opposite side, wherein the upper non-connected side is continuous with the connected side and not connected with the first plate section, and the upper opposite side is contained in the part of the opposite side, the lower projection is defined by an outer edge comprising a lower non-connected side and a lower opposite side, wherein the lower non-connected side is continuous with the connected side and not connected with the first plate section, and the lower opposite side is contained in the part of the opposite side, and the upper unconnected side, the upper opposite side, the lower unconnected side and the lower opposite side are bent in the direction of at least one end of the wound electrode group. [3] Battery according to claim 1 or 2, wherein the width of the connecting plate section in the direction in which the leg section extends is greater than the width of the first plate section in the direction in which the leg section extends. [4] Battery according to any one of claims 1 to 3, wherein the terminal plate section comprises: a third plate section adjacent to the connecting plate section and forming a part of the terminal plate section; and a fourth plate section extending continuously from the third plate section and forming a further part of the terminal plate section, the fourth plate section comprises the following: a second connected side that is connected to the third plate section; a second unconnected side that extends along one direction, in which the second connected side extends and is not connected to the third plate section; and a second opposite side, positioned on a side opposite the second connected side and the second non-connected side, wherein the fourth plate section includes a second projection defined by an outer edge encompassing the second non-connected side and the second opposite side, wherein the second projection extends relative to the third plate section along the direction in which the leg section extends, and wherein the second unconnected side and part of the second opposite side are bent at the second projection towards at least one end of the wound electrode group. [5] Battery according to any one of claims 1 to 4, wherein the connecting plate section has a rectangular plate shape and is bent to surround at least one end of the wound electrode group. [6] Battery according to any one of claims 1 to 5, wherein the wound electrode group comprises a positive electrode current collector which is wound in several layers and a negative electrode current collector which is wound in several layers, wherein the positive electrode current collector is arranged at one end of the wound electrode group in the direction of the winding axis and the negative electrode current collector is arranged at another end of the wound electrode group in the direction of the winding axis, and The battery includes the following: a first positive electrode conductor, which collectively clamps the positive electrode current collection attachment, which is wound in several layers; a first negative electrode conductor, which collectively clamps the negative electrode current collection assembly, which is wound in several layers; a second positive electrode lead that is electrically connected to the first positive electrode lead; and a second negative electrode lead that is electrically connected to the first negative electrode lead, and wherein both the first positive electrode lead and the first negative electrode lead are the first lead according to any one of claims 1 to 5, and wherein both the second positive electrode lead and the second negative electrode lead are the second lead according to any one of claims 1 to 5. [7] Battery pack comprising the battery according to any one of claims 1 to 6.

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