JP6448107B2 - Secondary battery - Google Patents

Description

  The present invention relates to a secondary battery that can be repeatedly charged and discharged.

  Secondary batteries are rechargeable batteries, unlike primary batteries that cannot be recharged, and are widely used in the field of small advanced electronic devices such as mobile phones, PDAs (Personal Digital Assistants), and notebook computers. ing.

  While secondary batteries are used in various fields, reliability tests based on the usage environment of secondary batteries have been taken up as an important issue. Typical reliability test items include durability due to temperature, drop strength, ESD (Electrostatic Discharge) prevention, and charge and discharge tests.

  Among these test items, the drop strength affects not only the mechanical characteristics of the secondary battery but also the operation. For example, when the secondary battery falls or when a strong impact is applied from the outside, if the secondary battery is damaged, an electrical short circuit may occur or the electrolyte may leak, causing the secondary battery to be damaged. Does not work properly.

US Patent Application Publication No. 2011/0081573 US Patent Application Publication No. 2011/0045340 Korean Published Patent No. 20-0326873

  The problem to be solved by the present invention is to provide a secondary battery that is robust or resistant to dropping.

  In order to achieve the above object, according to one aspect of the present invention, an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween, and the electrode assembly are inserted. As described above, an opening is formed on one side, and a can that houses the electrode assembly therein and a cap plate that seals the opening of the can, and at least one of the corners of the can One corner portion has a round shape, and a secondary battery having a larger outer curvature radius than the inner curvature radius is provided.

  According to one feature of the invention, the round corner is at least one of the corners surrounding the bottom of the can located on the opposite side of the cap plate.

  According to still another aspect of the present invention, the can includes a first surface extending in a first direction with respect to the round-shaped corner portion, and a second surface with respect to the round-shaped corner portion. A second surface extending in a direction, and the thickness of the first surface is greater than the thickness of the second surface.

  According to still another aspect of the present invention, the first surface is a bottom surface of the can located on the opposite side of the cap plate, and the second surface is provided between the cap plate and the bottom surface. A side surface of the can that is bent substantially perpendicular to the bottom surface.

  According to still another aspect of the present invention, the can has a generally hexahedron shape in which the opening is formed at a position corresponding to an upper surface, and a bottom surface located on the opposite side of the cap plate; the cap plate; A first side surface provided between the bottom surface and bent substantially perpendicular to the bottom surface; provided between the cap plate and the bottom surface; bent substantially perpendicular to the bottom surface; A second side surface facing one side surface, a third side surface provided between the cap plate and the bottom surface, bent substantially perpendicular to the bottom surface, and provided between the cap plate and the bottom surface. And a fourth side surface that is bent substantially perpendicularly to the bottom surface and faces the front surface.

  According to still another aspect of the present invention, the bottom surface is thicker than the first side surface, the second side surface, the third side surface, and the fourth side surface.

  According to still another aspect of the present invention, the bottom surface has a thickness of 0.57 mm to 0.63 mm, and each of the first side surface, the second side surface, the third side surface, and the fourth side surface. The thickness is 0.28 mm to 0.32 mm.

  According to still another aspect of the present invention, the round-shaped corner portion is formed at a position where the first side surface and the bottom surface are in contact with each other, and the round-shaped first corner portion having an outer curvature radius larger than the inner curvature radius. And a second corner portion having a round shape formed at a position where the second side surface and the bottom surface are in contact with each other and having an outer radius of curvature larger than the inner radius of curvature.

  According to still another aspect of the present invention, a third corner portion having a round shape formed at a position where the third side surface and the bottom surface are in contact with each other, the outer curvature radius being larger than the inner curvature radius, the fourth side surface, A fourth corner portion formed in a position where the bottom surface is in contact with each other and having an outer curvature radius larger than the inner curvature radius.

  According to still another aspect of the present invention, a first corner portion having a round shape formed at a position where the first side surface and the bottom surface are in contact with each other and having an outer curvature radius larger than an inner curvature radius, the second side surface, A second corner portion having a round shape formed at a position where the bottom surface is in contact with each other and having an outer curvature radius larger than the inner curvature radius.

  According to still another aspect of the present invention, the inner radius of curvature is 0.4 mm to 0.6 mm. According to still another aspect of the present invention, the outer radius of curvature is 1.0 mm to 1.2 mm.

  According to still another aspect of the present invention, an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween, and one side so that the electrode assembly is inserted. A can that accommodates the electrode assembly therein, and a cap plate that seals the opening of the can, and at least one of the corners of the can The corner portion has a round shape, and an outer radius of curvature of the corner portion of the round shape is larger than an inner radius of curvature, and the thickness of the first surface extending in the first direction around the corner portion of the round shape. Rechargeable batteries different from the thickness of the second surface extending in the second direction are provided.

  According to still another aspect of the present invention, an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween, and one side so that the electrode assembly is inserted. A can that accommodates the electrode assembly therein and a cap plate that seals the opening of the can, and the can is positioned on the opposite side of the cap plate. And a first side surface, a second side surface, a third side surface, and a fourth side surface that are provided between the cap plate and the bottom surface and are bent substantially perpendicularly to the bottom surface. The corner portion formed at a position where at least one side surface of the fourth side surface contacts the bottom surface has a round shape, and the outer radius of curvature of the corner portion of the round shape is larger than the inner radius of curvature. To provide a pond.

  According to one aspect of the present invention, the can is formed at a position where the first corner portion formed at a position where the bottom surface and the first side surface contact each other, and a position where the bottom surface contacts the second side surface. A second corner portion, a third corner portion formed at a position where the bottom surface and the third side surface are in contact, and a fourth corner portion formed at a position where the bottom surface and the fourth side surface are in contact.

  According to still another aspect of the present invention, the bottom surface is thicker than the first side surface, the second side surface, the third side surface, and the fourth side surface.

  According to an aspect of the present invention, the first side surface and the second side surface are parallel, the third side surface and the fourth side surface are parallel, and the first corner portion and the second corner portion are parallel to each other. The outer radius of curvature of each part is greater than the inner radius of curvature.

  The width of the first side surface and the width of the second side surface may be narrower than the width of the third side surface and the width of the fourth side surface.

  According to another aspect of the invention, the first side surface and the second side surface are parallel, the third side surface and the fourth side surface are parallel, and the third corner portion and the fourth corner portion. The outer radius of curvature of each is greater than the inner radius of curvature.

  According to one feature of the invention, the inner radius of curvature is between 0.4 mm and 0.6 mm and the outer radius of curvature is between 1.0 mm and 1.2 mm.

  According to the present invention, the outer curvature radius of each corner portion is made larger than the inner curvature radius, and the curvature of the inner surface of the corner portion is made larger than the curvature of the outer surface, so that the physical strength of the can can be ensured. Further, the physical strength of the can can be further improved by forming the bottom surface thicker than the side surface. Therefore, even if the secondary battery falls to the ground or an external impact is applied, the phenomenon that the can is damaged by the tensile force applied to the corner portion of the secondary battery can be effectively prevented.

1 is a perspective view schematically showing a secondary battery according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of FIG. 1. It is sectional drawing by the III-III line of FIG. It is drawing which shows the lower part among sectional drawings by the IV-IV line of FIG. It is sectional drawing which extracted and expanded the A part of FIG. It is sectional drawing which extracted and expanded the B section of FIG.

  While the present invention is capable of various transformations and has various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this should not be construed as limiting the invention to any particular embodiment, but should be understood to include all transformations, equivalents or alternatives that fall within the spirit and scope of the invention. In the description of the present invention, when it is determined that a specific description of a related known technique obscures the gist of the present invention, a detailed description thereof will be omitted. The first and second terms are used to describe various components, but the components should not be limited by the terms. Terminology must be used to distinguish one component from another. The terms used in the present application are merely used to describe particular embodiments, and are not intended to limit the present invention. The singular expression includes the plural unless the context clearly dictates otherwise. In this application, the term “comprising” or “having” is intended to specify the presence of a feature, number, step, action, component, part, or combination thereof described in the specification; It should be understood that the existence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof is not excluded in advance. Meanwhile, “/” used below may be interpreted as “and” or “or” depending on the situation.

  In the drawing, the thickness is shown enlarged to clearly show a plurality of layers and regions. Similar parts throughout the specification have been given the same reference numerals. When any one component is “on” or “on” another component, this is not only when it is directly above the other component, but also between the other components This includes cases where there is an element.

  1 is a perspective view schematically showing a secondary battery 100 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a line III-III in FIG. 4 is a drawing showing only the lower part of the sectional view taken along the line IV-IV in FIG.

  1 to 3, a rechargeable battery 100 according to an embodiment of the present invention includes an electrode assembly 110, a can 120 that houses the electrode assembly 110, and a cap plate 130 that seals the inside of the can 120.

  The electrode assembly 110 includes a first electrode plate 111 coated with an electrode active material, a second electrode plate 112, and a separator 113 interposed therebetween. The electrode assembly 110 is manufactured by forming a laminate in which the first electrode plate 111, the separator 113, and the second electrode plate 112 are sequentially laminated, and then winding the electrode assembly into a jelly roll shape. Each of the first electrode plate 111 and the second electrode plate 112 is electrically connected to a first electrode tab 114 and a second electrode tab 115 for extracting the charge formed by the chemical reaction to the outside. The first electrode tab 114 and the second electrode tab 115 extend in the same direction. For example, the first and second electrode tabs 114 and 115 extend toward the opening OP of the can 120.

  Although the case where the electrode assembly 110 has a jelly roll configuration has been described in the present embodiment, the present invention is not limited to this. In another embodiment, the electrode assembly 110 has a laminated structure in which a first electrode plate 111, a second electrode plate 112, and a separator 113 are interposed therebetween.

  The can 120 has a hexahedral shape in which one surface, that is, a surface corresponding to the upper surface is opened, and is made of a metallic material in order to ensure strength. For example, the can 120 is made of aluminum or an aluminum alloy. An electrode assembly 110 impregnated with an electrolyte is accommodated inside the can. At this time, the electrode assembly 110 is accommodated in the can 120 while being surrounded by the insulating sheet 170 so as not to cause an unnecessary short circuit with the can 120 formed of a metallic material. After the electrode assembly 110 is accommodated in the can 120, the opening OP is sealed by the cap plate 130. The portion where the cap plate 130 and the can 120 are in contact with each other can be kept airtight by being joined by laser welding.

  The cap plate 130 is provided with an electrolyte inlet 131. After the cap plate 130 and the can 120 are joined, the electrolyte is injected through the electrolyte inlet 131, and the electrolyte inlet 131 is sealed by the stopper 132. In another embodiment, the cap plate 130 may not include the electrolyte inlet 131. In this case, the electrolyte is injected before the cap plate 130 and the can 120 are joined together by laser welding.

  An electrode terminal 140 is disposed on the cap plate 130. The upper surface of the electrode terminal 140 is exposed to the outside through the upper part of the cap plate 130, and the lower part passes through the cap plate 130 toward the inside of the can 120.

  Similar to the can 120, the cap plate 130 is made of a metallic material. As shown in FIG. 3, the electrode terminal 140 is electrically connected to the first electrode tab 114 of the electrode assembly 110 and has a first polarity, and the cap plate 130 is connected to the second electrode tab 110 of the electrode assembly 110. It is electrically connected to the electrode tab 115 and has a second polarity. At this time, the can 120 connected to the cap plate 130 through welding also has the second polarity.

  For example, the cap plate 130 serves as a positive electrode of the secondary battery 100, and the electrode terminal 140 serves as a negative electrode of the secondary battery 100. At this time, a first gasket 145 and a second gasket 146 including an insulating material are provided between the cap plate 130 and the electrode terminal 140 in order to prevent a short circuit therebetween. The first gasket 145 is disposed so as to contact the upper surface of the cap plate 130, and the second gasket 146 is disposed so as to contact the lower surface of the cap plate 130. In FIG. 2, the first and second gaskets 145 and 146 are shown as separate members, but the first and second gaskets 145 and 146 are integrated. Meanwhile, in order to electrically insulate the can 120 having the second polarity from an external object or other secondary battery 100 through welding with the cap plate 130, the first and second cans 120 are disposed on both sides of the can 120. The insulating film 160 covering the two side surfaces 120s1 and 120s2 is attached.

  A first insulating material 150 located on the upper part of the electrode assembly 110 is disposed inside the can 120. The first insulating material 150 insulates the electrode assembly 110 from the cap plate 130. In another embodiment, the first insulating material 150 insulates the electrode assembly 110 from the cap plate 130 and restricts the movement of the electrode assembly 110 inside the can 120. The first insulating material 150 includes a through hole so that the first and second electrode tabs 114 and 115 extend toward the opening OP, and corresponds to the electrolyte inlet 131 so that the electrolyte flowing in through the electrolyte inlet 131 passes therethrough. The hole formed in the position to be included. On the other hand, a second insulating material 180 is disposed under the electrode assembly 110 to prevent an unnecessary short circuit between the metallic material can 120 and the electrode assembly 110.

  As shown in FIGS. 2 to 4, the can 120 includes an opening OP formed at a position corresponding to the upper surface, and a bottom surface 120 bt located on the opposite side of the opening OP, between the opening OP and the bottom surface 120 bt. And a first side surface 120s1, a second side surface 120s2, a third side surface 120s3, and a fourth side surface 120s4 that are bent perpendicularly to the bottom surface 120bt. The first side surface 120s1 and the second side surface 120s2 are provided on opposite sides in a parallel state, and the third side surface 120s3 and the fourth side surface 120s4 are provided on opposite sides in a parallel state. The can 120 is manufactured in a substantially rectangular parallelepiped shape. In this case, the width of the first side surface 120s1 and the second side surface 120s2 is narrower than the width of the third side surface 120s3 and the fourth side surface 120s4.

  According to the embodiment of the present invention, the first corner portion 120R1 formed at the portion where the first side surface 120s1 and the bottom surface 120bt are in contact, and the second corner formed at the portion where the second side surface 120s2 and the bottom surface 120bt are in contact. The part 120R2 is also a round form. That is, the first side surface 120s1 extends in the z-axis direction around the first corner 120R1 in the round shape, the bottom surface 120bt extends in the x-axis direction, and the second corner 120R2 in the z-axis direction as the center. The second side surface 120s2 extends and the bottom surface 120bt extends in the x-axis direction.

  In addition, the third corner portion 120R3 formed at the portion where the third side surface 120s3 and the bottom surface 120bt are in contact, and the fourth corner portion 120R4 formed at the portion where the fourth side surface 120s4 and the bottom surface 120bt are in contact are also round. . That is, the third side surface 120s3 extends in the z-axis direction around the third corner portion 120R3 in the round shape, the bottom surface 120bt extends in the x-axis direction, and the fourth corner portion 120R4 in the round shape serves as the center in the z-axis direction. The fourth side surface 120s4 extends, and the bottom surface 120bt extends in the x-axis direction.

  Hereinafter, the structure of the first and second corner portions 120R1 and 120R2 and the structure of the third and fourth corner portions 120R3 and 120R4 will be described.

  FIG. 5 is an enlarged view showing an extracted portion A of FIG. 3, and FIG. 6 is an enlarged view showing an extracted portion B of FIG.

  First, the structure of the first and second corner portions 120R1 and 120R2 will be described in more detail with reference to FIG. Since the structure of the first corner part 120R1 and the structure of the second corner part 120R2 are the same, the following description will focus on the structure of the first corner part 120R1, and the description regarding the structure of the second corner part 120R2 will be described below. It replaces with the description regarding the structure of 1st corner part 120R1.

  Referring to FIG. 5, the first corner portion 120R1 is located at a portion where the first side surface 120s1 and the bottom surface 120bt are in contact with each other, and has a round shape as a whole. The outer radius of curvature R and the inner radius of curvature r of the first corner portion 120R1 have different values. For example, the outer radius of curvature R of the first corner portion 120R1 is larger than the inner radius of curvature r. That is, the outer curvature of the first corner portion 120R1 is smaller than the inner curvature. As an example, the outer radius of curvature R is about 1.0 mm to 1.2 mm, and the inner radius of curvature r is about 0.4 mm to 0.6 mm.

  A first side surface 120s1 extends in the z-axis direction around the first corner portion 120R1, and a bottom surface 120bt extends in the x-axis direction. At this time, the thickness T of the bottom surface 120bt is formed to be thicker than the thickness t of the first side surface 120s1. For example, the thickness T of the bottom surface 120bt is about 0.57 mm to 0.63 mm, and the thickness t of the first side surface 120s1 is 0.28 mm to 0.32 mm, resulting in a difference of about twice.

  When the secondary battery 100 falls on a hard ground or floor surface, the corner portion may fall first on the ground or floor surface, so that the corner portion may be easily damaged. In particular, as in the present embodiment, if the secondary battery 100 is a rectangular parallelepiped shape, the first and second corner portions 120R1 and 120R2 formed on the first and second side surfaces 120s1 and 120s2 having a narrow width are first placed on the ground. There is a greater chance of falling. For this reason, there is a possibility that the first and second corner portions 120R1 and 120R2 are likely to be damaged.

  A comparative example of the present invention will be described in which the outer curvature radius R and the inner curvature radius r of the first corner portion 120R1 are formed to be the same. If an impact force is applied to the first corner portion 120R1 of the secondary battery 100 according to the comparative example due to a drop impact, the metal that forms a can by receiving forces that are pulled in opposite directions around the first corner portion 120R1. The can 120 is damaged in the vicinity of the first corner portion 120R1 while being pushed out.

  However, in the case of the secondary battery 100 according to the embodiment of the present invention, the outer corner radius R of the first corner portion 120R1 is formed larger than the inner radius of curvature r, so that the force applied to the first corner portion 120R1 Disperse primarily on the outside of the large radius and minimize the extrusion of the metal forming the can 120 by the tensile force.

  In particular, when the thickness T of the bottom surface 120bt is made thicker than the thickness t of the first side surface 120s1, the metal forming the can 120 is pushed out by the impact force (tensile force) applied to the first corner portion 120R1. Even so, the metal forming the relatively thick bottom surface 120bt prevents damage to the can 120 by filling the extruded portion.

  The structure of the third and fourth corner portions 120R3 and 120R4 will be described in more detail with reference to FIG. Since the structure of the third corner part 120R3 and the structure of the fourth corner part 120R4 are the same, the following description will focus on the structure of the third corner part 120R3, and the description of the structure of the fourth corner part 120R4 will be as follows. Instead of the description of the structure of the third corner portion 120R3.

  Referring to FIG. 6, the third corner portion 120R3 is located at a portion where the third side surface 120s3 and the bottom surface 120bt are in contact with each other, and has a round shape as a whole. The outer radius of curvature R and the inner radius of curvature r of the third corner portion 120R3 have different values. For example, the outer radius of curvature R of the third corner portion 120R3 is larger than the inner radius of curvature r. That is, the outer curvature of the third corner portion 120R3 is smaller than the inner curvature. As an example, the outer radius of curvature R is about 1.0 mm to 1.2 mm, and the inner radius of curvature r is about 0.4 mm to 0.6 mm.

  A third side surface 120s3 extends in the z-axis direction around the third corner portion 120R3, and a bottom surface 120bt extends in the x-axis direction. At this time, the thickness T of the bottom surface 120bt is formed to be thicker than the thickness t of the third side surface 120s3. For example, the thickness T of the bottom surface 120bt is about 0.57 mm to 0.63 mm, and the thickness t of the third side surface 120s3 is 0.28 mm to 0.32 mm, resulting in a difference of about twice.

  When the secondary battery 100 falls on a hard ground surface or floor surface, the corner portion first falls on the ground surface or floor surface, so that the corner portion may be easily damaged.

  As a comparative example of the present invention, a case will be described in which the outer radius of curvature R and the inner radius of curvature r of the third corner portion 120R3 are formed to be the same. If an impact force is applied to the third corner portion 120R3 of the secondary battery according to the comparative example due to the drop impact, the metal that forms the can receives the force pulled in the opposite directions around the third corner portion 120R3. While being pushed out, a phenomenon occurs in which the can is damaged in the vicinity of the third corner portion 120R3.

  However, in the case of the secondary battery 100 according to the embodiment of the present invention, the outer radius of curvature R of the third corner portion 120R3 is formed larger than the inner radius of curvature r, so that the force applied to the third corner portion 120R3 Disperse primarily on the outside with a large radius to minimize the extrusion of the metal forming the can 120 by tensile forces.

  In particular, when the thickness T of the bottom surface 120bt is made thicker than the thickness t of the third side surface 120s3, even if the metal forming the can 120 is extruded by the tensile force applied to the third corner portion 120R3, The metal forming the relatively thick bottom surface 120bt compensates for the extruded portion, thereby preventing the can 120 from being damaged.

  As described above, in the embodiment of the present invention, the case where each of the first to fourth corner portions 120R1 to 120R4 has a round shape has been described, but the present invention is not limited thereto. In still another embodiment, only the first and second corner portions 120R1 and 120R2 have a round shape in which the outer radius of curvature is larger than the inner radius of curvature. In still another embodiment, only the third and fourth corner portions 120R3 and 120R4 have a round shape in which the outer radius of curvature is larger than the inner radius of curvature.

  As described above, when the secondary battery falls to the ground by forming the outer radius of curvature of each corner larger than the inner radius of curvature and the thickness of the bottom surface larger than the thickness of the side surface (or external impact etc. ) Effectively prevents the can from being damaged by the impact force applied to the corner.

  Even though the present invention has been described in connection with the preferred embodiments described above, various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the scope of the claims includes such modifications and variations as long as they belong to the gist of the present invention.

  The present invention can be suitably applied to the technical field related to batteries.

100 Secondary Battery 110 Electrode Assembly 111 First Electrode Plate 112 Second Electrode Plate 113 Separator 114 First Electrode Tab 115 Second Electrode Tab 120 Can 120s1 First Side of Can 120s2 Second Side of Can 120s3 Third Side of Can 120s4 4th side surface of can 120bt bottom surface of can 130 cap plate 132 electrolyte inlet 132 plug 140 electrode terminal 145 first gasket 146 second gasket 160 insulating film 170 first insulating material 180 second insulating material 120R1 first corner portion 120R2 first 2 corner portion 120R3 3rd corner portion 120R4 4th corner portion r inner radius of curvature t thickness of first to fourth side surfaces OP opening R outer radius of curvature T thickness of bottom surface

Claims (18)

An electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween;
An opening is formed on one side so that the electrode assembly is inserted, and a can that houses the electrode assembly therein,
A cap plate for sealing the opening of the can,
The corner portion of the can has a round shape, and an outer radius of curvature of the corner portion of the round shape is larger than an inner radius of curvature, and a circle defined by the outer radius of curvature and a circle defined by the inner radius of curvature. Is a concentric circle,
The can has a first surface extending toward the bottom surface of the can with reference to the round-shaped corner portion, and a first surface extending toward the side surface of the can with respect to the round-shaped corner portion. Including two sides,
The secondary battery is thicker than the second surface.   The secondary battery according to claim 1, wherein the round-shaped corner portion is a corner portion surrounding a bottom surface of the can located on the opposite side of the cap plate. The first surface is a bottom surface of the can located on the opposite side of the cap plate;
The secondary battery according to claim 1, wherein the second surface is a side surface of the can that is provided between the cap plate and the bottom surface and is bent substantially perpendicularly to the bottom surface. . The can has a generally hexahedral shape in which the opening is formed at a position corresponding to the upper surface,
A bottom surface located on the opposite side of the cap plate;
A first side surface provided between the cap plate and the bottom surface and bent substantially perpendicular to the bottom surface;
A second side surface provided between the cap plate and the bottom surface, bent substantially perpendicular to the bottom surface and facing the first side surface;
A third side surface provided between the cap plate and the bottom surface and bent substantially perpendicular to the bottom surface;
A fourth side surface provided between the cap plate and the bottom surface, bent substantially perpendicular to the bottom surface and facing the front surface;
The secondary battery according to claim 1, comprising:   5. The secondary battery according to claim 4, wherein a thickness of the bottom surface is greater than a thickness of each of the first side surface, the second side surface, the third side surface, and the fourth side surface. The thickness of the bottom surface is 0.57 mm to 0.63 mm,
The thickness of each of said 1st side surface, said 2nd side surface, said 3rd side surface, and said 4th side surface is 0.28 mm-0.32 mm, The 2 of Claim 4 or 5 characterized by the above-mentioned. Next battery. The round-shaped corner is
A first corner portion having a round shape formed at a position where the first side surface and the bottom surface are in contact with each other, the outer curvature radius being larger than the inner curvature radius;
7. A second corner portion formed at a position where the second side surface and the bottom surface are in contact with each other, and having an outer curvature radius larger than the inner curvature radius. 7. Secondary battery described in 1. A third corner portion in a round shape formed at a position where the third side surface and the bottom surface are in contact with each other, the outer curvature radius being larger than the inner curvature radius;
8. A fourth corner portion formed at a position where the fourth side surface and the bottom surface are in contact with each other and having an outer curvature radius larger than the inner curvature radius. 8. Secondary battery described in 1. A first corner portion having a round shape formed at a position where the first side surface and the bottom surface are in contact with each other, the outer curvature radius being larger than the inner curvature radius;
9. A second corner portion formed at a position where the second side surface and the bottom surface are in contact with each other, and having an outer curvature radius larger than the inner curvature radius. 9. Secondary battery described in 1.   The secondary battery according to claim 1, wherein the inner radius of curvature is 0.4 mm to 0.6 mm.   The secondary battery according to any one of claims 1 to 10, wherein the outer curvature radius is 1.0 mm to 1.2 mm. An electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween;
A hexahedral shape with an opening formed on one side so that the electrode assembly is inserted; and a can that houses the electrode assembly therein;
A cap plate for sealing the opening of the can,
The corner portion of the can has a round shape, and an outer radius of curvature of the corner portion of the round shape is larger than an inner radius of curvature, and a circle defined by the outer radius of curvature and a circle defined by the inner radius of curvature. Is a concentric circle, and the thickness of the first surface extending in the direction of the bottom surface of the can and the thickness of the second surface extending in the direction of the side surface of the can are different from each other about the round corner portion. battery. An electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween;
A rectangular parallelepiped shape with an opening formed on one side so that the electrode assembly is inserted; and a can that houses the electrode assembly therein;
A cap plate for sealing the opening of the can,
The can includes a bottom surface located on the opposite side of the cap plate, a first side surface, a second side surface, and a third side surface provided between the cap plate and the bottom surface and bent substantially perpendicularly to the bottom surface. And a fourth side,
The corner portion formed at a position where the first to fourth side surfaces and the bottom surface are in contact with each other has a round shape, and an outer curvature radius of the round shape corner portion is larger than an inner curvature radius, and is determined by the outer curvature radius. and the circle defined, Ri concentric der the circle defined by the inner radius of curvature,
The thickness of the bottom surface is a secondary battery that is thicker than the thickness of each of the first side surface, the second side surface, the third side surface, and the fourth side surface . The can is a first corner portion formed at a position where the bottom surface and the first side surface are in contact with each other;
A second corner portion formed at a position where the bottom surface and the second side surface are in contact with each other;
A third corner portion formed at a position where the bottom surface and the third side surface are in contact with each other;
The secondary battery according to claim 13, further comprising a fourth corner portion formed at a position where the bottom surface and the fourth side surface are in contact with each other. The first side surface and the second side surface are parallel, the third side surface and the fourth side surface are parallel,
The secondary battery according to claim 14, wherein an outer radius of curvature of each of the first corner portion and the second corner portion is larger than an inner radius of curvature. The secondary according to any one of claims 13 to 15 , wherein a width of the first side surface and a width of the second side surface are narrower than a width of the third side surface and a width of the fourth side surface. battery. The first side surface and the second side surface are parallel, the third side surface and the fourth side surface are parallel,
The secondary battery according to claim 14, wherein an outer curvature radius of each of the third corner portion and the fourth corner portion is larger than an inner curvature radius. The inner radius of curvature is 0.4 mm to 0.6 mm, the outer radius of curvature, second according to any one of claims 13 to 17, characterized in that the 1.0mm~1.2mm Next battery.

Images