Secondary battery

Abstract

A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case accommodating the electrode assembly; a positive electrode current collector in the case and electrically connected to the first electrode plate; a rivet terminal having one side connected to the positive electrode current collector and the other side extending to the outside of the case; an inner insulating portion between the positive electrode current collector and the case to block an electrical connection between the positive electrode current collector and the case; and a distance maintaining member between the inner insulating portion and the positive electrode current collector to maintain a distance between the inner insulating portion and the positive electrode current collector.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0040161 filed in the Korean Intellectual Property Office on March 25, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Aspects of embodiments of the present disclosure relate to a secondary battery. Background Art

[0004] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be recharged and discharged. Low-capacity secondary batteries can be used in small portable electronic devices such as smartphones, feature phones, notebook computers, digital cameras, and video cameras, while high-capacity secondary batteries can be used as power sources for driving motors and power storage batteries in hybrid vehicles or electric vehicles. A secondary battery may include an electrode assembly having a positive electrode and a negative electrode, a housing that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0005] The above information disclosed in the art used as background art of the present disclosure is only for enhancement of understanding of the background art of the present disclosure and therefore may include information that does not constitute related art. Summary of the Invention

[0006] Embodiments of the present disclosure provide a secondary battery capable of preventing a short circuit between a negative electrode of an electrode assembly and a rivet terminal.

[0007] These and other aspects and features of the present disclosure will be described in or will be apparent from the following description of embodiments of the present disclosure.

[0008] According to one embodiment of the present disclosure, a secondary battery includes: an electrode assembly, including a first electrode plate, a second electrode plate and a separator; a shell, which accommodates the electrode assembly; a positive electrode collector, which is in the shell and electrically connected to the first electrode plate; a rivet terminal, which has one side connected to the positive electrode collector and the other side extending to the outside of the shell; an inner insulating portion, which is between the positive electrode collector and the shell to block the electrical connection between the positive electrode collector and the shell; and a distance maintaining member, which is between the inner insulating portion and the positive electrode collector to maintain the distance between the inner insulating portion and the positive electrode collector.

[0009] In some embodiments, the positive electrode current collector may have an upper surface that is coplanar with or lower than a lower surface of the rivet terminal.

[0010] In some embodiments, the distance keeping member may have a plate shape with an inner hole configured to allow the rivet terminal to be positioned therein.

[0011] In some embodiments, the distance keeping member may include at least one of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET).

[0012] In some embodiments, a vertical length of the rivet terminal protruding into the housing may be equal to or greater than a sum of a vertical length of the inner insulating portion and a vertical length of the distance keeping member.

[0013] In some embodiments, the inner insulating part and the distance keeping member may be formed integrally with each other.

[0014] In some embodiments, the distance keeping member may be provided in plural, and the distance keeping member may protrude from the inner insulating part toward the positive electrode current collector and may be radially installed around the rivet terminal.

[0015] In some embodiments, the distance keeping member and the positive electrode current collector may be formed integrally with each other.

[0016] In some embodiments, the distance keeping member may protrude from the positive electrode current collector toward the inner insulating part.

[0017] In some embodiments, the distance keeping member may be provided in plural, and the distance keeping member may have a convex shape.

[0018] In some embodiments, the positive electrode current collector may include: a current collecting body mounted in contact with and electrically connected to a first electrode plate; an inner body in a spaced hole in the center of the current collecting body and fixed to a rivet terminal; and a bridge interconnecting the current collecting body and the inner body.

[0019] In some embodiments, the current collecting body may be integrally formed with the distance keeping member.

[0020] In some embodiments, the distance keeping member may include a hemispherical protrusion or a rectangular parallelepiped protrusion protruding from the current collecting body toward the inner insulating part.

[0021] In some embodiments, the distance keeping member may be provided in plural, and the distance keeping member may be installed radially around the inner body.

[0022] According to another embodiment of the present disclosure, a secondary battery includes: an electrode assembly, including a first electrode plate and a second electrode plate; a shell, accommodating the electrode assembly; a positive electrode collector, in the shell and electrically connected to the first electrode plate; a rivet terminal, having one side connected to the positive electrode collector and the other side extending to the outside of the shell; and a distance maintaining member, between the shell and the positive electrode collector, to maintain the distance between the shell and the positive electrode collector.

[0023] In some embodiments, the distance keeping member may be made of an insulating material and may have a plate shape with an inner hole configured to allow the rivet terminal to be positioned therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings attached to this specification illustrate embodiments of the present disclosure and, together with the detailed description of the present disclosure, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the drawings:

[0025] Figure 1 is a perspective view of a secondary battery according to an embodiment of the present disclosure;

[0026] Figure 2 yes Figure 1 A cross-sectional view of a secondary battery shown in ;

[0027] Figure 3 yes Figure 2 A close-up cross-section of a portion of

[0028] Figure 4 yes Figure 2 and Figure 3 A perspective view of a distance maintaining member shown in FIG;

[0029] Figure 5 is a close-up cross-sectional view of a portion of a secondary battery according to another embodiment of the present disclosure;

[0030] Figure 6 is a close-up cross-sectional view of a portion of a secondary battery according to another embodiment of the present disclosure;

[0031] Figure 7 yes Figure 6 A perspective view of the inner insulating portion and the distance keeping member shown in FIG;

[0032] Figure 8 is a close-up cross-sectional view of a portion of a secondary battery according to another embodiment of the present disclosure;

[0033] Figure 9 yes Figure 8 A perspective view of a positive electrode current collector and a distance keeping member shown in FIG;

[0034] Figure 10 is a perspective view of a distance maintaining member according to another embodiment of the present disclosure;

[0035] Figure 11A and Figure 11B is a perspective view of a battery pack including a secondary battery according to an embodiment of the present disclosure; and

[0036] Figure 12A and Figure 12BAccording to one embodiment of the present disclosure, Figure 11A and Figure 11B Perspective and side views of a vehicle with a battery pack shown in FIG. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Terms or words used in this specification and claims should not be restrictively interpreted as conventional or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical idea of ​​the present disclosure based on the principle that the inventor can be his / her own lexicographer to appropriately define terminology concepts to describe his / her invention in the best possible manner.

[0038] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some of the embodiments of the present disclosure and do not represent all of the technical spirit, aspects, and features of the present disclosure. Therefore, it should be understood that at the time of filing this application, various equivalents and modifications that can replace or modify the embodiments described herein may exist.

[0039] In addition, the terms "include" and / or "comprising", when used in this specification, specify the existence of stated shapes, numbers, steps, operations, components, elements and / or groups thereof, but do not exclude the existence or addition of one or more other shapes, numbers, steps, operations, components, elements and / or groups thereof.

[0040] In addition, in order to facilitate the understanding of the present invention, the accompanying drawings are not depicted to scale; for the sake of clarity, the sizes of some components may be exaggerated. In addition, the same components in different embodiments may be indicated by the same reference numerals.

[0041] When two compared objects are referred to as being the same, this means that the two objects are "substantially the same." Thus, substantially the same can include deviations that are considered low in the art, such as less than 5%. Furthermore, when a parameter is uniform in a region, this can mean that the parameter is uniform from an average perspective.

[0042] Although "first" and "second" etc. are used to describe various components, these components are of course not limited by these terms. These terms are only used to distinguish one component from other components, and unless otherwise stated, the first component can be called the second component.

[0043] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0044] When any element is referred to as being “disposed on (or below)” a component or “disposed on (or under)” the component, this not only means that the arbitrary element is disposed in contact with the upper surface (or lower surface) of the component, but also means that other elements may be interposed between the component and any element disposed on (or under) the component.

[0045] When a component is described in this patent document as being "connected," "coupled," or "engaged" to another component, it should be understood that the components can be directly connected or engaged to each other. However, it should also be interpreted that an intervening component can be between one component and another component, or each component can be "connected," "coupled," or "engaged" through another intervening component. In addition, when a part is described as being electrically connected (electrically coupled) to another part, this includes not only direct connection, but also situations where other elements are located therebetween, thereby facilitating an indirect connection.

[0046] Throughout this specification, the term "A and / or B" should be interpreted as A, B, or both A and B, unless an alternative interpretation is explicitly stated. Therefore, "and / or" includes any and all possible combinations of the listed items. Similarly, when "C to D" is mentioned, it should be understood to mean C and up to and including D, unless otherwise stated. The terminology used herein is intended only to describe specific embodiments and should not be considered to limit the scope of the present disclosure.

[0047] Figure 1 is a perspective view of a secondary battery 100 according to an embodiment of the present disclosure, and Figure 2 yes Figure 1 sectional view of the secondary battery 100 shown in FIG. Figure 1 and Figure 2 As shown in , according to an embodiment of the present disclosure, a secondary battery 100 may include a case 110, an electrode assembly 120, a negative electrode current collector 130, a positive electrode current collector 150, a rivet terminal 144, a distance maintaining member 180, and a vent plate 160. In some embodiments, the secondary battery 100 may further include at least one of an insulating gasket 171, an upper insulating member 172, a cap gasket 173, and an inner insulating portion 174. According to an embodiment of the present disclosure, the secondary battery 100 may be a cylindrical secondary battery, but the present disclosure is not limited thereto.

[0048] The housing 110 may be modified in various ways (e.g., may have various shapes) as long as the electrode assembly 120 is accommodated in the housing 110. The electrode assembly 120 may include a first electrode plate 121 and a second electrode plate 122. The housing 110 may house the electrode assembly 120 and the electrolyte in the housing 110 and may define the appearance of the secondary battery 100 together with the exhaust plate 160. The housing 110 may include or may be referred to as a can, an outer shell, or an outer body. The housing 110 may include a housing upper wall 111 having a generally disk-shaped shape and a cylindrical housing side wall 112 extending downward from the housing upper wall 111. In some embodiments, the housing 110 may have various suitable shapes other than a cylindrical shape, such as a bag shape. The housing 110 may include a metal such as steel, nickel-plated steel, alloy steel, aluminum, aluminum alloy, or deep-drawn cold-rolled steel (SPCE), or a laminated film or plastic constituting the bag. The housing side wall 112 may have a rolled portion (e.g., a rolled portion) 113 that is pressed inward toward the interior of the housing 110. The case side wall 112 may be provided with a crimping portion (e.g., a crimping end) 114 bent toward the inside of the case 110 at a lower end of the case side wall 112. If the case 110 includes a crimping portion 113 and a crimping portion 114, the crimping portion 114 may be located below the crimping portion 113. The crimping portion 113, together with the case upper wall 111, may suppress movement of the electrode assembly 120 in the case 110. The crimping portion 114 may press the peripheral portion of the exhaust plate 160 via the cover gasket 173, thereby firmly fixing the exhaust plate 160 to the case 110.

[0049] The electrode assembly 120 may be housed in the housing 110 together with the electrolyte. The electrode assembly 120 may include or may be referred to as an electrode group, an electrode body, or an electrode core. The electrode assembly 120 may include a first electrode plate 121, a second electrode plate 122, and a separator 123 disposed between the first electrode plate 121 and the second electrode plate 122, and may be wound in a cylindrical shape. In some embodiments, the electrode assembly 120 may have a vertical longitudinal direction (e.g., Figure 2 In some embodiments, a center pin may be provided in the hollow core 124 (eg, may be coupled to the hollow core 124).

[0050] The first electrode plate 121 may include a first substrate 1211 and a first active material layer 1212 on the first substrate 1211. The first substrate 1211 may have a first uncoated portion (or first tab) 1213 where the first active material layer 1212 is not present. The first uncoated portion (or first tab) 1213 of the first substrate 1211 may extend outward (e.g., upward), and the first tab 1213 may be electrically connected to the positive electrode current collector 150. According to an embodiment of the present disclosure, the first tab 1213 may be referred to as a first uncoated portion or a positive electrode substrate tab.

[0051] The second electrode plate 122 may include a second substrate 1221 and a second active material layer 1222 on the second substrate 1221. The second substrate 1221 may have a second uncoated portion (or second tab) 1223 where the second active material layer 1222 is absent. The second uncoated portion (or second tab) 1223 of the second substrate 1221 may extend outward (e.g., downward), and the second tab 1223 may be electrically connected to the negative electrode current collector 130. In some embodiments, the first tab 1213 and the second tab 1223 may extend in opposite directions. According to embodiments of the present disclosure, the second tab 1223 may be referred to as a second uncoated portion or a negative electrode substrate tab.

[0052] The first electrode plate 121 can serve as a positive electrode. In this embodiment, the first substrate 1211 can be formed of, for example, aluminum foil, and the first active material layer 1212 can include, for example, a transition metal oxide. The second electrode plate 122 can serve as a negative electrode. In this embodiment, the second substrate 1221 can be formed of, for example, copper foil or nickel foil, and the second active material layer 1222 can include, for example, graphite and / or silicon.

[0053] The separator 123 can prevent a short circuit between the first electrode plate 121 and the second electrode plate 122 while allowing lithium ions to move therebetween. In some embodiments, the separator 123 can be located on each of the two opposing side surfaces of the first electrode plate 121, or can be located on each of the two opposing side surfaces of the second electrode plate 122.

[0054] The negative electrode current collector 130 may be variously modified, as long as it is welded to the housing 110 and electrically connected to the electrode assembly 120. The negative electrode current collector 130 may be connected to a second tab 1223 of the electrode assembly 120. The negative electrode current collector 130 may include or may be referred to as a second current collecting body, a second conductive body, or a second conductive plate. In some embodiments, the negative electrode current collector 130 may be formed into a generally disc shape. A plurality of second tabs 1223 extending / protruding from the electrode assembly 120 may be electrically connected to the upper surface of the negative electrode current collector 130. The second tabs 1223 may be bent inwardly toward (e.g., toward) the hollow core 124, or in outwardly away from (e.g., away from) the hollow core 124, and may extend straight in a vertical direction. The second tabs 1223 may be laser welded to the upper surface of the negative electrode current collector 130. The negative electrode current collector 130 may include copper, a copper alloy, nickel, a nickel alloy, aluminum, or an aluminum alloy. In some embodiments, the negative electrode current collector 130 may be assembled between the crimping portion 113 and the cap gasket 173 to be electrically connected to the case 110. According to the illustrated embodiment, the negative electrode current collector 130 may include a body portion 132 mounted in contact with the second electrode plate 122 and a wing portion 136 extending outward from the body portion 132 and fixed to the case 110 by welding.

[0055] The positive electrode current collector 150 may be variously modified, as long as the positive electrode current collector 150 is located in the housing 110 and electrically connected to the first electrode plate 121. The positive electrode current collector 150 may be connected to the first tab 1213 of the electrode assembly 120. The positive electrode current collector 150 may include or may be referred to as a first current collecting body, a first conductive body, or a first conductive plate. In some embodiments, the positive electrode current collector 150 may be formed into a generally disc shape. A plurality of first tabs 1213 extending / protruding from the electrode assembly 120 may be electrically connected to the lower surface of the positive electrode current collector 150. In some embodiments, the first tab 1213 may be bent in an inward direction toward (e.g., toward) the hollow core 124, or in an outward direction away from (e.g., away from) the hollow core 124 to be laser welded to the lower surface of the positive electrode current collector 150. The positive electrode current collector 150 may include aluminum, an aluminum alloy, copper, a copper alloy, nickel, or a nickel alloy.

[0056] The positive electrode current collector 150 may be located between the electrode assembly 120 and the rivet terminal 144 , and may be electrically connected to the first electrode plate 121 and the rivet terminal 144 .

[0057] The positive electrode current collector 150 may have a shape corresponding to the shape of the upper portion of the electrode assembly 120 and may be formed as, for example, a circular metal plate. The planar size of the positive electrode current collector 150 may be equal to or smaller than the size of the upper surface of the electrode assembly 120. The positive electrode current collector 150 may be made of aluminum (Al). The lower surface of the positive electrode current collector 150 may be fixed by welding while in contact with the upper portion of the electrode assembly 120. The positive electrode current collector 150 may be fixed and electrically connected to the first electrode plate 121 exposed (or protruding or extending) upward from the electrode assembly 120. Because the upper surface of the positive electrode current collector 150 is fixed by welding while in contact with the lower surface of the rivet terminal 144, the positive electrode current collector 150 may be fixed and electrically connected to the rivet terminal 144. Because the positive electrode collector 150 is located between and electrically connected to the first electrode plate 121 of the electrode assembly 120 and the rivet terminal 144 , the positive electrode collector 150 may serve as a current flow path.

[0058] According to an embodiment of the present disclosure, the positive electrode current collector 150 may include: a current collecting body 151 that contacts and is electrically connected to the first electrode plate 121; an inner body 153 that is located in a spacing hole (e.g., a center hole or opening) 154 formed in the center of the current collecting body 151 and is fixed to the rivet terminal 144; and a bridge 152 that interconnects the current collecting body 151 and the inner body 153 (e.g., see FIG. 1 ). Figure 9 ).

[0059] The current collecting body 151 may have a disc shape and may be located in the housing 110. The current collecting body 151 and the first electrode plate 121 may be fixed to each other by welding. The spacing hole 154 may be formed as a hole that penetrates (or extends through) the current collecting body 151, and the inner body 153 may be located at the center of the spacing hole 154. The inner body 153 may be welded and electrically connected to the central body of the rivet terminal 144. The inner body 153 may be formed in a disc shape. The inner body 153 and the current collecting body 151 may be connected to each other via a bridge 152.

[0060] The rivet terminal 144 may be variously modified as long as one side of the rivet terminal 144 is connected to the positive electrode current collector 150 and the other side extends to the outside of the case 110. The upper surface of the positive electrode current collector 150 may be coplanar with or lower than the lower surface of the rivet terminal 144.

[0061] The rivet terminal 144 may be coupled to the case 110 to be electrically connected to the electrode assembly 120. According to an embodiment of the present disclosure, the rivet terminal 144 may include or may be referred to as a rivet or a terminal.

[0062] The rivet terminal 144 may include a rivet post 141, a rivet head 142, and a rivet leg 143. The rivet post 141 may be coupled to the housing upper wall 111 while penetrating (or extending through) the housing upper wall 111. The rivet head 142 may be connected to the upper end of the rivet post 141 and may be located above the housing upper wall 111. The rivet leg 143 may be connected to the lower end of the rivet post 141 and may be located below the housing upper wall 111. In some embodiments, an insulating gasket 171 may be interposed between the rivet post 141 and the housing upper wall 111. In some embodiments, an upper insulating member 172 may be interposed between the rivet head 142 and the upper side of the housing upper wall 111. In some embodiments, an inner insulating portion 174 may be installed between the rivet leg 143 and the lower side of the housing upper wall 111. The inner insulating portion 174 may be variously modified as long as the inner insulating portion 174 is installed between the rivet terminal 144 and the housing 110 and blocks electrical connection between the rivet terminal 144 and the housing 110 .

[0063] In some embodiments, the insulating liner 171, the upper insulating member 172, and the inner insulating portion 174 may be provided separately. In some embodiments, the insulating liner 171, the upper insulating member 172, and the inner insulating portion 174 may not be integral with each other. In some embodiments, the insulating liner 171 and the upper insulating member 172 may be integral with each other, and the inner insulating portion 174 may be provided separately. In some embodiments, the insulating liner 171, the upper insulating member 172, and the inner insulating portion 174 may be integral with each other. In some embodiments, the insulating liner 171 and the inner insulating portion 174 may be integral with each other, and the upper insulating member 172 may be provided separately. In some embodiments, the rivet post 141 may have a rivet recess 1411 formed therein. In some embodiments, the rivet leg 143 may be electrically connected to the positive electrode current collector 150. In some embodiments, a laser beam may be irradiated through the rivet recess 1411 to weld the rivet leg 143 to the positive electrode current collector 150. In some embodiments, after the welding process, the rivet recess 1411 can be filled with metal or blocked by a metal plate. The rivet terminal 144 can include aluminum, an aluminum alloy, copper, a copper alloy, nickel, or a nickel alloy. The rivet terminal 144 can be used as an external terminal electrically connected to an external device. In some embodiments, the upper wall 111 of the housing can also be used as an external terminal electrically connected to an external device. Because the gap between the housing 110 and the rivet terminal 144 is blocked (e.g., filled) by the insulating liner 171 and the upper insulating member 172, leakage of the electrolyte can be prevented.

[0064] If the cylindrical housing 110 has a large diameter, the cylindrical secondary battery 100 may be referred to as a large-diameter secondary battery. In a large-diameter secondary battery 100, the distance between the second active material layer 1222 of the second electrode plate 122 and the rivet terminal 144 should be maintained above a certain value to ensure safety. During the process of welding the negative electrode current collector 130 to the electrode assembly 120, the electrode assembly 120 may be compressed. In this case, the distance between the second electrode plate 122 and the rivet terminal 144 may be reduced after welding the negative electrode current collector 130 and the electrode assembly 120.

[0065] For example, if the vertical length of the rivet terminal 144 protruding into the case 110 is 1.3 mm, the vertical length of the inner insulating portion 174 may be 0.8 mm, and the distance between the positive electrode current collector 150 and the inner insulating portion 174 may be 0.5 mm. In the above description, the protruding length of the rivet terminal 144, the vertical length of the inner insulating portion 174, and the distance between the positive electrode current collector 150 and the inner insulating portion 174 are provided only as examples and various modifications may be made. According to an embodiment of the present disclosure, the vertical length may be referred to as a thickness.

[0066] The distance-keeping member 180 may be installed in an empty space on (e.g., above) the positive electrode current collector 150 to prevent the positive electrode current collector 150 from bending upward toward the upper wall 111 of the case. By preventing the positive electrode current collector 150 from bending in an upward direction, the electrode assembly 120 welded to the positive electrode current collector 150 can be prevented from moving upward together with the positive electrode current collector 150, and a safe distance between the second electrode plate 122 and the rivet terminal 144 can be ensured. For example, if the vertical length of the rivet terminal 144 protruding into the case 110 is 1.3 mm and the vertical length of the inner insulating portion 174 is 0.8 mm, the vertical length of the distance-keeping member 180 can be in the range of about 0.3 to about 0.5 mm. If the vertical length of the distance-keeping member 180 is about 0.3 mm, the distance between the distance-keeping member 180 and the positive electrode current collector 150 can be maintained at about 0.2 mm or less; however, the present disclosure is not limited thereto. The vertical length of the distance keeping member 180 and the distance between the distance keeping member 180 and the positive electrode current collector 150 are provided merely as examples and may be variously modified.

[0067] The distance keeping member 180 may be variously implemented, for example, implemented as a separate spacer, increasing the thickness of the inner insulating part 174 , or adding a separate protrusion to the positive electrode current collector 150 .

[0068] The exhaust plate 160 can be modified in various ways, as long as the exhaust plate 160 shields (e.g., seals) the open inlet of the housing 110. The exhaust plate 160 can be coupled between the crimped portion 113 of the housing 110 and the crimped portion 114 of the housing 110, with the cover gasket 173 interposed between the crimped portion 113 of the housing 110 and the crimped portion 114 of the housing 110. The exhaust plate 160 can include or be referred to as a cover plate, a cover assembly, a safety vent, a conductive plate, or a sealing plate. In some embodiments, the exhaust plate 160 can be directly welded to the housing sidewall 112, or can be coupled to the housing sidewall 112 by crimping or sewing without forming the crimped portion 113 and the crimped portion 114.

[0069] In some embodiments, the vent plate 160 may have a vent recess 161 formed in the upper or lower surface of the vent plate 160, such that the portion of the vent plate 160 corresponding to the vent recess 161 has a reduced thickness. In some embodiments, the vent plate 160 may have a peripheral region 162 fitted between the crimping portion 113 and the crimping portion 114; an inner region 163 connected to the peripheral region 162 and formed lower than the peripheral region 162; and a central region 164 connected to the inner region 163 and formed higher than the inner region 163. The vent recess 161 may be formed in the inner region 163. In some embodiments, the central region 164 may be closer to the electrode assembly 120 than the peripheral region 162 and the inner region 163. If the pressure in the secondary battery 100 exceeds a reference pressure, the vent recess 161 may rupture to discharge internal gas. The vent plate 160 may include steel, nickel-plated steel, stainless steel, aluminum, or an aluminum alloy. In some embodiments, the housing 110 and the exhaust plate 160 coupled to the housing 110 may be collectively referred to as the housing 110 .

[0070] The cap gasket 173 may be variously modified as long as the cap gasket 173 has a shape surrounding the outer circumference of the exhaust plate 160 and is installed to block electrical connection between the negative electrode current collector 130, the case 110, and the exhaust plate 160. According to an embodiment of the present disclosure, the cap gasket 173 may be installed between the exhaust plate 160 and the wing portion 136 of the negative electrode current collector 130.

[0071] Figure 3 yes Figure 2 A close-up cross-sectional view showing that a distance keeping member 180 according to an embodiment of the present disclosure is installed between the inner insulating portion 174 and the positive electrode current collector 150, and Figure 4 yes Figure 3 A perspective view of the distance keeping member 180 is shown in FIG. Figure 3 and Figure 4As shown in , the inner insulating portion 174 may be variously modified as long as the inner insulating portion 174 is installed between the positive electrode current collector 150 and the case 110 and blocks the electrical connection between the positive electrode current collector 150 and the case 110. The inner insulating portion 174 may be interposed between the case 110 and the rivet terminal 144. The inner insulating portion 174 may be in contact with the case upper wall 111 or may be bonded to the case upper wall 111. In some embodiments, a portion of the inner insulating portion 174 may be in contact with the rivet post 141 or bonded to the rivet post 141.

[0072] The distance-keeping member 180 can be modified in various ways, as long as it is located between the inner insulating portion 174 and the positive electrode current collector 150 and maintains the distance between the inner insulating portion 174 and the positive electrode current collector 150. According to one embodiment of the present disclosure, the distance-keeping member 180 can be made of an insulating material and can be formed into a plate shape, with a first inner hole 182 formed in the distance-keeping member 180 to allow the rivet terminal 144 to be located in the first inner hole 182 (e.g., pass through the first inner hole 182). In some embodiments, the distance-keeping member 180 can include at least one of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The distance-keeping member 180 can be located below the inner insulating portion 174 and above the positive electrode current collector 150. The distance-keeping member 180 can be provided separately from the inner insulating portion 174 and can be modified in various ways in shape and thickness. According to the illustrated embodiment, the distance-keeping member 180 can have a disc shape, and the first inner hole 182 is located at the center of the distance-keeping member 180. The vertical length of the rivet terminal 144 protruding into the case 110 may be greater than or equal to the sum of the vertical length of the inner insulating portion 174 and the vertical length of the distance-keeping member 180. If the distance-keeping member 180 is additionally installed between the positive electrode current collector 150 and the inner insulating portion 174, the distance between the second electrode plate 122 and the rivet terminal 144 can be prevented from being reduced or minimized. The vertical length of the distance-keeping member 180 may be set (or determined) by the distance between the positive electrode current collector 150 and the inner insulating portion 174 or the distance between the positive electrode current collector 150 and the case upper wall 111.

[0073] Figure 5 FIG is a cross-sectional view of a secondary battery including a distance maintaining member 184 according to another embodiment of the present disclosure. Figure 5As shown in the embodiment shown, the distance keeping member 184 according to the embodiment shown can be formed integrally with the inner insulating portion 174. For example, only the distance keeping member 184 can be installed between the positive electrode current collector 150 and the upper wall 111 of the case. As described in conjunction with the above embodiment, the distance keeping member 184 can serve as the inner insulating portion 174. The distance keeping member 184 can be made of an insulating material and can include at least one of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET).

[0074] The horizontal length of the distance keeping member 184 may be greater than that of the positive electrode current collector 150 , thereby preventing contact between the positive electrode current collector 150 and the case 110 and improving electrical safety.

[0075] The vertical length of the rivet terminal 144 protruding into the housing 110 through the housing upper wall 111 can be equal to or greater than the vertical length of the distance-keeping member 184. If the vertical length of the rivet terminal 144 protruding into the housing 110 is greater than the vertical length of the distance-keeping member 184, the distance-keeping member 184 and the positive electrode current collector 150 can be spaced apart from each other at a set distance. The spacing distance between the distance-keeping member 184 and the positive electrode current collector 150 can be set to approximately 0.2 mm. However, the spacing distance between the distance-keeping member 184 and the positive electrode current collector 150 can be modified in various ways, as long as the distance-keeping member 184 prevents the positive electrode current collector 150 from deforming upward. If there is no spacing between the distance-keeping member 184 and the positive electrode current collector 150, the spacing between the positive electrode current collector 150 and the electrode assembly 120 may be reduced to below a safe distance during the assembly process, thereby reducing electrical safety.

[0076] Figure 6 is a cross-sectional view of a secondary battery including a distance keeping member 186 according to another embodiment of the present disclosure, and Figure 7 yes Figure 6 A perspective view of the inner insulating portion 174 and the distance keeping member 186 is shown in FIG. Figure 6 and Figure 7As shown in , the distance keeping member 186 according to the illustrated embodiment may be provided in plurality, and the plurality of distance keeping members 186 may protrude from the inner insulating portion 174 toward the positive electrode current collector 150 and may be radially installed (or arranged) around the rivet terminal 144. The inner insulating portion 174 may be formed in a disc shape with a central hole 175 formed therein, and the distance keeping members 186 radially installed around the central hole 175 may be integrally formed with the inner insulating portion 174, or may be bonded or fixed to the inner insulating portion 174. The distance keeping member 186 may be made of an insulating material and may include at least one of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET).

[0077] The vertical length of the rivet terminal 144 protruding into the housing 110 through the housing upper wall 111 may be equal to or greater than the sum of the vertical length of the inner insulating portion 174 and the vertical length of the distance holding member 186. Figure 6 As shown in the figure, the vertical length of the rivet terminal 144 protruding into the shell 110 through the shell upper wall 111 can be greater than the sum of the vertical length of the inner insulating portion 174 and the vertical length of the distance keeping member 186, and the distance keeping member 186 and the positive electrode current collector 150 can be spaced apart from each other at a set interval.

[0078] Figure 8 is a cross-sectional view of a secondary battery including a distance keeping member 188 according to another embodiment of the present disclosure, and Figure 9 yes Figure 8 A perspective view of the positive electrode current collector 150 and the distance keeping member 188 is shown in FIG. Figure 8 and Figure 9 As shown in , the distance keeping member 188 according to the illustrated embodiment may be variously modified as long as the distance keeping member 188 protrudes from the positive electrode current collector 150 toward the inner insulating part 174 .

[0079] The positive electrode current collector 150 may include: a current collecting body 151, which is installed to contact the electrode assembly 120 and is electrically connected to the electrode assembly 120; an inner body 153, which is located in a spacing hole 154 formed in the center of the current collecting body 151 and fixed to the rivet terminal 144; and a bridge 152, which interconnects the current collecting body 151 and the inner body 153. The distance keeping member 188 can be implemented as a plurality of protrusions. That is, the distance keeping member 188 can be provided in plurality, and the distance keeping member 188 can have a protruding shape. The distance keeping member 188 can be formed integrally with the current collecting body 151 of the positive electrode current collector 150. In some embodiments, the distance keeping member 188 may include a hemispherical protrusion or a rectangular parallelepiped protrusion protruding from the current collecting body 151 toward the inner insulating portion 174.

[0080] The vertical length of the rivet terminal 144 protruding into the housing 110 through the housing upper wall 111 may be equal to or greater than the sum of the vertical length of the inner insulating portion 174 and the vertical length of the distance holding member 188. Figure 8 As shown in , the vertical length of the rivet terminal 144 protruding into the housing 110 can be greater than the sum of the vertical length of the inner insulating portion 174 and the vertical length of the distance keeping member 188, and the distance keeping member 188 and the inner insulating portion 174 can be spaced apart from each other at a set interval.

[0081] The distance keeping member 188 according to the illustrated embodiment (e.g., the protrusion included in the distance keeping member 188) may be installed radially around the inner body 153. The protrusion included in the distance keeping member 188 may be made of the same material as the positive electrode current collector 150. The protrusion included in the distance keeping member 188 may protrude upward from the positive electrode current collector 150 to face (e.g., contact) the inner insulating portion 174. The protrusion included in the distance keeping member 188 and the inner insulating portion 174 may be installed to contact each other or to be spaced apart from each other at a set interval. Figure 9 As shown in FIG, the protrusions included in the distance keeping member 188 may have a hemispherical shape and may be installed (or arranged) in a cross shape or a radial shape around the inner body 153.

[0082] Figure 10 FIG is a perspective view of a distance maintaining member 189 according to another embodiment. Figure 10 As shown in , the distance keeping member 189 according to the illustrated embodiment may be made of the same material as the positive electrode current collector 150 and may be formed in a rectangular parallelepiped strip shape. Figure 10 The distance keeping member 189 shown in FIG. 1 may include a plurality of rectangular parallelepiped belt-shaped protrusions, and the plurality of belt-shaped protrusions may be installed (or arranged) in a cross shape or a radial shape around the inner body 153 .

[0083] The electrode assembly 120 according to an embodiment of the present disclosure will be described in more detail below.

[0084] A compound capable of reversibly intercalating and deintercalating lithium (eg, a lithiated intercalation compound) may be used as the positive electrode active material. For example, at least one composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0085] The composite oxide may be a lithium transition metal composite oxide, and examples thereof may include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, or combinations thereof.

[0086] As an example, a compound represented by any one of the following chemical formulas can be used: Lia A 1-b X b O 2-c D c (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Mr 2-b X b O 4-c D c (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2);Li a Ni 1-b- c Mr b X c O 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2);Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0≤d≤0.5,0≤e≤0.1);Li a NiG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a CoG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mr 1-b G b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mn2G b O4(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mr 1-g G g PO4(0.90≤a≤1.8,0≤g≤0.5);Li (3-f) Fe2(PO4)3(0≤f≤2);Li a FePO4(0.90≤a≤1.8)。

[0087] In the above chemical formula: A is Ni, Co, Mn or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D is O, F, S, P or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; and L 1 It is Mn, Al or a combination thereof.

[0088] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0089] Based on 100 wt % of the positive electrode active material layer, the content of the positive electrode active material is in the range of about 90 wt % to about 99.5 wt %, and based on 100 wt % of the positive electrode active material layer, the content of the binder and the conductive material are respectively in the range of about 0.5 wt % to about 5 wt %.

[0090] The current collector may be aluminum (Al), but is not limited thereto.

[0091] The negative electrode active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0092] The material capable of reversibly intercalating / deintercalating lithium ions may be a carbon-based negative electrode active material, which may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may include graphite, such as natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon, hard carbon, pitch carbide, mesophase pitch carbide, and sintered coke, etc.

[0093] Si-based negative electrode active materials or Sn-based negative electrode active materials can be used as materials capable of doping and dedoping lithium. Si-based negative electrode active materials can be silicon, silicon-carbon composites, SiO x (0<x<2), Si-based alloys or combinations thereof.

[0094] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0095] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core including crystalline carbon and silicon particles and an amorphous carbon coating on the surface of the core.

[0096] A negative electrode for a lithium secondary battery may include a current collector and a negative electrode active material layer disposed on the current collector. The negative electrode active material layer may include a negative electrode active material and may further include a binder and / or a conductive material.

[0097] For example, the negative electrode active material layer may include about 90 wt % to about 99 wt % of the negative electrode active material, about 0.5 wt % to about 5 wt % of the binder, and about 0 wt % to about 5 wt % of the conductive material.

[0098] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used as the binder. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0099] One selected from the group consisting of copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a conductive metal-coated polymer matrix, and combinations thereof may be used as the negative electrode current collector.

[0100] An electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0101] The non-aqueous organic solvent serves as a medium through which ions participating in the electrochemical reaction of the battery can move.

[0102] The non-aqueous organic solvent may be a carbonate, ester, ether, ketone, alcohol solvent, or an aprotic solvent, and may be used alone or in combination of two or more.

[0103] Furthermore, when a carbonate-based solvent is used, a mixture of a cyclic carbonate and a chain carbonate may be used.

[0104] Depending on the type of lithium secondary battery, a separator may be present between a first electrode plate (eg, a negative electrode) and a second electrode plate (eg, a positive electrode). Polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof may be used as the separator.

[0105] The separator may include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof on one or both surfaces of the porous substrate.

[0106] The organic material may include polyvinylidene fluoride-based antibodies or (meth)acrylate polymers.

[0107] The inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof, but is not limited thereto.

[0108] The organic material and the inorganic material may be mixed in one coating layer, or may be in the form of a coating layer containing an organic material and a coating layer containing an inorganic material stacked on each other.

[0109] The battery according to the above-described embodiment can be used to manufacture a battery pack.

[0110] Figure 11A and Figure 11B is a perspective view of a battery pack including a secondary battery according to an embodiment of the present disclosure.

[0111] See also Figure 11A and Figure 11B , the battery pack 300 may include a plurality of battery modules 200 and a housing 310 for accommodating the plurality of battery modules 200. For example, the housing 310 may include a first housing 311 and a second housing 312 coupled in a facing direction, and the plurality of battery modules 200 are interposed between the first housing 311 and the second housing 312. The plurality of battery modules 200 may be electrically connected to each other using bus bars 251, and the plurality of battery modules 200 may be electrically connected in series / parallel or a mixed series-parallel manner to obtain the desired electrical output. In the accompanying drawings, for convenience, components such as bus bars, cooling units, and external terminals for electrical connection of battery cells are omitted. In some embodiments, the battery pack 300 may be mounted on a vehicle. For example, the vehicle may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle and a two-wheeled vehicle.

[0112] Figure 12A and Figure 12B They include Figure 11A and Figure 11B 1 and 2 are perspective and side views of vehicles 400 , 500 showing a battery pack 300 .

[0113] exist Figure 12A In the embodiment, battery pack 300 may include a pack cover 311, which is part of a vehicle chassis 410 and may correspond to a first housing; and a pack frame 312, which is positioned below the vehicle chassis 410 and may correspond to a second housing. The pack cover 311 and the pack frame 312 may be structurally integrated with the vehicle floor panel 420. The vehicle chassis 410 separates the interior and exterior of the vehicle, and the pack frame 312 may be located on the exterior of the vehicle.

[0114] like Figure 12B As shown in FIG, a vehicle 500 may be assembled with additional components such as a hood 510 in front of a vehicle body 400 and fenders 520 at the front and rear of the vehicle. The vehicle 500 includes a battery pack 300 including a pack cover 311 and a pack frame 312, and the battery pack 300 may be coupled to the vehicle body part 400.

[0115] As apparent from the above description, according to the embodiments of the present disclosure, since the distance maintaining member is installed between the positive electrode collector and the inner insulating part, a short circuit between the negative electrode of the electrode assembly and the rivet terminal may be prevented.

[0116] However, the effects achievable through the present invention are not limited to those described above, and other unmentioned technical effects can be clearly understood by those skilled in the art through the description of the present invention provided above.

Claims

1. A secondary battery comprising: an electrode assembly comprising a first electrode plate, a second electrode plate and a separator; a housing for accommodating the electrode assembly; a positive electrode current collector in the housing and electrically connected to the first electrode plate; a rivet terminal having one side connected to the positive electrode current collector and another side extending to the outside of the case; an inner insulating portion between the positive electrode current collector and the housing to block electrical connection between the positive electrode current collector and the housing; as well as A distance maintaining member is provided between the inner insulating portion and the positive electrode current collector to maintain a distance between the inner insulating portion and the positive electrode current collector. 2 . The secondary battery according to claim 1 , wherein the positive electrode current collector has an upper surface that is coplanar with or lower than a lower surface of the rivet terminal. 3 . The secondary battery according to claim 1 , wherein the distance keeping member has a plate shape with an inner hole configured to allow the rivet terminal to be positioned therein. 4 . The secondary battery according to claim 1 , wherein the distance keeping member comprises at least one of polyethylene, polypropylene, and polyethylene terephthalate. 5 . The secondary battery according to claim 1 , wherein a vertical length of the rivet terminal protruding into the case is equal to or greater than a sum of a vertical length of the inner insulating part and a vertical length of the distance keeping member. 6 . The secondary battery according to claim 1 , wherein the inner insulating part and the distance keeping member are formed integrally with each other.

7. The secondary battery according to claim 1 or 6, wherein the distance keeping member is provided in plural, and The distance keeping member protrudes from the inner insulating portion toward the positive electrode current collector and is radially installed around the rivet terminal. 8 . The secondary battery according to claim 1 , wherein the distance keeping member and the positive electrode current collector are formed integrally with each other. 9 . The secondary battery according to claim 1 , wherein the distance keeping member protrudes from the positive electrode current collector toward the inner insulating part.

10. The secondary battery according to claim 9, wherein the distance keeping member is provided in plural, and The distance maintaining member has a convex shape.

11. The secondary battery according to claim 1, wherein the positive electrode current collector comprises: a current collecting body mounted in contact with the first electrode plate and electrically connected to the first electrode plate; an inner body in the spaced hole in the center of the current collecting body and fixed to the rivet terminal; as well as a bridge interconnecting the current collecting body and the inner body, and The current collecting body and the distance keeping member are formed integrally. 12 . The secondary battery according to claim 11 , wherein the distance keeping member comprises a hemispherical protrusion or a rectangular parallelepiped protrusion protruding from the current collecting body toward the inner insulating part.

13. The secondary battery according to claim 11 or 12, wherein the distance keeping member is provided in plural, and The distance keeping member is radially mounted around the inner body.

14. A secondary battery comprising: An electrode assembly comprising a first electrode plate and a second electrode plate; a housing for accommodating the electrode assembly; a positive electrode current collector in the housing and electrically connected to the first electrode plate; a rivet terminal having one side connected to the positive electrode current collector and another side extending to the outside of the case; as well as A distance maintaining member is provided between the case and the positive electrode current collector to maintain a distance between the case and the positive electrode current collector. 15 . The secondary battery according to claim 14 , wherein the distance keeping member is made of an insulating material and has a plate shape with an inner hole configured to allow the rivet terminal to be positioned therein.

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