Collector plate and battery cell comprising same

Abstract

The present disclosure relates to a collector plate and a cell including the same, the collector plate according to one embodiment being a disk-shaped collector plate in which a raised surface including a central axis is raised, the collector plate may include: a raised space formed by the raised surface being raised; a raised opening portion defining an entrance of the raised space, the area of the raised opening portion being larger than the area of the raised surface; the connecting surface comprises the inner side surface of the raised space; a base surface including a surface other than the raised surface and the connecting surface; and a plurality of slits.

Description

Technical Field

[0001] This disclosure relates to a current collector and a battery cell including the current collector. More specifically, this disclosure relates to a current collector with improved mechanical rigidity and a battery cell with improved safety by including the current collector. Background Technology

[0002] A secondary battery is a battery that stores electrical energy by converting it into chemical energy and can be reused multiple times through charging and discharging. To obtain the desired output and performance, multiple secondary batteries can be grouped and manufactured into battery modules for use. Such battery modules can include multiple secondary batteries, or multiple cells, within their internal space, as described above.

[0003] Secondary batteries can be classified into can-type secondary batteries and bag-type secondary batteries based on the shape of their casing. Furthermore, can-type secondary batteries can be further classified into cylindrical secondary batteries and prismatic secondary batteries based on the shape of the can (or casing).

[0004] On the other hand, if the mechanical rigidity of each cell constituting the battery pack is not sufficiently ensured, the internal components of the cell may deteriorate or be damaged due to vibrations, impacts, or other external forces applied to the battery pack. Such deterioration or damage may lead to short circuits, potentially causing safety issues such as internal fires. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] According to one aspect of this disclosure, a current collector with improved mechanical rigidity, particularly its resistance to impact from external forces, and a battery cell including the current collector can be provided.

[0007] According to another aspect of this disclosure, a battery cell with improved safety can be provided.

[0008] On the other hand, this disclosure can be widely applied to electric vehicles, battery charging stations, energy storage systems (ESS), and other green technologies that utilize batteries, such as solar power (photovoltaics) and wind power. Furthermore, this disclosure can also be used for eco-friendly mobility, including electric vehicles and hybrid vehicles, to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0009] (II) Technical Solution

[0010] According to this disclosure, the current collector is a disc-shaped current collector with a raised surface including a central axis. The current collector may include: a raised space formed by the raised surface; a raised opening defining the entrance of the raised space, the area of ​​the raised opening being larger than the area of ​​the raised surface; a connecting surface including the inner surface of the raised space; a base surface including surfaces other than the raised surface and the connecting surface; and a plurality of slits.

[0011] According to one embodiment of the current collector, the raised surface and the base surface may be parallel to each other.

[0012] According to one embodiment of the current collector, the current collector may comprise aluminum.

[0013] According to one embodiment of the current collector, the thickness of the current collector can be from 0.3 mm to 0.6 mm.

[0014] According to one embodiment of the current collector, the height of the raised space can be from 0.1 mm to 3.0 mm.

[0015] According to one embodiment, the current collector may include: a first region, which is circular and has a predetermined first radius centered on the central axis on the raised surface; a second region, which is ring-shaped and has an inner diameter of a predetermined second radius and an outer diameter of a predetermined third radius centered on the central axis on the base surface; and a third region, which includes the region other than the first region and the second region, wherein the plurality of slits may be formed in the third region at predetermined intervals along the circumferential direction of the raised space.

[0016] According to one embodiment of the current collector, the second radius may be larger than the first radius.

[0017] According to one embodiment of the current collector, the third radius may be larger than the second radius.

[0018] According to one embodiment of the current collector, the plurality of slits may be formed in an area of ​​less than 10% of the total area of ​​the third region.

[0019] According to one embodiment of the current collector, the number of the plurality of slits can be four.

[0020] According to one embodiment, the current collector may further include: a bridging portion, formed in the third region between an adjacent pair of slits in the plurality of slits, and connecting the first region and the second region.

[0021] According to one embodiment of the current collector, the bridging portion may include at least one virtual path that bypasses the plurality of slits in the third region and connects the first region and the second region with the shortest distance.

[0022] According to one embodiment of the current collector, the bridging portion may include: a first boundary, which is connected to the periphery of the first region; and a second boundary, which is connected to the inner periphery of the second region, wherein at least one of the widths of the bridging portion defined along the circumferential direction of the first region may be greater than the length of the first boundary and also greater than the length of the second boundary.

[0023] A battery cell according to an embodiment of the present disclosure may include: a current collector according to an embodiment of the present disclosure; a housing having an internal receiving space; electrode terminals passing through at least a portion of the housing; and an electrode assembly wound around a winding shaft and electrically connected to the current collector, wherein the electrode assembly and the current collector can be housed in the receiving space, a raised surface of the current collector can be connected to the electrode terminals, and a base surface of the current collector can be connected to the electrode assembly.

[0024] According to one embodiment of the battery cell, the current collector may include: a first region, which is circular, having a predetermined first radius on the raised surface with the central axis as the center, and the electrode terminals may be connected to the current collector in the first region.

[0025] According to one embodiment of the battery cell, the electrode assembly may include: a first electrode including a first uncoated portion; a second electrode including a second uncoated portion; and a separator disposed between the first electrode and the second electrode, wherein the first uncoated portion may be connected to the base surface.

[0026] According to one embodiment of the battery cell, the current collector may include: a second region, which is annular, on the base surface, having an inner diameter with a preset second radius and an outer diameter with a preset third radius centered on the central axis, wherein the first uncoated portion may be connected to the current collector in the second region.

[0027] According to one embodiment of the battery cell, at least one first welding portion may be formed in the first region, and the electrode terminals may be welded to the current collector at the first welding portion.

[0028] According to one embodiment of the battery cell, at least one second welded portion may be formed in the second region, and the first uncoated portion may be welded to the current collector at the second welded portion.

[0029] According to one embodiment of the battery cell, multiple second welding portions can be formed, and the multiple second welding portions can be formed radially in the second region.

[0030] (III) Beneficial Effects

[0031] According to one aspect of this disclosure, a current collector with improved mechanical rigidity, particularly its resistance to impact from external forces, and a battery cell including the current collector can be provided.

[0032] According to another aspect of this disclosure, a battery cell with improved safety can be provided.

[0033] On the other hand, this disclosure can be widely applied to electric vehicles, battery charging stations, energy storage systems (ESS), and other green technologies that utilize batteries, such as solar power (photovoltaics) and wind power. Furthermore, this disclosure can also be used for eco-friendly mobility, including electric vehicles and hybrid vehicles, to prevent climate change by suppressing air pollution and greenhouse gas emissions. Attached Figure Description

[0034] Figure 1 This is a diagram illustrating an example of a current collector according to an embodiment of the present disclosure.

[0035] Figure 2 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from one direction.

[0036] Figure 3 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from another direction.

[0037] Figure 4 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from one direction.

[0038] Figure 5 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from another direction.

[0039] Figure 6 It is shown in magnification Figure 1 The diagram of region A.

[0040] Figure 7 This is a diagram illustrating an example of a battery cell according to an embodiment of the present disclosure.

[0041] Figure 8 It is shown Figure 7 A cross-sectional view of region B of the battery cell.

[0042] Figure 9 This is a diagram illustrating another example of a current collector according to an embodiment of the present disclosure.

[0043] Explanation of reference numerals in the attached figures:

[0044] 10: Battery Cell

[0045] 100: Current collector

[0046] 105: Raised Space 109: Raised Opening

[0047] 110: Raised surface; 120: Connecting surface; 130: Base surface

[0048] 140: Slit; 150: Bridging section

[0049] 171: Area 1 172: Area 2 173: Area 3

[0050] 1715: First welding section; 1725: Second welding section

[0051] 1721: Edge area; 1722: Welding area

[0052] 200: Electrode assembly

[0053] 210: First uncoated part

[0054] 311: Side wall portion; 312: Closed end portion

[0055] 400: Electrode terminal Detailed Implementation

[0056] The embodiments described in this specification can be modified in many other ways, and therefore, the technology according to one embodiment is not limited to the embodiments described below. Furthermore, throughout the specification, unless specifically stated to the contrary, the words "comprising," "provided with," "containing," or "having" a component do not imply the exclusion of other components, but rather may further include other components, and do not exclude elements, materials, or processes not additionally listed.

[0057] In this specification, unless otherwise specified, "identical or uniform" can mean identical or uniform to each other within an acceptable error range. For example, identical components or physical property measurements can mean not only that the two objects being compared are exactly the same, but also that they are identical within an error range. On the other hand, identical physical property measurements can mean that the difference between measurements between objects is approximately less than 5%, specifically less than 3%, and more specifically less than 1%.

[0058] In this specification, the angle formed by two objects being perpendicular or parallel can include not only geometrically perpendicular or parallel, but also cases within a small margin of error.

[0059] The numerical ranges used in this specification include lower and upper limits, as well as all values ​​within that range, increments logically derived from the form and width of the defined range, all values ​​with double limits, and all possible combinations of upper and lower limits of numerical ranges defined in different forms.

[0060] In this specification, unless otherwise defined, “about” can be considered as a value within 30%, 25%, 20%, 15%, 10% or 5% of the specified value.

[0061] In this specification, the use of terms such as "first," "second," and "third" before a component is solely to avoid confusion and is unrelated to the order, importance, or hierarchical relationship between the components. For example, an invention that excludes the first component and includes only the second component could also be implemented.

[0062] In this specification, "electrical connection" can refer to any connection method that enables multiple objects to be connected in a manner that allows them to be electrically connected to each other, and is not limited thereto.

[0063] In this specification, a construction defined as “…part” can refer to a single component, or a collection of two or more identical or similar components that share common functions, and is not limited thereto.

[0064] In this specification, "first direction DR1", "second direction DR2" and "third direction DR3" can refer to any direction that forms a mutually perpendicular orthogonal coordinate system in three-dimensional space.

[0065] In this specification, "set up" can refer to the positional relationship that allows one object to be placed adjacent to another object, and is not limited thereto. As a non-limiting example, it can refer to coating one object onto another object, or bonding one object to another object with an adhesive, or fusing by applying heat, pressure, etc., or simply placing one object in any space so that at least a portion of one object is in contact with at least a portion of another object.

[0066] In this specification, the term "covering" another object can refer to a functional or structural relationship in which one object is positioned at least adjacent to another object, thereby blocking or mitigating any external factors that may be imposed on the other object or a third object, without limitation. Alternatively, it can refer to a functional or structural relationship in which one object is positioned at least adjacent to a third object, thereby blocking or mitigating any external factors that may be imposed on the other object by one object and a third object, without limitation.

[0067] As used in this specification, the term "secondary battery" can refer to a battery that generates electrical energy through oxidation and reduction reactions when ions, specifically lithium ions and other cations, are inserted and extracted in the positive and negative electrodes. Specifically, "secondary battery" can refer to any one of the following: lithium-cobalt battery, lithium-high nickel battery, lithium iron phosphate battery, lithium-ion battery, lithium polymer battery, lithium-sulfur battery, nickel-metal hydride battery, nickel-cadmium battery, sodium battery, and all-solid-state battery. More specifically, the term "secondary battery" as used in this specification can refer to lithium-ion secondary batteries, but is not limited to this.

[0068] As used in this specification, the term "battery cell" can refer to the basic unit of a secondary battery that is capable of charging and discharging electrical energy.

[0069] The present disclosure will now be described in detail. However, this is merely exemplary, and the present disclosure is not limited to the specific embodiments described herein.

[0070] Figure 1 This is a diagram illustrating an example of a current collector according to an embodiment of the present disclosure.

[0071] Figure 2 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from one direction.

[0072] Figure 3 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from another direction.

[0073] According to one embodiment of the present disclosure, the current collector 100 is a disc-shaped current collector 100 with a raised surface 110 including a central axis. The current collector 100 may include: a raised space 105 formed by the raised surface 110; a raised opening 109 defining the entrance of the raised space 105, the area of ​​the raised opening 109 being larger than the area of ​​the raised surface 110; a connecting surface 120 including the inner side surface of the raised space 105; a base surface 130 including surfaces other than the raised surface 110 and the connecting surface 120; and a plurality of slits 140.

[0074] Reference Figures 1 to 3 The current collector 100 can be a disc-shaped current collector with a raised surface 110 including a central axis.

[0075] In one embodiment, the raised surface 110 may refer to a surface on the current collector 100 that has a circular, elliptical, oblong, square, rectangular, or square or rectangular shape with at least a portion of its edges rounded, having a central axis that is the same as the central axis of the current collector 100.

[0076] like Figure 1 and Figure 3 As shown, the raised surface 110 can refer to the surface that is raised along the third direction DR3 on the current collector plate 100.

[0077] The current collector 100 having the above shape may include a raised space 105 formed by the raised surface 110, a raised opening 109 defining the entrance of the raised space 105, a connecting surface 120 including the inner side surface of the raised space 105, and a base surface 130 including the surface other than the raised surface 110 and the connecting surface 120.

[0078] In one embodiment, the raised space 105 may include a raised opening 109.

[0079] In one embodiment, the area of ​​the raised opening 109 may be larger than the area of ​​the raised surface 110.

[0080] Reference Figure 3 In one embodiment, the raised space 105 may refer to the space formed by the raised surface 110. According to an exemplary embodiment, as described above, since the raised surface 110 has a shape that rises along a third direction DR3, and the area of ​​the raised opening 109 may be larger than the area of ​​the raised surface 110, the raised space 105 may have a generally truncated cone shape, or a frustum shape, with its top and bottom surfaces each having a circular, elliptical, oblong, square, rectangular, or square or rectangular shape with at least a portion of its edges rounded.

[0081] Reference Figure 3In one embodiment, the raised opening 109 may define the entrance to the raised space. In this case, the raised opening 109 may refer to a region in the raised space 105 that is parallel to the base surface 130 described below and may be included in the region extending from the base surface 130. Alternatively, in the raised space 105 having a generally frustoconical shape, when the top surface corresponds to the raised surface 110, the raised opening 109 may also refer to the bottom surface of the raised space 105.

[0082] Refer again Figures 1 to 3 In one embodiment, the connecting surface 120 may include the inner side surface of the raised space 105. That is, as previously described, when the raised space 105 has a generally frustoconical shape, the connecting surface 120 may correspond to the side surface of the raised space 105. Therefore, according to an exemplary embodiment, the connecting surface 120 may have the shape of a frustum or a frustoconical side surface as described above.

[0083] In one embodiment, the connecting surface 120 may refer to the surface that connects the raised surface 110 and the base surface 130.

[0084] Reference Figures 1 to 3 In one embodiment, the base surface 130 may refer to a surface that includes surfaces other than the raised surface 110 and the connecting surface 120. Alternatively, the raised reference surface of the raised surface 110 may be the base surface 130. That is, the raised surface 110 may be a surface that rises from the region where the base surface 130 is located along a third direction DR3.

[0085] Therefore, if we assume that the base surface 130 is located on a virtual surface parallel to the first direction DR1 and the second direction DR2, then the raised surface 110 exists in a region separated from the virtual surface by a third direction DR3, and the connecting surface 120 connects the raised surface 110 and the base surface 130, and can be formed at an angle to form an obtuse angle with either the base surface 130 or the raised surface 110.

[0086] Reference Figures 1 to 3 In one embodiment, the raised surface 110 and the base surface 130 may be parallel to each other.

[0087] In one embodiment, the raised surface 110, the connecting surface 120, and the base surface 130 can be combined to define the current collector 100. That is, each part of the current collector 100 can be defined by the raised surface 110, the connecting surface 120, and the base surface 130.

[0088] In one embodiment, the raised surface 110, the connecting surface 120, and the base surface 130 may be integrally formed. However, this is not a limitation; as needed, the raised surface 110, the connecting surface 120, and the base surface 130 may also be formed separately.

[0089] In one embodiment, the current collector 100 may comprise conductive materials such as copper, gold, silver, stainless steel, nickel, aluminum, titanium, or alloys thereof, or conductive polymers. Alternatively, in one embodiment, the current collector 100 may comprise aluminum or stainless steel surface-treated with carbon, nickel, titanium, or silver.

[0090] In a specific embodiment, the current collector 100 may contain aluminum. The material of the current collector 100 may contain only aluminum, or it may be treated with coating, doping, etc., or it may contain an aluminum alloy.

[0091] In one embodiment, the thickness of the current collector 100 can be from 0.3 mm to 0.6 mm. In a specific embodiment, the thickness of the current collector 100 can be from 0.3 mm to 0.5 mm. It is not limited thereto, but in a more specific embodiment, the thickness of the current collector 100 can be 0.4 mm.

[0092] In one embodiment, the thickness of the raised surface 110, the connecting surface 120, and the base surface 130 can each be from 0.3 mm to 0.6 mm, specifically from 0.3 mm to 0.5 mm.

[0093] In one embodiment, the thickness of the raised surface 110, the connecting surface 120, and the base surface 130 can all be the same.

[0094] However, in an exemplary embodiment, the thickness of the raised surface 110, the connecting surface 120, and the base surface 130 may all be 0.4 mm.

[0095] In one embodiment, the height h of the raised space 105 can be from 0.1 mm to 3.0 mm. Within this range, as described below, in the cell 10 with the welded structure of the current collector 100, electrode terminals 400, and electrode assembly 200, when vibration or impact is applied to the cell 10, the force transmitted from the current collector 100 to the electrode assembly 200 can be easily attenuated, thereby ultimately mitigating the load applied to the electrode assembly 200 and electrode terminals 400. On the other hand, when the height h is below the above range, the aforementioned attenuation effect may be difficult to achieve.

[0096] Reference Figure 3In one embodiment, the height h of the raised space 105 can refer to the length of the raised space 105 along the third direction DR3. Alternatively, the height h can refer to the step difference between the raised surface 110 and the base surface 130 along the third direction DR3.

[0097] In one embodiment, the current collector 100 may include a plurality of slits 140.

[0098] In one embodiment, the slit 140 may refer to an area opening on the current collector 100. According to an exemplary embodiment, the slit 140 may refer to an area opening along both sides of the current collector 100. (Refer to...) Figures 1 to 3 The slit 140 may refer to the region that opens along the direction through the current collector 100 in the third direction DR3.

[0099] In one embodiment, one of the slits 140 may refer to a continuous opening region.

[0100] Furthermore, details regarding the plurality of slits 140 will be described below.

[0101] Figure 4 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from one direction.

[0102] Figure 5 This is a diagram showing the appearance of a current collector according to an embodiment of the present disclosure as viewed from another direction.

[0103] In one embodiment, the current collector 100 may include: a first region 171, which is circular and has a predetermined first radius r1 centered on the central axis R on the raised surface 110; a second region 172, which is ring-shaped and has an inner diameter of a predetermined second radius r2 and an outer diameter of a predetermined third radius r3 centered on the central axis R on the base surface 130; and a third region 173, which includes the region other than the first region 171 and the second region 172, wherein the plurality of slits 140 may be formed in the third region 173 at predetermined intervals along the circumferential direction of the raised space 105.

[0104] Reference Figure 4 and Figure 5 In one embodiment, the first region 171 may refer to a circular region on the raised surface 110, centered on the central axis R, with a preset first radius r1.

[0105] In an exemplary embodiment, the first region 171 may refer to a virtual region located on at least a portion of the current collector 100, and may also refer to a virtual region located on at least a portion of the raised surface 110.

[0106] Reference Figure 4 and Figure 5 In one embodiment, the second region 172 may refer to an annular region on the base surface 130, centered on the central axis R, having an inner diameter with a preset second radius r2 and an outer diameter with a preset third radius r3.

[0107] In an exemplary embodiment, the second region 172 may refer to a virtual region located on at least a portion of the current collector 100, and may also refer to a virtual region located on at least a portion of the base surface 130.

[0108] In one embodiment, the cross-sectional radius of the current collector 100 may be the same as the third radius r3. In this case, the outer periphery of the current collector may be the same as the outer periphery of the second region 172.

[0109] In one embodiment, the second region 172 may include an edge region 1721 extending a predetermined distance inward from the outer periphery and a region other than the edge region 1721, namely a welding region 1722. Details will be described below.

[0110] Reference Figure 4 and Figure 5 The third region 173 may refer to a region that includes regions other than the first region 171 and the second region 172.

[0111] In an exemplary embodiment, the third region 173 may be a virtual region located on at least a portion of the current collector 100. Alternatively, the third region 173 may refer to a virtual region encompassing the entirety of the connection surface 120 and at least a portion of the first region 171 and / or the second region 172 adjacent to the connection surface 120.

[0112] In an exemplary embodiment, the third region 173 may have a shape in which one edge of one face is connected to another face at a different angle, or in which one edge of one face is connected to another face at a different angle, and another face is connected to another edge of the other face opposite to the first edge at a different angle, and the first face and the second face are parallel to each other, but is not limited thereto.

[0113] According to an exemplary embodiment, the plurality of slits 140 may be formed only in the third region 173.

[0114] In one embodiment, the second radius r2 may be greater than the first radius r1.

[0115] In one embodiment, the second radius r2 can be 1.8 to 2.2 times the first radius r1.

[0116] In one embodiment, the third radius r3 may be greater than the second radius r2.

[0117] In one embodiment, the third radius r3 can be 1.8 to 2.3 times the second radius r2.

[0118] Within the aforementioned numerical range, as described below, in the cell 10 with the welded structure of the current collector 100, electrode terminals 400, and electrode assembly 200, when vibration or impact is applied to the cell 10, the stress generated on the current collector 100 is mostly vertical stress, thereby minimizing the generation of shear stress. Furthermore, as described below, damage to the areas where the electrode terminals 400 and the electrode assembly 200 are welded to the current collector 100, namely the first region 171 and the second region 172, that may be caused by vibration or impact of the cell 10, can be minimized.

[0119] Refer again Figures 1 to 5 In one embodiment, the plurality of slits 140 may be formed at predetermined intervals in the third region 173 along the circumferential direction of the raised space 105.

[0120] In one embodiment, the plurality of slits 140 may be formed in an area of ​​less than 10% of the total area of ​​the third region 173. In a specific embodiment, the plurality of slits 140 may occupy more than 0.1% of the area of ​​the third region 173, and less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%.

[0121] Within the aforementioned numerical range, as described below, in the cell 10 of the welded structure of the current collector 100, electrode terminals 400, and electrode assembly 200, when vibration or impact is applied to the cell 10, most of the stress generated on the current collector 100 can be vertical stress, thereby minimizing the generation of shear stress. Furthermore, as described below, damage to the welded areas of the electrode terminals 400 and the electrode assembly 200 with the current collector 100, namely the first region 171 and the second region 172, that may be caused by vibration or impact of the cell 10 can be minimized.

[0122] Reference Figures 1 to 5 In one embodiment, the number of the plurality of slits 140 may be four.

[0123] On the other hand, in one embodiment, the spacing of the plurality of slits 140 may all be the same.

[0124] In an exemplary embodiment, the four slits 140 of the current collector 100 may be formed at equal intervals along the circumferential direction of the raised space 105 in the third region 173. In this case, any two of the four slits 140 may be formed symmetrically with respect to the central axis R, and the other two slits 140 may also be formed symmetrically with respect to the central axis R.

[0125] Figure 6 It is shown in magnification Figure 1 The diagram of region A.

[0126] Reference Figure 6 In one embodiment, the current collector 100 may further include a bridging portion 150, formed in the third region 173 between an adjacent pair of slits 140 among the plurality of slits 140, and connecting the first region 171 and the second region 172.

[0127] In one embodiment, the bridging portion 150 may include at least one virtual path (P) that bypasses the plurality of slits 140 in the third region 173 and connects the first region 171 and the second region 172 by the shortest distance.

[0128] In one embodiment, the bridging portion 150 may be formed between an adjacent pair of slits 140 among the plurality of slits 140. In another embodiment, the bridging portion 150 may be located in the third region 173 of the current collector 100.

[0129] That is, in the current collector 100 structure having a plurality of slits 140 formed in the third region 173, the bridging portion 150 can function as a bridge between the raised surface 110 and the base surface 130. Through the bridging portion 150, the raised surface 110 and the base surface 130 can be continuously connected.

[0130] On the other hand, the virtual path (P) may also refer to at least a portion of a path extending radially from the central axis R of the current collector 100 toward the outer periphery of the current collector 100. That is, the bridging portion 150 may include at least one path extending radially from the central axis R of the current collector 100 toward the outer periphery of the current collector 100, while avoiding the plurality of slits 140.

[0131] Refer again Figure 6In one embodiment, the bridging portion 150 may include: a first boundary that connects to the periphery of the first region 171; and a second boundary that connects to the inner periphery of the second region 172. At least one of the widths WB of the bridging portion 150 defined along the circumferential direction of the first region 171 may be greater than the length L1 of the first boundary and the length L2 of the second boundary.

[0132] Reference Figure 6 The first boundary can refer to the boundary line between the bridging portion 150 and the periphery of the first region 171, and the second boundary can refer to the boundary line between the bridging portion 150 and the inner periphery of the second region 172. On the other hand, the width WB of the bridging portion 150 can be defined along the circumferential direction of the first region 171, and therefore can have an arc shape.

[0133] From the perspective of the virtual path (P) described above, in a path starting from a point adjacent to the first region 171 and extending toward a point adjacent to the second region 172, the width of the bridging portion 150 can gradually increase as the path extends from the starting point, and then the width of the bridging portion 150 can decrease again starting from a point on a certain path within the bridging portion 150.

[0134] That is, refer to again Figure 6 The bridging portion 150 may have a tapered shape with the widest central portion relative to the two ends adjacent to the first region 171 and the second region 172, respectively.

[0135] With the construction of the slits 140 and bridging portions 150 as described above, when an impact is applied to the current collector 100, the plurality of slits 140 and each bridging portion 150 can absorb a considerable portion of the shear stress applied to the current collector.

[0136] By incorporating the structure described above, as explained below, in the battery cell 10 with the welded joint structure of the current collector 100, electrode terminals 400, and electrode assembly 200, when vibration or impact is applied to the battery cell 10, the stress generated on the current collector 100 is mostly vertical stress, thereby minimizing the generation of shear stress. Furthermore, as described below, damage to the welded areas of the electrode terminals 400 and the electrode assembly 200 with the current collector 100, namely the first region 171 and the second region 172, that may be caused by vibration or impact of the battery cell 10 can be minimized.

[0137] Figure 7 This is a diagram illustrating an example of a battery cell according to an embodiment of the present disclosure.

[0138] Figure 8 It is shown Figure 7 A cross-sectional view of region B of the battery cell.

[0139] According to one embodiment of the present disclosure, a battery cell 10 may include: a current collector 100 according to one embodiment of the present disclosure; a housing 300 having an internal receiving space; an electrode terminal 400 passing through at least a portion of the housing 300; and an electrode assembly 200 wound around a winding shaft C and electrically connected to the current collector 100, wherein the electrode assembly 200 and the current collector 100 can be accommodated in the receiving space, the raised surface 110 of the current collector 100 can be connected to the electrode terminal 400, and the base surface 130 of the current collector 100 can be connected to the electrode assembly 200.

[0140] In one embodiment, the housing 300 may include: a sidewall portion 311, which is cylindrical and has an internal receiving space; a closed end portion 312 formed at one end of the sidewall portion 311; and an opening portion disposed at the other end of the sidewall portion 311.

[0141] In one embodiment, the sidewall portion 311 may be formed in a cylindrical shape. In a specific embodiment, the sidewall portion 311 may be formed in a cylindrical shape with an internal accommodating space. The sidewall portion 311 can accommodate the electrode assembly 200 and the current collector 100 in the internal accommodating space.

[0142] like Figure 7 and Figure 8 As shown, the battery cell 10 according to one embodiment of the present disclosure may be a cylindrical can-type secondary battery, but is not limited thereto.

[0143] In one embodiment, the closed end 312 may be formed at one end of the sidewall portion 311. In a specific embodiment, the closed end 312 may be formed at one end of the sidewall portion 311 in a direction perpendicular to the extending direction of the sidewall portion 311, to seal one end of the sidewall portion 311. Here, "one end" may refer to either end of the cylindrical sidewall portion 311, with reference to the extending direction of the sidewall portion 311.

[0144] In one embodiment, the closed end 312 may extend from one end of the sidewall portion 311. That is, in this case, the closed end 312 may be integrally formed with the sidewall portion 311.

[0145] In contrast, in one embodiment, the closed end 312 may be formed at one end of the sidewall portion 311, or it may be formed separately from the sidewall portion 311. In this embodiment, the closed end 312 may be formed as a structure that can be separated from the sidewall portion 311.

[0146] In one embodiment, the closed end 312 may define a cover assembly together with the electrode terminal 400 and gasket 410, as described below. This will be described in detail below.

[0147] In one embodiment, the opening may be located at the other end of the sidewall portion 311. Here, the other end may refer to the other end of the two ends of the cylindrical sidewall portion 311, excluding the first end, with reference to the extending direction of the sidewall portion 311.

[0148] In one embodiment, the opening may communicate with the receiving space. Therefore, the electrode assembly 200 and the current collector 100 can be received inside the housing 300 through the opening. In one embodiment, the opening may be sealed by a cover plate (not shown) described below. When the opening is covered by the cover plate (not shown), the receiving space can be sealed relative to the outside by the sidewall portion 311, the closed end 312, and the cover plate (not shown).

[0149] In one embodiment, the opening may refer to the space that communicates with the receiving space, i.e., a circular, elliptical, or oblong planar space that contacts the other end.

[0150] In one embodiment, the cover plate (not shown) may cover the opening. As previously mentioned, the opening may be sealed by the cover plate (not shown).

[0151] In one embodiment, the cover plate (not shown) may further include, as needed, a liquid injection section for injecting electrolyte or a notch for venting gas.

[0152] In one embodiment, the cover plate (not shown) may be welded to the housing 300. In an exemplary embodiment, the method is not particularly limited, as long as the welding is a welding method applicable to the intermetallic bonding.

[0153] In one embodiment, the cover plate (not shown) may be beaded with the housing 300. In an exemplary embodiment, the beading may be performed as follows: at least a portion of the area of ​​the sidewall portion 311 adjacent to the opening and including the other end is beaded along the periphery of the sidewall portion 311; then, the cover plate (not shown) is positioned in the beaded area to cover the opening; and then the area of ​​the sidewall portion 311 including the other end is crimped, but is not limited thereto.

[0154] In one embodiment, the housing 300 and the cover (not shown) may be made of the same material. Conversely, the housing 300 and the cover (not shown) may also be made of different materials.

[0155] Refer again Figure 7 and Figure 8 In one embodiment, the battery cell 10 may include electrode terminals 400 passing through at least a portion of the housing 300. Referring to the above embodiment, in one embodiment, the electrode terminals 400 may pass through the closed end 312.

[0156] As described above, the closed end 312 can be used together with the electrode terminal 400 and the gasket 410 to define a cover assembly.

[0157] According to an exemplary embodiment, the electrode terminal 400 has a generally "H" shaped cross-section and is formed to pass through the closed end 312, one end of which may be located within the receiving space, and the other end may protrude from outside the receiving space along the extending direction of the housing 300.

[0158] According to an exemplary embodiment, the electrode terminal 400 can be electrically connected to any one of the electrodes (positive and negative) within the accommodating space. According to an exemplary embodiment, the electrode terminal 400 can be directly connected to at least one of the electrode current collectors (positive and negative current collectors), or it can be connected via a separate connecting component. Here, the electrode can be a positive electrode, but is not limited thereto.

[0159] According to an exemplary embodiment, the electrode terminal 400 can function as an external terminal through the above-described configuration.

[0160] According to an exemplary embodiment, the gasket 410 may be configured to prevent electrical contact between the electrode terminal 400 and the closed end 312 of the housing 300.

[0161] On the other hand, unlike this, the battery cell 10 according to one embodiment of the present disclosure may also have a configuration in which the opening is covered by a separate cover assembly. In this case, the battery cell 10 may not include a separate cover plate (not shown), and the electrode terminals 400 may also be located on the side of the opening.

[0162] In one embodiment, the electrode assembly 200 may be housed within the receiving space of the housing 300. In a specific embodiment, the electrode assembly 200 may be wound in a coil and housed within the receiving space of the housing 300.

[0163] In one embodiment, the electrode assembly may include electrodes and a separator, the electrodes comprising a positive electrode (Cathode) and a negative electrode (Anode). In a specific embodiment, the electrode assembly may be formed by sequentially stacking a positive electrode, a separator, and a negative electrode, and the stack may be wound in a roll shape around a winding axis C, thereby being housed in the receiving space. Such a stack wound in a roll shape can be called a jelly roll. The cross-section of the roll shape may be circular, but is not limited to this; it may have various shapes such as elliptical, oblong, or a rectangle including curves.

[0164] According to an exemplary embodiment, the electrode may include a first electrode and a second electrode.

[0165] According to an exemplary embodiment, the electrodes (first electrode and second electrode) may each include an electrode current collector and an electrode active material coated on at least one side of the electrode current collector.

[0166] In one embodiment, the first electrode can be a positive electrode and the second electrode can be a negative electrode.

[0167] According to an exemplary embodiment, the positive electrode may include a positive electrode current collector and a positive electrode active material. The positive electrode current collector may include a conductive material known within the range that does not cause a chemical reaction within the lithium secondary battery. The positive electrode current collector may, for example, comprise any one of stainless steel, nickel (Ni), aluminum (Al), titanium (Ti), copper (Cu), and alloys thereof, and may be provided in various forms such as film, sheet, and foil. The positive electrode active material may comprise a material in which lithium ions can intercalate and deintercalate. The positive electrode active material may, for example, be a lithium metal oxide.

[0168] According to an exemplary embodiment, the negative electrode may include a negative electrode current collector and a negative electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material coated on at least one side of the negative electrode current collector. The negative electrode current collector may contain a known conductive material that does not cause a chemical reaction within the lithium secondary battery. The negative electrode current collector may, for example, contain any one of stainless steel, nickel (Ni), aluminum (Al), titanium (Ti), copper (Cu), and alloys thereof, and may be provided in various forms such as film, sheet, and foil. The negative electrode active material may contain a material in which lithium ions can intercalate and deintercalate. The negative electrode active material may, for example, contain carbon-based materials such as crystalline carbon, amorphous carbon, carbon composites, carbon fibers, lithium alloys, silicon (Si), and tin (Sn), or combinations thereof.

[0169] According to an exemplary embodiment, the first electrode and the second electrode may each further include an adhesive and a conductive material to improve mechanical stability and conductivity.

[0170] According to an exemplary embodiment, the membrane may be included to prevent electrical short circuits between the first and second electrodes and to allow ion flow. For example, the membrane may include a porous polymer film or a porous nonwoven fabric.

[0171] According to an exemplary embodiment, the electrode assembly 200 may be immersed in an electrolyte within the housing 300. The electrolyte may be a non-aqueous electrolyte. The electrolyte may contain lithium salts and organic solvents, and may further contain additives as needed.

[0172] According to an exemplary embodiment, the first electrode and the second electrode may each include an uncoated portion of the current collector at both ends.

[0173] According to an exemplary embodiment, the first electrode may include a first uncoated portion 210, and the second electrode may include a second uncoated portion (not shown).

[0174] According to an exemplary embodiment, the first uncoated portion 210 and the second uncoated portion (not shown) may be independently configured to extend in directions toward the opening and the closed end 312, respectively. In an exemplary embodiment, the first uncoated portion 210 and the second uncoated portion (not shown) may also be configured to extend simultaneously in either the direction toward the opening or the direction toward the closed end 312.

[0175] According to an exemplary embodiment, the first uncoated portion 210 and the second uncoated portion (not shown) may each include a flag structure in which at least a portion of the area between adjacent pairs of cut portions is folded along a predetermined direction after a plurality of cut portions are formed at predetermined intervals and depths at their respective outer ends. As described below, the current collector 100 may be combined with the portion of the uncoated portion of the electrode assembly 200 in which the above-described flag structure is formed.

[0176] According to an exemplary embodiment, the electrode assembly 200 can be wound in a roll shape, and a cavity can be formed along the winding axis C. The cavity can be formed in a cylindrical shape. When electrolyte is injected during the manufacturing process of the cell 10, the cavity can function as an electrolyte injection channel. The cavity can be formed as a path connecting the center of the cover plate (not shown) and the center of the closed end 312.

[0177] According to an exemplary embodiment, the battery cell 10 may further include an insulating component within the receiving space to prevent electrical short circuits between components. The insulating component may be disposed within the receiving space in the form of an insulating pad, washer, or the like.

[0178] According to an exemplary embodiment, the insulating component may be located between the current collector 100 and the closed end 312 and / or side wall portion 311 of the housing 300 to prevent electrical contact between the current collector 100 and the housing 300.

[0179] In one embodiment, the current collector 100 includes: a first region 171, which is circular, and has a preset first radius r1 on the raised surface 110 with the central axis R as the center, and the electrode terminal 400 can be connected to the current collector 100 in the first region 171.

[0180] Reference Figure 8 The current collector 100 can be located within the receiving space in a region adjacent to one end of the housing 300. On the other hand, as described above, the electrode terminal 400 can pass through the closed end 312, so that one end of it can be located within the receiving space.

[0181] Therefore, refer to again Figure 7 and Figure 8 The current collector 100 and the electrode terminal 400 can be connected by the raised surface 110 of the current collector 100 and one end of the electrode terminal 400 along a third direction DR3. Details of the connection will be described below.

[0182] In one embodiment, the electrode assembly 200 includes: a first electrode including a first uncoated portion 210; a second electrode including a second uncoated portion (not shown); and a diaphragm disposed between the first electrode and the second electrode, wherein the first uncoated portion 210 may be connected to the base surface 130.

[0183] In one embodiment, the current collector 100 includes a second region, which is annular and located on the base surface 130, centered on the central axis R, having an inner diameter of a preset second radius r2 and an outer diameter of a preset third radius r3. The first uncoated portion 210 can be connected to the current collector 100 in combination with the second region 172.

[0184] Refer again Figure 8 The current collector 100 can be located within the receiving space and in the region between the electrode assembly 200 wound along the winding axis C and the closed end 312. On the other hand, as described above, the uncoated portions can be formed at both ends of the current collector. Thus, in the wound electrode assembly 200, uncoated portions (a first uncoated portion and a second uncoated portion) can be formed at both ends of the length direction of the roll.

[0185] Therefore, the current collector 100 and the electrode assembly 200 can be bonded to the first uncoated portion 210 of the electrode assembly 200 via the base surface 130 of the current collector 100, along the third direction DR3. Details regarding the bonding will be described below.

[0186] On the other hand, as described above, both the first uncoated portion 210 and the second uncoated portion (not shown) may each include a flag structure at their outer ends. Furthermore, the flag structures may each be folded in a predetermined direction as previously described. Therefore, the plurality of flag structures folded in the first uncoated portion 210 may also be connected to the base surface 130.

[0187] According to an exemplary embodiment, the electrode terminal 400 can be a positive terminal, and the first electrode can be a positive electrode, but is not limited thereto.

[0188] Refer again Figure 7 and Figure 8 Due to the aforementioned structural features of the current collector 100, the positions where the current collector 100 is connected to the electrode terminal 400 and the positions where the current collector 100 is connected to the electrode assembly 200 can be separated by a predetermined distance with reference to a third direction DR3. On the other hand, this separation distance can be the same as the bulge height h.

[0189] On the other hand, as previously described, the plurality of slits 140 may be formed in the third region 173. Alternatively, the entire area of ​​the connecting surface 120 may be included in the third region 173. Therefore, the plurality of slits 140 may be... Figure 8 It is formed on the cross section at a predetermined angle.

[0190] Reference Figures 1 to 6 The current collector 100 described according to an embodiment of the present disclosure includes, as referenced Figure 7 and Figure 8 In the battery cell 10 described according to an embodiment of the present disclosure, when vibration or impact is applied to the battery cell 10, the stress generated on the current collector 100 is mostly vertical stress, thereby minimizing the generation of shear stress. Generally, considering the weakness of disk-shaped metal current collectors being easily damaged under shear stress, the mechanical rigidity of the current collector according to an embodiment of the present disclosure can be improved. Furthermore, as described below, damage or load that may be caused by vibration or impact of the battery cell 10 to the electrode terminals 400 and the electrode assembly 200 and the welding areas with the current collector 100, namely the first region 171 and the second region 172, can be minimized.

[0191] Figure 9 This is a diagram illustrating another example of a current collector according to an embodiment of the present disclosure.

[0192] In one embodiment, at least one first welding portion 1715 is formed on the first region 171, and the electrode terminal 400 can be welded to the current collector 100 at the first welding portion 1715.

[0193] In one embodiment, the first weld portion 1715 may be formed with an area smaller than that of the first region 171. Alternatively, the first weld portion 1715 may be formed with the same area as the first region 171.

[0194] As described above, the current collector 100 and the electrode terminal 400 can be connected by the raised surface 110 of the current collector 100 and one end of the electrode terminal 400 along a third direction DR3. Therefore, one end of the electrode terminal 400 can be welded to the first welding portion 1715 on the first region 171 on the raised surface 110.

[0195] In one embodiment, at least one second weld portion 1725 is formed on the second region 172, and the first uncoated portion 210 can be welded to the current collector 100 at the second weld portion 1725.

[0196] In one embodiment, a plurality of second weld portions 1725 may be formed, and the plurality of second weld portions 1725 may be formed radially on the second region 172.

[0197] Reference Figure 9 In one embodiment, the plurality of second weld portions 1725 may be formed radially on the second region 172. Or as... Figure 9 As shown, the plurality of second weld portions 1725 can be distinguished in the second region 172 into regions where the plurality of second weld portions 1725 are formed and regions where the second weld portions 1725 are not formed. They can be distinguished in various ways as needed, or they can be not distinguished as described above, and the plurality of second weld portions 1725 can be formed in the entire region of the second region 172.

[0198] As described above, the current collector 100 and the electrode assembly 200 can be connected via the base surface 130 of the current collector 100 to a plurality of flag structures folded in the first uncoated portion 210 of the electrode assembly 200 along a third direction DR3. Therefore, the first uncoated portion 210 can be welded to the second weld portion 1725 on the second region 172 of the base surface 130; specifically, the plurality of flag structures can be welded to the plurality of formed second weld portions 1725 respectively.

[0199] In one embodiment, the second region 172 may include an edge region 1721 extending inward from the outer periphery by a predetermined distance and a region other than the edge region 1721, namely a welding region 1722. In this embodiment, the plurality of second weld portions 1725 may be formed radially on the welding region 1722.

[0200] like Figure 9 As shown, the plurality of second weld portions 1725 can distinguish between areas where the plurality of second weld portions 1725 are formed and areas where the second weld portions 1725 are not formed on the welding area 1722. They can be distinguished in various ways as needed, or they can be not distinguished as described above, and the plurality of second weld portions 1725 can be formed in the entire area of ​​the welding area 1722.

[0201] In one embodiment, the battery cell 10 may further include a second current collector (not shown).

[0202] According to an exemplary embodiment, the second current collector (not shown) may be disposed between the cover plate (not shown) and the electrode assembly 200, thereby electrically connecting the cover plate (not shown) and the electrode assembly 200. In this case, the second current collector (not shown) may be connected to the second uncoated portion (not shown) of the electrode assembly 200.

[0203] In contrast, in one embodiment, the cell 10 may not include a second current collector (not shown), and the second uncoated portion (not shown) of the electrode assembly 200 may be directly connected to the side wall portion 311 of the housing 300 and / or the cover plate (not shown).

[0204] In one embodiment, the battery cell 10 can be a cylindrical battery with a form factor of 18650, 21700, 26650, 32700, 32140, 46110, 4680, 4695, 48110, 4875, or 4880. In a specific embodiment, the form factor can be 46110, 4680, 4695, 48110, 4875, or 4880. In a more specific embodiment, the form factor of the battery cell 10 can be 4680, with a diameter of approximately 46 mm and a height of approximately 80 mm, but it is not limited to this.

[0205] According to one embodiment of this disclosure, the battery cell 10 can be used not only as a power source for small devices, but also preferably as a unit battery for battery modules and / or battery packs in medium to large-sized devices that include multiple battery cells. Examples of small devices may include mobile phones, laptops, cameras, etc., and examples of medium to large-sized devices may include electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, power storage systems, etc., but are not limited to these.

[0206] The above description is merely an example of applying the principles of this disclosure, and other constructions may be further included without departing from the scope of this disclosure.

Claims

1. A current collector, which is a disk-shaped current collector with a raised surface including a central axis, the current collector comprising: The raised space is formed by the raised surface; A raised opening defines the entrance to the raised space, and the area of ​​the raised opening is larger than the area of ​​the raised surface; The connecting surface includes the inner surface of the raised space; The base surface includes surfaces other than the raised surface and the connecting surface; and Multiple slits.

2. The current collector according to claim 1, wherein, The raised surface and the base surface are parallel to each other.

3. The current collector according to claim 1, wherein, The current collector contains aluminum.

4. The current collector according to claim 1, wherein, The thickness of the current collector is 0.3 mm to 0.6 mm.

5. The current collector according to claim 1, wherein, The height of the raised space is between 0.1 mm and 3.0 mm.

6. The current collector according to claim 1, comprising: The first region is circular and has a predetermined first radius centered on the central axis on the raised surface; The second region is annular and has an inner diameter of a predetermined second radius and an outer diameter of a predetermined third radius on the base surface, with the central axis as the center. as well as The third region includes all regions other than the first and second regions. The plurality of slits are formed at predetermined intervals along the circumferential direction of the raised space in the third region.

7. The current collector according to claim 6, wherein, The second radius is larger than the first radius.

8. The current collector according to claim 6, wherein, The third radius is greater than the second radius.

9. The current collector according to claim 6, wherein, The plurality of slits are formed in an area of ​​less than 10% of the total area of ​​the third region.

10. The current collector according to claim 6, wherein, The number of the multiple slits is 4.

11. The current collector according to claim 6, further comprising: A bridging portion, in the third region, is formed between an adjacent pair of slits among the plurality of slits and connects the first region and the second region.

12. The current collector according to claim 11, wherein, The bridging portion includes at least one virtual path, which bypasses the plurality of slits in the third region and connects the first region and the second region with the shortest distance.

13. The current collector according to claim 11, wherein, The bridging portion includes: The first boundary is adjacent to the perimeter of the first region; and The second boundary connects to the inner perimeter of the second region. At least one of the widths of the bridging portion defined along the circumferential direction of the first region is greater than the length of the first boundary and also greater than the length of the second boundary.

14. A battery cell, comprising: The current collector according to claim 1; The shell has internal storage space; Electrode terminals, passing through at least a portion of the housing; as well as The electrode assembly is wound around a winding shaft and electrically connected to the current collector. The electrode assembly and the current collector are housed within the housing space. The raised surface of the current collector is connected to the electrode terminal, and the base surface of the current collector is connected to the electrode assembly.

15. The battery cell according to claim 14, wherein, The current collector includes: a first region, which is circular, having a predetermined first radius on the raised surface, centered on the central axis. The electrode terminals are connected to the current collector in the first region.

16. The battery cell according to claim 14, wherein, The electrode assembly includes: The first electrode includes a first uncoated portion; The second electrode includes a second uncoated portion; and A diaphragm is disposed between the first electrode and the second electrode. The first uncoated portion is connected to the base surface.

17. The battery cell according to claim 16, wherein, The current collector includes: a second region, which is annular, on the base surface, having an inner diameter with a predetermined second radius and an outer diameter with a predetermined third radius, centered on the central axis. The first uncoated portion is connected to the current collector in the second region.

18. The battery cell according to claim 15, wherein, At least one first weld portion is formed in the first region. The electrode terminals are welded to the current collector at the first welding section.

19. The battery cell according to claim 17, wherein, At least one second weld portion is formed in the second region. The first uncoated portion is welded to the current collector at the second welded portion.

20. The battery cell according to claim 19, wherein, The second welding part is formed in multiple ways. Multiple second welded portions are formed radially on the second region.

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