Current collector and battery cell comprising the same

Abstract

The present disclosure provides an electric chip including: an electrode assembly including a positive electrode, a negative electrode, and a separator; a chip housing accommodating the electrode assembly; a cover plate connected with the chip housing; an electrode terminal provided on the cover plate and including a coupling hole; and a current collector electrically connecting the electrode assembly with the electrode terminal, the current collector including: a current collecting plate electrically connected with the electrode assembly; and a current collecting pin connected to the current collecting plate and welded with the electrode terminal in a state of being inserted into the coupling hole, the current collecting pin including a hollow portion recessed toward the current collecting plate at a first end portion spaced apart from the current collecting plate.

Description

Technical Field

[0001] This disclosure relates to a current collector used in a rechargeable and dischargeable battery cell (secondary battery) and a battery cell including the same. Background Technology

[0002] Unlike primary batteries, secondary batteries can be charged and discharged, so they can be used in various fields such as digital cameras, mobile phones, laptops, hybrid vehicles, and electric vehicles.

[0003] These secondary batteries can be manufactured as flexible pouch cells or rigid can cells. Can cells can be further classified according to their shape into prismatic cells, cylindrical cells, coin-shaped cells, etc.

[0004] Multiple battery cells can be arranged in a specific configuration to form a battery module. At least one battery module can be configured into various forms of battery devices, such as battery modules, battery packs, and energy storage devices. Summary of the Invention

[0005] (a) Technical problems to be solved Existing battery cells can have a structure in which electrode assemblies and electrode terminals are housed within the cell housing via a current collector. The current collector may include a current collector plate electrically connected to the electrode assemblies and a current collector pin connected to the electrode terminals. The current collector pin may be soldered to the electrode terminals after being inserted into a mating hole that engages with the electrode terminals.

[0006] The welded portion between the electrode terminal and the current collector pin can solidify after being melted. During the solidification process of the weld between the electrode terminal and the current collector pin, the stress caused by shrinkage acts on the weld, which may cause cracks in the weld.

[0007] According to one aspect of this disclosure, a current collector and a battery cell including the current collector can be provided that are capable of absorbing or reducing stress generated at the weld between the electrode terminal and the current collector (current collector pin).

[0008] According to one aspect of this disclosure, a current collector and a battery cell including the current collector can be provided, which are capable of preventing or reducing cracking at the weld between the electrode terminal and the current collector pin.

[0009] According to one aspect of this disclosure, a current collector and a battery cell including the current collector can be provided, which can improve the quality of the weld between the electrode terminals and the current collector pin.

[0010] The current collector and battery cells including the current collector disclosed herein can be widely used in electric vehicles, battery charging stations, and other green technology fields such as solar power generation and wind power generation that utilize batteries. In addition, the current collector and battery cells including the current collector disclosed herein can be used in eco-friendly electric vehicles, hybrid vehicles, etc., to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0011] (II) Technical Solution The battery cell according to this disclosure may include: an electrode assembly including a positive electrode, a negative electrode, and a separator; a battery cell housing housing the electrode assembly; a cover plate connected to the battery cell housing; electrode terminals disposed on the cover plate and including mating holes; and a current collector electrically connecting the electrode assembly to the electrode terminals. The current collector may include: a current collector plate electrically connected to the electrode assembly; and a current collector pin connected to the current collector plate and welded to the electrode terminals in a state of being inserted into the mating holes. The current collector pin may include a hollow portion recessed toward the current collector plate at a first end spaced apart from the current collector plate.

[0012] According to one embodiment, in a cross section perpendicular to a first direction in which the collector pin extends from the collector plate, the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion may each have a circular cross-sectional shape.

[0013] According to one embodiment, the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion can form concentric circles.

[0014] According to one embodiment, the electrode terminal may include: a first body exposed on the outer side of the cover plate; and a second body connected to the first body and inserted into a through hole in the cover plate.

[0015] According to one embodiment, the second body may have a riveting structure that joins the cover plate to the first body.

[0016] According to one embodiment, the first body and the second body of the electrode terminal can be integrally formed, and the electrode terminal is riveted to the cover plate.

[0017] According to one embodiment, the thickness between the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion can be 0.5 mm or more, and the inner diameter of the hollow portion can be 0.5 mm or more.

[0018] According to one embodiment, the depth of the hollow portion may be a value of more than 0.1 times and less than 3 times the outer diameter of the collector pin.

[0019] According to one embodiment, the depth of the hollow portion can be set to a value greater than or equal to the depth of the welded portion, which is formed by the electrode terminal and the current collector pin through the solidification of molten metal from welding.

[0020] According to one embodiment, the hollow portion may include at least a portion in the region from the first end toward the current collector with an inner diameter smaller than the inner diameter at the first end.

[0021] According to one embodiment, the collector pin and the collector plate can be welded together.

[0022] According to one embodiment, the collector pin can be inserted into and engaged with an insertion hole formed on the collector plate.

[0023] According to one embodiment, the collector pin may further include a diameter expansion portion having a larger diameter than the periphery at the portion connected to the collector plate.

[0024] According to one embodiment, the collector pin and the collector plate can be integrally formed.

[0025] According to this disclosure, a current collector for a battery cell may include: a current collector plate; and a current collector pin connected to the current collector plate, the current collector pin having a hollow portion recessed toward the current collector plate at a first end spaced apart from the current collector plate.

[0026] According to one embodiment, on a cross section perpendicular to a first direction in which the collector pin extends from the collector plate, the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion can each have a circular cross-sectional shape, and the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion can form concentric circles.

[0027] (III) Beneficial Effects According to one embodiment of this disclosure, stress generated at the weld between the electrode terminal and the current collector (current collector pin) can be reduced.

[0028] According to one embodiment of this disclosure, cracks can be prevented or reduced in the weld between the electrode terminal and the collector pin.

[0029] According to one embodiment of this disclosure, the quality of the weld between the electrode terminal and the collector pin can be improved. Attached Figure Description

[0030] Figure 1 This is a perspective view of a battery cell according to one embodiment.

[0031] Figure 2 yes Figure 1 The image shown is an exploded 3D view of the battery cell.

[0032] Figure 3It is along Figure 1 The longitudinal cross-section diagram taken from the I-I' line.

[0033] Figure 4 This is an exploded perspective view of a cover assembly according to one embodiment.

[0034] Figure 5 yes Figure 4 The diagram shows a cross-sectional view of the cover assembly.

[0035] Figure 6 This is a perspective view of a current collector according to one embodiment.

[0036] Figure 7 yes Figure 6 The cross-sectional view of the current collector is shown.

[0037] Figure 8 It is shown Figure 7 Cross-sectional view of a variant of the current collector shown.

[0038] Figure 9 This is a perspective view showing the cover assembly and current collector in their pre-assembly state according to one embodiment.

[0039] Figure 10 It is along Figure 1 Line II-II' shows a cross-sectional view of the cover assembly and current collector before and after joining, according to one embodiment.

[0040] Figure 11 It is shown Figure 10 The illustrated embodiment shows a cross-sectional view of the force acting on the welded portion while the electrode terminals and current collector are welded.

[0041] Figure 12 (a) is a cross-sectional view showing the combined state of the cover assembly and the current collector according to the comparative example. Figure 12 (b) is shown Figure 12 The cross-sectional view of the force acting on the welded part in the state of welding the electrode terminals and the current collector in the comparative example shown in (a).

[0042] Figure 13 This is a cross-sectional view showing the cover assembly and the current collector before and after joining, according to another embodiment.

[0043] Figures 14 to 16 This is a cross-sectional view showing various variations of the hollow section installed in the current collector.

[0044] Figure 17 This is a perspective view of a battery cell according to another embodiment.

[0045] Figure 18 This is a perspective view of a battery cell according to yet another embodiment.

[0046] Figure 19 This is a perspective view of a battery device according to one embodiment.

[0047] Explanation of reference numerals in the attached figures: 100: Battery cell; 110: Battery cell casing 111: Storage space; 115: Exhaust vent 120: Electrode assembly; 121: Positive electrode 122: Negative electrode; 123: Diaphragm 125: Electrode tabs 126: Avoidance section 130: Cover assembly 130a: First cover assembly 130b: Second cover assembly; 131: Cover plate 132: Through hole; 133: Mounting groove 134: Injection hole; 135: Terminal insulator 136: Washer; 137: Cover insulator 138: Fixing plate; 139: Injection port cap 140: Electrode terminal; 141: First body 141a: Terminal hole; 142: Second body 143: Connecting hole; 150: Current collector 151: Current collector 152: Insertion hole 155: Collector pin 155a: First end 156: Edge section 157: Hollow section 158: Joint 159: Diameter Expansion Section 200: Battery assembly; 210: Side panel D1: Outer diameter of the collector pin; D2: Inner diameter of the hollow section. D3: Outer diameter of the expansion section; IN: Current collector insulator. t: The thickness between the outer circumferential surface of the collector pin and the inner circumferential surface of the hollow part. W: Welding section Detailed Implementation

[0048] The same reference numerals or symbols used in the various figures of this specification denote parts or components that perform substantially the same function. For ease of description and understanding, the same reference numerals or symbols may also be used in different embodiments. That is, even if components with the same reference numerals are shown in multiple figures, the multiple figures do not represent the same embodiment.

[0049] In the following description, unless the context clearly indicates otherwise, singular expressions include plural expressions. Terms such as “comprising” or “constituting” should be understood as being intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, rather than precluding the presence or additional possibilities of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0050] Additionally, it should be noted that in the following descriptions, terms such as top, upper, lower, side, front, and back are based on the direction shown in the diagram. If the direction of the corresponding object changes, it can be described in a different way.

[0051] Furthermore, in this specification and claims, terms including ordinal numbers such as "first" and "second" may be used to distinguish components. These ordinal numbers are used to distinguish identical or similar components, and the meaning of the terms should not be interpreted restrictively by using these ordinal numbers. For example, the order of use or arrangement of components combined with these ordinal numbers should not be interpreted restrictively by these ordinal numbers. Each ordinal number may also be used interchangeably as needed.

[0052] The present disclosure will now be described in detail with reference to the accompanying drawings. However, these are merely examples, and the present disclosure is not limited to the specific embodiments described herein.

[0053] The following is for reference Figures 1 to 18 The battery cell disclosed herein will be described. Figures 1 to 17 The present invention uses a prismatic cell as an example to illustrate the cell of this invention, but the cell of this invention is not limited to prismatic cells, such as... Figure 18 As shown, it can also be applied to cylindrical battery cells.

[0054] Figure 1 This is a perspective view of the battery cell 100 according to one embodiment. Figure 2 yes Figure 1 The exploded perspective view of cell 100 shown is shown. Figure 3 It is along Figure 1 The longitudinal cross-section diagram taken from the I-I' line.

[0055] Reference Figures 1 to 3 According to one embodiment, the battery cell 100 may include: an electrode assembly 120 including a positive electrode 121, a negative electrode 122 and a separator 123; a battery cell housing 110 for housing the electrode assembly 120; a cover plate 131 connected to the battery cell housing 110; an electrode terminal 140 disposed on the cover plate 131 and including a connection hole 143; and a current collector 150 for electrically connecting the electrode assembly 120 and the electrode terminal 140.

[0056] The cell housing 110 and the cover plate 131 form the appearance of the cell 100 and can form a space inside to accommodate the electrode assembly 120.

[0057] The cell housing 110 can form a receiving space 111 for accommodating the electrode assembly 120. As an example, the cell housing 110 can form a tubular receiving space 111. In the case of a prismatic cell, the cell housing 110 can have a shape extending in a quadrilateral cross section.

[0058] The cell housing 110 may have a shape with at least one opening at one of its two ends. For example, the cell housing 110 may have a shape with a first opening 112a and a second opening 112b respectively provided on one side and the other side of the receiving space 111. However, the cell housing 110 may also have a shape with an opening on only one of its two ends (see reference). Figure 17 ).

[0059] Electrode assembly 120 may include a positive electrode 121, a negative electrode 122, and a separator 123. The positive electrode 121 and negative electrode 122 may be disposed with the separator 123 sandwiched between them. As an example, electrode assembly 120 may have a wound structure in which the positive electrode 121, negative electrode 122, and separator 123 are wound together. However, electrode assembly 120 of this disclosure is not limited to a wound structure. For example, electrode assembly 120 of this disclosure may also have a stacking shape, a zigzag-folding shape, or a stack-folding shape.

[0060] Both the positive electrode 121 and the negative electrode 122 may include electrode tabs 125. Electrode tabs 125 can be defined as regions in both the positive electrode 121 and the negative electrode 122 that are not coated with active material for electrical connection to the current collector 150. Electrode tabs 125 may include positive electrode tabs disposed in the positive electrode 121 and negative electrode tabs disposed in the negative electrode 122.

[0061] The cover plate 131 can be connected to the cell housing 110. The cover plate 131 can be connected to at least one of the two ends of the tubular cell housing 110. The cover plate 131 can be manufactured separately from the cell housing 110 and then cover the end of the opening of the cell housing 110. As an example, the cover plate 131 can be welded to the end of the opening of the cell housing 110. However, the connection structure between the cell housing 110 and the cover plate 131 is not limited to the above-described structure; for example, the cover plate 131 and the cell housing 110 can also be integrally formed.

[0062] The cover plate 131 may include an injection hole 134 for injecting electrolyte into the receiving space 111 of the cell housing 110. Figure 4An injection port cap 139 with a closed injection hole 134 can be attached to the cover plate 131.

[0063] Electrode terminals 140 are disposed on cover plate 131 and may include mating holes 143. Electrode terminals 140 may include a first body 141 exposed on the outer side of cover plate 131.

[0064] In this disclosure, "cover plate 131" can be defined as a plate on which electrode terminals 140 are provided. For example, when electrode terminals 140 are provided on at least one of the plurality of surfaces forming the appearance of the cell 100, the plate constituting the surface on which electrode terminals 140 are provided can be referred to as cover plate 131.

[0065] The cover assembly 130 may include a cover plate 131 and electrode terminals 140. That is, the cover plate 131 and electrode terminals 140 may be combined with each other to form the cover assembly 130. The cover assembly 130 may be combined with the cell housing 110.

[0066] When the two ends of the cell housing 110 have open shapes, cover assemblies 130 can be respectively attached to the two ends of the cell housing 110. As an example, the cover assembly 130 may include a first cover assembly 130a attached to a first opening 112a provided on one side of the cell housing 110 and a second cover assembly 130b attached to a second opening 112b provided on the other side of the cell housing 110. The first cover assembly 130a and the second cover assembly 130b may respectively include a cover plate 131 and an electrode terminal 140.

[0067] The current collector 150 can electrically connect the electrode assembly 120 to the electrode terminal 140. The current collector 150 may include a current collector plate 151 and a current collector pin 155 connected to the current collector plate. The current collector 150 may include: a current collector plate 151, electrically connected to the electrode assembly 120; and a current collector pin 155, connected to the current collector plate 151 and soldered to the electrode terminal 140 in a state of being inserted into the connection hole 143.

[0068] The current collector 151 has a plate shape and can be electrically connected to the electrode tabs 125 of the electrode assembly 120. The current collector 151 can be physically bonded to the electrode tabs 125. As an example, the electrode tabs 125 can be bent to cover the outer surface of the current collector 151, and with the electrode tabs 125 covering the current collector 151, the electrode tabs 125 and the current collector 151 can be welded. As an example, the electrode tabs 125 and the current collector 151 can be bonded by laser welding. However, the bonding structure and method of the electrode tabs 125 and the current collector 151 can be varied.

[0069] The current collector pin 155 may have a pin shape extending from the current collector plate 151 toward the electrode terminal 140. The current collector pin 155 may have a shape protruding from the current collector plate 151.

[0070] The electrode tab 125 may include a recess 126 to allow the current collector 150 to be exposed to the outside of the electrode tab 125 when the electrode tab 125 is bent to cover the outer side of the current collector plate 151. As an example, the recess 126 may have a notch or groove shape in which a portion of the electrode tab 125 is cut.

[0071] The cell housing 110 may include a vent 115, and a vent cap 160 may be attached to the vent 115. As an example, the vent cap 160 may be welded to the cell housing 110 to cover the vent 115. However, the structure of the vent cap 160 is not limited to being attached to the vent 115, and it may also be formed directly on the surface of the cell housing 110 by machining, etching, etc.

[0072] exist Figures 1 to 3 In the example, the vent 115 and vent cover 160 are provided on the cell housing 110, but the vent 115 and vent cover 160 can also be provided on the cover plate 131 (see reference). Figure 17 ).

[0073] Figure 4 This is an exploded perspective view of the cover assembly 130 according to one embodiment. Figure 5 yes Figure 4 The cross-sectional view of the cover assembly 130 shown. Figure 4 and Figure 5 Show Figure 2 An exploded perspective view of the first cover assembly 130a shown. Figure 2 The second cover assembly 130b shown may also have the same or similar structure as the first cover assembly 130a.

[0074] Simultaneously refer to Figure 4 and Figure 5 and Figure 2 The cover assembly 130 will be described below. The cover assembly 130 may include a cover plate 131 and an electrode terminal 140, and may further include at least a portion of a terminal insulator 135, a gasket 136, a cover insulator 137, and a fixing plate 138.

[0075] The cover plate 131 may cover the end of the opening of the cell housing 110. The cover plate 131 may include a mounting groove 133 for mounting the electrode terminals 140. The cover plate 131 may include a through hole 132 for mounting the electrode terminals 140. The through hole 132 may be located in the center of the mounting groove 133.

[0076] The cover plate 131 may further include an injection hole 134 for injecting electrolyte into the receiving space 111 of the cell housing 110.

[0077] The electrode terminal 140 may include: a first body 141 exposed on the outer side of the cover plate 131; and a second body 142 connected to the first body 141 and inserted into the through hole 132 of the cover plate 131. The first body 141 and the second body 142 may have a structure that is combined after being manufactured separately, or they may be integrally formed.

[0078] The first body 141 is exposed on the outer surface of the cover plate 131 and can be used for electrical connection with an adjacent battery cell 100. As an example, at least a portion of the first body 141 may have a plate shape, but is not limited thereto. The first body 141 may be disposed in a mounting groove 133 of the cover plate 131. The first body 141 may include a terminal hole 141a for accommodating a second body 142 in a central region.

[0079] The second body 142 may include a mating hole 143 into which a current collector pin 155 of the current collector 150 is inserted. As an example, the mating hole 143 may have a circular cross-section.

[0080] The second body 142 can be connected to the first body 141 through the terminal hole 141a of the first body 141. The second body 142 can be inserted into the terminal hole 141a of the first body 141 and the through hole 132 of the cover plate 131, thus combining the first body 141 and the cover plate 131. As an example, the second body 142 can apply pressure to the first body 141 and the cover plate 131 to secure them.

[0081] The second body 142 may have a riveting structure that joins the cover plate 131 to the first body 141. With the second body 142 inserted into the terminal hole 141a of the first body 141 and the through hole 132 of the cover plate 131, at least one of the outer and inner ends of the second body 142 may be deformed outwards. The second body 142 can be deformed under pressure to secure the cover plate 131 and the first body 141.

[0082] A terminal insulator 135 may be provided between the cover plate 131 and the electrode terminal 140 to electrically insulate the cover plate 131 from the electrode terminal 140. The terminal insulator 135 may be formed of an insulating material to electrically insulate the cover plate 131 from the first body 141. The terminal insulator 135 may be sealing to seal the space between the cover plate 131 and the first body 141.

[0083] A gasket 136 can be provided between the through hole 132 of the cover plate 131 and the electrode terminal 140 to seal the space between the cover plate 131 and the electrode terminal 140. The gasket 136 is inserted into the through hole 132 of the cover plate 131 and can seal the space between the through hole 132 and the second body 142. Since the gasket 136 seals the space between the electrode terminal 140 and the through hole 132, it can prevent the material inside the cell 100 from flowing out to the outside or the material outside the cell 100 from flowing into the inside. The gasket 136 can also perform the function of electrically insulating the electrode terminal 140 from the cover plate 131.

[0084] Gasket 136 may contain a compressible insulating material for sealing and insulation. For example, the material of gasket 136 may contain at least one of polybutylene terephthalate (PBT) and perfluoroalkoxy alkane (PFA).

[0085] With a terminal insulator 135 and / or a washer 136 provided between the cover plate 131 and the electrode terminal 140, the electrode terminal 140 and the cover plate 131 can be crimped together.

[0086] exist Figure 4 and Figure 5 The diagram shows that the terminal insulator 135 and the washer 136 have a structure that is separate from each other, but the terminal insulator 135 and the washer 136 can also have an integral structure formed from a single component.

[0087] An insulator 137 may be provided on the inner side of the cover plate 131 to electrically insulate the cover plate 131 from the current collector 150 or the electrode assembly 120.

[0088] A fixing plate 138 may be provided between the cover plate 131 and the second body 142. When the inner portion of the second body 142 is deformed under pressure, the fixing plate 138 serves to protect the cover insulator 137. The fixing plate 138 may be formed of a metallic material. The fixing plate 138 may also be formed of a rigid material to minimize deformation during press-fitting.

[0089] Figure 4 and Figure 5An example of the cover assembly 130 is shown. The shape or structure of the first body 141 and the second body 142, as well as the position, shape, and structure of the portion of the second body 142 that is deformed under pressure, can be varied. Additionally, the cover assembly 130 may not include at least a portion of the terminal insulator 135, the washer 136, the cover insulator 137, and the fixing plate 138, and the shape or arrangement of the terminal insulator 135, the washer 136, the cover insulator 137, and the fixing plate 138 disposed in the cover assembly 130 can also be varied.

[0090] Figure 6 This is a perspective view of the current collector 150 according to one embodiment. Figure 7 yes Figure 6 The cross-sectional view of the current collector 150 is shown.

[0091] Simultaneously refer to Figure 6 and Figure 7 and Figure 5 The current collector 150 will be described.

[0092] The current collector 150 may include a current collector plate 151 and current collector pins 155. The current collector plate 151 has a plate shape and can be connected to the electrode assembly 120. Figure 2 Electrical connection. The collector pin 155 may have a shape that connects to the collector plate 151 and extends vertically from the surface of the collector plate 151.

[0093] The current collector pin 155 can be manufactured separately from the current collector plate 151 and then joined together to form the current collector 150. As an example, the current collector pin 155 and the current collector plate 151 can be welded together. Since the contact portions of the current collector pin 155 and the current collector plate 151 solidify after being melted by welding, a physically stable bond can be achieved. In this case, since smooth current flow can be achieved through the welded portion of the current collector pin 155 and the current collector plate 151, a stable current flow from the electrode assembly 120 to the electrode terminal 140 can be ensured. However, the joining method of the current collector pin 155 and the current collector plate 151 is not limited to welding.

[0094] The collector pin 155 can be inserted into and engaged with the insertion hole 152 formed on the collector plate 151. For example, the collector pin 155 may include a engagement portion 158 at the end adjacent to the collector plate 151, and the engagement portion 158 of the collector pin 155 can be inserted into and engaged with the insertion hole 152 of the collector plate 151.

[0095] The collector pin 155 and the collector plate 151 can be welded together with the connecting part 158 ​​inserted into the insertion hole 152. Figure 7The diagram shows the connecting portion 158 of the current collector pin 155 being inserted into the insertion hole 152 from the upper side of the current collector plate 151, but the shape or connection method of the current collector pin 155 and the current collector plate 151 can be varied. For example, the current collector pin 155 may also have a shape that allows it to be inserted into the insertion hole 152 from the lower side of the current collector plate 151.

[0096] The collector pin 155 may include a hollow portion 157 recessed toward the collector plate 151 at its first end 155a, which is spaced apart from the collector plate 151. The hollow portion 157 may have an upper part open. The hollow portion 157 may correspond to an empty space formed in the collector pin 155. The hollow portion 157 may have a shape recessed from the first end 155a of the collector pin 155 at a predetermined depth H. The hollow portion 157 may perform the function of dispersing the force applied to the collector pin 155. For example, when the collector pin 155 is melted and solidified during welding, the hollow portion 157 may absorb the shrinkage stress acting on the collector pin 155. When the hollow portion 157 is formed in the collector pin 155, when stress acts around the hollow portion 157, since the main body of the collector pin 155 can deform slightly, the stress acting on the collector pin 155 or its surroundings can be minimized.

[0097] On a cross-section perpendicular to the first direction (X-axis direction) in which the collector pin 155 extends from the collector plate 151, the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 can each have a circular cross-sectional shape. When the outer peripheral surface of the collector pin 155 has a circular cross-section, the mating hole 143 of the electrode terminal 140 into which the collector pin 155 is inserted... Figure 5 It can also have a circular cross-section. When the hollow part 157 has a circular cross-section, the hollow part 157 can be easily formed in the collector pin 155 by using a rotary tool such as an electric drill.

[0098] When the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow part 157 each have a circular cross-sectional shape, the outer peripheral surface of the collector pin 155 can have an outer diameter D1 of a first diameter, and the inner peripheral surface of the hollow part 157 can have an inner diameter D2 of a second diameter.

[0099] The outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 can form concentric circles. When the center of the collector pin 155 and the center of the hollow portion 157 are the same, the thickness t between the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 can be constant. Therefore, the hollow portion 157 can uniformly absorb the stress acting on the collector pin 155 when the collector pin 155 is welded.

[0100] A chamfered inclined surface can be formed between the first end 155a of the collector pin 155 and the side surface. An edge portion 156 can be provided at the portion where the inclined surface of the collector pin 155 meets the side surface. The edge portion 156 can be defined as the area between the collector pin 155 and the electrode terminal 140. Figure 2 (The boundary part of the contact)

[0101] The current collector pin 155 may further include a diameter expansion portion 159 having a larger diameter than its periphery at the portion where it connects to the current collector plate 151. The diameter expansion portion 159 may have a larger cross-sectional area than its periphery. When welding the current collector pin 155 and the electrode terminal 140, the welding heat can be dispersed, thus preventing or mitigating damage to the electrode assembly 120 caused by welding heat.

[0102] Furthermore, during the use of the battery cell 100, when current flows through the collector pin 155, the increased resistance at the connection between the pin and the collector plate 151 may lead to increased heat generation. In this case, the temperature of the connection between the collector pin 155 and the collector plate 151 rises, which may cause adverse effects such as damage to the electrode assembly 120. As in the embodiment, when a diameter expansion portion 159 is formed in the collector pin 155, the cross-sectional area of ​​the collector pin 155 in the portion connected to the collector plate 151 increases, thereby reducing resistance and heat generation, and thus reducing the temperature rise of the collector pin 155.

[0103] The outer diameter D3 of the diameter expansion portion 159 can be larger than the outer diameter D1 of the outer circumferential surface of the collector pin 155. The outer diameter D3 or height of the diameter expansion portion 159 can be set taking into account the heat generated during welding or use.

[0104] Figure 8 It is shown Figure 7 A cross-sectional view of a variant of the current collector 150 shown.

[0105] and Figure 7 Compared to the current collector 150 shown, Figure 8 The difference in the current collector 150 shown is that it has a structure in which the current collector plate 151 and the current collector pin 155 are integrally formed. In the... Figure 6 and Figure 7 In the description, content other than the differences can also be applied. Figure 8 .

[0106] exist Figure 8 In the current collector 150 shown, the current collector pin 155 and the current collector plate 151 can be integrally formed. That is, the current collector pin 155 and the current collector plate 151 can be integrally formed by forging or other processes.

[0107] During forging, the thinner current collector plate 151 and the relatively thicker current collector pin 155 can be integrally formed. After forging, a recessed hollow portion 157 can be formed at the first end 155a of the current collector pin 155 by machining. When the current collector pin 155 and the current collector plate 151 are integrally formed as a single component, the number of components constituting the current collector 150 is reduced, thus making the manufacturing of the battery cell 100 easier.

[0108] Figure 9 This is a perspective view showing the cover assembly 130 and the current collector 150 in their pre-assembly state according to one embodiment. Figure 10 It is along Figure 1 Line II-II' shows a cross-sectional view of the cover assembly 130 and the current collector 150 before and after their assembly, according to one embodiment.

[0109] Reference Figure 9 and Figure 10 The cover assembly 130 may have an electrode terminal 140 and a cover plate 131 joined together. The electrode terminal 140 may include a first body 141 exposed to the outside and a second body 142 connected to the first body 141. The second body 142 may have a riveting structure that joins the cover plate 131 and the first body 141. The structure of the cover assembly 130 can be adapted to... Figure 5 Explanation.

[0110] The current collector 150 may include a current collector plate 151 and current collector pins 155. The current collector plate 151 may be electrically connected to the electrode assembly 120 housed inside the cell housing 110. As an example, the electrode tabs 125 of the electrode assembly 120 may be soldered to the current collector plate 151 while covering the outer side of the current collector plate 151. A clearance portion 126 may be formed on the electrode tab 125 to prevent the electrode tab 125 from interfering with the current collector pin 155 when covering the outer side of the current collector plate 151. A current collector insulator IN may be provided between the inner side of the current collector plate 151 and the electrode assembly 120, thereby insulating the current collector plate 151 from the main body of the electrode assembly 120.

[0111] With the electrode assembly 120 and the current collector 150 combined, the electrode assembly 120 can be housed inside the cell housing 110. The cover assembly 130 can cover the end of the opening in the cell housing 110. The cover assembly 130 and the cell housing 110 can be welded together at the contact points to form a bond.

[0112] When the cover assembly 130 is near the cell housing 110, the current collector pin 155 of the current collector 150 can be inserted into the mating hole 143 of the electrode terminal 140. The current collector pin 155 can be welded to the electrode terminal 140 while inserted into the mating hole 143 of the electrode terminal 140. The current collector pin 155 can also be welded to the second body 142 of the electrode terminal 140.

[0113] The weld portion W can be formed by solidifying the electrode terminal 140 and the current collector pin 155 through welding. The weld portion W can be formed along the edge portion 156, which serves as the boundary between the current collector pin 155 and the electrode terminal 140. The depth H1 of the weld portion W can be defined as the depth of the portion solidified after the current collector pin 155 and the electrode terminal 140 are melted through welding.

[0114] During the solidification and shrinkage of molten metal, shrinkage stress can act on the weld portion W. The hollow portion 157 of the current collector pin 155 can absorb the stress acting on the weld portion W. When the hollow portion 157 is formed in the current collector pin 155, when the molten metal solidifies and shrinks, the main body of the current collector pin 155 can deform slightly around the hollow portion 157, thus minimizing the stress applied to the weld portion W. Therefore, by minimizing the generation of cracks in the weld portion W, weld defects can be improved.

[0115] The depth H of the hollow portion 157 can be 0.1 times or more and 3 times or less of the outer diameter D1 of the collecting pin 155. The depth H of the hollow portion 157 can be 0.1 times or more, 0.2 times or more, 0.3 times or more, 0.4 times or more, or 0.5 times or more of the outer diameter D1 of the collecting pin 155. The depth H of the hollow portion 157 can be less than 3 times, less than 2.5 times, less than 2 times, less than 1.5 times, or less than 1 time of the outer diameter D1 of the collecting pin 155.

[0116] Within the overall height of the welded portion W, the stress acting on the welded portion W can have a relatively large value on the outer portion of the welded portion W. Therefore, even when the hollow portion 157 is formed at a lower depth in the portion adjacent to the first end 155a of the collector pin 155, the stress acting on the welded portion W can be dispersed. When the depth H of the hollow portion 157 is less than 0.1 times the outer diameter D1 of the collector pin 155, the hollow portion 157 may be too small to adequately absorb the stress acting on the welded portion W.

[0117] Conversely, when the depth H of the hollow portion 157 is greater than three times the outer diameter D1 of the collector pin 155, the rigidity of the collector pin 155 decreases, and the portion with the hollow portion 157 may undergo significant deformation during the welding of the collector pin 155.

[0118] The depth H of the hollow portion 157 can be set to have a value greater than or equal to the depth H1 of the welded portion W. The meaning of the hollow portion 157 having a depth H greater than or equal to the depth H1 of the welded portion W can be defined as follows: when the welded portion W is projected onto a direction perpendicular to the direction of extension of the collector pin 155 (X-axis direction), the depth H of the hollow portion 157 is set such that the welded portion W and the hollow portion 157 have an overlapping shape.

[0119] When the depth H of the hollow portion 157 is greater than or equal to the depth H1 of the welded portion W, the main body of the collector pin 155 can be slightly deformed around the hollow portion 157 within the overall height of the welded portion W, thus relieving the stress acting on the welded portion W through the hollow portion 157.

[0120] Simultaneously refer to Figure 9 and Figure 10 and Figure 7 The thickness t between the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow part 157 and the inner diameter D2 of the hollow part 157 are explained.

[0121] The thickness t between the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 can be 0.5 mm or more. When the thickness t between the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 is less than 0.5 mm, welding may cause most of the first end 155a of the collector pin 155 to melt, potentially resulting in poor welding. The thickness t between the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 can be smaller than the radius of the collector pin 155.

[0122] The inner diameter D2 of the hollow portion 157 can be 0.5 mm or more. When the inner diameter D2 of the hollow portion 157 is less than 0.5 mm, the size of the hollow portion 157 is too small, and it may be difficult to fully absorb the stress acting on the welded portion W. The inner diameter D2 of the hollow portion 157 can be smaller than the outer diameter D1 of the collector pin 155.

[0123] Figure 11 It is shown Figure 10 The illustrated embodiment shows a cross-sectional view of the force acting on the welded portion W while the electrode terminal 140 and the current collector 150 are welded.

[0124] Reference Figure 11 The second body 142 of the electrode terminal 140 and the current collector pin 155 of the current collector 150 can be welded to form a welded portion W. The outer peripheral surface of the current collector pin 155 can be a circular cross-section with an outer diameter D1 having a first diameter, and the hollow portion 157 of the current collector pin 155 can be a circular cross-section with an inner diameter D2 having a second diameter.

[0125] The welded portion W is formed by melting and solidifying metal during welding. During the solidification process, stress generated by shrinkage can act on the welded portion W. Since the hollow portion 157 forms an empty space in the central region of the current collector pin 155, it can absorb the stress acting on the welded portion W. That is, the hollow portion 157 provides space for the portion of the current collector pin 155 located between the edge portion 156 and the hollow portion 157, and for the welded portion W to deform towards the center of the current collector pin 155. Therefore, the hollow portion 157 can prevent cracks from forming in the welded portion W or at its boundary due to stress acting on it.

[0126] The outer peripheral surface of the current collector pin 155 can be a circular cross-section with an outer diameter D1 having a first diameter, and the hollow portion 157 of the current collector pin 155 can be a circular cross-section with an inner diameter D2 having a second diameter. The welding portion W can be formed in a ring shape along the edge portion 156 that serves as the boundary between the current collector pin 155 and the electrode terminal 140.

[0127] When the outer peripheral surface of the collector pin 155 and the inner peripheral surface of the hollow portion 157 form concentric circles, the thickness of the collector pin 155 around the hollow portion 157 is constant, and the stress acting on the collector pin 155 can be uniformly absorbed by the hollow portion 157 on the entire outer edge of the hollow portion 157.

[0128] Figure 12 (a) is a cross-sectional view showing the combined state of the cover assembly 130 and the current collector 150' according to the comparative example. Figure 12 (b) is shown Figure 12 The cross-sectional view of the force acting on the welded part W in the state of welding electrode terminal 140 and current collector 150' shown in Comparative Example (a).

[0129] and Figure 10 and Figure 11 Compared to the embodiments shown, Figure 12 (a) and Figure 12 The only difference in the comparative example shown in (b) is that a hollow portion 157 is not formed on the current collector pin 155' of the current collector 150'. Figure 10 That is, in Figure 12 (a) and Figure 12 In the comparative example shown in (b), the cover assembly 130 and Figure 10 and Figure 11 The cover assembly 130 shown is identical, and the collector pin 155' has a shape without a hollow portion 157 formed.

[0130] exist Figure 12 (a) and Figure 12In the comparative example shown in (b), the weld portion W can be formed in a ring shape along the edge portion 156 that serves as the boundary between the current collector pin 155 and the electrode terminal 140. During the solidification process of the welded metal, the stress generated by shrinkage can act on the weld portion W. In the case of the comparative example, since the inner side of the weld portion W consists of a closed space, a large shrinkage stress may act on the weld portion W. In this case, a crack CR may form in the stress concentration area of ​​the weld portion W. This crack not only reduces the quality of the weld portion W, but also, as the crack CR grows larger, may make the connection and electrical connection between the current collector pin 155' and the electrode terminal 140 unstable.

[0131] Conversely, according to embodiments of this disclosure, such as Figure 10 and Figure 11 As shown in one example, since a hollow portion 157 is formed in the collector pin 155, defects such as cracks CR can be prevented from occurring in the welded portion W.

[0132] Figure 13 This is a cross-sectional view showing the cover assembly 130 and the current collector 150 before and after joining, according to another embodiment.

[0133] With reference Figures 1 to 11 Compared to the illustrated embodiments, Figure 13 The difference in the other embodiment shown is only that the first body 141 and the second body 142 of the electrode terminal 140 are integrally formed. Figures 1 to 11 In the description, content other than the differences can also be applied. Figure 13 .

[0134] The first body 141 and the second body 142 of the electrode terminal 140 can be integrally formed, and the electrode terminal 140 is riveted to the cover plate 131.

[0135] The first body 141 is the portion exposed on the outer side of the cover plate 131, and the second body 142 is the portion inserted into the through hole 132 of the cover plate 131. The first body 141 and the second body 142 can be integrally formed from a single component.

[0136] When the first body 141 and the second body 142 are integrally formed, the electrode terminal 140 can function as a riveting-type electrode terminal that performs riveting functions. Figure 13 In one embodiment, the electrode terminal 140 may have a structure that presses against at least one of the outer and inner surfaces of the cover plate 131.

[0137] At least a portion of a terminal insulator 135, a washer 136, a cover insulator 137, and a fixing plate 138 may be provided between the electrode terminal 140 and the cover plate 131, and the electrode terminal 140 may form a riveting structure that presses together the components provided between the electrode terminal 140 and the cover plate 131 in one go.

[0138] Figures 14 to 16 This is a cross-sectional view showing various variations of the hollow portion 157 provided in the current collector 150.

[0139] and Figures 1 to 11 Compared to the embodiments shown, Figures 14 to 16 The difference in the variant shown lies in the shape of the hollow portion 157 provided in the collector pin 155. In the... Figures 1 to 11 In the description, the content other than the differences can be applied to Figures 14 to 16 The variant example shown. Additionally, for... Figure 13 The explanation can also be applied to Figures 14 to 16 The variant example shown.

[0140] exist Figures 14 to 16 In the illustrated embodiment, the collector pin 155 may have a hollow portion 157 of various shapes. The hollow portion 157 may include at least a portion in the region from the first end 155a toward the collector plate 151 whose inner diameter is smaller than the inner diameter D2 at the first end 155a.

[0141] Reference Figure 14 The hollow portion 157 can have a shape in which the inner diameter D2 gradually decreases. For example, Figure 14 The hollow portion 157 may include a cone or frustum shape.

[0142] Reference Figure 15 The hollow portion 157 may include an upper portion with a constant diameter and a lower portion with a decreasing diameter. The lower portion of the hollow portion 157 may include a conical or frustum-shaped portion.

[0143] Reference Figure 16 The hollow portion 157 may include an upper portion with a constant diameter and a lower portion with a circular cross-section. The lower portion of the hollow portion 157 may have an arc-shaped cross-section.

[0144] Figure 17 This is a perspective view of cell 100a according to another embodiment.

[0145] and Figures 1 to 11 The embodiments shown are different. Figure 17 The shown cell 100a differs in the shape of the cell housing 110 and the arrangement structure of the cover assembly 130.

[0146] exist Figure 17In another embodiment shown, the battery cell 100a may include a battery cell housing 110 with an opening on one side and a cover assembly 130 covering one end of the opening of the battery cell housing 110. The cover assembly 130 may include a cover plate 131 and two electrode terminals 140 disposed on the cover plate 131. In the battery cell 100a according to another embodiment, the two electrode terminals 140 may have a structure disposed on a cover plate 131. A collector pin 155 may be soldered to the electrode terminal 140 in an inserted and coupled state to each electrode terminal 140.

[0147] exist Figures 1 to 11 , Figures 13 to 16 The connection structure between the current collector pin 155 of the current collector 150 and the electrode terminal 140 described herein can also be applied to a battery cell 100a with a structure in which the two electrode terminals 140 are arranged in the same direction.

[0148] Figure 18 This is a perspective view of cell 100b according to yet another embodiment.

[0149] and Figures 1 to 11 The embodiments shown are different. Figure 18 The difference in the cell 100b shown is that it is constructed as a cylindrical cell.

[0150] Even in the case of a cylindrical battery cell 100b, it may include electrode terminals 140 and a cover plate 131 on which the electrode terminals 140 are provided. The cover plate 131 may be formed separately from the battery cell housing 110, or it may be formed integrally with the battery cell housing 110. The current collector pin 155 may be welded to the electrode terminals 140 in a state of being inserted and coupled to the electrode terminals 140.

[0151] exist Figures 1 to 11 , Figures 13 to 16 The connection structure between the current collector pin 155 and the electrode terminal 140 of the current collector 150 described herein can also be applied to the cylindrical cell 100b.

[0152] Figure 19 This is a perspective view of a battery device 200 according to one embodiment.

[0153] Figure 19 The battery device 200 shown may include a plurality of battery cells 100. The battery cells 100 may be arranged in a predetermined configuration to form a battery cell assembly. As an example, the battery cells 100 may be used in… Figures 1 to 11 The battery cell is 100 as described in the description.

[0154] The battery device 200 may include a side plate 210 covering at least one side of a plurality of battery cells 100 to protect the plurality of battery cells 100. The side plate 210 may be provided as part of the device housing of the battery device 200. As an example, the side plate 210 may have a structure disposed at both ends of the plurality of battery cells 100. However, the side plate 210 or the device housing may be applied in various forms.

[0155] The above description is merely an example of applying the principles of this disclosure, and other configurations may be included without departing from the scope of the invention. Furthermore, the above embodiments can be implemented by deleting some components, and the embodiments can also be combined with each other.

Claims

1. A battery cell, comprising: Electrode assembly, including positive electrode, negative electrode and separator; A cell housing that accommodates the electrode assembly; The cover plate is connected to the battery cell housing; Electrode terminals are disposed on the cover plate and include mating holes; as well as A current collector is used to electrically connect the electrode assembly to the electrode terminals. The current collector includes: The current collector is electrically connected to the electrode assembly; as well as A current collector pin is connected to the current collector plate and soldered to the electrode terminal while being inserted into the connection hole. The collector pin includes a hollow portion recessed toward the collector plate at a first end separated from the collector plate.

2. The battery cell according to claim 1, wherein, On a cross section perpendicular to a first direction in which the collector pin extends from the collector plate, the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion each have a circular cross-sectional shape.

3. The battery cell according to claim 2, wherein, The outer circumferential surface of the collector pin and the inner circumferential surface of the hollow part form concentric circles.

4. The battery cell according to claim 1, wherein, The electrode terminals include: The first main body is exposed on the outer side of the cover plate; and The second body is connected to the first body and inserted into the through hole of the cover plate.

5. The battery cell according to claim 4, wherein, The second body has a riveting structure that connects the cover plate to the first body.

6. The battery cell according to claim 4, wherein, The first body and the second body of the electrode terminal are integrally formed, and the electrode terminal is riveted to the cover plate.

7. The battery cell according to any one of claims 1 to 6, wherein, The thickness between the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow part is 0.5 mm or more. The inner diameter of the hollow part is 0.5 mm or more.

8. The battery cell according to any one of claims 1 to 6, wherein, The depth of the hollow portion is more than 0.1 times and less than 3 times the outer diameter of the collector pin.

9. The battery cell according to any one of claims 1 to 6, wherein, The depth of the hollow portion is set to a value greater than or equal to the depth of the welded portion, which is formed by the electrode terminal and the current collector pin through the solidification of molten metal from welding.

10. The battery cell according to any one of claims 1 to 6, wherein, The hollow portion includes at least a portion in the region from the first end toward the current collector where the inner diameter is smaller than the inner diameter at the first end.

11. The battery cell according to any one of claims 1 to 6, wherein, The collector pin and the collector plate are welded together.

12. The battery cell according to any one of claims 1 to 6, wherein, The collector pin is inserted into and engaged with the insertion hole formed on the collector plate.

13. The battery cell according to any one of claims 1 to 6, wherein, The collector pin further includes a diameter expansion portion having a larger diameter than its periphery at the portion connected to the collector plate.

14. The battery cell according to any one of claims 1 to 6, wherein, The collector pin and the collector plate are integrally formed.

15. A current collector for a battery cell, comprising: Current collector; as well as The collector pin is connected to the collector plate. The collector pin includes a hollow portion recessed toward the collector plate at a first end separated from the collector plate.

16. The current collector for a battery cell according to claim 15, wherein, On a cross-section perpendicular to a first direction in which the collector pin extends from the collector plate, the outer peripheral surface of the collector pin and the inner peripheral surface of the hollow portion each have a circular cross-sectional shape. The outer circumferential surface of the collector pin and the inner circumferential surface of the hollow part form concentric circles.

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