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 case accommodating the electrode assembly; a cover plate connected with the chip case and including a through hole; an electrode terminal disposed in the through hole of 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 inserted into the coupling hole, the current collecting pin including: a first portion disposed at an outer side spaced apart from the current collecting plate; a third portion connected with the current collecting plate; and a second portion between the first portion and the third portion, at least one of an outer diameter of the second portion and a maximum outer diameter of the third portion having a value greater than an outer diameter of the first portion.

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 inside the cell casing via current collectors. The current collector may include a current collector plate electrically connected to the electrode assemblies and current collector pins electrically connected to the electrode terminals.

[0006] The current collector pin can have a shape with a protrusion of predetermined thickness extending from the current collector plate. During the charging and discharging of the battery cell, the current collector generates heat, and the diameter (cross-sectional area) of the portion of the current collector pin that connects to the current collector plate is smaller than that of the current collector plate. Therefore, the portion of the current collector pin that connects to the current collector plate may generate significant heat due to high resistance, which may not only reduce the performance and lifespan of the battery cell but also potentially damage the electrode assembly.

[0007] Furthermore, increasing the diameter of the current collector pin to reduce heat generation may increase the welding heat input because the welding path when soldering the current collector pin and electrode terminals becomes longer. This welding heat causes the current collector temperature to rise, potentially damaging components near the current collector, such as the electrode assembly.

[0008] According to one aspect of this disclosure, a current collector and a battery cell including the current collector can be provided that can reduce the heating of the current collector due to the increase in resistance of the current collector during charging and / or discharging of the battery cell.

[0009] According to one aspect of this disclosure, a current collector capable of preventing degradation of the performance and lifespan of a battery cell, and a battery cell including the current collector, can be provided.

[0010] According to one aspect of this disclosure, a current collector and a battery cell including the current collector can be provided that can reduce or prevent damage to electrode assemblies due to welding heat.

[0011] 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.

[0012] (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 and including a through hole; electrode terminals disposed in the through hole of the cover plate and including a mating hole; 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 inserted into the mating hole. The current collector pin may include: a first portion disposed on an outer side spaced apart from the current collector plate; a third portion connected to the current collector plate; and a second portion located between the first portion and the third portion, wherein at least one of the outer diameter of the second portion and the maximum outer diameter of the third portion may have a value greater than the outer diameter of the first portion.

[0013] According to one embodiment, at least a portion of the third portion may have an outer diameter greater than that of the first portion and a outer diameter greater than or equal to that of the second portion.

[0014] According to one embodiment, the outer peripheral surface of the collector pin may have a circular cross-sectional shape in a cross-section perpendicular to a first direction in which the collector pin extends from the collector plate.

[0015] According to one embodiment, the bonding hole of the electrode terminal may include a first region that contacts the side of the first portion and a second region that contacts the side of the second portion.

[0016] 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.

[0017] According to one embodiment, the second body may have a riveting structure that joins the cover plate to the first body.

[0018] 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.

[0019] According to one embodiment, the first portion and the electrode terminal may be welded together along the boundary between the first portion and the electrode terminal.

[0020] According to one embodiment, the first part and the second part can be connected by a connecting surface, which can have a shape in which the diameter gradually increases from the first part toward the second part.

[0021] According to one embodiment, the outer diameter of the first portion can be 1 mm or more, and the outer diameter of the second portion can be more than 1.05 times the outer diameter of the first portion and less than the inner diameter of the through hole.

[0022] According to one embodiment, the maximum outer diameter of the third portion may be greater than the outer diameter of the second portion.

[0023] According to one embodiment, the third portion of the current collector pin may include: a connecting portion that inserts into and connects to an insertion hole formed on the current collector plate; and a diameter expansion portion having a diameter larger than that of the second portion.

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

[0025] According to one embodiment, the collector pin and the collector plate can be integrally formed.

[0026] 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 may include: a first portion disposed on an outer side spaced apart from the current collector plate; a third portion connected to the current collector plate; and a second portion located between the first portion and the third portion, at least one of the outer diameter of the second portion and the maximum outer diameter of the third portion may have a value greater than the outer diameter of the first portion.

[0027] According to one embodiment, at least a portion of the third portion may have an outer diameter greater than that of the first portion and a outer diameter greater than or equal to that of the second portion.

[0028] (III) Beneficial Effects According to one embodiment of this disclosure, the heat generation of the current collector due to the increased resistance of the current collector during charging and / or discharging of the battery cell can be reduced.

[0029] According to one embodiment of this disclosure, damage to the electrode assembly due to welding heat can be reduced or prevented. 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 3 It 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 This is a cross-sectional view showing the combined state of the cover assembly and the current collector according to the comparative example.

[0041] Figure 12 This is a cross-sectional view showing the cover assembly and the current collector before and after joining, according to another embodiment.

[0042] Figure 13 This is a perspective view of a battery cell according to another embodiment.

[0043] Figure 14 This is a perspective view of a battery cell according to yet another embodiment.

[0044] Figure 15 This is a perspective view of a battery device according to one embodiment.

[0045] 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: Centralized Sales 156: Part One 157: Part Three 157a: Joint 157b: Diameter expansion section; 158: Second part 200: Battery assembly; 210: Side panel D1: Outer diameter of the first part; D2: Outer diameter of the second part D3: Maximum outer diameter of the third part; DH: Inner diameter of the through hole. IN: Current collector insulator; W: Welded part Detailed Implementation

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The following is for reference Figures 1 to 14 The battery cell disclosed herein will be described. Figures 1 to 13 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 14 As shown, it can also be applied to cylindrical battery cells.

[0052] 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.

[0053] 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, housing the electrode assembly 120; and a cover plate 131, connected to the battery cell housing 110, and including a through hole 132. Figure 4 ); Electrode terminal 140, disposed in through hole 132 of cover plate 131 ( Figure 4The electrode assembly 120 includes a connecting hole 143 and a current collector 150 for electrically connecting the electrode assembly 120 to the electrode terminal 140.

[0054] 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.

[0055] 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.

[0056] 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 13 ).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The cover plate 131 may include an injection hole 134 for injecting electrolyte into the receiving space 111 of the cell housing 110. Figure 4 An injection port cap 139 with a closed injection hole 134 can be attached to the cover plate 131.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 inserted into a connection hole 143.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] exist Figures 1 to 3 The example shown is a structure where 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 13 ).

[0071] 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.

[0072] 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.

[0073] 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 terminal 140. The cover plate 131 may include a through hole 132 for mounting the electrode terminal 140. The through hole 132 may be located in the center of the mounting groove 133. The through hole 132 may have an inner diameter DH that allows at least a portion of the electrode terminal 140 to pass through.

[0074] The cover plate 131 may further include an injection hole 134 for injecting electrolyte into the receiving space 111 of the cell housing 110.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] The connecting hole 143 may have a shape that corresponds to or contacts at least a portion of the collector pin 155. The connecting hole 143 may include regions with different inner diameters. For example, the connecting hole 143 may include a first region 143a located on the outer side and a second region 143b located on the inner side and having a larger diameter than the first region 143a. The first region 143a and the second region 143b may be connected by an inclined surface or curved surface whose width gradually widens towards the second region 143b.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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).

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] Simultaneously refer to Figure 6 and Figure 7 and Figure 5 The current collector 150 will be described.

[0091] 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.

[0092] The collector pin 155 may include: a first portion 156 disposed on the outer side spaced apart from the collector plate 151; a third portion 157 connected to the collector plate 151; and a second portion 158 located between the first portion 156 and the third portion 157.

[0093] The first portion 156 of the current collector pin 155 is for welding to the electrode terminal 140 and can be exposed to the outside of the electrode terminal 140 through the mating hole 143. The second portion 158 can be located between the first portion 156 and the current collector plate 151. The third portion 157 is the portion that connects to the cover plate and can be positioned closer to the cover plate than the second portion 158.

[0094] The collector pin 155 can generally have a shape in which the diameter gradually increases from the outer end of the first part 156 toward the collector plate 151.

[0095] At least one of the outer diameter D2 of the second part 158 ​​and the maximum outer diameter D3 of the third part 157 can have a value greater than the outer diameter D1 of the first part 156. When at least one of the outer diameter D2 of the second part 158 ​​and the maximum outer diameter D3 of the third part 157 is greater than the outer diameter D1 of the first part 156, the heat generation of the current collector 150 due to the increased resistance during charging and / or discharging can be reduced. In addition, since the heat generation of the current collector 150 is reduced, the performance and lifespan of the battery cell can be prevented from deteriorating.

[0096] At least a portion of the outer diameter of the third part 157 can have a value greater than the outer diameter D1 of the first part 156, and a value greater than or equal to the outer diameter D2 of the second part 158. In this case, since the change in cross-sectional area at the third part 157 where the current collector 151 and the current collector 150 are connected is small, the resistance and heat generation at the third part 157 and the second part 158 ​​can be reduced during charging and discharging.

[0097] The first part 156 and the second part 158 ​​are connected by a connecting surface 156a, which may have a shape in which the diameter gradually increases from the first part 156 toward the second part 158. The connecting surface 156a, as the surface connecting the first part 156 and the second part 158, may be formed as an inclined surface or a curved surface. Because the connecting surface 156a has a gradually increasing diameter, the phenomenon of increased resistance and heat generation due to abrupt changes in cross-sectional area can be prevented.

[0098] Reference Figure 5 The coupling hole 143 of the electrode terminal 140 may include a first region 143a that contacts the side of the first portion 156 and a second region 143b that contacts the side of the second portion 158. In this case, the first region 143a of the coupling hole 143 may have an inner diameter substantially the same as the outer diameter D1 of the first portion 156, and the second region 143b of the coupling hole 143 may have an inner diameter substantially the same as the outer diameter D2 of the second portion 158. When the first portion 156 and the second portion 158 of the current collector 155 contact the first region 143a and the second region 143b of the coupling hole 143, respectively, the heat generation of the current collector 155 can be reduced due to the increased current flow area.

[0099] The third portion 157 of the collector pin 155 may include: a connecting portion 157a, which inserts into and connects to an insertion hole 152 formed on the collector plate 151; and a diameter expansion portion 157b, having a diameter larger than that of the second portion 158. The connecting portion 157a of the collector pin 155 can be inserted into the insertion hole 152 connected to the collector plate 151. The outer diameter D4 of the connecting portion 157a can be set to a size that allows it to be inserted into the insertion hole 152. The diameter expansion portion 157b can prevent a sharp increase in resistance between the collector plate 151 and the collector pin 155 by increasing the cross-sectional area of ​​the portion connected to the collector plate 151.

[0100] The maximum outer diameter D3 of the third part 157 can be greater than the outer diameter D2 of the second part 158. For example, the diameter expansion portion 157b can have an outer diameter greater than the outer diameter D2 of the second part 158. When the outer diameter D1 of the first part 156, the outer diameter D2 of the second part 158, and the maximum outer diameter D3 of the third part 157 increase sequentially, the resistance and heat generation during charging and discharging can be significantly reduced because the change in cross-sectional area decreases.

[0101] 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.

[0102] The collector pin 155 and the collector plate 151 can be welded together with the connecting part 157a inserted into the insertion hole 152. Figure 7 The diagram shows the connecting portion 157a 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.

[0103] In 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 may 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 collector pin 155 and the mating hole 143 have circular cross-sections, the collector pin 155 can be easily inserted into the mating hole 143.

[0104] A chamfered bevel can be formed on the upper edge of the collector pin 155. When the collector pin 155 is inserted into the mating hole 143, the beveled bevel can guide the insertion of the collector pin 155.

[0105] Figure 8 It is shown Figure 7 A cross-sectional view of a variant of the current collector 150 shown.

[0106] 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 .

[0107] 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.

[0108] During forging, the thinner current collector plate 151 and the relatively thicker current collector pin 155 can be integrally formed. 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] When the cover assembly 130 is close to the cell housing 110, the current collector pin 155 of the current collector 150 can be inserted into the connection hole 143 of the electrode terminal 140. The first portion 156 of the current collector pin 155 can contact the first region 143a of the connection hole 143, and the second portion 158 of the current collector pin 155 can contact the second region 143b of the connection hole 143. As the contact area between the current collector pin 155 and the electrode terminal 140 increases, the heat generated by the current collector pin 155 can be reduced due to the increased current flow area. However, to facilitate insertion of the current collector pin 155 into the connection hole 143, the second portion 158 of the current collector pin 155 can also be configured not to contact the second region 143b of the connection hole 143.

[0114] In addition, in order to increase the contact area, the connecting surface 156a of the first part 156 and the second part 158 ​​can also be configured to contact the inner peripheral surface of the connecting hole 143, but is not limited thereto.

[0115] The collector pin 155 can be welded to the electrode terminal 140 while inserted into the engagement hole 143. The first portion 156 of the collector pin 155 and the electrode terminal 140 can be welded and joined along the boundary between the first portion 156 and the electrode terminal 140. The collector pin 155 can be welded to the second body 142 of the electrode terminal 140.

[0116] The welded portion W can be formed by solidifying the molten metal from the electrode terminal 140 and the current collector pin 155 through welding. The welded portion W can be formed along the boundary between the first portion 156 of the current collector pin 155 and the electrode terminal 140.

[0117] Simultaneously refer to Figure 9 and Figure 10 and Figure 7 The outer diameter D1 of the first part 156 and the outer diameter D2 of the second part 158 ​​of the collector pin 155 are explained.

[0118] The outer diameter D1 of the first portion 156 of the collector pin 155 can be 1 mm or more. Since the weld portion W is formed along the boundary between the first portion 156 of the collector pin 155 and the second body of the electrode terminal 140, when the outer diameter D1 of the first portion 156 is less than 1 mm, the weld between the collector pin 155 and the electrode terminal 140 is incomplete, which may prevent a stable bond from being ensured. Furthermore, when the outer diameter of the first portion is less than 1 mm, the current flow between the collector pin 155 and the electrode terminal 140 may be impeded due to the short weld line of the weld portion W. The outer diameter D1 of the first portion 156 can have a value smaller than the outer diameter D2 of the second portion 158.

[0119] The outer diameter D2 of the second part 158 ​​can be more than 1.05 times the outer diameter D1 of the first part 156 and less than the inner diameter DH of the through hole 132.

[0120] When the outer diameter D2 of the second part 158 ​​is less than 1.05 times the outer diameter D1 of the first part 156, the difference in cross-sectional area between the second part 158 ​​and the first part 156 is too small, making it difficult to expect a heat reduction effect by increasing the cross-sectional area of ​​the second part 158. Furthermore, when the difference in cross-sectional area between the second part 158 ​​and the first part 156 is too small, the outer diameter D1 of the first part 156 may become larger. In this case, the welding path becomes longer, leading to an increase in welding heat input, which in turn causes the temperature of the current collector 150 to rise, potentially damaging components such as electrode assemblies located near the current collector 150.

[0121] Since the mating hole 143 of the electrode terminal 140 is located inside the through hole 132 of the cover plate, the outer diameter D2 of the second part 158 ​​inserted into the mating hole 143 can be set to have a value smaller than the inner diameter of the through hole 132.

[0122] Figure 11 This is a cross-sectional view showing the combined state of the cover assembly and the current collector 150' according to the comparative example.

[0123] and Figure 10 Compared to the embodiments shown, Figure 11 The only difference in the comparative example shown is the shape of the current collector pin 155' of the current collector 150'. That is, in Figure 11 In the comparative example shown, cover assembly 130 and Figure 10 The cover assembly 130 shown is identical, and the collector pin 155' has a shape that extends from the collector plate 151 with a predetermined cross section (diameter).

[0124] exist Figure 11 In the comparative example shown, the cross-sectional area of ​​portion A where the collector pin 155' connects to the collector plate 151 changes significantly. That is, compared to the collector plate 151, the cross-sectional area of ​​portion A where the collector pin 155' connects to the collector plate 151 is drastically reduced, and the resistance can increase significantly. Therefore, the heat generated at portion A where the collector pin 155' connects to the collector plate 151 increases, and the temperature may rise. In this case, the performance and lifespan of the battery cell may decrease.

[0125] Conversely, according to embodiments of this disclosure, such as Figure 10 As shown in one example, since the outer diameter D2 of the second portion 158 of the current collector 155 and / or the maximum outer diameter D3 of the third portion 157 are larger than the outer diameter D1 of the first portion 156, the heat generated by the current collector 150 due to the increased resistance during charging and / or discharging can be reduced. Furthermore, the reduced heat generation of the current collector 150 prevents a decrease in cell performance and lifespan.

[0126] On the other hand, Figure 11 In the comparative example, when the diameter of the current collector 155' is increased to reduce heat generation, the welding path when welding the current collector 155' and the electrode terminal 140 becomes longer, which may increase the amount of welding heat input. Therefore, in the case of the comparative example, the temperature of the current collector 150' rises due to welding heat, which may damage components such as the electrode assembly that are close to the current collector 150'.

[0127] Conversely, according to embodiments of this disclosure, such as Figure 10 As shown in one example, the outer diameter D1 of the first portion 156 can have a smaller value than the outer diameter D2 of the second portion 158 and / or the maximum outer diameter D3 of the third portion 157. When the outer diameter D1 of the first portion 156 is smaller, the welding heat input is reduced because the welding path when welding the current collector pin 155 and the electrode terminal 140 is shorter. This reduces or prevents the welding heat from causing the temperature of the current collector 150 to rise and damage to components close to the current collector 150, such as the electrode assembly.

[0128] Figure 12 This is a cross-sectional view showing the cover assembly 130 and the current collector 150 before and after joining, according to another embodiment.

[0129] With reference Figures 1 to 10 Compared to the illustrated embodiments, Figure 12 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 10 In the description, content other than the differences can also be applied. Figure 12 .

[0130] 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.

[0131] 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.

[0132] 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 140 that performs riveting functions. Figure 12 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.

[0133] 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.

[0134] Figure 13 This is a perspective view of cell 100a according to another embodiment.

[0135] and Figures 1 to 10 The embodiments shown are different. Figure 13 The shown cell 100a differs in the shape of the cell housing 110 and the arrangement structure of the cover assembly 130.

[0136] exist Figure 13 In 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.

[0137] exist Figures 1 to 10 , Figure 12 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.

[0138] Figure 14This is a perspective view of cell 100b according to yet another embodiment.

[0139] and Figures 1 to 10 The embodiments shown are different. Figure 14 The difference in the cell 100b shown is that it is constructed as a cylindrical cell.

[0140] 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.

[0141] exist Figures 1 to 10 , Figure 12 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.

[0142] Figure 15 This is a perspective view of a battery device 200 according to one embodiment.

[0143] Figure 15 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 10 The battery cell is 100 as described in the description.

[0144] 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.

[0145] 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; The battery cell housing houses the electrode assembly; A cover plate, connected to the cell housing, and including through holes; Electrode terminals are disposed in the through holes of 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; and A current collector pin is connected to the current collector plate and inserted into the coupling hole. The power collection system includes: The first part is located on the outer side, separated from the current collector; The third part is connected to the current collector; and The second part is located between the first part and the third part. At least one of the outer diameter of the second part and the maximum outer diameter of the third part has a value greater than the outer diameter of the first part.

2. The battery cell according to claim 1, wherein, At least one of the third portions has an outer diameter greater than that of the first portion and has an outer diameter greater than or equal to that of the second portion.

3. The battery cell according to claim 1, wherein, The connection hole of the electrode terminal includes a first region that contacts the side of the first portion and a second region that contacts the side of the second portion.

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 claim 1, wherein, The first portion and the electrode terminal are welded together along the boundary between the first portion and the electrode terminal.

8. The battery cell according to any one of claims 1 to 7, wherein, The first part and the second part are connected by a connecting surface. The connecting surface has a shape in which the diameter gradually increases from the first part toward the second part.

9. The battery cell according to any one of claims 1 to 7, wherein, The outer diameter of the first part is 1 mm or more. The outer diameter of the second part is more than 1.05 times the outer diameter of the first part and less than the inner diameter of the through hole.

10. The battery cell according to any one of claims 1 to 7, wherein, The maximum outer diameter of the third part is greater than the outer diameter of the second part.

11. The battery cell according to any one of claims 1 to 7, wherein, The third part of the power collection device includes: The connecting portion, inserted into and connected to the insertion hole formed on the current collector plate; and The diameter expansion portion has a larger diameter than the second portion.

12. The battery cell according to any one of claims 1 to 7, wherein, The collector pin and the collector plate are welded together.

13. The battery cell according to any one of claims 1 to 7, wherein, The collector pin and the collector plate are integrally formed.

14. A current collector for a battery cell, comprising: Current collector; as well as The collector pin is connected to the collector plate. The power collection system includes: The first part is located on the outer side, separated from the current collector; The third part is connected to the current collector; and The second part is located between the first part and the third part. At least one of the outer diameter of the second part and the maximum outer diameter of the third part has a value greater than the outer diameter of the first part.

15. The current collector for a battery cell according to claim 14, wherein, At least one of the third portions has an outer diameter greater than that of the first portion and has an outer diameter greater than or equal to that of the second portion.

Images