Battery cell and battery pack including same

Abstract

A battery cell according to an embodiment of the present invention includes: an electrode assembly; a battery housing for accommodating the electrode assembly; and a current collector disposed on one surface of the electrode assembly in the battery housing, wherein the current collector includes one or more electrolyte flow grooves allowing electrolyte to flow therethrough. A battery cell and a battery pack according to an embodiment of the present invention facilitate electrolyte flow, thereby improving electrolyte impregnation.

Description

Battery cell and battery pack including the same

[0001] The present invention relates to a battery cell and a battery pack including the same, and more specifically, to a battery cell in which the fluidity of the electrolyte is secured at a current collector plate and a battery pack including the same.

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries refer to batteries capable of charging and discharging, and are applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electric power sources.

[0003] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit cells, is approximately 2.5V to 4.6V. Therefore, if a higher output voltage is required, a battery pack is formed by connecting multiple battery cells in series. Additionally, a battery pack is formed by connecting multiple battery cells in parallel depending on the charge / discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0004] When configuring a battery pack by connecting multiple battery cells in series or parallel, it is common practice to first configure a battery module consisting of at least one battery cell, preferably multiple battery cells, and then use at least one such battery module and add other components to form a battery pack. Here, a battery module refers to a component in which multiple battery cells are connected in series or parallel, and a battery pack may refer to a component in which multiple battery modules are connected in series or parallel to increase capacity and output.

[0005] Battery cells are classified into pouch type, cylindrical type, prismatic type, etc., depending on the shape of the battery case.

[0006] Among these, cylindrical cells offer excellent safety as they primarily utilize a metal case with a cylindrical structure. They also have the advantage of high energy density by housing a jelly-roll type electrode assembly inside the case, and make it easy to configure a large-capacity power storage device by connecting multiple cells in series or parallel.

[0007] The electrode assembly, housed in a cylindrical case, is a rechargeable power generation device composed of a stacked structure of an anode, a separator, and a cathode, and is classified into jellyroll, stack, and stack / folding types. The jellyroll type is formed by winding a separator between long sheet-shaped anodes and cathodes coated with active material; the stack type is formed by sequentially stacking multiple anodes and cathodes of a predetermined size with a separator in between; and the stack / folding type is a composite structure of the jellyroll and stack types. Among these, the jellyroll electrode assembly has the advantages of being easy to manufacture and having a high energy density per unit weight.

[0008] In the manufacturing process of a cylindrical battery cell, a positive electrode current collector or a negative electrode current collector may be bonded to the upper or lower side of a jellyroll electrode assembly, and after the jellyroll electrode assembly with the bonded positive or negative electrode current collector is inserted into a cylindrical can, an electrolyte may be injected into the cylindrical can.

[0009] During this electrolyte injection process, there is a problem in that the positive (negative) current collector plate is welded to the jellyroll electrode assembly, thereby blocking the flow of the electrolyte in the direction passing through the plate at that point.

[0010] The present invention aims to solve the problems described above by providing a battery cell and a battery pack in which the fluidity of the electrolyte is secured and the impregnation of the electrolyte is improved.

[0011] A battery cell according to one embodiment of the present invention comprises: an electrode assembly; a battery housing for accommodating the electrode assembly; and a current collector plate disposed on one surface of the electrode assembly within the battery housing; wherein the current collector plate comprises one or more electrolyte flow grooves for the flow of an electrolyte.

[0012] In addition, the above electrolyte flow grooves are arranged radially in multiple numbers.

[0013] In addition, the electrolyte flow groove extends from the edge of the current collector plate toward the center.

[0014] In addition, the plurality of the above-mentioned electrolyte flow grooves are spaced apart at a certain angle.

[0015] In addition, the current collector plate is positioned on the lower side of the electrode assembly.

[0016] In addition, the current collector plate further includes one or more connecting grooves connecting the two electrolyte flow grooves between the two electrolyte flow grooves.

[0017] In addition, the above connecting groove is formed in the shape of an arc.

[0018] In addition, the above electrolyte flow groove has an inclined surface at the inner end in the longitudinal direction.

[0019] In addition, the depth of the above electrolyte flow groove gradually increases towards the outside.

[0020] In addition, one end of the electrolyte flow groove is connected to the upper surface of the current collector plate and has a constant angle of inclination.

[0021] In addition, the current collector plate is positioned below the electrode assembly and is electrically connected to one electrode in the electrode assembly.

[0022] In addition, the above battery cell may be a cylindrical battery cell.

[0023] Additionally, the current collector plate comprises a rivet joint portion in its center that is coupled to a rivet located on the bottom surface of the battery housing; and one or more slits around the rivet joint portion.

[0024] In addition, a bridge portion is disposed between the plurality of the above slits, and the bridge portion can be bent upward.

[0025] Additionally, the current collector plate further includes a rivet joint portion at its center that is coupled to a rivet located on the bottom surface of the battery housing; and a bent portion that is bent upward between the rivet joint portion and the current collector plate portion disposed on the bottom surface of the electrode assembly.

[0026] In addition, the above-mentioned bend may be inclined toward the center of the electrode assembly as it extends upward from the edge of the above-mentioned rivet joint.

[0027] The battery cell and battery pack according to the present invention ensure electrolyte fluidity, thereby improving the impregnation of the electrolyte.

[0028] FIG. 1 is a drawing illustrating a cylindrical battery cell in one embodiment of the present invention, and

[0029] FIG. 2 is a perspective view showing a cross-sectional view of a cylindrical battery cell in one embodiment of the present invention, and

[0030] FIG. 3 is a detailed cross-sectional view of a cylindrical battery cell in one embodiment of the present invention, and

[0031] FIG. 4 is a drawing for explaining that a current collector plate is coupled to an electrode assembly in one embodiment of the present invention, and

[0032] FIG. 5 is a drawing showing the lower part of the cylindrical battery cell in FIG. 3, and

[0033] FIG. 6 is a perspective view of a current collector plate in the first embodiment of the present invention, and

[0034] FIG. 7 is a plan view of a current collector plate in the first embodiment of the present invention, and

[0035] FIG. 8 is a cross-sectional view of a current collector plate in the first embodiment of the present invention, and

[0036] FIG. 9 is a cross-sectional view of a current collector plate in the second embodiment of the present invention, and

[0037] FIG. 10 is a perspective view of a current collector plate in a third embodiment of the present invention, and

[0038] FIG. 11 is a perspective view of a current collector plate in the fourth embodiment of the present invention, and

[0039] FIG. 12 is a plan view of a current collector plate in the fifth embodiment of the present invention, and

[0040] FIG. 13 is a cross-sectional view of a current collector plate in the fifth embodiment of the present invention, and

[0041] FIG. 14 is a cross-sectional view of a current collector plate in the sixth embodiment of the present invention, and

[0042] FIG. 15 is a drawing illustrating a battery pack in an embodiment of the present invention, and

[0043] FIG. 16 is a drawing illustrating an electric vehicle equipped with a battery pack in one embodiment of the present invention.

[0044] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid the present invention being interpreted ambiguously. Throughout the specification, like reference numerals refer to like components.

[0045] In drawings, thicknesses may be enlarged to clearly represent multiple layers and regions. Throughout the specification, the same reference numerals are used for similar parts. When a part such as a layer, film, region, or plate is described as being "above" another part, this includes not only cases where it is "immediately above" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately above" another part, it means that there is no other part in between. Furthermore, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only cases where it is "immediately below" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately below" another part, it means that there is no other part in between.

[0046] A battery cell (1) according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0047] FIG. 1 is a drawing illustrating a cylindrical battery cell in an embodiment of the present invention, FIG. 2 is a perspective view showing a longitudinal section of a cylindrical battery cell in an embodiment of the present invention, FIG. 3 is a detailed longitudinal section of a cylindrical battery cell in an embodiment of the present invention, FIG. 4 is a drawing for explaining that a current collector plate is coupled to an electrode assembly in an embodiment of the present invention, FIG. 5 is a drawing illustrating the lower part of the cylindrical battery cell in FIG. 3, FIG. 6 is a perspective view of a current collector plate in a first embodiment of the present invention, FIG. 7 is a plan view of a current collector plate in a first embodiment of the present invention, FIG. 8 is a cross-sectional view of a current collector plate in a first embodiment of the present invention, FIG. 9 is a cross-sectional view of a current collector plate in a second embodiment of the present invention, FIG. 10 is a perspective view of a current collector plate in a third embodiment of the present invention, FIG. 11 is a perspective view of a current collector plate in a fourth embodiment of the present invention, FIG. 12 is a plan view of a current collector plate in a fifth embodiment of the present invention, FIG. Figure 13 is a cross-sectional view of a current collector plate in the fifth embodiment of the present invention, Figure 14 is a cross-sectional view of a current collector plate in the sixth embodiment of the present invention, Figure 15 is a drawing showing a battery pack in one embodiment of the present invention, and Figure 16 is a drawing showing an electric vehicle equipped with a battery pack in one embodiment of the present invention.

[0048] For convenience of explanation, in this specification, the direction following the longitudinal direction of the winding axis of an electrode assembly wound in a jelly roll shape may be referred to as the "axial direction," "vertical direction," or "height direction." Additionally, the direction surrounding the winding axis may be referred to as the "circumferential direction" or "peripheral direction." Furthermore, the direction approaching or moving away from the winding axis may be referred to as the "radial direction." Among the radial directions, the direction approaching the winding axis may be referred to as the "centripetal direction," and the direction moving away from the winding axis may be referred to as the "centrifugal direction."

[0049] The battery cell (1) may include an electrode assembly (10), a battery housing (20), a first current collector plate (30), a battery cap (40), a sealing gasket (50), a second current collector plate (60), a rivet (70), and an insulating part (80). The battery cell (1) including the electrode assembly (10) is not limited to the shape of the battery cell (1) shown in FIGS. 1 to 3 and can be applied to batteries of other shapes. The battery cell (1) may be a cylindrical secondary battery (cylindrical battery cell).

[0050] The electrode assembly (10) may be provided in a cylindrical shape having a core and an outer surface, wherein a first electrode (e.g., a negative electrode), a second electrode (e.g., a positive electrode), and a separator interposed between these electrodes are wound around a winding axis. The electrode assembly (10) may be a jelly-roll type electrode assembly. An additional separator may be provided on the outer surface of the electrode assembly (10) for insulation from the battery housing (20). The electrode assembly (10) may be provided without limitation to have a winding structure well known in the art of the present invention.

[0051] The first electrode of the electrode assembly (10) may include a first electrode current collector and a first electrode active material applied on one or both sides of the first electrode current collector. A non-coated portion in which the first electrode active material is not applied may exist at one end (upper portion) in the width direction (a direction parallel to the height direction of the battery cell) of the first electrode. That is, the first electrode may include a first non-coated portion (11) that is exposed to the outside of the separator and is not coated with active material at one long end along the winding direction, and a first retaining portion coated with active material. The first non-coated portion (11) may be provided at the upper portion based on the height direction of the electrode assembly (10) housed within the battery housing (20). At least a portion of the first non-coated portion (11) may be used as an electrode tab itself. The first non-coated portion (11) may be, for example, a negative electrode tab.

[0052] The second electrode of the electrode assembly (10) may include a second electrode current collector and a second electrode active material applied on one or both sides of the second electrode current collector. Based on the width direction (height direction) of the second electrode (12), a non-coated portion where the second electrode active material is not applied may exist at the other end. That is, the second electrode may include a second non-coated portion (12) that is exposed to the outside of the separator and where the active material is not coated at the other long end along the winding direction, and a second retaining portion coated with the active material. The second non-coated portion (12) may be provided at the bottom based on the height direction of the electrode assembly (10) housed within the battery housing (20). At least a portion of the second non-coated portion (12) may be used as an electrode tab itself. The second non-coated portion (12) may be, for example, a positive electrode tab.

[0053] The battery housing (20) may be a roughly cylindrical receptacle with an opening formed on one side. The battery housing (20) may be provided with a conductive metal material. The battery housing (20) may be configured to accommodate the electrode assembly (10) of the secondary battery. The side of the battery housing (20) and the lower surface located opposite the opening (20a) may be formed integrally. The battery housing (20) may be configured to accommodate the electrode assembly (10) and the electrolyte through the opening (20a) formed on its upper side.

[0054] The battery housing (20) may have a beading portion (21) formed in an end region adjacent to an opening (20a) provided at the top thereof, and a crimping portion (22) formed on the beading portion (21). The beading portion (21) has a shape in which the outer circumference of the battery housing (20) is pressed in to a predetermined depth. The beading portion (21) may have a shape in which it is pressed inward in the region between the opening (20a) of the battery housing (20) and the internal receiving space that accommodates the electrode assembly (10).

[0055] The beading portion (21) may provide a support surface on which a sealing gasket (50) and a battery cap (40) can be seated. Additionally, the beading portion (21) may provide a support surface on which at least a portion of the edge perimeter of the first current collector plate (30) can be seated and joined. At least a portion of the edge perimeter of the current collector plate (30), at least a portion of the edge perimeter of the sealing gasket (50), and at least a portion of the edge perimeter of the battery cap (40) can be seated on the upper surface of the beading portion (21). The beading portion (21) may be formed by pressing the outer circumference of the battery housing (20) inward in an area adjacent to the opening (20a) of the battery housing (20) while the electrode assembly (10) is received within the battery housing (20) through the opening (20a).

[0056] In order to stably support the first current collector plate (30), the battery cap (40), and the sealing gasket (50), the upper surface of the beading portion (21) may have a shape that extends along a direction approximately parallel to the lower surface of the battery housing (20), that is, a shape that extends in a direction approximately perpendicular to the side wall of the battery housing (20). The beading portion (21) can function as a support portion on which the battery cap (40), etc., is seated, while preventing the electrode assembly (10), which has a size corresponding to the inner diameter of the internal receiving space of the battery housing (20), from coming out through the opening (20a) formed at the top of the battery housing (20).

[0057] The crimping portion (22) extends upward from the beading portion (21) and is formed on the upper part of the beading portion (21). The crimping portion (22) has a bent shape that extends to wrap around the edge perimeter and part of the upper surface of the battery cap (40) placed on the upper part of the beading portion (21). The battery cap (40) is fixed on the beading portion (21) by the crimping portion (22). The crimping portion (22) may have a shape that extends inward in the radial direction (centripetal direction) of the battery cell (1) from the upper perimeter of the battery housing (20). The crimping portion (22) is provided in an area corresponding to the edge perimeter of the upper surface of the battery cap (40) to fix the battery cap (40) and prevent the battery cap (40) from moving upward.

[0058] The upper portion of the crimping portion (22) is formed by bending so that it extends inward by a predetermined distance along the radial direction of the battery cell (1) to wrap around a part of the upper surface of the battery cap (40), thereby securing the perimeter of the upper surface of the battery cap (40). The perimeter area of ​​the battery cap (40) is interposed between the upper portion of the crimping portion (22) and the beading portion (21) and is secured to the battery housing (20), covering the opening (20a) of the battery housing (20).

[0059] The first current collector plate (30) is housed inside the battery housing (20). The first current collector plate (30) is made of a conductive metal material and can be electrically connected to the electrode assembly (10). The first current collector plate (30) can be electrically connected to the battery housing (20). That is, the first current collector plate (30) can electrically connect the first electrode of the electrode assembly (10) and the battery housing (20). The first current collector plate (30) may be provided with a support portion (31), a tab coupling portion (32), and a housing coupling portion (33).

[0060] The support portion (31) and the tab connecting portion (32) of the first current collector plate (30) may be positioned on the upper part of the electrode assembly (10). The support portion (31) may be positioned on one side of the electrode assembly (10). The tab connecting portion (32) may extend from the support portion (31) and be connected to the first non-reinforced portion (11) of the electrode assembly (10). For example, the tab connecting portion (32) may be connected to the electrode assembly (10) by welding a certain area while seated on the first non-reinforced portion (11) of the electrode assembly (10). The tab connecting portion (32) of the first current collector plate (30) may be located below the lower surface of the beading portion (21).

[0061] A through hole may be formed in the first collector plate (30) to allow flames generated inside the battery cell (1) to escape smoothly. Accordingly, even if a thermal runaway phenomenon occurs on the side of the electrode assembly (10), the flames and venting gas generated from the electrode assembly (10) can be smoothly discharged through the through hole without being blocked by the first collector plate (30) located on the upper side of the electrode assembly (10). Therefore, it is possible to prevent the flames from moving toward the beading part (21) located in the vicinity of the electrode assembly (10) and the first collector plate (30) and causing pinholes in the beading part (21), and to prevent the fire from spreading to other battery cells (1) located around the battery cell (1) where the fire occurred.

[0062] The support member (31) may be provided with a current collector hole (H2) formed at a position corresponding to a winding hole (H1) formed approximately in the center of the electrode assembly (10). The winding hole (H1) and the current collector hole (H2), which are in communication with each other, do not need to function as a passage for a welding rod or laser beam for welding between the electrode terminal of the electrode assembly (10) and the current collector, or between the electrode terminal and a lead tab (not shown). Therefore, the energy density of the electrode assembly (10) can be increased by reducing the size of the winding hole (H1) and the current collector hole (H2). If the diameter of the current collector hole (H2) is excessively smaller than the diameter of the winding hole (H1), the hole formed in the winding hole (H1) may be obscured, which may reduce liquid injection performance. Accordingly, so that the current collector hole (H2) does not obstruct the winding hole (H1) formed in the core of the electrode assembly (10), it may have a diameter substantially the same as or larger than that of the winding hole (H1) of the electrode assembly (10).

[0063] The housing coupling portion (33) may be connected to the inner surface of the battery housing (20) by extending from the support portion (31) to a periphery area. The housing coupling portion (33) may be electrically connected to the inner surface of the battery housing (20) by extending from the support portion (31). For example, the housing coupling portion (33) may be connected to the upper surface of the beading portion (21) on the inner surface of the battery housing (20).

[0064] The inner diameter of the battery housing (20) in the area where the beading portion (21) is formed may be smaller than the diameter of the electrode assembly (10). For stable contact and connection, the beading portion (21) may have a shape that extends along a direction approximately parallel to the lower surface of the battery housing (20), that is, a direction approximately perpendicular to the side wall of the battery housing (20). The housing connection portion (33) may be welded to the upper surface of the beading portion (21). For welding the connection between the battery housing (20) and the first current collector plate (30), for example, laser welding, ultrasonic welding, or spot welding may be applied.

[0065] A battery cap (40) may be provided to cover an opening (20a) of a battery housing (20). The battery cap (40) may be coupled to the battery housing (20) to seal the opening (20a) of the battery housing (20) through a crimping process via a sealing gasket (50). The battery cap (40) may be provided with a venting portion (41) formed to prevent an increase in internal pressure caused by gas generated inside the battery housing (20).

[0066] The venting portion (41) may be configured to break when the internal pressure of the battery housing (20) increases above a certain level. The venting portion (41) is formed in a part of the battery cap (40) and may be a structurally weaker area than the surrounding area so that it can easily break when pressure is applied to the inside due to thermal runaway, etc. For example, the venting portion (41) may be an area having a thinner thickness compared to the surrounding area. The venting portion (41) may be formed as a roughly circular closed loop.

[0067] The battery cap (40) can cover an opening (20a) formed on one side of the battery housing (20). The battery cap (40) can be secured by a crimping portion (22) formed on the top of the battery housing (20).

[0068] A sealing gasket (50) is interposed between the battery housing (20) and the battery cap (40), and between the first current collector plate (30) and the battery cap (40), to improve fixing strength and sealing performance of the battery housing (20). The sealing gasket (50) seals the upper opening of the battery housing (20) between the battery cap (40) and the crimping portion (22) of the battery housing (20), and can electrically insulate the battery housing (20) and the battery cap (40). The sealing gasket (50) may include a material having insulating and elastic properties. The sealing gasket (50) may include, for example, a polymer resin.

[0069] Accordingly, the first current collector plate (30) may be interposed between the beading portion (21) of the battery housing (20) and the sealing gasket (50). The first current collector plate (30) interposed between the beading portion (21) and the sealing gasket (50) may be secured by the bending of the crimping portion (22) extending upward from the beading portion (21). The sealing gasket (50) is provided to surround the battery cap (40) to seal the space between the battery cap (40) and the battery housing (20). The sealing gasket (50) serves to maintain airtightness between the battery housing (20) and the battery cap (40). A rivet (70) is inserted into and joined to an opening formed in the bottom portion (23) of the battery housing (20). An insulating portion (80) may be interposed between the rivet (70) and the opening of the battery housing (20). The insulating part (80) can insulate the rivet (70) from the battery housing (20).

[0070] FIG. 4 is a drawing illustrating that current collector plates (30, 60) are attached to the upper and / or lower surfaces of an electrode assembly (10), and the first and second current collector plates (30, 60) can be joined to the electrode assembly (10) by welding.

[0071] In the first electrode current collector of the first electrode, a plurality of notching tabs may be formed along the longitudinal direction on the edge of the first electrode current collector in the first uncoated portion (11) where the electrode active material is not coated, and similarly, in the second electrode current collector of the second electrode, a plurality of notching tabs may be formed along the longitudinal direction on the edge of the second electrode current collector in the second uncoated portion (12) where the electrode active material is not coated.

[0072] In this way, the first and second unoccupied portions (11, 12) in which notching tabs are formed at the first and second electrodes can each be bent in the direction of the core, and the first and second current collector plates (30, 60) can be welded to the first and second unoccupied portions (11, 12) of the first electrode and / or the second electrode that are bent in the direction of the core.

[0073] Hereinafter, the second current collector plate (60) in this embodiment will be described in detail with reference to FIGS. 5 to 8.

[0074] As shown in FIGS. 5 to 8, the second current collector plate (60) may be formed in the shape of a disc and may include a plurality of electrolyte flow grooves (61).

[0075] The second current collector plate (60) may be placed at the bottom of the electrode assembly (10) inside the battery housing (20). The second current collector plate (60) may be a positive current collector plate. As another example, the second current collector plate (60) may be a negative current collector plate.

[0076] The second current collector plate (60) is made of a conductive metal material and can be electrically connected to the electrode assembly (10). The second current collector plate (60) can be electrically connected to the second electrode of the electrode assembly (10). A rivet (70) can be placed on the lower surface of the battery housing (20), and the rivet (70) can form an electrode terminal, and the second current collector plate (60) can be electrically connected to the electrode terminal formed by the rivet (70).

[0077] The second current collector plate (60) may include an electrode coupling portion (62) and an electrolyte flow groove (61).

[0078] The electrode coupling portion (62) and the electrolyte flow groove (61) of the second current collector plate (60) may be positioned at the bottom of the electrode assembly (10). The electrode coupling portion (61) may be positioned on one side of the electrode assembly (10). The electrode coupling portion (62) may be coupled to the second non-coupling portion (12) of the electrode assembly (10). For example, the electrode coupling portion (62) may be coupled to the electrode assembly (10) by welding a certain area while seated on the second non-coupling portion (12) of the electrode assembly (10).

[0079] The electrode coupling portion (62) may be located between the second current collector plate (60) and the electrolyte flow groove (61) and / or inside the electrolyte flow groove (61) (the center of the second current collector plate (60)).

[0080] A plurality of electrolyte flow grooves (61) may be formed radially from the edge of the second collector plate (60) toward the center. A plurality of electrolyte flow grooves (61) may be spaced apart from each other at a certain angle. Each electrolyte flow groove (61) may be formed by making the entire thickness of the second collector plate (60) concave downward, or by pressing a disc constituting the collector plate with a punch portion. Accordingly, the electrolyte flow grooves (61) may be formed in a folded shape on the second collector plate (60).

[0081] Both sides of the electrolyte flow groove (61) may be formed vertically or as downwardly inclined surfaces.

[0082] If the second current collector plate (60) is formed as a disc, the flow of the electrolyte may be blocked by the current collector plate during the electrolyte injection process, making it difficult for the electrolyte to flow. In this embodiment, as such, a plurality of electrolyte flow grooves (61) are arranged radially on the second current collector plate (60), so that the electrolyte flow grooves (61) act as passages for the electrolyte to flow, allowing the electrolyte to flow easily from the second current collector plate (60), and thus improving the impregnation of the electrolyte.

[0083] Meanwhile, as shown in FIGS. 6 to 8 of this embodiment, the depth of the bottom of the electrolyte flow groove (61) may be constant.

[0084] In another embodiment, the depth of the electrolyte flow groove (61) may vary. FIG. 9 is a cross-sectional view of a current collector plate (60) according to a second embodiment of the present invention. In the second embodiment of the present invention, the depth of the electrolyte flow groove (61) may gradually increase from the center of the second current collector plate (60) toward the edge.

[0085] In the second embodiment, the electrolyte flow groove (61) may be formed as an inclined surface that gradually increases in depth toward the outside. In this case, one end of the electrolyte flow groove (61) may be connected to the upper surface of the second collector plate (60), and as the depth gradually increases, the other end of the electrolyte flow groove (61) may be located at the edge of the second collector plate (60).

[0086] The angle (α) formed by the electrolyte flow groove (61) with the upper surface of the second collector plate (60) may be 10 to 70 degrees, or 20 to 50 degrees.

[0087] In the second embodiment, the electrolyte flow groove (61) may be formed by connecting two first and second inclined surfaces with different inclination angles in the longitudinal direction, and the inclination angle of the first inclined surface closer to the center of the second collector plate (60) may be greater than that of the second inclined surface.

[0088] Meanwhile, FIG. 10 is a drawing illustrating a second current collector plate (60) in the third embodiment of the present invention. The difference between the third embodiment and the first embodiment is that one end near the center of the electrolyte flow groove (61) is formed as an inclined surface (61a), and a connecting groove (63) is arranged between the two electrolyte flow grooves (61).

[0089] In the electrolyte flow groove (61), one end (inner end in the longitudinal direction) close to the center of the second collector plate (60) can be formed as an inclined surface (61a), and by forming one end as an inclined surface (61a), the electrolyte can easily flow into the electrolyte flow groove (61) and move along the electrolyte flow groove (61). The angle formed by the inclined surface (61a) with the upper surface of the second collector plate (60) can be 10-80 degrees or 20-70 degrees.

[0090] Additionally, a connecting groove (63) may be formed between each of the two electrolyte flow grooves (61). The connecting groove (63) between the two electrolyte flow grooves (61) may be in the shape of an arc or a straight line. The depth of the connecting groove (63) may be the same as the electrolyte flow groove (61) or may be shallower than the electrolyte flow groove (63).

[0091] By having a connecting groove (63) connecting two electrolyte flow grooves (61) placed between the electrolyte flow grooves (61), the electrolyte on the second collector plate (60) can flow quickly through the electrolyte flow grooves (61), and the impregnation can be further improved.

[0092] FIG. 11 is a perspective view illustrating a second current collector plate (60) in the fourth embodiment of the present invention. In the fourth embodiment, the thickness of the electrolyte flow groove (61) is formed to be thinner than the thickness of the other parts. That is, the electrolyte flow groove (61) can be formed in a concave shape on the upper surface of the second current collector plate (60) in the shape of a disc.

[0093] FIG. 12 is a drawing illustrating a second collector plate (60) in the fifth embodiment of the present invention. The difference between the fifth embodiment and the previous embodiment is that a rivet joint (65) is placed in the center of the second collector plate (60), and a slit (67) is placed on the outer side thereof.

[0094] In this embodiment, the rivet joint (65) may be positioned in the center of the second collector plate (60), and the rivet joint (65) may be joined to the rivet (70). The rivet joint may be joined to the rivet by welding or the like.

[0095] A plurality of slits (67) may be arranged along the circumferential direction on the outer side of the rivet joint (65).

[0096] Multiple slits (67) may be arranged on the outer side of the rivet joint (65) at regular intervals (angles) along the circumferential direction. The slits (67) may be formed in a roughly triangular shape, as illustrated. In this embodiment, four slits (67) are shown arranged, but their shape and number are not limited to this and can be changed, and there may be four or more.

[0097] A bridge portion (66) may be disposed between multiple slits (67). One end of the bridge portion (66) may be connected to a rivet joint portion (65), and the other end of the bridge portion (66) may be connected to a second collector plate (60) body portion located outside the slit (67).

[0098] FIG. 13 illustrates a cross-section of the second collector plate (60) in the fifth embodiment, wherein a bridge portion (66) may be disposed between the rivet joint portion (65) which is joined to the rivet (70) and the body portion of the second collector plate (60) located outside the slit (67). There may be a height gap between the rivet joint portion (65) and the body portion of the second collector plate (60) located outside the slit (67), and the bridge portion (66) may be formed in a shape that is bent (or curved) upward from the edge of the rivet joint portion (65) to compensate for this height gap, as shown in FIG. 13.

[0099] The body portion of the second current collector plate (60) located outside the slit (67) may include an electrode coupling portion (62) and an electrolyte flow groove (61) disposed on the lower surface of the electrode assembly (10).

[0100] In this embodiment, the bridge portion (66) is formed in a shape that is bent upwards, so that it can correspond to the gap between the collector plate and the rivet (70).

[0101] In addition, by arranging a plurality of slits (67) around the rivet joint (65), a fusing function can be implemented such as by breaking the bridge part (66) when a high current is applied to the cell (1) in an internal or external short circuit situation.

[0102] Other configurations and effects may be the same as in the previous embodiment, and a detailed description thereof is omitted.

[0103] FIG. 14 illustrates a cross-section of the second current collector plate (60) in the sixth embodiment, wherein a bend portion (68) may be disposed between the rivet joint portion (65) which is joined to the rivet (70) and the body portion of the second current collector plate (60) which is disposed on the lower surface of the electrode assembly (10). There may be a height gap between the rivet joint portion (65) and the body portion of the second current collector plate (60) which is disposed on the lower surface of the electrode assembly (10), and the bend portion (68) may be formed in a shape that is bent upward from the edge of the rivet joint portion (65) to compensate for this height gap, as shown in FIG. 14.

[0104] In this embodiment, the bent portion (68) is bent upward from the edge of the rivet joint portion (65), and the bending direction may be formed to be inclined toward the center (C) of the electrode assembly (10). That is, the bent portion (68) may be formed along the circumferential direction of the rivet joint portion (65), and the diameter of the bent portion (68) may be formed to become smaller as it goes upward. As shown in FIG. 14, the bent portion (68) may form an S-shaped bent form.

[0105] In this embodiment, a bent portion (68) that is bent upward from the edge of the rivet joint portion (65) is arranged so that it can correspond to the gap between the collector plate and the rivet (70) and the weldability of the rivet joint portion (65) can be improved. In addition, the bent portion (68) can act as a plate spring to cushion the impact.

[0106] A plurality of slits (67) may be arranged in the bent portion (68) as in the fifth embodiment.

[0107] Other configurations and effects may be the same as in the previous embodiment, and a detailed description thereof is omitted.

[0108] Meanwhile, a plurality of cylindrical battery cells (100) can be accommodated in a pack case (2100) to form a battery pack (2000) (see FIG. 15).

[0109] The battery pack (2000) may additionally include various control and protection systems such as a Battery Management System (BMS), and the battery pack (2000) may be applied to various devices. Specifically, it may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, or to an Energy Storage System (ESS), but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0110] FIG. 16 is a drawing illustrating an electric vehicle (V) equipped with a battery pack (2000). In the electric vehicle (V), the wheels are driven by a motor that receives power from the battery pack (2000), allowing the electric vehicle to operate.

[0111] Although the present invention has been described with reference to preferred embodiments as described above, it is not limited to the aforementioned embodiments, and various changes and modifications may be made by those skilled in the art within the scope of the invention without departing from the spirit of the invention.

[0112] The present invention can provide a battery cell and a battery pack in which the fluidity of the electrolyte is secured and the impregnation of the electrolyte is improved.

Claims

1. Electrode assembly; A battery housing for accommodating the electrode assembly; and A current collector plate disposed on one surface of the electrode assembly within the battery housing; Includes, The above current collector plate is a battery cell comprising one or more electrolyte flow grooves for the electrolyte to flow.

2. In Paragraph 1, The above electrolyte flow grooves are a plurality of radially arranged battery cells.

3. In Paragraph 2, The above electrolyte flow groove is a battery cell extending from the edge of the current collector plate toward the center.

4. In Paragraph 3, A battery cell in which a plurality of the above-mentioned electrolyte flow grooves are spaced apart at a certain angle.

5. In Paragraph 2, The above current collector plate is a battery cell positioned on the lower side of the electrode assembly.

6. In Paragraph 2, The above-mentioned current collector plate is a battery cell further comprising one or more connecting grooves connecting the two electrolyte flow grooves between the two electrolyte flow grooves.

7. In Paragraph 6, The above connecting groove is a battery cell formed in the shape of an arc.

8. In Paragraph 2, The above electrolyte flow groove is a battery cell having an inclined surface at the inner end in the longitudinal direction.

9. In Paragraph 2, The above electrolyte flow groove is a battery cell in which the depth gradually increases toward the outer side.

10. In Paragraph 9, The above electrolyte flow groove has one end connected to the upper surface of the above current collector plate and is a battery cell having a constant angle of inclination.

11. In Paragraph 1, The above current collector plate is positioned below the electrode assembly and is electrically connected to one electrode in the electrode assembly.

12. In Paragraph 1, The above battery cell is a cylindrical battery cell.

13. In Paragraph 1, The above-mentioned current collector plate comprises a rivet joint portion that is joined to a rivet located on the bottom surface of the battery housing at its center; and a battery cell further comprising one or more slits around the rivet joint portion.

14. In Paragraph 13, A bridge portion is disposed between a plurality of the above-mentioned slits, and The above bridge part is a battery cell bent upward.

15. In Paragraph 1, A battery cell further comprising: a rivet joint portion in the center thereof that is coupled to a rivet located on the bottom surface of the battery housing; and a bent portion bent upward between the rivet joint portion and the portion of the current collector plate disposed on the bottom surface of the electrode assembly.

16. In Paragraph 15, The above-mentioned bending portion is inclined toward the center of the electrode assembly as it extends upward from the edge of the above-mentioned rivet joint portion.

17. A battery pack comprising a plurality of battery cells according to paragraph 1.

18. An automobile comprising a battery pack pursuant to paragraph 17.

Images