Secondary battery and battery pack having same

Abstract

A secondary battery according to an embodiment of the present invention may comprise: a cylindrical can including a circular upper surface part having at least one notch, and a side part extending from the upper surface part and having an open end; an electrode assembly which is wound and accommodated in the can and includes a first electrode plate having a first substrate tab, a second electrode plate having a second substrate tab, and a separator interposed between the first electrode plate and the second electrode plate; a cap plate coupled to the open end of the side part and having a penetrating injection hole; and a terminal coupled to the upper surface part so as to allow insulation and electrically connected to the first substrate tab. According to an embodiment of the present invention, loss of the internal space in the secondary battery may be reduced by eliminating the cap plate provided on the bottom of the secondary battery, and the sealed and shaped space for the cap plate. Accordingly, dead space in the secondary battery may be reduced, thereby increasing capacity. In addition, due to the improved structure of the lower portion of the secondary battery, a space acting as an insulating layer during cooling of the lower portion is no longer present, thereby enabling efficient cooling of the lower portion of the secondary battery.

Description

Secondary battery and battery pack having the same

[0001] An embodiment of the present invention relates to a secondary battery.

[0002] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include an electrode assembly comprising a positive and negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0004] An embodiment of the present invention provides a secondary battery having a structure capable of reducing loss of internal space and efficiently cooling the lower portion.

[0005] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0006] A secondary battery according to an embodiment of the present invention may include a cylindrical can including a circular upper portion having at least one notch and a side portion extending from the upper portion and having an open end; an electrode assembly including a first electrode plate having a first substrate tab, a second electrode plate having a second substrate tab, and a separator interposed between the first electrode plate and the second electrode plate, the electrode assembly being wound and accommodated in the can; a cap plate coupled to the open end of the side portion and having a liquid injection hole penetrating therethrough; and a terminal coupled to the upper portion in an insulative manner and electrically connected to the first substrate tab.

[0007] The above notch may be positioned spaced apart from the terminal.

[0008] The notch may be provided on at least one of a plate surface facing the electrode assembly and a plate surface facing in the opposite direction of the electrode assembly.

[0009] The notch provided on the plate facing the electrode assembly and the notch provided on the plate facing the opposite direction of the electrode assembly may be arranged to be staggered from each other.

[0010] The above notch may be any of circular, C-shaped, or discontinuous linear.

[0011] The above cap plate can be directly connected to the end of the side.

[0012] A step-structured joint is provided at the end of the above side, and the cap plate can be placed on the joint and joined to each other.

[0013] It may include a flat portion having the above-mentioned injection hole, and a connecting portion that is integrally provided with the flat portion and protrudes outward from the flat portion to be connected to the can.

[0014] The above-mentioned connecting portion may be provided with the above-mentioned notch.

[0015] The above-mentioned injection hole can be closed with any one of a blind rivet, a ball, a pin, and a injection plug after the electrolyte is injected.

[0016] The above cap plate may have a flat shape.

[0017] A sealing member that closes the injection hole after the electrolyte injection may be further included.

[0018] It is characterized by undergoing a flattening process after closing the above-mentioned injection hole.

[0019] In addition, according to another embodiment of the present invention, a secondary battery includes a cylindrical can including a circular upper portion having at least one notch and a side portion extending from the upper portion and having an open end; an electrode assembly including a first electrode plate having a first substrate tab, a second electrode plate having a second substrate tab, and a separator interposed between the first electrode plate and the second electrode plate, the electrode assembly being wound and accommodated in the can; a cap plate coupled to the opened end of the side portion; and a terminal insulatively coupled to the upper portion and electrically connected to the first substrate tab, wherein the can may further include a beading portion provided inwardly concavely adjacent to an end of the side portion, and a crimping portion provided by bending an end of the side portion inward.

[0020] The above notch may be positioned spaced apart from the terminal.

[0021] The notch may be provided on at least one of a plate surface facing the electrode assembly and a plate surface facing in the opposite direction of the electrode assembly.

[0022] The notch provided on the plate facing the electrode assembly and the notch provided on the plate facing the opposite direction of the electrode assembly may be arranged to be staggered from each other.

[0023] It can be any of the discontinuous linear ones.

[0024] The above cap plate can be inserted between the beading portion and the crimping portion.

[0025] It may further include a gasket of insulating material inserted between the cap plate and the side of the can.

[0026] A cooling member may further be included between the cap plate and the electrode assembly.

[0027] The above cooling member is characterized by being made of a heat-dissipating material.

[0028] In addition, the present invention can provide a battery pack including a plurality of secondary batteries according to the above-described embodiment; a case accommodating the secondary batteries; a bus bar electrically connected to the secondary batteries; a circuit module electrically connected to the bus bar; and a cooling module that cools the secondary batteries by contacting the cap plate of the secondary batteries.

[0029] According to an embodiment of the present invention, the internal space loss of the secondary battery can be reduced by eliminating the cap plate provided at the bottom of the secondary battery and the sealed molding space for configuring the cap plate. Accordingly, the dead space of the secondary battery can be reduced, thereby increasing its capacity.

[0030] In addition, as the lower structure of the secondary battery is improved, the space that acts as an insulating layer when cooling the lower part is eliminated, so the lower part of the secondary battery can be cooled efficiently.

[0031] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0032] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0033] Figure 1 is a perspective view of a secondary battery according to one embodiment of the present invention.

[0034] Figure 2 is a cross-sectional view of a secondary battery according to Figure 1.

[0035] Figures 3 and 4 are cross-sectional views of a secondary battery according to another embodiment of the present invention.

[0036] FIGS. 5 to 10 are drawings illustrating various examples of notches according to embodiments of the present invention.

[0037] FIG. 11 is a drawing illustrating a process for finishing a charging hole of a secondary battery according to another embodiment of the present invention.

[0038] Figure 12 is a schematic diagram briefly illustrating an electrode assembly according to another embodiment of the present invention.

[0039] Fig. 13 is a plan view showing a current collector applied to the electrode assembly of Fig. 12.

[0040] Figure 14 is a schematic diagram briefly illustrating an electrode assembly according to another embodiment of the present invention.

[0041] Fig. 15 is a perspective view showing a current collector applied to the electrode assembly of Fig. 14.

[0042] FIGS. 15 and 16 are perspective views illustrating a battery pack including an exemplary secondary battery according to the present invention.

[0043] FIGS. 17 and 18 are perspective and side views illustrating a vehicle including an exemplary battery pack according to the present invention.

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0045] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0046] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0047] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0048] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0049] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0050] Any configuration being placed on (or below) a component or above (or below) a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of the component, but also that another configuration may be interposed between the component and any configuration placed on (or below) the component.

[0051] Additionally, when it is described that a component is connected, coupled, or connected to another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may be interposed between the components, or that each component may be connected, coupled, or connected through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0052] When reference is made throughout the specification to A and / or B, this means A, B, or A and B, unless otherwise stated. That is, and / or includes all or any combination of the listed items. When reference is made to C through D, this means C or more and D or less, unless otherwise stated.

[0053] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0054] Hereinafter, secondary batteries according to embodiments of the present invention will be described in detail with reference to the attached drawings.

[0055] Fig. 1 is a perspective view of a secondary battery according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of the secondary battery according to Fig. 1.

[0056] Referring to FIGS. 1 and 2, a secondary battery (10) according to an embodiment of the present invention may include a can (100), an electrode assembly (200), a first current collector (300), a terminal (400), an insulating member (500), a cap plate (600), and a liquid cap (700).

[0057] The can (100) constitutes the outer shape of the secondary battery (10) and may have a cylindrical shape with one end opened. The can (100) may include or be referred to as a case, housing, or outer material. The can (100) may include a top surface (110) in the shape of a disc and a side surface (120) in the shape of a cylinder extending downward from the top surface (110).

[0058] A terminal (400) and an insulating member (500) may be coupled to the upper surface (110). For this purpose, a terminal hole (not shown) may be formed through the center of the upper surface (110). In addition, the upper surface (110) may be provided with at least one notch (112). The notch (112) will be described later.

[0059] The side (120) has an open bottom, and a cap plate (600) to be described later can be coupled to the bottom. For this purpose, a coupling portion (122) may be provided along the inner circumference of the bottom of the side (120). The coupling portion (122) may be provided in various shapes, such as a step-shaped step, a diagonal slope, a nearly diagonal streamlined shape, a groove corresponding to the edge shape of the cap plate (600), etc. The coupling portion (122), which is the inner edge of the side (120), and the edge of the cap plate (600) may be coupled by laser welding, etc. The coupling portion may be coated with a rust inhibitor, etc., to prevent damage such as rust.

[0060] In this embodiment, the example is described based on an example in which the bottom of the can (100) is open, but conversely, the top of the can (100) may be open. The can (100) may be provided with a metal such as steel, nickel-plated steel, steel alloy, aluminum, aluminum alloy, deep drawing cooling sheet (SPCE), or a laminate film or plastic material constituting a pouch. An electrode assembly (200) may be accommodated inside the can (100) together with an electrolyte.

[0061] The electrode assembly (200) may include or be referred to as an electrode group, an electrode body, or a jelly roll. The electrode assembly (200) may include a first electrode plate, a second electrode plate, and a separator. The electrode assembly (200) may have a separator interposed between the first and second electrode plates, and the first and second electrode plates may be wound in a cylindrical shape. In some examples, the electrode assembly (120) may have an approximately empty central region. The empty central region may also be referred to as a core (240). A cylindrical center pin (optional) may be inserted into the core (240) for support. The core (240) may serve as a passage through which pressure is discharged when the internal pressure of the secondary battery (10) becomes greater than a reference pressure. In some examples, when internal pressure is applied to the upper surface (110) through the core (240), the internal pressure of the secondary battery (10) may be reduced as the notch (112, 622) described later is broken.

[0062] The first electrode plate may be either a negative electrode plate or a positive electrode plate. The first electrode plate may include a first substrate, which is a metal thin plate, a first active material layer provided on at least one surface of the first substrate, and a first non-coated portion on which the first active material is not provided. The first non-coated portion may be referred to as the first substrate. The first non-coated portion may be notched in a certain shape to serve as the first substrate tab (210). Alternatively, the first non-coated portion itself may serve as the first substrate tab (210) without being notched. In the embodiments of FIGS. 1 and 2, the first substrate tab (210) may protrude upward from the separator (230). The first substrate tab (210) may be electrically connected to the first current collector plate (300), which will be described later, without separate notching. Alternatively, the first substrate tab (210) may be notched in a certain shape to be electrically connected to the first current collector plate (300). For example, the connection method may be laser welding, etc.

[0063] For example, the first electrode plate may function as an anode. The first substrate may include aluminum foil, and the first active material layer may include a transition metal oxide.

[0064] In some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) may be used as the cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from the group consisting of cobalt, manganese, nickel, and combinations thereof may be used.

[0065] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0066] As an example, a compound represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaMn2-bXbO4-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNi1-b-cMnbXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNibCocL1dGeO2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); LiaNiGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-bGbO2 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-gGgPO4 (0.90=a=1.8, 0=g=0.5); Li(3-f)Fe2(PO4)3(0=f=2); LiaFePO4(0.90=a=1.8).

[0067] In the chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L1 is Mn, Al, or a combination thereof.

[0068] A positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0069] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0070] Aluminum may be used as the current collector, but is not limited thereto.

[0071] The second electrode plate may be the other of the negative electrode plate and the positive electrode plate. The second electrode plate may include a second substrate which is a metal sheet, a second active material layer provided on at least one surface of the second substrate, and a second non-coated portion where the second active material layer is not provided. The second non-coated portion may be referred to as a second substrate. The second non-coated portion may be notched in a specific shape to serve as a second substrate tab (220). Alternatively, the second non-coated portion itself may serve as the second substrate tab (220) without being notched. In the embodiments of FIGS. 1 and 2, the second substrate tab (220) protrudes downward from the separator (230) and may be electrically connected to the cap plate (600) described below without a separate notch. For example, the connection method may be laser welding, etc.

[0072] For example, the second electrode plate may function as a cathode. The second substrate may include copper or nickel foil, and the second active material layer may include a carbon-based material, Si, Sn, tin oxide, a tin alloy composite, a transition metal oxide, lithium metal nitrite, or a metal oxide.

[0073] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0074] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0075] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material can be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0076] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0077] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0078] A negative electrode for a lithium secondary battery may include a current collector (e.g., a second substrate) and a negative electrode active material layer formed on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0079] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0080] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0081] The current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0082] A separator (230) is interposed between the first electrode plate and the second electrode plate and serves to prevent a short circuit between the first electrode plate and the second electrode plate. For example, the separator (230) may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0083] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0084] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0085] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0086] An electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0087] The non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move. The non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more.

[0088] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0089] As illustrated in FIG. 2, the first collector plate (300) may be disposed between the insulating member (500) to be described later and the first substrate tab (210). More specifically, the first collector plate (300) may be welded to the first substrate tab (210) by being in contact with it. The first collector plate (300) may have an approximately circular shape. The first collector plate (300) may be electrically connected to the terminal (400) at the central portion. A hollow space may be provided at the center of the first collector plate (300). Since the first collector plate (300) must be insulated from the can (100), an insulating tape (540) may be attached to an area other than the area connected to the terminal (400).

[0090] The terminal (400) may include a body (410) inserted into the can (100) and a head (420) positioned outside the can (100). For example, the terminal (400) may be a rivet terminal that is fixed by a rivet method from the outside of the can (100) while the body (410) is inserted into the inside of the can (100). For this purpose, a groove (412) may be provided at the center of the head (420) and the body (410). An insulating member (500) may be provided between the terminal (400) and the upper surface (110). The terminal (400) may be electrically connected to the first current collector (300) and thus may function as a positive terminal.

[0091] The insulating member (500) is made of an insulating material and may include first to fourth insulating members (510 to 540). The first insulating member (510) may insulate between the upper surface (110) and the head (420) of the terminal (400). The second insulating member (520) may insulate between the upper surface (110) and the terminal hole. The third insulating member (530) may insulate between the upper surface (110) and the first current collector (300). The fourth insulating member (540) may be provided on the upper surface of the first current collector (300). For example, the aforementioned insulating tape (540) may replace the fourth insulating member (540) (therefore, in FIG. 2, the insulating tape and the fourth insulating member are indicated by the same reference numeral). The first to third insulating members (510 to 530) may be provided separately or may be provided as one. The first to third insulating members (510 to 530) may each have a hollow space through which the terminal (400) passes. The fourth insulating member (540) may also have a hollow space. In some embodiments, when the fourth insulating member (540) is provided as an insulating tape, its thickness may be smaller than that of the third insulating member (530). The terminal (400) may be insulated from the can (100) and the first collector plate (300) by the insulating member (500). A cap plate (600) may be coupled to the opposite side facing the terminal (400).

[0092] The cap plate (600) can seal the open end (the end of the side (120)) of the can (100). In addition, the cap plate (600) can be in direct contact with the second substrate tab (220) and be electrically connected thereto. The cap plate (600) has a roughly circular shape when viewed from above and can be provided with a material that is the same as or similar to that of the can (100). A filling hole (not numbered) can be formed through the center of the cap plate (600). A filling stopper (700), which will be described later, can be inserted into the filling hole. Some areas of the cap plate (600) provided with the filling hole can be provided concavely from the edge of the cap plate (600). With respect to the filling hole, some areas of the cap plate (600) can protrude upward from a plate surface having the filling hole. Based on the state in which the cap plate (600) is coupled to the can (100), the area where the injection hole is provided may be closer to the electrode assembly (200) than the end of the side (120). That is, based on FIG. 2, the area where the injection hole is arranged may be provided in a concave shape from other areas. Since the area where the injection hole is arranged must be electrically connected to the second substrate tab (220), it must be flat. In addition, since this area must be electrically connected to the second substrate tab (220), it may occupy most of the cap plate (600). In the present embodiment, this area is referred to as a flat portion (610). In one embodiment, the flat portion (610) may be electrically connected to the second substrate tab (220) by a method such as laser welding. Alternatively, the flat portion (610) and the second substrate tab (220) may be electrically connected through a separate current collector. The area that protrudes convexly from the flat portion (610) is referred to as a connecting portion (620).

[0093] The connecting portion (620) has a gap with the electrode assembly (200), so it can serve as a buffer space where gases generated during charging and discharging of the secondary battery (10) collect. For example, the cap plate (600) can be processed by a method such as drawing or pressing to create a concave flat portion (610). Once the flat portion (610) is created in this way, the remaining area naturally forms the connecting portion (620). The connecting portion (620) can be provided with at least one notch (622). The notch (622) will be described later.

[0094] The main cap (700) may include a rivet-shaped cap (710) and a sealing member (720) for additional sealing.

[0095] The cap (710) can be installed by riveting using a general blind rivet, etc. One end of the cap (710) is positioned inside the can (100) by penetrating the filling hole, and the other end is positioned outside the filling hole. The cap (710) is deformed by riveting and fixed on the cap plate (500), thereby closing the filling hole. Since the location of the cap (710) is the core (240) of the electrode assembly (200), a separate space for the cap (710) is unnecessary. Therefore, the secondary battery (10) can be designed more compactly overall. If necessary, a ring-shaped sealing member (720) for additional sealing can be inserted between the cap (710) and the cap plate (600).

[0096] The sealing member (720) is in the shape of a ring with a hollow hole in the center, and if it has a sealing function, it can be provided with various materials such as metal material, insulating material, plastic material, polymer material, and elastic or non-elastic material.

[0097] For example, in some manufacturing steps, the upper surface (110) of the can (100) may be placed facing downward. Thereafter, the cap plate (600) and the second non-conductive portion (220) may be connected and inserted into the can (100). Alternatively, the electrode assembly (200) may be first inserted into the can (100), and then the cap plate (600) may be electrically connected to the connecting portion (122) provided on the side portion (120) described above. Then, the electrolyte may be injected through the injection hole, and the injection hole may be closed with the injection stopper portion (700).

[0098] Figures 3 and 4 are cross-sectional views of a secondary battery according to another embodiment of the present invention.

[0099] In the embodiment according to FIG. 3, the secondary battery (10') may have the same structure as the embodiment of FIG. 2 except for the cap plate (600'). Unlike the cap plate (600) according to FIG. 2, the cap plate (600') may have a circular shape without a curve. That is, the cap plate (600') according to FIG. 3 may have a circular shape without a step. The cap plate (600') may be in direct contact with the second substrate tab (220). The cap plate (600') may be electrically connected to the second substrate tab (220) by welding or the like. Referring to FIG. 3, a charging hole (610') may be formed through the center of the cap plate (600'). The charging hole (610') may be closed by a sealing member (700') such as a ball, a pin, or a charging stopper after electrolyte injection. Since the cap plate (600') has a circular shape without steps, the notch (112) can be provided only on the upper surface (110) of the can (100).

[0100] In the embodiment according to Fig. 4, the secondary battery (10) may be provided with a beading portion (122) and a crimping portion (124) on the side portion (120) of the can (100). In addition, the secondary battery (10) may further include a second current collector plate (350) and a lead (352). In addition, the secondary battery (10) may further include a cap plate (600), a gasket (800), and a cooling member (900). In addition to the configuration described below, the secondary battery (10) according to Fig. 4 may have a structure similar to or identical to the embodiment of Fig. 2.

[0101] In some manufacturing stages, the upper portion (110) may be placed downward, and the electrode assembly (200) together with the electrolyte may be inserted, and then the beading portion (122) may be formed. The beading portion (122) may be provided by concavely processing the lower end of the side portion (120) toward the inside of the can (100). After the beading portion (122) is formed, the cap plate (600) and the gasket (800) may be assembled. Thereafter, the crimping portion (124) may be formed to prevent the cap plate (600) from being detached. The crimping portion (124) may be formed by bending the end of the side portion (120) toward the inside of the can (100). A secondary battery (10) having this structure does not require a separate injection hole.

[0102] In addition, in the embodiment of FIG. 4, the cap plate (600) is not directly connected to the second substrate tab (220). Here, the second substrate tab (220) may be electrically connected to the second current collector (350) by welding or the like. The second current collector (350) may be provided with a plurality of leads (352). The leads (352) may be inserted between the beading portion (122) and the gasket (800) described above. That is, since the leads (352) come into contact with the side portion (120) of the can (100), the can (100) has a negative polarity. Therefore, as described above, the cap plate (600) is neutral, and the can (100) has a negative polarity.

[0103] The cap plate (600) has a roughly circular shape and can be joined to the side (120) via a gasket (800). The cap plate (600) can be fixed to the can (100) by the beading portion (122) and the crimping portion (124). Since the gasket (800) is placed between the cap plate (600) and the side (120), the cap plate (600) can be fixed to the can (100). Therefore, the cap plate (600) becomes neutral, not having a negative or positive polarity. In addition, the cap plate (600) can be divided into a first region (610), which is a central region, a second region (620) connected to the first region (610), and a third region (630) connected to the second region (620) and which is an edge of the plate. For example, the first region (610) and the third region (630) may be arranged on the same line as in FIG. 4 when viewed from the side. The cooling member (900) may be in contact with the first region (610). The second region (620) may protrude outwardly compared to the first region (610) and the third region (630). A notch (622) may be provided in the second region (620). The notch (622) will be described later. The third region (630) is an area covered by the gasket (800).

[0104] The cooling member (900) may be inserted between the second collector plate (350) and the first region (610) of the cap plate (600). For example, the cooling member (900) may be in contact with the second collector plate (350) and the first region (610) of the cap plate (600), respectively. The cooling member (900) may quickly transfer heat inside the secondary battery (10) to the cap plate (600). In addition, the cooling member (900) may quickly transfer cold air from a cooling component (not shown) outside the cap plate (600) to the inside of the secondary battery (10). To this end, the cooling member (900) may be provided in the form of a pad or sheet including a heat-radiating material or a coolant. Additionally, the cooling member (900) may be provided with a material that does not react with the electrolyte and does not conduct electricity with the second collector plate (350).

[0105] Below, a structure according to an additional embodiment applicable to the aforementioned secondary batteries is described.

[0106] First, the notch will be described in detail with reference to FIGS. 5 to 10.

[0107] FIGS. 5 to 10 are drawings illustrating various examples of notches according to embodiments of the present invention.

[0108] The notch (112) functions as a safety vent that ruptures and discharges gas when the gas pressure inside the secondary battery (10) increases. Referring to FIG. 5, the notch (112) may be provided on the outer surface of the upper surface (110). Alternatively, although not shown in the drawing, the notch (112) may be provided on the inner surface of the upper surface (110). Alternatively, as shown in FIG. 6, the notch (112) may be provided on both the outer and inner surfaces of the upper surface (110) (in this case, the notches on the outer and inner surfaces may be provided facing each other or staggered). That is, the notch (112) may be provided one or more. In addition, the notch (112) may have various shapes. For example, as shown in FIG. 7, the notch (112) may have a circular ring shape when viewed from a plan view. Alternatively, as shown in FIG. 8, the notch (112) may have a partial ring shape such as a C shape. Alternatively, the notch (112) may have a discontinuous linear shape. For example, as shown in FIG. 9, the notch (112) may be provided as two streamlined shapes that are not connected to each other. As shown in FIG. 10, the notch (112) may be provided as a plurality of streamlined shapes that are not connected to each other. In this case, the notch (112) may be provided in a position and shape that does not interfere with a bus bar (not shown). Although not illustrated in detail in the drawing, the structure of the notch (112) may be equally applied to the cap plates (600, 600) according to FIGS. 2 and 4.

[0109] Next, the main hole finishing process is explained.

[0110] FIG. 11 is a drawing illustrating a process for finishing a charging hole of a secondary battery according to another embodiment of the present invention.

[0111] In the case where a liquid injection hole (610') is provided in the cap plate (600') as in the embodiment of Fig. 3, the liquid injection hole finishing process of Fig. 11 can be performed (although not shown in the drawing, the same can be applied when a liquid injection hole is provided in the positive terminal).

[0112] First, a filling hole plug, such as a ball (700'), can be inserted into the filling hole (610') by applying pressure (step a of FIG. 11). In some examples, the ball (700') may include aluminum or an aluminum alloy that is softer than the cap plate (600'). Thereafter, the ball (700') may be plastically deformed to completely fill the filling hole (610') (step b of FIG. 11). Finally, the ball (700') may be fixed to the cap plate (600') by laser welding at the boundary between the ball (700') and the cap plate (600'). At this time, a thin metal plate or the like may be placed on the ball (700') and laser welded. Accordingly, the surface of the cap plate (600') may be flattened. In addition, the ball (700') and its surroundings may be coated with a resin. In some examples, the resin may include an ultraviolet curing agent. Therefore, by performing an ultraviolet curing process on the coated resin, the sealing of the injection hole can be completed. In some examples, the resin may include a polyimide-based resin, a fluorine-based resin, or a natural rubber-based resin.

[0113] Next, electrode assemblies according to various embodiments are described.

[0114] Fig. 12 is a schematic diagram briefly illustrating an electrode assembly according to another embodiment of the present invention. Fig. 13 is a plan view illustrating a current collector applied to the electrode assembly of Fig. 12. Fig. 14 is a schematic diagram briefly illustrating an electrode assembly according to another embodiment of the present invention. Fig. 15 is a perspective view illustrating a current collector applied to the electrode assembly of Fig. 14 (reference numbers in Figs. 12 to 15 apply only to the corresponding embodiments, and descriptions of features identical to those of the above-described embodiments are omitted).

[0115] In the embodiments described above, the first substrate tab (210) and the second substrate tab (220) are arranged in opposite directions. However, referring to FIG. 12, a plurality of first substrate tabs (1211) and a plurality of second substrate tabs (1221) may all be arranged on the upper side of the electrode assembly (200).

[0116] The electrode assembly (120) may include a first electrode plate, which is a positive electrode plate, a second electrode plate, which is a negative electrode plate, and a separator. In some examples, the first electrode plate may include a plurality of first substrate tabs (1211) extending upwardly. The second electrode plate may include a plurality of second substrate tabs (1221) extending upwardly. The first substrate tabs (1211) may be electrically connected to the first current collector plate (131) and the positive electrode terminal. The second substrate tabs (1221) may be electrically connected to the can.

[0117] The separator may be provided to be slightly larger than the width of the first electrode plate and the second electrode plate, and may protrude further in the upper, lower, left, and right directions than the first electrode plate and the second electrode plate, respectively. Accordingly, the separator may prevent the first electrode plate and the second electrode plate from directly contacting the can in the upper, lower, and / or left, right directions of the electrode assembly (120). In some examples, the separator may protrude and extend a certain length in the upper and lower directions of the electrode assembly (120) without the first substrate tab (1211) and the second substrate tab (1221).

[0118] Referring to FIG. 13, the collector plate assembly (130) may include a first collector plate (131) and a second collector plate (132). The collector plate assembly (130) may further include an insulating plate (not shown).

[0119] The first current collector (131) can electrically connect the first electrode plate of the electrode assembly (120) and the positive terminal. The first current collector (131) may include or be referred to as a current collector, a conductor, or a conductive lead. The first current collector (131) may be made of aluminum or an aluminum alloy. For example, the first current collector (131) may include a first current collector first connection area (1311), a first current collector connection area (1312), and a first current collector second connection area (1313). The first current collector first connection area (1311) may be electrically connected to a plurality of first substrate tabs (1211) by a method such as laser welding. The first current collector connection area (1312) may be bent and extended upward from the first current collector first connection area (1311). The first collector plate second connection area (1313) can be bent and extended from the first collector plate connection area (1312) and electrically connected to the positive terminal by a method such as laser welding. In this way, the first collector plate (131) can serve as a current flow path between the electrode assembly (120) and the positive terminal.

[0120] The second current collector (132) can electrically connect the second electrode plate of the electrode assembly (120) and the upper surface of the can. The second current collector (132) may include or be referred to as a current collector, a conductor, or a conductive lead. The second current collector (132) may be made of copper, a copper alloy, nickel, or a nickel alloy. The second current collector (132) may be made by a punching process using a die and a punch of a metal plate, or may be made by casting a molten metal. In some examples, the second current collector (132) may include a second current collector first connection area (1321), a second current collector connection area (1322), and a second current collector second connection area (1323). The second current collector first connection area (1321) may be electrically connected to the plurality of second substrate tabs (1221) described above by a method such as laser welding. The second collector plate connection area (1322) can be bent and extended upward from the second collector plate first connection area (1321). The second collector plate second connection area (1323) can be bent and extended from the second collector plate connection area (1322) and electrically connected to the upper surface of the can through a method such as laser welding. In this way, the second collector plate (132) can become a current flow path between the electrode assembly (120) and the can.

[0121] An insulating plate may be interposed between the first collector plate (131) and the second collector plate (132). The insulating plate may include or be referred to as an insulator, an insulating block, or an insulating phaser. The insulating plate may be made of polypropylene, polyethylene, EPDM, or nylon, which does not react with the electrolyte. In some examples, the first collector plate (131), the second collector plate (132), and the insulating plate may be manufactured through a double injection molding process.

[0122] Referring to FIG. 14, the electrode assembly (120) may include a first electrode plate, which is a positive electrode plate, a second electrode plate, which is a negative electrode plate, and a separator. In some examples, the first electrode plate, the separator, and the second electrode plate may be rolled in a substantially cylindrical shape while being stacked. The first electrode plate may include a first substrate tab (1211) extending upward from approximately the center of the electrode assembly (120). The second electrode plate may include a second substrate tab (1221) extending upward from approximately the periphery of the electrode assembly (120). The first substrate tab (1211) may be electrically connected to the first current collector plate (131) and the positive electrode terminal. The second substrate tab (1221) may be electrically connected to the upper surface of the can.

[0123] The separator may be provided to be slightly larger than the width of the first electrode plate and the second electrode plate, and may protrude further in the upper, lower, left, and right directions than the first electrode plate and the second electrode plate, respectively. Accordingly, the separator may prevent the first electrode plate and the second electrode plate from directly contacting the can in the upper, lower, and / or left, right directions of the electrode assembly (120). In some examples, the separator may protrude and extend a certain length in the upper and lower directions of the electrode assembly (120) without the first substrate tab (1211) and the second substrate tab (1221).

[0124] The collector plate assembly (130) may include a first collector plate (131) and a second collector plate (132). The collector plate assembly (130) may further include an insulating plate (133).

[0125] The first collector plate (131) can electrically connect the first electrode plate of the electrode assembly (120) and the positive terminal. For example, the first collector plate (131) can include a first collector plate first connection area (1311), a first collector plate connection area (1312), and a first collector plate second connection area (1313). The first collector plate first connection area (1311) can be electrically connected to the first substrate tab (1211) having a roughly circular ring shape described above by a method such as laser welding. The first collector plate connection area (1312) can be bent and extended upward from the first collector plate first connection area (1311). The first collector plate second connection area (1313) can be bent and extended from the first collector plate connection area (1312) and electrically connected to the positive terminal by a method such as laser welding. In this way, the first collector plate (131) can serve as a current flow path between the electrode assembly (120) and the positive terminal.

[0126] The second collector plate (132) can electrically connect the second electrode plate (122) of the electrode assembly (120) and the upper surface of the can. For example, the second collector plate (132) can include a second collector plate first connection area (1321), a second collector plate connection area (1322), and a second collector plate second connection area (1323). The second collector plate first connection area (1321) can be electrically connected to the second substrate tab (1221) having a roughly circular ring shape described above by a method such as laser welding. The second collector plate connection area (1322) can be bent and extended upward from the second collector plate first connection area (1321). The second collector plate second connection area (1323) can be bent and extended from the second collector plate connection area (1322) and electrically connected to the upper surface of the can through a method such as laser welding. In this way, the second collector plate (132) can serve as a current flow path between the electrode assembly (120) and the can.

[0127] An insulating plate (133) may be interposed between the first collector plate (131) and the second collector plate (132). In some examples, the insulating plate (133) may be provided on a substantially same horizontal plane as the first collector plate (131) and the second collector plate (132). In some examples, a portion of the insulating plate (133) may be interposed between the second connection area (1323) of the second collector plate and the electrode assembly (120).

[0128] The electrode assembly (120) of the above-described structure can provide a secondary battery having a low electrical resistance and a short current path, since the first substrate tab (1211) and the second substrate tab (1221) are provided in the same direction. In addition, the first current collector plate (131) and the second current collector plate (132) are three-dimensionally bonded and provided in the same area, thereby occupying a small volume in the internal space of the can. Accordingly, a secondary battery can be provided in which a relatively large electrode assembly (120) is accommodated inside the can.

[0129] In addition, the secondary battery according to the above-described embodiment can be used to manufacture a battery pack (reference numbers of the components described below are reference numbers that apply only to the corresponding drawing).

[0130] FIGS. 16 and 17 are perspective views illustrating a battery pack (300) including an exemplary cylindrical secondary battery according to the present invention. Referring to FIGS. 16 and 17, the battery pack (300) may include a plurality of battery modules (200) and a housing (310) for accommodating the plurality of battery modules (200). For example, the housing (310) may include first and second housings (311, 312) that are coupled in a direction facing each other with the plurality of battery modules (200) interposed therebetween. The plurality of battery modules (210) may be electrically connected to each other using a bus bar (251), and the plurality of battery modules (200) may be electrically connected to each other in a series / parallel or series-parallel hybrid manner to obtain a required electrical output. In the drawings, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrically connecting battery cells are omitted. In some examples, the battery pack (300) may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0131] Figures 18 and 19 are perspective views and side views illustrating a vehicle (400, 500) including an exemplary battery pack (300) according to the present invention. In Figure 18, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is a part of a vehicle underbody (410) and a pack frame (312) (which may correspond to the second housing) which is disposed at a lower portion of the vehicle underbody (410). The battery pack cover (311) and the pack frame (312) may be formed integrally with the vehicle floor (420). The vehicle underbody (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed at the exterior of the vehicle.

[0132] As illustrated in FIG. 19, a vehicle (500) may be formed by combining additional components, such as a hood (510) at the front of the vehicle and fenders (520) positioned at the front and rear of the vehicle, respectively, with a body (400). The vehicle (500) includes a battery pack (300) including a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with a body component (400).

[0133] The above description is only one embodiment for carrying out the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, it will be said that the technical spirit of the present invention exists to the extent that anyone with ordinary skill in the art to which the present invention pertains can make various modifications without departing from the gist of the present invention.

Claims

1. A cylindrical can including a circular upper portion having at least one notch and a side portion extending from the upper portion and having an open end; An electrode assembly comprising a first electrode plate having a first substrate tab, a second electrode plate having a second substrate tab, and a separator interposed between the first electrode plate and the second electrode plate, and which is wound and accommodated in the can; A cap plate coupled to the open end of the above side and having a liquid injection hole through it; and A secondary battery comprising a terminal insulatively bonded to the upper surface and electrically connected to the first substrate tab.

2. In paragraph 1, A secondary battery in which the above notch is arranged spaced apart from the above terminal.

3. In paragraph 1, A secondary battery, wherein the notch is provided on at least one of a plate surface facing the electrode assembly and a plate surface facing in the opposite direction of the electrode assembly.

4. In paragraph 1, A secondary battery in which the notches provided on the plate facing the electrode assembly and the notches provided on the plate facing the opposite direction of the electrode assembly are arranged in an alternating manner.

5. In paragraph 1, The above notch is one of a circular shape, a C shape, and a discontinuous linear shape, and is a secondary battery.

6. In paragraph 1, The above cap plate is a secondary battery directly connected to the end of the side.

7. In paragraph 6, A secondary battery having a step-structured joint portion at the end of the above side, and wherein the cap plate is seated in the joint portion and is mutually coupled.

8. In paragraph 7, A secondary battery, wherein the cap plate includes a flat portion having the injection hole, and a connecting portion that is integrally formed with the flat portion and protrudes outward from the flat portion to be connected to the can.

9. In paragraph 8, A secondary battery having the above notch provided in the above connecting portion.

10. In paragraph 8, A secondary battery, wherein the above-mentioned injection hole is closed with any one of a blind rivet, a ball, a pin, and an injection plug after the electrolyte is injected.

11. In paragraph 7, The above cap plate is a secondary battery having a flat shape.

12. In paragraph 11, A secondary battery further comprising a sealing member that closes the electrolyte injection hole after the electrolyte injection.

13. In paragraph 12, A secondary battery characterized in that it undergoes a flattening process after closing the above-mentioned injection hole.

14. A cylindrical can comprising a circular upper portion having at least one notch and a side portion extending from the upper portion and having an open end; An electrode assembly comprising a first electrode plate having a first substrate tab, a second electrode plate having a second substrate tab, and a separator interposed between the first electrode plate and the second electrode plate, and which is wound and accommodated in the can; a cap plate coupled to the opened end of the above side; and A terminal is insulatively bonded to the upper surface and electrically connected to the first substrate tab, A secondary battery, wherein the can further includes a beading portion provided inwardly concavely adjacent to an end of the side portion, and a crimping portion provided by bending an end of the side portion inward.

15. In paragraph 14, A secondary battery in which the above notch is arranged spaced apart from the above terminal.

16. In paragraph 14, A secondary battery, wherein the notch is provided on at least one of a plate surface facing the electrode assembly and a plate surface facing in the opposite direction of the electrode assembly.

17. In paragraph 14, A secondary battery in which the notches provided on the plate facing the electrode assembly and the notches provided on the plate facing the opposite direction of the electrode assembly are arranged in an alternating manner.

18. In paragraph 14, The above notch is one of a circular shape, a C shape, and a discontinuous linear shape, and is a secondary battery.

19. In paragraph 14, A secondary battery, wherein the cap plate is inserted between the beading portion and the crimping portion.

20. In paragraph 19, A secondary battery further comprising a gasket of insulating material inserted between the cap plate and the side of the can.

21. In paragraph 20, A secondary battery further comprising a cooling member disposed between the cap plate and the electrode assembly.

22. In paragraph 21, A secondary battery, characterized in that the above cooling member is a heat-dissipating material.

23. A plurality of secondary batteries according to any one of paragraphs 1 to 22; A case that accommodates the secondary battery; A bus bar electrically connected to the secondary battery; A circuit module electrically connected to the above bus bar; and A battery pack including a cooling module that contacts the cap plate of the secondary battery and cools the secondary battery.

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