Battery, battery pack, and device comprising same

Abstract

A battery according to the present invention comprises: an electrode assembly including a plurality of stacked electrodes, a tab array formed by stacking a plurality of electrode tabs respectively extending from the plurality of electrodes, and a cover member covering the tab array; and an electrode lead electrically connected to the tab array. The cover member may include: an electrode cover part covering at least a partial surface of an electrode arranged at the outermost side among the plurality of stacked electrodes; and a tab cover part extending from the electrode cover part, arranged to face the tab array, and electrically connected to the electrode lead.

Description

Batteries, battery packs and devices containing the same

[0001] The present invention relates to a battery, a battery pack and a device including the same.

[0002] Unlike primary batteries, secondary batteries can be recharged and discharged, making them suitable for a wide range of applications, including digital cameras, mobile phones, laptops, hybrid and electric vehicles, and aircraft. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-hydrogen batteries, with lithium-ion batteries gaining widespread use recently.

[0003] In the case of conventional lithium ion batteries, copper or aluminum foil, etc., is used as a metal current collector for the negative electrode or positive electrode, and a negative electrode active material or positive electrode active material is laminated on both sides to produce the positive electrode or negative electrode.

[0004] In contrast, next-generation batteries like lithium-sulfur (Li-S) batteries or lithium metal batteries (Li-Metal) can have a cathode composed entirely of lithium metal. In this case, the lithium metal constituting the cathode plate can be extended to form a cathode tab. However, lithium metal is the lowest-density metal, is soft, and is highly reactive with moisture in the air, raising concerns about deterioration during long-term storage.

[0005] In this way, the electrode tab made of lithium metal has a problem in that it is pressed by pressure during the welding process with the electrode lead and sticks to the welding device, or even after welding is completed, it has a soft material property and a short circuit occurs at the boundary between the electrode and the electrode tab during use of the battery.

[0006] The present invention has been created in consideration of the above-described problems, and the problem that the present invention seeks to solve is to provide a battery, a battery pack, and a device including the same, which are configured to prevent an electrode tab from being pressed by pressure during a welding process and from being stuck to a welding device.

[0007] In addition, the present invention provides a battery, a battery pack, and a device including the same configured to minimize short circuits at the boundary between an electrode and an electrode tab.

[0008] According to one embodiment of the present invention, a battery includes an electrode assembly including a plurality of stacked electrodes, a plurality of electrode tabs formed by stacking and extending from each of the plurality of electrodes, a tab assembly formed by stacking and extending from the plurality of electrodes, and a cover member covering the tab assembly, and an electrode lead electrically connected to the tab assembly, wherein the cover member may include an electrode cover part covering at least a portion of a surface of an electrode disposed at the outermost end of the plurality of stacked electrodes, and a tab cover part extending from the electrode cover part and disposed to face the tab assembly and electrically connected to the electrode lead.

[0009] The tab assembly is formed by stacking a plurality of electrode tabs in one direction, and the cover member can cover two electrode tabs located at the outermost sides of one side and the other side of the tab assembly, respectively.

[0010] The tab assembly can be electrically connected to the electrode lead via the tab cover portion.

[0011] The electrode cover portion may be made of a material having a higher tensile strength than the plurality of electrode tabs.

[0012] The plurality of electrode tabs are made of lithium metal, and the cover member may be nickel foil or copper foil.

[0013] The electrode cover portion can cover one surface of the electrode positioned at the outermost end among the plurality of stacked electrodes.

[0014] A battery characterized in that the electrode cover part is bonded to one surface of the electrode arranged at the outermost end among a plurality of stacked electrodes.

[0015] The width of the tab cover portion may be wider than the width of the tab assembly.

[0016] The tab cover portion may be positioned between the electrode lead and the tab assembly and welded to the electrode lead.

[0017] A battery pack according to one embodiment of the present invention may include a battery according to the present invention.

[0018] A device according to one embodiment of the present invention may include a battery pack according to the present invention.

[0019] According to one aspect of the present invention, the tab can be prevented from being pressed by pressure during the welding process and sticking to the welding device.

[0020] According to another aspect of the present invention, since the cover member covers the tab assembly, the tab assembly is spread out by the pressure applied in the welding process, and the tab cover part comes out of the cover area covered, causing interference with the lead film, thereby hindering the sealing property of the battery case, and preventing an electrical short circuit from occurring between the tab assembly and the battery case.

[0021] According to another aspect of the present invention, it is possible to minimize short circuits occurring at the boundary between an electrode and an electrode tab.

[0022] Figure 1 is an exploded perspective view of a battery according to one embodiment of the present invention.

[0023] FIG. 2 is a part of a plan view of a battery according to one embodiment of the present invention.

[0024] FIG. 3 is a drawing showing a plurality of electrodes and a cover member included in a battery according to one embodiment of the present invention.

[0025] Fig. 4 is an exemplary cross-sectional view along the A-A' section of Fig. 3.

[0026] FIG. 5 is a drawing showing a cover member included in a battery according to one embodiment of the present invention.

[0027] FIG. 6 is a drawing showing a cover member included in a battery according to another embodiment of the present invention.

[0028] FIG. 7 and FIG. 8 are drawings showing a device according to one embodiment of the present invention.

[0029] Before going into the detailed description of the present invention, it should be noted that the terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his own invention in the best way. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of this application.

[0030] The same reference numbers or symbols used in each drawing attached to this specification represent parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols may be used in different embodiments. In other words, even if components with the same reference numbers are depicted in multiple drawings, they do not necessarily represent a single embodiment.

[0031] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprises" or "comprises" should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] In addition, in the description below, expressions such as top, upper, lower, lower, side, front, and rear are expressed based on the direction shown in the drawing, and it is noted in advance that they may be expressed differently if the direction of the object in question changes.

[0033] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited manner. For example, components associated with these ordinals should not be interpreted in a restricted manner, such as in the order of use or arrangement, based on their numbers. If necessary, each ordinal number may be used interchangeably.

[0034] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, the spirit of the present invention is not limited to the presented embodiments. For example, those skilled in the art who understand the spirit of the present invention may propose other embodiments within the spirit of the present invention by adding, modifying, or deleting components, etc., but such embodiments will also be considered within the spirit of the present invention. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0035] Fig. 1 is an exploded perspective view of a battery (1) according to one embodiment of the present invention. Fig. 2 is a part of a plan view of a battery (1) according to one embodiment of the present invention. Fig. 3 is a drawing showing a plurality of electrodes (10) and a cover member (30) included in a battery (1) according to one embodiment of the present invention. Fig. 4 is an exemplary cross-sectional view taken along section A-A' of Fig. 3. Fig. 5 is a drawing showing a cover member (30) included in a battery (1) according to one embodiment of the present invention.

[0036] Referring to FIGS. 1 to 5, a battery (1) according to the present invention may include an electrode assembly (3), an electrode lead (L), a battery case (50), and a lead film (40).

[0037] The electrode assembly (3) may include a plurality of electrodes (10), a tab assembly (C) and a cover member (30).

[0038] A plurality of electrodes (10) may be stacked. The plurality of electrodes (10) may include a first electrode (11) and a second electrode (12). The first electrode (11) and the second electrode (12) may have opposite polarities. The first electrode (11) and the second electrode (12) may be stacked with a separator (13) interposed therebetween.

[0039] A separator (13) may be interposed between the first electrode (11) and the second electrode (12) to prevent electrical short-circuiting between the first electrode (11) and the second electrode (12) and to be configured to be impregnated with an electrolyte so that ions can pass through. The separator (13) may be formed of a porous polymer film or a porous non-woven fabric, etc. However, in addition to the above materials, any material commonly used in lithium secondary batteries may be used without special restrictions as long as it is used.

[0040] The tab assembly (C) can be formed by stacking a plurality of electrode tabs (T) each formed by extending from a plurality of electrodes (10). The tab assembly (C) can be formed by stacking a plurality of electrode tabs (T) in one direction. The tab assembly (C) can be formed by gathering electrode tabs (T) having the same polarity.

[0041] The electrode lead (L) can be electrically connected to the tab assembly (C). The electrode lead (L) can be made of a conductive metal material. For example, the electrode lead (L) can be made of nickel (Ni), aluminum (Al), copper (Cu), and iron (Fe), or an alloy containing these metals. As an example, the electrode lead (L) can be mutually connected to the tab assembly (C) by welding or the like while the cover member (30) is interposed therebetween. The electrode leads (L) can be provided as a pair and provided on one side as illustrated in FIG. 1, but alternatively, they can be provided on both sides, respectively.

[0042] The battery case (50) may be configured to accommodate the electrode assembly (3). The battery case (50) may be configured such that the electrode lead (L) extends outward from the battery case (50). The battery case (50) may include an upper case (52) and a lower case (51). The battery case (50) may include an electrode receiving portion (53) and a sealing portion (54) disposed along an edge of the electrode receiving portion (53). The electrode receiving portion (53) is formed by joining the upper case (52) and the lower case (51) together vertically, and may have an internal space in which the electrode assembly (3) is accommodated. The sealing portion (54) is formed by pressing or heat-welding the edges of the upper case (52) and the lower case (51) along the edge of the electrode receiving portion (53), thereby preventing foreign substances or moisture from outside the battery case (50) from entering the electrode assembly (3) contained inside the electrode receiving portion (53).

[0043] The battery case (50) may be a pouch-shaped case made of a flexible material. For example, the battery case (50) may be made of an aluminum laminate sheet. However, in addition to the above-described pouch-shaped case, the battery case (50) may also be made of a can-shaped (or square) case or a cylindrical case made of a metal material such as aluminum.

[0044] A lead film (40) may be provided between the battery case (50) and the electrode lead (L). The lead film (40) may be provided as a film having heat sealing properties so as to increase the sealing force of the battery case (50) in the area where the electrode lead (L) is drawn out. The lead film (40) may be configured to include an insulating material to prevent short-circuiting of the electrode lead (L).

[0045] The cover member (30) can cover the tab assembly (C). The cover member (30) can cover each of the two electrode tabs located at the outermost portion of the tab assembly (C). The cover member (30) can cover each of the two electrodes located at the outermost portion of the plurality of stacked electrodes (10).

[0046] Referring to FIGS. 3 and 5 together, the cover member (30) may include an upper cover member (30B) that covers an electrode (10B) located at the uppermost part (in the positive extension direction of the Z-axis) of the plurality of stacked electrodes (10) and an electrode tab (T) that extends from the electrode, and a lower cover member (30A) that covers an electrode (10A) located at the lowermost part (in the negative extension direction of the Z-axis) of the plurality of stacked electrodes (10) and an electrode tab (T) that extends from the electrode.

[0047] The cover member (30) may include an electrode cover portion (33) that covers at least a portion of a surface of an electrode (10A, 10B) disposed at the outermost end among a plurality of stacked electrodes (10), and a tab cover portion (31) that extends from the electrode cover portion (33) and is disposed to face the tab assembly (C) and is electrically connected to the electrode lead (L). The electrodes of the plurality of electrodes (10) illustrated in FIG. 3 are all electrodes having the same polarity, and electrodes of the opposite polarity that constitute the electrode assembly (3) are omitted from the drawing. For example, electrodes of the opposite polarity may be disposed between the plurality of electrodes (10) illustrated in FIG. 3.

[0048] The tab cover portion (31) of the cover member (30) can be positioned to face the tab assembly (C). The tab cover portion (31) can cover one side of the tab assembly (C).

[0049] The electrode cover part (33) can be placed facing the electrode (10A, 10B) placed at the outermost end among the plurality of stacked electrodes (10).

[0050] The cover member (30) may be made of a material having a higher tensile strength than the material constituting the tab assembly (C). For example, when the individual electrode tabs (T) constituting the tab assembly (C) are made of lithium metal, the cover member (30) may be a nickel foil or copper foil having a higher tensile strength than the lithium metal. The cover member (30) may be made of a metal or alloy other than the lithium metal itself. That is, the cover member (30) may be a metal having stronger physical properties than the lithium metal.

[0051] The cover member (30) can cover the boundary between the electrode (10) and the electrode tab (T) by including a tab cover portion (31) and an electrode cover portion (33).

[0052] The tab cover portion (31) of such a cover member (30) can be joined to the electrode lead (L) by ultrasonic welding (W) between the region where the electrode lead (L) and the tab assembly (C) overlap along the height direction (the direction parallel to the Z-axis), as illustrated in FIGS. 2 and 4. Accordingly, the tab assembly (C) can be electrically connected to the electrode lead (L) via the tab cover portion (31).

[0053] According to this configuration of the present invention, it is possible to prevent the electrode tab (T) from being pressed by pressure during the welding process and seized in the welding device. Since the cover member (30) is provided at the outermost part of the tab assembly (C), the electrode tab (T) does not come into contact with the horn and anvil for ultrasonic welding when ultrasonic welding is performed to connect the electrode lead (L) and the tab assembly (C). Therefore, the tab assembly (C) is provided between a pair of cover members (30) covering the upper and lower surfaces of the tab assembly (C) and is connected to the electrode lead (L) in a non-contact state with the welding device.

[0054] In addition, since the cover member (30) covers the tab assembly (C), the tab assembly (C) is spread out by the pressure applied during the welding process and comes out of the cover area covered by the tab cover part (31), causing interference with the lead film (40), thereby hindering the sealing of the battery case (50), and preventing an electrical short circuit between the tab assembly (C) and the battery case (50).

[0055] In addition, it is possible to minimize short circuits occurring at the boundary between the electrode (10) and the electrode tab (T). The portion where the electrode tab (T) extends from the electrode (10) has a structure in which the width is rapidly reduced, which may be structurally vulnerable. This structure may easily cause short circuits to occur when the battery (1) repeatedly swells and shrinks due to swelling, etc. during the use of the battery (1). In particular, the electrodes (10A, 10B) located at the outermost end among the plurality of stacked electrodes (10) may experience greater structural changes due to swelling, etc. than the electrodes located at the inner end. Therefore, by arranging the cover member (30) to face the electrodes (10A, 10B) located at the outermost end, it is possible to minimize short circuits occurring at the boundary between the electrode (10) and the electrode tab (T).

[0056] The above effects can be maximized when the battery (1) according to the present invention is a lithium metal battery or a lithium sulfur battery. The negative electrode plate of the lithium metal battery or the lithium sulfur battery can have an integral structure made of a lithium metal sheet. The lithium metal sheet is a flat member made of a lithium or lithium alloy material, and the negative electrode tab can be implemented by appropriately processing the shape of the lithium metal sheet. Therefore, when the battery (1) is a lithium metal battery or a lithium sulfur battery, the plurality of electrode tabs (T) included in the battery (1) can include lithium metal (lithium or an alloy including lithium).

[0057] In this case, when the negative electrode plate is made of a lithium metal sheet, the problem of the electrode tab (T) sticking to the welding device or a short circuit occurring at the boundary between the electrode (10) and the electrode tab (T) may be further aggravated due to the soft physical properties of the lithium metal. However, as described above, this problem can be minimized by providing a cover member (30) made of a metal material having properties stronger than lithium metal at the outermost surface of the tab assembly (C) including lithium metal.

[0058] In particular, when measuring the tensile strength of a combination in which a tab assembly (C) including lithium metal is joined to an electrode lead (L), there was a problem in that the vicinity of the extension formed from the electrode (10) to the electrode tab (T) was first broken before the joint between the tab assembly (C) and the electrode lead (L) was released, resulting in a low tensile strength. This problem can be solved by providing a cover member (30) made of a metal material having a tensile strength stronger than that of lithium metal at the outermost portion of the tab assembly (C), thereby improving the tensile strength of a combination in which the tab assembly (C) and the electrode lead (L) are joined.

[0059] FIG. 6 is a drawing showing a cover member (30) included in a battery (1) according to another embodiment of the present invention.

[0060] Referring to FIG. 6, the cover member (30) according to the present invention will be described in more detail.

[0061] The electrode cover portion (33) can cover one surface of the electrode (10A, 10B) positioned at the outermost end among the plurality of stacked electrodes (10). The electrode cover portion (33) can have the same area as one surface of the electrode (10).

[0062] The electrode cover part (33) can be bonded to one surface of the electrode (10A, 10B) arranged at the outermost end among the plurality of stacked electrodes (10). The electrode cover part (33) can be bonded to one surface of the electrode (10) by ultrasonic welding or laser welding. The electrode cover part (33) can be bonded to one surface of the electrode (10) by a polymer binder.

[0063] The process of bonding the electrode cover part (33) to one side of the electrode (10) may be performed before the process of stacking multiple electrodes. That is, the electrodes (10A, 10B) positioned at the outermost ends may be stacked with the electrode cover part (33) bonded. This stacking method may be used without any special restrictions as long as it is a stacking method commonly used in lithium secondary batteries, in addition to the ZIG-ZAG method and the STACK&FOLDING method.

[0064] The tab cover portion (31) can cover a wider area than the tab assembly (C). The tab cover portion (31) can have a wider width than the tab assembly (C). The tab cover portion (31) can have a longer length than the tab assembly (C).

[0065] The tab assembly (C) and the electrode lead (L) are welded along the width direction (parallel to the X-axis) of the tab (T) with the tab cover portion (31) interposed therebetween. During the welding process, the tab assembly (C) may spread along the width direction (parallel to the X-axis) of the electrode tab (T) due to the pressure applied during the welding process and may come out of the cover area of ​​the tab cover portion (31), so that the width setting of the tab cover portion (31) to prevent this is particularly important.

[0066] The width of the tab cover portion (31) may be related to the thickness of the tab assembly (C), the thickness of the electrode lead (L), and the thickness of the cover member (30). For example, if the thickness of the tab assembly (C) is thick, the tab assembly (C) may be spread to a large extent by the pressure applied during the welding process, so the width of the tab cover portion (31) may need to be set large.

[0067] Accordingly, the width of the tab cover portion (31) may be proportional to the sum of the thickness of the tab assembly (C), the thickness of the electrode leads (L), and the thicknesses of the two facing cover members (30). For example, the one-sided spacing along the width direction (parallel to the X-axis) between the tab cover portion (31) and the electrode tabs (T) may be set to 0.2 to 0.4 times the sum of the thickness of the tab assembly, the thickness of the electrode leads, and the thicknesses of the two facing cover members. The one-sided spacing along the width direction (parallel to the X-axis) between the tab cover portion (31) and the electrode tabs (T) may be 1 to 2 mm. The other-sided spacing along the width direction (parallel to the X-axis) between the tab cover portion (31) and the electrode tabs (T) may be set equal to the one-sided spacing, so that the tab assembly (C) may be positioned at the center of the tab cover portion (31) along the width direction.

[0068] By this configuration, when the tab cover part (31) is joined by welding between the electrode lead (L) and the tab assembly (C), the effect of preventing the tab assembly (C) from being spread out by the pressure applied in the welding process and coming out of the cover area of ​​the tab cover part (31) and interfering with the lead film (40) or sticking to the welding device can be increased.

[0069] The process of joining the tab cover portion (31) between the electrode lead (L) and the tab assembly (C) by welding may be performed after the process of stacking the plurality of electrodes (10). After the process of joining the tab cover portion (31) between the electrode lead (L) and the tab assembly (C) by welding, the process may include a process of wrapping the electrode assembly (3) with a separator (13) once again and / or a process of accommodating the electrode assembly (3) in a battery case (50) and / or a process of sealing the battery case (50).

[0070] Meanwhile, although not illustrated in detail, the battery pack according to the present invention may include one or more batteries (1) according to the present invention. The battery pack may further include various components other than the battery (1), such as components of a battery pack known at the time of filing of the present invention, such as a BMS, a bus bar, a pack case, a relay, a current sensor, etc.

[0071] FIG. 7 and FIG. 8 are drawings showing a device (B) according to one embodiment of the present invention.

[0072] Referring to FIGS. 7 and 8, a device (B) according to the present invention may include a battery (1) according to the present invention. For example, the device illustrated in FIG. 7 may be an automobile, and the device illustrated in FIG. 8 may be an aircraft.

[0073] Referring to FIG. 7, when the device (B) according to the present invention is an automobile, the automobile may further include various other components included in the automobile in addition to the battery (1). For example, in addition to the battery (1) according to the present invention, the automobile may further include a body, a motor, a control device such as an ECU (electronic control unit), etc.

[0074] Referring to FIG. 8, if the device (B) according to the present invention is an aircraft, the aircraft may further include various other components included in the aircraft in addition to the battery (1). For example, if the aircraft is a drone, the drone may further include a transmitter / controller, a motor, a propeller, a control board, etc. in addition to the battery (1) according to the present invention.

[0075] However, the device (B) is not limited to means of transportation or moving means such as automobiles and aircraft as described above, and can be applied to various types of devices that can use a battery (1), including an ESS (Energy Storage System).

[0076] While the present invention has been described with reference to the accompanying drawings, focusing on preferred embodiments, it will be apparent to those skilled in the art that numerous obvious modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should be construed as encompassing the many examples of such modifications within the scope of the claims.

[0077] [Explanation of symbols]

[0078] B device

[0079] 1 battery

[0080] 3 electrode assembly

[0081] 10 electrodes

[0082] 11 First electrode

[0083] 12 Second electrode

[0084] 13 Membrane

[0085] T electrode tab

[0086] C tab set

[0087] L electrode lead

[0088] 30 Cover Absence

[0089] 31 tab cover

[0090] 33 Electrode cover

[0091] 40 lead film

[0092] 50 Battery Case

[0093] 51 Lower Case

[0094] 52 Upper Case

[0095] 53 Electrode Receptacle

[0096] 54 shillings

Claims

1. An electrode assembly including a plurality of stacked electrodes, a tab assembly formed by stacking a plurality of electrode tabs each extending from the plurality of electrodes, and a cover member covering the tab assembly; and comprising an electrode lead electrically connected to the above tab assembly; The above cover member, An electrode cover portion covering at least a portion of the surface of an electrode positioned at the outermost end among the plurality of stacked electrodes; and A battery including a tab cover portion extending from the electrode cover portion and positioned facing the tab assembly and electrically connected to the electrode lead.

2. In paragraph 1, The above tab set is, Multiple electrode tabs are formed by stacking in one direction, The above cover member, A battery characterized in that it covers two electrode tabs located at the outermost sides of one side and the other side of the above tab assembly.

3. In paragraph 1, A battery characterized in that the tab assembly is electrically connected to the electrode lead via the tab cover portion.

4. In paragraph 1, A battery characterized in that the electrode cover portion is made of a material having a higher tensile strength than the plurality of electrode tabs.

5. In paragraph 1, The above plurality of electrode tabs are made of lithium metal, A battery characterized in that the above cover member is nickel foil or copper foil.

6. In paragraph 1, A battery characterized in that the electrode cover part covers one surface of the electrode arranged at the outermost end among the plurality of stacked electrodes.

7. In paragraph 6, A battery characterized in that the electrode cover part is bonded to one surface of the electrode arranged at the outermost end among the plurality of stacked electrodes.

8. In paragraph 6, A battery characterized in that the width of the tab cover portion is wider than the width of the tab assembly.

9. In paragraph 6, The above tab cover part, A battery characterized in that it is disposed between the electrode lead and the tab assembly and is welded to the electrode lead.

10. A battery pack comprising a battery according to any one of claims 1 to 9.

11. A device comprising a battery pack according to Article 10.

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