Secondary battery, battery pack, and electronic device

Abstract

An objective of the present invention is to provide a secondary battery, a battery pack and an electronic device, to improve the energy density and safety of the secondary battery.SOLUTION: The present invention provides a secondary battery, comprising: a top cover and an electrode terminal provided on the top cover; an electrode member comprising a battery core body and an electrode tab protruding from the battery core body, wherein a rivet hole is provided on the electrode tab; and a rivet connected to the electrode terminal and passing through the rivet hole to rivet the electrode terminal and the electrode tab.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a secondary battery, a battery pack, and an electronic device. [Background technology]

[0002] Over the past few decades, the development of lithium-ion batteries has attracted attention with the rise of new energy vehicles and electrochemical energy storage stations. During the lithium-ion battery production process, the electrode components / wound battery cores (JR) must be connected to the electrode terminals on the top cover after winding or lamination and hot pressing. Currently, most batteries use riveting, screws, or ultrasonic welding to connect the electrode tabs of the electrode components to the connector plate, and then laser welding to connect the electrode terminals to the connector plate. To improve space utilization and energy density, some batteries do not use connector plates and instead directly connect the electrode tabs to the electrode terminals using laser welding. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the problems existing in the related art, an object of the present invention is to provide a secondary battery, a battery pack and an electronic device, and to improve the energy density and safety of the secondary battery. [Means for solving the problem]

[0004] To achieve the above object, the present invention provides a secondary battery comprising: a top cover, an electrode terminal installed on the top cover; a battery core body, an electrode tab protruding from the battery core body, with rivet holes installed on the electrode tab; and a rivet connected to the electrode terminal and passing through the rivet hole to rivet the electrode terminal and the electrode tab together.

[0005] In some embodiments, the rivet is provided on the side of the electrode terminal facing the electrode member.

[0006] In some embodiments, the electrode terminal and the rivet are a single piece.

[0007] In some embodiments, the electrode terminals include a positive terminal and a negative terminal, the electrode tabs include a positive electrode tab and a negative electrode tab, and the positive electrode terminal is riveted to the positive electrode tab through a rivet and the negative electrode terminal is riveted to the negative electrode tab through another rivet.

[0008] In some embodiments, the secondary battery includes one or more electrode members, and the electrode terminals are connected with a corresponding number of rivets to connect the electrode tabs of the one or more electrode members.

[0009] In some embodiments, the rivet is a solid or hollow structure, and when projected along a direction from the electrode member to the electrode terminal, the shape of the outer boundary of the rivet is one or a combination of a circle, an oval, a square, a rectangle, a diamond, and a triangle.

[0010] In some embodiments, the marginal area of ​​the rivet is welded integrally with the electrode terminal, the electrode tab.

[0011] In some embodiments, the electrode member is a wound or stacked electrode member.

[0012] An embodiment of the present invention also provides a battery pack including any of the secondary batteries described above.

[0013] An embodiment of the present invention also provides an electronic device including the battery pack. [Effects of the Invention]

[0014] Beneficial technical effects of the present invention include the use of rivets to fasten the electrode tabs and electrode terminals, eliminating the need for connector plates, thereby effectively reducing the weight of the secondary battery and improving the battery's energy density. Furthermore, the use of rivets in the present invention effectively alleviates the safety risk to the electrode components caused by solder residues that are generated when welding the electrode tabs and electrode terminals using conventional ultrasonic welding or laser welding, thereby improving the safety performance of the secondary battery. Furthermore, the use of riveting in the present invention effectively alleviates the problem of cracks occurring in the electrode tabs when welding the electrode tabs and electrode terminals using conventional techniques, thereby improving the yield rate of secondary batteries and reducing the production costs of secondary batteries.

[0015] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required in the description of the embodiments or the prior art. The drawings described below are some embodiments of the present invention, and it is obvious to those skilled in the art that other drawings can be obtained based on these drawings without any creative efforts. [Brief explanation of the drawings]

[0016] [Figure 1] 1 illustrates an electricity-using device according to an embodiment of the present invention. [Figure 2] 1 illustrates an electrode member according to an embodiment of the present invention. [Figure 3] 1 illustrates a bottom view of a top cover and structure thereon according to an embodiment of the present invention. [Figure 4] 1 illustrates a front view of a top cover and structure thereon according to an embodiment of the present invention. [Figure 5] 1 shows a partial structure of a secondary battery according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] In order to better understand the spirit of the embodiments of the present invention, the following will further describe them in combination with some preferred embodiments of the present invention.

[0018] The embodiments of the present invention are described in detail below. Throughout the specification of the present invention, identical or similar components and components having identical or similar functions are represented by similar drawing symbols. The embodiments related to the drawings described herein are of explanatory and illustrative nature and are intended to provide a basic understanding of the present invention. The embodiments of the present invention should not be construed as limiting the present invention.

[0019] As used herein, the terms "approximately," "generally," "substantially," and "about" are used to describe and account for small variations. When used in conjunction with an event or circumstance, the term can refer to instances in which the event or circumstance occurs exactly, as well as instances in which the event or circumstance occurs very approximately.

[0020] In this specification, unless otherwise specified or limited, relative terms such as "center," "longitudinal," "lateral," "front," "rear," "right," "left," "inner," "outer," "lower," "higher," "horizontal," "vertical," "upper," "lower," "upper," "lower," "top," "bottom," and derivatives thereof (e.g., "horizontally," "downward," "upward," etc.) should be construed as referring to the orientations described in the discussion or shown in the drawings. These relative terms are used for convenience of description only and do not require the invention to be constructed or operated in a particular orientation.

[0021] For convenience of description, terms such as "first," "second," "third," etc. may be used in the text to distinguish between different elements of a figure or series of figures. "First," "second," "third," etc. are not intended to describe corresponding elements.

[0022] As described in the background art, when connecting electrode tabs and electrode terminals via connector plates, the connector plates occupy a certain amount of space and weight within the battery, resulting in a low energy density of the battery. Meanwhile, when connecting electrode tabs to the inner surfaces of electrode terminals directly by laser welding, cracks are likely to occur in the welded areas of the electrode tabs, affecting the performance and consistency of the battery. Furthermore, in conventional production, the process of connecting electrode tabs and electrode terminals using ultrasonic welding or laser welding is likely to generate metal fragments, which, if remaining inside the electrode members, pose a serious safety risk to the electrode members.

[0023] The present invention provides an electronic device 1000. In the following embodiments, for convenience of explanation, the electronic device 1000 is described as a vehicle. Referring to FIG. 1 , a battery pack 1002 is installed inside the vehicle, and the battery pack 1002 can be installed at the bottom, front, or rear of a vehicle body 1001. The battery pack 1002 can be used to supply power to the vehicle. For example, the battery pack 1002 functions as an operating power source for the vehicle. The operating unit of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain power support. The vehicle may be a gasoline-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be, but is not limited to, a pure electric vehicle, a hybrid vehicle, or a range-extended vehicle. The operating unit is the vehicle body, and the battery pack 1002 is installed at the bottom of the vehicle body to provide power support for running the vehicle or operating electrical components inside the vehicle. However, in some other embodiments, the electronic device 1000 may be a mobile phone, a portable device, a laptop, a boat, a spacecraft, an electric toy, an electric tool, or the like. Spacecraft include airplanes, rockets, spaceships, and airships. The operating unit may be a unit component that receives power from the battery pack 1002 and performs a corresponding operation, such as a blade rotation unit of a fan or a suction unit of a vacuum cleaner. Electric toys include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy boats, and electric toy airplanes. Electric tools include metal cutting tools, polishing tools, assembly tools, and railway tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The embodiment of the present invention does not impose any particular limitations on the electronic device 1000.

[0024] 2 shows an electrode member 120 according to an embodiment of the present invention, FIG. 3 shows a bottom view of a top cover 172 according to an embodiment of the present invention and the structure thereon (i.e., showing the inside of the cover plate 172 facing the electrode member 120), FIG. 4 shows a front view of the top cover 172 according to an embodiment of the present invention and the structure thereon, FIG. 5 shows a partial structure of a secondary battery 100 according to an embodiment of the present invention, FIG. 5 shows the top cover 172 and the two electrode members 120 unfolded to rivet the electrode tabs 122 and the electrode terminals 50, and further shows a bottom view of the top cover 172, and after the riveting is completed, the electrode tabs 122 are bent at the position where they are connected to the battery core body 124, and the two electrode members 120 are bundled together and then placed in a battery housing.

[0025] The secondary battery 100 includes a battery housing, electrode members 120, and electrode terminals 50. The battery housing includes a top cover 172, end walls, and side walls surrounding the end walls. The connection between the end walls and the side walls can be achieved in various ways, such as integral press molding, integral casting, or split welding, as long as a stable seal and electrical connection can be formed. The side walls can be enclosed in any manner, including a cylindrical or prismatic shape, or any other closed loop shape that fits the end walls. A receiving chamber is formed within the battery housing to accommodate the electrode members 120, electrolyte, and other necessary battery components. The diameter of the battery housing can be determined based on the specific dimensions of the electrode members 120. Battery housings can be made of a variety of materials, including copper, iron, aluminum, steel, and aluminum alloys. To prevent the battery housing from rusting during long-term use, a rust-preventing material such as metallic nickel can be applied to the surface of the battery housing.

[0026] The electrode member 120 is housed in the battery casing and is a component where an electrochemical reaction occurs in the secondary battery 100. One or more electrode members 120 may be contained within the battery casing. The electrode member 120 is a wound or stacked electrode member and includes a stacked and / or wound positive electrode plate, a first separator, a negative electrode plate, and a second separator. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer coated on the positive electrode current collector. The positive electrode current collector is formed with a first coated region where the positive electrode active material layer is coated and a first uncoated region where the positive electrode active material layer is not coated. The first coated region and the first uncoated region are arranged along the height direction of the electrode member 120, and the first uncoated region extends outside the separator at one end in the height direction of the secondary battery 100 to form a bent positive electrode tab 125. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer coated on the negative electrode current collector. The negative electrode current collector has a second coated region coated with the negative electrode active material layer and a second uncoated region uncoated with the negative electrode active material layer. The second coated region and the second uncoated region are arranged along the height direction of the electrode member 120. The second uncoated region also extends to the outside of the separator at one end of the height direction of the secondary battery 100 to form a bent negative electrode tab 126. The first and second separators are disposed between the positive and negative electrode plates to separate the positive and negative electrode active material layers. Taking the lithium-ion secondary battery 100 as an example, the positive electrode current collector may be made of aluminum, and the positive electrode active material layer includes a positive electrode active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, or the like. The negative electrode current collector may be made of copper, and the negative electrode active material layer may include a negative electrode active material, which may be carbon or silicon. The substrate material of the first separator and the second separator may be made of PP (polypropylene) or PE (polyethylene). To protect and insulate the battery cell, the outside of the battery cell may be coated with an insulating film, which may be made of PP, PE, PET, PVC, or other high molecular weight polymer materials.

[0027] Furthermore, the positive electrode tab 125 and the negative electrode tab 126 in the present invention face each other and are electrically connected to the positive terminal 55 and the negative terminal 56 on the top cover 172, respectively. The top cover 172 is hermetically attached to the side wall of the battery housing. The outer edge shape of the top cover 172 corresponds to the shape of the opening in the side wall, and the attachment method of the top cover 172 includes, but is not limited to, mechanical sealing or welding sealing.

[0028] 2 to 5 , an embodiment of the present invention provides a secondary battery 100. The secondary battery 100 includes a battery housing and an electrode member 120 housed within the battery housing. The battery housing includes a top cover 172 and an electrode terminal 50 mounted on the top cover 172. The electrode member 120 includes a battery core body 124 and an electrode tab 122 protruding from the battery core body 124, with a rivet hole 1220 formed in the electrode tab 122. A rivet 10 connects to the electrode terminal 50 and passes through the rivet hole 1220 to rivet the electrode terminal 50 to the electrode tab 122. In an embodiment of the present invention, the electrode tab 122 is riveted to the electrode terminal 50 using the rivet 10, eliminating the need for a connector plate. This effectively reduces the weight of the secondary battery 100 and improves the energy density of the battery. Furthermore, this method avoids the safety risk to the electrode member 120 caused by solder residue when welding the electrode tab to the electrode terminal using conventional ultrasonic welding or laser welding, thereby improving the safety performance of the secondary battery 100. Furthermore, in the embodiment of the present invention, the use of a riveting method effectively improves the situation in which cracks occur in the electrode tab when welding the electrode tab to the electrode terminal in the conventional technology, thereby improving the yield rate of the secondary battery 100 and reducing the production cost of the secondary battery 100.

[0029] 3 to 5, the rivet 10 is set on the side of the electrode terminal 50 facing the electrode member 120 and passes through a rivet hole 1220 on the electrode tab 122 of the electrode member 120 to rivet the electrode tab 122. The electrode terminal 50 and the rivet 10 may be an integral part, and the rivet may be connected to the electrode terminal 50 by another process (e.g., welding). At this stage, there is no need to worry about solder residue because the rivet is not yet connected to the electrode member 120 and solder residue will not remain in the battery housing and affect the electrode member 120. The electrode terminal 50 includes a positive terminal 55 and a negative terminal 56, and the electrode tab 122 includes a positive electrode tab 125 and a negative electrode tab 126. The positive terminal 55 is riveted to the positive electrode tab 125 through a rivet 10, and the negative terminal 56 is riveted to the negative electrode tab 126 through another rivet 10. One or more (for example, two are shown in FIG. 5 , but this is not limited to) electrode members 120 can be housed within the battery housing, and the electrode terminals 50 are connected to a corresponding number of rivets 10 to connect to the electrode tabs 122 of one or more electrode members 120.

[0030] 3, when projected from the electrode member 120 toward the electrode terminal 50, the shape of the outer boundary of the rivet 10 is one or a combination of a circle, an oval, a square, a rectangle, a diamond, and a triangle, but the rivet 10 may have other shapes, and the shape of the rivet hole 1220 on the electrode tab 122 corresponds to the rivet 10. Referring to FIG. 5, the rivet 10 has a hollow structure, and after the rivet 10 passes through the rivet hole 1222, the edge is folded back outward to secure the electrode tab 122. The rivet 10 may also have a staple-type solid structure, and the rivet shaft that protrudes after passing through the rivet hole 1220 is thickened using axial force to form a rivet head to secure the electrode tab 122.

[0031] In other embodiments, the peripheral areas of the rivet 10 can be welded (eg, laser welded or resistance welded) to the electrode terminal 50 and electrode tab 122 to improve the riveting strength.

[0032] After the positive electrode plate, negative electrode plate, and separator are wound (or stacked) and thermocompression-bonded, the electrode member 120 is formed. The thermocompression-bonded (or thermocompression-matched) electrode member 120 first undergoes ultrasonic pre-welding to form electrode tabs 122. After the electrode tabs 122 are formed, rivet holes 1220 that match the rivets 10 are drilled in the electrode tabs 122. After the rivet holes 1220 in the electrode tabs 122 are drilled, the rivets 10 connected to the electrode terminals 50 of the top cover 172 are inserted into the rivet holes 1220 in the electrode tabs 122, and then a corresponding riveting operation is performed to connect the electrode member 120 and the top cover 172 by riveting. The lower plastic 180 is located inside the top cover 172 and is made of an insulating material to provide insulation for the electrode member 120. The explosion-proof valve 182 is provided on the top cover 172 and is used to exhaust the secondary battery 100. When exhausting, the gas can break the explosion-proof valve 182, preventing the secondary battery 100 from exploding, thereby improving the safety performance of the secondary battery 100. The liquid filling hole 186 is located on the top cover 172, and after the structure shown in FIG. 5 is integrated and placed inside the battery housing, electrolyte is poured into the secondary battery 100 through the liquid filling hole 186.

[0033] An embodiment of the present invention also provides a battery pack 1002 including any of the secondary batteries 100 described above, and the battery pack 1002 can have the beneficial effects described for the secondary battery 100 described above.

[0034] The embodiment of the present invention also provides an electronic device 1000 including the battery pack 1002 , which can have the beneficial effects described for the secondary battery 100 and the battery pack 1002 .

[0035] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Those skilled in the art will appreciate that the present invention can be modified or changed in various ways. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention. [Industrial Applicability]

[0036] The secondary battery, battery pack and electronic device of the present invention can be applied to the field of battery technology. [Explanation of symbols]

[0037] 10: Rivet 50: Electrode terminal 55: Positive terminal 56: Negative terminal 100: Secondary battery 120: Electrode member 122: Electrode tab 124: Battery core body 125: Positive electrode tab 126: Negative electrode tab 172: Top cover 180: Lower plastic 182: Explosion-proof valve 186: Liquid injection hole 1000:Electronic equipment 1001: Body 1002: Battery pack 1220: Rivet hole

Claims

1. a top cover and an electrode terminal installed on the top cover; an electrode member including a battery core body and an electrode tab protruding from the battery core body, with a rivet hole provided on the electrode tab; a rivet connected to the electrode terminal and passing through the rivet hole to rivet the electrode terminal and the electrode tab together.

2. The secondary battery according to claim 1 , wherein the rivet is provided on a side of the electrode terminal facing the electrode member.

3. The secondary battery according to claim 1 , wherein the electrode terminal and the rivet are an integral part.

4. 2. The secondary battery according to claim 1, wherein the electrode terminals include a positive terminal and a negative terminal, the electrode tabs include a positive electrode tab and a negative electrode tab, the positive terminal being riveted to the positive electrode tab through the rivet, and the negative terminal being riveted to the negative electrode tab through another rivet.

5. The secondary battery according to claim 1 , wherein the secondary battery includes one or more of the electrode members, and the electrode terminals are connected to a corresponding number of the rivets to connect the electrode tabs of the one or more electrode members.

6. 2. The secondary battery according to claim 1, wherein the rivet has a solid structure or a hollow structure, and when projected in a direction from the electrode member to the electrode terminal, the shape of the outer boundary of the rivet is one or a combination of a circle, an ellipse, a square, a rectangle, a diamond, and a triangle.

7. The peripheral area of ​​the rivet is integrally welded to the electrode terminal and the electrode tab. The secondary battery according to claim 1 .

8. 2. The secondary battery according to claim 1, wherein the electrode member is a wound or laminated electrode member.

9. A battery pack comprising the secondary battery according to any one of claims 1 to 8.

10. An electronic device comprising the battery pack according to claim 9.

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