Battery structure and method for manufacturing the same

Abstract

To provide a button battery structure that can effectively increase energy density within a limited volume.SOLUTION: The battery structure includes a case 10, a cap assembly 20, and an electrode assembly. An accommodation chamber is provided in the case. The electrode assembly is placed in the accommodation chamber. The accommodation chamber is further filled with an electrolyte. The electrode assembly is provided with two electrodes. One of the electrodes is electrically connected to the cap assembly. The other of the electrodes is electrically connected to the case. The case is connected to a side wall in a combination with the cap assembly. This invention reduces a wall thickness in comparison with a multi-layered side wall of a conventional button battery, effectively increases volume of the accommodation chamber and increases an amount of electrolyte filling, so as to enable effectively increasing battery energy density.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and particularly to battery structures and their manufacturing methods.

Background Art

[0002] Rechargeable lithium-ion batteries such as button batteries in mobile phones and Bluetooth (registered trademark) earphones are widely used in handheld electronic devices. For example, in small and precise devices such as hearing aids, wireless Bluetooth earphones, electronic watches, and gastrointestinal endoscope equipment, the volumetric energy density of the battery is an important consideration factor.

[0003] Conventional button batteries generally use a double-cylindrical upper case and a lower case. The upper case and the lower case are overlapped and fitted, and then a sealing insulation layer is provided in the middle. The overall volume of the button battery is limited. The upper case, the lower case, and the sealing insulation layer have thicknesses, and the only way to ensure that the overall volume size does not change is to compress the volume of the battery cavity, and the battery energy density cannot be increased. Therefore, increasing the energy density within a limited volume is an urgent problem to be solved.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide a battery structure and its manufacturing method.

Means for Solving the Problems

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] In a first embodiment, an embodiment of the present invention provides a battery structure comprising a case, a cap assembly, and an electrode assembly, wherein a housing chamber is provided within the case, the electrode assembly is placed in the housing chamber, the housing chamber is further filled with an electrolyte, the electrode assembly is provided with two electrodes, one of the electrodes is electrically connected to the cap assembly, and the other of the electrodes is electrically connected to the case, and the case is connected to the side wall in combination with the cap assembly.

[0007] In one specific embodiment, the cap assembly includes a lid, a retaining plate, and an insulating layer, the insulating layer being located between the lid and the retaining plate, the lid having an opening, the retaining plate having a boss, the boss protruding from the opening, and the case being connected to the lid.

[0008] In one specific embodiment, the case is provided with an upper end surface, a connecting wall extends from the lid, the connecting wall is provided with a lower end surface, and the upper end surface is connected to the lower end surface.

[0009] In one specific embodiment, the upper end face and the lower end face are welded together to achieve a sealed connection.

[0010] In one specific embodiment, the thickness of the connecting wall is the same as the thickness of the case.

[0011] In one specific embodiment, the thickness of the case is 0.1 mm to 0.25 mm.

[0012] In one specific embodiment, the insulating layer is an insulating ring, and the width of the insulating ring is greater than the overlapping width of the retaining plate and the lid.

[0013] In one specific embodiment, the overlapping width between the retaining plate and the lid is 0.5 mm to 10 mm.

[0014] In one specific embodiment, the case is columnar, and its cross-section is elliptical, angular, or heart-shaped.

[0015] The battery structure of the present invention has the following advantages compared to the prior art: A housing chamber is provided in the case, an electrode assembly is placed in the housing chamber, the housing chamber is further filled with electrolyte, two electrodes are provided in the electrode assembly, one electrode is electrically connected to the cap assembly, and the other electrode is electrically connected to the case, and the case is connected to the side wall in combination with the cap assembly, thereby reducing the wall thickness compared to the multi-layered side wall of conventional button batteries, effectively increasing the volume of the housing chamber and increasing the amount of electrolyte that can be filled, and thereby effectively improving the battery energy density.

[0016] In a second embodiment, an embodiment of the present invention provides a method for manufacturing the above-described battery structure, comprising the steps of: placing an insulating layer between a lid and a retaining plate, assembling the lid and the retaining plate, heating and cooling to form a cap assembly; placing an electrode assembly in a case, electrically connecting the two electrodes of the electrode assembly to the cap assembly and the case, respectively; and injecting an electrolyte into the case, welding and sealing the cap assembly and the case to complete the manufacturing of the battery structure.

[0017] The manufacturing method of the battery structure of the present invention has the following advantages compared to the prior art: By placing an insulating layer between the lid and the retaining plate, assembling the lid and the retaining plate, heating and cooling to form the cap assembly, then electrically connecting the two electrodes of the electrode assembly to the cap assembly and the case respectively, finally injecting the electrolyte into the case, and welding and sealing the cap assembly and the case to complete the manufacturing of the battery structure, the wall thickness can be reduced compared to the multi-layered side walls of conventional button batteries, effectively increasing the volume of the housing chamber and the amount of electrolyte that can be filled, thereby effectively improving the battery energy density.

[0018] The present invention will be further described below in reference to the attached drawings and specific embodiments.

Brief Description of the Drawings

[0019] To more clearly explain the technical solution in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments or the prior art will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0020] [Figure 1] It is a schematic configuration diagram of the battery structure according to the embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view of the battery structure according to the embodiment of the present invention. [Figure 3] It is a schematic explosion diagram of the battery structure according to the embodiment of the present invention. [Figure 4] It is a flowchart of the manufacturing method of the battery structure according to the embodiment of the present invention.

Modes for Carrying Out the Invention

[0021] To make the object, technical solution and advantages of the present invention clearer, the present invention will be described in more detail below in connection with the accompanying drawings and specific embodiments.

[0022] Hereinafter, in connection with the drawings in the embodiments of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present invention.

[0023] In the description of the present invention, terms indicating orientation or positional relationship such as "center", "vertical direction", "horizontal direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "upper", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for facilitating the description of the present invention and simplifying the explanation, and do not indicate or suggest that the indicated device or element must have a specific orientation and be configured and operate in a specific orientation, and should not be understood as a limitation to the present invention.

[0024] Furthermore, the terms "first" and "second" are used only for the purpose of explanation, and should not be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, "plurality" means two or more unless specifically and clearly limited.

[0025] In the present invention, unless specifically and clearly defined and limited, terms such as "mounting", "connection", "coupling", "fixing", etc. should be understood in a broad sense. For example, it may be a connection, a detachable connection, or an integral one. It may be a mechanical connection or an electrical connection. It may be directly connected, indirectly connected through an intermediate medium, or an internal connection between two elements or an interaction relationship between two elements. A person skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific situation.

[0026] In the present invention, unless otherwise specifically defined and limited, the presence of a first feature "above" or "below" a second feature may include direct contact between the first and second features, or contact between them not through direct contact but through another feature between them. Furthermore, the presence of a first feature "above," "above," and "on the top surface" of a second feature simply indicates that the first feature is directly above and diagonally above the second feature, or that the horizontal height of the first feature is greater than that of the second feature. The presence of a first feature "below," "below," and "on the bottom surface" of a second feature simply indicates that the first feature is directly below and diagonally below the second feature, or that the horizontal height of the first feature is less than that of the second feature.

[0027] In this specification, any reference to terms such as “one embodiment,” “several embodiments,” “example,” “specific example,” or “several examples” means that the specific features, structures, materials, or characteristics described in relation to that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the general expressions of the above terms should not necessarily be understood to apply to the same embodiment or example. Furthermore, any specific features, structures, materials, or characteristics described may be combined in appropriate ways in any one or more embodiments or examples. Furthermore, those skilled in the art may combine or combine different embodiments or examples described herein.

[0028] As shown in Figures 1 to 3, the present invention discloses a battery structure comprising a case 10, a cap assembly 20, and an electrode assembly 30, wherein a housing chamber 11 is provided within the case 10, the electrode assembly 30 is placed in the housing chamber 11, the housing chamber 11 is further filled with an electrolyte (not shown), the electrode assembly 30 is provided with two electrodes, one of the electrodes is electrically connected to the cap assembly 20, the other of the electrodes is electrically connected to the case 10, and the case 10 is connected to the side wall in combination with the cap assembly 20.

[0029] In one embodiment, the electrodes include a positive electrode 31 and a negative electrode 32. The positive electrode 31 is electrically connected to the cap assembly 20 or the case 10. The negative electrode 32 is electrically connected to the case 10 or the cap assembly 20. It is preferable that the positive electrode 31 is electrically connected to the cap assembly 20 and the negative electrode 32 is electrically connected to the case 10.

[0030] Specifically, this battery structure has a housing chamber 11 inside the case 10, where the electrode assembly 30 is placed, and the housing chamber 11 is further filled with electrolyte. The electrode assembly 30 has two electrodes, one of which is electrically connected to the cap assembly 20, and the other of which is electrically connected to the case 10. The case 10 is then connected to the side wall in combination with the cap assembly 20, thereby achieving a seal. Compared to the multi-layered side walls of conventional button batteries, the wall thickness is reduced, the volume of the housing chamber 11 is effectively increased, and the amount of electrolyte that can be filled is increased, thereby effectively improving the battery energy density.

[0031] Specifically, the electrolyte uses conventional technology and will not be explained in detail here.

[0032] In one embodiment, the cap assembly 20 includes a lid 21, a retaining plate 22, and an insulating layer 23, the insulating layer 23 being located between the lid 21 and the retaining plate 22, the lid 21 having an opening 211, the retaining plate 22 having a boss 221, the boss 221 protruding from the opening 211, and the case 10 being connected to the lid 21.

[0033] Specifically, the insulating layer 23 is provided between the lid 21 and the retaining plate 22 to perform insulating and sealing functions. Both the lid 21 and the retaining plate 22 are made of metal. By heating the metal using high-frequency induction, the insulating layer 23 reaches a molten state and adheres tightly to the lid 21 and the retaining plate 22. After cooling, they become one unit, providing good sealing and insulating effects. In other embodiments, the same effect can be achieved by heating the cap assembly 20 at a constant temperature using a heating block or heating equipment, or by using a combination of the two heating methods described above.

[0034] Preferably, both the lid 21 and the retaining plate 22 are made of stainless steel, which has high strength and excellent corrosion resistance.

[0035] Furthermore, in practical terms, if high temperatures occur inside the battery structure, the insulating layer 23 melts, creating a gap between the lid 21 and the retaining plate 22. This allows gas from inside the battery structure to escape through the gap, reducing the likelihood of explosion and providing an explosion-proof effect.

[0036] In one embodiment, the case 10 is provided with an upper end surface 12, a connecting wall 212 extends from the lid 21, the connecting wall 212 is provided with a lower end surface (not shown), and the upper end surface 12 is connected to the lower end surface.

[0037] Specifically, a connecting wall 212 with a lower end surface extends from the lid 21, and its upper end surface 12 is connected to the lower end surface. The connecting wall 212 and the case 10 are butted together to form a good weld line, and the upper end surface 12 and the lower end surface are sealed by welding. This battery structure can be laser-welded from the side, effectively increasing the yield rate. Preferably, docking welding is used to increase the volume of the battery housing chamber 11. The welding is performed using a laser method, and the welding parameters are as follows: welding current: 15-50A, pulse width: 0.5-5ms, frequency / duty cycle: 40 / 50%, start speed: 10-25mm / s, processing speed: 5-200mm / s, acceleration: 5-20mm / s 2The spot diameter is 0.1 to 0.5 mm.

[0038] In one embodiment, the thickness of the connecting wall 212 is the same as the thickness of the case 10, and the contact surfaces of the two are aligned, thereby improving the welding effect between the lid 21 and the case 10 and improving the sealing effect.

[0039] In one embodiment, the specific thickness value of case 10 can be set as needed and is not particularly limited thereto. Preferably, the thickness of case 10 is 0.1 mm to 0.25 mm.

[0040] In one embodiment, the insulating layer 23 is an insulating ring, and the width of the insulating ring is greater than the overlapping width of the retaining plate 22 and the lid 21.

[0041] Specifically, the insulating ring is annular in shape to match the cover 21 and the retaining plate 22 in order to provide good insulation, and the width of the insulating ring is designed to be greater than the overlapping width of the retaining plate 22 and the cover 21. In addition, the insulating ring cannot cover the area of ​​the boss 221.

[0042] Preferably, the insulating layer 23 is made of a three-layer polypropylene material with good insulating and sealing properties.

[0043] In one embodiment, the overlap width between the retaining plate 22 and the lid 21 is 0.5 mm to 10 mm. The overlap width is the width of the battery's sealing wire.

[0044] Specifically, the exact thickness value of the overlapping width between the retaining plate 22 and the lid 21 can be set as needed and is not specifically limited here. Preferably, the overlapping width is 0.5 mm to 10 mm.

[0045] In one embodiment, case 10 is columnar in shape, and its cross-section is elliptical, angular, or heart-shaped, etc., for application to different scenes.

[0046] In one embodiment, the electrode includes a positive electrode 31 made of aluminum foil and a negative electrode 32 made of copper foil.

[0047] Specifically, the positive electrode 31 and the negative electrode 32 are separated by a battery separator, and the electrode assembly 30 is manufactured by spiral winding or lamination. The electrode assembly 30 then realizes an energy storage function. The battery separator refers to a film made of plastic such as polypropylene.

[0048] Specifically, the active material is uniformly coated on both sides of an aluminum foil with a thickness of 0.06 to 0.016 mm to form the positive electrode 31. The active material is uniformly coated on both sides of a copper foil with a thickness of 0.06 to 0.012 mm to form the negative electrode 32. Examples of the active material include lithium cobalt oxide, lithium titanate, or graphite. Lithium cobalt oxide and lithium titanate are used for the positive electrode 31, and graphite is used for the negative electrode 32.

[0049] Preferably, the positive electrode 31 is electrically connected to a boss 221 for outputting power externally, and the negative electrode 32 is electrically connected to the bottom of the case 10, thereby forming an electrical cycle.

[0050] Referring to Figure 4, the present invention also discloses a method for manufacturing the above-described battery structure, which includes the following steps.

[0051] In step S1, an insulating layer is placed between the lid and the retaining plate, the lid and the retaining plate are assembled, heated, and cooled to form the cap assembly.

[0052] In one embodiment, a lid, retaining plate, and case are pressed in advance as spares using a mold, a sealing insulating rubber is produced as a spare sheet insulating layer using a mold of the corresponding shape, and an electrode assembly of the corresponding shape and size is produced as a spare as needed.

[0053] Specifically, the fabricated insulating layer is placed between the lid and the retaining plate, and after assembling the lid and retaining plate, the cap assembly is formed by combining them using jigs and other means. The specific process parameters are shown in Table 1.

[0054] [Table 1]

[0055] In S2, the electrode assembly is placed in the case, and the two electrodes of the electrode assembly are electrically connected to the cap assembly and the case, respectively.

[0056] Specifically, the electrode assembly is placed in a case, the positive electrode is electrically connected to the boss, and the negative electrode is electrically connected to the case.

[0057] Here, electrical connections are made using either resistance welding or laser welding. Specifically, the parameters for resistance welding are shown in Table 2.

[0058] [Table 2]

[0059] Specifically, after step S2, the process further includes baking and dehumidifying electrically connected semi-finished products in a high vacuum environment. Specific parameters are shown in Table 3.

[0060] [Table 3]

[0061] In step S3, the electrolyte is injected into the case, and the cap assembly and case are welded together to complete the manufacturing of the battery structure.

[0062] Specifically, the electrolyte is injected into the case, and after injection, the contact surface between the lid and the case is welded using a laser in an environment with a relative humidity of less than 1% to complete the battery package. The parameters for laser welding are shown in Table 4.

[0063] [Table 4]

[0064] Specifically, after S4, the process further includes activating, chemically converting, and volume-dividing the welded battery to complete the battery fabrication. Here, activation means allowing the electrolyte to stand after injection to allow it to fully permeate the electrical core; chemical conversion means pre-charging the battery to activate it; and volume-dividing means testing the battery capacity.

[0065] Here, a comparison of the effectiveness of a battery manufactured using the present invention and a conventional button battery is shown, for example, in Table 5.

[0066] [Table 5]

[0067] The present invention provides a method for manufacturing a battery structure by placing an insulating layer between a lid and a retaining plate, assembling the lid and retaining plate, heating and cooling to form a cap assembly, then electrically connecting the two electrodes of the electrode assembly to the cap assembly and case respectively, finally injecting electrolyte into the case, and welding and sealing the cap assembly and case to complete the manufacturing of the battery structure. This method reduces the wall thickness compared to the multi-layered side walls of conventional button batteries, effectively increases the volume of the housing chamber, increases the amount of electrolyte that can be filled, and thereby effectively improves the battery energy density.

[0068] The battery structure of the present invention has the characteristics of being simple in structure, having low manufacturing costs, and having excellent sealing performance, while at the same time being able to increase the volume of the battery housing and being able to have a variety of shapes.

[0069] The embodiments described above are preferred embodiments of the present invention, and in addition, the present invention can be realized in other ways. Any obvious substitutions are protected within the scope of the present invention without departing from the concept of the present invention.

[0070] (Note) (Note 1) The apparatus includes a case, a cap assembly, and an electrode assembly, wherein a housing chamber is provided within the case, the electrode assembly is placed in the housing chamber, the housing chamber is further filled with an electrolyte, the electrode assembly is provided with two electrodes, one of the electrodes is electrically connected to the cap assembly, the other of the electrodes is electrically connected to the case, and the case is connected to the side wall in combination with the cap assembly. A battery structure characterized by the following features.

[0071] (Note 2) The cap assembly includes a lid, a retaining plate, and an insulating layer, the insulating layer being located between the lid and the retaining plate, the lid having an opening, the retaining plate having a boss, the boss protruding from the opening, and the case being connected to the lid. The battery structure described in Appendix 1, characterized by the features described herein.

[0072] (Note 3) The case is provided with an upper end surface, a connecting wall extends from the lid, the connecting wall is provided with a lower end surface, and the upper end surface is connected to the lower end surface. The battery structure described in Appendix 2, characterized by the features described herein.

[0073] (Note 4) The upper end surface and the lower end surface are welded together to achieve a sealed connection. The battery structure described in Appendix 3, characterized by the features described herein.

[0074] (Note 5) The thickness of the connecting wall is the same as the thickness of the case. The battery structure described in Appendix 3, characterized by the features described herein.

[0075] (Note 6) The thickness of the aforementioned case is 0.1 mm to 0.25 mm. The battery structure described in Appendix 5, characterized by the features described herein.

[0076] (Note 7) The insulating layer is an insulating ring, and the width of the insulating ring is greater than the overlapping width of the retaining plate and the lid. The battery structure described in Appendix 2, characterized by the features described herein.

[0077] (Note 8) The overlapping width between the retaining plate and the lid is 0.5 mm to 10 mm. The battery structure described in Appendix 7, characterized by the features described herein.

[0078] (Note 9) The aforementioned case is columnar, and its cross-section is elliptical, angular, or heart-shaped. The battery structure described in Appendix 2, characterized by the features described herein.

[0079] (Note 10) A method for manufacturing a battery structure as described in any one of the appendices 2 to 9, The steps include: placing an insulating layer between the lid and the retaining plate, assembling the lid and the retaining plate, heating and cooling to form the cap assembly; The steps include placing the electrode assembly into the case and electrically connecting the two electrodes of the electrode assembly to the cap assembly and the case, respectively. The process includes the steps of injecting electrolyte into the case and welding the cap assembly and case together to complete the manufacturing of the battery structure. A method for manufacturing a battery structure characterized by the following:

Claims

1. A battery structure including a case, a cap assembly, and an electrode assembly, A housing chamber is provided within the case, the electrode assembly is placed in the housing chamber, the housing chamber is further filled with electrolyte, two electrodes are provided in the electrode assembly, one of the electrodes is electrically connected to the cap assembly, and the other of the electrodes is electrically connected to the case. The cap assembly includes a lid, a retaining plate, and an insulating layer, wherein the lid, the insulating layer, and the retaining plate are stacked from top to bottom so that the retaining plate is pressed by the lid and the insulating layer, an opening is provided in the lid, a boss is provided in the retaining plate, the boss protrudes from the opening, the upper surface of the boss is flush with the upper surface of the lid, and the case is connected to the lid. The thickness of the case is 0.1 mm to 0.25 mm, and the overlapping width between the retaining plate and the lid is 0.5 mm to 10 mm. The lid and the retaining plate are both made of metal, and the insulating layer is made of a three-layer polypropylene material. The case is provided with an upper end surface, a connecting wall extends from the lid, the thickness of the connecting wall is the same as the thickness of the case, the connecting wall is provided with a lower end surface, and the upper end surface is connected to the lower end surface. The insulating layer is an insulating ring, the width of the insulating ring is greater than the overlapping width of the retaining plate and the cover, and the insulating ring does not cover the area of ​​the boss. A battery structure characterized in that when high temperature is generated inside the battery structure, the insulating ring melts, and a gap is created between the lid and the retaining plate.

2. The upper end surface and the lower end surface are welded together to achieve a sealed connection. The battery structure according to feature 1.

3. The aforementioned case is columnar, and its cross-section is elliptical, angular, or heart-shaped. The battery structure according to feature 1.

4. A method for manufacturing a battery structure according to any one of claims 1 to 3, The steps include: placing an insulating layer between the lid and the retaining plate, assembling the lid and the retaining plate, heating and cooling to form the cap assembly; The steps include placing the electrode assembly into the case and electrically connecting the two electrodes of the electrode assembly to the cap assembly and the case, respectively. The process includes the steps of injecting electrolyte into the case and welding the cap assembly and case together to complete the manufacturing of the battery structure. A method for manufacturing a battery structure characterized by the following:

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