Battery composite aluminum foil structure

Abstract

The utility model belongs to the technical field of button cells, and discloses a battery composite aluminum foil structure which comprises a composite aluminum foil and a positive electrode material coating, a plurality of groups of convex columns are arranged on one side of the composite aluminum foil, galling is arranged on one side of the composite aluminum foil away from the convex columns, and the positive electrode material coating is coated on one side of the composite aluminum foil with the plurality of groups of convex columns. The battery composite aluminum foil structure can be applied to a button cell and comprises a positive pole shell and a negative pole shell, and a composite aluminum foil, a positive pole material coating, a diaphragm, a negative pole piece, a gasket and an elastic piece are arranged in a cavity between the positive pole shell and the negative pole shell. The composite aluminum foil is compact and reasonable in structural design, the composite aluminum foil can be better combined with a positive electrode material coating, the coating can be prevented from being wetted and falling off by electrolyte, a gasket arranged below can be omitted, a process is omitted, the button cell is simpler to manufacture, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of button batteries, in particular to a battery composite aluminum foil structure. Background Art

[0002] In the field of button-type battery technology, the positive and negative electrodes are the most critical materials. The preparation process for both electrodes is identical, differing in that the positive electrode is coated on aluminum foil, while the negative electrode is coated on copper foil. Firstly, both copper and aluminum foils have relatively good conductivity, are relatively soft, and are relatively inexpensive. However, aluminum is inherently reactive. At low potentials, it will intercalate lithium with aluminum, forming a lithium-aluminum alloy, making it unsuitable for use as the negative electrode current collector. If aluminum foil is used as the negative electrode current collector, the aluminum will alloy with lithium and then pulverize, severely impacting the battery's lifespan and performance. Finally, copper easily oxidizes at high potentials, making it unsuitable for use as the positive electrode current collector. The oxide layer on the copper surface is a semiconductor, conducting electrons. A thicker oxide layer increases impedance. Furthermore, lithium will not form an intercalation alloy with other materials at the same potential. As a result, the vast majority of button-type batteries use aluminum foil as the positive electrode material.

[0003] In the assembly and production of button batteries, it is generally started from the positive electrode shell. The positive electrode shell is larger and easier to assemble from bottom to top. When assembling button batteries: 1. Place the gasket in the center of the positive electrode shell, 2. Place the positive electrode sheet on the gasket, 3. Apply electrolyte on the gasket. 4. Place the diaphragm on the electrolyte, 5. Apply electrolyte on the diaphragm, 6. Continue to place the negative electrode sheet on top, 7. Place the gasket on the negative electrode sheet, 8. Place the spring on the gasket, 9. Cover the negative electrode shell and flatten it. Except for the two additions of electrolyte and the final covering and flattening of the negative electrode shell, the remaining processes must ensure that the placed components are located in the center. If offset occurs, the button battery will short-circuit, have a low open circuit voltage, and other conditions. Such batteries are unqualified. The positive electrode sheet is prone to powdering during installation and after installation when the electrolyte is coated. That is, the positive electrode material coating on the positive electrode sheet falls off from the aluminum foil. Powdering will affect the quality of the button battery. Severe powdering will cause the button battery to have low voltage and unqualified quality. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the present invention provides a battery composite aluminum foil structure to solve the problems raised in the above background technology, such as the positive electrode material falling off from the positive electrode sheet and the complicated button battery production process.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a battery composite aluminum foil structure, including a composite aluminum foil and a positive electrode material coating, wherein one side of the composite aluminum foil is provided with multiple groups of protrusions, and the side of the composite aluminum foil facing away from the protrusions is provided with roughening, and the positive electrode material coating is coated on the side of the composite aluminum foil with multiple groups of protrusions.

[0006] Preferably, the composite aluminum foil comprises a coated aluminum layer and a plastic film, and the coated aluminum layer is evaporated on both the upper and lower surfaces of the plastic film.

[0007] Preferably, the battery composite aluminum foil structure can be applied to button batteries, including a positive electrode shell, a negative electrode shell, and an internal structure. The negative electrode shell is installed on the positive electrode shell, and the internal structure is provided in the cavity between the positive electrode shell and the negative electrode shell.

[0008] Preferably, a restriction ring is welded on the positive electrode shell, a convex ring is welded on the negative electrode shell at a position corresponding to the restriction ring, an insulating rubber ring is installed between the restriction ring and the convex ring, and the negative electrode shell is installed above the positive electrode shell using the insulating rubber ring.

[0009] Preferably, the internal structure includes a composite aluminum foil, a positive electrode material coating, a diaphragm, a negative electrode sheet, a gasket and a spring. The composite aluminum foil and the positive electrode material coating are installed at the bottom of the positive electrode shell. A diaphragm is arranged above the positive electrode material coating. The cavity between the positive electrode material coating and the diaphragm is a first electrolyte cavity, which is filled with electrolyte. A negative electrode sheet is arranged above the diaphragm. The cavity between the diaphragm and the negative electrode sheet is a second electrolyte cavity, which is filled with electrolyte. A gasket is installed on the negative electrode sheet, and a spring is installed on the gasket. The open end of the spring is against the gasket, and the other end of the spring is against the top of the positive electrode shell.

[0010] Compared with the prior art, the present invention provides a battery composite aluminum foil structure with the following beneficial effects:

[0011] 1. The battery composite aluminum foil structure is provided with multiple groups of protrusions and roughening, which can better combine the composite aluminum foil with the positive electrode material coating, prevent the coating from being infiltrated and falling off by the electrolyte, and can eliminate the gasket set at the bottom, eliminating a process, making the button battery manufacturing simpler and improving production efficiency.

[0012] 2. Multiple groups of convex columns are provided on one side of the composite aluminum foil, which can better combine with the positive electrode material coating and prevent the coating from being infiltrated and falling off by the electrolyte.

[0013] 3. The side of the composite aluminum foil connected to the positive electrode shell is provided with a rough surface. The rough surface can make the composite aluminum foil and the positive electrode shell in better contact, thereby improving the electrical connection effect. The gasket set under the positive electrode sheet can be omitted, eliminating a process, making the button battery manufacturing simpler and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structure of the utility model;

[0015] Figure 2 This is a schematic diagram of the composite aluminum foil of the utility model;

[0016] Figure 3This is a schematic diagram of the composite aluminum foil of the utility model;

[0017] Figure 4 This is a schematic cross-sectional view of the composite aluminum foil of the utility model;

[0018] Figure 5 This is a schematic diagram of a button battery used in the present utility model;

[0019] Figure 6 This is a cross-sectional schematic diagram of a button-type battery of the present invention.

[0020] In the figure: 1. Composite aluminum foil; 2. Positive electrode material coating; 3. Boss; 4. Roughening; 5. Coated aluminum layer; 6. Plastic film; 7. Positive electrode shell; 8. Negative electrode shell; 9. Restriction ring; 10. Boss ring; 11. Insulating rubber ring; 12. First electrolyte chamber; 13. Diaphragm; 14. Second electrolyte chamber; 15. Negative electrode sheet; 16. Gasket; 17. Spring clip. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] See also Figure 1-6 , the utility model provides a technical solution:

[0023] A battery composite aluminum foil structure comprises a composite aluminum foil 1 and a positive electrode material coating 2. One side of the composite aluminum foil 1 is provided with multiple groups of protrusions 3, and the side of the composite aluminum foil 1 facing away from the protrusions 3 is provided with roughening 4. The positive electrode material coating 2 is applied to the side of the composite aluminum foil 1 with the multiple groups of protrusions 3. The coating comprises positive electrode material, conductive agent, and binder in a recommended ratio of 80:10:10. The coating is dissolved in an appropriate amount of solvent and evenly coated on the composite aluminum foil 1 using a coating machine. The coating is then dried and pressed using a roller mill or tablet press to a thickness of 15-60 μm.

[0024] Furthermore, the composite aluminum foil 1 includes a coated aluminum layer 5 and a plastic film 6. The coated aluminum layer 5 is vapor-deposited on both the upper and lower surfaces of the plastic film 6. It is recommended to use vacuum suspension vapor deposition to vapor-deposit aluminum on both sides of the plastic film 6. The plastic film 6 is recommended to have a thickness of 4-8 μm, and the coating thickness is recommended to be 4-10 μm.

[0025] Furthermore, the battery composite aluminum foil structure can be applied to button-type batteries, comprising a positive electrode shell 7, a negative electrode shell 8, and an internal structure. The negative electrode shell 8 is mounted on the positive electrode shell 7, and the internal structure is provided in the cavity between the positive electrode shell 7 and the negative electrode shell 8. The composite aluminum foil structure can be applied to button-type batteries and is equivalent to the positive electrode sheet of the button-type battery.

[0026] Furthermore, a restraining ring 9 is welded to the positive electrode housing 7, and a protruding ring 10 is welded to the negative electrode housing 8 at a position corresponding to the restraining ring 9. An insulating rubber ring 11 is installed between the restraining ring 9 and the protruding ring 10. The negative electrode housing 8 is installed above the positive electrode housing 7 using the insulating rubber ring 11. The insulating rubber ring 11 is a flexible rubber ring that can prevent the positive electrode housing 7 and the negative electrode housing 8 from connecting to prevent short circuits, and its elasticity can fix the negative electrode housing 8 to the positive electrode housing 7.

[0027] Furthermore, the internal structure includes a composite aluminum foil 1, a positive electrode material coating 2, a diaphragm 13, a negative electrode sheet 15, a gasket 16 and a spring 17. The composite aluminum foil 1 and the positive electrode material coating 2 are installed at the bottom of the positive electrode shell 7. A diaphragm 13 is arranged above the positive electrode material coating 2. The cavity between the positive electrode material coating 2 and the diaphragm 13 is a first electrolyte cavity 12. The first electrolyte cavity 12 is filled with electrolyte. A negative electrode sheet 15 is arranged above the diaphragm 13. The cavity between the diaphragm 13 and the negative electrode sheet 15 is a second electrolyte cavity 14. The second electrolyte cavity 14 is filled with electrolyte. A gasket 16 is installed on the negative electrode sheet 15. A spring 17 is installed on the gasket 16. The open end of the spring 17 is against the gasket 16, and the other end of the spring 17 is against the top of the positive electrode shell 7. The diameter of the diaphragm 13 should be slightly larger than the composite aluminum foil 1, the positive electrode material coating 2 and the negative electrode sheet 15. The function of the diaphragm 13 is to prevent contact between the composite aluminum foil 1, the positive electrode material coating 2 and the negative electrode sheet 15. The diaphragm 13 is generally made of a polymer material such as polyethylene, which is non-conductive. There are many micropores in its structure that allow ions to pass through. The main function of the spring 17 is to support the battery and prevent the battery from being pressed very flat during the battery pressing step. The roughening 4 at the bottom of the composite aluminum foil 1 can make the composite aluminum foil 1 better contact with the positive electrode shell 7, so that the composite aluminum foil 1 and the positive electrode shell 7 are more tightly electrically connected, thereby eliminating the gasket between the positive electrode sheet and the positive electrode shell.

[0028] Working principle: When it is necessary to use this device to assemble and make button batteries, lay the positive electrode shell 7 with the opening facing upward, place the composite aluminum foil 1 and the positive electrode material coating 2 inside the positive electrode shell 7, with the positive electrode material coating 2 facing upward and the composite aluminum foil 1 facing downward, use a rubber-tipped dropper to soak the surface of the positive electrode material coating 2 with electrolyte, place the diaphragm 13 on top so that it covers the positive electrode material coating 2, use a rubber-tipped dropper again to soak the electrolyte to the surface above the diaphragm 13, place the negative electrode sheet 15 in the center of the diaphragm 13, place the gasket 16 on the negative electrode sheet 15, and then place the spring 17 on the gasket 16. Finally, use the negative electrode shell 8 to cover the opening of the positive electrode shell 7, perform the flattening operation, and the button battery is assembled.

[0029] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A battery composite aluminum foil structure, characterized by: The invention comprises a composite aluminum foil (1) and a positive electrode material coating (2), wherein one side of the composite aluminum foil (1) is provided with a plurality of groups of protrusions (3), and a side of the composite aluminum foil (1) facing away from the protrusions (3) is provided with roughening (4), and the positive electrode material coating (2) is coated on the side of the composite aluminum foil (1) with the plurality of groups of protrusions (3).

2. The battery composite aluminum foil structure according to claim 1, characterized in that: The composite aluminum foil (1) comprises a coated aluminum layer (5) and a plastic film (6), and the coated aluminum layer (5) is vapor-deposited on both the upper and lower surfaces of the plastic film (6).

3. The battery composite aluminum foil structure according to claim 2, characterized in that: The battery composite aluminum foil structure can be applied to button batteries, and comprises a positive electrode shell (7), a negative electrode shell (8), and an internal structure. The negative electrode shell (8) is mounted on the positive electrode shell (7), and the internal structure is provided in a cavity between the positive electrode shell (7) and the negative electrode shell (8).

4. The battery composite aluminum foil structure according to claim 3, characterized in that: A limiting ring (9) is welded on the positive electrode shell (7), a convex ring (10) is welded on the negative electrode shell (8) at a position corresponding to the limiting ring (9), an insulating rubber ring (11) is installed between the limiting ring (9) and the convex ring (10), and the negative electrode shell (8) is installed above the positive electrode shell (7) using the insulating rubber ring (11).

5. The battery composite aluminum foil structure according to claim 4, characterized in that: The internal structure comprises a composite aluminum foil (1), a positive electrode material coating (2), a diaphragm (13), a negative electrode sheet (15), a gasket (16) and a spring (17); the composite aluminum foil (1) and the positive electrode material coating (2) are mounted on the bottom of the positive electrode shell (7); a diaphragm (13) is arranged above the positive electrode material coating (2); a cavity between the positive electrode material coating (2) and the diaphragm (13) is a first electrolyte cavity (12); the first electrolyte cavity (12 ) is filled with electrolyte, a negative electrode sheet (15) is arranged above the diaphragm (13), and the middle cavity between the diaphragm (13) and the negative electrode sheet (15) is a second electrolyte chamber (14), and the second electrolyte chamber (14) is filled with electrolyte. A gasket (16) is installed on the negative electrode sheet (15), and a spring (17) is installed on the gasket (16), and the open end of the spring (17) is against the gasket (16), and the other end of the spring (17) is against the top of the positive electrode shell (7).

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