Electrochemical device and electronic apparatus

Abstract

The invention discloses an electrochemical device and electronic equipment. The electrochemical device comprises a shell, an electrode assembly, a tab and tab glue. Wherein the shell comprises a top wall, a first through hole is formed in the top wall, and the top wall comprises a sealing area surrounding the first through hole. The electrode assembly is contained in the shell and comprises a first end face facing the top wall. The tab comprises a connecting part connected with the electrode assembly and a bent part bent towards the first end face. A connecting area is arranged on the surface of the side, facing the top wall, of the bent part. And the tab glue is arranged between the connecting area and the sealing area and is used for connecting the connecting area and the sealing area. The structure of the electrochemical device is beneficial to improving the energy density of the electrochemical device.

Description

Electrochemical devices and electronic devices Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an electrochemical device and an electronic device. Background Art

[0002] As electronic devices develop towards miniaturization and lightweight, people expect that the electrochemical devices used in these electronic devices can maintain high energy density while being miniaturized and lightweight to meet the needs of long battery life of electronic devices.

[0003] Summary of the Invention

[0004] The present application provides an electrochemical device and an electronic device using the electrochemical device, which can reduce the overall volume of the electrochemical device and thus improve the energy density of the electrochemical device.

[0005] In a first aspect, the present application provides an electrochemical device comprising a shell, an electrode assembly, a tab and tab glue. The shell comprises a top wall, the top wall is provided with a first through hole, and the top wall comprises a sealing area surrounding the first through hole. The electrode assembly is accommodated in the shell, and the electrode assembly comprises a first end face facing the top wall. The tab comprises a connecting portion connected to the electrode assembly and a bent portion bent toward the first end face. A connection area is provided on the side surface of the bent portion facing the top wall. The tab glue is provided between the connection area and the sealing area, and the tab glue is used to connect the connection area and the sealing area. In this way, by bending the tab and connecting it to the sealing area of ​​the top wall of the shell, there is no need to lead the tab out of the shell, which reduces the space occupied by the head of the electrochemical device and reduces the overall volume of the electrochemical device, thereby improving the energy density of the electrochemical device.

[0006] In some embodiments, the housing includes an encapsulation layer, and the encapsulation layer includes a first polymer. This facilitates a sealed connection between the tab and the top wall, thereby improving the safety of the electrochemical device.

[0007] In some embodiments, the housing further includes a barrier layer located on the surface of the encapsulation layer. The barrier layer comprises at least one of a metal, an inorganic oxide, or a nitride. This improves the housing's structural strength and ability to block moisture, thereby enhancing the safety of the electrochemical device.

[0008] In some embodiments, the first polymer includes at least one of polyethylene, ethylene propylene copolymer, polypropylene, anhydride-modified polypropylene, polyvinyl chloride, polystyrene, polyurethane, polyamide, polyester, amorphous α-olefin copolymer, or derivatives thereof.

[0009] In some embodiments, the shell further comprises a protective layer located on a surface of the barrier layer, wherein the protective layer comprises a second polymer.

[0010] In some aspects, the second polymer includes at least one of polyester, polyamide, polyacrylonitrile, polyvinyl chloride, polyurethane, or polyolefin.

[0011] In some aspects, the metal includes at least one of aluminum, copper, iron, titanium, or nickel.

[0012] In some embodiments, the inorganic oxide includes at least one of titanium dioxide, aluminum oxide, hafnium dioxide, silicon dioxide, iron oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, zinc oxide, tin oxide, zirconium titanium oxide, or vanadium oxide.

[0013] In some aspects, the nitride includes at least one of silicon nitride, silicon oxynitride, boron nitride, titanium nitride, or aluminum nitride.

[0014] In some embodiments, an insulating member is provided on the surface of the bent portion facing the first end face. This reduces the risk of the bent portion of the tab contacting the electrode sheet in the electrode assembly during impact, such as when the electrochemical device is dropped, leading to a short circuit and improving the safety of the electrochemical device.

[0015] In some solutions, the tab glue is provided with a second through hole, which is connected to the first through hole. In this way, the electrical connection of the tab can be easily led out through the second through hole and the first through hole.

[0016] In some embodiments, the electrode assembly further includes a second end surface opposite the first end surface, and a spacer is disposed between the first end surface and / or the second end surface and the housing. This reduces the risk of short-circuiting the electrode sheets at the first end surface and / or the second end surface of the electrode assembly during impacts such as drops, thereby improving the safety of the electrochemical device.

[0017] In some solutions, a first groove is formed on the spacer, and the bent portion is located in the first groove. In this way, the tab can be positioned to prevent shaking during use and reduce the risk of the tab becoming disconnected.

[0018] In some embodiments, the connection area is provided with a third through hole. Thus, the electrochemical device can be easily injected with liquid through the third through hole. In some embodiments, the third through hole is provided with a sealing member for sealing the electrochemical device after injection.

[0019] In some embodiments, a second groove is formed on a surface of the insulating member facing the electrode assembly. This allows the insulating member to store electrolyte, replenishing electrolyte consumed during the electrochemical device's cycling, and thereby extending the cycle life of the electrochemical device.

[0020] In some embodiments, the electrochemical device further includes a conductive member connected to the bent portion via the first through hole, thereby electrically leading the tab out and facilitating connection of the electrochemical device to an external circuit.

[0021] In a second aspect, the present application also provides an electronic device comprising the electrochemical device as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on the structures shown in these drawings.

[0023] FIG1 is a schematic structural diagram of an existing electrochemical device;

[0024] FIG2 is a cross-sectional view of an electrochemical device according to an embodiment of the present application along the length direction;

[0025] FIG3 is a cross-sectional view of the shell of the electrochemical device according to an embodiment of the present application;

[0026] FIG4 is a schematic diagram showing the connection between the electrode assembly and the tab of the electrochemical device according to an embodiment of the present application;

[0027] FIG5 is an exploded view of the electrode assembly and tabs of the electrochemical device according to an embodiment of the present application;

[0028] FIG6 is an exploded view of an electrode assembly and tabs of an electrochemical device according to an example of the present application;

[0029] FIG7 is an exploded view of an electrode assembly and a tab of an electrochemical device according to another example of the present application;

[0030] FIG8 is an exploded view of an electrode assembly and a tab of an electrochemical device according to another example of the present application.

[0031] Explanation of the accompanying drawings: 1. Shell; 11. Top wall; 12. First through hole; 13. Sealing area; 1a. Encapsulation layer; 1b. Barrier layer; 1c. Protective layer; 2. Electrode assembly; 2a. First end face; 2b. Second end face; 21. Positive pole piece; 22. Negative pole piece; 23. Isolation membrane; 3. Tab; 31. Connecting portion; 32. Bending portion; 33. Connecting area; 34. Third through hole; 4. Tab glue; 41. Second through hole; 5. Insulator; 51; Second groove; 6. Spacer; 61; First groove; A. Electrode assembly; B. Shell; C. Tab: D. Sealing area. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. When an element is referred to as being "disposed on" another element, it may be directly disposed on the other element or there may be an intermediate element.

[0034] In the description of this application, it should be understood that the terms "first," "second," etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] As shown in Figure 1, conventional electrochemical devices typically use a casing B (e.g., an aluminum-plastic film) to encapsulate the electrode assembly A. At the top seal, the inner layer of the aluminum-plastic film (e.g., a polypropylene layer) is thermally fused to the tab adhesive on the tab C. Because the tab C is stretched during heat sealing with the aluminum-plastic film, this packaging method creates a sealed area D of a certain width at the top seal. To ensure a good seal, the width of this sealed area D cannot be effectively reduced, resulting in ineffective volume in the electrochemical device and a loss in energy density.

[0036] In response to the technical problem of how to improve the energy density of electrochemical devices, the present application focuses on improving the packaging structure of electrochemical devices. An embodiment of the present application provides an electrochemical device. As shown in Figures 2 and 3, the electrochemical device of the embodiment of the present application includes a shell 1, an electrode assembly 2 and a tab 3. The shell 1 is used to accommodate the electrode assembly 2 and the tab 3. The shell 1 can be a rigid shell or a flexible shell. The shell 1 has multiple side walls, one of which is a top wall 11 forming the top of the electrochemical device. A first through hole 12 is opened on the top wall 11, and the top wall 11 is provided with a sealing area 13 surrounding the first through hole 12.

[0037] The electrode assembly 2 is composed of a positive electrode sheet 21, a negative electrode sheet 22, and a separator 23. Specifically, a plurality of positive electrode sheets 21 and a plurality of negative electrode sheets 22 are alternately stacked, and the separator 23 is arranged between adjacent positive electrode sheets 21 and negative electrode sheets 22 to form a laminated electrode assembly 2. Alternatively, the positive electrode sheets 21, the separator 23, and the negative electrode sheets 22 are sequentially stacked and wound to form a wound electrode assembly 2. When the electrode assembly 2 is housed in the housing 1, one end face of the electrode assembly 2 faces the top wall 11. For convenience of explanation, the end face of the electrode assembly 2 facing the top wall 11 is referred to as the first end face 2a, and the end face of the electrode assembly 2 facing away from the top wall 11 is referred to as the second end face 2b.

[0038] The tab 3 is connected to the electrode assembly 2. Specifically, the tab 3 is connected to the positive electrode sheet 21 and the negative electrode sheet 22 of the electrode assembly 2. The tab 3 and the positive electrode sheet 21 or the tab 3 and the negative electrode sheet 22 can be independent components or integrally formed components. As shown in Figures 4 and 5, the tab 3 of the embodiment of the present application includes a connecting portion 31 connected to the electrode assembly 2 and a bent portion 32 bent toward the first end face 2a. A connection area 33 is provided on the side surface of the bent portion 32 facing the top wall 11.

[0039] As shown in FIG. 3 to FIG. 5 , the tab glue 4 is disposed between the connection area 33 and the sealing area 13 and is used to connect the connection area 33 and the sealing area 13 .

[0040] In conjunction with Figures 1 and 2, by comparing the electrochemical device of the embodiment of the present application with the existing electrochemical device, it can be seen that the electrochemical device of the embodiment of the present application eliminates the sealing area D of the existing electrochemical device by bending the electrode ear 3 toward the first end face 2a and connecting it to the sealing area 13 of the top wall 11 of the shell 1, thereby reducing the space occupied by the head of the electrochemical device and reducing the overall volume of the electrochemical device, thereby being able to improve the energy density of the electrochemical device.

[0041] When preparing the electrochemical device of the present application, the tab glue 4 can be pre-set on the tab 3. In some embodiments, the tab glue 4 is provided with a second through hole 41, which is connected to the first through hole 12. Optionally, the tab glue 4 is an annular member, and the orthographic projection of the tab glue 4 on the inner surface of the top wall 11 surrounds the first through hole 12, thereby eliminating the need to provide the second through hole 41 after the tab glue 4 is connected to the sealing area 13, thereby improving manufacturing efficiency.

[0042] In the embodiment of the present application, at least a portion of the bent portion 32 is exposed outward through the first through hole 12 and the second through hole 41 . The exposed bent portion 32 can be connected to an electronic device, thereby providing power to the electronic device.

[0043] As shown in Figures 4 and 5 , in some embodiments, an insulating member 5 is provided on the side of the bent portion 32 facing the first end face 2a. This allows the bent portion 32 to be positioned as close to the first end face 2a of the electrode assembly 2 as possible while preventing contact between the bent portion 32 and the electrode plate on the first end face 2a and causing a short circuit. This further reduces the overall size of the electrochemical device and improves its energy density. Preferably, to replenish electrolyte consumed during cycling and improve the cycle life of the electrochemical device, as shown in Figure 2 , a second groove 51 is provided on the side of the insulating member 5 facing the electrode assembly 2. Multiple second grooves 51 may be provided. After electrolyte is injected into the electrochemical device, the electrolyte is stored in the second grooves 51, thereby replenishing electrolyte consumed during cycling and improving the cycle life of the electrochemical device. For example, the insulating member 5 may be an array of insulating pillars or insulating protrusions. The specific shape of the insulating pillars or insulating protrusions depends on actual needs and is not specifically limited here.

[0044] Furthermore, in some embodiments, the electrochemical device of the present invention further includes a conductive member (not shown). The conductive member is connected to the bent portion 32 via the first through-hole 12 to facilitate electrical connection between the electronic device and the electrochemical device of the present invention. For example, the conductive member of the present invention can be one of a contact terminal, a contact spring, a pole, and a contact wire, but is not limited thereto.

[0045] Optionally, as shown in FIG4 , in some embodiments, a third through hole 34 may be provided in the connection region 33. The third through hole 34 communicates with the second through hole 41 and the first through hole 12. In the embodiments of the present application, the third through hole 34 may serve as an electrolyte injection hole. After the electrolyte is injected into the housing 1 through the third through hole 34, the third through hole 34 should be sealed. Therefore, in some embodiments, the third through hole 34 is provided with a seal to prevent the electrolyte in the housing 1 from leaking to the outside.

[0046] To improve the drop safety of the electrochemical device, as shown in Figure 6, in some embodiments, an insulating spacer 6 is provided between the first end surface 2a of the electrode assembly 2 and the housing 1, thereby improving the top impact resistance of the electrochemical device. In some embodiments, the spacer 6 has a first groove 61 formed therein, and the bent portion 32 is located in the first groove 61. In this way, the spacer 6 can limit the bent portion 32 of the tab 3, preventing it from shaking and improving the safety of the electrochemical device.

[0047] As shown in FIG. 7 , in some embodiments, a spacer 6 is provided between the second end surface 2 b of the electrode assembly 2 and the housing 1 , thereby improving the bottom impact resistance of the electrochemical device.

[0048] As shown in Figure 8, in some other embodiments, spacers 6 are provided between the first end surface 2a of the electrode assembly 2 and the housing 1, and between the second end surface 2b and the housing 1. The spacer 6 between the first end surface 2a and the housing 1 defines a first groove 61, with the bent portion 32 located in the first groove 61. This improves the overall impact resistance of the electrochemical device.

[0049] To improve the toughness of the electrochemical device, in some embodiments, housing 1 is a flexible housing, specifically a flexible housing having a composite layer structure. As shown in Figure 3, housing 1 comprises an encapsulation layer 1a, a barrier layer 1b, and a protective layer 1c, stacked in sequence. Encapsulation layer 1a forms the inner surface of housing 1, while protective layer 1c forms the outer surface.

[0050] In some embodiments, the encapsulation layer 1a is made of a first polymer material. This facilitates a sealed connection between the tab 3 and the top wall 11, improving the safety of the electrochemical device. The first polymer material is at least one of polyethylene, ethylene-propylene copolymer, polypropylene, anhydride-modified polypropylene, polyvinyl chloride, polystyrene, polyurethane, polyamide, polyester, amorphous α-olefin copolymer, or derivatives thereof.

[0051] In some embodiments, the barrier layer 1b is made of at least one of a metal material, an inorganic oxide material, and a nitride material. The metal material includes at least one of aluminum, copper, iron, titanium, or nickel. The inorganic oxide material includes at least one of titanium dioxide, aluminum oxide, hafnium dioxide, silicon dioxide, iron oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, zinc oxide, tin oxide, titanium zirconium oxide, or vanadium oxide. The nitride material includes at least one of silicon nitride, silicon oxynitride, boron nitride, titanium nitride, or aluminum nitride.

[0052] In some embodiments, the protective layer 1c is made of a second polymer material, wherein the second polymer material includes at least one of polyester, polyamide, polyacrylonitrile, polyvinyl chloride, polyurethane, or polyolefin.

[0053] The present application also provides a method for preparing the electrochemical device of the present application, which may specifically include the following steps.

[0054] Step S1 : connecting the ring-shaped tab glue 4 to the connection area 33 of the tab 3 which is subsequently bent toward the first end surface 2 a of the electrode assembly 2 and serves as the bent portion 32 .

[0055] Step S2: hot-melt the ring-shaped tab adhesive 4 and the packaging film (as the packaging layer 1 a ); remove the packaging film corresponding to the hollow area of ​​the ring-shaped tab adhesive 4 to form a first through hole 12 , exposing the tab 3 .

[0056] Step S3: bend the tab 3 to form a bent portion 32, and fold the packaging film to wrap the electrode assembly 2 and the tab 3, and heat-seal the two sides of the packaging film.

[0057] Step S4: After injecting electrolyte through the unsealed open area on the second end face 2b side of the electrode assembly 2, the packaging film on the second end face 2b side is heat-sealed to complete the preparation of the electrochemical device.

[0058] Optionally, step S4 further includes step S5: coating the surface of the encapsulation layer 1a with a barrier layer 1b.

[0059] Optionally, step S5 further includes step S6: coating the surface of the barrier layer 1b with a protective layer 1c.

[0060] Optionally, step S1 further includes providing an insulating member 5 on a surface of the electrode tab 3 that faces the first end face 2 a after the tab 3 is subsequently bent toward the first end face 2 a of the electrode assembly 2 and serves as a bent portion 32 .

[0061] Optionally, before step S3, the process further includes: providing an insulating spacer 6 on the first end surface 2a of the electrode assembly 2. Furthermore, the spacer 6 is provided with a first groove 61 for accommodating the tab, and the bent portion 32 of the tab 3 is accommodated in the first groove 61.

[0062] Optionally, before step S3 , the method further includes: arranging a spacer 6 with insulating properties on the second end surface 2 b of the electrode assembly 2 .

[0063] The present application also provides an electronic device comprising the electrochemical device described in the above embodiment. The electronic device includes but is not limited to mobile terminal devices such as mobile phones, tablet computers, Bluetooth headsets, VR glasses, and electronic watches.

[0064] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An electrochemical device, in, include: The housing comprises a top wall, the top wall is provided with a first through hole, and the top wall comprises a sealing area surrounding the first through hole; an electrode assembly, housed in the housing, the electrode assembly comprising a first end surface facing the top wall; The electrode ear comprises a connecting portion connected to the electrode assembly and a bending portion bent toward the first end surface; a connecting area is provided on a surface of the bending portion facing the top wall; and The ear glue is arranged between the connection area and the sealing area, and the ear glue connects the connection area and the sealing area.

2. The electrochemical device according to claim 1, in, The housing includes an encapsulation layer including a first polymer.

3. The electrochemical device according to claim 2, in, At least one of the following conditions is met: (i) the shell further comprises a barrier layer located on the surface of the encapsulation layer, the barrier layer comprising at least one of a metal, an inorganic oxide or a nitride; (ii) The first polymer comprises at least one of polyethylene, ethylene-propylene copolymer, polypropylene, anhydride-modified polypropylene, polyvinyl chloride, polystyrene, polyurethane, polyamide, polyester, amorphous α-olefin copolymer or derivatives thereof.

4. The electrochemical device according to claim 3, in, At least one of the following conditions is met: (i) the shell further comprises a protective layer located on the surface of the barrier layer, the protective layer comprises a second polymer, and the second polymer comprises at least one of polyester, polyamide, polyacrylonitrile, polyvinyl chloride, polyurethane or polyolefin; (ii) the metal comprises at least one of aluminum, copper, iron, titanium or nickel; (iii) the inorganic oxide comprises at least one of titanium dioxide, aluminum oxide, hafnium dioxide, silicon dioxide, iron oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, zinc oxide, tin oxide, zirconium titanium oxide or vanadium oxide; (iv) The nitride includes at least one of silicon nitride, silicon oxynitride, boron nitride, titanium nitride or aluminum nitride.

5. The electrochemical device according to claim 1, in, At least one of the following conditions is met: (1) an insulating member is provided on a surface of the bent portion facing the first end surface; (ii) The tab glue is provided with a second through hole, and the second through hole is connected to the first through hole.

6. The electrochemical device according to claim 1, in, The electrode assembly further includes a second end surface opposite to the first end surface, and a spacer is disposed between the first end surface and / or the second end surface and the shell.

7. The electrochemical device according to claim 6, in, Satisfy at least one of the following conditions: (1) A first groove is formed on the spacer, and the bending portion is located in the first groove; (ii) The connection area is provided with a third through hole.

8. The electrochemical device according to claim 5, in, A second groove is formed on a surface of the insulating member facing the electrode assembly.

9. The electrochemical device according to claim 1, in, The electrochemical device further includes a conductive member connected to the bent portion via the first through hole.

10. An electronic device comprising the electrochemical device according to any one of claims 1 to 9.

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