Battery cell structure, secondary battery and wearable device

Abstract

The utility model discloses a battery cell structure, a secondary battery and a wearable device, and relates to the field of batteries, the battery cell structure comprises a positive electrode wire and a negative electrode wire, and the positive electrode wire and the negative electrode wire are arranged adjacently; the positive electrode wire comprises a positive current collector and a positive active material layer, the positive active material layer wraps the circumferential surface of the positive current collector, and at least one end part of the positive current collector extends out of the positive active material layer to form a positive tab; the negative electrode wire comprises a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer wraps the circumferential surface of the negative electrode current collector, and at least one end part of the negative electrode current collector extends out of the negative electrode active material layer to form a negative electrode lug. In the embodiment of the invention, the electrode is linear, and the flexibility of the linear electrode is higher, so that the linear electrode can be randomly folded or bent by being matched with the shape of the wearable equipment and cannot be damaged in the bending process of the wearable equipment, and the durability of the wearable equipment is further improved.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically to cell structure, secondary batteries and wearable devices. Background Technology

[0002] With the rapid development of wearable devices such as smartwatches, users' demand for flexible and high-performance energy storage systems is also increasing.

[0003] However, traditional energy storage devices are often planar or block-shaped. Due to the lack of flexibility of planar or block-shaped energy storage devices, if traditional energy storage devices are placed in wearable devices, the electrode materials of the traditional energy storage devices may break during the folding or bending of the wearable devices, thereby affecting the performance and durability of the wearable devices. Utility Model Content

[0004] This application provides a cell structure, a secondary battery, and a wearable device, which can solve the technical problem of insufficient flexibility in traditional energy storage devices in the prior art.

[0005] In a first aspect, embodiments of this application provide a battery cell structure, including: a positive electrode line and a negative electrode line, wherein the positive electrode line and the negative electrode line are disposed adjacent to each other; the positive electrode line includes a positive current collector and a positive active material layer, the positive active material layer wraps around the circumferential surface of the positive current collector, and at least one end of the positive current collector extends from the positive active material layer to form a positive electrode tab; the negative electrode line includes a negative current collector and a negative active material layer, the negative active material layer wraps around the circumferential surface of the negative current collector, and at least one end of the negative current collector extends from the negative active material layer to form a negative electrode tab.

[0006] In conjunction with the first aspect, in one embodiment, a plurality of positive electrode lines are arranged in parallel to form a positive electrode line layer, and a plurality of negative electrode lines are arranged in parallel to form a negative electrode line layer, with the positive electrode line layer and the negative electrode line layer being staggered and stacked.

[0007] In conjunction with the first aspect, in one embodiment, the positive electrode lines in each positive electrode layer are staggered with the negative electrode lines in the adjacent negative electrode layer.

[0008] In conjunction with the first aspect, in one embodiment, a plurality of positive electrode lines are arranged side by side to form a ring-shaped positive electrode layer, and a plurality of negative electrode lines are arranged side by side to form a ring-shaped negative electrode layer, with the positive electrode layer and the negative electrode layer being nested sequentially from the inside out.

[0009] In conjunction with the first aspect, in one embodiment, at least one negative electrode line is provided at the center of the positive electrode line layer of the innermost annular structure.

[0010] In conjunction with the first aspect, in one embodiment, the diameter of the negative electrode line located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the positive electrode line in the positive electrode line layer, and the diameter of the negative electrode line located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the negative electrode line in the negative electrode line layer.

[0011] In conjunction with the first aspect, in one embodiment, the longitudinal section of the battery cell structure is circular.

[0012] In conjunction with the first aspect, in one embodiment, a diaphragm is disposed outside the positive electrode active material layer and / or the negative electrode active material layer; the gaps between adjacent positive electrode lines and negative electrode lines are filled with PVDF binder.

[0013] Secondly, embodiments of this application provide a secondary battery, comprising: a cell structure as described in any of the above embodiments; an insulating layer surrounding the cell structure; a housing, the housing including a cavity for housing the cell structure and the insulating layer; and an output terminal welded to the housing.

[0014] In conjunction with the second aspect, in one embodiment, the shell has an elongated cylindrical structure.

[0015] Thirdly, embodiments of this application provide a wearable device including the secondary battery described in any of the above embodiments.

[0016] The beneficial effects of the technical solutions provided in this application include:

[0017] The battery cell structure provided in this application embodiment includes a positive electrode line and a negative electrode line, which are arranged adjacent to each other. Since both the positive and negative electrode lines in this application embodiment are linear, the flexibility of linear electrodes is greater than that of traditional planar or block-shaped energy storage devices. They can be folded or bent to fit the shape of wearable devices without being damaged during bending, thus further improving the durability of the wearable device. The positive electrode line includes a positive current collector and a positive active material layer. The positive active material layer covers the circumferential surface of the positive current collector, and at least one end of the positive current collector extends from the positive active material layer to form a positive electrode tab. The negative electrode line includes a negative current collector and a negative active material layer. The negative active material layer covers the circumferential surface of the negative current collector, and at least one end of the negative current collector extends from the negative active material layer to form a negative electrode tab. In this embodiment, the current collector can form an ion-conducting channel, enabling lithium ions to conduct between the positive and negative electrodes, thereby realizing the charging and discharging process of the cell structure and ensuring the performance of the wearable device. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a battery cell structure provided in an embodiment of this application;

[0020] Figure 2 This is a partial structural side view of a battery cell structure provided in an embodiment of this application;

[0021] Figure 3 A side view of a cell structure provided in another embodiment of this application;

[0022] Figure 4 This is a schematic diagram of the structure of a secondary battery provided in an embodiment of this application.

[0023] In the diagram: 1. Positive electrode wire; 11. Positive current collector; 12. Positive active material layer; 13. Positive electrode tab; 2. Negative electrode wire; 21. Negative current collector; 22. Negative active material layer; 23. Negative electrode tab; 3. Housing; 4. Output terminal. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0025] This application provides a cell structure that can solve the technical problem of insufficient flexibility in traditional energy storage devices in the prior art.

[0026] Figure 1 This is a schematic diagram of a battery cell structure provided in an embodiment of this application. Figure 2 This is a partial structural side view of a battery cell structure provided in one embodiment of this application. (Referring to...) Figure 1 and Figure 2This application provides a battery cell structure, including: a positive electrode line 1 and a negative electrode line 2, which are arranged adjacent to each other; the positive electrode line 1 includes a positive current collector 11 and a positive active material layer 12, the positive active material layer 12 covers the circumferential surface of the positive current collector 11, and at least one end of the positive current collector 11 extends from the positive active material layer 12 to form a positive electrode tab 13; the negative electrode line 2 includes a negative current collector 21 and a negative active material layer 22, the negative active material layer 22 covers the circumferential surface of the negative current collector 21, and at least one end of the negative current collector 21 extends from the negative active material layer 22 to form a negative electrode tab 23.

[0027] Since both the positive electrode line 1 and the negative electrode line 2 in this embodiment are linear, taking the positive electrode line as an example, the positive current collector 11 can be a slender columnar structure, not limited to cylinders, polygonal columns, etc. The positive active material 12 is coated on the surface of the positive current collector 11 to form a columnar positive electrode battery line 1 with a larger cross-sectional area. The linear electrode is more flexible than traditional planar or block-shaped energy storage devices, and can be folded or bent to fit the shape of the wearable device without being damaged during the bending process of the wearable device, thereby further improving the durability of the wearable device.

[0028] Reference Figure 1 and Figure 2 In one embodiment, multiple positive electrode lines 1 are arranged side by side as a positive electrode layer, and multiple negative electrode lines 2 are arranged side by side as a negative electrode layer. The positive electrode layers and negative electrode layers are stacked alternately, and the multilayer electrode layers in the cell structure are arranged sequentially in the order of one layer of positive electrode layer stacked with one layer of negative electrode layer.

[0029] Furthermore, in each positive electrode layer of this application embodiment, the positive electrode lines are staggered with the negative electrode lines in the adjacent negative electrode layer. It can be understood that, since the electrodes in this application embodiment are linear, the relative position of a positive electrode line in one layer of positive electrode layer is between two negative electrode lines in the adjacent negative electrode layer. That is, in a cross-section perpendicular to the length of the positive electrode layer, the center of a positive electrode line in one layer of positive electrode layer corresponds to the midpoint of the distance between the centers of two negative electrode lines in the adjacent negative electrode layer.

[0030] Similarly, in the embodiments of this application, the negative lines in each negative electrode layer are staggered with the positive lines in the adjacent positive electrode layer. The relative position of a negative electrode in a negative electrode layer between two positive lines in an adjacent positive electrode layer is such that, in a cross-section perpendicular to the length of the negative electrode layer, the center of a negative electrode in a negative electrode layer corresponds to the midpoint of the distance between the centers of two positive lines in an adjacent positive electrode layer.

[0031] This allows for a more compact structure of the stacked multilayer electrode lines, which better aligns with the design trend of lightweight wearable devices.

[0032] In this embodiment, the current collector gathers and outputs the current generated by the active material in the active material layer, thereby realizing the process of converting chemical energy into electrical energy. In this embodiment, the positive electrode active material layer 12 can be made of lithium manganese oxide, lithium cobalt oxide, or lithium nickel cobalt manganese oxide, the positive electrode current collector 11 can be made of aluminum, the negative electrode active material layer 22 can be made of graphite or carbon with a similar graphite structure, and the negative electrode current collector 21 can be made of copper.

[0033] Furthermore, the diameter of the cross-section of the positive electrode current collector 11 in the length direction perpendicular to the cell structure is between 20 μm and 30 μm, and optionally, it can be 20 μm to 22 μm, 22 μm to 24 μm, 24 μm to 26 μm, 26 μm to 28 μm, or 28 μm to 30 μm. The diameter of the cross-section of the negative electrode current collector 21 in the length direction perpendicular to the cell structure is between 15 μm and 20 μm, and optionally, it can be 15 μm to 16 μm, 16 μm to 17 μm, 17 μm to 18 μm, 18 μm to 19 μm, or 19 μm to 20 μm.

[0034] Therefore, on the one hand, the space occupied by the positive electrode line 1 and the negative electrode line 2 in the cell structure is smaller, which is in line with the design trend of lightweight wearable devices. On the other hand, it can ensure that the positive electrode line 1 and the negative electrode line 2 are not too thin, thereby avoiding the cell structure from being easily damaged.

[0035] like Figure 2 As shown in the embodiment of this application, the positive electrode active material layer 12 wraps around the circumferential surface of the positive electrode current collector 11, and at least one end of the positive electrode current collector 11 extends out from the positive electrode active material layer 12 to form a positive electrode tab 13; the negative electrode active material layer 22 wraps around the circumferential surface of the negative electrode current collector 21, and at least one end of the negative electrode current collector 21 extends out from the negative electrode active material layer 22 to form a negative electrode tab 23.

[0036] Specifically, since the embodiments of this application are composed of multiple layers of positive electrode lines and negative electrode lines stacked together, and each positive electrode line layer or negative electrode line layer includes multiple positive electrode lines 1 or negative electrode lines 2 arranged in parallel, the embodiments of this application can have multiple positive electrode current collectors 11 and negative electrode current collectors 21 extending out as tabs. Since the embodiments of this application have multiple positive electrode tabs 13 and multiple negative electrode tabs 23, the charging and discharging efficiency can be improved, thereby realizing fast charging and discharging of the cell structure.

[0037] See Figure 3As shown in the embodiment of this application, a battery cell structure is also provided, including: a positive electrode layer with a plurality of positive electrode lines 1 arranged in a ring structure, and a negative electrode layer with a plurality of negative electrode lines 2 arranged in a ring structure, wherein the positive electrode layer and the negative electrode layer are sequentially nested from the inside to the outside.

[0038] In this embodiment, the positive electrode layer and the negative electrode layer are nested sequentially from the inside to the outside, so the longitudinal section of the cell structure is circular, which is more flexible than the cell structure in the previous embodiment.

[0039] Specifically, the positive electrode line 1 in the annular positive electrode layer and the negative electrode line 2 in the adjacent annular negative electrode layer are arranged alternately.

[0040] As a result, the multiple electrode wire layers nested sequentially from the inside out are more flexible, and the inner electrode wire layer is not easily damaged, further improving the structural stability of the battery cell.

[0041] In this embodiment, the diameter of the negative electrode line 2 located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the positive electrode line 1 in the positive electrode line layer, and the diameter of the negative electrode line 2 located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the negative electrode line 2 in the negative electrode line layer.

[0042] The negative electrode line 2 may include a central negative electrode line and a circumferential negative electrode line. Multiple positive electrode lines 1 form a ring-shaped positive electrode line layer around the central negative electrode line, and multiple circumferential negative electrode lines form a ring-shaped negative electrode line layer around the positive electrode line 1. Multiple ring-shaped positive electrode line layers and multiple ring-shaped negative electrode line layers are nested sequentially from the inside to the outside.

[0043] Specifically, in the direction perpendicular to the length of the cell structure, the cross-sectional area of ​​the central negative electrode wire can be six times that of the circumferential negative electrode wire. In some other embodiments of this application, the cross-sectional area of ​​the central negative electrode wire can also be set to four, five, or other multiples of the circumferential negative electrode wire, which is not limited here.

[0044] In a cross-section perpendicular to the length of the cell structure, the cross-sectional area of ​​the negative electrode active material 22 in the central negative electrode line is larger than that in the circumferential negative electrode line. Therefore, on the one hand, the central negative electrode line provides a certain supporting force, supporting the positive electrode line 1 arranged around it, thus further improving the structural stability of the multiple electrode line layers nested sequentially from the inside out. On the other hand, it makes the overall structure of the cell more compact.

[0045] In the embodiments of this application, the diaphragm can be a PP (polypropylene) diaphragm, a PE (polyethylene) diaphragm, a ceramic diaphragm, a glass fiber diaphragm, or a fiber nonwoven fabric diaphragm, as long as it satisfies the function of separating the positive electrode line 1 and the negative electrode line 2 and preventing short circuits caused by contact between electrode lines of different polarities. No limitation is made here.

[0046] In this embodiment, the gaps between adjacent electrode lines are filled with PVDF adhesive.

[0047] Specifically, PVDF (Polyvinylidene Fluoride) is a thermoplastic polymer material polymerized from vinyl fluoride monomers. Multiple positive electrode lines 1, multiple negative electrode lines 2, and positive electrode lines 1 and negative electrode lines 2 are bonded together using PVDF adhesive.

[0048] Due to its physical adsorption and chemical bonding properties, PVDF binder exhibits high adhesive performance. Furthermore, PVDF binder also possesses electrical insulation and high-temperature resistance. Therefore, using PVDF binder to bond adjacent electrode lines ensures the structural stability of the battery cell. Moreover, as PVDF is an inherent additive in lithium battery manufacturing, its use as a binder does not introduce new substances, thus avoiding side reactions. In some other embodiments of this application, other binders may be used to bond adjacent electrode lines; this is not a limitation.

[0049] The battery cell structure provided in this application includes a positive electrode line and a negative electrode line, which are arranged adjacent to each other. Since the electrodes in this application embodiment are linear, the flexibility of linear electrodes is greater than that of traditional planar or block-shaped energy storage devices. They can be folded or bent freely to fit the shape of wearable devices without being damaged during bending, thus further improving the durability of the wearable devices. In this application embodiment, the current collector can form an ion-conducting channel, allowing lithium ions to conduct between the positive and negative electrodes, thereby realizing the charging and discharging process of the battery cell structure and ensuring the performance of the wearable device. Another embodiment of this application provides a battery cell structure using multiple electrode wire loops arranged sequentially from the inside out, which can further improve the flexibility of the battery cell structure. The inner electrode wire loops are not easily damaged, further improving the structural stability of the battery cell structure.

[0050] Figure 4 This is a schematic diagram of the structure of a secondary battery provided in one embodiment of this application. (Reference) Figure 4This application also provides a secondary battery, including the cell structure described in any of the above embodiments; an insulating layer wrapped around the cell structure; a housing 3, the housing 3 including a cavity for accommodating the cell structure and the insulating layer; and an output terminal 4, the output terminal 4 being welded to the housing 3.

[0051] Specifically, the housing 3 can be in the form of a long cylindrical structure. The housing 3 also has a certain degree of flexibility. When the secondary battery provided in the embodiments of this application is used in the wearable device, the secondary battery will not be damaged during the bending process of the wearable device, thereby further improving the durability of the wearable device.

[0052] For any related settings not mentioned in this embodiment, please refer to the previous embodiment, and they will not be repeated here.

[0053] This application also provides a wearable device, including the secondary battery provided in any of the above embodiments. In one specific embodiment, the wearable device can be an electronic watch, in which case the secondary battery provided in this application embodiment can be placed inside the watch strap. Since the secondary battery in this application embodiment has a highly flexible linear shape, it can fold or bend along with the strap when the user wears the electronic watch. Furthermore, the arrangement of the positive and negative electrode lines in the secondary battery in this application embodiment is relatively compact, resulting in a smaller space occupied by the secondary battery within the electronic watch, thus making the electronic watch design more lightweight.

[0054] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0055] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A battery cell structure, characterized in that, include: A positive electrode line (1) and a negative electrode line (2) are arranged adjacent to each other. The positive electrode wire (1) includes a positive current collector (11) and a positive active material layer (12). The positive active material layer (12) wraps around the circumferential surface of the positive current collector (11), and at least one end of the positive current collector (11) extends out from the positive active material layer (12) to form a positive electrode tab (13). The negative electrode wire (2) includes a negative current collector (21) and a negative active material layer (22). The negative active material layer (22) wraps around the circumferential surface of the negative current collector (21), and at least one end of the negative current collector (21) extends out from the negative active material layer (22) to form a negative electrode tab (23).

2. The cell structure according to claim 1, characterized in that: Multiple positive electrode lines (1) are arranged in parallel to form a positive electrode layer, and multiple negative electrode lines (2) are arranged in parallel to form a negative electrode layer. The positive electrode layer and the negative electrode layer are stacked alternately.

3. The cell structure according to claim 2, characterized in that: The positive electrode lines (1) in each positive electrode layer are interspersed with the negative electrode lines (2) in the adjacent negative electrode layer.

4. The cell structure according to claim 1, characterized in that: Multiple positive electrode lines (1) are arranged in a ring-shaped positive electrode layer, and multiple negative electrode lines (2) are arranged in a ring-shaped negative electrode layer. The positive electrode layer and the negative electrode layer are nested from the inside to the outside.

5. The cell structure according to claim 4, characterized in that: At least one negative electrode line is provided at the center of the innermost annular positive electrode line layer (2).

6. The cell structure according to claim 5, characterized in that: The diameter of the negative electrode line (2) located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the positive electrode line (1) in the positive electrode line layer, and the diameter of the negative electrode line (2) located at the center of the positive electrode line layer of the innermost annular structure is larger than the diameter of the negative electrode line (2) in the negative electrode line layer.

7. The cell structure according to claim 4, characterized in that: The longitudinal section of the battery cell structure is circular.

8. The cell structure according to claim 1, characterized in that: A diaphragm is provided outside the positive electrode active material layer (12) and / or the negative electrode active material layer (22); the gaps between adjacent positive electrode lines (1) and negative electrode lines (2) are filled with PVDF binder.

9. A secondary battery, characterized in that, include: The cell structure according to any one of claims 1-8 above; An insulating layer that surrounds the battery cell structure; The housing (3) includes a cavity for housing the battery cell structure and the insulating layer; Output terminal (4), which is welded to the housing (3).

10. A wearable device, characterized in that, Includes the secondary battery as described in claim 9.

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