Electrochemical device and electronic equipment

Abstract

The application discloses an electrochemical device and an electronic device. The electrochemical device comprises a first pole piece, a separator and a second pole piece. The separator is arranged between the first pole piece and the second pole piece, and the first pole piece, the separator and the second pole piece are wound together. The first pole piece has a first hollow foil area and a second hollow foil area arranged at intervals along the winding direction, and the projections of the two areas in the thickness direction do not overlap. The first pole lug comprises a first connecting part connected to the first hollow foil area and a first lead-out part with a protruding long side. The second pole lug comprises a second connecting part connected to the second hollow foil area and a second lead-out part connected to the first lead-out part. The third pole lug comprises a third connecting part arranged on the second pole piece. The projection of the second hollow foil area covers the third connecting part, and the second connecting part and the third connecting part do not overlap. In the application, the first lead-out part and the second lead-out part are connected to form an internal partial flow, shorten the electron transport path, reduce the resistance of the electron transport path, and support larger rate charging and discharging.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage technology, and in particular to an electrochemical device and electronic equipment. Background Technology

[0002] In related technologies, wound battery cells typically employ a center-mounted tab structure. However, with the continuous increase in battery cell performance requirements, especially in fast charging scenarios, the center-mounted tab structure is unable to meet the requirements of high-rate charging and discharging. Utility Model Content

[0003] The main purpose of this application is to propose an electrochemical device and electronic device, which aims to improve the problem of easy separation between the vane and roller during low-frequency operation of existing compressors, and help the compressor to operate at even lower frequencies.

[0004] To address the aforementioned problems, this application proposes an electrochemical device comprising:

[0005] A first electrode, a separator, and a second electrode, wherein the separator is disposed between the first electrode and the second electrode; the first electrode, the separator, and the second electrode are wound together.

[0006] The first electrode has a first empty foil region and a second empty foil region spaced apart along the winding direction, and the projections of the first empty foil region and the second empty foil region in the thickness direction of the electrochemical device do not overlap.

[0007] The first electrode tab includes a first connecting portion and a first lead-out portion. The first connecting portion is connected to the first empty foil area, and the first lead-out portion protrudes from the long side of the first electrode sheet along the width direction of the first electrode sheet.

[0008] The second electrode includes a second connecting part and a second lead-out part, the second connecting part being connected to the second empty foil area, and the second lead-out part being connected to the first lead-out part;

[0009] The third tab includes a third connecting portion and a third lead-out portion. The third connecting portion is disposed on the second electrode plate. Along the thickness direction of the electrochemical device, the projection of the second empty foil area covers the third connecting portion, and the second connecting portion and the third connecting portion do not overlap.

[0010] The battery cell electrode sheet according to the embodiments of this application has at least the following beneficial effects: the first electrode sheet and the second electrode sheet are wound together to form an alternating stacked structure through a separator film, and the first electrode tab and the second electrode tab are respectively connected to two non-overlapping empty foil areas to form a dual lead-out path. Compared with the electrode tab center placement scheme, it can shorten the electron transmission path, reduce the resistance of the electron transmission path, and improve the current collection efficiency, thereby supporting a higher rate of charge and discharge.

[0011] In some embodiments, the second lead-out portion has a first segment, and the first segment and the first lead-out portion are stacked together along the thickness direction of the electrochemical device.

[0012] In some embodiments, the end of the first segment is flush with the end of the first lead-out portion; and / or,

[0013] The first segment and the first lead-out part are connected as a single structure.

[0014] In some embodiments, the second lead-out portion further includes a second segment, the two ends of which are respectively connected to the second connecting portion and the first segment, and the second segment is located outside the long side of the first electrode and extends along the long side direction of the first electrode.

[0015] In some embodiments, the second empty foil area includes a first edge and a second edge disposed opposite to each other along the long side direction of the first electrode, the second connecting portion is disposed adjacent to the first edge, and a receiving groove is formed between the second connecting portion and the second edge;

[0016] Along the thickness direction of the electrochemical device, the projection of the receiving tank covers the third connection portion.

[0017] In some embodiments, the electrochemical device further includes a first protective adhesive disposed between the second connecting portion and the separating membrane, wherein the two ends of the first protective adhesive are respectively bonded to the outer sides of the first edge and the second edge.

[0018] In some embodiments, the electrochemical device further includes a second protective adhesive disposed between the third connection portion and the separator membrane, and the second protective adhesive is bonded to the outer edge of the first empty foil region.

[0019] In some embodiments, the second electrode has a third empty foil region and a fourth empty foil region spaced apart along the winding direction;

[0020] The electrochemical device further includes a fourth tab, which comprises a fourth connection portion and a fourth lead-out portion.

[0021] The third connecting part is connected to the third empty foil area, the fourth connecting part is connected to the fourth empty foil area, and the fourth lead-out part is connected to the third lead-out part;

[0022] Along the thickness direction of the electrochemical device, the projection of the fourth empty foil region covers the first connection portion, and the first connection portion and the fourth connection portion do not overlap.

[0023] In some embodiments, tab adhesive is provided between the second lead-out portion and the fourth lead-out portion.

[0024] This application also proposes an electronic device that includes any of the electrochemical devices described herein.

[0025] The battery cell electrode sheet according to the embodiments of this application has at least the following beneficial effects: by applying the above-mentioned electrochemical device, the requirements for high-rate charging and discharging can be met.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0028] Figure 1 This is a schematic diagram of the structure of an electrochemical device in one embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the connection structure of the first electrode plate, the first electrode tab, and the second electrode tab in one embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of the first electrode in one embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the connection structure of the second electrode plate, the third electrode lug, and the fourth electrode lug in one embodiment of this application.

[0032] Figure label:

[0033] 100, First electrode; 110, First empty foil area; 120, Second empty foil area; 121, First edge; 122, Second edge; 123, Receiving slot;

[0034] 200, Second electrode; 210, Third empty foil region; 220, Fourth empty foil region;

[0035] 300. Separating membrane;

[0036] 400. First electrode tab; 410. First connecting part; 420. First lead-out part;

[0037] 500. Second pole piece; 510. Second connecting part; 520. Second lead-out part; 521. First segment; 522. Second segment;

[0038] 600. Third electrode tab; 610. Third connecting part; 620. Third lead-out part;

[0039] 700. Fourth pole piece; 710. Fourth connecting part; 720. Fourth lead-out part;

[0040] 810, First protective adhesive; 820, Second protective adhesive. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The embodiments of this application may omit unnecessary detailed descriptions. For example, detailed descriptions of well-known matters and repeated descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0042] In this application, the technical features described in an open-ended manner include both closed-ended technical solutions consisting of the listed features and open-ended technical solutions that include the listed features. As used herein, the terms "generally," "substantially," and "about" are used to describe and explain minor variations.

[0043] When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely and examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, if the difference between two numerical values ​​is less than or equal to ±10% of the average of the values ​​(e.g., less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%), then the two numerical values ​​can be considered "substantially" the same.

[0044] Furthermore, for ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0045] Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits, but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified. In the detailed description and claims, a list of items connected by the terms “one of,” “among,” “one of,” or other similar terms may mean any of the listed items. For example, if items A and B are listed, the phrase “one of A and B” means only A or only B. In another instance, if items A, B, and C are listed, the phrase “one of A, B, and C” means only A; only B; or only C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0046] In the detailed description and claims, the list of items connected by the term "at least one of" can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C.

[0047] In the following description, all figures disclosed in this application are approximate values, regardless of whether the terms "about" or "approximately" are used in conjunction. They may vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a range of values ​​with a lower limit (RL) and an upper limit (RU) is disclosed, any values ​​falling within that range are specifically disclosed. Specifically, the following values ​​within this range are specifically disclosed: R = RL + k * (RU - RL), where k is a variable with a 1% increment from 1% to 100%, that is, k is 1%, 2%, 3%, 4%, 5%, ..., 50%, 51%, 52%, ..., 95%, 96%, 97%, 98%, 99%, or 100%. Furthermore, any range of values ​​defined by the two R values ​​as defined above are also specifically disclosed.

[0048] Throughout this specification, references to "implementation," "partial implementation," "one implementation," "another implementation," "specific method," or "partial method" mean that at least one implementation or embodiment in this application includes the specific features, structures, materials, or characteristics described in that implementation or embodiment.

[0049] In this application, numerical ranges are involved. Unless otherwise specified, the numerical ranges mentioned above are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form a range not explicitly stated.

[0050] In existing technologies, wound battery cells generally adopt a centrally located tab structure, where the tabs are concentrated in the central region of the electrochemical device. However, with the widespread adoption of fast charging technology, the demand for high-rate charging and discharging places higher requirements on battery cell performance. The centrally located tab structure, due to its longer current transmission path, leads to increased internal resistance, and uneven current distribution can easily cause localized overheating, affecting the stability and lifespan of the battery cell, making it difficult to meet the requirements of high-rate charging and discharging.

[0051] To address the aforementioned problems, this application proposes an electrochemical device, such as... Figures 1 to 4 As shown, in some embodiments, the electrochemical device includes a first electrode 100, a separator 300, and a second electrode 200. The separator 300 is disposed between the first electrode 100 and the second electrode 200. The first electrode 100, the separator 300, and the second electrode 200 are wound together to form a multilayer structure. The first electrode 100 has a first empty foil region 110 and a second empty foil region 120 spaced apart along the winding direction, and their projections in the thickness direction do not overlap. A first tab 400 includes a first connecting portion 410 connecting the first empty foil region 110 and a first lead-out portion 420 protruding from the long side. A second tab 500 includes a second connecting portion 510 connecting the second empty foil region 120 and a second lead-out portion 520 connected to the first lead-out portion 420. A third tab 600 includes a third connecting portion 610 disposed on the second electrode 200. The projection of the second empty foil region 120 covers the third connecting portion 610, and the second connecting portion 510 and the third connecting portion 610 do not overlap.

[0052] In this embodiment, the first electrode 100 and the second electrode 200 are wound together by the separator 300 to form an alternating stacked structure. The first tab 400 and the second tab 500 are respectively connected to two non-overlapping empty foil areas to form a dual lead-out path. Compared with the tab-centered scheme, this can shorten the electron transmission path, reduce the resistance of the electron transmission path, and improve the current collection efficiency, thereby supporting a higher rate of charge and discharge.

[0053] Furthermore, the second empty foil area 120 forms a recessed space during winding to accommodate the third connecting portion 610 of the third electrode tab 600 on the second electrode 200, thus avoiding mechanical interference when multiple layers are stacked.

[0054] In this design, one of the first electrode 100 and the other of the second electrode 200 is a positive electrode, and the other is a negative electrode. Both the first electrode 100 and the second electrode 200 are electrode structures, comprising a current collector and active material layers disposed on both sides of the current collector. The difference between the first electrode 100 and the second electrode 200 lies in the materials of the current collector and the active material. The empty foil area refers to the area on the current collector that is not coated with active material, which can be formed through laser cleaning, blade removal, or masking processes.

[0055] The separator 300 refers to the insulating material layer placed between two electrodes with opposite polarities. Specifically, it can be made of polypropylene or polyethylene porous film. Its function is to prevent short circuits caused by direct contact between electrodes of opposite polarities.

[0056] In this application, two empty foil regions, a first empty foil region 110 and a second empty foil region 120, can be provided on the positive electrode sheet, that is, the first electrode sheet 100 is the positive electrode sheet and the second electrode sheet 200 is the negative electrode sheet; alternatively, two empty foil regions, a first empty foil region 110 and a second empty foil region 120, can be provided on the negative electrode sheet, that is, the first electrode sheet 100 is the negative electrode sheet and the second electrode sheet 200 is the positive electrode sheet; alternatively, two empty foil regions can be provided on both the positive and negative electrode sheets, that is, the first electrode sheet 100 is the positive electrode sheet with a first empty foil region 110 and a second empty foil region 120, and the second electrode sheet 200 is the negative electrode sheet with a third empty foil region 210 and a fourth empty foil region 220. This application does not limit this.

[0057] The following explanation uses the example of two empty foil regions in both the positive and negative electrode plates.

[0058] In some embodiments, such as Figure 3 As shown, the electrochemical device includes a first electrode 100, a second electrode 200, a first tab 400, a second tab 500, a third tab 600, and a fourth tab 700. The first tab 400 and the second tab 500 are connected to the first electrode 100, and the third tab 600 and the fourth tab 700 are connected to the second electrode 200.

[0059] The first electrode 100 has a first empty foil area 110 and a second empty foil area 120 spaced apart along the winding direction. The first electrode tab 400 includes a first connecting portion 410 and a first lead-out portion 420. The first connecting portion 410 is connected to the first empty foil area 110, and the first lead-out portion 420 protrudes from the long side of the first electrode 100. The second electrode tab 500 includes a second connecting portion 510 and a second lead-out portion 520. The second connecting portion 510 is connected to the second empty foil area 120, and a portion of the structure of the second lead-out portion 520 is connected to the first lead-out portion 420.

[0060] The second electrode 200 has a third empty foil region 210 and a fourth empty foil region 220 spaced apart along the winding direction. The third electrode tab 600 includes a third connecting portion 610 and a third lead-out portion 620. The third connecting portion 610 is connected to the third empty foil region 210, and the third lead-out portion 620 protrudes from the long side of the second electrode 200. The fourth electrode tab 700 includes a fourth connecting portion 710 and a fourth lead-out portion 720. The fourth connecting portion 710 is connected to the fourth empty foil region 220, and part of the structure of the fourth lead-out portion 720 is connected to the third lead-out portion 620.

[0061] Furthermore, along the thickness direction of the electrochemical device, the projection of the second empty foil region 120 covers the third connecting portion 610, and the second connecting portion 510 and the third connecting portion 610 do not overlap; the projection direction of the fourth empty foil region 220 covers the first connecting portion 410, and the fourth connecting portion 710 and the first connecting portion 410 do not overlap.

[0062] Through a spatially staggered design, the first lead-out portion 420 and the second lead-out portion 520 are connected, and the third lead-out portion 620 and the fourth lead-out portion 720 are connected, forming a structure with two exposed tabs and four internal tabs. This creates an internal current-sharing design, reducing the current density per unit area, making the current density more balanced, and reducing the risk of localized heating. The connection points of the first connection portion 410 and the second connection portion 510 to the first electrode 100 are spaced apart along the long side of the first electrode 100, and the connection points of the third connection portion 610 and the fourth connection portion 710 to the second electrode 200 are spaced apart along the long side of the second electrode 200. Compared to a centrally located tab structure, this shortens the electron transport path to both ends of the first electrode 100, reduces the resistance of the electron transport path, and improves the current collection efficiency, thereby supporting higher charge and discharge rates. The low internal resistance design reduces polarization during charge and discharge, thereby reducing the risk of lithium plating.

[0063] Specifically, the first electrode 100 is the positive electrode, and the second electrode 200 is the negative electrode. The first connecting portion 410, which connects to the positive electrode, is embedded in the fourth empty foil area 220 of the negative electrode. The first connecting portion 410 and the fourth connecting portion 710 are staggered in the long side direction. At the same time, the third connecting portion 610, which connects to the negative electrode, is embedded in the second empty foil area 120 of the positive electrode. The first connecting portion 410 and the fourth connecting portion 710 are staggered in the long side direction, and the second connecting portion 510 and the third connecting portion 610 are staggered in the long side direction. In this nested design between electrodes of opposite polarity, the first connecting portion 410 can be accommodated using the redundant space of the fourth empty foil area 220 of the negative electrode, and the third connecting portion 610 can be accommodated using the redundant space of the second empty foil area 120 of the positive electrode. While achieving a compact arrangement, the spacing creates a natural insulating gap, avoiding the risk of short circuits caused by stacking misalignment.

[0064] As can be seen from the above, the connection relationship between the first electrode 100, the first electrode tab 400, and the second electrode tab 500 is similar to the connection relationship between the second electrode 200, the third electrode tab 600, and the fourth electrode tab 700. The following explanation will take one side as an example.

[0065] In some embodiments, such as Figures 1 to 4 As shown, the second lead-out portion 520 has a first segment 521 and a second segment 522. The second segment 522 connects the second connecting portion 510 and the first segment 521. The second connecting portion 510 is connected to the second empty foil area 120. The first segment 521 is electrically connected to the first lead-out portion 420. It should be noted that dividing the second electrode tab 500 into the first segment 521, the second segment 522, and the second connecting portion 510 according to their connection relationship is only for ease of description. The first segment 521 is used for end contact, the second segment 522 is used for lateral extension, and the second connecting portion 510 is used for root fixation. The first segment 521, the second segment 522, and the second connecting portion 510 are an integral structure, and there is no clear boundary between the first segment 521, the second segment 522, and the second connecting portion 510.

[0066] The first segment 521 and the first lead-out portion 420 are stacked along the thickness direction of the electrochemical device, so that the first tab 400 and the second tab 500 form a stable contact, avoiding connection failure caused by planar misalignment.

[0067] The first segment 521 and the first lead-out portion 420 are stacked together and extend to the outside of the electrochemical device package to connect with the external circuit. The overlapping area of ​​the first segment 521 and the first lead-out portion 420 forms a parallel conductive path, allowing current to be transmitted simultaneously through the contact surfaces of the two leads. This structure multiplies the conductive cross-sectional area per unit area while shortening the lateral flow distance of current between the leads, thereby reducing the overall circuit impedance and supporting higher charge and discharge rates.

[0068] The end of the first segment 521 is flush with the end of the first lead-out portion 420 to ensure the continuity of the current transmission path, eliminate the "discontinuity" in current transmission, and avoid a surge in local current density caused by misalignment.

[0069] The first segment 521 and the first lead-out portion 420 are connected as a single unit. The first segment 521 and the first lead-out portion 420 can be formed into a single unit by ultrasonic welding or laser welding, which further reduces the contact resistance of the first tab 400 and the second tab 500, and improves tensile and shear resistance.

[0070] The two ends of the second segment 522 are connected to the second connecting part 510 and the first segment 521, respectively. The second segment 522 is located outside the long side of the first electrode 100 and extends along the long side of the first electrode 100. The second segment 522 realizes the transition connection between the first segment 521 and the second connecting part 510, and the positional error between the first lead-out part 420 and the first segment 521 can be absorbed by the slight deformation of the second segment 522.

[0071] It should be noted that a tab adhesive (not labeled) is provided between the second lead-out section 520 and the fourth lead-out section 720. The tab adhesive refers to the insulating material layer covering the outer periphery of the second section 522. The tab adhesive on the outer periphery of the second section 522 can prevent direct metal contact between this section and the metal of the tabs in the same or adjacent layers, eliminating the risk of short circuit. The tab adhesive can specifically be polyacrylate or polyimide adhesive.

[0072] In some embodiments, the second empty foil region 120 includes a first edge 121 and a second edge 122 disposed opposite to each other along the long side direction of the first electrode 100. A second connecting portion 510 is disposed adjacent to the first edge 121, that is, the second connecting portion 510 is connected to the portion of the second empty foil region 120 near the first edge 121, and a receiving groove 123 is formed between the second connecting portion 510 and the second edge 122. Along the thickness direction of the electrochemical device, the projection of the receiving groove 123 covers the third connecting portion 610. That is, the receiving groove 123 is used to receive the connecting portion of the first tab 400 of another battery cell electrode when the electrode is wound to form a battery cell.

[0073] The second connecting portion 510 is positioned close to the first edge 121, meaning that the tab maintains a preset distance from the second edge 122 along the long side of the second empty foil area 120, reserving space to accommodate the third connecting portion 610. This can be achieved using a tab welding position offset process, ensuring that the width of the receiving groove 123 matches the size of the third connecting portion 610 through position control. Thus, the second empty foil area 120 can simultaneously accommodate the second connecting section of the second tab 500 and the third connecting portion 610 of the third tab 600; and by reserving the receiving groove 123, the second connecting portion 510 and the third connecting portion 610 are spaced apart along the long side, rather than stacked along the thickness direction, avoiding the size overlap problem caused by the stacking of tabs along the thickness direction in traditional designs, thus helping to maintain the flatness of the cell surface; at the same time, it avoids the compression deformation of the second connecting portion 510 and the third connecting portion 610 during winding, reducing the risk of interlayer short circuits and insulation failure.

[0074] Based on the above embodiments, the electrochemical device further includes a first protective adhesive 810, which is disposed between the second connecting portion 510 and the separating membrane 300, and both ends of the first protective adhesive 810 are respectively bonded to the outer sides of the first edge 121 and the second edge 122. The first protective adhesive 810 refers to an insulating material layer covering the back of the second connecting portion 510, which can specifically be polyimide tape or a ceramic coating, used to isolate metal parts from contact during the winding process.

[0075] In this embodiment, the first protective adhesive 810 is bonded to the outer side of both sides, forming a continuous protective structure that spans the receiving groove 123. This prevents the second connecting part 510 from warping under winding stress and ensures that the third connecting part 610 and the second connecting part 510 maintain a distance after winding. The first protective adhesive 810 forms an insulating layer between the second connecting part 510 and the third connecting part 610, preventing direct contact between metal parts and short circuits.

[0076] Furthermore, the electrochemical device also includes a second protective adhesive 820, which is disposed between the third connecting portion 610 and the separator 300, and is bonded to the outer edge of the first empty foil area 110. The second protective adhesive 820 refers to an insulating material layer covering the outside of the tab connecting portion, which can be implemented using polypropylene tape or polyimide tape, and is used to isolate the third connecting portion 610 from adjacent components during the winding process, further reducing the risk of short circuit.

[0077] After winding, the second protective adhesive 820 and the first protective adhesive 810 are stacked along the thickness direction, forming a double-layer isolation structure between the second connecting part 510 and the third connecting part 610, and between the second empty foil area 120 and the third connecting part 610.

[0078] In addition, this application also proposes an electronic device, which includes the electrochemical device described above, and the electrochemical device serves as a driving source or energy storage source for the electronic device.

[0079] The electronic device described in this application is not particularly limited and can be any electronic device known in the prior art. According to some embodiments of this application, the electronic device includes, but is not limited to, mobile phones, smartphones, laptops, tablets, wearable devices, smartwatches, smart bracelets, smart glasses, power banks, televisions, game consoles, game controllers, digital cameras, smart speakers, headphones, keyboards, mice, monitors, drones, audio equipment, home appliances, toys, power tools, automobiles, motorcycles, electric bicycles, bicycles, robots, robotic dogs, industrial robots, and android robots.

[0080] Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above embodiments should not be construed as limiting the present application, and that changes, substitutions and modifications can be made to the embodiments without departing from the spirit, principles and scope of the present application.

Claims

1. An electrochemical device, characterized in that, include: A first electrode, a separator, and a second electrode, wherein the separator is disposed between the first electrode and the second electrode; The first electrode, the separator, and the second electrode are wound together. The first electrode has a first empty foil region and a second empty foil region spaced apart along the winding direction, and the projections of the first empty foil region and the second empty foil region in the thickness direction of the electrochemical device do not overlap. The first electrode tab includes a first connecting portion and a first lead-out portion. The first connecting portion is connected to the first empty foil area, and the first lead-out portion protrudes from the long side of the first electrode sheet along the width direction of the first electrode sheet. The second electrode includes a second connecting part and a second lead-out part, the second connecting part being connected to the second empty foil area, and the second lead-out part being connected to the first lead-out part; The third tab includes a third connecting portion and a third lead-out portion. The third connecting portion is disposed on the second electrode plate. Along the thickness direction of the electrochemical device, the projection of the second empty foil area covers the third connecting portion, and the second connecting portion and the third connecting portion do not overlap.

2. The electrochemical device according to claim 1, characterized in that, The second lead-out portion has a first segment, and the first segment and the first lead-out portion are stacked together along the thickness direction of the electrochemical device.

3. The electrochemical device according to claim 2, characterized in that, The end of the first segment is flush with the end of the first lead-out portion; and / or, The first segment and the first lead-out part are connected as a single structure.

4. The electrochemical device according to claim 2, characterized in that, The second lead-out portion further includes a second segment, the two ends of which are connected to the second connecting portion and the first segment, respectively. The second segment is located outside the long side of the first electrode and extends along the long side of the first electrode.

5. The electrochemical device according to claim 1, characterized in that, The second empty foil area includes a first edge and a second edge disposed opposite to each other along the long side of the first electrode sheet, the second connecting portion is disposed adjacent to the first edge, and a receiving groove is formed between the second connecting portion and the second edge; Along the thickness direction of the electrochemical device, the projection of the receiving tank covers the third connection portion.

6. The electrochemical device according to claim 5, characterized in that, The electrochemical device further includes a first protective adhesive, which is disposed between the second connecting portion and the separating membrane, and the two ends of the first protective adhesive are respectively bonded to the outer sides of the first edge and the second edge.

7. The electrochemical device according to claim 1, characterized in that, The electrochemical device further includes a second protective adhesive, which is disposed between the third connecting portion and the separating membrane, and is bonded to the outer edge of the first empty foil area.

8. The electrochemical device according to claim 1, characterized in that, The second electrode has a third empty foil area and a fourth empty foil area spaced apart along the winding direction; The electrochemical device further includes a fourth tab, which comprises a fourth connection portion and a fourth lead-out portion. The third connecting part is connected to the third empty foil area, the fourth connecting part is connected to the fourth empty foil area, and the fourth lead-out part is connected to the third lead-out part; Along the thickness direction of the electrochemical device, the projection of the fourth empty foil region covers the first connection portion, and the first connection portion and the fourth connection portion do not overlap.

9. The electrochemical device according to claim 8, characterized in that, An electrode tab is provided between the second lead-out portion and the fourth lead-out portion.

10. An electronic device, characterized in that, The electrochemical device includes any one of claims 1 to 9.

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