Electrode assembly, battery, battery pack and electric device

Abstract

The invention provides an electrode assembly, a battery, a battery pack and a power utilization device. The electrode assembly comprises a positive plate and a negative plate which are overlapped along the thickness direction, through holes are formed in the positive plate and the negative plate, the through hole of the positive plate and the through hole of the negative plate at least partially coincide in the axis direction of the through holes, and the through holes form an exhaust channel; and the plurality of through holes are formed in the central area of the positive plate and / or the negative plate. The through holes in the electrode plate can discharge gas collected in the central area of the electrode plate, so that the situation that excessive gas occupies the space of the electrode plate to influence the electrolyte infiltration speed is avoided, the electrolyte infiltration difficulty is reduced, complete electrolyte infiltration is ensured, and the phenomenon of brown spots or lithium precipitation after the battery is charged is avoided. In addition, the through holes in the positive plate and the through holes in the negative plate at least partially coincide, enough space of the negative plate is ensured, and lithium precipitation on the surface of the negative plate and influence on battery performance are avoided.

Description

Technical Field

[0001] The present application belongs to the field of battery manufacturing technology, and specifically relates to an electrode assembly, a battery, a battery pack and an electrical device. Background Art

[0002] Currently, various industries have an increasing demand for high-capacity and high-energy-density batteries, especially in the field of power batteries in the new energy industry. This has led to larger and larger battery designs and thicknesses. As a result, the time it takes for the battery to be fully immersed after injection has become longer and longer. At the same time, the battery's exhaust level has become worse and worse.

[0003] In the relevant battery manufacturing process, after injection, the electrolyte usually starts to spread from the periphery of the pole piece to the center of the pole piece, causing the gas in the battery and the pores of the pole piece to gather in the middle of the pole piece, making it difficult to discharge the gas, and even forming a "holding breath" phenomenon, which increases the difficulty of electrolyte infiltration in the middle of the pole piece. If the pole piece is difficult to vent and the electrolyte infiltration is incomplete, the battery will precipitate lithium or form brown spots at the edge of the dry area during the formation or circulation process, thereby reducing the battery capacity and even causing safety accidents. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide an electrode assembly, a battery, a battery pack and an electrical device, which can solve the problem of incomplete electrolyte infiltration caused by difficulty in venting the electrode in the related art.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides an electrode assembly, comprising a positive electrode sheet and a negative electrode sheet stacked along a thickness direction of the electrode assembly;

[0007] The positive electrode sheet and the negative electrode sheet are both provided with through holes, along the axis direction of the through holes, the through holes of the positive electrode sheet and the through holes of the negative electrode sheet at least partially overlap, and each of the through holes forms an exhaust channel;

[0008] The plurality of through holes are arranged in the central area of ​​the positive electrode sheet and / or the negative electrode sheet.

[0009] Optionally, the distances between the centers of the through holes at different positions outside the central area and the edges of the positive electrode sheet and / or the negative electrode sheet are equal, which are all d.

[0010] Optionally, the central area is oval, circular or square.

[0011] Optionally, the positive electrode sheet and / or the negative electrode sheet is rectangular, the central area is elliptical, the long axis of the ellipse is parallel to the long side of the rectangle, and the short axis of the ellipse is parallel to the wide side of the rectangle.

[0012] Optionally, at least one surface of the positive electrode sheet and / or the negative electrode sheet is provided with a plurality of wire grooves extending along the length direction or width direction of the electrode sheet, and the plurality of wire grooves extend in the same direction and are not interconnected.

[0013] Optionally, a plurality of rows of the wire grooves 4 are arranged along the length direction and / or width direction of the pole piece, each row of the wire grooves 4 includes at least two wire grooves 4, and the wire grooves 4 in each row are not connected to each other.

[0014] Optionally, on the positive electrode sheet and / or the negative electrode sheet, the length of the rectangle is H, and 1 / 10*H≤d≤1 / 4*H.

[0015] Optionally, on the positive electrode sheet and / or the negative electrode sheet, the major axis size of the ellipse is a, the minor axis size is b, the width of the rectangle is W, and b / a=(W-2d) / (H-2d).

[0016] Optionally, along the axial direction of the through hole, the range of the center position deviation of a plurality of the through holes at corresponding positions is λ, and λ≤0.2 mm.

[0017] Optionally, the diameter of the through hole on the positive electrode sheet is R1, 1.0 mm ≤ R1 ≤ 2 mm.

[0018] Optionally, the distance between the edges of two adjacent through holes on the positive electrode sheet is L1, and R1≤L1≤1.5*R1.

[0019] Optionally, the diameter of the through hole on the negative electrode sheet is R2, 0.3mm≤R2≤R1-0.2mm.

[0020] Optionally, the distance between the edges of two adjacent through holes on the negative electrode sheet is L2, and R2≤L2≤1.5*R2.

[0021] Optionally, the electrode assembly further comprises a diaphragm;

[0022] The separator is arranged between the positive electrode sheet and the negative electrode sheet.

[0023] In a second aspect, an embodiment of the present application further provides a battery, comprising a housing, a pole, a pole ear, and an electrode assembly as described in any one of the above items;

[0024] The pole tab and the electrode assembly are located in the shell, the pole post is connected to the shell and is partially located outside the shell, and the pole tab is connected between the pole post and the positive electrode sheet or the negative electrode sheet.

[0025] In a third aspect, an embodiment of the present application further provides a battery pack comprising the above-mentioned battery.

[0026] In a fourth aspect, an embodiment of the present application further provides an electrical device, comprising the battery or battery pack described in the above embodiment.

[0027] The electrode assembly provided in the embodiment of the present application includes a positive electrode sheet and a negative electrode sheet stacked in the thickness direction of the electrode assembly. Both the positive electrode sheet and the negative electrode sheet are provided with through holes, which penetrate in the thickness direction of the electrode sheet. Multiple through holes are provided in the central area of ​​the positive electrode sheet or the negative electrode sheet. Each through hole forms an exhaust channel, which can discharge the gas collected in the middle of the electrode sheet, avoid excessive gas occupying the electrode sheet space and affecting the electrolyte infiltration speed, reduce the difficulty of electrolyte infiltration, ensure complete electrolyte infiltration, and avoid the formation of brown spots or lithium precipitation after the battery is charged. In addition, along the axial direction of the through hole, the through hole on the positive electrode sheet at least partially overlaps with the through hole on the negative electrode sheet, wherein, when the through hole on the positive electrode sheet includes the through hole on the corresponding negative electrode sheet, where the positive electrode sheet is not provided with a through hole, the corresponding negative electrode sheet is also not provided with a through hole. In other words, where the positive electrode has foil, the negative electrode also has foil. Therefore, the capacity of the negative electrode is greater than that of the positive electrode, satisfying the battery design concept of the negative electrode super-positive electrode, ensuring sufficient space for the negative electrode, avoiding lithium deposition on the surface of the negative electrode, and affecting the battery performance.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a schematic cross-sectional view of a battery provided in an embodiment of the present application;

[0031] Figure 2 Schematic diagram of the through hole of the positive electrode sheet in the embodiment of the present application;

[0032] Figure 3 Schematic diagram of the through hole of the negative electrode sheet in the embodiment of the present application;

[0033] Figure 4 is a schematic diagram of the through-hole distribution morphology of an embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of the position of the wire duct in the embodiment of the present application.

[0035] Description of reference numerals:

[0036] 1-positive electrode sheet, 2-negative electrode sheet, 3-through hole, 3a-positive electrode through hole, 3b-negative electrode through hole, 4-wire slot, 5-diaphragm, 6-shell, 7-pole, 7a-positive electrode column, 7b-negative electrode column, 8-pole ear, 8a-positive electrode ear, 8b-negative electrode ear. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0039] The electrode assembly, battery, and electrical device provided in the embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0040] Reference Figure 1 and Figure 2 An embodiment of the present application provides an electrode assembly, comprising a positive electrode sheet 1 and a negative electrode sheet 2 stacked along the thickness direction of the electrode assembly; both the positive electrode sheet 1 and the negative electrode sheet 2 are provided with a through hole 3, and along the axial direction of the through hole 3, the through hole 3 of the positive electrode sheet 1 and the through hole 3 of the negative electrode sheet 2 at least partially overlap, and each of the through holes 3 forms an exhaust channel; a plurality of the through holes 3 are arranged in the central area of ​​the positive electrode sheet 1 and / or the negative electrode sheet 2.

[0041] Specifically, if Figure 1 and Figure 2As shown in the figure, the electrode assembly is also called a bare cell, comprising at least one positive electrode sheet 1 and at least one negative electrode sheet 2, which are overlapped and connected along the thickness direction Z. When the battery adopts the lamination process, multiple positive electrode sheets 1 and multiple negative electrode sheets 2 are alternately arranged along the thickness direction Z, that is, each positive electrode sheet 1 is sandwiched between two negative electrode sheets 2, and each negative electrode sheet 2 is sandwiched between two positive electrode sheets 1, and a separator 5 is arranged between the positive electrode sheet 1 and the negative electrode sheet 2. When the battery adopts the winding process, the arrangement sequence of the negative electrode sheet 2, the separator 5, the positive electrode sheet 1 and the separator 5 is usually adopted for winding to form a cylindrical or square cell, and the electrode sheets of each circle are arranged along the thickness direction Z. Through holes 3 are provided on both the positive electrode sheet 1 and the negative electrode sheet 2. When a stacking process battery is used, each positive electrode sheet 1 and each negative electrode sheet 2 are provided with through holes 3, the positive electrode sheet 1 is provided with a positive electrode through hole 3a, and the negative electrode sheet 2 is provided with a negative electrode through hole 3b; when a winding process battery is used, each electrode sheet corresponding to each circle is provided with a through hole 3, and multiple through holes 3 are provided on each positive electrode sheet 1 and the negative electrode sheet 2. Since the electrolyte usually infiltrates and spreads from the periphery of the electrode sheet to the center of the electrode sheet, causing the gas in the pores of the electrode sheet to gather in the middle of the electrode sheet, multiple through holes 3 are provided in the central area of ​​the electrode sheet including the positive electrode sheet 1 and / or the negative electrode sheet 2, and this central area includes the central position of the electrode sheet. At this time, the efficiency of gas discharge is the highest, and each through hole 3 forms an exhaust channel to ensure the effective infiltration of the electrolyte. When multiple through holes 3 are provided on each electrode sheet, the through hole 3 in the middle position is located at the center of the electrode sheet or slightly offset from the center. The shapes of the through holes 3 include but are not limited to circle, diamond, rectangle and other shapes that can be used by those skilled in the art. The forming process of the through holes 3 includes but is not limited to laser drilling, stamping, rolling, punching and the like.

[0042] Specifically, if Figures 1 to 3 As shown in the figure, a plurality of positive through holes 3a are provided on the positive electrode sheet 1, and a plurality of negative through holes 3b are provided on the negative electrode sheet 2. Along the axial direction Z of the through hole 3, a negative through hole 3b is provided at each positive through hole 3a, and the positive through hole 3a and the negative through hole 3b at least partially overlap. In one embodiment, along the axial direction Z of the through hole 3, each positive through hole 3a includes all the corresponding negative through holes 3b. Where the positive electrode sheet 1 is not provided with a positive through hole 3a, the corresponding negative electrode sheet 2 is also not provided with a negative through hole 3b. In other words, the area where the positive electrode sheet 1 has a foil material also has a foil material on the negative electrode sheet 2. Therefore, the capacity of the negative electrode sheet 2 is greater than that of the positive electrode sheet 1, which meets the battery design concept of the negative electrode super-positive electrode, ensures sufficient space for the negative electrode, and avoids lithium deposition on the surface of the negative electrode, which affects the battery performance.

[0043] The electrode assembly provided in the embodiment of the present application has a through hole on both the pole piece and the negative pole piece, and the through hole is located at the center of the pole piece. During the charging process, the gas in the pores in the middle of the pole piece can be discharged to the outside of the pole piece through the exhaust channel formed by the through hole, so as to avoid excessive gas occupying the pole piece space and affecting the electrolyte infiltration speed, reduce the difficulty of electrolyte infiltration, ensure complete electrolyte infiltration, and avoid the formation of brown spots or lithium precipitation after the battery is charged. In addition, the positive through hole and the negative through hole at least partially overlap, and the positive through hole can be set to include the corresponding negative through holes, so as to further avoid the problem of lithium precipitation on the negative electrode surface.

[0044] Optionally, refer to Figure 2 and Figure 3 The distances between the centers of the through holes 3 at different outermost positions of the central area and the edges of the positive electrode sheet 1 and / or the negative electrode sheet 2 are equal, both being d.

[0045] Optionally, the central area is oval, circular or square.

[0046] Specifically, if Figure 2 and Figure 3 As shown in the figure, there are multiple through holes 3 on the positive electrode sheet 1 and / or the negative electrode sheet 2, that is, multiple through holes 3 are provided on at least one electrode sheet. In this embodiment, multiple through holes 3 are provided on both the positive electrode sheet 1 and the negative electrode sheet 2. On each electrode sheet, the central area is the shape formed by multiple through holes 3, and the distances between the centers of the through holes 3 at different positions outside this shape and the corresponding electrode sheet edges are equal, all being d. The shape of the central area is related to the shape of the electrode sheet. For example, when the positive electrode sheet 1 or the negative electrode sheet 2 is a square, the central area is a square, a circle or a rectangle; when the positive electrode sheet 1 or the negative electrode sheet 2 is a rectangle, the distribution of the through holes 3 is a rectangle, an ellipse or a rectangle with rounded corners, and the long and short sides of the rectangle and the ellipse correspond. Therefore, the distances between the multiple through holes 3 and the electrode sheet edges at different positions can be equal, and the figure formed by the multiple through holes 3 is located in the central area of ​​the electrode sheet, ensuring the gas discharge efficiency in the central area of ​​the electrode sheet, reducing the difficulty of electrolyte infiltration, and ensuring complete electrolyte infiltration.

[0047] Optionally, refer to Figure 2 and Figure 3 The positive electrode sheet 1 and / or the negative electrode sheet 2 is rectangular, the central area is elliptical, the long axis direction of the ellipse is parallel to the long side direction of the rectangle, and the short axis direction of the ellipse is parallel to the wide side direction of the rectangle.

[0048] Specifically, if Figure 2 and Figure 3As shown in the figure, at least one of the positive electrode sheet 1 and the negative electrode sheet 2 is rectangular, and the positive electrode sheet 1 and the negative electrode sheet 2 of this embodiment are both rectangular. Among them, the length of the rectangle of the positive electrode sheet 1 is H1, and the width is W1, and the length of the rectangle of the negative electrode sheet 2 is H2, and the width is W2. The distribution of the positive through hole 3a on the positive electrode sheet 1, that is, the central area is elliptical, and the long axis direction of the ellipse is parallel to the long side direction of the rectangle of the positive electrode sheet 1, and the short axis direction is parallel to the short side direction of the rectangle of the positive electrode sheet 1. The distribution of the negative through hole 3b on the negative electrode sheet 2 is also elliptical, and the long axis direction of the ellipse is parallel to the long side direction of the rectangle of the negative electrode sheet 2, and the short axis direction is parallel to the short side direction of the rectangle of the negative electrode sheet 2. This distribution feature can ensure that the distance between each through hole 3 outside the ellipse and the corresponding electrode edge is equal. Specifically, the distance between the outermost positive through hole 3a of the ellipse on the same positive electrode sheet 1 and the corresponding edge of the positive electrode sheet 1 is equal, which is d, and the distance between the outermost negative through hole 3b of the ellipse on the same negative electrode sheet 2 and the corresponding edge of the negative electrode sheet 2 is equal, which is also d. The number of positive through holes 3a and negative through holes 3b is equal, and the positions correspond one to one, which can ensure that the positive through holes include the corresponding negative through holes. The above-mentioned setting method of the elliptical shape can ensure that the distance between the through holes 3 at each edge and the edge of the electrode sheet is equal, and the through holes 3 are located in the middle of the electrode sheet as a whole.

[0049] Optionally, refer to Figure 1 and Figure 5 At least one surface of the positive electrode sheet 1 and / or the negative electrode sheet 2 is provided with a plurality of wire grooves 4 extending along the length direction or width direction of the electrode sheet, and the extension directions of the plurality of wire grooves 4 are the same and are not interconnected.

[0050] Specifically, if Figure 1 and Figure 5 As shown in the figure, at least one surface of at least one electrode sheet is provided with a wire groove 4 along the length Y direction or the width X direction. In this embodiment, a plurality of wire grooves 4 are provided only on the two surfaces of the positive electrode sheet 1 along the width X direction, and the plurality of wire grooves 4 are not connected to each other. The electrolyte can infiltrate from both sides to the middle along the wire grooves 4 on the positive electrode sheet 1. The predetermined extension direction of the wire grooves limits the electrolyte infiltration direction and improves the infiltration rate. The wire grooves 4 are provided in the coating area of ​​the positive electrode sheet 1, and can be provided outside the area of ​​the through hole 3, or the wire grooves 4 pass through the area of ​​the through hole 3, which is not limited in this embodiment. The electrode sheet provided with the wire grooves 4 improves the wetting ability of the entire coating area of ​​the electrode sheet, thereby avoiding the formation of brown spots or lithium precipitation after the battery is charged and affecting the battery performance.

[0051] Optionally, a plurality of rows of the wire grooves 4 are arranged along the length direction and / or width direction of the pole piece, each row of the wire grooves 4 includes at least two wire grooves 4, and the wire grooves 4 in each row are not connected to each other.

[0052] Specifically, the wire groove 4 can be set as a long wire groove or a discontinuous short wire groove. For example, multiple rows of wire grooves 4 are set along the length direction and / or width direction of the pole piece, and each row of wire grooves 4 includes at least two short wire grooves distributed at intervals. Each row of wire grooves 4 is not connected to each other. This arrangement of short wire grooves reduces the manufacturing cost on the basis of ensuring the wettability of the pole piece coating area.

[0053] Optionally, refer to Figure 2 and Figure 3 , on the positive electrode sheet 1 and / or the negative electrode sheet 2, the length of the rectangle is H, 1 / 10*H≤d≤1 / 4*H.

[0054] Specifically, if Figure 2 As shown in the figure, the length of the rectangular positive electrode sheet 1 is H1, and the distance d between the outer side of the ellipse of the positive through hole 3a and the edge of the positive electrode sheet 1 is 1 / 10*H1≤d≤1 / 4*H1. Figure 3 As shown in the figure, the length of the rectangular negative electrode sheet 2 is H2, and the distance d between the outer side of the ellipse of the negative through hole 3b and the edge of the negative electrode sheet 2 is 1 / 10*H2≤d≤1 / 4*H2. If the distance d is less than 1 / 10*H, the setting area of ​​the through hole 3 is too large, which increases the difficulty of processing and manufacturing, and is easy to reduce the strength of the electrode structure. If the distance d is greater than 1 / 4*H, the setting area of ​​the through hole 3 is too small, and the exhaust rate and electrolyte infiltration effect cannot be guaranteed.

[0055] Optionally, refer to Figures 2 to 4 On the positive electrode sheet 1 and / or the negative electrode sheet 2, the major axis size of the ellipse is a, the minor axis size is b, the width of the rectangle is W, and b / a=(W-2d) / (H-2d).

[0056] Specifically, if Figure 2 and Figure 4 As shown in the figure, in this embodiment, the through holes 3 on the positive electrode sheet 1 and the negative electrode sheet 2 are distributed in an elliptical shape. The major axis size of the ellipse is a, and the minor axis size is b. For the positive electrode sheet, the length of the rectangle is H1, the width is W1, and b / a=(W1-2d) / (H1-2d). For the negative electrode sheet, the length of the rectangle is H2, the width is W2, and b / a=(W2-2d) / (H2-2d). That is, the ratio of the major axis to the minor axis of the ellipse is equal to the ratio of the length to the width of the rectangle formed by the periphery of the through hole, that is, the ellipse is inscribed in the rectangle formed by the periphery of the through hole. At this time, the distribution of the through holes on the electrode sheet is closest to the middle of the electrode sheet, and the exhaust effect for the gas in the middle of the electrode sheet is best.

[0057] Optionally, refer to Figure 1 Along the axial direction of the through hole 3, the extreme difference of the center position deviation of the plurality of through holes 3 at corresponding positions is λ, λ≤0.2mm.

[0058] Specifically, if Figure 1 As shown in the figure, along the axis direction Z direction of the through hole 3, multiple through holes 3 at corresponding positions are coaxially arranged. However, in the actual processing process, due to manufacturing errors, it is impossible to achieve complete coaxiality, but the deviation λ of the center of the through hole 3 at the corresponding position is required to be λ≤0.2mm. Because along the Z direction, the gas can be discharged from the exhaust channel formed by each coaxial or approximately coaxial through hole 3, thereby improving the exhaust rate.

[0059] Optionally, refer to Figure 2 The diameter of the through hole 3 on the positive electrode sheet 1 is R1, 1.0mm≤R1≤2mm.

[0060] Specifically, if Figure 2 As shown in the figure, the diameter of the positive through hole 3a on the positive electrode sheet 1 is R1, 1.0mm≤R1≤2mm. When R1 is greater than 2mm, the large opening diameter will affect the structural strength of the positive electrode sheet 1; when R1 is less than 1mm, the small opening diameter will cause the gas in the positive electrode sheet 1 to be discharged unsmoothly.

[0061] Optionally, refer to Figure 2 The distance between the edges of two adjacent through holes 3 on the positive electrode sheet 1 is L1, and R1≤L1≤1.5*R1.

[0062] Specifically, if Figure 2 As shown in the figure, the distance between the outer edges of two adjacent positive through holes 3a on the positive electrode sheet 1 is L1, R1≤L1≤1.5*R1. This distance is the distance between the outer edges of two adjacent through holes 3 that are closest to each other. When the distance L1 is less than R1, the distance between the positive through holes is too small and inconvenient to process; when the distance L1 is greater than 1.5*R1, the distance between the positive through holes is too large, the positive exhaust concentration is low, and the exhaust effect is poor.

[0063] Optionally, refer to Figure 3 The diameter of the through hole 3 on the negative electrode sheet 2 is R2, 0.3mm≤R2≤R1-0.2mm.

[0064] Specifically, if Figure 3 As shown in the figure, the diameter of the negative through hole 3b on the negative electrode sheet 2 is R2, 0.3mm≤R2≤R1-0.2mm. Since the positive through hole 3a needs to correspond to all the negative through holes 3b, the diameter of the negative through hole needs to be smaller than the diameter of the positive through hole. In addition, when R2 is less than 1mm, the small opening diameter will cause the gas in the negative electrode sheet 2 to be discharged unsmoothly.

[0065] Optionally, refer to Figure 3 The distance between two adjacent through holes 3 on the negative electrode sheet 2 is L2, and R2≤L2≤1.5*R2.

[0066] Specifically, if Figure 3As shown in the figure, the distance between the outer edges of two adjacent negative through holes 3b on the negative electrode sheet 2 is L2, R2≤L2≤1.5*R2. When the distance L2 is less than R2, the distance between the negative through holes is too small and inconvenient to process; when the distance L2 is greater than 1.5*R2, the distance between the negative through holes is too large, the negative electrode sheet exhaust concentration is low, and the exhaust effect is poor.

[0067] Optionally, refer to Figure 1 The electrode assembly further includes a diaphragm 5 ; the diaphragm 5 is disposed between the positive electrode sheet 1 and the negative electrode sheet 2 .

[0068] Specifically, if Figure 1 As shown in the figure, a separator 5 is provided between each positive electrode sheet 1 and each negative electrode sheet 2. It is used to separate the positive and negative electrode sheets of the battery to prevent the positive and negative electrodes from contacting and short-circuiting. In addition, the separator also has the function of allowing lithium ions to pass through. The separator 5 can also be provided with through holes and / or wire grooves. On the basis of ensuring the structural stability of the separator 5, the wetting ability is improved, and the through holes and wire grooves may not be provided.

[0069] An embodiment of the present application also provides a battery, comprising a shell 6, a pole 7, a pole lug 8 and the electrode assembly described in any of the above embodiments; the pole lug 8 and the electrode assembly are located in the shell 6, the pole 7 is connected to the shell 6, and partially located outside the shell 6, and the pole lug 8 is connected between the pole 7 and the positive electrode sheet 1 or the negative electrode sheet 2.

[0070] Specifically, if Figure 1 As shown in the figure, the battery includes a shell 6, a positive electrode column 7a, a positive electrode ear 8a, a negative electrode column 7b, a negative electrode ear 8b, a positive electrode sheet 1, a negative electrode sheet 2 and a diaphragm 5. It can be understood that the shell 6 usually includes a cover plate, the electrode column is insulated and connected to the cover plate, and the battery leads the electrode assembly to the outside of the shell 6 through the electrode column, thereby realizing the extraction of the positive and negative electrodes of the battery. Exemplarily, a square battery is used, the positive electrode column 7a and the negative electrode column 7b are respectively located at both ends of the shell 6, the positive electrode ear 8a is connected between the positive electrode sheet 1 and the positive electrode column 7a, and the negative electrode ear 8b is connected between the negative electrode sheet 2 and the negative electrode column 7b. This embodiment can use a primary battery or a secondary battery, the battery process can be wound or laminated, and the battery form is a square shell or a soft pack battery. The gas is discharged through the through hole on the electrode sheet to ensure that the electrolyte is completely infiltrated, avoid the formation of brown spots or lithium precipitation after the battery is charged, and improve the battery performance.

[0071] The embodiment of the present application also provides a battery pack, including the battery described in the above embodiment, wherein the electrolyte is fully infiltrated by opening holes in the electrode plates to improve the performance of the battery pack.

[0072] The present application also provides an electric device, including the battery or battery pack of the above embodiment. When a soft pack battery is used, the electric device is a consumer electronic device, and when a square shell battery is used, the electric device is a battery pack, which can be used in new energy vehicles.

[0073] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0074] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. An electrode assembly, characterized in that: It comprises a positive electrode sheet (1) and a negative electrode sheet (2) stacked along the thickness direction of the electrode assembly; The positive electrode sheet (1) and the negative electrode sheet (2) are both provided with through holes (3), along the axis direction of the through holes (3), the through holes (3) of the positive electrode sheet (1) and the through holes (3) of the negative electrode sheet (2) at least partially overlap, and each of the through holes (3) forms an exhaust channel; The plurality of through holes (3) are arranged in the central area of ​​the positive electrode sheet (1) and / or the negative electrode sheet (2).

2. The electrode assembly according to claim 1, characterized in that: The distances between the centers of the through holes (3) at different outermost positions of the central area and the edges of the positive electrode sheet (1) and / or the negative electrode sheet (2) are equal, both being d.

3. The electrode assembly according to claim 2, characterized in that: The central area is oval, circular or square.

4. The electrode assembly according to claim 3, characterized in that: The positive electrode sheet (1) and / or the negative electrode sheet (2) is rectangular, the central area is elliptical, the long axis direction of the ellipse is parallel to the long side direction of the rectangle, and the short axis direction of the ellipse is parallel to the wide side direction of the rectangle.

5. The electrode assembly according to claim 1, characterized in that: At least one surface of the positive electrode sheet (1) and / or the negative electrode sheet (2) is provided with a plurality of wire grooves (4) extending along the length direction or width direction of the electrode sheet, and the plurality of wire grooves (4) extend in the same direction and are not interconnected.

6. The electrode assembly according to claim 5, characterized in that: A plurality of rows of the wire grooves (4) are arranged along the length direction and / or width direction of the pole piece, each row of the wire grooves (4) comprises at least two wire grooves (4), and the wire grooves (4) in each row are not interconnected.

7. The electrode assembly according to claim 4, characterized in that: On the positive electrode sheet (1) and / or the negative electrode sheet (2), the length of the rectangle is H, and 1 / 10*H≤d≤1 / 4*H.

8. The electrode assembly according to claim 4, characterized in that: On the positive electrode sheet (1) and / or the negative electrode sheet (2), the major axis dimension of the ellipse is a, the minor axis dimension is b, the width of the rectangle is W, and b / a=(W-2d) / (H-2d).

9. The electrode assembly according to claim 1, characterized in that: Along the axial direction of the through hole (3), the range of the central position deviation of a plurality of the through holes (3) at corresponding positions is λ, and λ≤0.2 mm.

10. The electrode assembly according to claim 1, characterized in that: The diameter of the through hole (3) on the positive electrode sheet (1) is R1, 1.0 mm ≤ R1 ≤ 2 mm.

11. The electrode assembly according to claim 9, characterized in that: The distance between the edges of two adjacent through holes (3) on the positive electrode sheet (1) is L1, and R1≤L1≤1.5*R1.

12. The electrode assembly according to claim 9, characterized in that The diameter of the through hole (3) on the negative electrode sheet (2) is R2, 0.3mm≤R2≤R1-0.2mm.

13. The electrode assembly according to claim 11, characterized in that The distance between the edges of two adjacent through holes (3) on the negative electrode sheet (2) is L2, and R2≤L2≤1.5*R2.

14. The electrode assembly according to any one of claims 1 to 13, characterized in that: The electrode assembly also includes a diaphragm (5); The separator (5) is arranged between the positive electrode sheet (1) and the negative electrode sheet (2).

15. A battery, characterized in that: It comprises a shell (6), a pole (7), a pole ear (8) and the electrode assembly according to any one of claims 1 to 14; The pole lug (8) and the electrode assembly are located inside the shell (6); the pole post (7) is connected to the shell (6) and is partially located outside the shell (6); the pole lug (8) is connected between the pole post (8) and the positive electrode sheet (1) or the negative electrode sheet (2).

16. A battery pack, characterized in that: Comprising the battery of claim 15.

17. An electrical device, characterized in that: Including the battery according to claim 15 or the battery pack according to claim 16.

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