Battery cells, batteries and electrical devices

Abstract

The present application relates to the field of battery technology, and in particular to a battery cell, a battery and an electrical device. In the technical solution of the embodiment of the present application, by setting a plurality of channels on the target area on the target pole piece close to the second side of the target pole piece, when the electrolyte infiltrates the target pole piece, it is beneficial to improve the wettability of the electrolyte to the area near the second side of the target pole piece, thereby being able to meet the wettability requirements of the electrolyte to the target pole piece and improving the charging capacity and energy density of the battery. Since the channels are located in the target area of ​​the target pole piece, rather than the entire area of ​​the target pole piece, the mechanical properties of the target pole piece are improved, thereby improving the safety performance of the battery. As a result, not only the charging capacity and energy density of the battery are improved, but also the safety performance of the battery is improved.

Description

Technical Field

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

[0002] The battery life of an electrical device is closely related to the energy density of the battery. However, the current charging capacity and energy density of batteries need to be improved. Utility Model Content

[0003] Based on this, the present application provides a battery cell, a battery and an electrical device, which can improve the charging capacity and energy density of the battery.

[0004] In the first aspect, the present application provides a battery cell, which includes a target pole piece, the target pole piece having a first side and a second side arranged opposite to each other; the target pole piece has a target area close to the second side, and the target pole piece is provided with a plurality of channels located in the target area; the direction of the first side pointing to the second side, the length direction of the target pole piece and the thickness direction of the target pole piece are perpendicular to each other; the second side is arranged above the first side along the direction of gravity.

[0005] In the technical solution of the embodiment of the present application, by setting a plurality of channels on the target area near the second side of the target electrode sheet on the target electrode sheet, when the electrolyte infiltrates the target electrode sheet, it is beneficial to improve the wettability of the electrolyte to the area near the second side of the target electrode sheet, thereby being able to meet the wettability requirements of the electrolyte to the target electrode sheet and improve the charging capacity and energy density of the battery. Since the channels are located in the target area of ​​the target electrode sheet, rather than the entire area of ​​the target electrode sheet, the mechanical properties of the target electrode sheet are improved, thereby improving the safety performance of the battery. As a result, not only the charging capacity and energy density of the battery are improved, but also the safety performance of the battery is improved.

[0006] In some embodiments, along the direction from the first side to the second side, the target area is located between the second side and the first reference plane; the first reference plane is perpendicular to the direction from the first side to the second side; the target pole piece has a first central axis parallel to the length direction, and the first central axis is located on the first reference plane.

[0007] In this way, the target area is made closer to the second side as a whole, and the area where the channel is provided on the target electrode can be further reduced. While improving the wettability of the electrolyte to the area near the second side of the target electrode, the mechanical properties of the target electrode are further improved, thereby further improving the safety performance of the battery.

[0008] In some embodiments, along the direction from the first side to the second side, the ratio of the size of the target area to the size of the target pole piece is one fifth to two fifths.

[0009] In this way, by controlling the ratio between the corresponding dimensions of the target area and the corresponding dimensions of the target electrode piece, the wettability of the electrolyte to the area near the second side of the target electrode piece can be improved while further improving the mechanical properties of the target electrode piece.

[0010] In some embodiments, a ratio of a size of the target region to a size of the target pole piece along a direction from the first side to the second side is one third.

[0011] At this time, by setting the ratio of the corresponding size of the target area to the corresponding size of the target pole piece to one third, the mechanical properties of the target pole piece can be improved to a greater extent while satisfying the wettability of the electrolyte to the area near the second side of the target pole piece.

[0012] In some embodiments, along the direction from the first side to the second side, the target area has a first boundary line and a second boundary line that are arranged opposite to each other; wherein the first boundary line and the boundary line of the target pole piece located on the second side coincide with each other. In some embodiments, along the direction from the first side to the second side, the target area has a first boundary line and a second boundary line that are arranged opposite to each other; wherein the second boundary line is located between the first boundary line and the first reference surface.

[0013] In this way, by controlling the positions of the first boundary line and the second boundary line of the target area, it is possible to determine the target area according to the positions of the first boundary line and the second boundary line, and then set the channel on the target area.

[0014] In some embodiments, along the length direction, the target region has a third boundary line and a fourth boundary line that are relatively set; wherein the third boundary line coincides with a boundary line on one side of the target pole piece along the length direction. In some embodiments, along the length direction, the target region has a third boundary line and a fourth boundary line that are relatively set; wherein the fourth boundary line coincides with a boundary line on the other side of the target pole piece along the length direction.

[0015] In this way, by controlling the positions of the third boundary line and the fourth boundary line of the target area, it is possible to determine the target area according to the positions of the third boundary line and the fourth boundary line, and then set the channel on the target area.

[0016] In some embodiments, the target pole piece includes: a current collector having a first surface and a second surface arranged opposite to each other along the thickness direction; and an active layer arranged on at least one of the first surface and the second surface; wherein, at least one of the current collector and the active layer is provided with a channel.

[0017] In this way, the hole can be flexibly set on the corresponding structure of the target pole piece according to the specific structure and use requirements of the target pole piece.

[0018] In some embodiments, the first surface and the second surface on which the active layer is disposed are defined as target surfaces, and multiple active layers are disposed on the target surfaces; among the active layers on the same target surface, at least one active layer has a pore.

[0019] When multiple active layers are arranged on the corresponding surface, holes can be arranged on at least one of the multiple active layers according to usage requirements, so that the arrangement of the holes is more flexible.

[0020] In some embodiments, in active layers located on the same target surface, multiple active layers are provided with channels; the active layer provided with channels is defined as a target active layer; among all target active layers located on the same target surface, multiple target active layers with different compaction densities exist.

[0021] The target active layer has different compaction densities, and thus different toughness. The smaller the compaction density of the target active layer, the greater the toughness of the target active layer. The greater the compaction density of the target active layer, the higher the energy density of the target active layer. In this way, the target electrode has a certain energy density while having certain mechanical properties. The smaller the compaction density of the target active layer, the fewer pores formed inside the active layer, the higher the capillary climbing ability of the electrolyte in the active layer, and the better the infiltration effect of the electrolyte. In this way, the infiltration effect of the electrolyte on the corresponding active layer can be further improved by controlling the compaction density of the target active layer and coordinating with the pores on the target active layer.

[0022] In some embodiments, in the target active layers located on the same target surface, the total area ratio of all pores of the target active layer with a higher compaction density on the target active layer is greater than the total area ratio of all pores of the target active layer with a lower compaction density in the target active layer.

[0023] In this way, by controlling the total area of ​​all the pores of the target active layer with a higher compaction density to account for a larger proportion on the target active layer, the wetting effect of the electrolyte on the corresponding active layer can be further improved while further improving the mechanical properties of the target electrode.

[0024] In some embodiments, among the target active layers located on the same target surface, the target active layer with a smaller compaction density is farther away from the current collector.

[0025] In this way, by moving the target active layer with a smaller compaction density further away from the current collector, that is, moving the target active layer with a larger compaction density closer to the current collector, it is beneficial to further improve the mechanical properties of the target electrode while improving the wetting effect of the electrolyte.

[0026] In some embodiments, a surface where an active layer is disposed on the first surface and the second surface is defined as a target surface; a plurality of active layers are disposed on the target surface; among all active layers located on the same target surface, the compaction density of the active layer farther away from the current collector is smaller.

[0027] By controlling the compaction density of the active layer farther from the current collector on the target surface to be smaller, that is, the compaction density of the active layer closer to the current collector is larger, the mechanical properties of the part of the target pole piece closer to the current collector are made better, so that the mechanical properties of each part of the target pole piece can be improved in sequence from the outside to the inside of the target pole piece. In this way, the mechanical properties of the target pole piece can be further improved.

[0028] In some embodiments, the active layer is provided with at least one layer; among all the pores, there are pores provided on the active layer; for the active layer provided with pores, the total area of ​​all the pores on the active layer on the active layer accounts for 2×10 -7-2N Up to 4×10 -1-2N ; Wherein, N is a positive integer greater than or equal to 1; N is the number of layers of the active layer on its surface, and the farther away from the current collector, the larger the number of layers of the active layer.

[0029] Based on the number of layers where the active layer with channels is located, controlling and setting the total area ratio corresponding to all channels on the active layer is not only beneficial to improving the wetting effect of the electrolyte on the active layer, but also beneficial to further improve the mechanical properties of different parts of the target electrode, thereby improving the mechanical properties of the target electrode as a whole.

[0030] In some embodiments, the active layer is provided with at least one layer; among all the pores, there are pores provided on the active layer; wherein, when the first active layer is provided with pores, the pore size of the pores on the first active layer is 0.01 mm to 1 mm. In some embodiments, the active layer is provided with at least one layer; among all the pores, there are pores provided on the active layer; wherein, when the Mth active layer is provided with pores, the pore size of the pores on the Mth active layer is 0.005 mm to 0.5 mm, M is a positive integer greater than or equal to 2, M is the number of layers of the active layer on its surface, and the number of layers of the active layer farther away from the current collector is larger.

[0031] Based on the number of layers of the active layer with the pores, controlling the pore size of the pores on the active layer is not only beneficial to improving the wetting effect of the electrolyte on the active layer, but also beneficial to further improve the mechanical properties of different parts of the target electrode, thereby improving the mechanical properties of the target electrode as a whole. In addition, by controlling the pore size of the pores, it is also convenient to process and manufacture the corresponding pores.

[0032] In some embodiments, a surface on which an active layer is disposed on the first surface and the second surface is defined as a target surface; among all the pores, there are pores disposed on the current collector and pores disposed on the active layer adjacent to the target surface; among the pores on the active layer adjacent to the target surface, there are pores connected to the pores on the current collector.

[0033] In this way, by providing pores on the active layer adjacent to the target surface that are connected to the pores on the current collector, the channels through which the electrolyte can enter can be further expanded with the help of the pores on the current collector, which is beneficial to further improve the wetting effect of the electrolyte.

[0034] In some embodiments, the pores on the active layer adjacent to the target surface are connected to the pores on the current collector in a one-to-one correspondence.

[0035] In this way, the pores on the current collector can be further utilized to further improve the wetting effect of the electrolyte.

[0036] In some embodiments, the pores on the active layer adjacent to the target surface overlap with the orthographic projections of the corresponding pores on the current collector on a second reference plane; the second reference plane is perpendicular to the thickness direction.

[0037] In this way, not only can the infiltration effect of the electrolyte be further improved by utilizing the pores on the current collector, but it is also easier to manufacture and improves the manufacturing efficiency.

[0038] In some embodiments, there are channels on the current collector among all the channels; the total area of ​​all the channels on the current collector accounts for 2×10 -9 Up to 4×10 -3 .

[0039] By controlling the total area ratio corresponding to the channels on the current collector, it is beneficial to improve the wetting effect of the electrolyte while the current collector has certain mechanical properties.

[0040] In some embodiments, among all the pores, there are pores disposed on the current collector; and the pore diameter of the pores disposed on the current collector is 0.01 mm to 1 mm.

[0041] By controlling the pore size of the pores on the current collector, it is beneficial to improve the electrolyte infiltration effect while the current collector has certain mechanical properties.

[0042] In some embodiments, one of the current collector and the active layer having pores is defined as a target object; wherein, among the pores provided in the target object, there are pores that penetrate the target object along the thickness direction. In some embodiments, one of the current collector and the active layer having pores is defined as a target object; wherein, among the pores provided in the target object, there are pores that do not penetrate the target object along the thickness direction.

[0043] In this way, according to actual use requirements, a hole that penetrates or does not penetrate the target object can be set on the target object to meet the required electrolyte infiltration effect and the required mechanical properties of the target object.

[0044] In some embodiments, one of the current collector and the active layer having pores is defined as a target object; a plurality of pores are provided on the target object; and at least some of all pores on the same target object are arranged according to a preset rule.

[0045] In this way, the corresponding channels can be arranged in a required pattern according to the use requirements to obtain the required electrolyte infiltration effect and the required mechanical properties of the target object.

[0046] In some embodiments, the preset rule includes at least one of arrangement in a single direction and arrangement in an array.

[0047] In this way, the preset rules can be one or more, which makes it easy to flexibly set the channels according to usage requirements.

[0048] In some embodiments, at least some of the channels are arranged in rows along a direction from the first side to the second side, and are arranged in columns along a length direction.

[0049] In this way, at least part of the pores are arranged in a rectangular array, which is beneficial to improving the infiltration effect of the electrolyte and the mechanical properties of the target object while facilitating processing and manufacturing.

[0050] In some embodiments, active layers are disposed on both the first surface and the second surface; the active layer disposed on the first surface is symmetrically arranged with the active layer disposed on the second surface about the middle section of the current collector; the middle section is perpendicular to the thickness direction.

[0051] This is not only beneficial to improving the energy density of the target pole piece, but also beneficial to improving the consistency of the target pole piece on both sides of the middle section of the current collector, thereby further improving the mechanical properties of the target pole piece as a whole.

[0052] In some embodiments, an extension direction of at least one of all the channels is parallel to the thickness direction.

[0053] When the extension direction of the pores is parallel to the thickness direction, the pores are substantially extended in a straight line. Such pores can satisfy the infiltration effect of the electrolyte and are easy to manufacture.

[0054] In some embodiments, the cross-sectional shapes of all the channels along the thickness direction include at least one of regular shapes and irregular shapes.

[0055] In this way, the required cross-sectional shape of the channel can be flexibly set according to actual usage.

[0056] In some embodiments, the battery cell includes an electrode assembly, the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet is configured as a target electrode sheet; and / or the negative electrode sheet is configured as a target electrode sheet.

[0057] In this way, the positive electrode sheet and the negative electrode sheet can be flexibly arranged according to actual usage.

[0058] In some embodiments, the electrode assembly is a laminated structure. Thus, an electrode assembly with a laminated structure can be selected according to usage requirements.

[0059] In a second aspect, the present application provides a battery comprising any of the above battery cells.

[0060] In the technical solution of the embodiment of the present application, since the battery includes the battery cell in any of the above embodiments, it also has the advantages of the battery cell described in any of the above embodiments.

[0061] In a third aspect, the present application provides an electrical device, comprising any of the above batteries, the battery being used to provide electrical energy.

[0062] In the technical solution of the embodiments of the present application, since the electrical device includes the battery in any of the above embodiments, it also has the advantages of the battery described in any of the above embodiments.

[0063] 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

[0064] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0065] Figure 1 A schematic diagram of the structure of a vehicle in some embodiments of the present application;

[0066] Figure 2 Schematic diagram of the exploded structure of the battery in some embodiments of the present application;

[0067] Figure 3 This is a schematic diagram of the structure of a battery module in some embodiments of the present application;

[0068] Figure 4 A schematic diagram of the exploded structure of a battery cell in some embodiments of the present application;

[0069] Figure 5 A schematic diagram of the structure of a target pole piece in some embodiments of the present application at a viewing angle;

[0070] Figure 6 It is a schematic structural diagram of an electrode piece without a hole in some related embodiments after being soaked in electrolyte at one viewing angle;

[0071] Figure 7 Schematic diagram of the relationship between a pole piece without a hole and a target area in some related embodiments;

[0072] Figure 8 for Figure 5 The target pole piece shown in the figure shows a structural schematic diagram of the target area range;

[0073] Fig. 9 In some embodiments of the present application Figure 5 A schematic diagram of the cross-sectional structure of the target pole piece in the cross-sectional direction AA;

[0074] Fig.10 In some embodiments of the present application Figure 5 The schematic diagram of the structure of the target pole piece in the cross-sectional direction BB is shown;

[0075] Fig.11 In other embodiments of the present application Figure 5 The schematic diagram of the structure of the target pole piece in the cross-sectional direction BB is shown;

[0076] Fig.12 A schematic projection diagram of a hole on a target pole piece in some embodiments of the present application;

[0077] Fig.13 In some other embodiments of the present application Figure 5 The schematic diagram of the structure of the target pole piece in the cross-sectional direction BB is shown;

[0078] Fig.14 This is a schematic diagram of the structure of the electrode assembly in some embodiments of the present application.

[0079] The reference numerals in the specific implementation manner are as follows:

[0080] Vehicle 1;

[0081] Battery 10, controller 20, motor 30;

[0082] Box body 100, first part 110, second part 120;

[0083] Battery cell 200, end cap 210, electrode terminal et, shell 220, electrode assembly 230, target electrode sheet 231, electrode tab ta, current collector 2311, first surface m1, second surface m2, target surface mt, active layer 2312, first active layer 2312a, second active layer 2312b, third active layer 2312c, fourth active layer 2312d, target active layer u, positive electrode sheet 231a, negative electrode sheet 231b, first side s1, second side s2, separator 232, target area z, first boundary line z1, second boundary line z2, third boundary line z3, fourth boundary line z4, channel p, first channel p1, second channel p2;

[0084] first size h1, second size h2, first distance d1, second distance d2, aperture x, first aperture x1, second aperture x2;

[0085] First reference plane E1, second reference plane E2, mid-section MS, first central axis C1, first projection y1, second projection y2;

[0086] Pole piece I, wetted area j1, unwetted area j2;

[0087] Width direction W, thickness direction T, length direction L, first direction F1, second direction F2, third direction F3, cross-sectional directions AA and BB. DETAILED DESCRIPTION

[0088] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0090] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0091] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0092] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0093] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0094] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0095] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0096] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0097] The battery life of an electrical device is closely related to the energy density of the battery. As the energy density increases, the thickness and compaction density of the electrode become larger, which makes it difficult for the electrolyte to penetrate the electrode, resulting in poor electrode wetting, which in turn impairs the fast charging performance and energy density of the battery.

[0098] In order to improve the charging capacity and energy density of the battery, the embodiments of the present application improve the wetting effect of the electrolyte in the area of ​​the pole piece where poor wetting is likely to occur, thereby improving the wetting effect of the area of ​​the pole piece. Specifically, a channel that can be used to accommodate the electrolyte can be provided in the area where poor wetting is likely to occur, so as to improve the wetting effect of the electrolyte in the area through the channel, thereby improving the charging capacity and energy density of the battery.

[0099] Based on this, in order to improve the problem of reducing the charging capacity and energy density of the battery due to poor infiltration of the electrolyte, an embodiment of the present application provides a battery cell. By setting channels in corresponding areas on the target electrode, a structure that can improve the infiltration effect of the electrolyte is constructed, thereby improving some of the aforementioned problems.

[0100] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical devices such as vehicles, ships or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device, which is helpful to improve the problem of reduced battery charging capacity and energy density due to poor electrolyte infiltration.

[0101] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0102] For the convenience of description, the following embodiments are described by taking a vehicle 1 as an example of an electrical device in some embodiments of the present application.

[0103] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1 provided for some embodiments of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 10 is provided inside the vehicle 1, and the battery 10 may be provided at the bottom, head or tail of the vehicle 1. The battery 10 may be used to power the vehicle 1, for example, the battery 10 may be used as an operating power source for the vehicle 1. The vehicle 1 may also include a controller 20 and a motor 30, and the controller 20 is used to control the battery 10 to power the motor 30, for example, for starting, navigating and operating power requirements of the vehicle 1 during driving.

[0104] In some embodiments of the present application, the battery 10 can be used not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0105] Please refer to Figure 2 , Figure 2 A schematic diagram of the exploded structure of a battery 10 provided for some embodiments of the present application. The battery 10 includes a box 100 and a battery cell 200, and the battery cell 200 is contained in the box 100. Among them, the box 100 is used to provide a storage space for the battery cell 200, and the box 100 can adopt a variety of structures. In some embodiments, the box 100 may include a first part 110 and a second part 120, and the first part 110 and the second part 120 cover each other, and the first part 110 and the second part 120 jointly define a storage space for accommodating the battery cell 200. The second part 120 may be a hollow structure with one end open, and the first part 110 may be a plate-like structure, and the first part 110 covers the open side of the second part 120, so that the first part 110 and the second part 120 jointly define a storage space; the first part 110 and the second part 120 may also be hollow structures with one side open, and the open side of the first part 110 covers the open side of the second part 120. Of course, the box body 100 formed by the first part 110 and the second part 120 can be in various shapes, such as a cylinder, a cuboid, etc.

[0106] Please refer to Figure 3 , Figure 3A schematic diagram of the structure of a battery module provided for some embodiments of the present application. In the battery 10, there may be a plurality of battery cells 200, and a plurality of battery cells 200 may constitute a battery module. A plurality of battery cells 200 may be connected in series, in parallel, or in a mixed connection, and a mixed connection means that a plurality of battery cells 200 are both connected in series and in parallel. A plurality of battery cells 200 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the plurality of battery cells 200 is accommodated in the case 100; of course, the battery 10 may also be a battery module in which a plurality of battery cells 200 are first connected in series, in parallel, or in a mixed connection, and a plurality of battery modules are then connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the case 100. The battery 10 may also include other structures. For example, the battery 10 may also include a busbar component for realizing electrical connection between a plurality of battery cells 200.

[0107] Each battery cell 200 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 200 may be cylindrical, flat, rectangular, or in other shapes, and the present application embodiment does not limit this.

[0108] Please refer to Figure 4 , Figure 4 The schematic diagram of the exploded structure of the battery cell 200 provided in some embodiments of the present application. The battery cell 200 refers to the smallest unit constituting the battery 10. Figure 3 The battery cell 200 includes an end cap 210, a shell 220, an electrode assembly 230 and other functional components.

[0109] The end cap 210 refers to a component that covers the opening of the shell 220 to isolate the internal environment of the battery cell 200 from the external environment. Without limitation, the shape of the end cap 210 can be adapted to the shape of the shell 220 to match the shell 220. Optionally, the end cap 210 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 210 is not easily deformed when it is squeezed and collided, so that the battery cell 200 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals et can be provided on the end cap 210. The electrode terminal et can be used to electrically connect to the electrode assembly 230 for outputting or inputting electrical energy of the battery cell 200. In some embodiments, the end cap 210 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 200 reaches a threshold. In some embodiments, the end cap 210 can also be provided with a liquid injection hole for injecting electrolyte into the interior of the battery cell 200. The material of the end cap 210 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the present embodiment. In some embodiments, an insulating member can be provided on the inner side of the end cap 210, and the insulating member can be used to isolate the electrical connection components in the housing 220 from the end cap 210 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0110] The shell 220 is a component used to cooperate with the end cap 210 to form the internal environment of the battery cell 200, wherein the formed internal environment can be used to accommodate the electrode assembly 230, the electrolyte and other components. The shell 220 and the end cap 210 can be independent components, and an opening can be set on the shell 220, and the internal environment of the battery cell 200 is formed by covering the opening with the end cap 210 at the opening. Without limitation, the end cap 210 and the shell 220 can also be integrated. Specifically, the end cap 210 and the shell 220 can form a common connection surface before other components are put into the shell, and when it is necessary to encapsulate the interior of the shell 220, the end cap 210 covers the shell 220. The shell 220 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 220 can be determined according to the specific shape and size of the electrode assembly 230. The shell 220 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0111] The electrode assembly 230 is a component in the battery cell 200 where an electrochemical reaction occurs. The housing 220 may contain one or more electrode assemblies 230. Fig.14The electrode assembly 230 is mainly formed by winding or stacking a positive electrode sheet 231a and a negative electrode sheet 231b, and a separator 232 is usually provided between the positive electrode sheet 231a and the negative electrode sheet 231b. The parts of the positive electrode sheet 231a and the negative electrode sheet 231b with active materials constitute the main body of the electrode assembly 230, and the parts of the positive electrode sheet 231a and the negative electrode sheet 231b without active materials each constitute a tab ta (which can be combined with the schematic diagram shown later). Figure 5 ). The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 10, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab ta connects the electrode terminal et to form a current loop. The separator 232 is used to isolate the positive electrode sheet 231a and the negative electrode sheet 231b, and prevent the electrons in the battery cell 200 from passing freely, allowing the ions in the electrolyte to flow freely between the positive electrode sheet 231a and the negative electrode sheet 231b. The separator 232 may be a thin film made of materials such as PE (polyethylene) and PP (polypropylene).

[0112] According to some embodiments of this application, please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of the target pole piece 231 provided in some embodiments of the present application at a viewing angle. Figure 4 In the figure, the first direction F1 is the height direction of the battery cell 110, the second direction F2 is the thickness direction of the battery cell 200, and the third direction F3 is the length direction of the battery cell 200. The first direction F1, the second direction F2 and the third direction F3 are perpendicular to each other. The length direction L of the pole piece 231 is parallel to the third direction F3, the width direction W of the pole piece 231 is parallel to the first direction F1, and the thickness direction T of the pole piece 231 is parallel to the second direction F2. The length direction L, the width direction W and the thickness direction T of the pole piece 231 are perpendicular to each other. In the figure, two directions parallel to each other are indicated by an arrow.

[0113] It can be understood that the first direction F1, the second direction F2 and the third direction F3 are only for the convenience of description and are not limitations to the embodiments of the present application.

[0114] The battery cell 200 includes a target electrode piece 231, and the target electrode piece 231 has a first side s1 and a second side s2 that are arranged opposite to each other. The target electrode piece 231 has a target area z close to the second side s2. The target electrode piece 231 is provided with a plurality of holes p located in the target area z. The direction from the first side s1 to the second side s2, the length direction L of the target electrode piece 231, and the thickness direction T of the target electrode piece 231 are perpendicular to each other. In the embodiment of the present application, the direction from the first side s1 to the second side s2 is parallel to the width direction W of the target electrode piece 231, and the second side s2 is arranged above the first side s1 along the gravity direction.

[0115] The target region z close to the second side s2 means that the distance between the boundary line of the side of the target region z close to the second side s2 and the second side s2 of the target pole piece 231 is smaller than the distance between the boundary line of the side of the target region z close to the first side s1 and the first side s1 of the target pole piece 231. In this way, the target region z is a region closer to the second side s2 of the target pole piece 231 as a whole.

[0116] The pore p is a channel with a certain accommodation space. Compared with the portion of the target electrode 231 where the pore p is not provided, the electrolyte is more likely to flow into the accommodation space of the pore p through the pore p, thereby facilitating the improvement of the electrolyte infiltration effect of the target area z where the pore p is provided.

[0117] Combined with reference Figure 6 and Figure 7 , Figure 6 is a schematic structural diagram of a pole piece 1 at a viewing angle after being soaked in electrolyte in some related embodiments without a hole p, Figure 7 Schematic diagram of the relationship between the electrode piece I without the hole p and the target area z in some related embodiments. After the electrode piece I is infiltrated by the electrolyte, a wetted area j1 and a non-wetted area j2 appear. Among them, the wetted area j1 is the area close to the first side s1 of the electrode piece I, and the non-wetted area j2 is the area close to the second side s2 of the electrode piece I, that is, the non-wetted area j2 can be roughly regarded as the upper area of ​​the electrode piece I. The boundary line between the wetted area j1 and the non-wetted area j2 is roughly arc-shaped, and the boundary line is convexly arranged toward the second side s2 of the electrode piece I.

[0118] In the embodiment of the present application, since the target area z is closer to the second side s2 of the electrode 231, the target area z can be closer to the unwetted area j2 or at least partially overlap with the unwetted area j2, thereby improving the wetting effect of the electrolyte in the unwetted area j2. Exemplarily, the target area z and the unwetted area j2 can overlap or partially overlap with each other. In the case where the target area z and the unwetted area j2 partially overlap, Figure 7For example, the target area z may be partially overlapped with the non-wetted area j2 and partially overlapped with the wetted area j1. The target area z may be determined on the electrode 231 according to specific usage conditions, and is not specifically limited here.

[0119] By setting a plurality of holes p on the target area z near the second side s2 of the target electrode 231 on the target electrode 231, when the electrolyte infiltrates the target electrode 231, it is beneficial to improve the wettability of the electrolyte to the area near the second side s2 of the target electrode 231, so as to meet the wettability requirements of the electrolyte to the target electrode 231, thereby improving the charging capacity and energy density of the battery. In addition, compared with the method of setting the holes p on the entire area of ​​the target electrode 231, since the holes p are located in the target area z of the target electrode 231, rather than the entire area of ​​the target electrode 231, not only the tensile strength of the target electrode 231 is improved, thereby improving the mechanical properties of the target electrode 231, but also the particles generated by setting too many holes p can be improved, thereby improving the safety performance of the battery as a whole. Therefore, the target electrode 231 provided in the embodiment of the present application not only improves the charging capacity and energy density of the battery, but also improves the safety performance of the battery.

[0120] It is understandable that the battery cell 200 includes a positive electrode sheet 231a and a negative electrode sheet 231b, and the positive electrode sheet 231a can be the target electrode sheet 231, and the negative electrode sheet 231b can also be the target electrode sheet 231. Of course, both the positive electrode sheet 231a and the negative electrode sheet 231b can be the target electrode sheet 231. It can be set according to actual use conditions and is not specifically limited here.

[0121] According to some embodiments of this application, please continue to refer to Figure 5 , and combined with reference Figure 8 , Figure 8 for Figure 5 The target pole piece 231 shown in the figure shows a schematic diagram of the structure of the target area z range. Along the direction from the first side s1 to the second side s2, the target area z is located between the second side s2 and the first reference plane E1. The first reference plane E1 is perpendicular to the direction from the first side s1 to the second side s2. The target pole piece 231 has a first central axis C1 parallel to the length direction L, and the first central axis C1 is located on the first reference plane E1. Of course, it can be understood that the target pole piece 231 can also have a central axis parallel to the width direction W (not shown in the figure). Since the first reference plane E1 is perpendicular to the width direction W, Figure 5 and Figure 8 In the viewing angle shown, the first reference surface E1 is in a straight line shape.

[0122] In this way, the target area z can be roughly regarded as being located at the upper part of the target electrode piece 231, which makes the target area z closer to the second side s2 as a whole, and can further reduce the area where the channel p is provided on the target electrode piece 231. While being able to improve the wettability of the electrolyte to the area near the second side s2 of the target electrode piece 231, it can further improve the mechanical properties of the target electrode piece 231, thereby further improving the safety performance of the battery.

[0123] According to some embodiments of this application, please continue to refer to Figure 5 and Figure 8 , along the direction from the first side s1 to the second side s2, the ratio of the size of the target area z to the size of the target pole piece 231 is one-fifth to two-fifths. That is, the size of the target area z along the width direction W is the first size h1, the size of the target pole piece 231 along the width direction W is the second size h2, and the ratio of the first size h1 to the second size h2 is one-fifth to two-fifths. Exemplarily, the ratio may be 0.2, 0.25, 0.28, 0.29, 0.3, 0.33, 0.35, 0.38, 0.39 or 0.4.

[0124] In this way, by controlling the ratio between the corresponding size of the target area z and the corresponding size of the target electrode piece 231, the wettability of the electrolyte to the area near the second side s2 of the target electrode piece 231 can be improved while further improving the mechanical properties of the target electrode piece 231.

[0125] According to some embodiments of this application, please continue to refer to Figure 5 and Figure 8 , along the direction from the first side s1 to the second side s2, the ratio of the size of the target area z to the size of the target pole piece 231 is one third. That is, the ratio of the first size h1 to the second size h2 is one third.

[0126] At this time, by setting the ratio of the corresponding size of the target area z to the corresponding size of the target pole piece 231 to one third, the mechanical properties of the target pole piece 231 are improved to a greater extent while satisfying the wettability of the electrolyte to the area near the second side s2 of the target pole piece 231.

[0127] According to some embodiments of this application, please continue to refer to Figure 5 and Figure 8 , along the direction from the first side s1 to the second side s2, the target area z has a first boundary line z1 and a second boundary line z2 that are arranged opposite to each other. The first boundary line z1 and the boundary line of the target pole piece 231 located on the second side s2 coincide with each other. According to some embodiments of the present application, please continue to refer to Figure 5 and Figure 8 , the second boundary line z2 is located between the first boundary line z1 and the first reference plane E1.

[0128] Of course, in some other embodiments, the first boundary line z1 may not coincide with the boundary line of the target pole piece 231 located on the second side s2, and the second boundary line z2 may be parallel or non-parallel to the first reference plane E1, which is not specifically limited here.

[0129] In this way, by controlling the positions of the first boundary line z1 and the second boundary line z2 of the target area z, it is possible to determine the target area z according to the positions of the first boundary line z1 and the second boundary line z2, and then set the channel p on the target area z.

[0130] According to some embodiments of this application, please continue to refer to Figure 5 and Figure 8 , along the length direction L, the target area z has a third boundary line z3 and a fourth boundary line z4 which are arranged opposite to each other; wherein the third boundary line z3 and the boundary line of one side of the target pole piece 231 along the length direction L coincide with each other. According to some embodiments of the present application, please continue to refer to Figure 5 and Figure 8 , the fourth boundary line z4 coincides with the boundary line on the other side of the target pole piece 231 along the length direction L.

[0131] Of course, in some other embodiments, the third boundary line z3 may not coincide with the boundary line on one side of the target pole piece 231 along the length direction L, the third boundary line z3 may be parallel or non-parallel to the boundary line on one side of the target pole piece 231 along the length direction L, the fourth boundary line z4 may not coincide with the boundary line on the other side of the target pole piece 231 along the length direction L, the fourth boundary line z4 may be parallel or non-parallel to the boundary line on the other side of the target pole piece 231 along the length direction L, and no specific limitation is made here.

[0132] In this way, by controlling the positions of the third boundary line z3 and the fourth boundary line z4 of the target area z, it is possible to determine the target area z according to the positions of the third boundary line z3 and the fourth boundary line z4, and then set the channel p on the target area z.

[0133] It should be noted that the boundary lines illustrated above can be straight lines, broken lines, or curves, and are not specifically limited here. Figure 8 Take as an example, it shows the situation that all boundary lines are straight lines. Figure 8, the first boundary line z1 of the target area z coincides with the boundary line of the target pole piece 231 on the second side s2, the second boundary line z2 of the target area z is located between the first boundary line z1 and the first reference plane E1, the third boundary line z3 of the target area z coincides with the boundary line of the target pole piece 231 on one side along the length direction L, the fourth boundary line z4 of the target area z coincides with the boundary line of the target pole piece 231 on the other side along the length direction L, and the target area z is substantially rectangular. Of course, the target area z can also be set in other shapes, which is not specifically limited here.

[0134] According to some embodiments of this application, please continue to refer to Figure 5 , and combined with reference Figures 9 to 11 , Fig. 9 In some embodiments of the present application Figure 5 The schematic cross-sectional structure diagram of the target pole piece 231 in the cross-sectional direction AA is shown. Fig.10 In some embodiments of the present application Figure 5 The schematic diagram of the structure of the target pole piece 231 in the cross-sectional direction BB is shown. Fig.11 In other embodiments of the present application Figure 5 The target pole piece 231 is shown in a schematic diagram of the structure in the cross-sectional direction BB. The target pole piece 231 includes a current collector 2311 and an active layer 2312. The current collector 2311 has a first surface m1 and a second surface m2 that are arranged opposite to each other along the thickness direction T. The active layer 2312 is arranged on at least one of the first surface m1 and the second surface m2. At least one of the current collector 2311 and the active layer 2312 is provided with a hole p.

[0135] The current collector 2311 is a component for carrying active materials, and its main function is to collect the current generated by the active materials so as to form a larger current output. Therefore, the current collector 2311 should be in full contact with the active material, and the internal resistance should be as small as possible. Depending on the active material carried, the current collector 2311 can be different. For example, when carrying negative active materials, the current collector 2311 can be copper foil, and when carrying positive active materials, the current collector 2311 can be aluminum foil.

[0136] The current collector 2311 may be a single-layer component (such as aluminum foil, copper foil), or a composite layer component. When the current collector 2311 is a composite layer component, the current collector 2311 may include an intermediate layer and two current collecting metal layers stacked on both sides of the intermediate layer, and the active material is carried on the side of the current collecting metal layer opposite to the intermediate layer. The intermediate layer may be a polymer support layer, specifically a polyethylene support layer, a polypropylene support layer, a polymethyl methacrylate support layer, a polystyrene support layer, and the like.

[0137] The active layer 2312 is usually formed by applying a slurry containing active materials to the current collector 2311 and then cold pressing. The active materials contained in the active layers 2312 of different polarities are different. When the active layer 2312 is a negative electrode active layer 2312, the active materials contained therein are negative electrode active materials, such as carbon negative electrode materials, tin-based negative electrode materials, lithium-containing transition metal nitride negative electrode materials, alloy negative electrode materials, and nano-scale negative electrode materials. When the active layer 2312 is a positive electrode active layer 2312, the active materials contained therein are positive electrode active materials, such as lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, nickel cobalt manganese ternary materials, and nickel cobalt aluminum oxide. In some embodiments, a polymer coating can also be provided on the surface of the current collector 2311 where the active layer 2312 is required to be provided, so as to increase the bonding force between the active layer 2312 and the current collector 2311.

[0138] An active layer 2312 may be provided on the first surface m1 or the second surface m2 of the current collector 2311 to Fig. 9 and Fig.10 As an example, the active layer 2312 is coated on the first surface m1 of the current collector 2311. Fig.11 For example, the active layer 2312 may be coated on both the first surface m1 and the second surface m2 of the current collector 2311, and the polarities of the active layers 2312 on both sides may be the same or different. Generally, the two active layers 2312 coated on the opposite sides of the current collector 2311 along the thickness direction T have opposite polarities, one serving as the positive electrode active layer 2312 and the other serving as the negative electrode active layer 2312.

[0139] At least one of the current collector 2311 and the active layer 2312 is provided with a pore p, that is, the pore p can be provided on the current collector 2311, the pore p can be provided on the active layer 2312, or the pore p can be provided on both the current collector 2311 and the active layer 2312. Fig.10 and Fig.11 As an example, the case where the pores p are provided on both the current collector 2311 and the active layer 2312 is illustrated. In the case where the active layer 2312 is provided on both the first surface m1 and the second surface m2 of the current collector 2311, the pores p may be provided on the active layer 2312 on the first surface m1 and / or the active layer 2312 on the second surface m2. Fig.11 For example, the active layer 2312 on the first surface m1 and the active layer 2312 on the second surface m2 are both provided with channels p.

[0140] In this way, the hole p can be flexibly arranged on the corresponding structure of the target pole piece 231 according to the specific structure and usage requirements of the target pole piece 231 .

[0141] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.11 , define the surface on which the active layer 2312 is provided on the first surface m1 and the second surface m2 as the target surface mt, on which multiple active layers 2312 are provided; in the active layers 2312 on the same target surface mt, at least one active layer 2312 is provided with a pore p. Fig.11 In the illustrated case, both the first surface m1 and the second surface m2 are target surfaces mt, and both the first surface m1 and the second surface m2 are covered with two active layers 2312 , and all the active layers 2312 are provided with pores p.

[0142] Of course, in some other embodiments, one active layer 2312 may be provided on the first surface m1, and multiple active layers 2312 may be provided on the second surface m2, or multiple active layers 2312 may be provided on the first surface m1, and one active layer 2312 may be provided on the second surface m2, or at least one active layer 2312 may be provided on the first surface m1 or the second surface m2. In the case where multiple active layers 2312 are provided on the same surface, the pores p may be provided on one active layer 2312 of the multiple active layers 2312, or on multiple active layers 2312 of the multiple active layers 2312. The pores p may be provided according to the specific usage, and are not specifically limited here.

[0143] When a plurality of active layers 2312 are provided on the corresponding surface, a channel p can be provided on at least one active layer 2312 of the plurality of active layers 2312 according to usage requirements, so that the arrangement of the channel p is more flexible.

[0144] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.11 , in the active layer 2312 located on the same target surface mt, the multi-layer active layer 2312 is provided with a pore p. The active layer 2312 provided with the pore p is defined as the target active layer u. Among all the target active layers u located on the same target surface mt, there are multiple target active layers u with different compaction densities. That is, for the set of compaction densities of all the target active layers u located on the same target surface mt, the values ​​in the set include multiple values. Fig.11 As an example, it illustrates the situation where all active layers 2312 are target active layers u.

[0145] It should be noted that the compaction density of the active layer 2312 refers to the compaction density of the active material coated on the current collector 2311, and the compaction density of the active layer 2312 is equal to the ratio of the surface density to the thickness of the active material. Among them, the thickness of the active material refers to the thickness after cold pressing, and the surface density refers to the mass per unit area of ​​the active material of a specified thickness. The calculation of the compaction density is a common method in this field and will not be repeated here. The greater the compaction density of the active layer 2312, the more pores are formed inside it. The smaller the compaction density of the active layer 2312, the higher the capillary climbing ability of the electrolyte in the active layer 2312. Capillary climbing ability refers to the ability of the electrolyte to flow from bottom to top along the active layer 2312 under the capillary force possessed by the capillary channels formed by the internal pores of the active layer 2312. The stronger the capillary climbing ability, the higher the rising height of the electrolyte, and the better the infiltration effect of the electrolyte.

[0146] Of course, in the case where there are multiple target active layers u with different compaction densities among all target active layers u located on the same target surface mt, all target active layers u located on the same target surface mt may include multiple target active layers u with the same compaction density. In some other embodiments, the compaction density of all target active layers u may be the same.

[0147] Therefore, in the case where there are multiple target active layers u with different compaction densities among all the target active layers u located on the same target surface mt, the compaction densities of the target active layers u are different, and the toughness of the target active layers u is different. The smaller the compaction density of the target active layer u, the greater the toughness of the target active layer u, making it less likely that the target pole piece 231 will be damaged due to bending. The greater the compaction density of the target active layer u, the higher the energy density of the target active layer u. In this way, the target pole piece 231 has a certain energy density while having certain mechanical properties. The smaller the compaction density of the target active layer u, the fewer pores are formed inside the active layer 2312, the higher the capillary climbing ability of the electrolyte in the active layer 2312, and the better the infiltration effect of the electrolyte. In this way, the infiltration effect of the electrolyte on the corresponding active layer 2312 can be further improved by controlling the compaction density of the target active layer u and cooperating with the pores p on the target active layer u.

[0148] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.11 , in the target active layer u located on the same target surface mt, the total area ratio of all the pores p in the target active layer u with a larger compaction density is greater than the total area ratio of all the pores p in the target active layer u with a smaller compaction density.

[0149] “The total area ratio of all pores p of the target active layer u on the target active layer u” refers to the ratio of the sum of the cross-sectional areas of all pores p on the same target active layer u to the cross-sectional area of ​​the target active layer u, where the cross-sectional areas of the pores p and the cross-sectional areas of the target active layer u are both surfaces cut by a plane perpendicular to the thickness direction T. The relevant total area ratios involved in the following text can be understood with reference to this and will not be repeated here.

[0150] It can be understood that the target pole piece 231 can be photographed at a preset magnification by SEM (Scanning Electron Microscope), and the size of the aperture on the target pole piece 231 can be determined based on the image obtained by the photograph and the preset magnification. By slicing the target pole piece 231 and combining the image obtained by SEM photography, the relevant parameters of each active layer and current collector in the target pole piece 231 can be obtained. Further, combined with the size of the target pole piece 231, the total area proportion corresponding to the channel p can be determined. Of course, other methods can also be used to determine the various parameters on the target pole piece 231.

[0151] In this way, by controlling the total area of ​​all the pores p on the target active layer u with a higher compaction density to account for a larger proportion on the target active layer u, the wetting effect of the electrolyte on the corresponding active layer 2312 can be further improved while further improving the mechanical properties of the target electrode 231.

[0152] It can be understood that for the target active layer u, a larger compaction density is matched with a larger total area share, and a smaller compaction density is matched with a smaller total area share. Thus, the corresponding target active layers u can cooperate with each other, thereby enabling the target electrode 231 to have a certain energy density and mechanical properties as a whole while improving the wetting effect of the electrolyte.

[0153] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.11 , in the target active layer u located on the same target surface mt, the target active layer u with a smaller compaction density is farther away from the current collector 2311.

[0154] For example, Fig.11For example, the two active layers 2312 arranged on the first surface m1 and the two active layers 2312 arranged on the second surface m2 are both target active layers u, the active layer 2312 adjacent to the first surface m1 is the first active layer 2312a, the active layer 2312 arranged on the side surface of the first active layer 2312a away from the first surface m1 is the second active layer 2312b, the active layer 2312 adjacent to the second surface m2 is the third active layer 2312c, the active layer 2312 arranged on the side surface of the third active layer 2312c away from the second surface m2 is the fourth active layer 2312d, the compaction density of the first active layer 2312a is greater than the compaction density of the second active layer 2312b, and the compaction density of the third active layer 2312c is greater than the compaction density of the fourth active layer 2312d.

[0155] Of course, in some other embodiments, the target active layer u with a higher compaction density may be further away from the current collector 2311 .

[0156] In this way, by moving the target active layer u with a smaller compaction density further away from the current collector 2311, that is, moving the target active layer u with a larger compaction density closer to the current collector 2311, it is beneficial to further improve the mechanical properties of the target electrode 231 while improving the wetting effect of the electrolyte.

[0157] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.11 , define the surface on which the active layer 2312 is provided on the first surface m1 and the second surface m2 as the target surface mt, and the target surface mt is provided with multiple active layers 2312. Among all the active layers 2312 located on the same target surface mt, the compaction density of the active layer 2312 that is farther away from the current collector 2311 is smaller. Among all the active layers 2312, only one active layer 2312 may be provided with a pore p, or multiple active layers ... Fig.11 The entire active layer 2312 is shown to be provided with holes p.

[0158] Of course, in some other embodiments, the compaction density of all active layers 2312 may be the same.

[0159] By controlling the compaction density of the active layer 2312 farther away from the current collector 2311 on the target surface mt to be smaller, that is, the compaction density of the active layer 2312 closer to the current collector 2311 is greater, so that the mechanical properties of the part of the target pole piece 231 closer to the current collector 2311 are better, so that in the direction from the outside to the inside of the target pole piece 231, the mechanical properties of each part of the target pole piece 231 can be improved in sequence. In this way, the mechanical properties of the target pole piece 231 can be further improved. In addition, combined with the situations illustrated in some of the above embodiments, the pores p can be further set according to the compaction density of the corresponding active layer 2312, and the total area proportion of the pores p can be controlled in coordination, so as to improve the influence of the active layer 2312 with a larger compaction density on the electrolyte infiltration, thereby further improving the electrolyte infiltration effect on the basis of the target pole piece 231 having certain mechanical properties.

[0160] According to some embodiments of this application, please continue to refer to Figure 5 , Fig.10 and Fig.11 , the active layer 2312 is provided with at least one layer. Among all the pores p, there are pores p provided on the active layer 2312. For the active layer 2312 provided with pores p, the total area of ​​all pores p on the active layer 2312 accounts for 2×10 -7-2N Up to 4×10 -1-2N Wherein, N is a positive integer greater than or equal to 1. N is the number of layers of the active layer 2312 on the surface on which it is located. The number of layers of the active layer 2312 is greater the farther away from the current collector 2311. For example, the total area of ​​all the pores p on the active layer 2312 on the active layer 2312 may account for 2×10 -7-2N , 0.000002×10 -2N , 0.00002×10 -2N , 0.0002×10 -2N , 0.002×10 -2N , 0.005×10 -2N , 0.1×10 -2N , 0.2×10 -2N , 0.3×10 -2N , 0.35×10 -2N or 0.4×10 -2N .

[0161] by Fig.10 For example, an active layer 2312 is provided on the first surface m1 of the current collector 2311. The active layer 2312 is the first active layer 2312. That is, the total area of ​​all the pores p on the active layer 2312 on the active layer 2312 accounts for 2×10 -9 Up to 4×10 -3.by Fig.11 For example, for the first surface m1 of the current collector 2311, the first active layer 2312a is the first active layer 2312, the second active layer 2312b is the second active layer 2312, for the second surface m2 of the current collector 2311, the third active layer 2312c is the first active layer 2312, the fourth active layer 2312d is the second active layer 2312, and the total area of ​​all the pores p on the first active layer 2312a on the first active layer 2312a accounts for 2×10 -9 Up to 4×10 -3 The total area of ​​all the holes p on the second active layer 2312b is 2×10 -11 Up to 4×10 -5 , the total area of ​​all the holes p on the third active layer 2312c accounts for 2×10 -9 Up to 4×10 -3 , the total area of ​​all the holes p on the fourth active layer 2312d accounts for 2×10 -11 Up to 4×10 -5 .

[0162] Based on the layer number of the active layer 2312 with the pores p, controlling the total area ratio corresponding to all the pores p on the active layer 2312 is not only beneficial to improving the wetting effect of the electrolyte on the active layer 2312, but also beneficial to further improve the mechanical properties of different parts of the target electrode 231, thereby improving the mechanical properties of the target electrode 231 as a whole.

[0163] According to some embodiments of this application, please continue to refer to Figure 5 , Fig.10 and Fig.11 , the active layer 2312 is provided with at least one layer, and among all the pores p, there are pores p provided on the active layer 2312. Wherein, in the case where the pores p are provided on the first active layer 2312, the pore diameter x of the pores p on the first active layer 2312 is 0.01 mm to 1 mm. According to some embodiments of the present application, please continue to refer to Figure 5 , Fig.10 and Fig.11 , the active layer 2312 is provided with at least one layer; among all the pores p, there are pores p provided on the active layer 2312; wherein, when a pore p is provided on the Mth active layer 2312, the pore diameter x of the pore p on the Mth active layer 2312 is 0.005 mm to 0.5 mm, M is a positive integer greater than or equal to 2, M is the number of layers of the active layer 2312 on its surface, and the farther away from the current collector 2311, the larger the number of layers of the active layer 2312.

[0164] by Fig.11 For example, the first active layer 2312a and the third active layer 2312c are both the first active layer 2312 on the corresponding surface, and the pore size x of the pores p on the first active layer 2312a and the third active layer 2312c can be 0.01 mm to 1 mm, the second active layer 2312b and the fourth active layer 2312d are both the second active layer 2312 on the corresponding surface, and the pore size x of the pores p on the second active layer 2312b and the fourth active layer 2312d can be 0.005 mm to 0.5 mm. Exemplarily, the pore size x of the pores p on the first active layer 2312 can be 0.01 mm, 0.02 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.6 mm, 0.8 mm or 1 mm. The pore size x of the pores p on the Mth active layer 2312 may be 0.005 mm, 0.01 mm, 0.03 mm, 0.08 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm. The pore sizes x of the pores p on the same active layer 2312 may be the same or different. Figure 5 , Fig.10 and Fig.11 In the illustrated case, the pore diameters x of the pores p on the same active layer 2312 are all the same.

[0165] Based on the number of layers of the active layer 2312 provided with the pores p, controlling the pore diameter x of the pores p on the active layer 2312 is not only conducive to improving the ability of the electrolyte to enter the pores p, thereby improving the infiltration effect of the electrolyte on the active layer 2312, but also conducive to further improving the mechanical properties of different parts of the target electrode 231, thereby improving the mechanical properties of the target electrode 231 as a whole. In addition, by controlling the pore diameter x of the pores p, it is also convenient to process and manufacture the corresponding pores p.

[0166] Of course, in some other embodiments, when the corresponding active layer 2312 is provided with a plurality of pores p, the minimum pore size x of the pores p on the active layer 2312 with a greater compaction density can be made larger than the maximum pore size x of the pores p on the active layer 2312 with a smaller compaction density. The distance between the axes of two adjacent pores p of the active layer 2312 with a greater compaction density can also be made smaller than the distance between the axes of two adjacent pores p of the active layer 2312 with a smaller compaction density.

[0167] For example, Fig.11For example, the compaction density of the first active layer 2312a is greater than the compaction density of the second active layer 2312b, the aperture x of the channel p on the first active layer 2312a is the first aperture x1, the aperture x of the channel p on the second active layer 2312b is the second aperture x2, and the first aperture x1 is greater than the second aperture x2. The distance between the axes of two adjacent channels p on the first active layer 2312a is the first distance d1, and the distance between the axes of two adjacent channels p on the second active layer 2312b is the second distance d2, and the first distance d1 is less than the second distance d2. Of course, in combination with the relevant implementation methods of the total area ratio illustrated in some of the aforementioned embodiments, the required total area ratio can be obtained by adjusting the size of the aperture x and the distance between adjacent channels p. It can be set according to actual use requirements and will not be described in detail here.

[0168] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , the surface on which the active layer 2312 is provided on the first surface m1 and the second surface m2 is defined as the target surface mt. Among all the pores p, there are pores p provided on the current collector 2311 and pores p provided on the active layer 2312 adjacent to the target surface mt. Among the pores p on the active layer 2312 adjacent to the target surface mt, there are pores p connected to the pores p on the current collector 2311.

[0169] In this way, by providing a hole p in the hole p on the active layer 2312 adjacent to the target surface mt, which is connected to the hole p on the current collector 2311, the channel through which the electrolyte can enter can be further expanded with the help of the hole p on the current collector 2311, which is conducive to further improving the infiltration effect of the electrolyte. Fig.11 For example, when the active layer 2312 is covered on both the first surface m1 and the second surface m2 of the current collector 2311, the two sides of the current collector 2311 along the thickness direction T can be connected by means of the channels p on the current collector 2311, so that the electrolyte can flow on both sides of the current collector 2311 along the thickness direction T, thereby further improving the wetting effect of the electrolyte.

[0170] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , the pores p on the active layer 2312 adjacent to the target surface mt are connected to the pores p on the current collector 2311 in a one-to-one correspondence.

[0171] It can be understood that the active layer 2312 adjacent to the current collector 2311 is the first active layer 2312 mentioned in some of the aforementioned embodiments. One-to-one correspondence means that the number of pores p on the first active layer 2312 corresponds to the number of pores p on the current collector 2311, and the positions also correspond one-to-one. One-to-one correspondence in position means that the pores p on the first active layer 2312 can be connected to the pores p on the current collector 2311. That is, the pores p on the first active layer 2312 and the pores p on the current collector 2311 can be completely aligned or partially aligned. In this way, the pores p on the current collector 2311 can be further utilized to further improve the wetting effect of the electrolyte.

[0172] Of course, in some other embodiments, some of the pores p on the current collector 2311 may be connected to some of the pores p on the first active layer 2312 .

[0173] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , and combined with reference Fig.12 , Fig.12 Schematic diagram of the projection of the channel p on the target pole piece 231 in some embodiments of the present application. The channel p on the active layer 2312 adjacent to the target surface mt overlaps with the orthographic projection of the corresponding channel p on the current collector 2311 on the second reference plane E2. The second reference plane E2 is perpendicular to the thickness direction T. The orthographic projection of the channel p on the first active layer 2312 on the second reference plane E2 is the first projection y1, and the orthographic projection of the channel p on the current collector 2311 on the second reference plane E2 is the second projection y2, and the first projection y1 and the second projection y2 coincide with each other. That is, the channel p on the first active layer 2312 can be completely aligned with the channel p on the current collector 2311.

[0174] In this way, not only can the infiltration effect of the electrolyte be further improved by means of the pores p on the current collector 2311, but it is also easy to manufacture and improves the manufacturing efficiency.

[0175] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , among all the pores p, there are pores p on the current collector 2311. The total area of ​​all the pores p on the current collector 2311 accounts for 2×10 -9 Up to 4×10 -3 The exemplary value of the total area ratio of all the pores p on the current collector 2311 on the current collector 2311 can be implemented by referring to the value of the total area ratio of all the pores p on the first active layer 2312 shown above, which will not be repeated here.

[0176] By controlling the total area ratio corresponding to the pores p on the current collector 2311, it is beneficial to improve the wetting effect of the electrolyte while the current collector 2311 has certain mechanical properties. It can be understood that when the current collector 2311 has certain mechanical properties and the active layer 2312 is formed by a coating process, the situation of the current collector 2311 breaking can be improved.

[0177] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , among all the pores p, there are pores p provided on the current collector 2311, and the pore diameter x of the pores p provided on the current collector 2311 is 0.01 mm to 1 mm. The exemplary value of the pore diameter x of the pores p provided on the current collector 2311 can be implemented with reference to the value of the pore diameter x of the pores p on the first active layer 2312 illustrated above, and will not be repeated here.

[0178] By controlling the pore size x of the pores p on the current collector 2311 , it is beneficial to improve the wetting effect of the electrolyte while the current collector 2311 has certain mechanical properties.

[0179] According to some embodiments of this application, please continue to refer to Fig.10 and Fig.11 , and combined with reference Fig.13 , Fig.13 In some other embodiments of the present application Figure 5 The target electrode 231 is shown in the cross-sectional view BB. The current collector 2311 and the active layer 2312 are defined as the target object. Among the holes p provided in the target object, there are holes p that penetrate the target object along the thickness direction T. According to some embodiments of the present application, please continue to refer to Fig.10 and Fig.11 , and combined with reference Fig.13 , in the channel p of the target object, there exists a channel p that does not penetrate the target object along the thickness direction T.

[0180] The hole p that penetrates the target object is the first hole p1, and the hole p that does not penetrate the target object is the second hole p2. Fig.10 and Fig.11 As an example, the current collector 2311 and the active layer 2312 are both target objects, and the pores p on the current collector 2311 and the active layer 2312 are both first pores p1. Fig.13Taking the example, the situation where the current collector 2311 and all the active layers 2312 are target objects is illustrated, the channels p on the current collector 2311, the third active layer 2312c and the fourth active layer 2312d are all first channels p1, a part of the channels p on the first active layer 2312a and the second active layer 2312b are first channels p1, and another part of the channels p are second channels p2.

[0181] In this way, a hole p that penetrates or does not penetrate the target object can be set on the target object according to actual use requirements to meet the required electrolyte infiltration effect and the required mechanical properties of the target object.

[0182] According to some embodiments of this application, please continue to refer to Figure 5 , Figures 10 to 12 , one of the current collector 2311 and the active layer 2312 having a pore p is defined as a target object, and a plurality of pores p are provided on the target object. At least some of the pores p on the same target object are arranged according to a preset rule.

[0183] In this way, the corresponding channels p can be arranged in a required pattern according to the use requirements to obtain the required electrolyte infiltration effect and the required mechanical properties of the target object.

[0184] According to some embodiments of this application, please continue to refer to Figure 5 , Figures 10 to 12 The preset rule includes at least one of arrangement in a single direction and array arrangement.

[0185] It should be noted that the array arrangement can be a rectangular array or a circular array. That is to say, the preset rule can be arranged in a single direction, or it can be an array arrangement, or it can include a single direction arrangement and an array arrangement. In the case where the preset rule is a single direction arrangement, the number of preset rules is one, and the type of preset rule is one. In the case where the preset rule is an array arrangement, it can be regarded as the number of preset rules is one, and the type of preset rule is one; of course, the array arrangement can also be regarded as two single direction arrangements, in which case the number of preset rules is two, and the type of preset rule is one. In other examples, the preset rule can also include arrangements according to a preset pattern, repeated arrangements according to a preset pattern, and the like. According to a preset pattern refers to the arrangement of multiple channels p along a preset path to form a preset pattern. The shape formed by the preset path can be a circle, a triangle or a rectangle, etc., which is not specifically limited here. Repeated arrangement according to a preset pattern refers to the arrangement of multiple channels p to form multiple preset patterns. The repetition of the preset pattern can also be carried out according to a certain rule, which is not specifically limited here.

[0186] In this way, the preset rules can be one or more, so as to flexibly set the channel p according to usage requirements.

[0187] According to some embodiments of this application, please continue to refer to Figure 5 and Fig.12 At least part of the channels p are arranged in rows along the direction from the first side s1 to the second side s2, and arranged in columns along the length direction L. Figure 5 As an example, it is shown that all the holes p on the active layer 2312 are arranged in a rectangular array. Fig.12 As an example, it is illustrated that all the holes p on the corresponding active layer 2312 and the current collector 2311 are arranged in a rectangular array.

[0188] In this way, at least part of the pores p are arranged in a rectangular array, which is beneficial to improving the infiltration effect of the electrolyte and the mechanical properties of the target object while facilitating processing and manufacturing. The pores p can be arranged according to the shape of the target electrode 231 and the shape of the target area z, which can make the arrangement of the pores p more uniform, not only facilitating the control of the corresponding total area proportion of the pores p, but also facilitating the improvement of the mechanical properties of the target electrode 231.

[0189] According to some embodiments of this application, please continue to refer to Fig.11 and Fig.13 , an active layer 2312 is disposed on both the first surface m1 and the second surface m2. The active layer 2312 disposed on the first surface m1 is symmetrically disposed with the active layer 2312 disposed on the second surface m2 about the middle section MS of the current collector 2311, and the middle section MS is perpendicular to the thickness direction T. Fig.11 and Fig.13 In the illustrated perspective, the middle section MS is straight-line.

[0190] It can be understood that, along the thickness direction T, the middle section MS is located in the middle position of the current collector 2311, and the distances from the middle section MS to the first surface m1 and the second surface m2 of the current collector 2311 are equal. Along the thickness direction T, the maximum distance between the first surface m1 and the second surface m2 is the thickness of the current collector 2311. If the first surface m1 and the second surface m2 are planes, the thickness of the current collector 2311 is measured based on the first surface m1 and the second surface m2. If there are convex or concave portions on the first surface m1 and / or the second surface m2, the thickness of the current collector 2311 is measured based on the plane area of ​​the corresponding surface. In the embodiment of the present application, the first surface m1 and the second surface m2 are both planes, and the first surface m1, the second surface m2 and the middle section MS are parallel to each other.

[0191] This is not only beneficial to improving the energy density of the target pole piece 231 , but also beneficial to improving the consistency of the target pole piece 231 on both sides of the mid-section MS of the current collector 2311 , thereby further improving the mechanical properties of the target pole piece 231 as a whole.

[0192] According to some embodiments of this application, please continue to refer to Fig.10 , Fig.11 and Fig.13 , the extension direction of at least one of the pores p is parallel to the thickness direction T. That is, the extension directions of all the pores p can be the same or different. The extension direction of the pores p can be a straight line direction, a curved line direction, or a broken line direction. Fig.10 , Fig.11 and Fig.13 As an example, the situation where the extension directions of all the channels p are parallel to the thickness direction T is illustrated.

[0193] When the extension direction of the pore p is parallel to the thickness direction T, the pore p is substantially extended in a straight line. Such a pore p can satisfy the infiltration effect of the electrolyte and is easy to manufacture.

[0194] According to some embodiments of this application, please continue to refer to Figures 10 to 13 , the cross-section shape of all the channels p along the thickness direction T includes at least one of a regular shape and an irregular shape. The regular shape includes a triangle, a circle, an ellipse or a rectangle. Exemplarily, the cross-section shape of the channel p along the thickness direction T is a circle.

[0195] It can be understood that, when the cross-section of the pore p along the thickness direction T is circular, the aperture x of the pore p mentioned above is the diameter of the cross-section of the pore p along the thickness direction T. When the cross-section of the pore p along the thickness direction T is not circular, the aperture x of the pore p mentioned above can be the major diameter or minor diameter of the cross-section of the pore p along the thickness direction T. For example, Fig.11 For example, the aperture x of the channel p on the first active layer 2312a is the first aperture x1, and the aperture x of the channel p on the second active layer 2312b is the second aperture x2. The first aperture x1 is greater than the second aperture x2, that is, the minimum value of the first aperture x1 is greater than the maximum value of the second aperture x2. The minimum value of the first aperture x1 can be regarded as the value corresponding to the short diameter, and the maximum value of the second aperture x2 can be regarded as the value corresponding to the long diameter.

[0196] In this way, the required cross-sectional shape of the channel p can be flexibly set according to actual usage.

[0197] The following is an exemplary description of the manufacturing process of the target pole piece 231 provided in the embodiment of the present application with reference to the situations illustrated in some of the above embodiments.

[0198] Combined with reference Figure 5 and Fig.11First, a current collector 2311 is provided; secondly, a first active layer 2312a is coated on the first surface m1 of the current collector 2311, and a third active layer 2312c is coated on the second surface m2 by a coating process; thirdly, a fourth active layer 2312d is coated on the side of the third active layer 2312c away from the second surface m2 by a coating process; subsequently, a hole is punched on the first surface m1 side of the current collector 2311 by a punching process, and a through channel p is provided on the current collector 2311, the first active layer 2312a and the third active layer 2312c; then, a second active layer 2312b is coated on the side of the first active layer 2312a away from the first surface m1 by a coating process; then, a hole p penetrating the second active layer 2312b is formed on the second active layer 2312b by a punching process, and a hole p penetrating the fourth active layer 2312d is formed on the fourth active layer 2312d.

[0199] It should be noted that the manufacturing process of the target electrode 231 can also be made in other ways. For example, before forming the second active layer 2312b, a hole can be punched on the fourth active layer 2312d by a punching process. The above steps can be adjusted, increased or reduced according to specific usage conditions, and no specific limitation is made here.

[0200] According to some embodiments of this application, please refer to Fig.14 , Fig.14 The schematic diagram of the structure of the electrode assembly 230 in some embodiments of the present application is shown in FIG. 2 . The battery cell 200 includes the electrode assembly 230, and the electrode assembly 230 includes a positive electrode sheet 231a, a negative electrode sheet 231b, and a separator 232 disposed between the positive electrode sheet 231a and the negative electrode sheet 231b. The positive electrode sheet 231a is configured as the target electrode sheet 231; and / or the negative electrode sheet 231b is configured as the target electrode sheet 231.

[0201] In this way, the positive electrode sheet 231 a and the negative electrode sheet 231 b can be arranged according to actual use requirements.

[0202] According to some embodiments of this application, please continue to refer to Fig.14 The electrode assembly 230 is a laminated structure. Thus, the electrode assembly 230 with a laminated structure can be selected according to the use requirements.

[0203] According to some embodiments of the present application, the present application provides a battery 10, comprising the battery cell 200 in any of the above embodiments.

[0204] In the technical solution of the embodiment of the present application, since the battery 10 includes the battery cell 200 in any of the above embodiments, it also has the advantages of the battery cell 200 described in any of the above embodiments.

[0205] According to some embodiments of the present application, the present application provides an electrical device, comprising the battery 10 of any one of the above items, and the battery 10 is used to provide electrical energy.

[0206] In the technical solution of the embodiment of the present application, since the electrical device includes the battery 10 in any of the above embodiments, it also has the advantages of the battery 10 described in any of the above embodiments.

[0207] According to some embodiments of this application, please refer to Figure 4 , Figure 5 , Figure 8 and Fig.11 The battery cell 200 includes a target pole piece 231, and the target pole piece 231 includes a current collector 2311 and an active layer 2312. The current collector 2311 has a first surface m1 and a second surface m2 that are oppositely arranged along the thickness direction T. The first surface m1 is provided with a first active layer 2312a and a second active layer 2312b in sequence, and the second surface m2 is provided with a third active layer 2312c and a fourth active layer 2312d in sequence. The target pole piece 231 has a first side s1 and a second side s2 that are oppositely arranged, and the target pole piece 231 has a target area z close to the second side s2. In the direction from the first side s1 to the second side s2, the ratio of the first size h1 of the target area z to the second size h2 of the target pole piece 231 is one third. The first boundary line z1 of the target area z coincides with the boundary line of the target pole piece 231 on the second side s2, the second boundary line z2 is located between the first boundary line z1 and the first reference plane E1, the third boundary line z3 coincides with the boundary line of the target pole piece 231 on one side along the length direction L, and the fourth boundary line z4 coincides with the boundary line of the target pole piece 231 on the other side along the length direction L. The target pole piece 231 is provided with a plurality of channels p located within the target area z. The extension direction of the channels p is parallel to the thickness direction T of the target pole piece 231, and the cross-sectional shape of the channels p along the thickness direction T is circular. A portion of all the channels p is provided in the current collector 2311 and penetrates the current collector 2311, and another portion is provided in each layer of the active layer 2312 and penetrates the active layer 2312. The total area of ​​the corresponding channels p on the first active layer 2312a and the third active layer 2312c accounts for 2×10 -9 Up to 4×10 -3 The total area of ​​the corresponding channels p on the second active layer 2312b and the fourth active layer 2312d accounts for 2×10 -11 Up to 4×10 -5. The pore size x of the pores p on the current collector 2311, the first active layer 2312a and the third active layer 2312c is 0.01 mm to 1 mm, and the pore size x of the corresponding pores p on the second active layer 2312b and the fourth active layer 2312d is 0.005 mm to 0.5 mm. The compaction density of the first active layer 2312a and the third active layer 2312c is the first compaction density, and the compaction density of the second active layer 2312b and the fourth active layer 2312d is the second compaction density, and the first compaction density is greater than the second compaction density. The pores p on the current collector 2311, the first active layer 2312a and the third active layer 2312c are connected to each other one by one. The first active layer 2312 a and the third active layer 2312 c are symmetrically arranged with respect to the middle section MS of the current collector 2311 , and the second active layer 2312 b and the fourth active layer 2312 d are symmetrically arranged with respect to the middle section MS of the current collector 2311 .

[0208] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell (200), characterized in that: The battery cell (200) comprises a target pole piece (231); the target pole piece (231) has a first side (s1) and a second side (s2) arranged opposite to each other; the target pole piece (231) has a target area (z) close to the second side (s2); and the target pole piece (231) is provided with a plurality of holes (p) located in the target area (z); The direction in which the first side (s1) points to the second side (s2), the length direction (L) of the target pole piece (231), and the thickness direction (T) of the target pole piece (231) are perpendicular to each other; the second side (s2) is arranged above the first side (s1) along the direction of gravity.

2. The battery cell (200) according to claim 1, characterized in that: Along the direction from the first side (s1) to the second side (s2), the target area (z) is located between the second side (s2) and the first reference surface (E1); The first reference plane (E1) is perpendicular to the first side (s1) and points to the second side (s2); the target pole piece (231) has a first central axis (C1) parallel to the length direction (L), and the first central axis (C1) is located on the first reference plane (E1).

3. The battery cell (200) according to claim 2, characterized in that: Along the direction from the first side (s1) to the second side (s2), the ratio of the size of the target area (z) to the size of the target pole piece (231) is one fifth to two fifths.

4. The battery cell (200) according to claim 3, characterized in that: Along the direction from the first side (s1) to the second side (s2), the ratio of the size of the target area (z) to the size of the target pole piece (231) is one third.

5. The battery cell (200) according to claim 2, characterized in that: Along the direction from the first side (s1) to the second side (s2), the target area (z) has a first boundary line (z1) and a second boundary line (z2) which are arranged opposite to each other; wherein the first boundary line (z1) coincides with a boundary line of the target pole piece (231) located on the second side (s2); and / or The second boundary line (z2) is located between the first boundary line (z1) and the first reference surface (E1).

6. The battery cell (200) according to claim 2, characterized in that: Along the length direction (L), the target area (z) has a third boundary line (z3) and a fourth boundary line (z4) arranged opposite to each other; wherein the third boundary line (z3) coincides with a boundary line of the target pole piece (231) on one side along the length direction (L); and / or The fourth boundary line (z4) coincides with a boundary line on the other side of the target pole piece (231) along the length direction (L).

7. The battery cell (200) according to any one of claims 1 to 6, characterized in that: The target pole piece (231) comprises: A current collector (2311) having a first surface (m1) and a second surface (m2) arranged opposite to each other along the thickness direction (T); and an active layer (2312), provided on at least one of the first surface (m1) and the second surface (m2); Wherein, the pore (p) is provided on at least one of the current collector (2311) and the active layer (2312).

8. The battery cell (200) according to claim 7, characterized in that: The first surface (m1) and the second surface (m2) are defined as surfaces provided with the active layer (2312) as target surfaces (mt), and the target surface (mt) is provided with multiple layers of the active layer (2312); In the active layers (2312) located on the same target surface (mt), at least one of the active layers (2312) is provided with the channel (p).

9. The battery cell (200) according to claim 8, characterized in that: In the active layer (2312) located on the same target surface (mt), the pores (p) are provided on multiple layers of the active layer (2312); The active layer (2312) provided with the pores (p) is defined as a target active layer (u); among all the target active layers (u) located on the same target surface (mt), there are multiple layers of the target active layers (u) having different compaction densities.

10. The battery cell (200) according to claim 9, characterized in that: In the target active layer (u) located on the same target surface (mt), the total area ratio of all the pores (p) of the target active layer (u) with a larger compaction density on the target active layer (u) is greater than the total area ratio of all the pores (p) of the target active layer (u) with a smaller compaction density in the target active layer (u).

11. The battery cell (200) according to claim 9, characterized in that: In the target active layer (u) located on the same target surface (mt), the target active layer (u) with a smaller compaction density is farther away from the current collector (2311).

12. The battery cell (200) according to claim 7, characterized in that: defining the surface on which the active layer (2312) is provided on the first surface (m1) and the second surface (m2) as a target surface (mt); A plurality of active layers (2312) are provided on the target surface (mt); among all the active layers (2312) located on the same target surface (mt), the compaction density of the active layer (2312) that is farther away from the current collector (2311) is smaller.

13. The battery cell (200) according to claim 7, characterized in that: The active layer (2312) is provided with at least one layer; among all the pores (p), there are pores (p) provided on the active layer (2312); For the active layer (2312) provided with the pores (p), the total area of ​​all the pores (p) on the active layer (2312) accounts for 2×10 -7-2N Up to 4×10 -1-2N ; Wherein, N is a positive integer greater than or equal to 1; N is the number of layers of the active layer (2312) on its surface, and the number of layers of the active layer (2312) is greater the further away from the current collector (2311).

14. The battery cell (200) according to claim 7, characterized in that: The active layer (2312) is provided with at least one layer; among all the pores (p), there are pores (p) provided on the active layer (2312); Wherein, when the pore (p) is provided on the first active layer (2312), the pore diameter (x) of the pore (p) on the first active layer (2312) is 0.01 mm to 1 mm; and / or When the pore (p) is provided on the Mth active layer (2312), the pore size (x) of the pore (p) on the Mth active layer (2312) is 0.005 mm to 0.5 mm, M is a positive integer greater than or equal to 2, and M is the number of layers of the active layer (2312) on its surface, and the farther away from the current collector (2311), the larger the number of layers of the active layer (2312).

15. The battery cell (200) according to claim 7, characterized in that: defining the surface on which the active layer (2312) is provided on the first surface (m1) and the second surface (m2) as a target surface (mt); Among all the pores (p), there are pores (p) provided on the current collector (2311) and pores (p) provided on the active layer (2312) adjacent to the target surface (mt); Among the pores (p) on the active layer (2312) adjacent to the target surface (mt), there are pores (p) that are connected to the pores (p) on the current collector (2311).

16. The battery cell (200) according to claim 15, characterized in that: The pores (p) on the active layer (2312) adjacent to the target surface (mt) are connected to the pores (p) on the current collector (2311) in a one-to-one correspondence.

17. The battery cell (200) according to claim 16, characterized in that: The pores (p) on the active layer (2312) adjacent to the target surface (mt) overlap with the orthographic projections of the pores (p) on the corresponding current collector (2311) on the second reference plane (E2); The second reference surface (E2) is perpendicular to the thickness direction (T).

18. The battery cell (200) according to claim 7, characterized in that: Among all the pores (p), there is a pore (p) provided on the current collector (2311); The total area of ​​all the channels (p) on the current collector (2311) on the current collector (2311) accounts for 2×10 -9 Up to 4×10 -3 .

19. The battery cell (200) according to claim 7, characterized in that: Among all the pores (p), there is a pore (p) provided on the current collector (2311); The pore size (x) of the channel (p) provided on the current collector (2311) is 0.01 mm to 1 mm.

20. The battery cell (200) according to claim 7, characterized in that: defining one of the current collector (2311) and the active layer (2312) in which the pore (p) is provided as a target object; wherein, in the channel (p) provided in the target object, there is a channel (p) penetrating the target object along the thickness direction (T); and / or Among the holes (p) provided in the target object, there are holes (p) that do not penetrate the target object along the thickness direction (T).

21. The battery cell (200) according to claim 7, characterized in that: One of the current collector (2311) and the active layer (2312) having the pore (p) is defined as a target object; a plurality of pores (p) are provided on the target object; At least some of the holes (p) in all the holes (p) on the same target object are arranged according to a preset rule.

22. The battery cell (200) according to claim 21, characterized in that: The preset rule includes at least one of arrangement in a single direction and arrangement in an array.

23. The battery cell (200) according to claim 21, characterized in that: The at least some of the channels (p) are arranged in rows along a direction from the first side (s1) to the second side (s2), and are arranged in columns along the length direction (L).

24. The battery cell (200) according to claim 7, characterized in that: The active layer (2312) is provided on both the first surface (m1) and the second surface (m2); The active layer (2312) disposed on the first surface (m1) is symmetrically arranged with the active layer (2312) disposed on the second surface (m2) about a mid-section (MS) of the current collector (2311); the mid-section (MS) is perpendicular to the thickness direction (T).

25. The battery cell (200) according to any one of claims 1 to 6, characterized in that: The extension direction of at least one of the pores (p) is parallel to the thickness direction (T); and / or The cross-sectional shapes of all the channels (p) along the thickness direction (T) include regular shapes, and the regular shapes include triangles, circles, ellipses or rectangles.

26. The battery cell (200) according to any one of claims 1 to 6, characterized in that: The battery cell (200) comprises an electrode assembly (230), wherein the electrode assembly (230) comprises a positive electrode sheet (231a), a negative electrode sheet (231b), and a separator (232) disposed between the positive electrode sheet (231a) and the negative electrode sheet (231b); Wherein, the positive electrode sheet (231a) is configured as the target electrode sheet (231); and / or, the negative electrode sheet (231b) is configured as the target electrode sheet (231).

27. The battery cell (200) according to claim 26, characterized in that: The electrode assembly (230) is a laminated structure.

28. A battery (10), characterized in that: Comprising the battery cell (200) according to any one of claims 1 to 27.

29. An electrical device, characterized in that: Comprising a battery (10) as claimed in claim 28, the battery (10) is used to provide electrical energy.

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