Pole piece, battery and electric equipment

Abstract

The utility model relates to a pole piece, a battery and electric equipment, the pole piece comprises a pole piece main body, the pole piece main body is provided with a runner hole penetrating along the thickness direction of the pole piece main body, and the runner hole is used for shortening the infiltration path of electrolyte on the pole piece main body. According to the application, the runner hole penetrating through the pole piece main body is formed in the pole piece main body, and the infiltration path of the electrolyte entering the pole piece main body is shortened by utilizing the runner hole, so that the electrolyte can rapidly permeate into the pole piece main body, the electrolyte in the pole piece main body is ensured to be sufficient, and the performance of the battery is improved.

Description

Technical Field

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

[0002] With the rapid development of the new energy era, the design requirements for lithium-ion batteries are getting higher and higher. How to design a high-energy-density battery while ensuring the most basic safety and reliability of the battery is currently the hottest research direction in the lithium-ion battery industry. Among them, the battery can increase the thickness of the pole piece and the number of pole piece stacks to improve the energy density of the battery.

[0003] However, as the thickness of the electrode and the number of electrode stacks increase, it becomes difficult for the electrolyte to penetrate into the electrode, which may reduce the performance of the battery. Utility Model Content

[0004] To solve the above problems, the present application provides a pole piece, which can improve the problem of electrolyte infiltration difficulty by optimizing the structure of the pole piece in a targeted manner to ensure that there is sufficient electrolyte inside the pole piece. In addition, the present application also provides a battery and an electrical device including the pole piece, which specifically include the following solutions:

[0005] In a first aspect, the present application provides a pole piece, including a pole piece body, wherein the pole piece body is provided with a flow channel hole penetrating along the thickness direction thereof, and the flow channel hole is used to shorten the infiltration path of the electrolyte to the pole piece body.

[0006] It can be understood that the electrode of the present application is provided with a flow channel hole that runs through the electrode body, and the flow channel hole is used to shorten the infiltration path of the electrolyte into the interior of the electrode body, so that the electrolyte can quickly penetrate into the interior of the electrode body, thereby ensuring that the electrolyte inside the electrode body is sufficient and improving the performance of the battery.

[0007] In one embodiment, the flow channel hole is arranged on the side wall of the pole piece body, and the side wall is parallel to the thickness direction of the pole piece body.

[0008] In this embodiment, flow channel holes are provided on the side walls parallel to the thickness direction of the pole piece body, so that the electrolyte can penetrate into the interior of the pole piece body from the side of the pole piece body.

[0009] In one embodiment, the pole piece body is a rectangular parallelepiped, the side wall includes a first side wall and a second side wall that are perpendicular and connected to each other, the length of the second side wall is greater than the length of the first side wall, and the flow channel hole is provided on the second side wall.

[0010] In this embodiment, by setting the side wall including the first side wall and the second side wall, and making the length dimension of the second side wall larger than the length dimension of the first side wall, and by setting the flow channel hole on the second side wall with the longer length of the electrode body, the electrolyte can have a shorter infiltration path for the entire electrode body, thereby further improving its electrochemical performance.

[0011] In one embodiment, the pole piece includes a pole ear, and the pole ear is arranged on the first side wall.

[0012] In this embodiment, a pole ear is provided on the first side wall to serve as a power lead-out terminal to lead out the electric energy generated by the pole piece body. In addition, the pole ear and the flow channel hole are provided on the side walls on different sides of the pole piece body to avoid the flow channel hole affecting the structural stability of the pole ear.

[0013] In one embodiment, the pole piece body includes two opposite second side walls, and both second side walls are provided with flow channel holes.

[0014] In this embodiment, flow channel holes are provided on both second side walls to further improve the wetting effect of the electrolyte.

[0015] In one embodiment, projections of the flow channel holes on the two second side walls on any second side wall completely overlap.

[0016] In this embodiment, by arranging the projections of the flow channel holes on the two second side walls on any second side wall to completely overlap, that is, the positions of the flow channel holes on the two second side walls are symmetrically arranged along the direction perpendicular to the arrangement of the two second side walls, the infiltration path of the electrolyte to the entire electrode body can be further shortened.

[0017] In one embodiment, projections of the flow channel holes on the two second side walls on any one of the second side walls partially overlap.

[0018] In this embodiment, by arranging the projections of the flow channel holes on the two second side walls to overlap on any second side wall, not only the infiltration path of the electrolyte to the electrode body can be shortened, but also the uniformity of the electrolyte infiltration to the electrode body can be increased.

[0019] In one embodiment, the flow channel holes on the two second side walls are symmetrically arranged along the center line of the first side wall.

[0020] In this embodiment, the flow channel holes on the two second side walls are symmetrically arranged along the center line of the first side wall so that the electrolyte can evenly penetrate into the interior of the electrode body.

[0021] In one embodiment, the flow channel holes on the two second side walls are staggered along the length direction of the second side walls.

[0022] In this embodiment, the flow channel holes on the two second side walls are staggered along the length direction of the second side walls so that the electrolyte can evenly penetrate into the pole piece body and can infiltrate and cover the entire pole piece body.

[0023] In one embodiment, along the length direction of the second side wall, the flow channel hole is at least located in the middle of the second side wall.

[0024] In this embodiment, the flow channel hole is arranged at least in the middle of the second side wall along its length direction, so that the electrolyte can quickly infiltrate the geometric center area of ​​the electrode body.

[0025] In one embodiment, along the length direction of the second side wall, the ratio of the length dimension of each flow channel hole to the length dimension of the second side wall is between 10% and 20%.

[0026] In this embodiment, along the length direction of the second side wall, the ratio of the length dimension of each flow channel hole to the length dimension of the second side wall is set to be between 10% and 20% to limit the flow channel hole to have an appropriate size, which can ensure that the electrolyte can quickly infiltrate into the interior of the electrode body while ensuring the proportion of the electrode body and avoiding reducing the energy density of the battery.

[0027] In one embodiment, along the length direction of the first side wall, the ratio of the maximum recessed depth of the flow channel hole relative to the second side wall to the length dimension of the first side wall is less than 5%.

[0028] In this embodiment, along the length direction of the first side wall, by setting the ratio of the maximum recessed depth of the flow channel hole relative to the second side wall to the length dimension of the first side wall to be less than 5%, it is possible to ensure that the electrolyte quickly infiltrates into the interior of the electrode body while ensuring the proportion of the electrode body, thereby avoiding reducing the energy density of the battery.

[0029] In one embodiment, the pole piece body includes a first surface, the first surface is perpendicular to the thickness direction of the pole piece body, and the flow channel hole is arranged on the first surface of the pole piece body.

[0030] In this embodiment, by arranging the flow channel hole on the first surface perpendicular to the thickness direction of the pole piece body, the flow channel hole can be used to retain the electrolyte, thereby preventing the electrolyte inside the pole piece body from being squeezed out of the pole piece body due to battery expansion.

[0031] In one embodiment, the number of the flow channel hole is one, and the geometric center of the one flow channel hole coincides with the geometric center of the pole piece body.

[0032] In this embodiment, the geometric center of the flow channel hole is arranged to coincide with the geometric center of the pole piece body, so as to ensure that the electrolyte in the flow channel hole can evenly infiltrate the center and various positions of the pole piece body.

[0033] In one embodiment, there are multiple flow channel holes, a line connecting the geometric centers of the multiple flow channel holes is a straight line, and the line connecting the geometric centers of the multiple flow channel holes passes through the geometric center of the pole piece body.

[0034] In this embodiment, the electrolyte infiltration speed can be increased by providing multiple flow channel holes. At the same time, the geometric center connection line of the multiple flow channel holes is set to be a straight line, and the geometric center connection line of the multiple flow channel holes is set to pass through the geometric center of the pole piece body, so that the electrolyte can quickly infiltrate the geometric center area of ​​the pole piece body.

[0035] In one embodiment, there are multiple flow channel holes, the pole piece body is a rectangular parallelepiped, and the pole piece body includes a side wall connected to the first surface, and the geometric center line of the multiple flow channel holes is parallel to the side wall.

[0036] In this embodiment, the geometric center line of multiple flow channel holes passes through the geometric center of the electrode body, and the line connecting the geometric centers of each flow channel hole is set parallel to the side wall to ensure that the electrolyte retained in the flow channel holes can spread quickly and evenly from the geometric center area of ​​the electrode body to the edge.

[0037] In one embodiment, the ratio of the total projected area of ​​each flow channel hole on the first surface along the thickness direction of the pole piece body to the area of ​​the first surface is less than 0.1.

[0038] In this embodiment, by setting the ratio of the total projected area of ​​the flow channel holes on the first surface to the area of ​​the first surface to be less than 0.1, it is possible to ensure that the electrolyte quickly infiltrates into the interior of the electrode body while ensuring the proportion of active materials in the electrode body, thereby avoiding reducing the energy density of the battery.

[0039] In a second aspect, the present application provides a battery, comprising a housing and a plurality of pole pieces as in any of the above embodiments, wherein the plurality of pole pieces are accommodated in the housing and stacked along their thickness direction, and the pole pieces are at least one of positive pole pieces or negative pole pieces.

[0040] It can be understood that the battery provided in the second aspect of the present application, because it adopts the electrode provided in the first aspect of the present application, also has all possible beneficial effects of the electrode provided in any of the above embodiments.

[0041] In a third aspect, the present application provides an electrical device, which includes a functional module and a pole piece as provided in any embodiment of the first aspect of the present application or a battery as provided in any embodiment of the second aspect of the present application, wherein the pole piece is used to provide electrical energy to the functional module.

[0042] It can be understood that the electrical equipment provided in the third aspect of the present application adopts the electrode provided in any embodiment of the first aspect of the present application or the battery provided in any embodiment of the second aspect, and thus also has all possible beneficial effects in any embodiment of the first aspect or the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A schematic diagram of a cross-sectional structure of a battery provided in one embodiment of the present application;

[0045] Figure 2 This is a schematic diagram of the planar structure of a pole piece provided in one embodiment of the present application;

[0046] Figure 3 This is a schematic diagram of the planar structure of a single pole piece body provided in one embodiment of the present application;

[0047] Figure 4 A schematic diagram of the planar structure of a single pole piece body provided in another embodiment of the present application;

[0048] Figure 5 A schematic diagram of the planar structure of a single pole piece body provided in another embodiment of the present application;

[0049] Figure 6 This is a schematic diagram of the planar structure of a single pole piece body provided in yet another embodiment of the present application;

[0050] Figure 7 This is a schematic diagram of the planar structure of a single pole piece body provided in yet another embodiment of the present application;

[0051] Figure 8 A schematic diagram of the planar structure of a pole piece body provided in another embodiment of the present application;

[0052] Fig. 9 A schematic diagram of the planar structure of a single pole piece body provided in another embodiment of the present application;

[0053] Fig.10 This is a schematic diagram of the planar structure of a single pole piece body provided in another embodiment of the present application.

[0054] Figure numbers: 100-battery; 10-shell; 20-pole piece; 20a-pole piece body; 21-side wall; 21a-first side wall; 21b-second side wall; 21c-left side wall; 21d-right side wall; 22-pole ear; 23-first surface; 30-flow channel hole; 40-diaphragm; 001-first direction; 002-second direction; 003-third direction. DETAILED DESCRIPTION

[0055] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0056] The following descriptions of the embodiments are with reference to the attached diagrams to illustrate specific embodiments that the present application can be used to implement. The serial numbers for the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, include direct and indirect connections (couplings). The directional terms mentioned in the present application, such as "upper", "lower", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0057] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including", "may include", "include", or "may include" used in this application indicate the existence of the corresponding functions, operations, elements, etc. disclosed, and do not limit one or more other functions, operations, elements, etc. In addition, the terms "including" or "include" indicate the existence of the corresponding features, numbers, steps, operations, elements, components, or combinations thereof disclosed in the specification, and do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, and are intended to cover non-exclusive inclusions.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0059] Please refer to Figure 1 and Figure 2 , Figure 1 Schematic diagram of the cross-sectional structure of a battery 100 provided in one embodiment of the present application. Figure 2 It is a schematic diagram of the planar structure of a pole piece 20 provided in one embodiment of the present application.

[0060] like Figure 1 and Figure 2As shown, the battery 100 of the present application includes a shell 10 and a pole piece 20. Among them, the number of pole pieces 20 is multiple, and the multiple pole pieces 20 are stacked in sequence along the first direction 001, and are accommodated and fixed in the inner cavity of the shell 10 to form a stacked battery. Among them, the first direction 001 is the thickness direction of the pole piece 20 itself. In another possible embodiment, the pole piece 20 can be wound around a rotating shaft to form a wound battery. That is, the scheme of the present application is applicable to both stacked batteries and wound batteries. The inner cavity of the shell 10 is also filled with an electrolyte (not shown in the figure), and the electrolyte is used to soak the pole piece 20. At the same time, each pole piece 20 includes a pole piece body 20a. The pole piece body 20a is provided with a plurality of flow channel holes 30, and the plurality of flow channel holes 30 all penetrate the pole piece body 20a along the first direction 001. Two adjacent electrode sheets 20 among the plurality of electrode sheets 20 are respectively a positive electrode sheet and a negative electrode sheet, and a separator 40 is provided between the positive electrode sheet and the negative electrode sheet to separate the positive electrode sheet from the negative electrode sheet.

[0061] The battery 100 of the present application is provided with a housing 10 for accommodating a fixed pole piece body 20 and containing an electrolyte. A plurality of pole pieces 20 stacked along their own thickness direction are provided as the main body for generating electric energy. At the same time, a diaphragm 40 is also provided between two adjacent pole pieces 20 to separate adjacent pole pieces 20 to avoid the undesirable phenomenon of short circuit caused by the conduction of pole pieces 20 of different polarities. The electrolyte can provide some active ions for the pole piece body 20a, and at the same time provide an ion channel for the pole piece body 20a, so as to facilitate the flow of ions in the pole piece body 20a, thereby generating electric energy.

[0062] The battery 100 of the present application is also provided with flow channel holes 30 penetrating through each electrode body 20a, so as to shorten the infiltration path of the electrolyte into the interior of the electrode body 20a due to capillary action, and can be used to retain the electrolyte, thereby ensuring that during the charge and discharge cycle of the battery 100, the electrolyte can quickly and evenly penetrate into the interior of the electrode body 20a, thereby ensuring that the electrolyte inside the electrode body 20a is sufficient, thereby improving the performance of the battery 100.

[0063] It should be noted that in the above-mentioned embodiment, the number and position of the flow channel holes 30 are only introduced as examples. That is, in some other embodiments, the flow channel holes 30 may be provided on part of the pole piece body 20a, or only on one pole piece body 20a, and the number of the flow channel holes 30 on the pole piece body 20a provided with the flow channel holes 30 may be one or more, which is also conducive to the electrolyte infiltration into the inside of the pole piece body 20a through the flow channel holes 30, and the present application does not make any special limitation on this.

[0064] Specifically, in Figure 1 and Figure 2In the embodiment shown, the flow channel hole 30 is provided on the side wall 21 of the pole piece body 20a. The side wall 21 is parallel to the first direction 001, that is, parallel to the thickness direction of the pole piece body 20a. It can be understood that the flow channel hole 30 is provided on the side wall 21 of the pole piece body 20a so that the electrolyte can penetrate into the inside of the pole piece body 20a from the side of the pole piece body 20a.

[0065] At the same time, Figure 1 and Figure 2 In the embodiment shown, the pole piece body 20a is a rectangular parallelepiped, and the side wall 21 includes a first side wall 21a and a second side wall 21b connected to each other, the first side wall 21a and the second side wall 21b are perpendicular, and the length dimension of the second side wall 21b is greater than the length dimension of the first side wall 21a. It should be noted that the length dimension of the first side wall 21a refers to the length of the first side wall 21a along the second direction 002, and the length dimension of the second side wall 21b refers to the length of the second side wall 21b along the third direction 003. The first direction 001, the second direction 002 and the third direction 003 are perpendicular to each other. That is, the first side wall 21a is located at the short side of the pole piece body 20a, and the second side wall 21b is located at the long side of the pole piece body 20a. Or it can be understood that the first side wall 21a is parallel to the width direction of the pole piece body 20a, and the second side wall 21b is parallel to the length direction of the pole piece body 20a. A pole ear 22 is protruding from the first side wall 21 a , and the pole ear 22 can serve as a power lead-out terminal to lead out the electric energy generated by the pole piece body 20 a . The flow channel hole 30 is disposed on the second side wall 21 b .

[0066] It can be understood that the present application arranges the pole ear 22 on the first side wall 21a with a smaller length dimension to ensure the effect of the pole ear 22 converging and reduce the internal resistance. At the same time, the flow channel hole 30 is arranged on the second side wall 21b with a larger length dimension, so that the electrolyte has a shorter infiltration path for the entire pole piece body 20a, thereby further improving its electrochemical performance and preventing the flow channel hole 30 from affecting the structural stability of the pole ear 22.

[0067] Please see Figure 3 , Figure 3 It is a schematic diagram of the planar structure of a single pole piece body 20a provided in one embodiment of the present application.

[0068] like Figure 2 and Figure 3 As shown, in one embodiment, the pole piece body 20a includes two opposite second side walls 21b, both second side walls 21b are provided with flow channel holes 30, and the flow channel holes 30 on any second side wall 21b on the two second side walls 21b partially overlap in their positive projection on the same second side wall 21b.

[0069] It can be understood that in this embodiment, the flow channel holes 30 are provided on both second side walls 21b, which can further improve the infiltration effect of the electrolyte. At the same time, by arranging the flow channel holes 30 on the two second side walls 21b to overlap the orthographic projections on any one of the second side walls 21b, not only can the infiltration path of the electrolyte to the electrode body 20a be further shortened, so that the electrolyte can quickly penetrate from the edge of the electrode body 20a to the middle area of ​​the electrode body 20a, but also the uniformity of the electrolyte infiltration to the electrode body 20a can be increased.

[0070] It should be noted that the positional relationship of the flow channel holes 30 on the two second side walls 21b in the above embodiment is only introduced as an example, that is, in some other embodiments of the present application, the corresponding flow channel holes 30 on the two second side walls 21b may also have other positional relationships.

[0071] For details, please refer to Figure 4 , Figure 4 It is a schematic diagram of the planar structure of a single pole piece body 20a provided in another embodiment of the present application.

[0072] like Figure 4 As shown, in one embodiment, the orthographic projections of the flow channel holes 30 on the two second side walls 21b on the same second side wall 21b completely overlap. That is, the flow channel holes 30 on the two second side walls 21b are symmetrically arranged along the center line of the first side wall 21a. It should be noted that the dotted line in the figure is the center line of the first side wall 21a.

[0073] It can be understood that in this embodiment, the flow channel holes 30 on the two second side walls 21b are symmetrically arranged along the center line of the first side wall 21a, so that the electrolyte can evenly penetrate into the interior of the electrode body 20a from both sides of the electrode body 20a and shorten the diffusion distance of the electrolyte.

[0074] In another possible embodiment, Figure 5 As shown, Figure 5 This is a schematic diagram of the planar structure of a single pole piece body 20a provided in another embodiment of the present application. The flow channel holes 30 on the two second side walls 21b are staggered along the length direction of the second side wall 21b. It should be noted in advance that, for ease of introduction, the two second side walls 21b are defined as the left side wall 21c and the right side wall 21d, respectively. Along the length direction of the pole piece body 20a, the projection of the first flow channel hole 30 on the left side wall 21c on the right side wall 21d is arranged with zero gap with the first flow channel hole 30 on the right side wall 21d, and the projection of the second flow channel hole 30 on the left side wall 21c on the right side wall 21d is arranged with zero gap with the first flow channel hole 30 and the second flow channel hole 30 on the right side wall 21d, respectively, and so on.

[0075] It can be understood that in this embodiment, the flow channel holes 30 on the two second side walls 21b are staggered along the length direction of the second side wall 21b, so that the electrolyte can evenly penetrate into the electrode body 20a and quickly infiltrate and cover the entire electrode body 20a.

[0076] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the planar structure of a single pole piece body 20a provided in yet another embodiment of the present application.

[0077] like Figure 6 As shown, in one embodiment, there are multiple flow channel holes 30, and the multiple flow channel holes 30 are of the same size. And along the length direction of the second side wall 21b, from one end of the second side wall 21b to the middle of the second side wall 21b, the number of flow channel holes 30 gradually increases. From the middle of the second side wall 21b to the other end of the second side wall 21b, the number of flow channel holes 30 gradually decreases. That is, along the length direction of the second side wall 21b, the flow channel holes 30 on the second side wall 21b are arranged in a manner of dense in the middle and sparse on both sides.

[0078] It can be understood that in this embodiment, along the length direction of the pole piece body 20a, a large number of flow channel holes 30 are arranged at a relatively middle position of the second side wall 21b so that the electrolyte can quickly infiltrate the geometric center area of ​​the pole piece body 20a.

[0079] like Figure 7 As shown, Figure 7 This is a schematic diagram of the planar structure of a single pole piece body 20a provided in another embodiment of the present application. In another possible embodiment, the sizes of the flow channel holes 30 are different. And along the length direction of the second side wall 21b, from one end of the second side wall 21b to the middle of the second side wall 21b, the projected area of ​​the flow channel hole 30 on the surface of the pole piece body 20a gradually increases. From the middle of the second side wall 21b to the other end of the second side wall 21b, the projected area of ​​the flow channel hole 30 on the pole piece body 20a gradually decreases.

[0080] It can be understood that in this embodiment, along the length direction of the pole piece body 20a, a relatively large flow channel hole 30 is provided at a relatively middle position of the second side wall 21b so that the electrolyte can quickly infiltrate the geometric center area of ​​the pole piece body 20a.

[0081] In one embodiment, along the length direction of the second side wall 21b, the ratio of the length dimension of each flow channel hole 30 to the length dimension of the second side wall 21b along the third direction 003 is between 10% and 20%. It should be noted that the length dimension of the flow channel hole 30 refers to the length of the flow channel hole 30 along the third direction 003, and the length dimension of the second side wall 21b refers to the length of the second side wall 21b along the third direction 003. It can be understood that the ratio of the length dimension of each flow channel hole 30 along the third direction 003 to the length dimension of the second side wall 21b along the third direction 003 is set between 10% and 20% to limit the flow channel hole 30 to have a suitable size, which can ensure that the electrolyte quickly infiltrates into the interior of the pole piece body 20a while ensuring the proportion of the pole piece body 20a, thereby avoiding reducing the energy density of the battery 100.

[0082] In one embodiment, along the length direction of the first side wall 21a, the ratio of the maximum depression depth of the plurality of flow channel holes 30 relative to the second side wall 21b to the length dimension of the first side wall 21a is less than 5%. It should be noted that the depression depth of the flow channel hole 30 refers to the depth of the flow channel hole 30 along the second direction 002, and the length dimension of the first side wall 21a refers to the length of the first side wall 21a along the second direction 002. It can be understood that along the second direction 002, the ratio of the maximum depression depth of the flow channel hole 30 relative to the second side wall 21b to the length dimension of the first side wall 21a is set to be less than 5%, which can ensure that the electrolyte quickly infiltrates into the interior of the pole piece body 20a while ensuring the proportion of the pole piece body 20a, thereby avoiding reducing the energy density of the battery 100.

[0083] Please see Figure 8 , Figure 8 It is a schematic diagram of the planar structure of a pole piece body 20a provided in another embodiment of the present application.

[0084] like Figure 1 and Figure 8 As shown, in one embodiment, the pole piece body 20a includes a first surface 23, and the first surface 23 is perpendicular to the thickness direction of the pole piece body 20a. The flow channel hole 30 is circular, and the flow channel hole 30 is arranged on the first surface 23, and runs through the pole piece body 20a. It should be noted that the electrolyte will penetrate into the interior of the pole piece body 20a after a period of time, and during the charge and discharge cycle of the battery 100, the battery 100 will expand, which may expel the electrolyte inside the pole piece body 20a. The battery 100 of the present application sets the flow channel hole 30 on the first surface 23, and a certain amount of electrolyte can be pre-stored. At the same time, during the expansion of the battery 100, the flow channel hole 30 can also accommodate the expelled electrolyte so that it can be immersed in the interior of the pole piece body 20a again.

[0085] In one embodiment, the flow channel hole 30 penetrates the pole piece body 20a along the thickness direction of the pole piece body 20a, that is, the flow channel hole 30 is set in the form of a through hole. At this time, the diaphragm 40 adjacent to the pole piece body 20a cooperates with the flow channel hole 30 to form a liquid storage cavity to retain the electrolyte. The battery 100 of the present application can increase the capacity of the flow channel hole 30 by setting the flow channel hole 30 to penetrate the pole piece body 20a along the thickness direction of the pole piece body 20a, and can also use the flow channel hole 30 to absorb the gas generated by the electrolyte to avoid the generation of black spots, thereby improving the performance of the battery 100.

[0086] like Fig. 9 As shown, in one embodiment, the pole piece body 20a includes a first surface 23 along a direction perpendicular to its thickness. The number of the flow channel hole 30 is one, and the geometric center of the flow channel hole 30 coincides with the geometric center of the pole piece body 20a. That is, the projection of the geometric center of the flow channel hole 30 on the first surface 23 coincides with the geometric center of the first surface 23. It can be understood that the projection of the geometric center of the flow channel hole 30 on the first surface 23 coincides with the geometric center of the first surface 23 to ensure that the electrolyte in the flow channel hole 30 can be evenly infiltrated from the center of the pole piece body 20a to various positions of the pole piece body 20a.

[0087] In another embodiment, if Fig.10 As shown, the number of flow channel holes 30 is multiple. The line connecting the geometric centers of the multiple flow channel holes 30 is a straight line, and the line connecting the geometric centers of the multiple flow channel holes 30 passes through the geometric center of the pole piece body 20a. That is, the projection of the line connecting the geometric centers of the multiple flow channel holes 30 on the first surface 23 passes through the geometric center of the first surface 23. Specifically, the pole piece body 20a is a rectangular parallelepiped, and the pole piece body 20a includes a side wall 21 connected to the first surface 23. The line connecting the geometric centers of the multiple flow channel holes 30 is parallel to the side wall 21. Furthermore, the line connecting the geometric centers of the multiple flow channel holes 30 is parallel to the side wall 21 with a larger length dimension. That is, the line connecting the geometric centers of the multiple flow channel holes 30 is parallel to the third direction 003.

[0088] It can be understood that in this embodiment, based on the projection of the line connecting the geometric centers of the multiple flow channel holes 30 on the first surface 23 passing through the geometric center of the first surface 23, the line connecting the geometric centers of each flow channel hole 30 is set to be parallel to the larger side wall 21 to ensure that the electrolyte retained in the flow channel hole 30 can spread quickly and evenly from the geometric center area of ​​the electrode body 20a to the edge.

[0089] In one embodiment, the ratio of the total projected area of ​​each flow channel hole 30 on the first surface 23 along the first direction 001 to the area of ​​the first surface 23 is less than 0.1. It should be noted that the flow channel holes 30 within this ratio range can ensure that the electrolyte quickly infiltrates into the inside of the pole piece body 20a, while also ensuring the proportion of the pole piece body 20a, thereby avoiding reducing the energy density of the battery 100.

[0090] It should be noted that, in the above-mentioned embodiments, the size, shape, number of the flow channel holes 30 and the gaps between adjacent flow channel holes 30 are only introduced as examples, that is, the size, shape, number of the flow channel holes 30 and the gaps between adjacent flow channel holes 30 can be adaptively adjusted according to the actual application scenario, and the present application does not make any special limitation on this.

[0091] It should also be noted that the battery 100 of the present application can be applied to electrical equipment to provide electrical energy to functional modules in the electrical equipment. Exemplarily, the electrical equipment can be an electric vehicle. Specifically, a plurality of batteries 100 of the present application can be connected in series or in parallel to provide driving power for the electric vehicle. Alternatively, the battery 100 of the present application can also be mounted on an electric vehicle alone, and can also provide driving power for the electric vehicle. In another embodiment, the battery 100 of the present application can also be applied to other electrical equipment, which is not particularly limited in the present application.

[0092] In conjunction with the accompanying drawings, several possible embodiments of the present application and a typical embodiment in the prior art (Comparative Example 1) are selected below to compare and illustrate the beneficial effects that the battery of the present application may achieve:

[0093] Embodiment 1: A rectangular electrode body 20a with a length of 550mm (excluding the pole ear) and a width of 200mm is selected as the positive electrode body, and 5 flow channel holes 30 with equal distances are respectively set on the two side walls 21 parallel to the length direction. The shape of the flow channel hole 30 is rectangular, and the length of the flow channel hole 30 is 50mm, the depth of the depression is 5mm, and the distance between two adjacent flow channel holes 30 on the same side wall 21 is 50mm. At the same time, the corresponding flow channel holes 30 on the two side walls 21 are symmetrically arranged. Similarly, a pole piece body 20a with a length of 550mm (excluding the pole ear) and a width of 202mm is selected as the negative electrode body, and the design is completely based on the flow channel hole 30 of the aforementioned positive electrode body. Then, the diaphragm-negative electrode body-diaphragm-positive electrode body are laminated and hot-pressed into a pole core with a thickness of 24mm, and then loaded into a shell, injected with electrolyte, formed and divided into capacities to obtain a single battery.

[0094] Embodiment 2: A rectangular pole piece body 20a with a length of 550mm (excluding the pole ear) and a width of 200mm is selected as the positive pole piece body, and 5 flow channel holes 30 with equal distances are respectively set on the two side walls 21 parallel to the length direction. The shape of the flow channel hole 30 is rectangular, and the length of the flow channel hole 30 is 50mm, the depth of the depression is 5mm, and the distance between two adjacent flow channel holes 30 on the same side wall 21 is 50mm. At the same time, the corresponding flow channel holes 30 on the two side walls 21 are staggered. Similarly, a rectangular pole piece body 20a with a length of 550mm (excluding the pole ear) and a width of 202mm is selected as the negative pole piece body, and is designed completely according to the flow channel hole 30 of the aforementioned positive pole piece body, and then the diaphragm-negative pole piece body-diaphragm-positive pole piece body is laminated and hot-pressed into a pole core with a thickness of 24mm, and then loaded into a shell, injected with electrolyte, formed and divided into capacities to obtain a single battery.

[0095] Embodiment 3: A rectangular electrode body 20a with a length of 550 mm (excluding the pole ear) and a width of 200 mm is selected as the positive electrode body, and five flow channel holes 30 are arranged at equal distances along the length direction of the electrode body 20a on the surface of the electrode body 20a perpendicular to its thickness. The shape of the flow channel hole 30 is circular, and the radius of the flow channel hole 30 is 10 mm, and the distance between two adjacent flow channel holes 30 is 80 mm. The projection of the geometric center line of each flow channel hole 30 on the surface of the electrode body coincides with the midline on the wide side of the electrode body 20a. Similarly, a pole piece body 20a with a length of 550mm (excluding the pole ear) and a width of 202mm is selected as the negative pole piece body, and is designed completely according to the flow channel hole 30 of the aforementioned positive pole piece body. Then, the diaphragm-negative pole piece body-diaphragm-positive pole piece body are stacked and hot-pressed into a pole core with a thickness of 24mm, and then loaded into a shell, injected with electrolyte, formed and divided into volumes to obtain a single cell.

[0096] Comparative Example 1: A pole piece body with a length of 550 mm (excluding the pole ear) and a width of 200 mm is selected as the positive pole piece body, and a pole piece body with a length of 550 mm (excluding the pole ear) and a width of 202 mm is selected as the negative pole piece body, and the diaphragm-negative pole piece body-diaphragm-positive pole piece body are stacked and hot-pressed into a pole core with a thickness of 24 mm, which is then loaded into a shell, injected with electrolyte, formed and divided into volumes to obtain a single cell.

[0097] Three batteries from each of the above embodiments and comparative examples were taken, and after circulating three times in a constant temperature room at 25° C., they were disassembled in an empty and charged state, and the residual electrolyte in the batteries was weighed and statistically analyzed to obtain Table 1.

[0098] Table 1:

[0099]

[0100]

[0101] Assuming that the electrolyte consumed by the battery in three cycles is the same, analysis of the data in the above table shows that after disassembling the batteries in Example 1, Example 2 and Example 3 using the technical solution of the present application, the amount of residual electrolyte is less than the residual electrolyte in the control example. This shows that the battery in the embodiments of the present application has a better ability to absorb electrolyte, that is, the electrolyte infiltration effect is better.

[0102] After further processing and comparison of the data, it can also be seen that the proportion of electrolyte absorbed and consumed in the embodiments of the present application is higher than that in the control example. This shows that the technical solution of the present application can improve the wetting problem of the electrolyte inside the electrode body by setting flow channel holes on the side wall of the electrode body or on the surface of the electrode body perpendicular to its own thickness direction, so as to ensure that there is sufficient electrolyte inside the electrode body, thereby improving the performance of the battery.

[0103] It should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0105] It should be understood that the application of this application is not limited to the above examples. For ordinary technicians in this field, they can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments are implemented, and equivalent changes made according to the claims of this application still fall within the scope covered by this application.

Claims

1. A pole piece, characterized in that: It comprises a pole piece body, wherein the pole piece body is provided with a flow channel hole penetrating along the thickness direction thereof, and the flow channel hole is used to shorten the infiltration path of the electrolyte to the pole piece body.

2. The pole piece according to claim 1, characterized in that: The flow channel hole is arranged on the side wall of the pole piece body, and the side wall is parallel to the thickness direction of the pole piece body.

3. The pole piece according to claim 2, characterized in that: The pole piece body is in the form of a rectangular parallelepiped, the side wall comprises a first side wall and a second side wall which are perpendicular to and connected to each other, the length of the second side wall is greater than the length of the first side wall, and the flow channel hole is arranged on the second side wall.

4. The pole piece according to claim 3, characterized in that: The pole piece includes a pole ear, and the pole ear is arranged on the first side wall.

5. The pole piece according to claim 3, characterized in that: The pole piece body includes two opposite second side walls, and the two second side walls are both provided with the flow channel hole.

6. The pole piece according to claim 5, characterized in that: The projections of the flow channel holes on the two second side walls on any one of the second side walls completely overlap, or the projections of the flow channel holes on the two second side walls on any one of the second side walls partially overlap.

7. The pole piece according to claim 3, characterized in that: Along the length direction of the second side wall, the flow channel hole is at least located in the middle of the second side wall.

8. The pole piece according to claim 3, characterized in that: Along the length direction of the second side wall, the ratio of the length dimension of each of the flow channel holes to the length dimension of the second side wall is between 10% and 20%; and / or, Along the length direction of the first side wall, a ratio of a maximum recessed depth of the flow channel hole relative to the second side wall to a length dimension of the first side wall is less than 5%.

9. The pole piece according to claim 1, characterized in that: The pole piece body includes a first surface, the first surface is perpendicular to the thickness direction of the pole piece body, and the flow channel hole is arranged on the first surface.

10. The pole piece according to claim 9, characterized in that: The number of the flow channel hole is one, and the geometric center of the one flow channel hole coincides with the geometric center of the pole piece body; or, The number of the flow channel holes is multiple, the geometric center line of the multiple flow channel holes is a straight line, and the geometric center line of the multiple flow channel holes passes through the geometric center of the pole piece body.

11. The pole piece according to claim 10, characterized in that: There are multiple flow channel holes, the pole piece body is a rectangular parallelepiped, and the pole piece body includes a side wall connected to the first surface, and a line connecting geometric centers of the multiple flow channel holes is parallel to the side wall.

12. The pole piece according to claim 9, characterized in that: The ratio of the total projected area of ​​each of the flow channel holes on the first surface along the thickness direction of the pole piece body to the area of ​​the first surface is less than 0.

1.

13. A battery, characterized in that: It comprises a shell and a plurality of pole pieces as described in any one of claims 1 to 12, wherein the plurality of pole pieces are accommodated in the shell and stacked along the thickness direction thereof, and the pole piece is at least one of a positive pole piece or a negative pole piece.

14. An electrical device, characterized in that: It comprises a functional module and a pole piece as described in any one of claims 1 to 12, or comprises a battery as described in claim 13, wherein the pole piece is used to provide electrical energy to the functional module.

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