Electrode assembly, battery and hot pressboard

Abstract

The utility model provides an electrode assembly, battery, hot pressboard, the electrode assembly includes a plurality of infiltrating portion and a plurality of support portion in the direction perpendicular to the thickness direction, at least one support portion is arranged between two adjacent infiltrating portions, the infiltrating portion is communicated with the support portion, the infiltrating portion is provided with a protruding portion protruding relative to the support portion, and the protruding portion is provided with a plurality of through holes. And the lug bosses absorb the electrolyte and flow to the adjacent supporting parts through the infiltration parts, so that the infiltration efficiency of the electrolyte on the electrode assembly is improved.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to an electrode assembly, a battery, and a hot press plate. Background Technology

[0002] The relevant technology applies pressure to the electrode assembly using two smooth, heatable flat plates, making the electrode assembly into a template for easy assembly. After the electrode assembly is hot-pressed or preheated and pressurized, the diaphragm and positive and negative electrodes are completely adhered and compacted, which is not conducive to electrolyte wetting of the electrode assembly. Moreover, although the electrode assembly is templated after hot pressing, the physical properties of the diaphragm change, and the electrode assembly cannot completely absorb the electrolyte, resulting in local wetting differences. It cannot provide a smooth electrolyte transport channel, inevitably blocking the wetting of the electrolyte in the electrode assembly, which affects the long-term cycle performance of the electrode assembly.

[0003] Therefore, the electrode assembly in the relevant technology suffers from the technical problem of low electrolyte wetting efficiency. Utility Model Content

[0004] The embodiments of this utility model provide an electrode assembly, a battery, and a hot press plate, which can improve the technical problem of low electrolyte wetting efficiency in the electrode assembly in the prior art.

[0005] In a first aspect, embodiments of the present invention provide an electrode assembly comprising, along the thickness direction of the electrode assembly, a first electrode, a second electrode, and a diaphragm located between the first electrode and the second electrode, wherein the electrode assembly comprises, at least along the length direction of the electrode assembly, the following:

[0006] A plurality of wetting portions and a plurality of supporting portions, wherein at least one of the supporting portions is disposed between two adjacent wetting portions, and the wetting portion is in communication with the adjacent supporting portion;

[0007] The immersion portion is provided with a protrusion that protrudes relative to the support portion.

[0008] In one embodiment, at least one of the impregnating portions is provided with an impregnation channel, and the impregnating portion is connected to an adjacent supporting portion through the impregnation channel, wherein the density of the impregnating portion is less than the density of the supporting portion.

[0009] In one embodiment, the density of the wetted portion is less than the density of the support portion.

[0010] The bonding force between the first electrode located in the wetted portion and the diaphragm is less than the bonding force between the first electrode located in the support portion and the diaphragm, and / or the bonding force between the second electrode located in the wetted portion and the diaphragm is less than the bonding force between the second electrode located in the support portion and the diaphragm.

[0011] In one embodiment, the thickness of the support portion is T1, and the thickness of the impregnated portion is T2, wherein the range of (T2-T1) / T2 is greater than or equal to 0.03.

[0012] In one embodiment, the total area of ​​the plurality of wetted portions is smaller than the total area of ​​the plurality of support portions.

[0013] In one embodiment, the wetting portion includes a first portion extending along the width direction of the electrode assembly and a second portion extending along the length direction of the electrode assembly, wherein the width of the first portion and the second portion ranges from 0.5 mm to 5 mm.

[0014] In one embodiment, the protrusion and the support have a connecting chamfer, which is rounded.

[0015] Thirdly, embodiments of the present invention provide a battery, the battery including the electrode assembly as described in any of the above embodiments.

[0016] Thirdly, embodiments of this utility model provide a hot press plate for fabricating electrode assemblies as described in any of the above embodiments, comprising:

[0017] The first and second boards are set relative to each other;

[0018] The first plate includes a flat portion and a concave portion. The concave portion is provided with a groove, which is corresponding to the wetting portion. The flat portion is corresponding to the supporting portion.

[0019] In one embodiment, a connecting chamfer is provided between the concave portion and the planar portion, and the connecting chamfer is rounded.

[0020] In one embodiment, adjacent wetting portions are arranged at intervals, and the outline shape of the wetting portions is either curved or oblique.

[0021] In one embodiment, the cross-sectional shape of the immersion portion is any one of a semi-circle, trapezoid, or triangle.

[0022] The beneficial effects of the embodiments of this utility model are as follows: by providing a wetting part between adjacent support parts, the wetting part is connected to the support part, and the wetting part is provided with a protrusion that protrudes relative to the support part, the electrolyte can be absorbed by the protrusion and flow to the adjacent support part through the wetting part, thereby achieving the wetting of the support part and improving the wetting efficiency of the electrolyte on the electrode assembly. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is the front view of the electrode assembly provided in the embodiments of this utility model.

[0025] Figure 2 This is a top view of the electrode assembly provided in an embodiment of this utility model.

[0026] Figure 3 This is a side view of the electrode assembly provided in the embodiments of this utility model.

[0027] Figure 4 This is a first schematic diagram of the electrode assembly provided in an embodiment of the present invention from a top view.

[0028] Figure 5 This is a second schematic diagram of the electrode assembly provided in an embodiment of the present invention from a top view.

[0029] Figure 6 This is a third schematic diagram of the electrode assembly provided in the embodiment of this utility model from a top view.

[0030] Figure 7 This is a schematic diagram of the assembly of the hot press plate and the electrode assembly provided in an embodiment of this utility model. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0032] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4The electrode assembly 1 provided in the embodiment of the present invention includes a first electrode 10, a second electrode 20 and a diaphragm located between the first electrode 10 and the second electrode 20 along the thickness direction of the electrode assembly 1. The electrode assembly 1 includes a plurality of wetting portions 30 and a plurality of support portions 40 in the direction perpendicular to the thickness direction. At least one support portion 40 is disposed between two adjacent wetting portions 30. At least one wetting portion 30 is provided with a wetting channel, which extends along the direction of the wetting portion 30 toward the adjacent support portion 40.

[0033] Understandably, during the pressing process of the hot press plate 2, the wetting part 30 is not compacted relative to the support part 40, which makes the wetting part 30 form multiple wetting channels. The electrolyte is more easily absorbed by the wetting part 30. Therefore, during the wetting process of the electrode assembly 1, the wetting part 30 is used to absorb the electrolyte. The electrolyte flows towards the support part 40 through the wetting channels in the wetting part 30 and completes the wetting of the support part 40.

[0034] The wetted portion can be entirely protruding relative to the support portion, or it can be partially protruding relative to the support portion.

[0035] In this embodiment, a wetting portion 30 is provided between adjacent support portions 40. The wetting portion 30 is connected to the support portion 40. The wetting portion 30 is provided with a protrusion 50 that protrudes relative to the support portion 40. The electrolyte can be absorbed by the protrusion 50 and flow through the wetting portion 30 to the adjacent support portion 40, thereby improving the wetting efficiency of the electrolyte on the support portion 40 of the electrode assembly 1.

[0036] The technical solution of this application will now be described in conjunction with specific embodiments.

[0037] The thickness range, width range, area ratio, quantity, etc. of this application are only described with reference to the best or preferred embodiment. Other embodiments that can meet the forming and wetting requirements of electrode assembly 1 should also fall within the protection scope of this utility model, and will not be described in detail here.

[0038] In one embodiment, please refer to Figure 3 The thickness of the support part 40 is T1, and the thickness of the impregnated part 30 is T2, wherein the range of (T2-T1) / T2 is greater than or equal to 0.03.

[0039] The range of (T2-T1) / T2 can be less than or equal to 0.1.

[0040] The value of (T2-T1) / T2 can be 0.03, 0.05, 0.065, 0.08, or 0.1.

[0041] The thickness of the wetted portion 30 is equal to the sum of the thickness of the supporting portion 40 and the thickness of the protrusion 50 of the wetted portion 30 that extends beyond the supporting portion 40. In other words, T2-T1 is the thickness of the protrusion 50, and the thickness of the protrusion 50 (T2-T1) is 3% to 10% of the thickness T2 of the wetted portion 30.

[0042] It is understandable that when the thickness of the protrusion 50 is less than 3% of the thickness of the wetting portion 30, the wetting portion 30 is compacted, resulting in low wetting efficiency; when the thickness of the protrusion 50 is greater than 10% of the thickness of the wetting portion 30, the forming effect of the electrode assembly 1 is reduced, which is not conducive to the forming of the electrode assembly 1.

[0043] It should be noted that the protrusion 50 includes a first protrusion located on one side of the electrode assembly 1 and a second protrusion located on the opposite side of the electrode assembly 1. The thickness of the first protrusion and the second protrusion may be the same or different. The positions of the first protrusion and the second protrusion may be relative or staggered.

[0044] In this embodiment, by making the thickness of the protrusion 50 greater than or equal to 3% of the thickness of the support 40, it is beneficial for the electrolyte to enter the wetting part 30 from the protrusion 50, thereby increasing the liquid storage capacity of the wetting part 30 and further improving the wetting efficiency of the electrolyte on the electrode assembly 1.

[0045] In one embodiment, please refer to Figure 3 The first protrusion and the second protrusion have the same thickness, and the first protrusion and the second protrusion are arranged opposite to each other.

[0046] The first and second protrusions can have the same shape and size, so that the wetting portion 30 has a first and second protrusion of equal thickness at both ends along the thickness direction. The electrolyte can be uniformly absorbed by the first and second protrusions at both ends of the wetting portion 30, which helps to improve the uniformity of the electrolyte wetting effect.

[0047] It is understandable that, since the first protrusion and the second protrusion are correspondingly arranged with respect to the groove on the hot press plate 2, the thickness of the first protrusion and the second protrusion can be equal, and the first protrusion and the second protrusion are arranged opposite to each other, which is also conducive to the formation of the groove on the hot press plate 2. The groove on the first plate 60 and the second plate 70 on the hot press plate 2 can be formed using the same mold, thereby reducing the cost of forming the groove.

[0048] In this embodiment, by arranging the first protrusion and the second protrusion opposite each other and having the same thickness, the uniformity of the electrolyte wetting effect is improved, and the cost is reduced.

[0049] In one embodiment, at least one of the impregnating portions 30 is provided with an impregnation channel, and the impregnating portion 30 is connected to the adjacent supporting portion 40 through the impregnation channel. The density of the impregnating portion 30 is less than the density of the supporting portion 40.

[0050] The material used to prepare the impregnated portion 30 can be the same as the material used to prepare the support layer.

[0051] It is understandable that during the process of pressing the electrode assembly 1 with the hot press plate 2, the wetting part 30 and the support part 40 can be obtained by hot pressing on the same flat surface. Since the wetting part 30 corresponds to the groove on the hot press plate 2, the wetting part 30 is not compacted during the pressing process, so that the density of the wetting part 30 is less than the density of the support part 40, which makes it easier for the wetting part 30 to absorb and contain the electrolyte.

[0052] In this embodiment, the density of the wetting part 30 is less than that of the support part 40, which makes it easier for the wetting part 30 to absorb the electrolyte and accelerates the wetting efficiency of the electrolyte.

[0053] In one embodiment, the bonding force between the first electrode 10 of the immersion portion 30 and the diaphragm is less than the bonding force between the first electrode 10 of the support portion 40 and the diaphragm.

[0054] The bonding force between the second electrode 20 of the wetted portion 30 and the diaphragm is less than that between the second electrode 20 of the support portion 40 and the diaphragm.

[0055] It is understandable that the bonding force between the first electrode 10, the diaphragm, and the second electrode 20 in the support portion 40 is relatively strong, which facilitates the forming of the electrode assembly 1. The bonding force between the first electrode 10, the diaphragm, and the second electrode 20 in the wetting portion 30 is relatively weak compared to the support portion 40, which facilitates the absorption of electrolyte by the wetting portion 30.

[0056] In this embodiment, the diaphragm in the support portion 40 has a stronger bonding force with the first electrode 10 and the second electrode 20 on both sides, which is beneficial to the forming of the electrode assembly 1 and avoids deformation of the electrode assembly 1 during the assembly process.

[0057] In one embodiment, please refer to Figure 3 The wetting portion 30 protrudes in the thickness direction relative to the support portion 40.

[0058] It is understandable that, since the wetting part 30 is not compacted relative to the support part 40, the two ends of the wetting part 30 in the thickness direction will protrude more than the two ends of the support part 40 in the thickness direction, forming a protrusion 50. The electrolyte is absorbed by the protrusion 50 and enters the wetting part 30, and then flows to the adjacent support part 40 through the wetting part 30.

[0059] In one embodiment, please refer to Figure 2 The total area of ​​the multiple wetting parts 30 is smaller than the total area of ​​the multiple support parts 40.

[0060] The ratio of the total area of ​​the immersion part 30 to the total area of ​​the support part 40 is less than 1:4.

[0061] It is understandable that the uncompacted density of the wetted part 30 is relatively small, which is not conducive to the compression molding of the electrode assembly 1, while the compacted density of the support part 40 is relatively large, which is conducive to the molding of the electrode assembly 1. Therefore, when the ratio of the total area of ​​the wetted part 30 to the total area of ​​the support part 40 is less than 1:4, the molding effect of the electrode assembly 1 will be better.

[0062] In one embodiment, please refer to Figure 4 The number of wetting portions 30 ranges from 1 to 1000.

[0063] In order to improve the wetting efficiency, at least one wetting part 30 is required. If the number of wetting parts 30 is greater than 1000, the support part 40 will not be able to support the electrode assembly 1, which will affect the forming effect of the electrode assembly 1.

[0064] In one embodiment, please refer to Figure 3 The width d of the wetted portion ranges from 0.5 mm to 5 mm.

[0065] In one embodiment, please refer to Figure 5 The wetting portion 30 includes a first portion 301 extending along the width direction of the electrode assembly 1 and a second portion 302 extending along the length direction of the electrode assembly 1. The widths of the first portion 301 and the second portion 302 range from 0.5 mm to 5 mm.

[0066] Among them, such as Figure 5 As shown, the first width 100 of the first portion 301 ranges from 0.5 mm to 5 mm, and the second width 110 of the first portion 301 ranges from 0.5 mm to 5 mm.

[0067] The widths of the first part 301 and the second part 302 can be independently selected from any one of 0.5 mm, 2 mm, 3 mm, 4.5 mm, and 5 mm.

[0068] It is understandable that when the width of at least one of the first part 301 and the second part 302 is less than 0.5 mm, it will result in low wetting efficiency; when the width of at least one of the first part 301 and the second part 302 is greater than 5 mm, it will be detrimental to the forming of the electrode assembly 1.

[0069] In one embodiment, the electrode assembly 1 includes a first region with a support portion 40 and a second region with a wetting portion 30. The electrode assembly 1 also includes a diaphragm and an electrode. In the first region, the diaphragm and the electrode are compacted and tightly fitted together. In the second region, a wetting channel is formed between the diaphragm and the electrode.

[0070] The wetting channel can be formed by the uncompacted gap between the diaphragm and the electrode.

[0071] In one embodiment, please refer to Figure 5 , Figure 6 The adjacent wetting portions 30 are arranged at intervals, and the outline shape of the wetting portions 30 is either curved or oblique.

[0072] In one embodiment, the spacing between adjacent wetted portions 30 is equal.

[0073] The equal spacing between the wetting portions 30 ensures that the distance of the wetting path from each wetting portion 30 to the adjacent support portion 40 is the same, which can improve the overall wetting uniformity of the electrode assembly 1.

[0074] In one embodiment, the electrode assembly 1 further includes a first tab and a second tab.

[0075] The first electrode 10 includes a first electrode tab, and the second electrode 20 includes a second electrode tab. The first electrode 10 is a positive electrode and the first electrode tab is a positive electrode tab. The second electrode 20 is a negative electrode and the second electrode tab is a negative electrode tab.

[0076] The outlines of the first and second electrodes can be either inverted T-shaped or rectangular.

[0077] The materials used to prepare the first electrode 10 and the second electrode 20 include aluminum.

[0078] In one embodiment, a reinforcing layer is provided on the outer peripheral surface of the electrode assembly 1. The reinforcing layer can protect the electrode assembly 1 and prevent operators or robotic arms from injuring the electrode assembly 1.

[0079] The reinforcing layer can be adhered to the outer peripheral surface of the electrode assembly 1 using an adhesive.

[0080] The reinforcing layer can be an organic insulating material, an inorganic insulating material, or a mixed insulating material. This embodiment does not impose specific restrictions on the material of the reinforcing layer.

[0081] Please see Figure 7 The present invention also provides a hot press plate 2 for preparing the electrode assembly 1 as described in any of the above embodiments, comprising:

[0082] The first plate is set to 60 and the second plate to 70.

[0083] The first plate 60 includes a flat portion 80 and a concave portion 90. The concave portion 90 is provided with a groove, which is corresponding to the wetting portion 30. The flat portion 80 is corresponding to the support portion 40.

[0084] In one embodiment, please refer to Figure 7 The groove can be square, round, or triangular in shape or a combination thereof.

[0085] Multiple grooves can be arranged in an array or scattered.

[0086] In one embodiment, the groove is square in shape, and the width of the groove ranges from 0.5 mm to 5 mm.

[0087] The groove corresponds to the wetting part 30, and the width of the groove is the same as the width of the wetting part 30.

[0088] In one embodiment, the first plate 60 is fixed, and the second plate 70 is controlled by a servo electric cylinder. The servo electric cylinder controls the second plate 70 to move up and down, and the electrode assembly 1 is squeezed by the relatively arranged first plate 60 and second plate 70.

[0089] In one embodiment, a connecting chamfer is provided between the concave portion 90 and the flat portion 80, and the connecting chamfer is rounded.

[0090] It is understandable that setting the chamfer of the connection to a rounded corner can prevent the diaphragm from breaking or the first electrode 10 and the second electrode 20 from shedding powder due to excessive local stress at the chamfer.

[0091] In one embodiment, the first plate 60 may also be provided with a clamping plate, and the clamping plate may move relative to the first plate 60. The second plate 70 may also be provided with a support plate, and the support plate may move relative to the second plate 70. The clamping plate and the support plate are distributed opposite each other.

[0092] Understandably, when the electrode assembly 1 is actually hot-pressed, after the electrode assembly 1 enters the hot-pressing space between the hot-pressing plates 2, the clamping plate moves relative to the first plate 60 toward the hot-pressing space, and the support plate moves relative to the second plate 70 toward the hot-pressing space, so that the electrode assembly 1 can first be located between the clamping plate and the support plate, and the electrode assembly 1 is placed on the support plate, so that the support plate can support the electrode assembly 1 and enhance the stability of the electrode assembly 1. Then the clamping plate moves toward the direction closer to the support plate so that the clamping plate and the support plate can fix the electrode assembly 1.

[0093] In one embodiment, during the hot pressing process, little or no pressure may be applied to the area forming the wetted portion 30, so that the wetted portion 30 is not compacted relative to the support portion 40. The wetted portion 30 is used for the absorption of electrolyte, and the support portion 40 is used to support the forming of the electrode assembly 1, maintain the rigidity and hardness of the electrode assembly 1, and prevent the electrode assembly 1 from deforming.

[0094] The diaphragm of the wetting portion 30 is attached to the first electrode 10 and the second electrode 20 but not bonded, and forms a wetting channel.

[0095] Understandably, during the pressing process of the hot press plate 2 on the electrode assembly 1, the groove exerts no or weak pressure on the wetting part 30 of the electrode assembly 1, while the flat part 80 exerts strong pressure on the supporting part 40 of the electrode assembly 1. This results in the wetting part 30 not being compacted and forming a wetting channel, while the supporting part 40 is compacted. The diaphragm of the supporting part 40 is tightly bonded to the first electrode 10 and the second electrode 20, making the electrode assembly 1 rigid and plate-shaped. The supporting part 40 supports the electrode assembly 1 so that it does not deform during the assembly process.

[0096] This utility model designs a hot press plate 2, which includes a first plate 60 and a second plate 70 having a concave portion 90 and a flat portion 80. The concave portion 90 corresponds to the wetting portion 30 of the electrode assembly 1, and the surface of the wetting portion 30 along the thickness direction of the electrode assembly 1 extends beyond the support portion 40 to form a protrusion 50. The protrusion 50 of the wetting portion 30 is used to absorb electrolyte. The absorbed electrolyte can flow through the wetting channel in the wetting portion 30 to the adjacent support portion 40, thereby completing the wetting of the support portion 40 and improving the wetting effect and wetting efficiency.

[0097] This application also proposes a battery including the aforementioned electrode assembly. The battery can be a single battery cell, a battery module composed of multiple battery cells, a battery pack composed of multiple battery cells, or a battery pack composed of multiple battery modules.

[0098] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An electrode assembly, characterized in that, The electrode assembly includes a first electrode, a second electrode, and a diaphragm located between the first electrode and the second electrode along its thickness direction, and the electrode assembly includes at least the following along its length direction: A plurality of wetting portions and a plurality of supporting portions, wherein at least one of the supporting portions is disposed between two adjacent wetting portions, and the wetting portion is in communication with the adjacent supporting portion; The immersion portion is provided with a protrusion that protrudes relative to the support portion.

2. The electrode assembly according to claim 1, characterized in that, At least one of the impregnating portions is provided with an impregnation channel, and the impregnating portion is connected to the adjacent supporting portion through the impregnation channel.

3. The electrode assembly according to claim 2, characterized in that, The density of the wetted portion is less than the density of the supporting portion.

4. The electrode assembly according to claim 2, characterized in that, The bonding force between the first electrode located in the wetted portion and the diaphragm is less than the bonding force between the first electrode located in the support portion and the diaphragm, and / or the bonding force between the second electrode located in the wetted portion and the diaphragm is less than the bonding force between the second electrode located in the support portion and the diaphragm.

5. The electrode assembly according to claim 4, characterized in that, The thickness of the support portion is T1, and the thickness of the impregnated portion is T2, wherein the range of (T2-T1) / T2 is greater than or equal to 0.

03.

6. The electrode assembly according to claim 5, characterized in that, The total area of ​​the plurality of wetted portions is less than the total area of ​​the plurality of support portions.

7. The electrode assembly according to claim 6, characterized in that, The wetting portion includes a first portion extending along the width direction of the electrode assembly and a second portion extending along the length direction of the electrode assembly, wherein the width of the first portion and the second portion ranges from 0.5 mm to 5 mm.

8. The electrode assembly according to any one of claims 1 to 5, characterized in that, The protrusion and the support have a connecting chamfer, which is rounded.

9. The electrode assembly according to any one of claims 1 to 5, characterized in that, The adjacent wetting portions are arranged at intervals, and the outline shape of the wetting portions is either curved or oblique.

10. The electrode assembly according to any one of claims 1 to 5, characterized in that, The cross-sectional shape of the immersion part can be any one of a semi-circle, trapezoid, or triangle.

11. A battery, characterized in that, The battery includes the electrode assembly as described in any one of claims 1 to 10.

12. A hot press plate for preparing an electrode assembly as described in any one of claims 1 to 10, characterized in that, include: The first and second boards are set relative to each other; The first plate includes a flat portion and a concave portion. The concave portion is provided with a groove, which is corresponding to the wetting portion. The flat portion is corresponding to the supporting portion.

13. The hot press plate according to claim 12, characterized in that, The concave portion and the planar portion have a connecting chamfer, which is rounded.

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