Battery monomer and battery

Abstract

The utility model provides a single battery and a battery, and relates to the technical field of batteries. The shell comprises a first shell body and a second shell body which are oppositely arranged, the edge part of the first shell body and the edge part of the second shell body are packaged to form a containing part, the containing part is provided with a plurality of sealing edges and a containing cavity, the sealing edges comprise the first sealing edge and the second sealing edge, and an opening is formed in the first sealing edge; the electrode assembly is arranged in the accommodating cavity and is provided with an end face and a plurality of side faces connected to the end face, and at least one end face is provided with a tab extending out; the tab is connected to the electrode assembly and extends out of the opening, and the tab and the shell are sealed to seal the opening; the liquid absorption part is arranged between the electrode assembly and the shell and used for storing electrolyte. The single battery provided by the utility model can solve the problems that the internal resistance is increased and the capacity is quickly attenuated in the working process of the single battery. And the problems of increased packaging difficulty and even liquid leakage caused by electrolyte residue can be avoided, so that the yield of battery monomer production is improved.

Description

Technical Field

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

[0002] Soft-pack lithium-ion batteries are batteries that are packaged with aluminum-plastic film. Compared with aluminum-shell batteries, soft-pack lithium-ion batteries have obvious advantages in energy density due to their unique packaging structure, which makes soft-pack lithium-ion batteries widely used.

[0003] During the manufacturing process of soft-pack lithium-ion batteries, secondary packaging is required. During the secondary packaging process, a large amount of free electrolyte will be extracted. Insufficient electrolyte will lead to increased internal resistance and rapid capacity decay during the working process of the battery cell; in addition, a large amount of electrolyte will remain in the packaging area inside the aluminum-plastic film during the extraction process, making the temperature of this area low, increasing the difficulty of packaging, and even causing leakage, thereby increasing the defective rate of battery cell production. Utility Model Content

[0004] In view of this, the present application provides a battery cell and a battery to solve the problem that insufficient electrolyte will lead to increased internal resistance and rapid capacity decay during the operation of the battery cell, and a large amount of electrolyte will remain in the packaging area inside the aluminum-plastic film during the extraction process, making the temperature of this area low, increasing the difficulty of packaging, and even causing leakage, thereby causing an increase in the defective rate of battery cell production.

[0005] According to one aspect of the present application, a battery cell is provided, comprising:

[0006] The housing comprises a first shell and a second shell arranged opposite to each other, the edge of the first shell and the edge of the second shell are sealed to form a receiving portion, the receiving portion has a plurality of sealed edges and a receiving cavity, the sealed edges include a first sealed edge and a second sealed edge, and an opening is formed on the first sealed edge;

[0007] An electrode assembly is disposed in the accommodating cavity, wherein the electrode assembly has an end face and a plurality of side faces connected to the end face, and at least one of the end faces has a tab extending therefrom;

[0008] A tab connected to the electrode assembly and extending from the opening, wherein the tab is sealed with the housing to close the opening;

[0009] The liquid absorbing member is arranged between the electrode assembly and the shell to store electrolyte.

[0010] Preferably, the liquid absorbing member includes a first liquid absorbing member, and the end surface includes a first end surface and a second end surface that are arranged opposite to each other;

[0011] Wherein, the electrode ear extends from the first end surface, and the first liquid absorbing member is arranged on the first end surface;

[0012] Alternatively, the electrode tab extends from the first end surface and the second end surface, and the first liquid absorbing member is arranged on at least one of the first end surface and the second end surface.

[0013] Preferably, the first liquid absorbing member covers the first end surface, and a long hole is provided on the first liquid absorbing member for the pole ear to extend out.

[0014] Preferably, the liquid-absorbing member includes a second liquid-absorbing member, and at least one of the side surfaces is provided with the second liquid-absorbing member.

[0015] Preferably, the side surfaces include two wide side surfaces and two narrow side surfaces, the cross-sectional dimensions of the wide side surfaces are larger than the cross-sectional dimensions of the narrow side surfaces, and the second liquid-absorbing member is disposed on at least one of the wide side surfaces.

[0016] Preferably, a pit is formed on the first shell, the electrode assembly is placed in the pit, the second shell is planar, and the second liquid absorbent member covers the wide side surface opposite to the first shell.

[0017] Preferably, the liquid absorbing member further comprises a third liquid absorbing member, the third liquid absorbing member comprises a bottom wall and a side wall connected to the bottom wall, the bottom wall and the side wall form a receiving groove with openings at both ends, for accommodating the end of the electrode assembly corresponding to the first end surface;

[0018] The opening includes a first opening and a second opening, the first opening is the same as the end face of the electrode assembly, and the bottom wall is provided with the second opening spaced from the edge of the bottom wall; the side wall is pressed against the edge of the first liquid-absorbing part, the bottom wall is pressed against the edge of the second liquid-absorbing part, and the second opening is used to expose the first liquid-absorbing part.

[0019] Preferably, the liquid absorbing member is made of foam.

[0020] Preferably, the liquid absorbent members all have pores, and the porosity of the first liquid absorbent member is greater than the porosity of the second liquid absorbent member.

[0021] According to another aspect of the present application, a battery is provided, comprising a plurality of battery cells as described above.

[0022] In the battery cell of the present application, the liquid absorbing member can absorb the electrolyte, which can prevent a large amount of electrolyte from being drawn out during the secondary packaging process, thereby preventing the problem of increased internal resistance and rapid capacity decay during the working process of the battery cell. At the same time, during the secondary packaging process, the electrolyte is absorbed in the liquid absorbing member, and the electrolyte will not remain in the packaging area inside the aluminum-plastic film, thereby avoiding the problem of increased packaging difficulty caused by electrolyte residue, and even causing leakage, thereby improving the yield of battery cell production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram showing the three-dimensional structure of a battery cell according to an embodiment of the utility model;

[0025] Figure 2 A schematic diagram showing a planar structure of a battery cell according to an embodiment of the present utility model from one viewing angle;

[0026] Figure 3 A schematic diagram showing the planar structure of a battery cell in another perspective of an embodiment of the utility model;

[0027] Figure 4 A schematic structural diagram of the third liquid-absorbing member is shown.

[0028] Icons: 1-electrode assembly; 2-electrode ear; 3-first liquid absorbent member; 4-second liquid absorbent member; 5-third liquid absorbent member; 51-first opening; 52-second opening; 53-receiving groove; 54-bottom wall; 55-side wall; L1-length direction; L2-width direction; L3-thickness direction. DETAILED DESCRIPTION

[0029] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0030] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0031] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0032] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0033] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0034] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be located "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0035] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0036] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0037] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0038] The following will be combined Figures 1 to 3 The battery cell of the present application is described for convenience in Figures 1 to 3 The structure inside the middle shell, Figures 1 to 3 The housing is not shown.

[0039] According to one aspect of the present application, a battery cell is provided, the battery cell includes a shell, an electrode assembly 1 and a pole ear 2, the shell includes a first shell and a second shell arranged opposite to each other, the edge of the first shell and the edge of the second shell are encapsulated to form a receiving portion, the receiving portion has a plurality of sealed edges and a receiving cavity, the sealed edges include a first sealed edge and a second sealed edge, an opening is formed on the first sealed edge; the electrode assembly 1 is arranged in the receiving cavity, the electrode assembly 1 has an end face and a plurality of side faces connected to the end face, at least one end face has a pole ear 2 extending therefrom; the pole ear 2 is connected to the electrode assembly 1 and extends from the opening, the pole ear 2 and the shell are sealed to close the opening; the liquid absorbing member is arranged between the electrode assembly 1 and the shell for storing electrolyte.

[0040] In the battery cell of the present application, the liquid absorbing member can absorb the electrolyte, which can prevent a large amount of electrolyte from being drawn out during the secondary packaging process, thereby preventing the problem of increased internal resistance and rapid capacity decay during the working process of the battery cell. At the same time, during the secondary packaging process, the electrolyte is absorbed in the liquid absorbing member, and the electrolyte will not remain on the packaging area of ​​the shell, thereby avoiding the problem of increased packaging difficulty caused by electrolyte residue, and even causing leakage, thereby improving the yield of battery cell production.

[0041] Optionally, the outer shell may be an aluminum-plastic film, and the first shell and the second shell may be two parts located on both sides of a fold after the aluminum-plastic film is bent.

[0042] In the embodiment of the present application, the end surface of the electrode assembly 1 includes a first end surface and a second end surface, and the first end surface and the second end surface are located on both sides in the length direction L1.

[0043] Furthermore, in the battery cell of the present application, the pole lug 2 may extend only from the first end surface, or may extend from both the first end surface and the second end surface.

[0044] In the embodiments of the present application, Figures 1 to 3 As shown, the liquid absorbing member includes a first liquid absorbing member 3, and the first liquid absorbing member 3 is disposed on at least one of the first end face and the second end face, and the electrolyte can be absorbed by the first liquid absorbing member 3 to prevent the electrolyte from overflowing from the side of the pole ear 2 during the secondary packaging process. In one arrangement form of the pole ear 2, the pole ear 2 can extend from the first end face, and the first liquid absorbing member 3 is disposed on the first end face. In another arrangement form of the pole ear 2, the pole ear 2 extends from both the first end face and the second end face, and the first liquid absorbing member 3 is disposed on at least one of the first end face and the second end face.

[0045] Preferably, the pole ear 2 can extend from the first end surface, and the first liquid absorption member 3 is arranged on the first end surface. At this time, the pole ear 2 and the first liquid absorption member 3 are located on the same side, and the first absorption member can store electrolyte to prevent the electrolyte from overflowing from the opening on the same side as the pole ear 2 during the secondary packaging process.

[0046] Furthermore, the first liquid absorbing member 3 covers the first end surface, and a long hole is provided on the first liquid absorbing member 3, and the pole lug 2 extends from the long hole. Two pole lugs 2 can extend from the first end surface, and two long holes are provided on the first end surface, and the two long holes correspond to the two pole lugs 2 respectively, and the pole lugs 2 extend from the corresponding long holes.

[0047] In the embodiments of the present application, Figure 1 and Figure 2 As shown, the liquid absorbing member includes a second liquid absorbing member 4, and at least one side is provided with the second liquid absorbing member 4, and the second liquid absorbing member 4 can provide a stable storage space for the free electrolyte.

[0048] The side surface includes two wide side surfaces and two narrow side surfaces, the two wide side surfaces are located on both sides in the thickness direction L3, the two narrow side surfaces are located on both sides in the width direction L2, the cross-sectional dimensions of the wide side surfaces are larger than the cross-sectional dimensions of the narrow side surfaces, and the second liquid-absorbing member is arranged on at least one wide side surface. Optionally, the second liquid-absorbing member 4 may be arranged on only one wide side surface, or only two wide side surfaces, or two wide side surfaces and one narrow side surface, or two narrow side surfaces and one wide side surface, or two wide side surfaces and two narrow side surfaces.

[0049] Preferably, a second liquid absorbing member 4 is disposed on one wide side surface. In this case, the second liquid absorbing member 4 has a larger volume and can provide more sufficient storage space for the free electrolyte.

[0050] In the embodiments of the present application, Figure 4 As shown, the absorbent member also includes a third absorbent member 5, which is a hollow structure. The third absorbent member 5 has a bottom wall 54 and a side wall 55 connected to the bottom wall 54. The bottom wall 54 and the side wall 55 form a receiving groove 53 with openings at both ends. The openings include a first opening 51 and a second opening 52. The bottom wall 54 is provided with a second opening 52 spaced from the edge of the bottom wall 54. The bottom wall 54 is a wall facing the side where the second absorbent member 4 is located, and the side wall 55 is a groove wall of the receiving groove 53.

[0051] In one embodiment of the third liquid-absorbing component 5, the first opening 51 is the same as the end face of the electrode assembly, the side wall 55 is pressed on the edge of the first liquid-absorbing component 3, and the bottom wall 54 is pressed on the edge of the second liquid-absorbing component 4. The end of the electrode assembly 1 corresponding to the first end face extends into the accommodating groove 53 through the first opening 51, and the second opening 52 allows the first liquid-absorbing component 3 to leak out.

[0052] In another embodiment of the third liquid-absorbing member 5, Figure 3 As shown, the side wall 55 is pressed on the edge of the first liquid absorbent component 3, and the bottom wall 54 is pressed on the end faces of the second liquid absorbent component 4 and the electrode assembly 1. The electrode assembly 1 does not penetrate into the accommodating groove 53. The area of ​​the end face of the whole formed by the electrode assembly 1 and the second liquid absorbent component 4 in the length direction L1 is equal to the area of ​​the end face of the whole formed by the first liquid absorbent component 3 and the third liquid absorbent component 5 in the length direction L1.

[0053] When the battery cell is repackaged, the first liquid absorbent component 3 can store the electrolyte overflowing from the opening on the side where the pole ear 2 is located during the secondary packaging process, and the third liquid absorbent component 5 can absorb the electrolyte overflowing from the first liquid absorbent component 3 during the secondary packaging process. In this way, a large amount of electrolyte can be avoided from being extracted during the secondary packaging process, thereby avoiding the problem of increased internal resistance and rapid capacity decay during the operation of the battery cell.

[0054] Optionally, the material of the liquid absorbent member is foam, and the first liquid absorbent member 3, the second liquid absorbent member 4 and the third liquid absorbent member 5 all have pores, so that the first liquid absorbent member 3, the second liquid absorbent member 4 and the third liquid absorbent member 5 can absorb the foam, and the foam material can be one or more of PU, PE, EVA, EPE, and SBR.

[0055] In the embodiment of the present application, the porosity of the first liquid absorbent member 3 is greater than the porosity of the second liquid absorbent member 4 , so that the second liquid absorbent member 4 can store sufficient electrolyte in a limited space, and the first liquid absorbent member 3 can absorb more electrolyte discharged from the side of the electrode tab 2 .

[0056] Optionally, the porosity of the first liquid absorbent member 3 is greater than 60%, for example, the porosity of the first liquid absorbent member 3 may be 65%, 68%, 70% or 75%, etc. The first liquid absorbent member 3 has a large porosity, which can ensure that the first liquid absorbent member 3 absorbs the electrolyte discharged from the side of the tab 2 during the negative pressure process.

[0057] In an embodiment of the present application, the porosity of the second adsorbent is greater than 25%. For example, the porosity of the second liquid absorbent 4 may be 28%, 30%, 32% or 35%. The second liquid absorbent 4 has a large porosity and can store sufficient electrolyte in a limited space.

[0058] Furthermore, the tensile strength of the second liquid absorbent member 4 can be 1-10Mpa. The second liquid absorbent member 4 having the above tensile strength can prevent the electrolyte from being squeezed out of the second liquid absorbent member 4 during the negative pressure process. At the same time, it can ensure that during the cycle of the battery cell, the electrolyte can be discharged from the second liquid absorbent member 4 under the compression of the binding force and then enter the electrode assembly 1.

[0059] In addition, the thickness of the second liquid absorbent member 4 is in the range of 3-8 mm. Sufficient thickness can provide sufficient liquid storage space. At the same time, the thickness below 8 mm enables the second liquid absorbent member 4 to discharge the electrolyte for use by the electrode assembly 1 under the working pressure of the battery cell, thereby avoiding excessive electrolyte remaining in the second liquid absorbent member 4 during the operation of the battery cell.

[0060] Optionally, the porosity of the third adsorption component is less than 30%, for example, the porosity of the third liquid absorbent component 5 can be 28%, 26%, 25% or 23%, etc. The porosity of the third liquid absorbent component 5 is less than the porosity of the first liquid absorbent component 3, which can increase the difficulty of electrolyte discharge and prevent the electrolyte in the first liquid absorbent component 3 from overflowing, thereby preventing the electrolyte from overflowing from the side where the electrode ear 2 is located during negative pressure.

[0061] In an embodiment of the present application, a pit is formed on the first shell, the electrode assembly 1 is placed in the pit, the second shell is planar, the second liquid absorbent component 4 covers the wide side opposite to the first shell, and the depth of the pit can be equal to the sum of the thickness of the second liquid absorbent component 4 and the electrode assembly 1.

[0062] By providing the first liquid absorbing member 3, the second liquid absorbing member 4 and the third liquid absorbing member 5, the problem of liquid loss during the secondary sealing process can be improved, and the yield rate of the battery cell can be improved. In order to clarify the role of the first liquid absorbing member 3, the second liquid absorbing member 4 and the third liquid absorbing member 5, the battery cell can be trial-produced, and the defective rate of the secondary sealing and the capacity retention rate after 1000 cycles can be tested. Specifically, the following 4 embodiments and 7 comparative examples can be trial-produced.

[0063] Example 1

[0064] The internal structure of the housing of the battery cell in Example 1 is as follows Figures 1 to 3 As shown, in this test group, the first liquid absorbent member 3, the second liquid absorbent member 4 and the third liquid absorbent member 5 are made of EVA material, wherein the porosity of the first absorbent member is 70%, the thickness of the second absorbent member is 5 mm, the porosity of the second absorbent member is 50%, the tensile strength of the second absorbent member is 2 MPa, and the porosity of the third liquid absorbent member 5 is 70%. After the internal structure of the battery cell shell is assembled, the top and side sealing, baking, liquid injection, formation, and secondary sealing processes are carried out to complete the battery cell production.

[0065] Example 2

[0066] The difference between Example 2 and Example 1 is that the thickness of the second liquid absorbent member 4 is 3 mm, the porosity of the second liquid absorbent member 4 is 70%, and the tensile strength of the second liquid absorbent member 4 is 1 MPa. The rest of the design is the same as that of Example 1;

[0067] Example 3

[0068] The difference between Example 3 and Example 1 is that the thickness of the second liquid absorbent member 4 is 8 mm, the porosity of the second liquid absorbent member 4 is 25%, and the tensile strength of the second liquid absorbent member 4 is 10 MPa. The rest of the design is the same as that of Example 1.

[0069] Example 4

[0070] The difference between Example 4 and Example 1 is that the porosity of the third liquid absorbent member 5 is 30%, and the porosity of the first liquid absorbent member 3 is 60%. The rest of the design is the same as that of Example 1.

[0071] Comparative Example 1

[0072] The difference between comparative example 1 and comparative example 1 is that the first liquid absorbing member 3, the second liquid absorbing member 4 and the third liquid absorbing member 5 are eliminated, and the electrode assembly 1 is directly installed in the accommodating cavity.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Comparative Example 1 is that the second liquid-absorbing member 4 has a thickness of 1 mm and a porosity of 10%. The rest of the design is the same as that of Comparative Example 1.

[0075] Comparative Example 3

[0076] The difference between Comparative Example 3 and Comparative Example 1 is that the tensile strength of the second liquid-absorbing member 4 is 0.5 MPa. The rest of the designs are the same as those of Comparative Example 1.

[0077] Comparative Example 4

[0078] The difference between Comparative Example 4 and Comparative Example 1 is that the tensile strength of the second liquid-absorbing member 4 is 20 MPa. The rest of the designs are the same as those of Comparative Example 1.

[0079] Comparative Example 5

[0080] The difference between Comparative Example 5 and Comparative Example 1 is that the second liquid-absorbing member 4 has a thickness of 20 mm. The rest of the designs are the same as those of Comparative Example 1.

[0081] Comparative Example 6

[0082] The difference between Comparative Example 6 and Comparative Example 1 is that the porosity of the third liquid-absorbing member 5 is 80%. The rest of the designs are the same as those of Comparative Example 1.

[0083] Comparative Example 7

[0084] The difference between Comparative Example 7 and Comparative Example 1 is that the porosity of the first liquid-absorbing member 3 is 20%. The rest of the designs are the same as those of Comparative Example 1.

[0085] During the trial production process, record the injection volume and the second seal liquid loss volume, and the liquid loss rate = second seal liquid loss volume / injection volume; after the second seal is completed, use the seal to scrape the edge for inspection. If the seal is delaminated, it is defective. Count the number of defective samples per 1,000, which is the second seal defect rate; perform 1C / 1C charge and discharge cycles on the trial-produced battery cells, and record the discharge capacity of each cycle. The capacity retention rate = 1,000th full discharge capacity / first cycle discharge capacity. The data of the second seal defect rate and the capacity retention rate after 1,000 cycles of the above 4 and 7 embodiments are as follows:

[0086]

[0087] It can be seen from the above table that the defective rate of the second seal and the capacity retention rate after 1000 cycles of Examples 1, 2, 3 and 4 all meet the design requirements. In Example 1, the first liquid absorbing member 3, the second liquid absorbing member 4 and the third liquid absorbing member 5 are cancelled, and the free electrolyte has nowhere to be stored. During the negative pressure process, the electrolyte is discharged from the side of the pole ear 2 and flows through the shell, which makes packaging difficult. Therefore, the liquid loss rate and the second seal defective rate are much higher than those of the embodiment. Due to the small amount of electrolyte, the capacity retention rate is also greatly attenuated. In Example 2, the thickness of the second liquid absorbing member 4 is too thin, and the porosity is too low, and the electrolyte storage capacity is low, resulting in the increase of the residual free electrolyte being extracted and the liquid loss rate, but it still has certain advantages compared with Example 1. In Example 3, the tensile strength of the foam is too low, and it is severely squeezed and deformed during the negative pressure process of the second seal, resulting in the discharge of the electrolyte and a high liquid loss rate. In comparative example 4, the first liquid absorbent member 3, the second liquid absorbent member 4 and the third liquid absorbent member 5 can effectively store electrolyte, but the tensile strength of the second liquid absorbent member 4 is too large, resulting in the inability of the stored electrolyte to be discharged into the electrode assembly 1 during the working process of the battery cell, and the battery cell cycle performance is low. Comparative example 5 is similar to comparative example 4. The thickness of the second liquid absorbent member 4 is too thick. During the working process of the battery cell, some electrolyte cannot be discharged from the second liquid absorbent member 4 into the electrode assembly 1, and the battery cell cycle performance is low. In comparative example 6, the porosity of the third liquid absorbent member 5 is too large, and it cannot effectively protect the electrolyte in the first liquid absorbent member 3 from overflowing, resulting in excessive electrolyte discharge from the side of the pole ear 2 during the second seal negative pressure process, and the second seal defect rate is increased. In comparative example 7, the porosity of the first liquid absorbent member 3 is too low, and it cannot store the electrolyte discharged from the side of the pole ear 2 during the second seal negative pressure process, resulting in the electrolyte overflowing from the gap between the electrode assembly 1 and the foam, causing the second seal defect rate to increase.

[0088] It can be seen from the trial production of the above four embodiments and seven comparative examples that the first liquid absorbent member 3 , the second liquid absorbent member 4 and the third liquid absorbent member 5 can improve the secondary sealing yield of the battery cell and the capacity retention rate after 1000 cycles.

[0089] According to another aspect of the present application, a battery is provided, which includes a plurality of the above-mentioned battery cells, and has the same technical effects as the above-mentioned battery cells, which will not be described in detail herein.

[0090] Finally, it should be noted that the above comparative examples are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above comparative examples, a person skilled in the art should understand that the technical solutions described in the above comparative examples can still be modified, or some or all of the technical features can be replaced by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the comparative examples of the present invention.

Claims

1. A battery cell, characterized in that: include: The housing comprises a first shell and a second shell arranged opposite to each other, the edge of the first shell and the edge of the second shell are sealed to form a receiving portion, the receiving portion has a plurality of sealed edges and a receiving cavity, the sealed edges include a first sealed edge and a second sealed edge, and an opening is formed on the first sealed edge; An electrode assembly is disposed in the accommodating cavity, wherein the electrode assembly has an end face and a plurality of side faces connected to the end face, and at least one of the end faces has a tab extending therefrom; A tab connected to the electrode assembly and extending from the opening, wherein the tab is sealed with the housing to close the opening; The liquid absorbing member is arranged between the electrode assembly and the shell to store electrolyte.

2. The battery cell according to claim 1, characterized in that: The liquid absorbing member includes a first liquid absorbing member, and the end surface includes a first end surface and a second end surface that are arranged opposite to each other; Wherein, the electrode ear extends from the first end surface, and the first liquid absorbing member is arranged on the first end surface; Alternatively, the electrode tab extends from the first end surface and the second end surface, and the first liquid absorbing member is arranged on at least one of the first end surface and the second end surface.

3. The battery cell according to claim 2, characterized in that: The first liquid absorbing member covers the first end surface, and a long hole is provided on the first liquid absorbing member for the pole ear to extend out.

4. The battery cell according to claim 2, characterized in that: The liquid-absorbing member includes a second liquid-absorbing member, and at least one of the side surfaces is provided with the second liquid-absorbing member.

5. The battery cell according to claim 4, characterized in that: The side surfaces include two wide side surfaces and two narrow side surfaces, the cross-sectional dimensions of the wide side surfaces are larger than the cross-sectional dimensions of the narrow side surfaces, and the second liquid-absorbing member is disposed on at least one of the wide side surfaces.

6. The battery cell according to claim 5, characterized in that: A pit is formed on the first shell, and the electrode assembly is placed in the pit. The second shell is planar, and the second liquid-absorbing member covers the wide side surface opposite to the first shell.

7. The battery cell according to claim 6, characterized in that: The liquid absorbing member further comprises a third liquid absorbing member, wherein the third liquid absorbing member comprises a bottom wall and a side wall connected to the bottom wall, wherein the bottom wall and the side wall form a receiving groove with openings at both ends for receiving the end of the electrode assembly corresponding to the first end surface; The opening includes a first opening and a second opening, the first opening is the same as the end face of the electrode assembly, and the bottom wall is provided with the second opening spaced from the edge of the bottom wall; the side wall is pressed on the edge of the first liquid-absorbing component, the bottom wall is pressed on the edge of the second liquid-absorbing component, and the second opening is used to expose the first liquid-absorbing component.

8. The battery cell according to claim 1, characterized in that: The material of the liquid absorbing member is foam.

9. The battery cell according to claim 5, characterized in that: The liquid-absorbing members are all provided with pores, and the porosity of the first liquid-absorbing member is greater than the porosity of the second liquid-absorbing member.

10. A battery, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 9.

Images