Isolating membrane and battery

Abstract

The utility model provides an isolating membrane and a battery, which belong to the technical field of batteries, and the isolating membrane has a set thickness and comprises a first base membrane layer and a second base membrane layer. The first base film layer and the second base film layer are arranged in the thickness direction of the isolating film and are connected with each other, and a liquid storage gap for storing electrolyte is formed between the first base film layer and the second base film layer. According to the isolating membrane and the battery provided by the embodiment of the utility model, the liquid storage gap between the first base membrane layer and the second base membrane layer can provide a deformation space for the first base membrane layer and the second base membrane layer; the first base film layer or the second base film layer is extruded by dendritic crystals to deform towards the liquid storage gap, and the isolating film is not prone to being punctured. In addition, the electrolyte stored in the liquid storage gap can also infiltrate the pole piece in contact with the first base film layer or the second base film layer, so that the infiltration degree of the pole piece is higher, and lithium precipitation is not easy.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a separator and a battery. Background Technology

[0002] In related technologies, lithium-ion batteries require a separator to isolate the positive and negative electrodes, conduct ions, and isolate electrons to prevent short circuits between the electrodes. Existing technologies commonly use single-layer polymer separators. During battery cycling, the expanded electrodes occupy the space originally used to retain electrolyte between the electrode and the separator, leading to insufficient electrode wetting and increased susceptibility to lithium deposition. Furthermore, lithium dendrites may deposit on the electrode surface, piercing the separator and causing thermal runaway. While existing technologies have proposed using separators with multi-layer structures to prevent dendrite piercing, these solutions, to some extent, result in thicker separators and smaller gaps between the electrode and separator, leading to insufficient electrolyte between the electrode and separator, affecting electrode wetting and making lithium deposition more likely. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a separator that can increase the wettability of the electrode while improving the stability of the separator, making the electrode less prone to lithium deposition.

[0004] This utility model also proposes a battery having the above-mentioned separator.

[0005] The separator according to a first aspect embodiment of the present invention has a predetermined thickness, including:

[0006] First base film layer;

[0007] The second base film layer; the first base film layer and the second base film layer are arranged along the thickness direction of the separator and connected to each other, and there is also a liquid storage gap between them for storing electrolyte.

[0008] The separator according to the embodiments of this utility model has at least the following beneficial effects: both the first base film layer and the second base film layer can allow ions to pass through and insulate electrons, thereby preventing short circuits between the positive and negative electrodes during normal battery operation. The liquid storage gap between the first base film layer and the second base film layer provides space for deformation of the first and second base film layers. When dendrites on the electrode contact the first or second base film layer, the first or second base film layer will be squeezed by the dendrites and deformed towards the liquid storage gap, making the separator less prone to puncture. The electrolyte stored in the liquid storage gap can also wet the electrode contacting the first or second base film layer, resulting in a higher degree of electrode wettability and making lithium deposition less likely.

[0009] According to some embodiments of the present invention, the isolation membrane further includes a plurality of protrusions, the plurality of protrusions being connected to the side of the first base film layer near the second base film layer, and the side of the protrusions facing away from the first base film layer contacting the second base film layer.

[0010] According to some embodiments of the present invention, the isolation membrane further includes a support layer, which is located between and connects the first base film layer and the second base film layer. The support layer also divides the liquid storage gap into a first gap and a second gap in the thickness direction of the isolation membrane, with the first gap close to the first base film layer and the second gap close to the second base film layer.

[0011] According to some embodiments of the present invention, the isolation membrane further includes a plurality of first support portions and a plurality of second support portions. The first support portions are connected to the side of the support layer near the first base film layer, and the side of the first support portion facing away from the support layer contacts the first base film layer. The second support portions are connected to the side of the support layer near the second base film layer, and the side of the second support portion facing away from the support layer contacts the second base film layer.

[0012] According to some embodiments of the present invention, the isolation membrane includes a plurality of first support portions and a plurality of second support portions. The first support portions and the second support portions are strip-shaped structures. The plurality of first support portions are arranged at intervals along a first direction and divide the first gap into a plurality of first accommodating cavities in the first direction. The plurality of second support portions are arranged at intervals along a second direction and divide the second gap into a plurality of second accommodating cavities in the second direction. Both the first direction and the second direction are perpendicular to the thickness direction of the isolation membrane.

[0013] According to some embodiments of the present invention, each of the first support portions has a first groove recessed toward the support layer, and a plurality of first receiving cavities are interconnected through the first groove; each of the second support portions has a second groove recessed toward the support layer, and a plurality of second receiving cavities are interconnected through the second groove.

[0014] Alternatively, each of the first support portions has a first exchange channel, and the plurality of first accommodating cavities are interconnected through the first exchange channel; each of the second support portions has a second exchange channel, and the plurality of second accommodating cavities are interconnected through the second exchange channel.

[0015] According to some embodiments of the present invention, both the first direction and the second direction are parallel to the length direction of the separator.

[0016] According to some embodiments of the present invention, the isolation membrane includes an adhesive, the first base film layer and the second base film layer are connected to the support layer by the adhesive, the adhesive connecting the first base film layer is spaced apart from the first support portion, and the adhesive connecting the second base film layer is spaced apart from the second support portion.

[0017] According to some embodiments of the present invention, the support layer has a porous structure, and the pore diameter of the support layer ranges from 5 μm to 15 μm.

[0018] The battery according to a second aspect of the present invention includes a separator as described in any of the above embodiments.

[0019] The battery according to the embodiments of the present invention has at least the following beneficial effects: the battery using the separator of the present invention is less likely to cause thermal runaway due to puncture of the separator, and is less likely to cause lithium plating, thus the battery is safer and its service life can be further extended.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a schematic diagram of the isolation membrane according to some embodiments of the first aspect of this utility model;

[0023] Figure 2 This is a schematic diagram of the isolation membrane according to some embodiments of the second aspect of this utility model;

[0024] Figure 3 This is a schematic diagram of the isolation membrane according to some embodiments of the third aspect of this utility model;

[0025] Figure 4 for Figure 2 A top view diagram showing the removal of adhesive and base film layers;

[0026] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0027] Figure 6 for Figure 2 A top view of the adhesive coating on the base film layer;

[0028] Figure 7 for Figure 2 A top view diagram showing the removal of the base film layer.

[0029] Figure label:

[0030] 10 separator membranes;

[0031] First base film layer 100;

[0032] Second base film layer 200;

[0033] Liquid storage gap 300, first gap 310, first receiving cavity 311, second gap 320, second receiving cavity 321;

[0034] 400mm protrusion;

[0035] Support layer 500;

[0036] First support part 600, first exchange channel 610, first groove 620;

[0037] Second support 700, second exchange channel 710, second groove 720;

[0038] Adhesive 800. Detailed Implementation

[0039] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0040] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0043] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] Please refer to Figures 1-7 As shown, this invention proposes a separator 10, comprising a first base film layer 100 and a second base film layer 200. The base film layer of this invention can conduct ions while isolating electrons, thereby preventing direct conduction between the positive and negative electrode plates within the battery, which could cause a short circuit. Those skilled in the art can use commonly used base film materials, such as polyethylene, polypropylene, and other polymeric materials, to fabricate the base film layer of this invention.

[0045] The first base film layer 100 and the second base film layer 200 of this invention are arranged along the thickness direction of the separator 10 and connected to each other, and there is also a liquid storage gap 300 between them for storing electrolyte.

[0046] The liquid storage gap 300 located between the first base film layer 100 and the second base film layer 200 in this invention provides space for deformation of the first base film layer 100 and the second base film layer 200 in the thickness direction. This allows the base film layer to weaken the puncture effect of the dendrites when compressed by lithium dendrites deposited from the electrode by deforming towards the other base film layer, thus enhancing the puncture resistance of the separator 10. Please refer to... Figure 1 As shown, Figure 1 The positive and negative electrode sheets are not shown. In some embodiments, the positive electrode sheet, separator 10 and negative electrode sheet of the battery are stacked and arranged, with the positive electrode sheet located on the side closer to the first base film layer 100 and the negative electrode sheet located on the side closer to the second base film layer 200. When the negative electrode sheet expands due to charging and squeezes the second base film layer 200, the squeezed part of the second base film layer 200 is more likely to deform toward the first base film layer 100 and is less likely to be pierced by dendrites on the surface of the negative electrode sheet.

[0047] In the existing technology, after long-term battery cycling, the space between the electrode and the separator repeatedly expands and contracts, which can easily lead to a lack of liquid between the electrode and the separator. This can further cause a portion of the electrode to fail to react with a sufficient number of lithium ions during charging and discharging, making lithium plating more likely.

[0048] Since the electrolyte storage gap 300 located between the first base film layer 100 and the second base film layer 200 of this invention can also store electrolyte, the lithium ions of the electrolyte located in the electrolyte storage gap 300 can flow into the liquid-deficient position between the electrode and the separator 10, and can react with the electrode after long-term cycling, thus reducing the risk of lithium plating on the electrode after long-term cycling.

[0049] Please refer to Figure 1 As shown, in some embodiments, the separator 10 further includes a plurality of protrusions 400, which are connected to the side of the first base film layer 100 near the second base film layer 200, and the side of the protrusions 400 facing away from the first base film layer 100 contacts the second base film layer 200. Through this design, the protrusions 400 can restrict the movement of the portion of the second base film layer 200 in contact with the protrusions 400 toward the first base film layer 100, thereby maintaining a distance between the first base film layer 100 and the second base film layer 200 in the thickness direction of the separator 10, thus enhancing the structural stability of the separator 10. Based on the above inventive concept, those skilled in the art can provide a plurality of protrusions 400 on the side of the first base film layer 100 near the second base film layer 200, further enabling the first base film layer 100 and the second base film layer 200 to maintain a certain distance at multiple positions perpendicular to the separator 10, further increasing the structural stability of the separator 10.

[0050] Please refer to Figure 1 As shown, in some embodiments, the separator 10 includes a plurality of protrusions 400, each protrusion 400 having the same shape and being evenly distributed on the surface of the first base film layer 100 near the second base film layer 200. Through this design, the spacing between the first base film layer 100 and the second base film layer 200 can maintain good consistency, which is beneficial for adjusting the overall size of the battery during battery production.

[0051] This invention does not limit the connection method between the protrusion 400 and the first base film layer 100. As a preferred embodiment, the protrusion 400 is integrally connected to the first base film layer 100. The connection strength between the protrusion 400 and the first base film layer 100 in the above embodiment is higher, which is beneficial to increasing the overall stability of the separator 10.

[0052] Without departing from the inventive concept of this utility model, this utility model does not limit the connection method between the first base film layer 100 and the second base film layer 200. In some embodiments, the first base film layer 100 and the second base film layer 200 are connected by partial pressing.

[0053] Please refer to Figure 1 As shown, where Figure 1The adhesive 800 in the diagram is only for illustrative purposes. As a preferred embodiment, in some cases, the first base film layer 100 is connected to the second base film layer 200 via the adhesive 800. Through this method, the adhesive 800 not only maintains the connection between the first base film layer 100 and the second base film layer 200, but also restricts the first base film layer 100 from approaching the second base film layer 200, thereby maintaining a distance between them. Based on the above inventive concept, those skilled in the art can apply the adhesive 800 at multiple locations between the first base film layer 100 and the second base film layer 200 to further strengthen the connection between them and maintain a certain distance between them at multiple locations perpendicular to the separator 10, thereby further improving the structural stability of the separator 10.

[0054] Please refer to Figure 1 As shown, in some embodiments, as a preferred embodiment, the surface of the first base film layer 100 near the second base film layer 200 is uniformly provided with multiple coating areas of the same size, and the coating areas are coated with the same amount of adhesive 800. Through this approach, the first base film layer 100 and the second base film layer 200 can maintain good connection strength at various points, which is beneficial to enhancing the stability of the separator 10. Furthermore, it allows for good consistency in the spacing between the first base film layer 100 and the second base film layer 200, which is beneficial for adjusting the overall size of the battery during battery production.

[0055] The previous section described a scheme involving multiple protrusions 400 on the base film layer. Please refer to the following for further details. Figure 1 As shown, in some embodiments, the adhesive 800 and the protrusion 400 are spaced apart. This design further enables the first base film layer 100 and the second base film layer 200 to maintain a certain distance at multiple locations distributed perpendicular to the thickness direction of the separator 10.

[0056] Please refer to Figure 2 As shown, in some embodiments, the separator 10 further includes a support layer 500, which is located between and connects the first base film layer 100 and the second base film layer 200. The support layer 500 also divides the electrolyte storage gap 300 into a first gap 310 and a second gap 320 in the thickness direction of the separator 10. The first gap 310 is close to the first base film layer 100, and the second gap 320 is close to the second base film layer 200. Providing a support layer 500 between the first base film layer 100 and the second base film layer 200 helps to enhance the overall strength of the separator 10, improve its puncture resistance, and reduce the risk of battery thermal runaway. It should be noted that the first gap 310 and the second gap 320 can also be used to store electrolyte, thereby reducing the risk of lithium plating on the electrode.

[0057] Without departing from the inventive concept of this utility model, this utility model does not limit the connection method between the first base film layer 100 and the support layer 500, or between the second base film layer 200 and the support layer 500. In some embodiments, the first base film layer 100 and the support layer 500, and the second base film layer 200 and the support layer 500 are connected by partial pressing.

[0058] As previously mentioned, the base film layer of this invention can conduct ions while isolating electrons. In the above embodiments, since the support layer 500 is located between the first base film layer 100 and the second base film layer 200, it does not need to isolate electrons. Therefore, the material used to make the support layer 500 is not limited to the materials used in the base film layer. As a preferred embodiment, the support layer 500 is made of synthetic fiber materials such as nylon and spandex. These synthetic fiber materials have better puncture resistance and can further reduce the risk of battery thermal runaway.

[0059] In order to allow ions in the first gap 310 and the second gap 320 to flow between each other, in some embodiments, the support layer 500 is provided with a through hole connecting the first gap 310 and the second gap 320, through which ions in the first gap 310 and the second gap 320 can exchange.

[0060] Furthermore, in some embodiments, the support layer 500 has a porous structure with pore diameters ranging from 5 μm to 15 μm. Ions in the first gap 310 and the second gap 320 can exchange through the pores of the support layer 500. When the pore diameter of the support layer 500 is greater than 5 μm, the pores within the support layer 500 can store more electrolyte, further reducing the risk of lithium plating on the electrode. When the pore diameter of the support layer 500 is less than 15 μm, the support layer 500 has better strength, and the separator 10 has stronger puncture resistance.

[0061] In some embodiments, the support layer 500 has a mesh structure. Through the above scheme, when dendrites on the electrode surface pierce the base film layer and enter the mesh of the support layer 500, the mesh structure of the support layer 500 can apply frictional force to the dendrites, thereby preventing the dendrites from further penetrating into the support layer 500, avoiding further damage to the separator 10, and reducing the risk of battery thermal runaway.

[0062] Please refer to Figure 2As shown, in some embodiments, the separator 10 further includes a plurality of first support portions 600 and a plurality of second support portions 700. The first support portions 600 are connected to the side of the support layer 500 near the first base film layer 100, and the side of the first support portion 600 facing away from the support layer 500 contacts the first base film layer 100. The second support portions 700 are connected to the side of the support layer 500 near the second base film layer 200, and the side of the second support portion 700 facing away from the support layer 500 contacts the second base film layer 200.

[0063] Through the above solutions, the first support portion 600 can restrict the movement of the portion of the first base film layer 100 in contact with the first support portion 600 toward the support layer 500, thereby maintaining a certain distance between the first base film layer 100 and the support layer 500 in the thickness direction of the separator 10, thus increasing the structural stability of the separator 10. Similarly, the second support portion 700 can restrict the movement of the portion of the second base film layer 200 in contact with the second support portion 700 toward the support layer 500, maintaining a certain distance between the second base film layer 200 and the support layer 500 in the thickness direction of the separator 10, thus increasing the structural stability of the separator 10.

[0064] On the other hand, the above-described solution simplifies the structure of the base film layer, allowing those skilled in the art to directly use existing base films as the first base film layer 100 and the second base film layer 200 in the above embodiments. In some embodiments, the first support portion 600 and the second support portion 700 are integrally connected to the support layer 500. The connection strength between the first support portion 600 and the support layer 500, and between the second support portion 700 and the support layer 500 in the above embodiments is higher, which helps to increase the overall stability of the separator 10.

[0065] In some embodiments, the separator 10 includes a plurality of first support portions 600 and a plurality of second support portions 700. The plurality of first support portions 600 can support the first base film layer 100 at a plurality of positions distributed perpendicular to the thickness direction of the separator 10, further enabling the first base film layer 100 and the support layer 500 to maintain a certain distance at the plurality of positions perpendicular to the separator 10. The plurality of second support portions 700 can support the second base film layer 200 at a plurality of positions distributed perpendicular to the thickness direction of the separator 10, further enabling the second base film layer 200 and the support layer 500 to maintain a certain distance at the plurality of positions perpendicular to the separator 10, thereby increasing the structural stability of the separator 10.

[0066] Without departing from the inventive concept of this utility model, the shape of the first support portion 600 and the second support portion 700 is not limited. In some embodiments, the first support portion 600 and the second support portion 700 can be block-shaped structures that protrude relative to the surface of the support portion.

[0067] Please refer to Figure 2 , Figure 4 As shown, where Figure 4 Not all support portions and cavities are shown in the figures. As a preferred embodiment, in some embodiments, the separator 10 includes multiple first support portions 600 and multiple second support portions 700. Both the first support portions 600 and the second support portions 700 are strip-shaped structures. The multiple first support portions 600 are arranged at intervals along a first direction, dividing the first gap 310 into multiple first cavities 311 in the first direction. The multiple second support portions 700 are arranged at intervals along a second direction, dividing the second gap 320 into multiple second cavities 321 in the second direction. The strip-shaped support portions can further increase the contact area with the base film layer, thereby enabling the base film layer and the support layer 500 to maintain a certain distance at multiple positions perpendicular to the separator 10, increasing the structural stability of the separator 10. The multiple first support portions 600 arranged at intervals along the first direction divide the first gap 310 into multiple first cavities 311 in the first direction. The two ends of the first support portions 600 extend to both sides of the support layer 500 perpendicular to the thickness direction of the separator 10, which can further improve the support effect of the first support portions 600. Multiple second support portions 700 arranged at intervals along the second direction divide the second gap 320 into multiple second receiving cavities 321 in the second direction. The two ends of the second support portions 700 extend to both sides of the support layer 500 in the direction perpendicular to the thickness of the isolation membrane 10, which can further improve the support effect of the second support portions 700.

[0068] Specifically, taking the first support section 600 as an example, please refer to... Figure 4 As shown, in some embodiments, a plurality of first support portions 600 are arranged along a first direction (i.e., Figure 4 The first support portion 600 is arranged in a left-right direction and divides the first gap 310 into multiple first receiving cavities 311. The two ends of the first support portion 600 extend to both sides of the support layer 500 perpendicular to the thickness direction of the separator 10 (i.e., Figure 4 (The front and back directions in the middle).

[0069] Without departing from the inventive concept of this utility model, the above embodiments do not limit the specific orientation of the first and second directions. As a preferred embodiment, please refer to... Figure 4 As shown, both the first and second directions are parallel to the length direction of the separator 10 (i.e., both the first and second directions are parallel to the length direction of the separator 10). Figure 4 (in the left-right direction). In existing battery production, the separator 10 needs to be wound with an axis parallel to its own width direction as a reference. With the above solution, the separator 10 is less affected by the first support 600 and the second support 700 during the winding process, which is beneficial to improving battery production efficiency.

[0070] It should be noted that each of the above embodiments can be used individually to store electrolyte. The lithium ions in the electrolyte located in the cavity can flow into the liquid-deficient position between the electrode and the separator 10, and can react with the electrode after long-term cycling, thereby reducing the risk of lithium plating on the electrode after long-term cycling.

[0071] Based on the above solutions, please refer to Figure 3 Furthermore, in some embodiments, each first support portion 600 has a first exchange channel 610, and multiple first accommodating cavities 311 are interconnected through the first exchange channel 610; each second support portion 700 has a second exchange channel 710, and multiple second accommodating cavities 321 are interconnected through the second exchange channel 710.

[0072] During battery charging and discharging, certain areas of the separator 10 may be more susceptible to pressure from the electrodes. For example, unevenness may occur in the electrodes and separator 10 during winding, making them more prone to mutual pressure in these uneven areas. When a particular area of ​​the separator 10 is more susceptible to electrode pressure, the electrolyte content and lithium-ion content remaining in that area are lower. Consequently, lithium-ions in the electrolyte within the cavity near that area are preferentially consumed.

[0073] In the above embodiments, multiple cavities are interconnected through exchange channels. When the lithium ions in the electrolyte of one cavity are insufficient, the lithium ions in the electrolyte of other cavities can permeate into the electrolyte of the cavity through the exchange channels to replenish it. This allows the electrode to still obtain lithium ions from the electrolyte of the cavity after long-term cycling, further reducing the risk of lithium plating.

[0074] Please refer to Figure 2 , Figure 4 , Figure 5 As shown, where Figure 5 Not all grooves are shown. In some embodiments, each first support portion 600 has a first groove 620 recessed towards the support layer 500, and multiple first receiving cavities 311 are interconnected through the first grooves 620. Each second support portion 700 has a second groove 720 recessed towards the support layer 500, and multiple second receiving cavities 321 are interconnected through the second grooves 720. When the lithium ions in the electrolyte of a certain receiving cavity are insufficient, lithium ions from the electrolyte of other receiving cavities can permeate into the electrolyte of the aforementioned receiving cavity through the grooves to replenish it. This allows the electrode to still obtain lithium ions from the electrolyte of the aforementioned receiving cavities after long-term cycling, further reducing the risk of lithium plating. In the above embodiments, both the first groove 620 and the second groove 720 are recessed towards the support layer 500, so lithium ions in the electrolyte located in the grooves can also directly react with the electrode through the base film layer.

[0075] Please refer to Figure 2 As shown, in some embodiments, the separator 10 further includes an adhesive 800, and the first base film layer 100 and the second base film layer 200 are connected to the support layer 500 by the adhesive 800. Through the above solution, the adhesive 800 not only enables the first base film layer 100 to maintain a connection with the support layer 500 and the second base film layer 200 to maintain a connection with the support layer 500, but also restricts the first base film layer 100 and the second base film layer 200 from approaching the support layer 500, thereby maintaining a distance between the base film layers and the support layer 500.

[0076] Please refer to Figure 6 , Figure 7 As shown, further, the adhesive 800 connecting the first base film layer 100 is spaced apart from the first support portion 600, and the adhesive 800 connecting the second base film layer 200 is spaced apart from the second support portion 700. This arrangement further enables the adhesive 800 and the support portion to jointly support the base film layer, which is beneficial for maintaining a certain distance between the first base film layer 100 and the second base film layer 200 at multiple positions perpendicular to the separator 10.

[0077] Without departing from the inventive concept of this utility model, those skilled in the art can adjust the coating method of adhesive 800. Please refer to... Figure 6 , Figure 7 As shown, in a preferred embodiment, the adhesive 800 is applied between the base film layer and the support layer 500 using a dispensing process. This method reduces the amount of adhesive 800 used and further increases the electrolyte content.

[0078] This invention also proposes a battery comprising a separator 10 as described in any of the above embodiments. Batteries using the separator 10 of this invention are less prone to thermal runaway due to puncture of the separator 10, and are less prone to lithium plating, thus offering better battery safety and extending service life.

[0079] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A separating membrane having a predetermined thickness, characterized in that: include: First base film layer; The second base film layer; the first base film layer and the second base film layer are arranged along the thickness direction of the separator and connected to each other, and there is also a liquid storage gap between them for storing electrolyte.

2. The separator membrane according to claim 1, characterized in that, The isolation membrane further includes a plurality of protrusions, which are connected to the side of the first base film layer near the second base film layer, and the side of the protrusions facing away from the first base film layer contacts the second base film layer.

3. The separator membrane according to claim 1, characterized in that, The isolation membrane further includes a support layer, which is located between and connects the first base film layer and the second base film layer. The support layer also divides the liquid storage gap into a first gap and a second gap in the thickness direction of the isolation membrane. The first gap is close to the first base film layer and the second gap is close to the second base film layer.

4. The separator membrane according to claim 3, characterized in that, The isolation membrane further includes a plurality of first support portions and a plurality of second support portions. The first support portions are connected to the side of the support layer near the first base film layer, and the side of the first support portion facing away from the support layer contacts the first base film layer. The second support portions are connected to the side of the support layer near the second base film layer, and the side of the second support portion facing away from the support layer contacts the second base film layer.

5. The separator according to claim 4, characterized in that, The isolation membrane includes a plurality of first support portions and a plurality of second support portions. The first support portions and the second support portions are strip-shaped structures. The plurality of first support portions are arranged at intervals along a first direction and divide the first gap into a plurality of first accommodating cavities in the first direction. The plurality of second support portions are arranged at intervals along a second direction and divide the second gap into a plurality of second accommodating cavities in the second direction. Both the first direction and the second direction are perpendicular to the thickness direction of the isolation membrane.

6. The separator according to claim 5, characterized in that, Each of the first support portions has a first groove recessed toward the support layer, and a plurality of first receiving cavities are interconnected through the first groove; each of the second support portions has a second groove recessed toward the support layer, and a plurality of second receiving cavities are interconnected through the second groove. Alternatively, each of the first support portions has a first exchange channel, and the plurality of first accommodating cavities are interconnected through the first exchange channel; each of the second support portions has a second exchange channel, and the plurality of second accommodating cavities are interconnected through the second exchange channel.

7. The separator according to claim 5, characterized in that, Both the first direction and the second direction are parallel to the length direction of the separator.

8. The separator membrane according to claim 4, characterized in that, The separator includes an adhesive, and the first base film layer and the second base film layer are connected to the support layer by the adhesive. The adhesive connecting the first base film layer is spaced apart from the first support portion, and the adhesive connecting the second base film layer is spaced apart from the second support portion.

9. The separator according to claim 3, characterized in that, The support layer has a porous structure, and the pore diameter of the support layer ranges from 5μm to 15μm.

10. A battery, characterized in that, include: The separator as described in any one of claims 1 to 9.

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