Battery cell insulation film, battery cell, and battery pack

Abstract

The utility model relates to a battery technical field discloses a kind of electric core insulating film, electric core and battery package. Among them, electric core insulating film includes: n layer substrate layer and n layer glue layer, wherein, n is the positive integer greater than or equal to 1;Along the thickness direction of electric core insulating film, substrate layer and glue layer are alternately stacked, the thickness of single layer substrate layer is t1, the thickness of single layer glue layer is t2, the relationship between n, t1, t2 satisfies: 36%≤n×t1 / n×(t1+t2)≤48%.The utility model controls the proportion of substrate layer total thickness in the total thickness of electric core insulating film between 36% to 48%, can guarantee electric core insulating film with good insulation performance while, improve the adhesive strength between glue layer and substrate layer, electric core shell, effectively avoid the problem that insulation film and electric core shell peeling or insulation film delamination due to insufficient adhesion.

Description

Technical Field

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

[0002] New energy batteries are widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high working voltage, strong charge retention capacity and long cycle life.

[0003] A battery pack typically consists of multiple battery cells, which are fixed inside the pack's casing. A battery cell generally includes a cover, casing, electrode assembly, electrode assembly end plates, bare cell insulating sheets, insulating film (such as blue film), and a cover plate patch. The cover is welded to the casing and forms a sealed space protecting the electrode assembly. The bare cell insulating sheets cover the electrode assembly to protect it and prevent short circuits caused by contact between the electrode assembly and the casing. The electrode assembly end plates secure the tabs and provide space for their protection. The insulating film mainly covers the outside of the casing, providing external insulation. The insulating film consists of an adhesive layer and an insulating substrate layer, with the insulating substrate layer bonded to the casing via the adhesive layer.

[0004] In general, in order to securely assemble multiple cells inside the battery pack, structural adhesive is usually applied between two adjacent cells and between multiple cells and the inner wall of the battery pack, so as to bond and fix the cells inside the battery pack.

[0005] However, since the adhesive strength of the adhesive layer is often less than that of the structural adhesive, when the battery pack is subjected to mechanical vibration or impact, the cells are prone to relative displacement with the inner wall of the battery pack due to insufficient adhesive strength of the adhesive layer, thereby reducing the overall reliability of the battery pack structure. Utility Model Content

[0006] In view of this, the present invention provides a cell insulating film, a cell, and a battery pack to solve the problem of insufficient adhesive strength of the adhesive layer leading to a decrease in the overall structural reliability of the battery pack.

[0007] In a first aspect, this utility model provides a battery cell insulating film, comprising: n substrate layers and n adhesive layers, wherein n is a positive integer greater than or equal to 1; the substrate layers and the adhesive layers are alternately stacked along the thickness direction of the battery cell insulating film, the thickness of a single substrate layer is t1, the thickness of a single adhesive layer is t2, and the relationship between n, t1, and t2 satisfies: 36%≤n×t1 / n×(t1+t2)≤48%.

[0008] Beneficial Effects: This invention controls the proportion of the total thickness of the substrate layer to the total thickness of the cell insulation film between 36% and 48%. This ensures good insulation performance of the cell insulation film while improving the adhesion strength between the adhesive layer and the substrate layer and the cell casing, effectively avoiding problems such as peeling or delamination of the insulation film from the cell casing due to insufficient adhesion. Specifically, when the total thickness of the substrate layer is in the range of 36% to 48%, the adhesive layer retains sufficient thickness and contact area, enhancing the interfacial bonding force with the substrate layer. It also more fully fills minor imperfections on the surface of the cell casing, improving the tightness of the fit with the casing and reducing the risk of peeling or delamination of the insulation film from the cell casing due to insufficient adhesion, thereby ensuring the structural reliability of the subsequent battery pack.

[0009] In one optional embodiment, the thickness t1 of the single substrate layer is in the range of 20μm≤t1≤30μm.

[0010] Beneficial effects: This utility model controls the thickness of the single-layer substrate layer within the range of 20μm to 30μm, which can provide sufficient structural support and tensile strength for the battery cell insulation film, avoiding easy damage to the film and affecting the insulation performance due to the substrate being too thin; it can also prevent the substrate from being too thick and encroaching on the adhesive layer thickness space, ensuring that the adhesive layer has sufficient thickness to achieve effective bonding with the battery cell shell and the substrate layer. At the same time, the substrate layer within this thickness range can maintain the insulation film with appropriate flexibility while ensuring its own mechanical strength, which is convenient for achieving tight adhesion on the surface of the battery cell shell and reducing the probability of peeling or detachment after bonding.

[0011] In one optional embodiment, the thickness t2 of the single adhesive layer is in the range of 25μm≤t2≤35μm.

[0012] Beneficial effects: This utility model controls the thickness of the single-layer adhesive layer within the range of 25μm to 35μm, which can ensure that the adhesive layer has sufficient amount of adhesive to form a stable and reliable bonding effect, and ensure that the adhesion between the adhesive layer and the substrate layer and the battery cell shell meets the design requirements, avoiding the problem of insufficient bonding strength and easy debonding due to the adhesive layer being too thin; at the same time, it can also form a reasonable overall structural proportion with the thickness of the substrate layer, so that the insulating film can maintain good flexibility while meeting the bonding performance.

[0013] In one alternative embodiment, the total thickness of the cell insulating film is 70 μm to 150 μm.

[0014] Beneficial effects: This utility model controls the total thickness of the cell insulation film within the range of 70μm to 150μm, which can ensure that the cell insulation film has sufficient overall structural strength and insulation performance to meet the basic requirements of the cell for electrical isolation; it can also avoid the decrease in the flexibility of the insulation film due to excessive total thickness, making it difficult to adapt to the curvature or complex shape of the cell surface, and at the same time reduce the space occupied inside the battery pack, which is conducive to the miniaturization design of the battery pack.

[0015] In one alternative embodiment, the adhesive layer contains photoinitiator particles.

[0016] Beneficial Effects: The adhesive layer in this invention is a type of adhesive that combines the properties of pressure-sensitive adhesive and structural adhesive, and contains a photoinitiator. It not only ensures a certain initial tack but also guarantees high bonding strength after curing. Specifically, its initial tack stems from the characteristics of the pressure-sensitive adhesive. During battery pack assembly and cell insulation film molding, only slight pressure is required to quickly and tightly adhere the adhesive layer to the substrate layer and the cell shell surface, achieving immediate fixation and avoiding the hassle of waiting for a long time for initial curing, thus improving the convenience and efficiency of assembly. The presence of the photoinitiator allows the adhesive layer to cure rapidly under specific light sources (such as ultraviolet light), forming a strong bond after curing due to the structural adhesive properties. This high-strength bond locks the relative position of the cell shell and the cell insulation film, preventing delamination or peeling, and providing a solid structural guarantee for the long-term stable operation of the battery pack.

[0017] In one optional embodiment, the photoinitiator particles are free radical photoinitiator particles or cationic photoinitiator particles.

[0018] In one optional embodiment, after UV curing, the shear strength of the adhesive layer is ≥10 MPa; and / or, the pull-out strength of the adhesive layer is ≥10 MPa.

[0019] Beneficial effects: After the adhesive layer is cured by ultraviolet light, the shear strength and / or pull-out strength reach 10MPa and above, which means that the cell insulation film can be firmly bonded to the cell shell through the adhesive layer, and the adhesive layer will not easily delaminate from the substrate layer. This can effectively resist the shear and pull-out forces caused by vibration and impact during the use of the battery pack, and reduce the possibility of relative displacement between the cell and the inner wall of the battery pack box.

[0020] In one alternative embodiment, the battery cell insulating film further includes release paper, which is located on the outermost surface of the adhesive layer away from the substrate layer along the thickness direction of the battery cell insulating film.

[0021] Beneficial effects: The release paper effectively protects the tackiness of the top adhesive layer, preventing it from decreasing due to contact with dust, impurities, or other objects during storage, transportation, or assembly. This ensures that the adhesive layer can fully exert its initial bonding performance when bonded to the battery cell housing. At the same time, the release paper simplifies the assembly process of the insulating film through convenient peeling, reducing operational inconvenience or material waste caused by premature exposure of the adhesive layer, thereby improving production efficiency and ensuring the reliability of the insulating film.

[0022] Secondly, this utility model also provides a battery cell, comprising: The battery cell casing contains an internal electrode assembly. The aforementioned cell insulation film is wrapped around the outer surface of the cell housing and bonded to the cell housing through the adhesive layer.

[0023] Beneficial effects: The battery cell of this utility model includes the battery cell insulating film as described above, and has all the beneficial technical effects of the battery cell insulating film, which will not be repeated here.

[0024] Thirdly, this utility model also provides a battery pack, comprising: Box; Multiple of the aforementioned battery cells are arranged side-by-side inside the housing; Structural adhesive is applied to the bottom surface of each of the battery cells and to the opposite sides in the multiple battery cell arrangement directions. The structural adhesive is bonded and fixed to the battery cell insulating film to fix each of the battery cells to the housing.

[0025] Beneficial effects: The battery pack of this utility model includes the battery cell as described above and has all the beneficial technical effects of the battery cell, which will not be repeated here. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of a battery cell insulating film according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of a battery pack according to an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures: 1. Battery cell insulating film; 101. Substrate layer; 102. Adhesive layer; 103. Release paper; 2. Battery cell; 201. Battery cell housing; 202. Electrode assembly; 3. Housing; 4. Structural adhesive. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] To address the problem of insufficient adhesive strength in the adhesive layer leading to a decrease in the overall structural reliability of the battery pack, this utility model provides a cell insulating film, a cell, and a battery pack.

[0031] The following is combined Figures 1 to 3 The following describes embodiments of the present invention.

[0032] According to embodiments of the present invention, on the one hand, such as Figure 1 As shown, a battery cell insulating film 1 is provided, comprising: n substrate layers 101 and n adhesive layers 102, wherein n is a positive integer greater than or equal to 1; along the thickness direction of the battery cell insulating film 1, the substrate layers 101 and adhesive layers 102 are alternately stacked, the thickness of a single substrate layer 101 is t1, the thickness of a single adhesive layer 102 is t2, and the relationship between n, t1, and t2 satisfies: 36%≤n×t1 / n×(t1+t2)≤48%.

[0033] This embodiment of the invention controls the proportion of the total thickness of the substrate layer 101 to the total thickness of the cell insulating film 1 between 36% and 48%. This ensures that the cell insulating film 1 has good insulation performance while improving the adhesion strength between the adhesive layer 102 and the substrate layer 101 and the cell housing 201, effectively avoiding the problem of the insulating film peeling off from the cell housing 201 or the insulating film delamination due to insufficient adhesion. Specifically, when the total thickness of the substrate layer 101 is in the range of 36% to 48%, the adhesive layer 102 can retain sufficient thickness and contact area, enhancing the interfacial bonding force with the substrate layer 101. At the same time, it can also more fully fill the minor imperfections on the surface of the cell housing 201, improving the tightness of the fit with the housing, reducing the risk of the insulating film peeling off from the cell housing 201 or the insulating film delamination due to insufficient adhesion, thereby ensuring the structural reliability of the subsequent battery pack.

[0034] Specifically, the percentage of the total thickness of the substrate layer 101 can be, but is not limited to, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, or any value range between the two.

[0035] Specifically, in this embodiment, the material of the substrate layer 101 may be, but is not limited to, polyethylene terephthalate (PET) or polypropylene. Since PET or polypropylene possesses good mechanical strength, insulation properties, and high-temperature resistance, this embodiment of the invention selects PET or polypropylene as the material of the substrate layer 101. This ensures that the substrate layer 101 has good strength, providing stable structural support for the adhesive layer 102, and also allows the insulating film to be well-suited to the working environment of the battery cell 2.

[0036] According to one embodiment of the present invention, the thickness of the single-layer substrate layer 101 is in the range of 20μm≤t1≤30μm. This embodiment controls the thickness of the single-layer substrate layer 101 within the range of 20μm to 30μm. This provides sufficient structural support and tensile strength for the battery cell insulation film 1, preventing the film from being easily damaged and its insulation performance from being affected due to an excessively thin substrate. It also prevents the substrate from being too thick and encroaching on the adhesive layer 102, ensuring that the adhesive layer 102 has sufficient thickness to effectively bond with the battery cell housing 201 and the substrate layer 101. Simultaneously, this thickness range allows the substrate layer 101 to maintain appropriate flexibility while ensuring its own mechanical strength, facilitating tight adhesion to the surface of the battery cell housing 201 and reducing the probability of peeling or detachment after bonding.

[0037] Specifically, the thickness of the single-layer substrate layer 101 can be, but is not limited to, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm or any value range between the two.

[0038] According to one embodiment of this utility model, the thickness t2 of the single-layer adhesive layer 102 is in the range of 25μm≤t2≤35μm. This embodiment controls the thickness of the single-layer adhesive layer 102 within the range of 25μm to 35μm. This ensures that the adhesive layer 102 has sufficient adhesive content to form a stable and reliable bonding effect, ensuring that the adhesion between the adhesive layer 102 and the substrate layer 101 and the cell housing 201 meets the design requirements, and avoiding insufficient bonding strength and easy debonding problems due to an excessively thin adhesive layer 102. Simultaneously, it also forms a reasonable overall structural proportion with the thickness of the substrate layer 101, allowing the insulating film to maintain good flexibility while meeting bonding performance requirements.

[0039] Specifically, the thickness t2 of the single-layer adhesive layer 102 can be, but is not limited to, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm or any value range between the two.

[0040] According to one embodiment of the present invention, the total thickness of the cell insulating film 1 is 70μm to 150μm. This embodiment controls the total thickness of the cell insulating film 1 within the range of 70μm to 150μm, ensuring that the cell insulating film 1 possesses sufficient overall structural strength and insulation performance to meet the basic electrical isolation requirements of the cell 2; it also avoids the decrease in flexibility of the insulating film due to excessive total thickness, making it difficult to adapt to the surface curvature or complex shape of the cell 2, while reducing the space occupied inside the battery pack, which is beneficial for the miniaturization design of the battery pack.

[0041] Specifically, the total thickness of the cell insulating film 1 can be, but is not limited to, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, 140μm, 145μm or any value range between the two.

[0042] According to one embodiment of the present invention, photoinitiator particles are mixed in the adhesive layer 102. Specifically, the adhesive layer 102 in this embodiment is an adhesive that combines the characteristics of pressure-sensitive adhesive and structural adhesive 4 and contains a photoinitiator, which not only ensures a certain initial tack, but also ensures high bonding strength after curing. Specifically, its initial adhesion stems from the properties of the pressure-sensitive adhesive. During battery pack assembly and the molding of the cell insulating film 1, only slight pressure is required to quickly and tightly adhere the adhesive layer 102 to the substrate layer 101 and the surface of the cell housing 201, achieving immediate fixation. This avoids the hassle of waiting a long time for initial curing and improves the convenience and efficiency of assembly. Furthermore, the presence of the photoinitiator allows the adhesive layer 102 to cure rapidly under specific light sources (such as ultraviolet light). After curing, it forms a strong bond due to the properties of the structural adhesive 4, with shear strength and pull-out strength both reaching over 10 MPa. This high-strength bond can lock the relative position of the cell housing 201 and the cell insulating film 1, preventing delamination or peeling, and providing a solid structural guarantee for the long-term stable operation of the battery pack.

[0043] It should be noted that, in this embodiment, the photoinitiator may be, but is not limited to, a free radical photoinitiator and a cationic photoinitiator.

[0044] According to one embodiment of this utility model, after ultraviolet curing, the shear strength of the adhesive layer 102 is ≥10 MPa; and / or, the pull-out strength of the adhesive layer 102 is ≥10 MPa. It can be understood that when the adhesive layer 102 is cured by ultraviolet light, the shear strength and / or pull-out strength reach 10 MPa or higher, meaning that the cell insulation film 1 can be firmly bonded to the cell housing 201 through the adhesive layer 102, and the adhesive layer 102 will not easily delaminate from the substrate layer 101. This effectively resists the shear and pull-out forces generated by vibration and impact during battery pack use, reducing the possibility of relative displacement between the cell 2 and the inner wall of the battery pack housing 3.

[0045] It should be noted that the reason why the shear strength and pull-out strength of the adhesive layer 102 can be greatly improved after UV curing is that UV irradiation triggers the photoinitiator particles to generate active species (free radicals or cations), which promotes the rapid cross-linking polymerization reaction of resin molecules in the adhesive layer 102, forming a three-dimensional network structure. This allows the originally dispersed molecular chains to be tightly connected by chemical bonds, and the intermolecular forces are significantly enhanced. At the same time, the uniform dispersion of the particulate photoinitiator ensures the sufficiency and integrity of the cross-linking reaction, reduces curing defects, and thus greatly improves the cohesive strength and interfacial bonding of the adhesive layer 102, ultimately resulting in a significant increase in shear strength and pull-out strength.

[0046] According to one embodiment of the present invention, such as Figure 1 As shown, the battery cell insulating film 1 also includes release paper 103. Along the thickness direction of the battery cell insulating film 1, the release paper 103 is located on the surface of the outermost adhesive layer 102 away from the substrate layer 101. The release paper 103 effectively protects the adhesiveness of the top adhesive layer 102, preventing it from decreasing in adhesiveness due to contact with dust, impurities, or other objects during storage, transportation, or assembly. This ensures that the adhesive layer 102 can fully exert its initial bonding performance when bonded to the battery cell housing 201. At the same time, the release paper 103 simplifies the assembly process of the insulating film through convenient peeling, reducing operational inconvenience or material waste caused by premature exposure of the adhesive layer 102, thereby improving production efficiency and ensuring the reliability of the insulating film.

[0047] Specifically, the method for preparing the above-mentioned battery cell insulating film 1 includes the following steps: An adhesive is applied to the surface of the substrate layer 101, and the substrate layer 101 and the adhesive are alternately layered to prepare a pre-cured intermediate. The pre-cured intermediate is subjected to ultraviolet curing treatment to cure the adhesive and form adhesive layer 102.

[0048] This embodiment of the invention involves coating an adhesive onto the surface of a substrate layer 101 and layering them alternately, followed by UV curing to form an adhesive layer 102. This not only simplifies and improves the efficiency of the process but also facilitates continuous production. Furthermore, the alternating layering design ensures a uniform and tight bond between the substrate layer 101 and the adhesive layer 102. Combined with the rapid curing characteristics of UV curing, the curing degree and performance stability of the adhesive layer 102 can be precisely controlled, avoiding insufficient bonding strength due to uneven curing.

[0049] According to one embodiment of the present invention, a pre-cured intermediate is subjected to ultraviolet curing treatment to cure the adhesive into an adhesive layer 102, comprising: Under the conditions of ambient temperature of 20℃-30℃, relative humidity of 50±10%, and ultraviolet light wavelength range of 350 nm to 600 nm, the pre-cured intermediate was subjected to ultraviolet curing treatment using a UV lamp.

[0050] In this embodiment of the invention, the ambient temperature is set to 20℃-30℃ and the relative humidity is set to 50±10%. This not only avoids premature curing of the adhesive due to excessively high temperatures or delayed curing due to excessively low temperatures, but also reduces the adverse effects of abnormal humidity on the bonding performance of the adhesive layer 102 (such as excessive humidity may cause bubbles in the adhesive layer 102 and a decrease in adhesion). By controlling the ultraviolet light wavelength range between 350mm and 600mm, the absorption characteristics of the photoinitiator in the adhesive layer 102 can be precisely matched to ensure that it can efficiently initiate the polymerization reaction of the adhesive, so that the adhesive layer 102 can be cured more fully and uniformly, thereby stably achieving the designed shear strength and pull-out strength (≥10MPa).

[0051] Specifically, in this embodiment, the ambient temperature can be, but is not limited to, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, or any value between two of these; the relative humidity can be, but is not limited to, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, or any value between two of these; and the wavelength of the ultraviolet light can be, but is not limited to, 350mm, 360mm, 370mm, 380mm, 400mm, 420mm, 440mm, 470mm, 490mm, 500mm, 515mm, 522mm, 550mm, 588mm, 594mm, 600mm, or any value between two of these.

[0052] The technical effects of this utility model will be described below with reference to some embodiments and comparative examples.

[0053] Test conditions: The battery cell insulation film 1 in this embodiment of the present invention is bonded to a test piece made of aluminum. The design requirements are not less than shear strength ≥10 MPa and pull-out strength ≥10 MPa.

[0054] Table 1

[0055] It should be noted that the test standard for obtaining tensile strength is GB / T6329, and the test standard for obtaining shear strength is GB / T7124.

[0056] Taking the tensile strength of the bond between the cell insulation film 1 and the cell housing 201 as an example, the process of obtaining its specific value using a universal tensile testing machine is as follows: For the preparation of pull-out test specimens, cut three 100mm×25mm×2mm pull-out test specimens and select three 26mm×26mm battery cell insulation films 1. Adhere each of the three battery cell insulation films 1 to one side of its corresponding pull-out test specimen, with a bonding area of ​​25mm×25mm between the insulation film 1 and the specimen. Roll the insulation film 1 repeatedly five or more times using a 2kg roller and allow it to stand at room temperature (23±2℃) for 24 hours. Then begin the test. Fix the bonded insulation film 1 and the corresponding pull-out test specimen to a fixture. Use a universal tensile testing machine to stretch the upper surface of the insulation film 1 and the lower surface of the pull-out test specimen at a stretching speed of 50mm / min. Record the values. Divide the force on the insulation film 1 or the pull-out test specimen by the bonding surface area of ​​25mm×25mm to obtain the pull-out strength. Repeat the same steps for the remaining two groups to obtain the pull-out strengths for all three groups.

[0057] Taking the shear strength of the bond between the cell insulation film 1 and the cell housing 201 as an example, the process of obtaining its specific value using a universal tensile testing machine is as follows: For shear specimen preparation, cut three 100mm×25mm×2mm shear specimens and select three 26mm×26mm battery cell insulation films 1. Adhere each of the three insulation films 1 to one side of its corresponding shear specimen, with a bonding area of ​​25mm×25mm between the insulation film 1 and the specimen. Roll the insulation film 1 repeatedly five or more times using a 2kg roller and allow it to stand at room temperature (23±2℃) for 24 hours. Then begin testing. Fix the bonded insulation film 1 and its corresponding shear specimen to a fixture. Use a universal tensile testing machine to stretch the upper end of the insulation film 1 and the lower end of the shear specimen at a stretching speed of 50mm / min. Record the readings. Divide the force on the shear specimen by the bonding surface area of ​​25mm×25mm to obtain the shear strength. Repeat the same steps for the remaining two groups to obtain the shear strengths for all three groups.

[0058] It should be noted that both the pull-out and shear test specimens were made of Al3003.

[0059] According to an embodiment of the present invention, on the other hand, as... Figure 2 As shown, a battery cell 2 is also provided, including: a battery cell housing 201 and the aforementioned battery cell insulating film 1.

[0060] Specifically, the cell housing 201 has an electrode assembly 202 inside; the aforementioned cell insulating film 1 is wrapped around the outer surface of the cell housing 201 and bonded to the cell housing 201 through an adhesive layer 102. The cell 2 of this embodiment includes the cell insulating film 1 as described above and has all the beneficial technical effects of the cell insulating film 1, which will not be repeated here.

[0061] This embodiment of the invention does not impose any particular limitation on the type or shape of the battery cell 2, which can be any type of battery cell 2, such as a blade battery cell or a square battery cell. The battery cell 2 in this embodiment of the invention can be a lithium-ion battery cell, a potassium-ion battery cell, a sodium-ion battery cell, a lithium-sulfur battery cell, etc., and is particularly preferred to be a lithium-ion battery cell.

[0062] According to an embodiment of the present invention, on the other hand, as... Figure 3 As shown, a battery pack is also provided, including: a housing 3, a plurality of the above-mentioned battery cells 2, and structural adhesive 4.

[0063] Specifically, multiple battery cells 2 are arranged side by side inside the housing 3; structural adhesive 4 is applied to the bottom surface of each battery cell 2 and to the opposite sides in the direction of the arrangement of the multiple battery cells 2, and the structural adhesive 4 is bonded and fixed to the battery cell insulating film 1 to fix each battery cell 2 to the housing 3.

[0064] The battery pack of this utility model embodiment includes the battery cell 2 as described above, and has all the beneficial technical effects of the battery cell 2, which will not be repeated here.

[0065] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell insulating film, characterized in that, include: n substrate layers and n adhesive layers, where n is a positive integer greater than or equal to 1; Along the thickness direction of the battery cell insulating film, the substrate layer and the adhesive layer are alternately stacked. The thickness of a single substrate layer is t1, and the thickness of a single adhesive layer is t2. The relationship between n, t1, and t2 satisfies: 36%≤n×t1 / n×(t1+t2)≤48%.

2. The cell insulating film according to claim 1, characterized in that, The thickness t1 of the single-layer substrate layer is in the range of 20μm≤t1≤30μm.

3. The cell insulating film according to claim 1, characterized in that, The thickness t2 of the single adhesive layer is in the range of 25μm≤t2≤35μm.

4. The cell insulating film according to claim 1, characterized in that, The total thickness of the cell insulation film is 70 μm to 150 μm.

5. The cell insulating film according to claim 1, characterized in that, The adhesive layer contains photoinitiator particles.

6. The cell insulating film according to claim 5, characterized in that, The photoinitiator particles are either free radical type photoinitiator particles or cationic type photoinitiator particles.

7. The cell insulating film according to claim 5, characterized in that, After UV curing, the shear strength of the adhesive layer is ≥10 MPa; and / or, the pull-out strength of the adhesive layer is ≥10 MPa.

8. The cell insulating film according to any one of claims 1 to 7, characterized in that, The battery cell insulating film also includes release paper, which is located on the outermost surface of the adhesive layer away from the substrate layer along the thickness direction of the battery cell insulating film.

9. A battery cell, characterized in that, include: The battery cell casing contains an internal electrode assembly. The cell insulating film according to any one of claims 1 to 8 is wrapped around the outer surface of the cell housing and bonded to the cell housing through the adhesive layer.

10. A battery pack, characterized in that, include: Box; Multiple battery cells as described in claim 9 are arranged side by side inside the housing; Structural adhesive is applied to the bottom surface of each of the battery cells and to the opposite sides in the multiple battery cell arrangement directions. The structural adhesive is bonded and fixed to the battery cell insulating film to fix each of the battery cells to the housing.

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