Battery cell insulation film layer structure, battery cell and battery pack

Abstract

The utility model relates to battery technology field discloses electric core insulating film layer structure, electric core and battery package, wherein the electric core insulating film layer structure, include: insulating layer and glue layer, insulating layer includes the first surface and the second surface of opposite setting along the thickness direction, the first surface is suitable for through structural glue and battery package shell fixed bonding, the first surface is equipped with non -plane structure, the non -plane structure is used for expanding the contact area between insulating layer with structural glue, glue layer includes the third surface and the fourth surface of opposite setting along the thickness direction, the third surface and the second surface of insulating layer fixed bonding, the fourth surface is suitable for with electric core shell fixed bonding. The utility model is equipped with non -plane structure in the first surface of insulating layer and structural glue connection, expands the contact area of insulating layer and structural glue with non -plane structure, can promote the bonding strength between insulating layer and structural glue, connects firmly to reduce the risk that electric core insulating film layer structure falls off because of insulating layer and structural glue separation failure.

Description

Technical Field

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

[0002] Battery packs are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention capability, and long cycle life. A battery pack typically consists of multiple cells, which are fixed inside the battery pack casing. A cell generally includes a cell casing and electrode arrays. The cell casing forms a sealed space protecting the electrode arrays, which are covered with bare cell insulating sheets to prevent short circuits within the cell caused by contact between the electrode arrays and the cell casing.

[0003] Insulating films are widely used for insulation protection of battery cell casings due to their low cost and mature coating processes and equipment. For example... Figure 1 As shown, the insulating film 100 mainly covers the outer surface of the cell housing 7', achieving external insulation of the cell housing 7'. Figure 2 As shown, the insulating film 100 mainly includes an insulating layer 1' and an adhesive layer 2', with the adhesive layer 2' being fixedly bonded to the battery cell housing 7'. For ease of use, a protective layer 4' can be applied before the adhesive layer 2' is fixed to the battery cell housing 7'. The insulating layer 1' is fixedly bonded to the battery pack housing, primarily using PET (polyethylene terephthalate) film or PP (polypropylene) film, which has a smooth outer surface and low adhesion. When the insulating layer 1' is directly bonded to the battery pack housing using structural adhesive, during tests such as mechanical vibration or impact, the small contact area between the smooth insulating layer 1' and the structural adhesive, coupled with low adhesion, can easily lead to adhesion failure at the connection between the insulating layer 1' and the structural adhesive, causing the insulating film 100 to detach. Utility Model Content

[0004] In view of this, the present invention provides a cell insulating film layer structure, a cell and a battery pack to solve the problems of low adhesion of the insulating film layer, easy adhesion failure at the joint between the insulating film layer and the structural adhesive, and resulting in the detachment of the insulating film.

[0005] In a first aspect, this utility model provides a battery cell insulating film layer structure, comprising:

[0006] An insulating layer includes a first surface and a second surface disposed opposite to each other along the thickness direction. The first surface is adapted to be fixedly bonded to the battery pack housing by structural adhesive. The first surface has a non-planar structure, which is used to increase the contact area between the insulating layer and the structural adhesive.

[0007] The adhesive layer includes a third surface and a fourth surface disposed opposite to each other along the thickness direction. The third surface is fixedly bonded to the second surface of the insulating layer, and the fourth surface is adapted to be fixedly bonded to the battery cell housing.

[0008] Beneficial effects: This invention fixes the battery cell within the battery pack by first bonding the adhesive layer of the insulating film structure to the battery cell housing, and then bonding the insulating layer to the battery pack housing. A non-planar structure is provided on the first surface where the insulating layer connects to the structural adhesive. This non-planar structure increases the contact area between the insulating layer and the structural adhesive, improving the bonding strength and ensuring a firm connection. This reduces the risk of the insulating film structure detaching from the structural adhesive.

[0009] In one alternative embodiment, the second surface of the insulating layer is provided with the non-planar structure to increase the contact area between the insulating layer and the adhesive layer.

[0010] Beneficial effects: By setting a non-planar structure on the second side where the insulation layer and the adhesive layer are connected, the contact area between the insulation layer and the adhesive layer can be increased, which can improve the bonding strength between the insulation layer and the adhesive layer, making the connection firm and reducing the risk of the insulation layer and adhesive layer separating and failing, which would lead to the detachment of the battery cell insulation film layer structure.

[0011] In one alternative embodiment, the non-planar structure is a frosted reinforcing layer disposed on the insulating layer.

[0012] Beneficial effects: Processing the surface of the insulation layer through sandblasting and other techniques to form a frosted reinforcing layer, i.e., forming a micro-uneven structure, can improve the surface roughness of the insulation layer, thereby increasing the effective bonding area between the insulation layer and the structural adhesive and / or adhesive layer, and increasing the connection strength.

[0013] In one optional embodiment, the frosted reinforcement layer includes a frosted mesh layer or a frosted stripe layer;

[0014] And / or, the surface roughness of the frosted reinforcement layer is Ra, satisfying 1.2μm≤Ra≤2μm;

[0015] And / or, the thickness of the frosted reinforcement layer is T1, which satisfies 3μm≤T1≤5μm.

[0016] Beneficial effects: Setting the frosted reinforcement layer as a frosted mesh layer or frosted stripe layer can further increase the effective bonding area between the insulation layer and the structural adhesive and / or adhesive layer, thereby increasing the connection strength. By controlling the surface roughness of the frosted reinforcement layer within a suitable range, both connection strength and adhesive filling performance can be balanced. If Ra is too small, the connection strength between the insulation layer and the structural adhesive and / or adhesive layer will be insufficient, easily leading to the risk of peeling. If Ra is too large, air bubbles are easily formed between the insulation layer and the structural adhesive and / or adhesive layer, reducing the insulation effect. By controlling the thickness of the frosted reinforcement layer within a suitable range, a sufficiently large contact area between the insulation layer and the structural adhesive and / or adhesive layer can be ensured, guaranteeing the connection strength.

[0017] In one optional embodiment, the insulating layer and / or the adhesive layer are bent into a wavy shape with a wave amplitude of L1, satisfying 25μm≤L1≤40μm, and the spacing between adjacent wave peaks is L2, satisfying 60μm≤L2≤120μm.

[0018] Beneficial effects: Bending the insulating layer and / or adhesive layer into a wavy shape and controlling the wave amplitude and the spacing between the wave crests within a suitable range can increase the effective bonding area between the insulating layer and the structural adhesive and / or adhesive layer, thereby increasing the connection strength between the insulating layer and the structural adhesive and / or adhesive layer.

[0019] In one alternative embodiment, a plurality of grooves are spaced apart on the first and / or second surfaces of the insulating layer.

[0020] Beneficial effects: By providing multiple grooves at intervals on the first and / or second surfaces of the insulating layer, the effective bonding area between the insulating layer and the structural adhesive and / or adhesive layer can be expanded by utilizing the multiple grooves, thereby increasing the connection strength between the insulating layer and the structural adhesive and / or adhesive layer.

[0021] In one optional embodiment, the groove depth is T2, and the thickness of the insulating layer is T3, satisfying 7μm≤T2≤15μm and 0.4≤T2 / T3≤0.6;

[0022] And / or, the spacing between adjacent grooves is L3, satisfying 1mm≤L3≤5mm;

[0023] And / or, the total area of ​​the groove opening of each of the grooves is S1, and the surface area of ​​the side of the insulating layer with the plurality of grooves is S2, satisfying 0.3≤S1 / S2≤0.5.

[0024] Beneficial effects: The groove opening area and groove depth directly affect the contact area between the insulation layer and the structural adhesive and / or adhesive layer. By controlling the ratio of the groove depth to the insulation layer thickness within a suitable range, and the ratio between the total groove opening area and the surface area of ​​the side of the insulation layer with the groove within a suitable range, sufficient contact area between the insulation layer and the structural adhesive and / or adhesive layer can be ensured to guarantee connection strength, and the thickness of the grooved portion of the insulation layer can have sufficient structural strength and insulation performance. Furthermore, controlling the spacing between adjacent grooves can also ensure that the structural adhesive and / or adhesive layer can fully fill the groove.

[0025] In one optional embodiment, the thickness of the insulating layer is T3, which satisfies 20μm≤T3≤30μm;

[0026] And / or, the thickness of the adhesive layer is T4, satisfying 25μm≤T4≤45μm;

[0027] And / or, the tensile strength of the insulating layer is σ b Satisfying 150 MPa ≤ σ b ≤170Mpa;

[0028] And / or, the elongation of the insulating layer is δ, satisfying 50% ≤ δ ≤ 110%.

[0029] Beneficial effects: By controlling the thickness of the insulation layer within a suitable range, the insulation effect can be ensured, and a certain degree of mechanical protection can be provided. By controlling the thickness of the adhesive layer within a suitable range, the connection strength between the insulation layer and the cell casing can be ensured. By controlling the tensile strength and / or elongation of the insulation layer, the connection strength between the insulation layer and the structural adhesive and / or adhesive layer can be further improved.

[0030] Secondly, this utility model also provides a battery cell, comprising:

[0031] Battery cell casing;

[0032] In the above-described battery cell insulating film layer structure, the fourth side of the adhesive layer is fixedly bonded to the battery cell housing.

[0033] Beneficial effects: The battery cell of this invention is fixedly bonded to the battery cell shell first through the adhesive layer of the battery cell insulating film structure, and then fixedly bonded to the battery pack shell through the insulating layer, thereby fixing the battery cell inside the battery pack. A non-planar structure is provided on the first surface where the insulating layer and structural adhesive connect. This non-planar structure increases the contact area between the insulating layer and the structural adhesive, improving the bonding strength between them and ensuring a firm connection. This reduces the risk of the insulating layer and structural adhesive detaching and failing, leading to the battery cell insulating film structure falling off.

[0034] Thirdly, this utility model also provides a battery pack, comprising:

[0035] Battery pack casing;

[0036] The aforementioned battery cell is disposed within the battery pack housing, and the first surface of the insulating layer is fixedly bonded to the battery pack housing by structural adhesive.

[0037] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be repeated here. Attached Figure Description

[0038] 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.

[0039] Figure 1 This is a schematic diagram of the structure of an existing battery cell;

[0040] Figure 2 This is a schematic diagram of the existing battery cell insulating film structure;

[0041] Figure 3 This is a schematic diagram of the first type of battery cell insulating film layer structure and structural adhesive according to an embodiment of the present utility model;

[0042] Figure 4 This is a schematic diagram of the frosted mesh layer of a battery cell insulating film layer structure according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the second type of battery cell insulating film layer structure and structural adhesive according to an embodiment of the present utility model;

[0044] Figure 6 This is another schematic diagram of the second type of battery cell insulating film layer structure and structural adhesive according to an embodiment of the present utility model;

[0045] Figure 7 This is a schematic diagram of the second type of battery cell insulating film layer structure according to an embodiment of the present utility model;

[0046] Figure 8 This is a schematic diagram of the third type of battery cell insulating film layer structure and structural adhesive according to an embodiment of the present utility model;

[0047] Figure 9 This is a schematic diagram of the fourth type of battery cell insulating film layer structure and structural adhesive according to an embodiment of the present utility model;

[0048] Figure 10 for Figure 8 and Figure 9 A schematic diagram of the structure of the insulating layer and adhesive layer in the middle;

[0049] Figure 11 A schematic diagram of the fifth type of battery cell insulating film layer structure and structural adhesive in this embodiment of the present invention;

[0050] Figure 12 A schematic diagram of the sixth type of battery cell insulating film layer structure and structural adhesive in this utility model embodiment;

[0051] Figure 13 for Figure 11 and Figure 12 A schematic diagram of the structure of the insulating layer and adhesive layer.

[0052] Explanation of reference numerals in the attached figures:

[0053] Existing technology: 1' Insulating film; 1' Insulating layer; 2' Adhesive layer; 4' Protective layer; 7' Cell casing;

[0054] This application includes: 1. Insulating layer; 2. Adhesive layer; 3. Structural adhesive; 4. Protective layer; 5. Frosted reinforcing layer; 501. Frosted mesh layer; 502. Frosted stripe layer; 6. Groove. Detailed Implementation

[0055] 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.

[0056] The following is combined Figures 3 to 13 The following describes embodiments of the present invention.

[0057] According to embodiments of the present invention, on the one hand, such as Figure 3 As shown, a battery cell insulating film layer structure is provided, mainly comprising: an insulating layer 1 and an adhesive layer 2. The insulating layer 1 includes a first surface and a second surface disposed opposite to each other along its thickness direction. The first surface is adapted to be fixedly bonded to the battery pack casing by structural adhesive 3. The first surface has a non-planar structure, which is used to increase the contact area between the insulating layer 1 and the structural adhesive 3. The adhesive layer 2 includes a third surface and a fourth surface disposed opposite to each other along its thickness direction. The third surface is fixedly bonded to the second surface of the insulating layer 1, and the fourth surface is adapted to be fixedly bonded to the battery cell casing.

[0058] Therefore, the battery cell insulating film structure provided in this embodiment of the invention first fixes the battery cell to the battery cell housing through the adhesive layer 2, and then fixes the battery cell to the battery pack housing through the insulating layer 1, thereby fixing the battery cell inside the battery pack. A non-planar structure is provided on the first surface where the insulating layer 1 connects to the structural adhesive 3. This non-planar structure increases the contact area between the insulating layer 1 and the structural adhesive 3, improving the bonding strength between them and ensuring a firm connection. This reduces the risk of the insulating layer 1 detaching from the structural adhesive 3 and failing, leading to the battery cell insulating film structure falling off.

[0059] Specifically, such as Figure 3 As shown, insulating layer 1 and adhesive layer 2 are arranged sequentially along the thickness direction, as shown in the figure. Figure 3 As shown by arrow H, the overall structure of the cell insulation film layer is annular, with adhesive layer 2 located on the inner side for fixing and bonding to the cell housing, and insulation layer 1 located on the outer side for fixing and bonding to the battery pack housing via structural adhesive 3.

[0060] In addition, before use, a protective layer 4 can be fixed to the fourth side of the adhesive layer 2. The protective layer 4 can be made of release paper to temporarily protect the adhesive layer 2 and prevent dust from adhering to the adhesive layer 2, which would reduce the adhesion effect of the adhesive layer 2. When it is necessary to bond and fix the adhesive layer 2 to the battery cell housing, the protective layer 4 should be removed first.

[0061] It should be noted that the number of insulating layer 1 and adhesive layer 2 in this embodiment of the present invention can be selected to be one or more according to actual needs, and this embodiment of the present invention does not impose too many restrictions on this.

[0062] For example, such as Figure 3 As shown, the insulating layer 1 and the adhesive layer 2 are each composed of two layers, which are alternately stacked to form a double-layer structure. The uppermost insulating layer 1 is fixedly bonded to the battery pack shell by structural adhesive 3, and the lowermost adhesive layer 2 is covered with a protective layer 4 before use. Alternatively, as shown... Figure 8 As shown, an insulating layer 1 and an adhesive layer 2 are each provided to form a single-layer structure.

[0063] It should be noted that the material of the insulating layer 1 is not limited in this embodiment of the utility model. Any existing material can be selected as needed. For example, the insulating layer 1 can be a PET film or a PP film.

[0064] Furthermore, this embodiment of the invention does not limit the material of the adhesive layer 2. For example, the adhesive layer 2 can be made of pressure-sensitive adhesive.

[0065] In one embodiment, the second surface of the insulating layer 1 has a non-planar structure to increase the contact area between the insulating layer 1 and the adhesive layer 2. The non-planar structure on the second surface where the insulating layer 1 and the adhesive layer 2 connect further increases the contact area between them, improving the bonding strength and ensuring a firm connection. This reduces the risk of the insulating layer 1 detaching from the adhesive layer 2 and failing, leading to the loss of the battery cell's insulating film structure.

[0066] It should be noted that the present invention does not limit the specific structure of the non-planar structure, as long as the non-planar structure can increase the contact area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, and improve the bonding strength between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2.

[0067] In one embodiment, such as Figure 3 As shown, the non-planar structure is a frosted reinforcing layer 5 disposed on the insulating layer 1. The surface of the insulating layer 1 is treated by processes such as sandblasting to form the frosted reinforcing layer 5. The sandblasting abrasive can be alumina, silicon carbide, etc., which forms a micro-uneven structure on the surface of the insulating layer 1. This can increase the surface roughness of the insulating layer 1, thereby increasing the effective bonding area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, so that the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2 interlock and increase the connection strength.

[0068] In one embodiment, such as Figure 3 and Figure 4 As shown, the frosted reinforcing layer 5 includes a frosted mesh layer 501. Setting the frosted reinforcing layer 5 as a frosted mesh layer 501 means that a mesh-like frosted layer is provided on the surface of the insulating layer 1, which can further increase the effective bonding area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, and increase the connection strength between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2.

[0069] In one embodiment, such as Figures 5 to 7 As shown, the frosted reinforcing layer 5 includes a frosted stripe layer 502. Setting the frosted reinforcing layer 5 as a frosted stripe layer 502, that is, setting a striped frosted layer on the surface of the insulating layer 1, can further increase the effective bonding area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, and increase the connection strength between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2.

[0070] Furthermore, in one embodiment, the surface roughness of the frosted reinforcing layer 5 is Ra, satisfying 1.2μm≤Ra≤2μm. By controlling the surface roughness Ra of the frosted reinforcing layer 5 within a suitable range, both bonding strength and adhesive filling performance can be considered. If Ra is too small, the bonding strength between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2 will be insufficient, easily leading to the risk of peeling. If Ra is too large, air bubbles are easily formed between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, reducing the insulation effect.

[0071] For example, the surface roughness Ra of the frosted reinforcing layer 5 in this embodiment of the present invention can be 1.2μm, 1.5μm, 1.7μm, 2μm, etc.

[0072] Roughness Ra Measurement Method: The Tokyo Precision Roughness Tester uses the stylus method (probe method) for measurement. During measurement, the diamond stylus on the sensor maintains perpendicular contact with the surface being measured (the outer surface of the frosted reinforcing layer 5), and the sensor is dragged at a constant speed by a driver. The contour peaks and valleys of the surface being measured cause the stylus to move up and down. This displacement is synchronized with the magnetic core of the fulcrum, thereby changing the inductance of the differential inductor coil, and thus the roughness Ra is measured.

[0073] In one embodiment, such as Figure 5 As shown, the thickness of the frosted reinforcing layer 5 is T1, satisfying 3μm≤T1≤5μm. By controlling the thickness T1 of the frosted reinforcing layer 5 within a suitable range, a sufficiently large contact area can be ensured between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, guaranteeing the connection strength. If T1 is too small, the frosted reinforcing layer 5 will not be able to effectively cover the surface of the insulating layer 1, resulting in insufficient connection strength between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2, which may easily lead to peeling. If T1 is too large, the frosted reinforcing layer 5 will occupy too much space, potentially reducing the energy density of the battery cell.

[0074] For example, the thickness T1 of the frosted reinforcing layer 5 in this embodiment of the present invention can be 3μm, 4μm, 5μm, etc.

[0075] In one embodiment, such as Figures 8 to 10 As shown, insulating layer 1 and / or adhesive layer 2 are bent into a wavy shape. The wavy insulating layer 1 is fixedly bonded to the wavy structural adhesive 3, forming a non-planar structure. The wave amplitude is L1, satisfying 25μm≤L1≤40μm. Wave amplitude refers to the vertical distance between the crest and trough. The spacing between adjacent crests is L2, satisfying 60μm≤L2≤120μm. Bending insulating layer 1 and / or adhesive layer 2 into a wavy shape and controlling the wave amplitude and crest spacing within a suitable range can increase the effective bonding area between insulating layer 1 and structural adhesive 3 and / or adhesive layer 2, thereby increasing the connection strength between insulating layer 1 and structural adhesive 3 and / or adhesive layer 2.

[0076] For example, in the embodiments of the present invention, the wave amplitude L1 of the wave-shaped insulating layer 1 and / or adhesive layer 2 can be 25μm, 30μm, 35μm, 40μm, etc., and the spacing L2 between adjacent wave peaks can be 60μm, 80μm, 100μm, 120μm, etc.

[0077] In one embodiment, such as Figures 11 to 13 As shown, a plurality of grooves 6 are spaced apart on the first and / or second surfaces of the insulating layer 1, forming a non-planar structure. By providing a plurality of grooves 6 on the first surface of the insulating layer 1 where it connects to the structural adhesive 3 and / or the second surface where it connects to the adhesive layer 2, the effective bonding area between the insulating layer 1 and the structural adhesive 3 and / or the adhesive layer 2 can be increased, thereby increasing the bonding strength between the insulating layer 1 and the structural adhesive 3 and / or the adhesive layer 2.

[0078] Furthermore, in one embodiment, such as Figure 11 As shown, the groove depth of groove 6 is T2, and the thickness of insulating layer 1 is T3, satisfying 7μm≤T2≤15μm, 0.4≤T2 / T3≤0.6, and 20μm≤T3≤30μm.

[0079] Furthermore, the spacing between adjacent grooves 6 is L3, which satisfies 1mm≤L3≤5mm.

[0080] Furthermore, the total area of ​​the groove opening of each groove 6 is S1, and the surface area of ​​the side of the insulating layer 1 with multiple grooves 6 is S2, satisfying 0.3≤S1 / S2≤0.5.

[0081] The groove area and depth of the groove 6 directly affect the contact area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2. By controlling the ratio T2 / T3 of the groove depth to the thickness of the insulating layer 1 within a suitable range, and the ratio S1 / S2 of the total groove area of ​​each groove 6 to the surface area of ​​the side of the insulating layer 1 with the groove 6 within a suitable range, sufficient contact area between the insulating layer 1 and the structural adhesive 3 and / or adhesive layer 2 can be ensured to guarantee the connection strength, and the thickness of the portion of the insulating layer 1 with the groove 6 can be ensured to have sufficient structural strength and insulation performance. Furthermore, controlling the spacing L3 between adjacent grooves 6 can ensure that the structural adhesive 3 and / or adhesive layer 2 can fully fill the groove 6, ensuring effective connection and insulation performance. By controlling the thickness of the insulating layer 1 within a suitable range, insulation effect can be ensured, and a certain degree of mechanical protection can be provided.

[0082] For example, in this embodiment of the present invention, the groove depth T2 of the groove 6 can be 8 μm, and the thickness T3 of the insulating layer 1 can be 20 μm, then T2 / T3 is 0.4, the distance L3 between adjacent grooves 6 can be 1 mm, and S1 / S2 can be 0.3. Alternatively, the groove depth T2 of the groove 6 can be 15 μm, and the thickness T3 of the insulating layer 1 can be 25 μm, then T2 / T3 is 0.6, the distance L3 between adjacent grooves 6 can be 5 mm, and S1 / S2 can be 0.5. Alternatively, the groove depth T2 of the groove 6 can be 12.5 μm, and the thickness T3 of the insulating layer 1 can be 25 μm, then T2 / T3 is 0.5, the distance L3 between adjacent grooves 6 can be 3 mm, and S1 / S2 can be 0.4.

[0083] In one embodiment, such as Figure 5 As shown, the thickness of adhesive layer 2 is T4, satisfying 25μm≤T4≤45μm. By controlling the thickness of adhesive layer 2 within a suitable range, the connection strength between insulating layer 1 and the battery cell housing can be ensured.

[0084] Furthermore, such as Figure 5 As shown, the thickness of the protective layer 4 is T5, which satisfies 15μm≤T5≤25μm.

[0085] For example, the thickness T4 of the adhesive layer 2 in this embodiment of the present invention can be 25μm, 35μm, 45μm, etc. The thickness T5 of the protective layer 4 can be 15μm, 20μm, 25μm, etc.

[0086] In one embodiment, the tensile strength of the insulating layer 1 is σ. b Satisfying 150 MPa ≤ σ b The tensile strength is ≤170 MPa, and the testing standard is GB / T7124-2008, "Determination of Tensile Shear Strength of Adhesives (Rigid Material to Rigid Material)". The elongation of insulation layer 1 is δ, which meets the requirement of 50% ≤ δ ≤ 110%, and the testing standard is GB / T30776-2014, "Determination of Bond Strength of Adhesives (Metals and Plastics)". The mechanical strength of insulation layer 1 itself directly affects its bonding strength. If the strength of insulation layer 1 is poor or it is easily deformed, the bonding strength will be low. By controlling the tensile strength and / or elongation of insulation layer 1, the connection strength between insulation layer 1 and structural adhesive 3 and / or adhesive layer 2 can be further improved.

[0087] By way of example, the tensile strength σ of the insulating layer 1 in this embodiment of the present invention is... b The pressure can be 150 MPa, 160 MPa, 170 MPa, etc., and the elongation δ of the insulation layer 1 can be 50%, 80%, 110%, etc.

[0088] In one embodiment, the cell casing is made of aluminum, which can be tri-series aluminum (Al3003 aluminum-manganese alloy) with an aluminum content >99%, conforming to the testing standard GB / T 3190-2020, "Chemical Composition of Wrought Aluminum and Aluminum Alloys". The tensile strength of the aluminum casing is σ1, satisfying 185 MPa ≤ σ1 ≤ 245 MPa; the yield strength of the aluminum casing is σ2, satisfying 145 MPa ≤ σ2 ≤ 180 MPa; and the elongation of the aluminum casing is δ1, satisfying 8% ≤ δ1 ≤ 15%, conforming to the testing standard GB / T 33824-2017, "Aluminum and Aluminum Alloy Plates and Strips for New Energy Power Battery Casings and Covers". By controlling the structural performance parameters of the cell casing, the bonding strength between the adhesive layer 2 and the cell casing can be ensured, preventing the adhesive layer 2 from peeling off from the cell casing.

[0089] For example, the tensile strength σ1 of the aluminum shell can be 185 MPa, 215 MPa, 245 MPa, etc., the yield strength σ2 of the aluminum shell can be 145 MPa, 155 MPa, 165 MPa, 180 MPa, etc., and the elongation δ1 of the aluminum shell can be 8%, 10%, 12%, 15%, etc.

[0090] According to an embodiment of the present invention, another aspect provides a battery cell, which mainly includes: a battery cell housing and a battery cell insulating film layer structure, wherein the fourth side of the adhesive layer 2 is fixedly bonded to the battery cell housing.

[0091] The battery cell of this invention is first fixedly bonded to the battery cell shell via the adhesive layer 2 of the battery cell insulating film structure, and then fixedly bonded to the battery pack shell via the insulating layer 1, thereby fixing the battery cell inside the battery pack. A non-planar structure is provided on the first surface where the insulating layer 1 connects to the structural adhesive 3. This non-planar structure increases the contact area between the insulating layer 1 and the structural adhesive 3, improving the bonding strength between them and ensuring a firm connection. This reduces the risk of the insulating layer 1 detaching from the structural adhesive 3 and failing, leading to the detachment of the battery cell insulating film structure.

[0092] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, mainly comprising: a battery pack shell and a battery cell, wherein the battery cell is disposed inside the battery pack shell, and the first surface of the insulating layer 1 is fixedly bonded to the battery pack shell by structural adhesive 3.

[0093] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0094] 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 structure, characterized in that, include: An insulating layer includes a first surface and a second surface disposed opposite to each other along the thickness direction. The first surface is adapted to be fixedly bonded to the battery pack housing by structural adhesive. The first surface is provided with a non-planar structure, which is used to increase the contact area between the insulating layer and the structural adhesive. The adhesive layer includes a third surface and a fourth surface disposed opposite to each other along the thickness direction. The third surface is fixedly bonded to the second surface of the insulating layer, and the fourth surface is adapted to be fixedly bonded to the battery cell housing.

2. The cell insulating film layer structure according to claim 1, characterized in that, The second surface of the insulating layer has the non-planar structure to increase the contact area between the insulating layer and the adhesive layer.

3. The cell insulating film layer structure according to claim 1 or 2, characterized in that, The non-planar structure is a frosted reinforcing layer disposed on the insulating layer.

4. The cell insulating film layer structure according to claim 3, characterized in that, The frosted reinforcement layer includes a frosted mesh layer or a frosted stripe layer; And / or, the surface roughness of the frosted reinforcement layer is Ra, satisfying 1.2μm≤Ra≤2μm; And / or, the thickness of the frosted reinforcement layer is T1, which satisfies 3μm≤T1≤5μm.

5. The cell insulating film layer structure according to claim 1 or 2, characterized in that, The insulating layer and / or the adhesive layer are bent into a wave shape with a wave amplitude of L1, satisfying 25μm≤L1≤40μm, and the distance between adjacent wave peaks is L2, satisfying 60μm≤L2≤120μm.

6. The cell insulating film layer structure according to claim 1 or 2, characterized in that, The first and / or second surfaces of the insulating layer are provided with a plurality of grooves spaced apart.

7. The cell insulating film layer structure according to claim 6, characterized in that, The groove depth is T2, and the thickness of the insulating layer is T3, satisfying 7μm≤T2≤15μm and 0.4≤T2 / T3≤0.6; And / or, the spacing between adjacent grooves is L3, satisfying 1mm≤L3≤5mm; And / or, the total area of ​​the groove opening of each of the grooves is S1, and the surface area of ​​the side of the insulating layer with the plurality of grooves is S2, satisfying 0.3≤S1 / S2≤0.

5.

8. The cell insulating film layer structure according to claim 1 or 2, characterized in that, The thickness of the insulating layer is T3, which satisfies 20μm≤T3≤30μm; And / or, the thickness of the adhesive layer is T4, satisfying 25μm≤T4≤45μm; And / or, the tensile strength of the insulating layer is σ b Satisfying 150 MPa ≤ σ b ≤170Mpa; And / or, the elongation of the insulating layer is δ, satisfying 50% ≤ δ ≤ 110%.

9. A battery cell, characterized in that, include: Battery cell casing; According to any one of claims 1 to 8, the fourth side of the adhesive layer is fixedly bonded to the battery cell housing.

10. A battery pack, characterized in that, include: Battery pack casing; The battery cell of claim 9 is disposed within the battery pack housing, and the first surface of the insulating layer is fixedly bonded to the battery pack housing by structural adhesive.

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