Battery cell insulation film, battery cell, and battery pack

Abstract

The utility model relates to battery technology field discloses a kind of electric core insulating film, electric core and battery package.Electric core insulating film includes: bottom film, one side surface is outwardly convex and forms thickening area;Along X direction, the distance a between the edge of thickening area and the corresponding edge of bottom film is 3mm to 10mm;Along Y direction, the distance b between the edge of thickening area and the corresponding edge of bottom film is 1mm to 2mm;Side film is located in the opposite two sides or circumferential side of bottom film, and the connecting place of bottom film and side film is equipped with crease mark, and side film is suitable for being bent by crease mark relative to the side of bottom film with thickening area.In the bottom film, the thickening area that can replace split type support plate can be set, the design of "insulating film and support plate integration" can be realized, the separate process that support plate and insulating film need to be fixed by heat fusion in conventional scheme is saved, so subsequent only needs to utilize crease mark to wrap side film in the circumferential side of pole group, in this way, assembly process is simplified, and the production efficiency of electric core is improved.

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] The battery cell is the smallest unit of a battery pack. In existing technologies, a battery cell generally consists of electrode arrays, electrolyte, insulating film, support plate, cover plate, and casing. The casing and cover plate are welded together to form a closed space housing the electrode arrays. The insulating film and support plate wrap around the electrode arrays, providing electrical insulation and supporting and protecting them. Specifically, the support plate is fixed to the side of the electrode array facing the bottom of the battery pack via the insulating film.

[0003] However, since the support plate and the insulating film are separate structures, they need to be fixedly connected by heat fusion before assembly, and then the electrode assembly is wrapped. This increases the complexity of the assembly process and reduces the production efficiency of the battery cell. Utility Model Content

[0004] In view of this, the present invention provides a cell insulating film, a cell, and a battery pack to solve the problem of cumbersome cell assembly process and low production efficiency caused by the separate structure of the support plate and the bare cell insulating sheet.

[0005] In a first aspect, this utility model provides a battery cell insulating film, comprising: The base film has a thickened area formed by an outward convexity on one side surface; along the X direction, the distance a between the edge of the thickened area and the corresponding edge of the base film is 3mm to 10mm; along the Y direction, the distance b between the edge of the thickened area and the corresponding edge of the base film is 1mm to 2mm. Side films are located on opposite sides or around the bottom film. Fold lines are provided at the connection between the bottom film and the side films. The side films are adapted to be bent relative to the bottom film through the fold lines.

[0006] Beneficial effects: This utility model achieves an integrated design of "insulating film and supporting plate" by thickening the bottom film to form a thickened area that can replace the separate support plate. This eliminates the need for a separate process in conventional solutions, which requires heat-melting the supporting plate and insulating film together. As a result, the side film can be wrapped around the periphery of the electrode assembly using crease lines. This not only simplifies the assembly process and reduces the number of operation steps, thus improving the production efficiency of the battery cell, but also ensures that the bottom film can provide sufficient support for the electrode assembly through the thickened area, reducing the possibility of the electrode assembly colliding with the battery cell casing during battery cell use.

[0007] In one optional embodiment, the thickened area is provided with an exhaust channel extending along the X direction, and there are multiple exhaust channels arranged side by side along the Y direction.

[0008] Beneficial Effects: In conventional designs, there is usually no gap between the support plate and the electrode assembly after they are attached. However, since the electrode assembly also generates some gas during normal use of the cell, if this gas cannot be discharged in time, it can easily affect the performance and safety of the cell. Therefore, this invention provides a smooth discharge channel for the gas generated by the electrode assembly by setting multiple exhaust channels extending along the X direction and arranged side-by-side along the Y direction. This allows the gas to be discharged in time through the exhaust channels, effectively avoiding the problem of gas accumulation between the thickened area and the electrode assembly, ensuring the uniformity of stress on the electrode assembly, and improving the stability and safety of the cell during use.

[0009] In one optional implementation, along the Y direction, the width of the thickened area is W0, and the width of the exhaust channel is Wi. The relationship between Wi and W0 satisfies: 0.4≤nWi / W0≤0.65, where n is the number of exhaust channels.

[0010] Beneficial effects: When the ratio of nWi to W0 is between 0.4 and 0.65, the gas discharge speed will not be limited due to the small total width of the exhaust channel, ensuring that the gas generated by the electrode group can be quickly discharged through the exhaust channel and avoiding excessive accumulation pressure; nor will the structural integrity of the thickened area be excessively weakened due to the large total width of the channel, ensuring that the thickened area still has sufficient support to stabilize the electrode group.

[0011] In one optional implementation, the value of W0 is in the range of 10mm≤W0≤45mm; and / or, the value of Wi is in the range of 1.5mm≤Wi≤6mm.

[0012] Beneficial Effects: This invention limits W0 to between 10mm and 45mm, avoiding both insufficient support coverage for the electrode assembly due to excessive width, leading to unstable support, and excessive width, resulting in material waste. It also avoids spatial conflicts with other internal structures of the cell, ensuring a reasonable layout of the thickened area within the cell. Furthermore, controlling Wi within the range of 1.5mm to 6mm, combined with the aforementioned nWi / W0 ratio, further optimizes the venting capacity of the venting channels. Specifically, if Wi is too small, the venting channels may be easily blocked by minor deformations of the electrode assembly or impurities, affecting venting smoothness; if Wi is too large, it may reduce the number of venting channels while maintaining the same total width ratio, reducing the dispersion of the venting path.

[0013] In one optional embodiment, along the Z direction, the thickness of the bottom film at the thickened area is T0, the groove depth of the exhaust channel is T1, and the relationship between T1 and T0 satisfies: 0.5≤T1 / T0≤0.75.

[0014] Beneficial effects: When the ratio of T1 to T0 is between 0.5 and 0.75, it will not cause insufficient volume of the exhaust channel due to the shallow depth (too small ratio), affecting the gas flow efficiency and preventing the timely discharge of gas generated by the electrode group; nor will it cause excessive reduction of the remaining thickness of the thickened area due to the deep depth (too large ratio), making it difficult for the thickened area to support the electrode group and affecting the stability of the cell structure.

[0015] In one optional implementation, the value of T0 is in the range of 0.5mm ≤ T0 ≤ 2mm; and / or, the value of T1 is in the range of 0.3mm ≤ T1 ≤ 1.5mm.

[0016] Beneficial effects: This invention limits T0 to between 0.5mm and 2mm, providing a suitable base thickness for the thickened area. Specifically, if T0 is too small, the support thickness of the thickened area is insufficient, making it difficult to stably support the electrode assembly; if T0 is too large, it will increase the overall thickness and weight of the insulating film, which will not only conflict with the compact space design inside the cell but also cause unnecessary material consumption. T1, within the range of 0.3mm to 1.5mm, avoids both excessively shallow groove depth leading to narrow exhaust channels and affecting gas discharge speed, and excessively deep groove depth exceeding a reasonable proportion, thus weakening the support capacity of the thickened area.

[0017] In one alternative implementation, the length of the thickened region along the X direction is L0, and the value of L0 ranges from 130mm to 294mm or from 380mm to 580mm.

[0018] Beneficial effects: A range of 130mm to 294mm is suitable for supporting and covering square cell electrode assemblies, while a range of 380mm to 580mm is suitable for supporting and covering blade cell electrode assemblies. It can be understood that by setting the thickened area according to the above parameters, the thickened area can stably support electrode assemblies of different sizes, avoiding uneven distribution of support force due to insufficient length, or material waste and spatial conflicts with other internal structures of the cell due to excessive length.

[0019] In one alternative embodiment, the bottom film and the side film are integrally formed.

[0020] Beneficial effects: The bottom film and side film are integrally formed, which can eliminate the risk of insulation failure caused by weak points such as gaps and seams at the connection between the two, effectively improve the overall sealing and structural integrity of the insulation film, and provide more reliable insulation protection for the battery cell electrode assembly; on the other hand, it can reduce assembly processes and material consumption, reduce production costs and improve production efficiency.

[0021] Secondly, this utility model also provides a battery cell, comprising: The battery cell casing has an internal cavity. The cell electrode assembly is disposed within the cavity; The aforementioned cell insulating film is located between the cell housing and the cell electrode assembly, and wraps around the outside of the cell electrode assembly; a pair of side films are attached to the large surfaces of a pair of side walls of the cell electrode assembly, and the thickened area on the bottom film is attached to the bottom surface of the cell electrode assembly.

[0022] 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 insulating film, which will not be repeated here.

[0023] Thirdly, this utility model also provides a battery pack, comprising: a plurality of the above-mentioned battery cells.

[0024] 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

[0025] 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.

[0026] 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 for Figure 1 The diagram shows the structure of the battery cell insulation film from another perspective. Figure 3 for Figure 1 The diagram shows a side view of the insulating film of the battery cell. Figure 4 for Figure 1 The diagram shows the assembly of the battery cell insulation film after it is wrapped around the electrode assembly. Figure 5 This is another assembly diagram of the battery cell after the insulating film is wrapped around the electrode assembly as shown in Figure 1. Figure 6 This is a schematic diagram of the structure of another battery cell insulating film according to an embodiment of the present invention; Figure 7 for Figure 6 The diagram shows the structure of the battery cell insulation film from another perspective. Figure 8 for Figure 6 The diagram shows the assembly of the battery cell insulation film after it is wrapped around the electrode assembly.

[0027] Explanation of reference numerals in the attached figures: 1. Bottom film; 101. Thickened area; 1011. Vent groove; 2. Side film; 201. First side; 202. Second side; 203. Third side; 3. Fold line. Detailed Implementation

[0028] 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.

[0029] The following is combined with Figures 1 to 8 The following describes embodiments of the present invention.

[0030] According to embodiments of the present invention, on the one hand, such as Figures 1 to 3 , Figure 6 and Figure 7 As shown, a battery cell insulating film is provided, comprising: a bottom film 1 and a side film 2.

[0031] Specifically, one side surface of the base film 1 protrudes outward to form a thickened area 101; along the X direction, the distance a between the edge of the thickened area 101 and the corresponding edge of the base film 1 is 3mm to 10mm; along the Y direction, the distance b between the edge of the thickened area 101 and the corresponding edge of the base film 1 is 1mm to 2mm; the side film 2 is located on opposite sides or around the base film 1, and a fold line 3 is provided at the connection between the base film 1 and the side film 2, and the side film 2 is adapted to be bent relative to the side of the base film 1 with the thickened area 101 through the fold line 3.

[0032] This embodiment of the invention achieves an integrated design of "insulating film and supporting plate" by thickening the bottom film 1 to form a thickened area 101 that can replace the split support plate. This eliminates the need for a separate process in conventional solutions, which requires heat-melting the support plate and insulating film together. As a result, the side film 2 can be wrapped around the periphery of the electrode assembly using the crease 3. This not only simplifies the assembly process and reduces the number of steps, thus improving the production efficiency of the battery cell, but also ensures that the bottom film 1 can provide sufficient support for the electrode assembly through the thickened area 101, reducing the possibility of the electrode assembly colliding with the battery cell casing during battery cell use.

[0033] Furthermore, in this embodiment, the distance a between the edge of the thickened area 101 in the X direction and the corresponding edge of the bottom film 1 is controlled between 3mm and 10mm, and the distance b between the edge of the thickened area 101 in the Y direction and the corresponding edge of the bottom film 1 is controlled between 1mm and 2mm. This ensures that the thickened area 101 will not exceed the support range required by the electrode assembly due to its excessive size, thus avoiding interference with the bending operation of the side film 2 and affecting the fit of the wrapping; nor will it fail to provide stable and comprehensive support for the electrode assembly due to its excessive size.

[0034] It should be noted that the thickened area 101 in this embodiment is actually a thickening treatment of the area on the bottom film 1 where the support plate is originally to be placed. Therefore, this embodiment can achieve the thickening treatment of the bottom film 1 by injection molding, hot pressing, hot extrusion, etc.

[0035] It is understood that in this embodiment, the value of 'a' can be, but is not limited to, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, or any value between two of these. The value of 'b' can be, but is not limited to, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or any value between two of these.

[0036] It should be further noted that, if the cell insulating film in this embodiment is used to wrap a square cell, the distance 'a' between the edge of the thickened area 101 in the X direction and the corresponding edge of the bottom film 1 should be controlled between 3mm and 5mm; if the cell insulating film in this embodiment is used to wrap a blade cell, the distance 'a' between the edge of the thickened area 101 in the X direction and the corresponding edge of the bottom film 1 should be controlled between 5mm and 10mm. It is understood that the type of cell is not limited to square cells or blade cells; therefore, the values ​​of 'a' and 'b' can be adjusted adaptively according to actual design requirements.

[0037] According to one embodiment of the present invention, such as Figures 1 to 3As shown, the thickened area 101 is provided with multiple exhaust channels 1011 extending along the X direction, arranged side-by-side along the Y direction. In conventional designs, when the support plate and the electrode assembly are attached, there is usually no gap between them. However, since the electrode assembly also generates some gas during normal use of the cell, if this gas cannot be discharged in time, it is easy to accumulate between the support plate and the electrode assembly, resulting in uneven stress on the electrode assembly and affecting the structural stability of the cell. In addition, the pressure generated by gas accumulation may also pose a potential threat to the performance and safety of the cell. Based on this, this embodiment of the utility model provides a smooth discharge channel for the gas generated by the electrode assembly by setting multiple exhaust channels 1011 extending along the X direction and arranged side-by-side along the Y direction, so that the gas can be discharged in time through the exhaust channels 1011, effectively avoiding the problem of gas accumulation between the thickened area 101 and the electrode assembly, ensuring the uniformity of stress on the electrode assembly, and improving the stability and safety of the cell during use.

[0038] According to one embodiment of the present invention, such as Figure 2 , Figure 3 as well as Figure 7 As shown, along the Y direction, the width of the thickened region 101 is W0, and the width of the exhaust channel 1011 is Wi. The relationship between Wi and W0 satisfies: 0.4 ≤ nWi / W0 ≤ 0.65, where n is the number of exhaust channels 1011, and n is a positive integer greater than or equal to 2. It can be understood that when the ratio of nWi to W0 is between 0.4 and 0.65, the gas discharge speed will not be limited due to the total width of the exhaust channels 1011 being too small, ensuring that the gas generated by the electrode assembly can be quickly discharged through the exhaust channels 1011, avoiding excessive accumulation pressure; nor will the structural integrity of the thickened region 101 be excessively weakened due to the total width of the channels, ensuring that the thickened region 101 still has sufficient supporting force to stabilize the electrode assembly.

[0039] It is understood that the ratio of nWi to W0 in this embodiment can be, but is not limited to, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, or any value range between the two.

[0040] It should be noted that, as Figure 2 As shown, the exhaust channel 1011 is a channel that is open at both ends in one direction only. For better understanding, the corresponding concepts of closed channel and semi-closed channel are given here. A closed channel is a channel that is completely closed on all sides, and a semi-closed channel is a channel that is open at one end in one direction only.

[0041] Specifically, the cross-sectional shape of the exhaust channel 1011 is not limited and can be rectangular, semi-circular, trapezoidal or other common shapes.

[0042] It should be further noted that if the cell insulation film in this embodiment is used to wrap prismatic cells, the relationship between Wi and W0 satisfies: 0.4 ≤ nWi / W0 ≤ 0.65; if the cell insulation film in this embodiment is used to wrap blade cells, the relationship between Wi and W0 satisfies: 0.4 ≤ nWi / W0 ≤ 0.6. It is understood that the cell type is not limited to prismatic cells or blade cells; therefore, the range of values ​​for nWi / W0 can be adjusted adaptively according to actual design requirements.

[0043] According to one embodiment of the present invention, such as Figure 2 , Figure 3 as well as Figure 7 As shown, the value range of W0 is 10mm ≤ W0 ≤ 45mm; and / or, the value range of Wi is 1.5mm ≤ Wi ≤ 6mm. This embodiment of the invention limits W0 to between 10mm and 45mm, ensuring that the width is neither too small, resulting in insufficient support coverage for the electrode assembly and unstable support, nor too large, causing material waste. It also avoids spatial conflicts with other internal structures of the cell, ensuring a reasonable layout of the thickened area 101 within the cell. Controlling Wi within the range of 1.5mm to 6mm, combined with the aforementioned nWi / W0 ratio, further optimizes the venting capacity of the venting channel 1011. Specifically, if Wi is too small, the venting channel 1011 may be easily blocked by minor deformations of the electrode assembly or impurities, affecting venting smoothness; if Wi is too large, the number of venting channels 1011 may be reduced within the same total width ratio, decreasing the dispersion of the venting path.

[0044] It is understood that in this embodiment, the value of W0 can be, but is not limited to, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 27mm, 30mm, 32mm, 35mm, 36mm, 38mm, 40mm, 45mm or any value range between the two. Similarly, the value of Wi can be, but is not limited to, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.4mm, 3.5mm, 3.6mm, 3.9mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.2mm, 5.5mm, 6mm, or any value between the two.

[0045] It should be further noted that, in this embodiment, if the cell insulating film is used to wrap a blade cell, the value of W0 ranges from 10mm to 25mm, and the value of Wi ranges from 1.5mm to 3mm; if the cell insulating film is used to wrap a prismatic cell, the value of W0 ranges from 25mm to 45mm, and the value of Wi ranges from 3mm to 6mm. It is understood that the cell type is not limited to prismatic cells or blade cells; therefore, the value ranges of W0 and Wi can be adjusted adaptively according to actual design requirements.

[0046] According to one embodiment of the present invention, such as Figure 3 As shown, along the Z direction, the thickness of the bottom film 1 at the thickened area 101 is T0, and the depth of the exhaust channel 1011 is T1. The relationship between T1 and T0 satisfies: 0.5 ≤ T1 / T0 ≤ 0.75. When the ratio of T1 to T0 is between 0.5 and 0.75, it will not result in insufficient volume of the exhaust channel 1011 due to the channel depth being too shallow (too small ratio), affecting the gas flow efficiency and preventing the timely discharge of gas generated by the electrode group; nor will it result in excessive reduction of the remaining thickness of the thickened area 101 due to the channel depth being too deep (too large ratio), making it difficult for the thickened area 101 to support the electrode group and affecting the stability of the cell structure.

[0047] It is understood that, in this embodiment, the ratio of T1 to T0 can be, but is not limited to, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, or any value range between the two.

[0048] According to one embodiment of the present invention, such as Figure 3 As shown, the value range of T0 is 0.5mm ≤ T0 ≤ 2mm; and / or, the value range of T1 is 0.3mm ≤ T1 ≤ 1.5mm. It can be understood that limiting T0 to between 0.5mm and 2mm in this embodiment of the invention provides a suitable basic thickness for the thickened area 101. Specifically, if T0 is too small, the supporting thickness of the thickened area 101 is insufficient, making it difficult to stably support the electrode assembly; if T0 is too large, it will increase the overall thickness and weight of the insulating film, which will not only conflict with the compact space design inside the cell but also cause unnecessary material consumption. T1, within the range of 0.3mm to 1.5mm, avoids both excessively shallow groove depth leading to narrow exhaust channels and affecting gas exhaust speed, and excessively deep groove depth exceeding a reasonable proportion, thus weakening the supporting capacity of the thickened area 101.

[0049] It is understood that, in this embodiment, the value of T0 can be, but is not limited to, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or any value between two of these. Similarly, the value of T1 can be, but is not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or any value between two of these.

[0050] It should be noted that in this embodiment, the thickness of the area where the cell insulation film is not thickened ranges from 0.08 mm to 0.15 mm.

[0051] According to one embodiment of this utility model, the length of the thickened region 101 along the X direction is L0, and the value of L0 ranges from 130mm to 294mm or from 380mm to 580mm. It should be noted that the range of 130mm to 294mm is suitable for supporting and covering the square cell electrode assembly, and the range of 380mm to 580mm is suitable for supporting and covering the blade cell electrode assembly. It can be understood that by setting the thickened region 101 according to the above parameters, the thickened region 101 can stably support electrode assemblies of different sizes, avoiding uneven distribution of support force due to insufficient length, or material waste and spatial conflicts with other internal structures of the cell due to excessive length.

[0052] It is understandable that when the battery cell is a prismatic cell, the value of L0 can be, but is not limited to, 130mm, 150mm, 170mm, 180mm, 200mm, 220mm, 234mm, 255mm, 267mm, 288mm, 292mm, 294mm, or any value between two of these ranges. When the battery cell is a prismatic cell, the value of L0 can be, but is not limited to, 380mm, 400mm, 420mm, 465mm, 480mm, 500mm, 512mm, 534mm, 550mm, 570mm, 580mm, or any value between two of these ranges.

[0053] According to one embodiment of this utility model, the bottom film 1 and the side film 2 are integrally formed. It can be understood that the integral forming of the bottom film 1 and the side film 2 can, on the one hand, eliminate the risk of insulation failure caused by weak points such as gaps and seams at the connection between the two, effectively improve the overall sealing performance and structural integrity of the insulating film, and provide more reliable insulation protection for the battery cell electrode assembly; on the other hand, it can reduce assembly processes and material consumption, reduce production costs and improve production efficiency.

[0054] The technical effects of this utility model will be described below with reference to some embodiments and comparative examples. The cell types used in Table 1 below are all blade cells, and the cell types used in Table 2 are all square cells.

[0055] Table 1

[0056] Table 2

[0057] Unless otherwise stated, the values ​​of the parameters mentioned in this application can be determined using test methods commonly used in the art.

[0058] As shown in Tables 1 and 2 above, the addition of the venting groove 1011 structure significantly improved the cell safety test pass rate. When the width or depth of the venting groove 1011 is too small, or when there is no venting groove 1011 structure, the venting effect will be affected, and the cell safety test pass rate will decrease. It should be noted that "EA" in the above tables is an abbreviation for "Each," meaning "each." 5EA means 5 cells.

[0059] According to an embodiment of the present invention, on the other hand, as... Figure 4 , Figure 5 as well as Figure 8 As shown, a battery cell is also provided, comprising: a battery cell housing, a battery cell electrode assembly, and the aforementioned battery cell insulating film.

[0060] Specifically, the cell housing has a cavity inside; the cell electrode assembly is disposed in the cavity; the aforementioned cell insulating film is located between the cell housing and the cell electrode assembly, and wraps around the outside of the cell electrode assembly; a pair of side films 2 are attached to the large surfaces of a pair of side walls of the cell electrode assembly, and the thickened area 101 on the bottom film 1 is attached to the bottom surface of the cell electrode assembly.

[0061] The battery cell of this embodiment includes the battery cell insulating film as described above, and has all the beneficial technical effects of the insulating film, which will not be repeated here.

[0062] It should be noted that the present invention does not impose any particular limitations on the type or shape of the battery cell; it can be a blade cell, a square cell, or any other type of battery cell. The battery cell in the present invention can also be a lithium-ion cell, a potassium-ion cell, a sodium-ion cell, a lithium-sulfur cell, etc., with lithium-ion cells being particularly preferred.

[0063] In one example, the battery cell is a square battery cell. When the battery cell insulation film is in the unfolded state, the side film 2 includes a pair of first side surfaces 201 and a pair of second side surfaces 202. The pair of first side surfaces 201 are arranged opposite each other along the Y direction of the bottom film 1, and the pair of second side surfaces 202 are arranged opposite each other along the X direction of the bottom film 1. The size of the first side surface 201 is larger than the size of the second side surface 202. The fold line 3 is located at the connection between the first side surface 201 and the bottom film 1 and the connection between the second side surface 202 and the bottom film 1. This embodiment of the utility model adopts an asymmetrical side film 2 design in which the size of the first side surface 201 is larger than the size of the second side surface 202, and the fold line 3 is located at the connection between the side film 2 and the bottom film 1, achieving a variety of technical effects. Firstly, it can well adapt to the shape of the cell electrode assembly. The large-sized first side 201 can closely fit the wide sidewall of the cell electrode assembly, and the small-sized second side 202 can closely fit the narrow sidewall of the cell electrode assembly, thereby effectively isolating the cell electrode assembly from each side of the cell housing and reducing the risk of short circuit. Secondly, it optimizes the folding process. The asymmetrical structure makes the force more uniform during folding, avoids membrane displacement or wrinkles, improves the forming accuracy of the cylindrical structure, and facilitates automated assembly.

[0064] In another example, the battery cell is a blade battery cell; when the battery cell insulation film is in the unfolded state, the side film 2 includes a pair of third side surfaces 203, which are arranged opposite to each other along the Y direction of the bottom film 1; the crease 3 is located at the connection between the third side surface 203 and the bottom film 1.

[0065] According to an embodiment of the present invention, another aspect provides a battery pack comprising a plurality of the aforementioned battery cells.

[0066] The battery pack of this utility model embodiment includes the battery cell described above, and has all the beneficial technical effects of the battery cell, which will not be repeated here.

[0067] 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: The base film has a thickened area formed by an outward bulge on one side of its surface. Along the X direction, the distance a between the edge of the thickened area and the corresponding edge of the base film is 3mm to 10mm; along the Y direction, the distance b between the edge of the thickened area and the corresponding edge of the base film is 1mm to 2mm. Side films are located on opposite sides or around the base film. A fold line is provided at the connection between the base film and the side film. The side film is adapted to be bent relative to the side of the base film where the thickened area is located through the fold line.

2. The cell insulating film according to claim 1, characterized in that, The thickened area is provided with exhaust channels extending along the X direction, and there are multiple exhaust channels arranged side by side along the Y direction.

3. The cell insulating film according to claim 2, characterized in that, Along the Y direction, the width of the thickened area is W0, and the width of the exhaust channel is Wi. The relationship between Wi and W0 satisfies: 0.4≤nWi / W0≤0.65, where n is the number of exhaust channels.

4. The cell insulating film according to claim 3, characterized in that, The value range of W0 is 10mm≤W0≤45mm; and / or, the value range of Wi is 1.5mm≤Wi≤6mm.

5. The cell insulating film according to claim 2, characterized in that, Along the Z direction, the thickness of the bottom film at the thickened area is T0, and the depth of the exhaust channel is T1. The relationship between T1 and T0 satisfies: 0.5≤T1 / T0≤0.

75.

6. The cell insulating film according to claim 5, characterized in that, The value range of T0 is 0.5mm≤T0≤2mm; and / or, the value range of T1 is 0.3mm≤T1≤1.5mm.

7. The cell insulating film according to any one of claims 1 to 6, characterized in that, Along the X direction, the length of the thickened area is L0, and the value of L0 ranges from 130mm to 294mm or from 380mm to 580mm.

8. The cell insulating film according to any one of claims 1 to 6, characterized in that, The bottom membrane and the side membrane are integrally formed.

9. A battery cell, characterized in that, include: The battery cell casing has an internal cavity. The cell electrode assembly is disposed within the cavity; The cell insulating film according to any one of claims 1 to 8 is wrapped around the outside of the cell electrode assembly; a pair of side films are attached to the large surfaces of a pair of sidewalls of the cell electrode assembly, and the thickened area on the bottom film is attached to the bottom surface of the cell electrode assembly.

10. A battery pack, characterized in that, include: The battery cell as described in multiple claims 9.

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