Battery cell packaging process, battery cell and battery pack

Abstract

The invention relates to the technical field of battery cells, and discloses a battery cell packaging process, a battery cell and a battery pack. A packaging film in a non-tab area of a battery cell is packaged by adopting a packaging process of the battery cell, and the relationship among the temperature of a hot-sealing pressure head, the melting point of an inner layer of the packaging film, the heat-sealing pressure and the heat-sealing time is established through a formula # imgabs0 #, so that the temperature of a hot-pressing sealing head is higher than and close to the temperature of the melting point of the inner layer of the packaging film, and the inner layer of the packaging film can be ensured to be fully hot-melted during heat sealing; the phenomenon that the inner layer of the packaging film is overmelted due to the fact that the temperature of the heat sealing pressure head is too high can be prevented, so that corrosion caused by the fact that an aluminum layer of the inner layer of the packaging film is exposed and makes contact with electrolyte is prevented, and the packaging tension of the packaging film can be improved; meanwhile, the heat sealing effect can be prevented from being influenced by lower heat sealing temperature, the virtual sealing phenomenon is avoided, the packaging strength of the packaging film is high, the leakage of the electrolyte can be effectively prevented, and the safety performance of the battery cell can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cells, and in particular to a battery cell packaging process, a battery cell and a battery pack. Background Art

[0002] The soft-pack battery cell includes a pole ear, a pole group and a packaging film. The packaging film packages the pole group and the pole ear and is sealed by heat pressing. The packaging film is composed of a PET layer, an aluminum layer and a PP layer, etc., wherein the PP layer is located on the inner side of the packaging film. After the two layers of packaging film are butted, the PP layers are arranged relative to each other. The PP layers of the hot-pressed packaging film are melted to make the two PP layers miscible, so that the two layers of packaging film are bonded together through the PP layer. The existing packaging film has a poor packaging effect after packaging. When subjected to external force or gas is generated inside the battery cell, the packaging film is easily torn or stretched, causing the battery cell to leak liquid, affecting the safety performance of the battery cell. Summary of the invention

[0003] In view of this, the present invention provides a battery cell packaging process, a battery cell and a battery pack to solve the problem of poor packaging effect of the battery cell after packaging with a packaging film in the prior art.

[0004] In a first aspect, the present invention provides a packaging process for a battery cell, wherein the battery cell comprises an electrode group, a packaging film and an electrode ear, and the packaging process comprises:

[0005] Put the electrode group into the packaging film, fold the packaging film in half so that the packaging film wraps outside the electrode group, or butt-join two packaging films so that the packaging film wraps outside the electrode group;

[0006] The packaging film on the outside of the electrode group is heat-sealed using a heat-sealing head, the melting point of the inner layer of the packaging film is T1, the temperature of the heat-sealing head is T2, the heat-sealing pressure is P, and the heat-sealing time is t. Among them, the unit of T1 and T2 is ℃, the unit of P is MPa, and the unit of t is s.

[0007] Beneficial effect: The packaging film of the non-ear area of ​​the battery cell is packaged by the battery cell packaging process, and the formula Establish the relationship between the temperature of the heat sealing head and the melting point of the inner layer of the packaging film, the heat sealing pressure and the heat sealing time, so that the temperature of the heat sealing head is greater than and close to the melting point of the inner layer of the packaging film. During heat sealing, the temperature of the heat sealing head is transmitted to the inner layer of the packaging film, which can ensure that the inner layer of the packaging film is fully melted, and can prevent the temperature of the heat sealing head from being too high, resulting in over-melting of the inner layer of the packaging film, thereby preventing the aluminum layer of the inner layer of the packaging film from leaking out and contacting the electrolyte to cause corrosion, and can increase the packaging tension of the packaging film. When the battery cell is stressed or gas is generated inside the battery cell, it can prevent the packaging film from being torn or stretched, thereby avoiding electrolyte leakage; at the same time, the temperature of the heat sealing head meets It can also prevent the heat sealing effect from being affected by low heat sealing temperature and avoid the phenomenon of false sealing. The packaging film has high packaging strength, which can effectively prevent the leakage of electrolyte and is beneficial to improving the safety performance of the battery cell.

[0008] In an optional embodiment, 0.1 MPa≤P≤0.6 MPa.

[0009] Beneficial effects: The packaging process of the battery cell controls the heat sealing pressure between 0.1Mp and 0.6Mpa, which can ensure that the inner layer of the packaging film is fully melted and prevent the inner layer of the packaging film from over-melting. It can not only ensure the packaging strength and packaging effect after heat sealing, but also ensure that the edge resistance and edge voltage of the battery cell meet the requirements.

[0010] In an optional implementation, 1s≤t≤10s.

[0011] Beneficial effect: The heat sealing process of the present invention controls the heat sealing time t to be between 1s and 10s. This setting can ensure that there is enough time to transfer heat during the heat sealing process to ensure the heat sealing effect, and can also avoid the heat sealing time being too long and affecting the production efficiency of the production line.

[0012] In an optional embodiment, the melting point of the inner layer of the packaging film is T1, 120°C≤T1≤195°C, and the temperature of the heat sealing head is T2, 150°C≤T2≤230°C.

[0013] Beneficial effect: T1 and T2 are within their respective appropriate temperature ranges, and T2 is greater than T1, which can compensate for the loss when heat is transferred to the inner layer of the packaging film, ensuring that the heat sealing temperature can effectively heat-melt the inner layer of the packaging film.

[0014] In an optional embodiment, 140°C≤T1≤175°C, 160°C≤T2≤205°C.

[0015] In a second aspect, the present invention further provides a battery cell, which is packaged using any of the above-mentioned battery cell packaging processes, and the battery cell comprises:

[0016] Pole group;

[0017] A packaging film is coated outside the electrode group, and two layers of the packaging film outside the electrode group are packaged to form a packaging area;

[0018] A pole ear, one end of which is connected to the pole group and the other end of which extends outside the packaging film.

[0019] Beneficial effects: The battery cell can ensure that the inner layer of the packaging film is fully melted, and can prevent the temperature of the heat sealing head from being too high, which may cause the inner layer of the packaging film to be over-melted, thereby preventing the aluminum layer of the inner layer of the packaging film from leaking out and contacting the electrolyte to cause corrosion, and can increase the packaging tension of the packaging film. When the battery cell is stressed or gas is generated inside the battery cell, it can prevent the packaging film from being torn or stretched, thereby avoiding electrolyte leakage; at the same time, the temperature of the heat sealing head meets It can also prevent the heat sealing effect from being affected by low heat sealing temperature and avoid the phenomenon of false sealing. The packaging film has high packaging strength, which can effectively prevent the leakage of electrolyte and is beneficial to improving the safety performance of the battery cell.

[0020] In an optional implementation, the packaging tension of the packaging film in the packaging area is F, and F≥80N.

[0021] Beneficial effect: Such a configuration can ensure that the packaging film has sufficient packaging tension, prevent the packaging film from cracking when subjected to force, and prevent the packaging film at the tab from being stretched open when gas is generated inside the battery cell.

[0022] In an optional embodiment, the packaging area includes a top seal and a side seal, the electrode tab is arranged on the top seal, and the width of the side seal is W, 2mm≤W≤15mm.

[0023] Beneficial effect: This setting can control the edge sealing width of the side edge sealing within an appropriate range, which can save packaging film materials and heat sealing energy while ensuring the packaging tension, thereby reducing the cost of battery cell production.

[0024] In an optional embodiment, the thickness of the packaging film of the side edge seal before packaging is H1, the thickness of the packaging film of the side edge seal after packaging is h1, and the residual thickness rate of the packaging film is

[0025] Beneficial effects: This arrangement can control the thickness of the packaging film after heat sealing within an appropriate range, prevent the thickness after heat sealing from being too thin or too thick and affecting the packaging strength, effectively ensure the packaging effect of the non-ear area, and prevent leakage of the battery cell; at the same time, the thickness of the packaging film after heat sealing is appropriate, which can improve the edge resistance and edge voltage performance of the battery cell.

[0026] In a third aspect, the present invention further provides a battery pack, comprising any one of the above-mentioned battery cells. The battery pack comprises the battery cell, and has the same technical effect as the battery cell, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the present invention;

[0029] Figure 2 A side view of a battery cell according to an embodiment of the present invention;

[0030] Figure 3 for Figure 2 A is a partial enlarged schematic diagram;

[0031] Figure 4 is a schematic diagram of a battery cell according to an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of another battery cell according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Pole group; 2. Packaging film; 21. Top edge sealing; 22. Side edge sealing; 23. Sealing edge; 3. Pole ear; 4. Insulating part. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] The battery cell includes a pole lug 3, a pole group 1 and a packaging film 2. The packaging film 2 packages the pole group 1 and the pole lug 3 and seals them by heat pressing. The inventors have found that if the heat pressing temperature is too high during heat sealing, the PP layer of the packaging film will be over-melted, resulting in leakage of the aluminum layer inside the PP layer. The aluminum layer is easily corroded by the electrolyte when in contact with the electrolyte. At the same time, if the heat sealing temperature is too high, the PP layer of the packaging film is easily sealed, resulting in a sol channel between the PP layers of the two layers of the packaging film 2. The electrolyte inside the battery cell leaks out through the sol channel, which also causes a decrease in the heat sealing tension.

[0037] Combine the following Figures 1 to 5 , describing an embodiment of the present invention.

[0038] According to an embodiment of the present invention, on the one hand, a packaging process for a battery cell is provided, wherein the battery cell comprises an electrode group 1, a packaging film 2 and an electrode ear 3, and the packaging process comprises: placing the electrode group 1 into the packaging film 2, folding the packaging film 2 in half so that the packaging film 2 is wrapped outside the electrode group 1, or butting two packaging films 2 so that the packaging film 2 is wrapped outside the electrode group 1; using a heat sealing head to heat seal the packaging film 2 on the outside of the electrode group 1, the melting point of the inner layer of the packaging film 2 is T1, the temperature of the heat sealing head is T2, the heat sealing pressure is P, the heat sealing time is t, Among them, the unit of T1 and T2 is ℃, the unit of P is MPa, and the unit of t is s.

[0039] The packaging film 2 of the non-ear 3 area of ​​the battery cell is packaged by the battery cell packaging process, and the formula A relationship between the temperature of the heat-sealing head and the melting point of the inner layer of the packaging film 2, the heat-sealing pressure and the heat-sealing time is established, so that the temperature of the heat-sealing head is greater than and close to the melting point of the inner layer of the packaging film 2. During heat sealing, the temperature of the heat-sealing head is transmitted to the inner layer of the packaging film 2, which can ensure that the inner layer of the packaging film 2 is fully melted, and can prevent the temperature of the heat-sealing head from being too high, resulting in over-melting of the inner layer of the packaging film 2, thereby preventing the aluminum layer of the inner layer of the packaging film 2 from leaking out and contacting the electrolyte to cause corrosion, and can improve the packaging tension of the packaging film 2 (the packaging tension is the tensile strength of the packaging film after packaging). When the battery cell is subjected to force or gas is generated inside the battery cell, it can prevent the packaging film 2 from being torn or stretched, thereby avoiding electrolyte leakage; at the same time, the temperature of the heat-sealing head satisfies It can also prevent the heat sealing temperature from being too low and affecting the heat sealing effect, and avoid the phenomenon of virtual sealing. The packaging film 2 has a high packaging strength, which can effectively prevent the electrolyte from leaking out, which is beneficial to improving the safety performance of the battery cell.

[0040] In some embodiments, the battery cell includes a packaging film 2 , a receiving groove is punched on the packaging film 2 , the electrode group 1 is disposed in the receiving groove, and the packaging film 2 is folded along the center line of the packaging film 2 to wrap the electrode group 1 .

[0041] In other embodiments, the battery cell may further include two packaging films 2 , wherein a receiving groove is punched on at least one of the packaging films 2 , the electrode group 1 is disposed in the receiving groove, and the two packaging films 2 are butt-jointed to wrap the electrode group 1 .

[0042] Optionally, in some embodiments, the heat sealing pressure satisfies 0.1Mpa≤P≤0.6Mpa. If the heat sealing pressure is too small, the inner layer of the packaging film 2 cannot be fully melted. If the heat sealing pressure is too large, the packaging film 2 will be over-melted, resulting in too small residual thickness of the inner layer of the packaging film 2 after packaging, which can easily lead to poor edge resistance and edge voltage of the battery cell. The packaging process of this battery cell controls the heat sealing pressure between 0.1Mp and 0.6Mpa, which can ensure that the inner layer of the packaging film 2 is fully melted and prevent the inner layer of the packaging film 2 from being over-melted. It can not only ensure the packaging strength and packaging effect after heat sealing, but also ensure that the edge resistance and edge voltage of the battery cell meet the requirements.

[0043] Optionally, in some embodiments, 0.2Mpa≤P≤0.5Mpa. Such a setting can further optimize the heat sealing pressure, thereby further improving the heat sealing effect of the packaging film 2, and can improve the edge resistance and edge voltage performance of the battery cell.

[0044] In some embodiments, the heat sealing time t satisfies 1s≤t≤10s. During the heat sealing process, if the heat sealing time is too short, the heat of the heat sealing head cannot be completely transferred to the inner layer of the packaging film 2, which may easily lead to false welding and false sealing, which will affect the production efficiency and safety of the battery cell; if the heat sealing time is long, the production cycle will be extended, affecting the production efficiency of the production line. The heat sealing process of the present invention controls the heat sealing time t to 1s to 10s. This setting can ensure that there is enough time to transfer heat during the heat sealing process and ensure the heat sealing effect, while also avoiding the heat sealing time being too long and affecting the production efficiency of the production line.

[0045] Optionally, in some embodiments, 3s≤t≤8s. This setting can further optimize the heat sealing time, improve the heat sealing effect, and ensure production efficiency.

[0046] During heat sealing, the heat sealing head transfers heat to the inner layer of the packaging film 2. The inner layer of the packaging film 2 melts, mixes, and cools before the two layers of the packaging film 2 are bonded together. Heat loss occurs during the heat transfer process. In some embodiments, the melting point of the inner layer of the packaging film 2 is T1, 120°C≤T1≤195°C, and the temperature of the heat sealing head is T2, 150°C≤T2≤230°C. T1 and T2 are within their respective appropriate temperature ranges, and T2 is greater than T1. This can compensate for the loss of heat when it is transferred to the inner layer of the packaging film 2, ensuring that the heat sealing temperature can effectively melt the inner layer of the packaging film 2.

[0047] In some embodiments, 140°C≤T1≤175°C, 160°C≤T2≤205°C, which can further optimize the melting point of the inner layer of the packaging film 2 and the temperature of the heat sealing head, improve the packaging effect of the packaging film 2, and prevent electrolyte leakage.

[0048] Optionally, in some embodiments, the inner layer of the packaging film 2 includes a PP layer, and the packaging film 2 includes an aluminum-plastic film. The PP layer with the required melting point can be obtained by adjusting the reaction conditions during the polypropylene polymerization process or adding fillers or thickeners to the polypropylene.

[0049] like Figure 1 As shown, the packaging film 2 to be cut is extended beyond the side sealing edge 22 on one side of the packaging film 2, and the cross-section of the packaging film 2 is rectangular. The packaging films 2 on the other three sides except the packaging film 2 to be cut are first heat-sealed, and the electrolyte is injected into the battery cell through the packaging film 2 to be cut, and the edge of the packaging film 2 to be cut is heat-sealed to form a sealing edge 23, and the gas inside the battery cell is discharged to the area of ​​the packaging film 2 to be cut, and another sealing edge is sealed inside the sealing edge 23, and finally the side sealing edge 22 of the side where the packaging film 2 to be cut is located is heat-sealed, and then the packaging film 2 outside the side sealing edge 22 is cut off.

[0050] According to an embodiment of the present invention, on the other hand, a battery cell is also provided, which is packaged using the above-mentioned battery cell packaging process, and the battery cell includes a pole group 1, a packaging film 2 and a pole ear 3, wherein the packaging film 2 is coated on the outside of the pole group 1, and the two layers of packaging film 2 outside the pole group 1 are packaged to form a packaging area; the pole ear 3 has one end connected to the pole group 1, and the other end extends to the outside of the packaging film 2.

[0051] The battery cell packaged by the above-mentioned battery cell packaging process can ensure that the inner layer of the packaging film 2 is fully melted, and can prevent the temperature of the heat sealing head from being too high, resulting in over-melting of the inner layer of the packaging film 2, thereby preventing the aluminum layer of the inner layer of the packaging film 2 from leaking out and contacting the electrolyte to cause corrosion, and can increase the packaging tension of the packaging film 2. When the battery cell is stressed or gas is generated inside the battery cell, it can prevent the packaging film 2 from being torn or stretched, thereby avoiding electrolyte leakage; at the same time, the temperature of the heat sealing head meets It can also prevent the heat sealing temperature from being too low and affecting the heat sealing effect, and avoid the phenomenon of virtual sealing. The packaging film 2 has a high packaging strength, which can effectively prevent the electrolyte from leaking out, which is beneficial to improving the safety performance of the battery cell.

[0052] Optionally, in some embodiments, the packaging tension of the packaging film 2 in the packaging area is F, and F ≥ 80 N. This setting can ensure that the packaging film 2 has sufficient packaging tension to prevent the packaging film 2 from cracking when subjected to force, and can prevent the packaging film 2 at the tab 3 from being stretched open when gas is generated inside the battery cell.

[0053] like Figure 1As shown, the cross section of the battery cell is rectangular, the packaging area includes a top sealing edge 21 and a side sealing edge 22, the pole ear 3 is arranged on the top sealing edge 21, the pole ear 3 is provided on both sides of the battery cell, the pole ear 3 is located on the opposite sides of the battery cell, the packaging area on the side where the pole ear 3 is located is the top sealing edge 21, and the packaging area on the other two sides is the side sealing edge 22. The sealing width of the packaging area of ​​the packaging film 2 is proportional to the packaging tension. If the sealing width is too small, the packaging tension is small, and the packaging film 2 is easily stretched after being stressed, resulting in leakage of the battery cell, affecting the safety performance of the battery cell; if the sealing width is too large, it will cause waste of packaging film 2 and heat sealing energy. In order to take into account both packaging tension and cost, in some embodiments, the width of the side sealing edge 22 is W, 2mm≤W≤15mm. Such a setting can control the sealing width of the side sealing edge 22 within a suitable range, while ensuring the packaging tension, it can save the material of the packaging film 2 and save heat sealing energy, and reduce the cost of battery cell production.

[0054] In some embodiments, 4 mm ≤ W ≤ 10 mm, and such a setting can further optimize the edge sealing width of the side edge sealing 22 .

[0055] like Figure 5 As shown, in other embodiments, the battery cell has a single-side electrode tab 3, and the positive electrode tab and the negative electrode tab are located on the same side of the battery cell.

[0056] In some embodiments, the electrode ear 3 includes an internal electrode ear and an external electrode ear. The internal electrode ear is located inside the packaging film, and the two ends of the internal electrode ear are electrically connected to the electrode group 1 and the external electrode ear respectively. One end of the external electrode ear is located inside the packaging film 2 and the other end extends out of the packaging film 2. The insulating member 4 is bonded to the external electrode ear.

[0057] The inventors have found that the thickness of the heat-sealed packaging film 2 will affect the packaging effect of the packaging film 2. If the thickness of the heat-sealed packaging film 2 is too thick, it is easy to cause a virtual seal; if the thickness of the heat-sealed packaging film 2 is too thin, it will affect the packaging tension, thereby also causing an adverse effect on the packaging strength; in addition, the inventors have also found that if the thickness of the heat-sealed packaging film 2 is too thin or too thick, it will also lead to poor side resistance and side voltage of the battery cell. In order to solve these problems, Figure 3 As shown, in some embodiments, the thickness of the packaging film 2 of the side sealing edge 22 before packaging is H1, the thickness of the packaging film 2 of the side sealing edge 22 after packaging is h1, and the residual thickness rate of the packaging film 2 is This arrangement can control the thickness of the packaging film 2 after heat sealing within an appropriate range, prevent the thickness after heat sealing from being too thin or too thick and affecting the packaging strength, effectively ensure the packaging effect of the non-ear area, and prevent leakage of the battery cell; at the same time, the thickness of the packaging film 2 after heat sealing is appropriate, which can improve the edge resistance and edge voltage performance of the battery cell.

[0058] Different T1, T2, P and t values ​​were used to heat seal the cells. Nine cells were heat sealed in each group of embodiments. The heat sealing condition of the cell packaging film 2 was observed. The edge resistance and edge voltage of each cell were measured to observe the failure condition of the cell. The test results are shown in Table 1.

[0059] Table 1

[0060]

[0061] It can be seen from Examples 1 to 6 in Table 1 that when When the battery core is heat-sealed, no failure occurs; from Comparative Examples 1 and 2 in Table 1, it can be seen that when When the thickness of the packaging film is relatively large after side sealing, the internal PP is not fully melted, resulting in false sealing and virtual sealing, resulting in poor voltage and resistance of the battery cell; it can be seen from comparative example 3 that when When the side seal is applied, the internal melting of the packaging film occurs; from Comparative Examples 4 and 6, it can be seen that when When the thickness residual rate is large after packaging, the internal PP is not fully melted, forming a false seal, a virtual seal, resulting in poor voltage and resistance; from Comparative Example 5, it can be seen that when When the thickness of the battery cell is too low after side sealing, the internal melting of the packaging film may easily occur, resulting in battery cell leakage and poor side voltage and side resistance.

[0062] In some embodiments, the thickness H of the single-layer packaging film 2 satisfies 0.06 mm≤H≤1 mm.

[0063] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the above-mentioned battery cell.

[0064] The battery pack of this structure can ensure that the inner layer of the packaging film 2 is fully melted, and can prevent the temperature of the heat-sealing head from being too high, which may cause the inner layer of the packaging film 2 to be over-melted, thereby preventing the aluminum layer of the inner layer of the packaging film 2 from leaking out and contacting the electrolyte to cause corrosion, and can improve the packaging tension of the packaging film 2. When the battery cell is stressed or gas is generated inside the battery cell, it can prevent the packaging film 2 from being torn or stretched open, thereby avoiding electrolyte leakage, which is beneficial to improving the safety performance of the battery pack; at the same time, the temperature of the heat-sealing head meets It can also prevent the heat sealing temperature from being too low and affecting the heat sealing effect, and avoid the phenomenon of false sealing. The packaging film 2 has a high packaging strength, which can effectively prevent the electrolyte from leaking out, which is beneficial to improving the safety performance of the battery cell and the battery pack.

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

Claims

1. A packaging process for a battery cell, characterized in that: The battery cell includes a pole group, a packaging film and a pole ear. The packaging process includes: Put the electrode group into the packaging film, fold the packaging film in half so that the packaging film wraps outside the electrode group, or butt-join two packaging films so that the packaging film wraps outside the electrode group; The packaging film on the outside of the electrode group is heat-sealed using a heat-sealing head, the melting point of the inner layer of the packaging film is T1, the temperature of the heat-sealing head is T2, the heat-sealing pressure is P, and the heat-sealing time is t. Among them, the unit of T1 and T2 is ℃, the unit of P is MPa, and the unit of t is s.

2. The packaging process of the battery cell according to claim 1, characterized in that: 0.1Mpa≤P≤0.6Mpa.

3. The packaging process of the battery cell according to claim 1 or 2, characterized in that: 1s≤t≤10s.

4. The packaging process of the battery cell according to claim 1 or 2, characterized in that: The melting point of the inner layer of the packaging film is T1, 120°C≤T1≤195°C, and the temperature of the heat sealing head is T2, 150°C≤T2≤230°C.

5. The packaging process of the battery cell according to claim 4, characterized in that: 140℃≤T1≤175℃, 160℃≤T2≤205℃.

6. A battery cell, characterized in that: The battery cell is packaged using the packaging process of any one of claims 1 to 5, and the battery cell comprises: Pole group; A packaging film is coated outside the electrode group, and two layers of the packaging film outside the electrode group are packaged to form a packaging area; A pole ear, one end of which is connected to the pole group and the other end of which extends outside the packaging film.

7. The battery cell according to claim 6, characterized in that: The packaging tension of the packaging film in the packaging area is F, and F≥80N.

8. The battery cell according to claim 6 or 7, characterized in that: The packaging area includes a top sealing edge and a side sealing edge, the pole ear is arranged on the top sealing edge, and the width of the side sealing edge is W, 2mm≤W≤15mm.

9. The battery cell according to claim 8, characterized in that: The thickness of the packaging film of the side sealing edge before packaging is H1, the thickness of the packaging film of the side sealing edge after packaging is h1, and the residual thickness rate of the packaging film is 10. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 7 to 9.

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