Battery cell and battery

Abstract

The present disclosure provides an electric core and a battery, and relates to the technical field of batteries, wherein the electric core comprises an electric core body, a connecting piece, a protective layer, a glue layer and a blocking adhesive layer; the connecting piece is welded on the electric core body; the protective layer is arranged on the side of the connecting piece close to the electric core body; the glue layer is arranged around the connecting piece; the blocking adhesive layer is arranged on the outer surface of the glue layer; the length of the blocking adhesive layer in the length direction is less than the length of the glue layer in the length direction; and the melting point of the blocking adhesive layer is greater than the melting point of the glue layer. Compared with the thinning treatment of the battery packaging shell, the blocking adhesive layer is arranged on the outer surface of the glue layer to thin the glue layer, so that the preparation efficiency of the soft package battery can be improved.

Description

Technical Field

[0001] This disclosure relates to the technical field of batteries, specifically to a battery cell and a battery. Background Technology

[0002] Soft-pack batteries (such as soft-pack lithium-ion batteries) have advantages such as high specific energy density, long cycle life, good lightweight, flexible layout, and strong safety, and are widely used in the fields of electronics, communications, energy storage and transportation.

[0003] Because pouch batteries can expand due to gas generation during application, pressure relief areas or components are required to ensure their safety. Currently, most related technologies employ measures to thin the battery casing, using the thinned casing portion as a pressure relief area.

[0004] In application, it was found that the thinning process of the battery casing is time-consuming, which makes the manufacturing efficiency of pouch batteries relatively low. Summary of the Invention

[0005] The purpose of this disclosure is to provide a battery cell and battery to solve the technical problem of low manufacturing efficiency of pouch batteries in related technologies.

[0006] In this embodiment of the disclosure, a battery cell is provided, comprising:

[0007] The battery cell body, connectors, protective layer, adhesive layer, and anti-adhesive layer;

[0008] The connector is welded to the battery cell body, the protective layer is disposed on the side of the connector near the battery cell body, the adhesive layer is wrapped around the connector, the anti-adhesion layer is disposed on the outer surface of the adhesive layer, the length of the anti-adhesion layer in the longitudinal direction is less than the length of the adhesive layer in the longitudinal direction, and the melting point of the anti-adhesion layer is greater than the melting point of the adhesive layer.

[0009] In one embodiment, the width of the first end face of the barrier layer is greater than the width of the second end face of the barrier layer, the first end face is the end face of the barrier layer closer to the protective layer, and the second end face is the end face of the barrier layer farther away from the protective layer.

[0010] In one embodiment, the width of the adhesive barrier layer gradually decreases along the direction from the first end face to the second end face.

[0011] In one embodiment, the barrier layer is disposed on the outer surface of the adhesive layer near the protective layer.

[0012] In one embodiment, the ratio of the projected area of ​​the barrier layer on the adhesive layer to the total area of ​​the adhesive layer is between 0.1 and 0.6.

[0013] In one embodiment, the ratio of the length of the barrier layer in the longitudinal direction to the length of the adhesive layer in the longitudinal direction is between 0.2 and 0.8.

[0014] In one embodiment, the thickness of the protective layer is greater than or equal to 5 micrometers and less than or equal to 200 micrometers;

[0015] And / or,

[0016] The thickness of the barrier layer is greater than or equal to 5 micrometers and less than or equal to 200 micrometers.

[0017] In one embodiment, the projection area of ​​the protective layer on the connector and the projection area of ​​the anti-adhesive layer on the connector partially overlap.

[0018] In one embodiment, the protective layer and the barrier layer are integrally formed.

[0019] In this embodiment of the disclosure, a battery is also provided, comprising:

[0020] The battery includes an electrolyte, a battery casing, and a battery cell as described above, wherein the electrolyte wets the battery cell, the battery casing includes a first top seal and a second top seal disposed opposite to each other, and the adhesive layer and the resistance layer are located between the first top seal and the second top seal.

[0021] In this disclosure, the setting of the barrier layer on the outer surface of the adhesive layer can prevent the adhesive layer from adhering to the battery packaging shell during the encapsulation of the cell, so that the adhesive layer where the barrier layer is located exists as a pressure relief area. Compared with the method of thinning the battery packaging shell, the method of setting the barrier layer on the outer surface of the adhesive layer to thin the adhesive layer is more convenient. Therefore, the manufacturing efficiency of soft-pack batteries can be improved. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this disclosure;

[0023] Figure 2 This is a side view of a battery cell provided in an embodiment of this disclosure;

[0024] Figure 3 This is a side view of another battery cell provided in an embodiment of this disclosure;

[0025] Figure 4 This is a side view of yet another type of battery cell provided in this embodiment of the disclosure;

[0026] Figure 5a This is a schematic diagram of a battery cell according to the first embodiment provided in this disclosure;

[0027] Figure 5b This is a schematic diagram of a battery cell according to the second embodiment provided in this disclosure;

[0028] Figure 5c This is a schematic diagram of a battery cell according to a third embodiment provided in this disclosure;

[0029] Figure 5d This is a schematic diagram of a battery cell according to the fourth embodiment provided in this disclosure;

[0030] Figure 5e This is a schematic diagram of a battery cell according to the fifth embodiment provided in this disclosure;

[0031] Figure 5f This is a schematic diagram of a battery cell according to the sixth embodiment provided in this disclosure;

[0032] Figure 5g This is a schematic diagram of a battery cell according to the seventh embodiment provided in this disclosure;

[0033] Figure 5h This is a schematic diagram of a battery cell according to the eighth embodiment provided in this disclosure;

[0034] Figure 6 This is a schematic diagram of the structure of a battery provided in an embodiment of this disclosure.

[0035] Reference numerals: 101, tab portion; 102, connector; 103, protective layer; 104, adhesive layer; 105, anti-adhesion layer; 106, battery casing; 1061, top seal portion. Detailed Implementation

[0036] The technical solutions of the embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0037] Please see Figure 1 , Figure 1 This is a battery cell provided in an embodiment of the present disclosure, such as... Figure 1 As shown, the battery cell includes:

[0038] The battery cell body, connector 102, protective layer 103, adhesive layer 104, and anti-adhesion layer 105;

[0039] The connector 102 is welded to the battery cell body, the protective layer 103 is disposed on the side of the connector 102 near the battery cell body, the adhesive layer 104 is wrapped around the connector 102, the anti-adhesion layer 105 is disposed on the outer surface of the adhesive layer 104, the length of the anti-adhesion layer 105 in the longitudinal direction is less than the length of the adhesive layer 104 in the longitudinal direction, and the melting point of the anti-adhesion layer 105 is greater than the melting point of the adhesive layer 104.

[0040] For example, the connector 102 may include a welding portion, an adhesive portion, and an extension portion arranged sequentially along the length direction of the connector 102. The tab portion 101 of the cell body is welded to the welding portion. The protective layer 103 is disposed on the outer surface of at least one of the tab portion 101 of the cell body and the welding portion. In this disclosure, the cell body can be obtained by winding or stacking positive electrode sheets, negative electrode sheets, and separators. The tab portion 101 of the cell body is a portion reserved for welding the connector 102 when the cell body is wound or stacked.

[0041] The protective layer 103 is provided to prevent welding burrs (generated during welding of the electrode tab portion 101 of the cell body and the welding portion) from contacting the battery casing 106 (such as an aluminum-plastic film casing), so as to avoid the welding burrs piercing the battery casing 106, reduce the probability of electrolyte leakage, and ensure the safety of using the soft-pack battery.

[0042] For example, the protective layer 103 may be a layer structure formed by a protective adhesive applied to the welding area or a protective adhesive paper covering the welding area. The protective adhesive or protective adhesive paper may be thermoplastic polyester (PET) or polyimide (PI) material.

[0043] The aforementioned adhesive layer 104 is provided to cooperate with the battery casing 106 in sealing the battery cell body. For example, the aluminum-plastic film casing (i.e., the battery casing 106) includes a PET layer, an aluminum layer, and a polypropylene (PP) layer. When the battery cell body is placed inside the aluminum-plastic film casing, the adhesive layer 104 and the PP layers of the upper and lower aluminum-plastic film casings can be melted and bonded through high temperature and high pressure treatment, thereby completing the sealing of the internal cavity formed by the battery casing 106, that is, completing the sealing of the battery cell body.

[0044] The aforementioned barrier layer 105 is provided to prevent the adhesive layer 104 covered by the barrier layer 105 from bonding with the battery casing 106. This makes the adhesive force of the sealing area where the barrier layer 105 is located less than that of other sealing areas. Therefore, the sealing area where the barrier layer 105 is located can exist as a pressure relief area. When the internal pressure of the battery cell expands and reaches a certain level, directional pressure relief can be achieved through the aforementioned pressure relief area to ensure the safety of the soft-pack battery.

[0045] Specifically, the aforementioned length direction refers to the extension direction of the battery cell tabs, that is... Figure 1 The direction indicated by the double-headed arrow.

[0046] In some embodiments, the melting point of the barrier layer 105 is greater than or equal to 200 degrees Celsius.

[0047] In this disclosure, compared with the related technology of thinning the battery casing 106, it is more convenient to provide a barrier layer 105 on the outer surface of the adhesive layer 104 to thin the adhesive layer 104, thus improving the manufacturing efficiency of soft-pack batteries.

[0048] It should be noted that, in this disclosure, the battery cell may be a battery cell including one positive tab and one negative tab, or it may be a multi-tab battery cell including three or more tabs.

[0049] It should be noted that the adhesive layer 105 can be disposed in the top sealing portion 1061 corresponding to one tab of the battery cell, or it can be disposed in the top sealing portion 1061 corresponding to each tab of the battery cell, or it can be disposed in the top sealing portion 1061 corresponding to a portion of the tabs of the battery cell.

[0050] For example, when the battery cell includes three tabs (the three tabs correspond to three top sealing portions 1061 respectively), the adhesive layer 105 can be disposed in one of the three top sealing portions 1061, or disposed in each of the three top sealing portions 1061, or disposed in two of the three top sealing portions 1061.

[0051] Furthermore, for a certain tab with an adhesive barrier layer 105, such as Figure 2 As shown, an adhesive layer 105 can be provided on the first / second surface of the electrode tab;

[0052] Or, such as Figure 3 and Figure 4 As shown, an adhesive barrier layer 105 is provided on the first and second surfaces of the electrode tab, wherein the first and second surfaces are two opposite outer surfaces of the electrode tab;

[0053] When the first and second surfaces of the electrode are respectively provided with an adhesive layer 105 (referring to...) Figure 3 and Figure 4 When the protective layer 103 extends to the adhesive layer 104, the setting data of the barrier layer 105 disposed on the first surface may be the same as or different from the setting data of the barrier layer 105 disposed on the second surface. The setting data includes at least one of the setting area, setting length, setting width and setting position of the barrier layer 105 on the adhesive layer 104.

[0054] In one embodiment, the barrier layer 105 is disposed on the outer surface of the adhesive layer 104 near the protective layer 103.

[0055] In this embodiment, the barrier layer 105 is positioned on the outer surface of the adhesive layer 104 near the protective layer 103 to increase the probability of gas generated by the battery cell body leaking out through the area where the barrier layer 105 is located, thereby further ensuring the safety of the soft-pack battery.

[0056] In one embodiment, the width of the first end face of the adhesive barrier 105 is greater than the width of the second end face of the adhesive barrier 105.

[0057] Wherein, the first end face can be understood as the end face of the barrier layer 105 facing the cell body or the protective layer 103, and the second end face can be understood as the end face of the barrier layer 105 away from the cell body or the protective layer 103.

[0058] In this embodiment, by setting the width of the first end face of the barrier layer 105 to be greater than the width of the second end face of the barrier layer 105, the gas holding volume of the area where the first end face is located is greater than the gas holding volume of the area where the second end face is located. Under the same gas pressure conditions, the probability of gas leaking out from the area where the second end face of the barrier layer 105 when the internal gas of the soft pack battery is overpressurized can be increased, thereby improving the accuracy of directional pressure relief and further ensuring the safety of the soft pack battery.

[0059] For example, the shape of the projection of the above-mentioned barrier layer 105 onto the adhesive layer 104 can be a regular shape such as a triangle or a trapezoid, or it can be an irregular shape that satisfies the limitation that the width of the first end face is greater than the width of the second end face. This embodiment does not limit this.

[0060] In one embodiment, the width of the adhesive barrier layer 105 gradually decreases along the direction from the first end face to the second end face.

[0061] In this embodiment, the width of the barrier layer 105 gradually decreases along the direction from the first end face to the second end face. This can further increase the probability of gas leaking out from the area where the second end face of the barrier layer 105 is located when the gas inside the soft-pack battery is over-pressurized, thereby improving the accuracy of directional pressure relief and enhancing the safety of the soft-pack battery.

[0062] In one embodiment, the projection of the barrier layer 105 onto the adhesive layer 104 is a triangle.

[0063] In applications, the shapes of the barrier layer 105 and the protective layer 103 can be adapted to meet actual needs, such as... Figures 5a to 5h As shown, this embodiment does not limit the specific shapes of the barrier layer 105 and the protective layer 103.

[0064] In this embodiment, the projection of the barrier layer 105 onto the adhesive layer 104 is set as a triangle, so that the gas holding volume of the side of the barrier layer 105 away from the protective layer 103 is minimized. This further increases the probability that the gas inside the soft-pack battery will leak out from the area where the second end face of the barrier layer 105 is located when the internal gas is over-pressurized, improves the accuracy of directional pressure relief, and enhances the safety of the soft-pack battery.

[0065] In some embodiments, the protective layer 103 may be rectangular or trapezoidal in shape.

[0066] In one embodiment, the ratio of the projected area of ​​the barrier layer 105 on the adhesive layer 104 to the total area of ​​the adhesive layer 104 is between 0.1 and 0.6.

[0067] In this embodiment, by limiting the ratio of the projected area of ​​the barrier layer 105 on the adhesive layer 104 to the total area of ​​the adhesive layer 104 to be greater than or equal to 0.1, the problem of the barrier layer 105 being too small is avoided, thereby ensuring the normal application of the pressure relief function in the pressure relief area where the barrier layer 105 is located and reducing the risk of explosion of the pouch battery; while by limiting the ratio of the projected area of ​​the barrier layer 105 on the adhesive layer 104 to the total area of ​​the adhesive layer 104 to be less than or equal to 0.6, the problem of the barrier layer 105 being too large is avoided, thereby ensuring the normal application of the sealing function in the pressure relief area where the barrier layer 105 is located and reducing the risk of leakage of the pouch battery.

[0068] For example, in an application, the ratio of the projected area of ​​the barrier layer 105 on the adhesive layer 104 to the total area of ​​the adhesive layer 104 can be 0.1, 0.25, 0.6, etc.

[0069] In one embodiment, the ratio of the length of the barrier layer 105 in the longitudinal direction to the length of the adhesive layer 104 in the longitudinal direction ranges from 0.2 to 0.8.

[0070] In this embodiment, the length of the adhesive barrier layer 105 in the longitudinal direction is defined (referring to...). Figure 1 h1) and the length of the adhesive layer 104 in the length direction (referring to h1) Figure 1 The ratio of h2 to the length of the adhesive layer 104 in the specified length direction is greater than or equal to 0.2 to avoid the problem of excessively short extension length of the barrier layer 105, thereby ensuring the normal application of the pressure relief function in the pressure relief area where the barrier layer 105 is located and reducing the risk of explosion of the soft-pack battery. On the other hand, by limiting the ratio of the length of the barrier layer 105 in the specified length direction to the length of the adhesive layer 104 in the specified length direction to be less than or equal to 0.8, the problem of excessively long extension length of the barrier layer 105 can be avoided, thereby ensuring the normal application of the sealing function in the pressure relief area where the barrier layer 105 is located and reducing the risk of leakage of the soft-pack battery.

[0071] For example, in an application, the ratio of the length of the barrier layer 105 in the longitudinal direction to the length of the adhesive layer 104 in the longitudinal direction can be 0.2, 0.55, 0.8, etc.

[0072] In one embodiment, the thickness of the protective layer 103 is greater than or equal to 5 micrometers and less than or equal to 200 micrometers;

[0073] And / or,

[0074] The thickness of the barrier layer 105 is greater than or equal to 5 micrometers and less than or equal to 200 micrometers.

[0075] In this embodiment, by limiting the thickness of the protective layer 103 to be greater than or equal to 5 micrometers, the problem of the protective layer 103 being too thin can be avoided, ensuring the normal application of the protective function of the protective layer 103 and providing a stable barrier protection for welding burrs and battery casing 106; while limiting the thickness of the protective layer 103 to be less than or equal to 200 micrometers can avoid the problem of the protective layer 103 being too thick, enabling the soft-pack battery to have a high energy density.

[0076] Accordingly, limiting the thickness of the barrier layer 105 to greater than or equal to 5 micrometers can avoid the problem of the barrier layer 105 being too thin, ensure the normal application of the pressure relief function in the pressure relief area where the barrier layer 105 is located, and reduce the risk of explosion of the pouch battery; while limiting the thickness of the barrier layer 105 to less than or equal to 200 micrometers can avoid the problem of the protective layer 103 being too thick, so that the pouch battery can have a higher energy density.

[0077] In one embodiment, the projection area of ​​the protective layer 103 on the connector 102 and the projection area of ​​the anti-adhesion layer 105 on the connector 102 partially overlap.

[0078] In this embodiment, the projection area of ​​the protective layer 103 on the connector 102 and the projection area of ​​the barrier layer 105 on the connector 102 partially overlap, so that the pressure relief area where the barrier layer 105 is located can be connected to the inside of the soft pack battery. This can increase the probability of the gas inside the soft pack battery being directionally relieved through the pressure relief area when the gas inside the soft pack battery is over-pressurized, thereby improving the safety of the soft pack battery.

[0079] In one embodiment, the protective layer 103 and the anti-adhesion layer 105 are integrally formed.

[0080] In this embodiment, the protective layer 103 and the barrier layer 105 are integrally formed, which allows the barrier layer 105 to be placed at the same time as the protective layer 103. This eliminates the need for the barrier layer 105 placement step, simplifies the pouch battery manufacturing process, and further improves the manufacturing efficiency of the pouch battery.

[0081] Please see Figure 6, Figure 6 This is a battery provided in an embodiment of the present disclosure, such as... Figure 6 As shown, the battery includes an electrolyte, a battery casing 106, and a battery cell as described in the foregoing embodiment. The electrolyte wets the battery cell. The battery casing 106 includes a first top sealing edge and a second top sealing edge disposed opposite to each other. The adhesive layer 104 and the anti-adhesive layer 105 are located between the first top sealing edge and the second top sealing edge.

[0082] In this embodiment, by setting the barrier layer 105 on the outer surface of the adhesive layer 104, the adhesive layer 104 can prevent the bonding between the first top seal edge and the second top seal edge during the encapsulation of the battery cell. This allows the portion of the adhesive layer 104 containing the barrier layer 105 to exist as a pressure relief area. Compared to thinning the battery casing 106, setting the barrier layer 105 on the outer surface of the adhesive layer 104 to adaptively reduce the adhesive force of the adhesive layer 104 is more convenient, thus improving the battery manufacturing efficiency.

[0083] It should be noted that, in practical applications, a portion of the encapsulated adhesive layer 104 is located between the first top sealing edge and the second top sealing edge, while another portion overflows the area between the first top sealing edge and the second top sealing edge. The barrier layer 105 of this disclosure is disposed on the outer surface of the portion of the adhesive layer 104 between the first top sealing edge and the second top sealing edge, and the length of the barrier layer 105 in the longitudinal direction is less than the length of the portion of the adhesive layer 104 between the first top sealing edge and the second top sealing edge in the longitudinal direction.

[0084] For ease of understanding, the following example is provided:

[0085] Example 1: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0086] Apply solder joint protective adhesive to the electrode tab welding joint, wherein the solder joint protective adhesive (which can be understood as the aforementioned protective layer 103) and the electrode tab adhesive (which can be understood as the aforementioned adhesive layer 104) pre-installed on the connector do not come into contact with each other;

[0087] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0088] Example 2: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0089] Apply solder joint protective adhesive to the electrode tab welding joint, wherein the positive electrode solder joint protective adhesive overlaps with the electrode tab adhesive, and the overlapping part (which can be understood as the aforementioned barrier layer 105) accounts for 20% of the electrode tab adhesive area. The overlapping part is rectangular in shape, and the height of the overlapping part is 20% of the electrode tab height.

[0090] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0091] Example 3: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0092] Apply solder joint protective adhesive to the electrode tab welding joint, wherein the positive electrode solder joint protective adhesive overlaps with the electrode tab adhesive, the overlapping area accounts for 20% of the electrode tab adhesive area, the overlapping part is trapezoidal in shape, and the height of the overlapping part is 30% of the electrode tab height.

[0093] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0094] Example 4: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0095] Apply solder joint protective adhesive to the electrode tab welding joint, wherein the positive electrode solder joint protective adhesive overlaps with the electrode tab adhesive, the overlapping area accounts for 30% of the electrode tab adhesive area, the overlapping part is triangular in shape, and the height of the overlapping part is 40% of the electrode tab height.

[0096] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0097] Example 5: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0098] Apply solder joint protective adhesive to the electrode tab welding joint, wherein the positive electrode solder joint protective adhesive overlaps with the electrode tab adhesive, the overlapping area accounts for 40% of the electrode tab adhesive area, the overlapping part is triangular in shape, and the height of the overlapping part is 60% of the electrode tab height.

[0099] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0100] Example 6: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0101] Apply solder joint protective adhesive to the electrode tab welding joint. The solder joint protective adhesive for both the positive and negative electrodes overlaps with the electrode tab adhesive. The overlapping area accounts for 40% of the electrode tab adhesive area. The overlapping area is triangular in shape and the height of the overlapping area is 60% of the electrode tab height.

[0102] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0103] Example 7: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0104] Apply solder joint protective adhesive to the electrode tab welding joint. The solder joint protective adhesive for both the positive and negative electrodes overlaps with the electrode tab adhesive. The overlapping area accounts for 40% of the electrode tab adhesive area. The overlapping area is triangular in shape and the height of the overlapping area is 80% of the electrode tab height.

[0105] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0106] Example 8: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0107] Apply solder joint protective adhesive to the electrode tab welding joint, and apply adhesive tape to the electrode tab adhesive. The adhesive tape and solder joint protective adhesive should not be in contact with each other. The adhesive tape is made of the same material as the solder joint protective adhesive. The area of ​​the overlapping part of the adhesive tape and the electrode tab adhesive accounts for 40% of the area of ​​the electrode tab adhesive. The overlapping part is triangular in shape and the height of the overlapping part is 80% of the height of the electrode tab.

[0108] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0109] Example 9: The positive / negative electrode tabs of the battery cell are ultrasonically welded together with the positive / negative connectors to produce a semi-finished battery cell.

[0110] Apply solder joint protective adhesive to the electrode tab welding point, and apply adhesive tape to the electrode tab adhesive. The adhesive tape and the solder joint protective adhesive do not contact each other, and the adhesive tape is made of a different material than the solder joint protective adhesive. The area of ​​the overlapping part of the adhesive tape and the electrode tab adhesive accounts for 40% of the area of ​​the electrode tab adhesive. The overlapping part is triangular in shape, and the height of the overlapping part is 80% of the height of the electrode tab.

[0111] The semi-finished cells are then placed into a casing made of aluminum-plastic film that has been punched and shaped. After processes such as side sealing, top sealing, baking, liquid injection, formation, secondary sealing, and sorting, the finished soft-pack battery is obtained.

[0112] The performance of the batteries in Examples 1 to 9 was tested, and the test data obtained are shown in Table 1 below:

[0113]

[0114]

[0115] Table 1

[0116] As shown in Table 1, compared with Example 1 which did not have a barrier layer 105 (referring to the solder joint protective adhesive / paper overlapping the tab adhesive), Examples 2 to 9 which had a barrier layer 105 had lower burst pressures and the burst position was fixed at a preset pressure relief position. It can be seen that the setting of the barrier layer 105 can effectively reduce the explosion risk of the soft pack battery.

[0117] Furthermore, as the area and length of the adhesive layer 105 increase, the burst pressure of the corresponding pouch cell will gradually decrease.

[0118] The embodiments of this disclosure have been described above with reference to the accompanying drawings. However, this disclosure is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this disclosure without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this disclosure.

Claims

1. An electric cell, characterized by, The battery cell includes: The battery cell body, connectors, protective layer, adhesive layer, and anti-adhesive layer; The connector includes a welding part, an adhesive part, and an extension part arranged sequentially along the length of the connector. The tab part of the battery cell body is welded to the welding part. The protective layer is disposed on the outer surface of at least one of the tab part and the welding part of the battery cell body. The adhesive layer is wound around the connector and located at the adhesive portion. The barrier layer is disposed on the outer surface of the adhesive layer near the protective layer. The length of the barrier layer in the longitudinal direction is less than the length of the adhesive layer in the longitudinal direction. The melting point of the barrier layer is greater than the melting point of the adhesive layer. The projection area of ​​the protective layer on the connector and the projection area of ​​the anti-adhesion layer on the connector partially overlap, and the protective layer and the anti-adhesion layer are integrally formed. The ratio of the projected area of ​​the barrier layer on the adhesive layer to the total area of ​​the adhesive layer is between 0.1 and 0.6, and the ratio of the length of the barrier layer in the longitudinal direction to the length of the adhesive layer in the longitudinal direction is between 0.2 and 0.

8.

2. The electric cell of claim 1, wherein, The width of the first end face of the adhesive barrier is greater than the width of the second end face of the adhesive barrier.

3. The battery cell according to claim 2, characterized in that, Along the direction from the first end face to the second end face, the width of the adhesive layer gradually decreases.

4. The battery cell according to claim 1, characterized in that, The ratio of the projected area of ​​the barrier layer on the adhesive layer to the total area of ​​the adhesive layer is between 0.1 and 0.

6.

5. The battery cell according to claim 1, characterized in that, The ratio of the length of the barrier layer in the longitudinal direction to the length of the adhesive layer in the longitudinal direction ranges from 0.2 to 0.

8.

6. The battery cell according to claim 1, characterized in that, The thickness of the protective layer is greater than or equal to 5 micrometers and less than or equal to 200 micrometers; And / or, The thickness of the barrier layer is greater than or equal to 5 micrometers and less than or equal to 200 micrometers.

7. A battery, characterized in that, The battery includes an electrolyte, a battery casing, and a cell as described in any one of claims 1 to 6, wherein the electrolyte wets the cell, the battery casing includes a first top sealing edge and a second top sealing edge disposed opposite to each other, and the adhesive layer and the resistance layer are located between the first top sealing edge and the second top sealing edge.

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