Battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell and a battery pack. The battery cell comprises a pole group, a first electrode, a second electrode, a third electrode and a fourth electrode, the packaging film wraps the outer side of the pole group and forms a packaging edge on the periphery of the pole group, a packaging area is arranged on the packaging edge, the width of the packaging area is W1, and the W1 is larger than or equal to 0.8 mm and smaller than or equal to 50 mm; and one end of the tab is positioned in the packaging film, and the other end extends out of the packaging edge. The width W1 of the packaging area is set according to the parameters, on one hand, the situation that the width W1 of the packaging area is too small, and consequently the sealing effect of the packaging film becomes poor can be avoided; on the other hand, the situation that the width W1 of the packaging area is too large, so that material waste and excessive space occupation are caused, and the energy density of the battery cell is affected can be avoided.

Description

Technical Field

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

[0002] Soft-pack batteries are lithium-ion batteries that use soft packaging films, which have high energy density and good flexibility. In order to ensure that the pole group of the soft-pack battery is completely isolated from the external environment, a common solution is to wrap a layer of packaging film on the outside of the pole group, and then heat-press and seal the packaging film to achieve the effect of sealing the pole group. However, current soft-pack batteries may leak electrolyte during use, so how to ensure the sealing of the hot-pressing seal of the packaging film is crucial. Summary of the invention

[0003] In view of this, the present invention provides a battery cell and a battery pack to solve the problem that the sealing effect of the current packaging film heat-pressing sealing is poor, affecting the sealing of the battery cell.

[0004] In a first aspect, the present invention provides a battery cell, comprising:

[0005] A pole group, with pole ears at the ends;

[0006] A packaging film is wrapped around the outside of the electrode group and forms a packaging edge around the electrode group. A packaging area is provided on the packaging edge. The width of the packaging area is W1, and the range of W1 is 0.8mm≤W1≤50mm; one end of the electrode ear is located in the packaging film, and the other end extends out of the packaging edge.

[0007] Beneficial effect: The present invention sets the width W1 of the packaging area according to the above parameters. On the one hand, it can avoid the width W1 of the packaging area being too small, which leads to poor sealing effect of the packaging film; on the other hand, it can avoid the width W1 of the packaging area being too large, which leads to material waste and excessive space occupation, affecting the energy density of the battery cell. In addition, the width W1 of the packaging area is set between 0.8mm and 50mm. This range of selection enables the packaging film to flexibly adapt to pole groups of various sizes and shapes, meet diverse packaging requirements, and achieve efficient and reliable sealing effects.

[0008] In addition, placing one end of the pole ear inside the packaging film can prevent moisture and oxygen in the external environment from corroding the connection between the pole ear and the pole group, affecting the current flow capacity. Furthermore, placing the other end of the pole ear outside the packaging film not only makes it easier for operators to connect the pole ear to an external load, so that the pole group can output electrical energy to the external load through the pole ear, ensuring the normal operation of the external load. Similarly, it is also easier for operators to connect the pole ear to a charging device, so that the charging device can transmit electrical energy to the pole group through the pole ear for energy storage.

[0009] In an optional embodiment, the packaging edge includes an end seal and a side seal, the width of the packaging area on the end seal is W2, and the width of the packaging area on the side seal is W3; the range of W2 is 0.8mm≤W2≤50mm; the range of W3 is 1mm≤W3≤50mm, and W2 and W3 satisfy 0.1≤W2 / W3≤0.8.

[0010] Beneficial effects: Generally speaking, there are more components at the end of the pole group, so additional sealant will be used to ensure the sealing effect of the packaging edge at the end of the pole group. Taking the pole ear set at the end of the pole ear as an example, in order to ensure the current carrying capacity of the pole ear, the pole ear is usually made of metal and has no adhesiveness itself. Therefore, by bonding the insulating part to the pole ear, on the one hand, the pole ear and the end edge seal can be firmly connected together; on the other hand, the gap between the pole ear and the end edge seal can be effectively filled and sealed to ensure the sealing of the connection between the end edge seal and the pole ear, so the width W2 of the packaging area on the end edge seal can be relatively small. In addition, the relatively small size W2 can not only reduce the size of the battery cell in its length direction, making the overall structure of the battery cell more compact; at the same time, it can also ensure that when thermal runaway occurs, the heat generated inside the battery cell is released from the opening of the end edge seal, avoiding the eruption from the side edge seal causing the stacked adjacent battery cells to spread out of control.

[0011] In an optional embodiment, the packaging area on the end edge seal and the packaging area on the side edge seal are sequentially connected and surround the circumference of the pole group.

[0012] Beneficial effects: The end-sealed packaging area and the side-sealed packaging area are sequentially connected and surround the electrode group to form a continuous packaging structure. This continuous packaging structure can significantly enhance the overall sealing of the packaging film, effectively prevent electrolyte leakage and external environment from affecting the inside of the battery cell, thereby improving the safety and stability of the battery cell.

[0013] In an optional embodiment, the packaging area of ​​the end edge sealing and the packaging area of ​​the side edge sealing are both spaced apart from the side walls of the adjacent pole groups.

[0014] Beneficial effect: The end edge sealing packaging area and the side edge sealing packaging area are spaced apart from the side walls of the adjacent electrode group, which can avoid damage to the electrode group caused by the heat generated during the packaging film packaging process, thereby ensuring the structural integrity and performance of the electrode group.

[0015] In an optional implementation, the thickness of the battery cell is T, and the range of T is 1mm≤T≤500mm; T and W3 satisfy 0.5≤W3 / T≤50.

[0016] Beneficial effect: Generally speaking, as the battery cell is used for a longer time, its thickness will gradually expand and increase, and the pulling force on the packaging area will be greater. Based on the above reasons, the present invention can avoid the packaging area on the side edge sealing from being subjected to long-term force, thereby affecting the sealing effect of the packaging edge, by reasonably setting the thickness T of the battery cell and the width W3 of the packaging area on the side edge sealing.

[0017] In an optional embodiment, the pole ear includes an inner pole ear and an outer pole ear, the inner pole ear is located in the packaging film and connected to the outer pole ear; one end of the outer pole ear is welded to the inner pole ear, and the other end extends out of the end seal; along the length direction of the battery cell, a gap W4 is left between the outer pole ear and the pole group, and the range of W4 is 1mm≤W4≤100mm.

[0018] Beneficial effect: The welding point of the inner and outer tabs is located inside the packaging film, which means that the welding point of the inner and outer tabs can be protected by the packaging film, thereby greatly reducing the risk of moisture and corrosion at the welding point, and effectively improving the electrical safety of the battery cell.

[0019] Secondly, there is a gap W4 between the outer pole ear and the pole group, which means that there will be a gap between the welding point between the inner pole ear and the outer pole ear and the pole group. In this way, the stress generated during the welding process can be avoided from damaging the pole group and ensuring the structural integrity of the pole group. Furthermore, there is a gap W4 between the outer pole ear and the pole group, which can also prevent the outer pole ear from being inserted into the pole group after the battery cell is subjected to mechanical impact, causing a short circuit in the pole group and affecting the safety of the battery cell. Furthermore, setting the gap W4 between the outer pole ear and the pole group according to the above parameters can also reduce material waste and improve the space utilization of the battery cell.

[0020] In an optional embodiment, a transition fillet is formed at a corner of the outer pole ear close to one end of the pole group, and the radius of the transition fillet is R, and the range of R is R≥1 mm.

[0021] Beneficial effect: Setting the corner of the outer pole ear close to one end of the pole group into a transition fillet can reduce the probability of the outer pole ear damaging the pole group or the aluminum-plastic film and causing the battery cell to fail.

[0022] In an optional embodiment, an insulating member is provided on the outer pole ear, and the insulating member is located in the packaging area and connected to the packaging film; along the length direction of the battery cell, the insulating member and the transition fillet are spaced apart.

[0023] Beneficial effect: Since the outer pole ear is usually made of metal and has no adhesiveness, by bonding the insulating member to the outer pole ear, on the one hand, the outer pole ear can be firmly connected to the package edge; on the other hand, the gap between the pole ear and the package edge can be effectively filled and sealed to ensure the sealing of the connection between the package edge and the outer pole ear. Furthermore, the insulating member and the transition fillet are arranged at intervals, so that the insulating member and the outer pole ear have sufficient contact area, ensuring that the insulating member can be firmly bonded to the outer pole ear.

[0024] In an optional embodiment, in the length direction of the battery cell, a spacing between the insulating member and a side edge of the transition fillet extending along the length direction of the battery cell is W5, and the range of W5 is 0.2 mm ≤ W5 ≤ 50 mm.

[0025] Beneficial effect: If the spacing W5 between the insulating part and the transition fillet is too small, it may affect the encapsulation process of the tab during production, resulting in uneven encapsulation, which may peel off and expand after long-term use, leading to the risk of sealing failure. If the spacing W5 between the insulating part and the transition fillet is too large, it will waste space and materials and reduce the space utilization of the battery cell. Therefore, setting the spacing W5 between the insulating part and the transition fillet according to the above parameters can not only ensure production efficiency, but also improve the reliability of the battery cell.

[0026] In a second aspect, the present invention further provides a battery pack, comprising: a plurality of the above-mentioned battery cells.

[0027] Beneficial effect: The battery cell mentioned above improves the sealing of the battery cell by limiting the width of the packaging area on the packaging edge, thereby ensuring the safety of the battery cell. Therefore, the battery pack assembled from the above multiple battery cells will also have good sealing and safety in use. In addition, the battery pack of the present invention also has other advantages of the above battery cell, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 This is a schematic structural diagram of a battery cell according to an embodiment of the present invention;

[0030] Figure 2 is a schematic structural diagram of another battery cell according to an embodiment of the present invention;

[0031] Figure 3 for Figure 2A schematic side view of the battery cell shown.

[0032] Description of reference numerals:

[0033] 1. Pole group; 101. Pole ear; 1011. Inner pole ear; 1012. Outer pole ear; 10121. Transition fillet; 2. Packaging film; 201. Packaging edge; 2011. Packaging area; 2012. End sealing; 2013. Side sealing; 3. Insulating part. DETAILED DESCRIPTION

[0034] 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.

[0035] In view of the problem that the sealing effect of the hot-pressing sealing part of the current packaging film is poor and affects the sealing of the battery cell, the present invention provides a battery cell and a battery pack.

[0036] Combine the following Figures 1 to 3 , describing an embodiment of the present invention.

[0037] According to an embodiment of the present invention, on the one hand, Figures 1 to 3 As shown, a battery cell is provided, including: an electrode group 1 and a packaging film 2.

[0038] Specifically, a pole ear 101 is provided at the end of the pole group 1; the packaging film 2 is wrapped around the outside of the pole group 1 and forms a packaging edge 201 around the pole group 1, and a packaging area 2011 is provided on the packaging edge 201, and the width of the packaging area 2011 is W1, and the range of W1 is 0.8mm≤W1≤50mm; one end of the pole ear 101 is located in the packaging film 2, and the other end extends out of the packaging edge 201.

[0039] In this embodiment, the width W1 of the packaging area 2011 is set according to the above parameters. On the one hand, it can avoid the width W1 of the packaging area 2011 being too small, resulting in poor sealing effect of the packaging film 2; on the other hand, it can avoid the width W1 of the packaging area 2011 being too large, resulting in material waste and excessive space occupation, affecting the energy density of the battery cell. In addition, the width W1 of the packaging area 2011 is set between 0.8mm and 50mm. This range of selection enables the packaging film 2 to flexibly adapt to various sizes and shapes of pole groups 1, and meet diverse packaging requirements, achieving efficient and reliable sealing effects.

[0040] In addition, placing one end of the pole ear 101 inside the packaging film 2 can prevent moisture and oxygen in the external environment from corroding the connection between the pole ear 101 and the pole group 1, thereby affecting the current flow capacity. Furthermore, placing the other end of the pole ear 101 outside the packaging film 2 not only facilitates the operator to connect the pole ear 101 to the external load, so that the pole group 1 can output electrical energy to the external load through the pole ear 101, thereby ensuring the normal operation of the external load. Similarly, it is also convenient for the operator to connect the pole ear 101 to the charging device, so that the charging device can transmit electrical energy to the pole group 1 through the pole ear 101 for energy storage.

[0041] It is understood that in order to achieve the input and output of electric energy, it is ensured that the battery cell can be effectively connected to the external load or charging device. The battery cell generally has a pair of pole ears 101, one of which is a positive pole ear and the other is a negative pole ear. In one example, the positive pole ear and the negative pole ear are respectively arranged at opposite ends of the pole group 1. In another example, the positive pole ear and the negative pole ear are arranged at the same end of the pole group 1.

[0042] According to one embodiment of the present invention, Figure 1 and Figure 2 As shown, the packaging edge 201 includes an end sealing edge 2012 and a side sealing edge 2013, the width of the packaging area 2011 on the end sealing edge 2012 is W2, and the width of the packaging area 2011 on the side sealing edge 2013 is W3; the range of W2 is 0.8mm≤W2≤50mm; the range of W3 is 1mm≤W3≤50mm, and W2 and W3 satisfy 0.1≤W2 / W3≤0.8. Generally speaking, there will be more components at the end of the pole group 1, so additional sealant will be used to ensure the sealing effect of the packaging edge 201 at the end of the pole group 1. Take the pole ear 101 set at the end of the pole ear 101 as an example. In order to ensure the current flow capacity of the pole ear 101, the pole ear 101 is usually made of metal and has no adhesiveness itself. Therefore, by bonding the insulating member 3 on the pole tab 101, on the one hand, the pole tab 101 and the end seal 2012 can be firmly connected together; on the other hand, the gap between the pole tab 101 and the end seal 2012 can be effectively filled and sealed to ensure the sealing of the connection between the end seal 2012 and the pole tab 101, so the width W2 of the packaging area 2011 on the end seal 2012 can be relatively small. In addition, the relatively small size W2 can not only reduce the size of the battery cell in its length direction, making the overall structure of the battery cell more compact; at the same time, it can also ensure that when thermal runaway occurs, the heat generated inside the battery cell is released from the end seal 2012, avoiding the eruption from the side seal 2013 and causing the stacked adjacent battery cells to spread out of control.

[0043] It should be noted that the length direction of the battery cell is Figure 1 and Figure 2 The direction shown in is consistent with that shown in .

[0044] According to one embodiment of the present invention, Figure 2 As shown, the packaging area 2011 on the end edge seal 2012 and the packaging area 2011 on the side edge seal 2013 are sequentially connected and surround the periphery of the electrode group 1. The packaging area 2011 of the end edge seal 2012 and the packaging area 2011 of the side edge seal 2013 are sequentially connected and surround the periphery of the electrode group 1, forming a continuous packaging structure. This continuous packaging structure can significantly enhance the overall sealing of the packaging film 2, effectively prevent electrolyte leakage and the influence of the external environment on the inside of the battery cell, thereby improving the safety and stability of the battery cell.

[0045] According to one embodiment of the present invention, Figure 2 As shown, the packaging area 2011 of the end edge seal 2012 and the packaging area 2011 of the side edge seal 2013 are both spaced apart from the side wall of the adjacent electrode group 1. It can be understood that the packaging area 2011 of the end edge seal 2012 and the packaging area 2011 of the side edge seal 2013 are both spaced apart from the side wall of the adjacent electrode group 1, which can avoid the heat generated during the packaging process of the packaging film 2 from damaging the electrode group 1, thereby ensuring the structural integrity and performance of the electrode group 1.

[0046] According to one embodiment of the present invention, Figure 2 and Figure 3 As shown, the thickness of the battery cell is T, and the range of T is 1mm≤T≤500mm; T and W3 satisfy 0.5≤W3 / T≤50. Generally speaking, as the battery cell is used for a longer time, the thickness of the battery cell will gradually expand and increase, and the pulling force on the packaging area 2011 will be greater. Based on the above reasons, this embodiment can avoid the packaging area 2011 on the side sealing edge 2013 from being subjected to long-term force, thereby affecting the sealing effect of the packaging edge 201, by reasonably setting the thickness T of the battery cell and the width W3 of the packaging area 2011 on the side sealing edge 2013.

[0047] It should be noted that the thickness direction of the battery cell is Figure 3 The direction shown in is consistent with that shown in .

[0048] According to one embodiment of the present invention, Figure 1As shown, the pole ear 101 includes an inner pole ear 1011 and an outer pole ear 1012, the inner pole ear 1011 is located in the packaging film 2 and connected to the outer pole ear 1012; one end of the outer pole ear 1012 is welded to the inner pole ear 1011, and the other end extends out of the end seal 2012; along the length direction of the battery cell, a gap W4 is left between the outer pole ear 1012 and the pole group 1, and the range of W4 is 1mm≤W4≤100mm. It can be understood that the welding point of the inner pole ear 1011 and the outer pole ear 1012 is located in the packaging film 2, which means that the welding point of the inner pole ear 1011 and the outer pole ear 1012 can be protected by the packaging film 2, thereby greatly reducing the risk of moisture and corrosion at the welding point, and effectively improving the electrical safety of the battery cell.

[0049] Secondly, there is a gap W4 between the outer pole ear 1012 and the pole group 1, which means that there will be a gap between the welding point of the inner pole ear 1011 and the outer pole ear 1012 and the pole group 1. In this way, the stress generated during the welding process can be avoided from damaging the pole group 1, and the structural integrity of the pole group 1 can be ensured. Furthermore, the gap W4 between the outer pole ear 1012 and the pole group 1 can also prevent the outer pole ear 1012 from being inserted into the pole group 1 after the battery cell is subjected to mechanical impact, causing the pole group 1 to short-circuit, thereby affecting the safety of the battery cell. Furthermore, setting the gap W4 between the outer pole ear 1012 and the pole group 1 according to the above parameters can also reduce material waste and improve the space utilization rate of the battery cell.

[0050] According to one embodiment of the present invention, Figure 1 As shown, the corner of the outer pole ear 1012 close to one end of the pole group 1 forms a transition fillet 10121, and the radius of the transition fillet 10121 is R, and the range of R is R ≥ 1mm. Setting the corner of the outer pole ear 1012 close to one end of the pole group 1 as the transition fillet 10121 can reduce the probability of the outer pole ear 1012 damaging the pole group 1 or the aluminum-plastic film and causing the battery cell to fail.

[0051] According to one embodiment of the present invention, Figure 1 As shown, an insulating member 3 is provided on the outer pole tab 1012, and the insulating member 3 is located in the packaging area 2011 and connected to the packaging film 2; along the length direction of the battery cell, the insulating member 3 and the transition fillet 10121 are spaced apart. Since the outer pole tab 1012 is usually made of metal and does not have adhesiveness itself, by bonding the insulating member 3 on the outer pole tab 1012, on the one hand, the outer pole tab 1012 can be firmly connected to the packaging edge 201; on the other hand, the gap between the pole tab 101 and the packaging edge 201 can be effectively filled and sealed to ensure the sealing of the connection between the packaging edge 201 and the outer pole tab 1012. Furthermore, by spacing the insulating member 3 and the transition fillet 10121, the insulating member 3 and the outer pole tab 1012 have sufficient contact area, ensuring that the insulating member 3 can be firmly bonded to the outer pole tab 1012.

[0052] According to one embodiment of the present invention, Figure 1 As shown, in the length direction of the battery cell, the spacing between the insulating member 3 and the side of the transition fillet 10121 extending along the length direction of the battery cell is W5, and the range of W5 is 0.2mm≤W5≤50mm. It is understandable that if the spacing W5 between the insulating member 3 and the transition fillet 10121 is too small, it may affect the encapsulation process of the pole ear 101 during production on the production line, resulting in uneven encapsulation, which may peel off and expand after long-term use, leading to the risk of sealing failure. If the spacing W5 between the insulating member 3 and the transition fillet 10121 is too large, space and materials will be wasted, and the space utilization rate of the battery cell will be reduced. Therefore, setting the spacing W5 between the insulating member 3 and the transition fillet 10121 according to the above parameters can not only ensure production efficiency, but also improve the reliability of the battery cell.

[0053] According to an embodiment of the present invention, on the other hand, a battery pack is also provided, comprising: a plurality of the above-mentioned battery cells. The above-mentioned battery cells improve the sealing of the battery cells and ensure the safety of the battery cells by limiting the width of the packaging area 2011 on the packaging edge 201. Therefore, the battery pack assembled from the above-mentioned multiple battery cells will also have good sealing and safety of use. In addition, the battery pack of this embodiment also has other advantages of the above-mentioned battery cells, which will not be repeated here.

[0054] In conjunction with the following Table 1, the sealing effect of the battery cell provided by the embodiment of the present invention is verified through several groups of test examples.

[0055] Example 1

[0056] The packaging area W2 is set to 3 mm, the packaging area W3 is set to 3.75 mm, the thickness T of the battery cell is set to 3 mm, and the gap W4 is set to 3 mm;

[0057] Example 2

[0058] The packaging area W2 is set to 3 mm, the packaging area W3 is set to 5 mm, the thickness T of the battery cell is set to 10 mm, and the gap W4 is set to 5 mm;

[0059] Example 3

[0060] The packaging area W2 is set to 8 mm, the packaging area W3 is set to 16 mm, the thickness T of the battery cell is set to 8 mm, and the gap W4 is set to 1.10 mm;

[0061] Example 4

[0062] The packaging area W2 is set to 5 mm, the packaging area W3 is set to 8 mm, the thickness T of the battery cell is set to 5 mm, and the gap W4 is set to 3 mm;

[0063] Comparative Example 1

[0064] The packaging area W2 is set to 3 mm, the packaging area W3 is set to 3.66 mm, the thickness T of the battery cell is set to 5 mm, and the gap W4 is set to 3 mm;

[0065] Comparative Example 2

[0066] The packaging area W2 is set to 3 mm, the packaging area W3 is set to 5 mm, the thickness T of the battery cell is set to 10.42 mm, and the gap W4 is set to 4 mm;

[0067] Comparative Example 3

[0068] The packaging area W2 is set to 5 mm, the packaging area W3 is set to 8 mm, the thickness T of the battery cell is set to 5 mm, and the gap W4 is set to 0.9 mm.

[0069] Table 1

[0070]

[0071] From the comparison between the embodiment and the comparative example in Table 1, it can be seen that when W2 / W3 is greater than 0.8, after the battery cell circulates and produces gas and expands, the side seal 2013 will peel off, resulting in failure of the sealing of the packaging film 2; when W3 / T is less than 0.5, after the battery cell circulates and produces gas and expands, the end seal 2012 between a pair of pole ears 101 will peel off, resulting in failure of the sealing of the packaging film 2; when the gap W4 is less than 1 mm, the pole ear can easily be inserted into the pole group under the action of external force and destroy the diaphragm shape, resulting in overlapping and short-circuiting of the positive and negative pole sheets.

[0072] 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 battery cell, characterized in that: include: A pole group, with pole ears at the ends; A packaging film is wrapped around the outside of the electrode group and forms a packaging edge around the electrode group. A packaging area is provided on the packaging edge. The width of the packaging area is W1, and the range of W1 is 0.8mm≤W1≤50mm; one end of the electrode ear is located in the packaging film, and the other end extends out of the packaging edge.

2. The battery cell according to claim 1, characterized in that: The packaging edge includes an end sealing edge and a side sealing edge. The width of the packaging area on the end sealing edge is W2, and the width of the packaging area on the side sealing edge is W3. The range of W2 is 0.8mm≤W2≤50mm; the range of W3 is 1mm≤W3≤50mm, and W2 and W3 satisfy 0.1≤W2 / W3≤0.

8.

3. The battery cell according to claim 2, characterized in that: The packaging area on the end edge seal and the packaging area on the side edge seal are sequentially connected and surround the circumference of the pole group.

4. The battery cell according to claim 3, characterized in that: The packaging area of ​​the end edge sealing and the packaging area of ​​the side edge sealing are both spaced apart from the side walls of the adjacent pole groups.

5. The battery cell according to claim 2, characterized in that: The thickness of the battery cell is T, and the range of T is 1mm≤T≤500mm; T and W3 satisfy 0.5≤W3 / T≤50.

6. The battery cell according to claim 2, characterized in that: The pole ear comprises an inner pole ear and an outer pole ear, the inner pole ear is located in the packaging film and connected to the outer pole ear; one end of the outer pole ear is welded to the inner pole ear, and the other end extends out of the end seal; along the length direction of the battery cell, a gap W4 is left between the outer pole ear and the pole group, and the range of W4 is 1mm≤W4≤100mm.

7. The battery cell according to claim 6, characterized in that: A transition fillet is formed at a corner of the outer pole ear close to one end of the pole group, and the radius of the transition fillet is R, and the range of R is R≥1mm.

8. The battery cell according to claim 7, characterized in that: An insulating member is provided on the outer pole ear, and the insulating member is located in the packaging area and connected to the packaging film; along the length direction of the battery cell, the insulating member and the transition fillet are arranged at intervals.

9. The battery cell according to claim 8, characterized in that: In the length direction of the battery core, a spacing between the insulating member and a side edge of the transition fillet extending along the length direction of the battery core is W5, and the range of W5 is 0.2 mm≤W5≤50 mm.

10. A battery pack, characterized in that: include: A plurality of battery cells according to any one of claims 1 to 9.

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