Battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell and a battery pack. Wherein the battery cell comprises a pole group; the packaging film wraps the outer side of the pole group and forms a packaging edge on the periphery of the pole group, and a hot melting sealing area is arranged on the packaging edge; the tab is positioned at the end part of the pole group, one end of the tab is connected with the pole group, and the other end extends out of the packaging edge; the first insulating part is arranged on the outer side of the tab, one part of the first insulating part is located in the hot melting sealing area, and the other part of the first insulating part extends out of the hot melting sealing area. The first insulating part is arranged on the outer side of the tab, so that the gap between the tab and the hot-melting sealing area can be effectively filled and sealed, and the sealing performance of the joint of the hot-melting sealing area and the tab is ensured. Furthermore, one part of the first insulating part extends out of the hot melting sealing area, so that the sealing performance of the hot melting sealing area can be further enhanced, and the probability of electrolyte leakage and external moisture invasion is reduced.

Description

Technical Field

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

[0002] A soft-pack battery is a battery encapsulated with an aluminum-plastic film as the outer shell, which mainly includes tab, electrode assembly, and aluminum-plastic film. The function of the aluminum-plastic film is to wrap the electrode assembly and tab inside, and achieve sealing through a hot-pressing process, so as to ensure that the electrochemical reaction inside the battery occurs in a closed environment. However, during the use of the battery, the connection between the tab and the aluminum-plastic film often becomes loose due to vibration, resulting in poor sealing performance of the battery. 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 connection strength at the connection between the tab and the aluminum-plastic film is insufficient, resulting in poor sealing performance of the soft-pack battery.

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

[0005] An electrode assembly;

[0006] A packaging film, wrapped around the outside of the electrode assembly and forming a packaging edge around the electrode assembly, and a hot-melt sealing area is provided on the packaging edge;

[0007] A tab, located at the end of the electrode assembly, one end of the tab is connected to the electrode assembly, and the other end extends out of the packaging edge;

[0008] A first insulating member, disposed outside the tab, a part of the first insulating member is located in the hot-melt sealing area, and the other part extends out of the hot-melt sealing area.

[0009] Beneficial effects: Since the tab is usually made of metal and does not have self-adhesiveness, by providing a first insulating member on the tab, on the one hand, the tab can be firmly connected to the packaging edge; on the other hand, the gap between the tab and the hot-melt sealing area can be effectively filled and sealed, ensuring the sealing performance at the connection between the hot-melt sealing area and the tab. Further, making a part of the first insulating member extend out of the hot-melt sealing area can further enhance the sealing performance of the hot-melt sealing area, reducing the probability of electrolyte leakage and intrusion of external moisture into the battery cell. In this way, it helps to improve the use reliability of the battery cell and the product yield.

[0010] In an optional embodiment, both sides of the first insulating member extend out of the hot-melt sealing area along the length direction of the battery cell.

[0011] Beneficial effects: The two sides of the first insulating member extend out the hot melt sealing area along the length direction of the battery cell, which means that the first insulating member can fully contact the tab and the hot melt sealing area. While ensuring the stable connection between the two, the first insulating member can cooperate with the hot melt sealing area to increase the sealing area, reduce the probability of electrolyte leakage and the intrusion of external moisture into the battery cell, thereby extending the service life of the battery.

[0012] In an optional embodiment, the encapsulation edge includes an end encapsulation edge located at the end of the electrode group; along the length direction of the battery cell, there is a gap W1 between the hot melt sealing area on the end encapsulation edge and the edge of the encapsulation film, and the range of W1 is 0.5mm ≤ W1 ≤ 1.5mm.

[0013] Beneficial effects: If the hot melt sealing area is too close to the edge of the encapsulation film, that is, the gap between the hot melt sealing area and the edge of the encapsulation film is too small, it may cause uneven heat sealing and affect the sealing effect of the encapsulation film. That is to say, by leaving an unsealed area of a certain size between the hot melt sealing area and the edge of the encapsulation film, the integrity and consistency of the hot melt sealing area can be ensured, and the possibility of electrolyte leakage can be reduced. On the contrary, if the hot melt sealing area is too far from the edge of the encapsulation film, it will waste materials and increase costs.

[0014] In an optional embodiment, along the length direction of the battery cell, the side of the first insulating member away from the electrode group extends out of the encapsulation edge, and the width of the first insulating member extending out of the encapsulation edge is W2, and the range of W2 is 0.5mm ≤ W2 ≤ 3mm.

[0015] Beneficial effects: By making the side of the first insulating member away from the electrode group extend out of the encapsulation edge, the unsealed area between the hot melt sealing area and the edge of the encapsulation film can be filled to form an additional protective layer. In this way, it helps to enhance the sealing performance of the battery cell edge and effectively prevent electrolyte leakage and the intrusion of external moisture into the battery cell. Further, setting the width W2 of the first insulating member extending out of the encapsulation edge according to the above parameters can not only avoid the part of the first insulating member extending out of the encapsulation edge being too small to completely cover the edge of the encapsulation film and affect the sealing performance of the encapsulation film; at the same time, it can also avoid the edge of the encapsulation film accelerating aging and wear under the influence of stress and shortening the service life of the battery cell. Secondly, it can also avoid the part of the first insulating member extending out of the encapsulation edge being too large to cause material waste while reducing the operation difficulty of subsequent battery cell encapsulation.

[0016] In an optional embodiment, along the length direction of the battery cell, the width of the hot melt sealing area on the end encapsulation edge is W3, and the range of W3 is 2mm ≤ W3 ≤ 5mm; 1 / 4 ≤ W1 / W3 ≤ 1 / 3 is satisfied between W1 and W3.

[0017] Beneficial effects: By setting the width W3 of the hot melt sealing area according to the above parameters, on the one hand, it can avoid insufficient sealing of the encapsulation edge due to too small a width of the hot melt sealing area; at the same time, it can also prevent the hot melt sealing area from accelerating aging and wear under the influence of stress, thus shortening the service life of the battery cell. Secondly, it can also reduce the operation difficulty of subsequent battery cell encapsulation while avoiding material waste caused by too large a width of the hot melt sealing area.

[0018] In an optional embodiment, the tab includes an inner tab and an outer tab. The inner tab is located inside the encapsulation film and is connected to the outer tab; one end of the outer tab is welded to the inner tab, and the other end extends out of the end encapsulation edge; the welding position of the outer tab and the inner tab is between the hot melt sealing area and the electrode assembly.

[0019] Beneficial effects: The welding position of the inner tab and the outer tab is between the hot melt sealing area and the electrode assembly, which means that the welding position of the inner tab and the outer tab can be protected by the first insulating member and the encapsulation film at the same time, thereby greatly reducing the risk of moisture absorption and corrosion at the welding position and effectively improving the electrical safety of the battery cell.

[0020] In an optional embodiment, a second insulating member is provided outside the welding position of the inner tab and the outer tab, and a part of the second insulating member covers the first insulating member.

[0021] Beneficial effects: By providing a second insulating member outside the welding position of the inner tab and the outer tab, on the one hand, the second insulating member can be used to connect the welding position to the encapsulation film; on the other hand, the welding position can be isolated from the electrode assembly to prevent the solder joint at the welding position from piercing the electrode assembly and causing a short circuit or fire problem inside the electrode assembly. In this way, the use safety of the battery cell and the product yield are effectively improved. Further, covering a part of the first insulating member on the second insulating member can further enhance the sealing performance of the battery cell and prevent electrolyte leakage.

[0022] In an optional embodiment, the distance between the second insulating member and the hot melt sealing area is W4, and the range of W4 is 1mm ≤ W4 ≤ 3mm; the relationship between W3 and W4 satisfies 1 / 4 ≤ W4 / W3 ≤ 3 / 5.

[0023] Beneficial effects: By leaving a gap between the second insulating member and the hot melt sealing area, damage to the second insulating member during the heat sealing process can be avoided. Further, by setting the distance W4 between the second insulating member and the hot melt sealing area according to the above parameters, it can also avoid the gap occupying too much space and affecting the energy density of the battery cell.

[0024] In an alternative embodiment, the encapsulation edge further includes a side encapsulation edge located on the peripheral side of the electrode group. The side encapsulation edge is bent to form a bent edge, and the free end of the bent edge abuts against the side wall corresponding to the width direction of the battery cell.

[0025] Advantages: By bending the side encapsulation edge and making the free end of the bent edge abut against the side wall of the battery cell, the present invention can effectively reduce the size of the battery cell in its width direction, making the overall structure of the battery cell more compact. Furthermore, the probability of the side encapsulation edge being damaged by surrounding objects can be effectively reduced. Secondly, since the structure of the battery cell becomes more compact, more battery cells can be placed inside a battery pack of the same original size and specifications, thereby improving the energy density of the battery pack and the space utilization rate inside the battery pack.

[0026] In a second aspect, the present invention also provides a battery pack, including:

[0027] A housing;

[0028] A plurality of the above-mentioned battery cells, which are arranged in the housing in sequence along their thickness directions.

[0029] Advantages: Since the solution of extending a part of the first insulating member out of the heat-sealing area can improve the use safety and product yield of the battery cell. Therefore, the battery pack assembled from the above-mentioned plurality of battery cells will also have high use reliability and product yield. In addition, the battery pack of the present invention also has other advantages of the above-mentioned battery cell, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic structural diagram of a battery cell according to an embodiment of the present invention;

[0032] Figure 2 It is a partial structural diagram of a battery cell according to an embodiment of the present invention.

[0033] Description of the reference numerals:

[0034] 1. Electrode group; 2. Encapsulation film; 201. Encapsulation edge; 2011. Heat-sealing area; 2012. End encapsulation edge; 2013. Side encapsulation edge; 2014. Bent edge; 3. Tab; 301. Inner tab; 302. Outer tab; 4. First insulating member; 5. Second insulating member. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] Aiming at the problem that the connection strength at the connection between the tab and the aluminum-plastic film is insufficient, resulting in poor sealing performance of the soft-pack battery, the present invention provides a battery cell and a battery pack.

[0037] The following will describe the embodiments of the present invention in conjunction with Figures 1 to 2 to describe the embodiments of the present invention.

[0038] According to an embodiment of the present invention, on the one hand, as shown in Figure 1 and Figure 2 a battery cell is provided, including: a pole group 1, a packaging film 2, a tab 3, and a first insulating member 4.

[0039] Specifically, the packaging film 2 wraps around the outside of the pole group 1 and forms a packaging edge 201 around the pole group 1. A heat-sealing area 2011 is provided on the packaging edge 201; the tab 3 is located at the end of the pole group 1. One end of the tab 3 is connected to the pole group 1, and the other end extends out of the packaging edge 201; the first insulating member 4 is disposed outside the tab 3. A part of the first insulating member 4 is located within the heat-sealing area 2011, and the other part extends out of the heat-sealing area 2011.

[0040] It can be understood that since the tab 3 is usually made of metal and does not have adhesiveness itself, by providing the first insulating member 4 on the tab 3, on the one hand, the tab 3 can be firmly connected to the packaging edge 201; on the other hand, the gap between the tab 3 and the heat-sealing area 2011 can be effectively filled and sealed, ensuring the sealing performance at the connection between the heat-sealing area 2011 and the tab 3. Further, making a part of the first insulating member 4 extend out of the heat-sealing area 2011 can further enhance the sealing performance of the heat-sealing area 2011 and reduce the probability of electrolyte leakage and external moisture intrusion into the battery cell. In this way, it helps to improve the use reliability of the battery cell and the product yield rate.

[0041] It should be noted that the encapsulation film 2 in this embodiment is an aluminum-plastic film. The aluminum-plastic film includes a nylon layer, an aluminum foil layer, and a polypropylene layer stacked in sequence. Among them, the polypropylene layer abuts against the first insulating member. In this way, when the operator heat-seals the aluminum-plastic film, the polypropylene layer will be fully arranged with the first insulating member 4 on the tab 3, so as to form a tight sealing structure, thereby reducing the probability of electrolyte leakage and external moisture intrusion into the battery cell.

[0042] It should be added that the first insulating member 4 in this embodiment can be tab glue.

[0043] According to an embodiment of the present invention, as Figure 2 shown, hot-melt sealing areas 2011 extend along the length direction of the battery cell on both sides of the first insulating member 4. The hot-melt sealing areas 2011 extending along the length direction of the battery cell on both sides of the first insulating member 4 means that the first insulating member 4 can fully contact the tab 3 and the hot-melt sealing areas 2011. While ensuring the stable connection between the two, the first insulating member 4 can cooperate with the hot-melt sealing areas 2011 to increase the sealing area, reduce the probability of electrolyte leakage and external moisture intrusion into the battery cell, thereby extending the service life of the battery.

[0044] It should be noted that the length direction and width direction of the battery cell in this embodiment are consistent with those Figure 1 and Figure 2 shown in.

[0045] According to an embodiment of the present invention, as Figure 2 shown, the encapsulation edge 201 includes an end encapsulation edge 2012 located at the end of the electrode group 1; along the length direction of the battery cell, there is a gap W1 between the hot-melt sealing area 2011 on the end encapsulation edge 2012 and the edge of the encapsulation film 2, and the range of W1 is 0.5 mm ≤ W1 ≤ 1.5 mm. It can be understood that if the hot-melt sealing area 2011 is too close to the edge of the encapsulation film 2, that is, the gap between the hot-melt sealing area 2011 and the edge of the encapsulation film 2 is too small, it may cause uneven heat sealing and affect the sealing effect of the encapsulation film 2. That is to say, by leaving an unsealed area with a certain size between the hot-melt sealing area 2011 and the edge of the encapsulation film 2, the integrity and consistency of the hot-melt sealing area 2011 can be ensured, and the possibility of electrolytic cell leakage can be reduced. On the contrary, if the hot-melt sealing area 2011 is too far from the edge of the encapsulation film 2, it will waste materials and increase costs.

[0046] According to an embodiment of the present invention, as Figure 2As shown in the figure, along the length direction of the battery cell, a packaging edge 201 extends from the side of the first insulating member 4 away from the electrode group 1, and the width of the packaging edge 201 extended by the first insulating member 4 is W2, and the range of W2 is 0.5 mm ≤ W2 ≤ 3 mm. By extending the packaging edge 201 from the side of the first insulating member 4 away from the electrode group 1, the unsealed area between the heat-sealing area 2011 and the edge of the packaging film 2 can be filled to form an additional protective layer. In this way, it helps to enhance the sealing performance of the battery cell edge and effectively prevent the leakage of the electrolyte and the intrusion of external moisture into the interior of the battery cell. Further, by setting the width W2 of the packaging edge 201 extended by the first insulating member 4 according to the above parameters, not only can it avoid the situation that the part of the packaging edge 201 extended by the first insulating member 4 is too small to completely cover the edge of the packaging film 2, affecting the sealing performance of the packaging film 2; at the same time, it can also avoid the accelerated aging and wear of the edge of the packaging film under the influence of stress, shortening the service life of the battery cell. Secondly, it can also reduce the operation difficulty of subsequent battery cell packaging while avoiding the waste of materials caused by the excessive part of the packaging edge 201 extended by the first insulating member 4.

[0047] According to an embodiment of the present invention, as Figure 2 shown in the figure, along the length direction of the battery cell, the width of the heat-sealing area 2011 on the end packaging edge 2012 is W3, and the range of W3 is 2 mm ≤ W3 ≤ 5 mm; the relationship between W1 and W3 satisfies 1 / 4 ≤ W1 / W3 ≤ 1 / 3. By setting the width W3 of the heat-sealing area 2011 according to the above parameters, on the one hand, it can avoid the situation that the width of the heat-sealing area 2011 is too small to cause insufficient sealing of the packaging edge 201; at the same time, it can also avoid the accelerated aging and wear of the heat-sealing area 2011 under the influence of stress, shortening the service life of the battery cell. Secondly, it can also reduce the operation difficulty of subsequent battery cell packaging while avoiding the waste of materials caused by the excessive width of the heat-sealing area 2011.

[0048] The following combines specific examples to illustrate under what relationship between the gap W1 between the heat-sealing area 2011 on the end packaging edge 2012 and the edge of the packaging film 2 and the width W3 of the heat-sealing area 2011, the packaging edge 201 can have a good sealing effect while not causing material waste.

[0049] Example 1

[0050] Set the gap W1 to 0.5 mm and the width W3 of the heat-sealing area 2011 to 2 mm.

[0051] Example 2

[0052] Set the gap W1 to 1 mm and the width W3 of the heat-sealing area 2011 to 3 mm.

[0053] Example 3

[0054] Set the gap W1 to 1.5 mm and the width W3 of the heat-sealing area 2011 to 5 mm.

[0055] Comparative Example 1

[0056] Set the gap W1 to 0.3 mm and the width W3 of the heat-sealing area 2011 to 1.5 mm.

[0057] Comparative Example 2

[0058] Set the gap W1 to 0.4 mm and the width W3 of the heat-sealing area 2011 to 2 mm.

[0059] Comparative Example 3

[0060] Set the gap W1 to 2 mm and the width W3 of the heat-sealing area 2011 to 5 mm.

[0061] Comparative Example 4

[0062] Set the gap W1 to 2 mm and the width W3 of the heat-sealing area 2011 to 5.5 mm.

[0063] Table 1

[0064] W1 / W3 Verification result Example 1 0.25 The cell airtightness test passed Example 2 1 / 3 The cell airtightness test passed Example 3 0.3 The cell airtightness test passed Comparative example 1 0.2 The cell airtightness test failed Comparative example 2 0.2 The cell airtightness test failed Comparative example 3 0.4 Waste materials, not recommended for use Comparative example 4 0.36 Waste materials, not recommended for use

[0065] It can be seen from the comparison between the examples and the comparative examples in Table 1 that when W1 / W3 < 0.25, the heat-sealing area 2011 will be too close to the edge of the encapsulation film 2, so it may cause uneven heat-sealing of the encapsulation edge 201 and affect the sealing performance of the battery cell. When W1 / W3 > 1 / 3, the heat-sealing area 2011 will be too far from the edge of the encapsulation film 2, so there will be more materials at the edge of the encapsulation film 2 that are not reasonably utilized. In this way, it will cause waste of materials and an increase in production costs.

[0066] It can be understood that the above examples are only used to further illustrate the present application and cannot be construed as limiting the protection scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application fall within the protection scope of the present application. The specific process parameters and the like in the above examples are only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description in this article, and do not necessarily have to be limited to the specific values in the above examples.

[0067] According to an embodiment of the present invention, as Figure 2As shown in the figure, the tab 3 includes an inner tab 301 and an outer tab 302. The inner tab 301 is located inside the encapsulation film 2 and is connected to the outer tab 302. One end of the outer tab 302 is welded to the inner tab 301, and the other end extends out of the end encapsulation edge 2012. The welding position of the outer tab 302 and the inner tab 301 is between the heat-sealing area 2011 and the electrode assembly 1. It can be understood that the welding position of the inner tab 301 and the outer tab 302 being between the heat-sealing area 2011 and the electrode assembly 1 means that the welding position of the inner tab 301 and the outer tab 302 can be protected by both the first insulating member 4 and the encapsulation film 2 at the same time, thereby significantly reducing the risk of the welding position being affected by moisture and corrosion, and effectively improving the electrical safety of the battery cell.

[0068] According to an embodiment of the present invention, as Figure 2 shown, a second insulating member 5 is provided on the outside of the welding position of the inner tab 301 and the outer tab 302, and a part of the second insulating member 5 covers the first insulating member 4. In this embodiment, by providing the second insulating member 5 on the outside of the welding position of the inner tab 301 and the outer tab 302, on the one hand, the second insulating member 5 can be used to connect the welding position to the encapsulation film 2; on the other hand, the welding position can be isolated from the electrode assembly 1 to prevent the solder joint at the welding position from piercing the electrode assembly 1 and causing a short circuit or fire problem inside the electrode assembly 1. In this way, the use safety of the battery cell and the product yield are effectively improved. Further, covering a part of the first insulating member 4 on the second insulating member 5 can further enhance the sealing performance of the battery cell and prevent electrolyte leakage.

[0069] It should be added that in this embodiment, the second insulating member 5 can be a protective glue.

[0070] According to an embodiment of the present invention, as Figure 2 shown, the distance between the second insulating member 5 and the heat-sealing area 2011 is W4, and the range of W4 is 1 mm ≤ W4 ≤ 3 mm; the relationship between W3 and W4 satisfies 1 / 4 ≤ W4 / W3 ≤ 3 / 5. In this embodiment, by leaving a gap between the second insulating member 5 and the heat-sealing area 2011, damage to the second insulating member 5 during the heat-sealing process can be avoided. Further, setting the distance W4 between the second insulating member 5 and the heat-sealing area 2011 according to the above parameters can also avoid the gap occupying too much space and affecting the energy density of the battery cell.

[0071] Next, specific examples will be combined to illustrate under what relationship between the distance W4 between the second insulating member 5 and the heat-sealing area 2011 and the width W3 of the heat-sealing area 2011, the encapsulation edge 201 can have a good sealing effect while not causing material waste.

[0072] Example 1

[0073] Set the width W3 of the heat-sealing area 2011 to 2 mm and the spacing W4 to 1 mm.

[0074] Example 2

[0075] Set the width W3 of the heat-sealing area 2011 to 4 mm and the spacing W4 to 2 mm.

[0076] Example 3

[0077] Set the width W3 of the heat-sealing area 2011 to 5 mm and the spacing W4 to 3 mm.

[0078] Comparative Example 1

[0079] Set the width W3 of the heat-sealing area 2011 to 3 mm and the spacing W4 to 0.5 mm.

[0080] Comparative Example 2

[0081] Set the width W3 of the heat-sealing area 2011 to 3 mm and the spacing W4 to 0.7 mm.

[0082] Comparative Example 3

[0083] Set the width W3 of the heat-sealing area 2011 to 6 mm and the spacing W4 to 4 mm.

[0084] Comparative Example 4

[0085] Set the width W3 of the heat-sealing area 2011 to 6 mm and the spacing W4 to 4.5 mm.

[0086] Table 2

[0087]

[0088] From the comparison between the examples and the comparative examples in Table 2, it can be seen that when W4 / W3 < 0.25, the heat-sealing area 2011 is too close to the second insulating member 5. Therefore, when performing the heat-sealing operation on the encapsulation edge 201, it is very easy to damage the second insulating member 5, which will in turn affect the protection effect of the second insulating member 5. When W4 / W3 > 3 / 5, the heat-sealing area 2011 is too far from the second insulating member 5. Therefore, the spacing W4 between the second insulating member 5 and the heat-sealing area 2011 will occupy the installation space of the electrode group 1, thus affecting the energy density of the battery cell.

[0089] According to an embodiment of the present invention, as Figure 1As shown, the encapsulation edge 201 further includes a side encapsulation edge 2013 located on the peripheral side of the electrode group 1. The side encapsulation edge 2013 is bent to form a bent edge 2014, and the free end of the bent edge 2014 abuts against the side wall corresponding to the width direction of the battery cell. In this embodiment, by bending the side encapsulation edge 2013 and making the free end of the bent edge 2014 abut against the side wall of the battery cell, the size of the battery cell in its width direction can be effectively reduced, making the overall structure of the battery cell more compact. Furthermore, the probability of the side encapsulation edge 2013 being damaged by surrounding objects can be effectively reduced. Secondly, since the structure of the battery cell becomes more compact, more battery cells can be placed inside the battery pack with the same original size and specifications, thereby improving the energy density of the battery pack and the space utilization rate inside the battery pack.

[0090] Furthermore, to avoid the bent edge 2014 formed after bending the side encapsulation edge 2013 from affecting the thickness of the battery cell, it is necessary to select an appropriate bending length and control the bending angle of the side encapsulation edge 2013 between 90 degrees and 180 degrees so that the positive projection of the bent edge 2014 facing the side wall of the electrode group 1 is located on the side wall of the electrode group 1.

[0091] According to an embodiment of the present invention, on the other hand, a battery pack is also provided, including: a housing and a plurality of the above-mentioned battery cells. Specifically, the plurality of the above-mentioned battery cells are arranged in the housing in sequence along their thickness directions.

[0092] Since the solution of extending a part of the first insulating member 4 out of the heat fusion sealing area 2011 can improve the use safety and product yield rate of the battery cell. Therefore, the battery pack assembled from the above-mentioned plurality of battery cells will also have high use reliability and product yield rate. In addition, the battery pack of this embodiment also has other advantages of the above-mentioned battery cells, which will not be elaborated here.

[0093] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: Pole group; A packaging film, wrapped around the outside of the electrode group and forming a packaging edge around the electrode group, wherein a hot-melt sealing area is provided on the packaging edge; A pole ear, located at the end of the pole group, one end of the pole ear is connected to the pole group, and the other end extends out of the packaging edge; The first insulating member is arranged on the outer side of the pole ear, a part of the first insulating member is located in the hot-melt sealing area, and another part of the first insulating member extends out of the hot-melt sealing area.

2. The battery cell according to claim 1, characterized in that: The hot-melt sealing area is extended from both sides of the first insulating member along the length direction of the battery core.

3. The battery cell according to claim 2, characterized in that: The packaging edge includes an end packaging edge located at the end of the electrode group; along the length direction of the battery cell, a gap W1 is left between the hot melt sealing area on the end packaging edge and the edge of the packaging film, and the range of W1 is 0.5mm≤W1≤1.5mm.

4. The battery cell according to claim 3, characterized in that: Along the length direction of the battery core, the first insulating member extends out of the packaging edge at a side away from the electrode group, and the width of the first insulating member extending out of the packaging edge is W2, and the range of W2 is 0.5mm≤W2≤3mm.

5. The battery cell according to claim 3, characterized in that: Along the length direction of the battery core, the width of the hot melt sealing area on the end packaging edge is W3, and the range of W3 is 2mm≤W3≤5mm; between W1 and W3, 1 / 4≤W1 / W3≤1 / 3 is satisfied.

6. The battery cell according to claim 5, characterized in that: The pole ear comprises an inner pole ear and an outer pole ear, wherein 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 packaging edge; the welding point between the outer pole ear and the inner pole ear is located between the hot melt sealing area and the pole group.

7. The battery cell according to claim 6, characterized in that: A second insulating member is disposed outside the welding point between the inner pole tab and the outer pole tab, and a portion of the second insulating member covers the first insulating member.

8. The battery cell according to claim 7, characterized in that: The distance between the second insulating member and the hot-melt sealing area is W4, and the range of W4 is 1mm≤W4≤3mm; the distance between W3 and W4 satisfies 1 / 4≤W4 / W3≤3 / 5.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The packaging edge also includes a side packaging edge located at the peripheral side of the electrode group, the side packaging edge is bent to form a bent edge, and the free end of the bent edge is in contact with the corresponding side wall of the battery core in the width direction.

10. A battery pack, characterized in that: include: case; A plurality of battery cells according to any one of claims 1 to 9 are arranged in sequence in the casing along the thickness direction thereof.

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