Battery cell, single battery, battery pack and power utilization device

Abstract

The utility model provides a battery cell, a single battery using the battery cell, a battery pack comprising the single battery and an electric device comprising the battery pack or the single battery. The battery cell comprises a positive pole lug, an aluminum plastic film and a negative pole lug, wherein the positive pole lug sequentially comprises a first pole lug section, a second pole lug section and a third pole lug section; the aluminum plastic film wraps the outer side of the second tab section; the outer side of the negative pole lug is coated with an insulating glue layer which is used for insulating and isolating the negative pole lug and the aluminum plastic film; the second tab section is provided with a convex part, a melt adhesive layer is arranged between the second tab section and the aluminum-plastic film, the convex part at least comprises one convex structure, and the convex structure is in contact with an aluminum layer of the aluminum-plastic film, so that electrochemical reaction between the aluminum layer of the aluminum-plastic film and a negative electrode is avoided, corrosion in a battery cell is avoided, the safety of the battery is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular, to a battery cell, a single battery using the battery cell, a battery pack including the single battery, and an electrical device including the battery pack or the single battery. Background Art

[0002] Compared with cylindrical batteries and aluminum shell square batteries, batteries using aluminum plastic film have the advantages of light weight, small size, flexible size design and high safety, so they have a wide range of applications and are favored by many customers.

[0003] Aluminum-plastic film is the main component material of soft-pack batteries. Its complete sealing can provide a good and closed internal environment for lithium-ion batteries. The aluminum-plastic film mainly includes an outer nylon layer, an intermediate aluminum layer, and an inner PP layer. The nylon layer and the aluminum layer can block dust, moisture, and air. During packaging, the two pieces of aluminum-plastic film can be bonded together by hot-melting the PP layer to provide an isolated environment for lithium-ion batteries. However, the internal PP layer cannot be completely defect-free during the production process or in the subsequent packaging molding process, and microscopic cracks are easily generated. The electrolyte penetrates into these cracks and contacts the aluminum layer to form an ion path. At the same time, if an electronic circuit is generated between the aluminum layer and the negative electrode, the aluminum layer will react with the lithium ions in the electrolyte to form a lithium-aluminum alloy, causing electrochemical corrosion of the aluminum-plastic film, and eventually causing the aluminum-plastic film to rupture and the battery core to leak. Utility Model Content

[0004] In order to overcome the above technical problems, the utility model provides a battery cell capable of improving battery safety, a single battery using the battery cell, a battery pack including the single battery, and an electrical device including the battery pack or the single battery.

[0005] The first object of the utility model is to provide a battery cell, comprising a positive electrode tab, an aluminum-plastic film and a negative electrode tab, wherein the positive electrode tab comprises a first tab segment, a second tab segment and a third tab segment in sequence, the aluminum-plastic film is wrapped around the outside of the second tab segment, the outside of the negative electrode tab is wrapped with an insulating rubber layer, the insulating rubber layer is used to insulate and isolate the negative electrode tab from the aluminum-plastic film, the second tab segment is provided with a protruding portion, a melt-adhesive layer is provided between the second tab segment and the aluminum-plastic film, the protruding portion comprises at least one protruding structure, and the protruding structure is in contact with the aluminum layer of the aluminum-plastic film.

[0006] As a preferred solution of the utility model, the height of the protruding structure is A1, and the distance between the positive electrode ear and the aluminum layer of the aluminum-plastic film is A2, wherein 0≤(A1-A2) / A2≤5%, and the units of A1 and A2 are the same.

[0007] As a preferred solution of the utility model, the protrusion structure is a hollow structure.

[0008] As a preferred solution of the utility model, the protruding structure is a hemispherical structure.

[0009] As a preferred solution of the present invention, the number of the protrusion structures is 2 to 5.

[0010] As a preferred solution of the present invention, the protrusion and the second pole lug segment are an integral structure.

[0011] As a preferred solution of the present invention, a first protrusion is provided on the first surface of the second pole lug segment.

[0012] As a preferred solution of the present invention, the first protrusion portion includes a plurality of protrusion structures, and the plurality of protrusion structures are symmetrically arranged along a center line in a width direction of the positive electrode tab.

[0013] As a preferred solution of the present invention, a first protrusion is provided on the first surface of the second pole lug segment, and a second protrusion is provided on the second surface of the second pole lug segment.

[0014] As a preferred solution of the present utility model, the first protrusion portion includes a plurality of the protrusion structures, and the second protrusion portion includes a plurality of the protrusion structures, and the plurality of the protrusion structures of the first protrusion portion and the plurality of the protrusion structures of the second protrusion portion are symmetrically arranged along the center line in the width direction of the positive electrode tab.

[0015] As a preferred solution of the present utility model, the first protrusion portion includes a plurality of the protrusion structures, and the second protrusion portion includes a plurality of the protrusion structures, and the orthographic projections of the plurality of the protrusion structures of the first protrusion portion and the plurality of the protrusion structures of the second protrusion portion on the surface of the second pole lug segment are symmetrically arranged along the center line in the width direction of the positive pole lug.

[0016] As a preferred solution of the present invention, the plurality of protrusion structures are arranged in a straight line, a triangle, a quadrilateral or a pentagon.

[0017] As a preferred solution of the present invention, the orthographic projections of the plurality of protrusion structures of the first protrusion portion and the plurality of protrusion structures of the second protrusion portion on the surface of the second pole lug segment overlap.

[0018] As a preferred solution of the present invention, the orthographic projection spacing distances of the plurality of protrusion structures of the first protrusion portion and the orthographic projection spacing distances of the plurality of protrusion structures of the second protrusion portion on the surface of the second pole lug segment are equal.

[0019] The second object of the present utility model is to provide a single battery, wherein the single battery comprises the battery cell provided by the present disclosure.

[0020] The third object of the present utility model is to provide a battery pack, comprising a pack body and a single cell disposed in the pack body, wherein the single cell is the single cell provided by the present disclosure.

[0021] The fourth object of the present utility model is to provide an electrical device, wherein the electrical device is provided with the battery pack provided by the present disclosure or the single battery provided by the present disclosure.

[0022] The utility model arranges a protrusion in the second pole ear section, wherein the protrusion includes at least one protrusion structure, and the protrusion structure contacts the aluminum layer of the aluminum-plastic film, and at the same time, an insulating rubber layer is wrapped around the outer side of the negative pole ear, so that the aluminum layer of the aluminum-plastic film is in a stable state under a high potential, and electrochemical reaction between the aluminum layer of the aluminum-plastic film and the negative electrode is avoided to cause corrosion in the battery core, thereby improving the safety and service life of the battery.

[0023] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0025] Figure 1 It is a schematic structural diagram along the width direction of the second pole lug segment wrapped with an aluminum-plastic film on the outside according to the first embodiment of the present disclosure.

[0026] Figure 2 It is a schematic diagram of the structure of the positive electrode tab provided according to the first embodiment of the present disclosure.

[0027] Figure 3 It is a schematic diagram of the structure of a negative electrode tab provided according to the first embodiment of the present disclosure.

[0028] Figure 4 It is a schematic diagram of the structure of a positive electrode tab provided according to the second embodiment of the present disclosure.

[0029] Figure 5 It is a schematic diagram of the structure of a positive electrode tab provided according to a third embodiment of the present disclosure.

[0030] Figure 6 It is a schematic diagram of the structure of a positive electrode tab provided according to the fourth embodiment of the present disclosure.

[0031] Figure 7It is a schematic diagram of the structure of a positive electrode tab provided according to the fifth embodiment of the present disclosure.

[0032] Figure 8 It is a schematic diagram of the partial structure along the width direction of the second pole lug segment wrapped with an aluminum-plastic film on the outside provided according to the sixth embodiment of the present disclosure.

[0033] Fig. 9 It is a schematic structural diagram along the width direction of the second pole lug segment wrapped with an aluminum-plastic film on the outside according to the seventh embodiment of the present disclosure.

[0034] Fig.10 It is a schematic diagram of the arrangement of the protrusion structure of the first protrusion portion and the protrusion structure of the second protrusion portion provided according to the seventh embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0036] In the present invention, unless otherwise specified, directional words such as "up, down, left, right" are usually defined based on the drawing direction of the corresponding drawings, and "inside and outside" refer to the inside and outside of the corresponding component outline.

[0037] like Figures 1 to 9 As shown, the utility model provides a technical solution for a battery cell, a single cell using the battery cell, a battery pack using the single cell, and an electrical device using the battery pack or the single cell. The battery cell is arranged in a single cell, and a plurality of single cells are placed in a battery pack in series or in parallel to form a battery pack. In addition, in addition to the battery pack field, the various technical solutions provided in the utility model can also be widely used in other battery fields.

[0038] In order to clarify the technical solution of the utility model, the utility model is described through the following specific embodiments, but is not limited to these specific embodiments, and the features in each embodiment can be combined or replaced arbitrarily.

[0039] First, if Figures 1 to 9 As shown, the battery cell provided by the utility model includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0040] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0041] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0042] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0043] The second pole ear segment 101 is provided with a protrusion, which is located below the molten glue layer. The protrusion includes at least one protrusion structure 105. The more the protrusion structures 105 are, the larger the contact area between the molten glue and the positive pole ear is, and the more solid the structure is in the direction parallel to the positive pole ear body. The protrusion structure 105 is in contact with the aluminum layer of the aluminum-plastic film 100.

[0044] like Figures 1 to 3 As shown, in the first embodiment of the present disclosure, the battery cell provided by the utility model includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201, the positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence, the positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0045] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0046] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0047] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0048] A protrusion is provided on the first surface of the second pole ear segment 101. The first surface refers to one of the large surfaces of the positive pole ear. The protrusion is located below the melt layer. The protrusion includes two protrusion structures 105. The two protrusion structures 105 are symmetrically arranged along the center line of the width direction of the positive pole ear. Specifically, the two protrusion structures 105 are arranged in a straight line, and the protrusion structures 105 are in contact with the aluminum layer 103 of the aluminum-plastic film 100.

[0049] The above describes the battery cell provided by the first embodiment of the present disclosure. Figure 4 A battery cell provided in a second embodiment of the present disclosure is introduced.

[0050] like Figure 4 As shown, the second embodiment of the present disclosure provides a battery cell. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0051] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0052] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0053] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 201 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0054] Among them, in this embodiment, a protrusion is provided on the first surface of the second pole ear segment 101, the first surface refers to one of the large surfaces of the positive pole ear, the protrusion is located below the melt layer, and the protrusion includes three protrusion structures 105, and the protrusion structure 105 is in contact with the aluminum layer 103 of the aluminum-plastic film 100. The three protrusion structures 105 can be symmetrically arranged along the center line of the width direction of the positive pole ear, and specifically, the three protrusion structures 105 are arranged in a straight line.

[0055] like Figure 5 As shown, the third embodiment of the present disclosure provides a battery cell. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0056] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0057] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0058] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0059] Among them, in this embodiment, a protrusion is provided on the first surface of the second pole ear segment, the first surface refers to one of the large surfaces of the positive pole ear, the protrusion is located below the melt layer, and the protrusion includes three protrusion structures 105, and the protrusion structure 105 is in contact with the aluminum layer 103 of the aluminum-plastic film 100. The three protrusion structures 105 can be symmetrically arranged along the center line of the width direction of the positive pole ear. Specifically, the three protrusion structures 105 are arranged in an equilateral triangle, which is a stable structure. The symmetrical structure is also conducive to the balance of the positive pole ear, thereby enhancing the stability of the welding structure.

[0060] like Figure 6As shown, the fourth embodiment of the present disclosure provides a battery cell. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0061] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0062] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0063] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0064] Among them, in this embodiment, the first surface of the second pole ear segment 101 is provided with a protrusion, the first surface refers to one of the large surfaces of the positive pole ear, the protrusion is located below the melt layer, and the protrusion includes four protrusion structures 105, and the protrusion structure 105 is in contact with the aluminum layer 103 of the aluminum-plastic film 100. The four protrusion structures 105 can be symmetrically arranged along the center line of the width direction of the positive pole ear. Specifically, the four protrusion structures 105 are arranged in a quadrilateral, which is a stable structure, and the symmetrical structure is also conducive to the balance of the positive pole ear, thereby enhancing the stability of the welding structure.

[0065] like Figure 7 As shown, the fifth embodiment of the present disclosure provides a battery cell. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0066] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0067] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0068] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0069] Among them, in this embodiment, the first surface of the second pole ear segment 101 is provided with a protrusion, the first surface refers to one of the large surfaces of the positive pole ear, the protrusion is located below the melt layer, and the protrusion includes five protrusion structures 105, and the protrusion structure 105 is in contact with the aluminum layer 103 of the aluminum-plastic film 100. The five protrusion structures 105 can be symmetrically arranged along the center line of the width direction of the positive pole ear. Specifically, the five protrusion structures 105 are arranged in a pentagon, which is a stable structure. The symmetrical structure is also conducive to the balance of the positive pole ear, thereby enhancing the stability of the welding structure.

[0070] like Figure 8 As shown, a battery cell is provided in the sixth embodiment of the present disclosure. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0071] The aluminum-plastic film 10 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0072] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0073] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0074] Among them, in this embodiment, the first surface of the second pole lug segment 101 is provided with a first protrusion, and the second surface of the second pole lug segment 101 is provided with a second protrusion, the first surface refers to one of the large surfaces of the positive pole lug, and the second surface refers to the other large surface of the positive pole lug, the first protrusion and the second protrusion are both located below the melt layer, and the multiple protrusion structures 105 of the first protrusion overlap with the multiple protrusion structures 115 of the second protrusion on the surface of the second pole lug segment 101. The positive projection, so that there is an evenly divided constraint force between the point-like contacts, when the first pole lug segment 121 is pulled by a force perpendicular to the positive pole lug, the protrusions on the first surface and the second surface of the second pole lug segment 101 can play a buffering role, and the upper and lower symmetrical structure is more conducive to the stability of the positive pole lug structure, which can effectively avoid the occurrence of battery leakage when the positive pole lug is pulled, and can improve the safety of battery use.

[0075] In this embodiment, the first raised portion may include two raised structures 105, and the two raised structures 105 are symmetrically arranged along the center line of the width direction of the positive electrode ear. Specifically, the two raised structures 105 are arranged in a straight line, and the second raised portion also includes two raised structures 115. The two raised structures 105 of the first raised portion overlap with the two raised structures 115 of the second raised portion on the surface of the second ear segment 101. The first raised portion may include three raised structures 105, and the three raised structures 105 The three protrusions 105 are arranged symmetrically along the center line of the width direction of the positive electrode ear. Specifically, the three protrusions 105 are arranged in a straight line. The second protrusion also includes three protrusions 115. The three protrusions 105 of the first protrusion overlap with the three protrusions 115 of the second protrusion on the surface of the second ear segment 101. The first protrusion may include three protrusions 105, and the three protrusions 105 are arranged symmetrically along the center line of the width direction of the positive electrode ear. Specifically, the three protrusions 105 are arranged in an equilateral triangle. The first protrusion may include four protrusion structures 105, and the four protrusion structures 105 are symmetrically arranged along the center line of the width direction of the positive electrode ear. Specifically, the four protrusion structures 105 are arranged in a quadrilateral, and the second protrusion also includes four protrusion structures 115. The four protrusion structures 105 of the first protrusion overlap with the three protrusion structures 115 of the second protrusion on the surface of the second lug segment 101. 05 overlaps with the orthographic projection of the four protrusion structures 115 of the second protrusion portion on the surface of the second pole lug segment 101; the first protrusion portion may include five protrusion structures 105, and the five protrusion structures 105 are symmetrically arranged along the center line of the width direction of the positive pole lug. Specifically, the five protrusion structures 105 are arranged in a pentagon, and the second protrusion portion also includes five protrusion structures 115. The five protrusion structures 105 of the first protrusion portion overlap with the orthographic projection of the five protrusion structures 115 of the second protrusion portion on the surface of the second pole lug segment 101.

[0076] like Fig. 9 , Fig.10 As shown, the seventh embodiment of the present disclosure provides a battery cell. In this embodiment, similar to the first embodiment, the battery cell includes a positive electrode tab, an aluminum-plastic film 100 and a negative electrode tab 201. The positive electrode tab includes a first tab segment 121, a second tab segment 101 and a third tab segment 131 in sequence. The positive electrode tab is rectangular, and the positive electrode tab material includes but is not limited to aluminum.

[0077] The aluminum-plastic film 100 is wrapped around the outside of the second pole lug segment 101. The aluminum-plastic film 100 includes a nylon layer 104 on the outer surface, an aluminum layer 103 in the middle layer, and an insulating rubber layer 102 on the inner surface. The insulating rubber layer 102 is a combination of one or more of single-layer polypropylene, single-layer polyethylene, multi-layer polypropylene, and multi-layer polyethylene.

[0078] The outer side of the negative electrode tab 201 is wrapped with an insulating rubber layer 202 , which is used to insulate and isolate the negative electrode tab 201 from the aluminum-plastic film 100 . The insulating rubber layer 202 is arranged along the width direction of the negative electrode tab 201 , and the length of the insulating rubber layer 202 is greater than or equal to the width of the negative electrode tab 201 .

[0079] The second pole ear segment 101 is provided with pole ear glue, the basic material of the pole ear glue is polypropylene or polyethylene, the length of the pole ear glue is greater than the length of the positive pole ear body, and the width of the pole ear glue is equal to the seal width. During welding and sealing, the pole ear glue of the second pole ear segment 101 is bonded to the insulating glue layer 102 of the aluminum-plastic film 100 to form a molten glue layer, and the molten glue layer is located between the second pole ear segment 101 and the aluminum-plastic film 100.

[0080] Among them, in this embodiment, the first surface of the second pole lug segment 101 is provided with a first protrusion, and the second surface of the second pole lug segment 101 is provided with a second protrusion, the first surface refers to one of the large surfaces of the positive pole lug, and the second surface refers to the other large surface of the positive pole lug, the first protrusion and the second protrusion are both located below the melt layer, and the multiple protrusion structures 105 of the first protrusion and the multiple protrusion structures 105 of the second protrusion on the surface of the second pole lug segment 101 are at the same distance apart from each other. When the first pole lug segment 121 is pulled by a force perpendicular to the positive pole lug, the protrusions on the first surface and the second surface of the second pole lug segment 101 can play a buffering role. This arrangement can also avoid battery leakage when the positive pole lug is pulled to a certain extent, thereby improving the safety of battery use.

[0081] In this embodiment, the first raised portion may include two raised structures 105, specifically, the two raised structures 105 are arranged in a straight line, and the second raised portion also includes two raised structures 115, and the two raised structures 105 of the first raised portion and the two raised structures 115 of the second raised portion are at an equal distance from each other on the surface of the second pole ear segment 101, and the two raised structures 105 of the first raised portion and the two raised structures 115 of the second raised portion are aligned along the center line of the width direction of the positive pole ear. The first raised portion may include three raised structures 105, specifically, the three raised structures 105 are arranged in a straight line, the second raised portion also includes three raised structures 115, the three raised structures 105 of the first raised portion and the three raised structures 115 of the second raised portion are equidistant from the orthographic projections on the surface of the second pole lug segment 101, and the orthographic projections of the three raised structures 105 of the first raised portion and the three raised structures 115 of the second raised portion on the surface of the second pole lug segment 101 are symmetrically arranged along the center line of the width direction of the positive pole lug; Fig.10As shown, the dotted line indicates that the orthographic projections of the convex structure 105 of the first convex portion and the convex structure 115 of the second convex portion on the surface of the second pole lug segment 101 are along the central symmetry line of the width direction of the positive pole lug. The first convex portion may include three convex structures 105, specifically, the three convex structures 105 are arranged in an equilateral triangle, and the second convex portion also includes three convex structures 115. The orthographic projections of the three convex structures 105 of the first convex portion and the three convex structures 115 of the second convex portion on the surface of the second pole lug segment 101 are equidistantly spaced, and the orthographic projections of the three convex structures 105 of the first convex portion and the three convex structures 115 of the second convex portion on the surface of the second pole lug segment 101 are symmetrically arranged along the central line of the width direction of the positive pole lug; the first convex portion may include four convex structures 105, and the four convex structures 105 are arranged in a quadrilateral, and the second convex portion also includes four convex structures 11 5. The orthographic projection spacing distances of the four protruding structures 105 of the first protruding portion and the four protruding structures 115 of the second protruding portion on the surface of the second pole lug segment 101 are equal, and the orthographic projections of the four protruding structures 105 of the first protruding portion and the four protruding structures 115 of the second protruding portion on the surface of the second pole lug segment 101 are symmetrically arranged along the center line of the width direction of the positive pole lug; the first protruding portion may include five protruding structures 105, specifically, the five protruding structures 105 are arranged in a pentagon, and the second protruding portion also includes five protruding structures 115, and the orthographic projection spacing distances of the five protruding structures 105 of the first protruding portion and the five protruding structures 115 of the second protruding portion on the surface of the second pole lug segment 101 are equal, and the orthographic projections of the five protruding structures 105 of the first protruding portion and the five protruding structures 115 of the second protruding portion on the surface of the second pole lug segment 101 are symmetrically arranged along the center line of the width direction of the positive pole lug.

[0082] like Figures 1 to 10As shown, in various embodiments of the present disclosure, the height of the protruding structure 105 is A1, A1 refers to the vertical distance from the protruding structure 105 to the farthest surface of the positive pole ear, and the thickness of the encapsulation melt is A2, A2 refers to the vertical distance between the positive pole ear and the aluminum layer 103 of the aluminum-plastic film, and the units of A1 and A2 are the same. When the seal is completed, the protruding structure 105 of the second pole ear section 101 contacts the aluminum layer 103 of the aluminum-plastic film. When the contact area is insufficient, the resistance of the aluminum layer 103 increases and the resistivity is small. By changing the contact degree between the protruding structure 105 and the aluminum layer 103, the orientation can change the contact resistance. If A1 is less than A2, the protruding structure 105 fails to form a point contact with the aluminum layer 103 of the aluminum-plastic film, so that the conduction with the aluminum layer 103 of the aluminum-plastic film cannot be formed. If A1 is much larger than A2, it is easy to damage the aluminum layer 103 of the aluminum-plastic film. Therefore, the height of the protruding structure 105 should be greater than or equal to 5% of the melt width. Further preferably, the values ​​of A1 and A2 are equal to achieve point contact between the protruding structure 105 of the positive electrode tab and the aluminum layer 103 of the aluminum-plastic film. Specifically, the thickness of the positive electrode tab is 200um, the thickness of the tab glue is 200um, the thickness of the single-layer aluminum-plastic film 100 is 153um, and the thickness of the polypropylene layer is 70um. According to the melting rate standard of 32.65%, the melting rate = (single-layer aluminum-plastic film thickness * 2 + tab glue thickness - edge sealing thickness) / (aluminum-plastic film polypropylene layer thickness * 2 + tab glue thickness), then the total thickness after sealing is 595um, and the corresponding melting thickness of one side after sealing is 114.5um, then the height of the protruding structure 105 is 114.5um, which can make the positive electrode tab just point contact with the aluminum layer 103 of the aluminum-plastic film. The resistance corresponding to a single protruding structure 105 is R, then two protruding structures 105 are equivalent to two resistors in parallel, and the total resistance is R / 2, so the resistance can be flexibly changed by changing the number of protruding structures 105. The protruding point of the protruding structure 105 is an aluminum layer, which is oxidized to aluminum oxide on the outer surface, so that the resistance generated is greater than the aluminum itself. In the actual installation process, the resistivity of the point-like contact is less than 0.1GΩ·cm, and the resistance between the positive pole ear and the aluminum-plastic film aluminum layer 103 is between 25Ω and 20000Ω. The point-like contact will produce a shrinkage effect, and its value is the sum of the shrinkage resistance and the resistance value of the surface aluminum-plastic film 100. The resistance is obtained by adjusting the contact area, which is convenient for welding on the one hand, and the resistance formed by the point-like contact simplifies the way to obtain resistance using new materials on the other hand, which is beneficial to the actual production process of the material.

[0083] Preferably, the protruding structure 105 is a hollow structure. The hollow structure can ensure that the contact changes from point contact to circular contact during the welding process, so that the rigidity is poorer than that of the solid structure, which is beneficial for not damaging the aluminum layer during welding. On the other hand, the hollow structure has a large contact resistance, which is more conducive to the aluminum layer 103 of the aluminum-plastic film 100 being at a higher voltage.

[0084] Preferably, the raised structure 105 is a hemispherical structure, which facilitates point contact, forms a stable connection between the hemispherical raised structure 105 and the molten adhesive layer, and increases the stability of the positive electrode tab welding. The hemispherical raised structure 105 and the molten adhesive layer form a composite structure, which increases the contact area between the aluminum layer 103 of the aluminum-plastic film and the molten adhesive layer, and is beneficial to improving the strength of the overall structure of the positive electrode tab welding.

[0085] Preferably, the protrusion and the second pole lug segment 101 are an integrated structure, which is relatively simple, convenient for material processing, and reduces design difficulty and production cost.

[0086] In addition, each embodiment of the present disclosure further provides a single battery using the battery cell, a battery pack using the single battery, and an electrical device using the battery pack or the single battery.

[0087] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0088] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0089] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A battery cell, characterized in that: include: A positive electrode tab, wherein the positive electrode tab includes a first tab segment, a second tab segment, and a third tab segment in sequence; An aluminum-plastic film, the aluminum-plastic film being wrapped around the outer side of the second pole lug segment; A negative electrode tab, the outer side of which is wrapped with an insulating rubber layer, and the insulating rubber layer is used to insulate and isolate the negative electrode tab from the aluminum-plastic film; The second pole lug segment is provided with a protrusion, a melt layer is provided between the second pole lug segment and the aluminum-plastic film, the protrusion includes at least one protrusion structure, and the protrusion structure is in contact with the aluminum layer of the aluminum-plastic film.

2. The battery cell according to claim 1, characterized in that: The height of the protruding structure is A1, and the distance between the positive electrode tab and the aluminum layer of the aluminum-plastic film is A2, wherein 0≤(A1-A2) / A2≤5%, and the units of A1 and A2 are the same.

3. The battery cell according to claim 2, characterized in that: The protruding structure is a hollow structure.

4. The battery cell according to claim 2, characterized in that: The protruding structure is a hemispherical structure.

5. The battery cell according to claim 2, characterized in that: The number of the protruding structures is 2 to 5.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The protrusion and the second pole lug segment are an integral structure.

7. The battery cell according to claim 6, characterized in that: A first protrusion is provided on the first surface of the second pole lug segment.

8. The battery cell according to claim 7, characterized in that: The first protrusion portion includes a plurality of protrusion structures, and the plurality of protrusion structures are symmetrically arranged along a center line in a width direction of the positive electrode tab.

9. The battery cell according to claim 6, characterized in that: A first protrusion is disposed on a first surface of the second pole lug segment, and a second protrusion is disposed on a second surface of the second pole lug segment.

10. The battery cell according to claim 9, characterized in that: The first protrusion portion includes a plurality of the protrusion structures, and the second protrusion portion includes a plurality of the protrusion structures. The plurality of protrusion structures of the first protrusion portion and the plurality of protrusion structures of the second protrusion portion are symmetrically arranged along a center line in a width direction of the positive electrode tab.

11. The battery cell according to claim 9, characterized in that: The first protrusion includes a plurality of the protrusion structures, and the second protrusion includes a plurality of the protrusion structures. The orthographic projections of the plurality of the protrusion structures of the first protrusion and the plurality of the protrusion structures of the second protrusion on the surface of the second pole lug segment are symmetrically arranged along the center line of the width direction of the positive pole lug.

12. The battery cell according to any one of claims 8, 10 and 11, characterized in that: The plurality of protruding structures are arranged in a straight line, a triangle, a quadrilateral or a pentagon.

13. The battery cell according to claim 10, characterized in that: The orthographic projections of the plurality of protrusion structures of the first protrusion portion and the plurality of protrusion structures of the second protrusion portion on the surface of the second pole lug segment overlap.

14. The battery cell according to claim 11, characterized in that: The orthographic projection spacing distances of the plurality of protrusion structures of the first protrusion portion and the plurality of protrusion structures of the second protrusion portion on the surface of the second pole lug segment are equal.

15. A single cell battery, characterized in that: The single battery includes the battery cell according to any one of claims 1 to 14.

16. A battery pack, comprising a pack body and a single battery disposed in the pack body, characterized in that: The single cell is the single cell according to claim 15 .

17. An electrical device, characterized in that: The electrical device is provided with the battery pack according to claim 16 or the single battery according to claim 15 .

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