Secondary battery and electronic device

Abstract

The invention relates to a secondary battery and electronic equipment, the secondary battery comprises a shell, an electrode assembly and a packaging assembly, the electrode assembly is accommodated in the shell, the packaging assembly is electrically connected with the electrode assembly, the electrode assembly comprises a positive plate, a diaphragm and a negative plate which are stacked in sequence, a negative tab is arranged on the edge of the negative plate along the length direction of the electrode assembly, and the packaging assembly is electrically connected with the negative tab. The edge of the negative plate is provided with a first groove, and the edge of the diaphragm is provided with a second groove. The first groove and the second groove jointly form a first main groove, a first isolation piece is arranged on the inner wall of the shell along the groove wall of the first main groove, a first sealing cavity is defined by the first isolation piece and the shell, and at least part of the packaging assembly is contained in the first sealing cavity. According to the secondary battery and the electronic equipment, the energy density of the secondary battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a secondary battery and an electronic device. Background Art

[0002] Secondary batteries are often placed in the cabin of electronic equipment. As the power source of electronic equipment, they are the key to ensuring the normal use of electronic equipment. The structural design of secondary batteries has a great influence on energy density. Summary of the invention

[0003] The inventors of the present application have found that a secondary battery includes a shell, an electrode assembly and a packaging assembly. The electrode assembly provides power for the electronic device. The main function of the packaging assembly is to provide support, protection, thermal management and battery management for the secondary battery. The shell wraps the electrode assembly, and the packaging assembly is usually arranged outside the shell. Some components of the packaging assembly need to be waterproof, so a waterproof structure needs to be set. Since the accommodation space of the cabin of the electronic equipment is limited, the setting of the waterproof structure needs to reduce the volume of the electrode assembly, so the energy density of the secondary battery will be reduced. By providing a groove in the electrode assembly and an insulating member along the groove in the shell, a waterproof sealed cavity can be formed, and the components of the packaging assembly that need to be waterproof can be arranged in the sealed cavity in the shell, which can reduce the waterproof structure required for the waterproof components and increase the volume of the electrode assembly, thereby improving the energy density of the secondary battery.

[0004] The purpose of the present application is to provide a secondary battery and an electronic device, aiming to improve the energy density of the secondary battery.

[0005] According to the first aspect of the present application, a secondary battery is provided, comprising a shell, an electrode assembly and a packaging assembly, wherein the electrode assembly is accommodated in the shell, the packaging assembly is electrically connected to the electrode assembly, the electrode assembly comprises a positive electrode sheet, a diaphragm and a negative electrode sheet stacked in sequence, along the length direction of the electrode assembly, the edge of the negative electrode sheet is provided with a negative electrode ear, the edge of the negative electrode sheet is provided with a first groove, and the edge of the diaphragm is provided with a second groove. The first groove and the second groove together form a first main groove, the inner wall of the shell is provided with a first insulating member along the groove wall of the first main groove, the first insulating member and the shell are enclosed to form a first sealed cavity, and at least part of the packaging assembly is accommodated in the first sealed cavity.

[0006] In the above technical solution, a first groove is provided at the edge of the negative electrode sheet, a second groove is provided at the edge of the diaphragm, the first groove and the second groove together form a first main groove, a first insulating member is provided on the inner wall of the shell along the groove wall of the first main groove, the first insulating member and the shell are enclosed to form a waterproof first sealed cavity, at least part of the packaging component is accommodated in the first sealed cavity, the components of the packaging component that need to be waterproof can be arranged in the first sealed cavity, the waterproof structure required for the waterproof components can be reduced, the volume of the electrode assembly can be increased, and thus the energy density of the secondary battery is improved. In addition, the edge of the negative electrode sheet usually exceeds the positive electrode sheet in the length direction of the electrode assembly, and the first groove is provided at the edge of the negative electrode sheet, which can reduce the impact on the energy density of the electrode assembly.

[0007] In some preferred embodiments, along the thickness direction of the electrode assembly, the projection of the first groove overlaps at least partially with the second groove, which can increase the accommodation space of the first sealed cavity.

[0008] In some preferred embodiments, the negative electrode tab is spaced apart from the first sealed cavity along the width direction of the electrode assembly to reduce the possibility that the negative electrode tab affects part of the packaged components in the first sealed cavity.

[0009] In some preferred embodiments, along the length direction of the electrode assembly, the width of the first groove is W1, 1mm≤W1≤3mm. When W1<1mm, the space of the first sealed cavity is small and it is difficult to accommodate some components of the package assembly. When W1>3mm, the electrode assembly will lose more energy density.

[0010] In some preferred embodiments, along the width direction of the electrode assembly, the length of the first groove is L1, 5mm≤L1≤50mm. When L1<5mm, the space of the first sealed cavity is small and it is difficult to accommodate some components of the package assembly. When L1>50mm, the first sealed cavity will affect the space occupied by the tab, and the electrode assembly will lose more energy density.

[0011] In some preferred embodiments, a third groove is provided on the edge of the positive electrode sheet along the length direction of the electrode assembly, and the first groove, the second groove and the third groove together form a first main groove, which can increase the overlapping area between the positive electrode sheet and the negative electrode sheet in the thickness direction of the electrode assembly, improve the utilization rate of the active material of the electrode sheet, and improve the energy density.

[0012] In some preferred embodiments, along the thickness direction of the electrode assembly, the projection of the third groove overlaps at least partially with the first groove, which can increase the accommodation space of the first sealed cavity.

[0013] In some preferred embodiments, a positive electrode tab is provided at the edge of the positive electrode sheet along the length direction of the electrode assembly. The positive electrode tab is spaced apart from the first sealed cavity along the width direction of the electrode assembly, which can reduce the possibility that the positive electrode tab affects part of the packaged components in the first sealed cavity.

[0014] In some preferred embodiments, along the width direction of the electrode assembly, the positive electrode tab and the negative electrode tab are both located on the same side of the first sealed cavity, and the positive electrode tab and the negative electrode tab can be gathered together on the same side of the first sealed cavity to increase the available space of the first sealed cavity. Alternatively, along the width direction of the electrode assembly, the positive electrode tab and the negative electrode tab are respectively located on both sides of the first sealed cavity, and the positive electrode tab and the negative electrode tab can be gathered together on both sides of the first sealed cavity to increase the available space of the first sealed cavity.

[0015] In some preferred embodiments, along the width direction of the electrode assembly, the width of the electrode assembly is W2, the length of the first sealed cavity is L2, W2-L2≤24 mm, and the available space of the first sealed cavity can be increased.

[0016] In some preferred embodiments, the packaging assembly includes an electrically connected first part and a second part, the first part is accommodated in the first sealed cavity, the second part is arranged outside the shell, and the electrode assembly and the second part are arranged at intervals along the length direction of the electrode assembly. The first part can be a component of the packaging assembly that needs to be waterproof, and the second part can be a component of the packaging assembly that does not need to be waterproof. The first part is accommodated in the first sealed cavity to reduce the waterproof structure required for the packaging assembly. The electrode assembly and the second part are arranged at intervals along the length direction of the electrode assembly, and the second part can utilize the space occupied by the outer ear of the shell to reduce the additional space occupied by the packaging assembly.

[0017] In some preferred embodiments, the edge of the negative electrode sheet includes a first sub-edge and a second sub-edge, the first sub-edge is provided with a negative electrode tab, the second sub-edge is not provided with a negative electrode tab, the first sub-edge exceeds the positive electrode sheet by a length of T1, the second sub-edge exceeds the positive electrode sheet by a length of T2, T1>T2, so as to reduce the possibility of the negative electrode tab burr piercing the diaphragm and contacting the positive electrode sheet to short-circuit. And / or, the edge of the diaphragm includes a third sub-edge and a fourth sub-edge, the projection of the third sub-edge along the thickness direction of the electrode assembly overlaps at least part of the negative electrode tab, the projection of the fourth sub-edge along the thickness direction of the electrode assembly does not overlap with the negative electrode tab, the third sub-edge exceeds the negative electrode sheet by a length of T3, the fourth sub-edge exceeds the negative electrode sheet by a length of T4, T3>T4, which can enhance the effect of the diaphragm in blocking the negative electrode tab burr and reduce the possibility of the negative electrode tab burr contacting the positive electrode sheet to short-circuit.

[0018] In some preferred embodiments, a second sealed cavity is provided in the shell, and a first insulating member isolates the first sealed cavity from the second sealed cavity. The secondary battery also includes an electrolyte, and the electrolyte and the electrode assembly are accommodated in the second sealed cavity, which can reduce the possibility of the electrolyte entering the first sealed cavity and affecting the packaging assembly in the first sealed cavity.

[0019] In a second aspect, the present application further proposes an electronic device, comprising a secondary battery as in any embodiment of the first aspect above.

[0020] Additional aspects and advantages of the embodiments of the present application will be described, shown, or explained in part in the subsequent description through implementation of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the dimensions in the drawings do not constitute proportional limitations.

[0022] Figure 1 A schematic diagram of the structure of a secondary battery in some embodiments of the present application;

[0023] Figure 2 This is a schematic diagram of the structure of the electrode assembly of some embodiments of the present application;

[0024] Figure 3 Schematic diagram of the structure of the electrode assembly, the positive electrode tab and the negative electrode tab of some embodiments of the present application;

[0025] Figure 4 Schematic diagram of the structure of the electrode assembly, the positive electrode tab and the negative electrode tab of some embodiments of the present application;

[0026] Figure 5 Schematic diagram of the structure of the electrode assembly, the positive electrode tab and the negative electrode tab of some embodiments of the present application;

[0027] Figure 6 Schematic diagram of the structure of the electrode assembly, the positive electrode tab and the negative electrode tab of some embodiments of the present application;

[0028] Figure 7 Schematic diagram of the structure of the electrode assembly, the positive electrode tab and the negative electrode tab of some embodiments of the present application;

[0029] Figure 8 Schematic diagram of the structure of the electrode assembly, positive electrode tab and negative electrode tab of some embodiments of the present application.

[0030] Description of reference numerals:

[0031] 100. Secondary battery;

[0032] 10. housing; 10a. first sealed cavity; 10b. second sealed cavity;

[0033] 20, electrode assembly; 20a, first main groove; 21, positive electrode sheet; 21a, third groove; 22, negative electrode sheet; 22a, first groove; 221, first sub-edge; 222, second sub-edge; 23, separator; 23a, second groove; 231, third sub-edge; 232, fourth sub-edge;

[0034] 24. Positive electrode tab; 25. Negative electrode tab;

[0035] 30. Packaging assembly; 31. First part; 32. Second part;

[0036] 40. a first insulating member;

[0037] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0039] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] The term "perpendicular" is used to describe the ideal state between two components. In actual production or use, there may be a state that is approximately perpendicular between the two components. For example, in combination with numerical descriptions, perpendicularity can refer to the angle between two straight lines being between 90±10°, perpendicularity can also refer to the dihedral angle between two planes being between 90±10°, and perpendicularity can also refer to the angle between a straight line and a plane being between 90±10°. The two components described as "perpendicular" may not be absolute straight lines or planes, but may be roughly straight lines or planes. From a macroscopic perspective, a component can be considered a "straight line" or a "plane" if the overall extension direction is a straight line or a plane.

[0043] The first direction X, the second direction Y and the third direction Z of the present application are bidirectional directions, that is, the first direction X includes the direction indicated by the arrow in the drawing and the opposite direction thereof, the second direction Y includes the direction indicated by the arrow in the drawing and the opposite direction thereof, and the third direction Z includes the direction indicated by the arrow in the drawing and the opposite direction thereof.

[0044] The technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0045] In the first aspect, the embodiment of the present application provides a secondary battery 100, please refer to Figure 1 The secondary battery 100 includes a shell 10 and an electrode assembly 20 . The shell 10 can accommodate the electrode assembly 20 and an electrolyte (not shown in the figure). The electrolyte infiltrates the electrode assembly 20 in the shell 10 .

[0046] For the electrode assembly 20, please refer to Figure 2 , Figure 2 The lamination structure of the electrode assembly 20 is shown. The electrode assembly 20 includes a negative electrode sheet 22, a positive electrode sheet 21 and a separator 23. The positive electrode sheet 21 and the negative electrode sheet 22 are alternately stacked. A separator 23 is provided between adjacent positive electrode sheets 21 and negative electrode sheets 22. The separator 23 is used to insulate and separate the positive electrode sheet 21 and the negative electrode sheet 22. In the embodiment of the present application, the electrode assembly 20 is described as a lamination structure as an example. In some other embodiments, the electrode assembly 20 may also be a winding structure. For example, the positive electrode sheet 21, the separator 23 and the negative electrode sheet 22 are sequentially stacked and then wound to form a wound electrode assembly 20.

[0047] In some embodiments, please refer to Figure 1 and Figure 3Along the length direction (first direction X) of the electrode assembly 20, the edge of the negative electrode sheet 22 is provided with a negative electrode tab 25, which extends out of the housing 10 to assist the negative electrode sheet 22 in energy transmission with an external electronic device. Along the length direction of the electrode assembly 20, the edge of the positive electrode sheet 21 is provided with a positive electrode tab 24, which extends out of the housing 10 to assist the positive electrode sheet 21 in energy transmission with an external electronic device.

[0048] In some embodiments, please refer to Figure 1 The secondary battery 100 further includes a packaging assembly 30, which is electrically connected to the electrode assembly 20. The packaging assembly 30 is mainly used to provide support, protection, thermal management and battery management for the secondary battery 100. The packaging assembly 30 is usually arranged outside the housing 10. Some components of the packaging assembly 30 need to be waterproof, so a waterproof structure is required. The secondary battery 100 is usually accommodated in the cabin of an electronic device. Since the accommodation space of the cabin of the electronic device is limited, the waterproof structure needs to reduce the volume of the electrode assembly 20, so the energy density of the secondary battery 100 will be reduced.

[0049] To improve the above problems, please refer to Figure 1 and Figure 3 In the embodiment of the present application, along the length direction of the electrode assembly 20, the edge of the negative electrode sheet 22 is provided with a first groove 22a, and the edge of the separator 23 is provided with a second groove 23a. The first groove 22a and the second groove 23a together form a first main groove 20a, and the inner wall of the housing 10 is provided with a first insulating member 40 along the groove wall of the first main groove 20a. The first insulating member 40 and the housing 10 are enclosed to form a first sealed cavity 10a, and at least a part of the packaging assembly 30 is accommodated in the first sealed cavity 10a. By providing a first groove 22a at the edge of the negative electrode sheet 22, and providing a second groove 23a at the edge of the diaphragm 23, the first groove 22a and the second groove 23a together form a first main groove 20a, and the inner wall of the shell 10 is provided with a first insulating member 40 along the groove wall of the first main groove 20a, and the first insulating member 40 and the shell 10 are enclosed to form a waterproof first sealed cavity 10a, at least part of the packaging component 30 is accommodated in the first sealed cavity 10a, and the components of the packaging component 30 that need to be waterproof can be provided in the first sealed cavity 10a, which can reduce the waterproof structure required for the waterproof components, and the volume of the electrode assembly 20 can be increased, thereby improving the energy density of the secondary battery 100. In addition, the edge of the negative electrode sheet 22 usually exceeds the positive electrode sheet 21 in the length direction of the electrode assembly 20, and the first groove 22a is provided at the edge of the negative electrode sheet 22, which can reduce the impact on the energy density of the electrode assembly 20.

[0050] In some embodiments, the first insulating member 40 may be an insulating glue, a packaging wire or a welding member, which can increase the insulation effect of the first insulating member 40 on the packaging component 30 in the first sealed cavity 10a, and can increase the sealing effect of the first insulating member 40 on the first sealed cavity 10a, thereby reducing the possibility of electrolyte entering the first sealed cavity 10a.

[0051] In some embodiments, the packaging assembly 30 includes an electrically connected first part 31 and a second part 32, the first part 31 is accommodated in the first sealed cavity 10a, and the second part 32 is arranged outside the shell 10, and the electrode assembly 20 and the second part 32 are arranged at intervals along the length direction of the electrode assembly 20. The first part 31 can be a component of the packaging assembly 30 that needs to be waterproof, and the second part 32 can be a component of the packaging assembly 30 that does not need to be waterproof. The first part 31 is accommodated in the first sealed cavity 10a, which can reduce the waterproof structure required for the packaging assembly 30. The electrode assembly 20 and the second part 32 are arranged at intervals along the length direction of the electrode assembly 20, and the second part 32 can utilize the space occupied by the outer tab of the shell 10 to reduce the additional space occupied by the packaging assembly 30. For example, the second part 32 can be arranged in the head tab area of ​​the secondary battery 100, occupying the tab top seal area.

[0052] In some embodiments, the first part 31, the second part 32 and the electrode assembly 20 may be connected in pairs via leads, the first part 31 may include electronic components, a temperature sensor, and a humidity sensor, and the second part 32 may include an internal bracket and a fixing.

[0053] In some embodiments, a second sealed cavity 10b is provided in the shell 10, and the first insulating member 40 isolates the first sealed cavity 10a from the second sealed cavity 10b. The secondary battery 100 also includes an electrolyte, and the electrolyte and the electrode assembly 20 are contained in the second sealed cavity 10b, which can reduce the possibility of the electrolyte entering the first sealed cavity 10a and affecting the packaging assembly 30 in the first sealed cavity 10a.

[0054] In some embodiments, along the thickness direction (third direction Z) of the electrode assembly 20 , the projection of the first groove 22 a overlaps at least partially with the second groove 23 a , which can increase the accommodation space of the first sealed cavity 10 a .

[0055] In some embodiments, along the width direction (second direction Y) of the electrode assembly 20 , the negative electrode tab 25 is spaced apart from the first sealed cavity 10 a to reduce the possibility that the negative electrode tab 25 affects part of the packaging assembly 30 in the first sealed cavity 10 a .

[0056] In some embodiments, along the length direction of the electrode assembly 20, the width of the first groove 22a is W1, 1mm≤W1≤3mm. When W1<1mm, the space of the first sealed cavity 10a is small, and it is difficult to accommodate some components of the packaging assembly 30. When W1>3mm, the electrode assembly 20 will lose more energy density.

[0057] In some embodiments, along the width direction of the electrode assembly 20, the length of the first groove 22a is L1, 5mm≤L1≤50mm. When L1<5mm, the space of the first sealed cavity 10a is small, and it is difficult to accommodate some components of the packaging assembly 30. When L1>50mm, the first sealed cavity 10a will affect the space occupied by the tab, and the electrode assembly 20 will lose more energy density.

[0058] In some embodiments, please refer to Figure 1 and Figure 4 Along the length direction of the electrode assembly 20, a third groove 21a is provided at the edge of the positive electrode sheet 21. The first groove 22a, the second groove 23a and the third groove 21a together form a first main groove 20a, which can increase the overlapping area between the positive electrode sheet 21 and the negative electrode sheet 22 in the thickness direction of the electrode assembly 20, improve the utilization rate of the active material of the electrode sheet, and improve the energy density.

[0059] In some embodiments, along the thickness direction of the electrode assembly 20 , the projection of the third groove 21 a overlaps at least partially with the first groove 22 a , which can increase the accommodation space of the first sealed cavity 10 a .

[0060] In some embodiments, the positive electrode tab 24 and the first sealed cavity 10 a are spaced apart along the width direction of the electrode assembly 20 , which can reduce the possibility that the positive electrode tab 24 affects part of the packaged assembly 30 in the first sealed cavity 10 a .

[0061] In some embodiments, please refer to Figure 3 and Figure 4 Along the width direction of the electrode assembly 20, the positive electrode tab 24 and the negative electrode tab 25 are both located on the same side of the first sealed cavity 10a. The positive electrode tab 24 and the negative electrode tab 25 can be gathered together on the same side of the first sealed cavity 10a to increase the available space of the first sealed cavity 10a.

[0062] In some embodiments, please refer to Figure 5 and Figure 6, along the width direction of the electrode assembly 20, the positive electrode tab 24 and the negative electrode tab 25 are respectively located on both sides of the first sealed cavity 10a, and the positive electrode tab 24 and the negative electrode tab 25 can be respectively gathered on both sides of the first sealed cavity 10a to increase the available space of the first sealed cavity 10a. In some embodiments, the symmetry axis of the first groove 22a coincides with the symmetry axis of the second groove 23a to increase the available space of the first sealed cavity 10a. In some embodiments, the symmetry axis of the third groove 21a coincides with the symmetry axis of the first groove 22a to increase the available space of the first sealed cavity 10a.

[0063] In some embodiments, please refer to Figure 7 The edge of the negative electrode sheet 22 includes a first sub-edge 221 and a second sub-edge 222. The first sub-edge 221 is provided with a negative electrode tab 25, and the second sub-edge 222 is not provided with a negative electrode tab 25. The length of the first sub-edge 221 beyond the positive electrode sheet 21 is T1, and the length of the second sub-edge 222 beyond the positive electrode sheet 21 is T2, T1>T2, so as to reduce the possibility of the burrs of the negative electrode tab 25 piercing the diaphragm 23 and contacting the positive electrode sheet 21 for short circuit.

[0064] In some embodiments, the edge of the diaphragm 23 includes a third sub-edge 231 and a fourth sub-edge 232, the projection of the third sub-edge 231 along the thickness direction of the electrode assembly 20 overlaps with at least part of the negative electrode tab 25, the projection of the fourth sub-edge 232 along the thickness direction of the electrode assembly 20 does not overlap with the negative electrode tab 25, the length of the third sub-edge 231 exceeding the negative electrode sheet 22 is T3, and the length of the fourth sub-edge 232 exceeding the negative electrode sheet 22 is T4, T3>T4, which can enhance the effect of the diaphragm 23 in blocking the burrs of the negative electrode tab 25 and reduce the possibility of short circuit caused by the burrs of the negative electrode tab 25 contacting the positive electrode sheet 21.

[0065] In some embodiments, please refer to Figure 8 Along the width direction of the electrode assembly 20, the width of the electrode assembly 20 is W2, the length of the first sealed cavity 10a is L2, W2-L2≤24mm, and the available space of the first sealed cavity 10a can be increased.

[0066] In the second aspect of the present application, an electronic device is also proposed, including a secondary battery 100 as in any embodiment of the first aspect described above. The electronic device of the embodiment of the present application is not particularly limited, and it can be any electronic device known in the prior art. For example, electronic devices include but are not limited to Bluetooth headsets, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, electric airplane toys, and the like, and spacecraft can include airplanes, rockets, space shuttles, spacecraft, and the like.

[0067] Test part:

[0068] Example 1

[0069] 1. The bare cell (electrode assembly) is a laminated structure, which is composed of a cathode electrode (positive electrode), a diaphragm, an anode electrode (negative electrode), and a diaphragm. Multiple units are stacked in sequence;

[0070] 2. The anode pole piece is of a special-shaped structure. The anode super cathode in the tab area needs to be larger than the anode super cathode in the non-tab area. At the same time, the diaphragm super anode in the tab area needs to be larger than the diaphragm super anode in the non-tab area. The reason is that the burrs on the shoulders of the tabs in the cathode die-cutting area are easy to puncture the diaphragm and short-circuit the anode; and there is no cathode die-cut empty aluminum foil in the non-tab area.

[0071] 3. The cathode pole piece is a special-shaped structure. Similarly, the anode super cathode in the tab area needs to be larger than the anode super cathode in the non-tab area. When the cathode pole piece is a special-shaped structure, the sinking platform space provided by the non-tab area is large enough (the size of the sinking platform space depends on the width of the electrode assembly, because the width of the tab area is generally fixed, the width of the tab area is limited by the tab width, and the width of the tab is limited by the charge and discharge rate), which can provide a larger space for the Pack board (packaging assembly);

[0072] 4. The diaphragm is a conventional square, which can be thermally compounded with the anode first and then stacked with the cathode. After the single battery cell is stacked, the diaphragm in the non-tab area can be hot-stamped to achieve unequal length with the diaphragm in the tab area. The reason for hot-stamping is that the heat shrinkage temperature of the diaphragm is reached by a hot block at 80-120°C, and the diaphragm is shortened, thereby achieving the effect of unequal length of the diaphragm in the non-tab area and the tab area. This design is for the design of different pocket (shell) lengths in the tab area and the non-tab area;

[0073] 5. Pocket is designed with two compartments. The first sealed cavity is the Pack compartment, and the second sealed cavity is the battery compartment. The first isolation piece is the sealing line, and the sealing line is similar to the sealing area. The first sealed cavity / second sealed cavity is separated from the two compartments to achieve physical isolation;

[0074] 6. The first sealed cavity can be used to place devices that need to be waterproof in the pack board, such as electronic components, temperature sensors, and humidity sensors, all of which are equipped with waterproof structures. Non-waterproof devices can be placed outside the battery cell packaging shell, including brackets and fixings. These components do not require waterproof design.

[0075] 7. When there is enough space in the non-ear area to place the Pack circuit board, all the components of the Pack board can be set in the first sealed cavity. After the battery is Packed, it becomes a special-shaped battery, which is assembled and powered by the whole machine compartment without any gap.

[0076] Example 2

[0077] 1. The bare cell is a laminated structure, which is composed of multiple units of cathode electrode, diaphragm, anode electrode and diaphragm stacked in sequence;

[0078] 2. The anode pole piece is of a special-shaped structure. The anode super cathode in the tab area needs to be larger than the anode super cathode in the non-tab area. At the same time, the diaphragm super anode in the tab area needs to be larger than the diaphragm super anode in the non-tab area. The reason is that the burrs on the shoulders of the tabs in the cathode die-cutting area are easy to puncture the diaphragm and short-circuit the anode; and there is no cathode die-cut empty aluminum foil in the non-tab area.

[0079] 3. The cathode electrode piece is a conventional rectangular structure. Similarly, the anode super cathode in the tab area needs to be larger than the anode super cathode in the non-tab area. When the electrode piece is a conventional rectangle, the sink space provided in the non-tab area is relatively limited, and is only used to place some devices with a higher waterproof priority level.

[0080] 4. The diaphragm is a conventional square, which can be thermally compounded with the anode first and then stacked with the cathode. After the single battery cell is stacked, the diaphragm in the non-tab area can be hot-stamped to achieve unequal length with the diaphragm in the tab area. The reason for hot-stamping is that the heat shrinkage temperature of the diaphragm is reached by a hot block at 80-120°C, and the diaphragm is shortened, thereby achieving the effect of unequal length of the diaphragm in the non-tab area and the tab area. This design is for the design of different pocket lengths in the tab area and the non-tab area;

[0081] 5. Pocket is designed with two compartments. The first sealed cavity is the Pack compartment, and the second sealed cavity is the battery compartment. The first isolation piece is the sealing line, and the sealing line is similar to the sealing area. The first sealed cavity / second sealed cavity is separated from the two compartments to achieve physical isolation;

[0082] 6. The first sealed cavity can be used to place devices that need to be waterproof in the pack board, such as electronic components, temperature sensors, and humidity sensors, all of which are equipped with waterproof structures. Non-waterproof devices can be placed outside the battery cell packaging shell, including brackets and fixings, which do not require waterproof design.

[0083] 7. When there is not enough space in the non-tab area, the temperature sensor, humidity sensor, and electronic components in the Pack board can be placed in the first sealed cavity, while the brackets, fixtures and other devices can be placed in the tab top seal area. When the non-waterproof devices are large enough, they can be arranged in the entire battery width direction. At this time, the battery is a conventional rectangular battery and is assembled with the whole machine for power supply.

[0084] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A secondary battery, comprising a shell, an electrode assembly and a packaging assembly, wherein the electrode assembly is accommodated in the shell, the packaging assembly is electrically connected to the electrode assembly, the electrode assembly comprises a positive electrode sheet, a separator and a negative electrode sheet, and a negative electrode tab is provided at an edge of the negative electrode sheet along the length direction of the electrode assembly; It is characterized in that Along the length direction of the electrode assembly, the edge of the negative electrode sheet is provided with a first groove, and the edge of the separator is provided with a second groove; The first groove and the second groove together form a first main groove, the inner wall of the shell is provided with a first insulating member along the groove wall of the first main groove, the first insulating member and the shell are enclosed to form a first sealed cavity, and at least part of the packaging component is accommodated in the first sealed cavity.

2. The secondary battery according to claim 1, characterized in that: Along the thickness direction of the electrode assembly, a projection of the first groove overlaps at least partially with a projection of the second groove.

3. The secondary battery according to claim 1, characterized in that: Along the width direction of the electrode assembly, the negative electrode tab is spaced apart from the first sealed cavity.

4. The secondary battery according to claim 1, characterized in that: Along the length direction of the electrode assembly, the width of the first groove is W1, 1mm≤W1≤3mm.

5. The secondary battery according to claim 1, characterized in that: Along the width direction of the electrode assembly, the length of the first groove is L1, 5mm≤L1≤50mm.

6. The secondary battery according to claim 1, characterized in that: A third groove is provided at the edge of the positive electrode sheet along the length direction of the electrode assembly, and the first groove, the second groove and the third groove together form the first main groove.

7. The secondary battery according to claim 6, characterized in that: Along the thickness direction of the electrode assembly, a projection of the third groove overlaps at least partially with the first groove.

8. The secondary battery according to claim 1, characterized in that: A positive electrode tab is disposed at the edge of the positive electrode sheet along the length direction of the electrode assembly; the positive electrode tab and the first sealed cavity are spaced apart from each other along the width direction of the electrode assembly.

9. The secondary battery according to claim 8, characterized in that: Along the width direction of the electrode assembly, the positive electrode tab and the negative electrode tab are both located on the same side of the first sealed cavity; Alternatively, along the width direction of the electrode assembly, the positive electrode tab and the negative electrode tab are respectively located on two sides of the first sealed cavity.

10. The secondary battery according to claim 1, characterized in that: Along the width direction of the electrode assembly, the width of the electrode assembly is W2, the length of the first sealed cavity is L2, and W2-L2≤24 mm.

11. The secondary battery according to claim 1, characterized in that: The packaging assembly includes a first part and a second part that are electrically connected, the first part is accommodated in the first sealed cavity, the second part is arranged outside the shell, and the electrode assembly and the second part are spaced apart along the length direction of the electrode assembly.

12. The secondary battery according to any one of claims 1 to 11, characterized in that: The edge of the negative electrode sheet includes a first sub-edge and a second sub-edge, the first sub-edge is provided with the negative electrode tab, the second sub-edge is not provided with the negative electrode tab, the first sub-edge exceeds the positive electrode sheet by a length T1, the second sub-edge exceeds the positive electrode sheet by a length T2, and T1>T2; And / or, the edge of the diaphragm includes a third sub-edge and a fourth sub-edge, the projection of the third sub-edge along the thickness direction of the electrode assembly overlaps with at least part of the negative electrode tab, the projection of the fourth sub-edge along the thickness direction of the electrode assembly does not overlap with the negative electrode tab, the length of the third sub-edge exceeding the negative electrode sheet is T3, the length of the fourth sub-edge exceeding the negative electrode sheet is T4, and T3>T4.

13. The secondary battery according to any one of claims 1 to 11, characterized in that: A second sealed cavity is disposed in the shell, the first insulating member isolates the first sealed cavity from the second sealed cavity, the secondary battery further comprises an electrolyte, and the electrolyte and the electrode assembly are accommodated in the second sealed cavity.

14. An electronic device, characterized in that: The invention comprises the secondary battery according to any one of claims 1 to 13.

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