Battery, preparation method of battery and electronic device

Abstract

The invention discloses a battery, a preparation method of the battery and an electronic device. The battery comprises a battery cell and a circuit board assembly, the battery cell comprises a packaging bag and two electrode assemblies. The packaging bag comprises a main body part and a top sealing part. The main body part comprises two containing cavities arranged in the first direction in a spaced mode and an isolation sealing part located between the two containing cavities, and the isolation sealing part is connected with the top sealing part. The containing cavity comprises a first wall connected with the top sealing part, and the top sealing part is bent towards the first wall. And an electrode assembly is arranged in each accommodating cavity. The circuit board assembly is arranged on the surface of one side of the top sealing part, observed in the second direction, the circuit board assembly is at least partially overlapped with each containing cavity and the isolation sealing part, and the circuit board assembly is electrically connected with the electrode assembly. The second direction is perpendicular to the first direction. The battery is favorable for improving the energy density.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and particularly relates to a battery, a preparation method of the battery, and an electronic device. Background Art

[0002] A battery adopting a dual-cell solution can improve the charging speed and reduce the temperature rise. The existing dual-cell solution usually bonds two separate folded-top sealed cells with adhesive tape. Since a fold angle is formed at the connection between the top-sealed part and the side-sealed part of each folded-top sealed cell, when the dual-cell solution is used in the battery, four independent fold angles will be formed when the two cells are arranged side by side. The two adjacent fold angles in the middle will form a redundant convex structure, and the middle fold angle occupies the head space, making it impossible for the circuit board assembly to be installed flatly. It is necessary to adapt to the fold angle through additional slotting or avoidance design, which will make the circuit board assembly occupy a large space at the head of the battery, resulting in a decrease in the energy density of the battery. Summary of the Invention

[0003] In view of the above situation, the present application provides a battery, which is beneficial to improving the energy density.

[0004] An embodiment of the present application provides a battery, which includes a battery cell and a circuit board assembly. The battery cell includes a packaging bag and two electrode assemblies. The packaging bag includes a main body part and a top-sealed part. The main body part includes two accommodating cavities arranged at intervals along a first direction, and a partition sealing part located between the two accommodating cavities. The partition sealing part is connected to the top-sealed part. The accommodating cavity includes a first wall connected to the top-sealed part, and the top-sealed part is bent towards the first wall. One electrode assembly is arranged in each accommodating cavity. The circuit board assembly is arranged on one side surface of the top-sealed part. When observed along a second direction, the circuit board assembly at least partially overlaps with each accommodating cavity and the partition sealing part, and the circuit board assembly is electrically connected to the electrode assembly. The second direction is perpendicular to the first direction.

[0005] In the above battery, the main body part of the packaging bag separates two accommodating cavities through the partition sealing part, and the top-sealed part is integrally bent along the first direction and hermetically connected to the first walls of the two accommodating cavities, simplifying the four independent fold angles in the traditional solution into two outer fold angles to release the head space in the middle area. When observed along the second direction, the circuit board assembly at least partially overlaps with each accommodating cavity and the partition sealing part, so that the circuit board assembly spans across the two electrode assemblies along the first direction, facilitating the electrical connection between the circuit board assembly and the electrode assembly. When the circuit board assembly is arranged on one side surface of the top-sealed part, there is no need to avoid the middle fold angle, which is beneficial to improving the space utilization rate at the head of the battery and the energy density of the battery.

[0006] In some embodiments of the present application, the circuit board assembly is arranged on the surface of the top-sealed part facing away from the first wall, so as to reduce the space waste generated by the circuit board assembly at the head of the battery, which is beneficial to improving the space utilization rate at the head of the battery and the energy density of the battery.

[0007] In some embodiments of the present application, the circuit board assembly is arranged on the surface of the top seal portion facing the first wall to reduce the space waste caused by the circuit board assembly on the battery head, which is beneficial to improving the space utilization of the battery head and the energy density of the battery.

[0008] In some embodiments of the present application, along the first direction, the width of the isolation sealing portion is W 1 , 0.5mm≤W 1 ≤1.5mm, in order to improve the packaging strength of the isolation seal, and to improve the space utilization of the battery head and the energy density of the battery.

[0009] In some embodiments of the present application, 0.7 mm ≤ W 1 ≤1.2mm, so as to further improve the packaging strength of the isolation sealing part, and help to improve the space utilization of the battery head and the energy density of the battery.

[0010] In some embodiments of the present application, the packaging bag further comprises a side seal portion, and along the first direction, a side of the accommodating cavity away from the isolation seal portion is provided with the side seal portion, the side seal portion is connected to the top seal portion, and the side seal portion is used to improve the packaging stability of the main body. The side seal portion is bent toward the main body to reduce the space occupied by the side seal portion in the first direction, which is beneficial to improving the space utilization rate on both sides of the battery and the energy density of the battery.

[0011] In some embodiments of the present application, the top seal portion includes a top seal body portion, and along the second direction, the top seal body portion is arranged opposite to the first wall, and the circuit board assembly is arranged on a surface of the top seal body portion facing the first wall.

[0012] In some embodiments of the present application, the top seal portion includes a top seal body portion, which is arranged opposite to the first wall along the second direction, and the circuit board assembly is arranged on a surface of the top seal body portion facing away from the first wall.

[0013] In some embodiments of the present application, the accommodating cavity includes a second wall connected to the side sealing portion, and the side sealing portion is bent toward the second wall. A convex corner portion is formed at the connection between the top sealing portion and the side sealing portion, and along the first direction, the circuit board assembly and the convex corner portion at least partially overlap, so that the circuit board assembly and the convex corner portion share the space in the second direction, which is beneficial to improving the space utilization rate of the battery head and the energy density of the battery.

[0014] In some embodiments of the present application, the packaging bag is made of a packaging film, and the packaging film is an aluminum-plastic film.

[0015] In some embodiments of the present application, the packaging bag includes an upper housing and a lower housing, and the upper housing and the lower housing are connected. The upper housing is provided with two first pits spaced along a first direction, and the lower housing is provided with two second pits spaced along the first direction. Each first pit communicates with a second pit to form a receiving cavity, which is beneficial to expanding the capacity of the receiving cavity.

[0016] The embodiments of the present application also provide a preparation method of a battery including any one of the above-mentioned embodiments. The preparation method of the battery includes the following steps: Stamping and forming the packaging film. The packaging film is provided with two first pits spaced along a first direction, an isolation sealing area located between the two first pits, and a top sealing area located on one side of the two first pits; Placing the two electrode assemblies in the two first pits respectively, folding the packaging film, thermally pressing the isolation sealing area to form an isolation sealing portion, and thermally pressing the top sealing area to form a top sealing portion. The two first pits form two receiving cavities; Bending the top sealing portion towards the first wall, arranging the circuit board assembly on one side surface of the top sealing portion, and electrically connecting each electrode assembly to the circuit board assembly through a pole ear group.

[0017] In some embodiments of the present application, the packaging film is stamped and formed. The packaging film is provided with two second pits spaced along a first direction. Each first pit communicates with a second pit to form a receiving cavity, which is beneficial to expanding the capacity of the receiving cavity.

[0018] The embodiments of the present application also provide an electronic device, and the electronic device includes any one of the above-mentioned batteries.

[0019] In the above-mentioned battery, the preparation method of the battery, and the electronic device, the main body of the packaging bag is separated into two receiving cavities by the isolation sealing portion. The top sealing portion is bent integrally along the first direction and sealed to connect the first walls of the two receiving cavities, simplifying the four independent folding corners in the traditional solution into two outer folding corners to release the head space in the middle area. When observing along the second direction, the circuit board assembly at least partially overlaps with each receiving cavity and the isolation sealing portion, so that the circuit board assembly spans the two electrode assemblies along the first direction, facilitating the electrical connection between the circuit board assembly and the electrode assembly. When the circuit board assembly is arranged on one side surface of the top sealing portion, there is no need to avoid the middle folding corner, which is beneficial to improving the space utilization rate of the battery head and the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a battery in an embodiment of the present application.

[0021] Figure 2 is a schematic structural diagram of the packaging bag of the battery in an embodiment of the present application in an unfolded state.

[0022] Figure 3 It is a schematic structural diagram of a battery in another embodiment of the present application.

[0023] Figure 4 It is a schematic structural diagram of the packaging bag of the battery in an unfolded state in another embodiment of the present application.

[0024] Figure 5 It is a flowchart of a method for manufacturing a battery in an embodiment of the present application.

[0025] Figure 6 It is a schematic structural diagram of an electronic device in an embodiment of the present application.

[0026] Description of main component symbols Battery 100 Electronic device 200 Cell 10 Packaging bag 20 Main body part 21 Accommodation cavity 211 First wall 2111 Second wall 2112 Isolation and sealing part 212 Top sealing part 22 Top sealing main body part 221 Top sealing extension part 222 Side sealing part 23 Convex corner part 24 Packaging film 201 Upper housing 20A First pit 20A1 Isolation and sealing area 20A2 Top sealing area 20A3 Side sealing area 20A4 Lower housing 20B Second pit 20B1 First crease 20C Electrode assembly 30 Tab group 40 First tab 41 Second tab 42 Circuit board assembly 50 First direction X Second direction Y Third direction Z The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. Specific embodiments

[0027] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0028] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element. When an element is considered to be "disposed" on another element, it can be directly disposed on the other element or there may be an intermediate element.

[0029] When a numerical value is considered to be "equal" to another numerical value, it means that the two are equal within a set deviation, and the set deviation range is within 5%. That is to say, when at least one of the two numerical values fluctuates within the set deviation range, even if their values are not equal, they are still judged to be approximately equal. When the ratio of a numerical value to another numerical value is "1:1", it means that the two are equal within a set deviation, and the set deviation range is within 5%. That is to say, when at least one of the two numerical values fluctuates within the set deviation range, even if their values are not equal, they are still judged to have an equal ratio.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. The term "overlap" used herein means that the projection parts of two components overlap or the projections of two components coincide.

[0031] An embodiment of the present application provides a battery, which includes a battery cell and a circuit board assembly. The battery cell includes a packaging bag and two electrode assemblies. The packaging bag includes a main body portion and a top sealing portion. The main body portion includes two accommodation cavities spaced along a first direction, and a partition sealing portion located between the two accommodation cavities, and the partition sealing portion is connected to the top sealing portion. The accommodation cavity includes a first wall connected to the top sealing portion, and the top sealing portion is bent toward the first wall. One electrode assembly is disposed in each accommodation cavity. The circuit board assembly is disposed on one side surface of the top sealing portion. When observed in a second direction perpendicular to the first direction, the circuit board assembly at least partially overlaps each accommodation cavity and the partition sealing portion, and the circuit board assembly is electrically connected to the electrode assembly.

[0032] In the above battery, the main body of the packaging bag is separated into two accommodation cavities by a separation and sealing part. The top sealing part is bent integrally along the first direction and is hermetically connected to the first walls of the two accommodation cavities, simplifying the four independent folding corners in the traditional solution into two outer folding corners to release the head space in the middle area. When observed along the second direction, the circuit board assembly at least partially overlaps with each accommodation cavity and the separation and sealing part, so that the circuit board assembly spans across the two electrode assemblies along the first direction, facilitating the electrical connection between the circuit board assembly and the electrode assemblies. When the circuit board assembly is arranged on one side surface of the top sealing part, there is no need to avoid the middle folding corner, which is beneficial to improving the space utilization rate of the battery head and the energy density of the battery.

[0033] The following will further illustrate the embodiments of the present application with reference to the accompanying drawings.

[0034] Please refer to Figure 1 and Figure 2 An embodiment of the present application provides a battery 100. The battery 100 can be a secondary battery, which refers to a battery that can be activated by charging after discharging to continue use.

[0035] The battery 100 includes a battery cell 10 and a circuit board assembly 50. The battery cell 10 includes a packaging bag 20 and two electrode assemblies 30. The packaging bag 20 is made of a packaging film 201 by means of punching, folding and heat sealing. The electrode assembly 30 is formed by winding or stacking a positive electrode plate, a separator and a negative electrode plate arranged in sequence. The electrode assembly 30 is used to convert chemical energy into electrical energy.

[0036] The packaging bag 20 includes a main body part 21 and a top sealing part 22. The main body part 21 includes two accommodation cavities 211 arranged at intervals along the first direction X, and a separation and sealing part 212 located between the two accommodation cavities 211. Among them, the accommodation cavity 211 is the part of the packaging film 201 where the punching position is provided, and the separation and sealing part 212 is the part where the packaging film 201 overlaps and is joined. The separation and sealing part 212 is used to separate the two accommodation cavities 211 in the first direction X, so that the two accommodation cavities 211 respectively form independent cavities.

[0037] The top sealing part 22 is located on one side of the two accommodation cavities 211. Among them, the top sealing part 22 is the part where the packaging film 201 overlaps and is joined. The top sealing part 22 is used to improve the packaging stability of the main body part 21. The separation and sealing part 212 and the top sealing part 22 are connected to form an integral structure. The accommodation cavity 211 includes a first wall 2111 connected to the top sealing part 22, and the top sealing part 22 is bent towards the first wall 2111. The main body part 21 of the packaging bag 20 is separated into two accommodation cavities 211 by the separation and sealing part 212. The top sealing part 22 is bent integrally along the first direction X and is hermetically connected to the first walls 2111 of the two accommodation cavities 211, simplifying the four independent folding corners in the traditional solution into two outer folding corners to release the head space in the middle area.

[0038] One electrode assembly 30 is disposed in each accommodating cavity 211 to reduce the risk of interference between the two electrode assemblies 30. The circuit board assembly 50 is disposed on one side surface of the top sealing portion 22. The circuit board assembly 50 and the battery cell 10 are arranged along the second direction Y, and the second direction Y is perpendicular to the first direction X. When observed along the second direction Y, the circuit board assembly 50 at least partially overlaps with each accommodating cavity 211 and the isolation and sealing portion 212, so that the circuit board assembly 50 spans across the two electrode assemblies 30 along the first direction X. The circuit board assembly 50 is electrically connected to the electrode assembly 30. When the circuit board assembly 50 is disposed on one side surface of the top sealing portion 22, there is no need to avoid the middle fold angle, which is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0039] Moreover, through the integrated structure formed by the connection of the isolation and sealing portion 212 and the top sealing portion 22, the adhesive tape for connecting two separate battery cells in the traditional solution can be saved, so as to improve the energy density of the battery 100 and is beneficial to reducing the production cost.

[0040] It should be noted that the head of the battery 100 refers to the space on the side of the first wall 2111 facing the circuit board assembly 50.

[0041] In the above-mentioned battery 100, the main body portion 21 of the packaging bag 20 is separated into two accommodating cavities 211 by the isolation and sealing portion 212, and the top sealing portion 22 is integrally bent along the first direction X and sealed to connect the first walls 2111 of the two accommodating cavities 211, simplifying the four independent fold angles in the traditional solution into two outer fold angles to release the head space in the middle area. When observed along the second direction Y, the circuit board assembly 50 at least partially overlaps with each accommodating cavity 211 and the isolation and sealing portion 212, so that the circuit board assembly 50 spans across the two electrode assemblies 30 along the first direction X, facilitating the electrical connection between the circuit board assembly 50 and the electrode assembly 30. When the circuit board assembly 50 is disposed on one side surface of the top sealing portion 22, there is no need to avoid the middle fold angle, which is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0042] In some embodiments, the thickness direction of the battery cell 10 is the third direction Z, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other in pairs.

[0043] Please refer to Figure 1, in some embodiments, the battery 100 further includes two tab groups 40, and each electrode assembly 30 is electrically connected to the circuit board assembly 50 through a tab group 40. The tab group 40 includes a first tab 41 and a second tab 42, and the polarities of the first tab 41 and the second tab 42 are opposite. The first tab 41 extends from the top seal portion 22 to the outside, and both ends of the first tab 41 are respectively connected to the electrode assembly 30 and the circuit board assembly 50. The second tab 42 extends from the top seal portion 22 to the outside, and both ends of the second tab 42 are respectively connected to the electrode assembly 30 and the circuit board assembly 50.

[0044] Please refer to Figure 1 , in some embodiments, along the first direction X, the width of the isolation seal portion 212 is W 1 , 0.5 mm ≤ W 1 ≤ 1.5 mm. When W 1 is too small (e.g., less than 0.5 mm), it is likely to cause the packaging strength of the isolation seal portion 212 to be weak. When W 1 is too large (e.g., greater than 1.5 mm), it is likely to make the top seal portion 22 need to reserve more bending areas, resulting in a decrease in the space utilization rate of the head of the battery 100. By defining 0.5 mm ≤ W 1 ≤ 1.5 mm, the packaging strength of the isolation seal portion 212 is improved, and it is beneficial to improve the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0045] Optionally, W 1 is one of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm and any other value within the range of 0.5 mm ≤ W 1 ≤ 1.5 mm.

[0046] Furthermore, 0.7 mm ≤ W 1 ≤ 1.2 mm, so as to further improve the packaging strength of the isolation seal portion 212, and it is beneficial to improve the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0047] Please refer to Figure 2 , in some embodiments, along the extending direction of the top seal portion 22, the width of the top seal portion 22 is W 2 , 1 mm ≤ W 2 ≤ 3 mm. When W 2 is too small (e.g., less than 1 mm), it is likely to cause the packaging strength of the top seal portion 22 to be weak. When W 2 is too large (e.g., greater than 3 mm), it is likely to make the top seal portion 22 occupy a large space at the head of the battery 100, resulting in a decrease in the energy density of the battery 100. By defining 1 mm ≤ W 2≤3 mm, so as to improve the encapsulation strength of the isolation and sealing part 212, and is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0048] Optionally, W 2 is one of 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, and any other arbitrary value within the range of 1 mm ≤ W 2 ≤ 3 mm.

[0049] Please refer to Figure 1 , in some embodiments, when observing along the third direction Z, the isolation and sealing part 212 extends along the second direction Y, so as to make the forces on both sides of the isolation and sealing part 212 in the first direction X uniform, and improve the structural stability of the packaging bag 20.

[0050] It can be understood that, in some embodiments, when observing along the third direction Z, the isolation and sealing part 212 extends along a direction inclined relative to the second direction Y, or extends along an arc direction.

[0051] Please refer to Figure 1 , in some embodiments, the circuit board assembly 50 is disposed on the surface of the top sealing part 22 facing away from the first wall 2111, so as to reduce the space waste generated by the circuit board assembly 50 at the head of the battery 100, and is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0052] In some embodiments, the top sealing part 22 includes a top sealing body part 221. Along the second direction Y, the top sealing body part 221 is disposed opposite to the first wall 2111, and the circuit board assembly 50 is disposed on the side of the top sealing body part 221 away from the first wall 2111.

[0053] Please refer to Figure 3 , in some embodiments, the circuit board assembly 50 is disposed on the surface of the top sealing part 22 facing the first wall 2111, so as to reduce the space waste generated by the circuit board assembly 50 at the head of the battery 100, and is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0054] In some embodiments, the circuit board assembly 50 is disposed between the top sealing body part 221 and the first wall 2111.

[0055] Please refer to Figure 1 and Figure 3, in some embodiments, the thickness direction of the circuit board assembly 50 is parallel to the second direction Y, so as to further reduce the space waste generated by the circuit board assembly 50 at the head of the battery 100, which is beneficial to improving the space utilization rate at the head of the battery 100 and the energy density of the battery 100.

[0056] It should be noted that the circuit board assembly 50 includes a PCB board and electronic components disposed on the PCB board, and the thickness direction of the PCB board is used as the thickness direction of the circuit board assembly 50.

[0057] In some embodiments, the battery 100 further includes an injection molded part (not shown in the figure), the injection molded part is disposed at the head of the battery 100, and the injection molded part is connected to the first wall 2111, the top sealing part 22 and the circuit board assembly 50, so as to utilize the space saved by the circuit board assembly 50 and is beneficial to improving the structural stability of the head of the battery 100.

[0058] Please refer to Figure 1 、 Figure 2 and Figure 3 , in some embodiments, the packaging bag 20 further includes a side sealing part 23. Along the first direction X, a side sealing part 23 is provided on one side of each accommodating cavity 211 away from the isolation sealing part 212, and the side sealing part 23 is connected to the top sealing part 22. Wherein, the side sealing part 23 is the overlapping and joined part of the packaging film 201, and the side sealing part 23 is used to improve the encapsulation stability of the main body part 21. The side sealing part 23 is bent towards the main body part 21 to reduce the space occupied by the side sealing part 23 in the first direction X, which is beneficial to improving the space utilization rate on both sides of the battery 100 and the energy density of the battery 100. Specifically, the accommodating cavity 211 includes a second wall 2112 connected to the side sealing part 23, and the side sealing part 23 is bent towards the second wall 2112.

[0059] In some embodiments, the number of the side sealing parts 23 is two, and they are located on both sides of the two accommodating cavities 211 along the first direction X.

[0060] In some embodiments, the top sealing part 22 and the side sealing part 23 are integrally encapsulated by hot pressing, further improving the structural strength and sealing performance of the top sealing part 22 and the side sealing part 23.

[0061] Please refer to Figure 1 and Figure 3, in some embodiments, a convex corner portion 24 is formed at the connection between the top sealing portion 22 and the side sealing portion 23. Along the first direction X, the circuit board assembly 50 at least partially overlaps with the convex corner portion 24, so that the circuit board assembly 50 and the convex corner portion 24 share the space in the second direction Y, which is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100. Specifically, the top sealing portion 22 includes top sealing extension portions 222 located at both ends of the top sealing body portion 221 along the first direction X. Each top sealing extension portion 222 is connected to the side sealing portion 23 on one side in the second direction Y, and each top sealing extension portion 222 is bent to form the convex corner portion 24.

[0062] Please refer to Figure 1 , Figure 2 and Figure 3 , in some embodiments, the packaging bag 20 includes an upper shell 20A and a lower shell 20B, and the upper shell 20A and the lower shell 20B are connected along the third direction Z. The upper shell 20A is provided with two first pit positions 20A1 arranged at intervals along the first direction X and an isolation sealing area 20A2 located between the two first pit positions 20A1. The lower shell 20B is in a sheet structure, and the lower shell 20B and the two first pit positions 20A1 form two accommodating cavities 211. The isolation sealing area 20A2 and the part of the lower shell 20B overlapping with the isolation sealing area 20A2 form an isolation sealing portion 212. The part of the upper shell 20A on one side of the two first pit positions 20A1 along the second direction Y overlaps with the corresponding lower shell 20B to form the top sealing portion 22. The parts of the upper shell 20A on both sides of the two first pit positions 20A1 along the first direction X overlap with the corresponding lower shell 20B to form the side sealing portion 23.

[0063] In some embodiments, after the packaging film 201 is folded, a first crease 20C extending along the first direction X will be formed, and the upper shell 20A and the lower shell 20B are located on both sides of the first crease 20C.

[0064] Please refer to Figure 4 , in some embodiments, the lower shell 20B is provided with two second pit positions 20B1 arranged at intervals along the first direction X, and each first pit position 20A1 communicates with a second pit position 20B1 to form the accommodating cavity 211, which is beneficial to expanding the capacity of the accommodating cavity 211.

[0065] In some embodiments, the packaging film 201 is an aluminum-plastic film. The aluminum-plastic film includes a molten layer, an aluminum layer, and a nylon layer laminated in sequence from the inside to the outside. The molten layer includes polypropylene, and the molten layer will melt and have viscosity at a preset temperature, so as to facilitate the encapsulation of the packaging bag 20. After the aluminum layer is oxidized, a dense oxide film will be formed to isolate water vapor, which can reduce the risk of water vapor penetrating into the interior of the packaging bag 20. The aluminum layer can also improve the structural strength of the packaging bag 20. The nylon layer is used to resist external physical impacts.

[0066] Please refer to Figure 5 , an embodiment of the present application further provides a method for manufacturing a battery 100, including the following steps: Stamping and forming the packaging film 201. The packaging film 201 is provided with two first pit positions 20A1 spaced along the first direction X, an isolation and sealing area 20A2 located between the two first pit positions 20A1, and a top sealing area 20A3 located on one side of the two first pit positions 20A1; Place the two electrode assemblies 30 in the two first pit positions 20A1 respectively, fold the packaging film 201, perform hot pressing on the isolation and sealing area 20A2 to form an isolation and sealing portion 212, perform hot pressing on the top sealing area 20A3 to form a top sealing portion 22, and the two first pit positions 20A1 form two accommodating cavities 211.

[0067] Bend the top sealing portion 22 towards the first wall 2111, arrange the circuit board assembly 50 on one side surface of the top sealing portion 22, and electrically connect each electrode assembly 30 to the circuit board assembly 50 through a pole ear group 40.

[0068] In some embodiments, the packaging film 201 is provided with side sealing areas 20A4 located on both sides of the two first pit positions 20A1 along the first direction X, and perform hot pressing on the side sealing areas 20A4 to form side sealing portions 23.

[0069] Please refer to Figure 3 , in some embodiments, stamping and forming the packaging film 201. The packaging film 201 is provided with two second pit positions 20B1 spaced along the first direction X, and each first pit position 20A1 communicates with a second pit position 20B1 to form an accommodating cavity 211, which is beneficial to expanding the capacity of the accommodating cavity 211.

[0070] Please refer to Figure 6 , an embodiment of the present application further provides an electronic device 200. The electronic device 200 includes the battery 100A in any of the above embodiments. The electronic device 200 can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc.

[0071] In the above-mentioned battery 100, the method for preparing the battery 100, and the electronic device 200, the main body portion 21 of the packaging bag 20 is separated into two accommodating cavities 211 by the isolation and sealing portion 212, and the top sealing portion 22 is integrally bent along the first direction X and sealingly connected to the first walls 2111 of the two accommodating cavities 211, simplifying the four independent folding corners in the traditional solution into two outer folding corners to release the head space in the middle area. When observing along the second direction Y, the circuit board assembly 50 at least partially overlaps with each accommodating cavity 211 and the isolation and sealing portion 212, so that the circuit board assembly 50 straddles the two electrode assemblies 30 along the first direction X, facilitating the electrical connection between the circuit board assembly 50 and the electrode assemblies 30. When the circuit board assembly 50 is disposed on one side surface of the top sealing portion 22, there is no need to avoid the middle folding corner, which is beneficial to improving the space utilization rate of the head of the battery 100 and the energy density of the battery 100.

[0072] Hereinafter, examples and comparative examples are given to more specifically illustrate the embodiments of the present application. Various tests and evaluations are carried out according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0073] Method for measuring the energy density of the battery: Place the battery in an incubator at 25°C and let it stand for 30 minutes to make the battery reach a constant temperature. Charge the battery at a constant current of 0.5C until the voltage reaches 4.53V, and then charge it at a constant voltage of 4.53V until the current reaches 0.05C, and discharge it at 0.2C until the voltage reaches 3.0V, and record the discharge capacity and the plateau voltage.

[0074] Volume energy density = discharge capacity × plateau voltage / (length × width × thickness of the battery).

[0075] Calculation method for energy density gain: (energy density of the battery to be measured - energy density of Comparative Example 1) / energy density of Comparative Example 1.

[0076] Drop test method: The battery 100 is placed in an environment of 20°C (±5°C) and left to stand for 60 minutes, and then charged in the following steps: charge at a constant current of 0.7C until 3.0V, stand for 10 minutes, charge at a constant current of 0.5C rate until 4.5V, and charge at a constant voltage until 0.02C; drop freely from a position 1.5m above the marble floor in the following order: head - tail - four sides - right head corner - right tail corner - left head corner - left tail corner (angle: 45 ± 15°), and repeat 20 rounds. After the drop test, measure the width of the middle isolation seal area through a CCD. Passing criterion for the drop test: passing if there is an effective isolation seal area, and 100 batteries are tested in each group.

[0077] Example 1: A battery with an initial thickness of 4.8 mm, a length of 85 mm, and a width of 65 mm at 50% SOC. The assembly process is as follows: (1) Preparation of the negative electrode sheet: The negative electrode active material artificial graphite, conductive carbon black (Super P), and styrene-butadiene rubber (SBR) are mixed in a weight ratio of 96:1.5:2.5. Deionized water is added as a solvent to prepare a slurry with a weight percentage of 50 wt%. The slurry is stirred evenly and then uniformly coated on one surface of the copper foil. Then it is dried at 110 °C to obtain a negative electrode sheet with a negative electrode active material layer coated on one side. When preparing a double-sided coated negative electrode sheet, the above steps are repeated on the other surface of the negative electrode sheet to obtain a negative electrode sheet with a negative electrode active material layer coated on both sides. Then the coated electrode sheet is cold-pressed to a thickness of 105 μm, grooves are set in the negative electrode active material, and the negative electrode tab is welded to the copper foil exposed in the grooves.

[0078] (2) Preparation of the positive electrode sheet: The positive electrode active material lithium cobalt oxide (LiCoO 2 )), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) are mixed in a weight ratio of 97.5:1.0:1.5. N-methylpyrrolidone (NMP) is added as a solvent to prepare a slurry with a solid content of 75 wt%. The slurry is stirred evenly and then uniformly coated on one surface of the aluminum foil. Then it is dried at 90 °C to obtain a positive electrode sheet with a positive electrode active material coated on one side. When preparing a double-sided coated positive electrode sheet, the above coating steps are repeated on the other surface of the aluminum foil. Then the coated electrode sheet is cold-pressed to a thickness of 95 μm, grooves are set in the positive electrode active material, and the positive electrode tab is welded to the aluminum foil exposed in the grooves.

[0079] (3) Preparation of the electrolyte: In a dry argon atmosphere, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) are first mixed in a mass ratio of EC:EMC:DEC = 30:50:20 to form a basic organic solvent. Then lithium salt lithium hexafluorophosphate (LiPF 6 ) is added to the basic organic solvent and dissolved and mixed evenly to obtain an electrolyte with a lithium salt concentration of 1.15 mol / L.

[0080] (4) Preparation of the separator: A separator with a three-layer structure is used, which includes an adhesive layer, a base material layer, and an adhesive layer arranged in a stacked manner. The first base material layer is made of polyethylene (PE), the binder in the adhesive layer is PVDF, and the adhesive layer also contains inorganic particles boehmite.

[0081] (5) Preparation of the electrode assembly: The positive electrode sheet, the separator, and the negative electrode sheet are wound together.

[0082] (6) Battery assembly: A first crease extending in the first direction is provided on the unfolded aluminum-plastic film, and the aluminum-plastic film includes an upper housing and a lower housing located on both sides of the first crease; the aluminum-plastic film is stamped and formed, and the upper housing is provided with two first pits arranged at intervals in the first direction, an isolation and sealing area located between the two first pits, and a top-sealing area located on the side of the two first pits away from the first crease; two electrode assemblies are respectively placed in the two first pits; the lower housing is folded upward along the first crease toward the upper housing, the isolation and sealing area and the part of the lower housing overlapping with the isolation and sealing area are hot-pressed to form an isolation and sealing part, the top-sealing area and the part of the lower housing overlapping with the top-sealing area are hot-pressed to form a top-sealing part, and the lower housing and the two first pits form two accommodating cavities.

[0083] (7) Liquid injection and encapsulation: Electrolyte is injected into the assembled electrode assembly, and through processes such as vacuum encapsulation, standing, hot pressing and forming, and shaping, the battery is obtained.

[0084] (8) Circuit board connection: The top-sealing part is bent toward the first wall, the circuit board assembly is arranged on the side of the top-sealing part away from the first wall, and the tabs of the electrode assembly extend out of the top-sealing part and are electrically connected to the circuit board.

[0085] Comparative example 1: A conventional battery adopting a dual-cell scheme, and the specifications of the electrode assemblies of each cell are the same as those of the electrode assemblies in Example 1. It should be noted that other parameters of Comparative example 1 are the same as those in Example 1.

[0086] Note: In Table 1, "\ " means that the parameter is not included.

[0087] It can be seen from Comparative example 1 and Examples 1-6 that the main body of the packaging bag is separated into two accommodating cavities by the isolation and sealing part, the top-sealing part is bent as a whole in the first direction and hermetically connected to the first walls of the two accommodating cavities, simplifying the four independent folding corners in the traditional scheme into two outer folding corners to release the head space in the middle area. When the circuit board assembly is arranged on one surface of the top-sealing part, there is no need to avoid the middle folding corner, which is beneficial to improving the space utilization rate of the battery head and the energy density of the battery.

[0088] It can be seen from Examples 1-6 that by limiting 0.5mm ≤ W 1 ≤ 1.5mm, it is beneficial to improve the energy density of the battery and enhance the packaging strength and packaging reliability of the isolation and sealing part. By limiting 0.7mm ≤ W 1 ≤ 1.2mm, it is beneficial to further improve the energy density of the battery and further enhance the packaging strength and packaging reliability of the isolation and sealing part.

[0089] In addition, those skilled in the art can also make other changes within the spirit of this application. Of course, all such changes made in accordance with the spirit of this application should be included within the scope disclosed in this application.

Claims

1. A battery, characterized in that: The battery comprises: A battery cell, the battery cell comprising a packaging bag and two electrode assemblies, the packaging bag comprising a main body and a top seal, the main body comprising two accommodating cavities spaced apart along a first direction, and an isolation seal located between the two accommodating cavities, the isolation seal being connected to the top seal, the accommodating cavities comprising a first wall connected to the top seal, the top seal being bent toward the first wall, and one electrode assembly being arranged in each accommodating cavity; A circuit board assembly is arranged on a side surface of the top sealing portion. When viewed along a second direction, the circuit board assembly at least partially overlaps with each of the accommodating cavities and the isolation sealing portion. The circuit board assembly is electrically connected to the electrode assembly. The second direction is perpendicular to the first direction.

2. The battery according to claim 1, characterized in that The circuit board assembly is disposed on a surface of the top sealing portion facing away from the first wall, or the circuit board assembly is disposed on a surface of the top sealing portion facing the first wall.

3. The battery according to claim 1, characterized in that Along the first direction, the width of the isolation sealing portion is W1, 0.5 mm≤W1≤1.5 mm.

4. The battery according to claim 3, characterized in that 0.7mm≤W1≤1.2mm.

5. The battery according to claim 2, characterized in that The packaging bag further comprises a side seal portion, which is disposed on a side of the accommodating cavity away from the isolation seal portion along the first direction, is connected to the top seal portion, and is bent toward the main body portion.

6. The battery according to claim 5, characterized in that The top seal portion includes a top seal body portion, and along the second direction, the top seal body portion is arranged opposite to the first wall, and the circuit board assembly is arranged on the surface of the top seal body portion facing the first wall, or the circuit board assembly is arranged on the surface of the top seal body portion facing away from the first wall.

7. The battery according to claim 6, characterized in that The accommodating cavity includes a second wall connected to the side sealing portion, the side sealing portion is bent toward the second wall, and a convex corner portion is formed at the connection between the top sealing portion and the side sealing portion. Along the first direction, the circuit board assembly at least partially overlaps with the convex corner portion.

8. The battery according to claim 1, characterized in that The packaging bag is made of a packaging film, and the packaging film is an aluminum-plastic film.

9. The battery according to claim 1, characterized in that The packaging bag includes an upper shell and a lower shell, the upper shell and the lower shell are connected, the upper shell is provided with two first pits spaced apart along the first direction, the lower shell is provided with two second pits spaced apart along the first direction, each of the first pits is connected to one of the second pits to form the accommodating cavity.

10. A method for preparing a battery according to any one of claims 1 to 9, characterized in that: The method for preparing the battery comprises the following steps: Punching and forming a packaging film, wherein the packaging film is provided with two first pits spaced apart along the first direction, an isolation seal area between the two first pits, and a top seal area located on one side of the two first pits; Placing two electrode assemblies in the two first pits respectively, folding the packaging film, hot-pressing the isolation sealing area to form an isolation sealing portion, hot-pressing the top sealing area to form a top sealing portion, and the two first pits to form two accommodating cavities; The top seal portion is bent toward the first wall, the circuit board assembly is disposed on one side surface of the top seal portion, and each electrode assembly is electrically connected to the circuit board assembly through a tab group.

11. The method for preparing a battery according to claim 10, characterized in that: The packaging film is punched and formed, and the packaging film is provided with two second pits spaced apart along the first direction, and each of the first pits is connected to one of the second pits to form the accommodating cavity.

12. An electronic device, characterized in that: The electronic device comprises the battery according to any one of claims 1 to 9.

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