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

Abstract

The utility model provides a battery cell, a blade battery, a battery pack and an electric device. The battery cell comprises a plurality of stacked cells, a plurality of first connecting pieces and a plurality of second connecting pieces, the laminated core comprises multiple layers of positive plates and multiple layers of negative plates, one end of each layer of positive plate is provided with a positive tab, and one end of each layer of negative plate is provided with a negative tab. All the positive tabs are stacked in the first direction to form a first tab group, and all the tabs are stacked in the first direction to form a second tab group. The first connecting piece comprises a first integration part and a first fixing part; the first integration part is welded with the first tab group; the second connecting piece comprises a second integration part and a second fixing part, and the second integration part is welded with the second tab group. And the number of the first connecting pieces is equal to that of all the first tab groups. And the number of the second connecting pieces is equal to that of all the second tab groups. All the stacked cores are stacked in the first direction. And all the first fixing parts and all the second fixing parts are welded with the top cover of the blade battery, so that the welding yield of the tabs is improved.

Description

Technical Field

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

[0002] Blade batteries are suitable for various electrical devices due to their thin design, including power vehicles, energy storage, and other equipment.

[0003] In related technologies, too many layers of electrode sheets in a blade battery can lead to extremely thick tabs. Based on this, when welding the tabs to the top cover, the welding process cannot be broken through, resulting in a low welding yield of the tabs, thereby affecting the stability of the connection between the electrode sheet and the external circuit. Summary of the Utility Model

[0004] The present application provides a battery cell, a blade battery, a battery pack, and an electrical device, which improve the welding yield of the tabs.

[0005] In a first aspect, the present application provides a battery cell for use in a blade battery. The battery cell includes: a plurality of stacked cores, a plurality of first connectors, and a plurality of second connectors. Each of the stacked cores includes multiple layers of positive electrode sheets and multiple layers of negative electrode sheets. One end of each layer of the positive electrode sheet is provided with a positive tab, and one end of each layer of the negative electrode sheet is provided with a negative tab. The positive tabs in each of the stacked cores are stacked in a first direction to form a first tab group, and the negative tabs in each of the stacked cores are stacked in the first direction to form a second tab group. Herein, the first direction is the height direction of the battery cell. The first connector includes a first integrated portion and a first fixing portion, and the first integrated portion is welded to the first tab group. The second connector includes a second integrated portion and a second fixing portion, and the second integrated portion is welded to the second tab group. The number of the first connectors is equal to the number of all the first tab groups. The number of the second connectors is equal to the number of all the second tab groups. All the stacked cores are stacked in the first direction. All the first fixing portions and all the second fixing portions are welded to the top cover of the blade battery.

[0006] In the battery cell provided by the first aspect, in related technologies, all the positive tabs and negative tabs in the battery cell are directly welded to the top cover after pre-welding respectively. Based on this, in the battery cell provided by the present application, one first connector is provided to weld to the top cover instead of all the positive tabs in one first tab group, and one second connector is provided to weld to the top cover instead of all the negative tabs in one second tab group, reducing the thickness of the tab welded to the top cover and improving the welding yield of the tabs.

[0007] In a possible design, the number of layers of the positive electrode sheets in each of the stacked cores is less than or equal to 50. The number of layers of the negative electrode sheets in each of the stacked cores is less than or equal to 50.

[0008] Based on the description of the above embodiments, the number of positive electrode sheets in each stacked core is less than or equal to 50 layers to ensure the welding strength of the first ear group, thereby improving the welding yield of the positive electrode ear. The number of negative electrode sheets in each stacked core is less than or equal to 50 layers to ensure the welding strength of the second ear group, thereby improving the welding yield of the negative electrode ear.

[0009] In a possible design, the number of positive electrode ears in any two of the stacked cores is the same. The number of negative electrode ears in any two of the stacked cores is the same.

[0010] Based on the description of the above embodiments, the number of positive electrode ears in any two stacked cores is the same, so that the current passing amount between the positive electrode ears of any two stacked cores and the external circuit is the same, so as to evenly distribute the current passing amount of the battery positive electrode. The number of negative electrode ears in any two stacked cores is the same, so that the current passing amount between the negative electrode ears of any two stacked cores and the external circuit is the same, so as to evenly distribute the current passing amount of the battery negative electrode.

[0011] In a possible design, the two top covers are respectively arranged at both ends of the battery along the second direction. The second direction is perpendicular to the first direction. The first connecting member and the second connecting member are both welded to one of the top covers. Alternatively, the first connecting member is welded to one of the top covers, and the second connecting member is welded to the other top cover.

[0012] Based on the description of the above embodiments, the first connecting member and the second connecting member can be welded to the same top cover or respectively welded to two top covers. The operator can select and match according to needs.

[0013] In a possible design, a part of the first connecting members is welded to one of the top covers. Another part of the first connecting members is welded to the other top cover.

[0014] Based on the description of the above embodiments, a part of the first connecting members is welded to one of the top covers, and another part of the first connecting members is welded to the other top cover. This reduces the pre-welding thickness of the first ear group and further improves the welding yield of the positive electrode ear.

[0015] In a possible design, a part of the second connecting members is welded to one of the top covers. Another part of the second connecting members is welded to the other top cover.

[0016] Based on the description of the above embodiments, a part of the second connecting members is welded to one of the top covers, and another part of the second connecting members is welded to the other top cover. This reduces the pre-welding thickness of the second ear group and further improves the welding yield of the negative electrode ear.

[0017] In a possible design, the first connecting member is welded to the first adapter plate, and the first adapter plate is connected to the top cover. The second connecting member is welded to the second adapter plate, and the second adapter plate is connected to the top cover.

[0018] Based on the description of the above embodiments, a first adapter plate is provided between the top cover and the first connecting member. A second adapter plate is provided between the top cover and the second connecting member, making the connection between the battery cell and the external circuit more reliable.

[0019] In a second aspect, the present application provides a battery cell, including a housing, a top cover, and the battery cell described in any one of the above embodiments. Two of the top covers are respectively provided at both ends of the battery cell. The two top covers and the battery cell are all provided in the housing.

[0020] In a third aspect, the present application provides a battery pack, including the battery cell described in the above embodiments, and one or more of the blade batteries are provided in the battery pack.

[0021] In a fourth aspect, the present application provides an electrical device, including the battery pack described in the above embodiments, and the battery pack is used to provide electrical energy.

[0022] For the blade battery, battery pack, and electrical device provided in the above second, third, and fourth aspects, the beneficial effects can refer to the beneficial effects brought by the first aspect and each possible implementation manner of the first aspect, which will not be elaborated here. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic structural diagram of a battery cell provided by an embodiment of the present application.

[0025] Figure 2 It is a schematic structural diagram of four stacked battery cells provided by an embodiment of the present application.

[0026] Figure 3 It is a schematic structural diagram of a stacked battery cell provided by an embodiment of the present application.

[0027] Figure 4 It is a schematic structural diagram of another battery cell provided by an embodiment of the present application.

[0028] Description of the Reference Numerals:

[0029] 100 - battery cell;

[0030] 1 - Stacked core; 11 - First tab group; 111 - First part; 112 - Second part; 12 - Second tab group; 121 - Third part; 122 - Fourth part;

[0031] 13 - First connecting member; 131 - First integrated part; 132 - First fixing part; 14 - Second connecting member; 141 - Second integrated part; 142 - Second fixing part;

[0032] 15 - First adapter piece; 16 - Second adapter piece;

[0033] 2 - Top cover;

[0034] X - First direction; Y - Second direction; Z - Third direction. Detailed implementation manners

[0035] To make the objectives, 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 and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0036] 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 the present application in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0037] The terms "including" and "having" and any variations thereof in the description and claims of this application and the accompanying drawings are intended to cover but not exclude other elements. The word "a" or "an" does not exclude the presence of a plurality.

[0038] Referring to "embodiments" herein means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase "embodiments" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0039] In this document, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this document, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0040] The orientation terms appearing in the following descriptions are all the directions shown in the figures and do not limit the specific structure of this application. For example, in the description of this application, terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to this application.

[0041] In addition, expressions indicating directions such as the X direction, Y direction, and Z direction used to explain the operation and structure of each component of this embodiment are not absolute but relative. Although these indications are appropriate when the components of the battery pack are in the positions shown in the figures, when these positions change, these directions should have different interpretations to correspond to the change.

[0042] In addition, terms such as "first", "second", etc. in the description, claims, or the above-mentioned drawings of this application are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more of such features.

[0043] In the description of this application, unless otherwise specified, the meaning of "a plurality" refers to two or more (including two). Similarly, "a plurality of groups" refers to two or more groups (including two groups).

[0044] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "linked" should be understood in a broad sense. For example, the "connection" or "link" of a mechanical structure can refer to a physical connection. For example, a physical connection can be a fixed connection, such as a fixed connection through a fixing member, such as a fixed connection through screws, bolts, or other fixing members; a physical connection can also be a detachable connection, such as a snap connection or a clamping connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. The "connection" or "link" of a circuit structure can refer to not only a physical connection but also an electrical connection or a signal connection. For example, it can be a direct connection, that is, a physical connection, or it can be indirectly connected through at least one intermediate component, as long as the circuit is connected. It can also be the connection of two components inside; a signal connection can refer to not only a signal connection through a circuit but also a signal connection through a media medium, such as radio waves. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] An electrical appliance refers to an electrical device that uses electrical energy to complete specific functions. Electrical appliances can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, and so on. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric plane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc. The above devices are powered by connecting to a power source to provide various functions or services.

[0046] A battery pack, also known as a battery module or a battery array, is an integral formed by connecting multiple battery cells (such as lithium-ion battery cells) in series and / or in parallel in a specific manner. This integral is designed to provide a higher voltage and a larger capacity to meet the requirements of various applications, such as electric vehicles, energy storage systems, and drones.

[0047] A battery cell refers to the basic unit that makes up a battery pack, usually referring to a chemical device that can generate electrical energy. In a battery pack, multiple battery cells are connected in series or in parallel to form the required voltage and current. For example, the common AA battery is a single battery cell, which contains chemical substances inside and can convert chemical energy into electrical energy.

[0048] The blade battery is a type of lithium-ion battery with a flat shape, similar to a blade. The blade battery may include a housing, battery cells, and two top covers, and the battery cells and the top covers are both disposed in the housing. Each battery cell includes a positive electrode plate, a negative electrode plate, and a separator. Multiple layers of positive electrode plates, multiple layers of negative electrode plates, and multiple layers of separators are stacked together to form a battery cell structure. Among them, positive electrode tabs are provided on all the positive electrode plates, and negative electrode tabs are provided on all the negative electrode plates. During the preparation process of the battery cells of the blade battery, all the positive electrode tabs and all the negative electrode tabs need to be welded to the top cover. If the number of layers of the positive electrode plate or the negative electrode plate is too large, the thickness of the positive electrode tab or the negative electrode tab will be too thick, and the existing welding process cannot break through, resulting in a low yield of tab welding.

[0049] To solve the problem of low welding yield of ultra-thick tabs, the embodiments of the present application provide a battery cell, a battery module, a battery pack, and an electrical device. By providing multiple first connectors to weld to the top cover instead of the positive electrode tabs, and providing multiple second connectors to weld to the top cover instead of the negative electrode tabs, the thickness of the tab welded to the top cover is reduced, and the welding yield of the tabs is improved. The following will be described in detail with reference to the accompanying drawings. Figures 1-4 For detailed description.

[0050] In a first aspect, the present application provides a battery cell 100 for use in a blade battery. The battery cell 100 includes: multiple stacked battery cells 1, multiple first connectors 13, and multiple second connectors 14. Each stacked battery cell 1 includes multiple layers of positive electrode plates and multiple layers of negative electrode plates. One end of each layer of positive electrode plate is provided with a positive electrode tab, and one end of each layer of negative electrode plate is provided with a negative electrode tab. The positive electrode tabs in each stacked battery cell 1 are stacked along a first direction X to form a first tab group 11, and the negative electrode tabs in each stacked battery cell 1 are stacked along the first direction X to form a second tab group 12. Among them, the first direction X is the height direction of the battery cell 100. The first connector 13 includes a first integrated portion 131 and a first fixing portion 132, and the first integrated portion 131 is welded to the first tab group 11. The second connector 14 includes a second integrated portion 141 and a second fixing portion 142, and the second integrated portion 141 is welded to the second tab group 12. The number of the first connectors 13 is equal to the number of all the first tab groups 11. The number of the second connectors 14 is equal to the number of all the second tab groups 12. All the stacked battery cells 1 are stacked along the first direction X. All the first fixing portions 132 and all the second fixing portions 142 are welded to the top cover 2 of the blade battery.

[0051] One stacked battery cell 1 may include multiple layers of positive electrode plates and multiple layers of negative electrode plates.

[0052] Among them, one end of the positive electrode plate extends with a positive electrode tab, and one end of the negative electrode plate extends with a negative electrode tab. The positive electrode tab is used to connect the positive electrode plate to the positive electrode terminal, and the negative electrode tab is used to connect the negative electrode plate to the negative electrode terminal.

[0053] The top cover 2 is provided with a positive terminal and a negative terminal, and the terminals are used to provide a current path for an external circuit. The positive tab is connected to the top cover 2 so that the positive electrode plate is connected to the positive terminal, thereby connecting the positive electrode of the battery to the external circuit. The negative tab is connected to the top cover 2 so that the negative electrode plate is connected to the negative terminal, thereby connecting the negative electrode of the battery to the external circuit.

[0054] The positive tabs on all the positive electrode plates in the stacked core 1 are stacked in the first direction X to form a first tab group 11, and the first tab group 11 is welded to the first connecting member 13. The negative tabs on all the negative electrode plates in the stacked core 1 are stacked in the first direction X to form a second tab group 12, and the second tab group 12 is welded to the second connecting member 14. Herein, the first direction X is the height direction of the battery cell 100.

[0055] Furthermore, the battery cell 100 may include a plurality of stacked cores 1. One first tab group 11 in the stacked core 1 corresponds to one first connecting member 13, and one second tab group 12 in the stacked core 1 corresponds to one second connecting member 14. That is, the number of the first connecting members 13 is equal to the number of the first tab groups 11. The number of the second connecting members 14 is equal to the number of the second tab groups 12.

[0056] For an example, referring to Figure 2 , the battery cell 100 may include four stacked cores 1, and the four stacked cores 1 include four first tab groups 11 and four second tab groups 12. The four first tab groups 11 are respectively welded to the four first connecting members 13. At the same time, the above four first connecting members 13 are all welded to the top cover 2 so that the positive tabs in the above four stacked cores 1 are all connected to the top cover 2, thereby enabling the positive electrode of the battery to be connected to the external circuit.

[0057] Specifically, the first connecting member 13 may include a first integrated portion 131 and a first fixing portion 132. The first integrated portion 131 is one end of the first connecting member 13 close to the first tab group 11, and the first fixing portion 132 is one end of the first connecting member 13 close to the top cover 2. The above four first tab groups 11 are respectively welded to the four first integrated portions 131, and the above four first fixing portions 132 are welded together on the top cover 2 so that the first tab group 11 is connected to the top cover 2.

[0058] Similarly, the above four second tab groups 12 are respectively welded to the four second connecting members 14. At the same time, the above four second connecting members 14 are all welded to the top cover 2 so that the negative tabs in the above four stacked cores 1 are all connected to the top cover 2, thereby enabling the negative electrode of the battery to be connected to the external circuit.

[0059] Specifically, the second connecting member 14 may include a second integrated portion 141 and a second fixing portion 142. The second integrated portion 141 is one end of the second connecting member 14 close to the second tab group 12, and the second fixing portion 142 is one end of the second connecting member 14 close to the top cover 2. Weld the four second tab groups 12 to the four second integrated portions 141 respectively, and weld the top cover 2 to the second fixing portion 142, so as to connect the second tab group 12 with the top cover 2.

[0060] The first connecting member 13 and the second connecting member 14 may be of a thin plate structure. Among them, the shape of the thin plate structure may be rectangular, circular, polygonal, etc., and no specific limitation is made here.

[0061] Further, referring to Figure 2 , the four stacked cores 1 are stacked along the first direction X, and the first tab groups 11 and the second tab groups 12 of the four stacked cores 1 are respectively cut and integrated to different lengths to adapt to the different distances between the four stacked cores 1 and the top cover 2. Exemplarily, as Figure 3 shown is the first tab group 11 after cutting and integrating and the second tab group 12 without cutting and integrating in one of the stacked cores 1.

[0062] In the related art, all the positive tabs and negative tabs of the battery cell 100 are pre-welded respectively and then directly welded to the top cover 2. Based on this, in the battery cell 100 provided in the present application, a first connecting member 13 is provided to weld to the top cover 2 instead of all the positive tabs in one first tab group 11, and a second connecting member 14 is provided to weld to the top cover 2 instead of all the negative tabs in one second tab group 12, reducing the thickness of the tab welded to the top cover 2 and improving the welding yield of the tab.

[0063] For example, in one first tab group 11, there are 40 layers of positive tabs. After being shaped, the 40 layers of positive tabs are pre-welded to the first integrated portion 131 of a first connecting member 13. After the first tab group 11 is pre-welded to the first integrated portion 131, only the thickness of one layer of the connecting member needs to be welded for the first fixing portion 132 to be welded to the top cover 2.

[0064] In some embodiments, the number of positive electrode sheets in each stacked core 1 is less than or equal to 50 layers. The number of negative electrode sheets in each stacked core 1 is less than or equal to 50 layers.

[0065] According to the above content, all the positive tabs in the stacked core 1 need to be pre-welded to form the first tab group 11. Similarly, all the negative tabs in the stacked core 1 need to be pre-welded to form the second tab group 12. The pre-welding welds all the positive tabs in the stacked core 1 together, so that all the positive electrode sheets in the stacked core 1 are interconnected. Similarly, the pre-welding welds all the negative tabs in the stacked core 1 together, so that all the negative electrode sheets in the stacked core 1 are interconnected.

[0066] The number of pre-welded positive electrode sheets or pre-welded negative electrode sheets is less than or equal to or greater than 50 layers to ensure the welding strength of the pre-welding, thereby improving the welding yield of the positive electrode tab and the negative electrode tab.

[0067] Based on the description of the above embodiments, the number of positive electrode sheets in each stacked core 1 is less than or equal to 50 layers to ensure the welding strength of the first electrode tab group 11, thereby improving the welding yield of the positive electrode tab. The number of negative electrode sheets in each stacked core 1 is less than or equal to 50 layers to ensure the welding strength of the second electrode tab group 12, thereby improving the welding yield of the negative electrode tab.

[0068] In some embodiments, the number of positive electrode tabs in any two stacked cores 1 is the same. The number of negative electrode tabs in any two stacked cores 1 is the same.

[0069] According to the above content, the positive electrode of the battery is connected to the external circuit through the positive electrode tab. The more the number of positive electrode tabs, the greater the current passing amount between the positive electrode of the battery and the external circuit. The negative electrode of the battery is connected to the external circuit through the negative electrode tab. The more the number of negative electrode tabs, the greater the current passing amount between the negative electrode of the battery and the external circuit.

[0070] Based on the description of the above embodiments, the number of positive electrode tabs in any two stacked cores 1 is the same, so that the current passing amount between the positive electrode tabs of any two stacked cores 1 and the external circuit is the same, so as to evenly distribute the current passing amount of the positive electrode of the battery. The number of negative electrode tabs in any two stacked cores 1 is the same, so that the current passing amount between the negative electrode tabs of any two stacked cores 1 and the external circuit is the same, so as to evenly distribute the current passing amount of the negative electrode of the battery.

[0071] In some embodiments, the two top covers 2 are respectively arranged at both ends of the battery along the second direction Y. The second direction Y is perpendicular to the first direction X. The first connecting member 13 and the second connecting member 14 are both welded to one of the top covers 2. Or, the first connecting member 13 is welded to one of the top covers 2, and the second connecting member 14 is welded to the other top cover 2.

[0072] Refer to Figure 1 and Figure 4 , all the first electrode tab groups 11 and all the second electrode tab groups 12 can be arranged at the same end of the battery cell 100 along the second direction Y, or can be respectively arranged at both ends of the battery cell 100 along the second direction Y. Wherein, the second direction Y is the length direction of the battery cell 100.

[0073] When all the first electrode tab groups 11 and all the second electrode tab groups 12 are arranged at the same end of the battery cell 100, all the first connecting members 13 and all the second connecting members 14 are both welded to one of the top covers 2. At this time, there is a gap between all the first connecting members 13 and all the second connecting members 14 in the third direction Z to avoid short circuit between the positive and negative electrodes of the battery. Wherein, the third direction Z is the width direction of the battery cell 100.

[0074] When all the first tab groups 11 and all the second tab groups 12 are arranged at the same end of the battery cell 100 along the second direction Y, all the first connecting members 13 are welded to one of the top covers 2, and all the second connecting members 14 are welded to the other top cover 2.

[0075] Based on the description of the above embodiments, the first connecting member 13 and the second connecting member 14 can be welded to the same top cover 2, or can be welded to two top covers 2 respectively. The operator can select and match according to needs.

[0076] In some embodiments, a part of the first connecting members 13 are welded to one of the top covers 2. Another part of the first connecting members 13 are welded to the other top cover 2.

[0077] As can be seen from the above, the first tab group 11 and the first connecting member 13 need to be pre-welded.

[0078] Refer to Figure 4 , the first tab group 11 is divided into a first part 111 and a second part 112. The first part 111 is arranged at one end of the battery cell 100 along the second direction Y, and the second part 112 is arranged at the other end of the battery cell 100 along the second direction Y. The first part 111 is welded to the first connecting member 13 provided on one of the top covers 2, and the second part 112 is welded to the first connecting member 13 provided on the other top cover 2, reducing the pre-welding thickness of the first tab group 11 to improve the welding strength of the first part 111 and the second part 112, and further improving the welding yield of the positive tabs.

[0079] Based on the description of the above embodiments, a part of the first connecting members 13 are welded to one of the top covers 2, and another part of the first connecting members 13 are welded to the other top cover 2. The pre-welding thickness of the first tab group 11 is reduced, and the welding yield of the positive tabs is further improved.

[0080] In some embodiments, a part of the second connecting members 14 are welded to one of the top covers 2. Another part of the second connecting members 14 are welded to the other top cover 2.

[0081] As can be seen from the above, the second tab group 12 and the second connecting member 14 need to be pre-welded.

[0082] Refer to Figure 4, the second tab group 12 is divided into a third part 121 and a fourth part 122. The third part 121 is disposed at one end of the battery cell 100 along the second direction Y, and the fourth part 122 is disposed at the other end of the battery cell 100 along the second direction Y. The third part 121 is welded to the second connecting member 14 provided on one of the top covers 2, and the fourth part 122 is welded to the second connecting member 14 provided on the other top cover 2, reducing the pre-welding thickness of the second tab group 12 to improve the welding strength of the third part 121 and the fourth part 122, and further improving the welding yield of the negative tab.

[0083] Based on the description of the above embodiments, a part of the second connecting member 14 is welded to one of the top covers 2, and the other part of the second connecting member 14 is welded to the other top cover 2. The pre-welding thickness of the second tab group 12 is reduced, and the welding yield of the negative tab is further improved.

[0084] In some embodiments, the first connecting member is welded to the first adapter piece 15, and the first adapter piece 15 is connected to the top cover 2. The second connecting member is welded to the second adapter piece 16, and the second adapter piece 16 is connected to the top cover 2.

[0085] The adapter piece may include the following advantages:

[0086] 1. Provide good electrical connection to ensure effective contact between the positive and negative electrodes of the battery and the electrodes on the top cover 2, and ensure the normal operation of the battery;

[0087] 2. Enhance the mechanical strength between the tab and the top cover 2 to prevent fracture or damage of the top cover 2 and the tab caused by mechanical stress;

[0088] 3. Provide a heat dissipation path for the electrode plate to improve the thermal stability of the battery;

[0089] 4. It has detachability, which is convenient for replacing or repairing the battery; 5. It can be designed standardly to improve the consistency of the battery cell 100 and reduce performance problems caused by manufacturing tolerances.

[0090] Specifically, the connection method between the first adapter piece 15 and the top cover 2 may include, but is not limited to, welding, screwing, riveting, etc., and no specific limitation is made here. Similarly, the connection method between the second adapter piece 16 and the top cover 2 may include, but is not limited to, welding, screwing, riveting, etc., and no specific limitation is made here.

[0091] Based on the description of the above embodiments, a first adapter piece 15 is provided between the top cover 2 and the first connecting member. A second adapter piece 16 is provided between the top cover 2 and the second connecting member, making the connection between the battery cell 100 and the external circuit more reliable.

[0092] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments means that it is within the scope of this application and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0093] As described above, the above embodiments are only used to illustrate the technical solutions of this application, rather than to limit it; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of this application.

Claims

1. A battery cell, applied to a blade battery, characterized in that: The battery core comprises: a plurality of stacked cores, a plurality of first connecting members and a plurality of second connecting members; Each of the stacked cores comprises multiple layers of positive electrode sheets and multiple layers of negative electrode sheets, one end of each layer of the positive electrode sheets is provided with a positive electrode ear, and one end of each layer of the negative electrode sheets is provided with a negative electrode ear; The positive electrode tabs in each stacked core are stacked along the first direction to form a first electrode tab group, and the negative electrode tabs in each stacked core are stacked along the first direction to form a second electrode tab group; Wherein, the first direction is the height direction of the battery cell; The first connecting member includes a first integrated portion and a first fixed portion, and the first integrated portion is welded to the first tab group; The second connecting member includes a second integrated portion and a second fixed portion, and the second integrated portion is welded to the second tab group; The number of the first connecting members is equal to the number of all the first electrode tab groups; The number of the second connecting members is equal to the number of all the second electrode tab groups; All the stacked cores are stacked along the first direction; All of the first fixing parts and all of the second fixing parts are welded to the top cover of the blade battery.

2. The battery cell according to claim 1, characterized in that: The number of positive electrode sheets in each stacked core is less than or equal to 50; The number of negative electrode sheets in each stacked core is less than or equal to 50.

3. The battery cell according to claim 2, characterized in that: The number of positive electrode ears in any two of the stacked cores is the same; The number of negative electrode ears in any two of the stacked cores is the same.

4. The battery cell according to claim 3, characterized in that: The two top covers are respectively arranged at two ends of the battery along the second direction; The second direction is perpendicular to the first direction; The first connecting member and the second connecting member are both welded to one of the top covers; or, The first connecting member is welded to one of the top covers, and the second connecting member is welded to the other top cover.

5. The battery cell according to claim 3, characterized in that: A portion of the first connecting member is welded to one of the top covers; Another part of the first connecting member is welded to another of the top covers.

6. The battery cell according to claim 3, characterized in that: A portion of the second connecting member is welded to one of the top covers; Another part of the second connecting member is welded to another of the top covers.

7. The battery cell according to any one of claims 4 to 6, characterized in that: The first connecting member is welded to the first adapter plate, and the first adapter plate is connected to the top cover; The second connecting member is welded to the second adapter plate, and the second adapter plate is connected to the top cover.

8. A blade battery, characterized in that: Comprising a shell, a top cover, and a battery cell as described in any one of claims 1 to 6; The two top covers are respectively arranged at two ends of the battery core; The two top covers and the battery core are both arranged in the shell.

9. A battery pack, characterized in that: Comprising the battery cell described in any one of claims 1 to 7, one or more blade batteries are arranged in the battery pack.

10. An electrical device, characterized in that: The battery pack according to claim 9 is used to provide electrical energy.

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