Battery, battery preparation method, battery pack and electric device

Abstract

Provided in the present application are a battery, a battery preparation method, a battery pack and an electric device. The battery comprises: a bare cell and a casing. The bare cell comprises a plurality of positive electrode sheets and a plurality of negative electrode sheets, each positive electrode sheet being provided with a positive tab, and each negative electrode sheet being provided with a negative tab. All the positive tabs are stacked in a first direction to form a first tab group, and all the negative tabs are stacked in the first direction to form a second tab group, the first direction being the direction of height of the bare cell. The casing comprises a first top cover and a second top cover. The first top cover is provided with a positive terminal post, and the second top cover is provided with a negative terminal post. The side of the positive terminal post that is close to the bare cell is provided with a first opening. The side of the negative terminal post that is close to the bare cell is provided with a second opening. The first tab group is fitted within the first opening and welded to the positive terminal post, and the positive terminal post is pressed against the first tab group. The second tab group is fitted within the second opening and welded to the negative terminal post, and the negative terminal post is pressed against the second tab group. The welding of tabs to top covers is avoided, improving the welding success rate of the tabs.

Description

Batteries, battery manufacturing methods, battery packs and electrical devices This application claims priority to Chinese Patent Application No. 202410987538.X, filed on July 23, 2024, entitled "Battery, Battery Preparation Method, Battery Pack and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery, a battery preparation method, a battery pack, and an electrical device. Background Technology

[0002] Blade batteries are suitable for a variety of electrical devices due to their thin design, including electric vehicles and energy storage devices.

[0003] In related technologies, too many electrode layers in blade batteries can lead to excessively thick tabs. Consequently, the welding process for soldering the tabs to the top cover cannot be improved, resulting in low tab welding yield and affecting the stability of the connection between the electrode and the external circuitry. Summary of the Invention

[0004] This application provides a battery, a battery manufacturing method, a battery pack, and an electrical device, which improves the stability of the connection between the electrode and the external circuit.

[0005] In a first aspect, this application provides a battery, comprising: a bare cell and a casing. The bare cell includes multiple layers of positive electrode sheets and multiple layers of negative electrode sheets, each layer of the positive electrode sheet having a positive electrode tab, and each layer of the negative electrode sheet having a negative electrode tab. All the positive electrode tabs are stacked along a first direction to form a first tab group, and all the negative electrode tabs are stacked along the first direction to form a second tab group, the first direction being the height direction of the bare cell. The casing includes a first top cover and a second top cover. The first top cover and the second top cover are respectively disposed on both sides of the bare cell along a second direction. The second direction is perpendicular to the first direction. A positive electrode post is provided on the first top cover, and a negative electrode post is provided on the second top cover. A first opening is provided on the side of the positive electrode post near the bare cell. A second opening is provided on the side of the negative electrode post near the bare cell. The first tab group is sleeved within the first opening and welded to the positive electrode post, such that the positive electrode post presses against the first tab group. The second tab group is sleeved within the second opening and welded to the negative electrode post, such that the negative electrode post presses against the second tab group.

[0006] In summary, in the related technology, the first tab assembly is welded to the first top cover to electrically connect the positive electrode to the external circuit. The second tab assembly is welded to the second top cover to electrically connect the negative electrode to the external circuit. Excessive layers of the positive or negative electrode will result in an excessively thick first or second tab assembly, leading to a low welding yield between the tabs and the top cover.

[0007] Based on this, the first tab assembly is fitted into the first opening of the positive terminal post, and the positive terminal post presses against the first tab assembly, ensuring a stable connection between the first tab assembly and the positive terminal post. Welding the first tab assembly to the positive terminal post within the first opening avoids direct welding between the first tab assembly and the first top cover, thus solving the problem of low welding yield for the positive tab and improving the stability of the connection between the positive electrode and the external circuit. The second tab assembly is fitted into the second opening of the negative terminal post, and the negative terminal post presses against the second tab assembly, ensuring a stable connection between the second tab assembly and the negative terminal post. Welding the second tab assembly to the negative terminal post within the second opening avoids direct welding between the second tab assembly and the second top cover, thus solving the problem of low welding yield for the negative tab and improving the stability of the connection between the negative electrode and the external circuit.

[0008] In one possible design, both the positive and negative terminals are made of ductile conductive materials.

[0009] Based on the description of the above embodiments, both the positive and negative terminals are made of ductile conductive materials, which allows the positive and negative terminals to be easily shaped while having good conductivity, making it convenient for the positive and negative terminals to be pressed together.

[0010] In one possible design, both the positive and negative terminals can be made of aluminum.

[0011] Based on the description of the above embodiments, in addition to its good ductility and conductivity, aluminum material also possesses characteristics such as light weight and low cost. Using aluminum material for both the positive and negative terminals can reduce the battery's weight and lower its production cost.

[0012] In one possible design, the bare cell comprises one or more stacked cores, each stacking multiple layers of the positive electrode and multiple layers of the negative electrode. The positive electrode tabs of all the stacked cores are stacked along the first direction to form a first tab group. The negative electrode tabs of all the stacked cores are stacked along the first direction to form a second tab group.

[0013] Based on the description of the above embodiments, operators can freely combine one or more stacked cells to obtain bare cells with different numbers of electrodes, thereby obtaining batteries with different energy densities.

[0014] In one possible design, the weld width between the first tab assembly and the positive terminal is greater than or equal to 5 mm. The weld width between the second tab assembly and the negative terminal is greater than or equal to 5 mm.

[0015] Based on the description of the above embodiments, the weld width between the first tab assembly and the positive terminal post is greater than or equal to 5 mm, which is used to improve the stability of the connection between the positive electrode and the external circuit. The weld width between the second tab assembly and the negative terminal post is greater than or equal to 5 mm, which is used to improve the stability of the connection between the negative electrode and the external circuit.

[0016] Secondly, this application provides a method for preparing a battery, used to prepare the battery described in any of the above embodiments, the method comprising:

[0017] Obtain a bare battery cell, the bare battery cell comprising multiple layers of positive electrode sheets and multiple layers of negative electrode sheets stacked along a first direction.

[0018] A first tab assembly is obtained by stacking along a first direction on all the said positive electrode sheets.

[0019] Obtain a second tab assembly stacked along a first direction on all the said negative electrode sheets.

[0020] Obtain the positive and negative terminals.

[0021] A first opening is made on the positive terminal, and a second opening is made on the negative terminal.

[0022] The positive terminal is placed on the first top cover.

[0023] The negative terminal is placed on the second top cover.

[0024] The first electrode assembly is fitted into the first opening.

[0025] The positive terminal is pressed onto the first tab assembly by the first clamp.

[0026] The first tab assembly is welded onto the positive electrode post.

[0027] The second electrode assembly is fitted into the second opening.

[0028] The negative electrode post is pressed onto the second electrode assembly using a second clamp.

[0029] The second electrode assembly is welded onto the negative electrode post.

[0030] In one possible design, welding the first tab assembly to the positive terminal post includes: the first fixture having a first welding groove. The first tab assembly is welded to the positive terminal post along the first welding groove.

[0031] Based on the description of the above embodiments, when the first clamp clamps the first opening, the first electrode lug is welded to the positive electrode post along the first welding groove provided on the first clamp, which simplifies the welding process and reduces time costs.

[0032] In one possible design, welding the second tab assembly to the negative electrode post includes: the second clamp having a second welding groove. The second tab assembly is welded to the negative electrode post along the second welding groove.

[0033] Based on the description of the above embodiments, when the second clamp clamps the second opening, the second electrode lug is welded to the negative electrode post along the second welding groove provided on the second clamp, which simplifies the welding process and reduces time costs.

[0034] Thirdly, this application provides a battery pack including the battery described in any of the above embodiments, wherein one or more of the batteries are disposed in the battery pack.

[0035] Fourthly, this application provides an electrical device including the battery pack described in the above embodiments, the battery pack being used to provide electrical energy.

[0036] The battery manufacturing method, battery pack, and power-consuming device provided in the second, third, and fourth aspects and the embodiments of the second aspect above can be referred to for the beneficial effects brought about by the first aspect and the various possible implementations of the first aspect above, and will not be repeated here. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a cross-sectional view of a battery structure in an embodiment of this application.

[0039] Figure 2 is an enlarged view of part A in Figure 1.

[0040] Figure 3 is a schematic diagram of a bare battery cell in an embodiment of this application.

[0041] Figure 4 is a view from another perspective of Figure 3.

[0042] Figure 5 is a fracture view of a battery structure in an embodiment of this application.

[0043] Explanation of reference numerals in the attached figures:

[0044] 100 - Battery; 1 - Bare cell; 11 - First tab assembly; 12 - Second tab assembly; 2 - Housing; 21 - First top cover; 22 - Second top cover; 23 - Upper plastic; 24 - Lower plastic; 3 - Positive terminal; 31 - First opening; 4 - Negative terminal; 41 - Second opening; X - First direction; Y - Second direction. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0047] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and drawings of this application are intended to cover without excluding other meanings. The words "a" or "an" do not exclude the presence of multiples.

[0048] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0050] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0051] Furthermore, the descriptions of directions such as the X, Y, and Z directions used to explain the operation and construction of the components in this embodiment are not absolute but relative. Although these directions are appropriate when the components of the battery pack are in the positions shown in the figure, they should be interpreted differently when these positions change to correspond to the changes.

[0052] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0053] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).

[0054] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, "connection" or "linkage" in mechanical structures can refer to a physical connection, such as a fixed connection, for example, a connection fixed by fasteners, such as a connection fixed by screws, bolts, or other fasteners; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. In circuit structures, "connection" or "linkage" can refer not only to a physical connection but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is connected; it can also refer to the internal connection of two components. Signal connection can refer not only to signal connection through a circuit but also to signal connection through a media, such as radio waves. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0055] Electrical devices refer to electrical equipment that uses electrical energy to perform specific functions. Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. These devices provide various functions or services by being connected to a power source.

[0056] A battery pack, also known as a battery module or battery array, is a unit composed of multiple battery cells (such as lithium-ion battery cells) connected in series and / or parallel in a specific manner. This unit is designed to provide higher voltage and greater capacity to meet the needs of various applications, such as electric vehicles, energy storage systems, and drones.

[0057] A battery is the basic unit that makes up a battery pack, generally referring to a chemical device capable of generating electrical energy. In a battery pack, multiple individual batteries are connected in series or parallel to create the required voltage and current. For example, a common AA battery is a single cell containing chemical substances that convert chemical energy into electrical energy.

[0058] Blade batteries are a type of lithium-ion battery with a flat, blade-like shape. A blade battery can include a casing, a battery cell, a positive terminal, a negative terminal, and two top covers, with the battery cell and top covers housed within the casing.

[0059] The battery cell comprises a positive electrode, a negative electrode, and a separator. Multiple layers of positive electrode, negative electrode, and separator are stacked together to form the battery cell structure. Each positive electrode has a positive tab, and multiple layers of positive tabs stacked together form the first tab group. Each negative electrode has a negative tab, and multiple layers of negative tabs stacked together form the second tab group. Positive and negative terminals are respectively located on two top covers. The first tab group is electrically connected to the positive terminal, and the second tab group is electrically connected to the negative terminal.

[0060] In the manufacturing process of the blade battery cell, the first and second tab groups are welded to two top covers, respectively, so that the first tab group is electrically connected to the positive terminal and the second tab group is electrically connected to the negative terminal. Excessive layers in the positive or negative electrode result in an excessively thick first or second tab group, which existing welding processes cannot overcome, leading to low tab welding yield and thus affecting the stability of the connection between the electrode and the external circuitry.

[0061] To address the issue of low electrode tab welding yield, embodiments of this application provide a battery, a battery manufacturing method, a battery pack, and an electrical device. By providing openings on the positive and negative terminals and fitting the first and second electrode tab groups within these openings, welding of the first and second electrode tab groups to the top cover is avoided, thereby improving the electrode tab welding yield. The following detailed description is provided in conjunction with Figures 1-5 of the specification.

[0062] In a first aspect, as shown in Figures 1-3, this application provides a battery 100, including: a bare cell 1 and a casing 2. The bare cell 1 includes multiple layers of positive electrode sheets and multiple layers of negative electrode sheets. Each layer of positive electrode sheets has a positive electrode tab, and each layer of negative electrode sheets has a negative electrode tab. All positive electrode tabs are stacked along a first direction X to form a first tab group 11, and all negative electrode tabs are stacked along the first direction X to form a second tab group 12. The first direction X is the height direction of the bare cell 1. The casing 2 includes a first top cover 21 and a second top cover 22. The first top cover 21 and the second top cover 22 are respectively disposed on both sides of the bare cell 1 along a second direction Y. The second direction Y is perpendicular to the first direction X. The first top cover 21 has a positive electrode post 3, and the second top cover 22 has a negative electrode post 4. The positive electrode post 3 has a first opening 31 on the side near the bare cell 1. The negative electrode post 4 has a second opening 41 on the side near the bare cell 1. The first tab assembly 11 is fitted into the first opening 31 and welded to the positive electrode post 3, with the positive electrode post 3 pressing against the first tab assembly 11. The second tab assembly 12 is fitted into the second opening 41 and welded to the negative electrode post 4, with the negative electrode post 4 pressing against the second tab assembly 12.

[0063] The bare cell 1 may include a positive electrode, a negative electrode, and a separator.

[0064] Positive electrode sheet: The positive electrode sheet is mainly composed of active materials, conductive agents, binders, etc. These components are mixed into a slurry and coated on the current collector (usually aluminum foil or copper foil).

[0065] During charging and discharging, the active material on the positive electrode participates in chemical reactions, releasing or accepting electrons, thereby achieving energy storage and release.

[0066] Negative electrode sheet: The negative electrode sheet is mainly composed of active materials, conductive agents, binders, etc. These components are mixed into a slurry and coated on the current collector (usually copper foil).

[0067] During charging and discharging, the active material on the negative electrode accepts electrons from the external circuit, participates in chemical reactions, and stores energy.

[0068] Separator: The separator is located between the positive and negative electrodes of the battery 100 and is a very thin and breathable porous material. The separator is used to isolate the positive and negative electrodes, preventing them from coming into direct contact and causing a short circuit, while allowing lithium ions or other charged particles to pass through freely.

[0069] The diaphragm material is usually selected from materials with high chemical corrosion resistance, low electrical resistance, high mechanical strength and good thermal stability, such as polyolefins, ceramic-coated polyolefins or fluoropolymers.

[0070] Furthermore, as shown in Figure 1, a lower plastic 24 can also be provided in the housing 2 to press the diaphragm in the bare battery cell 1.

[0071] The terminals are an internal part of the battery 100, used to connect the positive and negative terminals of the battery 100 and provide a current path to the outside. Therefore, the terminals can be divided into positive terminal 3 and negative terminal 4.

[0072] Specifically, the positive terminal 3, also known as the positive terminal, is used to connect to the positive electrode material of the battery 100 and is usually marked with "+".

[0073] The negative terminal 4, also known as the negative terminal, is used to connect to the negative electrode material of the battery 100 and is usually marked with "-".

[0074] The positive electrode material of battery 100 can be a positive electrode sheet, and the negative electrode material of battery 100 can be a negative electrode sheet.

[0075] The top cover is one of the important components of the battery 100 package, mainly used to seal the inside of the battery 100 and prevent electrolyte leakage. As shown in Figure 2, the battery 100 may include a first top cover 21 and a second top cover 22, which are respectively disposed at both ends of the battery 100 along a second direction Y. As shown in Figure 1, the second direction Y is the length direction of the battery 100.

[0076] Specifically, the positive electrode post 3 can be fixed to the first top cover 21 by means of welding, threading or fasteners, providing a connection point for the positive electrode to the external circuit.

[0077] The negative electrode post 4 can be fixed to the second top cover 22 by means of welding, threading or fasteners, providing a connection point for the negative electrode to the external circuit.

[0078] Furthermore, as shown in Figure 2, a plastic 23 can also be provided in the housing 2 to fix the positive terminal 3 and the negative terminal 4.

[0079] The bare cell 1 may include multiple electrode material units. Each electrode material unit may include a positive electrode layer, a separator layer, a negative electrode layer, and a separator layer stacked sequentially along a first direction X. As shown in Figure 3, the first direction X is the height direction of the bare cell 1. Therefore, the bare cell 1 may include multiple layers of positive electrode sheets stacked along the first direction X and multiple layers of negative electrode sheets stacked along the first direction X.

[0080] Each layer of positive electrode sheet is provided with a positive electrode tab, and the positive electrode tabs in the multi-layer positive electrode sheet are stacked along the first direction X to form a first electrode tab group 11. The first electrode tab group 11 is connected to the positive electrode post 3 or the first top cover 21, so that the positive electrode sheet is connected to the external circuit.

[0081] Each layer of negative electrode sheet has a negative electrode tab, and the negative electrode tabs in the multi-layer negative electrode sheet are stacked along the first direction X to form a second electrode tab group 12. The second electrode tab group 12 is connected to the negative electrode post 4 or the second top cover 22, so that the positive electrode sheet is connected to the external circuit.

[0082] The positive terminal 3 may include two sides, one side close to the bare cell 1 and the other side away from the bare cell 1.

[0083] As shown in Figure 2, the positive electrode post 3 has a first opening 31 on the side near the bare cell 1. A first tab assembly 11 is fitted into the first opening 31, allowing it to be soldered to the positive electrode post 3 within the opening 31. The side of the positive electrode post 3 furthest from the bare cell 1 is located outside the housing 2 and is used for electrical connection to an external circuit. Furthermore, the positive electrode post 3 presses against the first tab assembly 11, ensuring a stable connection between the first tab assembly 11 and the positive electrode post 3, thereby guaranteeing a stable connection between the positive electrode and the external circuit. Specifically, the positive electrode post 3 is tightened by external force at the first opening 31, so that the positive electrode post 3 tightly wraps around the first tab assembly 11, thus pressing against the first tab assembly 11.

[0084] The negative electrode post 4 has a second opening 41 on the side near the bare cell 1. The second tab assembly 12 is fitted into the second opening 41, so that the second tab assembly 12 is soldered to the negative electrode post 4 within the second opening 41. The side of the negative electrode post 4 away from the bare cell 1 is located on the outside of the housing 2, for electrical connection with an external circuit. Furthermore, the negative electrode post 4 presses the second tab assembly 12, so that the second tab assembly 12 and the negative electrode post 4 are firmly connected, thereby ensuring a stable connection between the negative electrode and the external circuit. Specifically, the negative electrode post 4 is tightened by external force at the second opening 41, so that the negative electrode post 4 tightly wraps the second tab assembly 12, thereby pressing the second tab assembly 12.

[0085] The blade battery 100 increases its energy density and charging efficiency by increasing the number of positive and negative electrode plates. Clearly, the number of positive electrode plates is positively correlated with the thickness of the first tab group 11. Similarly, the number of negative electrode plates is positively correlated with the thickness of the second tab group 12.

[0086] In summary, in the related technology, the first tab assembly 11 is welded to the first top cover 21 to electrically connect the positive electrode to the external circuit. The second tab assembly 12 is welded to the second top cover 22 to electrically connect the negative electrode to the external circuit. Excessive layers of the positive or negative electrode will result in an excessively thick first tab assembly 11 or second tab assembly 12, leading to a low welding yield between the tabs and the top cover.

[0087] Based on this, the first tab assembly 11 is fitted into the first opening 31 of the positive electrode post 3, and the positive electrode post 3 presses the first tab assembly 11 firmly, so that the first tab assembly 11 and the positive electrode post 3 are stably connected. The first tab assembly 11 is welded to the positive electrode post 3 within the first opening 31, which avoids direct welding of the first tab assembly 11 to the first top cover 21, thereby solving the problem of low welding yield of the positive tab and improving the stability of the connection between the positive electrode sheet and the external circuit. The second tab assembly 12 is fitted into the second opening 41 of the negative electrode post 4, and the negative electrode post 4 presses the second tab assembly 12 firmly, so that the second tab assembly 12 and the negative electrode post 4 are stably connected. The second tab assembly 12 is welded to the negative electrode post 4 within the second opening 41, which avoids direct welding of the second tab assembly 12 to the second top cover 22, thereby solving the problem of low welding yield of the negative tab and improving the stability of the connection between the negative electrode sheet and the external circuit.

[0088] In some embodiments, both the positive electrode post 3 and the negative electrode post 4 are conductive materials with ductility.

[0089] Good conductive materials with good ductility usually refer to metals and alloys with good mechanical flexibility and ductility. These materials can still maintain good electrical conductivity when stretched, bent and repeatedly deformed.

[0090] Ductile materials possess properties such as high mechanical strength and strong deformability. Using ductile materials to make the terminals makes them less prone to breakage under compression stress, thus increasing their durability. It also allows for easy shaping of the positive terminal 3 and the negative terminal 4, facilitating their compression.

[0091] Based on the description of the above embodiments, both the positive electrode post 3 and the negative electrode post 4 are conductive materials with ductility, which allows the positive electrode post 3 and the negative electrode post 4 to be easily shaped while having good conductivity, making it convenient for the positive electrode post 3 and the negative electrode post 4 to be pressed together.

[0092] Furthermore, in some embodiments, both the positive electrode post 3 and the negative electrode post 4 can be made of aluminum.

[0093] Based on the description of the above embodiments, in addition to having good ductility and conductivity, aluminum material also has the characteristics of being lightweight and inexpensive. Using aluminum material for the positive electrode post 3 and the negative electrode post 4 can reduce the weight of the battery 100 and lower its production cost.

[0094] In some embodiments, the bare cell 1 includes one or more stacked cores, each stacked core including multiple layers of positive electrode plates and multiple layers of negative electrode plates. The positive electrode tabs of all the stacked cores are stacked along a first direction X to form a first tab group 11. The negative electrode tabs of all the stacked cores are stacked along the first direction X to form a second tab group 12.

[0095] A stacked core may include multiple electrode material units. A bare cell 1 may include one or more stacked cores.

[0096] When a bare cell 1 includes a stacked core, the number of electrodes in the bare cell 1 is equal to the number of electrodes in the stacked core.

[0097] When a bare cell 1 includes multiple stacked cores, the number of electrodes in the bare cell 1 is the sum of the number of electrodes in the multiple stacked cores.

[0098] The number of electrode layers in each pair of stacked cores can be the same or different.

[0099] For example, a bare cell 1 comprises three stacked cores. The first and second stacked cores each contain 10 positive electrode plates and 10 negative electrode plates, while the third stacked core contains 20 positive electrode plates and 20 negative electrode plates. In this case, bare cell 1 comprises 40 positive electrode plates and 40 negative electrode plates.

[0100] As can be seen from the above, the blade battery 100 increases its energy density by increasing the number of positive and negative electrode plates. Clearly, the operator can control the number of positive and negative electrode plates in the bare cell 1 according to the required energy density of the battery 100.

[0101] In summary, operators can freely combine one or more stacked cells to obtain bare cells 1 with different numbers of electrodes, thereby obtaining batteries 100 with different energy densities.

[0102] In some embodiments, the weld width between the first tab group 11 and the positive electrode post 3 is greater than or equal to 5 mm. The weld width between the second tab group 12 and the negative electrode post 4 is greater than or equal to 5 mm.

[0103] The first tab assembly 11 and the positive electrode post 3 can be connected by laser welding. The weld width of the laser welding needs to be at least 5mm to ensure the welding strength between the first tab assembly 11 and the positive electrode post 3, thereby improving the stability of the connection between the positive electrode and the external circuit.

[0104] Similarly, the second tab assembly 12 and the negative electrode post 4 can be connected by laser welding. The weld width of the laser welding needs to be at least 5mm to ensure the welding strength between the second tab assembly 12 and the negative electrode post 4, thereby improving the stability of the connection between the negative electrode and the external circuit.

[0105] Based on the description of the above embodiments, the weld width between the first tab group 11 and the positive electrode post 3 is greater than or equal to 5 mm, which is used to improve the stability of the connection between the positive electrode and the external circuit. The weld width between the second tab group 12 and the negative electrode post 4 is greater than or equal to 5 mm, which is used to improve the stability of the connection between the negative electrode and the external circuit.

[0106] Secondly, this application provides a method for preparing a battery, used to prepare the battery described in any of the above embodiments, the method comprising:

[0107] Step 1: Obtain a bare cell, which includes multiple layers of positive electrode sheets and multiple layers of negative electrode sheets stacked along a first direction.

[0108] Step 2: Obtain the first tab group stacked along the first direction on all the positive electrode sheets.

[0109] Step 3: Obtain the second tab assembly stacked along the first direction on all the negative electrode sheets.

[0110] Step 4: Obtain the positive and negative terminals.

[0111] Step 5: Open a first opening on the positive terminal and open a second opening on the negative terminal.

[0112] Step 6: Place the positive terminal on the first top cover.

[0113] Step 7: Place the negative terminal on the second top cover.

[0114] Step 8: Fit the first electrode assembly into the first opening.

[0115] Step 9: Press the positive terminal onto the first tab assembly using the first clamp.

[0116] Step 10: Weld the first tab assembly onto the positive terminal post.

[0117] Step 11: Fit the second electrode assembly into the second opening.

[0118] Step 12: Press the negative terminal onto the second electrode assembly using the second clamp.

[0119] Step 13: Weld the second electrode assembly onto the negative electrode post.

[0120] In some embodiments, step ten includes: the first fixture is provided with a first welding groove. The first electrode assembly is welded to the positive electrode post along the first welding groove.

[0121] Based on the description of the above embodiments, when the first clamp clamps the first opening, the first electrode lug is welded to the positive electrode post along the first welding groove provided on the first clamp, which simplifies the welding process and reduces time costs.

[0122] Furthermore, the width of the first welding groove needs to be greater than or equal to 5mm so that the weld width between the first electrode lug and the positive electrode post is greater than or equal to 5mm.

[0123] In some embodiments, step twelf includes: the second fixture having a second welding groove; and the second electrode lug being welded to the negative electrode post along the second welding groove.

[0124] Based on the description of the above embodiments, when the second clamp clamps the second opening, the second electrode lug is welded to the negative electrode post along the second welding groove provided on the second clamp, which simplifies the welding process and reduces time costs.

[0125] Furthermore, the width of the second welding groove needs to be greater than or equal to 5mm so that the weld width between the second electrode lug and the negative electrode post is greater than or equal to 5mm.

[0126] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0127] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery, characterized by, The battery includes a bare cell and a shell. The bare cell includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, each of the positive electrode sheets being provided with a positive tab, and each of the negative electrode sheets being provided with a negative tab. All the positive tabs are stacked into a first tab group along a first direction, and all the negative tabs are stacked into a second tab group along the first direction, the first direction being a height direction of the bare cell. The shell includes a first top cover and a second top cover. The first top cover and the second top cover are respectively arranged on two sides of the bare cell along a second direction. The second direction is perpendicular to the first direction. The first top cover is provided with a positive post, and the second top cover is provided with a negative post. The positive post is provided with a first opening near one side of the bare cell. The negative post is provided with a second opening near one side of the bare cell. The first tab group is sleeved in the first opening and welded with the positive post, and the positive post is pressed against the first tab group. The second tab group is sleeved in the second opening and welded with the negative post, and the negative post is pressed against the second tab group.

2. The battery of claim 1, wherein, The positive post and the negative post are both made of a ductile conductive material.

3. The battery of claim 2, wherein, The positive post and the negative post are both made of aluminum material.

4. The battery of claim 1, wherein, The bare cell includes one or more stacked cells, and each of the stacked cells includes a plurality of the positive electrode sheets and a plurality of the negative electrode sheets. The positive tabs of all the stacked cells are stacked into the first tab group along the first direction. The negative tabs of all the stacked cells are stacked into the second tab group along the first direction.

5. The battery of claim 1, wherein, The welding seam width between the first tab group and the positive post is greater than or equal to 5 mm. The welding seam width between the second tab group and the negative post is greater than or equal to 5 mm.

6. A method for producing a battery according to any one of claims 1 to 5, characterized by The method includes: obtaining a bare cell, the bare cell including a plurality of positive electrode sheets and a plurality of negative electrode sheets stacked along a first direction; obtaining a first tab group stacked along the first direction on all the positive electrode sheets; obtaining a second tab group stacked along the first direction on all the negative electrode sheets; obtaining a positive post and a negative post; opening a first opening on the positive post and a second opening on the negative post; arranging the positive post on a first top cover; arranging the negative post on a second top cover; sleeving the first tab group in the first opening; pressing the positive post against the first tab group by a first clamp; welding the first tab group on the positive post; sleeving the second tab group in the second opening; pressing the negative post against the second tab group by a second clamp; and welding the second tab group on the negative post.

7. The method of claim 6, wherein, The welding of the first tab group on the positive post includes: the first clamp is provided with a first welding groove; the first tab group is welded on the positive post along the first welding groove.

8. The method of claim 6, wherein, The welding of the second tab group on the negative post includes: the second clamp is provided with a second welding groove; the second tab group is welded on the negative post along the second welding groove.

9. A battery pack including the battery of any one of claims 1-5, and the battery pack being provided with one or more of the batteries.

10. An electrically powered device comprising the battery pack of claim 9, the battery pack being used to provide electrical power.

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