Cylindrical battery cell preparation method, cylindrical battery cell, battery, battery pack and electrical equipment

Abstract

The present invention relates to the field of vehicle manufacturing technology, and discloses a method for preparing a cylindrical battery cell, a cylindrical battery cell, a battery, a battery pack and an electrical device, including: preparing a plurality of battery cell stacks, the plurality of battery cell stacks including a diaphragm stack, a negative electrode stack and a positive electrode stack; stacking the plurality of battery cell stacks in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, placing a battery cell rod on the battery cell stack with the smallest length along the width direction, and rolling the plurality of battery cell stacks in turn outside the battery cell rod; fixing the plurality of battery cell stacks after rolling. The method for preparing a cylindrical battery cell of an embodiment of the present invention can avoid uneven distribution of structural stress of the inner ring battery cell stack, causing the inner ring battery cell stack to break, etc., by rolling the plurality of battery cell stacks in turn outside the battery cell rod, thereby extending the service life of the cylindrical battery cell, ensuring the reliability of the use of the cylindrical battery cell, and having a simple and easy-to-control process, low preparation cost, better use effect and wider application range.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle manufacturing, and in particular to a method for preparing a cylindrical battery cell, a cylindrical battery cell, a battery, a battery pack and electrical equipment. Background Art

[0002] Cylindrical cells are the most common lithium-ion batteries. Cylindrical cells are usually packaged in cylindrical steel shells, and the bare cells are made using a winding process. Cylindrical cells have the advantages of good consistency, high production efficiency, and strong heat dissipation capabilities at the system level. Traditional cylindrical cells are mostly set to a winding structure. The winding structure of cylindrical cells has high production efficiency and a simple and easy-to-control process. However, traditional cylindrical cells are spirally wound, and the structural stress distribution is uneven. The inner circle stress is large and the radial stress decreases. In long-term cycle tests, the inner circle is more likely to break, and there is room for improvement. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for preparing a cylindrical battery cell, which has a simple and easy-to-control process, low preparation cost, and can make the structural stress distribution of the cylindrical battery cell uniform, thereby extending the service life of the cylindrical battery cell.

[0004] A method for preparing a cylindrical battery cell according to an embodiment of the present invention comprises:

[0005] Prepare a plurality of battery core stacks, wherein the plurality of battery core stacks include a diaphragm stack, a negative electrode stack and a positive electrode stack;

[0006] Stacking the plurality of battery cell stacks in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, placing a battery cell stick on the battery cell stack with the smallest length and width along the width direction, and rolling the plurality of battery cell stacks around the battery cell stick in turn;

[0007] The plurality of battery core stacks after rolling are fixed.

[0008] According to the method for preparing a cylindrical battery cell of an embodiment of the present invention, by sequentially rolling a plurality of battery cell stacks around the outside of a battery cell rod, uneven distribution of structural stress of the inner circle battery cell stacks, resulting in breakage of the inner circle battery cell stacks, etc., can be avoided. The service life of the cylindrical battery cell can be extended, and the reliability of the use of the cylindrical battery cell can be ensured. The process is simple and easy to control, the preparation cost is low, the use effect is better, and the scope of application is wider.

[0009] According to some embodiments of the present invention, the method for preparing a cylindrical battery cell comprises preparing a plurality of battery cell stacks including:

[0010] Obtain the specification information of the target cylindrical battery cell;

[0011] According to the specification information, a stacking width and a stacking length of each battery cell stack are obtained in combination with a calculation method.

[0012] According to the method for preparing a cylindrical battery cell in some embodiments of the present invention, the combining calculation method to obtain the stacking width and stacking length of each battery cell stack includes:

[0013] Combined with the full circle calculation method, the stack width and stack length of each battery cell stack are calculated.

[0014] According to some embodiments of the present invention, in the method for preparing a cylindrical battery cell, fixing the plurality of battery cell stacks after rolling includes:

[0015] A plurality of the battery core stacks are rolled and bonded together, and the adjacent negative electrode stacks and positive electrode stacks are separated by the separator stack in the middle.

[0016] According to some embodiments of the present invention, the method for preparing a cylindrical battery cell, the preparing a plurality of battery cell stacks further comprises:

[0017] The tabs are prepared on the battery core stack formed into the negative electrode stack and the positive electrode stack.

[0018] According to some embodiments of the present invention, the method for preparing a cylindrical battery cell comprises:

[0019] Obtaining the preparation factors of the tab;

[0020] According to the manufacturing factors, the target number of the tabs of each of the battery cell stacks and the target area size of each of the tabs are determined.

[0021] According to the method for preparing a cylindrical battery cell in some embodiments of the present invention, the preparation factors include the minimum current capacity and current density of the tab.

[0022] According to some embodiments of the present invention, in the method for preparing a cylindrical battery cell, determining the target number of the tabs of each battery cell stack and the target area size of each tab according to the preparation factors includes:

[0023] Adjusting the number of tests on the tabs and the size of the test area on the tabs;

[0024] When the ratio of the total area of ​​the plurality of tabs of each battery cell stack to the total area of ​​the corresponding battery cell stack is between a set upper limit and a set lower limit, the corresponding test quantity is taken as the target quantity and the test area size is taken as the target area size.

[0025] According to the method for preparing a cylindrical battery cell in some embodiments of the present invention, preparing the tab comprises:

[0026] A plurality of the tabs are arranged at intervals on the long sides of the battery core stack.

[0027] The method for preparing a cylindrical battery cell according to some embodiments of the present invention further includes:

[0028] The tabs of a plurality of battery core stacks are connected together.

[0029] According to some embodiments of the present invention, in the method for preparing a cylindrical battery cell, connecting the tabs of the plurality of battery cell stacks comprises:

[0030] Bend at least part of the pole ears located in the same quadrant in the same direction, and stack and distribute them along the radial direction of the electric core rod;

[0031] Sequentially electrically connecting the tabs of the plurality of battery core stacks located in the same quadrant;

[0032] Among them, the tabs of the battery cell stack located in the innermost circle are stacked in a direction away from the battery cell rod, and the tabs of the battery cell stack located in the outermost circle are stacked in a direction close to the battery cell rod.

[0033] According to the method for preparing a cylindrical battery cell in some embodiments of the present invention, the tabs of a plurality of battery cell stacks are sequentially welded and connected.

[0034] According to some embodiments of the present invention, in the method for preparing a cylindrical battery cell, connecting the tabs of the plurality of battery cell stacks comprises:

[0035] The tabs located in the same quadrant are suitable for being connected by spot welding.

[0036] The invention also provides a cylindrical battery core.

[0037] According to the cylindrical battery cell of the embodiment of the present invention, the cylindrical battery cell comprises:

[0038] A plurality of battery cell stacks, wherein the plurality of battery cell stacks include a diaphragm stack, a negative electrode stack and a positive electrode stack;

[0039] A battery cell rod, wherein the plurality of battery cell stacks are sequentially rolled around the outside of the battery cell rod from the inside to the outside along the radial direction of the battery cell rod, and the plurality of battery cell stacks are sequentially stacked in the radial direction of the battery cell rod in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack.

[0040] According to some embodiments of the cylindrical battery cell of the present invention, each of the negative electrode stack is provided with a negative electrode tab, and each of the positive electrode stack is provided with a positive electrode tab;

[0041] Wherein, the negative electrode tabs of the plurality of negative electrode stacks are stacked in sequence along the radial direction of the battery rod;

[0042] And / or, the positive electrode tabs of the plurality of positive electrode stacks are stacked in sequence along the radial direction of the battery core rod.

[0043] According to some embodiments of the cylindrical battery cell of the present invention, among the plurality of negative electrode stacks, the negative electrode tab of at least one of the negative electrode stacks located in the innermost circle is stacked in a direction away from the battery cell rod, and the negative electrode tab of at least one of the negative electrode stacks located in the outermost circle is stacked in a direction close to the battery cell rod;

[0044] And / or, among the multiple positive electrode stacks, the positive electrode tabs of at least one of the positive electrode stacks located in the innermost circle are stacked in a direction away from the battery cell rod, and the positive electrode tabs of at least one of the positive electrode stacks located in the outermost circle are stacked in a direction close to the battery cell rod.

[0045] According to the cylindrical battery cell of some embodiments of the present invention, the positive electrode tab and the negative electrode tab are respectively located at two ends of the cylindrical battery cell in the width direction.

[0046] According to some embodiments of the cylindrical battery cell of the present invention, the width of the positive electrode stack is smaller than the width of the negative electrode stack, and the width of the negative electrode stack is smaller than the width of the diaphragm stack;

[0047] And / or, the areas of the multiple negative electrode tabs of each of the negative electrode stacks are the same;

[0048] And / or, the areas of the multiple positive electrode tabs of each of the positive electrode stacks are the same.

[0049] The invention also provides a battery.

[0050] A battery according to an embodiment of the present invention comprises any one of the cylindrical cells described above, wherein the cylindrical cell comprises a positive electrode tab and a negative electrode tab;

[0051] And, a shell, a negative electrode current collector and a positive electrode current collector, the battery rod and the plurality of battery core stacks are fixedly installed in the shell;

[0052] The negative electrode tabs in the same quadrant of the plurality of negative electrode stacks are welded and connected in sequence, and the negative electrode tabs in different quadrants of the plurality of negative electrode stacks are connected through the negative electrode current collecting plate;

[0053] And / or, the positive electrode tabs in the same quadrant of the plurality of positive electrode stacks are welded together in sequence, and the positive electrode tabs in different quadrants of the plurality of positive electrode stacks are connected through the positive current collecting plate.

[0054] The invention also provides a battery pack.

[0055] A battery pack according to an embodiment of the present invention includes the battery described above.

[0056] The invention also provides an electric device.

[0057] An electric device according to an embodiment of the present invention includes the battery pack described above.

[0058] The cylindrical battery cell, the battery, the battery pack, the electrical equipment and the method for preparing the cylindrical battery cell have the same advantages as those of the prior art, which will not be described in detail herein.

[0059] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0061] Figure 1 The process of preparing a cylindrical battery cell according to an embodiment of the present invention is as follows Figure 1 ;

[0062] Figure 2 The process of preparing a cylindrical battery cell according to an embodiment of the present invention is as follows Figure 2 ;

[0063] Figure 3 The process of preparing a cylindrical battery cell according to an embodiment of the present invention is as follows Figure 3 ;

[0064] Figure 4 The process of preparing a cylindrical battery cell according to an embodiment of the present invention is as follows Figure 4 ;

[0065] Figure 5 The process of preparing a cylindrical battery cell according to an embodiment of the present invention is as follows Figure 5 ;

[0066] Figure 6 Schematic diagram of the structure of a cylindrical battery cell according to an embodiment of the present invention Figure 1 ;

[0067] Figure 7 is a schematic diagram of a stacking process of battery cell stacks according to an embodiment of the present invention;

[0068] Figure 8 Schematic diagram of the structure of a cylindrical battery cell according to an embodiment of the present invention Figure 2 .

[0069] Reference numerals:

[0070] Cylindrical battery cell 100,

[0071] Battery cell rod 1, battery cell stack 2, and pole ear 3. DETAILED DESCRIPTION

[0072] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0073] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0074] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] Reference below Figure 1-Figure 8 The method for preparing the cylindrical battery cell 100 according to an embodiment of the present invention is described. The process is simple and easy to control, the preparation cost is low, and the structural stress distribution of the cylindrical battery cell 100 can be uniform, thereby extending the service life of the cylindrical battery cell 100.

[0076] As 1- Figure 8 As shown, a method for preparing a cylindrical battery cell 100 according to an embodiment of the present invention includes:

[0077] S1. Prepare a plurality of battery cell stacks 2, wherein the plurality of battery cell stacks 2 include a diaphragm stack, a negative electrode stack and a positive electrode stack;

[0078] S2, stacking a plurality of battery cell stacks 2 in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, placing a battery cell stick 1 on the battery cell stack 2 with the smallest length along the width direction, and rolling a plurality of battery cell stacks 2 around the battery cell stick 1 in sequence;

[0079] S3, fixing the multiple battery cell stacks 2 after rolling.

[0080] Among them, the cylindrical battery cell 100 is the most common lithium-ion battery. The cylindrical battery cell 100 is usually packaged in a cylindrical steel shell, and the bare battery cell is made using a winding process. The cylindrical battery cell 100 has the advantages of good consistency, high production efficiency, and strong heat dissipation capacity at the system level. When the cylindrical battery cell 100 is connected to an external load, the positive electrode material in the cylindrical battery cell 100 begins to chemically react with the negative electrode material. In this process, the positive electrode material releases oxygen ions and reduces itself to oxide. At the same time, the negative electrode material absorbs the above oxygen ions and oxidizes itself to lithium ions. And the electrons generated in the above process will flow through the external load, thereby generating current.

[0081] Specifically, a cell stack 2 is arranged in the cylindrical battery cell 100, and the cell stack 2 is arranged in plurality. When preparing the cylindrical battery cell 100, multiple cell stacks 2 need to be prepared. According to different specifications of the cylindrical battery cell 100, the length and width of the cell stack 2 arranged therein are also different. Therefore, cell stacks 2 of different sizes need to be prepared according to the actual specifications of the cylindrical battery cell 100. The multiple cell stacks 2 are all provided with a diaphragm stack, a negative electrode stack and a positive electrode stack. The diaphragm stack can be arranged between the negative electrode stack and the positive electrode stack to avoid short circuit caused by contact between the negative electrode stack and the positive electrode stack, and micropores are formed in the diaphragm stack to allow lithium ions to pass through to form a charge and discharge circuit, thereby ensuring operational reliability.

[0082] Among them, the battery cell stacks 2 can be stacked in sequence in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, that is, when multiple battery cell stacks 2 are stacked in sequence, it can be ensured that diaphragm stacks are arranged between the negative electrode stacks and the positive electrode stacks to ensure the operating reliability of the cylindrical battery cell 100, and the stacking order of the battery cell stacks 2 arranged on the outermost side of the cylindrical battery cell 100 in the radial direction can be set to diaphragm stack / negative electrode stack / diaphragm stack, that is, the innermost stack among the multiple battery cell stacks 2 is set as the diaphragm stack, and the outermost stack among the multiple battery cell stacks 2 is also set as the diaphragm stack, so as to isolate the external structure from affecting the operation of the negative electrode stack and the positive electrode stack, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0083] Furthermore, when the battery cell stacks 2 are stacked in sequence, a battery cell rod 1 is arranged at the top, that is, the battery cell rod 1 is close to the battery cell stack 2 with the smallest length and is arranged along the width direction, the battery cell rod 1 is arranged as a cylindrical structure, and multiple battery cell stacks 2 are arranged in sequence from the inside to the outside along the radial direction of the battery cell rod 1, each battery cell stack 2 is rolled around the outside of the battery cell rod 1, and in order to ensure that each battery cell stack 2 can be completely rolled around the outside of the battery cell rod 1, the length of the battery cell stack 2 from the inside to the outside along the radial direction of the battery cell rod 1 needs to be set to increase in sequence. That is, the length of the battery stack 2 arranged close to the battery rod 1 is the shortest, and the length of the battery stack 2 arranged far away from the battery rod 1 is the longest. The multiple battery stacks 2 are rolled in sequence from the inside to the outside along the radial direction to avoid staggering and the like, thereby ensuring installation reliability. The battery rod 1 and the multiple battery stacks 2 are all centrally aligned and stacked, so that the connections of the multiple battery stacks 2 after rolling are all aligned along the radial direction of the battery rod 1, and after the multiple battery stacks 2 are rolled, they can be fixed by using a stop glue or the like.

[0084] Among them, rolling refers to setting the battery cell rod 1 along the width direction of the battery cell stack 2, and the battery cell rod 1 is placed on the battery cell stack 2, that is, the battery cell rod 1 can be placed at the end of the battery cell stack 2, or at the middle of the battery cell stack 2, and the placement position is flexible. Both ends of the battery cell stack 2 surround the battery cell rod 1 along the circumference of the battery cell stack 2 at the same time, and each battery cell stack 2 in the preparation method is independent, so that the tension exerted on multiple battery cell stacks 2 after being stacked outside the battery cell rod 1 is uniform and the stress size is consistent, thereby avoiding the problem of easy breakage of the inner circle battery cell stack 2 and extending the service life of the cylindrical battery cell 100.

[0085] According to the method for preparing the cylindrical battery cell 100 of the embodiment of the present invention, by sequentially rolling a plurality of battery cell stacks 2 around the battery cell rod 1, it is possible to avoid uneven distribution of structural stress of the inner circle battery cell stacks 2, which would cause breakage of the inner circle battery cell stacks 2, thereby extending the service life of the cylindrical battery cell 100 and ensuring the reliability of the use of the cylindrical battery cell 100. The process is simple and easy to control, the preparation cost is low, the use effect is better, and the scope of application is wider.

[0086] In some embodiments, Figure 2 As shown, preparing a plurality of battery core stacks 2 includes:

[0087] S11, obtaining specification information of the target cylindrical battery cell 100;

[0088] S12. Obtain the stack width and stack length of each battery cell stack 2 according to the specification information and in combination with a calculation method.

[0089] Specifically, the specifications of the cylindrical battery cells 100 are different, and the lengths and widths of the battery cell stacks 2 arranged therein are also different. In order to ensure that each battery cell stack 2 can be completely rolled around the battery cell rod 1, the lengths of the battery cell stacks 2 from the inside to the outside along the radial direction of the battery cell rod 1 need to be set to increase sequentially. When preparing multiple battery cell stacks 2, it is necessary to first obtain the specification information of the target cylindrical battery cell 100, and then the stack width and stack length of each battery cell stack 2 can be obtained according to the specification information of the target cylindrical battery cell 100, so as to ensure that each battery cell stack 2 can be rolled around the battery cell rod 1 in turn, so as to ensure that the tension on each battery cell stack 2 is uniform and the stress is consistent, so as to avoid problems such as the inner circle battery cell stack 2 being easy to break, thereby extending the service life of the cylindrical battery cell 100.

[0090] Furthermore, the width of the positive electrode stack is set to d 正 , the width of the negative electrode stack is set to d 负 , the inner cavity height of the shell is set to d 壳 , and satisfies: d 正 <d 负 <d 壳 The width of the positive electrode stack and the width of the negative electrode stack are set to fixed values ​​according to the specification information of the target battery, and the battery cell stack 2 can be stacked in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack.

[0091] In some embodiments, obtaining the stack width and stack length of each battery cell stack 2 in combination with the calculation method includes:

[0092] S121, calculating the stack width and stack length of each battery cell stack 2 by using the full circle calculation method.

[0093] Specifically, according to the specification information, the stacking width and stacking length of each battery cell stack 2 are calculated in combination with the whole circle calculation method. The width of the positive electrode stack and the width of the negative electrode stack are set to fixed values ​​according to the specification information of the target battery. The battery cell stack 2 can be stacked in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack. The whole circle calculation method refers to calculating the length of each battery cell stack 2 according to the circumferential size of the battery cell rod 1 and the thickness of the battery cell stack 2. The battery cell stack 2 close to the battery cell rod 1 only needs to subtract its own thickness to calculate the radial dimension of the roll to calculate its own length. The battery cell stack 2 set away from the battery cell rod 1 needs to remove its own thickness and the thickness of the battery cell stack 2 between itself and the battery cell rod 1 to calculate the radial dimension of the roll, and the length of the battery cell stack 2 radially outward along the battery cell rod 1 gradually increases.

[0094] Combined with the full circle calculation method, the length of each layer of the battery stack 2 is equal to the circumference of each layer and can be set to L. The length of the diaphragm stack arranged close to the battery rod 1 can be set to L. 隔膜min The length of the positive electrode stack arranged near the battery rod 1 can be set to L 正minThe length of the negative electrode stack arranged near the battery rod 1 can be set to L 负min , the circumference of the hollow rod is set to L0, and satisfies: L0<L 隔膜min <L 负min <L 正min The length of the diaphragm stack set away from the electric core rod 1 can be set to L 隔膜max The length of the positive electrode stack set away from the battery rod 1 can be set to L 正max The length of the negative electrode stack set away from the battery rod 1 can be set to L 负max , the circumference of the shell cavity can be set to L1, and satisfy: L 正max <L 负max <L 隔膜max <L1, and in actual setting, the battery cell stack 2 is in accordance with L min To L max Direction for stacking.

[0095] In actual settings, the cylindrical battery cell 100 specifications can be selected: capacity is 45Ah, aluminum foil thickness is 0.015mm, copper foil thickness is 0.008mm, positive electrode stack thickness is 0.13mm, negative electrode stack thickness is 0.105mm, diaphragm stack thickness is 0.014mm, unit thickness is set to t, and t=diaphragm stack thickness*4+negative electrode stack thickness*2+positive electrode stack thickness*2, that is, t=0.562mm, the diameter of the battery cell rod 1 is set to 10mm, and the stacking is carried out in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, and combined with the whole circle calculation method, the positive electrode stacking process is as follows: Figure 7 As shown, the length of each positive electrode stack is equal to the circumference of each circle and is set to L 正 , the length L of the positive electrode stack arranged near the battery rod 1 正min The minimum circumference is equal to 34.256 mm, and the length L of the positive electrode stack set away from the battery rod 1 正max It is the maximum circumference and is equal to 136.710mm.

[0096] In some embodiments, fixing the multiple battery cell stacks 2 after rolling includes: bonding the multiple battery cell stacks 2 after rolling, and separating the adjacent negative electrode stacks and positive electrode stacks by the middle diaphragm stack, the multiple battery cell stacks 2 are arranged in sequence from the inside to the outside along the radial direction of the battery cell rod 1, and the length of the battery cell stack 2 from the inside to the outside along the radial direction of the battery cell rod 1 needs to be set to increase in sequence, each battery cell stack 2 is rolled outside the battery cell rod 1, and after the multiple battery cell stacks 2 are rolled, they can be fixed at the joints at both ends of the battery cell stack 2 by using a stop glue or the like to ensure the operating reliability of the battery cell stack 2.

[0097] Among them, after each battery cell stack 2 is stacked, rolled and bonded, the diaphragm stack in the battery cell stack 2 needs to completely separate the negative electrode stack and the positive electrode stack in the battery cell stack 2, thereby ensuring the operating reliability of the cylindrical battery cell 100, and after the battery cell stack 2 is rolled, it can also be connected and fixed by other methods besides bonding, thereby improving the flexibility of the setting.

[0098] In some embodiments, preparing a plurality of battery cell stacks 2 further comprises:

[0099] S13, preparing the tabs 3 on the battery cell stack 2 which is constructed as a negative electrode stack and a positive electrode stack.

[0100] Specifically, a pole ear 3 is provided in the cylindrical battery cell 100, and both the negative electrode stack and the positive electrode stack are connected to the pole ear 3. The pole ear 3 is set as a metal conductor, and the pole ear 3 can lead out the negative electrode stack and the positive electrode stack. After the battery cell stack 2 is prepared, the pole ear 3 can be prepared corresponding to the negative electrode stack and the positive electrode stack in the battery cell stack 2 to connect the pole ear 3 to the corresponding negative electrode stack and the positive electrode stack.

[0101] In some embodiments, Figure 3 As shown, preparing the tab 3 includes:

[0102] S131, obtaining preparation factors of the tab 3;

[0103] S132 . Determine the target number of the tabs 3 of each battery cell stack 2 and the target area size of each tab 3 according to the manufacturing factors.

[0104] Specifically, a pole lug 3 is provided in the cylindrical battery cell 100, and both the negative electrode stack and the positive electrode stack are connected to the pole lug 3, and the pole lug 3 can lead out the negative electrode stack and the positive electrode stack. After the battery cell stack 2 is prepared, the pole lug 3 can be prepared for the negative electrode stack and the positive electrode stack in the battery cell stack 2. The pole lug 3 is set at the end of the positive electrode stack and the negative electrode stack, and has a pole lug length and a pole lug width. Current can flow through the pole lug 3, and then when setting the pole lug 3, its minimum current flow capacity and other preparation factors need to be considered, and then the required pole lug 3 can be prepared according to the preparation factors to determine the target number of pole lugs 3 of each battery cell stack 2 and the target area size of each pole lug 3.

[0105] In some embodiments, the preparation factors include:

[0106] S1311, minimum current capacity and current density of tab 3.

[0107] Specifically, the pole lug 3 can be laser die-cut, and the pole lug 3 is integrally formed with the positive electrode stack and the negative electrode stack. Considering the machinability of winding or welding equipment, the pole lug width can be set to be equal to the pole lug height, and can be set to a fixed value. In actual setting, the processing capability of the process corresponding to the pole lug 3 must also be considered. The pole lug width can also be determined by the length of the stack close to the battery cell rod 1, and the preparation factors of the pole lug 3 include but are not limited to the minimum current capacity and current density of the pole lug 3. While satisfying the machinability of winding or welding equipment, it is necessary to ensure that the minimum current capacity and current density of the pole lug 3 meet the operation requirements of the cylindrical battery cell 100 to ensure the operational reliability of the cylindrical battery cell 100.

[0108] In some embodiments, Figure 4 As shown, according to the preparation factors, determining the target number of tabs 3 of each battery cell stack 2 and the target area size of each tab 3 includes:

[0109] S1321, adjusting the test quantity of the tab 3 and the test area size of the tab 3;

[0110] S1322. When the ratio of the total area of ​​the plurality of tabs 3 in each battery cell stack 2 to the total area of ​​the corresponding battery cell stack 2 is between a set upper limit and a set lower limit, the corresponding test quantity is used as the target quantity and the test area size is used as the target area size.

[0111] Specifically, both the negative electrode stack and the positive electrode stack are connected with a pole lug 3, and a plurality of battery cell stacks 2 are stacked in sequence from the inside to the outside along the radial direction of the battery cell rod 1, so that the pole lug 3 can be set to be multiple, and the number of pole lugs 3 of each battery cell stack 2 and the area size of each pole lug 3 can be determined according to the minimum current flow capacity and current density, that is, in actual setting, the test number of pole lugs 3 and the test area size of pole lugs 3 can be adjusted so that the minimum current flow capacity and current density of the pole lug 3 meet the use requirements.

[0112] And the number of tabs 3 can be determined by L min Decision, L. min is the minimum length of the battery core stack 2. If too many tabs 3 are provided, it is not easy to bend, and if too few tabs are provided, it is not easy to dissipate heat. In actual setting, taking the positive electrode stack as an example, L 正min =34.256mm, the width and length of the pole lug are set to 5mm according to the process capability of the die-cutting equipment. At this time, the number of pole lugs 3 of the inner ring positive electrode stack is at most 4, that is, the number of pole lugs 3 can be set to be less than or equal to 4. Considering the heat generation, the position of the pole lug 3 and the welding capability, the number of pole lugs 3 can be set to be less than or equal to 8.

[0113] Furthermore, when the pole tabs 3 are set, the ratio of the total area of ​​the multiple pole tabs 3 of each battery cell stack 2 to the total area of ​​the corresponding battery cell stack 2 is set to T, and T can reflect the current density. By adjusting the T value, the current density distribution of adjacent battery cell stacks 2 can be optimized. The T value is set with a set upper limit value and a set lower limit value. When setting the number of pole tabs 3 of each battery cell stack 2, the size of T must be considered to ensure that the set upper limit value of T is close to the set lower limit value of T, thereby ensuring that the current density of each battery cell stack 2 is consistent, and the corresponding test quantity can be used as the target quantity and the test area size can be used as the target area size.

[0114] In some embodiments, preparing the tab 3 comprises:

[0115] S133 , a plurality of tabs 3 are arranged at intervals on the long sides of the battery cell stack 2 .

[0116] Specifically, a pole ear 3 is provided in the cylindrical battery cell 100, and both the negative electrode stack and the positive electrode stack are connected with the pole ear 3, and the pole ear 3 can lead out the negative electrode stack and the positive electrode stack. After the battery cell stack 2 is prepared, the pole ear 3 can be prepared for the negative electrode stack and the positive electrode stack in the battery cell stack 2. The pole ear 3 is provided at the ends of the positive electrode stack and the negative electrode stack. When a plurality of battery cell stacks 2 are sequentially rolled outside the battery cell rod 1, the plurality of pole ears 3 of each battery cell stack 2 are spaced apart and distributed on the long side of the battery cell stack 2, that is, the plurality of pole ears 3 of the positive electrode stack can be spaced apart and distributed on the long side of the positive electrode stack, and the plurality of pole ears 3 of the negative electrode stack can be spaced apart and distributed on the long side of the negative electrode stack, so that the negative electrode stack and the positive electrode stack can be led out, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0117] In some embodiments, it also includes:

[0118] S4, connecting the tabs 3 of the plurality of battery cell stacks 2.

[0119] Specifically, a pole ear 3 is provided in the cylindrical battery cell 100, and both the negative electrode stack and the positive electrode stack are connected to the pole ear 3, and the pole ear 3 can lead out the negative electrode stack and the positive electrode stack. After the battery cell stack 2 is prepared, that is, after a plurality of battery cell stacks 2 are stacked, rolled and bonded, the plurality of pole ears 3 of each battery cell stack 2 can be distributed spaced apart in the circumferential direction of the battery cell stack 2, and then the pole ears 3 located at the same end of the cylindrical battery cell 100 can be connected, so as to connect a plurality of positive electrode stacks or negative electrode stacks through a plurality of pole ears 3, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0120] In actual settings, the widths of the negative electrode stack and the positive electrode stack can be set to be the same or different, but after each battery cell stack 2 is stacked, rolled and bonded, the diaphragm stack in the battery cell stack 2 needs to completely separate the negative electrode stack and the positive electrode stack in the battery cell stack 2, thereby ensuring the operating reliability of the cylindrical battery cell 100, and after the battery cell stack 2 is rolled, it can also be connected and fixed by other methods besides bonding, thereby improving the flexibility of the setting.

[0121] In some embodiments, Figure 5 As shown, connecting the tabs 3 of a plurality of battery cell stacks 2 includes:

[0122] S41, bending at least part of the pole lugs 3 located in the same quadrant in the same direction, and aligning and stacking them along the radial direction of the electric core rod 1;

[0123] S42, electrically connecting the tabs 3 of the plurality of battery cell stacks 2 located in the same quadrant in sequence;

[0124] S43, wherein the tabs 3 of the battery cell stack 2 located in the innermost circle are stacked in a direction away from the battery cell rod 1, and the tabs 3 of the battery cell stack 2 located in the outermost circle are stacked in a direction close to the battery cell rod 1.

[0125] Specifically, a plurality of battery cell stacks 2 are provided, and the plurality of battery cell stacks 2 are stacked in sequence from the inside to the outside along the radial direction of the battery cell rod 1, a positive electrode stack and a negative electrode stack are provided in the battery cell stack 2, and the positive electrode stack and the negative electrode stack are also distributed in sequence from the inside to the outside along the radial direction of the battery cell rod 1, and both the positive electrode stack and the negative electrode stack are provided with pole ears 3, that is, the pole ears 3 located in the inner circle are arranged close to the battery cell rod 1, and the pole ears 3 located in the outer circle are arranged away from the battery cell rod 1, and at least part of the pole ears 3 located in the same quadrant can be bent in the same direction, and are opposite and stacked along the radial direction of the battery cell rod 1, so that the plurality of stacked pole ears 3 located in the same quadrant can be electrically connected.

[0126] Furthermore, the pole lugs 3 of the battery cell stack 2 arranged in the innermost circle are all stacked in the direction away from the battery cell rod 1, that is, multiple pole lugs 3 close to the battery cell rod 1 can be stacked in the direction away from the battery cell rod 1, and the pole lugs 3 of the battery cell stack 2 arranged in the outermost circle are all stacked in the direction close to the battery cell rod 1, that is, multiple pole lugs 3 away from the battery cell rod 1 can be stacked in the direction close to the battery cell rod 1. Arranging the pole lugs 3 of the inner circle to be stacked in the direction away from the battery cell rod 1 can avoid the pole lugs 3 affecting the center of the battery cell rod 1, and arranging the pole lugs 3 of the outer circle to be stacked in the direction close to the battery cell rod 1 can avoid the pole lugs 3 from contacting the shell, thereby ensuring the operating reliability of the cylindrical battery cell 100, and the pole lugs 3 stacked in the direction away from the battery cell rod 1 and the pole lugs 3 stacked in the direction close to the battery cell rod 1 are staggered in the radial direction.

[0127] In actual settings, the length of the pole lug 3 arranged close to the battery cell rod 1 can be set to be slightly shorter, thereby avoiding blocking the center of the battery cell rod 1, and the product of the number of pole lugs 3 and the width of the pole lug 3 in the same stack needs to be set to be less than or equal to the width of the stack, thereby ensuring that there is a gap between the pole lugs 3 in the stack, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0128] In some embodiments, the tabs 3 of multiple battery cell stacks 2 are welded together in sequence. After the multiple battery cell stacks 2 are stacked outside the battery cell rod 1, the tabs 3 of the multiple battery cell stacks 2 can be connected by welding or the like, so that each positive electrode stack can be connected, and each negative electrode stack can be connected, thereby ensuring the reliability of the cylindrical battery cell 100.

[0129] In some embodiments, connecting the tabs 3 of a plurality of battery cell stacks 2 includes:

[0130] S44. The pole tabs 3 located in the same quadrant are suitable for connection by spot welding.

[0131] Specifically, the battery cell stack 2 is provided in plurality, and each battery cell stack 2 is provided with a positive electrode stack and a negative electrode stack, that is, the positive electrode stack and the negative electrode stack can also be provided in plurality, and the positive electrode stack and the negative electrode stack are provided with a pole ear 3, and the battery cell stack 2 can be arranged to be rolled around the outside of the battery cell rod 1 in sequence from the inside to the outside along the radial direction of the battery cell rod 1. After the plurality of battery cell stacks 2 are stacked, the plurality of pole ears 3 inside can be as shown in FIG. Figure 7 As shown, the pole ears 3 distributed in different quadrants and located in the same quadrant are suitable for being connected in sequence by spot welding. The pole ears 3 arranged close to the battery cell rod 1 are stacked in the direction away from the battery cell rod 1, and the pole ears 3 arranged away from the battery cell rod 1 are stacked in the direction close to the battery cell rod 1. The installation is simple and the operational reliability can be guaranteed.

[0132] The present invention also provides a cylindrical battery cell 100 .

[0133] According to the cylindrical battery cell 100 of the embodiment of the present invention, the cylindrical battery cell 100 includes: a plurality of battery cell stacks 2 and a battery cell rod 1 .

[0134] The multiple battery cell stacks 2 include a diaphragm stack, a negative electrode stack and a positive electrode stack. The multiple battery cell stacks 2 are sequentially rolled around the outside of the battery cell rod 1 from the inside to the outside along the radial direction of the battery cell rod 1, and the multiple battery cell stacks 2 are sequentially stacked in the radial direction of the battery cell rod 1 in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack.

[0135] Specifically, Figure 6As shown, a cell stack 2 is arranged in the cylindrical battery cell 100, and the cell stack 2 is arranged in plurality, and the plurality of cell stacks 2 are all provided with a diaphragm stack, a negative electrode stack and a positive electrode stack. The diaphragm stack can be arranged between the negative electrode stack and the positive electrode stack to avoid the negative electrode stack and the positive electrode stack from contacting each other to form a short circuit, and micropores are formed in the diaphragm stack to allow lithium ions to pass through to form a charge and discharge loop to ensure operational reliability. The cell stacks 2 can be stacked in sequence in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, that is, when a plurality of cell stacks 2 are stacked in sequence, it can be ensured that a diaphragm stack is arranged between the negative electrode stack and the positive electrode stack to ensure the operational reliability of the cylindrical battery cell 100.

[0136] Furthermore, the stacking order of the outermost cell stacks 2 of the cylindrical battery cell 100 along the radial direction can be set to diaphragm stack / negative electrode stack / diaphragm stack, that is, the innermost stack among the multiple cell stacks 2 is set to be the diaphragm stack, and the outermost stack among the multiple cell stacks 2 is also set to be the diaphragm stack, so as to isolate the external structure from affecting the operation of the negative electrode stack and the positive electrode stack, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0137] Furthermore, when the battery cell stacks 2 are stacked in sequence, a battery cell rod 1 is arranged at the top, the battery cell rod 1 is arranged in a cylindrical structure, and multiple battery cell stacks 2 are stacked in sequence from the inside to the outside along the radial direction of the battery cell rod 1, each battery cell stack 2 is rolled around the outside of the battery cell rod 1, and to ensure that each battery cell stack 2 can be completely rolled around the outside of the battery cell rod 1, the length of the battery cell stack 2 from the inside to the outside along the radial direction of the battery cell rod 1 needs to be set to increase in sequence, that is, the length of the battery cell stack 2 arranged close to the battery cell rod 1 is the shortest, and the length of the battery cell stack 2 arranged far from the battery cell rod 1 is the longest, and multiple battery cell stacks 2 are rolled in sequence from the inside to the outside along the radial direction to avoid staggering and the like, thereby ensuring installation reliability.

[0138] The battery rod 1 and multiple battery stacks 2 are all stacked in a center-aligned manner, so that the connections of the multiple battery stacks 2 after rolling are all aligned along the radial direction of the battery rod 1, and after the multiple battery stacks 2 are rolled, they can be fixed by using a stop glue or the like. The battery stacks 2 of the cylindrical battery cell 100 are all independently arranged, so that the tension exerted on the multiple battery stacks 2 after being stacked outside the battery rod 1 is uniform and the stress is consistent, thereby avoiding problems such as the inner circle battery stack 2 being easy to break, thereby extending the service life of the cylindrical battery cell 100.

[0139] According to the cylindrical battery cell 100 of the embodiment of the present invention, by sequentially rolling a plurality of battery cell stacks 2 around the battery cell rod 1, uneven distribution of structural stress of the inner circle battery cell stacks 2, which may cause breakage of the inner circle battery cell stacks 2, etc., can be avoided. The service life of the cylindrical battery cell 100 can be extended, and the reliability of the use of the cylindrical battery cell 100 is ensured. The process is simple and easy to control, the preparation cost is low, the use effect is better, and the scope of application is wider.

[0140] In some embodiments, each negative electrode stack is provided with a negative electrode tab, and each positive electrode stack is provided with a positive electrode tab, wherein the negative electrode tabs of multiple negative electrode stacks are stacked in sequence along the radial direction of the battery cell rod 1; and / or, the positive electrode tabs of multiple positive electrode stacks are stacked in sequence along the radial direction of the battery cell rod 1.

[0141] Specifically, a pole ear 3 is provided in the cylindrical battery cell 100, and the pole ear 3 is set as a metal conductor. Each positive electrode stack is provided with a positive pole ear, and each negative electrode stack is provided with a negative pole ear. The negative pole ear can lead out the negative electrode stack and the positive electrode stack, and the negative pole ear can lead out the negative electrode stack to one end of the cylindrical battery cell 100, and the positive pole ear can lead out the positive electrode stack to the other end of the cylindrical battery cell 100, thereby avoiding the positive electrode stack and the negative electrode stack from influencing each other, and ensuring the operating reliability of the positive electrode stack and the negative electrode stack.

[0142] Furthermore, a plurality of negative electrode stacks are provided, and each negative electrode stack is provided with a negative electrode ear, that is, a plurality of negative electrode ears are provided, and after a plurality of battery cell stacks 2 are sequentially rolled around the battery cell rod 1, a plurality of negative electrode ears can be sequentially arranged radially at one end of the cylindrical battery cell 100, and a plurality of negative electrode ears can be sequentially stacked radially along the battery cell rod 1, and then a plurality of negative electrode ears can be interconnected by welding or the like, so that the negative electrode ears can be fully welded to avoid waste and reduce the setting cost.

[0143] At the same time, there are multiple positive electrode stacks, and each positive electrode stack is provided with a positive electrode ear, that is, there are multiple positive electrode ears. After multiple battery cell stacks 2 are rolled around the battery cell rod 1 in turn, multiple positive electrode ears can be arranged in sequence along the radial direction at the other end of the cylindrical battery cell 100, and multiple positive electrode ears can be stacked in sequence along the radial direction of the battery cell rod 1, and then the multiple positive electrode ears can be connected by welding and the like, so that the positive electrode ears can be fully welded to avoid waste and reduce the setting cost.

[0144] In some embodiments, among multiple negative electrode stacks, the negative electrode tabs of at least one negative electrode stack located in the innermost circle are stacked in a direction away from the battery cell rod 1, and the negative electrode tabs of at least one negative electrode stack located in the outermost circle are stacked in a direction close to the battery cell rod 1.

[0145] Specifically, a plurality of battery cell stacks 2 are provided, and the plurality of battery cell stacks 2 are stacked sequentially from the inside to the outside along the radial direction of the battery cell rod 1, and a negative electrode stack is provided in the battery cell stack 2, that is, a plurality of negative electrode stacks are also provided, and the plurality of negative electrode stacks are also distributed sequentially from the inside to the outside along the radial direction of the battery cell rod 1, and each negative electrode stack is provided with a negative electrode ear, that is, the negative electrode ear of the negative electrode stack located in the inner circle is also arranged close to the battery cell rod 1, and the negative electrode ear of the negative electrode stack located in the outer circle is also arranged away from the battery cell rod 1.

[0146] Furthermore, the negative electrode tabs of at least one negative electrode laminate arranged in the innermost circle are stacked in the direction away from the battery cell rod 1, that is, the negative electrode tabs closest to the battery cell rod 1 may be provided with one, two or three etc. stacked in the direction away from the battery cell rod 1, and the negative electrode tabs of at least one negative electrode laminate arranged in the outermost circle are stacked in the direction close to the battery cell rod 1, that is, the negative electrode tabs farthest from the battery cell rod 1 may be provided with one, two or three etc. stacked in the direction close to the battery cell rod 1. Arranging the negative electrode tabs of the inner circle to be stacked in the direction away from the battery cell rod 1 can avoid the negative electrode tabs affecting the holes of the battery cell rod 1, and arranging the negative electrode tabs of the outer circle to be stacked in the direction close to the battery cell rod 1 can avoid the negative electrode tabs from contacting the shell, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0147] In other embodiments, among the multiple positive electrode laminates, the positive electrode lugs of at least one positive electrode laminate located in the innermost circle are stacked in a direction away from the battery cell rod 1, and the positive electrode lugs of at least one positive electrode laminate located in the outermost circle are stacked in a direction close to the battery cell rod 1.

[0148] Specifically, a plurality of battery cell stacks 2 are provided, and the plurality of battery cell stacks 2 are stacked sequentially from the inside to the outside along the radial direction of the battery cell rod 1, and a positive electrode stack is provided in the battery cell stack 2, that is, a plurality of positive electrode stacks are also provided, and the plurality of positive electrode stacks are also distributed sequentially from the inside to the outside along the radial direction of the battery cell rod 1, and each positive electrode stack is provided with a positive electrode ear, that is, the positive electrode ear of the positive electrode stack located in the inner circle is also arranged close to the battery cell rod 1, and the positive electrode ear of the positive electrode stack located in the outer circle is also arranged away from the battery cell rod 1.

[0149] Furthermore, the positive electrode ears of at least one positive electrode laminate arranged in the innermost circle are stacked in the direction away from the battery cell rod 1, that is, the positive electrode ears closest to the battery cell rod 1 can be provided with one, two or three etc. stacked in the direction away from the battery cell rod 1, and the positive electrode ears of at least one positive electrode laminate arranged in the outermost circle are stacked in the direction close to the battery cell rod 1, that is, the positive electrode ears farthest from the battery cell rod 1 can be provided with one, two or three etc. stacked in the direction close to the battery cell rod 1. Arranging the positive electrode ears of the inner circle to be stacked in the direction away from the battery cell rod 1 can avoid the positive electrode ears affecting the holes of the battery cell rod 1, and arranging the positive electrode ears of the outer circle to be stacked in the direction close to the battery cell rod 1 can avoid the positive electrode ears from contacting the shell, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0150] In some embodiments, the positive electrode tab and the negative electrode tab are respectively located at two ends of the cylindrical battery cell 100 in the width direction.

[0151] Specifically, the battery cell stack 2 is provided in plurality, and each battery cell stack 2 is provided with a positive electrode stack, that is, the positive electrode stack is also provided in plurality, and each positive electrode stack is provided with a positive electrode tab. After the plurality of battery cell stacks 2 are stacked outside the battery cell rod 1, the positive electrode tabs of the plurality of positive electrode stacks inside the battery cell rod 1 can be as shown in FIG. Figure 6 As shown, they are distributed in different quadrants. At the same time, each battery cell stack 2 is provided with a negative electrode stack, that is, the negative electrode stack is also provided in plurality, and each negative electrode stack is provided with a negative electrode tab. After the plurality of battery cell stacks 2 are stacked outside the battery cell rod 1, the negative electrode tabs of the plurality of negative electrode stacks inside the battery cell rod 1 can also be as shown. Figure 6 As shown, they are distributed in different quadrants, and the positive electrode tab and the negative electrode tab are respectively located at the two ends of the cylindrical battery cell 100, thereby avoiding the mutual influence between the positive electrode tab and the negative electrode tab, thereby ensuring the operating reliability of the cylindrical battery cell 100.

[0152] In some embodiments, the width of the positive electrode stack is smaller than the width of the negative electrode stack, and the width of the negative electrode stack is smaller than the width of the separator stack.

[0153] Specifically, the widths of the multiple battery stacks 2 along the axial direction of the battery rod 1 are set to be different, and the multiple battery stacks 2 are provided with positive electrode stacks and negative electrode stacks. The width of the positive electrode stack is smaller than the width of the negative electrode stack, and the width of the negative electrode stack is smaller than the width of the diaphragm stack. After each battery stack 2 is stacked, rolled and bonded, the diaphragm stack in the battery stack 2 can completely separate the negative electrode stack and the positive electrode stack in the battery stack 2, thereby ensuring the operating reliability of the cylindrical battery 100, and after the battery stack 2 is rolled, it can also be connected and fixed by other methods besides bonding, thereby improving the flexibility of the setting.

[0154] In other embodiments, the heights of the plurality of battery cell stacks 2 along the axial direction of the battery cell rod 1 are the same, and the lengths of the plurality of battery cell stacks 2 are arranged to increase sequentially from the inside to the outside along the radial direction of the battery cell rod 1 .

[0155] Specifically, when the battery cell stacks 2 are stacked in sequence, a battery cell rod 1 is arranged at the top, the battery cell rod 1 is set to a cylindrical structure, and multiple battery cell stacks 2 are arranged in sequence from the inside to the outside along the radial direction of the battery cell rod 1, and each battery cell stack 2 is rolled outside the battery cell rod 1, and to ensure that each battery cell stack 2 can be completely rolled outside the battery cell rod 1, the length of the battery cell stack 2 needs to be set to increase from the inside to the outside along the radial direction of the battery cell rod 1, that is, the length of the battery cell stack 2 arranged close to the battery cell rod 1 is the shortest, and the length of the battery cell stack 2 arranged away from the battery cell rod 1 is the longest. Multiple battery cell stacks 2 are rolled in sequence from the inside to the outside along the radial direction to avoid interlacing and the like, thereby ensuring installation reliability, and the battery cell rod 1 and multiple battery cell stacks 2 are stacked with center alignment, so that the multiple battery cell stacks 2 are aligned along the radial direction of the battery cell rod 1 at the connection after rolling, and after the multiple battery cell stacks 2 are rolled, they can be fixed by terminating glue or the like.

[0156] In other embodiments, the areas of the multiple negative electrode tabs of each negative electrode stack are the same, and / or the areas of the multiple positive electrode tabs of each positive electrode stack are the same, that is, only the areas of the multiple negative electrode tabs of each negative electrode stack are set to be the same, or only the areas of the multiple positive electrode tabs of each positive electrode stack are set to be the same, or the areas of the multiple negative electrode tabs of each negative electrode stack are set to be the same. At the same time, the areas of the multiple positive electrode tabs of each positive electrode stack are set to be the same, which improves the setting flexibility. The areas of the multiple positive electrode tabs of each positive electrode stack are set to be the same, and the areas of the multiple negative electrode tabs of each negative electrode stack are set to be the same, which is convenient for processing, and the conductivity of each tab 3 can be ensured to be the same, thereby improving the reliability of the cylindrical battery cell 100.

[0157] In other embodiments, the lug width and lug length of the battery cell stack 2 are equal, the lug 3 can be laser die-cut, and the lug 3 is integrally formed with the positive electrode stack and the negative electrode stack. Considering the machinability of winding or welding equipment, the lug width can be set to be equal to the lug height and can be set to a fixed value, thereby improving processing efficiency and facilitating manufacturing.

[0158] The invention also provides a battery.

[0159] The battery according to an embodiment of the present invention comprises any of the above-mentioned cylindrical battery cells 100, wherein the cylindrical battery cells 100 comprise positive electrode tabs and negative electrode tabs, as well as a shell, a negative electrode current collecting plate and a positive electrode current collecting plate, and the battery cell rod 1 and a plurality of battery cell stacks 2 are fixedly installed in the shell.

[0160] Specifically, the battery is provided with a cylindrical battery cell 100, which also includes a positive electrode tab, a negative electrode tab, a shell, a negative current collector and a positive current collector. The battery cell rod 1 and a plurality of battery cell stacks 2 are fixedly installed in the shell. The cylindrical battery cell 100 is provided with a shell, which is configured as a cylindrical shell. The shell can provide an installation space for the internal components of the cylindrical battery cell 100, and can provide support and protection for the internal components to improve safety of use. The internal components are arranged in the shell, and a closed space can be provided in the shell to avoid affecting the operating reliability of the internal components.

[0161] At the same time, after multiple battery cell stacks 2 are stacked radially from the inside to the outside on the outside of the battery cell rod 1, they can be installed in the shell together with the battery cell rod 1, and the pole ears 3 of the multiple battery cell stacks 2 can be welded to the collecting disk. After the battery cell stacks 2 are installed in the shell, the collecting disk can be welded to the shell, and then liquid is injected into the shell, and then the shell is sealed, etc., and the positive electrode of the cylindrical battery cell 100 is provided with a positive current collecting disk, and the positive pole ear can be welded to the positive current collecting disk, and the negative electrode of the cylindrical battery cell 100 is provided with a negative current collecting disk, and the negative pole ear can be welded to the negative current collecting disk, which can ensure the operating reliability of the cylindrical battery cell 100.

[0162] In some embodiments, negative electrode tabs in the same quadrant of a plurality of negative electrode stacks are welded together in sequence, and negative electrode tabs in different quadrants of a plurality of negative electrode stacks are connected via a negative electrode current collecting plate.

[0163] Specifically, the battery cell stack 2 is provided in plurality, and each battery cell stack 2 is provided with a negative electrode stack, that is, the negative electrode stack is also provided in plurality, and each negative electrode stack is provided with a negative electrode tab, and the battery cell stack 2 can be arranged to be sequentially rolled on the outside of the battery cell rod 1 from the inside to the outside along the radial direction of the battery cell rod 1. After the plurality of battery cell stacks 2 are stacked, the negative electrode tabs of the plurality of negative electrode stacks inside the battery cell stack can be as shown in FIG. Figure 6 As shown, the negative electrode tabs distributed in different quadrants and in the same quadrant are welded together in sequence, the negative electrode tabs arranged close to the battery cell rod 1 are stacked in the direction away from the battery cell rod 1, and the negative electrode tabs arranged away from the battery cell rod 1 are stacked in the direction close to the battery cell rod 1.

[0164] Furthermore, in actual settings, the quadrants may not be limited to four quadrants, and the negative electrode is also provided with a negative electrode collector plate, and the negative electrode tabs in different quadrants of the multiple negative electrode stacks can be connected to the negative electrode collector plate by welding, so that the negative electrode tabs in different quadrants of the multiple negative electrode stacks can be connected through the negative electrode collector plate, which is simple to install and can ensure operational reliability.

[0165] In other embodiments, the positive electrode tabs in the same quadrant of the multiple positive electrode stacks are welded together in sequence, and the positive electrode tabs in different quadrants of the multiple positive electrode stacks are connected through the positive electrode collector plate.

[0166] Specifically, the battery cell stack 2 is provided in plurality, and each battery cell stack 2 is provided with a positive electrode stack, that is, the positive electrode stack is also provided in plurality, and each positive electrode stack is provided with a positive electrode ear, and the battery cell stack 2 can be arranged to be sequentially rolled on the outside of the battery cell rod 1 from the inside to the outside along the radial direction of the battery cell rod 1. After the plurality of battery cell stacks 2 are stacked, the positive electrode ears of the plurality of positive electrode stacks inside the battery cell stack can be as shown in FIG. Figure 6 As shown, the positive electrode ears distributed in different quadrants and in the same quadrant are welded together in sequence, the positive electrode ears arranged close to the battery cell rod 1 are stacked in the direction away from the battery cell rod 1, and the positive electrode ears arranged away from the battery cell rod 1 are stacked in the direction close to the battery cell rod 1.

[0167] Furthermore, in actual settings, the quadrants may not be limited to four quadrants, and the positive electrode is also provided with a positive current collecting disk. The positive electrode tabs in different quadrants of the multiple positive electrode stacks can be connected to the positive current collecting disk by welding, so that the positive electrode tabs in different quadrants of the multiple positive electrode stacks can be connected through the positive current collecting disk, which is simple to install and can ensure operational reliability.

[0168] The invention also provides a battery pack.

[0169] A battery pack according to an embodiment of the present invention includes any one of the above batteries.

[0170] According to the battery pack of the embodiment of the present invention, a battery is provided, and the battery is provided with a cylindrical battery cell 100. The cylindrical battery cell 100 can avoid uneven distribution of structural stress of the inner circle battery cell stack 2, resulting in breakage of the inner circle battery cell stack 2, by rolling a plurality of battery cell stacks 2 in sequence outside the battery cell rod 1. The service life of the cylindrical battery cell 100 can be extended, and the reliability of the use of the cylindrical battery cell 100 is ensured. The process is simple and easy to control, the preparation cost is low, the use effect is better, and the scope of application is wider.

[0171] The invention also provides an electric device.

[0172] The electric device according to the embodiment of the present invention includes the above-mentioned battery pack, and the electric device may refer to a vehicle or the like.

[0173] The electrical equipment according to the embodiment of the present invention is provided with a battery pack. The cylindrical battery cells 100 in the battery pack can avoid uneven distribution of structural stress of the inner circle battery cell stacks 2, resulting in breakage of the inner circle battery cell stacks 2, by sequentially rolling a plurality of battery cell stacks 2 around the battery cell rod 1. This can extend the service life of the cylindrical battery cells 100 and ensure the reliability of the use of the cylindrical battery cells 100. The process is simple and easy to control, the preparation cost is low, the use effect is better, and the scope of application is wider.

[0174] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0175] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a cylindrical battery cell, characterized in that: include: Prepare a plurality of battery core stacks, wherein the battery core stacks include a diaphragm stack, a negative electrode stack and a positive electrode stack; Stacking the plurality of battery cell stacks in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack, placing a battery cell stick on the battery cell stack with the smallest length along the width direction, and rolling the plurality of battery cell stacks around the battery cell stick in turn; Fixing the plurality of rolled battery core stacks, and separating the adjacent negative electrode stacks and the positive electrode stacks by the separator stack in the middle; Wherein, the preparation of a plurality of battery core stacks comprises: Obtain the specification information of the target cylindrical battery cell; According to the specification information, a calculation method is used to obtain a stacking width and a stacking length of each of the battery cell stacks; And, the combined calculation method to obtain the stack width and stack length of each battery core stack includes: Combined with the full circle calculation method, the stack width and stack length of each battery cell stack are calculated.

2. The method for preparing a cylindrical battery cell according to claim 1, characterized in that: The step of fixing the plurality of battery core stacks after rolling includes: A plurality of the battery core stacks are rolled up and then bonded together.

3. The method for preparing a cylindrical battery cell according to claim 1, characterized in that: The preparing of a plurality of battery core stacks further comprises: The tabs are prepared on the battery core stack formed into the negative electrode stack and the positive electrode stack.

4. The method for preparing a cylindrical battery cell according to claim 3, characterized in that: The preparation of the tab comprises: Obtaining the preparation factors of the tab; According to the manufacturing factors, the target number of the tabs of each of the battery cell stacks and the target area size of each of the tabs are determined.

5. The method for preparing a cylindrical battery cell according to claim 4, characterized in that: The manufacturing factors include the minimum current carrying capacity and current density of the tab.

6. The method for preparing a cylindrical battery cell according to claim 4, characterized in that: Determining the target number of the tabs of each of the battery cell stacks and the target area size of each tab according to the preparation factors includes: Adjusting the number of tests on the tabs and the size of the test area on the tabs; When the ratio of the total area of ​​the plurality of tabs of each battery cell stack to the total area of ​​the corresponding battery cell stack is between a set upper limit and a set lower limit, the corresponding test quantity is taken as the target quantity and the test area size is taken as the target area size.

7. The method for preparing a cylindrical battery cell according to claim 3, characterized in that: The preparation of the tab comprises: A plurality of the tabs are arranged at intervals on the long sides of the battery core stack.

8. The method for preparing a cylindrical battery cell according to claim 3, characterized in that: Also includes: The tabs of a plurality of battery core stacks are connected together.

9. The method for preparing a cylindrical battery cell according to claim 8, characterized in that: The step of connecting the tabs of the plurality of battery core stacks comprises: Bend at least part of the pole ears located in the same quadrant in the same direction, and stack and distribute them along the radial direction of the electric core rod; Sequentially electrically connecting the tabs of the plurality of battery core stacks located in the same quadrant; Among them, the tabs of the battery cell stack located in the innermost circle are all stacked in a direction away from the battery cell rod, and the tabs of the battery cell stack located in the outermost circle are all stacked in a direction close to the battery cell rod.

10. The method for preparing a cylindrical battery cell according to claim 9, characterized in that: The tabs of the plurality of battery core stacks are welded and connected in sequence.

11. The method for preparing a cylindrical battery cell according to claim 9, characterized in that: The step of connecting the tabs of the plurality of battery core stacks comprises: The tabs located in the same quadrant are suitable for being connected by spot welding.

12. A cylindrical battery cell, characterized in that: The cylindrical battery cell is made by the method for preparing a cylindrical battery cell according to any one of claims 1 to 11, and the cylindrical battery cell comprises: A plurality of battery cell stacks, wherein the battery cell stacks include a diaphragm stack, a negative electrode stack and a positive electrode stack; A battery cell rod, wherein the plurality of battery cell stacks are sequentially rolled around the outside of the battery cell rod from the inside to the outside along the radial direction of the battery cell rod, and the plurality of battery cell stacks are sequentially stacked in the radial direction of the battery cell rod in the order of diaphragm stack / negative electrode stack / diaphragm stack / positive electrode stack.

13. The cylindrical battery cell according to claim 12, characterized in that: Each of the negative electrode stacks is provided with a negative electrode tab, and each of the positive electrode stacks is provided with a positive electrode tab; Wherein, the negative electrode tabs of the plurality of negative electrode stacks are stacked in sequence along the radial direction of the battery rod; And / or, the positive electrode tabs of the plurality of positive electrode stacks are stacked in sequence along the radial direction of the battery core rod.

14. The cylindrical battery cell according to claim 13, characterized in that: Among the plurality of negative electrode laminations, the negative electrode tab of at least one of the negative electrode laminations located in the innermost circle is stacked in a direction away from the battery core rod, and the negative electrode tab of at least one of the negative electrode laminations located in the outermost circle is stacked in a direction close to the battery core rod; And / or, among the multiple positive electrode stacks, the positive electrode tabs of at least one of the positive electrode stacks located in the innermost circle are stacked in a direction away from the battery cell rod, and the positive electrode tabs of at least one of the positive electrode stacks located in the outermost circle are stacked in a direction close to the battery cell rod.

15. The cylindrical battery cell according to claim 13, characterized in that: The positive electrode tab and the negative electrode tab are respectively located at two ends of the cylindrical battery cell in a width direction.

16. The cylindrical battery cell according to claim 13, characterized in that: The width of the positive electrode stack is smaller than that of the negative electrode stack, and the width of the negative electrode stack is smaller than that of the diaphragm stack; And / or, the areas of the multiple negative electrode tabs of each of the negative electrode stacks are the same; And / or, the areas of the multiple positive electrode tabs of each of the positive electrode stacks are the same.

17. A battery, characterized in that: A cylindrical battery cell comprising any one of claims 12 to 16, wherein the cylindrical battery cell comprises a positive electrode tab and a negative electrode tab; And, a shell, a negative electrode current collector and a positive electrode current collector, the battery rod and the plurality of battery core stacks are fixedly installed in the shell; The negative electrode tabs in the same quadrant of the plurality of negative electrode stacks are welded and connected in sequence, and the negative electrode tabs in different quadrants of the plurality of negative electrode stacks are connected through the negative electrode current collecting plate; And / or, the positive electrode tabs in the same quadrant of the plurality of positive electrode stacks are welded together in sequence, and the positive electrode tabs in different quadrants of the plurality of positive electrode stacks are connected through the positive current collecting plate.

18. A battery pack, characterized in that: Comprising the battery of claim 17.

19. An electrical equipment, characterized in that: Comprising the battery pack as claimed in claim 18.

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