A cylindrical battery

Abstract

The utility model belongs to cylindrical battery technical field, specifically discloses a cylindrical battery, it includes: roll core, roll core includes coating area and two pole lug area, the pole lug area is divided into pole lug outer edge area, pole lug rubbing flat area, pole lug beat flat area, pole lug inner edge area from outside to inside in proper order, the length that pole lug rubbing flat area extends outwardly from coating area is gradually reduced from outside to inside, the length that pole lug beat flat area extends outwardly from coating area is same from outside to inside. The pole piece of pole lug rubbing flat area is trapezoidal distribution from high to low, then can optimize the electric field distribution in the battery, reduces local overheat phenomenon, promotes battery overall stability, and the length that pole lug beat flat area extends outwardly from coating area is same from outside to inside, then can guarantee the pole piece edge of inner ring of roll core is even, then can let the current collecting disc and pole lug area weld, let the current collecting disc and roll core accurate cooperation better, let the welding effect is better, improves battery energy density, enhances battery charge and discharge performance.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cylindrical battery. Background Technology

[0002] Currently, cylindrical all-tab batteries have gained widespread attention in the field of new energy applications due to their advantages such as low internal resistance and high-power charging and discharging. However, existing cylindrical all-tab batteries have many problems: the traditional core structure is prone to inconsistent height of the outer electrode sheets, resulting in uneven electric field distribution and local overheating, which affects battery life and safety; secondly, in terms of battery welding process, it is difficult to precisely match the core and current collector, resulting in problems such as poor welding and high contact resistance, which limits battery performance. Utility Model Content

[0003] The purpose of this invention is to provide a cylindrical battery to solve the technical problems in the prior art where uneven electric field distribution and local overheating easily occur in the core structure, affecting battery life and safety.

[0004] To achieve the above objectives, this utility model provides a cylindrical battery comprising: a core; the core including a coating area and two tab areas; the two tab areas are respectively disposed at both ends of the coating area in the height direction; the tab areas are sequentially divided from the outside to the inside into an outer edge area, a flattened area, a flattened area, and an inner edge area; the length of the flattened area relative to the coating area gradually decreases from the outside to the inside, the length of the flattened area relative to the coating area is the same from the outside to the inside, and the length of the flattened area relative to the coating area is not greater than the minimum value of the length of the flattened area relative to the coating area.

[0005] Preferably, it further includes: a collector plate; the collector plate is welded to the tab flattening area and the tab patting area.

[0006] Preferably, the collector plate is provided with a flat surface for welding to the tab flattening area and a conical surface for welding to the tab kneading area.

[0007] Preferably, the core has a central hole extending along the height direction in its middle portion.

[0008] Preferably, the length by which the outer edge region of the electrode extends outward relative to the coating area is the same as the length by which the inner edge region of the electrode extends outward relative to the coating area.

[0009] Preferably, the length of the outer edge region of the electrode relative to the coating region extending outward is less than the length of the flattened region of the electrode relative to the coating region extending outward.

[0010] Preferably, the core includes a first electrode, a second electrode, and a diaphragm; the first electrode, the diaphragm, and the second electrode are sequentially stacked and wound to form the core.

[0011] Preferably, the first electrode includes a first current collector and a first active material layer; the first active material layer is coated on the first current collector, and the first current collector is provided with a first empty foil area for forming the tab region.

[0012] Preferably, the second electrode includes a second current collector and a second active material layer; the second active material layer is coated on the second current collector, and the second current collector is provided with a second empty foil region for forming the tab region.

[0013] Preferably, the first empty foil area includes a first continuous blank area and a first gap blank area; the first continuous blank area is used to form the tab flattening area, and the first gap blank area is used to form the tab flattening area; the second empty foil area includes a second continuous blank area and a second gap blank area; the second continuous blank area is used to form the tab flattening area, and the second gap blank area is used to form the tab flattening area.

[0014] The cylindrical battery provided by this utility model has the following advantages: the length of the electrode sheet extending outward from the coating area in the flattened tab area gradually decreases from the outside to the inside, which makes the electrode sheet in the flattened tab area form a trapezoidal distribution from high to low. This optimizes the electric field distribution inside the battery, reduces local overheating, and improves the overall stability of the battery. Moreover, the length of the electrode sheet extending outward from the coating area in the flattened tab area is the same from the outside to the inside, which ensures that the edge of the electrode sheet in the inner ring of the core is flat. This allows the current collector to make better contact with the electrode sheet in the entire inner ring of the core when welding the current collector to the tab area, so as to better match the current collector with the core, improve the welding effect, reduce contact resistance, optimize the current conduction path, improve the current conduction efficiency, increase the battery energy density, and enhance the battery charge and discharge performance.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the disassembled cross-sectional structure of the cylindrical battery according to an embodiment of the present invention;

[0017] Figure 2 This is a top view structural schematic diagram of the core of this utility model embodiment;

[0018] Figure 3 This is a schematic diagram of the structure of the first electrode sheet in an embodiment of this utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the second electrode sheet in an embodiment of this utility model.

[0020] In the diagram, 100 is the core; 110 is the coating area; 120 is the tab area; 121 is the outer edge area of ​​the tab; 122 is the flattened tab area; 123 is the flattened tab area; 124 is the inner edge area of ​​the tab; 130 is the center hole; 200 is the collector plate; 210 is the flat surface; 220 is the conical surface; 300 is the first electrode; 310 is the first current collector; 311 is the first empty foil area; 312 is the first continuous blank area; 313 is the first gap blank area; 320 is the first active material layer; 400 is the second electrode; 410 is the second current collector; 411 is the second empty foil area; 412 is the second continuous blank area; 413 is the second gap blank area; and 420 is the second active material layer. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0023] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0024] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0025] Please refer to the following: Figures 1 to 4 The cylindrical battery provided in the embodiments of this utility model will now be described.

[0026] Reference Figures 1 to 2 The cylindrical battery of this utility model embodiment includes: a core 100; the core 100 includes a coating area 110 and two tab areas 120; the two tab areas 120 are respectively disposed at both ends of the coating area 110 in the height direction Z; the tab areas 120 are divided into an outer edge area 121, a flattened area 122, a flattened area 123, and an inner edge area 124 from the outside to the inside; the length H of the flattened area 122 extending outward relative to the coating area 110 gradually decreases from the outside to the inside, and the length G of the flattened area 123 extending outward relative to the coating area 110 is the same from the outside to the inside, and the length of the flattened area 123 extending outward relative to the coating area 110 is not greater than the minimum value of the length of the flattened area 122 extending outward relative to the coating area 110, that is, G≤H.

[0027] The coating area 110 is the area on the core 100 containing active material. The active material can be made of lithium iron phosphate or ternary materials (such as lithium nickel cobalt manganese oxide) to ensure conductivity.

[0028] The two tab areas 120 correspond to the positive and negative poles of the core 100, respectively, to ensure that the positive and negative poles are located at both ends of the core 100, so as to facilitate welding with the current collector 200 of the cylindrical battery to connect the positive and negative poles.

[0029] The tab flattening area 122 corresponds to the outer ring of the core 100, and the length of the electrode sheet in the tab flattening area 122 extending outward from the coating area 110 gradually decreases from the outside to the inside. This allows the electrode sheets in the tab flattening area 122 to be distributed in a trapezoidal shape from high to low, which can optimize the electric field distribution inside the battery, reduce local overheating, and improve the overall stability of the battery. Moreover, the tab flattening area 123 corresponds to the inner ring of the core 100. Since the length of the tab flattening area 123 extending outward from the coating area 110 is the same from the outside to the inside, it can ensure that the edges of the electrode sheets in the inner ring of the core 100 are flat. This allows the current collector 200 to make better contact with the electrode sheets in the entire inner ring of the core 100 when welding to the tab area 120, so that the current collector 200 and the core 100 can fit together more precisely, resulting in better welding effect, reduced contact resistance, optimized current conduction path, improved current conduction efficiency, and enhanced battery charge and discharge performance.

[0030] In this embodiment, the length of the electrode sheet extending outward from the coating area 110 in the flattened area 122 of the cylindrical battery gradually decreases from the outside to the inside. This results in a trapezoidal distribution of the electrode sheets in the flattened area 122 from high to low, which optimizes the electric field distribution inside the battery, reduces local overheating, and improves the overall stability of the battery. Furthermore, the length of the electrode sheet extending outward from the coating area 110 in the flattened area 123 is the same from the outside to the inside. This ensures that the edges of the electrode sheets on the inner ring of the core 100 are flat. This allows the current collector 200 to make better contact with the electrode sheets on the entire inner ring of the core 100 when welding to the electrode sheet area 120. This results in a better and more precise fit between the current collector 200 and the core 100, leading to better welding results, reduced contact resistance, optimized current conduction path, improved current conduction efficiency, increased battery energy density, and enhanced battery charge and discharge performance.

[0031] In some embodiments of this utility model, reference is made to Figure 1 The cylindrical battery also includes a current collector 200; the current collector 200 is welded to the tab flattening area 122 and the tab flattening area 123, that is, the current collector 200 is only welded to the tab flattening area 122 and the tab flattening area 123, so that the current collector 200 is connected to the core 100, so that the current is concentrated in the tab flattening area 122 and the tab flattening area 123, thereby optimizing the current conduction path and improving the current conduction efficiency.

[0032] In some embodiments of this utility model, reference is made to Figure 1 To facilitate better welding of the current collector 200 to the tab flattening area 122 and the tab patting area 123, the current collector 200 is provided with a flat surface 210 for welding to the tab patting area 123 and a conical surface 220 for welding to the tab flattening area 122. Since the length of the electrode sheet extending outward from the coating area 110 in the tab flattening area 122 gradually decreases from the outside to the inside, the tab flattening area 122 forms a conical support surface. Therefore, the conical surface 220 on the current collector 200 allows for better contact between the current collector 200 and the tab flattening area 122, resulting in better welding, reducing the occurrence of incomplete welds, decreasing the contact resistance between the current collector 200 and the tab flattening area 122, improving current conduction efficiency, increasing battery energy density, and enhancing battery charge and discharge performance. Similarly, since the length of the tab flattening area 123 extending outward relative to the coating area 110 is the same from the outside to the inside, the tab flattening area 123 forms a flat support surface. Therefore, the flat surface 210 on the current collector 200 can better allow the current collector 200 to contact the tab flattening area 123, so as to better weld the current collector 200 and the tab flattening area 123, reduce the occurrence of poor welding, reduce the contact resistance between the current collector 200 and the tab flattening area 123, improve the current conduction efficiency, increase the battery energy density, and enhance the battery charge and discharge performance.

[0033] In some embodiments of this utility model, reference is made to Figure 1 To prevent excessive internal pressure in the battery, a central hole 130 extending along the height direction is provided in the middle of the winding core 100. The central hole 130 is mainly used to release gas and heat generated during charging and discharging to prevent excessive internal pressure in the battery and avoid battery expansion or explosion.

[0034] In some embodiments of this utility model, reference is made to Figure 1 The length L extending outward from the outer edge region 121 of the electrode relative to the coating region 110 is the same as the length K extending outward from the inner edge region 124 of the electrode relative to the coating region 110. That is, L = K, so that the electrode heights of the inner edge region 124 and the outer edge region 121 of the electrode are the same, so as to facilitate electrode fabrication.

[0035] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 To ensure better contact between the tab flattening area 123 and the tab smoothing area 122 and the collector plate 200, the length of the outer edge area 121 of the tab extending outward relative to the coating area 110 is less than the length of the tab flattening area 123 extending outward relative to the coating area 110. Therefore, both the tab flattening area 123 and the tab smoothing area 122 protrude more than the outer edge area 121 and the inner edge area 124 of the tab, allowing the collector plate 200 to be aligned with the tab flattening area 123 and the tab smoothing area 122 for assembly, facilitating welding.

[0036] In some embodiments of this utility model, the wound core 100 includes a first electrode 300, a second electrode 400, and a diaphragm; the first electrode 300, the diaphragm, and the second electrode 400 are sequentially stacked and wound to form the wound core 100. That is, the wound core 100 is a wound battery cell, formed by stacking and winding two electrodes and a diaphragm, one of which is a positive electrode and the other is a negative electrode, so as to connect to different tab regions 120 respectively.

[0037] Based on the above, and referring to Figure 3The first electrode 300 includes a first current collector 310 and a first active material layer 320. The first active material layer 320 is coated on the first current collector 310, and the first current collector 310 is provided with a first empty foil area 311 for forming the tab region 120. The first active material layer 320 is responsible for storing and releasing electrical energy and can be made of active materials such as lithium iron phosphate or ternary materials (such as lithium nickel cobalt manganese oxide) to ensure conductivity. The first current collector 310 can be made of copper foil or aluminum foil, and the material can be selected according to the function of the specific battery. When the first electrode 300 is wound, the first empty foil area 311 forms the tab region 120 so that it can be connected to the current collector 200 through the tab region 120.

[0038] Reference Figure 4 The second electrode 400 includes a second current collector 410 and a second active material layer 420. The second active material layer 420 is coated on the second current collector 410, and the second current collector 410 is provided with a second empty foil region 411 for forming the tab region 120. The second active material layer 420 is responsible for storing and releasing electrical energy and can be made of active materials such as lithium iron phosphate or ternary materials (such as lithium nickel cobalt manganese oxide) to ensure conductivity. The second current collector 410 can be made of copper foil or aluminum foil, and the material can be selected according to the specific function of the battery. When the second electrode 400 is wound, the second empty foil region 411 forms the tab region 120 so that it can be connected to the current collector 200 through the tab region 120.

[0039] Reference Figure 3 and Figure 4 The first empty foil area 311 includes a first continuous blank area 312 and a first gap blank area 313; the length of the first continuous blank area 312 extending outward relative to the first active material layer 320 is also trapezoidal, so that the first continuous blank area 312 is used to form the tab flattening area 122, and the first gap blank area 313 is used to form the tab flattening area 123; the second empty foil area 411 includes a second continuous blank area 412 and a second gap blank area 413; the length of the second continuous blank area 412 extending outward relative to the second active material layer 420 is also trapezoidal, so that the second continuous blank area 412 is used to form the tab flattening area 122, and the second gap blank area 413 is used to form the tab flattening area 123.

[0040] When the first electrode 300, the second electrode 400, and the diaphragm are stacked and wound to form the core 100, the first continuous blank area 312 and the second continuous blank area 412 form the tab flattening area 122, and the first gap blank area 313 and the second gap blank area 413 form the tab flattening area 123, so that the core 100 can be directly processed by the flattening process and the flattening process, and the core 100 of this embodiment can be formed.

[0041] In summary, in this embodiment, the length of the electrode sheet extending outward from the coating area 110 in the flattened tab area 122 of the cylindrical battery gradually decreases from the outside to the inside. This results in a trapezoidal distribution of the electrode sheets in the flattened tab area 122 from high to low, which optimizes the electric field distribution inside the battery, reduces local overheating, and improves the overall stability of the battery. Furthermore, the length of the electrode sheet extending outward from the coating area 110 in the flattened tab area 123 is the same from the outside to the inside. This ensures that the edges of the electrode sheets on the inner ring of the core 100 are flat. This allows the current collector 200 to make better contact with the electrode sheets on the entire inner ring of the core 100 when welding to the tab area 120, resulting in a better and more precise fit between the current collector 200 and the core 100, improved welding effect, reduced contact resistance, optimized current conduction path, improved current conduction efficiency, increased battery energy density, and enhanced battery charge and discharge performance.

[0042] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.

Claims

1. A cylindrical battery, characterized in that, include: The core includes a coating area and two tab areas. The two tab areas are respectively located at both ends of the coating area in the height direction. The tab areas are divided into an outer edge area, a flattening area, a patting area, and an inner edge area from the outside to the inside. The length of the flattening area relative to the coating area gradually decreases from the outside to the inside. The length of the patting area relative to the coating area is the same from the outside to the inside. The length of the patting area relative to the coating area is not greater than the minimum length of the flattening area relative to the coating area.

2. The cylindrical battery according to claim 1, characterized in that, Also includes: Collector plate; the collector plate is welded to the tab flattening area and the tab patting area.

3. The cylindrical battery according to claim 2, characterized in that, The collector plate is provided with a flat surface for welding to the flattened area of ​​the electrode tab and a conical surface for welding to the flattened area of ​​the electrode tab.

4. The cylindrical battery according to claim 1, characterized in that, The core has a central hole extending along the height direction in its middle.

5. The cylindrical battery according to claim 1, characterized in that, The length by which the outer edge region of the electrode extends outward relative to the coating area is the same as the length by which the inner edge region of the electrode extends outward relative to the coating area.

6. The cylindrical battery according to claim 5, characterized in that, The length of the outer edge region of the electrode relative to the coating area is less than the length of the flattened region of the electrode relative to the coating area.

7. The cylindrical battery according to claim 1, characterized in that, The core includes a first electrode, a second electrode, and a diaphragm; the first electrode, the diaphragm, and the second electrode are sequentially stacked and wound to form the core.

8. The cylindrical battery according to claim 7, characterized in that, The first electrode includes a first current collector and a first active material layer; the first active material layer is coated on the first current collector, and the first current collector is provided with a first empty foil area for forming the tab region.

9. The cylindrical battery according to claim 8, characterized in that, The second electrode includes a second current collector and a second active material layer; the second active material layer is coated on the second current collector, and the second current collector is provided with a second empty foil area for forming the tab region.

10. The cylindrical battery according to claim 9, characterized in that, The first empty foil area includes a first continuous blank area and a first gap blank area; the first continuous blank area is used to form the tab flattening area, and the first gap blank area is used to form the tab flattening area; the second empty foil area includes a second continuous blank area and a second gap blank area; the second continuous blank area is used to form the tab flattening area, and the second gap blank area is used to form the tab flattening area.

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