Roll core structure, battery structure and electric equipment

Abstract

The utility model discloses a roll core structure, a battery structure and electric equipment, and relates to the technical field of batteries, and the roll core structure comprises a roll core main body and an electrode structure. The electrode structure is arranged on the roll core main body, the electrode structure comprises a plurality of tabs, and the widths of the tabs are not completely equal. The plurality of tabs comprise middle tabs, other tabs except the middle tabs are at least partially widened, and the width of an overlapping area of the widened tabs and the middle tabs is greater than or equal to the length of ultrasonic welding marks. According to the invention, the width of the overlapped region of the widened tab and the middle tab is greater than or equal to the length of the ultrasonic welding mark, so that the plurality of tabs have enough overlapped region after being staggered, the length of the ultrasonic welding mark is prevented from being greater than the width of the overlapped region, the material utilization rate is improved, the production cost is reduced, and the production efficiency is improved. And the overall performance of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a winding core structure, a battery structure and an electrical device. Background Art

[0002] In the field of modern battery manufacturing, the secondary battery winding process is a crucial link. However, in the existing secondary battery winding process, the misalignment problem of the winding core tab width direction often troubles manufacturers. The emergence of this problem is mainly affected by the following two factors.

[0003] When the electrode is coated with positive and negative electrode materials, the coating amount at the initial and final stages is often less stable than that in the middle stage. The winding process tension of the core also tends to show poor stability at the initial and final stages. This is mainly due to the combined effect of multiple factors such as the performance limitations of the winding equipment, the skill level of the operator, and the characteristics of the material itself.

[0004] When the winding tension is unstable, the core is easily deformed during the winding process, causing the tabs to be misaligned in the width direction. During welding, the available welding area will be occupied by the misaligned part, resulting in a reduction in the actual welding area. Tab misalignment will also cause waste of copper and aluminum foil during the die-cutting process. Utility Model Content

[0005] The present application provides a winding core structure, a battery structure and an electrical device, which can make the width of the overlapping area between the widened pole ear and the middle pole ear greater than or equal to the length of the ultrasonic weld mark, thereby ensuring that a plurality of pole ears have sufficient overlapping area after being misaligned, avoiding the length of the ultrasonic weld mark being greater than the width of the overlapping area, and improving material utilization, reducing production costs, and also helping to improve the overall performance of the battery.

[0006] In a first aspect, the present application provides a winding core structure, the winding core structure comprising a winding core body and an electrode structure. The electrode structure is arranged on the winding core body, the electrode structure comprises a plurality of pole tabs, and the widths of the plurality of pole tabs are not completely equal.

[0007] The plurality of pole tabs include a middle pole tab, and the pole tabs other than the middle pole tab are at least partially widened, and the width of the overlapping area between the widened pole tab and the middle pole tab is greater than or equal to the length of the ultrasonic weld mark.

[0008] The electrode structure is arranged on the winding core body, including multiple tabs. These tabs play the role of current transmission in the battery, so the setting of the electrode structure needs to fully consider the efficiency and stability of current transmission. It is worth noting that the widths of multiple tabs are not completely equal. This setting method takes into account the width of the ultrasonic weld mark and the uniformity of current distribution, and also takes into account the rational use of the internal space of the battery.

[0009] Among multiple tabs, the middle tab can be used as a reference. In order to further improve the efficiency and stability of current transmission, the tabs other than the middle tab are specially widened. These tabs are at least partially widened to increase their surface area, thereby increasing the channel for current transmission. At the same time, the width of the overlapping area between the widened tab and the middle tab is carefully calculated to ensure that it is greater than or equal to the length of the ultrasonic weld mark. Such a setting can not only ensure the current flow capacity between the tab and the weld mark, avoid thermal runaway problems caused by excessive current, but also effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell.

[0010] In addition, the setting of this electrode structure also fully considers the issue of material utilization. In the battery production process, some die-cut pole pieces are often produced. By rationally utilizing these discarded pole pieces and setting them into widened pole ears, it can not only improve material utilization and reduce production costs, but also help improve the overall performance of the battery.

[0011] In some examples, the electrode structure can be ultrasonically welded to a transfer sheet on the top cover, and the maximum width of the pole ear in the electrode structure is less than a preset width, where the preset width is a width at which the pole ear interferes with other structures on the top cover.

[0012] The multiple tabs of the above electrode structure do not simply present a uniform width, but are set to have unequal widths according to actual needs. This differentiated setting not only enhances the flexibility of the electrode structure, but also enables the battery to distribute current more evenly and stably during charging and discharging, thereby improving the performance of the battery.

[0013] In some examples, the electrode structure further includes a first pole tab and a last pole tab, wherein the first pole tab is the first pole tab wound, and the last pole tab is the last pole tab wound.

[0014] The widening direction of the first pole ear is opposite to the offset direction of the first pole ear relative to the middle pole ear during the winding process, and the widening direction of the last pole ear is opposite to the offset direction of the last pole ear relative to the middle pole ear during the winding process. Before the multiple pole ears are widened, they are evenly arranged in the direction from the first pole ear to the last pole ear.

[0015] The electrode structure 120 includes not only the intermediate pole ear 122 mentioned above, but also a first pole ear 121 and a last pole ear 123. The first pole ear 121 refers to the first pole ear to be wound in the electrode winding process, and the first pole ear 121 has the function of locating the winding center in the manufacture and installation of the entire electrode. The last pole ear 123 refers to the last pole ear to be wound in the electrode winding process, and the last pole ear 123 can locate and monitor the winding end of the winding core body 110.

[0016] The widening direction of the first pole ear 121 is opposite to the offset direction of the first pole ear 121 relative to the middle pole ear 122 during the winding process. Such a design can ensure that the first pole ear 121 has more overlapping areas with other pole ears after winding, ensuring the stability and integrity of the ultrasonic weld mark. Similarly, the widening direction of the last pole ear 123 is also opposite to the offset direction of the last pole ear 123 relative to the middle pole ear 122 during the winding process. Such a design can ensure that the last pole ear 123 has more overlapping areas with other pole ears after the winding process, ensuring the stability and integrity of the ultrasonic weld mark.

[0017] In some examples, the width of the multiple pole ears widened from the first pole ear toward the middle pole ear gradually decreases, and the width of the multiple pole ears widened from the middle pole ear toward the last pole ear gradually increases; wherein the width of the other pole ears before widening is the same as the width of the middle pole ear.

[0018] These tabs differ in width, and this arrangement not only optimizes the performance of the battery in which the corresponding core structure is located, but also improves material utilization.

[0019] Specifically, in the arrangement of the electrode structure, the width of the multiple tabs from the first tab to the middle tab gradually decreases, and the width of these tabs is always greater than the width of the middle tab. The middle tab can be used as a basic width reference, and the width of the middle tab is greater than the length of the ultrasonic weld mark. The widths of the multiple tabs are widened based on the middle tab. In addition, the width of the overlapping part of all tabs after stacking can be greater than the length of the ultrasonic weld mark, thereby improving the stability and reliability of the electrode structure welding.

[0020] In some examples, the cross-sectional shape of the multiple pole ears stacked from the first pole ear toward the middle pole ear is a first trapezoid, and the cross-sectional shape of the multiple pole ears stacked from the middle pole ear toward the last pole ear is a second trapezoid, and the first trapezoid is symmetrical with the second trapezoid.

[0021] The electrode structure has a unique cross-sectional shape. Specifically, after the multiple pole ears from the first pole ear to the middle pole ear are stacked on each other, their cross-sectional shape presents an obvious first trapezoid. And after the multiple pole ears from the middle pole ear to the last pole ear are stacked on each other, their cross-sectional shape presents a second trapezoid. It is worth noting that the two trapezoids are symmetrical at the center position. The above setting method can reduce the difficulty of the process and make the stacked multiple pole ears more beautiful. And this setting helps to achieve the distribution of current between the pole ears and improve the current capacity of the battery.

[0022] In some examples, the first trapezoid and the second trapezoid are two centrally symmetric right-angled trapezoids.

[0023] The straight side of the first trapezoid can be flush with the first side of the middle pole ear, and the straight side of the second trapezoid can be flush with the second side of the middle pole ear, so as to make the widening of the pole ear more material-saving. It is also not necessary to set the first trapezoid and the second trapezoid to be strictly right-angled trapezoids, depending on the needs and process settings.

[0024] In some examples, all the pole tabs between the first pole tab and the middle pole tab widen toward a first direction, and all the pole tabs between the last pole tab and the middle pole tab widen toward a second direction, and the first direction is opposite to the second direction.

[0025] The above structure can ensure the current capacity of the pole ear and the weld mark, avoiding safety problems caused by thermal runaway; it can effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell; it can also effectively utilize the die-cut pole pieces to improve material utilization.

[0026] Between the first pole lug and the middle pole lug, the width of all pole lugs gradually widens in the first direction. This setting not only enhances the contact area between the pole lug and the weld mark, improves the current carrying capacity, but also effectively avoids the risk of thermal runaway caused by excessive current. Thermal runaway is a dangerous situation that may occur during the use of the battery. When the temperature inside the battery rises abnormally, it may cause safety problems such as fire or explosion. Therefore, this setting undoubtedly provides a strong guarantee for the safety of the battery.

[0027] In some examples, the first pole tab widens toward the first direction, and after the first pole tab is widened, the widened length of the first pole tab in the first direction does not exceed the width of the middle pole tab.

[0028] The final pole ear widens toward the second direction. After the final pole ear is widened, the widened length of the final pole ear in the second direction does not exceed the width of the middle pole ear.

[0029] In the setting of the first pole ear, the first pole ear is widened in the first direction. This widening setting helps to improve the current capacity of the first pole ear, so that the battery can maintain stable performance during high current discharge. At the same time, the widening length of the widened first pole ear in the first direction is strictly controlled to ensure that it does not exceed the width of the middle pole ear. This setting helps to avoid interference or short circuit between the pole ear and other structures on the top cover, thereby improving the safety performance of the battery.

[0030] Corresponding to the first pole ear is the last pole ear, which is widened in the second direction. The widening of the last pole ear also helps to improve the current capacity and improve the heat dissipation performance of the battery to a certain extent. Similarly, the widening length of the last pole ear in the second direction is also strictly limited to ensure that there is no excessive overlap with the first pole ear. Such a setting helps to maintain the compactness of the battery structure while improving the energy utilization efficiency of the battery cell.

[0031] In a second aspect, the present application provides a battery structure, including a shell and the above-mentioned winding core structure, wherein the winding core structure is arranged in the shell.

[0032] The battery structure with the winding core structure can improve the material utilization rate, reduce the production cost, and help improve the overall performance of the battery. At the same time, such a setting can not only ensure the current flow capacity between the tab and the weld mark, avoid the thermal runaway problem caused by excessive current, but also effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell.

[0033] In a third aspect, the present application provides an electrical device, comprising the above-mentioned battery structure and a device body, wherein the battery structure is arranged in the device body.

[0034] The equipment with the winding core structure can improve the material utilization rate, reduce production costs, and help improve the overall performance of the battery. At the same time, such a setting can not only ensure the current flow capacity between the tab and the weld mark, avoid thermal runaway problems caused by excessive current, but also effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the examples or prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some examples of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is a schematic diagram of the structure of an electrical device in an example of this application;

[0037] Figure 2 It is a structural schematic diagram of a winding core structure in the prior art;

[0038] Figure 3 It is a structural schematic diagram showing the width of ultrasonic welding marks on a winding core structure in the prior art;

[0039] Figure 4 It is a schematic diagram of the structure of the winding core structure in the prior art when it is connected to the adapter sheet;

[0040] Figure 5It is a structural schematic diagram of a top cover in the prior art when two winding core structures are connected at the same time;

[0041] Figure 6 This is a schematic structural diagram of a winding core structure in an example of the present application;

[0042] Figure 7 This is a structural schematic diagram showing the width of the ultrasonic weld mark on the core structure in an example of the present application;

[0043] Figure 8 This is a schematic diagram of the structure of the winding core structure in an example of the present application when it is connected to the adapter sheet;

[0044] Fig. 9 This is a schematic diagram of the structure when the top cover in an example of the present application is connected to two winding core structures at the same time.

[0045] Reference numerals:

[0046] 1000, electrical equipment; 1100, battery structure; 1200, controller; 1300, motor;

[0047] 100, winding core structure; 110, winding core body; 120, electrode structure; 121, first pole ear; 122, middle pole ear; 123, last pole ear; 200, top cover; 210, adapter; 220, pole; a, ultrasonic weld mark width. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described here are only used to explain the present application and are not used to limit the present application.

[0049] In the field of modern battery manufacturing, the secondary battery winding process is a crucial link. However, in the existing secondary battery winding process, the misalignment problem of the winding core tab width direction often troubles manufacturers. The emergence of this problem is mainly affected by the following two factors.

[0050] When the electrode is coated with positive and negative electrode materials, the coating amount in the initial and final stages is often not stable enough compared to the middle stage. This phenomenon is often due to factors such as the precision limitation of the coating equipment and the uniformity of the coating slurry. Due to the fluctuation of the coating amount, the thickness of the electrode in the initial and final stages after coating varies greatly. In the subsequent winding process, these uneven thickness electrode segments will directly affect the neatness of the winding core, causing the pole ears to be greatly misaligned in the width direction.

[0051] The winding tension of the core also tends to show poor stability at the beginning and end stages. This is mainly due to the combined effect of multiple factors such as the performance limitations of the winding equipment, the skill level of the operator, and the characteristics of the material itself. When the winding tension is unstable, the core is prone to deformation during the winding process, resulting in misalignment of the tabs in the width direction. For details, refer to Figures 2 to 5 .

[0052] Reference Figures 2 to 5 , the emergence of the tab misalignment problem has brought many challenges to the battery welding process. First, the available welding area will be occupied by the misaligned part during welding, resulting in a reduction in the actual welding area. This not only increases the difficulty of welding, but also easily leads to quality problems such as welding cracks in the tab during the welding process. Secondly, due to the insufficient effective welding area, the current capacity between the tab and the weld mark is reduced, and the temperature rise becomes larger, thereby increasing the safety risk of thermal runaway. In addition, the misalignment of the tab may also cause the internal resistance to increase, thereby affecting the energy utilization efficiency of the battery cell.

[0053] In addition to welding problems, the misalignment of the tabs will also cause waste of copper and aluminum foil during the die-cutting process. Due to the misalignment of the tabs, the misaligned parts need to be cut off during die-cutting, which not only increases production costs but also reduces material utilization.

[0054] In order to solve the above problems, the embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0055] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0056] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery structure 1100 is provided inside the vehicle 1000, and the battery structure 1100 may be provided at the bottom, head or tail of the vehicle 1000. The battery structure 1100 may be used to power the vehicle 1000, for example, the battery structure 1100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1200 and a motor 1300, and the controller 1200 is used to control the battery structure 1100 to power the motor 1300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.

[0057] In some embodiments of the present application, the battery structure 1100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0058] The present application also provides a battery structure, including a shell and the above-mentioned electrode structure, wherein the electrode structure is arranged in the shell. By arranging the electrode structure of the present application, the battery structure can improve material utilization and reduce production costs. Specifically, by reasonably utilizing these discarded pole pieces and arranging them into widened pole ears, not only can material utilization be improved and production costs be reduced, but also the overall performance of the battery can be improved.

[0059] The battery structure and electrical equipment with the winding core structure can improve the material utilization rate, reduce production costs, and help improve the overall performance of the battery. At the same time, such a setting can not only ensure the current flow capacity between the tab and the weld mark, avoid thermal runaway problems caused by excessive current, but also effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell.

[0060] To solve the above technical problems, please refer to Figure 6-Figure 9 As shown, the present application proposes a winding core structure 100, which can make the width of the overlapping area between the widened pole ear and the middle pole ear greater than or equal to the length of the ultrasonic weld mark, thereby ensuring that multiple pole ears have sufficient overlapping area after being misaligned, avoiding the length of the ultrasonic weld mark being greater than the width of the overlapping area, and can improve material utilization, reduce production costs, and help improve the overall performance of the battery.

[0061] The widening of the tabs in the winding core structure 100 of the present application is designed before the pole piece is wound and when the tabs are die-cut after coating. Figure 6 and Figure 7In some examples, the core structure 100 includes a core body 110 and an electrode structure 120. The electrode structure 120 is disposed on the core body 110, and the electrode structure 120 includes a plurality of tabs, and the widths of the plurality of tabs are not completely equal.

[0062] The plurality of tabs include a middle tab 122, and the other tabs other than the middle tab 122 are at least partially widened, and the width of the overlap area between the widened tab and the middle tab 122 is greater than or equal to the length of the ultrasonic weld mark. The tab structure in the present application is applicable to both positive tabs and negative tabs, and is adaptively adjusted according to specific needs.

[0063] The rationality of the configuration of the core structure 100 and the stability of its performance will directly affect the performance and safety of the battery product. The core structure 100 may include a core body 110 and an electrode structure 120 .

[0064] The electrode structure 120 is arranged on the winding core body 110, and includes a plurality of tabs. These tabs play a role in current transmission in the battery, so the arrangement of the electrode structure 120 needs to fully consider the efficiency and stability of current transmission. It is worth noting that the widths of the plurality of tabs are not completely equal. This arrangement takes into account the uniformity of the ultrasonic weld width a and the current distribution, and also takes into account the reasonable use of the internal space of the battery.

[0065] Among the multiple pole ears, the middle pole ear 122 can be used as a reference benchmark. In order to further improve the efficiency and stability of current transmission, the other pole ears except the middle pole ear 122 are specially widened. These pole ears are at least partially widened to increase their surface area, thereby increasing the channel for current transmission. At the same time, the width of the overlapping area between the widened pole ear and the middle pole ear 122 is carefully calculated to ensure that it is greater than or equal to the length of the ultrasonic weld mark. Such a setting can not only ensure the current flow capacity between the pole ear and the weld mark, avoid thermal runaway problems caused by excessive current, but also effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell.

[0066] In addition, the arrangement of the electrode structure 120 also fully considers the issue of material utilization. In the battery production process, some die-cut pole pieces are often produced. By rationally utilizing these discarded pole pieces and setting them into widened pole ears, not only can the material utilization rate be improved and the production cost be reduced, but it also helps to improve the overall performance of the battery.

[0067] The electrode structure 120 of the present application, which includes multiple tabs of unequal widths, achieves comprehensive improvement in current transmission efficiency, energy utilization efficiency, and material utilization rate through reasonable optimization arrangement and application, which helps to improve the performance and quality of battery products.

[0068] The widening in the present application is a relative widening, which means that less die-cutting is done during the die-cutting process of the existing electrode structure 120, thereby achieving a relative widening of the tab. For example, after the first tab 121 is partially die-cut less, the new first tab 121 will be wider than the existing first tab 121.

[0069] Reference Figure 8 and Fig. 9 In some examples, the electrode structure 120 can be ultrasonically welded to the adapter sheet 210 on the top cover 200 , and the maximum width of the electrode ear in the electrode structure 120 is less than a preset width, which is the width at which the electrode ear interferes with other structures on the top cover 200 .

[0070] The multiple tabs of the electrode structure 120 are not simply of uniform width, but are arranged to have unequal widths according to actual needs. This differentiated arrangement not only enhances the flexibility of the electrode structure 120, but also enables the battery to distribute current more evenly and stably during the charge and discharge process, thereby improving the performance of the battery.

[0071] In the actual application of the electrode structure 120, these tabs can be accurately connected to the adapter 210 on the top cover 200 by ultrasonic welding technology. In order to ensure the smooth progress of the welding process and avoid any interference, the maximum width of the tabs in the electrode structure 120 is controlled below the preset width. This preset width is obtained through careful calculation and experimental verification. The preset width ensures that the tabs will not interfere with other structures on the top cover 200 during the welding process, thereby ensuring the reliability and stability of the welding. Other structures include the pole 220, the raised part in the middle of the lower plastic of the top cover, and other structures. The above settings can ensure the performance of the battery.

[0072] Taking the first tab 121 as an example in the above-mentioned preset width, the minimum extension distance of the tab after widening does not exceed the middle convex part of the lower plastic of the top cover 200, and the corresponding battery structure will not allow the middle convex part to press on the electrode structure 120 during the assembly process. The preset width of the first tab 121 can be set to be less than or equal to one quarter of the length of the top cover 200.

[0073] The advantage of this electrode structure 120 is that it can effectively avoid safety problems caused by thermal runaway while ensuring the current capacity of the tabs and weld marks. By setting the width reasonably, the tabs can better withstand the impact of current and reduce the risk of thermal runaway caused by excessive current. In addition, this structure can effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell. The reduction in internal resistance means that the battery can reduce energy loss during the charging and discharging process, thereby improving the overall performance of the battery.

[0074] In some examples, the electrode structure 120 further includes a first pole tab 121 and a last pole tab 123 , wherein the first pole tab 121 is the first pole tab wound, and the last pole tab 123 is the last pole tab wound.

[0075] The widening direction of the first pole ear is opposite to the offset direction of the first pole ear relative to the middle pole ear during the winding process, and the widening direction of the last pole ear is opposite to the offset direction of the last pole ear relative to the middle pole ear during the winding process. Before the multiple pole ears are widened, they are evenly arranged in the direction from the first pole ear to the last pole ear.

[0076] The electrode structure 120 includes not only the intermediate pole ear 122 mentioned above, but also a first pole ear 121 and a last pole ear 123. The first pole ear 121 refers to the first pole ear to be wound in the electrode winding process, and the first pole ear 121 has the function of locating the winding center in the manufacture and installation of the entire electrode. The last pole ear 123 refers to the last pole ear to be wound in the electrode winding process, and the last pole ear 123 can locate and monitor the winding end of the winding core body 110.

[0077] The widening direction of the first pole ear 121 is opposite to the offset direction of the first pole ear 121 relative to the middle pole ear 122 during the winding process. Such a design can ensure that the first pole ear 121 has more overlapping areas with other pole ears after winding, ensuring the stability and integrity of the ultrasonic weld mark. Similarly, the widening direction of the last pole ear 123 is also opposite to the offset direction of the last pole ear 123 relative to the middle pole ear 122 during the winding process. Such a design can ensure that the last pole ear 123 has more overlapping areas with other pole ears after the winding process, ensuring the stability and integrity of the ultrasonic weld mark.

[0078] In addition, before widening, these tabs can be evenly arranged in the direction from the first tab 121 to the last tab 123. This uniform arrangement design can ensure the stability and reliability of the electrode during the winding process, thereby improving the use effect and service life of the electrode. The tabs can also be arranged unevenly before widening as needed, and the specific arrangement method can be set as needed.

[0079] The advantage of the electrode structure 120 of the present application is that it can effectively ensure the current capacity of the tabs and weld marks, thereby avoiding safety issues such as thermal runaway. Thermal runaway is a runaway phenomenon caused by internal heat accumulation during the operation of the battery, which may cause the battery to catch fire or explode in severe cases. By optimizing the tab settings, we can effectively reduce this risk and improve the safety of the battery.

[0080] In some examples, the width of the multiple pole tabs widened from the first pole tab 121 toward the middle pole tab 122 gradually decreases, and the width of the multiple pole tabs widened from the middle pole tab 122 toward the last pole tab 123 gradually increases; wherein the width of the other pole tabs before widening is the same as the width of the middle pole tab 122 .

[0081] These tabs differ in width, and this arrangement not only optimizes the performance of the battery in which the corresponding winding core structure 100 is located, but also improves material utilization.

[0082] Specifically, in the arrangement of the electrode structure 120, the width of the multiple pole ears from the first pole ear 121 toward the middle pole ear 122 gradually decreases, and the width of these pole ears is always greater than the width of the middle pole ear 122. The middle pole ear 122 can be used as a basic width reference. The width of the middle pole ear 122 is greater than the length of the ultrasonic weld mark. The widths of the above multiple pole ears are widened based on the middle pole ear 122. In addition, the width of the overlapping part of all the pole ears after stacking can be greater than the length of the ultrasonic weld mark, which improves the stability and reliability of the welding of the electrode structure 120. The width of the above other pole ears before widening can be the same as the width of the middle pole ear 122, or can be set differently as needed.

[0083] This setting can ensure that the current can be better distributed when flowing through the tabs, avoiding overcurrent, thereby effectively preventing safety problems such as thermal runaway. At the same time, this setting also helps to reduce the internal resistance of the battery cell, improve the energy utilization efficiency of the battery cell, and make the battery have higher energy density and longer service life during operation.

[0084] On the other hand, the width of the multiple pole ears from the middle pole ear 122 to the final pole ear 123 gradually increases. The width of these pole ears is always greater than the width of the middle pole ear 122. The middle pole ear 122 can be used as a basic width reference. The width of the middle pole ear 122 is greater than the length of the ultrasonic weld mark. The widths of the above multiple pole ears are widened based on the middle pole ear 122. In addition, the width of the overlapping part of all the pole ears after stacking can be greater than the length of the ultrasonic weld mark, thereby improving the stability and reliability of the welding of the electrode structure 120.

[0085] Moreover, this arrangement enables the current to flow better at the terminal ear 123, thereby ensuring that the battery can provide sufficient current output during the discharge process. In addition, this arrangement also helps to optimize the heat distribution inside the battery, reduce heat concentration, and improve the thermal stability of the battery.

[0086] It is worth mentioning that the electrode structure 120 also makes full use of the die-cut pole pieces. In the battery production process, some pole pieces that do not meet the requirements are often produced and discarded. However, in the electrode structure 120, these discarded pole pieces can be effectively utilized, thereby improving the utilization rate of materials and reducing production costs.

[0087] In some examples, the cross-sectional shape of the multiple pole tabs stacked from the first pole tab 121 toward the middle pole tab 122 is a first trapezoid, and the cross-sectional shape of the multiple pole tabs stacked from the middle pole tab 122 toward the last pole tab 123 is a second trapezoid, and the first trapezoid is symmetrical to the second trapezoid.

[0088] The electrode structure 120 is arranged with a unique cross-sectional shape. Specifically, after the multiple pole ears from the first pole ear 121 to the middle pole ear 122 are stacked on each other, their cross-sectional shape presents an obvious first trapezoid. And after the multiple pole ears from the middle pole ear 122 to the last pole ear 123 are stacked on each other, their cross-sectional shape presents a second trapezoid. It is worth noting that the two trapezoids are symmetrical at the center position. The above arrangement can reduce the difficulty of the process and make the stacked multiple pole ears more beautiful. And this arrangement helps to achieve the distribution of current between the pole ears and improve the current capacity of the battery.

[0089] The first trapezoid and the second trapezoid can be an isosceles trapezoid, a right-angle trapezoid or other types of trapezoidal structures, the upper and lower sides of the corresponding trapezoids are parallel, and the angles between the two sides corresponding to the two waists and other adjacent sides are set as needed, and the corresponding angles can be in the range of 60° to 135°. As long as the width of the overlapping part of all the tabs after stacking is greater than the length of the ultrasonic weld mark, the stability and reliability of the welding of the electrode structure 120 can be improved.

[0090] By optimizing the setting of the pole ear, the electrode structure 120 can ensure the current capacity of the pole ear and the weld mark (it can better transfer the current from the pole ear to the corresponding adapter 210), thereby effectively avoiding safety problems such as thermal runaway. Secondly, this setting helps to reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell. In addition, the structure can also effectively utilize the die-cut pole piece, reduce material waste, improve material utilization, and further reduce production costs.

[0091] In practical applications, this electrode structure 120 has been widely used in many fields. For example, the electrode structure 120 can be applied to batteries of electric vehicles, smart phones, laptop computers and other devices.

[0092] In some examples, the first trapezoid and the second trapezoid are two right-angled trapezoids that are centrally symmetrical. The straight side of the first trapezoid can be flush with the first side of the middle pole ear 122, and the straight side of the second trapezoid can be flush with the second side of the middle pole ear 122, so as to make the widening of the pole ear more material-saving. It is also possible not to set the first trapezoid and the second trapezoid to be strictly right-angled trapezoids, depending on the needs and process settings.

[0093] In some examples, all the pole ears between the first pole ear 121 and the middle pole ear 122 widen toward the first direction, and all the pole ears between the last pole ear 123 and the middle pole ear 122 widen toward the second direction, and the first direction is opposite to the second direction. The above structure can ensure the current capacity of the pole ears and weld marks, avoid safety problems caused by thermal runaway; can effectively reduce the internal resistance of the battery cell and improve the energy utilization efficiency of the battery cell; and can also effectively utilize the die-cut pole pieces to improve material utilization.

[0094] Between the first pole lug 121 and the middle pole lug 122, the width of all pole lugs gradually widens toward the first direction. This setting not only enhances the contact area between the pole lug and the weld mark, improves the current carrying capacity, but also effectively avoids the risk of thermal runaway caused by excessive current. Thermal runaway is a dangerous situation that may occur during the use of the battery. When the temperature inside the battery rises abnormally, it may cause safety problems such as fire or explosion. Therefore, this setting undoubtedly provides a strong guarantee for the safety of the battery.

[0095] Between the final pole ear 123 and the middle pole ear 122, the width of all pole ears gradually widens toward the second direction, and the first direction is completely opposite to the second direction. This symmetrical arrangement not only makes the electrode structure 120 look more beautiful, but also has its unique advantages in practical applications. It helps to balance the current distribution inside the battery, reduce the internal resistance of the battery cell, and thus improve the energy utilization efficiency of the battery cell.

[0096] In some examples, the first tab 121 widens toward the first direction, and after the first tab 121 is widened, the widening length of the first tab 121 in the first direction does not exceed the width of the middle tab 122. The first direction is the direction opposite to the offset direction of the first tab 121 relative to the middle tab 122 during the winding process.

[0097] The final pole ear 123 widens in the second direction, and after the final pole ear 123 is widened, the widening length of the final pole ear 123 in the second direction does not exceed the width of the intermediate pole ear. The second direction is the direction opposite to the offset direction of the final pole ear 123 relative to the intermediate pole ear 122 during winding.

[0098] In the setting of the first pole lug 121, the first pole lug 121 is widened in the first direction. This widening setting helps to improve the current capacity of the first pole lug 121, so that the battery can maintain stable performance during high current discharge. At the same time, the widening length of the widened first pole lug 121 in the first direction is strictly controlled to ensure that it does not exceed the width of the middle pole lug, that is, the cumulative maximum width of the first pole lug 121 will not be higher than 2 times the width of the middle pole lug 122. Such a setting helps to avoid interference or short circuit between the pole lug and other structures on the top cover 200, thereby improving the safety performance of the battery.

[0099] Corresponding to the first pole ear 121 is the last pole ear 123, which is widened in the second direction. The widening setting of the last pole ear 123 also helps to improve the current capacity and improve the heat dissipation performance of the battery to a certain extent. Similarly, the widening length of the last pole ear 123 in the second direction is also strictly limited to ensure that the widened width of the last pole ear 123 does not exceed the width of the middle pole ear, that is, the cumulative maximum width of the last pole ear 123 will not be higher than 2 times the width of the middle pole ear 122. Such a setting helps to maintain the compactness of the battery structure while improving the energy utilization efficiency of the battery cell.

[0100] The benefits of this electrode structure 120 are not only reflected in improving the current capacity and safety performance. By adjusting the width and position of the pole ear, the internal resistance of the battery cell can also be effectively reduced. The reduction of internal resistance means that the energy loss of the battery during the charging and discharging process is reduced, thereby improving the energy utilization efficiency of the battery cell. In addition, this setting can also effectively utilize the die-cut pole pieces, avoid material waste, and further improve the utilization rate of materials.

[0101] The same or similar numbers in the drawings of this application correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0102] The above are only preferred examples of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A winding core structure, characterized in that: The winding core structure comprises: The core body; An electrode structure is arranged on the winding core body, the electrode structure comprises a plurality of pole ears, and the widths of the plurality of pole ears are not completely equal; The plurality of pole tabs include a middle pole tab, and the pole tabs other than the middle pole tab are at least partially widened, and the width of the overlapping area between the widened pole tab and the middle pole tab is greater than or equal to the length of the ultrasonic weld mark.

2. The winding core structure according to claim 1, characterized in that: The electrode structure can be ultrasonically welded to the adapter sheet on the top cover. The maximum width of the pole ear in the electrode structure is smaller than a preset width, and the preset width is a width at which the pole ear interferes with other structures on the top cover.

3. The winding core structure according to claim 1, characterized in that: The electrode structure further comprises a first pole ear and a last pole ear, wherein the first pole ear is the first pole ear wound, and the last pole ear is the last pole ear wound; The widening direction of the first pole ear is opposite to the offset direction of the first pole ear relative to the middle pole ear during the winding process, and the widening direction of the last pole ear is opposite to the offset direction of the last pole ear relative to the middle pole ear during the winding process. Before the multiple pole ears are widened, they are evenly arranged in the direction from the first pole ear to the last pole ear.

4. The winding core structure according to claim 3, characterized in that: The width of the multiple pole ears widened from the first pole ear toward the middle pole ear gradually decreases, and the width of the multiple pole ears widened from the middle pole ear toward the last pole ear gradually increases; wherein the width of the other pole ears before widening is the same as the width of the middle pole ear.

5. The winding core structure according to claim 3, characterized in that: The cross-sectional shape of the stacked multiple pole tabs from the first pole tab toward the middle pole tab is a first trapezoid, and the cross-sectional shape of the stacked multiple pole tabs from the middle pole tab toward the last pole tab is a second trapezoid. The first trapezoid is symmetrical to the second trapezoid.

6. The winding core structure according to claim 5, characterized in that: The first trapezoid and the second trapezoid are two right-angled trapezoids that are centrally symmetrical.

7. The winding core structure according to claim 3, characterized in that: All the pole tabs between the first pole tab and the middle pole tab widen toward a first direction, and all the pole tabs between the last pole tab and the middle pole tab widen toward a second direction, and the first direction is opposite to the second direction.

8. The winding core structure according to claim 3, characterized in that: The first pole tab is widened toward the first direction, and after the first pole tab is widened, the widened length of the first pole tab in the first direction does not exceed the width of the middle pole tab; The final pole ear widens toward the second direction. After the final pole ear is widened, the widened length of the final pole ear in the second direction does not exceed the width of the middle pole ear.

9. A battery structure, characterized in that: include: case; The winding core structure according to any one of claims 1 to 8, wherein the winding core structure is arranged in the shell.

10. An electrical device, characterized in that: include: The battery structure as claimed in claim 9; and, The device body is provided with the battery structure.

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