Dual-purpose current collector plate for positive and negative electrodes and double-winding cylindrical secondary battery

Abstract

This utility model relates to a dual-purpose positive and negative electrode current collector and a double-core cylindrical secondary battery, belonging to the field of battery technology. It includes: a collector body; a tail body, one end of which is connected to the collector body along its length; arc-shaped grooves are provided on both sides of the tail body extending along its length, the portion of the tail body with grooves being a fusible zone, and the portion without grooves being a non-fusible zone; the width of the fusible zone decreases first and then increases along the length of the tail body; wherein, the ratio of the width W1 of the non-fusible zone to the radius R1 of the collector body is greater than or equal to 10.5% and less than or equal to 14.3%; the ratio of the minimum width W10 of the fusible zone to the width W1 of the non-fusible zone is greater than or equal to 46.2% and less than or equal to 61.5%. This application, through reasonable design of the shape and parameters of the tail body, enables the fusible zone to break in time when the battery experiences overcurrent, thereby achieving circuit breaking protection, while ensuring the structural strength of the tail body and preventing deformation and breakage.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and in particular relates to a current collector that can be used for both positive and negative electrodes and a double-core cylindrical secondary battery. Background Technology

[0002] The current collector is an important component of a battery. Its function is to collect and conduct the current generated by the electrodes. A current collector typically consists of a body and a tail, which are connected to different parts of the battery to facilitate current conduction.

[0003] In practical applications, batteries may experience external short circuits, internal short circuits, or severe overcharging. When an external short circuit, internal short circuit, or severe overcharging occurs, an abnormally large current will continuously flow through the battery, causing the temperature to rise sharply, which may lead to battery fire or explosion and adverse consequences.

[0004] Patent CN222896754U discloses a positive electrode current collector that reduces the width of the tail section by creating grooves. In the event of a battery short circuit, the narrower portion of the tail section breaks, providing current-blow protection. While this method effectively protects the battery, it also reduces the strength of the tail section, making it more susceptible to deformation and breakage. Although the patent optimizes the dimensions of the grooves and tail section, the design of key dimensional parameters remains incomplete.

[0005] In view of the above, this application is hereby submitted. Utility Model Content

[0006] To address the shortcomings of related technologies, this utility model provides a dual-purpose positive and negative electrode current collector and a double-core cylindrical secondary battery. By setting a groove in the tail body to form a fusing area, and by rationally designing the ratio of the tail body width to the disk radius and the ratio of the fusing area width to the tail body width, the fusing area can be broken in time when the battery is overcurrent, thereby achieving circuit break protection. At the same time, it can also ensure the structural strength of the tail body and avoid deformation and breakage of the tail body.

[0007] This utility model provides a dual-purpose positive and negative electrode current collector, comprising:

[0008] Disk body;

[0009] The tail body has one end connected to the disc body along its length. The tail body has arc-shaped grooves on both sides extending along its length. The part of the tail body with grooves is the fusing zone, and the part of the tail body without grooves is the non-fusing zone. The width of the fusing zone first decreases and then increases along the length of the tail body.

[0010] Among them, the ratio of the width W1 of the non-fusing zone (123) to the radius R1 of the disk body is greater than or equal to 10.5% and less than or equal to 14.3%;

[0011] The ratio of the minimum width W10 of the fused zone to the width W1 of the non-fused zone (123) is greater than or equal to 46.2% and less than or equal to 61.5%.

[0012] In the technical solution, arc-shaped grooves are set on both sides of the tail body to form a fusing zone. The arc-shaped grooves can reduce stress concentration and reduce the risk of deformation and fracture during normal use of the tail body. The design of the fusing zone width decreasing and then increasing along the length of the tail body can ensure that the fusing zone can reliably disconnect when an abnormally large current flows through during a short circuit, thus achieving current fusing protection. Furthermore, the ratio of the tail body width to the disk radius and the ratio of the fusing zone width to the tail body width are reasonably designed to ensure that the fusing zone effectively melts during a short circuit, while also ensuring the structural strength of the tail body and the fusing zone, avoiding deformation and fracture due to insufficient strength during normal use. Thus, while achieving universal compatibility of positive and negative electrodes, it also takes into account the battery's safety protection function and the structural reliability of the current collector.

[0013] In some embodiments, the ratio of the length L1 of the tail body to the radius R1 of the disk body is greater than or equal to 80% and less than or equal to 89.5%.

[0014] In some embodiments, the ratio of the dimension L10 of the fuse zone along the length of the tail body to the length L1 of the tail body is greater than or equal to 19.1% and less than or equal to 28.1%.

[0015] In some embodiments, the distance from the center of the groove to the disc along the length of the tail body is L11, and the ratio of L11 to the length of the tail body L1 is greater than or equal to 44.9% and less than or equal to 53.9%.

[0016] In some embodiments, the distance from the connection point between the disc body and the tail body to the center of the disc body is R11, and the ratio of R11 to the radius R1 of the disc body is greater than or equal to 79% and less than or equal to 88.6%.

[0017] In some embodiments, the disk body is provided with a plurality of through holes, which are arranged around the central circumference of the disk body; the ratio of the radius r1 of the through hole to the radius R1 of the disk body is greater than or equal to 17.1% and less than or equal to 22.9%.

[0018] In some embodiments, the area of ​​the disk body is calculated as S1 based on the radius R1 of the disk body; the area of ​​a single through hole is calculated based on the radius r1 of the through hole, and the sum of the areas of all through holes is obtained as S100, wherein the ratio of S100 to S1 is greater than or equal to 11.8% and less than or equal to 20.9%.

[0019] In some embodiments, the ratio of the minimum distance L21 from the outer edge of the through hole to the center of the disk to the radius R1 of the disk is greater than or equal to 27.6% and less than or equal to 33.3%.

[0020] In some embodiments, the ratio of the minimum distance L20 between the outer edges of adjacent through holes to the radius R1 of the disk body is greater than or equal to 24.8% and less than or equal to 36.2%.

[0021] In addition, this utility model also provides a dual-core cylindrical secondary battery, comprising:

[0022] case;

[0023] A first core assembly is disposed within the housing; the first core assembly includes:

[0024] The first core includes a first core positive electrode tab and a first core negative electrode tab;

[0025] The first positive current collector is welded to the first core positive current collector lug; the first positive current collector is also welded to the positive terminal at the top of the shell;

[0026] The first negative current collector is welded to the first core negative current collector lug;

[0027] A second core assembly, which is arranged axially along the housing with the first core assembly, includes:

[0028] The second core includes a second core positive electrode tab and a second core negative electrode tab.

[0029] The second positive current collector is welded to the second core positive current collector lug;

[0030] The second negative current collector is welded to the negative current collector lug of the second core; the second negative current collector is also welded to the negative terminal at the bottom of the housing;

[0031] Among them, the first negative current collector and the second positive current collector are the aforementioned dual-purpose current collectors for both positive and negative electrodes.

[0032] Based on the above technical solution, the dual-purpose positive and negative electrode current collector and the double-core cylindrical secondary battery in this utility model form a fusing zone by setting an arc-shaped groove in the tail body. This allows the width of the fusing zone to first decrease and then increase along the length of the tail body, thereby optimizing the stress distribution of the tail body and preventing the tail body from breaking due to stress concentration. Furthermore, the ratio of the tail body width to the disk radius and the ratio of the fusing zone width to the tail body width are rationally designed so that the fusing zone can break in time when the battery is overcurrent, thus achieving circuit breaking protection. At the same time, parameter balancing further ensures the structural strength of the tail body and prevents the tail body from deforming and breaking. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the structure of one embodiment of the dual-purpose positive and negative electrode collector of this utility model;

[0035] Figure 2 This is a dimensional drawing of one embodiment of the dual-purpose positive and negative electrode collector of this utility model;

[0036] Figure 3 This is a schematic diagram of the structure of one embodiment of the dual-core cylindrical secondary battery of this utility model;

[0037] Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle;

[0038] Figure 5 This is a schematic diagram of the structure of the first winding core assembly in one embodiment of the dual-purpose positive and negative electrode current collector and the double-wound cylindrical secondary battery of this utility model.

[0039] Figure 6 This is a schematic diagram of the structure of the second core assembly in one embodiment of the dual-purpose positive and negative electrode current collector and the double-core cylindrical secondary battery of this utility model.

[0040] In the picture:

[0041] 100, current collector; 200, first core assembly; 300, housing; 400, second core assembly; 500, connecting tab;

[0042] 110. Disc body; 120. Tail body;

[0043] 111. Through hole; 121. Groove; 122. Fuse-resistant zone; 123. Non-fuse-resistant zone;

[0044] 210. First core; 220. First negative current collector; 230. First positive current collector;

[0045] 211. First core negative electrode tab; 212. First core positive electrode tab;

[0046] 310. First shell; 320. Second shell;

[0047] 410. Second core; 420. Second positive current collector; 430. Second negative current collector;

[0048] 411. Positive tab of the second core; 412. Negative tab of the second core. Detailed Implementation

[0049] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0050] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation 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.

[0051] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0052] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0053] As attached Figure 1 As shown in an illustrative embodiment of the dual-purpose positive and negative electrode current collector 100 of this utility model, the dual-purpose positive and negative electrode current collector 100 includes a disk body 110 and a tail body 120; one end of the tail body 120 in the length direction is connected to the disk body 110; the tail body 120 has arc-shaped grooves 121 on both sides extending along its length direction, the part of the tail body 120 with grooves 121 is the fusing area 122, and the part of the tail body 120 without grooves 121 is the non-fusing area 123; the width of the fusing area 122 first decreases and then increases along the length direction of the tail body 120 to optimize the force distribution on the tail body 120 and avoid the tail body 120 from reducing its overall strength due to the grooves 121.

[0054] It should be noted that the fusing zone 122 is located in the middle part of the tail body 120 along the length direction of the tail body 120, and the non-fusing zone 123 includes two parts. The two non-fusing zones 123 are located on both sides of the fusing zone 122 along the length direction of the tail body 120, and the width of the non-fusing zone 123 is usually the same.

[0055] like Figure 2 As shown, the ratio of the width W1 of the non-fusing zone 123 to the radius R1 of the disc body 110 is greater than or equal to 10.5% and less than or equal to 14.3%. This not only ensures that the non-fusing zone 123 has sufficient strength, thereby giving the tail body 120 a high overall strength, but also prevents the fusing zone 122 from being difficult to fuse due to the non-fusing zone 123 being too wide, effectively balancing the structural strength and fusing reliability of the tail body 120.

[0056] If the ratio of the width W1 of the non-fusing zone 123 to the radius R1 of the disk body 110 is too large, the width of the part of the tail body 120 without the groove 121 will be large, and the overall structural strength of the tail body 120 will be too high. This will cause the fusing zone 122 to require a larger current or a longer time to fuse during a short circuit, making it difficult to concentrate heat and resulting in a poor fusing effect.

[0057] If the ratio of the width W1 of the non-fusing zone 123 to the radius R1 of the disk body 110 is too small, the width of the part of the tail body 120 without the groove 121 will be small, the overall structural strength of the tail body 120 will be insufficient, and the battery will be prone to deformation due to vibration, stress, etc. during normal use.

[0058] The ratio of the minimum width W10 of the fused zone 122 to the width W1 of the non-fused zone 123 is greater than or equal to 46.2% and less than or equal to 61.5%.

[0059] If the ratio of the minimum width W10 of the fusing zone 122 to the width W1 of the non-fusing zone 123 is too small, the minimum width W10 of the fusing zone 122 will be small, resulting in weak overcurrent capacity and a faster fusing speed. During normal charging and discharging, the fusing zone 122 may break, leading to a short circuit and battery failure. Furthermore, a smaller minimum width W10 reduces the strength of the fusing zone 122, lowers the overall strength of the tail body 120, and increases the difficulty of welding the tail body 120 to other components. Especially in dual-core cylindrical secondary batteries, where the current is inherently greater than that of conventional single-core cylindrical secondary batteries, a smaller minimum width W10 of the fusing zone 122 not only makes it difficult for the fusing zone 122 to effectively perform its fusing protection function but also makes it prone to breakage during normal operation, leading to battery failure and disposal.

[0060] If the ratio of the minimum width W10 of the fuse zone 122 to the width W1 of the non-fuse zone 123 is too large, the width W10 of the fuse zone 122 will be large, and the fuse zone 122 will not be able to play a timely overcurrent fuse role. When the battery is in thermal runaway, the fuse zone 122 will not break to form an open circuit, and the battery's safety valve may not be able to open in time, increasing the battery's risk factor.

[0061] The ratio of the length L1 of the tail body 120 to the radius R1 of the disk body 110 is greater than or equal to 80% and less than or equal to 89.5% to ensure that the length of the tail body 120 is moderate, ensuring that the tail body 120 has sufficient length to distribute stress, while optimizing the current path resistance, which not only ensures connection reliability and deformation resistance, but also keeps the position of the fusing zone 122 far away from the disk body 110, so that heat is concentrated in the fusing zone 122 and the fusing effect is reliable.

[0062] If the ratio of the length L1 of the tail body 120 to the radius R1 of the disk body 110 is too large, it will easily lead to the tail body 120 being too long. When the tail body 120 is subjected to force, it is easy to bend and deform, and the overall structural strength of the tail body 120 will be reduced. In addition, the fusing zone 122 is far away from the disk body 110, the current path is long, the heat is dispersed, the fusing speed is slow and the effect is poor.

[0063] If the ratio of the length L1 of the tail body 120 to the radius R1 of the disk body 110 is too small, the tail body 120 will be too short, the fuse zone 122 will be close to the disk body 110, the heat capacity of the fuse zone 122 will be small, the melting speed will be too fast, and it will be easily triggered by mistake. In addition, when the battery is short-circuited, the heat will be easily conducted to the disk body 110, causing it to deform. Moreover, the insufficient length of the tail body 120 may affect the connection with other components, the stress concentration at the connection point, and the structural strength will be affected by the heat of the disk body 110.

[0064] In some embodiments, the radius R1 of the disk body 110 is greater than or equal to 9.5 mm and less than or equal to 11.5 mm.

[0065] The ratio of the dimension L10 of the fusing zone 122 along the length of the tail body 120 to the length L1 of the tail body 120 is greater than or equal to 19.1% and less than or equal to 28.1%, so that the length of the fusing zone 122 is moderate, the heat accumulation rate of the fusing zone 122 is limited, the heat is concentrated and distributed reasonably, and the fusing is completed quickly at the preset position (the minimum point of W10) without affecting the rigidity of the tail body 120, thus ensuring the reliability of the fusing zone 122. At the same time, the fusing zone 122 can fully disperse the stress, ensuring the overall structural strength of the tail body 120.

[0066] It should be noted that the dimension of the fusing zone 122 along the length direction of the tail body 120 is the length of the fusing zone 122.

[0067] If the ratio of the dimension L10 of the fuse zone 122 along the length of the tail body 120 to the length L1 of the tail body 120 is too large, the fuse zone 122 will be too long, the heat distribution in the fuse zone 122 will be more dispersed, making it difficult to concentrate the melting and resulting in poor melting effect; moreover, an excessively long fuse zone 122 will also reduce the overall strength of the tail body 120, and the tail body 120 will be prone to twisting and deformation during battery production, increasing the scrap rate of production.

[0068] If the ratio of the dimension L10 of the fuse zone 122 along the length of the tail body 120 to the length L1 of the tail body 120 is too small, the fuse zone 122 will be too short. Heat will concentrate too quickly in the fuse zone 122, but the fracture surface will be too small, and it may not be able to completely break the fuse. Other components may burn out before the fuse zone 122 melts, reducing the safety of the battery. In addition, a fuse zone 122 that is too short is prone to stress concentration, and the battery is prone to breakage during normal use.

[0069] The distance from the center of the groove 121 to the disk 110 along the length of the tail body 120 is L11. The ratio of L11 to the length L1 of the tail body 120 is greater than or equal to 44.9% and less than or equal to 53.9%, so that the center of the groove is located in the middle of the tail body 120, thereby keeping the fusing zone 122 away from the disk body 110 and the end of the tail body 120, so that the heat is concentrated in the fusing zone 122. This not only ensures that the fusing zone 122 is reliably fusing, but also avoids affecting other parts, and the overall structural strength is stable.

[0070] It should be noted that the center of the groove 121 is located on the horizontal extension line of the minimum width of the fusing zone 122, and the distance from the center of the groove 121 along the length of the tail body 120 to the disk body 110 can be considered as part of the minimum width of the guide disk body 110 of the fusing zone 122.

[0071] For ease of description, the end of the tail body 120 that is away from the disc body 110 is called the end of the tail body 120.

[0072] If the ratio of the distance L11 from the center of the groove 121 to the disk 110 to the length L1 of the tail 120 is too large, the fuse zone 122 will be located close to the end of the tail 120, which may lead to insufficient strength at the end of the tail 120 and easy breakage in the non-fusible zone; and heat may be easily conducted to the connecting parts at the end of the tail 120 during short circuit, and a residual current path may remain after the fuse is broken.

[0073] If the ratio of the distance L11 from the center of the groove 121 to the disk body 110 to the length L1 of the tail body 120 is too small, the fuse zone 122 will be set close to the disk body 110. The heat of the fuse zone 122 will be easily conducted to the connection between the disk body 110 and the tail body 120, causing deformation and damage at the connection. The high temperature will also be easily conducted to the disk body 110, causing electrode damage.

[0074] The distance from the connection point between the disc body 110 and the tail body 120 to the center of the disc body 110 is R11. The ratio of R11 to the radius R1 of the disc body 110 is greater than or equal to 79% and less than or equal to 88.6%, so that the connection position between the disc body 110 and the tail body 120 is appropriate, the connection strength between the disc body 110 and the tail body 120 is high, the position of the fuse zone 122 to the disc body 110 is appropriate, and the current conduction path is reasonable. This not only ensures the overall structural strength, but also does not affect the current conduction efficiency when the fuse is broken.

[0075] If the ratio of the distance R11 from the connection point of the disc 110 and the tail 120 to the center of the disc 110 to the radius R1 of the disc 110 is too large, the connection point of the disc 110 and the tail 120 will be close to the edge of the disc 110, the contact area between the tail 120 and the disc 110 will be small, the connection strength will be insufficient, and the current will have a long path from the center of the disc 110 to the connection point, resulting in high resistance, which may affect the current collection efficiency; in addition, the tail 120 is prone to contact with the shell after bending, causing a short circuit.

[0076] If the ratio of the distance R11 from the connection point of the disc body 110 and the tail body 120 to the center of the disc body 110 to the radius R1 of the disc body 110 is too small, the connection point of the disc body 110 and the tail body 120 will be close to the center of the disc body 110. After the tail body 120 is bent, it will easily contact the disc body 110, resulting in current shunting, causing poor internal contact of the battery, and failure of the fuse structure when the battery is short-circuited.

[0077] The disk body 110 is provided with multiple through holes 111, which are arranged around the central circumference of the disk body 110 to dissipate heat from the disk body 110 and to allow the electrolyte to flow through.

[0078] In some embodiments, four through holes 111 are provided, and the four through holes 111 are evenly distributed along a circle with the center of the disk body 110 as the center and the radius from the center of the through hole 111 to the center of the disk body 110 as the radius.

[0079] The ratio of the radius r1 of the through hole 111 to the radius R1 of the disk body 110 is greater than or equal to 17.1% and less than or equal to 22.9%, so that the through hole 111 is of appropriate size and ensures that the through hole 111 has both liquid guiding and heat dissipation functions without affecting the rigidity of the disk body 110.

[0080] If the ratio of the radius r1 of the through hole 111 to the radius R1 of the disk body 110 is too large, the through hole 111 will be too large, the remaining area of ​​the disk body 110 will be small, the current flow area will be reduced, the current flow capacity will be weak, the internal resistance of the battery will be increased, the structural strength of the disk body 110 will be reduced, and the current conduction path will be reduced, which may lead to a decrease in current collection efficiency. During a short circuit, the disk body 110 is prone to deformation, which will affect the heat concentration in the fuse zone 122 and will also affect the subsequent welding of the current collector disk 100 to the core.

[0081] If the ratio of the radius r1 of the through hole 111 to the radius R1 of the disk body 110 is too small, the through hole 111 will be too small, resulting in low electrolyte flow efficiency, increased body weight, and poor heat dissipation, which may cause heat accumulation in the disk body 110 during short circuits, affecting the heat concentration in the fuse zone 122.

[0082] The area of ​​disk 110 is calculated as S1 based on the radius R1 of disk 110; the area of ​​a single through hole 111 is calculated based on the radius r1 of through hole 111, and the sum of the areas of all through holes 111 is obtained as S100. The ratio of S100 to S1 is greater than or equal to 11.8% and less than or equal to 20.9% to ensure that the area ratio of through holes 111 is reasonable, disk 110 has sufficient strength, and maximizes the function of through holes 111 while maintaining the conductivity of disk 110, thus avoiding the risk of thermal runaway.

[0083] If the ratio of the area S100 of all through holes 111 on the disk 110 to the area S1 of the disk 110 after removing the through holes 111 is too large, the total area of ​​the through holes 111 will be too large, the number of through holes 111 will be too large, the distribution of through holes 111 will be too dense, the overall strength of the disk 110 will be lower, it will be easy to deform and break, and the current conduction area will be insufficient, affecting the current collection efficiency; when short-circuited, the disk 110 is easy to deform, affecting the heat concentration in the melting zone 122, and will also affect the subsequent welding of the current collector disk 100 and the core.

[0084] If the ratio of the area S100 of all through holes 111 on the disk 110 to the area S1 of the disk 110 after removing the through holes 111 is too small, the total area of ​​the through holes 111 will be too small, the number of through holes 111 will be small, the distribution of the through holes 111 will be relatively scattered, the battery heat dissipation capacity will be poor, the electrolyte flow efficiency will be low, the weight will increase, and poor heat dissipation may lead to heat accumulation in the disk 110 during a short circuit, affecting the heat concentration in the fuse zone 122. The ratio of the minimum distance L21 from the outer edge of the through hole 111 to the center of the disk 110 to the radius R1 of the disk 110 should be greater than or equal to 27.6% and less than or equal to 33.3% to ensure that the position of the through hole 111 is moderately far from the center, so as not to affect the central structure, while ensuring edge strength, structural stability, and uniform radial current distribution of the disk 110.

[0085] If the ratio of the minimum distance L21 from the outer edge of the through hole 111 to the center of the disk body 110 to the radius R1 of the disk body 110 is too large, the welding area of ​​the collector plate 100 will be small, increasing the difficulty of the process and affecting the overall strength of the collector plate 100.

[0086] If the ratio of the minimum distance L21 from the outer edge of the through hole 111 to the center of the disk 110 to the radius R1 of the disk 110 is too small, the through hole 111 will be too close to the center hole, resulting in low overall strength of the current collector 100, affecting the liquid injection speed, and increasing the risk of collapse of the center hole during battery cycling; the process window will also be too small.

[0087] The ratio of the minimum distance L20 between the outer edges of adjacent through holes 111 to the radius R1 of the disk body 110 is greater than or equal to 24.8% and less than or equal to 36.2%, so that the spacing between adjacent through holes 111 is reasonable, the disk body 110 has greater strength, and a sufficient number of through holes 111 can be arranged on the disk body 110 to meet functional requirements, without affecting the stability of the disk body 110 when it is melted.

[0088] If the ratio of the minimum distance L20 between the outer edges of adjacent through holes 111 to the radius R1 of the disk body 110 is too large, the spacing between adjacent through holes 111 will be too large, the number of through holes 111 will be insufficient, affecting the liquid injection speed and the battery heat dissipation will be poor.

[0089] If the ratio of the minimum distance L20 between the outer edges of adjacent through holes 111 to the radius R1 of the disk body 110 is too small, the spacing between through holes 111 will be too small, the overall strength of the current collector 100 will be low, affecting the battery's current carrying capacity and increasing the battery's internal resistance.

[0090] It should be noted that in a cylindrical secondary battery, the current collector 100 typically includes a positive current collector and a negative current collector. The positive current collector is usually connected to the top of the casing and the positive electrode tab of the winding core, while the negative current collector is usually connected to the negative electrode tab of the winding core and the bottom of the casing. Some current collectors can only be used as positive current collectors, and some can only be used as negative current collectors. The current collector provided by this invention can be used as both a positive and a negative current collector.

[0091] The aforementioned dual-purpose positive and negative electrode current collector 100 forms a fusing zone 122 by setting an arc-shaped groove 121 in the tail body 120. The width of the fusing zone 122 first decreases and then increases along the length of the tail body 120 to optimize the stress distribution of the tail body 120 and prevent the tail body 120 from breaking due to stress concentration. The ratio of the width of the tail body 120 to the radius of the disk body 110 and the ratio of the width of the fusing zone 122 to the width of the tail body 120 are reasonably designed so that the fusing zone 122 can break in time to achieve circuit breaking protection when the battery is overcurrent. At the same time, the structural strength of the tail body 120 is further guaranteed by parameter balancing to prevent the tail body 120 from deforming and breaking.

[0092] Based on the above-mentioned dual-purpose positive and negative electrode current collector 100, this utility model also provides a dual-core cylindrical secondary battery, which includes a housing 300, a first core assembly 200, a second core assembly 400, and connecting tabs 500.

[0093] like Figure 3 and Figure 4As shown, the housing 300 is used to accommodate the first core assembly 200, the second core assembly 400, and the connecting tab 500; the top to the bottom of the housing 300 are the two ends of the axial direction of the housing 300. In this embodiment, the axial direction of the housing 300 is arranged in the vertical direction, and the axial direction of the housing 300 is also the height direction of the housing 300.

[0094] In some embodiments, such as Figure 3 As shown, the housing 300 includes a first housing 310 and a second housing 320, the first housing 310 and the second housing 320 are arranged along the axial direction of the housing 300, and the first housing 310 and the second housing 320 are welded together; the first core assembly 200 is located inside the first housing 310, and the second core assembly 400 is located inside the second housing 320.

[0095] In actual assembly, the first core assembly 200 is first assembled with the first housing 310, the second core assembly 400 is assembled with the second housing 320, and then the first housing 310 and the second housing 320 are welded together.

[0096] like Figure 5 As shown, the first core assembly 200 is disposed within the first housing 310; the first core assembly 200 includes a first core 210, a first positive current collector 230, and a first negative current collector 220; the first core 210 includes a first core positive electrode tab 212 and a first core negative electrode tab 211, the first core positive electrode tab 212 being located at the positive electrode of the first core 210, and the first core negative electrode tab 211 being located at the negative electrode of the first core 210; the first positive current collector 230 is welded to the first core positive electrode tab 212; the first positive current collector 230 is also welded to the positive terminal at the top of the first housing 310; the first negative current collector 220 is welded to the first core negative electrode tab 211.

[0097] like Figure 6 As shown, the second core assembly 400 is disposed within the second housing 320. The second core assembly 400 and the first core assembly 200 are arranged along the axial direction of the housing 300. The second core assembly 400 includes a second core 410, a second positive current collector 420, and a second negative current collector 430. The second core 410 includes a second core positive electrode tab 411 and a second core negative electrode tab 412. The second core positive electrode tab 411 is located at the positive electrode of the second core 410, and the second core negative electrode tab 412 is located at the negative electrode of the second core 410. The second positive current collector 420 is welded to the second core positive electrode tab 411. The second negative current collector 430 is welded to the second core negative electrode tab 412. The second negative current collector 430 is also welded to the negative terminal at the bottom of the second housing 320.

[0098] It should be noted that the first positive current collector 230, the first core 210, the first negative current collector 220, the second positive current collector 420, the second core 410, and the second negative current collector 430 are arranged sequentially from top to bottom along the height direction of the shell 300.

[0099] like Figure 4 As shown, the connecting tab 500 is located between the first negative current collector 220 and the second positive current collector 420 and is welded to the first negative current collector 220 and the second positive current collector 420 so that current can be transmitted between the first negative current collector 220 and the second positive current collector 420. The connecting tab 500 is S-shaped to buffer vibration and impact, reduce stress concentration, and ensure the stability of current transmission and structural reliability.

[0100] Among them, the first negative current collector 220 and the second positive current collector 420 are the aforementioned dual-purpose positive and negative current collector 100.

[0101] In the aforementioned dual-core cylindrical secondary battery, by making the first positive current collector 230, the first negative current collector 220, the second positive current collector 420, and the second negative current collector 430 the aforementioned current collectors 100, the dual-core cylindrical secondary battery can ensure the stability of current collection and conduction while balancing the fusing effect and structural strength by utilizing the fusing area 122 formed by the arc-shaped groove 121 of the tail body 120 of the current collector 100 and the optimized size ratio. This ensures that the fusing area 122 of each current collector 100 can reliably disconnect to achieve protection when the battery experiences abnormalities such as short circuits, and also avoids the current collectors 100 from deforming and breaking due to insufficient strength during normal use. Furthermore, the universal characteristic of positive and negative electrodes is adapted to the structure of the dual-core axial arrangement, thereby improving the overall safety and reliability of the battery.

[0102] Through the description of several embodiments of the dual-purpose positive and negative electrode current collector 100 and the double-core cylindrical secondary battery of this utility model, it can be seen that the embodiments of the dual-purpose positive and negative electrode current collector 100 and the double-core cylindrical secondary battery of this utility model have at least one or more of the following advantages:

[0103] 1. By setting arc-shaped grooves 121 on both sides of the tail body 120 to form a fusing area 122, and making the width of the fusing area 122 first decrease and then increase along the length of the tail body 120, the stress distribution of the tail body 120 is optimized, the stress concentration problem caused by the grooves 121 is avoided, the overall structural strength of the tail body 120 is significantly improved, and the breakage due to vibration or stress deformation during normal use is prevented. At the same time, it ensures that the heat is concentrated at the minimum width point during short circuit to achieve precise fusing.

[0104] 2. The ratio of the width W1 of the non-fusing zone 123 to the radius R1 of the disk body 110 is limited to 10.5%-14.3%, which ensures that the tail body 120 has sufficient strength to support the structure, and avoids the non-fusing zone 123 being too wide, which would cause the fusing resistance of the fusing zone 122 to be too large.

[0105] 3. The ratio of the minimum width W10 of the fusing zone 122 to the width W1 of the tail body 120 is limited to 46.2%-61.5% to ensure that the fusing zone 122 can carry the high current of the dual-cell battery during normal charging and discharging, while maintaining sufficient mechanical strength to reduce welding difficulty.

[0106] 4. The ratio of the length L1 of the tail body 120 to the radius R1 of the disk body 110 is limited to 80%-89.5%, so that the position of the fuse zone 122 is far away from the disk body 110, and the heat is efficiently concentrated in the fuse zone 122 during short circuit; at the same time, it ensures that the length of the tail body 120 is sufficient to disperse stress, reduce stress concentration at the connection point, and optimize the current path resistance, taking into account both deformation resistance and fuse reliability.

[0107] 5. The ratio of the length L10 of the fusing zone 122 to the length L1 of the tail body 120 is limited to 19.1%-28.1% to ensure that the heat accumulation rate is controllable and that fusing is completed quickly at the preset minimum width point, avoiding incomplete fracture or heat dispersion failure due to an excessively small fusing area. At the same time, this ratio maintains the rigidity of the tail body 120, reducing the scrap rate due to torsion and deformation during the production process.

[0108] 6. The ratio of the distance L11 from the center of the groove 121 to the disk 110 to the length L1 of the tail 120 is limited to 44.9%-53.9%, so that the fuse zone 122 is located in the middle of the tail 120, away from the disk 110 and the end connection point, so that when the battery is short-circuited, the heat is concentrated in the fuse zone 121, avoiding conduction to the disk 110 to cause electrode damage or to the end to cause the non-fuse zone to break.

[0109] 7. The ratio of the distance R11 from the connection point of the tail body 120 and the center of the disk body 110 to the radius R1 of the disk body 110 is limited to 79%-88.6% to balance the connection strength and the current path, and at the same time to avoid short circuits in the shell after the tail body 120 is bent.

[0110] 8. By limiting the radius r1 of the through hole 111, the total area of ​​the through hole 111, the position of the through hole 111, and the spacing of the through holes 111, the current carrying capacity and structural rigidity of the disk 110 are guaranteed while ensuring the electrolyte flow and heat dissipation efficiency, thus meeting the requirements of the dual-core cylindrical secondary battery.

[0111] 9. The current collector 100 is designed to be usable for both positive and negative electrodes, so that the current collector 100 can be used as a positive current collector or a negative current collector, which improves the versatility and adaptability of the current collector 100, especially to meet the structural requirements of dual-core cylindrical secondary batteries, and improves the versatility of components and assembly flexibility.

[0112] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0113] The above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A dual-purpose positive and negative electrode current collector, characterized in that, include: Disk body (110); A tail body (120) is provided, with one end of the tail body (120) connected to the disc body (110) along its length direction; the tail body (120) has arc-shaped grooves (121) on both sides extending along its length direction, the portion of the tail body (120) with the grooves (121) is a fusible zone (122), and the portion of the tail body (120) without the grooves (121) is a non-fusible zone (123); the width of the fusible zone (122) first decreases and then increases along the length direction of the tail body (120); The ratio of the width W1 of the non-fusing zone (123) to the radius R1 of the disk body (110) is greater than or equal to 10.5% and less than or equal to 14.3%. The ratio of the minimum width W10 of the fused zone (122) to the width W1 of the non-fused zone (123) is greater than or equal to 46.2% and less than or equal to 61.5%.

2. The dual-purpose positive and negative electrode current collector according to claim 1, characterized in that, The ratio of the length L1 of the tail body (120) to the radius R1 of the disc body (110) is greater than or equal to 80% and less than or equal to 89.5%.

3. The dual-purpose positive and negative electrode current collector according to claim 1, characterized in that, The ratio of the dimension L10 of the fuse zone (122) along the length direction of the tail body (120) to the length L1 of the tail body (120) is greater than or equal to 19.1% and less than or equal to 28.1%.

4. The dual-purpose positive and negative electrode current collector according to claim 1, characterized in that, The distance from the center of the groove (121) to the disk (110) along the length of the tail body (120) is L11, and the ratio of L11 to the length L1 of the tail body (120) is greater than or equal to 44.9% and less than or equal to 53.9%.

5. The dual-purpose positive and negative electrode current collector according to claim 1, characterized in that, The distance from the connection point between the disc (110) and the tail (120) to the center of the disc (110) is R11, and the ratio of R11 to the radius R1 of the disc (110) is greater than or equal to 79% and less than or equal to 88.6%.

6. The dual-purpose positive and negative electrode current collector according to claim 1, characterized in that, The disk body (110) is provided with a plurality of through holes (111), and the plurality of through holes (111) are arranged around the central circumference of the disk body (110); the ratio of the radius r1 of the through hole (111) to the radius R1 of the disk body (110) is greater than or equal to 17.1% and less than or equal to 22.9%.

7. The dual-purpose positive and negative electrode current collector according to claim 6, characterized in that, The area of ​​the disk body (110) is calculated as S1 based on the radius R1 of the disk body (110); the area of ​​a single through hole (111) is calculated based on the radius r1 of the through hole (111), and the sum of the areas of all through holes (111) is obtained as S100, wherein the ratio of S100 to S1 is greater than or equal to 11.8% and less than or equal to 20.9%.

8. The dual-purpose positive and negative electrode current collector according to claim 6, characterized in that, The ratio of the minimum distance L21 from the outer edge of the through hole (111) to the center of the disk (110) to the radius R1 of the disk (110) is greater than or equal to 27.6% and less than or equal to 33.3%.

9. The dual-purpose positive and negative electrode current collector according to claim 6, characterized in that, The ratio of the minimum distance L20 between the outer edges of adjacent through holes (111) to the radius R1 of the disk body (110) is greater than or equal to 24.8% and less than or equal to 36.2%.

10. A dual-core cylindrical secondary battery, characterized in that, include: case; The first core assembly (200) is disposed within the housing; The first core assembly (200) includes: The first core includes a first core positive tab (212) and a first core negative tab (211); The first positive current collector (230) is welded to the first core positive current collector lug (212); the first positive current collector (230) is also welded to the positive terminal at the top of the housing; The first negative electrode current collector (220) is welded to the first core negative electrode lug (211); A second core assembly (400), which is arranged axially along the housing with the first core assembly (200), the second core assembly (400) comprising: The second core includes a second core positive electrode tab (411) and a second core negative electrode tab (412); The second positive current collector (420) is welded to the second core positive current collector lug (411); The second negative current collector (430) is welded to the second core negative current collector lug (412); the second negative current collector (430) is also welded to the negative terminal at the bottom of the housing; Wherein, the first negative electrode current collector (220) and the second positive electrode current collector (420) are respectively the positive and negative electrode dual-purpose current collectors according to any one of claims 1-9.

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