Storage battery

Abstract

The invention relates to the technical field of storage batteries, in particular to a storage battery which comprises a shell in which a plurality of groove units isolated from one another are arranged; the battery cover is arranged at the top opening of the shell; the plurality of pole group structures are respectively arranged in the plurality of groove body units; the plate group structure comprises a plurality of positive plates and a plurality of negative plates, a plurality of negative plates; a plurality of partitions; the positive tab of the first end positive plate or the positive tab of the second end positive plate is provided with a first bending structure, and the first bending structure extends towards the middle positive plate; a negative tab of the first end negative plate or a negative tab of the second end negative plate is provided with a second bending structure, and the second bending structure extends towards the middle negative plate; the bent end tab is closer to the middle pole plate, the conduction distance of current from the end pole plate to the busbar is reduced, the ohmic resistance is reduced, and therefore heat is reduced, and the high-rate discharge performance is improved.

Description

Technical Field

[0001] This invention relates to the field of storage battery technology, and in particular to a storage battery. Background Technology

[0002] The electrode assembly is the core electrochemical reaction unit and basic energy storage unit that constitutes a single lead-acid battery cell. It is assembled from positive plates, negative plates, and separators arranged in a specific alternating order. Each electrode plate includes a grid and active material. The grid provides mechanical support for the active material and provides channels for ion diffusion and electrolyte flow. The separator is placed between adjacent positive and negative plates to physically isolate them and prevent internal short circuits.

[0003] For example, patent number 2024221060529 discloses a lead-acid battery electrode group. This patent provides a first arc-shaped structure on the positive grid and / or negative grid, with arc-shaped ribs arranged laterally in the frame. The bending direction of the first arc-shaped structure is consistent with the bending direction of the arc-shaped ribs, so that the positive grid and / or negative grid form an equipotential surface. The current flows from the electrode tab through various positions of the positive grid and / or negative grid, greatly improving the consistency of the current density. This makes the utilization rate of the active material carried on the positive grid and / or negative grid more uniform, delaying the corrosion of the positive grid and the mudding of the active material, as well as the sulfation of the active material in the negative grid.

[0004] For example, patent number 2024213264007 discloses a high specific energy electrode group. The upper and lower parts of the electrode group have an equal number of tabs. Combined with the rib grid, the electrical performance of the upper and lower parts of the electrode group is more uniform, which can extend the cycle life of the battery and improve the specific energy of the battery.

[0005] After the electrode group is assembled, all positive electrode tabs must be cast-welded to the positive busbar, and all negative electrode tabs must be cast-welded to the negative busbar to form an effective current collection and conduction path. In conventional designs, to ensure the conductive cross-sectional area, mechanical strength, and reliable connection with the terminals, the structural dimensions of the busbar are usually significantly larger than those of a single tab. Specifically, the thickness of the busbar is typically designed to be about 4 to 5 times the thickness of a single tab, the width of the busbar is typically designed to be about 1.5 times the width of a single tab, and the length of the busbar must cover and connect all parallel tabs of the same type (i.e., all positive electrode tabs or all negative electrode tabs). For the two patents mentioned above, the specific electrode group structure requires the use of larger-sized positive and negative buses during busbar casting, especially since their length must extend to cover the entire parallel tab array. However, longer positive and negative buses can easily lead to increased resistance, thus affecting the battery's electrical performance. Summary of the Invention

[0006] In view of the shortcomings or problems existing in the prior art, this disclosure provides a battery with low resistance.

[0007] The technical solution adopted by this disclosure to solve the above-mentioned technical problem is: a storage battery, comprising: The housing contains multiple isolated groove units. The battery cover is located at the top opening of the casing; Multiple pole group structures are respectively disposed in the multiple slot units, and each pole group structure corresponds one-to-one with each slot unit; The pole group structure includes: Multiple positive plates, each with a positive tab at one end; Multiple negative plates, each negative plate having a negative electrode tab at one end, and the multiple negative plates and multiple positive plates are arranged alternately along a first direction; Multiple separators are placed between adjacent positive and negative plates to isolate adjacent positive and negative plates. The pole group structure has a first end and a second end that are arranged opposite to each other along the first direction; The positive plate located at the first end is defined as the first end positive plate, and the negative plate located at the first end is defined as the first end negative plate; The positive plate located at the second end is defined as the positive plate at the second end, and the negative plate located at the second end is defined as the negative plate at the second end. The positive electrode plate located between the first end positive electrode plate and the second end positive electrode plate is defined as the intermediate positive electrode plate; The negative electrode plate located between the first end negative electrode plate and the second end negative electrode plate is defined as the intermediate negative electrode plate; The positive electrode tab of the first end positive electrode plate or the positive electrode tab of the second end positive electrode plate is provided with a first bending structure, and the first bending structure extends toward the middle positive electrode plate. The negative electrode tab of the first end negative electrode plate or the negative electrode tab of the second end negative electrode plate is provided with a second bending structure, which extends toward the middle negative electrode plate.

[0008] In a preferred embodiment, the battery cover and the housing are bonded by hot-melt welding or adhesive; the positive electrode tab of the first end positive electrode plate is defined as the first positive electrode tab, and the positive electrode tab of the second end positive electrode plate is defined as the second positive electrode tab, and both the first positive electrode tab and the second positive electrode tab are provided with a first bending structure.

[0009] In a preferred embodiment, the positive electrode tab of the intermediate positive electrode plate is defined as the intermediate positive electrode tab, and the ends of the first positive electrode tab, the second positive electrode tab, and the intermediate positive electrode tab are arranged on the same plane.

[0010] In a preferred embodiment, the first bending structure includes a first bending segment and a second bending segment connected together, with one side of the first bending segment abutting against its adjacent middle positive electrode tab.

[0011] In a preferred embodiment, the length of the middle positive electrode tab is H0, and the lengths of the first positive electrode tab and the second positive electrode tab are equal, which is H1, where H0 < H1 < 1.5H0.

[0012] In a preferred embodiment, H1 = 1.2H0.

[0013] In a preferred embodiment, the length of the first bending segment is L1, where ½H0≤L1≤⅔H0.

[0014] In a preferred embodiment, the angle between the first bending segment and the second bending segment is 90 degrees.

[0015] In a preferred embodiment, the negative electrode tab of the first end negative electrode plate is defined as the first negative electrode tab, and the negative electrode tab of the second end negative electrode plate is defined as the second negative electrode tab. Both the first negative electrode tab and the second negative electrode tab are provided with a second bending structure.

[0016] In a preferred embodiment, the negative electrode tab of the intermediate negative electrode plate is defined as the intermediate negative electrode tab, and the ends of the first negative electrode tab, the second negative electrode tab, and the intermediate negative electrode tab are arranged on the same plane.

[0017] In a preferred embodiment, the second bending structure includes a third bending segment and a fourth bending segment connected together, with one side of the third bending segment fitting against its adjacent intermediate negative electrode tab.

[0018] In a preferred embodiment, the length of the middle negative electrode tab is H2, and the lengths of the first negative electrode tab and the second negative electrode tab are equal, which is H3, where H2 < H3 < 1.5H2.

[0019] In a preferred embodiment, H3 = 1.2H2.

[0020] In a preferred embodiment, the length of the fourth bending segment is L2, where ½H2≤L2≤⅔H2.

[0021] In a preferred embodiment, the angle between the third bending segment and the fourth bending segment is 90 degrees.

[0022] In a preferred embodiment, it further includes a positive bus and a negative bus, wherein the first positive electrode, the middle positive electrode, and the second positive electrode are connected in sequence through the positive bus, and the first negative electrode, the middle negative electrode, and the second negative electrode are connected in sequence through the negative bus.

[0023] In a preferred embodiment, the positive busbar is connected to a positive terminal; the negative busbar is connected to a negative terminal.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the traditional straight end tabs may touch the battery casing due to excessive length, which is eliminated by bending; the bent end tabs are closer to the middle plate, reducing the current conduction distance from the end plate to the busbar, reducing ohmic resistance, thereby reducing heat generation and improving high-rate discharge performance; the end plate is easy to dissipate heat due to its proximity to the battery casing, which may lead to a temperature gradient. The bending structure optimizes the current path, alleviates the polarization difference between the end and middle plates, and extends the cycle life of the battery. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a storage battery according to this application; Figure 2 This is a schematic diagram of the shell structure of this application; Figure 3 This is one of the structural schematic diagrams of the pole group structure in this application; Figure 4 For this application Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a cross-sectional view of the pole group structure of this application; Figure 6 This is the second schematic diagram of the pole group structure in this application.

[0026] In the diagram: 1. First end positive electrode plate; 2. Second end positive electrode plate; 3. First end negative electrode plate; 4. Second end negative electrode plate; 5. Separator; 6. First positive electrode tab; 7. Second positive electrode tab; 8. First negative electrode tab; 9. Second negative electrode tab; 10. First bending structure; 11. Second bending structure; 12. Middle positive electrode tab; 13. Middle negative electrode tab; 14. First bending section; 15. Second bending section; 16. Third bending section; 17. Fourth bending section; 18. Positive busbar; 19. Negative busbar; 100. Housing; 200. Battery cover; 300. Tank unit. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this disclosure, the following detailed, clear, and complete description of this disclosure is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0028] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., 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 invention 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, the above terms should not be construed as limiting this invention.

[0029] Please refer to Figures 1-6As shown, this application discloses a storage battery, including a casing 100, a battery cover 200, and multiple electrode groups. The casing 100 contains multiple isolated slot units 300. The battery cover 200 is located at the top opening of the casing 100. The multiple electrode groups are respectively disposed within the multiple slot units 300, with each electrode group corresponding to one of the slot units 300. Each electrode group includes multiple positive plates, multiple negative plates, and multiple separators 5. Each positive plate has a positive tab at one end, and each negative plate has a negative tab at one end. The multiple negative plates and multiple positive plates are arranged alternately along a first direction. Multiple separators 5 are disposed between adjacent positive and negative plates to isolate them. It should be noted that the electrode group structure of this application has one more negative plate than positive plate, and they are arranged sequentially along the first direction in the order of negative plate-separator 5-positive plate-separator 5-negative plate-separator 5...-negative plate. The electrode group structure has a first end and a second end arranged opposite to each other along a first direction; the positive electrode plate located at the first end is defined as the first end positive electrode plate 1, and the negative electrode plate located at the first end is defined as the first end negative electrode plate 3; the positive electrode plate located at the second end is defined as the second end positive electrode plate 2, and the negative electrode plate located at the second end is defined as the second end negative electrode plate 4; the positive electrode plate located between the first end positive electrode plate 1 and the second end positive electrode plate 2 is defined as the intermediate positive electrode plate; the negative electrode plate located between the first end negative electrode plate 3 and the second end negative electrode plate 4 is defined as the intermediate negative electrode plate. It is understood that the number of intermediate positive plates can be 0, and the number of intermediate negative plates is at least 1. Preferably, in this application, the number of intermediate positive plates is at least 1, and the number of intermediate negative plates is at least 2. The positive electrode tab of the first end positive plate 1 or the positive electrode tab of the second end positive plate 2 is provided with a first bending structure 10, which extends toward the intermediate positive plate. The negative electrode tab of the first end negative plate 3 or the negative electrode tab of the second end negative plate 4 is provided with a second bending structure 11, which extends toward the intermediate negative plate. Preferably, the positive electrode tabs of the first end positive plate 1 and the second end positive plate 2 are both provided with the first bending structure 10, and the negative electrode tabs of the first end negative plate 3 and the second end negative plate 4 are both provided with the second bending structure 11. Since both the positive and negative tabs at the ends extend towards the middle electrode plate, the distance between the tabs (first positive tab 6 and second positive tab 7) of the first positive electrode plate 1 and the second positive electrode plate 2 is reduced, as is the distance between the tabs (first negative tab 8 and second negative tab 9) of the first negative electrode plate 3 and the second negative electrode plate 4. When welding the busbar, a shorter busbar length can meet the requirements, thereby saving the amount of busbar material used and reducing costs. Since the busbar length of each electrode group structure is reduced, the overall weight of the battery can be reduced after assembly.Traditional straight end tabs may touch the battery casing due to excessive length; bending eliminates this risk. The bent end tabs are closer to the middle plate, reducing the current conduction distance from the end plate to the busbar, lowering ohmic resistance, thereby reducing heat generation and improving high-rate discharge performance. The end plate is prone to heat dissipation due to its proximity to the battery casing, which may lead to temperature gradients. The bending structure optimizes the current path, alleviates the polarization difference between the end and middle plates, and extends the battery's cycle life.

[0030] The battery cover 200 and the housing 100 are bonded together by thermofusion welding or adhesive. Specifically, thermofusion welding refers to using high temperature to melt the connecting parts (usually thermoplastic materials such as polypropylene) of the battery cover 200 and the housing 100, and then fusing them together after cooling to form a sealed connection. Adhesive bonding involves applying a special sealant (such as epoxy resin adhesive, polyurethane adhesive, etc.) to the mating surfaces of the battery cover 200 and the housing 100, and achieving bonding and sealing through the curing of the adhesive. The sealed connection between the battery cover 200 and the housing 100 ensures the battery's airtightness and prevents electrolyte leakage and internal gas escape.

[0031] Please continue reading. Figure 3 and Figure 4 As shown, further, the positive electrode tab of the first end positive electrode plate 1 is defined as the first positive electrode tab 6, and the positive electrode tab of the second end positive electrode plate 2 is defined as the second positive electrode tab 7. Both the first positive electrode tab 6 and the second positive electrode tab 7 are provided with a first bending structure 10. The positive electrode tab of the intermediate positive electrode plate is defined as the intermediate positive electrode tab 12. The ends of the first positive electrode tab 6, the second positive electrode tab 7, and the intermediate positive electrode tab 12 are coplanar. It can be understood that the first positive electrode tab 6 and the second positive electrode tab 7 are both provided with the first bending structure 10. The root of the electrode tab is connected to the electrode plate. Here, "end" refers to the free end of the electrode tab. The ends of the first positive electrode tab 6, the second positive electrode tab 7, and the intermediate positive electrode tab 12 are coplanar to form a reference plane for casting and welding the positive busbar 18. This eliminates the need for special welding molds for the end-bending tabs, reducing equipment debugging time and improving the yield of automated welding. After all the positive tab tops are coplanar, they can be positioned at once using the same fixture, ensuring that the positive busbar 18 is fully in contact with the contact surface of each positive tab, avoiding poor welding caused by unevenness.

[0032] It should be noted that the first bending structure 10 is formed by bending the first positive tab 6 and the second positive tab 7 using corresponding clamps. The first bending structure 10 includes a first bending segment 14 and a second bending segment 15 connected together. One end of the second bending segment 15 is connected to the root of the tab, and the other end is connected to the first bending segment 14. The top of the first bending segment 14 is flush with the end of the intermediate positive tab 12, and one side of the first bending segment 14 is in contact with the adjacent intermediate positive tab 12, so that the first bending structure 10 is laterally fitted and positioned, making it easier to assemble or transport. The first bending structure 10 is designed so that the first positive tab 6 and the second positive tab 7 at the ends bend inward and then extend upward. Since the plates will expand and contract thermally during battery charging and discharging, the first bending structure 10 provides elasticity, reduces the mechanical stress of the welding points of the first positive tab 6 and the second positive tab 7 with the positive busbar 18, and avoids cracking due to long-term fatigue. Understandably, in order to further secure the first bent structure 10, the first bent segment 14 can be bonded together with its adjacent intermediate positive electrode tab 12 using an adhesive (such as double-sided tape).

[0033] The length of the intermediate positive electrode tab 12 is H0, and the lengths of the first positive electrode tab 6 and the second positive electrode tab 7 are equal, both H1, where H0 < H1 < 1.5H0. Preferably, H1 = 1.2H0, as this results in the highest yield. The length of the first bending segment 14 is L1, where ½H0 ≤ L1 ≤ ⅔H0. This setting ensures that the first bending segment 14 has sufficient length. The longer the first bending segment 14 is, the longer its contact length with the adjacent intermediate positive electrode tab 12, and the more stable the first bending structure 10 becomes. Simultaneously, cost and performance must be considered; therefore, ½H0 ≤ L1 ≤ ⅔H0.

[0034] Specifically, the angle between the first bending segment 14 and the second bending segment 15 is greater than or equal to 90 degrees. Preferably, the angle between the first bending segment 14 and the second bending segment 15 is equal to 90 degrees. To maintain the stability of this angle, a support member (such as foam) can be provided below the second bending segment 15.

[0035] The negative tab of the first end negative plate 3 is defined as the first negative tab 8, and the negative tab of the second end negative plate 4 is defined as the second negative tab 9. Both the first negative tab 8 and the second negative tab 9 are provided with a second bending structure 11. The bent end tabs are closer to the middle plate, reducing the current conduction distance from the end plate to the busbar, reducing ohmic resistance, thereby reducing heat generation and improving high-rate discharge performance. In addition, the positive and negative busbars 19 of this application are shorter than ordinary positive and negative busbars 19 under the same conditions, which can effectively reduce resistance. The conventional straight end tabs may touch the battery casing due to excessive length, and the bending eliminates this risk. The end plates are easy to dissipate heat due to their proximity to the battery casing, which may lead to temperature gradients. The bending structure alleviates the polarization difference between the end and middle plates by optimizing the current path, thus extending the cycle life of the battery.

[0036] The negative electrode tab of the intermediate negative electrode plate is defined as intermediate negative electrode tab 13. The ends of the first negative electrode tab 8, the second negative electrode tab 9, and the intermediate negative electrode tab 13 are coplanar to form a reference plane for casting and welding the negative busbar 19. In this way, there is no need to design special welding molds for the end bending tabs, reducing equipment debugging time and improving the yield of automated welding. After all the tops of the negative electrode tabs are coplanar, they can be positioned at once by the same fixture, ensuring that the contact surface of the negative busbar 19 and each negative electrode tab is completely in contact, avoiding poor welding caused by unevenness.

[0037] It should be noted that the second bending structure 11 is formed by bending the first negative electrode tab 8 and the second negative electrode tab 9 using corresponding clamps. The second bending structure 11 includes a third bending segment 16 and a fourth bending segment 17 connected together. One end of the fourth bending segment 17 is connected to the root of the electrode tab, and the other end is connected to the third bending segment 16. One side of the third bending segment 16 is in contact with its adjacent intermediate negative electrode tab 13. The arrangement of the second bending structure 11 causes the first negative electrode tab 8 and the second negative electrode tab 9 at the ends to bend inward and then extend upward. Since the plates expand and contract with temperature during battery charging and discharging, the second bending structure 11 provides elasticity, reducing the mechanical stress at the welding points of the first negative electrode tab 8 and the second negative electrode tab 9 with the negative busbar 19, and avoiding cracking due to long-term fatigue. It is understood that, in order to further fix the second bending structure 11, the third bending segment 16 can be bonded to its adjacent intermediate negative electrode tab 13 using an adhesive (such as double-sided tape).

[0038] The length of the intermediate negative electrode tab 13 is H2, and the lengths of the first negative electrode tab 8 and the second negative electrode tab 9 are equal, both H3, where H2 < H3 < 1.5H2. Preferably, H3 = 1.2H2. The length of the fourth bending segment 17 is L2, where ½H2 ≤ L2 ≤ ⅔H2. This arrangement ensures the stability of the second bending structure 11 while balancing cost and performance.

[0039] Furthermore, the angle between the third bending segment 16 and the fourth bending segment 17 is greater than or equal to 90 degrees. Preferably, the angle between the third bending segment 16 and the fourth bending segment 17 is equal to 90 degrees. To maintain the stability of this angle, a support member (such as foam) can be provided below the fourth bending segment 17.

[0040] Please refer to Figure 6 As shown, in one embodiment of this disclosure, a positive busbar 18 and a negative busbar 19 are also included. The first positive tab 6, the intermediate positive tab 12, and the second positive tab 7 are connected sequentially through the positive busbar 18, and the first negative tab 8, the intermediate negative tab 13, and the second negative tab 9 are connected sequentially through the negative busbar 19. Both the first positive tab 6 and the second positive tab 7 are provided with a first bending structure 10, and both the first negative tab 8 and the second negative tab 9 are provided with a second bending structure 11. This makes the length of the positive busbar 18 and the length of the negative busbar 19 shorter than the length of the corresponding busbar under the same conditions, effectively reducing material consumption and lowering costs. The reduction in the length of the positive busbar 18 and the negative busbar 19 can directly reduce their internal resistance, thereby reducing the internal resistance of the entire battery.

[0041] Furthermore, the positive bus 18 is connected to a positive terminal, specifically, one end of the positive terminal is welded to the positive bus 18, and the other end passes through the battery cover 200. The negative bus 19 is connected to a negative terminal, specifically, one end of the negative terminal is welded to the negative bus 19, and the other end passes through the battery cover 200.

[0042] More specifically, this application preferably includes a housing 100 with six slot units 300, each slot unit 300 containing an electrode group structure, comprising three negative electrode plates and two positive electrode plates, with the positive and negative electrode plates alternately arranged and separated by a partition 5. The first positive electrode tab 6 and the second positive electrode tab 7 both have a first bending structure 10, and the positive busbar 18 is 4-6 cm shorter than a positive busbar 18 under the same conditions. The first negative electrode tab 8 and the second negative electrode tab 9 both have a second bending structure 11, and the negative busbar 19 is 4-6 cm shorter than a negative busbar 19 under the same conditions. Electrical performance tests were performed on four batteries from this preferred embodiment.

[0043] Electrical performance testing: The four batteries in the above preferred embodiment are labeled A, B, C, and D. Four ordinary storage batteries are used as comparative examples, and they are denoted as a, b, c and d respectively; A, B, C, D, a, b, c, and d are batteries produced in the same batch. Batteries A, B, C, and D use the electrode group structure of this application, while batteries a, b, c, and d use ordinary electrode groups (without bending structures at the end tabs). Apart from this, batteries a, b, c, and d are identical to batteries A, B, C, and D in all other aspects.

[0044] Discharge batteries A, B, C, D, a, b, c, and d respectively under full charge conditions (discharge current 36A, discharge termination voltage 10.5V), and record the discharge time (as shown in the table below).

[0045]

[0046] The data in the table shows that batteries A, B, C, and D have a longer discharge time than batteries a, b, c, and d. This is because batteries A, B, C, and D have lower internal resistance and less energy loss.

[0047] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A storage battery, characterized in that, include: The housing (100) contains a plurality of isolated groove units (300). A battery cover (200) is provided at the top opening of the housing (100); Multiple pole group structures are respectively disposed in the multiple slot units (300), and each pole group structure corresponds one-to-one with each slot unit (300); The pole group structure includes: Multiple positive plates, each with a positive tab at one end; Multiple negative plates, each negative plate having a negative electrode tab at one end, and the multiple negative plates and multiple positive plates are arranged alternately along a first direction; Multiple separators (5) are disposed between adjacent positive and negative plates to isolate adjacent positive and negative plates; The pole group structure has a first end and a second end that are arranged opposite to each other along the first direction; The positive plate located at the first end is defined as the first end positive plate (1), and the negative plate located at the first end is defined as the first end negative plate (3). The positive plate located at the second end is defined as the second end positive plate (2), and the negative plate located at the second end is defined as the second end negative plate (4). The positive plate located between the first end positive plate (1) and the second end positive plate (2) is defined as the intermediate positive plate; The negative electrode plate located between the first end negative electrode plate (3) and the second end negative electrode plate (4) is defined as the intermediate negative electrode plate; The positive electrode tab of the first end positive electrode plate (1) or the positive electrode tab of the second end positive electrode plate (2) is provided with a first bending structure (10), and the first bending structure (10) extends toward the middle positive electrode plate; The negative electrode tab of the first end negative electrode plate (3) or the negative electrode tab of the second end negative electrode plate (4) is provided with a second bending structure (11), which extends toward the middle negative electrode plate.

2. The storage battery according to claim 1, characterized in that, The battery cover (200) and the housing (100) are bonded by hot melt welding or adhesive; the positive electrode tab of the first end positive electrode plate (1) is defined as the first positive electrode tab (6), and the positive electrode tab of the second end positive electrode plate (2) is defined as the second positive electrode tab (7). The first positive electrode tab (6) and the second positive electrode tab (7) are both provided with a first bending structure (10).

3. The storage battery according to claim 2, characterized in that, The positive electrode tab of the intermediate positive electrode plate is defined as the intermediate positive electrode tab (12), and the ends of the first positive electrode tab (6), the second positive electrode tab (7) and the intermediate positive electrode tab (12) are arranged in the same plane.

4. The storage battery according to claim 3, characterized in that, The first bending structure (10) includes a first bending segment (14) and a second bending segment (15) connected together, with one side of the first bending segment (14) fitting against its adjacent intermediate positive electrode lug (12).

5. The storage battery according to claim 4, characterized in that, The length of the middle positive electrode (12) is H0, the lengths of the first positive electrode (6) and the second positive electrode (7) are equal and are H1, H0 < H1 < 1.5H0; the length of the first bending segment (14) is L1, ½H0 ≤ L1 ≤ ⅔H0; the angle between the first bending segment (14) and the second bending segment (15) is 90 degrees.

6. The storage battery according to claim 1, characterized in that, The negative electrode tab of the first end negative electrode plate (3) is defined as the first negative electrode tab (8), and the negative electrode tab of the second end negative electrode plate (4) is defined as the second negative electrode tab (9). Both the first negative electrode tab (8) and the second negative electrode tab (9) are provided with a second bending structure (11).

7. The storage battery according to claim 6, characterized in that, The negative electrode tab of the intermediate negative electrode plate is defined as the intermediate negative electrode tab (13), and the ends of the first negative electrode tab (8), the second negative electrode tab (9) and the intermediate negative electrode tab (13) are arranged in the same plane.

8. The storage battery according to claim 7, characterized in that, The second bending structure (11) includes a third bending section (16) and a fourth bending section (17) connected together, with one side of the third bending section (16) fitting against its adjacent intermediate negative electrode lug (13).

9. The storage battery according to claim 8, characterized in that, The length of the middle negative electrode (13) is H2, the lengths of the first negative electrode (8) and the second negative electrode (9) are equal and are H3, H2 < H3 < 1.5H2; the length of the fourth bending segment (17) is L2, ½H2 ≤ L2 ≤ ⅔H2; the angle between the third bending segment (16) and the fourth bending segment (17) is 90 degrees.

10. The storage battery according to claim 3 or 7, characterized in that, It also includes a positive bus (18) and a negative bus (19). The first positive electrode (6), the middle positive electrode (12) and the second positive electrode (7) are connected in sequence through the positive bus (18), and the first negative electrode (8), the middle negative electrode (13) and the second negative electrode (9) are connected in sequence through the negative bus (19).

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