Positive electrode confluence plate and cylindrical battery
By designing a positive electrode bus disk with a boss, support plate and overcurrent channel, the problem of poor welding between the pole group and the bus disk is solved, the battery performance and overcurrent capability are improved, and safety is enhanced.
Patent Information
- Application Number
- CN202421487720.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-06-27
AI Technical Summary
In the prior art, welding problems between the pole group and the busbar disc cause battery performance to be affected, especially because the busbar is bending due to thermal stress, resulting in poor welding.
A positive electrode bus disk is designed, which includes a bus disk main sheet, a boss, a support sheet and an overcurrent channel. The structure of the boss and the support plate ensures that the busbar is closely fitted with the pole. The overcurrent channel improves the overcurrent capability of the battery. The porous design of the central hole, isolation hole and cutting hole enhances the flowability of the electrolyte.
By increasing the welding area and improving the fit between the bus disk and the pole column, the problem of poor welding is solved, the battery performance is improved, and the overcurrent capability and safety of the battery are enhanced through the porous design and the setting of the overcurrent channel.
Smart Images
Figure CN222995730U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of batteries, and particularly relates to a positive current collector plate and a cylindrical battery. Background Art
[0002] A cylindrical battery is a battery with high capacity and long life. The current collector plate (also known as current collector sheet, current collecting plate) of a cylindrical battery is an important part connecting the positive and negative electrodes of the battery, and it can effectively collect and conduct current. The current collector plate of a large cylindrical battery is usually made of conductive materials such as copper and aluminum. Its shape matches the positive and negative electrode structures of the large cylindrical battery to ensure good contact and conductive performance. The main function of the current collector plate is to collect the current generated inside the battery and conduct it to the external circuit. It can withstand large currents and voltages to meet the high-power requirements of large cylindrical batteries.
[0003] In the automated production process of the single-end sealing process of a cylindrical battery, one of the process steps is: first, weld the battery cell (also known as the electrode group) together with the positive current collector plate, then put the battery cell into the battery case. The bottom of the battery case has a positive electrode post. At this time, the positive current collecting plate is in contact with the positive electrode post. Then, extend the ultrasonic welding equipment to the bottom of the battery cell to weld the positive current collector plate and the positive electrode post together, and finally form a cylindrical battery.
[0004] The positive current collector plate is an important part inside a large cylindrical battery, and its functions are mainly as follows:
[0005] 1. It has good electrical conductivity, connects with the positive electrode post on one side and the electrode group on the other side, facilitating current conduction.
[0006] 2. When the charging and discharging current of the positive electrode post and the electrode group is too large, it plays a certain fusing protection role.
[0007] 3. The positive current collector plate can help disperse the heat generated inside the battery to prevent the battery from overheating.
[0008] The welding problem between the electrode group and the current collector plate affects the performance of the battery, mainly manifested as: on the one hand, when welding the electrode group and the current collector plate, it is required that the welding area must be closely attached to prevent virtual welding and over-welding. If the degree of fit is not good, it will lead to poor current collection effect and ultimately affect the battery performance. On the other hand, the current collector plate needs to be closely attached to the electrode post to prevent the current collector plate from bending due to thermal stress problems, but there is no current collector plate in the prior art that can solve this problem. Utility Model Content
[0009] The purpose of the present utility model is to overcome the defects in the prior art and provide a positive current collector plate and a cylindrical battery.
[0010] To achieve the above object, the present utility model adopts the following technical solutions:
[0011] A positive busbar plate, comprising a main busbar plate, a boss provided at the center of the main busbar plate, a plurality of support plates provided around the circumference of the boss, and current-carrying channels provided between adjacent support plates.
[0012] The thickness of the boss is L3, and L3 = L4+(0.1 - 0.5) mm; where L4 is the thickness of the main busbar plate.
[0013] The plurality of support plates form a circle concentric with the boss.
[0014] The outer radius of the support plate is R1, and R1≥R6 + 1.5 mm; where R6 is the radius of the boss.
[0015] An excision hole is provided between the support plate and the main busbar plate; the outer radius R2 of the excision hole = R1+(0.5 - 1) mm; where R1 is the outer radius of the support plate.
[0016] The main busbar plate is composed of a plurality of busbar segments; a plurality of isolation holes are provided between adjacent busbar segments.
[0017] Current-carrying channels are provided between adjacent support plates; the current-carrying channels are located on the center line of the busbar segments; arranging the current-carrying channels on the center line can ensure that the heat received by the current-carrying channels is more uniform, so as to better play the role of fusing protection.
[0018] The thickness of the main busbar plate is L4, and L4=(0.2 - 0.4) mm.
[0019] The boss is provided with a central hole; the radius of the central hole is R5; R5 = 0, or R5 = r-(0.5 - 1) mm; where r is the radius of the central hole of the electrode group.
[0020] Positioning holes are provided on the outer periphery of the main busbar plate.
[0021] The present utility model further includes a cylindrical battery, comprising an electrode group, a battery case provided outside the electrode group, a positive electrode post, and the positive busbar plate provided between the positive electrode post and the electrode group.
[0022] Compared with the prior art, the beneficial effects of the present utility model are:
[0023] The utility model utilizes welding between the main plate of the bus bar plate and the electrode group, and the weldable area is relatively large. The structures of the boss and the support plate can ensure the tight fit between the bus bar plate and the pole column, making up for the gap between the pole column and the bus bar plate caused by the relatively thick encapsulating tape of the electrode group; meanwhile, it can prevent the virtual soldering phenomenon in the welding process of the pole column due to the thermal deformation of the main plate of the bus bar plate during welding.
[0024] As a preferred form, an overcurrent channel is provided. This structure fully considers the influence of the impedance of the bus bar plate on the overcurrent capacity of the battery. According to the principle of "the straight line between two points is the shortest", for an overcurrent channel with the same cross-sectional material, the shorter the length, the smaller the impedance value and the stronger the overcurrent capacity. When the charging and discharging current of the pole column and the electrode group is too large during confluence, it can play a fusing protection role and reduce potential safety hazards.
[0025] The multi-hole design of the central hole, the isolation hole and the cutting hole enables strong electrolyte fluidity.
[0026] Meanwhile, its overall structure can be completed by stamping, the forming process is simpler, and the cost control is lower; it is light in weight and conforms to the lightweight rule. A positioning hole is provided for convenient positioning. Description of the Drawings
[0027] Figure 1 is the front view structural schematic diagram of the bus bar plate of the utility model;
[0028] Figure 2 is the cross-sectional view structural schematic diagram of the bus bar plate of the utility model;
[0029] Figure 3 is Figure 2 the enlarged partial structural schematic diagram at A of the bus bar plate of the utility model;
[0030] Figure 4 is the front view schematic diagram of the distance relationship between the components of the bus bar plate of the utility model;
[0031] Figure 5 is Figure 4 the side view schematic diagram in the A-A direction of the distance relationship between the components of the bus bar plate of the utility model;
[0032] Figure 6 is Figure 5 the enlarged partial schematic diagram at B of the distance relationship between the components of the bus bar plate of the utility model;
[0033] Figure 7 is the structural schematic diagram of a cylindrical battery. Detailed Embodiment
[0034] In order to enable those skilled in the art of this technical field to better understand the technical solution of the utility model, the following further detailed description of the utility model is provided in conjunction with the drawings and the best embodiments.
[0035] Figure 1-6 A positive electrode current collector plate is shown, which includes a main current collector plate 6, a boss 2 arranged at the center of the main current collector plate, and a plurality of support plates 3 arranged around the circumference of the boss 2.
[0036] The thickness of the boss 2 is L3, and L3 = L4+(0.1 - 0.5) mm, where L4 is the thickness of the main current collector plate 6. The structure of the boss 2 is circular, and its thickness is slightly greater than the thickness of the main current collector plate, so that the battery positive electrode post (hereinafter referred to as the pole post) can be closely attached to the positive electrode current collector plate (hereinafter referred to as the current collector plate), making up for the gap between the pole post and the current collector plate caused by the pole group encapsulation tape; at the same time, it prevents the virtual soldering phenomenon in the welding process of the positive electrode post due to the thermal deformation of the main current collector plate welding.
[0037] The boss 2 adopts a stamping process, so a boss stamping groove 9 will be formed. The thickness L2 of the boss stamping groove = the thickness L4 of the main current collector plate 6. Compared with the extrusion manufacturing process (thickness L2 > L4), the stamping forming process is simpler and the cost control is lower. This only involves the cost control problem and is an optional item, not a mandatory item.
[0038] The plurality of support plates form a circle concentric with the boss, preferably 4 support plates. The outer radius of the support plate is R1, and R1≥R6 + 1.5 mm, where R6 is the radius of the boss. It is required that the support plate has enough space to support the boss 2 without deformation, ensuring at least 1.5 mm. It plays a role in stably supporting the boss 2 to make it fit the pole post.
[0039] An excision hole 5 is arranged between the support plate 3 and the main current collector plate 6. The outer radius R2 of the excision hole = R1+(0.5 - 1) mm, where R1 is the outer radius of the support plate. The excision hole 5 can play the following roles: 1) It can greatly relieve the thermal stress generated by welding the main current collector plate 6, and at the same time weaken the influence of its internal stress on the support plate 3, improving the welding quality; 2) It forms an overcurrent channel 4 with a protective effect; 3) It reduces the weight.
[0040] The main current collector plate 6 is composed of a plurality of current collector plate segments. A plurality of isolation holes 7 are arranged between adjacent current collector plate segments. The thickness of the main current collector plate is L4, and L4=(0.2 - 0.4) mm.
[0041] The isolation holes 7 are symmetrically distributed, dividing the main current collector plate 6 into four parts. The shape is not limited to rectangles, circles, ellipses, etc. It plays the following roles: 1) It can greatly relieve the thermal stress generated by welding the main current collector plate 6, improving the welding quality; 2) The connecting band formed by the unexcised part plays a role in heat conduction and overcurrent, thereby reducing thermal deformation; 3) It reduces the weight.
[0042] The main plate 6 of the current collector plate, as one of the implementation manners, is a four-lobe centrosymmetric structure as a whole and is concentric with the boss 2. It is designed according to specific processes and is separated by the isolation holes 7. It is mainly used for welding with the main body of the electrode group. Almost all the welding areas between the current collector plate and the electrode group are concentrated in this part.
[0043] An overcurrent channel 4 is provided between adjacent support plates 3. It is formed by cutting the cutting holes 5 from the main plate 6 of the current collector plate and is connected to the support plate 3 and the main plate 6 of the current collector plate at the same time. The thickness of the overcurrent channel 4 is equal to the thickness L4 of the main plate of the current collector plate. It is located on the center line of the lobes of the current collector plate, and the width L1 can be designed according to the requirements of the battery overcurrent capacity. When the charging and discharging current of the pole column and the electrode group is too large, it plays a role in fusing protection.
[0044] The boss 2 is provided with a central hole 1, and the radius of the central hole is R5; R5 = 0, or R5 = r - (0.5 to 1) mm, where r is the radius of the central hole of the electrode group.
[0045] The positive current collector plate has the following characteristics: 1) When adopting the process structure of injecting liquid through the positive pole column and penetration welding connection, the radius R5 of the central hole of the current collector plate = r - (0.5 to 1) mm, where r is the radius of the central hole of the electrode group. The radius of the central hole of the current collector plate is slightly smaller than the radius of the central hole of the electrode group, so that the positive current collector plate can completely cover the positive electrode tab and prevent the electrode tab from being exposed. At this time, the main function of the central hole 1 is: to facilitate the circulation of the electrolyte and provide an effective welding area for the penetration welding of the positive pole column. 2) When using the process structure without a liquid injection hole on the positive pole column, the radius R5 of the central hole 1 of the current collector plate = 0, that is, there is no central hole on the current collector plate.
[0046] The outer periphery of the main plate of the current collector plate is provided with positioning holes 8, R7 = R4 - R3, generally satisfying R3 = R4 - (2.5 to 4) mm, R4 is the overall outer radius of the current collector plate, R3 is the distance from the vertex of the positioning hole 8 to the center point of the current collector plate, and R7 is the radius of the positioning hole. Taking the points on the R4 outer circle trajectory as the center, the generated arc-shaped positioning holes and the isolation holes 7 are distributed on the same axis, mainly playing a positioning role to make the welding of the current collector plate more accurate. This part can be omitted when using other positioning methods.
[0047] Figure 7 A cylindrical battery is shown, including an electrode group 12, a battery case 13 arranged outside the electrode group, a positive pole column 11, and the positive current collector plate 10 arranged between the positive pole column 11 and the electrode group 12.
[0048] The specific implementation process is as follows: 1. First, the busbar 10 and the electrode group 12 are welded. After positioning and limiting through the positioning holes 8, the welding of the main busbar piece 6 of the busbar and the electrode group 12 is completed. The top of the battery case 13 has a positive electrode post 11. After the electrode group 12 is coated with glue and then placed into the battery case 13 as a whole, it is positioned through the central hole 1, and the boss 2 is aligned and connected with the positive electrode post 11. Then, the laser welding equipment extends in and welds the boss 2 and the positive electrode post 11 together.
[0049] In summary, it can be seen that the utility model welds the main busbar piece of the busbar and the electrode group, and the weldable area is relatively large. The structure of the boss and the support piece can ensure the close fit between the busbar and the electrode post, making up for the gap between the electrode post and the busbar caused by the relatively thick glue tape of the electrode group coating; at the same time, it can prevent the virtual soldering phenomenon in the welding process of the electrode post due to the thermal deformation of the main busbar piece of the busbar.
[0050] An overcurrent channel is provided. This structure fully considers the influence of the busbar impedance on the overcurrent capacity of the battery. According to the principle of "the straight line between two points is the shortest", for the overcurrent channel with the same cross-sectional material, the shorter the length, the smaller the impedance value and the stronger the overcurrent capacity. When the charging and discharging current of the electrode post and the electrode group is too large and converges, it can play a fusing protection role and reduce potential safety hazards.
[0051] The multi-hole design of the central hole, the isolation hole and the cutting hole makes the electrolyte have strong fluidity.
[0052] At the same time, its overall structure can be completed by stamping, the forming process is simpler, the cost control is lower, the weight is light, and it conforms to the lightweight rule. Positioning holes are provided for convenient positioning.
[0053] The above content is only the preferred embodiment of the utility model. For those of ordinary skill in the art, based on the idea of the utility model, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the utility model.
Claims
1. A positive busbar, characterized in that: It includes a main plate of a busbar, a boss arranged at the center of the main plate of the busbar, and a plurality of support plates arranged around the boss; a cut-out hole is arranged between the support plate and the main plate of the busbar; the outer circle radius of the cut-out hole is R2=R1+(0.5~1)mm; wherein R1 is the outer circle radius of the support plate; and a positioning hole is arranged on the outer circumference of the main plate of the busbar.
2. The positive busbar according to claim 1, characterized in that: The thickness of the boss is L3, L3=L4+(0.1~0.5) mm; wherein L4 is the thickness of the main plate of the busbar.
3. The positive busbar according to claim 1, characterized in that: The plurality of support sheets form a circle concentric with the boss; the outer circle radius of the support sheet is R1, R1≥R6+1.5mm; wherein R6 is the boss radius.
4. The positive busbar according to claim 1, characterized in that: The main plate of the busbar is composed of a plurality of busbar petals; a plurality of isolation holes are arranged between adjacent busbar petals.
5. The positive busbar according to claim 4, characterized in that: A flow passage is provided between adjacent support sheets; the flow passage is located on the center line of the busbar petal.
6. The positive busbar according to claim 1, characterized in that: The thickness of the main plate of the busbar is L4, L4=(0.2~0.4) mm.
7. The positive busbar according to claim 1, characterized in that: The boss is provided with a center hole; the radius of the center hole is R5; R5=0, or R5=r-(0.5~1) mm; wherein r is the radius of the center hole of the pole group.
8. A cylindrical battery, characterized in that: The invention comprises an electrode group, a battery shell arranged outside the electrode group, a positive electrode column, and a positive electrode busbar according to any one of claims 1 to 7 arranged between the positive electrode column and the electrode group.