Mechanical part for ultrafast charging structure
By abolishing the adapter, the welding piece with H-shaped structure and integrated molded pole, the mechanical parts structure of the lithium-ion battery cell is optimized, and the problem that traditional mechanical parts cannot meet the overcurrent capacity is solved, achieving high efficiency of the battery cell Fast charging and long life.
Patent Information
- Application Number
- CN202421029622.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-05-13
AI Technical Summary
The traditional mechanical parts structure of the existing lithium-ion battery cells cannot meet the high requirements of overcurrent capability, resulting in insufficient thickness of the adapter sheet and difficulty in welding, and insufficient overcurrent of the electrodes, which increases the difficulty of welding and the volume of the battery cells.
A mechanical part for ultrafast charging structure was designed, and the adapter was eliminated. The welding piece of H-shaped structure and the integrated forming pole column were used. The welding process of the pole ear was optimized through ultrasonic welding technology to reduce the height of the pole ear. and bending difficult.
The maximum overcurrent capability of the battery cell is achieved, the process is reduced, the internal space utilization of the battery cell is improved, the cost, energy density and fast charging performance are taken into account, and the service life of the battery cell is extended.
Smart Images
Figure CN222483632U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of new energy batteries, and in particular to a mechanical part for an ultra-fast charging structure. Background Art
[0002] Lithium-ion batteries are a type of secondary battery that can be repeatedly charged and discharged. They are composed of main components such as anode and cathode electrodes, isolation membranes, electrolytes, and mechanical parts. Currently, the size of lithium-ion batteries is getting larger and larger, and with the increasing requirements for fast charging, the requirements for the current capacity of mechanical parts are also getting higher and higher. The traditional mechanical structure and combination mode of wound square shell batteries have made it difficult to meet the current requirements.
[0003] At present, there are two prominent shortcomings in overcurrent. The thickness of the adapter is not enough, but thickening it will make laser welding of the adapter and the pole difficult. The main manifestation is that the energy of the laser cannot penetrate the thick adapter, resulting in cold welding. At the same time, it will occupy the space above the battery cell, reducing the volume energy density of the battery cell; another disadvantage is that the traditional method of one pole ear per circle leads to the pole ear overcurrent not being satisfied, so two pole ears are chosen to be welded in one circle, but in this way, the number of pole ears that need to be welded at the same time is doubled, and the test of ultrasonic welding is significantly increased. If the equipment power is large, the upper pole ear will be welded cracked, and if the equipment power is reduced, the pole ear will have a cold weld; when there are too many pole ears, when the battery cell is put into the shell, the bending resistance of the pole ear is greater, and the thickness space occupied by the pole ear after bending will also increase, which also occupies the space above the battery cell, reduces the volume energy density of the battery cell, and increases the risk of the pole ear folding into the bare battery cell and causing a short circuit. Utility Model Content
[0004] The purpose of the utility model is to solve the problems mentioned in the above background technology and to propose a mechanical part for an ultra-fast charging structure.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A mechanical part for an ultra-fast charging structure comprises a top cover, a negative pole column and a positive pole column, wherein the negative pole column and the positive pole column are symmetrically mounted on the top cover, and the negative pole column and the positive pole column are both provided with welding sheets on the inner side of the top cover, and the welding sheets are used for welding battery pole ears.
[0007] Preferably, the welding sheet is an H-shaped structure, and the negative electrode column, the positive electrode column and the welding sheet are all manufactured by integral molding.
[0008] Preferably, a pole protection shell is provided on the outside of the top cover at the negative pole and the positive pole, and the top cover and the pole protection shell are made of plastic.
[0009] Preferably, an explosion-proof valve hole is opened in the middle of the top cover.
[0010] Preferably, a liquid injection hole is provided on the top cover.
[0011] Compared with the prior art, the utility model has the following advantages:
[0012] The utility model realizes the maximum current carrying capacity of the wound battery cell with minimal changes to the existing process. The elimination of the adapter solves the problem caused by the insufficient current carrying capacity of the existing adapter, and also reduces a process step, ensuring that the internal space utilization of the battery cell is maximized while ensuring the advance of the current carrying capacity, and is an optimal structural component combination solution that takes into account cost, energy density, and fast charging. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a structural schematic diagram of the utility model.
[0014] Figure 2 It is a structural schematic diagram of the utility model from another angle.
[0015] Figure 3 It is a structural schematic diagram of the pole part in the utility model.
[0016] Figure 4 It is an assembly diagram of the utility model.
[0017] Figure 5 Schematic diagram of the tab area of a bare cell in a battery cell.
[0018] Figure 6 This is a side view of the first ultrasonic welding of the utility model.
[0019] Figure 7 This is a side view of the second ultrasonic welding of the present invention.
[0020] Figure 8 1 is the temperature rise voltage curve of the first three cycles of the embodiment.
[0021] Fig. 9 The temperature rise voltage curve of the first three cycles of the comparative example.
[0022] Fig.10 The cell capacity cycle decay curves of the embodiment and the comparative example.
[0023] In the figure: 1 top cover, 2 negative pole, 3 positive pole, 4 welding piece, 5 explosion-proof valve hole, 6 liquid injection hole, 7 pole protective shell. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.
[0025] Reference Figure 1-4 As shown, a mechanical part for an ultra-fast charging structure includes a top cover 1, a negative electrode column 2 and a positive electrode column 3, wherein the negative electrode column 2 and the positive electrode column 3 are symmetrically mounted on the top cover 1, and the negative electrode column 2 and the positive electrode column 3 are both located on the inner side of the top cover 1 and are provided with welding plates 4, and the welding plates 4 are used for welding the battery tabs.
[0026] In this embodiment, the welding sheet 4 is an H-shaped structure, and the negative electrode column 2 and the positive electrode column 3 are all manufactured with the welding sheet 4 by integrated molding. The shape of the bottom of the electrode column is changed to allow the pole ear to be better welded to the electrode column, while minimizing the area of the base while meeting the overcurrent condition, thereby reducing the proportion of inactive materials inside the battery cell.
[0027] In this embodiment, pole protection shells are provided on the outer side of the top cover 1 at the negative pole 2 and the positive pole 3, and the top cover 1 and the pole protection shell 7 are made of plastic.
[0028] In this embodiment, an explosion-proof valve hole 5 is opened in the middle of the top cover 1, and a liquid injection hole 6 is opened on the top cover 1. The shape of the H-shaped welding piece 4 can avoid the position of the liquid injection hole 6 and the installation position of the explosion-proof valve hole 5.
[0029] Working process and principle:
[0030] When in use, the bare cell combination is as follows Figure 5 As shown, ultrasonic welding is used. First, the bare cell is placed in an ultrasonic welding fixture and placed horizontally, that is, the bare cell and the fixture of the top cover 1 are 180 degrees. The first welding sequence is to weld the outer pole ear of the bare cell first, and then weld the outer pole ear to the welding sheet 4, as shown in FIG. Figure 5 As shown in the figure, after the first welding is completed, adjust the fixture, rotate the non-ear end of the bare battery cell upward by 30-45 degrees, and then weld the inner ear. Figure 6 As shown, the folding at a certain angle is to reduce the height of the tab and reduce the difficulty of bending the tab, while also reducing the risk of inserting the bare cell after the tab is bent. The tab staggered setting is for batch welding, reducing the thickness of the tab during ultrasonic welding, avoiding the problem of difficult welding, and also avoiding the problem of difficulty in bending the tab together.
[0031] Example
[0032] Preparation of mechanical parts: The design drawings of the 100Ah top cover are processed into a new top cover for fast charging, and other materials are existing mature materials.
[0033] Battery cell assembly: 1. When die-cutting the positive and negative electrode sheets, the pole ears are cut out according to the latest pole ear method, and laser die-cutting is adopted; 2. The die-cut positive and negative electrode sheets are sequentially divided into strips, wound, and hot-pressed to form bare battery cells to be ultrasonically welded. Since the adapter sheet is eliminated, the width of a single film strip here can be 1mm higher than the width of the film in comparative example 1; 3. Ultrasonic welding: Place the bare battery cell in an ultrasonic welding fixture, horizontally, that is, the battery cell and the fixture of the top cover are 180°, push aside half of the pole ears on the upper layer, and weld half of the pole ears on the lower layer first; after the first welding is completed, weld the second weld mark, at this time adjust the fixture, and weld the bare battery cell The non-ear end is rotated upward by 30-45°, and the upper half of the ear is smoothed. After fixing the fixture, the welding head is moved to weld; 4. The bare battery cell after ultrasonic welding is insulated, bent, bundled, and wrapped with Mylar, and then put into the shell to form a semi-finished battery cell without power; 5. The semi-finished battery cell is baked, injected, formed, sealed, and the capacity and internal resistance are tested in sequence to form a finished battery cell. The average 0.3C capacity is about 107Ah. The battery cell is randomly selected for fast charging cycle test. The maximum temperature rise of the battery cell in the first three cycles is about 3.7℃. The current cycle life is about 500 cycles and the capacity retention rate is about 97.5%.
[0034] Comparative Example
[0035] Mechanical parts preparation: Use conventional means to thicken and widen the adapter, widen the shape of the tabs, and increase the number.
[0036] Battery cell assembly: 1. When die-cutting the positive and negative electrode sheets, the tabs are cut out in the conventional way, and the overcurrent tabs are widened; 2. The die-cut positive and negative electrode sheets are sequentially striped, wound, and hot-pressed to form bare battery cells to be ultrasonically welded; 3. Laser welding of adapter sheets: The widened and thickened adapter sheets are laser welded, but the quality rate is less than 95%. Normally, the quality rate of this process is as high as 99.5%; 4. Ultrasonic welding: Place the bare battery cell in the ultrasonic welding fixture, horizontally, that is, the battery cell and the top cover fixture are 180°, and weld. The quality rate of a single process is less than 95%, and the quality rate of this process is normally as high as 99%; 5. Insulate, bend, bundle, and wrap the bare battery cell after ultrasonic welding, and put it into the shell to form a semi-finished battery cell without electricity; 6. The semi-finished battery cell is baked, injected, formed and sealed in turn to form a finished battery cell. The average 0.3C capacity is about 102.5Ah. The battery cell is randomly selected for fast charging cycle test. The highest temperature rise of the battery cell in the first three cycles is about 8.7℃. The current cycle life is about 500 cycles and the capacity retention rate is about 95.8%.
[0037] In summary, it can be clearly seen from the data of the embodiments and comparative examples that the new mechanical parts can make the temperature of the battery cell more stable and increase the service life of the battery cell.
[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A mechanical part for an ultra-fast charging structure, characterized in that: The invention comprises a top cover (1), a negative pole column (2) and a positive pole column (3), wherein the negative pole column (2) and the positive pole column (3) are symmetrically mounted on the top cover (1), and the negative pole column (2) and the positive pole column (3) are both provided with welding plates (4) located on the inner side of the top cover (1), and the welding plates (4) are used for welding the battery pole ears.
2. The mechanical part for the ultra-fast charging structure according to claim 1, characterized in that: The welding sheet (4) is of an H-shaped structure, and the negative electrode column (2) and the positive electrode column (3) are all manufactured by integral molding with the welding sheet (4).
3. The mechanical part for the ultra-fast charging structure according to claim 1, characterized in that: A pole protection shell is provided on the outside of the top cover (1) at the negative pole (2) and the positive pole (3), and the top cover (1) and the pole protection shell (7) are made of plastic.
4. The mechanical part for the ultra-fast charging structure according to claim 1, characterized in that: An explosion-proof valve hole (5) is provided in the middle of the top cover (1).
5. The mechanical part for the ultra-fast charging structure according to claim 1, characterized in that: The top cover (1) is provided with a liquid injection hole (6).