Battery cell, battery cell module, power battery pack and vehicle

Abstract

The application relates to the technical field of power batteries, and particularly provides an electric core, an electric core module, a power battery pack and a vehicle, and aims to solve the problem of poor overcurrent capacity of an existing long electric core. The electric core provided by the application comprises an electric core, a first lug connected to one of short edges of the electric core, and a second lug connected to one of long edges of the electric core; an outer shell comprising a shell body and a first cover plate and a second cover plate connected to two ends of the shell body respectively, and a pole is arranged on the first cover plate, wherein the electric core is arranged in the outer shell, the first lug is electrically connected to the pole, the second lug is electrically connected to the shell body, and the second lug can be electrically connected to the second cover plate by means of the shell body as an electronic flow passage. The electric core provided by the application can greatly improve the overcurrent capacity of the electric core, improve the energy density of the electric core, and has simple structure and low cost.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, specifically providing a battery cell, a battery cell module, a power battery pack, and a vehicle. Background Technology

[0002] With the rapid development of the new energy vehicle market, power battery technology is also rapidly iterating and upgrading. The driving range and fast charging of pure electric vehicles are two focuses that consumers pay close attention to.

[0003] Among existing power batteries, Tesla's 4680 large cylindrical battery and BYD's long blade battery are the more mainstream technologies. Compared to the blade battery, the large cylindrical battery with all tabs has obvious advantages in energy density and fast charging, but its space utilization rate in the battery pack is relatively lower. The large space utilization rate of the long blade battery pack is related to its tab arrangement. To improve space utilization, the positive and negative tabs connected to the long electrode plates are distributed on the short side, respectively. Figure 1 This is a schematic diagram of the current loop state of a long battery cell during the charging process in the prior art, such as... Figure 1 As shown in the diagram, during charging, electrons in the positive electrode of the existing long battery cell 1' enter the negative electrode from the external circuit from left to right along a counter-clockwise path, forming a circuit loop. It can be seen from the diagram that as electrons enter the negative electrode from left to right, the current density gradually decreases, and the electrons are unevenly distributed within the negative electrode, reducing its overcurrent capacity. This significantly limits the cell's charging capacity, typically to only 2C, which cannot meet the fast charging requirements of the entire vehicle. Summary of the Invention

[0004] The present invention aims to solve or at least alleviate the above-mentioned technical problems, namely, to solve the problem of poor overcurrent capability of existing long battery cells.

[0005] In a first aspect, the present invention provides a battery cell comprising: an electrode core including an electrode sheet and a tab connected to the electrode sheet, the electrode sheet having a long side and a short side, the tab including a first tab connected to one of the short sides and a second tab connected to one of the long sides; and a housing including a housing and a first cover plate and a second cover plate respectively connected to both ends of the housing, the first cover plate having a terminal post disposed thereon, wherein the electrode core is disposed within the housing, the first tab is electrically connected to the terminal post, and the second tab is electrically connected to the housing, so that the housing serves as an electron flow channel, thereby enabling the second tab to be electrically connected to the second cover plate.

[0006] The battery cell provided by this invention features a first and a second tab positioned on one of the long sides of an electrode sheet and electrically connected to a housing. The housing is electrically connected to a second cover plate on the short side. The other tab is positioned on one of the short sides of the electrode sheet and electrically connected to a terminal post of the first cover plate. This design allows the battery cell to function as an electron flow channel between the tab on the long side and the second cover plate, eliminating the need for a terminal post on the long side. This prevents a reduction in the battery cell's space utilization due to increased current handling capacity. Furthermore, the second cover plate on the short side does not require a terminal post. Compared to existing technologies, the tabs can further improve the space utilization of the battery cell, thereby increasing the energy density of the battery cell. In addition, since the tabs are connected to the long side, the path for electrons to enter the corresponding electrode is greatly shortened, which can multiply the charging or discharging rate of the battery cell. Furthermore, since the tabs have a wider contact surface along the length of the electrode, the current density entering the corresponding electrode can be evenly distributed along the length, thus solving the problem of uneven current density in existing battery cells. Finally, it can also simplify the battery cell structure, reduce the number of structural components, and thus reduce the cost of the battery cell.

[0007] In some feasible implementations of the aforementioned battery cell, the second tab is either a positive tab or a negative tab.

[0008] The second tab in this invention can be either a positive tab or a negative tab. When the second tab is a positive tab, the discharge rate of the corresponding battery cell can be increased by a factor of two; when the second tab is a negative tab, the charging rate of the corresponding battery cell can be increased by a factor of two.

[0009] In some feasible implementations of the aforementioned battery cell, the second tab is a full tab or multiple die-cut tabs.

[0010] Understandably, when the second tab is both a positive tab and a full tab, the longer the full tab is, the more uniform the current density distribution within the positive electrode, resulting in better current carrying capacity. However, this will reduce the energy density of the cell to some extent (compared to the solution using die-cut tabs). Therefore, the length of the full tab can be determined based on the length of the electrode, selecting an appropriate length while balancing energy density and current carrying capacity.

[0011] When the second tab is a positive tab and a die-cut tab, the internal space utilization of the cell is higher, the weight of the tab is relatively small, and the energy density of the cell is higher than that of a cell using all tabs.

[0012] Similarly, when the second tab is a negative tab, either a full tab or a die-cut tab can be used.

[0013] In some feasible embodiments, the second tab is welded to the housing for the aforementioned battery cell.

[0014] Understandably, the welding methods can be ultrasonic welding, laser welding, or a combination of ultrasonic welding and laser welding, etc.

[0015] In some feasible embodiments, for the aforementioned battery cell, a connecting piece is also provided inside the housing, and the positive electrode tab is welded to the housing through the connecting piece.

[0016] By setting up connecting tabs, it is easier to connect the second electrode tab to the casing smoothly and firmly, ensuring stable battery performance.

[0017] In some feasible embodiments, the cross-sectional shape of the connecting piece for the aforementioned battery cell is approximately “Ω”.

[0018] By setting the connecting piece to have a cross-sectional shape approximately "Ω", when it is connected to the top of the second electrode, a portion of the second electrode can extend into the interior of the connecting piece, thereby further improving the connection stability between the second electrode, the connecting piece, and the housing.

[0019] In some feasible implementations of the above-mentioned battery cell, when the second tab is the positive tab, the connecting piece is made of aluminum, and / or the housing is made of aluminum.

[0020] In some feasible implementations of the above-mentioned battery cell, when the second tab is a negative tab, the connecting piece is made of copper, and / or the housing is made of steel or copper.

[0021] In some feasible implementations of the above-mentioned battery cell, the electrode includes a positive electrode and a negative electrode, which are arranged in a stacked manner.

[0022] In a second aspect, the present invention also provides a battery cell module, the battery cell module comprising a packaging frame and a plurality of battery cells as described in any of the foregoing technical solutions packaged within the packaging frame.

[0023] In a third aspect, the present invention also provides a power battery pack, wherein the power battery pack is configured with the cell module described in the foregoing technical solution.

[0024] In a fourth aspect, the present invention also provides a vehicle, characterized in that the vehicle is equipped with the power battery pack described in the foregoing technical solution.

[0025] Understandably, vehicles equipped with power battery packs can be either pure electric vehicles or hybrid vehicles.

[0026] Those skilled in the art will understand that, since the aforementioned battery cell module, power battery pack, and vehicle are equipped with the aforementioned battery cells, they possess all the technical effects of the aforementioned battery cells, which will not be elaborated upon here.

[0027] Solution 1. A battery cell, characterized in that the battery cell comprises:

[0028] An electrode core includes an electrode sheet and tabs connected to the electrode sheet, the electrode sheet having a long side and a short side, and the tabs including a first tab connected to one of the short sides and a second tab connected to one of the long sides;

[0029] The outer casing includes a housing and a first cover plate and a second cover plate respectively connected to both ends of the housing. An electrode post is disposed on the first cover plate.

[0030] The electrode core is disposed inside the outer casing. The first electrode tab is electrically connected to the electrode post, and the second electrode tab is electrically connected to the casing, so that the casing can be used as an electron flow channel, thereby enabling the second electrode tab to be electrically connected to the second cover plate.

[0031] Option 2. The battery cell according to Option 1, characterized in that the second tab is a positive tab or a negative tab.

[0032] Scheme 3. The battery cell according to Scheme 2, characterized in that the second tab is a full tab or multiple die-cut tabs.

[0033] Option 4. The battery cell according to Option 3, characterized in that the second electrode tab is welded to the housing.

[0034] Option 5. The battery cell according to Option 4, characterized in that a connecting piece is further provided inside the housing, and the second electrode tab is welded to the housing through the connecting piece.

[0035] Option 6. The battery cell according to Option 5, characterized in that the cross-sectional shape of the connecting piece is approximately “Ω”.

[0036] Option 7. The battery cell according to Option 5, characterized in that,

[0037] When the second electrode tab is a positive electrode tab, the connecting piece is made of aluminum, and / or the housing is made of aluminum; or,

[0038] When the second electrode is a negative electrode, the connecting piece is made of copper, and / or the housing is made of steel or copper.

[0039] Scheme 8. The battery cell according to any one of Schemes 1 to 7, characterized in that the electrode comprises a positive electrode and a negative electrode, wherein the positive electrode and the negative electrode are arranged in a stacked manner.

[0040] Scheme 9. A battery cell module, characterized in that the battery cell module includes a packaging frame and a plurality of battery cells as described in any one of Schemes 1 to 8 packaged within the packaging frame.

[0041] Solution 10. A power battery pack, characterized in that the power battery pack is configured with the cell module described in Solution 9.

[0042] Option 11. A vehicle, characterized in that the vehicle is equipped with the power battery pack described in Option 10. Attached Figure Description

[0043] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0044] Figure 1 This is a schematic diagram of the current loop state of a long battery cell during the charging process in the prior art;

[0045] Figure 2 This is a schematic diagram of the battery cell structure provided in Embodiment 1 of the present invention;

[0046] Figure 3 for Figure 2 Rear view;

[0047] Figure 4 for Figure 3 Sectional view along line AA in the middle;

[0048] Figure 5 This is a schematic diagram of the structure of the pole core provided in Embodiment 1 of the present invention;

[0049] Figure 6 This is a schematic diagram of the connecting piece provided in Embodiment 1 of the present invention;

[0050] Figure 7 This is a schematic diagram of the connection structure between the Mylar film and the positioning plastic part provided in Embodiment 1 of the present invention;

[0051] Figure 8 This is a schematic diagram of the connection structure between the electrode tab and the connecting piece provided in Embodiment 1 of the present invention;

[0052] Figure 9 for Figure 8 A magnified view of a portion of the image;

[0053] Figure 10 This is a schematic diagram of the structure of the first cover plate provided in Embodiment 1 of the present invention;

[0054] Figure 11 This is a schematic diagram of the structure of the second cover plate provided in Embodiment 1 of the present invention;

[0055] Figure 12 This is a schematic diagram of the battery cell in the charging state provided in Embodiment 1 of the present invention;

[0056] Figure 13 This is a schematic diagram of the battery cell structure provided in Embodiment 2 of the present invention;

[0057] Figure 14 This is a schematic diagram of the structure of the pole core provided in Embodiment 2 of the present invention;

[0058] Figure 15 This is a schematic diagram of the connection structure between the electrode tab and the connecting piece provided in Embodiment 2 of the present invention;

[0059] List of reference numerals in the attached diagram:

[0060] 1'. Existing long battery cells;

[0061] 1. Battery cell; 10. Housing; 11. First cover plate; 110. First pole post; 111. Explosion-proof valve; 12. Second cover plate; 120. Injection hole; 121. Second pole post; 122. Explosion-proof valve; 20. Electrode; 21. Negative electrode tab; 22. Positive electrode tab; 23. Mylar membrane; 24. Positioning plastic part; 30. Connecting piece. Detailed Implementation

[0062] First, it should be noted that the following embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0063] Secondly, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced even without certain specific details.

[0064] In the description of this invention, terms such as "upper," "lower," "left," "right," "top," and "bottom," which indicate direction or positional relationships, are based on actual application and are used merely for ease of description. They do not indicate or imply that the device to be protected must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] Furthermore, in this invention, "not indicated" means that the corresponding structure is shown in the drawings but not labeled, and "not illustrated" means that the corresponding structure is not shown in the drawings.

[0066] The battery cell provided by the present invention will now be described with reference to the accompanying drawings.

[0067] Example 1

[0068] Reference Figures 2 to 12 , Figure 2 This is a schematic diagram of the battery cell structure provided in Embodiment 1 of the present invention; Figure 3 for Figure 2 Rear view; Figure 4 for Figure 3 Sectional view along line AA in the middle; Figure 5 This is a schematic diagram of the structure of the pole core provided in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the connecting piece provided in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the connection structure between the Mylar film and the positioning plastic part provided in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the connection structure between the electrode tab and the connecting piece provided in Embodiment 1 of the present invention; Figure 9 for Figure 8 A magnified view of a portion of the image; Figure 10 This is a schematic diagram of the structure of the first cover plate provided in Embodiment 1 of the present invention; Figure 11 This is a schematic diagram of the structure of the second cover plate provided in Embodiment 1 of the present invention; Figure 12 This is a schematic diagram of the battery cell in the charging state provided in Embodiment 1 of the present invention.

[0069] The battery cell provided in this embodiment includes a casing and an electrode core disposed inside the casing.

[0070] Specifically, such as Figure 5 As shown, the electrode core includes an electrode sheet 20 and tabs connected to the electrode sheet 20. The electrode sheet 20 includes a positive electrode sheet and a negative electrode sheet, which are separated by a separator (not shown) to prevent short circuits. In this embodiment, the positive and negative electrode sheets are arranged in a stacked manner. Typically, to improve the utilization rate of the electrode sheets in the cell 1, the number of negative electrode sheets is one more than the number of positive electrode sheets. Both the positive and negative electrode sheets have long and short sides, and the electrode core in the stacked state has a plate-like structure under the enclosure.

[0071] In the battery core, each positive electrode plate is connected to a positive tab, and each negative electrode plate is connected to a negative tab. Traditionally, the positive and negative tabs are located at opposite ends of the battery cell's length. Figure 1 The two short sides of the electrode are connected. In this embodiment, the negative tab 21 is connected to the top long side of the negative electrode sheet, and the positive tab 22 is connected to the right short side of the positive electrode sheet. More specifically, in this embodiment, the negative tab 21 is a full tab, and the positive tab 22 is a die-cut tab. Full tabs do not require die-cutting during the manufacturing process; they are generally slitted after coating and rolling. Compared to die-cut tabs, full tabs have better current carrying capacity and rate performance, and the electrode sheet manufacturing process requires one less step, resulting in lower manufacturing costs.

[0072] Alternatively, the negative electrode in this embodiment can also use multiple die-cut electrodes. Die-cut electrodes require an additional die-cutting process compared to full electrodes. When multiple die-cut electrodes are used for the negative electrode, the internal space utilization of the cell is higher, the electrode weight ratio is relatively smaller, and for the same volume of cell, the energy density of the cell using die-cut electrodes is higher than that of the cell using full electrodes.

[0073] In addition, the negative electrode tab can be connected to the bottom long side of the negative electrode plate, and the positive electrode tab can be connected to the left short side of the positive electrode plate.

[0074] The outer casing provides a fully enclosed space for the electrode core, which is housed within the casing. The outer casing includes a hollow shell 10 with openings at both ends, and a first cover plate 11 (or positive cover plate) and a second cover plate 12 (or negative cover plate) connected to the two ends of the shell 10, respectively. In this embodiment, a first electrode post 110 is provided on the first cover plate 11, which is electrically connected to the positive electrode tab 22.

[0075] The structure of the first cover plate 11 is as follows: Figure 10 As shown, the first terminal 110 serves as the terminal connecting the battery cell 1 to the external circuit. The first cover plate 11 is also equipped with an explosion-proof valve 111. During operation, the battery cell 1 will generate a certain amount of gas. The explosion-proof valve 111 will discharge the gas, which can effectively prevent the battery cell 1 from exploding due to excessive internal pressure.

[0076] The structure of the second cover plate 12 is as follows: Figure 11 As shown, since the second cover plate 12 does not need to be directly connected to the negative electrode tab 21, it does not need to be equipped with a terminal post and can serve as a terminal for connection to external circuits. The second cover plate 12 is provided with an electrolyte injection hole 120. After the battery cell 1 is assembled, electrolyte is added through the electrolyte injection hole 120. A rubber plug (not shown) is also provided at the electrolyte injection hole 120 for sealing.

[0077] In this embodiment, the positive electrode tab 22 located on the short right side of the electrode core is electrically connected to the first electrode post 110, and the negative electrode tab 21 located on the long top side of the electrode core is electrically connected to the housing 10. The housing 10 is made of high-strength steel and is made into a very thin steel shell with a thickness of 0.1mm. The steel shell is connected to the second cover plate 12 on the left side as an integral structure. In this way, during the charging process of the battery cell 1, electrons freed from the positive electrode can quickly reach the negative electrode through the electron channel constructed by the housing 10 and the second cover plate 12 to form a current loop, thereby improving the charging rate of the battery cell 1.

[0078] Furthermore, to facilitate the connection between the negative electrode tab 21 and the housing 10, this embodiment also includes a connecting piece 30. The negative electrode tab 21 is connected to the housing 10 via the connecting piece 30. Specifically, the negative electrode tab 21, the connecting piece 30, and the housing 10 are welded together, preferably using laser penetration welding technology. (Refer to...) Figure 3 , Figure 4 and Figure 6 As shown, the connecting piece 30 is a strip structure with a cross-sectional shape approximately "Ω" shaped, and it has several through holes. The through holes facilitate the smooth welding of the negative electrode tab 21, the connecting piece 30 and the housing 10, and also help to reduce the weight of the battery cell 1.

[0079] like Figures 7 to 9 As shown, the electrode core also includes a Mylar film 23 wrapped around the outer periphery of the electrode sheet and a positioning plastic component 24. The Mylar film 23 serves as insulation to prevent short circuits inside the battery cell 1. The positioning plastic component 24 is used for positioning during the process of the Mylar film 23 covering the electrode sheet. A long strip-shaped through hole is opened in the middle of the positioning plastic component 24. The long strip-shaped negative electrode sheet passes through the long strip-shaped through hole and connects to the connecting piece 30, and is further welded to the housing 10. In this embodiment, the connecting piece 30 is made of copper and has a thickness of 0.6 mm.

[0080] In this embodiment, since the negative electrode tab 21 is a full-pole tab, in order to further reduce the weight of the battery cell 1, a shorter connecting piece 30 can be provided only at both ends near the negative electrode tab 21. The specific arrangement is as follows: Figure 8 As shown in the image.

[0081] The working principle of the battery cell 1 provided in this embodiment is as follows: Figure 12 As shown, when charging cell 1, external circuits are connected at the first terminal 110 and the second cover plate 12, respectively. Electrons from the positive electrode sequentially enter the external circuit through the positive tab 22 and the first terminal 110. After reaching the second cover plate 12, the electrons pass through the housing 10 to the negative tab 21, and then further enter the negative electrode uniformly from top to bottom through the negative tab 21. In this process, because the path of electrons from the negative tab 21 to the negative electrode is very short and the contact surface between the negative tab 21 and the negative electrode is large, electrons can quickly enter the negative electrode, thereby improving the fast charging capability of cell 1. In this process, the current density of the charging current is basically uniform throughout the negative electrode, thus effectively solving the problem of uneven current density caused by the long electrode length in the prior art.

[0082] It should be noted that during the assembly process, the negative electrode tab 21 first undergoes ultrasonic flattening, then the Mylar film 23 with positioning plastic parts 24 is fitted on it, followed by bending, and then laser-welded to the housing 10 via connecting piece 30. The positive electrode tab 22 also undergoes ultrasonic flattening, and after bending, it is directly laser-welded to the first cover plate 11. High-temperature resistant insulating tape is used to wrap the exposed metal part of the positive electrode inside the cell 1 to prevent it from contacting the housing 10 and causing a short circuit. Then, the Mylar film 23 is fixed with insulating tape, and both ends are fixed to the plastic of the cover plate by heat fusion. Finally, the first cover plate 11 and the second cover plate 12 are welded to the housing 10 by continuous laser welding, thus completing the assembly of the cell 1. After the assembled battery cell 1 is baked, injected with electrolyte, formed, aged, and replenished with electrolyte a second time, the injection hole 120 is plugged with a rubber stopper and sealed with a sealing aluminum sheet by laser welding. Then, it is cleaned, coated and capacity tested to complete the preparation of battery cell 1.

[0083] The experimental parameters of the battery cell in this embodiment can be found in Table 1:

[0084] Table 1

[0085] Item unit Cell parameters size mm 20*700*115 type / Lithium iron phosphate capacity Ah 230 weight kg 3.67 Voltage V 3.2 internal resistance of communication mΩ 0.2 Specific energy Wh / kg 201 Charging capability / 5C

[0086] As can be seen from Table 1, after adopting the battery cell in the embodiment, the charging capacity of the battery cell increases several times, and the charging capacity is greatly improved.

[0087] Example 2

[0088] This embodiment shares the same technical concept as Embodiment 1, both involving placing one of the tabs on the long side of the electrode core and electrically connecting it to the housing 10. The housing 10 serves as an electron flow channel, thereby maintaining a uniform current density during electron flow. The difference between this embodiment and Embodiment 1 is that the second tab in this embodiment is a positive tab 22. When the positive tab 22 is placed on the long side of the electrode core, the discharge rate of the cell 1 can be effectively increased.

[0089] Specifically, refer to Figure 13 and Figure 14 As shown, in this embodiment, the positive electrode tab 22 uses multiple die-cut tabs, which are evenly arranged on the top long side of the positive electrode sheet and welded together with it. Specifically, ultrasonic welding or laser welding can be used. The negative electrode tab 21 uses a die-cut tab, which is connected to the right short side of the negative electrode sheet by ultrasonic welding or laser welding. Ultrasonic welding produces a smoother weld mark, allowing for the welding of multiple layers of tabs together. Its smooth surface facilitates subsequent laser welding.

[0090] In this embodiment, the negative electrode 21 is connected to the short side. The negative electrode 21 needs to be electrically connected to the electrode post. Therefore, a second electrode post 121 is provided on the second cover plate 12 in this embodiment. Figure 13 As shown, the negative electrode tab 21 is electrically connected to the second electrode post 121. An explosion-proof valve 122 is also provided on the second cover plate 12 to discharge gases generated during battery operation.

[0091] It is understandable that, since the positive electrode tab 22 in this embodiment is electrically connected to the housing 10, there is no need to set a pole on the first cover plate 11.

[0092] In this embodiment, the negative electrode tab 21 located on the short right side of the electrode core is electrically connected to the second electrode post 121, and the positive electrode tab 22 located on the long top side of the electrode core is electrically connected to the housing 10. The housing 10 is made of aluminum with a thickness of 0.3 mm. The connecting piece 30 in this embodiment is also made of aluminum with a thickness of 0.8 mm. (Comparison) Figure 2 and Figure 13 In this embodiment, the laser solder joint (not shown) between the positive tab 22 and the housing 10 differs from that between the negative tab 21 and the housing 10 in Embodiment 1. In this embodiment, the solder joint between the multi-tab structure and the housing 10 consists of multiple solder lines. As a result, during the discharge process after the battery cell 1 is connected to a load, electrons ionized from the negative electrode first enter the external circuit via the second electrode post 121. Electrons in the external circuit can then quickly reach each positive tab 22 via the electron channel constructed by the housing 10 and the first cover plate 11. The electrons then uniformly reach the positive electrode from top to bottom through each positive tab 22. During this process, because the path of electrons from the positive tab 22 into the positive electrode is very short, and the positive tabs 22 are uniformly distributed along the long side of the positive electrode, electrons can quickly enter the positive electrode. The current density is essentially uniform throughout the positive electrode, effectively solving the problem of uneven current density caused by the long core length in the prior art, and improving the fast discharge capability of the battery cell 1.

[0093] Alternatively, the positive tab 22 in this embodiment can also be an all-pole tab. Furthermore, the positive tab 22 can be connected to the bottom long side of the positive electrode plate, and the negative tab 21 can be connected to the left short side of the negative electrode plate.

[0094] It should be noted that, since the positive electrode tab 22 in this embodiment uses multiple die-cut tabs, the length of the connecting piece 30 is longer than that in embodiment 1. The length of the connecting piece 30 is approximately equal to the distance between the two outermost positive electrode tabs 22, such as... Figure 15 As shown, the structure of the connecting piece 30 in this embodiment is the same as that of the connecting piece 30 in Embodiment 1.

[0095] The experimental parameters of the battery cell in this embodiment can be found in Table 2.

[0096] Table 2

[0097] Item unit Cell parameters size mm 9*500*80 type / High-nickel ternary capacity Ah 60 weight kg 0.995 Voltage V 3.65 internal resistance of communication mΩ 0.35 Specific energy Wh / kg 220 Discharge capability / 10C

[0098] As can be seen from Table 2, by connecting multiple positive tabs to the top long side of the positive electrode, electrons can be evenly conducted to each positive tab through the shell during the flow process, and then quickly enter the positive electrode with the shortest distance, thereby improving the discharge capacity of the cell. Compared with the discharge capacity of existing cells, the discharge rate increases the cost.

[0099] It should be noted that the values ​​in the above examples are merely exemplary and should not be construed as limiting the scope of protection of this invention. Those skilled in the art can transform the values ​​in the above examples within a reasonable range as needed.

[0100] This invention also provides a battery cell module, which consists of multiple battery cells and a packaging frame for encapsulating the battery cells. The packaging frame serves as a unified boundary for the multiple battery cells to achieve connection with external circuitry.

[0101] This invention also provides a power battery pack, which includes one or more cell modules, a BMS (battery management system), and a thermal management system, etc. The multiple cell modules within the battery pack are connected in series, parallel, or other ways. It is understood that the multiple cells in a cell module can simultaneously include the fast-charging cell in Embodiment 1 and the fast-discharging cell in Embodiment 2. The cell module formed by connecting the fast-charging and fast-discharging cells in series and parallel can balance fast-charging and fast-discharging performance, thereby effectively improving the performance of the power battery pack.

[0102] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that, The battery cell includes: An electrode core includes an electrode sheet and tabs connected to the electrode sheet, the electrode sheet having a long side and a short side, and the tabs including a first tab connected to one of the short sides and a second tab connected to one of the long sides; The outer casing includes a housing and a first cover plate and a second cover plate respectively connected to both ends of the housing. An electrode post is disposed on the first cover plate. The electrode core is disposed inside the outer casing. The first electrode tab is electrically connected to the electrode post, and the second electrode tab is electrically connected to the casing, so that the casing can be used as an electron flow channel, thereby enabling the second electrode tab to be electrically connected to the second cover plate. The housing is also provided with a connecting piece, and the second electrode tab is welded to the housing through the connecting piece; The cross-sectional shape of the connecting piece is approximately "Ω" shaped; The second electrode extends into the "Ω" of the connecting piece, and the second electrode is a full electrode or multiple die-cut electrodes.

2. The battery cell according to claim 1, characterized in that, The second electrode ear can be either a positive electrode ear or a negative electrode ear.

3. The battery cell according to claim 1, characterized in that, The second electrode tab is welded to the housing.

4. The battery cell according to claim 3, characterized in that, When the second electrode tab is a positive electrode tab, the connecting piece is made of aluminum, and / or the housing is made of aluminum; or, When the second electrode is a negative electrode, the connecting piece is made of copper, and / or the housing is made of steel or copper.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The electrode includes a positive electrode and a negative electrode, which are arranged in a stacked manner.

6. A battery cell module, characterized in that, The battery cell module includes a packaging frame and a plurality of battery cells as described in any one of claims 1 to 5 packaged within the packaging frame.

7. A power battery pack, characterized in that, The power battery pack is equipped with the cell module as described in claim 6.

8. A vehicle, characterized in that, The vehicle is equipped with the power battery pack as described in claim 7.

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