Battery module and energy storage power supply
By adding a drag-reducing section to the busbar body to adjust the internal resistance, the problem of high charging and low discharging caused by different aluminum busbar shapes in the battery module was solved, achieving consistency in voltage acquisition and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN HELLO TECH ENERGY CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-06-05
AI Technical Summary
In existing battery modules, the inconsistent internal resistance caused by different aluminum busbar shapes leads to the problem of high charging and low discharging during battery charging. Existing solutions increase chip costs or voltage sampling errors.
By adding a resistance-reducing section to the main body of the busbar and adjusting its internal resistance to be consistent with other buses, the voltage can be detected by a voltage sampling chip, thereby reducing the number of voltage sampling nickel strips and lowering costs.
It improves the consistency of voltage acquisition in battery modules, reduces manufacturing costs, and enhances mechanical strength and conductivity, while solving the problem of high charging and low discharging.
Smart Images
Figure CN224328781U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of energy storage product technology, and in particular to a battery module and energy storage power supply. Background Technology
[0002] Lithium-ion batteries, as a new energy battery, have advantages such as high operating voltage, high specific capacity, long charge-discharge life, and no memory effect, and are widely used in energy storage devices and new energy vehicles. Cylindrical battery packs have a simple design, flexible size, simple assembly, and simple automation equipment, making them widely used in containerized energy storage, industrial and commercial energy storage, home energy storage, portable energy storage, and RV batteries. They are especially useful in small energy storage devices, as they are easy to carry, meet various structural designs, have a small volume, and a compact and exquisite appearance.
[0003] To accommodate various energy storage configurations, the cells within cylindrical battery packs are arranged in complex and varied configurations, resulting in different shapes of the aluminum busbars within the battery module (e.g., ...). Figure 1 (As shown). Aluminum busbars of different shapes can easily affect the accuracy of battery voltage sampling, and may result in the same battery module exhibiting high charging and low discharging phenomena, failing to protect batteries with actual voltages that are high or low during charging and discharging.
[0004] To address this issue, current battery modules employ two methods: First, a voltage compensation method is used in the Battery Management System (BMS). This method results in large voltage errors because the compensated voltage varies at different charging rates and temperatures, requiring extensive testing and impacting overall performance. Second, using at least two voltage sampling points on the same aluminum busbar can avoid the phenomenon of high charging followed by low discharging (e.g., ...). Figure 2 (As shown in the image) However, this method increases the number of voltage sampling points, leading to an increase in the number of voltage sampling nickel strips. Furthermore, different voltage sampling points require different chips, increasing chip costs. Moreover, sometimes using the same bracket to accommodate different battery capacities can result in chip incompatibility with multiple voltage sampling points. For example, a different analog front-end chip (AFE chip) is used for batteries with 10 or fewer strings, while a different AFE chip is used for batteries with 11 to 16 strings. In this case, not only the chip needs to be replaced, but the BMS board also needs to be replaced, increasing battery manufacturing costs. Utility Model Content
[0005] The purpose of this invention is to provide a battery module and energy storage power supply to solve the problem of high charging and low discharging of batteries, and to reduce manufacturing costs.
[0006] To achieve this objective, the present invention adopts the following technical solution:
[0007] In a first aspect, this utility model provides a battery module, including a cell group and a voltage sensing chip. The cell group comprises at least two cells, each cell group including multiple cells. Multiple cells in the same cell group are connected in series and / or in parallel via a busbar. The busbar includes a first busbar and a second busbar. The first busbar includes a body portion and a resistance-reducing portion. The body portion connects to multiple cells in the same cell group. The internal resistance of the body portion is greater than the internal resistance of the first busbar. The resistance-reducing portion is disposed on the body portion along its width and / or thickness direction, so that the internal resistance of the first busbar is the same as the internal resistance of the second busbar. The voltage sensing chip is connected to each busbar to detect the voltage of each cell group.
[0008] In one embodiment, the drag-reducing part is integrally formed with the main body part.
[0009] In one embodiment, the body portion includes a guide portion and a plurality of connecting portions, the connecting portions being correspondingly connected to each of the cells in the same cell group, the guide portion being connected to each of the connecting portions, and the drag-reducing portion being disposed on the guide portion.
[0010] In one embodiment, the drag-reducing portion and the guiding portion are arranged on the same plane; or the drag-reducing portion and the guiding portion are arranged perpendicular to each other; or the drag-reducing portion is stacked on the side of the guiding portion away from the cell assembly.
[0011] In one embodiment, the battery module further includes a bracket located on one side of the battery cell's terminal post to limit the position of multiple battery cells.
[0012] In one embodiment, the first busbar connects to the edge of the cell array formed by multiple cell groups, and the drag-reducing part is disposed on the body part along the width direction of the body part, and the drag-reducing part is partially attached to the outer peripheral surface of the bracket.
[0013] In one embodiment, the first busbar connects to the cell group at the edge of the cell array formed by multiple cell groups, the drag reduction part is disposed on the body part along the width direction of the body part, the bracket is provided with a clearance groove, and the drag reduction part is inserted into the clearance groove.
[0014] In one embodiment, the busbar is made of aluminum.
[0015] In one embodiment, multiple drag-reducing sections are provided.
[0016] Secondly, this utility model provides an energy storage power supply, which includes a housing and a battery module as described in any of the above claims. The housing has a recessed cavity, and the battery module is located within the recessed cavity. The beneficial effects of this utility model are:
[0017] In the battery module and energy storage power supply provided by this utility model, the first bus increases the local cross-sectional area of the first bus by adding a drag-reducing part in the width direction and / or the thickness direction of the body part, so that the internal resistance of the first bus and the second bus are the same, thereby improving the consistency of the sampled voltage and effectively solving the problem of high charging and low discharging of the battery module. Moreover, compared with setting multiple sampling nickel strips, the manufacturing cost is low. Attached Figure Description
[0018] Figure 1 This is a structural schematic diagram of a battery module provided in a related technology;
[0019] Figure 2 This is a structural schematic diagram of a battery module provided in another related technology;
[0020] Figure 3 This is a partial structural schematic diagram of a battery module provided in one embodiment of the present invention;
[0021] Figure 4 yes Figure 3 A schematic diagram of the structure of the first busbar in the system;
[0022] Figure 5 This is a partial structural schematic diagram of a battery module provided in another embodiment of the present invention;
[0023] Figure 6 yes Figure 5 A schematic diagram of the structure of the first busbar in the system;
[0024] Figure 7 This is a partial structural schematic diagram of the battery module provided in another embodiment of the present invention;
[0025] Figure 8 This is a partial structural schematic diagram of a battery module provided in another embodiment of the present invention;
[0026] Figure 9 yes Figure 8 A three-dimensional structural diagram of the first busbar provided in the diagram;
[0027] Figure 10 yes Figure 8 The side view of the first bus provided in the image.
[0028] In the picture:
[0029] 1. Busbar; 1a. First busbar; 11. Body; 111. Connecting part; 112. Guiding part; 12. Drag reduction part; 2. Battery cell; 3. Bracket; 31. Clearance groove; 4. Pressure sampling chip; 5. Pressure sampling nickel strip. Detailed Implementation
[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0033] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0034] "High charge, low discharge" refers to the phenomenon where a single cell string in a battery pack reaches its protection limit (high charge) too early during charging and its protection limit (low discharge) too early during discharging. The BMS controls the charging and discharging of the battery module based on the battery module's voltage. If the voltage of a cell string reaches the voltage protection limit, charging will stop; if the voltage of a cell string reaches the voltage protection limit, charging will also stop.
[0035] It can be known that the voltage U collected by the PCB during the charging process is U = U bat +U 汇流排 =U bat +IR汇流排 U bat Represents battery voltage; U 汇流排 Represents bus voltage; R 汇流排 Represents the bus internal resistance; the voltage U = U measured by the PCB during the discharge process. bat -U 汇流排 =U bat -IR 汇流排 In other words, the voltage sampled by the PCB is affected by both the battery voltage and the bus voltage. The cell string connected to a bus with higher internal resistance will reach its voltage protection upper and lower limits first due to its higher internal resistance, affecting the charging and discharging of other cell strings. Therefore, within the same battery module, the internal resistance of the busbars should be kept as consistent as possible to ensure accurate voltage sampling. However, in product design, because different busbars connect to cells at different locations within the battery module, it is difficult to ensure the consistency of the busbar shape, which in turn makes it difficult to maintain consistent internal resistance.
[0036] Based on this, refer to Figures 3-10 As shown, an embodiment of this utility model provides a battery module, which includes a voltage sampling chip 4 and at least two cell groups. Each cell group includes multiple cells 2. The multiple cells 2 in the same cell group are connected in series and / or in parallel through a busbar 1. The busbar 1 can be made of aluminum. The voltage sampling chip 4 is connected to each busbar 1 through a voltage sampling nickel strip 5. The voltage sampling chip 4 is used to collect the voltage of the cell 2.
[0037] Bus 1 includes a first bus 1a and a second bus (not shown in the figure). The first bus 1a and the second bus are respectively connected to different battery cell groups. The first bus 1a includes a body portion 11 and a resistance reduction portion 12. The body portion 11 is used to connect multiple battery cells 2. The internal resistance of the body portion 11 is greater than the internal resistance of the first bus 1a. The resistance reduction portion 12 is disposed on the body portion 11 along the width direction and / or thickness direction so that the internal resistance of the first bus 1a is the same as the internal resistance of the second bus.
[0038] According to the calculation method of busbar 1 internal resistance R = ρL / S (where R represents the resistance value of busbar 1, ρ represents the resistivity of busbar 1, L represents the length of busbar 1, and S represents the cross-sectional area of busbar 1), it can be seen that the internal resistance R of busbar 1 is directly proportional to the length of busbar 1, that is, the longer busbar 1 is, the greater its internal resistance; the internal resistance R of busbar 1 is inversely proportional to its cross-sectional area, that is, the larger the cross-sectional area of busbar 1 is, the smaller its internal resistance. Therefore, when a certain busbar 1 is longer than other busbar 1s due to the different positions of the connected cell 2 cells, its internal resistance will also be greater than that of other busbar 1s, thus causing the phenomenon of high charging and low discharging in the same battery module. The first busbar 1a in the aforementioned battery module increases its local cross-sectional area by adding a drag-reducing part 12 in the width direction (referring to the direction perpendicular to the current flow direction in the plane of the body part 11) and / or the thickness direction of the body part 11. This makes the internal resistance of the first busbar 1a the same as that of the second busbar, improving the consistency of the sampled voltage. This effectively solves the problem of high charging and low discharging in the battery module. Moreover, compared with setting multiple sampling nickel strips 5, the manufacturing cost is low, and the busbar 1 made of aluminum is recyclable. Modifying the structure of the busbar 1 is more economical in mass production.
[0039] Furthermore, the increased thickness and / or width of the first bus 1a reduces heat accumulation during current transmission to some extent, optimizes the heat dissipation path, and improves overall conductivity. Moreover, the increased width and thickness of the first bus 1a also enhances its mechanical strength, effectively supporting the arrangement of the battery cells 2 and reducing deformation caused by vibration or impact. It is worth emphasizing that the statement that the internal resistances of the first bus 1a and the second bus are the same allows for a certain degree of error, and is not absolute. For example, if the internal resistance of the first bus 1a is within the range of 0.8-1.2 times that of the second bus, it is considered that the internal resistances of the first bus 1a and the second bus are the same.
[0040] refer to Figures 5-7 As shown, the battery module also includes a bracket 3 for limiting the position of the battery cell 2. The bracket 3 is located on the side where each battery cell 2 is provided with a terminal post, and the bracket 3 is provided with a first through hole through which the terminal post of the battery cell 2 passes and a second through hole for the busbar to connect with the battery cell 2.
[0041] In some embodiments, in order not to occupy additional space in the battery module, the orthogonal projection of the first busbar 1a toward the bracket 3 should fall on the bracket 3 as much as possible. Therefore, for the first busbar 1a connecting the cell group located at the edge of the cell array composed of multiple cell groups, the provision of the drag-reducing part 12 on the first busbar 1a along the width direction of the first busbar 1a may cause the first busbar 1a to protrude from the bracket 3. In this case, the first busbar 1a is bent.
[0042] Specifically, the bracket 3 is provided with a relief groove 31 for the drag-reducing part 12 to be inserted, and the drag-reducing part 12 is bent and inserted into the relief groove 31; or, the part of the first busbar 1a that protrudes from the bracket 3, i.e. the part of the drag-reducing part 12, is bent and made to fit against the outer peripheral surface of the bracket 3.
[0043] refer to Figures 8-10 As shown, based on the premise that the drag-reducing part 12 is disposed on the body part 11 along the thickness direction of the body part 11, it can be understood that the shape of the drag-reducing part 12 is not necessarily the same as the shape of the body part 11. That is to say, the arrangement of the drag-reducing part 12 can be equivalent to locally thickening the first busbar 1a, or it can be equivalent to thickening the first busbar 1a as a whole. Moreover, the drag-reducing part 12 can be disposed on one side of the body part 11 opposite to each other along the thickness direction, or it can be disposed on both sides of the body part 11 opposite to each other along the thickness direction. That is, multiple drag-reducing parts 12 can be disposed, or only one can be disposed. Specifically, in order to reduce the processing difficulty, the drag-reducing part 12 is integrally formed with the body part 11. Of course, the thickness of the drag-reducing part 12 needs to be considered based on the area of the drag-reducing part 12 covering the body part 11. Under the premise of ensuring that the internal resistance of the first busbar 1a and the second busbar are the same, the larger the area of the drag-reducing part 12 covering the body part 11, the smaller the thickness of the drag-reducing part 12.
[0044] In some embodiments, the main body 11 further includes a guide portion 112 and at least two connecting portions 111, wherein the connecting portions 111 are welded to the battery cell 2, and the guide portion 112 connects each connecting portion 111. In addition, in order to reduce the difficulty of welding the connecting portions 111 to the battery cell 2 and at the same time make the charging and discharging conditions of each battery cell 2 similar, the resistance reduction portion 12 is provided on the guide portion 112.
[0045] Specifically, the drag-reducing part 12 may be arranged coplanarly with the guide part 112; or the drag-reducing part 12 and the guide part 112 may be arranged perpendicular to each other; or the drag-reducing part 12 may be stacked on the side of the guide part 112 away from the cell assembly, so as to avoid interfering with the welding of the connection part 111 and the cell 2.
[0046] When the resistance-reducing part 12 is located on the side of the guide part 112 away from the battery cell assembly, during the processing of the first busbar 1a, after the main body 11 and the resistance-reducing part 12 are integrally formed, the connecting part 111 is obtained by thinning the area where the connecting part 111 is located, so that the thickness of the connecting part 111 is consistent with that of the second busbar. Therefore, during welding, there is no need to adjust the parameters of the welding equipment. Of course, depending on the actual required resistance value of the first busbar 1a, the guide part 112 can also be locally thinned. For example, during the processing, the end where the guide part 112 connects to the connecting part 111 is thinned.
[0047] An embodiment of this utility model also proposes an energy storage power supply, including a housing and the aforementioned battery module. The housing has a receiving cavity, and the battery module is located within the receiving cavity. Since this energy storage power supply includes the aforementioned battery module, it possesses the advantages of a battery module, which will not be elaborated further here.
[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A battery module, characterized in that, include: At least two cell groups, each of the cell groups comprising multiple cells, the multiple cells in the same cell group being connected in series and / or in parallel via a busbar; The bus includes a first bus and a second bus. The first bus includes a body and a drag-reducing part. The body connects multiple cells of the same cell group. The internal resistance of the body is greater than the internal resistance of the first bus. The drag-reducing part is disposed on the body along the width direction and / or thickness direction of the body so that the internal resistance of the first bus is the same as the internal resistance of the second bus. A voltage sensing chip is connected to each of the busbars to detect the voltage of each of the battery cells.
2. The battery module according to claim 1, characterized in that, The drag-reducing part is integrally formed with the main body.
3. The battery module according to claim 1, characterized in that, The main body includes a guide portion and multiple connecting portions, the multiple connecting portions being connected to each of the cells in the same cell group, the guide portion being connected to each of the connecting portions, and the resistance reduction portion being disposed on the guide portion.
4. The battery module according to claim 3, characterized in that, The drag-reducing part and the guiding part are arranged on the same plane; or The drag-reducing section and the guiding section are arranged perpendicularly to each other; or The drag-reducing portion is stacked on the side of the guide portion away from the battery cell assembly.
5. The battery module according to claim 1, characterized in that, The battery module also includes a bracket located on one side of the battery cell's terminal post to limit the position of multiple battery cells.
6. The battery module according to claim 5, characterized in that, The first busbar connects to the edge of the cell array formed by multiple cell groups, and the drag reduction part is disposed on the body part along the width direction of the body part, and the drag reduction part is partially attached to the outer peripheral surface of the bracket.
7. The battery module according to claim 5, characterized in that, The first busbar connects to the battery cells at the edge of the battery cell array, which is composed of multiple battery cell groups. The drag reduction part is disposed on the body part along the width direction of the body part. The bracket is provided with a clearance groove, and the drag reduction part is inserted into the clearance groove.
8. The battery module according to any one of claims 1-7, characterized in that, The busbar is made of aluminum.
9. The battery module according to any one of claims 1-7, characterized in that, The drag reduction section is provided in multiple parts.
10. An energy storage power source, characterized in that, The energy storage power supply includes a housing and a battery module as described in any one of claims 1-9, wherein the housing has a receiving cavity and the battery module is located within the receiving cavity.