Battery modules for electrically driven vehicles and electrically driven vehicles
By employing a multi-row cell arrangement and fusible connector design in the battery module, the problem of short-circuit propagation caused by cell thermal runaway is solved, improving the safety and space utilization efficiency of the battery system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BMW BRILLIANCE AUTOMOTIVE
- Filing Date
- 2025-05-07
- Publication Date
- 2026-05-26
Smart Images
Figure CN224288460U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a battery module for an electrically driven vehicle and an electrically driven vehicle. Background Technology
[0002] In some electrically driven vehicles, battery modules are used for electric drive. The cells in the battery modules are connected in parallel and then in series to meet the energy requirements of the whole vehicle.
[0003] When one of the cells in a series-connected battery system experiences thermal runaway, the separator inside that cell decomposes and the current collector melts, potentially creating a resistor with a low resistance value. In this situation, other cells connected in parallel with this resistor may form a short circuit, causing the thermal runaway to propagate to the parallel cells, leading to a failure of the entire battery system and increasing the risk of fire and explosion. Utility Model Content
[0004] The purpose of this invention is to provide a battery module for an electrically driven vehicle and an electrically driven vehicle, which can at least solve one of the problems mentioned above.
[0005] To achieve the above objectives, this utility model proposes a battery module for electrically driven vehicles, characterized in that the battery module comprises multiple cell groups connected in series, and each cell group comprises at least two cells connected in parallel.
[0006] The battery module comprises at least two cell rows, each cell row including multiple groups of cells arranged sequentially in a first direction, and the at least two cell rows are arranged sequentially in a second direction transverse to the first direction.
[0007] In the second direction, the series connection between adjacent cell groups in each of the two outermost cell rows is achieved through a first busbar, and the series connection between adjacent cell groups in different cell rows in the second direction is achieved through a second busbar. During normal operation of the battery module's cells, the direction of current flow through the first busbar is transverse to the direction of current flow through the second busbar.
[0008] In this embodiment, at least one of one or two second buses electrically connected to one or two terminals of each cell has at least two body portions and at least one tab connecting adjacent body portions to each other over a portion of their length in the second direction. Each body portion is electrically connected to two adjacent cells in the second direction of different cell groups, and the tab is configured to melt when the current flowing through the tab is greater than a predetermined threshold.
[0009] The technical effects achieved by the battery module of this utility model include, but are not limited to: providing a novel compact and space-saving arrangement of battery cells, and based on this arrangement, adding a function to each battery cell, for example, to prevent thermal diffusion to parallel battery cells in the event of thermal runaway.
[0010] Advantageously, the contact is configured such that, in the event of thermal runaway in one of the cells, current flows through the contact electrically connected to the body of the cell, and the current is greater than the predetermined threshold.
[0011] Advantageously, the predetermined threshold is related to the material of the patch and / or the cross-sectional area of the patch.
[0012] Advantageously, at least two tabs are spaced apart in the second direction between adjacent main body sections of the same second busbar. This enhances the torsional resistance of adjacent main body sections relative to each other, facilitating transportation and installation.
[0013] Advantageously, at least three rows of second buses are arranged sequentially in the second direction, and at least one row of the at least three rows of second buses does not have the contact plate. Here, for example, in the case of three consecutive rows of second buses, the middle row of second buses may not have a contact plate, that is, it may not have a short-circuit protection function. Instead, the two rows of second buses on both sides have contact plates, which still ensures that each cell is equipped with at least one second bus with a contact plate.
[0014] Advantageously, the battery module is configured such that, during normal operation of the battery module's cells, current flows through two adjacent second busbars in the first direction in opposite directions.
[0015] Advantageously, the battery module is configured such that, during normal operation of the battery cells, current flows successively through the first busbar and the second busbar in a serpentine pattern.
[0016] Advantageously, the solder joints on each first busbar that are welded to the terminals of the battery cell are arranged in a linear pattern, while the solder joints on each second busbar that are welded to the terminals of the battery cell are arranged in a rectangular pattern.
[0017] Advantageously, the battery cell is a prismatic cell. This arrangement of prismatic cells allows for a more compact and space-saving layout.
[0018] To achieve the above objectives, the present invention also proposes an electrically driven vehicle, characterized in that the vehicle has a battery module for an electrically driven vehicle according to the present invention. Attached Figure Description
[0019] The present invention will now be explained in more detail with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described in the drawings and detailed below. The drawings are as follows:
[0020] Figure 1a This is a 3D view of a battery module in the prior art;
[0021] Figure 1b yes Figure 1a An exploded view of the battery module in the diagram;
[0022] Figure 1c yes Figure 1a A top view of the battery module, omitting the busbar;
[0023] Figure 1d yes Figure 1a A top view of the battery module, showing the direction of current flow on the busbar during normal operation;
[0024] Figure 1e yes Figure 1d An enlarged top view of a busbar, on which the direction of current flow is drawn;
[0025] Figure 1f yes Figure 1a The top view of the battery module shows the direction of short-circuit current flow in the short-circuit loop formed when one of the cells experiences thermal runaway.
[0026] Figure 1g yes Figure 1f An enlarged top view of a busbar, on which the direction of short-circuit current flow is drawn;
[0027] Figure 1h yes Figure 1a The process by which thermal runaway occurs in one of the battery cells in a battery module, and the heat spreads to the cells connected in parallel.
[0028] Figure 2a This is a perspective view of the battery module in an embodiment of this utility model;
[0029] Figure 2b yes Figure 2a An exploded view of the battery module in the diagram;
[0030] Figure 3a yes Figure 2a The top view of the battery module in the image shows the serpentine or meandering current flow inside the module, omitting the busbars.
[0031] Figure 3b yes Figure 2a A top view of the battery module, showing the direction of current flow on the first and second busbars during normal operation;
[0032] Figure 3c yes Figure 3b An enlarged top view of a second bus in the diagram, on which the direction of current flow is drawn;
[0033] Figure 4a yes Figure 2a The top view of the battery module shows the direction of short-circuit current flow in the short-circuit loop formed when one of the cells experiences thermal runaway.
[0034] Figure 4b yes Figure 4a An enlarged top view of a second busbar, on which the direction of short-circuit current flow through the contacts is drawn;
[0035] Figure 4c yes Figure 4b A schematic diagram of the fuse-breaking process of the lower three contacts of the second bus in a computer simulation environment;
[0036] Figure 4d yes Figure 2a In the event of thermal runaway in one of the battery cells, the battery module uses a second bus to prevent thermal diffusion to the parallel-connected cells.
[0037] Figure 5a This is a top view of another embodiment of the second busbar of this utility model;
[0038] Figure 5b This is a top view of yet another embodiment of the second busbar of this utility model; and
[0039] Figure 5c This is a top view of yet another embodiment of the second busbar of this utility model. Detailed Implementation
[0040] The following describes illustrative embodiments of the present invention. In this specification, various systems, structures, and devices are schematically depicted in the accompanying drawings for illustrative purposes only, and not all features of actual systems, structures, and devices are described. For example, well-known functions or structures are not described in detail to avoid unnecessary detail that could obscure the present invention. It should be understood that in any practical application, many specific implementation decisions need to be made to achieve the specific goals of the developer or user, and system-related and industry-related limitations need to be followed. These specific goals may vary depending on the practical application. Furthermore, it should be understood that while such implementation decisions are complex and time-consuming, they are routine tasks for those skilled in the art who will benefit from the present invention.
[0041] The terms and phrases used herein should be understood and interpreted in accordance with the understanding of those skilled in the art. The consistent use of terms or phrases herein is not intended to imply a specific definition, i.e., a definition different from the common and conventional meaning understood by those skilled in the art. For terms or phrases intended to have a specific meaning, i.e., a meaning different from that understood by those skilled in the art, such specific definition will be explicitly listed in the specification, giving the specific definition of the term or phrase directly and unambiguously.
[0042] Unless otherwise required by the content, throughout the following description, the word “including” and its variations, such as “comprising” and “having”, will be interpreted in an open-ended, inclusive sense, that is, as “including but not limited to”.
[0043] For ease of understanding, identical or similar parts are referred to by the same reference numerals.
[0044] Battery module 1 can be installed in an electrically driven vehicle (not shown), such as a car, to provide the electrical energy required for the operation of the vehicle.
[0045] Figures 1a to 1b A schematic overview of a battery module 1 in the prior art is shown. As can be seen, the existing battery module 1 has a module frame 2 surrounding a rectangular receiving cavity and a plurality of square battery cells 3 arranged sequentially in a single row, i.e., a unique cell row 4. The module frame 2 includes two opposing end plates 5 and two opposing side plates 6, wherein the two end plates 5 fix the cell row 4 from both ends, and the two side plates 6 fix the cell row 4 from both sides.
[0046] See also in this article Figure 1c and Figure 3a The direction along which the cells 3 of a cell array 4 are arranged sequentially is defined as the first direction S1 of the battery module 1. Therefore, the first direction S1 is also the longitudinal extension direction of the side plate 6. The direction perpendicular to the first direction S1, or the horizontal extension direction of a single cell 3, is defined as the second direction S2 of the battery module 1. Therefore, the second direction S2 is also the longitudinal extension direction of the end plate 5, or the longitudinal extension direction of a single cell 3. Therefore, in the prior art, the cells 3 of the cell array 4 are arranged sequentially in the first direction S1 of the battery module 1, while only one unique cell array 4 is set in the second direction S2 of the battery module 1.
[0047] See Figure 1c To meet the energy requirements of the vehicle, typically two (or more) adjacent cells 3 in the first direction S1 are first connected in parallel to form a cell group 7. Figure 1cThe diagram schematically shows three cell groups 7, which are then connected in series. For this purpose, the cells 3 of each cell group 7 are arranged such that their positive terminals 8 are side-by-side or on the same side, and their negative terminals 9 are side-by-side or on the same side. Furthermore, the cells 3 of every two adjacent cell groups 7 are arranged such that the terminals 8 and 9 of each cell 3 in one cell group 7 are side-by-side with the opposite terminals 9 and 8 of each cell 3 in the other cell group 7. See also... Figure 1d The parallel connection between cells 3 in the same cell group 7 and the series connection between cells 3 in different cell groups 7 are both achieved through the first busbar 10. This means that the first busbar 10 is welded to the corresponding terminals 8 and 9 of the cell 3 to facilitate current transmission between the cells 3. (See also...) Figure 1d and Figure 1e The solder joints 20 on each first busbar 10 are arranged linearly.
[0048] See Figure 1d Except for the two first busbars 10 located at the positive main terminal of battery module 1 in the upper left corner and the negative main terminal of battery module 1 in the upper right corner, which connect the cells 3 of the first and last cell groups 7 in parallel respectively, each other first busbar 10 connects the cells 3 of two adjacent cell groups 7 in parallel first and then in series. During normal operation of battery module 1, the current flow direction between two adjacent cell groups 7 connected in series via the first busbars 10 is shown by the (blue) arrow. Specifically, the current in the first cell group 7 from left to right flows through the first first busbar 10 in the lower left corner to the second cell group 7, then the current in the second cell group 7 flows through the second first busbar 10 in the upper left corner to the third cell group 7, and so on. See also Figure 1d and Figure 1e During normal operation of battery module 1, the current flow direction on each first busbar 10 is parallel to the first direction S1 of battery module 1. Therefore, each first busbar 10 is designed to have a sufficiently large cross-sectional area (where the cross-section is perpendicular to the first direction S1) to ensure that the current-carrying capacity of the first busbar 10 during normal operation is sufficient to withstand the current intensity flowing through it during normal operation. Here, "normal operation" means that the corresponding cell 3 has not experienced a failure event, such as thermal runaway.
[0049] The applicant discovered during the thermal diffusion test, see [link / reference] Figure 1hThe schematic circuit diagram shows that when a cell 3 in battery module 1 experiences thermal runaway, the separator inside the cell 3 decomposes and the current collector melts, which may create a resistor 11 with a low resistance value. In this case, other cells 3 connected in parallel with this cell 3 will form a short-circuit loop with this resistor 11 through the first busbar 10, which may lead to an external short circuit in the parallel cells 3. Consequently, the parallel cells 3 may also experience thermal runaway due to the external short circuit, causing a risk of thermal diffusion in the battery pack.
[0050] See you again Figure 1f This example illustrates that when the left cell 3 of the first cell group 7 on the left undergoes thermal runaway, a resistor 11 is formed, and a short-circuit loop is formed between the left cell 3 and the right cell 3 connected in parallel, via the first busbar 10. See also Figure 1g The diagram shows the flow direction of the short-circuit current on the first busbar 10 below (indicated by the red arrow), which remains parallel to the first direction S1 of the battery module 1. The first busbar 10 cannot be melted due to its large current-carrying capacity in this first direction S1, thus failing to provide external short-circuit protection between parallel batteries after thermal runaway. Furthermore, because the current-carrying capacity of the first busbar 10 in this first direction S1 must be guaranteed during normal operation, further specialized external short-circuit protection structure design is not feasible.
[0051] Therefore, in the prior art, the external short circuit caused by thermal runaway of cell 3 will cause heat to spread to cell 3 connected in parallel, which will also cause thermal runaway, resulting in the failure of the entire battery system and the risk of fire and explosion.
[0052] According to national standards, if one cell 3 of battery module 1 experiences thermal runaway, it must not spread to other cells 3.
[0053] Next, combine Figures 2a to 5c An exemplary embodiment of the battery module 1 of this utility model is described below.
[0054] Figures 2a to 2b The battery module 1 according to an embodiment of the present invention is shown schematically. As can be seen, the battery module 1 has a module frame 2 surrounding a rectangular receiving cavity and a plurality of square battery cells 3 arranged in the receiving cavity, these battery cells 3 being arranged in two rows, forming two rectangular cell rows 4. The module frame 2 also includes two opposing end plates 5 and two opposing side plates 6, wherein the two end plates 5 respectively fix the cell rows 4 from both ends in a first direction S1, and the two side plates 6 respectively fix the cell rows 4 from the outside of the two cell rows 4 in a second direction S2. The inner surfaces of the two cell rows 4 face each other and their battery cells 3 abut against each other directly or indirectly.
[0055] Therefore, in this embodiment, each cell 3 of each cell row 4 is arranged sequentially on the first direction S1 of the battery module 1, while two cell rows 4 are arranged sequentially on the second direction S2 of the battery module 1. In other embodiments, three or more cell rows 4 may be arranged sequentially on the second direction S2 of the battery module 1.
[0056] See Figure 3a To meet the energy requirements of the entire vehicle, first connect every two (or more) adjacent cells 3 in each cell bank 4 in parallel to form a cell group 7, and then connect all cell groups 7 in series. For details, see [link to relevant documentation]. Figure 3a In each cell group 7 of each cell stack 4, the cells 3 are arranged such that their positive terminals 8 are side-by-side or on the same side, and their negative terminals 9 are side-by-side or on the same side. In each cell stack 4, the cells 3 of every two adjacent cell groups 7 are arranged such that the terminals 8, 9 of each cell 3 in one cell group 7 are side-by-side with the opposite terminals 9, 8 of each cell 3 in the other cell group 7. In different cell stacks 4, the cells 3 of every two adjacent cell groups 7 are arranged such that the terminals 8, 9 of each cell 3 in one cell group 7 are side-by-side with the opposite terminals 9, 8 of each cell 3 in the other cell group 7.
[0057] See Figure 3b The series and parallel connections between the cells 3 are made through the two outermost rows of first busbars 10 and the middle row of second busbars 12 on the second direction S2 of the battery module 1. That is, the first busbars 10 and second busbars 12 are welded to the corresponding terminals 8 and 9 of the cells 3 to facilitate current transmission between the cells 3. It can be seen that the parallel connections between cells 3 of the same cell group 7 in the same cell row 4, as well as the series connections between cells 3 of adjacent different cell groups 7 in the same cell row 4, are all made through the first busbars 10, which can be designed as in the prior art; while the series connections between cells 3 of adjacent or abutting cell groups 7 in two adjacent cell rows 4 are all made through the second busbars 12. Furthermore, see... Figure 3b The solder joints 20 on the first busbar 10 that are welded to the terminals 8 and 9 of the battery cell 3 are arranged in a linear pattern, while the solder joints 20 on the second busbar 12 that are welded to the terminals 8 and 9 of the battery cell 3 are arranged in a rectangular pattern.
[0058] See also Figure 3a and Figure 3bHere we can see the current flow path between the series-connected cell groups 7 of the two cell rows 4, which generally exhibits a serpentine or meandering pattern. Specifically, firstly, in the second direction S2 of the battery module 1, the current flows from the first cell group 7 on the left side of the upper cell row 4 through the first middle second busbar 12 on the left side to the first cell group 7 on the left side of the lower cell row 4. Then, in the first direction S1 of the battery module 1, the current flows from the first cell group 7 on the left side of the lower cell row 4 through the first lower first busbar 10 on the left side to the second cell group 7 on the left side of the lower cell row 4. Then, in the second direction S2 of the battery module 1, the current flows from the second cell group 7 on the left side of the lower cell row 4 through the second middle second busbar 12 on the left side to the second cell group 7 on the left side of the upper cell row 4, and so on, ultimately forming a serpentine or meandering current flow pattern. In other words, see... Figure 3b The current flow direction on each of the outermost (upper and lower) first busbars 10 is parallel to the first direction S1 of the battery module 1, as in the prior art, while the current flow direction on each of the middle second busbars 12 is parallel to the second direction S2 of the battery module 1. That is, during normal operation, the current flow direction on the first busbars 12 is transverse to, and here perpendicular to, the current flow direction on the first busbars 10. The current flow directions on every two adjacent second busbars 12 are opposite to each other.
[0059] Figure 3c The schematic diagram illustrates the structural design of one embodiment of the second busbar 12. Here, the second busbar 12 may have two opposing rectangular main bodies 121, the longitudinal direction of which is parallel to the second direction S2 of the battery module 1. Each main body 121 has a solder point 20 at each end, and the four solder points 20 on each second busbar 12 are arranged in a rectangular pattern. The left main body 121 is electrically connected by its two solder points 20 to two left-side cells 3 of two adjacent cell groups 7 in the two cell groups 4, connecting these two left-side cells 3 in series. Similarly, the right main body 121 is electrically connected by its two solder points 20 to two right-side cells 3 of the two cell groups 7, connecting these two right-side cells 3 in series. Figure 3c It can also be seen that during the normal operation of the battery cell 3 of the battery module 1, the current flow direction on each main body 121 of the second busbar 12 is as shown by the (blue) arrow, which is parallel to the second direction S2 of the battery module 1. Each main body 121 of the second busbar 12 is designed to have a sufficiently large cross-sectional area (where the cross-section is perpendicular to the second direction S2) to ensure that the current carrying capacity of each main body 121 of the second busbar 12 is sufficient to carry the current intensity flowing through it during normal operation.
[0060] Furthermore, the two main body portions 121 of the second busbar 12 are connected to each other integrally by at least one, shown herein as six, tabs extending transversely to and perpendicularly to the main body portions 121. Each second busbar 12 can be integrally formed and can have a uniform thickness. In the second direction S2 of the battery module 1, the width of each tab 123 and the sum of the widths of all tabs 123 are much smaller than the longitudinal length of the main body portion 121. Therefore, the tabs 123 between adjacent main body portions 121 connect them to each other only in a small local area. Here, the tabs 123 are configured such that when the current flowing through the tab 123 exceeds a predetermined threshold, the tab 123 is melted, thereby realizing the fuse function or short-circuit protection function of the tab 123, which will be mentioned later.
[0061] Combination Figures 4a to 4c This example illustrates the short-circuit protection function of the second bus 12 using its contact 123. As can be seen here, when the left cell 3 in the lower cell group 7 experiences thermal runaway and forms a resistor 11, the parallel right cell 3 forms a short-circuit loop with this resistor 11. See also... Figure 4a and Figure 4b At this time, the short-circuit current (indicated by the red arrow) flows through the contact 123 of the second busbar 12 in the first direction S1 of the battery module 1. The contact 123 heats up and melts due to its narrow width or small cross-sectional area (and therefore small current carrying capacity), thus breaking the short-circuit circuit and acting as a fuse. The second busbar 12 thus has short-circuit protection function by utilizing its contact 123. Figure 4c The diagram schematically illustrates the melting process of the lower three contacts 123 in a computer simulation environment. It can be inferred that the upper three contacts 123 will also melt in the same way, disconnecting the two main body sections 121 and thus disconnecting the cell 3 that experienced thermal runaway and the cell 3 connected in parallel with it. Similarly, when the rightmost cell 3 in the lower cell group 7 experiences thermal runaway, or when one of the cells 3 in the upper cell group 7 experiences thermal runaway, this same second bus 12 provides the same short-circuit protection function. In other words, a second bus 12 can simultaneously provide short-circuit protection for all the cells 3 connected to it, preventing heat diffusion.
[0062] Then use Figure 4d The schematic circuit diagram of this utility model illustrates the short-circuit protection principle of the second bus 12. Figure 4d The left figure shows a cell 3 in battery module 1 experiencing thermal runaway. Figure 4d The middle diagram shows that cell 3, which has undergone thermal runaway, forms a resistor 11 with a small resistance value and thus forms a short circuit loop with cell 3 connected in parallel. Figure 4dThe right figure shows that under the action of short-circuit current, the contact 123 of the second bus 12 is melted and the circuit is broken at this point, thereby cutting off the thermal diffusion from the thermally runaway cell 3 to the parallel cell 3, protecting the parallel cell 3 and the entire battery module 1.
[0063] exist Figure 3c and Figure 4b In the embodiment of the connector 123 shown, six connectors 123 are arranged (or spaced apart) in the longitudinal direction between the two main body portions 121 of the second busbar 12. The arrangement of these connectors 123 allows the two main body portions 121 of the second busbar 12 to have a certain torsional resistance relative to each other, which facilitates the transportation and installation of the second busbar 12.
[0064] Of course, the number and arrangement of the 123 splices are not limited to... Figure 3c The illustrated embodiment. Figures 5a to 5c Other embodiments of the connector 123 are illustrated in the examples below. Among them, in... Figure 5a The number of main body portions 121 is 2, and the number of tabs 123 is 2, with the tabs 123 respectively disposed close to the solder joints 20 of the main body portions 121; Figure 5b The number of main body portions 121 is 2, and the number of connecting pieces 123 is 1, with the single connecting piece 123 positioned at the center of the main body portion 121 in the longitudinal direction. Figure 5c In this configuration, the second busbar 12 has three main sections 121 and six connectors 123 connecting adjacent main sections 121 to each other. This second busbar 12 with three main sections 121 is suitable for a cell group 7 having three parallel cells 3. Similarly, a second busbar 12 with n main sections 121 is suitable for a cell group 7 having n parallel cells 3, where n ≥ 2.
[0065] It can be stipulated here that when one of the battery cells 3 experiences thermal runaway, the current flowing through the contact 123 of the second busbar 12 electrically connected to that battery cell 3 exceeds the predetermined threshold mentioned above. The predetermined threshold can correspond to the current-carrying capacity of the contact 123; that is, the contact 123 is melted when the flowing current exceeds its current-carrying capacity. Therefore, the predetermined threshold is related to the material and cross-sectional area of the contact 123. The cross-sectional area of the contact 123 here mainly refers to the total cross-sectional area of all contacts 123 between adjacent body portions 121. For example, for an aluminum busbar 10, the correspondence between the total cross-sectional area of the contacts 123 between adjacent body portions 121 and the current threshold can be designed as follows: for a short-circuit current threshold of 100A, a 5mm² cross-sectional area can be used. 2The total cross-sectional area of the contact piece 123 is such that when the short-circuit current flowing through the contact piece 123 exceeds 100A, the contact piece 123 will melt; for a short-circuit current threshold of 200A, a 10mm² thickness is designed. 2 The total cross-sectional area of the contact piece, that is, when the short-circuit current flowing through the contact piece 123 is greater than 200A, the contact piece 123 will be melted.
[0066] In summary, the second busbar 12 can meet the current carrying capacity under normal operating conditions through its main body 121, and through the narrow neck structure formed by the tabs 123 between adjacent main bodies 121, it can automatically realize the short circuit protection function or fuse function when any cell 3 experiences thermal runaway, and prevent heat from spreading to the parallel cells 3.
[0067] Alternatively, it can be conceivable that, for example, when the battery module 1 uses three consecutive rows of second busbars 12 in the second direction S2, the middle row of second busbars 12 may not have a contact 123 and therefore does not have a fuse function. Instead, the other two rows of second busbars 12 may have contact 123. This still ensures that the battery cells 3 electrically connected to the middle row of second busbars 12 are each equipped with a second busbar 12 with short-circuit protection. In other words, it is necessary to ensure that each battery cell 3 is equipped with at least one second busbar 12 with a contact 123, or that at least one second busbar 12 electrically connected to each battery cell 3 has a contact 123 to achieve short-circuit protection. In other words, one or two terminals 8, 9 of each battery cell 3 may be electrically connected to one or two second busbars 12 depending on the arrangement of the battery cell 3, wherein at least one second busbar 12 should have a contact 123. This at least one second busbar 12 with a contact 123 can provide short-circuit protection for the battery cell 3.
[0068] The design advantages of the battery module 1 of this utility model include, but are not limited to:
[0069] Compared to existing designs, the battery module 1 with multiple rows of cells 3 can fully utilize the second busbar 12 with a narrow neck (i.e., contact 123). When one cell 3 in the cell pack 7 experiences thermal runaway, the contact 123 of the second busbar 12 can function as a fuse, protecting the other parallel cells 3 in the cell pack 7 from thermal runaway due to external short circuits. This improves the overall safety of the battery system and new energy vehicles when cell 3 experiences thermal runaway.
[0070] Furthermore, when an external short circuit occurs due to thermal runaway of cell 3, the current transmission direction on the second bus 12 changes from that under normal operation (the two are perpendicular to each other). Therefore, the second bus 12 is allowed to be structurally designed to meet the current carrying capacity requirements under normal operation and to have the function of short circuit protection by using a narrow neck design.
[0071] Finally, the cells 3 in the battery module 1 are arranged such that, under normal operation, the current flow in different cell rows of the battery module 1 is generally serpentine or meandering. This is especially true for square cells 3, which can achieve a more compact and space-saving arrangement.
[0072] Finally, it should be noted that the above embodiments are merely for understanding and explaining the present invention, and do not constitute a limitation on the scope of protection of the present invention. Those skilled in the art can make modifications or recombinations based on the above embodiments, and none of these modifications or recombinations depart from the scope of protection of the present invention.
Claims
1. A battery module for an electrically driven vehicle, characterized in that, The battery module (1) includes multiple cell groups (7) connected in series, and each cell group (7) includes at least two cells (3) connected in parallel. The battery module (1) comprises at least two cell rows (4) formed by the cells (3). Each cell row (4) includes multiple cell groups (7) arranged sequentially in a first direction (S1), and the at least two cell rows (4) are arranged sequentially in a second direction (S2) transverse to the first direction (S1). In the second direction (S2), the series connection between adjacent cell groups (7) in the first direction (S1) of each of the two outermost cell rows (4) is achieved through a first busbar (10), and the series connection between adjacent cell groups (7) in the second direction (S2) of different cell rows (4) is achieved through a second busbar (12). During normal operation of the cells (3) of the battery module (1), the direction of current flow through the first busbar (10) is transverse to the direction of current flow through the second busbar (12). At least one of the two second busbars (12) electrically connected to one or two terminals (8, 9) of each cell (3) has at least two body portions (121) and at least one tab (123) connecting adjacent body portions (121) to each other over a portion of their length in the second direction (S2). Each body portion (121) is electrically connected to two adjacent cells (3) of different cell groups (4) in the second direction (S2), and the tab (123) is configured to melt when the current flowing through the tab (123) is greater than a predetermined threshold.
2. The battery module for an electrically driven vehicle according to claim 1, characterized in that, The contact (123) is configured such that when one of the cells (3) experiences thermal runaway, current flows through the contact (123) which is electrically connected to the body portion (121) of the cell (3), and the current is greater than the predetermined threshold.
3. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, The predetermined threshold is related to the material of the patch (123) and / or the cross-sectional area of the patch (123).
4. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, At least two tabs (123) are provided spaced apart in the second direction (S2) between adjacent main body portions (121) of the same second busbar (12).
5. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, At least three rows of second busbars (12) are arranged successively in the second direction (S2), and at least one of the at least three rows of second busbars (12) is not provided with the connector (123).
6. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, The battery module (1) is configured such that, during the normal operation of the battery cell (3) of the battery module (1), the current flows through two adjacent second busbars (12) in the first direction (S1) in opposite directions.
7. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, The battery module (1) is configured such that, during the normal operation of the battery cell (3) of the battery module (1), the current flows successively through the first busbar (10) and the second busbar (12) in a serpentine direction.
8. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, The solder joints (20) on each first bus (10) that are welded to the terminals (8, 9) of the cell (3) are arranged in a linear pattern, while the solder joints (20) on each second bus (12) that are welded to the terminals (8, 9) of the cell (3) are arranged in a rectangular pattern.
9. The battery module for an electrically driven vehicle according to claim 1 or 2, characterized in that, The battery cell (3) is a square battery cell (3).
10. An electrically driven vehicle, characterized in that, The vehicle has a battery module for an electrically driven vehicle according to any one of claims 1 to 9.