Battery pack having double-layer structure, solid-state lithium-ion battery, electric vehicle

Abstract

The present application discloses a battery pack having a double-layer structure, a solid-state lithium-ion battery, and an electric vehicle. The battery pack having a double-layer structure comprises a lower-layer module structure, an upper-layer module structure, modules, same-layer connection copper bars, and cross-layer connection copper bars. The lower-layer module structure is divided, by a middle transverse beam and a middle longitudinal beam, into three regions for placing modules: a first region, a second region, and a third region; the first region is located on one side of the middle transverse beam, and the second region and the third region are located on the other side of the middle transverse beam and are respectively located on two sides of the middle longitudinal beam; the upper-layer module structure is divided, by a side transverse beam, into two regions for placing modules: a fourth region and a fifth region; the connection sequence of the modules in the regions is: the first region, the second region, the fifth region, the third region, and the fourth region; the first region and the second region are connected by using a same-layer connection copper bar; and the second region and the fifth region, the fifth region and the third region, the third region and the fourth region, the fourth region and the first region are all connected by using cross-layer connection copper bars, and the module in the fourth region that is close to a BDU is connected back to the positive electrode of the BDU in the first region by using a cross-layer connection copper bar.

Description

A dual-layer battery pack, solid-state lithium-ion battery, electric vehicle Cross-references to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411021082.8, filed on July 29, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of new energy vehicle battery technology, and in particular to a dual-layer battery pack, a solid-state lithium-ion battery, and an electric vehicle. Background Technology

[0003] To increase the driving range of electric vehicles, most existing electric vehicles use a stacked double-layer module design for their power battery packs. Figure 1 shows the distribution structure of the stacked double-layer modules in the battery pack. From bottom to top, the components are: 1. Lower housing of the battery pack; 2. Lower battery modules and BDU (Battery Disconnect Unit) structure; 3. Support bracket; 4. Liquid cooling plate; 5. Upper battery modules. Single-layer modules are connected by copper busbars, and the upper and lower battery modules also need to be connected by inter-layer copper busbars to form a circuit. Because of the large number of inter-layer copper busbars used, which occupy a significant amount of space, the assembly and disassembly of the stacked double-layer modules become cumbersome and difficult, thus posing safety risks. Summary of the Invention

[0004] To address or partially resolve the technical problem of cumbersome assembly and disassembly of stacked double-layer modules due to the large number and space occupied by interlayer copper busbars, this application provides a double-layer battery pack, solid-state lithium-ion battery, and electric vehicle. It employs a regional module placement method, where modules within each region are connected in series sequentially. The connection order between modules in each region is strictly controlled. By changing the module connection order between regions, the number of interlayer connecting copper busbars is reduced, and their length is significantly shortened. This strictly controls the space occupied by the interlayer connecting copper busbars, ensuring that the assembly and disassembly of the double-layer battery pack are not affected by the number and length of the copper busbars, reducing the difficulty of assembly and disassembly, and thus lowering safety risks.

[0005] To address the aforementioned technical problems, the first aspect of this application discloses a dual-layer battery pack, comprising: a lower module structure, an upper module structure, a module, a same-layer connecting copper busbar, and a cross-layer connecting copper busbar.

[0006] The lower module structure includes a central crossbeam and a central longitudinal beam. The central longitudinal beam connects to the middle of the central crossbeam to form a T-shaped structure, dividing the lower module structure into three areas for placing the modules: a first area, a second area, and a third area. The first area is located on one side of the central crossbeam, and the second and third areas are located on the other side of the central crossbeam and on opposite sides of the central longitudinal beam. A battery pack disconnect unit (BDU) is installed inside the first area, and the negative terminal of the BDU is connected to a module located close to it within the first area.

[0007] The upper module structure is divided into two areas for placing the modules by a side beam: the fourth area and the fifth area.

[0008] The modules within each region are connected in series using the same layer of connecting copper busbars, and the module connection sequence between regions is: the first region, the second region, the fifth region, the third region, and the fourth region;

[0009] Specifically, the first region and the second region are connected by the same-layer connecting copper busbar; the second region and the fifth region, the fifth region and the third region, the third region and the fourth region, and the fourth region and the first region are all connected by the cross-layer connecting copper busbar; the module in the fourth region that is close to the BDU is connected back to the positive terminal of the BDU in the first region by the cross-layer connecting copper busbar.

[0010] Optionally, the single module located in the second region and the single module located in the fifth region connected by the cross-layer connecting copper busbar are mapped to the same position in the vertical direction;

[0011] The cross-layer connecting copper busbar connects a single module located in the fifth region and a single module located in the third region, which are vertically mapped to the same position.

[0012] The cross-layer connecting copper busbar connects a single module located in the third region and a single module located in the fourth region, which are vertically mapped to the same position.

[0013] The modules with the positive and negative terminals of the BDU are mapped to the same position in the vertical direction.

[0014] Optionally, the installation positions of each module in the lower module structure are mapped one-to-one with the installation positions of each module in the upper module structure in the vertical direction.

[0015] Optionally, the dual-layer battery pack further includes: a separate BMS control board and a separate sampling harness;

[0016] The split-type BMS control board includes: a BMS control main board, a first BMS control slave board, and a second BMS control slave board; the BMS control main board and the second BMS control slave board are located on one side of the lower module structure, and the first BMS control slave board is located on the other side of the lower module structure.

[0017] The split-type sampling harness includes: a first set of sampling harnesses and a second set of sampling harnesses;

[0018] The BMS control motherboard and the second BMS control slave board share the first set of sampling harnesses; the first BMS control slave board uses the second set of sampling harnesses.

[0019] Optionally, the first region, the second region, and the fourth region share the first set of sampling harnesses to collect module information; the fifth region and the third region share the second set of sampling harnesses to collect module information.

[0020] Optionally, the BMS control motherboard is connected to the lower sampling harness segment located in the first region and the second region of the first set of sampling harnesses, and is used to collect module information in the first region and the second region;

[0021] The second BMS control slave board connects to the upper sampling harness segment located in the fourth region of the first set of sampling harnesses, and is used to collect information of each module in the fourth region;

[0022] The first BMS control slave board is connected to the upper sampling harness segment located in the fifth region of the second set of sampling harnesses, and to the lower sampling harness segment located in the third region of the second set of sampling harnesses, for collecting module information in the third region and the fifth region respectively.

[0023] Optionally, the BMS control mainboard is connected to the first BMS control slave board, and the first BMS control slave board is connected to the second BMS control slave board.

[0024] Optionally, the first BMS control slave board is mounted in the third region.

[0025] A second aspect of this application discloses a solid-state lithium-ion battery, comprising: a battery pack with a dual-layer structure as described in the first aspect.

[0026] A third aspect of this application discloses an electric vehicle comprising a battery pack with a dual-layer structure as described in the first aspect.

[0027] Through one or more technical solutions of this application, this application has the following beneficial effects or advantages:

[0028] The technical solution of this application reduces the number of cross-layer connecting copper busbars and greatly shortens their length by changing the module connection order between different areas. This strictly controls the space occupied by the cross-layer connecting copper busbars, ensuring that the disassembly and assembly of the double-layer battery pack are not affected by the number and length of the copper busbars, thus reducing the difficulty of disassembly and assembly and reducing safety risks.

[0029] The technical solution of this application reduces the length of the cross-layer copper busbar and optimizes the spatial layout of the wiring harness, making the assembly and disassembly of the double-layer battery pack easier and reducing safety risks. Furthermore, it reduces the wiring pressure on one side of the battery pack, thereby reducing the risk of interference from the battery on one side.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0032] Figure 1 shows the distribution structure of a stacked double-layer module in a prior art battery pack;

[0033] Figure 2 shows a schematic diagram of a double-layer battery pack according to a technical solution of this application;

[0034] Figure 3 shows a schematic diagram of a cross-layer connecting copper busbar connecting two-layer module structures according to a technical solution of this application;

[0035] Figures 4A and 4B show schematic diagrams of the routing layout of the sampling harness in the prior art;

[0036] Figures 5A and 5B show schematic diagrams of the layout of the first set of sampling harnesses according to a technical solution of this application;

[0037] Figures 6A and 6B show schematic diagrams of the layout of a second set of sampling harnesses according to a technical solution of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Lower housing; 2. Lower battery module and BDU structure; 3. Support bracket; 4. Liquid cooling plate; 5. Upper battery module; 6. BMS control board connection harness; 7. High-voltage interlock harness; 8. Upper module sampling harness; 9. Lower module sampling harness; 10. External low-voltage interface; 11. Lower module structure; 12. Upper module structure; 13. Same-layer connecting copper busbar; 14. Cross-layer connecting copper busbar; 15. Middle longitudinal beam; 16. Side cross beam; 17. Liquid cooling plate structure; 18. BMS control main board; 19. First BMS control slave board; 20. Second BMS control slave board; 21. Adapter interface; 22. BDU control harness; 23. Located in the first area 001. The following are sampled data points: 24 (lower sampling harness segment 24 for modules M01-M03), 25 (upper sampling harness segment 25 for modules M16-M22 in the fourth region 004), 26 (lower sampling harness segment 26 for modules M04-M07 in the second region 002), 27 (upper sampling harness segment 27 for modules M08-M11 in the fifth region 005), 28 (lower sampling harness segment 28 for modules M12-M15 in the third region 003), first region 001, second region 002, third region 003, fourth region 004, and fifth region 005. Detailed Implementation

[0040] Exemplary technical solutions of this application will now be described in more detail with reference to the accompanying drawings. While exemplary technical solutions of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the technical solutions set forth herein. Rather, these technical solutions are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0041] In the first aspect, as shown in Figure 2, the technical solution of this application provides a schematic diagram of a double-layer battery pack, which mainly includes: a lower module structure 11, an upper module structure 12, a module, a same-layer connecting copper busbar 13, and a cross-layer connecting copper busbar 14.

[0042] The lower module structure 11 is a box structure used to load modules.

[0043] The upper module structure 12 includes a support bracket structure and a liquid cooling plate structure 18. The support bracket provides support, and the liquid cooling plate structure 18 has several holes for various copper busbars connecting the module and various wire harnesses used to collect module information to pass through, such as the high-voltage interlock wire harness 7, the BDU control wire harness 23, the sampling wire harness, etc.

[0044] Copper busbars are primarily used for conducting high currents and transmitting power, playing a crucial role, especially in series connections between battery modules. Wiring harnesses are mainly responsible for transmitting information; for example, sampling harnesses are used to transmit communication signals and sensor signals from the battery management system, as well as to collect module information.

[0045] For ease of reference, Figure 2 shows the lower module structure 11 and the upper module structure 12 in a two-dimensional plane, excluding the support bracket structure and the liquid cooling plate structure 18, which can be seen in Figures 5A and 5B. Figure 2 shows the same-layer connecting copper busbar 13 and the cross-layer connecting copper busbar 14. In the actual three-dimensional spatial structure, the upper module structure 12 is translated above the lower module structure 11 according to the direction of the arrow. At this time, the installation positions of each module in the lower module structure 11 are mapped one-to-one with the installation positions of each module in the upper module structure 12 in the vertical direction.

[0046] Multiple modules are installed in both the lower module structure 11 and the upper module structure 12. The number of modules is not limited in this application and can be designed according to actual conditions. Taking Figure 2 as an example, 22 modules are installed, numbered M01 to M22 respectively. The following uses the mapping of module installation positions to illustrate the process. In the three-dimensional spatial structure, modules M01 to M03 overlap vertically with modules M22 to M20. Overlapping means that they are mapped to the same position in the vertical direction; that is, modules M01 and M22 are mapped to the same position in the vertical direction, modules M02 and M21 are mapped to the same position in the vertical direction, and modules M03 and M20 are mapped to the same position in the vertical direction. Similarly, modules M04 and M19 overlap vertically, modules M05 and M18 overlap vertically, modules M14 and M17 overlap vertically, modules M15 and M16 overlap vertically, modules M07 and M08 overlap vertically, modules M06 and M09 overlap vertically, modules M13 and M10 overlap vertically, and modules M12 and M11 overlap vertically.

[0047] The lower module structure 11 includes a central crossbeam 15 and a central longitudinal beam 16. The central longitudinal beam 16 connects to the middle of the central crossbeam 15 to form a T-shaped structure, dividing the lower module structure 11 into three areas for placing modules: a first area 001, a second area 002, and a third area 003. The first area 001 is located on one side of the central crossbeam 15, while the second area 002 and the third area 003 are located on the other side of the central crossbeam 15 and on either side of the central longitudinal beam 16, respectively. A battery pack disconnect unit (BDU) is installed inside the first area 001, and the negative terminal of the BDU is connected to a module located close to it within the first area 001.

[0048] In the upper module structure 12, a side beam 17 is provided, which is arranged in parallel with the middle beam 15. The upper module structure 12 is divided into two areas for placing modules by the side beam 17: the fourth area 004 and the fifth area 005.

[0049] Given the requirement for sequential series connection of modules, modules within each region are connected in series using copper busbars 13 on the same layer (as shown in Figure 2). Considering that in practical applications, the gaps between the middle section of the crossbeam 15 and the entire longitudinal beam 16 and the liquid cooling plate structure 18 in the upper module structure 12 are very small, preventing copper busbars from passing through, a module series connection scheme that avoids copper busbars passing through the middle section of the crossbeam 15 and the entire longitudinal beam 16 needs to be designed. Therefore, in the technical solution of this application, the module connection sequence between regions is designed as follows: first region 001, second region 002, fifth region 005, third region 003, and fourth region 004.

[0050] The module numbers in regions 001, 002, 005, 003, and 004 increase progressively. The smallest module number in region 002 is greater than the largest module number in region 001 and they are adjacent; the smallest module number in region 005 is greater than the largest module number in region 002 and they are adjacent; the smallest module number in region 003 is greater than the largest module number in region 005 and they are adjacent; and the smallest module number in region 004 is greater than the largest module number in region 003 and they are adjacent. The smallest-numbered module in region 001 is connected to the negative terminal of the BDU, and the largest-numbered module in region 004 is connected to the positive terminal of the BDU.

[0051] The module number for area 001 is: ;in, And it is a positive integer.

[0052] The module number for area 002 is: ;in, And it is a positive integer. and The number of intervals between them is uncertain.

[0053] The module number for area 005 is: ;in, And it is a positive integer. and The number of intervals between them is uncertain.

[0054] The module number for area 003 is: ;in, And it is a positive integer. and The number of intervals between them is uncertain.

[0055] The module number for area 004 is: ;in, And it is a positive integer. and The number of intervals between them is uncertain.

[0056] The following explanation uses Figure 2 as an example.

[0057] The first region 001 is located on one side of the central crossbeam 15 and is used to place modules M01 to M03. The second region 002 and the third region 003 are located on both sides of the central longitudinal beam 16 and are both on the same side of the central crossbeam 15. The second region 002 is used to place modules M04 to M07, the fifth region 005 is used to place modules M08 to M11, the third region 003 is used to place modules M012 to M15, and the fourth region 004 is used to place modules M016 to M22. Furthermore, a BDU is installed inside the first region 001. The negative terminal (main negative) of the BDU is connected to the module M01 located nearby within the first region 001. The positive terminal (main positive) of the BDU is connected to the module M22 located nearby within the fourth region 004.

[0058] In the series connection scheme of each module, the modules within each region are connected in series using copper busbars 13 on the same layer. In the lower module structure 11, the first region 001 and the second region 002 are connected by copper busbars 13 on the same layer. Considering that the middle part of the middle beam 15 is not allowed to pass through, the copper busbars 13 on the same layer pass through the edge of the middle beam 15.

[0059] The second region 002 and the fifth region 005, the fifth region 005 and the third region 003, the third region 003 and the fourth region 004, and the fourth region 004 and the first region 001 are all connected by cross-layer connecting copper busbars 14. The modules in the fourth region 004 that are close to the BDU are connected back to the positive terminal of the BDU in the first region 001 by cross-layer connecting copper busbars 14.

[0060] Specifically, because the central longitudinal beam 16 cannot pass through, the second region 002 needs to connect to the fifth region 005 in the upper module structure 12, and then from the fifth region 005 to the third region 003. This requires two cross-layer connecting copper busbars 14, connecting modules M07~M08 and M11~M12 respectively. Furthermore, because the positive terminal (main positive) of the BDU is located inwards, due to the presence of the central cross beam 15, the copper busbar connecting to the positive terminal of the BDU cannot originate from the third region 003. Therefore, the fourth region 004 in the upper module structure 12 uses cross-layer connecting copper busbars 14 to connect to the positive terminal of the BDU, i.e., module M22-BDU. At this time, the third region 003 needs to connect to the fourth region 004 in the upper module structure 12 via cross-layer connecting copper busbars 14, i.e., modules M15~M16. Therefore, it can be seen that the dual-layer battery pack of this technical solution actually uses only four cross-layer connecting copper busbars 14, keeping the number of cross-layer connecting copper busbars 14 to a minimum.

[0061] When the upper module structure 12 is located above the lower module structure 11, the single module located in the second region 002 connected by the cross-layer connecting copper busbar 14 and the single module located in the fifth region 005 connected by the cross-layer connecting copper busbar 14 are vertically mapped to the same position. Taking Figures 2 and 3 as examples, Figure 3 is a schematic diagram of the cross-layer connecting copper busbar 14 connecting two module structures. Among them, modules M07 to M08 are vertically mapped to the same position. At this time, the length of the cross-layer connecting copper busbar 14 connecting modules M07 to M08 is equal to the vertical distance between the upper module structure 12 and the lower module structure 11, and the length of the cross-layer connecting copper busbar 14 can be controlled to a minimum.

[0062] When the upper module structure 12 is located above the lower module structure 11, the single module located in the fifth region 005 connected by the cross-layer connecting copper busbar 14 and the single module located in the third region 003 connected by the cross-layer connecting copper busbar 14 are vertically mapped to the same position. For example, modules M11 to M12 are vertically mapped to the same position. At this time, the length of the cross-layer connecting copper busbar 14 connecting modules M11 to M12 is equal to the vertical distance between the upper module structure 12 and the lower module structure 11, and the length of the cross-layer connecting copper busbar 14 can be controlled to a minimum.

[0063] When the upper module structure 12 is located above the lower module structure 11, the single module located in the third region 003 connected by the cross-layer connecting copper busbar 14 and the single module located in the fourth region 004 connected by the cross-layer connecting copper busbar 14 are vertically mapped to the same position. For example, modules M15 to M16 are vertically mapped to the same position. At this time, the length of the cross-layer connecting copper busbar 14 connecting modules M15 to M16 is equal to the vertical distance between the upper module structure 12 and the lower module structure 11, and the length of the cross-layer connecting copper busbar 14 can be controlled to a minimum.

[0064] When the upper module structure 12 is located above the lower module structure 11, the modules connected to the positive and negative terminals of the BDU are vertically mapped to the same position. That is, the single module located in the fourth region 004 and the single module located in the first region 001 connected by the cross-layer connecting copper busbar 14 are vertically mapped to the same position. For example, modules M01 to M22 are vertically mapped to the same position, and the length of the cross-layer connecting copper busbar 14 connecting module M22 to the BDU can be minimized.

[0065] As can be seen, the length of each cross-layer connecting copper busbar 14 in this technical solution is minimized, and most of the cross-layer connecting copper busbars 14 in this technical solution are oriented in the same direction. Therefore, the battery pack assembly difficulty of this technical solution is lower than that of the prior art.

[0066] In existing technology, referring to Figure 1, after the lower battery module and BDU, one end of the interlayer copper busbar connected to the lower module is bolted, while the other end is left suspended. Then, upper components such as the support bracket 3 and liquid cooling plate 4 are installed vertically downwards, allowing the interlayer copper busbar to pass through the support bracket 3 and liquid cooling plate 4 before finally connecting to the upper module. Taking the installation of the liquid cooling plate 4 as an example, because the orientation of the interlayer copper busbars in existing technologies varies, and the liquid cooling plate 4 is generally installed vertically downwards, when the interlayer copper busbar passes through the liquid cooling plate 4, due to its varying orientation, it is prone to rubbing against the liquid cooling plate 4, damaging the insulation layer of the copper busbar and potentially causing high-voltage short circuits.

[0067] In this technical solution, since three of the four interlayer connecting copper busbars 14 are installed in the same vertical direction, when the liquid cooling plate structure 18 is installed vertically downwards, the three interlayer copper busbars can pass through the liquid cooling plate structure 18 together without rubbing against it or being damaged. The remaining interlayer connecting copper busbar 14 simply needs to find a suitable angle to pass through the liquid cooling plate structure 18. The interlayer connecting copper busbars 14 in this technical solution are very easy to install and remove, the probability of installation accidents is low, and there is no risk of high-voltage short circuits, thus ensuring the safety of the battery pack.

[0068] In existing technologies, due to the large number of modules and sampling lines contained in a double-layer battery pack, and the fact that the BMS control board needs to collect module information in a sequence from total negative to total positive, existing technologies use a single sampling harness to sample both the upper and lower layers of modules. Figures 4A and 4B show the wiring layout of the sampling harness in the existing technology. This includes: BMS control board connection harness 6, high-voltage interlock harness 7, upper-layer module sampling harness 8, lower-layer module sampling harness 9, external low-voltage interface 10, and BDU control harness 22. In the existing technology, each harness is routed around the liquid cooling plate 4, with the liquid cooling plate 4 nested in the middle. Since the BMS control board of this sampling harness is concentrated on one side of the liquid cooling plate 4 (one side of the lower housing of the existing battery pack), and this side also integrates high-voltage connectors, fast-charging connectors, and some copper busbars for connecting to the vehicle's electrical equipment, the space pressure for wiring on one side of the battery pack housing is relatively large, and the harness is more susceptible to electromagnetic interference.

[0069] To address this issue, the technical solution of this application employs a split BMS control board combined with a split sampling harness design. This allows the sampling harness to follow the BMS control board and be arranged on both sides of the lower module structure 11, alleviating the tight layout on one side of the lower module structure 11. Furthermore, the cross-layer connecting copper busbar 14 in this application's technical solution uses a vertical connection design between the two modules, which also avoids the copper busbar running on only one side of the lower module structure 11, further relieving the pressure of routing on one side of the lower module structure 11.

[0070] The split-type BMS control board includes: a BMS control main board 19, a first BMS control slave board 20, and a second BMS control slave board 21. The BMS control main board 19 and the second BMS control slave board 21 are located on one side of the lower module structure 11, while the first BMS control slave board 20 is located on the other side. Since the voltage signal of a module is determined by the voltage difference between the preceding and following modules, the module acquisition sequence is fixed. In this technical solution, the module acquisition sequence is: first region 001, second region 002, fifth region 005, third region 003, and fourth region 004. Based on this, the acquisition sequence of the BMS control board is: BMS control main board 19, first BMS control slave board 20, and second BMS control slave board 21. Therefore, the connection sequence of the three BMS control boards is: BMS control main board 19 is connected to the first BMS control slave board 20, and the first BMS control slave board 20 is connected to the second BMS control slave board 21. The connection method can be achieved using adapter 22, but this is not a limitation. It is worth noting that although the BMS control motherboard 19 and the second BMS control slave board 21 are located on the same side of the lower module structure 11, they cannot be replaced by the same BMS integrated board. Instead, a separate design must be adopted to avoid causing confusion in the data acquisition sequence.

[0071] To accommodate the design of a split-type BMS control board, the technical solution of this application also includes a split-type sampling harness, which comprises a first set of sampling harnesses and a second set of sampling harnesses.

[0072] The BMS control motherboard 19 and the second BMS control slave board 21 share the first set of sampling harnesses; the first BMS control slave board 20 uses the second set of sampling harnesses.

[0073] When dividing the data into regions, Region 1 (001), Region 2 (002), and Region 4 (004) share the first set of sampling harnesses to collect module information. Specifically, the first set of sampling harnesses includes three sampling harness segments: the lower sampling harness segment of Region 1 (001), the lower sampling harness segment of Region 2 (002), and the upper sampling harness segment of Region 4 (004). Region 5 (005) and Region 3 (003) share the second set of sampling harnesses to collect module information. Specifically, the second set of sampling harnesses includes two sampling harness segments: the upper sampling harness segment of Region 5 (005) and the lower sampling harness segment of Region 3 (003).

[0074] Furthermore, the BMS control motherboard 19 connects to the lower sampling harness segments located in the first region 001 and the second region 002 of the first set of sampling harnesses, for collecting module information in the first region 001 and the second region 002. Taking Figure 2 as an example, since the information of each module needs to be collected sequentially from the main negative (the first cell of module M01) to the main positive (the last cell of module M22), the BMS control motherboard 19 collects module information from modules M01 to M07. Specifically, the BMS control motherboard 19 connects to the lower sampling harness segments of modules M01 to M03, and the lower sampling harness segments of modules M04 to M07 in the first set of sampling harnesses.

[0075] The second BMS control board 21 connects to the upper sampling harness segment located in the fourth region 004 of the first set of sampling harnesses, and is used to collect information from each module in the fourth region 004. Taking Figure 2 as an example, the second BMS control board connects to the upper sampling harness segment of modules M16 to M22 in the first set of sampling harnesses, and is used to collect information from modules M16 to M22.

[0076] The first BMS control slave board 20 connects to the upper sampling harness segment located in the fifth region 005 of the second set of sampling harnesses, and also connects to the lower sampling harness segment located in the third region 003 of the second set of sampling harnesses, for collecting module information in the third region 003 and the fifth region 005 respectively. Taking Figure 2 as an example, the first BMS slave board collects module information for modules M08 to M15. Specifically, the first BMS control slave board 20 connects to the upper sampling harness segments of modules M08 to M11 in the second set of sampling harnesses, and also connects to the lower sampling harness segments of modules M12 to M15 in the second set of sampling harnesses. It is worth noting that the first BMS control slave board 20 is installed in the third region 003; therefore, the lower harness segment used for sampling modules M12 to M15 in the third region 003 is relatively short.

[0077] For ease of explanation and interpretation of the invention, please refer to Figures 5A and 5B, which are schematic diagrams of the layout of the first set of sampling harnesses. The layout reference is the liquid-cooled plate structure 18. It includes: an external low-voltage interface 10, a high-voltage interlock harness 7, a BDU control harness 23, a lower sampling harness segment 24 located in the first region 001 for collecting data from modules M01 to M03, an upper sampling harness segment 25 located in the fourth region 004 for collecting data from modules M16 to M22, and a lower sampling harness segment 26 located in the second region 002 for collecting data from modules M04 to M07.

[0078] The lower sampling harness segment 24 in the first region 001 and the lower sampling harness segment 26 in the second region 002 are both located below the liquid-cooled plate structure 18. The lower sampling harness segment 24 in the first region 001 is located at the edge of the first region 001 and is wrapped together with the BDU control harness 23. The lower sampling harness segment 26 in the second region 002 is located at the edge beam mapping position of the second region 002.

[0079] The upper sampling harness segment 25 in the first set of sampling harnesses, located in the fourth region 004, is positioned at the middle crossbeam mapping position above the liquid-cooled plate structure 18.

[0080] By placing more of the sampling section wiring harness inside the liquid cooling plate structure 18 rather than at the edge, it is possible to minimize the wiring harness routing on the side of the lower module structure 11, thereby alleviating the pressure of side routing and reducing the risk of electromagnetic interference.

[0081] Referring to Figures 6A and 6B, the layout of the second set of sampling harnesses is shown, with the liquid cooling plate structure 18 as the reference. The fifth region 005 and the third region 003 share the second set of sampling harnesses to collect module information. The second set of sampling harnesses includes: an upper sampling harness segment 27 located in the fifth region 005 for collecting data from modules M08 to M11, and a lower sampling harness segment 28 located in the third region 003 for collecting data from modules M12 to M15.

[0082] The upper sampling harness segment 27 of the fifth region 005 is located above the liquid-cooled plate structure 18 and at the mapping position of the side beam in the liquid-cooled plate structure 18. The lower sampling harness segment 28 of the third region 003 is located below the liquid-cooled plate structure 18 and at the mapping position of the side beam in the liquid-cooled plate structure 18. It can be seen that the second set of sampling harnesses are all located inside the liquid-cooled plate structure 18 rather than at the edge, which can alleviate the pressure on the side wiring of the lower module structure 11 and reduce the risk of electromagnetic interference.

[0083] A comparison of the technical solution of this application with the prior art reveals the following:

[0084] The existing technology uses wiring harnesses on one side of the battery pack enclosure, which include not only high-voltage interlock wiring harnesses for external interfaces such as the rear motor and BDU control wiring harness 23, but also sampling wiring harnesses for eight modules in the third area 003 and the fifth area 005. The combined wire diameter is large, resulting in large wiring on one side of the enclosure, which is susceptible to electromagnetic interference. Excessive wiring can also easily cause tangling and rubbing at the rear corner of the enclosure.

[0085] In this technical solution, both the BMS control board and the wiring harness adopt a split design. The split BMS control board is placed on both sides of the lower module structure 11, dividing the total sampling wiring harness into two sets. The module sampling wiring harness segments of the third region 003 and the fifth region 005 are placed on the opposite side of the lower module structure 11 along with the first BMS control slave board 20, changing the sampling wiring harness from the existing closed, encircling type to a semi-open type. By reducing the sampling wiring harness on one side of the lower module structure 11, the wire diameter of the wiring harness is reduced, decreasing the risk of electromagnetic interference to the wiring harness and reducing the probability of tangling and rubbing at the rear corner of the enclosure.

[0086] Secondly, based on the same inventive concept as the dual-layer battery pack provided in the first aspect of the technical solution, this application also provides a solid-state lithium-ion battery, including: a dual-layer battery pack as described in the first aspect.

[0087] It should be noted that the specific operation method of the solid-state lithium-ion battery provided in this application has been described in detail in the technical solution provided in the first aspect above. The specific implementation process can be referred to the technical solution provided in the first aspect above, and will not be described in detail here.

[0088] Thirdly, based on the same inventive concept as the double-layer battery pack provided in the first aspect of the technical solution, this application also provides an electric vehicle, including: a double-layer battery pack as described in the first aspect.

[0089] It should be noted that the specific method of operation of the electric vehicle provided by the technical solution of this application has been described in detail in the technical solution provided in the first aspect above. The specific implementation process can be referred to the technical solution provided in the first aspect above, and will not be described in detail here.

[0090] Although preferred technical solutions have been described in this application, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these technical solutions. Therefore, the appended claims are intended to be interpreted as including the preferred technical solutions as well as all changes and modifications falling within the scope of this application.

[0091] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A battery pack with a double-layer structure, characterized in that, The application relates to a double-layer battery pack structure. The lower-layer module structure comprises a middle cross beam and a middle longitudinal beam; the middle longitudinal beam is connected to the middle of the middle cross beam to form a T-shaped structure, so that the lower-layer module structure is divided into three areas for placing modules, namely a first area, a second area and a third area; the first area is located on one side of the middle cross beam, and the second area and the third area are located on the other side of the middle cross beam and on two sides of the middle longitudinal beam respectively; a battery pack disconnecting unit (BDU) is arranged in the first area; the BDU negative pole is connected to the module close to the position of the BDU in the first area. The upper-layer module structure is divided into two areas for placing modules, namely a fourth area and a fifth area, by a side cross beam. The modules in each area are connected in series by the same-layer connecting copper bars; the connection sequence of the modules between areas is as follows: the first area, the second area, the fifth area, the third area, the fourth area. The first area and the second area are connected by the same-layer connecting copper bars; the second area and the fifth area, the fifth area and the third area, the third area and the fourth area and the fourth area and the first area are connected by the cross-layer connecting copper bars; the module close to the position of the BDU in the fourth area is connected to the BDU positive pole in the first area by the cross-layer connecting copper bars. The single module in the second area connected by the cross-layer connecting copper bars and the single module in the fifth area are mapped to the same position in the vertical direction.

2. The battery pack of claim 1, wherein, The single module in the fifth area connected by the cross-layer connecting copper bars and the single module in the third area are mapped to the same position in the vertical direction. The single module in the third area connected by the cross-layer connecting copper bars and the single module in the fourth area are mapped to the same position in the vertical direction. The modules connected by the BDU positive and negative poles are mapped to the same position in the vertical direction. The module mounting positions in the lower-layer module structure are one-to-one mapped to the module mounting positions in the upper-layer module structure in the vertical direction.

3. The battery pack of claim 1 or 2, wherein The double-layer battery pack further comprises a split BMS control board and a split sampling harness.

4. The battery pack of claim 1, wherein, The split BMS control board comprises a BMS control main board, a first BMS control slave board and a second BMS control slave board; the BMS control main board and the second BMS control slave board are located on one side of the lower-layer module structure, and the first BMS control slave board is located on the other side of the lower-layer module structure. The split sampling harness comprises a first set of sampling harnesses and a second set of sampling harnesses. The BMS control main board and the second BMS control slave board use the first set of sampling harnesses; the first BMS control slave board uses the second set of sampling harnesses. ​ 5. The battery pack of claim 4, wherein the first and second layers are formed from a material selected from the group consisting of: aluminum, steel, and a combination thereof. The first region, the second region and the fourth region jointly use the first set of sampling harnesses to collect module information; and the fifth region and the third region jointly use the second set of sampling harnesses to collect module information.

6. The battery pack of claim 4 or 5, wherein, The BMS control main board is connected with lower sampling harness segments in the first set of sampling harnesses located in the first region and the second region, and is used to collect module information of the first region and the second region. The second BMS control slave board is connected with upper sampling harness segments in the first set of sampling harnesses located in the fourth region, and is used to collect module information of the fourth region. The first BMS control slave board is connected with upper sampling harness segments in the second set of sampling harnesses located in the fifth region, and is connected with lower sampling harness segments in the second set of sampling harnesses located in the third region, and is used to collect module information of the third region and the fifth region respectively.

7. The battery pack of claim 4, wherein the first and second layers are formed of a material selected from the group consisting of aluminum, steel, and a combination thereof. The BMS control main board is connected with the first BMS control slave board, and the first BMS control slave board is connected with the second BMS control slave board.

8. The battery pack of claim 4, wherein, The first BMS control slave board is installed in the third region.

9. A solid-state lithium-ion battery, characterized by The battery pack of claim 1-8. The battery pack of claim 1-8.

10. An electric vehicle, characterized by The battery pack of claim 1-8. ​

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