WO2024031996A1

WO2024031996A1 - Module of battery cell stacks connected in series by means of tabs

Info

Publication number: WO2024031996A1
Application number: PCT/CN2023/083338
Authority: WO
Inventors: 张志远; 杨丹; 刘浩; 李世敬
Original assignee: 合肥国轩高科动力能源有限公司
Priority date: 2022-08-09
Filing date: 2023-03-23
Publication date: 2024-02-15
Also published as: CN115377622A

Abstract

The present invention relates to a module of battery cell stacks connected in series by means of tabs. The module comprises battery cell stacks, a middle sampling connection assembly and a shell, wherein at least one battery cell is provided in each battery cell stack, tabs are provided at two ends of the battery cell, and there are at least two battery cell stacks; the middle sampling connection assembly is arranged between two battery cell stacks and is connected to a tab on one side of each of the two battery cell stacks, such that battery cells corresponding to each other in adjacent battery cell stacks are connected in series, and thus all battery cell stacks form a battery cell group; and the shell is arranged outside the battery cell group. In the present module, a plurality of battery cell stacks are connected in series by means of tabs to form a battery cell group, such that the integration efficiency of the module is improved, thereby improving the energy density of a system and improving the endurance capability of the system.

Description

A battery core stack and lug series module

Technical field

The present invention relates to the field of battery technology, and in particular to a series module of battery core stacks and tabs.

Background technique

The endurance of electric vehicles is an important indicator of electric vehicles, so it is necessary to increase the energy density of the battery system within the limited vehicle space. Improving the energy density of the battery system can be achieved by increasing the energy density of the battery cells, improving the integration efficiency of the module, and improving the integration efficiency of the system.

Among the above three paths, the energy density of the battery core is limited by the characteristics of the material itself, and improvement requires a long period of research and development verification. Blindly increasing the energy density of the battery core will inevitably bring huge challenges to the thermal safety protection of the battery system. The integration efficiency of the system is limited by issues such as process, manufacturing capabilities, and technical barriers, resulting in difficult transformation and high investment costs. Therefore, how to improve the integration efficiency of high-energy-density and safe soft-packed batteries at the module level and thereby increase the module energy density has become an effective way to increase system energy density and improve system endurance.

Existing high integration efficiency (energy density) modules are only based on high energy density cell design and do not involve high integration efficiency design. For example, a high energy density ternary lithium battery module, the means to improve energy density are only based on high energy density. Ternary lithium batteries do not involve the specific design of the module end to improve integration efficiency and thus increase the energy density of the module. For example, a high-energy-density battery module does not involve specific means of achieving high energy density.

Therefore, there is an urgent need to develop a high-energy-density module that can be based on the existing high-energy-density ternary battery cell and improve the integration efficiency at the design end, thereby increasing the system energy density and improving the system endurance.

Contents of the invention

In response to the above problems, the purpose of the present invention is to provide a series module of battery core stacks and tabs, which connects multiple battery core stacks in series to form a battery core group. By improving the module integration efficiency, a high energy density module can be obtained, thereby improving the system efficiency. Energy density improves system endurance.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A battery core stack and lug series module, including:

A battery core stack is provided with at least one battery core, poles are provided at both ends of the battery core, and the number of the battery core stack is at least two;

The middle sampling connection component is disposed between the two battery core stacks and connected to the tabs on both sides thereof, so that the corresponding battery cores in the adjacent battery core stacks are connected in series, so that all the batteries The core stack forms a battery core group;

A casing is provided outside the battery core group.

Preferably, the housing includes:

Side plates are provided on both sides of all the battery packs;

End plates are provided at both ends of the battery core group and connected to the side plates;

A bottom plate is provided on the bottom surface of the battery core group and connected to the side plate;

The top plate is arranged on the top surface of the battery core group and connected with the side plate.

Preferably, the middle sampling connection assembly includes a base and a U-shaped conductive row. A plurality of grooves are provided on the base. The lower parts of the U-shaped conductive row are inserted into the grooves, and the adjacent conductive rows are inserted into the grooves. The tabs of the core stack are connected through the U-shaped conductive row; the base is arranged on the bottom plate.

Preferably, the bottom of the base is provided with ribs, the bottom plate is provided with a limiting groove, and the ribs are inserted into the limiting groove.

Preferably, the middle sampling connection assembly further includes a middle sampling nickel piece, and the middle sampling nickel piece is connected to the top of the U-shaped conductive row through a locking screw.

Preferably, it includes an end sampling component disposed between the end plate and the battery core group.

Preferably, the end sampling assembly includes an end sampling nickel piece, a bus bar and a low-voltage interface, the end sampling nickel piece is connected to the bus bar, and the end sampling nickel piece collects signals through an end flexible and the transmission component is connected to the low-voltage interface; the low-voltage interface is electrically connected to the middle sampling nickel piece through the middle signal transmission flexible component.

Preferably, the extended end of the end flexible signal collection and transmission component is provided with a temperature sensor, and the temperature collected by the temperature sensor is transmitted to the low-pressure interface.

Preferably, the temperature sensor contact is provided at the bottom of the battery core group.

Preferably, the top plate is a liquid cooling plate with a liquid flow channel inside.

Since the present invention adopts the above technical solutions, it has the following advantages:

1. The battery core stack and tabs series module of the present invention connects multiple battery core stacks in series through tabs to form a battery core group, which improves the module integration efficiency, thereby increasing the system energy density and improving the system endurance.

2. The cell stack and lug series module of the present invention can flexibly adjust the number of series cells according to the system space and energy density requirements to meet the needs of different energy densities.

3. The battery core stack lug series module of the present invention integrates liquid cooling. Compared with the overall liquid cooling design at the system level, it can provide more efficient and uniform heat dissipation for each battery core and further reduce the battery core temperature difference.

4. The cell stack lug series module of the present invention can sample the cell voltage and temperature to prevent the cell group from being in a non-monitoring or invalid monitoring state, timely and accurately input abnormal signals to the battery management system, and improve the safety performance of the system. .

5. The battery core stack lug series module of the present invention adopts snap-on plastic end plates, which further reduces the weight of the module, increases the energy density of the module while reducing material costs, and reduces the difficulty of assembly industry compared with conventional welding.

Description of drawings

Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. It will become clear to technicians. The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the invention. Throughout the drawings, the same reference numbers refer to the same parts. In the attached picture:

Figure 1 is a schematic exploded structural diagram of a series module of battery core stacks and tabs according to an embodiment of the present invention;

Figure 2 is a schematic diagram of the overall structure of this embodiment of the present invention;

Figure 3 is a schematic diagram of the connection between battery core stacks in this embodiment of the present invention;

Figure 4 is a partially enlarged schematic diagram of the flange buckle structure of this embodiment of the present invention;

Figure 5 is a partially enlarged schematic diagram of the snap-in structure of this embodiment of the present invention;

Figure 6 is a schematic diagram of the flange buckle and buckle matching according to this embodiment of the present invention;

Figure 7 is a schematic diagram of the exploded structure of the middle sampling connection assembly in this embodiment of the present invention;

Figure 8 is an enlarged schematic diagram of the structure of the end sampling component of this embodiment of the present invention;

Figure 9 is a schematic structural diagram of the end sampling assembly from another perspective according to this embodiment of the present invention.

The symbols in the drawings are as follows:
1 is the battery core stack, 101 is the pole lug, 102 is the battery core, 2 is the side plate, 201 is the snap connection, 202 is the fixed lug, 3
is the end plate, 301 is the flange buckle, 4 is the bottom plate, 401 is the limit groove, 5 is the base, 501 is the groove, 502 is the separation rib, 503 is the rib rib, 6 is the U-shaped conductive bar, 7 is the middle part Sampling nickel piece, 8 is the locking screw, 9 is the middle signal transmission flexible component, 10 is the low-voltage interface, 11 is the end sampling nickel piece, 12 is the bus bar, 13 is the end flexible signal collection and transmission component, 14 is the temperature For the sensor, 15 is the top plate and 16 is the epoxy plate.

Detailed ways

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a thorough understanding of the invention, and to fully convey the scope of the invention to those skilled in the art.

The battery core stack lug series module provided by the present invention improves the integration efficiency by connecting multiple battery cells in series to form a battery core group, thereby obtaining a high energy density module, thereby increasing the system energy density and improving the system endurance.

Below, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example

As shown in Figures 1, 2 and 7, the cell stack lug series module provided in this embodiment includes a cell stack 1, a middle sampling connection component, and a casing. The cell stack 1 is provided with at least one cell The battery core 102 is provided with tabs 101 at both ends of the battery core 102. The number of the battery core stack 1 is at least two. In this embodiment, two batteries are used as an example. The middle sampling connection component is arranged between the two battery core stacks 1 and is connected to the tabs 101 on both sides of the battery core stack 1, so that the corresponding battery cores 102 in the adjacent battery core stacks 1 are connected in series, so that all the battery core stacks 1 Form a battery cell group to achieve the transformation from "small battery cells" to "large battery cells". The number of battery core stacks 1 in the battery cell group can be adjusted according to specific system requirements. A casing is provided outside the battery core group, and includes a side plate 2 , an end plate 3 , a bottom plate 4 and a top plate 15 .

In specific applications, as shown in Figure 1 and Figure 3, the battery core stack 1 can be one battery core 102 or a soft-packed battery core of multiple battery cores 102. As the different battery cores in the leftmost battery core stack 1 The tabs 101 on the side of the battery core 102 close to the end plate 3 are connected in series and parallel through the bus bar 12. In Figure 3, three battery cores 102 are connected in parallel. With reference to Figure 7, the battery core stack 1 can be connected through U The U-shaped conductive bar 6 connects each other's tabs 101 together, that is, the corresponding cells 102 in the two cell stacks 1 connect each other's tabs 101 in series through the U-shaped conductive bar 6 . Correspondingly, different battery cores 102 in the rightmost battery core stack 1 are connected in series and parallel in the same way, that is, the tabs 101 close to the end plate 3 side are connected in series and parallel through the busbar 12 . Finally, all battery core stacks are connected in series and parallel and then assembled into modules. The tab 101 and the U-shaped conductive bar 6 can be connected by welding, and the welded battery core group can be used as a "large battery core" to avoid promotion limitations caused by the complexity of the large battery core process.

As shown in Figure 1, the side plates 2 are arranged on both sides of all battery core groups. The side plates 2 are integrally extruded, which has the advantage of high structural strength. The side plate 2 is provided with fixed ears 202, and there are multiple fixed ears 202. The fixed ears 202 are evenly distributed along the straight line on the outside of the side plate 2, and can cooperate with the external system beam to provide a limit for the entire series module, thereby ensuring the stability of the series module in the system. stability.

As shown in Figures 4 to 6, the end plates 3 are provided at both ends of the battery pack. The end plates 3 are made of plastic material and are connected to the side plates 2 on both sides. Specifically, the end plates 3 are provided with flange buckles. 301, cooperates with the snap connection 201 of the side plate 2, and plays the role of limiting and fixing. The flange buckle 301 is an elastic buckle with an extended hook structure.

The bottom plate 4 is arranged on the bottom surface of the battery pack and is connected to the side plate 2. The bottom plate 4 is a sheet metal bending part.

The top plate 15 is arranged on the top surface of the battery pack and is fixedly connected to the side plate 2 .

In this implementation, the battery core stack lug series module is assembled. First, the battery core stacks 1 are connected in series through the middle sampling connection assembly, and the side plates 2 and the bottom plate 4 are fixedly connected through welding. The end plate 3 cooperates with the buckle 201 of the side plate 2 through the flange buckle 301 to realize the limit fixation of the side plate 2.

As shown in Figure 7, in this embodiment, the middle sampling connection assembly includes a base 5 and a U-shaped conductive row 6. A plurality of grooves 501 are provided on the base 5, and the lower part of each U-shaped conductive row 6 is inserted into the groove. In 501, the tabs 101 of adjacent cell stacks 1 are connected through U-shaped conductive rows 6; the base 5 is arranged on the bottom plate 4. The base 5 is designed with separation ribs 502 to achieve insulation between adjacent tabs 101 and avoid short circuits. The bottom of the base 5 is provided with ribs 503, and the bottom plate 4 is provided with a limiting groove 401. The ribs 503 are inserted into the limiting groove 401 to realize the positioning and fixation of the base 5 on the bottom 4. The middle sampling connection assembly also includes a middle sampling nickel piece 7. The middle sampling nickel piece 7 is connected to the top of the U-shaped conductive bar 6 through a locking screw 8. The U-shaped conductive bar 6 can be a U-shaped copper bar, which has better conductivity.

In a specific application, the tabs 101 of the series-connected single cell stacks 1 are welded and connected through the U-shaped conductive bar 6. The bottom of the U-shaped conductive bar 6 matches the groove 501 on the plastic base 5, and the groove 501 is filled with Structural glue is used to realize the fixed limit of the U-shaped conductive row 6. The base 5 is designed with separation ribs 502 to achieve insulation between adjacent tabs 101 on the U-shaped conductive bar 6 and avoid short circuits. The bottom ribs 503 of the base 5 cooperate with the limiting grooves 401 on the bottom plate 4 to limit the position of the base 5 . After the battery core stack 1 is connected in series and the U-shaped conductive row 6 is reliably limited, U The conductive row 6 is designed with an embedded nut, which cooperates with the locking screw 8 to fix the middle sampling nickel piece 7, providing reliable crimping and fixation for the middle sampling nickel piece 7, and realizing the voltage signal collection in the middle of the single string battery pack. The collected voltage signal is transported to the low-voltage interface 10 of the end sampling assembly through the middle signal transmission flexible component 9 . The low-voltage interface 10 and the middle sampling nickel piece 7 are electrically connected through the middle signal transmission flexible component 9 .

As shown in FIG. 8 , in this embodiment, the module also includes an end sampling component, which is disposed between the end plate 3 and the end of the battery core group. The end sampling assembly includes an end sampling nickel piece 11, a bus bar 12 and a low-voltage interface 10. The end sampling nickel piece 11 is connected to the bus bar 12. At the same time, the end sampling nickel piece 11 passes through the end flexible signal collection and transmission component 13 Connect to low voltage interface 10. Specifically, the end flexible signal collection and transmission component 13 can be a PCB board, and the low-voltage interface 10 is provided on the PCB board.

As shown in Figure 9, in this embodiment, a temperature sensor 14 is provided at the extended end of the end flexible signal collection and transmission component 13. The temperature sensor 14 is contact-disposed at the bottom of the battery pack to transmit the collected temperature to the low-voltage interface. 10.

In this embodiment, a top plate 15 is installed on the top of the battery pack and is fixedly connected to the side plate 2. Specifically, the top plate 15 is designed with a flange structure, which is overlapping and matched with the side plate 2 and then welded and fixed. The top 15 is a liquid cooling plate, which is equipped with a liquid flow channel. When in use, the liquid flow channel is connected to the external coolant system to achieve cooling of the battery pack. The module integrates liquid cooling and is integrated with the existing module. Compared with the overall liquid-cooling design at the system level among existing technologies, it can provide more efficient and uniform heat dissipation for each cell and further reduce the temperature difference between the cells. In specific applications, the liquid cooling plate is made of three-series aluminum tailor welding, and the inner surface in contact with the battery core stack 1 is insulated to avoid leakage through the liquid cooling plate.

In this implementation, the voltage signal transmitted from the middle sampling nickel plate 7 is integrated into the low-voltage interface 10. The end voltage signal is collected through the end sampling nickel plate 11 welded to the bus bar 12. The end voltage signal is also transmitted to the low-voltage interface. 10 interfaces. A temperature sensor 14 is arranged at the end of the end flexible signal collection and transmission component 13. In order to avoid the influence of low temperature caused by the liquid cooling plate and ensure the sampling accuracy of the actual temperature of the battery core stack 1, it is arranged at the bottom of the battery core group. , the temperature signal collected by the temperature sensor 14 is also transmitted to the low-voltage interface 10 through the end flexible signal collection and transmission component 13 . At the same time, in order to avoid pressure on the temperature sensor 14 and avoid local stress concentration in the soft-packed battery core stack 1, an epoxy plate 16 is provided at the bottom of the battery core stack to achieve direct contact between the battery core stack 1 and the temperature sensor 14, thereby achieving Long-term safe and reliable sampling of temperature. The end acquisition component realizes the integrated extraction function of voltage signal, end voltage signal and temperature signal in the middle of the module. The middle sampling component is to collect the voltage in the middle part. The voltage difference between the middle voltage and the voltage at the other end of the battery core stack 1 is formed, so the status of each battery core can be monitored. Through the above implementation methods, a fully functional, long-term safe and reliable integrated module based on soft-packed battery core tabs in series and liquid cooling is finally realized. The cells are stacked into groups and put directly into the box to improve the system grouping efficiency. The module assembly is easy to install, simple to operate, has high grouping efficiency, strong reliability, thermal safety, and a wide range of application scenarios, which can achieve high energy density battery system assembly. Group.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these Modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

A battery core stack and lug series module, which is characterized by including:

A battery core stack is provided with at least one battery core, poles are provided at both ends of the battery core, and the number of the battery core stack is at least two;

The middle sampling connection component is disposed between the two battery core stacks and connected to the tabs on both sides thereof, so that the corresponding battery cores in the adjacent battery core stacks are connected in series, so that all the batteries The core stack forms a battery core group;

A casing is provided outside the battery core group.
The battery core stack lug series module according to claim 1, characterized in that the housing includes:

Side plates are provided on both sides of all the battery packs;

End plates are provided at both ends of the battery core group and connected to the side plates;

A bottom plate is provided on the bottom surface of the battery core group and connected to the side plate;

The top plate is arranged on the top surface of the battery core group and connected with the side plate.
The battery core stack lug series module according to claim 2, wherein the middle sampling connection assembly includes a base and a U-shaped conductive row, the base is provided with a plurality of grooves, and the U-shaped conductive row The lower parts of the rows are respectively inserted into the grooves, and the tabs of adjacent battery core stacks are connected through the U-shaped conductive row; the base is provided on the bottom plate.
The battery core stack lug series module according to claim 3, characterized in that the bottom of the base is provided with ribs, the bottom plate is provided with a limiting groove, and the ribs are inserted into the limiting groove. middle.
The cell stack pole series module according to claim 3, wherein the middle sampling connection assembly further includes a middle sampling nickel piece, and the middle sampling nickel piece is connected to the U-shaped conductive row through locking screws. top connection.
The battery core stack tab series module according to claim 5, characterized by comprising an end sampling component disposed between the end plate and the battery core group.
The cell stack pole series module according to claim 6, wherein the end sampling assembly includes an end sampling nickel plate, a bus bar and a low-voltage interface, and the end sampling nickel plate is connected to the bus bar. The end sampling nickel pieces are connected to the low-voltage interface through the end flexible signal collection and transmission components; the low-voltage interface and the middle sampling nickel piece are electrically connected through the middle signal transmission flexible components.
The battery core stack lug series module according to claim 7, characterized in that a temperature sensor is provided at the extended end of the end flexible signal collection and transmission component, and the temperature collected by the temperature sensor is transmitted to the Low voltage interface.
The battery core stack tab series module according to claim 8, characterized in that the temperature sensor contact is provided at the bottom of the battery core group.
The battery core stack lug series module according to claim 1, characterized in that the top plate is liquid-cooled Plate with liquid flow channels inside.