CN117895172A - A battery module - Google Patents

Abstract

The invention relates to the field of batteries, and discloses a battery module, which comprises: the battery module comprises a module shell, a battery cell group, a BMS module, a battery cell bracket and a tab, wherein the battery cell group, the BMS module, the battery cell bracket and the tab are contained in the module shell; the battery cell group comprises at least two battery cells which are arranged in parallel; the BMS module comprises a voltage acquisition module connected with an acquisition line; the battery cell bracket comprises two bracket components which are respectively arranged at two ends of the battery cell group and made of insulating materials; the bracket assembly includes: the bracket comprises a bracket body, at least two assembly structures arranged on the bracket body and a limiting channel arranged between every two assembly structures; the electrode lug comprises an electrode welding part and a voltage acquisition part which are connected into a whole; the voltage acquisition part is limited in the limiting channel, and the end part of the voltage acquisition part is electrically connected with the acquisition line. In the invention, the voltage acquisition part can be well insulated and protected by the bracket body made of the insulating material, so that the voltage acquisition part is prevented from being in electrical contact with other adjacent cells and the like, the risk of short circuit is effectively reduced, and the safety performance of the battery is improved.

Description

A battery module

Technical Field

The present invention relates to the technical field of batteries, and in particular to a battery module.

Background technique

Lithium-ion battery modules are usually composed of multiple cells connected in series or parallel through tabs. In order to ensure the safety of the battery module, it is necessary to collect voltage for each string of batteries. For this purpose, a voltage collection unit is often set on the tab, and the voltage collection unit is welded to the collection line of the voltage collection module to collect voltage signals. However, after the voltage collection unit and the collection line are welded, they will be bent and pressed. The space inside the lithium-ion battery module is small and there is no good insulation protection. Therefore, the voltage collection unit is easy to come into electrical contact with other adjacent cells, thereby causing risks such as short circuit and fire.

Summary of the invention

The purpose of the present invention is to provide a battery module to reduce the risks of short circuit and fire caused by inadequate insulation protection in the prior art.

To achieve this object, the present invention adopts the following technical solutions:

A battery module comprises: a module shell, and a battery cell group, a BMS module, a battery cell bracket and at least two tabs contained in the module shell;

The battery cell group comprises at least two battery cells arranged in parallel;

The BMS module comprises a voltage acquisition module, and the voltage acquisition module is electrically connected to an acquisition line;

The battery cell support comprises two support assemblies made of insulating material and arranged at both ends of the battery cell group; the support assembly comprises: a support body, at least two assembly structures arranged on the support body for positioning the ends of the battery cell, and a limiting channel arranged between each two assembly structures on the outer wall of the support body;

The electrode tab includes an electrode welding portion and a voltage collection portion connected as one body; the electrode welding portion is electrically connected to the electrode at the end of the corresponding battery cell, and the voltage collection portion is limited in a limiting channel and its end is electrically connected to the collection line.

Optionally, the electrode tab includes two connected electrode welding parts and a voltage collection part, and the voltage collection part is connected to the outer edge of one of the electrode welding parts or a position between the two electrode welding parts.

Optionally, the assembly structure includes: a mounting hole for accommodating the end of the battery cell, and a plurality of limiting portions; the plurality of limiting portions are arranged on the outer wall of the bracket body, surrounding the mounting hole and partially extending into the mounting hole.

Optionally, different limiting portions located between two adjacent mounting holes cooperate to form the limiting channel.

Optionally, a shunt groove is also provided on the electrode welding portion.

Optionally, the module housing further includes a BMS fixing structure stacked on the upper layer of the battery cell group;

The BMS module is fixed on the BMS fixed structure, and the BMS fixed structure is fixedly connected to the module housing.

Optionally, the module housing and/or the BMS fixing structure are made of aluminum alloy material.

Optionally, an insulating plate is further provided between the BMS fixing structure and the battery cell group, and between the battery cell group and the module housing.

Optionally, a buffer structure is provided inside the module housing on the outer side of the insulating plate.

Optionally, the battery module further includes an output connector located outside the module housing, and the output connector is connected to the BMS module via a signal transmission line and a switch line.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

The battery module of the embodiment of the present invention utilizes a cell holder to support and fix the cell group, and at the same time, the voltage collection part of the pole ear is limited by a limiting channel provided by the cell holder. The limiting channel is not only arranged on the outer wall of the holder body of the cell holder (that is, the side surface away from the cell group), but also located between two adjacent assembly structures (that is, the idle position between two adjacent cells), so that the voltage collection part can be well insulated and protected by the holder body made of insulating material to avoid electrical contact with other adjacent cells, thereby effectively reducing the risk of short circuit and improving the safety performance of the battery module.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is an overall structural diagram of a battery module provided by an embodiment of the present invention;

FIG2 is a structural assembly diagram of a battery module provided by an embodiment of the present invention, excluding a module housing;

FIG3 is a cross-sectional structural diagram of a battery module provided by an embodiment of the present invention;

FIG4 is a structural assembly diagram of a battery module provided by an embodiment of the present invention, excluding a module housing, a buffer structure, and an insulating plate, at a viewing angle;

5 is a structural assembly diagram of a battery module provided by an embodiment of the present invention, excluding a module housing, a buffer structure, an insulating plate and an output connector from another viewing angle;

FIG6 is a structural diagram of a battery cell group of a battery module provided in an embodiment of the present invention;

FIG7 is a structural diagram of a cell support of a battery module provided by an embodiment of the present invention;

FIG8 is an assembly diagram of a cell group and a cell support of a battery module provided in an embodiment of the present invention;

FIG9 is a structural diagram of a tab of a battery module provided by an embodiment of the present invention;

FIG. 10 is another structural diagram of a tab of a battery module provided in an embodiment of the present invention.

Description of reference numerals:

Module shell 1, upper shell 11, lower shell 12, battery cell group 2, battery cell 21, BMS module 3, battery cell bracket 4, bracket assembly 41, bracket body 411, assembly structure 412, mounting hole 4121, limiting part 4122, limiting channel 413, pole ear 5, electrode welding part 51, voltage collection part 52, shunt groove 53, BMS fixed structure 6, insulating plate 7, buffer structure 8, output connector 9, handle 10.

Detailed ways

In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Please refer to FIG. 1 to FIG. 5 , an embodiment of the present invention provides a battery module, including: a module housing 1 , a battery cell group 2 accommodated in the module housing 1 , a BMS module 3 , a battery cell support 4 , and at least two tabs 5 .

A battery cell group 2, comprising at least two battery cells 21 arranged in parallel;

The BMS (Battery Management System) module is an important link between the battery pack 2 and the car, and is a management system specifically for the battery pack 2. It at least includes a voltage acquisition module, and the voltage acquisition module is electrically connected to an acquisition line;

The cell bracket 4 is used to support and fix the cell group 2, which specifically includes two bracket components 41 respectively arranged at both ends of the cell group 2 and made of insulating material; a single bracket component 41 is used to support and fix the same side ends of each cell 21 of the cell group 2, which specifically includes: a bracket body 411, at least two assembly structures 412 arranged on the bracket body 411 for positioning the ends of the cell 21, and a limiting channel 413 arranged between each two assembly structures 412 on the outer wall of the bracket body 411;

The tab 5 includes an electrode welding portion 51 and a voltage collection portion 52 connected as one body; the electrode welding portion 51 is electrically connected to the electrode at the end of the corresponding battery cell 21, and the voltage collection portion 52 is limited in the limiting channel 413 and its end is connected to the collection line through soldering.

The battery module of the embodiment of the present invention uses the battery cell holder 4 to support and fix the battery cell group 2, and at the same time, the voltage collection part 52 of the pole ear 5 is limited by the limiting channel 413 provided by the battery cell holder 4. The limiting channel 413 is not only arranged on the outer wall of the bracket body 411 of the battery cell holder 4 (that is, the side surface away from the battery cell group 2), but also located between two adjacent assembly structures 412 (that is, the idle position between two adjacent battery cells 21), so that the voltage collection part 52 can be well insulated and protected by the bracket body 411 made of insulating material, avoiding electrical contact with other adjacent battery cells 21, thereby effectively reducing the risk of short circuit and improving the safety performance of the battery module.

For ease of description, according to the placement direction of the battery module shown in the figure, one end of the battery cell group 2 in the arrangement direction of the positive and negative electrodes of its battery cells 21 is called the front end, and the other end is called the rear end.

Furthermore, the shape of each battery cell 21 included in the battery cell group 2 can be cylindrical as shown in FIG6 , or can be square. The specific arrangement of each battery cell 21 can be arranged in a single row in parallel, or in multiple rows in parallel; the embodiment of the present invention does not specifically limit this.

In addition, the arrangement directions of the positive and negative electrodes between each battery cell 21 can be the same or different, and can be designed according to the actual series or parallel design requirements. Exemplarily, as shown in FIG6, of any two adjacent battery cells 21, one is arranged in the forward direction, that is, the positive electrode faces forward, and the other is arranged in the reverse direction, that is, the negative electrode faces forward, so that the series connection of each battery cell 21 can be achieved through multiple tabs 5. Based on this, as shown in FIG9, the voltage collection part 52 is connected to the position between the two electrode welding parts 51, and the two electrode welding parts 51 are respectively connected to the positive and negative electrodes of the two adjacent battery cells 21 on the left and right to achieve the series connection of the two battery cells 21 on the left and right; or, as shown in FIG10, the tab 5 may include two connected electrode welding parts 51 and a voltage collection part 52, and the voltage collection part 52 is connected to the outer edge of one of the electrode welding parts 51, and the two electrode welding parts 51 are respectively connected to the positive and negative electrodes of the two adjacent battery cells 21 above and below to achieve the series connection of the upper and lower battery cells 21.

In the embodiment of the present invention, as shown in FIG9 and FIG10, a shunt groove 53 is also provided on the electrode welding portion 51 of the pole tab 5. This is because, when using resistance spot welding, the current path between the electrode heads must be carefully considered. Electrons will always flow along the path of minimum resistance, so when the pole tab 5 becomes thicker, the energy will be directly transferred on the surface of the pole tab 5 between the electrode heads and cannot be transferred to the set welding point. This phenomenon began to appear on the 125-micron thick nickel sheet pole tab 5. Therefore, in order to avoid the shunting of the current, a shunt groove 53 needs to be designed on the electrode welding portion 51 of the pole tab 5 to concentrate and guide the energy to a specific welding point.

The basic functions of the BMS module 3 include: monitoring various states of the battery cell group 2, such as voltage, current, temperature, etc.; providing necessary protection for the battery cell group 2 based on the monitoring data, so that the battery cell group 2 works in a safe environment, mainly including voltage and current control, temperature management, etc. during the charging and discharging process.

The hardware topology architecture of the BMS module 3 is divided into two types: centralized and distributed. Centralized: All electrical components (such as chips, resistors, capacitors, wiring terminals, etc.) are concentrated on a board (as shown in Figures 4 and 5); the advantages of this hardware architecture are simple circuit design and low cost; the disadvantages are that the wiring harness for single-cell sampling is relatively long, the sampling voltage drop is different, the sampling harness design is complex, the number of sampling channels is limited, and it is suitable for smaller battery packs. Distributed: The distributed hardware architecture includes a main board and a slave board (not shown in the figure); the advantage of this hardware architecture is that the sampling harness distance is uniform; the disadvantage is that the cost is high, and additional chips are required to send the information of each module to the main board. In actual applications, the BMS module 3 can choose any type of architecture, and the embodiments of the present invention do not specifically limit this.

The basic functions of the battery holder 4 include: supporting and fixing the battery group 2. Specifically, as shown in Figures 7 and 8, the holder assembly 41 disposed at the front end of the battery group 2 is used to fix the front end of each battery cell 21 of the battery group 2; the holder assembly 41 disposed at the rear end of the battery group 2 is used to fix the rear end of each battery cell 21 of the battery group 2.

In an optional embodiment, the assembly structure 412 on a single bracket assembly 41, as shown in FIG7 , may specifically include: a mounting hole 4121 for accommodating the end of the battery cell 21, and a plurality of limiting portions 4122; the plurality of limiting portions 4122 are arranged on the outer wall of the bracket body 411, surrounding the mounting hole 4121 and partially extending into the mounting hole 4121. Exemplarily, in the structure shown in FIG7 , four limiting portions 4122 are arranged around each mounting hole 4121 and partially extend into the hole.

In this way, during the assembly process, the two ends of a single battery cell 21 can be respectively inserted into the mounting holes 4121 at the corresponding positions, and limited by multiple limiting parts 4122 at the corresponding positions to prevent the battery cell 21 from being not inserted into place or falling out of the mounting hole 4121, so as to achieve precise assembly.

At the same time, different limiting parts 4122 located between two adjacent mounting holes 4121 can cooperate to form the limiting channel 413. Exemplarily, as shown in FIG7, in two adjacent mounting holes 4121, the limiting part 4122 at the upper right corner of one and the limiting part 4122 at the upper left corner of the other can cooperate to form a limiting channel 413 for the voltage collection part 52 of the pole ear 5 at the adjacent position to pass through. Based on this, after the voltage collection part 52 of the pole ear 5 is connected to the collection line of the voltage collection module through soldering, even if it is bent or pressed, it can be insulated and isolated by the bracket body 411, and cannot be electrically contacted with other battery cells 21 at the adjacent position, thereby eliminating the risk of short circuit.

As shown in FIG. 2 and FIG. 3 , the module housing 1 also includes a BMS fixing structure 6 stacked on the upper layer of the battery cell group 2; the BMS module 3 is fixed on the BMS fixing structure 6, and the BMS fixing structure 6 is fixedly connected to the module housing 1 by means of locking screws or the like.

The module housing 1 and/or the BMS fixed structure 6 are preferably made of aluminum alloy. Currently, many sheet metal housings of battery modules on the market are designed with SPCC cold-rolled plate materials. The density of SPCC cold-rolled plate materials is 7.9kg/ ^m3 , and the density of aluminum alloy materials is 2.7kg/ ^m3 . Therefore, under the same volume, the module housing 1 designed with aluminum alloy materials is about three times lighter than the module housing 1 designed with SPCC cold-rolled plate. Taking the 15S1P battery pack using 32140 large cylindrical cells as an example, the weight of a single cell is about 300g, and the weight of 15 cells is 4.5kg. The weight of the cell group 2 is relatively heavy, so the sheet metal housing is designed with aluminum alloy materials, which can effectively reduce the overall weight of the battery module, and even reduce the overall weight of the host, making the product lighter as a whole, and more convenient to transport and carry.

In addition, as shown in FIG. 1 , the module housing 1 can be assembled from an upper shell 11 and a lower shell 12 , and a handle 10 is fixed to the top of the upper shell 11 by screws for easy carrying.

As shown in FIG. 2 and FIG. 3 , an insulating plate 7 , such as an epoxy plate, is further provided between the BMS fixing structure 6 and the cell group 2 , and between the cell group 2 and the module housing 1 , so as to achieve an insulation effect between the cell group 2 and the module housing 1 and avoid the risk of short circuit.

As shown in FIG. 2 and FIG. 3 , a buffer structure 8 , such as foam, is provided inside the module housing 1 on the outside of the insulating plate 7 to prevent the battery cell group 2 from being damaged due to collision during transportation.

As shown in FIG. 2 , the battery module further includes an output connector 9 located outside the module housing 1 for connecting to a vehicle host. The output connector 9 connects a signal transmission line and a switch line. The signal transmission line and the switch line penetrate into the module housing 1 through the through-hole of the rubber sheath coil and are electrically connected to the BMS module 3.

In summary, the battery module provided by the embodiment of the present invention has good collision protection performance and safety performance, compact and reasonable overall space utilization, light overall weight, simple product structure installation, easy operation, strong practicality, and can be widely used in automobiles.

As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A battery module, comprising: the battery module comprises a module shell (1), a battery cell group (2), a BMS module (3), a battery cell bracket (4) and at least two electrode lugs (5), wherein the battery cell group (2), the BMS module (3) and the battery cell bracket are contained in the module shell (1);

the battery cell group (2) comprises at least two battery cells (21) which are arranged in parallel;

the BMS module (3) comprises a voltage acquisition module, and the voltage acquisition module is electrically connected with an acquisition line;

the battery cell bracket (4) comprises two bracket components (41) which are respectively arranged at two ends of the battery cell group (2) and made of insulating materials; the bracket assembly (41) comprises: the battery cell assembly comprises a bracket body (411), at least two assembly structures (412) arranged on the bracket body (411) and used for positioning the end part of a battery cell (21), and a limiting channel (413) arranged at a position between every two assembly structures (412) on the outer wall of the bracket body (411);

the electrode lug (5) comprises an electrode welding part (51) and a voltage acquisition part (52) which are connected into a whole; the electrode welding part (51) is electrically connected with the electrode at the end part of the corresponding battery cell (21), the voltage acquisition part (52) is limited in the limiting channel (413) and the end part of the voltage acquisition part is electrically connected with the acquisition line.

2. The battery module according to claim 1, wherein the tab (5) includes two electrode welding parts (51) and one voltage collecting part (52) connected, the voltage collecting part (52) being connected to an outer edge of one of the electrode welding parts (51) or a position between the two electrode welding parts (51).

3. The battery module according to claim 1, wherein the mounting structure (412) includes: a mounting hole (4121) for receiving an end portion of the battery cell (21), and a plurality of stopper portions (4122); the limiting parts (4122) are arranged on the outer wall of the bracket body (411), are arranged around the mounting hole (4121) in a surrounding mode, and partially extend into the mounting hole (4121).

4. A battery module according to claim 3, characterized in that different spacing portions (4122) between adjacent two mounting holes (4121) cooperate to form the spacing channel (413).

5. The battery module according to claim 1, wherein the electrode welding portion (51) is further provided with a shunt groove (53).

6. The battery module according to claim 1, further comprising a BMS fixing structure (6) stacked on an upper layer of the battery cell group (2) in the module case (1);

the BMS module (3) is fixedly arranged on the BMS fixing structural member (6), and the BMS fixing structural member (6) is fixedly connected with the module shell (1).

7. Battery module according to claim 6, characterized in that the module housing (1) and/or the BMS fixing structure (6) are made of an aluminum alloy material.

8. Battery module according to claim 1, characterized in that between the BMS fixing structure (6) and the battery cell group (2) and between the battery cell group (2) and the module housing (1) an insulating plate (7) is also provided.

9. The battery module according to claim 1, wherein a buffer structure (8) is further provided in the module case (1) outside the insulating plate (7).

10. The battery module according to claim 1, further comprising an output connector (9) located outside the module case (1), the output connector (9) being connected to the BMS module (3) through a signal transmission line and a switching line.