Lithium battery protection module

Abstract

The utility model provides a lithium battery protection module, which comprises: a shell having a frame structure with a hollow cavity, the shell comprising accommodating parts respectively arranged on the upper and lower end surfaces of the shell along the penetrating direction of the hollow cavity; and the control module and the power module are oppositely arranged in the accommodating parts of the upper and lower end faces of the shell respectively and abut against the upper and lower end faces of the shell so as to form a closed structure with the shell with the frame structure. Through the BMS modular design, the power module and the control module are arranged on the two sides of the shell frame respectively, the control module, the shell and the power module are arranged in an overlapped mode in the vertical space, the unit area is utilized to the maximum degree, and the power density is improved; the control circuit after modular design is integrated on one side of the shell, so that secondary development of a user is facilitated; in addition, the heat dissipation effect of the power module through the aluminum substrate is better than the existing effect of dissipating heat to the aluminum plate through a plastic package body, the heat dissipation path is optimized, the temperature rise is further suppressed, and the overheating problem of the high-power protection plate is effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a lithium battery protection module. Background Art

[0002] Lithium batteries are increasingly used as energy supply components in various electrical equipment to replace lead-acid batteries due to their advantages such as light weight, long cycle life, large discharge current, energy saving and environmental protection.

[0003] At present, low-voltage and high-current electric drive systems such as electric bicycles, light electric motorcycles, and electric tricycles are usually powered by 48V~72V battery systems. The batteries are ternary lithium batteries and lithium iron phosphate. However, since lithium elements are active and easily out of control, a battery management system (BMS) is required to monitor and manage the batteries, that is, to configure a lithium battery protection board for the battery. It plays an important role in monitoring, protecting, managing and optimizing the lithium battery system, helping to ensure the safe and reliable operation of lithium batteries, extend battery life, and improve the performance and efficiency of the battery system.

[0004] However, during use, the above-mentioned lithium battery protection board usually encounters various problems such as large wear and tear of the protection board itself, poor heat dissipation conditions, overheating of the protection board, and poor sealing of the protection board, which brings great safety hazards to the use of lithium batteries.

[0005] Therefore, it is necessary to provide a lithium battery protection technology solution to solve the above-mentioned existing problems. Summary of the invention

[0006] In view of the above-mentioned defects and deficiencies of the prior art, the purpose of the present application is to provide a lithium battery protection module for solving at least one or more problems encountered during the use of the existing lithium battery protection board.

[0007] In a first aspect, the present application provides a lithium battery protection module, comprising at least:

[0008] A shell, wherein the shell is a frame structure having a hollow cavity; along the penetration direction of the hollow cavity, the shell includes accommodating portions respectively arranged on the upper and lower end surfaces thereof;

[0009] The control module and the power module are respectively arranged in the accommodating parts of the upper and lower end surfaces of the shell and abut against the upper and lower end surfaces of the shell to form a closed structure with the shell having a frame structure;

[0010] The opposite side panel of the control module with components and the side panel of the power module with components are packaged inside the hollow cavity, and the power module is electrically connected to the control module.

[0011] In one embodiment, the accommodating portion includes a first accommodating portion located on the upper end surface of the shell for installing the control module; the first accommodating portion is a concave structure, and the depth of the concave structure is greater than or equal to the thickness of the control module.

[0012] In one embodiment, the accommodation portion includes a second accommodation portion located on the lower end surface of the shell for mounting the power module; the second accommodation portion is a concave platform structure continuously surrounding the shell.

[0013] In one embodiment, the base plate of the power module is an aluminum base plate.

[0014] In one embodiment, a side of the power module having components is provided with a positioning column, and the housing is provided with a positioning hole corresponding to the positioning column.

[0015] In one embodiment, the positioning hole is a countersunk hole extending downward from the upper end surface of the shell, and a glue-filled seam communicating with the hollow cavity is formed on a side wall of the countersunk hole.

[0016] In one embodiment, the height of the glue filling seam is greater than or equal to 0.8 mm.

[0017] In one embodiment, the glue filling seam is a continuous or discontinuous gap surrounding the side wall of the counterbore.

[0018] In one embodiment, the hollow cavity further includes a sealant layer, and the structure of the sealant layer is attached to the space structure formed by the hollow cavity and the power module.

[0019] In one embodiment, the power module has a side with positive and negative terminals on which components are provided, the housing is provided with through holes corresponding to the positive and negative terminals, and the height of the positive and negative terminals is greater than the depth of the through holes.

[0020] Compared with the prior art, the technical solution provided by this application has the following beneficial effects:

[0021] The technical solution of this application optimizes the "sandwich" structure of the existing lithium battery protection board by designing the lithium battery protection board as a stacked modular structure, and improves the existing design's problems such as low circuit board area utilization and difficulty in heat dissipation resulting in high operating temperature of components. This application separates the power part circuit from the control circuit through BMS modular design, and sets them on both sides of the shell frame respectively, so that the control module, shell and power module are overlapped in the vertical space to maximize the use of unit area and improve power density; and the control circuit after modular design is integrated on the control module on one side of the shell, which is conducive to users' secondary development of this part of the circuit; in addition, the power module adopts an aluminum substrate, and its heat dissipation effect is better than the effect of existing power board devices dissipating heat from the plastic package to the aluminum plate, which optimizes the heat dissipation path, further suppresses the temperature rise, and effectively solves the overheating problem of the high-power protection board. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a schematic diagram of a lithium battery protection board in the prior art;

[0023] Figure 2 Shown is a schematic diagram of the overall assembly structure of the lithium battery protection module provided by the present application;

[0024] Figure 3 Shown is a schematic diagram of the structure explosion of the lithium battery protection module provided by the present application;

[0025] Figure 4 The structure diagram shown is a bottom-up view of the housing;

[0026] Figure 5 The schematic diagram of the structure is shown as a top view of the shell;

[0027] Figure 6 A schematic diagram showing a structure of an embodiment of a positioning hole;

[0028] Figure 7 A schematic structural diagram of another embodiment of a positioning hole is shown.

[0029] Description of reference numerals:

[0030] 1 PCB

[0031] 2 Heat sink

[0032] 100 Control module

[0033] 200 Shell

[0034] 210 first accommodation part

[0035] 220 Second accommodation part

[0036] 230 Positioning hole

[0037] 231 Glue filling seam

[0038] 240 Through hole

[0039] 300 Power Module

[0040] 310 Aluminum PCB

[0041] 320 Power Devices

[0042] 330 Positioning column

[0043] 340 positive and negative terminals

[0044] D Concave depth

[0045] H Glue filling seam height DETAILED DESCRIPTION

[0046] At present, low-voltage and high-current electric drive systems such as electric bicycles, light electric motorcycles, and electric tricycles are usually powered by 48V~72V battery systems. The batteries for these applications are mostly 13~20 strings, with continuous currents ranging from 10A to 50A. The battery management system for this type of application is currently mostly in the form of pure hardware. Under higher current applications, an open "sandwich" structure is often adopted: Figure 1 As shown, the middle layer is a PCB board, on which power devices, various digital and analog chips, connectors, etc. are welded; the bottom and upper layers are heat dissipation parts composed of aluminum plates. This type of application of lithium battery protection board is usually assembled with lithium batteries in the same shell to make a battery pack, and its active heat dissipation conditions are poor, but the requirement of lithium battery for its battery cell temperature during use generally cannot exceed 60-70 degrees Celsius. Therefore, corresponding measures must be taken to reduce the temperature of the lithium battery protection board, such as reducing its own loss to reduce temperature generation, or increasing heat capacity to absorb the heat generated on the battery protection board to suppress temperature rise. At present, the strategy to reduce self-loss is usually to connect multiple power devices in parallel, but the more power devices there are, the larger the area occupied, and the corresponding overall size will also increase, which greatly compresses the battery cell space; in addition, since the heat dissipation path from the power device chip to the aluminum plate has not been optimized, there will still be a certain temperature difference that is difficult to eliminate.

[0047] Therefore, in response to the above practical problems, the present application provides a lithium battery protection module, which meets the good heat dissipation requirements of the lithium battery protection board through a modular design of the BMS. The technical scheme of the present application will be described in detail below through examples in combination with the drawings in the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application.

[0048] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0049] See also Figures 1 to 7 This embodiment provides a lithium battery protection module, which at least includes:

[0050] The shell 200 is a frame structure with a hollow cavity; along the penetrating direction of the hollow cavity, the shell 200 includes accommodating parts respectively arranged on the upper and lower end surfaces thereof; specifically, the accommodating part located on the upper end surface of the shell 200 is defined as the first accommodating part 210, and the accommodating part located on the lower end surface of the shell 200 is defined as the second accommodating part 220; usually, the shell 200 is made of polybutylene terephthalate fiber material, taking into account its structural strength and high temperature deformation resistance and other performance requirements;

[0051] The control module 100 and the power module 300 are respectively arranged in the receiving parts of the upper and lower end surfaces of the housing 200, and abut against the upper and lower end surfaces of the housing 200 to form a closed structure with the housing 200 having a frame structure. It can be understood that the closed structure is not a sealed structure, but a bottom surface is formed on one end surface of the frame structure, so that the penetrating housing forms a non-through assembly structure;

[0052] Among them, the control module 100 has a side panel with components and the power module 300 has a side panel with components encapsulated in the hollow cavity, and the power module 300 is electrically connected to the control module 100. It can be understood that the power module 300 and the control module 100 are basic conventional components of the lithium battery protection board in this field, and are hardware modules with mature technology. The power module 300 includes power MOS and basic peripheral devices, sampling resistors and control signal interfaces (such as Figure 3 As an illustrative power device 320), the control module 100 includes a hardware control circuit, a battery monitoring interface and a control signal interface, etc. The computer program required for optimizing the module connection method only involves the configuration of the conventional algorithm, and there is no need to improve the execution method itself, which will not be elaborated here.

[0053] By adopting the above technical solution, the lithium battery protection board is designed as a stacked modular structure, which optimizes the "sandwich" structure of the existing lithium battery protection board, and improves the existing design. The low utilization rate of the circuit board area and the difficulty in dissipating heat lead to high operating temperature of components. This application separates the power part circuit from the control circuit through the BMS modular design, and sets them on the two end surfaces of the frame structure of the shell 200 respectively, so that the control module 100, the shell 200 and the power module 300 are overlapped in the vertical space, and the unit area of ​​the lithium battery protection board is maximized to improve the power density; and the control circuit after modular design is integrated on the control module 100 on one side of the shell 200, which is conducive to the user's secondary development of this part of the circuit; the heat generated by the work of the components is dissipated to the external space through the bottom plate of the power module 300, and its heat dissipation effect is better than the effect of the existing power board device dissipating heat to the aluminum plate through the plastic package, which optimizes the heat dissipation path, further suppresses the temperature rise, and effectively solves the overheating problem of the high-power protection board.

[0054] In one embodiment, see Figure 3 , the accommodating portion includes a first accommodating portion 210 located on the upper end surface of the housing 200, for installing the control module 100; the first accommodating portion 210 is a concave platform structure, which is arranged above the inner side wall of the housing 200, and the depth D of the concave platform structure is greater than or equal to the thickness of the control module 100. As an example, the concave platform depth D is equal to the thickness of the control module 100, so that the control module 100 is engaged in the first accommodating portion 210, and the maximum utilization rate of the space of the housing 200 is achieved. As an example, the concave platform depth D can be greater than the thickness of the control module 100, so as to effectively protect the control module 100, prevent the control module 100 from being physically damaged by external mechanical collision or backlog, thereby affecting its circuit connection performance. Specifically, the concave platform depth D is greater than or equal to 1.0 mm, for example, D can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm or 3.0 mm.

[0055] In the above embodiment, the concave platform may be a table structure that continuously surrounds the inner side wall of the housing 200, or may be a plurality of concave platforms arranged at intervals to provide a plurality of mounting support points for the control module 100, or may be a concave platform structure with a table on opposite sides or three consecutive sides to provide a plurality of mounting planes for the control module 100. Figures 1-2 Screw holes may be provided near the edge of the control module 100 and at the corresponding position of the housing 200, so that after the control module 100 is engaged in the first receiving portion 210, it can be firmly installed on the housing 200 by means of fasteners such as screws. It is understandable that the control module 100 may also be installed by other means, such as different connection methods such as interlocking and bonding.

[0056] In one embodiment, see Figure 4The housing portion includes a second housing portion 220 located at the lower end surface of the housing 200, for mounting the power module 300; the second housing portion 220 is a concave platform structure that continuously surrounds the housing. Setting the second housing portion 220 as a continuously surrounding concave platform can enable the power module 300 to achieve seamless contact with the concave platform, which is conducive to the implementation of the subsequent glue filling process.

[0057] It can be understood that the width of the concave platform of the first accommodating portion 210 and the second accommodating portion 220 can be set according to the area occupied by the circuit board to achieve the best space utilization of the housing 200.

[0058] In one embodiment, the bottom plate of the power module 300 is an aluminum substrate 310. The heat dissipation effect of the aluminum substrate 310 is better than the heat dissipation effect of the existing power board device through the plastic package to the aluminum plate, optimizes the heat dissipation path, further suppresses the temperature rise, and effectively solves the overheating problem of the high-power protection board.

[0059] In one embodiment, see Figures 2-3 The power module 300 has a positive and negative terminal 340 on one side of the components, and the housing 200 is provided with a through hole 240 corresponding to the positive and negative terminal 340. The height of the positive and negative terminal 340 is greater than the depth of the through hole 240, so that the positive and negative terminal 340 can be connected to other supporting circuits. It can be understood that the positive and negative terminal 340 are respectively B-terminals and P-terminals, and the B-terminals and P-terminals are symmetrically arranged at both ends of the same frame of the housing 200.

[0060] In one embodiment, see Figures 3 to 5 The power module 300 has a positioning column 330 on one side of the components, and the housing 200 is provided with a positioning hole 230 corresponding to the positioning column 330. The positioning column 330 is arranged on at least two opposite frames of the housing 200. Usually, the positioning column 330 is soldered with solder paste to the aluminum substrate 310 after surface processing. The center of the positioning column 330 has a threaded hole, and the housing 200 and the power module 300 are installed and fixed by screws. As an example, Figure 5 The top view of the shell 200 shown is a reference orientation. Two positioning holes 230 can be symmetrically arranged on a frame where the through hole 240 is set. The two positioning holes 230 are set between the through holes 240. Two more positioning holes 230 can be further arranged at the bottom corner of the opposite frame parallel to the frame. The power module 300 is firmly connected to the shell 200 through four positioning holes.

[0061] In one embodiment, see Figures 6-7 The positioning hole 230 is a countersunk hole extending downward from the upper end surface of the shell 200, and a glue injection seam 231 communicating with the hollow cavity is formed on the side wall of the countersunk hole.

[0062] In one embodiment, see Figures 6-7 , the height H of the glue filling seam 231 is greater than or equal to 0.8 mm. As an example, the height H of the glue filling seam can be 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, so that the sealant can smoothly overflow through the glue filling seam 231 and can effectively prevent its backflow, so that the sealant fills the counterbore, so that the power module 300 and the housing 200 are effectively sealed.

[0063] In the above embodiment, at least one positioning hole 230 is provided with a glue filling slit 231 to ensure that the sealant has at least one overflow path; further, the positioning holes 230 located at the diagonal side can be provided with a glue filling slit 231 to allow the sealant to have a uniform flow path, ensuring that the hollow cavity of the housing 200 can be filled, and the positioning holes 230 on the other opposite side can be designed to be closed; further, all four positioning holes 230 can be provided with a glue filling slit 231 to achieve efficient flow of the sealant and efficient modular production of the product. It is understandable that the number of positioning holes 230 can also be more than four, such as six or eight.

[0064] In the above implementation, see Figure 6 , the glue injection seam 231 is a continuous or discontinuous gap surrounding the side wall of the countersunk hole. As an example, the glue injection seam 231 can surround the side wall structure of the countersunk hole at 180°, and the gap direction of the glue injection seam 231 faces the inner cavity of the shell 200 to achieve smooth overflow of the sealant. As an example, the glue injection seam 231 can also be arranged in the side wall of the countersunk hole as an interval gap to ensure the structural strength of the positioning hole 230 and prevent structural deformation caused by the opening of the glue injection seam 231. Of course, the glue injection seam 231 can also be set as a combination of multiple different gap structures according to actual conditions.

[0065] In the above implementation, see Figure 7 The glue filling seam 231 located at the bottom corner of the frame can also adopt the above-mentioned gap setting method, which will not be described in detail here. The formation method of the glue filling seam 231 located at the bottom corner of the frame can be regarded as sinking the table where the positioning hole 230 is located, so that a certain distance is generated between the part of the table with the center hole and the shell 200, thereby forming a gap, that is, the glue filling seam 231, which is convenient for the sealant layer to overflow and fill the part of the space above the table.

[0066] In some embodiments, the hollow cavity of the shell 200 also includes a sealant layer, and the structure of the sealant layer depends on the spatial structure formed by the hollow cavity and the power module 300, that is, the sealant layer fills the closed space formed by the power module 300 and the shell 200.

[0067] In order to better understand the technical solution of the present application, the manufacturing process of the lithium battery protection module in the embodiment of the present application is summarized as follows:

[0068] S100: First, the terminals and other components required by the power module 300 are welded to the aluminum substrate 310, and at the same time, a sealing layer is applied to the concave platform of the second receiving portion 220 of the housing 200 to facilitate the installation of the power module 300;

[0069] S200: The power module 300 is buckled into the second receiving portion 220 of the housing 200, and the positioning hole 230 is aligned with the positioning column 330 and then tightened with screws to form an intermediate product integrating the two modules;

[0070] S300: After the sealant layer is cured, a sealant, such as epoxy resin, is filled into the hollow cavity of the housing 200 until a preset height is reached, which allows the sealant to overflow from the glue filling seam 231 and cover the positioning column 330 and the fastening screw;

[0071] S400: After the sealant is cured, the integrated design of the two modules is completed, and the design and installation of the control module 100 can be continued.

[0072] It is understandable that the power device can also be directly replaced with a bare die package, and the epoxy resin can be replaced with silicone gel, etc., to further reduce the size and increase the power density. The manufacturing process of the lithium battery protection module provided in the embodiment of the present application is not limited to the above process sequence or process method.

[0073] In summary, the technical solution provided by the present application optimizes the "sandwich" structure of the existing lithium battery protection board by designing the lithium battery protection board as a stacked modular structure, and improves the existing design. The low utilization rate of the circuit board area and the difficulty in dissipating heat lead to high operating temperature of components. This application separates the power part circuit from the control circuit through the BMS modular design, and arranges them on both sides of the shell frame respectively, so that the control module, shell and power module are overlapped in the vertical space to maximize the utilization of unit area and improve power density; and the control circuit after modular design is integrated on the control module on one side of the shell, which is conducive to users to carry out secondary development for this part of the circuit; in addition, the power module adopts an aluminum substrate, and its heat dissipation effect is better than the effect of the existing power board device dissipating heat to the aluminum plate through the plastic package, which optimizes the heat dissipation path, further suppresses the temperature rise, and effectively solves the overheating problem of the high-power protection board. Therefore, this application effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0074] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A lithium battery protection module, characterized in that: At least: A shell, wherein the shell is a frame structure having a hollow cavity; along the penetration direction of the hollow cavity, the shell includes accommodating portions respectively arranged on the upper and lower end surfaces thereof; The control module and the power module are respectively arranged in the accommodating parts of the upper and lower end surfaces of the shell and abut against the upper and lower end surfaces of the shell to form a closed structure with the shell having a frame structure; The opposite side panel of the control module with components and the side panel of the power module with components are packaged inside the hollow cavity, and the power module is electrically connected to the control module.

2. The lithium battery protection module according to claim 1, characterized in that: The accommodating portion includes a first accommodating portion located on the upper end surface of the shell, for installing the control module; the first accommodating portion is a concave platform structure, and the depth of the concave platform structure is greater than or equal to the thickness of the control module.

3. The lithium battery protection module according to claim 1, characterized in that: The accommodating portion includes a second accommodating portion located on the lower end surface of the shell, which is used to install the power module; the second accommodating portion is a concave platform structure that continuously surrounds the shell.

4. The lithium battery protection module according to claim 1, characterized in that: The bottom plate of the power module is an aluminum base plate.

5. The lithium battery protection module according to claim 1, characterized in that: The power module has a side with a component provided with a positioning column, and the housing is provided with a positioning hole corresponding to the positioning column.

6. The lithium battery protection module according to claim 5, characterized in that: The positioning hole is a countersunk hole extending downward from the upper end surface of the shell, and a glue-filled seam communicating with the hollow cavity is formed on a side wall of the countersunk hole.

7. The lithium battery protection module according to claim 6, characterized in that: The height of the glue filling seam is greater than or equal to 0.8 mm.

8. The lithium battery protection module according to claim 6, characterized in that: The glue injection seam is a continuous or discontinuous gap surrounding the side wall of the countersunk hole.

9. The lithium battery protection module according to claim 1, characterized in that: The hollow cavity further includes a sealant layer, and the structure of the sealant layer is attached to the space structure formed by the hollow cavity and the power module.

10. The lithium battery protection module according to claim 1, characterized in that: The power module has a side with positive and negative terminals on which components are arranged, the shell is provided with through holes corresponding to the positive and negative terminals, and the height of the positive and negative terminals is greater than the depth of the through holes.

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