Secondary battery module

Abstract

The utility model provides a secondary battery module, which is characterized in that a shell is of a square barrel structure with an open upper side, and an inner cavity of the shell is uniformly divided into a plurality of monomer accommodating spaces by partition plates; the core body is a roll core, a stacked core or a soft package battery; a tab is arranged at one end of each core body, and each core body is accommodated in the single body accommodating space; the cover plate assembly is composed of a top cover main body, a pole assembly and an explosion-proof assembly; an explosion-proof assembly is installed in the middle of the top cover body, and pole assemblies are installed on the two sides of the top cover body respectively. The rivet is used for connecting the pole lug and the pole column assembly; according to the utility model, the tab is connected with the current collector on the pole assembly through the rivet, and the welding in the traditional mode is replaced by the riveting of the rivet, so that the damage to a battery cell below the tab during welding is effectively avoided, the operation is convenient, the space utilization rate is also improved, and the connection quality between the current collector and the tab is ensured.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion batteries, and in particular to a lithium-ion battery module in which the core (wound core, stacked core or pouch battery) is directly assembled into the module. Background Technology

[0002] Traditional battery system manufacturing methods involve first manufacturing battery cells, then assembling them into battery modules, and finally installing the battery modules into a battery casing. The Bill of Materials (BOM) cost of a battery system includes the cost of the battery cells, the cost of the modules, and the cost of the system pack materials. The manufacturing cost also includes the cost of manufacturing the battery cells, the cost of manufacturing the modules, and the cost of manufacturing the system.

[0003] To reduce costs and increase efficiency in battery systems, the JTM (Jerry-roll To Module) model was proposed. This model involves directly assembling the battery cells into a module within the battery pack, where all individual battery cells are connected in series and fixed together to form a complete battery module. Its advantages include improved battery pack volume utilization, reduced number of battery pack components, increased production efficiency, and lower costs.

[0004] In the traditional method, adjacent tabs are horizontally bent and pre-welded, and then horizontally welded to the lower surface of the electrode post. Torque welding or through welding is usually used to connect the tabs to the electrode post. Welding the tabs horizontally to the lower surface of the electrode post can easily damage the battery cell below, and the welding space is limited, making welding operations inconvenient.

[0005] To address this issue, we propose a secondary battery module to solve the tab connection problem in JTM mode. Utility Model Content

[0006] The purpose of this utility model is to overcome the shortcomings of the existing technology. To achieve the above objective, this utility model adopts the following technical solution:

[0007] A secondary battery module includes: a housing, the housing being a square cylindrical structure open at the top, the inner cavity of the housing being divided into multiple single-cell accommodating spaces by a dividing plate; a core, the core being a wound core, stacked core, or pouch battery; one end of the core is provided with a tab, and each core is accommodated within the single-cell accommodating space; a cover assembly, the cover assembly comprising a top cover body, a terminal post assembly, and an explosion-proof assembly; the explosion-proof assembly is installed in the middle of the top cover body, and terminal post assemblies are respectively installed on both sides of the top cover body; and rivets for connecting the tabs and the terminal post assemblies.

[0008] More preferably, the pole assembly consists of a plastic block and a current collector. The plastic block has a square through groove in the middle. The current collector is L-shaped. The vertical section of the current collector vertically inserts into and passes through the inner cavity of the plastic block. The horizontal section of the current collector is located at the bottom of the square through groove. The plastic block and the current collector are integrally formed by nano-injection molding.

[0009] More preferably, the electrode tab has a through hole.

[0010] More preferably, the horizontal section of the current collector has a riveting hole, and the riveting hole is located in the square through groove.

[0011] More preferably, the explosion-proof component includes an explosion-proof mounting block, which has a waist-shaped groove and a liquid injection hole. An explosion-proof valve is installed in the waist-shaped groove, and the explosion-proof mounting block and the explosion-proof valve are integrally formed by nano-injection molding.

[0012] More preferably, the bottom surface of the top cover body is provided with a slot.

[0013] More preferably, the slot engages with the dividing plate.

[0014] More preferably, the number of cores is the same as the number of accommodating spaces in the single unit.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This invention connects the tab to the current collector on the electrode assembly using rivets. The use of rivets replaces the welding in the traditional method, effectively avoiding damage to the battery cell below during welding. It is convenient to operate, improves space utilization, and ensures the connection quality between the current collector and the tab.

[0017] This utility model's lithium-ion battery module directly assembles and packages the core, forming a battery module from core to module. It proposes a novel concept of direct-to-module (JTM), where power batteries are directly assembled from cores (wound, stacked, or pouch batteries) into modules. This utility model's lithium-ion battery module directly assembles into modules by connecting them in series / parallel at the core level, reducing manufacturing costs and improving space utilization. Attached Figure Description

[0018] Figure 1 This is an exploded view of the present invention;

[0019] Figure 2 This is a structural schematic diagram of cover plate assembly 4;

[0020] Figure 3 This is an exploded view of cover plate assembly 4;

[0021] Figure 4 This is a cross-sectional view of the pole assembly 42;

[0022] Figure 5 This is a schematic diagram of the core 2.

[0023] Figure 6 This is a schematic diagram of the outer shell 1;

[0024] Figure 7 This is a schematic diagram of the structure when the cover plate assembly 4 is connected to the core 2;

[0025] Figure 8 This is an assembly diagram of the present invention.

[0026] In the diagram: 1. Outer shell; 2. Core; 3. Rivet; 4. Cover plate assembly; 11. Individual housing space; 12. Divider plate; 21. Electrode ear; 22. Through hole; 41. Top cover body; 42. Electrode post assembly; 43. Explosion-proof assembly; 421. Plastic block; 422. Current collector; 422. Riveting hole; 4221. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0028] Reference Figures 1-8 A secondary battery module, comprising:

[0029] The outer shell 1 is a square cylindrical structure with an open upper side. The inner cavity of the outer shell 1 is divided into multiple individual accommodating spaces 11 by a dividing plate 12.

[0030] The outer shell 1, as the outermost shell, serves as a protective and supportive layer and is used to house multiple cores 2. The dividing plate 12 can be an insert plate that is directly inserted into the interior of the outer shell 1 to divide the inner cavity of the outer shell 1 into multiple individual accommodating spaces 11; or the dividing plate 12 can also be a structure formed integrally with the outer shell 1.

[0031] In one specific embodiment of this utility model, the height of the upper end face of the dividing plate 12 is lower than the height of the upper end face of the outer shell 1, and the height difference between the upper end face of the dividing plate 12 and the upper end face of the outer shell 1 is 0.05-20mm; the height difference between the two can be any value between 1mm, 2mm, 3mm, 4mm, 5mm and 20mm.

[0032] In one specific embodiment of this utility model, both the outer shell 1 and the dividing plate 12 are made of aluminum.

[0033] In one specific embodiment of this utility model, both the outer shell 1 and the dividing plate 12 are made of plastic, such as PPS.

[0034] Core 2, wherein the core 2 is a wound core, stacked core or soft pack battery; one end of the core 2 is provided with a tab 21, and each core 2 is accommodated in the single cell accommodating space 11;

[0035] In one specific embodiment of this utility model, there are four cores 2, each disposed within one of four individual accommodating spaces 11. Each core 2 is prepared by rolling multiple small cells using a core-rolling process. One end of each core 2 is provided with a pair of positive electrode tabs and a pair of negative electrode tabs. First, the opposing positive and negative electrode tabs are horizontally folded towards the center to overlap. Then, the overlapping parts are ultrasonically pre-welded (e.g.,...). Figure 5 (As shown).

[0036] The cover plate assembly 4 is composed of a top cover body 41, a pole post assembly 42 and an explosion-proof assembly 43; the explosion-proof assembly 43 is installed in the middle of the top cover body 41, and the pole post assembly 42 is installed on both sides of the top cover body 41 respectively.

[0037] In one specific embodiment of this utility model, the top cover body 41 is made of plastic material, which is not limited here. It can be PPS material, or injection molded material such as PP, PET, PI, etc. The top cover body 41 is provided with an installation channel for the pole post assembly 42 and the explosion-proof assembly 43. The installation channel on the top cover body 41 can be fixedly connected to the pole post assembly 42 and the explosion-proof assembly 43 by ultrasonic hot melt welding or laser welding.

[0038] Rivet 3, which is used to connect the tab 21 and the pole assembly 42.

[0039] In one specific embodiment of this utility model, the tab 21 is connected to the current collector 422 on the pole assembly 42 by a rivet 3.

[0040] The pole assembly 42 is composed of a plastic block 421 and a current collector 422. The plastic block 421 has a square through groove in the middle. The current collector 422 is L-shaped. The vertical section of the current collector 422 is vertically inserted and passes through the inner cavity of the plastic block 421. The horizontal section of the current collector 422 is located at the bottom of the square through groove. The plastic block 421 and the current collector 422 are integrally formed by nano-injection molding.

[0041] In one specific embodiment of this utility model, the plastic block 421 is made of PPS material, and the current collector 422 is made of metal material. The current collector 422 includes a positive current collector and a negative current collector, such as the positive current collector being made of aluminum and the negative current collector being made of copper. The plastic block 421 and the current collector 422 are integrally formed by nano-injection molding. The integral forming by nano-injection molding improves the bonding stability between different materials, strengthens the connection strength between the plastic block 421 and the current collector 422, reduces the number of parts in the electrode assembly structure, simplifies the assembly of the electrode assembly, and makes the electrode assembly structure lightweight.

[0042] In one specific embodiment of this utility model, the current collector 42 has an L-shaped structure. The horizontal section of the current collector 422 is located at the bottom of the plastic block 421 to block the square through groove. The square through groove facilitates the insertion and connection of the rivet 3. The vertical section of the current collector 422 is vertically inserted and penetrates the plastic block 421. The penetration position of the current collector 422 is close to the square through groove. The current collector 422 that penetrates the upper end of the plastic block 421 is used for series / parallel connection between the cores 2.

[0043] The tab 21 has a through hole 22, and the horizontal section of the current collector 422 has a riveting hole 4221, which is located in the square through groove.

[0044] In one specific embodiment of this utility model, the rivet 3 passes through the through hole 22 and the riveting hole 4221 from bottom to top, and riveting the tab 21 and the current collector 422 together.

[0045] The explosion-proof component 43 includes an explosion-proof mounting block, which has a waist-shaped groove and a liquid injection hole. An explosion-proof valve is installed in the waist-shaped groove. The explosion-proof mounting block and the explosion-proof valve are integrally formed by nano-injection molding.

[0046] In one specific embodiment of this utility model, the explosion-proof mounting block is made of PPS material, and the explosion-proof valve is made of metal, such as aluminum. The explosion-proof mounting block and the explosion-proof valve are integrally formed by nano-injection molding. The integral forming by nano-injection molding improves the bonding stability between different materials and strengthens the connection strength between the explosion-proof mounting block and the explosion-proof valve. An injection pin is sealed and installed inside the injection hole.

[0047] The bottom surface of the top cover body 41 is provided with a slot, which is engaged with the dividing plate 12.

[0048] In one specific embodiment of this utility model, the slot on the bottom surface of the top cover body 41 is the gap between adjacent protrusions at the bottom of the top cover body 41. The slot is sealed and engaged with the dividing plate 12 to separate the individual accommodating space 11 and form an independent accommodating space.

[0049] In one specific embodiment of this utility model, a positioning groove is provided on the top surface of the top cover body 41, and the top cover body 41 and the dividing plate 12 can be welded together by through welding through the positioning groove.

[0050] The number of cores 2 is the same as the number of single-unit accommodating spaces 11.

[0051] In one specific embodiment of this utility model, the number of core 2 and single-unit accommodating space 11 is 4. The number of core 2 and single-unit accommodating space 11 is not limited here, and can be 5, 6, 7, 8, etc.

[0052] This utility model's lithium-ion battery module directly assembles and packages the core, forming a battery module from core to module. It proposes a novel concept of direct-to-module (JTM), where power batteries are directly assembled from cores (wound, stacked, or pouch batteries) into modules. This utility model's lithium-ion battery module directly assembles into modules by connecting them in series / parallel at the core level, reducing manufacturing costs and improving space utilization.

[0053] This invention connects the tab to the current collector on the electrode assembly using rivets. The use of rivets replaces the welding in the traditional method, effectively avoiding damage to the battery cell below during welding. It is convenient to operate, improves space utilization, and ensures the connection quality between the current collector and the tab.

Claims

1. A secondary battery module, characterized in that, include: The outer shell is a square cylindrical structure with an open top, and the inner cavity of the outer shell is divided into multiple individual accommodating spaces by a dividing plate; The core is a wound core, a stacked core, or a pouch battery; one end of the core is provided with a tab, and each core is accommodated within the single-cell housing space. A cover plate assembly, comprising a top cover body, a pole assembly, and an explosion-proof assembly; the explosion-proof assembly is installed in the middle of the top cover body, and pole assemblies are installed on both sides of the top cover body respectively; A rivet for connecting the tab and the pole assembly.

2. A secondary battery module according to claim 1, characterized in that, The electrode assembly consists of a plastic block and a current collector. A square through groove is provided in the middle of the plastic block. The current collector is L-shaped. The vertical section of the current collector is vertically inserted and passes through the inner cavity of the plastic block. The horizontal section of the current collector is located at the bottom of the square through groove. The plastic block and the current collector are integrally formed by nano-injection molding.

3. A secondary battery module according to claim 2, characterized in that, The electrode tab has a through hole.

4. A secondary battery module according to claim 2, characterized in that, The horizontal section of the current collector is provided with a riveting hole, and the riveting hole is located in the square through groove.

5. A secondary battery module according to claim 1, characterized in that, The explosion-proof component includes an explosion-proof mounting block, which has a waist-shaped groove and a liquid injection hole. An explosion-proof valve is installed in the waist-shaped groove. The explosion-proof mounting block and the explosion-proof valve are integrally formed by nano-injection molding.

6. A secondary battery module according to claim 1, characterized in that, The bottom surface of the top cover body is provided with a slot.

7. A secondary battery module according to claim 6, characterized in that, The slot engages with the dividing plate.

8. A secondary battery module according to claim 1, characterized in that, The number of cores is the same as the number of accommodating spaces in the single unit.

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