Lithium ion battery module

Abstract

The lithium ion battery module is characterized in that a pole assembly is integrally formed by a plastic block and a connecting piece through nanometer injection molding, the connecting piece is vertically inserted into an inner cavity of the plastic block in a penetrating mode, and the upper end and the lower end of the connecting piece penetrate through and extend out of the upper surface and the lower surface of the plastic block respectively; the lower end of the connecting sheet is fixedly connected with the tab in a vertical lap joint manner; a seal is formed between the top cover and the open square cylinder on the upper side of the shell and is used for accommodating a plurality of separated core bodies, and a plurality of pole mounting holes for mounting pole assemblies are formed in the surface of the top cover; according to the invention, the vertical lap joint welding of the penetrating connecting sheet and the tab is used for replacing the overlapped horizontal welding of the tab and the lower surface of the pole post after the tab is horizontally bent in a traditional mode, so that the damage to a battery cell below the tab during welding is effectively avoided, the welding space is increased, the operation is convenient, and the welding quality between the connecting sheet and the tab is ensured.

Description

Technical Field

[0001] The present invention relates to the field of lithium-ion batteries, and in particular to a lithium-ion battery structure in which a core (wound core, stacked core or soft-pack battery) is directly assembled into a module. Background Art

[0002] The traditional battery system manufacturing method is to first manufacture the battery cells, then assemble the battery cells into battery modules, and finally install the battery modules in the battery box. The BOM cost of the battery system includes the battery cell cost, module cost and system PACK material cost, and the manufacturing cost also includes the battery cell manufacturing cost, module manufacturing cost and system manufacturing cost.

[0003] In order to achieve cost reduction and efficiency improvement of battery system, the JTM (Jerry-roll To Module) model is proposed, which is a method of going directly from core to module, that is, all single cores are assembled and fixed in series in the battery box to form an overall module battery module. Its advantages are to improve the volume utilization of the battery box, reduce the number of battery pack components, improve production efficiency, and reduce costs.

[0004] However, in the traditional mode, the pole tab is horizontally bent and then welded horizontally to overlap with the lower surface of the pole. Torque welding or penetration welding is usually used to connect the pole tab and the pole. The horizontal welding of the pole tab to the lower surface of the pole can easily damage the battery cell underneath, and the welding space is limited, which is inconvenient for welding operations.

[0005] To this end, we propose a lithium-ion battery module to solve the connection problem of the tabs in the JTM mode. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings existing in the prior art. In order to achieve the above purpose, the present invention adopts the following technical solutions: A lithium-ion battery module comprises an outer shell, which is a square cylindrical structure with an open upper side, and the inner cavity of the outer shell is evenly divided into a plurality of single-cell accommodating spaces by a dividing plate; a core body, which is a rolled core, a stacked core or a soft-pack battery; a pole ear is provided at one end of the core body, and each of the core bodies is accommodated in the single-cell accommodating space; a pole assembly, which is integrally formed by a plastic block and a connecting piece by nano injection molding, the connecting piece is vertically inserted into the inner cavity of the plastic block, and the upper and lower ends of the connecting piece respectively extend through the upper and lower surfaces of the plastic block, and the lower end of the connecting piece is vertically overlapped and fixedly connected with the pole ear; a top cover, a seal is formed between the top cover and the square cylindrical body opened on the upper side of the outer shell for accommodating a plurality of separated core bodies, and a plurality of pole mounting holes for installing the pole assembly are provided on the surface of the top cover.

[0007] Further preferably, the top cover is provided with a plurality of waist-shaped grooves and a plurality of liquid injection holes.

[0008] Further preferably, the waist-shaped groove and the liquid injection hole are located in the middle of the top cover.

[0009] Further preferably, a plurality of slots are provided on the bottom surface of the top cover.

[0010] Further preferably, the card slot is sealed and snap-fitted with the partition plate.

[0011] Further preferably, the number of the cores is the same as the number of the monomer accommodating spaces.

[0012] Further preferably, the number of the waist-shaped grooves and the injection holes is the same as the number of the single body accommodating spaces.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention replaces the traditional method of horizontally bending the pole tab and then welding it horizontally so that it overlaps with the lower surface of the pole by vertically overlapping the penetrating connecting piece and the pole ear, effectively avoiding damage to the battery cell underneath during welding, and increasing the welding space for easy operation, thereby ensuring the welding quality between the connecting piece and the pole ear.

[0014] The lithium-ion battery module of the present invention directly assembles and packages the core to form a battery module from the core to the module, and proposes a new concept of core-to-module (JTM), which is a power battery directly assembled from the core (core, stacked core or soft-pack battery) into a module; the lithium-ion battery module of the present invention is directly assembled into a module by series / parallel connection from the core level, thereby reducing manufacturing costs and improving space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an explosion schematic diagram of the present invention; Figure 2 It is a schematic structural diagram of the pole assembly 3; Figure 3 It is a schematic diagram of the structure of the top cover 4; Figure 4 It is a schematic structural diagram of the core 2; Figure 5 It is a schematic diagram of the structure of the housing 1; Figure 6 It is a schematic diagram of the structure in which the shell 1 is installed into the core 2; Figure 7 It is a structural schematic diagram when the pole assembly 3 is connected to the core body 2; Figure 8 It is a schematic diagram of the assembly of the present invention.

[0016] In the figure: a housing 1, a core 2, a pole assembly 3, a top cover 4, a monomer accommodating space 11, a dividing plate 12, a pole ear 21, a plastic block 31, a connecting piece 32, a pole mounting hole 41, a waist-shaped groove 42, and a liquid injection hole 43. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] Reference Figure 1-Figure 8 A lithium-ion battery module comprises a housing 1, wherein the housing 1 is a square cylindrical structure with an open upper side, and the inner cavity of the housing 1 is evenly divided into a plurality of monomer accommodating spaces 11 by a partition plate 12; The outer shell 1, as the outermost shell, plays a protective supporting role and is used to accommodate multiple cores 2. The partition plate 12 can be an insert plate, which is directly inserted into the interior of the outer shell 1 to divide the inner cavity of the outer shell 1 into multiple single-body accommodating spaces 11; or the partition plate 12 can also be a structure formed by integral molding of the outer shell 1.

[0019] In a specific embodiment of the present invention, the shell 1 and the partition plate 12 are both made of aluminum.

[0020] The core 2 is a rolled core, a stacked core or a soft-pack battery; one end of the core 2 is provided with a tab 21, and each of the cores 2 is accommodated in the single-cell accommodating space 11; In a specific embodiment of the present invention, there are four core bodies 2, which are respectively arranged in four single-cell accommodating spaces 11. The core bodies 2 are prepared by curling multiple small battery cells through a core winding process, and one end of the core body 2 is respectively provided with a positive electrode ear and a negative electrode ear; wherein the positive electrode ear and the negative electrode ear are vertically arranged and fixedly connected to the lower end of the connecting piece 32.

[0021] The pole assembly 3 is formed by a plastic block 31 and a connecting piece 32 through nano injection molding, the connecting piece 32 is vertically inserted into the inner cavity of the plastic block 31, and the upper and lower ends of the connecting piece 32 respectively extend through the upper and lower surfaces of the plastic block 31, and the lower end of the connecting piece 32 is vertically overlapped and fixedly connected with the pole ear 21; In a specific embodiment of the present invention, the plastic block 31 is made of plastic material, which is not limited here and can be PPS material, or PP, PET, PI and other injection molding materials; the connecting piece 32 is made of metal material, and the connecting piece 32 includes a positive connecting piece and a negative connecting piece. For example, the material of the positive connecting piece is aluminum, and the material of the negative connecting piece is copper. The plastic block 31 and the connecting piece 32 are integrally formed by nano injection molding. The integral nano injection molding improves the bonding stability between different materials, which not only strengthens the connection strength between the plastic block 31 and the connecting piece 3, but also improves the sealing effect between the plastic block 31 and the connecting piece 32. At the same time, the number of parts of the pole assembly structure is reduced, the assembly of the pole assembly is simplified, and the pole assembly structure is lightweight.

[0022] In a specific embodiment of the present invention, the connecting piece 32 vertically penetrates the plastic block 31 from the middle, the connecting piece 32 located at the lower end of the plastic block 31 is used to vertically overlap with the pole ear 21, and the pole ear 21 and the connecting piece 32 are fixed by welding, and the connecting piece 32 located at the upper end of the plastic block 31 is used for series / parallel connection between the core bodies 2.

[0023] The present invention replaces the traditional mode of horizontally bending the pole ear and then horizontally welding it to overlap with the lower surface of the pole by vertically overlapping the penetrating connecting piece 32 and the pole ear 21, effectively avoiding interference from adjacent battery cells, thereby ensuring the welding quality between the connecting piece 32 and the pole ear 21.

[0024] The top cover 4 forms a seal with the square cylinder opened on the upper side of the housing 1 for accommodating a plurality of separated cores. The surface of the top cover 4 is provided with a plurality of pole mounting holes 41 for mounting the pole assembly 3 .

[0025] In a specific embodiment of the present invention, the top cover 4 and the outer shell 1 match each other to form a seal; ultrasonic hot melt welding or laser welding can be used to ensure the sealing of the entire shell and the sealing of the monomer accommodating space 11.

[0026] In a specific embodiment of the present invention, ultrasonic hot-melt welding or laser welding may be used between the plastic block 31 on the pole assembly 3 and the pole mounting hole 41 to ensure the sealing between the plastic block 31 and the top cover 4 .

[0027] In a specific embodiment of the present invention, the top cover 4 is made of aluminum.

[0028] In a specific embodiment of the present invention, the connecting piece 32 on the pole assembly 3 is first welded to the pole ear 21 on the core body 2 to form a bare cell assembly, and then the bare cell assembly is loaded into the single body accommodating space 11, and then the top cover 4 is put on the pole assembly 3 and matched with the outer shell 1, and finally the plastic block 31 and the top cover 4, and the outer shell 1 and the top cover 4 are fixed by welding.

[0029] The top cover 4 is provided with a plurality of waist-shaped grooves 42 and a plurality of liquid injection holes 43 ; the waist-shaped grooves and the liquid injection holes are located in the middle of the top cover 4 .

[0030] In a specific embodiment of the present invention, a waist-shaped groove 42 and a liquid injection hole 43 are provided on the top cover 4. The waist-shaped groove 42 is used to install an explosion-proof valve, and the liquid injection hole 43 is used to inject liquid and exhaust gas into the monomer accommodating space 11; electrolyte can be injected according to actual needs. The number of waist-shaped grooves 42 and liquid injection holes 43 is the same as the number of monomer accommodating spaces 11, so that the explosion-proof valve and the liquid injection holes are controlled separately from the corresponding monomer accommodating spaces 11.

[0031] The bottom surface of the top cover 4 is provided with a plurality of slots; the slots are sealed and engaged with the partition plate 12 .

[0032] In a specific embodiment of the present invention, the number of the card slots is three, and the shape of the card slots is convex. The card slots are sealed and connected with the partition plate 12 to separate the single-unit accommodating space 11 to form an independent accommodating space.

[0033] The number of the cores 2 is the same as the number of the single-unit accommodating spaces 11 .

[0034] In a specific embodiment of the present invention, the number of the core body 2 and the number of the monomer accommodating spaces 11 are both 4. The number of the core body 2 and the number of the monomer accommodating spaces 11 are not limited here, and can be 5, or 6, 7, 8, etc.

[0035] The number of the waist-shaped grooves 42 and the injection holes 43 is the same as the number of the single unit accommodating spaces 11 .

[0036] In a specific embodiment of the present invention, the waist-shaped groove 42 is used to install an explosion-proof valve, and the injection hole 43 is used to inject liquid and exhaust gas into the monomer accommodating space 11; electrolyte can be injected according to actual needs; the number of waist-shaped grooves 42 and injection holes 43 is the same as the number of monomer accommodating spaces 11, so that each monomer accommodating space 11 is installed with a corresponding explosion-proof valve and injection hole, so that each core 2 can be individually controlled.

[0037] The lithium-ion battery module of the present invention directly assembles and packages the core to form a battery module from the core to the module, and proposes a new concept of core-to-module (JTM), which is a power battery directly assembled from the core (core, stacked core or soft-pack battery) into a module; the lithium-ion battery module of the present invention is directly assembled into a module by series / parallel connection from the core level, thereby reducing manufacturing costs and improving space utilization.

[0038] The present invention replaces the traditional method of horizontally bending the pole tab and then welding it horizontally so that it overlaps with the lower surface of the pole by vertically overlapping the penetrating connecting piece and the pole ear, effectively avoiding damage to the battery cell underneath during welding, and increasing the welding space for easy operation, thereby ensuring the welding quality between the connecting piece and the pole ear.

Claims

1. A lithium-ion battery module, characterized in that: include: The outer shell is a square cylindrical structure with an open upper side, and the inner cavity of the outer shell is divided into a plurality of single-unit accommodating spaces by a dividing plate; A core body, wherein the core body is a rolled core, a stacked core or a soft-pack battery; a tab is provided at one end of the core body, and each of the core bodies is accommodated in the single-cell accommodating space; A pole assembly, wherein the pole assembly is integrally formed by a plastic block and a connecting piece through nano injection molding, wherein the connecting piece is vertically inserted into the inner cavity of the plastic block, and the upper and lower ends of the connecting piece respectively penetrate and extend out of the upper and lower surfaces of the plastic block, and the lower end of the connecting piece is vertically overlapped and fixedly connected with the pole lug; A top cover is provided, wherein a seal is formed between the top cover and the square cylinder body opened on the upper side of the shell for accommodating a plurality of separated core bodies, and a plurality of pole mounting holes for mounting pole assemblies are provided on the surface of the top cover.

2. A lithium-ion battery module according to claim 1, characterized in that: The top cover is provided with a plurality of waist-shaped grooves and a plurality of liquid injection holes.

3. A lithium-ion battery module according to claim 2, characterized in that: The waist-shaped groove and the liquid injection hole are located in the middle of the top cover.

4. A lithium-ion battery module according to claim 1, characterized in that: The bottom surface of the top cover is provided with a plurality of card slots.

5. A lithium-ion battery module according to claim 4, characterized in that: The clamping groove is sealed and clamped with the dividing plate.

6. A lithium-ion battery module according to claim 1, characterized in that: The number of the cores is the same as the number of the single-unit accommodating spaces.

7. A lithium-ion battery module according to claim 2, characterized in that: The number of the waist-shaped grooves and the liquid injection holes is the same as the number of the single-unit accommodating spaces.

Images