A connection structure of a soft package high-capacity battery cell and a pole

Abstract

The application provides a connection structure of a soft package large-capacity battery cell and a pole, belongs to the technical field of energy storage batteries, and comprises a soft package cell and a bus bar. A through hole is arranged on the bus bar, a connecting plate is arranged at the through hole, a tab is connected to the soft package cell, and the tab penetrates through the through hole of the bus bar and is attached to the connecting plate. The through hole is arranged on the bus bar, no hole is formed on the tab, and the internal resistance of the tab is not increased. Meanwhile, the tab is attached to the connecting plate, the connection area of the tab and the bus bar is increased, that is, the overcurrent area of the tab and the bus bar is increased, and false welding can be effectively prevented.

Description

Technical Field

[0001] This invention belongs to the field of energy storage battery technology, and relates to the connection technology between battery cells and terminals, specifically a connection structure between a soft-pack high-capacity battery cell and terminals. Background Technology

[0002] Soft-pack batteries are a type of battery that differs from hard-pack batteries. Their positive and negative electrodes, separators, and electrolytes are largely the same, the biggest difference being that soft-pack batteries use an aluminum-plastic composite film as their outer shell, while prismatic and cylindrical hard-pack batteries use metal materials. Soft-pack batteries offer numerous advantages, including high safety, light weight, high energy density, excellent electrochemical performance, and long lifespan. Therefore, driven by the three core requirements of high energy density, long driving range, and high safety for new energy vehicles and power batteries, power soft-pack batteries are rapidly developing and beginning to emerge in the pure electric passenger vehicle market. Furthermore, with major automotive brands continuously strengthening their presence in the pure electric vehicle sector, power soft-pack batteries will usher in even greater development opportunities in the future.

[0003] Traditionally, when connecting the tabs and busbars of a pouch cell, threaded holes need to be drilled on both the tabs and the busbar. Then, screws are passed through the threaded holes on the tabs and the busbar to connect the tabs to the busbar, and finally, heat shrink tubing is used for wrapping. This drilling connection method severely damages the current carrying capacity of the tabs on the cell and increases the internal resistance of the tabs, causing the cell temperature to rise during operation. At the same time, the screw connection between the tabs and the busbar is difficult to operate and easily damages the tabs on the cell. Furthermore, the use of heat shrink tubing severely affects the heat dissipation of the cell.

[0004] For example, patent CN206210909U discloses a connection structure between a lithium-ion pouch cell connector cap and a cell tab. The structure includes a battery cell connector cap, a pouch cell, and foam. An aluminum electrode, divided into a positive and a negative electrode, is embedded in the battery cell connector cap. A pouch cell is positioned at the lower end of the connector cap, and a cell tab is mounted on the upper end of the pouch cell. Foam with through holes is installed between two pouch cells. This process, which involves drilling holes in the tabs of each cell, severely impairs the current-carrying capacity of the cell tabs and increases their internal resistance. Summary of the Invention

[0005] To address the problem that drilling holes in the tabs in the prior art would severely affect the current-carrying capacity of the battery cell tabs and increase the internal resistance of the tabs, this invention proposes a connection structure between the soft-pack high-capacity battery cell and the terminal post.

[0006] This invention features a through-hole on the busbar, with a connecting plate fixed above the through-hole. By passing the tab through the through-hole and fixing it to the connecting plate, the connection area between the tab and the busbar is increased, thus increasing the current flow area. Furthermore, it eliminates the need for drilling holes in the tab, thus not affecting its internal resistance. The specific technical solution is as follows:

[0007] A connection structure between a soft-pack high-capacity battery cell and a terminal post includes a soft-pack battery cell and a busbar. The busbar has a through hole, and a connecting plate is provided at the through hole. A terminal tab is connected to the soft-pack battery cell, and the terminal tab passes through the through hole on the busbar and fits against the connecting plate.

[0008] Further specified, there are multiple soft-pack battery cells, and multiple through holes are arranged in parallel on the busbar;

[0009] The tabs on multiple pouch cells are configured to correspond one-to-one with the through holes on the busbar;

[0010] Multiple tabs on multiple pouch cells are connected to form multiple tab bundles, and each tab bundle is set to correspond to a through hole on the busbar.

[0011] Further specifying, the tabs on multiple pouch cells are bonded together with conductive and thermally conductive adhesive to form a tab bundle.

[0012] Furthermore, the through holes on the busbar are rectangular through holes that match the shape of the tabs or the shape of the tab bundle.

[0013] Further defining the battery module, multiple pouch cells are stacked side by side to form a battery module. A fixing plate is provided on the outside of the battery module to clamp and fix the multiple pouch cells. The fixing plate is arranged side by side with the pouch cells.

[0014] Further specifying, the fixing plates located on the opposite side of the battery module are connected by screws.

[0015] Further specified, the electrode tab or electrode tab bundle is welded to the connecting plate.

[0016] Furthermore, the connection structure between the soft-pack high-capacity battery cell and the terminal post also includes the terminal post, which has multiple grooves, the number of which is the same as the number of through holes; after the connecting plate is connected to the tab or tab bundle, it is inserted into the groove to connect the busbar to the terminal post.

[0017] Furthermore, the connecting plate is bonded to the groove wall using a conductive and thermally conductive adhesive.

[0018] Furthermore, the busbar and the pole are fixed together by clamps.

[0019] Further specified, the busbar is welded to the pole.

[0020] Furthermore, the pole is formed by splicing together multiple metal blocks, with a groove formed at the splicing point of two adjacent metal blocks, and a conductive and thermally conductive adhesive is coated at the splicing point of two adjacent metal blocks.

[0021] Furthermore, the electrode post is provided with a heat dissipation mechanism, which is a semiconductor cooling chip, heat dissipation fins, a cooling fan, or a heat pipe.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. This invention discloses a connection structure between a pouch cell and a terminal post for a high-capacity pouch battery. The structure includes a pouch cell and a busbar. A through-hole is provided on the busbar, and a connecting plate is disposed at the through-hole. A tab is connected to the pouch cell, passing through the through-hole on the busbar and fitting snugly to the connecting plate. This invention places the through-hole on the busbar, eliminating the need for holes in the tab, thus avoiding an increase in the internal resistance of the tab. Simultaneously, fitting the tab to the connecting plate increases the connection area between the tab and the busbar, thereby increasing the current-carrying area and effectively preventing cold solder joints.

[0024] 2. There are multiple soft-pack cells, and multiple through holes are set on the busbar. The tabs on the multiple soft-pack cells are set one-to-one with the through holes on the busbar; or the tabs on the multiple soft-pack cells are connected to form multiple tab bundles, and the multiple tab bundles are set one-to-one with the through holes on the busbar. This setting can ensure that the tabs on each soft-pack cell are connected to the connecting plate, avoiding missed connections or loose connections.

[0025] 3. The tabs on multiple pouch cells are bonded together with conductive and thermally conductive adhesive to form a tab bundle. The conductive and thermally conductive adhesive not only serves to bond the multiple tabs together, but also conducts the heat generated by the pouch cells to the busbar to achieve heat dissipation.

[0026] 4. The through holes on the busbar are rectangular through holes that match the shape of the tabs or the tab bundles; this allows the tabs or tab bundles to be easily inserted into the through holes, facilitating the mating of the tabs or tab bundles with the through holes.

[0027] 5. Multiple pouch cells are stacked side by side to form a battery module, and a fixing plate is provided on the outside of the battery module; the fixing plate can clamp and fix the multiple pouch cells to prevent misalignment between the multiple pouch cells.

[0028] 6. The connection structure between the soft-pack high-capacity battery cell and the terminal post of the present invention also includes the terminal post, on which grooves corresponding to the number and position of through holes are provided. During connection, the connecting plate on the busbar is fixed to the tab or tab bundle and then inserted into the groove, which facilitates the fixed connection between the terminal post and the busbar, and also increases the connection area between the busbar and the terminal post, that is, increases the current flow area between the busbar and the terminal post.

[0029] 7. The connecting plate and the groove wall are bonded together with conductive and thermally conductive adhesive. This adhesive not only increases the connection strength between the connecting plate and the groove, but also enhances the heat transfer efficiency from the busbar to the electrode.

[0030] 8. The busbar and the terminal are fixed with clamps, which makes the connection between the busbar and the terminal more secure and prevents misalignment.

[0031] 9. A heat dissipation mechanism is provided on the electrode post, which enhances the heat dissipation efficiency of the electrode post. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the connection structure between the cell and the terminal of a pouch battery with large capacity.

[0033] Figure 2 This is a schematic diagram showing the connection between the pouch cell and the busbar;

[0034] Figure 3 A schematic diagram of the structure for forming a tab bundle on multiple pouch cells;

[0035] Figure 4 A schematic diagram showing a through hole on one side of the busbar connection plate;

[0036] Figure 5 A schematic diagram showing the structure with through holes on opposite sides of the busbar connection plate;

[0037] Figure 6 A schematic diagram of a structure with grooves on the pole post;

[0038] Figure 7 This is a schematic diagram of the clamp structure;

[0039] Among them, 1-soft-pack battery cell, 2-fixing clamp, 3-screw, 4-busbar, 41-connecting plate, 42-through hole, 5-pole post, 51-groove, 6-pole tab, 61-pole tab bundle. Detailed Implementation

[0040] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described below.

[0041] This invention discloses a connection structure between a pouch battery cell and its terminals for a high-capacity battery. The structure comprises a pouch battery cell 1 and a busbar 4. The busbar 4 has through holes 42, and a connecting plate 41 is disposed at each through hole 42. A tab 6 is connected to the pouch battery cell 1, and the tab 6 passes through the through hole 42 on the busbar 4 and is fitted to the connecting plate 41. Multiple pouch battery cells 1 are present, and multiple through holes 42 are arranged in parallel on the busbar 4. The tabs 6 on the multiple pouch battery cells 1 correspond one-to-one with the through holes 42 on the busbar 4; or the tabs 6 on the multiple pouch battery cells 1 are connected to form multiple tab bundles 61, and the multiple tab bundles 61 correspond one-to-one with the through holes 42 on the busbar 4. The tabs 6 on the multiple pouch battery cells 1 are bonded together with conductive and thermally conductive adhesive to form tab bundles 61. The through holes 42 on the busbar 4 are rectangular through holes that match the shape of the tabs 6 or the tab bundles 61. Multiple pouch cells 1 are stacked side-by-side to form a battery module. A fixing plate 2 is provided on the outside of the battery module to clamp and fix the multiple pouch cells 1. The fixing plate 2 is arranged side-by-side with the pouch cells 1. The fixing plates 2 located on opposite sides of the battery module are connected by screws 3. The tabs 6 or tab bundles 61 are welded to the connecting plate 41. The connection structure between the pouch high-capacity battery cells and the terminals also includes terminals 5. The terminals 5 are provided with multiple grooves 51, the number of grooves 51 being the same as the number of through holes 42. After the connecting plate 41 is connected to the tabs 6 or tab bundles 61, it is inserted into the grooves 51 to connect the busbar 4 to the terminal 5. The connecting plate 41 and the groove wall of the groove 51 are bonded with conductive and thermally conductive adhesive. The busbar 4 and the terminal 5 are fixed by clamps. The busbar 4 and the terminal 5 are welded. The electrode post 5 is formed by splicing together multiple metal blocks, with a groove 51 formed at the splicing point of two adjacent metal blocks, and a conductive and thermally conductive adhesive is coated at the splicing point of two adjacent metal blocks. The electrode post 5 is provided with a heat dissipation mechanism, which may be a semiconductor cooling chip, heat sink fins, cooling fan, or heat pipe.

[0042] Example 1

[0043] See Figures 1-2 This embodiment discloses a connection structure between a soft-pack high-capacity battery cell and its terminals, comprising a soft-pack battery cell 1 and a busbar 4. The busbar 4 is divided into a positive busbar and a negative busbar. Both the positive and negative busbars are provided with through holes 42, and a connecting plate 41 is provided at the through holes 42. The busbar 4 is a plate-shaped structure with a rectangular cross-section. A tab 6 is connected to the soft-pack battery cell 1. The tab 6 is divided into a positive tab and a negative tab. The positive tab passes through the through hole on the positive busbar and is attached to the connecting plate 41 on the positive busbar. The negative tab passes through the through hole on the negative busbar and is attached to the connecting plate 41 on the negative busbar.

[0044] Preferably, in this embodiment, the through hole 42 is provided along the width direction of the busbar 4.

[0045] Preferably, in this embodiment, the connecting plate 41 is disposed above the through hole 42, that is, the connecting plate 41 and the soft-pack battery cell 1 are disposed opposite to each other along the panel of the busbar 4; preferably, the panel of the connecting plate 41 and the panel of the busbar 4 are perpendicular to each other.

[0046] Example 2

[0047] This embodiment describes a connection structure between a soft-pack high-capacity battery cell and its terminals. Based on embodiment 1, it has 50 soft-pack cells 1 arranged in two rows with 25 cells in each row. Each row has one positive busbar and one negative busbar.

[0048] The positive tab on the pouch cell 1 is connected to the corresponding through hole 42 on the positive busbar; the negative tab on the pouch cell 1 is connected to the corresponding through hole 42 on the negative busbar.

[0049] See Figure 3 Alternatively, five pouch cells 1 in each row can be grouped together. The positive tabs on the five pouch cells 1 in the same group are connected to form a tab bundle 61, and the negative tabs on the five pouch cells 1 in the same group are connected to form a tab bundle 61. That is, the positive and negative tabs formed in each row form five tab bundles 61 respectively. The tab bundles 61 formed by the positive tabs are connected one-to-one with the through holes 42 on the positive busbar; the tab bundles 61 formed by the negative tabs are connected one-to-one with the through holes 42 on the negative busbar.

[0050] In this embodiment, the positive or negative tabs on the soft-pack battery cell 1 in the same group are bonded together with adhesive, preferably with conductive and thermally conductive adhesive.

[0051] It should be noted that the number of pouch cells in this embodiment can be 3, 5, 10, 15, 20, or even more, depending on the different battery capacity requirements; the number of rows of pouch cells 1 can be 1, 2, 3, or even more, depending on the battery volume requirements; the number of positive or negative tabs corresponding to each tab bundle 61 can be 2, 3, 4, or even more.

[0052] Preferably, in this embodiment, the through hole 42 on the busbar 4 is a rectangular through hole that matches the shape of the tab 6 or the shape of the tab bundle 61.

[0053] Preferably, in this embodiment, the positive electrode tab and the positive electrode busbar are both made of aluminum, and in this embodiment, the negative electrode tab and the negative electrode busbar are both made of copper or copper-plated nickel.

[0054] See Figure 4 and Figure 5 A through hole 42 is provided on one or both sides of the connecting plate 41. If it is provided on both sides, the positive or negative electrode tab can be passed through from either side.

[0055] Preferably, in this embodiment, the tab 6 or tab bundle 61 is welded to the connecting plate 41.

[0056] Example 3

[0057] This embodiment describes a connection structure between a soft-pack high-capacity battery cell and its terminals. Based on embodiment 2, 30 soft-pack cells 1 are stacked side by side to form a battery module. A fixing plate 2 is provided on the outside of the battery module to clamp and fix the 30 soft-pack cells 1. The fixing plate 2 is arranged side by side with the soft-pack cells 1.

[0058] Preferably, in this embodiment, six screws 3 are provided between the two fixing plates 2, and the six screws 3 are in two groups, respectively located on opposite sides of the battery module.

[0059] The fixing plate 2 in this embodiment can be one of PP board, PE board, PVC board, PET board, PPS board, PPA board, PEEK board or LCP board; it can play an insulating role.

[0060] Example 4

[0061] See Figure 6 This embodiment provides a connection structure between a soft-pack high-capacity battery cell and a terminal post. Based on embodiment 3, it further includes a terminal post 5. The terminal post 5 is provided with grooves 51 in the same number as the through holes 42 on the busbar 4. After the connecting plate 41 is connected to the tab 6 or the tab bundle 61, it is inserted into the grooves 51 to connect the busbar 4 and the terminal post 5.

[0062] Preferably, in this embodiment, the connecting plate 41 is bonded to the tab 6 or the tab bundle 61 with a conductive and thermally conductive adhesive; more preferably, in this embodiment, the connecting plate 41 and the tab 6 or the tab bundle 61 are further welded after being bonded with the conductive and thermally conductive adhesive.

[0063] In this embodiment, the busbar 4 and the pole post 5 are fixed by a clamp; the clamp is set at the end or middle of the connection between the busbar 4 and the pole post 5.

[0064] See Figure 7 Preferably, the clamp in this embodiment is composed of a U-shaped retaining ring and a baffle. Both ends of the U-shaped retaining ring are provided with threads, and the baffle is provided with a retaining ring hole. In use, the retaining ring is wrapped around the outside of the busbar 4 and the pole post 5, and the baffle is fitted onto the retaining ring. After fitting, the retaining ring portion corresponding to the outside of the baffle is limited by a nut.

[0065] Alternatively, in this embodiment, the clamp is a rectangular ring structure. In use, the clamp is fitted onto the outside of the busbar 4 and the pole post 5, and the connection of the clamp is tightened and fixed by bolts.

[0066] Example 5

[0067] This embodiment describes a connection structure between a soft-pack high-capacity battery cell and an electrode post. Based on embodiment 4, the electrode post 5 is formed by splicing together 5 metal blocks. A groove 51 is formed at the splicing point of two adjacent metal blocks, and a conductive and thermally conductive adhesive is coated at the splicing point of two adjacent metal blocks. The two adjacent metal blocks are bonded together by the conductive and thermally conductive adhesive.

[0068] In this embodiment, a heat dissipation mechanism is provided at one or both ends of the electrode. This heat dissipation mechanism can be a thermoelectric cooler, heat sink fins, a cooling fan, or a heat pipe. Preferably, the heat dissipation mechanism is a thermoelectric cooler.

[0069] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments, and is not intended to limit the present invention. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be considered to fall within the patent protection scope defined by the submitted claims.

Claims

1. A connection structure of a soft package large capacity battery cell and a pole, characterized by, It includes a soft-pack battery cell and a busbar. The busbar has a through hole and a connecting plate at the through hole. The soft-pack battery cell is connected to a tab. The tab passes through the through hole on the busbar and fits into the connecting plate, increasing the current flow area between the tab and the busbar. The connection structure between the soft-pack high-capacity battery cell and the terminal post also includes the terminal post, which has multiple grooves, the number of which is the same as the number of through holes; after the connecting plate is connected to the tab or tab bundle, it is inserted into the groove to connect the busbar to the terminal post, thereby increasing the current flow area between the busbar and the terminal post.

2. The connection structure of the soft package large capacity battery cell and the pole according to claim 1, characterized in that, There are multiple soft-pack battery cells, and multiple through holes are arranged in parallel on the busbar; The tabs on multiple pouch cells are configured to correspond one-to-one with the through holes on the busbar; Multiple tabs on multiple pouch cells are connected to form multiple tab bundles, and each tab bundle is set to correspond one-to-one with the through holes on the busbar.

3. The connection structure of the pouch-type large-capacity battery cell and the pole according to claim 2, characterized in that, The tabs on multiple pouch cells are bonded together with conductive and thermally conductive adhesive to form a tab bundle.

4. The connection structure of the pouch-type large-capacity battery cell and the pole according to claim 3, characterized in that, The through holes on the busbar are rectangular through holes that match the shape of the tabs or the shape of the tab bundle.

5. The connection structure of the pouch-type large capacity battery cell and the pole according to claim 4, characterized in that, Multiple pouch cells are stacked side by side to form a battery module. A fixing plate is provided on the outside of the battery module to clamp and fix the multiple pouch cells. The fixing plate is arranged side by side with the pouch cells.

6. The connection structure of the pouch-type large-capacity battery cell and the pole according to claim 5, characterized in that, The fixing plates located on the opposite side of the battery module are connected by screws.

7. The connection structure of the pouch-type large-capacity battery cell and the pole according to claim 6, characterized in that, The electrode tabs or electrode tab bundles are welded to the connecting plate.

8. The connection structure of the pouch-type large capacity battery cell and the pole according to claim 7, characterized in that, The connecting plate is bonded to the groove wall with conductive and thermally conductive adhesive.

9. The connection structure of the pouch-type large capacity battery cell and the pole according to claim 8, characterized in that, The busbar and the pole are fixed together by clamps.

10. The connection structure of the pouch-type large capacity battery cell and the pole according to claim 9, characterized in that, The busbar is welded to the pole.

11. The connection structure of the pouch-type large capacity battery cell and the pole according to claim 10, characterized in that, The pole is formed by splicing together multiple metal blocks, with a groove formed at the splicing point of two adjacent metal blocks, and a conductive and thermally conductive adhesive is coated at the splicing point of two adjacent metal blocks.

12. The connection structure of the pouch-type large-capacity battery cell and the pole according to claim 11, characterized in that, The electrode post is provided with a heat dissipation mechanism, which is a semiconductor cooling chip, heat dissipation fins, a cooling fan, or a heat pipe.

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