Pole group assembly, pole group module and battery system

Abstract

The utility model discloses a pole group assembly, a pole group module and a battery system. The pole group assembly comprises a pole group combination body; the pole group combination body is formed by combining two end pole groups, at least one middle pole group arranged between the end pole groups and a heat insulation pad between the pole groups along the thickness direction; the pole group assembly is arranged in an insulated and hollow pole group isolation bag, and the pole group isolation bag completely wraps the side face and the bottom of the pole group assembly. The pole group assembly disclosed by the utility model can effectively improve the grouping efficiency of a battery system, can ensure that the electrical performance attenuation of batteries in a battery pack tends to be consistent, and overcomes the problems of non-uniform expansibility of the batteries during charge-discharge circulation and capacity attenuation caused by non-uniform electrolyte consumption of the batteries in the life cycle of the batteries.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery system technical field, especially to a kind of pole group assembly, pole group module and battery system. BACKGROUND

[0002] Current electric vehicle requires higher endurance mileage, which requires that the power battery system must have higher battery grouping efficiency. In order to improve the battery grouping efficiency, the current technology is basically a battery module-free scheme, i.e. the battery system is CTP (Cell to Pack), from battery to battery pack, CTC (Cell to Chassis), from battery to vehicle frame, CTB (Cell to Body) from battery to vehicle body, etc. These schemes all integrate the battery directly into the vehicle components. At present, these schemes have improved the battery grouping efficiency to a very high level, and the space for further improvement is basically limited.

[0003] The current battery system contains hundreds or thousands of batteries. Due to their congenital defects or improper use, it is impossible to ensure that the electrical performance of each battery will be consistent during its life cycle. If the difference in battery electrical performance is too large, it may cause the battery system to not meet the use requirements in terms of charging and discharging energy, power, etc., or shorten the system life. The current solution is basically to use BMS to charge and discharge the batteries with small current to ensure the balance of battery voltage. This solution only slows down the system degradation, but does not fundamentally solve the problem. SUMMARY

[0004] The utility model aims at overcoming the defects of prior art, and provides a pole group assembly, a pole group module and a battery system. The pole group assembly can effectively improve the grouping efficiency of the battery system and ensure that the electrical performance of the batteries in the battery pack tends to be consistent.

[0005] The first object of the present application is to provide a pole group assembly, which comprises a pole group assembly body formed by combining two end pole groups, at least one intermediate pole group placed between the end pole groups, and a heat insulation pad between the pole groups in the thickness direction; the pole group assembly body is placed in an insulated and hollow pole group isolation bag, and the pole group isolation bag completely wraps the pole group assembly body on the side and the bottom.

[0006] The end pole group comprises a pole column connected to a tab, and the intermediate pole group is a battery pole group without a pole column.

[0007] The positive and negative tabs in the end pole group and the intermediate pole group are alternately welded two by two.

[0008] The pole post comprises a busbar connected with a lower surface of the tab, an insulator and a metal frame, and the busbar and the metal frame are respectively arranged on the inner and outer sides of the boss of the insulator and fixed.

[0009] A second object of the present application is to provide a pole group module comprising at least one pole group assembly.

[0010] The pole group module comprises a battery box body, the battery box body comprises a box body and a cover plate connected with the box body, the inside of the box body is separated by a separation beam to form a plurality of pole group assembly placement grooves, and the pole group assembly is arranged in the pole group assembly placement groove.

[0011] The end part of the pole group cover plate assembly is provided with a pole post hole, the pole post on the end pole group passes out from the pole post hole of the pole group cover plate assembly, and the pole post is in sealing connection with the pole post hole to form an integral whole.

[0012] The pole group cover plate assembly is further provided with a busbar, the busbar comprises an output busbar and a series busbar, and the busbar and the upper surface of the busbar of the pole group assembly are welded in pairs of positive and negative pole posts to connect the pole group assemblies in series and form an electrical system for current passing.

[0013] The pole group cover plate assembly comprises a pole group cover plate and an insulating sheet attached to the bottom of the pole group cover plate, the pole group cover plate is provided with a liquid injection hole, an explosion-proof hole and a first pole post hole, the liquid injection hole is provided with a T-shaped column structure liquid injection hole cover, the liquid injection hole cover is welded with the battery cover plate assembly after sealing the liquid injection hole, the insulating sheet is composed of a heat insulation layer on the upper layer and an insulating layer on the lower layer, and the insulating layer is provided with a second pole post hole corresponding to the first pole post hole.

[0014] A third object of the present application is to provide a battery system comprising the pole group of the battery.

[0015] The pole group assembly can effectively improve the grouping efficiency of the battery system, ensure that the battery performance attenuation in the battery pack tends to be consistent, overcome the problem of uneven expansion force of the battery during charging and discharging cycle, and overcome the problem of capacity attenuation caused by uneven consumption of battery electrolyte in the life cycle of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the appearance diagram of the end pole group of the battery system of the utility model.

[0017] Figure 2Is the battery system of the utility model's middle pole group's appearance drawing.

[0018] Figure 3 Is the battery system of the utility model's pole group assembly's explosion map.

[0019] Figure 4 Is the battery system of the utility model's pole group assembly's appearance drawing.

[0020] Figure 5 Is the battery system of the utility model's battery system's explosion map.

[0021] Figure 6 Is the battery system of the utility model's pole group cover plate assembly's explosion map.

[0022] Figure 7 Is the battery system of the utility model's liquid injection hole cover's appearance drawing.

[0023] Figure 8 Is the battery system of the utility model's battery system's appearance drawing (not containing cover plate).

[0024] Figure 9 Is the battery system of the utility model's Figure 8 In the local enlarged view.

[0025] Figure 10 Is the battery system of the utility model's pole column plan view.

[0026] Figure 11 Is the battery system of the utility model's Figure 10 In A-A section view.

[0027] Figure 12 Is the battery system of the utility model's Figure 11 In the local enlarged view. Specific embodiments

[0028] The utility model will be further explained in detail below in combination with the drawings and specific embodiments.It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0029] In the utility model, please refer to Figure 1 , Figure 2 And Figure 3 , Figure 4 , Figure 5As shown, the utility model provides a kind of pole group assembly 5, the pole group assembly includes at least one pole group combination 5-1, the pole group combination 5-1 provided by two end pole groups 51, a plurality of intermediate pole groups 52 and heat insulation pad 54 between pole group are combined together along the thickness direction and form, one or more pole group combination 5-1 forms a pole group assembly 5, two end pole groups are arranged in the two ends of intermediate pole group part formed by at least one intermediate pole group;The pole group combination is placed in the hollow pole group isolation bag 53 of insulated, open upper end, bottom sealed made by non-metal material, and the pole group isolation bag 53 completely wraps the pole group combination in side and bottom.

[0030] Wherein, the end pole group 51 includes pole group main body 511 by winding or laminating process to be combined together positive electrode material, positive electrode current collector, diaphragm, negative electrode current collector, negative electrode material etc., tab 512 extended from positive electrode or negative electrode current collector and pole 513 welded on positive electrode or negative electrode tab 512.

[0031] Wherein, the positive electrode material includes but is not limited to NCM nickel cobalt manganese ternary, LFP lithium iron phosphate, LFMP lithium manganese iron phosphate, lithium cobaltate, lithium manganate etc., and the negative electrode material includes but is not limited to graphite, silicon-carbon graphite etc.;The length and width dimensions of the heat insulation pad are consistent with the appearance size of battery pole group, and the thickness is 0.5-5mm, and the typical value is 1mm;The intermediate pole group 52 is same with end pole group 51 except without pole 513.

[0032] Wherein, the positive tab and negative tab in the end pole group and intermediate pole group are respectively staggered and welded two by two, and the welding mode includes but is not limited to laser welding, hot-press welding, resistance welding, ultrasonic welding etc. together, and the welding area is adapted to meet the performance requirements of product, and the welding line includes but is not limited to circular, ring, square, day character, field character or other various special shapes.

[0033] As Figure 10 、 Figure 11 、 Figure 12 , the pole 513 includes busbar 5131, insulator 5132, metal frame 5133 (preferably aluminum frame), busbar 5131 and metal frame 5133 are respectively arranged on the inner and outer sides of insulator 5132, and the three are combined together by injection molding or hot-pressing process etc.

[0034] The insulator comprises a ring-shaped boss arranged on one side of the insulator, the busbar 5131 comprises a busbar upper surface 513-a and a busbar lower surface 513-b, the busbar lower surface 513-b and the side surface are connected with the inner step surface of the insulator, the metal frame comprises a metal frame lower surface 513-c and a metal frame side surface 513-d, the metal frame lower surface 513-c and the metal frame side surface 513-d are connected with the outer step surface of the insulator, and the tab 512 of the positive electrode or the negative electrode of the battery pole group is welded with the busbar lower surface 513-b of the pole column 513.

[0035] As shown in Figure 3 The pole group assembly 5-1 is placed into the pole group isolation bag 53 after extrusion during assembly; the pole group isolation bag is made of non-metallic materials including but not limited to polyamide PA, polypropylene PP, polycarbonate PC and the like, has a thickness of 0.02-0.3 mm, a typical value of 0.1 mm, is a hollow structure with an open upper end and a sealed bottom, is formed by using a plastic suction forming process, and completely wraps the pole group assembly 5-1 and plays an electrical insulation role.

[0036] During assembly of the battery system, the pole group assembly can be directly placed into the box body, so that jellyroll to pack grouping is directly realized, the space of the battery shell is saved, and the volume grouping efficiency is improved by 10% at most.

[0037] The battery pole group can automatically adjust the thickness T according to the expansion amount, so that the expansion forces of each battery pole group in the battery system due to space constraints are equal, all the battery pole groups uniformly expand when the battery performs a charging and discharging cycle, the battery performance tends to be consistent, the battery performance consistency of the battery system in the whole life cycle is ensured, the best use condition of the battery in the whole life cycle is ensured, and the effect of prolonging the service life of the battery is achieved.

[0038] In the utility model, when the battery performs a charging and discharging cycle, the battery pole groups of the pole group assembly have different electrolyte consumption amounts due to their own reasons, but the electrolyte is also stirred due to the breathing expansion of the battery cell and the blockage of other things, so that the electrolyte in the battery cell can freely flow in the pole group isolation bag, the electrolyte consumption amounts of each battery pole group in the life cycle are equal, the battery performance consistency of the battery system in the whole life cycle is ensured, and the cycle life of the battery system is further ensured.

[0039] Please refer to Figure 5 , Figure 6As shown, this utility model provides a pole assembly module, which is composed of at least one pole assembly component 5. Each pole assembly component 5 is composed of at least one pole assembly assembly 5-1. The pole assembly module includes a battery box, which includes a box body 6 and a cover plate 1 connected to the box body. The box body 6 is internally separated by a partition beam to form multiple pole assembly placement slots, in which the pole assembly components are placed. The pole assembly module also includes a pole assembly cover plate assembly 4, which is disposed between the box body 6 and the cover plate 1. The pole assembly cover plate assembly is circumferentially sealed to the box body and connected to the partition beam, thereby isolating the pole assembly components in the placement slots from the outside environment.

[0040] In use, each pole group component 5 of the pole group module is placed in the pole group component placement slot formed by the isolation beam in the housing body 6. A pole group cover plate assembly 4 is arranged above all pole group components 5, and a busbar 3 is on the pole group cover plate assembly 4.

[0041] In this application, the battery box body and its internal isolation beam are made of metal materials, such as aluminum alloy. The bottom of the electrode assembly cover plate has an insulating sheet. The electrode assembly cover plate is circumferentially sealed to the box body. The insulating sheet is connected to the isolation beam, so that the electrode assembly in the electrode assembly placement slot is isolated from the outside.

[0042] The electrode group cover plate assembly 4 is also provided with a busbar 3. The busbar 3 includes an output busbar 31 and a series busbar 32. Each busbar is laser-welded in series with the positive and negative poles on the upper surface 513-a of the busbar plate of each electrode group assembly to form an electrical system that can carry current. The output busbar and the series busbar both include an insulating protective sleeve 311 to ensure electrical safety when current flows through the busbar.

[0043] Among them, such as Figure 6 As shown, the electrode assembly 4 includes an electrode cover 41 and an insulating sheet 42 attached to its bottom. The electrode cover 41 is made of pure aluminum or aluminum alloy with a thickness of 1-5 mm (typically 1 mm). The insulating sheet 42 is a composite material with two layers: a heat insulation layer and an insulating layer. The heat insulation layer is made of mica with a thickness of 0.5-2 mm (typically 0.5 mm). The insulating layer is made of materials including, but not limited to, PP, PC, PA, and other elemental or composite materials with a thickness of 0.5-2 mm (typically 0.5 mm). When a battery electrode assembly in the battery system experiences thermal runaway, the high-temperature, high-pressure gas generated by the battery electrode assembly will break through the insulating sheet at the explosion-proof hole near its top, causing rapid internal depressurization. Because the insulating sheet is protected by the mica sheet, other explosion-proof holes are not affected by this high temperature, thus ensuring the safety of other electrode assemblies.

[0044] Among them, such asFigure 6 As shown, the pole group cover plate 41 is provided with liquid injection hole 411, explosion-proof hole 413, first pole hole 414 and welding indication groove 412-a; the insulation layer is provided with second pole hole 421, and the sizes of the two pole holes are same, and the number of the pole holes is same as that of the pole on the pole group assembly.

[0045] The liquid injection hole has a diameter of Φ3-Φ10, and a typical value of Φ5, and the number of the liquid injection holes is related to the process design and meets the normal production requirement, and is generally 1-20, typically 10, per pole group assembly, electrolyte is filled through the liquid injection hole 411, and the amount of electrolyte is designed according to the performance requirement of the battery product. After the electrolyte is filled, the lower cylindrical surface 21 of the liquid injection hole cover 2 is inserted into the liquid injection hole, and the upper cylindrical surface 22 is welded and sealed with the pole group cover plate.

[0046] The lower cylindrical surface 21 of the liquid injection hole cover 2 is consistent with the diameter of the liquid injection hole 411, and is slightly smaller by 0.05-0.1 mm, the material of the liquid injection hole cover is pure aluminum or aluminum alloy, and is consistent with the material of the pole group cover plate.

[0047] In the utility model, the box body 6 is made of aluminum alloy material, the internal space is separated into N grooves by internal beams, N is 1-10, typically 2 and 4, the pole group assembly is squeezed and put into the groove in the X direction, the pole group assembly has an outer dimension W, L and H which is slightly smaller than that of the groove, and the gap between the two is 0-1 mm, typically 0.5 mm, the pole group cover plate assembly 4 is arranged on the upper groove of the box body, and the plane shape of the pole group cover plate is smaller than the groove size of the box body by 0-1 mm, typically 0.5 mm.

[0048] In the pole group assembly 5, the pole on the end pole group is pulled out from the pole hole of the pole group cover plate assembly, the lower surface 513-c of the metal frame of the pole is arranged on the pole hole of the pole group cover plate, and the metal frame is full seam welded with the pole hole, so that an integral whole is formed. Figure 8 、 Figure 9 As shown, when assembled, the pole group cover plate and the X-direction groove 412-b and Y-direction groove 412-c on the upper part of the box body are full-circle laser welded and sealed, and the welding indication groove 412-a of the pole group cover plate and the upper surface of the beam of the box body are laser penetration welded, so that the pole group cover plate assembly and the box body are completely welded and completely isolated from the outside.

[0049] As shown, Figure 4 、 Figure 5 、 Figure 1As shown, along the battery system X direction, in the pole group assembly, the pole group thickness T is the same as the height HC of the end pole group, and the number of pole groups is constrained by the pole group main winding or lamination process capacity and equipment capacity and product performance requirements, generally, the battery pole group thickness T is 27-200mm, and the typical value is 50mm;Along the battery system Y direction, in the pole group assembly, the pole group width W is the same as the height WC of the end pole group, and the number of pole groups is constrained by the pole group main winding or lamination process capacity and equipment capacity and the adaptability of the pole group to the total width of the battery system and the direction of the output bus, generally, the battery pole group width W is 100-1200mm, and the typical value is 200, 300 or 600, and the number of pole groups is 1-10, and the typical value is 2, 4 or 6.

[0050] In the utility model, in X, Y direction, the appearance of the battery pole group includes but is not limited to square, circle or other special shape, preferably square, wherein, the direction of the battery pole group extrusion into the tank body inner groove can be the direction of the tank body inner groove as X, the battery pole group also arranges along X after entering the tank body, also can be the direction of the tank body inner groove as Y, the battery pole group also arranges along Y after entering the tank body.

[0051] Referring to Figure 5 、 6 As shown, the utility model also provides a battery system, including the pole group assembly 5, the pole group assembly 5 is multiple, is placed in the battery pole group groove formed by the isolation beam plate in the tank body 6, the upper end of the tank body 6 is provided with cover plate 1, and the battery system is formed together.

[0052] The battery system of the utility model directly puts the pole group into the tank body, realizes direct grouping from battery pole group to battery pack jellyroll to pack, saves the space of battery shell, and the volume grouping efficiency is improved by 10% at most;When the battery is charged and discharged, all battery pole groups will expand uniformly, so that the battery performance tends to be consistent, ensures the best use condition of the battery in the whole life cycle, and prolongs the service life of the battery.

[0053] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model, and for those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be realized in other specific forms without departing from the spirit or basic characteristics of the utility model;

[0054] Thus, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the description given above, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0055] Furthermore, it should be understood that although the description herein is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description herein is only for the sake of clarity, and those skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments which can be understood by those skilled in the art.

Claims

1. A pole assembly, characterized by The pole group assembly comprises a pole group assembly body formed by two end pole groups, at least one middle pole group between the end pole groups, and a heat insulation pad between the pole groups; the pole group assembly body is placed in an insulating and hollow pole group isolation bag which completely wraps the pole group assembly body on the sides and the bottom.

2. The pole assembly of claim 1, wherein, The end pole group comprises a pole post connected with a tab, and the middle pole group is a pole group without a pole post.

3. The pole assembly of claim 1, wherein, The positive and negative tabs in the end pole group and the middle pole group are alternately welded two by two.

4. The pole assembly of claim 2, wherein, The pole post comprises a busbar connected with the tab on the lower surface, an insulator, and a metal frame, the busbar and the metal frame are respectively arranged on the inner and outer sides of the boss of the insulator and fixed.

5. A pole pack module characterized by, The pole group assembly comprises at least one pole group assembly according to any one of claims 1-4.

6. The pole group module of claim 5, wherein, The pole group module comprises a battery box body, the battery box body comprises a box body and a cover plate connected with the box body, the inside of the box body is separated by a separation beam to form a plurality of pole group assembly placement grooves, and the pole group assembly is arranged in the pole group assembly placement groove; the pole group module is further provided with a pole group cover plate assembly, the pole group cover plate assembly is arranged between the box body and the cover plate; the pole group cover plate assembly is circumferentially sealed and connected with the box body and connected with the separation beam, so that the pole group assembly in the pole group assembly placement groove is isolated from the outside.

7. The pole group module of claim 6, wherein, The end of the pole group cover plate assembly is provided with a pole post hole, the pole post on the end pole group of the box body passes through the pole post hole of the pole group cover plate assembly, and the pole post is sealingly connected with the pole post hole to form an integral whole.

8. The pole group module of claim 7, wherein, The pole group cover plate assembly is further provided with a busbar, the busbar comprises an output busbar and a series busbar, the busbar and the upper surface of the busbar of the pole post of the pole group assembly are two by two positive and negative pole posts welded to connect the pole group assemblies in series to form an electrical system for current passing.

9. The pole group module of claim 6, wherein, The pole group cover plate assembly comprises a pole group cover plate and an insulating sheet attached to the bottom of the pole group cover plate; the pole group cover plate is provided with a liquid injection hole, an explosion-proof hole, and a first pole post hole, the liquid injection hole is provided with a T-shaped column structure liquid injection hole cover, the liquid injection hole cover is sealingly connected with the battery cover plate assembly after sealing the liquid injection hole; the insulating sheet is composed of an upper heat insulation layer and a lower insulating layer, and the insulating layer is provided with a second pole post hole corresponding to the first pole post hole.

10. A battery system characterized by, The pole group module comprises any one of claims 5-9.

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