Bipolar battery cell structure capable of being injected with liquid to prevent explosion

Abstract

The invention relates to an anti-explosion bipolar battery cell structure capable of being injected with liquid, which comprises a first end plate, at least one battery cell unit and a second end plate, and the battery cell unit is arranged between the first end plate and the second end plate; each battery cell unit comprises a first current collector, a cell body, a metal ring sealing ring and a second current collector; the first current collector, the metal ring sealing ring and the second current collector are sequentially stacked to form a sealed cavity, the metal ring sealing ring is arranged on the outer side of the core body in a sleeving mode, and the core body abuts against the first current collector and the second current collector; at least one anti-explosion liquid injection hole is formed in the metal ring sealing ring, and the anti-explosion liquid injection hole is communicated with the sealing cavity. According to the invention, the liquid injection and explosion-proof functions are realized through the metal sealing ring, the process and the function of a conventional lithium battery are better matched, the explosion-proof safety performance of the battery cell is enhanced, and the battery cell has relatively high practicability and economical efficiency and can be produced and used as a general product.

Description

Technical Field

[0001] The invention relates to the technical field of batteries, and in particular to a liquid-injectable explosion-proof bipolar battery core structure. Background Art

[0002] With the rise and development of new energy sources, lithium batteries are being used in more and more scenarios; however, due to the low voltage of a single cell, no matter which application scenario, the single cells must be connected in series to form a battery pack before they can be used.

[0003] The pole pieces used in the traditional battery cell structure are generally of the same polarity, that is, the front and back sides of the pole piece are of the same polarity (such as positive polarity or negative polarity), and each pole piece is connected in parallel by stacking, thereby increasing the capacity, but not the voltage. Moreover, the traditional battery cell structure generally realizes liquid injection by setting a liquid injection hole on the top cover, which easily leads to uneven cell infiltration and affects the performance of the battery cell. Summary of the invention

[0004] Based on this, the present invention provides a bipolar battery cell structure that can be injected with liquid to prevent explosion, aiming to solve the problems that the existing bipolar battery cell injection method through the top cover easily leads to uneven battery cell infiltration and affects the performance of the battery cell, the battery cell has low explosion-proof safety performance and high preparation cost.

[0005] To achieve the above-mentioned purpose, the embodiment of the present invention proposes the following technical solution: a liquid-injectable explosion-proof bipolar battery cell structure, comprising a first end plate, at least one battery cell unit and a second end plate, wherein the battery cell unit is arranged between the first end plate and the second end plate;

[0006] The battery cell units each include a first current collector, a core body, a metal ring sealing ring, and a second current collector; the first current collector, the metal ring sealing ring, and the second current collector are stacked in sequence to form a sealed cavity, the metal ring sealing ring is sleeved on the outside of the core body, and the core body is in contact with the first current collector and the second current collector respectively;

[0007] At least one explosion-proof liquid injection hole is arranged on the metal ring sealing ring, and the explosion-proof liquid injection hole is connected to the sealing cavity.

[0008] As a preferred embodiment, the metal ring sealing ring includes a metal ring and a sealing ring, and the metal ring is clamped in the sealing ring; the explosion-proof liquid injection hole is arranged in the metal ring, and the explosion-proof liquid injection hole extends from one side of the metal ring to the other side of the metal ring.

[0009] As a preferred embodiment, a through-hole screw is arranged in the explosion-proof injection hole; one end of the through-hole screw close to the core body is connected to the sealing cavity, and an explosion-proof nut is arranged at one end of the through-hole screw away from the core body.

[0010] As a preferred embodiment, a sealing gasket is provided at one end of the through hole screw close to the explosion-proof nut; the sealing gasket is sleeved on the through hole screw, and the sealing gasket is respectively disposed in contact with the explosion-proof nut and the metal ring.

[0011] As a preferred embodiment, the through-hole screw is matched with the explosion-proof liquid injection hole; the through-hole screw is matched with the explosion-proof nut and the sealing gasket respectively; and the metal ring is matched with the sealing ring.

[0012] As a preferred embodiment, the sealing ring is a "U"-shaped sealing ring; the opening of the "U"-shaped sealing ring is arranged toward the explosion-proof nut; and a first groove adapted to the through-hole screw is arranged on one side of the "U"-shaped sealing ring close to the core body.

[0013] As a preferred embodiment, the first groove surrounds the through-hole screw, and the first groove is adapted to fit the through-hole screw.

[0014] As a preferred embodiment, the metal ring is provided with a second groove adapted to the first groove, and the second groove is adapted to the first groove and the through-hole screw respectively; the first groove is covered on the outer side of the second groove, and the through-hole screw passes through the second groove and the first groove in sequence and is connected to the sealed chamber.

[0015] As a preferred embodiment, a third groove is further provided on the metal ring, and the explosion-proof nut and the sealing gasket are both accommodated in the third groove, and the explosion-proof nut and the sealing gasket are respectively adapted to the third groove.

[0016] As a preferred embodiment, the explosion-proof nut is connected to the through-hole screw via threads.

[0017] As a preferred embodiment, the explosion-proof nut is provided with a polygonal groove; and the bottom of the polygonal groove is provided with an explosion-proof notch.

[0018] As a preferred embodiment, the polygonal groove is one of a hexagonal groove, a pentagonal groove or a quadrangular groove.

[0019] As a preferred embodiment, the side surface of the metal ring is provided with convex ridges, and the convex ridges are circumferentially arranged on the side surface of the metal ring; the metal ring is a steel ring or a stainless steel ring.

[0020] As a preferred embodiment, the core body includes an insulating ring, a first pole piece, a second pole piece and a diaphragm; the insulating ring is sleeved on the outside of the diaphragm, the first pole piece abuts against one side of the diaphragm, and the second pole piece abuts against the other side of the diaphragm; and the insulating ring is sleeved on the outside of the first pole piece and the second pole piece; the insulating ring abuts against the sealing ring;

[0021] The first pole piece is disposed in contact with the first current collector, and the second pole piece is disposed in contact with the second current collector.

[0022] As a preferred embodiment, a circular hole connected to the through-hole screw is provided on the insulating ring; fourth grooves connected to the circular hole are provided on both sides of the insulating ring; a plurality of notches are provided on a side of each of the fourth grooves away from the sealing ring; and the plurality of notches are arranged at equal intervals.

[0023] As a preferred embodiment, the first pole piece is a positive pole piece, and the second pole piece is a negative pole piece; or, the first pole piece is a negative pole piece, and the second pole piece is a positive pole piece.

[0024] As a preferred embodiment, the first current collector abuts the first end plate, and the second current collector abuts the second end plate; one side of the first current collector is coated with a first coating, and the other side is coated with a second coating; one side of the second current collector is coated with a first coating, and the other side is coated with a second coating.

[0025] As a preferred embodiment, the first coating is a positive electrode coating, and the second coating is a negative electrode coating; or, the first coating is a negative electrode coating, and the second coating is a positive electrode coating; the area of ​​the positive electrode coating is smaller than the area of ​​the negative electrode coating.

[0026] As a preferred embodiment, the first end plate, the second end plate, the first current collector, the second current collector, the sealing ring and the metal ring are all provided with a plurality of bolt holes compatible with the bolts, and the plurality of bolt holes are evenly arranged circumferentially, and the bolts are fixed in the bolt holes; insulating gaskets are provided between the bolts and the first end plate and between the bolts and the second end plate; and the outer side of the bolts is sleeved with an insulating sleeve.

[0027] As a preferred embodiment, when a plurality of the battery cell units are provided, adjacent battery cell units are connected in series; two adjacent battery cell units share one of the first current collectors or two adjacent battery cell units share one of the second current collectors.

[0028] The beneficial effects achieved by the present invention are as follows: the present application sets an explosion-proof liquid injection hole on the metal ring sealing ring, and realizes the functions of liquid injection and explosion-proof through the metal ring sealing ring, so that the structure of the present application is more compatible with the process and function of conventional lithium batteries, solves the problem of liquid injection process of bipolar battery cells, and enhances the safety performance of explosion-proof battery cells. In addition, by adopting a metal ring sealing ring, the material used for the sealing ring can be reduced, and the price of the metal ring is much lower than that of the sealing ring (fluororubber), achieving effective cost reduction. The present application has a simple structure, is easy to install, is reliable and stable during use, has high practicality and economy, and can be produced and used as a general product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 This is a schematic diagram of the overall structure of a liquid-injectable explosion-proof bipolar battery cell according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of a partial explosion structure of a liquid-injectable explosion-proof bipolar battery cell structure;

[0032] Figure 3 for Figure 2 Schematic diagram of the overall structure of the metal ring seal;

[0033] Figure 4 for Figure 3 A schematic diagram of a partial cross-sectional structure of a metal ring seal;

[0034] Figure 5 for Figure 3 A schematic diagram of the structure of a metal ring;

[0035] Figure 6 for Figure 3 A schematic diagram of the structure of the sealing ring;

[0036] Figure 7 for Figure 3 Schematic diagram of the structure of the explosion-proof nut.

[0037] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0042] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] Specifically, Figures 1 to 5 As shown, the embodiment of the present invention proposes the following technical solution: a liquid-injectable explosion-proof bipolar battery structure, comprising a first end plate 10, at least one battery cell unit 20 and a second end plate 30, wherein the battery cell unit 20 is arranged between the first end plate 10 and the second end plate 30;

[0044] The battery cell units 20 each include a first current collector 21, a core body 22, a metal ring seal 23, and a second current collector 24; the first current collector 21, the metal ring seal 23, and the second current collector 24 are stacked in sequence to form a sealed cavity (not marked in the figure), the metal ring seal 23 is sleeved on the outside of the core body 22, and the core body 22 is in contact with the first current collector 21 and the second current collector 24 respectively;

[0045] At least one explosion-proof liquid injection hole 231 is provided on the metal ring sealing ring 23 , and the explosion-proof liquid injection hole 231 is connected to the sealing cavity.

[0046] As a preferred embodiment, see Figures 3 to 5 The metal ring sealing ring 23 includes a metal ring 232 and a sealing ring 233, and the metal ring 232 is clamped in the sealing ring 233; the explosion-proof liquid injection hole 231 is arranged in the metal ring 232, and the explosion-proof liquid injection hole 231 extends from one side of the metal ring 232 to the other side of the metal ring 232.

[0047] As a preferred embodiment, a through-hole screw 40 is provided in the explosion-proof injection hole 231 ; one end of the through-hole screw 40 close to the core body 22 is connected to the sealing cavity, and an explosion-proof nut 50 is provided at one end of the through-hole screw 40 away from the core body 22 .

[0048] As a preferred embodiment, a sealing gasket 60 is provided at one end of the through hole screw 40 close to the explosion-proof nut 50; the sealing gasket 60 is sleeved on the through hole screw 40, and the sealing gasket 60 is respectively disposed in contact with the explosion-proof nut 50 and the metal ring 232.

[0049] As a preferred embodiment, the through-hole screw 40 is matched with the explosion-proof injection hole 231 ; the through-hole screw 40 is matched with the explosion-proof nut 50 and the sealing gasket 60 respectively; the metal ring 232 is matched with the sealing ring 233 .

[0050] As a preferred embodiment, Figure 6 As shown, the sealing ring 233 is a "U"-shaped sealing ring; the opening of the "U"-shaped sealing ring is arranged toward the explosion-proof nut 50; the side of the "U"-shaped sealing ring close to the core body 22 is provided with a first groove 2331 adapted to the through-hole screw 40.

[0051] As a preferred embodiment, the first groove 2331 is disposed to surround the through-hole screw 40 , and the first groove 2331 is adapted to fit the through-hole screw 40 .

[0052] As a preferred embodiment, Figure 5 As shown, the metal ring 232 is provided with a second groove 2321 adapted to the first groove 2331, and the second groove 2321 is adapted to the first groove 2331 and the through-hole screw 40 respectively; the first groove 2331 is covered on the outer side of the second groove 2321, and the through-hole screw 40 passes through the second groove 2321 and the first groove 2331 in sequence and is connected to the sealed chamber.

[0053] As a preferred embodiment, a third groove 2322 is further provided on the metal ring 232 , and the explosion-proof nut 50 and the sealing gasket 60 are both accommodated in the third groove 2322 , and the explosion-proof nut 50 and the sealing gasket 60 are respectively adapted to the third groove 2322 .

[0054] As a preferred embodiment, the explosion-proof nut 50 is connected to the through-hole screw 40 via threads.

[0055] As a preferred embodiment, Figure 7 As shown, the explosion-proof nut 50 is provided with a polygonal groove 51 ; the bottom of the polygonal groove 51 is provided with an explosion-proof notch 52 .

[0056] As a preferred embodiment, the polygonal groove 51 is one of a hexagonal groove, a pentagonal groove or a quadrangular groove. Specifically, in this embodiment, the polygonal groove 51 is a hexagonal groove.

[0057] The explosion-proof nut is provided with a hexagonal groove for easy locking with a hexagonal tool. At the same time, an explosion-proof notch is engraved on the bottom of the groove, making it the weakest point in each cavity. When a large amount of gas is generated in the battery cell, the gas breaks through the explosion-proof notch of the explosion-proof nut through the through hole of the through-hole screw to release the gas, thereby realizing the explosion-proof function.

[0058] As a preferred embodiment, the side of the metal ring 232 is provided with convex ridges 2323, and the convex ridges 2323 are circumferentially arranged on the side of the metal ring 232; the metal ring 232 is a ring or a stainless steel ring. In this embodiment, there are two convex ridges 2323, and the metal ring 232 is a ring. By providing the convex ridges 2323, the sealing pressure between the metal ring and the sealing ring is increased, and the sealing performance is stronger.

[0059] As a preferred embodiment, Figure 2As shown, the core 22 includes an insulating ring 221, a first pole piece 222, a second pole piece 223 and a diaphragm 224; the insulating ring 221 is sleeved on the outside of the diaphragm 224, the first pole piece 222 abuts against one side of the diaphragm 224, and the second pole piece 223 abuts against the other side of the diaphragm 224; and the insulating ring 221 is sleeved on the outside of the first pole piece 222 and the second pole piece 223; the insulating ring 221 abuts against the sealing ring 233;

[0060] The first pole piece 222 is disposed in contact with the first current collector 21 , and the second pole piece 223 is disposed in contact with the second current collector 24 .

[0061] As a preferred embodiment, a circular hole 2211 connected to the through-hole screw 40 is provided on the insulating ring 221; fourth grooves 2212 connected to the circular hole 2211 are provided on both sides of the insulating ring 221; each of the fourth grooves 2212 is provided with a plurality of notches 2213 on a side away from the sealing ring 233; and the plurality of notches 2213 are arranged at equal intervals.

[0062] As a preferred embodiment, the first pole piece 222 is a positive pole piece, and the second pole piece 223 is a negative pole piece; or, the first pole piece 222 is a negative pole piece, and the second pole piece 223 is a positive pole piece.

[0063] As a preferred embodiment, the first current collector 21 is abutted against the first end plate 10, and the second current collector 24 is abutted against the second end plate 30; one side of the first current collector 21 is coated with a first coating (not marked in the figure), and the other side is coated with a second coating (not marked in the figure); one side of the second current collector 24 is coated with a first coating (not marked in the figure), and the other side is coated with a second coating (not marked in the figure).

[0064] As a preferred embodiment, the first coating is a positive electrode coating, and the second coating is a negative electrode coating; or, the first coating is a negative electrode coating, and the second coating is a positive electrode coating; the area of ​​the positive electrode coating is smaller than the area of ​​the negative electrode coating. In this way, it can be ensured that the positive electrode is completely covered by the negative electrode.

[0065] In an embodiment of the present application, when the first electrode sheet is a positive electrode sheet and the second electrode sheet is a negative electrode sheet, at this time, the coating of the first current collector close to the first electrode sheet is a negative electrode coating, and the coating of the first current collector close to the first end plate is a positive electrode coating; the coating of the second current collector close to the second electrode sheet is a positive electrode coating, and the coating of the second current collector close to the second end plate is a negative electrode coating.

[0066] When the first electrode sheet is a negative electrode sheet and the second electrode sheet is a positive electrode sheet, at this time, the coating of the first current collector close to the first electrode sheet is a positive electrode coating, and the coating of the first current collector close to the first end plate is a negative electrode coating; the coating of the second current collector close to the second electrode sheet is a negative electrode coating, and the coating of the second current collector close to the second end plate is a positive electrode coating.

[0067] As a preferred embodiment, a plurality of bolt holes A compatible with the bolts 70 are provided on the first end plate 10, the second end plate 30, the first current collector 21, the second current collector 24, the sealing ring 233 and the metal ring 232, and the plurality of bolt holes A are evenly arranged circumferentially, and the bolts 70 are fixed in the bolt holes A; insulating gaskets 80 are provided between the bolts 70 and the first end plate 10 and between the bolts 70 and the second end plate 30; and the outer side of the bolt 70 is sleeved on the insulating sleeve 71.

[0068] As a preferred embodiment, when a plurality of the battery cell units 20 are provided, adjacent battery cell units 20 are connected in series; two adjacent battery cell units 20 share one of the first current collectors 21 or two adjacent battery cell units 20 share one of the second current collectors 24 .

[0069] Two adjacent battery cell units 20 share one of the first current collectors 21 to achieve series connection; or, two adjacent battery cell units 20 share one of the second current collectors 24 to achieve series connection.

[0070] In the embodiment of the present application, a total of four battery cell units are connected in series. End plates are used at both ends to compress the sealing ring of each sealed cavity, thereby ensuring the sealing of each sealed cavity. The two end plates are locked by bolts and insulating gaskets, and the side of the bolts is covered with insulating sleeves to prevent short circuits between each sealed cavity. The positive and negative poles are separated by a diaphragm, and the diaphragm is fixed by an insulating ring to prevent the diaphragm from shifting and causing a short circuit. The bipolar battery cell structure of the present application is a cylindrical structure. In other embodiments, the battery cell structure may also be a rectangular parallelepiped, a cube or a polygonal structure.

[0071] After the cell structure is assembled but before liquid is injected, the explosion-proof nut and sealing ring are not installed, the through-hole screw is stuck in the first groove of the sealing ring and the explosion-proof injection hole, and the first groove of the sealing ring is stuck in the second groove of the metal ring, thereby fixing the through-hole screw. At the same time, the metal ring is stuck in the sealing ring, so that the metal ring, the current collector, and the positive and negative electrodes in the internal cavity are insulated. When the cell is injected, the electrolyte enters the cell through the through-hole screw and the circular hole of the insulating ring. After the cell is discharged, the sealing gasket is clamped and sealed through the internal thread of the explosion-proof nut and the external thread of the through-hole screw.

[0072] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0073] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0074] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A liquid-injectable explosion-proof bipolar battery cell structure, characterized in that: It includes a first end plate, at least one battery cell unit and a second end plate, wherein the battery cell unit is arranged between the first end plate and the second end plate; The battery cell units each include a first current collector, a core body, a metal ring sealing ring, and a second current collector; the first current collector, the metal ring sealing ring, and the second current collector are stacked in sequence to form a sealed cavity, the metal ring sealing ring is sleeved on the outside of the core body, and the core body is in contact with the first current collector and the second current collector respectively; At least one explosion-proof liquid injection hole is arranged on the metal ring sealing ring, and the explosion-proof liquid injection hole is connected to the sealing cavity.

2. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 1, characterized in that: The metal ring sealing ring comprises a metal ring and a sealing ring, wherein the metal ring is clamped in the sealing ring; the explosion-proof liquid injection hole is arranged in the metal ring, and the explosion-proof liquid injection hole extends from one side of the metal ring to the other side of the metal ring.

3. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 2, characterized in that: A through-hole screw is arranged in the explosion-proof liquid injection hole; one end of the through-hole screw close to the core body is connected to the sealing cavity, and one end of the through-hole screw away from the core body is arranged with an explosion-proof nut.

4. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 3, characterized in that: A sealing washer is arranged at one end of the through hole screw close to the explosion-proof nut; the sealing washer is sleeved on the through hole screw, and the sealing washer is respectively arranged in contact with the explosion-proof nut and the metal ring.

5. The liquid-injectable explosion-proof bipolar battery structure according to claim 3, characterized in that: The sealing ring is a "U"-shaped sealing ring; the opening of the "U"-shaped sealing ring is arranged toward the explosion-proof nut; the side of the "U"-shaped sealing ring close to the core body is provided with a first groove adapted to the through-hole screw.

6. The liquid-injectable explosion-proof bipolar battery structure according to claim 5, characterized in that: The first groove surrounds the through-hole screw, and the first groove is adapted to fit the through-hole screw; The metal ring is provided with a second groove adapted to the first groove, and the second groove is adapted to the first groove and the through-hole screw respectively; the first groove is covered on the outer side of the second groove, and the through-hole screw passes through the second groove and the first groove in sequence and is connected to the sealed chamber.

7. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 6, characterized in that: The metal ring is also provided with a third groove, the explosion-proof nut and the sealing gasket are both accommodated in the third groove, and the explosion-proof nut and the sealing gasket are respectively matched with the third groove.

8. The liquid-injectable explosion-proof bipolar battery structure according to claim 3, characterized in that: The explosion-proof nut is connected to the through-hole screw via threads; The explosion-proof nut is provided with a polygonal groove; the bottom of the polygonal groove is provided with an explosion-proof notch.

9. The liquid-injectable explosion-proof bipolar battery structure according to claim 2, characterized in that: The side surface of the metal ring is provided with convex ridges, and the convex ridges are circumferentially arranged on the side surface of the metal ring; the metal ring is a steel ring or a stainless steel ring.

10. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 2, characterized in that: The core body comprises an insulating ring, a first pole piece, a second pole piece and a diaphragm; the insulating ring is sleeved on the outside of the diaphragm, the first pole piece abuts against one side of the diaphragm, and the second pole piece abuts against the other side of the diaphragm; and the insulating ring is sleeved on the outside of the first pole piece and the second pole piece; the insulating ring abuts against the sealing ring; The first pole piece is disposed in contact with the first current collector, and the second pole piece is disposed in contact with the second current collector.

11. The liquid-injectable explosion-proof bipolar battery structure according to claim 10, characterized in that: The insulating ring is provided with a circular hole connected to the through-hole screw; both sides of the insulating ring are provided with fourth grooves connected to the circular hole; each of the fourth grooves is provided with a plurality of notches on a side away from the sealing ring; and the plurality of notches are arranged at equal intervals.

12. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 10, characterized in that: The first pole piece is a positive pole piece, and the second pole piece is a negative pole piece; or, the first pole piece is a negative pole piece, and the second pole piece is a positive pole piece; The first current collector is in contact with the first end plate, and the second current collector is in contact with the second end plate; one side of the first current collector is coated with a first coating, and the other side is coated with a second coating; one side of the second current collector is coated with a first coating, and the other side is coated with a second coating.

13. The liquid-injectable explosion-proof bipolar battery cell structure according to claim 12, characterized in that: The first coating is a positive electrode coating, and the second coating is a negative electrode coating; or, the first coating is a negative electrode coating, and the second coating is a positive electrode coating; the area of ​​the positive electrode coating is smaller than the area of ​​the negative electrode coating; The first end plate, the second end plate, the first current collector, the second current collector, the sealing ring and the metal ring are all provided with a plurality of bolt holes adapted to the bolts, the plurality of bolt holes are evenly arranged circumferentially, and the bolts are fixed in the bolt holes; insulating gaskets are provided between the bolts and the first end plate, and between the bolts and the second end plate; the outer side of the bolts is sleeved with an insulating sleeve; When a plurality of the battery cell units are provided, adjacent battery cell units are connected in series; two adjacent battery cell units share one of the first current collectors or two adjacent battery cell units share one of the second current collectors.

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