A pole piece assembly and a rapidly immersible battery cell

Abstract

The present invention belongs to the technical field of battery cells. Specifically, the present invention relates to a pole piece assembly and a rapidly immersible battery cell. The pole piece assembly includes a pole piece assembly body and a hollow groove provided on the pole piece assembly body; the hollow groove is located in the middle of the pole piece assembly body, extending from the side where the pole ear of the pole piece assembly body is located to the other side, and is used to provide a path for the fire-fighting medium to immerse into the pole piece assembly body. The rapidly immersible battery cell includes a shell and the pole piece assembly, and the pole piece assembly is installed in the shell; the shell includes a connected shell and a top cover, and the top cover is provided with an injection port, and the injection port is covered with an explosion-proof plate, and the injection port is used to provide a position for the injection of the fire-fighting medium. The present invention can solve the thermal runaway problem from the pole piece level, shorten the control time during thermal runaway, and reduce the risk of thermal runaway of the battery cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery cell structures, and in particular relates to a pole piece assembly and a rapidly immersible battery cell. Background Art

[0002] When a lithium-ion battery experiences thermal runaway, there are three solutions to the battery system fire accident: the first is "battery intrinsic safety," but this solution cannot achieve a technological breakthrough in a short period of time; the second is to isolate the battery system after a fire, preventing personal injury or damage to surrounding property, but this is costly, and the necessary condition for ejection is that the mechanical structure is not damaged during the battery's life cycle, so the operating and maintenance costs are too high; the third solution is to prevent the electrochemical reaction of the batteries inside the PACK box, preventing heat spread and providing sufficient time for firefighting.

[0003] The "silent" battery safety system falls under the third option. Silencing involves rapidly injecting a firefighting medium into the battery compartment when thermal runaway occurs. This medium isolates the battery compartment from oxygen, lowers the temperature, and prevents the spread of thermal runaway. This solution requires the complete immersion of the liquid-cooled PACK compartment that triggered the thermal runaway alarm within a short period of time. Through rapid cooling and localized asphyxiation, further reactions in the thermally runaway battery are blocked, preventing heat from spreading between cells and between PACKs. This allows for precise and rapid firefighting, suppressing the continued deterioration of thermal runaway and reducing the risk of loss of control.

[0004] In the patent application document with application number 202121104844.2 and application date May 19, 2021, entitled "A top cover structure and battery for preventing thermal runaway of a battery cell," an immersion solution is mentioned. In this solution, a flow channel is provided on the top cover structure, and the flow channel is filled with a flame retardant material. The flow channel releases the flame retardant material into the battery system at a preset temperature. In this solution, the firefighting medium can fill the outside of the battery cell, but immersion into the interior of the battery cell is more difficult and takes time. Once thermal runaway occurs in a lithium battery, the internal reaction speed accelerates and increases exponentially. Therefore, the sooner the thermal runaway is controlled, the greater the risk. Summary of the Invention

[0005] The present invention provides a pole piece assembly and a rapidly immersible battery cell, which can solve the technical problem in the prior art that it takes a long time to control thermal runaway of a battery.

[0006] In order to solve the above problems, the present invention provides a pole piece assembly and a rapidly immersible battery cell, and the technical solutions are as follows:

[0007] A pole piece assembly comprises a pole piece assembly body and a hollow slot provided on the pole piece assembly body; the hollow slot is located in the middle of the pole piece assembly body and extends from one side of the pole ear of the pole piece assembly body to the other side, and is used to provide a path for fire-fighting medium to penetrate into the pole piece assembly body.

[0008] The electrode assembly as described above is further preferably: the electrode assembly body is a laminated structure, including a stacked positive electrode sheet, a negative electrode sheet and a separator, and the separator is located between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet includes a positive electrode foil and a positive electrode coating layer, and the negative electrode sheet includes a negative electrode foil and a negative electrode coating layer; the empty slot includes a positive electrode blank area and a negative electrode blank area, the positive electrode blank area is located in the middle of the positive electrode coating layer, and the negative electrode blank area is located in the middle of the negative electrode coating layer.

[0009] The electrode assembly as described above is further preferably: the positive electrode sheet is provided with two positive electrode tabs, and the negative electrode sheet is provided with two negative electrode tabs; the width of the positive electrode tab ranges from 30mm to 50mm, and the height is greater than 15mm; the width of the negative electrode tab ranges from 30mm to 50mm, and the height is greater than 15mm.

[0010] The electrode assembly as described above is further preferably configured such that: the positive electrode blank area is located between the two positive electrode tabs, and the negative electrode blank area is located between the two negative electrode tabs.

[0011] The electrode assembly as described above is further preferably such that: along the side where the electrode ear of the electrode assembly body is located to the other side, the positive electrode blank area penetrates the positive electrode sheet, and the negative electrode blank area penetrates the negative electrode sheet.

[0012] The electrode assembly as described above is further preferably: on the positive electrode sheet, along the direction from one positive electrode tab to the other positive electrode tab, the width of the positive electrode blank area ranges from 2 mm to 5 mm; on the negative electrode sheet, along the direction from one negative electrode tab to the other negative electrode tab, the width of the negative electrode blank area ranges from 2 mm to 5 mm;

[0013] The electrode assembly as described above is further preferably configured such that: the width of the positive electrode blank area is consistent with the width of the negative electrode blank area, and both sides thereof in the width direction are aligned.

[0014] A rapidly immersible battery cell comprises a shell and a pole piece assembly, wherein the pole piece assembly is installed in the shell; the shell comprises a connected shell and a top cover, wherein the top cover is provided with an injection port, wherein the injection port is used to provide a position for injecting a fire-fighting medium, and an explosion-proof plate is provided on the injection port.

[0015] The battery cell that can be quickly impregnated as described above is further preferably configured such that: the injection port is located above the empty slot, and the explosion-proof plate covers the injection port; when projected in a direction perpendicular to the top cover, the symmetry line of the projection outline of the injection port coincides with the symmetry line of the projection outline of the empty slot.

[0016] The fast-immersable battery cell as described above is further preferably further provided with a stopper, which is located between the injection port and the pole piece assembly; a receiving port is provided on the top of the stopper, which corresponds to the injection port and is used to allow the fire-fighting medium to enter the stopper; a spray hole is provided on the bottom of the stopper, and there are multiple spray holes, which correspond to the empty slots and are used to spray the fire-fighting medium into the empty slots.

[0017] The battery cell capable of rapid immersion as described above is further preferably configured such that: the spray holes are any one of round holes, square holes, and diamond holes, or a combination thereof.

[0018] The battery cell that can be quickly immersed as described above is further preferably: the multiple spray holes are distributed in a rectangular array, and the number of rows is equal to the sum of the positive electrode blank area and the negative electrode blank area; each row of the spray holes corresponds to one positive electrode blank area or one negative electrode blank area.

[0019] The battery cell capable of rapid immersion as described above is further preferably configured such that: the length of the stopper is greater than the length of the injection port; and the width of the stopper is less than the width of the injection port.

[0020] The battery cell that can be quickly immersed as described above is further preferably configured such that: the stopper comprises a connected top wall, a front wall, a rear wall and a bottom wall; the receiving port is located on the top wall, and the spray hole is located on the bottom wall.

[0021] The battery cell capable of rapid immersion as described above is further preferably configured such that: the stopper is integrally formed and has a wall thickness ranging from 2 mm to 3 mm.

[0022] The battery cell capable of rapid immersion as described above is further preferably configured such that: the stopper is made of PP+EPDM material.

[0023] The fast-immersion battery cell as described above is further preferably configured such that: the explosion-proof plate is welded to the top of the top cover; and the thickness of the explosion-proof plate ranges from 0.2 mm to 0.4 mm.

[0024] The battery cell capable of rapid immersion as described above is further preferably configured such that: the top cover is made of aluminum alloy, and the explosion-proof sheet is an aluminum sheet.

[0025] Analysis shows that, compared with the prior art, the advantages and beneficial effects of the present invention are:

[0026] In the electrode assembly of the present invention, slots are provided in the electrode assembly body, allowing the firefighting medium to flow rapidly through the slots to each electrode, isolating it from oxygen and cooling it. This effectively addresses thermal runaway issues at the electrode level, shortening the control time during thermal runaway and reducing the risk of thermal runaway in the battery cell. Furthermore, the electrolyte can more easily penetrate the electrode assembly body during injection, improving electrolyte wetting and reducing formation time. Furthermore, when the electrode assembly body expands, the slots can absorb the expansion.

[0027] In the rapidly immersible battery cell of the present invention, the firefighting medium can be rapidly injected into the outer shell through the injection port, and the pole piece assembly body can be immersed from the outside of the pole piece assembly body and the empty groove, thereby solving the thermal runaway problem at the pole piece level, shortening the control time during thermal runaway, and reducing the risk of thermal runaway of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of the positive electrode sheet of the present invention;

[0029] Figure 2 It is a front view of the positive electrode sheet of the present invention;

[0030] Figure 3 It is a front view of the negative electrode sheet of the present invention;

[0031] Figure 4 Schematic diagram of the connection between the positive electrode sheet, the negative electrode sheet and the separator of the present invention;

[0032] Figure 5 Schematic diagram of the structure of the fast immersion battery cell of the present invention;

[0033] Figure 6 Schematic diagram of the injection port of the present invention;

[0034] Figure 7 It is a schematic diagram of the connection between the top cover and the stopper of the present invention;

[0035] Figure 8 Schematic diagram of the installation of the stopper of the present invention;

[0036] Figure 9 It is a schematic structural diagram of the stopper of the present invention;

[0037] Figure 10 It is a schematic diagram of the cooperation between the stopper and the pole piece assembly of the present invention.

[0038] In the figure: 1-positive electrode sheet; 2-positive electrode coating layer; 3-positive electrode blank area; 4-positive electrode tab; 5-negative electrode sheet; 6-negative electrode coating layer; 7-negative electrode blank area; 8-negative electrode tab; 9-diaphragm; 10-empty groove; 11-top cover; 12-explosion-proof disk; 13-housing; 14-injection port; 15-stopper; 16-spray hole. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0040] In the description of the present invention, the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0041] Please refer to Figures 1 to 10 ,in, Figure 1 Schematic diagram of the structure of the positive electrode sheet of the present invention; Figure 2 It is a front view of the positive electrode sheet of the present invention; Figure 3 It is a front view of the negative electrode sheet of the present invention; Figure 4 Schematic diagram of the connection between the positive electrode sheet, the negative electrode sheet and the separator of the present invention; Figure 5 Schematic diagram of the structure of the fast immersion battery cell of the present invention; Figure 6 Schematic diagram of the injection port of the present invention; Figure 7 It is a schematic diagram of the connection between the top cover and the stopper of the present invention; Figure 8 Schematic diagram of the installation of the stopper of the present invention; Figure 9 It is a schematic structural diagram of the stopper of the present invention; Figure 10 It is a schematic diagram of the cooperation between the stopper and the pole piece assembly of the present invention.

[0042] like Figures 1 to 4As shown, in one embodiment of the present invention, a pole piece assembly is provided, comprising a pole piece assembly body and a slot 10 formed in the pole piece assembly body. The slot 10 is located in the middle of the pole piece assembly body, extending from one side of the pole piece assembly body where the pole lug is located to the other side, and can provide a path for the firefighting medium to penetrate into the pole piece assembly body.

[0043] In this embodiment, a slot 10 is provided on the pole piece assembly body. When thermal runaway occurs in the pole piece assembly, the firefighting medium can flow rapidly through the slot 10 to each pole piece, isolating each pole piece from oxygen and cooling it. This solves the thermal runaway problem at the pole piece level, shortens the control time during thermal runaway, and reduces the risk of thermal runaway in the battery cell. Furthermore, the slot 10 on the pole piece assembly body allows the electrolyte to more easily penetrate the pole piece assembly body during injection, improving the electrolyte infiltration effect and reducing the formation time. Furthermore, when the pole piece of the pole piece assembly body expands, the slot 10 can also absorb the expansion.

[0044] like Figures 1 to 4 As shown, in one embodiment of the present invention, the electrode assembly body is a laminated structure, comprising a stacked positive electrode sheet 1, a negative electrode sheet 5, and a separator 9. Separator 9 is located between the positive electrode sheet 1 and the negative electrode sheet 5, separating the adjacent positive electrode sheet 1 from the negative electrode sheet 5. Specifically, the positive electrode sheet 1 comprises a positive electrode foil and a positive electrode coating layer 2, and the negative electrode sheet 5 comprises a negative electrode foil and a negative electrode coating layer 6. The empty slot 10 comprises a positive electrode blank area 3 and a negative electrode blank area 7. The positive electrode blank area 3 is located in the middle of the positive electrode coating layer 2, that is, the positive electrode blank area 3 is located in the middle of the positive electrode foil where the positive electrode coating layer 2 is not provided. The positive electrode blank area 3 forms a groove on the positive electrode sheet 1, dividing the positive electrode coating layer 2 into two equal parts on the left and right. When the electrode assembly is stacked, a gap is formed in the positive electrode blank area 3, which can provide a path for the fire-fighting medium to penetrate into the positive electrode sheet 1; the negative electrode blank area 7 is located in the middle of the negative electrode coating layer 6, that is, the negative electrode blank area 7 is located in the middle of the negative electrode foil where the negative electrode coating layer 6 is not provided. The negative electrode blank area 7 forms a groove on the negative electrode sheet 5, dividing the negative electrode coating layer 6 into two equal parts on the left and right. When the electrode assembly is stacked, a gap is formed in the negative electrode blank area 7, which can provide a path for the fire-fighting medium to penetrate into the negative electrode sheet 5.

[0045] like Figures 1 to 3As shown, in one embodiment of the present invention, two positive electrode tabs 4 are provided on the positive electrode sheet 1, and two negative electrode tabs 8 are provided on the negative electrode sheet 5. The design of the two tabs on each electrode sheet can ensure the connection reliability of the electrode assembly body during use. The positive electrode blank area 3 is located between the two positive electrode tabs 4, and the negative electrode blank area 7 is located between the two negative electrode tabs 8. In the event of thermal runaway, the electrode sheet can be immersed from the middle of each electrode sheet. As a preferred embodiment, along the side where the tabs are located to the other side of the electrode assembly body, the positive electrode blank area 3 passes through the positive electrode sheet 1, and the negative electrode blank area 7 passes through the negative electrode sheet 5. This can not only reduce the immersion resistance of the fire-fighting medium, but also enable the fire-fighting medium to penetrate into the electrode assembly body from both sides of the electrode assembly body, thereby shortening the immersion time.

[0046] Furthermore, in this embodiment, the width (m1) of the positive electrode tab 4 and the width (m2) of the negative electrode tab 8 are both in the range of 30 mm to 50 mm, for example, they can be 30 mm, 31 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, or any intermediate value between any two adjacent endpoint values ​​mentioned above; the height (h1) of the positive electrode tab 4 and the height (h2) of the negative electrode tab 8 are both greater than 15 mm.

[0047] like Figure 4 As shown, in one embodiment of the present invention, the width of the positive electrode blank area 3 is consistent with the width of the negative electrode blank area 7, and the two sides in the width direction are aligned. In other words, when projected in a direction perpendicular to the positive electrode foil, the projections of all positive electrode blank areas 3 and negative electrode blank areas 7 overlap. Therefore, when the firefighting medium immerses into the electrode assembly body, the resistance is reduced and the immersion time is shortened.

[0048] Furthermore, in this embodiment, on the positive electrode sheet 1, along the direction from one positive electrode tab 4 to the other positive electrode tab 4, the width (L1) of the positive electrode margin 3 ranges from 2 mm to 5 mm, and can be, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any intermediate value between any two adjacent endpoints. On the negative electrode sheet 5, along the direction from one negative electrode tab 8 to the other negative electrode tab 8, the width (L2) of the negative electrode margin 7 ranges from 2 mm to 5 mm, and can be, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any intermediate value between any two adjacent endpoints.

[0049] Based on the above-mentioned pole piece assembly, the present invention also provides a rapidly immersible battery cell. Since the rapidly immersible battery cell includes the pole piece assembly, the rapidly immersible battery cell has all the advantages of the pole piece assembly in the above-mentioned embodiments.

[0050] like Figure 5 and Figure 6 As shown, in one embodiment of the present invention, a rapidly immersible battery cell includes a housing and a pole piece assembly mounted within the housing. The housing includes a shell 13 and a top cover 11 connected thereto. The top cover 11 is provided with an injection port 14, which is covered with an explosion-proof disk 12.

[0051] In this embodiment, the explosion-proof disc 12 is positioned at the injection port 14 during normal use of the battery cell, allowing for rapid immersion. When the electrode assembly experiences thermal runaway, the pressure generated within the housing can cause the explosion-proof disc 12 to detach from the top cover 11 (the explosion-proof disc 12 can be completely detached from the top cover 11, or partially connected to the top cover 11, but with the injection port 14 exposed), thereby exposing the injection port 14, which provides a location for the injection of the firefighting medium. The firefighting medium can be rapidly injected into the housing through the injection port 14 and immerse the electrode assembly body from the outside of the electrode assembly body and the empty slot 10, thereby resolving the thermal runaway problem at the electrode level, shortening the control time during thermal runaway, and reducing the risk of thermal runaway in the battery cell.

[0052] like Figure 10 As shown, in one embodiment of the present invention, an injection port 14 is located above the empty tank 10, and the bursting disk 12 covers the injection port 14. Projected perpendicularly to the top cover, the symmetry line of the projected outline of the injection port 14 coincides with the symmetry line of the projected outline of the empty tank 10. This means that the injection port 14 is located directly above the empty tank 10. Consequently, when the firefighting medium is injected through the injection port 14, a portion of the firefighting medium can directly enter the empty tank 10, thereby shortening the immersion time.

[0053] like Figures 7 to 9 As shown, in one embodiment of the present invention, a stopper 15 is further included, and the stopper 15 is located between the injection port 14 and the electrode assembly. Specifically, a receiving port is provided at the top of the stopper 15, and the receiving port corresponds to the injection port 14; a spray hole 16 is provided at the bottom of the stopper 15, and there are multiple spray holes 16, and the multiple spray holes 16 correspond to the empty slot 10. In this embodiment, after the fire-fighting medium is injected from the injection port 14, a portion enters the receiving port and enters the stopper 15 through the receiving port. The fire-fighting medium can be sprayed into the empty slot 10 at the spray holes 16 of the stopper 15, thereby allowing the fire-fighting medium to quickly penetrate the internal space of the electrode assembly body.

[0054] Further, such as Figure 10As shown, in this embodiment, multiple spray holes 16 are distributed in a rectangular array, with each row and column of the rectangular array having multiple spray holes 16. Furthermore, the number of rows in the rectangular array is equal to the sum of the positive electrode blank areas 3 and the negative electrode blank areas 7. Each row of spray holes 16 corresponds to one positive electrode blank area 3 or one negative electrode blank area 7, thereby being able to directly spray the firefighting medium onto the positive electrode blank areas 3 and the negative electrode blank areas 7.

[0055] Furthermore, in this embodiment, the spray hole 16 can have various design forms, for example, it can be a round hole, a square hole, a diamond hole, or any combination of round holes, square holes, and diamond holes.

[0056] like Figure 9 As shown, in one embodiment of the present invention, the stopper 15 includes a connected top wall, a front wall, a rear wall, and a bottom wall. The receiving port is located on the top wall, and the spray hole 16 is located on the bottom wall. The length of the stopper 15 is greater than the length of the injection port 14, thereby ensuring that each positive electrode blank area 3 and negative electrode blank area 7 can be sprayed at the same time. The width of the stopper 15 is less than the width of the injection port 14, so that a portion of the fire-fighting medium injected from the injection port 14 can flow into the housing from both sides of the stopper 15, synchronously immersing the outside of the electrode assembly body.

[0057] Furthermore, in this embodiment, the stopper 15 is made of a soft PP+EPDM material that is less likely to damage the electrode assembly. Furthermore, the stopper 15 is integrally formed, reducing the number of parts and improving structural reliability. As a possible implementation, the wall thickness of the stopper 15 ranges from 2mm to 3mm, and can be, for example, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3mm, or any value intermediate between any two adjacent endpoints.

[0058] like Figure 5 As shown, in one embodiment of the present invention, the explosion-proof disc 12 is welded to the top of the top cover 11, ensuring both reliable sealing during normal use and reliable separation from the top cover 11 in the event of thermal runaway of the pole piece assembly. As a feasible implementation method, in this embodiment, the top cover 11 is made of aluminum alloy, and the explosion-proof disc 12 is an aluminum sheet. The structural strength of the explosion-proof disc 12 is less than that of the top cover 11, ensuring that the injection port 14 is promptly exposed in the event of thermal runaway. The thickness of the explosion-proof disc 12 ranges from 0.2 mm to 0.4 mm, and can be, for example, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, or 0.4 mm, or any intermediate value between any two adjacent endpoints.

[0059] like Figures 1 to 10 As shown, the working process of the present invention is described in detail below:

[0060] The pole piece assembly and retainer 15 are enclosed in an outer shell, which is sealed by the housing 13 and the top cover 11. A burst-proof disk 12 is welded to the injection port 14 of the top cover 11. If the pole piece assembly experiences thermal runaway, the pressure inside the shell increases, impacting the burst-proof disk 12. The disk 12 detaches from the top cover 11, which not only reduces pressure but also exposes the injection port 14, providing a location for injecting firefighting media.

[0061] The fire-fighting medium is injected manually or mechanically from the injection port 14. A portion of the fire-fighting medium is sprayed into each positive electrode blank area 3 and each negative electrode blank area 7 through the spray hole 16 of the stopper 15, and the other portion is immersed into the shell through both sides of the stopper 15, thereby enabling the fire-fighting medium to quickly immerse the pole piece assembly body, speeding up the immersion speed from the pole piece level, and solving the thermal runaway problem.

[0062] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. A pole piece assembly, characterized in that: include: A pole piece assembly body and a slot provided on the pole piece assembly body; The empty slot is located in the middle of the pole piece assembly body, extending from the side where the pole ear of the pole piece assembly body is located to the other side, and is used to provide a path for the fire fighting medium to penetrate into the pole piece assembly body; The electrode assembly body is a laminated structure, comprising a stacked positive electrode sheet, a stacked negative electrode sheet, and a separator, wherein the separator is located between the positive electrode sheet and the negative electrode sheet; The positive electrode sheet includes a positive electrode foil and a positive electrode coating layer, and the negative electrode sheet includes a negative electrode foil and a negative electrode coating layer; The empty slot includes a positive electrode blank area and a negative electrode blank area, the positive electrode blank area is located in the middle of the positive electrode coating layer, and the negative electrode blank area is located in the middle of the negative electrode coating layer; The positive electrode blank area is located between the two positive electrode tabs, and the negative electrode blank area is located between the two negative electrode tabs; Along the side where the pole ear of the pole piece assembly body is located to the other side, the positive electrode blank area penetrates the positive pole piece, and the negative pole blank area penetrates the negative pole piece; The width of the positive electrode blank area is consistent with that of the negative electrode blank area, and both sides thereof in the width direction are aligned.

2. The pole piece assembly according to claim 1, characterized in that: The positive electrode sheet is provided with two positive electrode tabs, and the negative electrode sheet is provided with two negative electrode tabs.

3. A fast-immersion battery cell, characterized in that: include: A housing and a pole piece assembly according to claim 1 or 2, wherein the pole piece assembly is installed in the housing; The housing comprises a shell and a top cover which are connected to each other. The top cover is provided with an injection port which is used to provide a position for injecting fire-fighting medium. The injection port is provided with an explosion-proof disk.

4. The fast-immersible battery cell according to claim 3, characterized in that: The injection port is located above the empty slot, and the explosion-proof disc covers the injection port; Projected in a direction perpendicular to the top cover, the symmetry line of the injection port projection outline coincides with the symmetry line of the slot projection outline.

5. The fast-immersible battery cell according to claim 4, characterized in that: Also included is a stopper, the stopper being located between the injection port and the pole piece assembly; A receiving port is provided on the top of the stopper, and the receiving port corresponds to the injection port and is used for allowing the fire-fighting medium to enter the stopper; The bottom of the stopper is provided with a spray hole, and there are multiple spray holes, which correspond to the empty slots and are used to spray fire-fighting media into the empty slots.

6. The fast-immersible battery cell according to claim 5, characterized in that: The plurality of spray holes are distributed in a rectangular array, and the number of rows is equal to the sum of the positive electrode blank area and the negative electrode blank area; Each row of the spray holes corresponds to one of the positive electrode blank areas or one of the negative electrode blank areas.

7. The fast-immersible battery cell according to claim 5, characterized in that: The length of the stopper is greater than the length of the injection port; The width of the stopper is smaller than the width of the injection port.

8. The fast-immersible battery cell according to claim 5, characterized in that: The stopper comprises a connected top wall, a front wall, a rear wall and a bottom wall; The receiving port is located on the top wall, and the spray hole is located on the bottom wall. The spray hole is any one of a circular hole, a square hole, and a diamond hole, or a combination thereof; The stopper is integrally formed and has a wall thickness ranging from 2 mm to 3 mm; The stopper is made of PP+EPDM material.

9. The fast-immersible battery cell according to claim 4, characterized in that: The explosion-proof disk is welded to the top of the top cover; The thickness of the explosion-proof disk ranges from 0.2 mm to 0.4 mm; The top cover is made of aluminum alloy, and the explosion-proof plate is an aluminum plate.

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