Battery cell cover plate and battery cell

Abstract

The utility model provides a battery cell cover plate and a battery cell, and belongs to the technical field of new energy batteries. The battery cell cover plate comprises a cover plate body, a pole and an overflowing assembly, the pole is arranged on one side of the cover plate body in a protruding mode, a liquid injection runner is formed in the pole in the axis direction in a penetrating mode, the overflowing assembly comprises current collecting discs and a sealing floating ball, and the current collecting discs are arranged on the other side of the cover plate body in parallel at intervals and connected with the pole in an overflowing mode. The sealing floating ball is arranged between the cover plate body and the flow collecting disc and connected with the flow collecting disc through an elastic piece, the sealing floating ball abuts against an opening, close to one side of the flow collecting disc, of the liquid injection flow channel, and the diameter of the sealing floating ball is larger than that of the opening. By adopting the battery cell cover plate to form the battery cell, the technical problems that the liquid injection and lithium supplement processes are complicated and the safety is difficult to guarantee due to the arrangement structure defects of the liquid injection holes in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy batteries, in particular to a battery cover and a battery. Background Art

[0002] Lithium-ion batteries, one of the most popular energy storage devices, are widely used in new energy vehicles, various portable electronic devices, and communications equipment. Lithium-ion battery cells typically have a pre-reserved injection hole in the cell casing. Once the cell is assembled, electrolyte needs to be injected into the cell casing through the injection hole to ensure that the inner core is fully soaked with electrolyte.

[0003] Conventional battery cell housings typically have independent injection holes located between the positive and negative electrodes. These holes are typically sealed using metal sealing pins or balls that create an interference fit with the holes. After the sealing pins or balls are inserted into the holes, they are secured using laser welding to achieve a seal.

[0004] The conventional sealing method, which utilizes an interference fit between the seal and the injection hole, requires a very small interference fit, requiring high machining precision and making it difficult to disassemble and re-use. If the interference fit is too large, or if improper handling is used during assembly or disassembly for lithium injection, the metal seal can rub against the wall of the injection hole, generating metal particles and burrs that can be introduced into the battery cell housing, causing a short circuit and posing a safety hazard. Utility Model Content

[0005] The present invention provides a battery cover and battery cell, which can solve the technical problems in the prior art caused by structural defects in the arrangement of the injection hole, such as the complicated injection and lithium replenishment process and the difficulty in ensuring safety. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a battery cell cover, comprising: a cover plate body, a pole and an overcurrent component.

[0007] The pole is protrudingly arranged on one side of the cover plate body, and the pole is provided with an injection channel along the axial direction. The flow-through component includes a collecting plate and a sealing float. The collecting plate is arranged in parallel and spaced apart on the other side of the cover plate body and is connected to the pole in a flow-through manner. The sealing float is arranged between the cover plate body and the collecting plate and is connected to the collecting plate through an elastic member. The sealing float abuts against the opening of the injection channel close to the side of the collecting plate, and the diameter of the sealing float is larger than the diameter of the opening.

[0008] Optionally, the collecting plate is connected to the pole via an elastic fluid flow.

[0009] Optionally, a plurality of the elastic flow-through fluids are provided, and the plurality of the elastic flow-through fluids are arranged at equal angles around the circumference of the injection channel.

[0010] Optionally, the injection channel includes a first section and a second section connected in sequence, the diameter of the first section is larger than the diameter of the second section, and the sealing float abuts against the opening of the second section.

[0011] Optionally, a conical chamfered section with a gradually decreasing diameter is provided at the connection between the first section and the second section.

[0012] Optionally, the first section is provided with an arc chamfered section at the opening on the pole.

[0013] Optionally, the pole includes a first pole and a second pole arranged at intervals, the injection channel is located on the first pole, the overflow assembly is also provided corresponding to the second pole, the second pole is provided with a pressure relief channel along the axial direction, the pressure relief channel includes a third section and a fourth section connected in sequence, the third section is close to the current collecting plate and has a diameter greater than the diameter of the fourth section, the diameter of the sealing float is greater than the diameter of the fourth section, the sealing float is located at an end of the fourth section away from the third section and abuts against the opening of the fourth section on the pole.

[0014] Optionally, the fourth section is provided with a spherical socket at the opening on the pole, and the sealing float is embedded in the spherical socket.

[0015] Optionally, the sealing float in the overflow assembly corresponding to the second pole is a hemispherical structure, and a sealing plate is provided on a side of the sealing float away from the current collecting plate.

[0016] In the second aspect, an embodiment of the utility model further provides a battery cell, comprising the battery cell cover plate described in the first aspect, and also comprising a winding core and a lower shell, wherein the winding core is arranged in the lower shell, the battery cell cover plate is fixedly arranged on the lower shell, and the collecting plate is used to connect the pole ear of the winding core with the current.

[0017] The beneficial effects of the technical solution provided by the embodiment of the utility model include at least:

[0018] In an embodiment of the present utility model, the cell cover plate is used to be assembled with the corresponding lower shell to form a cell shell to accommodate the winding core. It carries out structural expansion design for the pole arranged on the cover plate body, and replaces the traditional injection hole structure independently arranged on the cell cover plate by designing an injection channel that runs through the pole. At the same time, a flow-through component is arranged at the bottom of the cover plate body in conjunction with the setting of the injection channel. The current collecting plate spaced below the opening of the injection channel can be used to connect the pole ear of the winding core inside the cell to achieve flow connection with the pole. A sealing float is connected to the top of the current collecting plate by an elastic member. Under normal conditions, the elastic force of the elastic member is used to push the sealing float up and press it against the opening of the injection channel close to the side of the current collecting plate to achieve sealing under normal working conditions. When the battery cell needs to be replenished with lithium, liquid can be injected into the cell through the injection channel opening at the top of the pole. The external liquid pressure pushes downward to open the sealing float and flow into the cell. When the liquid is replenished and the replenishment device is removed, the sealing float will rebound under the elastic force of the elastic member to seal it. This pole form can quickly and easily perform secondary liquid injection and lithium replenishment operations, and can also achieve automatic sealing. There is no need for a separate liquid injection port on the cover plate, and there is no need for complex external sealing operations after liquid injection. This can solve the technical problems of the existing technology that the liquid injection and lithium replenishment process is complicated and difficult to ensure safety due to structural defects in the liquid injection hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the top structure of the battery cover provided by an embodiment of the present utility model;

[0021] Figure 2 This is a schematic diagram of the bottom structure of the battery cover provided by an embodiment of the present utility model;

[0022] Figure 3 This is a partial structural cross-sectional view of the battery cover at the first pole provided by an embodiment of the present utility model;

[0023] Figure 4 This is a partial structural cross-sectional view of the battery cover at the second pole provided by an embodiment of the present utility model;

[0024] Figure 5 It is a structural schematic diagram of the battery cell provided by an embodiment of the utility model.

[0025] In the figure: 1-cover plate; 2-pole; 2a-first pole; 2b-second pole; 3-flow assembly; 4-lower shell; 21-injection channel; 22-pressure relief channel; 31-collecting plate; 32-sealing float; 211-first section; 212-second section; 213-conical chamfered section; 214-arc chamfered section; 221-third section; 222-fourth section; 223-spherical socket; 311-elastic member; 312-elastic flow fluid; 321-sealing plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the top structure of the battery cover provided by an embodiment of the present utility model; Figure 2 This is a schematic diagram of the bottom structure of the battery cover provided by an embodiment of the present utility model; Figure 3 This is a partial structural cross-sectional view of the battery cover at the first pole provided by an embodiment of the present utility model; Figure 4 This is a partial structural cross-sectional view of the battery cover at the second pole provided by the embodiment of the present utility model. Figures 1 to 4 As shown, an embodiment of the present invention provides a battery cell cover, including a cover plate body 1, a pole 2 and an overcurrent component 3.

[0028] The pole 2 protrudes from one side of the cover plate 1, and a liquid injection channel 21 is provided along the pole 2's axis. The flow assembly 3 includes a collecting plate 31 and a sealing float 32. The collecting plate 31 is spaced parallel to and connected to the pole 2 on the other side of the cover plate 1. The sealing float 32 is positioned between the cover plate 1 and the collecting plate 31 and connected to the collecting plate 31 via an elastic member 311. The sealing float 32 abuts the opening of the liquid injection channel 21 on the side closest to the collecting plate 31, and its diameter is larger than the opening.

[0029] In an embodiment of the present utility model, the cell cover is used to be assembled with the corresponding lower shell to form a cell shell to accommodate the winding core. It carries out structural expansion design for the pole 2 provided on the cover plate body 1, and replaces the traditional independent liquid injection hole structure provided on the cell cover plate by designing a liquid injection channel 21 that passes through the pole 2. At the same time, a flow assembly 3 is provided at the bottom of the cover plate body 1 in conjunction with the setting of the liquid injection channel 21. The collecting plate 31 spaced below the opening of the liquid injection channel 21 can be used to connect the pole ear of the winding core inside the cell to achieve flow connection with the pole. The sealing float 32 is connected to the top of the collecting plate 31 by an elastic member 311. Under normal conditions, the elastic force of the elastic member 311 is used to push the sealing float 32 up and press it against the opening of the liquid injection channel 21 close to the collecting plate 31 to achieve sealing under normal working conditions. When the battery cell needs to be replenished with lithium, liquid can be injected into the cell through the liquid injection channel 21 at the top of the pole 2. The pressure of the external liquid pushes downward to open the sealing float 32 and flow into the cell. When the liquid is replenished and the replenishment device is removed, the sealing float 32 will rebound under the elastic force of the elastic member 311 to seal. The use of this pole 2 form can conveniently and quickly perform secondary liquid injection and lithium replenishment operations, and can also achieve automatic sealing. There is no need for a separate liquid injection port on the cover plate, and there is no need for complex external sealing operations after liquid injection. This can solve the technical problems of the existing technology that the liquid injection and lithium replenishment process is complicated and difficult to ensure safety due to structural defects in the liquid injection hole.

[0030] Optionally, the current collecting disc 31 is connected to the pole 2 via an elastic flow-through fluid 312. For example, in an embodiment of the present invention, the current collecting disc 31 is connected to the pole 2 by providing the elastic flow-through fluid 312. After the battery cell is assembled, the current collecting disc 31 can be pressed against the top of the internal winding core under the elastic action of the elastic flow-through fluid 312, facilitating welding with the tabs of the winding core, or directly establishing a flow-through connection with the full tab end face provided on the top of the winding core without welding. This simplifies the assembly process, eliminates the need for welding equipment, ensures the stability of the flow-through connection, and reduces the processing cost of the battery cell.

[0031] Optionally, a plurality of elastic fluid passages 312 are provided, and the plurality of elastic fluid passages 312 are arranged at equal angular intervals around the circumference of the injection channel 21. For example, in an embodiment of the present invention, the current collecting plate 31 is connected to the pole 2 by arranging the plurality of elastic fluid passages 312 at equal angular intervals, thereby ensuring the stability of the connection structure and the posture stability of the current collecting plate 31 when in contact with the winding core tab or the full tab flow surface. Stress is uniformly absorbed by multi-point support and fixation, thereby preventing the current collecting plate 31 from tilting or tilting relative to the winding core due to external vibrations and other factors during operation, thereby improving the stability of the connection.

[0032] Optionally, the injection channel 21 includes a first section 211 and a second section 212 connected in sequence, the diameter of the first section 211 being larger than the diameter of the second section 212, and the sealing float 32 abutting against the opening of the second section 212. For example, in an embodiment of the present invention, when performing injection and lithium replenishment, injection is performed by connecting to an external fluid replenishment device through the first section 211 having the larger diameter, facilitating docking. After the injection passes through the second section 212 with a reduced diameter, the pressure acting on the sealing float 32 is also greater due to the reduced diameter of the pipe, allowing the sealing float 32 to be pushed downward more smoothly into the interior of the battery cell, thereby improving the fluency and efficiency of the injection and lithium replenishment operation.

[0033] Optionally, a tapered chamfered section 213 with a gradually decreasing diameter is provided at the junction of the first section 211 and the second section 212. For example, in this embodiment of the present invention, when the liquid is injected from the first section 211 into the second section 212 with a smaller diameter, it can smoothly transition through the guidance of the tapered chamfered section 213 and form a vortex, allowing it to enter the second section 212 more smoothly, further improving the fluency and efficiency of the liquid injection and lithium replenishment operation.

[0034] Optionally, the first section 211 is provided with a circular chamfered section 214 at the opening on the pole 2. For example, in an embodiment of the present invention, by providing the circular chamfered section 214 at the opening of the first section 211 at the top of the pole 2, the docking process between the external fluid replenishment device and the injection channel 21 is made smoother, reducing scratches on the top end surface of the pole 2, avoiding damage, and improving the service life of the pole 2.

[0035] Optionally, the electrode 2 includes a first electrode 2a and a second electrode 2b arranged at intervals, the injection channel 21 is located on the first electrode 2a, and an overcurrent assembly 3 is also provided corresponding to the second electrode 2b. The second electrode 2b is provided with a pressure relief channel 22 extending along the axial direction. The pressure relief channel 22 includes a third section 221 and a fourth section 222 connected in sequence. The third section 221 is adjacent to the current collecting plate 31 and has a diameter greater than the diameter of the fourth section 222. The diameter of the sealing float 32 is greater than the diameter of the fourth section 222. The sealing float 32 is located at an end of the fourth section 222 away from the third section 221 and abuts against the opening of the fourth section 222 on the electrode 2. For example, in an embodiment of the present invention, two electrodes 2 are provided, the first electrode 2a and the second electrode 2b corresponding to the positive and negative poles of the battery cell, respectively, and the injection channel 21 is provided on the first electrode 2a, which is one of the electrodes. The second pole 2b of the other one can also be expanded by setting a pressure relief channel 22 and setting a sealing float 32 with a position structure opposite to that in the injection channel 21. Under normal working conditions, the sealing float 32 abuts against the opening of the fourth section 222 on the pole 2 under the elastic force of the elastic member 311, so as to block the pressure relief channel 22 from the top side of the pole 2. When the battery cell is working abnormally and thermal runaway or other accidents occur inside, resulting in excessive internal pressure, the gas generated inside will rush through the sealing float 32 from bottom to top and spread to the outside of the battery cell to achieve pressure relief. After the pressure relief is completed and the internal pressure is restored, the sealing float 32 will rebound under the action of the elastic member 311 to reseal the pressure relief channel 22 to prevent electrolyte leakage. Through this design, the second pole 2b can take into account the function of the explosion-proof valve on the traditional battery cell at the same time. There is no need to set a separate explosion-proof valve on the battery cell cover, which reduces the spacing required on the cover plate 1 and enables more free arrangement of the pole position. It is simple and efficient and can be applied to ternary battery cells to solve the safety problems of ternary battery cells.

[0036] Optionally, a spherical socket 223 is provided at the opening of the fourth section 222 on the pole 2, and the sealing float 32 is embedded in the spherical socket 223. For example, in an embodiment of the utility model, the sealing float 32 in the current overflow assembly 3 corresponding to the second pole 2b is a hemispherical structure, and a sealing plate 321 is provided on the side of the sealing float 32 away from the collecting plate 31. This design reduces the overall space occupied by the sealing float 32, so that it can sink into the pressure relief channel 22 as a whole and be embedded in the spherical socket 223 through the hemispherical structure of the lower half, ensuring stable abutment without lateral shaking. At the same time, the top is further sealed by cooperating with the side wall of the pressure relief channel 22 through the sealing plate 321, which does not affect the normal operation of the pole 2 while improving the sealing and aesthetics of the battery cover.

[0037] Figure 5 This is a schematic diagram of the structure of the battery cell provided by the embodiment of the present utility model. Figure 5As shown, the embodiment of the present invention also provides a battery cell, including Figures 1 to 4 The cell cover shown also includes a winding core and a lower shell 4. The winding core is arranged in the lower shell 4. The cell cover is fixedly covered on the lower shell 4 and is connected to the pole tab of the winding core by a current collecting plate 31. For example, in an embodiment of the present invention, the current collecting plate 31 can be pressed against the top of the internal winding core under the elastic action of the elastic fluid 312, which is convenient for welding with the pole tab of the winding core, or directly connected to the full pole tab end face set on the top of the winding core without welding. The assembly process is simple, no welding equipment is required, and the stability of the current connection can be guaranteed. Furthermore, the cell cover is used to form a shell for accommodating the winding core. The pole 2 set on the cover plate body 1 is structurally expanded and designed. The liquid injection channel 21 that passes through the pole 2 is designed to replace the traditional liquid injection hole structure independently set on the cell cover. At the same time, in conjunction with the setting of the injection channel 21, a flow assembly 3 is set at the bottom of the cover plate body 1. The collecting plate 31, which is spaced below the opening of the injection channel 21, can be used to connect the electrode tabs of the winding core inside the battery cell to achieve flow connection with the pole. The sealing float 32 is connected to the top of the collecting plate 31 through an elastic member 311. Under normal conditions, the elastic force of the elastic member 311 is used to push the sealing float 32 up and press it against the opening of the injection channel 21 near the collecting plate 31 to achieve sealing under normal working conditions. When it is necessary to inject liquid into the battery cell to replenish lithium, liquid can be injected into the battery cell through the opening of the injection channel 21 at the top of the pole 2. The pressure of the external liquid is used to push the sealing float 32 downward to flow into the battery cell. When the liquid is replenished and the replenishment device is removed, the sealing float 32 will rebound under the elastic force of the elastic member 311 to seal. The use of this pole 2 form can realize secondary liquid injection and lithium replenishment operation conveniently and quickly, and can realize automatic sealing at the same time, without the need to set an independent liquid injection port on the cover plate, and without the need to perform complicated external sealing operations after liquid injection. It can solve the technical problems in the prior art of complex liquid injection and lithium replenishment process caused by structural defects in the setting of liquid injection holes and difficulty in ensuring safety.

[0038] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present invention belongs. The terms "first", "second" and similar words used in the specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "include" or "comprising" mean that the elements or objects appearing before "include" or "comprising" include the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", and "right" are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery cover, characterized in that: include: Cover plate body (1), pole (2) and overcurrent component (3), The pole (2) is protrudingly arranged on one side of the cover plate body (1); the pole (2) is provided with an injection flow channel (21) extending through the pole (2) along the axial direction; the flow component (3) comprises a collecting plate (31) and a sealing float (32); the collecting plate (31) is arranged in parallel and spaced relation on the other side of the cover plate body (1) and is flow-connected with the pole (2); the sealing float (32) is arranged between the cover plate body (1) and the collecting plate (31) and is connected to the collecting plate (31) via an elastic member (311); the sealing float (32) abuts against an opening of the injection flow channel (21) close to the collecting plate (31) and the diameter of the sealing float (32) is larger than the diameter of the opening.

2. The battery cover according to claim 1, characterized in that: The collecting plate (31) is connected to the pole (2) via an elastic fluid (312).

3. The battery cover according to claim 2, characterized in that: A plurality of the elastic fluid-passing fluids (312) are provided, and the plurality of the elastic fluid-passing fluids (312) are arranged at equal angles around the circumference of the injection channel (21).

4. The battery cover according to claim 1, characterized in that: The injection channel (21) comprises a first section (211) and a second section (212) connected in sequence, the diameter of the first section (211) is larger than the diameter of the second section (212), and the sealing float (32) abuts against the opening of the second section (212).

5. The battery cover according to claim 4, characterized in that: A conical chamfered section (213) with a gradually decreasing diameter is provided at the connection between the first section (211) and the second section (212).

6. The battery cover according to claim 4, characterized in that: The first section (211) is provided with a circular arc chamfered section (214) at the opening on the pole (2).

7. The battery cell cover according to claim 1, characterized in that: The pole (2) comprises a first pole (2a) and a second pole (2b) arranged at intervals, the injection channel (21) is located on the first pole (2a), and the corresponding second pole (2b) is also provided with the overcurrent component (3), the second pole (2b) is provided with a pressure relief channel (22) along the axial direction, the pressure relief channel (22) comprises a third section (221) and a fourth section (222) connected in sequence, the third section (221) is close to the current collecting plate (31) and has a diameter greater than that of the fourth section (222), the sealing float (32) has a diameter greater than that of the fourth section (222), and the sealing float (32) is located at one end of the fourth section (222) away from the third section (221) and abuts against the opening of the fourth section (222) on the pole (2).

8. The battery cover according to claim 7, characterized in that: The fourth section (222) is provided with a spherical socket (223) at the opening on the pole (2), and the sealing float (32) is embedded in the spherical socket (223).

9. The battery cell cover according to claim 8, characterized in that: The sealing float (32) in the current overflow assembly (3) provided corresponding to the second pole (2b) is a hemispherical structure, and a sealing plate (321) is provided on the side of the sealing float (32) away from the current collecting plate (31).

10. A battery cell comprising the battery cell cover according to any one of claims 1 to 9, characterized in that: It also includes a winding core and a lower shell (4), wherein the winding core is arranged in the lower shell (4), the battery cover is fixedly arranged on the lower shell (4), and is connected to the pole tab of the winding core through the current collecting plate (31).

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