Battery cell, energy storage device and electric equipment

Abstract

The application discloses a battery monomer, an energy storage device and an electric equipment. The battery monomer comprises a shell, an electrode assembly, an end cover and a current collecting disc. The shell has an opening and a containing cavity in the shell, the electrode assembly is contained in the containing cavity, and a gap between an inner wall of the shell and an outer periphery of the electrode assembly is L1. The end cover covers the opening to seal the containing cavity. The current collecting disc is electrically connected between the electrode assembly and the end cover, and the current collecting disc comprises a disc body and a positioning table formed on a side of the disc body facing the end cover. The positioning table at least comprises a variable-diameter section with a cross section decreasing in a direction away from the disc body, and a radial length of the variable-diameter section is L2, and L1<=L2 is satisfied, wherein the cross section is a cross section parallel to the disc body. Thus, the variable-diameter section is provided for the current collecting disc to guide, and the assembly efficiency can be improved while the assembly process is simplified.

Description

Technical Field

[0001] This invention relates to the field of secondary batteries, and in particular to a battery cell, an energy storage device, and an electrical appliance. Background Technology

[0002] A battery cell typically includes a casing, electrode assembly, end cap, and current collector. The electrode assembly is located inside the casing, and the tabs on the electrode assembly are connected to the end cap through the current collector to enable current conduction. The end cap is located outside the current collector and is connected to the end cap to seal the battery cell.

[0003] In the current technology, when assembling battery cells, it is necessary to ensure that the end cap, current collector and electrode assembly are coaxially set, which makes the assembly process cumbersome and the assembly efficiency low. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a battery cell with a simple assembly process and high assembly efficiency.

[0005] Another object of the present invention is to provide an energy storage device having the above-mentioned battery cell.

[0006] Another object of the present invention is to provide an electrical device having the above-mentioned energy storage device.

[0007] According to a first aspect of the present invention, a battery cell includes: a housing, an electrode assembly, an end cap, and a current collector. The housing has an opening and a receiving cavity, the electrode assembly is received in the receiving cavity, and the gap between the inner wall of the housing and the outer periphery of the electrode assembly is L1; the end cap covers the opening to seal the receiving cavity; the current collector is electrically connected between the electrode assembly and the end cap, the current collector including a disk body and a positioning platform formed on the side of the disk body facing the end cap, the positioning platform including at least: a variable-diameter section with a decreasing cross-section in a direction away from the disk body, the radial length of the variable-diameter section being L2, and satisfying: L1 ≤ L2; wherein the cross-section is a section parallel to the disk body.

[0008] According to a first aspect embodiment of the present invention, in a battery cell, an electrode assembly is disposed within a receiving cavity of the housing, a current collector is electrically connected to the electrode assembly, and an end cap covers the outside of the current collector and is connected to the housing to seal the receiving cavity, thereby forming a closed housing for the battery cell. A positioning platform is provided on the side of the current collector facing the end cap, and the positioning platform can cooperate with the end cap to achieve positioning. The cross-section of the variable diameter section gradually decreases in the direction away from the plate body; that is, the variable diameter section forms an inclined surface on the current collector, which can provide guidance for the assembly of the current collector and the electrode assembly. The gap L1 between the inner wall of the casing and the outer periphery of the electrode assembly satisfies L1≤L2 with respect to the radial length L2 of the variable diameter section. During the assembly of the battery cell, the electrode assembly is first connected to the current collector, and then the electrode assembly and current collector are placed into the housing cavity of the casing. During the assembly process, the electrode assembly and current collector may wobble within the casing, causing the electrode assembly, current collector, and end cap to be out of axial alignment. Since L1≤L2, even if the outer periphery of the electrode assembly contacts the inner wall of the casing, the variable diameter section can still cooperate with the end cap, thus providing guidance for the electrode assembly and current collector. Under the guidance of the variable diameter section, rapid assembly of the battery cell can be achieved. Therefore, by setting a variable diameter section to guide the current collector, the assembly process can be simplified while improving assembly efficiency.

[0009] In some embodiments, the positioning stage further includes a straight section located at the end of the variable-diameter section away from the disk body. Thus, the straight section can engage with the through-hole of the end cap, making the fit between the collector disk and the end cap more secure.

[0010] In some embodiments, the angle between the variable diameter section and the surface of the disk is 105° to 130°. This improves the guiding effect of the variable diameter section, thereby increasing the assembly efficiency of the battery cells.

[0011] In some embodiments, the axial length of the straight section is 0.3mm-3mm. This allows for a more secure fit between the manifold and the end cap.

[0012] In some embodiments, the disk body is further provided with at least one mounting groove located on the periphery of the positioning platform and extending radially. This allows the tabs on the electrode assembly to connect with the mounting groove, thereby enabling current conduction and improving the reliability of the battery cell.

[0013] In some embodiments, the positioning stage is located at the center of the disk body, and the collector disk is further provided with a liquid injection hole that penetrates the positioning stage and the disk body along the thickness direction of the collector disk, and the liquid injection hole is coaxial with the positioning stage. This improves the liquid injection efficiency of the battery cell and the wetting efficiency of the electrode assembly.

[0014] Furthermore, a first recess is provided on the positioning platform, and the injection hole is formed at the bottom of the first recess. This allows for electrolyte flow and improves injection efficiency.

[0015] Alternatively, the depth of the first recess may be greater than the axial length of the straight segment. This improves electrolyte injection efficiency while preventing electrolyte overflow, thus increasing the safety of battery cell assembly.

[0016] In some embodiments, the end cap has a through hole communicating with the injection port, and a second recess communicating with the through hole is provided on the side of the end cap away from the collector plate. The battery cell also includes a sealing pin that blocks the injection port, and the welding line between the sealing pin and the end cap is located within the second recess. This allows the upper surface of the welding line to be lower than the upper surface of the end cap, preventing interference when multiple battery cells are connected and improving the stability of the battery cell connection.

[0017] According to a second aspect of the present invention, the energy storage device includes the battery cells in any of the above embodiments.

[0018] According to a third aspect of the present invention, the electrical equipment includes the energy storage device described in the above embodiments.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is an exploded view of a battery cell according to a first aspect embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of a battery cell according to a first aspect embodiment of the present invention.

[0023] Figure 3 This is a perspective view of the current collector of a battery cell according to a first aspect embodiment of the present invention.

[0024] Figure 4 This is a cross-sectional view of the current collector of a battery cell according to a first aspect embodiment of the present invention.

[0025] Figure 5 This is a perspective view of the end cap of a battery cell according to a first aspect embodiment of the present invention.

[0026] Figure 6 This is an exploded view of an energy storage device according to a second aspect embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of an electrical device according to a third aspect embodiment of the present invention.

[0028] Figure label:

[0029] 100 cells per battery

[0030] 10. Outer shell

[0031] Electrode assembly 20

[0032] End cap 30, through hole 31, second recess 32

[0033] Collector plate 40, plate body 41, mounting groove 411, vent hole 412, positioning platform 42, variable diameter section 421, straight section 422, first recess 423, injection hole 43.

[0034] Energy storage device 200

[0035] 300 electrical appliances Detailed Implementation

[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following is for reference. Figures 1-7 A battery cell 100, an energy storage device 200, and an electrical appliance 300 are described according to embodiments of the present invention.

[0038] like Figures 1-2 As shown, according to a first aspect embodiment of the present invention, the battery cell 100 includes: a housing 10, an electrode assembly 20, an end cap 30, and a current collector 40.

[0039] The outer casing 10 has an opening and a receiving cavity inside the outer casing 10, in which the electrode assembly 20 is received. The gap between the inner wall of the outer casing 10 and the outer periphery of the electrode assembly 20 is L1. The end cap 30 covers the opening to seal the receiving cavity. The collector plate 40 is electrically connected between the electrode assembly 20 and the end cap 30. The collector plate 40 includes a plate body 41 and a positioning platform 42 formed on the side of the plate body 41 facing the end cap 30. The positioning platform 42 includes at least a variable diameter section 421 whose cross-section decreases in the direction away from the plate body 41. The radial length of the variable diameter section 421 is L2, and satisfies: L1≤L2, wherein the cross-section is a section parallel to the plate body 41.

[0040] Specifically, the electrode assembly 20 is disposed within the receiving cavity of the housing 10, the current collector 40 is electrically connected to the electrode assembly 20, and the end cap 30 covers the outside of the current collector 40 and is connected to the housing to seal the receiving cavity, thereby forming a closed housing for the battery cell 100. The current collector 40 is provided with a positioning platform 42 on the side facing the end cap 30, which can cooperate with the end cap 30 to achieve positioning. The cross-section of the variable diameter section 421 gradually decreases in the direction away from the disk body 41, that is, the variable diameter section 421 forms an inclined surface on the current collector 40, which can provide guidance for the assembly of the current collector 40 and the electrode assembly 20. The gap L1 between the inner wall of the outer casing 10 and the outer periphery of the electrode assembly 20 and the radial length L2 of the variable diameter section 421 satisfy L1≤L2. During the assembly of the battery cell 100, the electrode assembly 20 is first connected to the current collector 40, and then the electrode assembly 20 and the current collector 40 are placed into the receiving cavity of the outer casing 10. During the assembly process, the electrode assembly 20 and the current collector 40 may shake inside the outer casing 10, causing the electrode assembly 20, the current collector 40 and the end cap 30 to not be in a coaxial position. Since L1≤L2, even if the outer periphery of the electrode assembly 20 contacts the inner wall of the outer casing 10, the variable diameter section 421 can still cooperate with the end cap 30, thereby providing a guiding effect for the electrode assembly 20 and the current collector 40. Under the guiding effect of the variable diameter section 421, the battery cell 100 can be quickly assembled.

[0041] According to the first aspect of the present invention, the battery cell 100 provides guidance for the collector 40 by setting a variable diameter section 421, which can simplify the assembly process and improve the assembly efficiency.

[0042] like Figure 3 As shown, in some embodiments, the positioning stage 42 further includes a straight section 422, which is located at the end of the variable diameter section 421 away from the disk body 41. Thus, the straight section 422 can engage with the through hole 31 of the end cover 30, making the engagement between the collector disk 40 and the end cover 30 more secure.

[0043] like Figure 4 As shown, in some embodiments, the angle between the variable diameter section 421 and the surface of the disk 41 is 105° to 130°. This improves the guiding effect of the variable diameter section 421, thereby increasing the assembly efficiency of the battery cell 100.

[0044] like Figure 3 As shown, in some embodiments, the axial length of the straight section 422 is 0.3mm-3mm. This allows for a more secure fit between the collector plate 40 and the end cap 30.

[0045] like Figure 2 As shown, in some embodiments, the disc body 41 is also provided with at least one mounting groove 411 located on the periphery of the positioning platform 42 and extending radially.

[0046] Specifically, the electrode assembly 20 is provided with tabs extending out of the electrode assembly 20. The charging and discharging of the battery cell 100 can be realized through the tabs. Since multiple tabs extend out of the electrode assembly 20, connecting the multiple tabs to the mounting groove 411 of the disk body 41 can ensure that current flows through each tab when the battery cell 100 is charging and discharging, which can improve the reliability of the battery cell 100. Furthermore, connecting multiple tabs to at least one mounting groove 411 can make the structure of the battery cell 100 more compact, further improving the reliability of the battery cell 100.

[0047] Therefore, the tabs on the electrode assembly 20 can be connected to the mounting groove 411, thereby enabling current conduction and improving the reliability of the battery cell 100.

[0048] Optionally, there are multiple mounting slots 411, which are evenly spaced along the periphery of the positioning platform 42. By providing multiple mounting slots 411, the mounting slots 411 can be connected to the tabs on the electrode assembly 20 at different positions of the battery cell 100, making the connection between the tabs and the current collector 40 more stable, thereby further improving the reliability of the battery cell 100.

[0049] Alternatively, the mounting groove 411 protrudes from the surface of the disk body 41 on the side of the current collector 40 away from the end cap 30. The mounting groove 411 protruding from the surface of the disk body 41 allows for closer contact with the electrode assembly 20, thereby further improving the reliability of the battery cell 100.

[0050] Preferably, the disk body 41 is provided with a vent 412 at the position where the mounting groove 411 is not provided. Since the mounting disk protrudes from the surface of the disk body 41, there is a gap between the disk body 41 and the electrode assembly 20 at the position where the mounting groove 411 is not provided. When the battery cell 100 experiences thermal runaway, the electrode assembly 20 will generate gas. The gas can be discharged through the vent 412 through the gap between the disk body 41 and the electrode assembly 20, thereby improving the rate of thermal runaway of the battery cell 100 and enhancing the safety of the battery cell 100.

[0051] like Figures 3-4 As shown, in some embodiments, the positioning platform 42 is located at the center of the disk body 41, and the collecting disk 40 is also provided with a liquid injection hole 43 that penetrates the positioning platform 42 and the disk body 41 along the thickness direction of the collecting disk 40. The liquid injection hole 43 is coaxial with the positioning platform 42.

[0052] Specifically, when assembling the battery cell 100, electrolyte needs to be injected into the housing 10 through the injection hole 43. By setting the injection hole 43 coaxially with the positioning platform 42, the injection hole 43 can be located at the center of the disk 41. When injecting electrolyte, injecting electrolyte from the center can make the battery cell 100 have a higher injection efficiency. The electrolyte flows in from the center of the electrode assembly 20, which can improve the wetting efficiency of the electrode assembly 20.

[0053] Therefore, the liquid injection efficiency of the battery cell 100 can be improved while the wetting efficiency of the electrode assembly 20 can be improved, thereby improving the assembly efficiency.

[0054] Furthermore, the positioning platform 42 has a first recess 423 that communicates with the injection hole 43, and the injection hole 43 is formed at the bottom of the first recess 423.

[0055] Specifically, when injecting electrolyte into the battery cell 100, the electrolyte needs to be injected into the housing 10 through the injection hole 43. The injection hole 43 on the positioning platform 42 is located at the bottom of the first recess 423, which can provide guidance for the electrolyte. Since the injection hole 43 is small in size, precise alignment is required when injecting electrolyte. The first recess 423 on the injection hole 43 can reduce the alignment accuracy of the injected electrolyte. When injecting electrolyte, it is only necessary to ensure that the electrolyte flows smoothly into the housing 10 within the first recess 423, which can reduce the difficulty of injection and thus improve the injection efficiency.

[0056] Therefore, the first recess 423 can provide a flow channel for the electrolyte and reduce the difficulty of electrolyte injection, thereby improving the injection efficiency.

[0057] It should be noted that there are no specific restrictions on the relationship between the diameter of the first recess 423 and the diameter of the injection hole 43. As long as the diameter of the first recess 423 is greater than the diameter of the injection hole 43, it can be adjusted according to actual needs.

[0058] Optionally, the inner diameter of the first recess 423 gradually decreases in the direction close to the disk 41. This allows the first recess 423 to form a slope in the radial cross-sectional direction, which can further guide the electrolyte flow during electrolyte injection into the battery cell 100, thereby improving the injection efficiency.

[0059] like Figure 4 As shown, optionally, the depth of the first recess 423 is greater than the axial length of the straight segment 422.

[0060] Specifically, the depth of the first recess 423 is greater than the axial length of the straight section 422, which can make the first recess 423 have a larger depth. When injecting electrolyte, if the amount of electrolyte injected is large or there are air bubbles in the outer casing 10, the electrolyte may overflow. Setting the groove depth of the first recess 423 to be deeper can prevent the electrolyte from flowing to the outside of the battery cell 100 when the electrolyte overflows.

[0061] Therefore, while improving the efficiency of electrolyte injection, electrolyte overflow can be prevented, thus increasing the safety of battery cell assembly.

[0062] Optionally, the end of the injection hole 43 that communicates with the first recess 423 is provided with a chamfer. When the electrolyte flows into the injection hole 43 through the first recess 423, the chamfer can provide further guidance for the electrolyte, thereby improving the guidance efficiency and preventing the electrolyte from remaining in the first recess 423, thus further improving the injection efficiency.

[0063] Alternatively, the end of the injection hole 43 that communicates with the first recess 423 is provided with a rounded corner. The first recess 423 with the rounded corner can provide a better flow effect for the electrolyte and further improve the injection efficiency.

[0064] like Figure 5 As shown, in some embodiments, the end cap 30 has a through hole 31 communicating with the liquid injection hole 43, and a second recess 32 communicating with the through hole 31 is provided on the side of the end cap 30 away from the collector plate 40. The battery cell 100 also includes a sealing pin, which blocks the liquid injection hole 43, and the welding line between the sealing pin and the end cap 30 is located in the second recess 32.

[0065] Specifically, after the sealing pin seals the injection hole 43, the connection between the sealing pin and the injection hole 43 needs to be welded to form a closed structure of the battery cell 100. After welding, the weld line is located in the second recess 32 of the end cover 30, meaning that the upper surface height of the weld line is lower than the upper surface height of the end cover 30. When assembling multiple battery cells 100, the end cover 30 of the battery cell 100 needs to be welded using connecting tabs to achieve current conduction. Since the height of the weld line is lower than that of the end cover 30, interference between the weld line and the welding of the connecting tab and the end cover 30 can be prevented, thereby ensuring a large welding area between the connecting tab and the end cover 30 and improving the stability of the connection of multiple battery cells 100.

[0066] like Figure 6 As shown, according to a second aspect embodiment of the present invention, the energy storage device 200 includes the battery cell 100 in any of the above embodiments.

[0067] like Figure 7 As shown, according to a third aspect embodiment of the present invention, the electrical equipment 300 includes the energy storage device 200 in the above embodiment.

[0068] In this application, the structure of the electrical equipment 300 is not limited. For example, the electrical equipment 300 can be a mobile device such as a vehicle, ship, or small aircraft, which includes a power source, including the aforementioned energy storage device 200. The electrical energy provided by the energy storage device 200 provides driving force for the electrical equipment 300. This mobile device can be a pure electric device, that is, the driving force of the electrical equipment 300 is entirely electrical energy, and the power source only includes the energy storage device 200. This mobile device can also be a hybrid power device, where the power source includes the energy storage device 200 and other power devices such as an engine. Taking a vehicle as an example, in some embodiments, the electrical equipment 300 is a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle, a range-extended electric vehicle, an electric tricycle, or a two-wheeled electric vehicle, etc.

[0069] For example, electrical equipment 300 can be an energy storage cabinet or other energy storage device, which can be used as a charging cabinet for mobile devices or as an energy storage device for other devices. For instance, solar power generation equipment can be equipped with an energy storage cabinet, where the electricity generated by solar power generation is temporarily stored to power devices such as streetlights and bus stop signs.

[0070] According to the embodiments of the present invention, the electrical equipment 300, by adopting the above-described energy storage device 200, has higher assembly efficiency, lower production cost, and can save on the operating cost of the electrical equipment 300.

[0071] In the description of this invention, it should be understood that the terms "center," "length," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. "First feature" and "second feature" may include one or more of the features. "A plurality of" means two or more. "Above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them. "Above," "above," and "over" the second feature include the first feature directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature.

[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: The outer casing (10) has an opening and a receiving cavity; Electrode assembly (20), the electrode assembly (20) is housed in the receiving cavity, and the gap between the inner wall of the outer shell (10) and the outer periphery of the electrode assembly (20) is L1; End cap (30), the end cap (30) covers the opening to seal the receiving cavity; A collector plate (40) is electrically connected between the electrode assembly (20) and the end cap (30). The collector plate (40) includes a plate body (41) and a positioning platform (42) formed on the side of the plate body (41) facing the end cap (30). The positioning platform (42) includes at least a variable diameter section (421) with a reduced cross-section in a direction away from the plate body (41). The radial length of the variable diameter section (421) is L2, and satisfies: L1≤L2; wherein the cross-section is a section parallel to the plate body (41). The positioning stage (42) also includes a straight section (422), which is located at the end of the variable diameter section (421) away from the disk body (41); The angle between the variable diameter section (421) and the surface of the disk body (41) is 105°~130°.

2. The battery cell according to claim 1, characterized in that, The axial length of the straight section (422) is 0.3mm-3mm.

3. The battery cell according to claim 1, characterized in that, The disc body (41) is also provided with at least one mounting groove (411) located on the periphery of the positioning platform (42) and extending radially.

4. The battery cell according to claim 3, characterized in that, The positioning platform (42) is located at the center of the disk body (41). The collecting disk (40) is also provided with a liquid injection hole (43) that penetrates the positioning platform (42) and the disk body (41) along the thickness direction of the collecting disk (40). The liquid injection hole (43) is coaxial with the positioning platform (42).

5. The battery cell according to claim 4, characterized in that, The positioning platform (42) has a first recess (423), and the injection hole (43) is formed at the bottom of the first recess (423).

6. The battery cell according to claim 5, characterized in that, The depth of the first recess (423) is greater than the axial length of the straight segment (422).

7. The battery cell according to claim 4, characterized in that, The end cap (30) has a through hole (31) communicating with the liquid injection hole (43). The end cap (30) is provided with a second recess (32) communicating with the through hole (31) on the side away from the collector plate (40). The battery cell also includes a sealing pin, which blocks the liquid injection hole (43), and the welding line between the sealing pin and the end cap (30) is located in the second recess (32).

8. An energy storage device, characterized in that, include: The battery cell according to any one of claims 1-7.

9. An electrical appliance, characterized in that, include: The energy storage device according to claim 8.

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