Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly. The shell has a first wall and a second wall opposite to each other along a first direction, and the first wall has a liquid injection hole for injecting electrolyte into the shell. The electrode assembly is arranged in the shell. The second wall is formed with a weak part and a pressure relief area, and the second wall is configured to be capable of cracking along the weak part to open the pressure relief area. The projection of the liquid injection hole and the projection of the weak part do not overlap each other on the same projection plane perpendicular to the first direction. The technical scheme provided by the application can improve the manufacturing efficiency of the battery device.

Description

Battery cell, battery device and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery cell, a battery device and an electric device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for its development.

[0003] In the development of battery technology, how to improve the manufacturing efficiency of the battery device is a technical problem that needs to be solved in the battery technology.

[0004] SUMMARY

[0005] The present application provides a battery cell, a battery device and an electric device. The technical scheme provided by the present application can improve the manufacturing efficiency of the battery device.

[0006] In a first aspect, some embodiments of the present application provide a battery cell, which comprises a shell and an electrode assembly. The shell has a first wall and a second wall opposite to each other along a first direction, and the first wall has a liquid injection hole for injecting electrolyte into the shell. The electrode assembly is arranged inside the shell. The second wall forms a weak part and a pressure relief area, and the second wall is configured to crack along the weak part to open the pressure relief area. The projection of the liquid injection hole and the projection of the weak part do not overlap on the same projection plane perpendicular to the first direction.

[0007] In the above scheme, on the one hand, the liquid injection hole and the weak part are arranged on the first wall and the second wall of the shell respectively, which can reduce the interference of the weak part or the liquid injection hole with other structural parts, thereby improving the space utilization of other structural parts at the battery device level, for example, reducing the interference of the weak part or the liquid injection hole with the external busbar part, thereby facilitating the improvement of the volume energy density of the battery device. On the other hand, by arranging the projections of the liquid injection hole and the weak part on the same projection plane perpendicular to the first direction to be non-overlapping, the impact of the pressure generated when the electrolyte is injected into the shell by the liquid injection hole on the weak part can be effectively reduced, thereby reducing the risk of damage and cracking of the weak part, resulting in the battery cell being scrapped, so that the battery cell has a high yield rate during manufacturing, thereby facilitating the improvement of the manufacturing efficiency of the battery cell, and further facilitating the improvement of the manufacturing efficiency of the battery device.

[0008] According to some embodiments of the present application, the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction is greater than or equal to 5 mm and less than or equal to 50 mm.

[0009] In the above scheme, by setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be greater than or equal to 5 mm, the influence of the pressure generated during electrolyte injection on the weakened portion can be effectively reduced, and the risk of battery cell scrapping due to the rupture of the weakened portion can be reduced. By setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be less than or equal to 50 mm, the interference of the liquid injection hole or the weakened portion with other structural components can be reduced, so that the battery device structure is compact when the battery device is stacked, which is beneficial to the improvement of the volume energy of the battery device. Therefore, by setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be greater than or equal to 5 mm and less than or equal to 50 mm, the manufacturing yield, manufacturing efficiency and volume energy density of the battery device can be effectively balanced.

[0010] According to some embodiments of the present application, the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction is greater than or equal to 10 mm and less than or equal to 20 mm.

[0011] In the above scheme, by setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be greater than or equal to 10 mm, the influence of the pressure generated during electrolyte injection on the weakened portion can be further reduced, and the risk of battery cell scrapping due to the rupture of the weakened portion can be reduced. By setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be less than or equal to 20 mm, the interference of the liquid injection hole or the weakened portion with other structural components can be effectively reduced, so that the battery device structure is compact when the battery device is stacked, which is beneficial to the improvement of the volume energy of the battery device. Therefore, by setting the minimum distance between the projection of the liquid injection hole and the projection of the weakened portion on the same projection plane perpendicular to the first direction to be greater than or equal to 10 mm and less than or equal to 20 mm, the manufacturing yield, manufacturing efficiency and volume energy density of the battery device can be effectively balanced.

[0012] According to some embodiments of the present application, the battery cell further comprises a first electrode terminal and a second electrode terminal, the polarities of the first electrode terminal and the second electrode terminal are opposite, the first electrode terminal and the second electrode terminal are respectively arranged on the first wall, and the first electrode terminal and the second electrode terminal are arranged in a spaced manner along the second direction, the first direction and the second direction are perpendicular to each other.

[0013] In the above scheme, on the one hand, the first electrode terminal and the second electrode terminal are both arranged on the first wall, so that the first electrode terminal and the second electrode terminal utilize the space on the same side, which is beneficial to the improvement of the space utilization rate of the battery monomer and the improvement of the volume energy density of the battery device; on the other hand, by arranging the first electrode terminal and the second electrode terminal and the weak part on the two wall parts opposite to each other respectively, the influence of the electrode terminal of the adjacent battery monomer caused by the rupture of the weak part to release the internal pressure of the battery monomer can be reduced, the risk of internal short circuit of the battery device is caused, and the reliability of the battery device is improved.

[0014] According to some embodiments of the present application, along the second direction, the injection hole is located between the first electrode terminal and the second electrode terminal.

[0015] In the above scheme, the injection hole is arranged between the first electrode terminal and the second electrode terminal, so that the distance between the injection hole and the first electrode terminal and the distance between the injection hole and the second electrode terminal are appropriate, which reduces the risk that the electrolyte is attached to the first electrode terminal or the second electrode terminal due to the too close distance between the injection hole and the first electrode terminal or the too close distance between the injection hole and the second electrode terminal during the electrolyte injection process, so as to affect the production rhythm, thereby improving the production rhythm of the battery monomer, and further improving the manufacturing efficiency of the battery device.

[0016] According to some embodiments of the present application, along the second direction, the distance between the injection hole and the first electrode terminal is equal to the distance between the injection hole and the second electrode terminal.

[0017] In the above scheme, along the second direction, by arranging the injection hole centrally between the first electrode terminal and the second electrode terminal, the distance between the injection hole and the first electrode terminal and the distance between the injection hole and the second electrode terminal are appropriate, which reduces the risk of affecting the production rhythm due to the attachment of the electrolyte to the electrode terminal during the electrolyte injection process.

[0018] According to some embodiments of the present application, along the second direction, the distance between the injection hole and the first electrode terminal is greater than the distance between the injection hole and the second electrode terminal.

[0019] In the above scheme, along the second direction, by arranging the injection hole farther away from the first electrode terminal, the risk of electrolyte attachment to the first electrode terminal can be effectively reduced, and under the condition that the injection hole and the weak part are misaligned, the weak part can be centrally arranged between the first electrode terminal and the second electrode terminal, so as to facilitate the rupture of the weak part under the internal pressure of the battery monomer and timely release of the internal pressure of the battery monomer, thereby improving the reliability of the battery monomer and further improving the reliability of the battery device.

[0020] According to some embodiments of the present application, the first wall has a first edge and a second edge in the third direction, and the distance between the injection hole and the first edge is equal to the distance between the injection hole and the second edge in the third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

[0021] In the above scheme, by centrally arranging the injection hole between the first edge and the second edge in the third direction, the distances between the injection hole and the first edge and between the injection hole and the second edge are appropriate, thereby reducing the risk of affecting the production rhythm due to the adhesion of the electrolyte to the two wall parts of the battery cell opposite to each other in the third direction during the electrolyte injection process.

[0022] According to some embodiments of the present application, the first wall has a first edge and a second edge in the third direction, and the distance between the injection hole and the first edge is greater than the distance between the injection hole and the second edge in the third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

[0023] In the above scheme, by arranging the injection hole farther away from the first edge in the third direction, and under the condition that the injection hole is misaligned with the weak part, the weak part can be centered in the second wall in the third direction, thereby facilitating the rupture of the weak part under the internal pressure of the battery cell and timely releasing the internal pressure of the battery cell, thereby facilitating the improvement of the reliability of the battery cell and further facilitating the improvement of the reliability of the battery device.

[0024] According to some embodiments of the present application, the distance between the injection hole and the first electrode terminal is greater than or equal to 40 mm in the second direction, and the distance between the injection hole and the second electrode terminal is greater than or equal to 40 mm in the second direction.

[0025] In the above scheme, by arranging the distance between the injection hole and the first electrode terminal to be greater than or equal to 40 mm in the second direction, the risk of affecting the production rhythm due to the adhesion of the electrolyte to the first electrode terminal during the electrolyte injection process can be effectively reduced; by arranging the distance between the injection hole and the second electrode terminal to be greater than or equal to 40 mm in the second direction, the risk of affecting the production rhythm due to the adhesion of the electrolyte to the second electrode terminal during the electrolyte injection process can be effectively reduced.

[0026] According to some embodiments of the present application, the injection hole comprises a first hole section and a second hole section, the first hole section and the second hole section are arranged in the direction of the first wall pointing to the second wall, and the aperture of the first hole section is greater than the aperture of the second hole section.

[0027] In the above scheme, by setting the injection hole as a stepped hole and setting the diameter of the first hole segment on the outside to be larger than the diameter of the second hole segment on the inside, it is possible for the injection equipment to inject liquid into the shell through the injection hole, providing more space for electrolyte injection, thereby reducing the risk of electrolyte splashing outward, which is conducive to improving the production cycle of battery cells and thus improving the manufacturing efficiency of battery devices.

[0028] According to some embodiments of this application, the diameter of the first hole segment is greater than or equal to 4 mm and less than or equal to 10 mm.

[0029] In the above scheme, by setting the diameter of the first hole segment to be greater than or equal to 4 mm, a larger space can be provided for the electrolyte, reducing the risk of electrolyte splashing outward and facilitating the improvement of the production cycle of battery cells; by setting the diameter of the first hole segment to be less than or equal to 10 mm, the space occupied by the injection hole on the first wall can be reduced, which is conducive to the layout of other structural components, making the battery device structure compact and improving the volumetric energy density of the battery device.

[0030] According to some embodiments of this application, the center of the weak portion coincides with the center of the second wall.

[0031] In the above scheme, by setting the center of the weak part to coincide with the center of the second wall, the internal pressure of the battery cell can be effectively applied to the weak part, thereby causing the weak part to rupture more promptly to release the internal pressure of the battery cell, reducing the risk of battery cell explosion, improving the reliability of the battery cell, and improving the reliability of the battery device.

[0032] According to some embodiments of this application, on the same projection plane perpendicular to the first direction, the projection of the injection hole and the projection of the pressure relief zone do not overlap.

[0033] In some embodiments of the above scheme, a pressure relief zone can be formed at the location of the weak part. By setting the projections of the injection hole and the pressure relief zone on the same projection plane perpendicular to the first direction to be non-overlapping, the impact of the pressure generated when injecting electrolyte into the casing through the injection hole on the pressure relief zone can be effectively reduced, which may cause the pressure relief zone, i.e. the weak part, to be damaged and ruptured, resulting in the scrapping of the battery cell. This allows the battery cell to have a higher yield rate during the manufacturing process, thereby improving the manufacturing efficiency of the battery cell and, in turn, the manufacturing efficiency of the battery device.

[0034] According to some embodiments of this application, the second wall is provided with a scoring groove, the bottom wall of the scoring groove is a weak part, and the scoring groove defines a pressure relief area.

[0035] In the above scheme, by arranging the score groove on the second wall, and forming the groove bottom wall of the score groove as a weak part, the second wall can be cracked along the score groove to open the pressure relief area under the action of the internal pressure of the battery cell, so that the internal pressure of the battery cell is discharged, thereby the battery cell has higher reliability. At the same time, the score groove is simple to manufacture, and the formation of the weak part by the score groove is beneficial to the improvement of the manufacturing efficiency of the battery cell.

[0036] According to some embodiments of the present application, the score groove includes a first groove segment, a second groove segment and a third groove segment, the first groove segment and the third groove segment are oppositely arranged along the second direction, and the second groove segment is located between the first groove segment and the third groove segment and connects the first groove segment and the third groove segment, the first groove segment, the second groove segment and the third groove segment jointly define the pressure relief area, and the first direction and the second direction are perpendicular to each other.

[0037] In the above scheme, the score groove structure is simple, which includes a first groove segment, a third groove segment and a second groove segment connecting the first groove segment and the third groove segment. When the internal pressure of the battery cell expands to a certain extent, the second wall can be cracked along the first groove segment, the second groove segment and the third groove segment, so that the battery cell has a larger pressure relief area, which is beneficial to the rapid discharge of the internal pressure of the battery cell, thereby improving the reliability of the battery cell, and further improving the reliability of the battery device.

[0038] According to some embodiments of the present application, on the same projection plane perpendicular to the first direction, the projection of the liquid injection hole is located between the projection of the first groove segment and the projection of the third groove segment.

[0039] In the above scheme, on the same projection plane perpendicular to the first direction, by arranging the projection of the liquid injection hole between the projection of the first groove segment and the projection of the second groove segment, on the one hand, the pressure generated during the electrolyte injection process can directly act on the groove bottom wall of the first groove segment and the groove bottom wall of the second groove segment, so as to reduce the risk of cracking of the second wall during the manufacturing process of the battery cell; on the other hand, the space utilization rate of the liquid injection hole and the weak part can be improved, so as to provide a larger space for other structural members of the battery device, which is beneficial to the spatial layout of other structural members of the battery device, thereby improving the volume energy density of the battery device.

[0040] According to some embodiments of the present application, the score groove includes a ring-shaped score groove, and the ring-shaped score groove surrounds to form the pressure relief area.

[0041] In the above scheme, the score groove is ring-shaped, which surrounds to form a larger pressure relief area, so that the battery cell has a larger pressure relief area, which can quickly discharge the internal pressure of the battery cell, and the battery device has higher reliability.

[0042] According to some embodiments of the present application, the annular score groove comprises a first straight segment, a second straight segment, a first arc segment and a second arc segment, the first straight segment and the second straight segment are oppositely arranged along a third direction, the first arc segment and the second arc segment are oppositely arranged along a second direction, one end of the first straight segment and one end of the second straight segment are connected by the first arc segment, the other end of the first straight segment and the other end of the second straight segment are connected by the second arc segment, the thickness of the groove bottom wall of the second straight segment, the thickness of the groove bottom wall of the first arc segment and the thickness of the groove bottom wall of the second arc segment are all less than the thickness of the groove bottom wall of the first straight segment, and the first direction, the second direction and the third direction are perpendicular to each other in pairs.

[0043] In the above scheme, by setting the thickness of the second wall along the second straight segment, the first arc segment and the second arc segment to be smaller, when the internal pressure of the battery cell expands to a certain extent, the second wall breaks along the second straight segment, the first arc segment and the second arc segment to quickly release the internal pressure of the battery cell, so that the battery device has higher reliability; at the same time, because the thickness of the groove bottom wall of the first straight segment is larger, the pressure relief area at the position of the first straight segment can remain in the second wall, reducing the risk of the weak part being impacted by the pressure to the adjacent battery cell or other structural parts of the battery device, causing the structure of the adjacent battery cell or other structural parts of the battery device to be damaged, thereby facilitating the improvement of the reliability of the battery device.

[0044] According to some embodiments of the present application, the score groove further comprises a fourth groove segment and a fifth groove segment, the fourth groove segment and the fifth groove segment are located in the pressure relief area, and the fourth groove segment and the fifth groove segment are respectively in the shape of a circular arc. The fourth groove segment and the fifth groove segment are oppositely arranged along the third direction, and the outer edge side of the fourth groove segment and the outer edge side of the fifth groove segment are tangent to each other, and the thickness of the groove bottom wall of the second straight segment, the thickness of the groove bottom wall of the first arc segment and the thickness of the groove bottom wall of the second arc segment are all less than or equal to the thickness of the groove bottom wall of the fourth groove segment, and the thickness of the groove bottom wall of the second straight segment, the thickness of the groove bottom wall of the first arc segment and the thickness of the groove bottom wall of the second arc segment are all less than or equal to the thickness of the groove bottom wall of the fifth groove segment.

[0045] In the above scheme, the score groove further comprises a fourth groove segment and a fifth groove segment, and the fourth groove segment and the fifth groove segment are located in the pressure relief area, which can reduce the structural strength of the part of the second wall located in the pressure relief area, thereby facilitating the rupture of the part where the pressure relief area is located when the weak part is subjected to the internal pressure of the battery cell, so as to quickly release the internal pressure of the battery cell, thereby effectively improving the reliability of the battery device.

[0046] According to some embodiments of the present application, the part where the outer edge side of the fourth groove segment and the outer edge side of the fifth groove segment are tangent to each other coincides with the center of the second wall.

[0047] In the above scheme, by setting the positions where the outer edge side of the fourth groove segment and the outer edge side of the fifth groove segment are tangent to each other to coincide with the center of the second wall, the internal pressure of the battery cell can be uniformly applied to the annular score groove through the fourth groove segment and the fifth groove segment, thereby facilitating the rupture of the second wall along the second straight line segment, the first arcuate segment, and the second arcuate segment to quickly release the internal pressure of the battery cell, and the battery device has high reliability.

[0048] According to some embodiments of the present application, along the second direction, one end of the first straight line segment is connected to one end of the fourth groove segment, and the other end of the first straight line segment is connected to the other end of the fourth groove segment; along the second direction, one end of the second straight line segment is connected to one end of the fifth groove segment, and the other end of the second straight line segment is connected to the other end of the fifth groove segment.

[0049] In the above scheme, by extending the two ends of the fourth groove segment to the first straight line segment and extending the two ends of the fifth groove segment to the second straight line segment, the internal pressure of the battery cell can be effectively applied to the annular score groove, thereby facilitating the rupture of the annular score groove to release the internal pressure of the battery cell, and further facilitating the improvement of the reliability of the battery device.

[0050] According to some embodiments of the present application, on the same projection plane perpendicular to the first direction, the projection of the liquid injection hole is located within the region enclosed by the projection of the first arcuate segment, the projection of the fourth groove segment, and the projection of the fifth groove segment.

[0051] In the above scheme, on the same projection plane perpendicular to the first direction, by setting the projection of the liquid injection hole in the region enclosed by the projection of the first arcuate segment, the projection of the fourth groove segment, and the projection of the fifth groove segment, on the one hand, the pressure generated during the electrolyte injection process can be directly applied to the score groove, thereby reducing the risk of the second wall rupturing during the manufacturing process of the battery cell; on the other hand, the space utilization rate of the liquid injection hole and the weak part can be improved, thereby providing a larger space for other structural components of the battery device, facilitating the spatial layout of other structural components of the battery device, and thereby facilitating the volume energy density of the battery device.

[0052] According to some embodiments of the present application, the weak part is integrally formed in the second wall.

[0053] In the above scheme, the weak part can be formed in the second wall by an integral forming process, which can reduce the manufacturing process of the battery cell, effectively improve the manufacturing efficiency of the battery cell, and further facilitate the improvement of the manufacturing efficiency of the battery device.

[0054] According to some embodiments of the present application, the second wall includes a wall body and a pressure relief member, and the weak part is formed in the pressure relief member. The wall body has a first through hole passing through along the first direction, and the pressure relief member is connected to the wall body and closes the first through hole.

[0055] In the scheme, the second wall comprises a wall body and a pressure relief member, the weak part is formed on the pressure relief member, and the first through hole of the wall body is closed by the connection of the pressure relief member and the wall body, so that the battery monomer has a pressure relief function, and the reliability of the battery monomer is improved.

[0056] According to some embodiments of the present application, the projection area of the pressure relief member on the projection plane perpendicular to the first direction is greater than or equal to 200mm 2 and less than or equal to 2000mm 2 .

[0057] In the scheme, the projection area of the pressure relief member along the first direction is greater than or equal to 200mm 2 , so that the battery monomer has a larger pressure relief area and a pressure relief rate, thereby improving the reliability of the battery monomer; and the projection area of the pressure relief member along the first direction is less than or equal to 2000mm 2 , so as to reduce the interference of the pressure relief member on other structural members of the battery device, provide a larger space for other structural members, so that the battery device is compact, and the volume energy density of the battery device is improved.

[0058] In a second aspect, some embodiments of the present application provide a battery device, which comprises any one of the battery monomers provided in the first aspect.

[0059] In a third aspect, some embodiments of the present application provide a power consumption device, which comprises the battery monomer provided in the first aspect and / or the battery device provided in the third aspect. The battery monomer is used to provide electric energy.

[0060] Additional aspects and advantages of the present application will be given in part in the following description, part will become apparent from the following description, or will be understood by those skilled in the art through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0062] Fig. 1 is a schematic view of a vehicle in some embodiments of the present application;

[0063] Fig. 2 is a perspective exploded view of a battery device in some embodiments of the present application;

[0064] Fig. 3 is a perspective view of a battery monomer in some embodiments of the present application;

[0065] Fig. 4 is a schematic view of a structure of a battery cell in some embodiments of the present application;

[0066] Fig. 5 is a sectional view along the A-A direction in Fig. 3;

[0067] Fig. 6 is a view of the positional relationship between the projection of the liquid injection hole and the projection of the weak portion in the same projection plane perpendicular to the first direction in some embodiments of the present application;

[0068] Fig. 7 is a plan view of a battery cell in some embodiments of the present application;

[0069] Fig. 8 is a plan view of a battery cell in some other embodiments of the present application;

[0070] Fig. 9 is an enlarged view of B in Fig. 5;

[0071] Fig. 10 is a schematic view of a second wall and a weak portion in some embodiments of the present application;

[0072] Fig. 11 is a schematic view of a second wall and a score groove in some embodiments of the present application;

[0073] Fig. 12 is a schematic view of a wall body and a pressure relief member in some embodiments of the present application.

[0074] Fig. 13 is a schematic view of a battery cell in some embodiments of the present application. Fig. 14 is a schematic view of a battery cell in some other embodiments of the present application. Fig. 15 is a schematic view of a battery cell in some other embodiments of the present application.

[0075] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0076] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0077] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0078] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0079] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0080] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length and width of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0081] "Multiple" appearing in the present application refers to two or more (including two).

[0082] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to be used.

[0083] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto.

[0084] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow the active ions to pass through.

[0085] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0086] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0087] In some embodiments, the electrode assembly further includes a separator arranged between the positive electrode and the negative electrode.

[0088] In some embodiments, the separator is a separator film. The type of separator film can be various, and any known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0089] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0090] In some embodiments, the electrode assembly is a roll structure. The positive electrode sheet and the negative electrode sheet are rolled into a roll structure.

[0091] In some embodiments, the electrode assembly is a stack structure.

[0092] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be arranged alternately.

[0093] As an example, a plurality of positive electrode sheets can be arranged, and the negative electrode sheet is folded to form a plurality of folded segments arranged in layers, and one positive electrode sheet is clamped between adjacent folded segments.

[0094] As an example, the positive electrode sheet and the negative electrode sheet are each folded to form a plurality of folded segments arranged in a stack.

[0095] As an example, a plurality of separators can be provided, each provided between any adjacent positive electrode sheet or negative electrode sheet.

[0096] As an example, the separators can be provided continuously, and provided between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0097] In some embodiments, the electrode assembly can have a shape of a cylinder, a flat, a polygonal prism, or the like.

[0098] In some embodiments, the electrode assembly can be provided with tabs, which can conduct current out of the electrode assembly. The tabs can include positive tabs and negative tabs.

[0099] In some embodiments, the battery cell can include a housing. The housing can be used to enclose components such as the electrode assembly and the electrolyte. The housing can be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite case), or an aluminum-plastic film, or the like.

[0100] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of another shape. The prismatic battery cell can include, but is not limited to, a square battery cell, a blade battery cell, a polygonal prism battery cell (e.g., a hexagonal prism battery cell), or the like.

[0101] A battery apparatus as referred to in embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0102] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells into a separate module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0103] In some embodiments, a battery apparatus can be a battery pack, which includes a case and one or more battery cell assemblies housed in the case.

[0104] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box by fixing the battery module in the box.

[0105] As an example, the battery cell assembly can also be accommodated in the box by fixing a plurality of battery cells directly to the box.

[0106] As an example, the box can include a first box and a second box. The first box and the second box are fastened so that an enclosed space is formed inside the box to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0107] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that an enclosed space is formed inside the box to accommodate the battery cell assembly.

[0108] As an example, the box can be part of the chassis structure of the vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0109] In some embodiments, the battery device can refer to an energy storage device, which includes a box having at least one side provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0110] As an example, the battery device includes a beam assembly and a battery cell assembly. The beam assembly can include a mounting beam and a mounting beam arranged relative to each other. The mounting beam is used to mount and fix the battery cell assembly, and the mounting beam is used to mount the battery on the body of the power utilization device to supply power to the body of the power utilization device. In some embodiments, the beam assembly can be part of the structure of the box.

[0111] The battery device has the advantages of high energy density, small environmental pollution, large power density, long service life, wide adaptability, small self-discharge coefficient, etc., and is an important part of the development of new energy. The development of battery technology needs to consider many design factors, such as cycle life, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the manufacturing efficiency of the battery cell also needs to be considered.

[0112] In battery technology, a battery cell generally comprises a housing, an electrode assembly and an electrolyte. The housing and the electrolyte are disposed in the housing, and the electrolyte serves to conduct ions between the positive and negative electrodes. Generally, the housing is provided with a liquid injection hole for injecting the electrolyte into the housing. The housing has a first wall and a second wall opposite to each other, for example, the first wall can be a top wall, and the second wall can be a bottom wall. The liquid injection hole can be provided with a liquid injection hole. During the charging and discharging process, gas is generated in the battery cell due to electrochemical reaction, and as the number of charging and discharging cycles of the battery cell increases, the internal pressure of the battery cell increases, and there is a risk of thermal runaway. In order to reduce the risk of thermal runaway, in the related art, the wall of the housing is also provided with a weak part, and when the internal pressure of the battery cell reaches a certain degree, the second wall can be broken along the weak part to release the internal pressure of the battery cell. At present, in some battery cells, the weak part is provided on the second wall, which is opposite to the liquid injection hole and at least partially opposite to the liquid injection hole. During the manufacturing process of the battery cell, the pressure generated during the electrolyte injection process acts on the weak part, causing the second wall to break and resulting in the battery cell being scrapped, which reduces the yield of the battery cell and affects the manufacturing efficiency of the battery cell and the battery device.

[0113] In view of this, in order to improve the problem that the pressure generated during the electrolyte injection process causes the second wall to break along the weak part, affecting the manufacturing efficiency of the battery cell and the manufacturing efficiency of the battery device, some embodiments of the present application provide a battery cell, which comprises a housing and an electrode assembly. The housing has a first wall and a second wall opposite to each other along a first direction z, and the first wall has a liquid injection hole for injecting the electrolyte into the housing. The electrode assembly is disposed in the housing. The second wall is formed with a weak part and a pressure relief area, and the second wall is configured to be able to break along the weak part to open the pressure relief area. The projection of the liquid injection hole and the projection of the weak part do not overlap on the same projection plane perpendicular to the first direction z.

[0114] In the above scheme, on the one hand, the liquid injection hole and the weak part are respectively provided on the first wall and the second wall of the housing opposite to each other, which can reduce the interference of the weak part or the liquid injection hole with other structural members, thereby improving the space utilization of other structural members at the battery device level, for example, reducing the interference of the weak part or the liquid injection hole with the external bus member, thereby facilitating the improvement of the volume energy density of the battery device. On the other hand, by setting the projections of the liquid injection hole and the weak part on the same projection plane perpendicular to the first direction z to be mutually non-overlapping, the impact of the pressure generated when the electrolyte is injected into the housing through the liquid injection hole on the weak part can be effectively reduced, thereby reducing the risk of damage and breakage of the weak part, causing the battery cell to be scrapped, and improving the yield of the battery cell during the manufacturing process, thereby facilitating the improvement of the manufacturing efficiency of the battery cell and the manufacturing efficiency of the battery device.

[0115] The technical solutions described in the embodiments of the present application are suitable for batteries and power consumption devices using the batteries.

[0116] The power consumption device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle, or an extended range vehicle, etc. The spacecraft includes an airplane, a rocket, a space shuttle, a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc. The embodiments of the present application do not specially limit the above power consumption devices.

[0117] The following embodiments take the vehicle as an example for convenience of description.

[0118] FIG. 1 is a schematic diagram of a vehicle 1000 in some embodiments of the present application.

[0119] The vehicle 1000 can be provided with a controller 200, a motor 300, and a battery device 100, and the controller 200 is used to control the battery device 100 to supply power to the motor 300. For example, the battery can be arranged at the bottom, the front, or the rear of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000. For example, the battery device 100 can be used as an operating power source of the vehicle 1000, and is used for circuit systems of the vehicle 1000, such as power consumption demand for starting, navigation, and operation of the vehicle 1000. In another embodiment of the present application, the battery device 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0120] Please refer to FIG. 2, which is a perspective exploded view of the battery device 100 in some embodiments of the present application.

[0121] The battery device 100 includes a battery cell 10 and a case 20, and the battery cell 10 is accommodated in the case 20. The case 20 is configured to provide an accommodation space for the battery cell 10, and the case 20 can have various structures. In some embodiments, the case 20 can include a first case portion 21 and a second case portion 22, and the first case portion 21 and the second case portion 22 are configured to cover each other and jointly define the accommodation space for the battery cell 10. The second case portion 22 can be a hollow structure with one end open, and the first case portion 21 can be a plate structure, and the first case portion 21 is configured to cover the open end of the second case portion 22 to jointly define the accommodation space with the second case portion 22. Alternatively, the first case portion 21 and the second case portion 22 can both be hollow structures with one end open, and the open end of the first case portion 21 is configured to cover the open end of the second case portion 22. Of course, the case 20 formed by the first case portion 21 and the second case portion 22 can have various shapes, such as a cylinder, a cuboid, etc.

[0122] In the battery device 100, the battery cell 10 can be one or multiple, and each battery cell 10 can be fixed to the case 20 by a connecting member (e.g., a bolt), or each battery cell 10 can be fixed to the case 20 by adhesion.

[0123] In some embodiments, the battery cells 10 in the case 20 can be electrically connected by a busbar component, so that the battery cells 10 in the case 20 are connected in series, in parallel, or in a mixed connection.

[0124] For example, the case 20 is provided with multiple battery cell assemblies, each battery cell assembly includes multiple battery cells 10 stacked with each other, and the multiple battery cells 10 are connected in series by a busbar component. In some embodiments, the multiple battery cell assemblies can be connected in series by a busbar component.

[0125] Referring to FIGS. 3-5, FIG. 3 is a perspective view of a battery cell 10 according to some embodiments of the present application, FIG. 4 is a structural schematic view of the battery cell 10 according to some embodiments of the present application, and FIG. 5 is a sectional view of the battery cell 10 according to some embodiments of the present application, taken along the A-A direction of FIG. 3. Some embodiments of the present application provide a battery cell 10, which includes a housing 11 and an electrode assembly 13. The housing 11 has a first wall 110 and a second wall 112 opposite to each other along a first direction z, and the first wall 110 has a liquid injection hole 12 for injecting an electrolyte into the housing 11. The electrode assembly 13 is disposed inside the housing 11. The second wall 112 is formed with a weak portion 14 and a pressure relief area 15, and the second wall 112 is configured to be able to crack along the weak portion 14 to open the pressure relief area 15. In the same projection plane perpendicular to the first direction z, the projection of the liquid injection hole 12 and the projection of the weak portion 14 do not overlap each other.

[0126] In some embodiments, the battery cell 10 includes a housing 11 and an electrode assembly 13, and the electrode assembly 13 and an electrolyte can be encapsulated in a closed space of the housing 11. The housing 11 can be a square housing, a cylindrical housing or a flat housing. Optionally, the housing 11 includes a plurality of wall portions which are connected to each other and enclose a receiving cavity for receiving the electrode assembly 13. For example, referring to FIGS. 3 and 4, the housing 11 includes a first wall 110 and a second wall 112 which are opposite to each other, a third wall 113 and a fourth wall 114 which are opposite to each other, and a fifth wall 115 and a sixth wall 116 which are opposite to each other, and the first wall 110, the second wall 112, the third wall 113, the fourth wall 114, the fifth wall 115 and the sixth wall 116 are connected to each other and collectively enclose the receiving cavity. For example, the housing 11 is cylindrical, and the housing 11 includes the first wall 110 and the second wall 112 which are opposite to each other, and a peripheral wall which is disposed between the first wall 110 and the second wall 112, one end of the peripheral wall is arranged around an edge of the first wall 110, and the other end of the peripheral wall is arranged around an edge of the second wall 112.

[0127] In some embodiments, the housing 11 can be a one-piece structure, or some wall portions of the housing 11 are a one-piece structure, or the wall portions of the housing 11 are separate structures which are connected to each other by welding, bonding, riveting or threaded connection. For example, the housing 11 includes a shell and the first wall 110, the shell includes the second wall 112, the shell has a first opening through which the electrode assembly 13 can be placed into the shell, and the first wall 110 is connected to the housing 11 and closes the first opening; or the housing 11 includes a shell, the first wall 110 and the second wall 112, the shell has a first opening and a second opening which are opposite to each other, the first wall 110 is connected to the shell and closes the first opening, and the second wall 112 is connected to the shell and closes the second opening.

[0128] In some embodiments, the housing 11 can be made of metal, such as aluminum, steel, composite metal, etc. Or in other embodiments, the housing 11 can be made of non-metal material, such as plastic.

[0129] In some embodiments, the materials of the wall portions of the housing 11 can be the same or different. For example, the first wall 110, the second wall 112, the third wall 113, the fourth wall 114, the fifth wall 115 and the sixth wall 116 are all made of steel; or the first wall 110 is made of aluminum, and the second wall 112, the third wall 113, the fourth wall 114, the fifth wall 115 and the sixth wall 116 are all made of steel.

[0130] In some embodiments, the first direction z can be a height direction of the battery cell 10, please refer to FIG. 3 and FIG. 4, the first wall 110 and the second wall 112 can be opposite to each other along the height direction of the battery cell 10. In some use scenarios, the first direction z can be parallel to the direction of gravity, the first wall 110 can be a top wall, and the second wall 112 can be a bottom wall; in other use scenarios, the height direction of the battery cell 10 can be parallel to the direction of gravity, and the second wall 112 can be a top wall, and the first wall 110 can be a bottom wall. In other use scenarios, the height direction of the battery cell 10 can also be parallel to the horizontal direction.

[0131] In some embodiments, the number of the electrode assemblies 13 can be one or more. Optionally, the battery cell 10 includes two electrode assemblies 13, and the two electrode assemblies 13 are stacked in the shell 11.

[0132] In some embodiments, the battery cell 10 further includes an electrode terminal, the electrode terminal is arranged on a wall of the shell 11, and the electrode terminal is used to connect the tab of the electrode assembly 13 and an external bus component (for example, a tab) to realize the input and output of the electrical energy of the battery cell 10. Optionally, the tab of the electrode assembly 13 is welded with the electrode terminal. Optionally, the tab of the electrode assembly 13 is electrically connected with the electrode terminal through an adapter. In some embodiments, the electrode terminal can be a cylindrical structure, or a polygonal prism structure, or a composite structure of a cylindrical structure and a polygonal prism structure. In some embodiments, the electrode terminal is made of a metal material, for example, made of aluminum, copper, iron, steel, alloy or composite metal.

[0133] In some embodiments, the electrode terminal includes a first electrode terminal 16 and a second electrode terminal 17 with opposite polarities, for example, the first electrode terminal 16 is a positive electrode terminal, and the second electrode terminal 17 is a negative electrode terminal. The first electrode terminal 16 is electrically connected with the tab with the corresponding polarity, and the second electrode terminal 17 is electrically connected with the tab with the corresponding polarity. In some embodiments, the first electrode terminal 16 and the second electrode terminal 17 can be arranged on the same wall of the shell 11, for example, the first wall 110, the second wall 112, the third wall 113, the fourth wall 114, the fifth wall 115 or the sixth wall 116, and exemplarily, the first electrode terminal 16 and the second electrode terminal 17 are arranged at intervals on the first wall 110. In other embodiments, the first electrode terminal 16 and the second electrode terminal 17 can be arranged on different walls of the shell 11, for example, the first electrode terminal 16 is arranged on the first wall 110, and the second electrode terminal 17 is arranged on the second wall 112.

[0134] The liquid injection hole 12 is a through-hole structure arranged on the first wall 110, and penetrates the first wall 110 along the thickness direction of the first wall 110. The liquid injection hole 12 is used to inject electrolyte, for example, electrolyte solution, into the inside of the shell 11.

[0135] In some embodiments, the injection hole 12 can be a circular hole, a square hole, a polygonal hole, or a through-hole structure of other shapes.

[0136] For example, when assembling the battery cell 10, the electrode assembly 13 can be placed into the interior of the case through the first opening, the first wall 110 is connected to the case to cover the first opening, so that the electrode assembly 13 is in the closed space, and finally the electrolyte is injected into the closed space through the injection hole 12 of the first wall 110 and the injection hole 12 is closed. In some embodiments, the battery cell 10 further comprises a closure 12a for closing the injection hole 12. The closure 12a can include a sealing pin, a threaded pin, a glue pin, etc.

[0137] In some embodiments, when assembling the battery cell 10, the electrolyte can be injected into the injection hole 12 by an injection device, for example, the injection device includes an injection head which is aligned with or inserted into the injection hole 12 to inject the electrolyte with a certain pressure into the outer shell 11.

[0138] Referring to FIG. 4, the second wall 112 is formed with a weak portion 14 and a pressure relief area 15, the structural strength of the weak portion 14 is lower than that of other parts of the second wall 112, so that when the pressure inside the battery cell 10 increases to a certain extent, the second wall 112 can be cracked along the weak portion 14, so that the pressure relief area 15 is opened, thereby connecting the interior of the outer shell 11 with the outside, and the pressure or substances in the interior of the outer shell 11 can be discharged through the opened pressure relief area 15.

[0139] In some embodiments, the weakened portion 14 can be formed directly or indirectly on the second wall 112. Optionally, the weakened portion 14 is integrally formed on the second wall 112, for example, the weakened portion 14 is a notched structure, a recessed structure or other weakened structure formed on the second wall 112. Optionally, the weakened portion 14 can be formed on the second wall 112 by processes such as die casting, turning, stamping, etc. Optionally, the weakened portion 14 is first formed on another structural member, and then the other structural member is integrated into the second wall 112. For example, the second wall 112 includes a wall body 1120 and a pressure relief member 1121, the wall body 1120 is formed with a first through hole 1122, the pressure relief member 1121 is integrally formed with the weakened portion 14, for example, the weakened portion 14 is a notched structure, a recessed structure or other weakened structure formed on the pressure relief member 1121, the pressure relief member 1121 is connected with the wall body 1120 and closes the first through hole 1122. Optionally, the weakened portion 14 can be formed on the pressure relief member 1121 by processes such as die casting, turning, stamping, etc. In some embodiments in which the second wall 112 includes the wall body 1120 and the pressure relief member 1121, the material of the wall body 1120 and the material of the pressure relief member 1121 can be the same or different, for example, the material of the wall body 1120 is steel, and the material of the pressure relief member 1121 can be aluminum, or the material of the wall body 1120 is aluminum, and the material of the pressure relief member 1121 is aluminum. It should be noted that the connection relationship between the wall body 1120 and the pressure relief member 1121 is various, and the connection relationship between the wall body 1120 and the pressure relief member 1121 includes but is not limited to bonding, welding, riveting, threaded connection or other connection modes. Optionally, the second wall 112 includes the wall body 1120, the structural strength of the wall body 1120 is greater than the structural strength of the weakened portion 14, the wall body 1120 is formed with the first through hole 1122, and the weakened portion 14 is connected with the wall body 1120 and closes the first through hole 1122.

[0140] The "the projection of the liquid injection hole 12 and the projection of the weakened portion 14 do not overlap on the same projection plane perpendicular to the first direction z" can be understood as that the liquid injection hole 12 and the weakened portion 14 do not overlap along the line of sight from the first wall 110 to the second wall 112, or can be understood as that the projection of the liquid injection hole 12 on the second wall 112 does not interfere with the weakened portion 14 along the direction from the first wall 110 to the second wall 112. Taking the weakened portion 14 as at least part of the structure of the notch formed on the second wall 112 as an example, the projection of the liquid injection hole 12 and the projection of the notch on the same projection plane perpendicular to the first direction z are independent of each other, and there is a distance between them. In the process of assembling the battery monomer 10, the electrolyte can be injected into the shell 11 from the liquid injection hole 12 along the direction from the first wall 110 to the second wall 112, and the direction of the injection pressure generated can not pass through the weakened portion 14, that is, the injection pressure can not directly impact the weakened portion 14 through the gap between the shell 11 and the electrode assembly 13, or the gap of the electrode assembly 13 itself.

[0141] Exemplarily, please refer to FIG. 6, which is a diagram of the positional relationship between the projection of the liquid injection hole 12 and the projection of the weak part 14 on the same projection plane perpendicular to the first direction z in some embodiments of the present application. As shown in FIG. 6, the same projection plane perpendicular to the first direction z is SS, the projection of the weak part 14 is annular, the projection of the liquid injection hole 12 is annular, the projection of the liquid injection hole 12 does not overlap with the projection of the weak part 14, and the projection of the liquid injection hole 12 can be located in the inner ring of the annular projection of the weak part 14.

[0142] In the above scheme, on one hand, the liquid injection hole 12 and the weak part 14 are respectively arranged on the first wall 110 and the second wall 112 opposite to each other of the shell 11, compared with the scheme in which the liquid injection hole 12 and the weak part 14 are arranged on the same wall, the interference of the weak part 14 or the liquid injection hole 12 with other structural members can be reduced, so as to improve the space utilization of other structural members at the level of the battery device 100, for example, to reduce the interference of the weak part 14 or the liquid injection hole 12 with the external bus member, thereby facilitating the improvement of the volumetric energy density of the battery device 100; on the other hand, by arranging the projection of the liquid injection hole 12 and the projection of the weak part 14 on the same projection plane perpendicular to the first direction z to be mutually non-overlapping, the impact of the pressure generated when the electrolyte is injected into the shell 11 by the liquid injection hole 12 on the weak part 14 can be effectively reduced, so as to reduce the risk of damage and rupture of the weak part 14 caused by the impact, to cause the battery monomer 10 to be scrapped, to make the battery monomer 10 have a higher yield rate in the manufacturing process, thereby facilitating the improvement of the manufacturing efficiency of the battery monomer 10, and further facilitating the improvement of the manufacturing efficiency of the battery device 100.

[0143] According to some embodiments of the present application, the minimum distance between the projection of the liquid injection hole 12 and the projection of the weak part 14 on the same projection plane perpendicular to the first direction z is greater than or equal to 5 mm and less than or equal to 50 mm.

[0144] The projection of the liquid injection hole 12 and the projection of the weak part 14 are spaced apart from each other on the same projection plane perpendicular to the first direction z, and the minimum distance therebetween is greater than or equal to 5 mm. For example, in FIG. 6, the minimum distance w between the outer periphery of the projection of the liquid injection hole 12 and the inner periphery of the projection of the weak part 14 on the same projection plane SS perpendicular to the first direction z can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm…19 mm, 20 mm, 21 mm, 22 mm…45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm or any value between adjacent two values.

[0145] In some embodiments, the minimum distance between the projection of the liquid injection hole 12 and the projection of the weak part 14 on the same projection plane perpendicular to the first direction z can be measured and obtained by projection method, laser ranging method or software drawing method.

[0146] In the above scheme, by setting the minimum distance between the projection of the injection hole 12 and the projection of the weakened portion 14 on the same projection plane perpendicular to the first direction z to be greater than or equal to 5 mm, the influence of the pressure generated during electrolyte injection on the weakened portion 14 can be effectively reduced, and the risk of the battery monomer 10 being scrapped due to the rupture of the weakened portion 14 can be reduced. By setting the minimum distance between the projection of the injection hole 12 and the projection of the weakened portion 14 on the same projection plane perpendicular to the first direction z to be less than or equal to 50 mm, the interference of the injection hole 12 or the weakened portion 14 with other structural members can be reduced, so that the battery device 100 is compact in structure when the battery device 100 is stacked, which is beneficial to the improvement of the volume energy of the battery device 100. Therefore, by setting the minimum distance between the projection of the injection hole 12 and the projection of the weakened portion 14 on the same projection plane perpendicular to the first direction z to be greater than or equal to 5 mm and less than or equal to 50 mm, the manufacturing yield, manufacturing efficiency of the battery monomer 10 and the volume energy density of the battery device 100 can be considered.

[0147] According to some embodiments of the present application, the minimum distance between the projection of the injection hole 12 and the projection of the weakened portion 14 on the same projection plane perpendicular to the first direction z is greater than or equal to 10 mm and less than or equal to 20 mm.

[0148] On the same projection plane perpendicular to the first direction z, the projection of the injection hole 12 and the projection of the weakened portion 14 are spaced apart from each other, and the minimum distance therebetween is greater than or equal to 5 mm. For example, as shown in FIG. 6, the minimum distance w between the outer periphery of the projection of the injection hole 12 and the inner periphery of the projection of the weakened portion 14 on the same projection plane SS perpendicular to the first direction z can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm or any value between two adjacent values.

[0149] In the above scheme, by setting the minimum distance between the projection of the injection hole 12 and the projection of the weak portion 14 on the same projection plane perpendicular to the first direction z to be greater than or equal to 10 mm, the influence of the pressure generated during electrolyte injection on the weak portion 14 can be further reduced, and the risk of the battery cell 10 being scrapped due to the rupture of the weak portion 14 can be reduced. By setting the minimum distance between the projection of the injection hole 12 and the projection of the weak portion 14 on the same projection plane perpendicular to the first direction z to be less than or equal to 20 mm, the interference of the injection hole 12 or the weak portion 14 with other structural members can be effectively reduced, so that the battery device 100 is compact in structure when the battery device 100 is stacked, and the volume energy of the battery device 100 is improved. Therefore, by setting the minimum distance between the projection of the injection hole 12 and the projection of the weak portion 14 on the same projection plane perpendicular to the first direction z to be greater than or equal to 10 mm and less than or equal to 20 mm, the manufacturing yield and manufacturing efficiency of the battery cell 10 and the volume energy density of the battery device 100 can be effectively balanced.

[0150] According to some embodiments of the present application, referring to FIG. 3, the battery cell 10 further includes a first electrode terminal 16 and a second electrode terminal 17, the polarities of the first electrode terminal 16 and the second electrode terminal 17 are opposite, the first electrode terminal 16 and the second electrode terminal 17 are respectively arranged on the first wall 110, and the first electrode terminal 16 and the second electrode terminal 17 are spaced apart along a second direction y, the first direction z and the second direction y are perpendicular to each other.

[0151] In some embodiments, the battery cell 10 includes a first electrode terminal 16 and a second electrode terminal 17 with opposite polarities. For example, the first electrode terminal 16 is a positive electrode terminal, and the first electrode terminal 16 is connected to a positive electrode tab through an adapter. The second electrode terminal 17 is a negative electrode terminal, and the second electrode terminal 17 is connected to a negative electrode tab through an adapter.

[0152] In some embodiments, the first electrode terminal 16 and the second electrode terminal 17 are both arranged on the first wall 110, and the first electrode terminal 16 and the second electrode terminal 17 are spaced apart along the second direction y. Alternatively, the first electrode terminal 16 is insulated and mounted on one end of the first wall 110 along the second direction y through an insulating structure, and the second electrode terminal 17 is insulated and mounted on the other end of the first wall 110 along the second direction y through an insulating structure.

[0153] The second direction y is perpendicular to the first direction z. Alternatively, the shell 11 is square, the first direction z is the height direction of the battery cell 10, and the second direction y can be the width direction of the battery cell 10, which is perpendicular to the thickness direction of the battery cell 10.

[0154] In the above scheme, on one hand, the first electrode terminal 16 and the second electrode terminal 17 are both arranged on the first wall 110, so that the first electrode terminal 16 and the second electrode terminal 17 utilize the space on the same side, which is conducive to the improvement of the space utilization of the battery monomer 10, thereby facilitating the improvement of the volume energy density of the battery device 100; on the other hand, by arranging the first electrode terminal 16 and the second electrode terminal 17 and the weak part 14 on two wall parts opposite to each other respectively, the influence of the rupture of the weak part 14 on the electrode terminals of the adjacent battery monomer 10 due to the leakage of the internal pressure of the battery monomer 10 can be reduced, the risk of internal short circuit of the battery device 100 is caused, and the reliability of the battery device 100 is improved.

[0155] According to some embodiments of the present application, referring to FIG. 3, along the second direction y, the liquid injection hole 12 is located between the first electrode terminal 16 and the second electrode terminal 17.

[0156] In some embodiments, along the second direction y, the liquid injection hole 12 is located between the first electrode terminal 16 and the second electrode terminal 17. Optionally, along the second direction y, the liquid injection hole 12 is centered between the first electrode terminal 16 and the second electrode terminal 17, that is, the distance between the liquid injection hole 12 and the first electrode terminal 16 is equal to the distance between the liquid injection hole 12 and the second electrode terminal 17. Optionally, along the second direction y, the liquid injection hole 12 is more inclined to one of the first electrode terminal 16 and the second electrode terminal 17, for example, the distance between the liquid injection hole 12 and the first electrode terminal 16 is greater than the distance between the liquid injection hole 12 and the second electrode terminal 17.

[0157] In the above scheme, the liquid injection hole 12 is arranged between the first electrode terminal 16 and the second electrode terminal 17, so that the distance between the liquid injection hole 12 and the first electrode terminal 16 and the distance between the liquid injection hole 12 and the second electrode terminal 17 are appropriate, which reduces the risk that, in the electrolyte injection process, the electrolyte adheres to the first electrode terminal 16 or the second electrode terminal 17 due to the too close distance between the liquid injection hole 12 and the first electrode terminal 16 or the too close distance between the liquid injection hole 12 and the second electrode terminal 17, so that the production personnel misjudge as battery monomer 10 liquid leakage and affect the production rhythm, thereby being capable of improving the production rhythm of the battery monomer 10, and further facilitating the improvement of the manufacturing efficiency of the battery device 100.

[0158] In other embodiments of the present application, along the second direction y, the liquid injection hole 12 can also be located on the side of the first electrode terminal 16 away from the second electrode terminal 17, or can also be located on the side of the second electrode terminal 17 away from the first electrode terminal 16. In other embodiments of the present application, along the second direction y, part of the liquid injection hole 12 is located between the first electrode terminal 16 and the second electrode terminal 17, and another part of the liquid injection hole 12 is located on the side of one of the first electrode terminal 16 and the second electrode terminal 17 away from the other.

[0159] According to some embodiments of the present application, along the second direction y, the distance between the liquid injection hole 12 and the first electrode terminal 16 is equal to the distance between the liquid injection hole 12 and the second electrode terminal 17.

[0160] In some embodiments, as shown in FIG. 3, along the second direction y, the distance between the liquid injection hole 12 and the first electrode terminal 16 is equal to the distance between the liquid injection hole 12 and the second electrode terminal 17, that is, the distance between the liquid injection hole 12 and the first electrode terminal 16 and the distance between the liquid injection hole 12 and the second electrode terminal 17 are both large, so that the risk of electrolyte splashing onto the first electrode terminal 16 and the second electrode terminal 17 during electrolyte injection is small during the assembly of the battery monomer 10.

[0161] In the above scheme, along the second direction y, by centrally arranging the liquid injection hole 12 between the first electrode terminal 16 and the second electrode terminal 17, the distance between the liquid injection hole 12 and the first electrode terminal 16 and the distance between the liquid injection hole 12 and the second electrode terminal 17 are appropriate, thereby reducing the risk of electrolyte adhering to the electrode terminal and affecting the production rhythm during electrolyte injection.

[0162] According to some embodiments of the present application, along the second direction y, the distance between the liquid injection hole 12 and the first electrode terminal 16 is greater than the distance between the liquid injection hole 12 and the second electrode terminal 17.

[0163] In some embodiments, as shown in FIG. 7, which is a top view of the battery monomer 10 according to some embodiments of the present application, along the second direction y, the distance between the liquid injection hole 12 and the first electrode terminal 16 is greater than the distance between the liquid injection hole 12 and the second electrode terminal 17, that is, the liquid injection hole 12 is eccentric between the first electrode terminal 16 and the second electrode terminal 17, and the distance between the liquid injection hole 12 and the first electrode terminal 16 is greater, so that the risk of electrolyte splashing onto the first electrode terminal 16 during electrolyte injection is smaller during the assembly of the battery monomer 10.

[0164] In the above scheme, along the second direction y, by arranging the liquid injection hole 12 farther away from the first electrode terminal 16, the risk of electrolyte adhering to the first electrode terminal 16 can be effectively reduced, and at the same time, under the condition that the liquid injection hole 12 is misaligned with the weak portion 14, the weak portion 14 can be arranged centrally between the first electrode terminal 16 and the second electrode terminal 17, thereby facilitating the rupture of the weak portion 14 under the pressure inside the battery monomer 10 and timely release of the pressure inside the battery monomer 10, thereby facilitating the improvement of the reliability of the battery monomer 10 and further facilitating the improvement of the reliability of the battery device 100.

[0165] According to some embodiments of the present application, as shown in FIG. 7 and FIG. 8, which is a top view of the battery monomer 10 according to some other embodiments of the present application.

[0166] The first wall 110 has a first edge 1100 and a second edge 1101 in the third direction x, and the distance between the first edge 1100 and the injection hole 12 and the distance between the second edge 1101 and the injection hole 12 are equal in the third direction x. The first direction z, the second direction y, and the third direction x are perpendicular to each other.

[0167] The third direction x, the second direction y, and the first direction z are perpendicular to each other. Optionally, the shell 11 is square, the first direction z is the height direction of the battery monomer 10, the second direction y can be the width direction of the battery monomer 10, and the third direction x is the thickness direction of the battery monomer 10.

[0168] In some embodiments, as shown in FIG. 8, the distance between the first edge 1100 and the injection hole 12 and the distance between the second edge 1101 and the injection hole 12 are equal in the third direction x, that is, the injection hole 12 is centered between the first edge 1100 and the second edge 1101 in the third direction x.

[0169] In the above scheme, by centering the injection hole 12 between the first edge 1100 and the second edge 1101 in the third direction x, the distance between the injection hole 12 and the first edge 1100 and the distance between the injection hole 12 and the second edge 1101 are appropriate, thereby reducing the risk of affecting the production rhythm due to the electrolyte adhering to the two wall parts of the battery monomer 10 opposite to each other in the third direction x during the electrolyte injection process.

[0170] According to some embodiments of the present application, the first wall 110 has a first edge 1100 and a second edge 1101 in the third direction x, and the distance between the first edge 1100 and the injection hole 12 is greater than the distance between the second edge 1101 and the injection hole 12 in the third direction x. The first direction z, the second direction y, and the third direction x are perpendicular to each other.

[0171] The third direction x, the second direction y, and the first direction z are perpendicular to each other. Optionally, the shell 11 is square, the first direction z is the height direction of the battery monomer 10, the second direction y can be the width direction of the battery monomer 10, and the third direction x is the thickness direction of the battery monomer 10. In some embodiments, as shown in FIG. 7, the distance between the first edge 1100 and the injection hole 12 is greater than the distance between the second edge 1101 and the injection hole 12 in the third direction x, that is, the injection hole 12 is eccentric between the first edge 1100 and the second edge 1101 in the third direction x, and the spacing between the injection hole 12 and the first edge 1100 is greater.

[0172] In the above scheme, along the third direction x, by setting the injection hole 12 further away from the first edge 1100, and under the condition that the injection hole 12 is misaligned with the weak part 14, the weak part 14 can be centered on the second wall 112 along the third direction x, thereby facilitating the rupture of the weak part 14 under the pressure inside the battery monomer 10, and timely releasing the pressure inside the battery monomer 10, thereby facilitating the improvement of the reliability of the battery monomer 10, and further facilitating the improvement of the reliability of the battery device 100.

[0173] According to some embodiments of the present application, along the second direction y, the distance between the injection hole 12 and the first electrode terminal 16 is greater than or equal to 40 mm, and the distance between the injection hole 12 and the second electrode terminal 17 is greater than or equal to 40 mm.

[0174] In some embodiments, along the second direction y, the minimum distance between the injection hole 12 and the first electrode terminal 16 can be greater than or equal to 40 mm, for example, as shown in FIG. 8, along the second direction y, the distance L1 between the injection hole 12 and the first electrode terminal 16 can be 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, a larger value or any value between two adjacent values.

[0175] In some embodiments, along the second direction y, the minimum distance between the injection hole 12 and the second electrode terminal 17 can be greater than or equal to 40 mm, for example, as shown in FIG. 8, along the second direction y, the distance L2 between the injection hole 12 and the second electrode terminal 17 can be 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, a larger value or any value between two adjacent values.

[0176] In some embodiments, along the second direction y, the distance between the injection hole 12 and the first electrode terminal 16, and the distance between the injection hole 12 and the second electrode terminal 17 can be measured by projection method, laser ranging method, or software drawing method.

[0177] In some embodiments, along the second direction y, the distance L1 between the injection hole 12 and the first electrode terminal 16 and the distance L2 between the injection hole 12 and the second electrode terminal 17 can be equal or not equal, for example, along the second direction y, the distance L1 between the injection hole 12 and the first electrode terminal 16 is 40 mm, and the distance L2 between the injection hole 12 and the second electrode terminal 17 is 40 mm, or along the second direction y, the distance L1 between the injection hole 12 and the first electrode terminal 16 is 45 mm, and the distance L2 between the injection hole 12 and the second electrode terminal 17 is 40 mm.

[0178] In the above scheme, by setting the distance between the injection hole 12 and the first electrode terminal 16 to be greater than or equal to 40 mm along the second direction y, the risk of the first electrode terminal 16 being attached during electrolyte injection and affecting the production rhythm can be effectively reduced; by setting the distance between the injection hole 12 and the second electrode terminal 17 to be greater than or equal to 40 mm along the second direction y, the risk of the second electrode terminal 17 being attached during electrolyte injection and affecting the production rhythm can be effectively reduced.

[0179] According to some embodiments of the present application, referring to FIG. 9, which is an enlarged view of B in FIG. 5. It should be noted that the closure 12a for closing the injection hole 12 is hidden in FIG. 5. The injection hole 12 includes a first hole section 120 and a second hole section 121, which are arranged along the first wall 110 in a direction pointing to the second wall 112, and the aperture of the first hole section 120 is greater than that of the second hole section 121.

[0180] In some embodiments, the injection hole 12 is a stepped hole, which can include a first hole section 120 and a second hole section 121 arranged along the first direction z, and the first hole section 120 is located outside the first wall 110 relative to the second hole section 121, that is, the second hole section 121 is closer to the inside of the shell 11.

[0181] In some embodiments, the diameter of the first hole section 120 is greater than that of the second hole section 121, that is, the size of the first hole section 120 is greater than that of the second hole section 121, that is, the area of the region surrounded by the projection of the first hole section 120 on the same projection plane perpendicular to the first direction z is greater than that of the second hole section 121.

[0182] In some embodiments, the first hole section 120 and the second hole section 121 can be transitioned by a flat surface; in other embodiments, the first hole section 120 and the second hole section 121 can be transitioned by an inclined surface or an arc surface.

[0183] In some embodiments, the injection hole 12 is a multi-section through-hole structure, which can include a first hole section 120, a second hole section 121, a third hole section, or more hole sections.

[0184] In the above scheme, by setting the injection hole 12 to be a stepped hole, and setting the aperture of the first hole section 120 located outside to be greater than that of the second hole section 121 located inside, the injection equipment can be facilitated to inject liquid into the shell 11 through the injection hole 12, providing a larger space for electrolyte injection, thereby reducing the risk of electrolyte splashing outward, facilitating the improvement of the production rhythm of the battery monomer 10, and further facilitating the improvement of the manufacturing efficiency of the battery device 100.

[0185] In some embodiments of the present application, the liquid injection hole 12 can be a hole section structure, and the hole wall of the liquid injection hole 12 extends straight along the first direction z and communicates the outer side and the inner side of the first wall 110.

[0186] According to some embodiments of the present application, the hole diameter of the first hole section 120 is greater than or equal to 4 mm and less than or equal to 10 mm.

[0187] In some embodiments, the hole wall of the first hole section 120 is a straight wall portion extending along the first direction z, and the diameter of the first hole section 120 can be greater than or equal to 4 mm and less than or equal to 10 mm.

[0188] In some embodiments, the hole wall of the first hole section 120 is an inclined wall portion, for example, the hole wall of the first hole section 120 is inclined inward along the direction of the first wall 110 pointing to the second wall 112, and the maximum hole diameter of the first hole section 120 can be greater than or equal to 4 mm and less than or equal to 10 mm.

[0189] For example, referring to FIG. 9, the hole diameter of the first hole section 120 is R1, and the value of R1 can be 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any value between two adjacent values.

[0190] In the above scheme, by setting the hole diameter of the first hole section 120 to be greater than or equal to 4 mm, a larger space can be effectively provided for the electrolyte, reducing the risk of electrolyte splashing outward, and facilitating the improvement of the production rhythm of the battery monomer 10; by setting the first hole section 120 to be less than or equal to 10 mm, the occupation of the space on the first wall 110 by the liquid injection hole 12 can be reduced, thereby facilitating the layout of other structural members, enabling the battery device 100 to be compact in structure, and improving the volume energy density of the battery device 100.

[0191] According to some embodiments of the present application, the center of the weakened portion 14 coincides with the center of the second wall 112.

[0192] In some embodiments, the center of the weakened portion 14 can be the geometric center of the weakened portion 14. For example, the weakened portion 14 is annular, and the center thereof can be in the inner ring thereof and located at the center of the inner ring. For another example, as shown in FIG. 10, the weakened portion 14 includes three sections, including a first groove section 141, a second groove section 142, and a third groove section 143, the second groove section 142 includes the first groove section 141 and the third groove section 143, and the center of the weakened portion 14 can be the center of the second groove section 142.

[0193] The center of the second wall 112 can be the geometric center of the second wall 112, and the center axis of the outer shell 11 can pass through the center of the second wall 112 along the first direction z.

[0194] The "center of the weak portion 14 coincides with the center of the second wall 112" can be understood as the center axis of the shell 11 can pass through the center of the second wall 112 and the center of the weak portion 14 along the first direction z.

[0195] In the above scheme, by setting the center of the weak portion 14 to coincide with the center of the second wall 112, the internal pressure of the battery monomer 10 can be effectively applied to the weak portion 14, so that the weak portion 14 breaks more timely to release the internal pressure of the battery monomer 10, reduces the risk of explosion of the battery monomer 10, and improves the reliability of the battery monomer 10 and the battery device 100.

[0196] According to some embodiments of the present application, the projection of the liquid injection hole 12 and the projection of the pressure relief area 15 do not overlap on the same projection plane perpendicular to the first direction z.

[0197] In some embodiments, the part where the weak portion 14 is located defines the pressure relief area 15, for example, the weak portion 14 is a non-closed notch structure, and optionally, the weak portion 14 includes one or more notches spaced from each other, and each notch breaks to release pressure when the internal pressure of the battery monomer 10 increases to a certain extent. In these embodiments, the part where the weak portion 14 is located defines the pressure relief area 15.

[0198] In the above scheme, in some embodiments, the part where the weak portion 14 is located can form the pressure relief area 15, by setting the projections of the liquid injection hole 12 and the pressure relief area 15 on the same projection plane perpendicular to the first direction z to not overlap, the impact of the pressure generated when the liquid injection hole 12 injects electrolyte into the shell on the pressure relief area can be effectively reduced, causing the pressure relief area 15, that is, the weak portion 14 to be damaged and broken, resulting in the risk of the battery monomer being scrapped, so that the battery monomer has a high yield during the manufacturing process, thereby improving the manufacturing efficiency of the battery monomer, and further improving the manufacturing efficiency of the battery device.

[0199] According to some embodiments of the present application, the second wall 112 is provided with a notch groove 140, the groove bottom wall of the notch groove 140 is the weak portion 14, and the notch groove 140 defines the pressure relief area 15.

[0200] In some embodiments, the weak portion 14 is a part of the second wall 112 with relatively weak structural strength compared to other parts of the second wall 112, for example, by providing a notch groove 140 on the second wall 112, so that the thickness of the groove bottom wall of the notch groove 140 is less than the thickness of other parts of the second wall 112, thereby forming a weak portion 14 with relatively weak structural strength.

[0201] In some embodiments, the score groove 140 can be directly or indirectly arranged on the second wall 112. Optionally, the score groove 140 can be directly arranged on the second wall 112 by a process such as die casting, stamping, turning, etc. Optionally, the score groove 140 can be first formed on another structural member, and then the another structural member is integrated into the second wall 112. For example, the second wall 112 includes a wall body 1120 and a pressure relief member 1121, the wall body 1120 is formed with a first through hole 1122, and the pressure relief member 1121 is integrally formed with the score groove 140. The pressure relief member 1121 is connected with the wall body 1120 and seals the first through hole 1122. Optionally, the score groove 140 can be formed on the pressure relief member 1121 by a process such as die casting, turning, stamping, etc.

[0202] In some embodiments, the score groove 140 includes a plurality of groove structures, and the plurality of groove structures can be connected with each other or independent of each other. Optionally, the score groove 140 includes a plurality of groove structures, and the plurality of groove structures are connected with each other to define a large-area pressure relief area 15. Optionally, the score groove 140 includes a plurality of groove structures, and the plurality of groove structures are independent of each other to define a plurality of pressure relief areas 15.

[0203] In the above scheme, by arranging the score groove 140 on the second wall 112 and forming the groove bottom wall of the score groove 140 as the weak portion 14, the second wall 112 can be cracked along the score groove 140 to open the pressure relief area 15 and release the internal pressure of the battery monomer 10 under the action of the internal pressure of the battery monomer 10, so that the battery monomer 10 has higher reliability. At the same time, the score groove 140 is simple to manufacture, and the formation of the weak portion 14 by the score groove 140 is conducive to improving the manufacturing efficiency of the battery monomer 10.

[0204] According to some embodiments of the present application, referring to FIG. 10, FIG. 10 is a schematic view of the second wall 112 and the weak portion 14 in some embodiments of the present application. The score groove 140 includes a first groove segment 141, a second groove segment 142, and a third groove segment 143. The first groove segment 141 and the third groove segment 143 are oppositely arranged along the second direction y. The second groove segment 142 is located between the first groove segment 141 and the third groove segment 143 and connects the first groove segment 141 and the third groove segment 143. The first groove segment 141, the second groove segment 142, and the third groove segment 143 jointly define the pressure relief area 15. The first direction z and the second direction y are perpendicular to each other.

[0205] In some embodiments, the score groove 140 comprises a three-segment groove structure, including a first groove segment 141, a second groove segment 142, and a third groove segment 143. The first groove segment 141 is a straight groove extending along the third direction x, the third groove segment 143 is a straight groove extending along the third direction x, and the second groove segment 142 is a straight groove extending along the second direction y. The second groove segment 142 is located between the first groove segment 141 and the third groove segment 143, one end of the second groove segment 142 is connected to the middle of the first groove segment 141, and the other end of the second groove segment 142 is connected to the middle of the third groove segment 143. Optionally, referring to FIG. 10, the first groove segment 141, the second groove segment 142, and the third groove segment 143 of the score groove 140 form a groove structure in the shape of H (or inverted H), that is, a H-shaped pressure relief area 15. For example, when the internal pressure of the battery cell 10 expands to a certain extent, the internal pressure will break the groove bottom walls of the first groove segment 141, the second groove segment 142, and the third groove segment 143, and the broken pattern can be in the shape of H.

[0206] In the above scheme, the score groove 140 has a simple structure, which includes the first groove segment 141, the third groove segment 143, and the second groove segment 142 connecting the first groove segment 141 and the third groove segment 143. When the internal pressure of the battery cell 10 expands to a certain extent, the second wall 112 can be cracked along the first groove segment 141, the second groove segment 142, and the third groove segment 143, so that the battery cell 10 has a larger pressure relief area, which is beneficial to the rapid relief of the internal pressure of the battery cell 10, thereby improving the reliability of the battery cell 10, and further improving the reliability of the battery device 100.

[0207] According to some embodiments of the present application, referring to FIG. 10, the projection of the liquid injection hole 12 is located between the projection of the first groove segment 141 and the projection of the third groove segment 143 in the same projection plane perpendicular to the first direction z.

[0208] In FIG. 10, the projection of the liquid injection hole 12 on the second wall 112 is represented by a dashed line. Along the third direction x, the liquid injection hole 12 can be located on one side of the second groove segment 142, and along the second direction y, the liquid injection hole 12 can be located between the first groove segment 141 and the third groove segment 143.

[0209] In the above scheme, in the same projection plane perpendicular to the first direction z, by arranging the projection of the liquid injection hole 12 between the projections of the first groove segment 141 and the second groove segment 142, on the one hand, the pressure generated during the electrolyte injection process can be reduced to directly act on the groove bottom walls of the first groove segment 141 and the second groove segment 142, so as to reduce the risk of the second wall 112 being broken during the manufacturing process of the battery cell 10; on the other hand, the space utilization of the liquid injection hole 12 and the weak portion 14 can be improved, so as to provide a larger space for other structural members of the battery device 100, which is conducive to the spatial layout of the other structural members of the battery device 100, thereby improving the volume energy density of the battery device 100.

[0210] In other embodiments, along the second direction y, the liquid injection hole 12 can be located on the side of the first groove segment 141 away from the third groove segment 143, or along the second direction y, the liquid injection hole 12 can be located on the side of the third groove segment 143 away from the first groove segment 141.

[0211] According to some embodiments of the present application, as shown in FIG. 11, the notch groove 140 includes a ring-shaped notch groove 140a, and the ring-shaped notch groove 140a surrounds to form the pressure relief area 15.

[0212] In some embodiments, the notch groove 140 is ring-shaped, which can be connected by one or more groove structures to form a ring-shaped notch groove 140a. For example, the ring-shaped notch groove 140a can be a circular ring, a polygonal ring, a flat ring, or other shapes. Optionally, the ring-shaped notch groove 140a includes four straight grooves connected in sequence. Optionally, the ring-shaped notch groove 140a can include two straight grooves and two arc-shaped grooves, and the two straight grooves are connected by the two arc-shaped grooves.

[0213] Optionally, when the internal pressure of the battery cell 10 expands to a certain extent, the internal pressure will break all the groove structures of the ring-shaped notch groove 140a to form a larger pressure relief gap on the second wall 112, so that the internal pressure is released.

[0214] Optionally, when the internal pressure of the battery cell 10 expands to a certain extent, the internal pressure will break part of the groove structures of the ring-shaped notch groove 140a to make part of the pressure relief area 15 surrounded by the ring-shaped notch groove 140a turn outward, and the other part is connected with the second wall 112, thereby releasing the internal pressure of the battery cell 10.

[0215] In the above scheme, the notch groove 140 is ring-shaped to surround to form a larger pressure relief area 15, so that the battery cell 10 has a larger pressure relief area to quickly release the internal pressure of the battery cell 10, so that the battery device 100 has higher reliability.

[0216] According to some embodiments of the present application, please refer to FIG. 11, which is a schematic view of the second wall 112 and the score groove 140 according to some embodiments of the present application.

[0217] The annular score groove 140a comprises a first straight segment 144, a second straight segment 145, a first arc segment 146 and a second arc segment 147. The first straight segment 144 and the second straight segment 145 are oppositely arranged along the third direction x, and the first arc segment 146 and the second arc segment 147 are oppositely arranged along the second direction y. One end of the first straight segment 144 and one end of the second straight segment 145 are connected by the first arc segment 146, and the other end of the first straight segment 144 and the other end of the second straight segment 145 are connected by the second arc segment 147. The thickness of the groove bottom wall of the second straight segment 145, the thickness of the groove bottom wall of the first arc segment 146 and the thickness of the groove bottom wall of the second arc segment 147 are all less than the thickness of the groove bottom wall of the first straight segment 144. The first direction z, the second direction y and the third direction x are perpendicular to each other.

[0218] In some embodiments, the first straight segment 144 is a flat groove extending along the second direction y, and the second straight segment 145 is a flat groove extending along the second direction y. The first straight segment 144 and the second straight segment 145 are oppositely arranged along the third direction x. The first arc segment 146 is a circular arc and is located on one side of the first straight segment 144 and the second straight segment 145 along the second direction y, and the second arc segment 147 is a circular arc and is located on the other side of the first straight segment 144 and the second straight segment 145 along the second direction y. Along the second direction y, one end of the first straight segment 144 and one end of the second straight segment 145 are connected by the first arc segment 146, and the other end of the first straight segment 144 and the other end of the second straight segment 145 are connected by the second arc segment 147.

[0219] The “the thickness of the groove bottom wall of the second straight segment 145, the thickness of the groove bottom wall of the first arc segment 146 and the thickness of the groove bottom wall of the second arc segment 147 are all less than the thickness of the groove bottom wall of the first straight segment 144” can be understood as that the structural strength of the groove bottom wall of the first straight segment 144 is greater than the structural strength of the groove bottom wall of the second straight segment 145, and the structural strength of the groove bottom wall of the first straight segment 144 is greater than the structural strength of the groove bottom wall of the first arc segment 146, and the structural strength of the groove bottom wall of the first straight segment 144 is greater than the structural strength of the groove bottom wall of the second arc segment 147; or it can be understood that when the internal pressure of the battery monomer 10 expands to a certain extent, the internal pressure will break the groove bottom wall of the second straight segment 145, the groove bottom wall of the first arc segment and the groove bottom wall of the second arc segment 147, and the groove bottom wall of the first straight segment 144 can not be broken, or it will be broken only when the internal pressure of the battery monomer 10 further increases.

[0220] In the above scheme, by setting the thickness of the second wall 112 along the second straight line segment 145, the first arcuate segment and the second arcuate segment 147 to be small, when the internal pressure of the battery monomer 10 expands to a certain extent, the second wall 112 along the second straight line segment 145, the first arcuate segment 146 and the second arcuate segment 147 breaks to quickly release the internal pressure of the battery monomer 10, so that the battery device 100 has higher reliability; at the same time, because the thickness of the groove bottom wall of the first straight line segment 144 is large, the pressure relief area 15 at the part of the first straight line segment 144 can remain in the second wall 112, reduce the risk of the whole reforming weak part 14 being impacted to the adjacent battery monomer 10 or other structural members of the battery device 100 due to pressure, causing the structure of the adjacent battery monomer 10 or other structural members of the battery device 100 to be damaged, thereby facilitating the improvement of the reliability of the battery device 100.

[0221] According to some embodiments of the present application, please refer to FIG. 11, the score groove 140 further includes a fourth groove segment 148 and a fifth groove segment 149, the fourth groove segment 148 and the fifth groove segment 149 are located in the pressure relief area 15, and the fourth groove segment 148 and the fifth groove segment 149 are respectively in the shape of a circular arc. Along the third direction x, the fourth groove segment 148 and the fifth groove segment 149 are oppositely arranged, and the outer edge side of the fourth groove segment 148 and the outer edge side of the fifth groove segment 149 are tangent to each other, the thickness of the groove bottom wall of the second straight line segment 145, the thickness of the groove bottom wall of the first arcuate segment and the thickness of the groove bottom wall of the second arcuate segment 147 are all less than or equal to the thickness of the groove bottom wall of the fourth groove segment 148, and the thickness of the groove bottom wall of the second straight line segment 145, the thickness of the groove bottom wall of the first arcuate segment and the thickness of the groove bottom wall of the second arcuate segment 147 are all less than or equal to the thickness of the groove bottom wall of the fifth groove segment 149.

[0222] In some embodiments, in the pressure relief area 15 defined by the annular score groove 140a, some groove structures can also be arranged to make the pressure relief area 15 more easily opened to release the internal pressure. Optionally, the fourth groove segment 148 and the fifth groove segment 149 can be arranged in the pressure relief area 15, the fourth groove segment 148 can be in the shape of a circular arc, the fifth groove segment 149 can be in the shape of a circular arc, along the third direction x, the center of the fourth groove segment 148 is located on the side away from the fifth groove segment 149, the center of the fifth groove segment 149 is located on the side away from the fourth groove segment 148, and the outer edge side of the fourth groove segment 148 and the outer edge side of the fifth groove segment 149 are tangent to each other.

[0223] The "thicknesses of the groove bottom walls of the second straight section 145, the first arc section, and the second arc section 147 are each less than or equal to the thickness of the groove bottom wall of the fourth groove section 148, and the thicknesses of the groove bottom walls of the second straight section 145, the first arc section, and the second arc section 147 are each less than or equal to the thickness of the groove bottom wall of the fifth groove section 149" can be understood as the structural strength of the groove bottom walls of the fourth groove section 148 and the fifth groove section 149 being greater than the structural strength of the groove bottom wall of the second straight section 145, and the structural strength of the groove bottom walls of the fourth groove section 148 and the fifth groove section 149 being greater than the structural strength of the groove bottom wall of the first arc section, and the structural strength of the groove bottom walls of the fourth groove section 148 and the fifth groove section 149 being greater than the structural strength of the groove bottom wall of the second arc section 147; or can be understood as, when the internal pressure of the battery cell 10 expands to a certain extent, the internal pressure will break the groove bottom walls of the second straight section 145, the first arc section, and the second arc section 147, and the groove bottom walls of the fourth groove section 148 and the fifth groove section 149 can not be broken, or will be broken only when the internal pressure of the battery cell 10 further increases.

[0224] In the above scheme, the score groove 140 further includes the fourth groove section 148 and the fifth groove section 149, and the fourth groove section 148 and the fifth groove section 149 are located in the pressure relief area 15, which can reduce the structural strength of the portion of the second wall 112 located in the pressure relief area 15, thereby facilitating the rupture of the portion where the pressure relief area 15 is located when the weakened portion 14 is subjected to the internal pressure of the battery cell 10, so as to quickly release the internal pressure of the battery cell 10, thereby effectively improving the reliability of the battery device 100.

[0225] According to some embodiments of the present application, the portions where the outer edge sides of the fourth groove section 148 and the fifth groove section 149 are tangent to each other coincide with the center of the second wall 112.

[0226] In some embodiments, along the first direction z, the central axis of the shell 11 can pass through the center of the second wall 112 and the portions where the outer edge sides of the fourth groove section 148 and the fifth groove section 149 are tangent to each other.

[0227] In the above scheme, by setting the portions where the outer edge sides of the fourth groove section 148 and the fifth groove section 149 are tangent to each other to coincide with the center of the second wall 112, the internal pressure of the battery cell 10 can be uniformly applied to the annular score groove 140a through the fourth groove section 148 and the fifth groove section 149, thereby facilitating the rupture of the second wall 112 along the second straight section 145, the first arc section, and the second arc section 147, so as to quickly release the internal pressure of the battery cell 10, so that the battery device 100 has higher reliability.

[0228] According to some embodiments of the present application, referring to FIG. 11, along the second direction y, one end of the first straight line segment 144 is connected to one end of the fourth groove segment 148, and the other end of the first straight line segment 144 is connected to the other end of the fourth groove segment 148. Along the second direction y, one end of the second straight line segment 145 is connected to one end of the fifth groove segment 149, and the other end of the second straight line segment 145 is connected to the other end of the fifth groove segment 149.

[0229] In some embodiments, the two ends of the fourth groove segment 148 respectively extend to the first straight line segment 144, so that the fourth groove segment 148 and the first straight line segment 144 are in communication with each other.

[0230] In some embodiments, the two ends of the fifth groove segment 149 respectively extend to the second straight line segment 145, so that the fifth groove segment 149 and the second straight line segment 145 are in communication with each other.

[0231] In the above scheme, by extending the two ends of the fourth groove segment 148 to the first straight line segment 144 and extending the two ends of the fifth groove segment 149 to the second straight line segment 145, the internal pressure of the battery monomer 10 can be effectively applied to the annular notch groove 140a, thereby facilitating the rupture of the annular notch groove 140a to release the internal pressure of the battery monomer 10, and further facilitating the improvement of the reliability of the battery device 100.

[0232] In other embodiments of the present application, the two ends of the fourth groove segment 148 can be spaced apart from each other, and the two ends of the fifth groove segment 149 can be spaced apart from each other.

[0233] According to some embodiments of the present application, referring to FIG. 11, in the same projection plane perpendicular to the first direction z, the projection of the liquid injection hole 12 is located in the area surrounded by the projection of the first arc segment, the projection of the fourth groove segment 148 and the projection of the fifth groove segment 149.

[0234] In FIG. 11, the projection of the liquid injection hole 12 projected onto the second wall 112 is represented by a dashed line. The projection of the liquid injection hole 12 is located in the area surrounded by the projection of the first arc segment, the projection of the fourth groove segment 148 and the projection of the fifth groove segment 149.

[0235] In the above scheme, in the same projection plane perpendicular to the first direction z, by setting the projection of the liquid injection hole 12 in the area surrounded by the projection of the first arc segment, the projection of the fourth groove segment 148 and the projection of the fifth groove segment 149, on the one hand, it can reduce the risk that the pressure generated during the electrolyte injection process directly acts on the notch groove 140, thereby causing the second wall 112 to rupture during the manufacturing process of the battery monomer 10; on the other hand, it can improve the space utilization of the liquid injection hole 12 and the weak part 14, so as to provide a larger space for other structural members of the battery device 100, which is conducive to the spatial layout of other structural members of the battery device 100, thereby facilitating the volume energy density of the battery device 100.

[0236] Optionally, in some other embodiments, the projection of the liquid injection hole 12 can be located within the area enclosed by the projection of the second arc segment 147, the projection of the fourth groove segment 148, and the projection of the fifth groove segment 149.

[0237] Optionally, in some other embodiments, the projection of the liquid injection hole 12 can be located outside the annular score groove 140a.

[0238] According to some embodiments of the present application, the weakened portion 14 is integrally formed on the second wall 112.

[0239] In some embodiments, the weakened portion 14 can be directly formed on the second wall 112, for example, by a process such as die casting, stamping, or turning to form a groove structure or a recess structure on the second wall 112 to form the weakened portion 14.

[0240] In the above scheme, the weakened portion 14 can be formed on the second wall 112 by an integral forming process, which can reduce the manufacturing process of the battery monomer 10, effectively improve the manufacturing efficiency of the battery monomer 10, and further facilitate the improvement of the manufacturing efficiency of the battery device 100.

[0241] According to some embodiments of the present application, please refer to FIG. 12, which is a schematic view of a wall body 1120 and a pressure relief member 1121 in some embodiments of the present application. The second wall 112 includes the wall body 1120 and the pressure relief member 1121, and the weakened portion 14 is formed on the pressure relief member 1121. The wall body 1120 has a first through hole 1122 through in the first direction z, and the pressure relief member 1121 is connected with the wall body 1120 and closes the first through hole 1122.

[0242] In some embodiments, the wall body 1120 is the main structure of the second wall 112, which can be used to enclose a closed space with the wall portion of the shell 11 to accommodate the electrode assembly 13. In the first direction z, the wall body 1120 is formed with a through first through hole 1122.

[0243] In some embodiments, the pressure relief member 1121 is a structural member connected with the wall body 1120, which can close the first through hole 1122. Optionally, the pressure relief member 1121 can be a plate-shaped structure, which is connected with the wall body 1120 to close the first through hole 1122. The connection relationship between the pressure relief member 1121 and the wall body 1120 can be various, including welding, bonding, injection molding, or threaded connection, etc. In some embodiments, the material of the wall body 1120 and the material of the pressure relief member 1121 can be the same or different. Optionally, the material of the wall body 1120 can be a metal material, such as aluminum, steel, or other metals. The material of the pressure relief member 1121 can be a metal or non-metal material, such as aluminum, steel, or other metals, or plastic and other non-metals.

[0244] The "weak portion 14 is formed on the pressure relief member 1121" can be understood as that the weak portion 14 is formed on the pressure relief member 1121, and the weak portion 14 is formed on the second wall 112 through the combination of the pressure relief member 1121 and the wall body 1120.

[0245] In some embodiments, the weak portion 14 can be formed on the pressure relief member 1121 by pressure casting, stamping, turning, etc.

[0246] In the above scheme, the second wall 112 includes the wall body 1120 and the pressure relief member 1121, the weak portion 14 is formed on the pressure relief member 1121, and the weak portion 14 is formed on the second wall 112 through the connection of the pressure relief member 1121 and the wall body 1120. This can reduce the first through hole 1122 of the wall body 1120 to be closed and achieve the setting of the weak portion 14 on the second wall 112, so that the battery monomer 10 has a pressure relief function, which is beneficial to the improvement of the reliability of the battery monomer 10.

[0247] According to some embodiments of the present application, the projection area of the pressure relief member 1121 in the projection plane perpendicular to the first direction z is greater than or equal to 200mm 2 and less than or equal to 2000mm 2 .

[0248] In the above scheme, by setting the projection area of the pressure relief member 1121 along the first direction z to be greater than or equal to 200mm 2 , the battery monomer 10 can have a larger pressure relief area and a pressure relief rate, so that the battery monomer 10 has higher reliability; by setting the projection area of the pressure relief member 1121 along the first direction z to be less than or equal to 2000mm 2 , the pressure relief member 1121 can reduce the interference with other structural members of the battery device 100, and provide a larger space for other structural members, so that the battery device 100 is compact in structure, and the volume energy density of the battery device 100 can be improved.

[0249] According to some embodiments of the present application, some embodiments of the present application provide a battery device 100, which includes any one of the battery monomers 10 provided in the first aspect.

[0250] Please refer to FIG. 2, the battery device 100 includes the battery monomer 10 and the box 20, and the battery monomer 10 is contained in the box 20.

[0251] Optionally, a plurality of battery monomer assemblies are arranged in the box 20, each battery monomer assembly includes a plurality of battery monomers 10 stacked with each other, and the plurality of battery monomers 10 are connected in series with each other through the busbar component. In some embodiments, the plurality of battery monomer assemblies can be connected in series with each other through the busbar component.

[0252] According to some embodiments of the present application, there is also provided an electric device, the electric device comprising the battery cell 10 provided above, and / or the battery device 100 provided above. The battery cell 10 provided above and / or the battery device 100 provided above are used to provide electric energy.

[0253] Optionally, the electric device is a vehicle 1000, the battery cell 10 can be used as a driving power source of the vehicle 1000, and / or a control power source.

[0254] According to some embodiments of the present application, there is provided a battery cell 10, as shown in FIGS. 3-12. The battery cell 10 comprises a housing 11 and an electrode assembly 13. The electrode assembly 13 is arranged in the housing 11. In a first direction z, the housing 11 comprises a first wall 110 and a second wall 112 opposite to each other. The first wall 110 is provided with a liquid injection hole 12 through which electrolyte can be injected into the interior of the housing 11. The liquid injection hole 12 can be a stepped hole, the hole diameter of the hole section away from the interior of the housing 11 can be larger than the hole diameter of the hole section close to the interior of the housing 11.

[0255] The second wall 112 is formed with a weakened portion 14 and a pressure relief area 15, the second wall 112 is configured to be able to crack along the weakened portion 14 to open the pressure relief area 15, the projection of the liquid injection hole 12 and the projection of the weakened portion 14 do not overlap each other in the same projection plane perpendicular to the first direction z. That is, it can be understood that the liquid injection hole 12 and the weakened portion 14 are not directly opposite in the first direction z.

[0256] In some embodiments, the first wall 110 is provided with a first electrode terminal 16 and a second electrode terminal 17, the first electrode terminal 16 and the second electrode terminal 17 are opposite in polarity, for example, the first electrode terminal 16 is a positive electrode terminal for electrically connecting with the positive tab of the electrode assembly 13, and the second electrode terminal 17 is a negative electrode terminal for electrically connecting with the negative tab of the electrode assembly 13. In a second direction y, the first electrode terminal 16 and the second electrode terminal 17 are spaced apart, and the liquid injection hole 12 is arranged between the first electrode terminal 16 and the second electrode terminal 17.

[0257] In some embodiments, the weakened portion 14 can be directly or indirectly formed on the second wall 112.

[0258] Optionally, the second wall 112 is integrally formed with a notch groove 140, the groove bottom wall of the notch groove 140 is the weakened portion 14, and the notch groove 140 defines the pressure relief area 15.

[0259] Optionally, the second wall 112 comprises a wall body 1120 and a pressure relief member 1121, the pressure relief member 1121 is integrally formed with a score groove 140, a groove bottom wall of the score groove 140 is the weak portion 14, and the score groove 140 defines the pressure relief area 15. The wall body 1120 has a first through hole 1122 penetrating through in the first direction z, and the pressure relief member 1121 is connected with the wall body 1120 and closes the first through hole 1122.

[0260] In some embodiments, referring to FIG. 10, the score groove 140 comprises a first groove segment 141, a second groove segment 142, and a third groove segment 143, the first groove segment 141 and the third groove segment 143 are oppositely arranged along the second direction y, the second groove segment 142 is located between and connected with the first groove segment 141 and the third groove segment 143, the first groove segment 141, the second groove segment 142, and the third groove segment 143 jointly define the pressure relief area 15, the first direction z and the second direction y are perpendicular to each other, and a projection of the liquid injection hole 12 is located between a projection of the first groove segment 141 and a projection of the third groove segment 143 on a same projection plane perpendicular to the first direction z.

[0261] In some embodiments, referring to FIG. 11, the score groove 140 includes a ring-shaped score groove 140a, a fourth groove segment 148, and a fifth groove segment 149. The ring-shaped score groove 140a encloses the pressure relief area 15. The ring-shaped score groove 140a includes a first straight segment 144, a second straight segment 145, a first arc segment, and a second arc segment 147. The first straight segment 144 and the second straight segment 145 are oppositely arranged along the third direction x, and the first arc segment and the second arc segment 147 are oppositely arranged along the second direction y. One end of the first straight segment 144 and one end of the second straight segment 145 are connected by the first arc segment, and the other end of the first straight segment 144 and the other end of the second straight segment 145 are connected by the second arc segment 147. The fourth groove segment 148 and the fifth groove segment 149 are located in the pressure relief area 15, and the fourth groove segment 148 and the fifth groove segment 149 are respectively in the shape of a circular arc. The fourth groove segment 148 and the fifth groove segment 149 are oppositely arranged along the third direction x, and the outer edge side of the fourth groove segment 148 and the outer edge side of the fifth groove segment 149 are tangent. In the same projection plane perpendicular to the first direction z, the projection of the liquid injection hole 12 is located in the area enclosed by the projection of the first arc segment, the projection of the fourth groove segment 148, and the projection of the fifth groove segment 149. Optionally, the thickness of the groove bottom wall of the second straight segment 145, the thickness of the groove bottom wall of the first arc segment, and the thickness of the groove bottom wall of the second arc segment 147 are all less than the thickness of the groove bottom wall of the first straight segment 144. The thickness of the groove bottom wall of the second straight segment 145, the thickness of the groove bottom wall of the first arc segment, and the thickness of the groove bottom wall of the second arc segment 147 are all less than or equal to the thickness of the groove bottom wall of the fourth groove segment 148, and the thickness of the groove bottom wall of the second straight segment 145, the thickness of the groove bottom wall of the first arc segment, and the thickness of the groove bottom wall of the second arc segment 147 are all less than or equal to the thickness of the groove bottom wall of the fifth groove segment 149.

[0262] In some embodiments, in the same projection plane perpendicular to the first direction z, the minimum distance between the projection of the liquid injection hole 12 and the projection of the groove bottom wall of the score groove 140 is greater than or equal to 5 mm and less than or equal to 50 mm. Optionally, in the same projection plane perpendicular to the first direction z, the minimum distance between the projection of the liquid injection hole 12 and the projection of the groove bottom wall of the score groove 140 is greater than or equal to 10 mm and less than or equal to 20 mm.

[0263] In the battery cell 10 with such a structure, by arranging the projections of the liquid injection hole 12 and the weakened portion 14 in the same projection plane perpendicular to the first direction z to be mutually non-overlapping, the risk of the liquid injection pressure directly impacting the weakened portion 14 and causing the weakened portion 14 to be damaged and broken, resulting in the battery cell 10 being scrapped, can be effectively reduced, so that the battery cell 10 has a high yield rate during manufacturing, thereby facilitating the improvement of the manufacturing efficiency of the battery cell 10, and further facilitating the improvement of the manufacturing efficiency of the battery device 100.

[0264] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing having a first wall and a second wall opposite to each other along a first direction, the first wall having a liquid injection hole for injecting electrolyte into the housing interior; an electrode assembly arranged in the housing interior; wherein the second wall is formed with a weak portion and a pressure relief area, the second wall is configured to be able to split along the weak portion to open the pressure relief area, and a projection of the liquid injection hole and a projection of the weak portion do not overlap each other on the same projection plane perpendicular to the first direction.

2. The battery cell according to claim 1, wherein a minimum distance between the projection of the liquid injection hole and the projection of the weak portion on the same projection plane perpendicular to the first direction is greater than or equal to 5 mm and less than or equal to 50 mm.

3. The battery cell according to claim 2, wherein a minimum distance between the projection of the liquid injection hole and the projection of the weak portion on the same projection plane perpendicular to the first direction is greater than or equal to 10 mm and less than or equal to 20 mm.

4. The battery cell according to any one of claims 1-3, wherein the battery cell further comprises a first electrode terminal and a second electrode terminal, the first electrode terminal and the second electrode terminal have opposite polarities, the first electrode terminal and the second electrode terminal are arranged on the first wall respectively, and the first electrode terminal and the second electrode terminal are arranged at intervals along a second direction, the first direction and the second direction are perpendicular to each other.

5. The battery cell according to claim 4, wherein the liquid injection hole is located between the first electrode terminal and the second electrode terminal along the second direction.

6. The battery cell according to claim 5, wherein a distance between the liquid injection hole and the first electrode terminal along the second direction is equal to a distance between the liquid injection hole and the second electrode terminal along the second direction.

7. The battery cell according to claim 5, wherein a distance between the liquid injection hole and the first electrode terminal along the second direction is greater than a distance between the liquid injection hole and the second electrode terminal along the second direction.

8. The battery cell according to any one of claims 5-7, wherein the first wall has a first edge and a second edge in a third direction, a distance between the liquid injection hole and the first edge along the third direction is equal to a distance between the liquid injection hole and the second edge along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other two by two.

9. The battery cell according to any one of claims 5-7, wherein the first wall has a first edge and a second edge in a third direction, a distance between the liquid injection hole and the first edge along the third direction is greater than a distance between the liquid injection hole and the second edge along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other two by two.

10. The battery cell according to any one of claims 5-9, wherein In the second direction, a distance between the liquid injection hole and the first electrode terminal is greater than or equal to 40 mm, and a distance between the liquid injection hole and the second electrode terminal is greater than or equal to 40 mm. 11.The battery cell of any one of claims 1-10, wherein The liquid injection hole comprises a first hole section and a second hole section, the first hole section and the second hole section are arranged in a direction of the first wall pointing to the second wall, and a hole diameter of the first hole section is greater than a hole diameter of the second hole section. 12.The battery cell of claim 11, wherein The hole diameter of the first hole section is greater than or equal to 4 mm and less than or equal to 10 mm. 13.The battery cell of any one of claims 1-12, wherein A center of the weakened portion and a center of the second wall coincide with each other. 14.The battery cell of any one of claims 1-13, wherein In the same projection plane perpendicular to the first direction, a projection of the liquid injection hole and a projection of the pressure relief zone do not overlap with each other. 15.The battery cell of any one of claims 1-13, wherein The second wall is provided with a score groove, a groove bottom wall of the score groove is the weakened portion, and the score groove defines the pressure relief zone. 16.The battery cell of claim 15, wherein The score groove comprises a first groove section, a second groove section, and a third groove section, the first groove section and the third groove section are oppositely arranged in a second direction, the second groove section is located between and connects the first groove section and the third groove section, the first groove section, the second groove section, and the third groove section jointly define the pressure relief zone, and the first direction and the second direction are perpendicular to each other. 17.The battery cell of claim 16, wherein In the same projection plane perpendicular to the first direction, a projection of the liquid injection hole is located between a projection of the first groove section and a projection of the third groove section. 18.The battery cell of any one of claims 15-17, wherein The score groove comprises a ring-shaped score groove, and the ring-shaped score groove encloses to form the pressure relief zone. 19.The battery cell of claim 18, wherein The ring-shaped score groove comprises a first straight line section, a second straight line section, a first arc line section, and a second arc line section, in a third direction, the first straight line section and the second straight line section are oppositely arranged, in a second direction, the first arc line section and the second arc line section are oppositely arranged, one end of the first straight line section and one end of the second straight line section are connected by the first arc line section, the other end of the first straight line section and the other end of the second straight line section are connected by the second arc line section; A thickness of a groove bottom wall of the second straight line section, a thickness of a groove bottom wall of the first arc line section, and a thickness of a groove bottom wall of the second arc line section are all less than a thickness of a groove bottom wall of the first straight line section, and the first direction, the second direction, and the third direction are all perpendicular to each other. ​ 20. The battery cell of claim 19, wherein the score groove further comprises a fourth groove segment and a fifth groove segment, the fourth groove segment and the fifth groove segment are located in the pressure relief area, the fourth groove segment and the fifth groove segment are respectively in a circular arc shape; in the third direction, the fourth groove segment and the fifth groove segment are oppositely arranged, and the outer edge side of the fourth groove segment and the outer edge side of the fifth groove segment are tangent to each other, the thickness of the groove bottom wall of the second straight line segment, the thickness of the groove bottom wall of the first arc line segment, and the thickness of the groove bottom wall of the second arc line segment are all less than or equal to the thickness of the groove bottom wall of the fourth groove segment, and the thickness of the groove bottom wall of the second straight line segment, the thickness of the groove bottom wall of the first arc line segment, and the thickness of the groove bottom wall of the second arc line segment are all less than or equal to the thickness of the groove bottom wall of the fifth groove segment.

21. The battery cell of claim 20, wherein the positions where the outer edge side of the fourth groove segment and the outer edge side of the fifth groove segment are tangent to each other coincide with the center of the second wall.

22. The battery cell of claim 20 or 21, wherein in the second direction, one end of the first straight line segment is connected to one end of the fourth groove segment, and the other end of the first straight line segment is connected to the other end of the fourth groove segment; in the second direction, one end of the second straight line segment is connected to one end of the fifth groove segment, and the other end of the second straight line segment is connected to the other end of the fifth groove segment.

23. The battery cell of any one of claims 20-22, wherein in the same projection plane perpendicular to the first direction, the projection of the injection hole is located in the area enclosed by the projection of the first arc line segment, the projection of the fourth groove segment, and the projection of the fifth groove segment.

24. The battery cell of any one of claims 1-23, wherein the weak part is integrally formed on the second wall.

25. The battery cell of any one of claims 1-23, wherein the second wall comprises a wall body and a pressure relief member, the weak part is formed on the pressure relief member; the wall body has a first through hole passing through in the first direction, and the pressure relief member is connected to the wall body and closes the first through hole.

26. The battery cell of claim 25, wherein In a projection plane perpendicular to the first direction, the projected area of the pressure relief member is greater than or equal to 200 mm 2 and less than or equal to 2000 mm 2 .

27. A battery device, characterized by the battery cell of any one of claims 1-26.

28. An electrical device, comprising: the battery cell of any one of claims 1-26, and / or the battery device of claim 27.

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