Battery cell and electric device

Abstract

The present application provides a battery cell and an electric device. An electrode assembly of the battery cell comprises a first electrode sheet. The first electrode sheet comprises a first main body and a first tab. The first main body comprises a first active material layer. Along the width direction of the first electrode sheet, the first main body has a first end surface and a second end surface opposite to each other, wherein the first tab is connected to the first end surface, and one end of the first active material layer extends to the second end surface. Along the length direction of the first electrode sheet, the first main body has two third end surfaces opposite to each other, wherein two ends of the first active material layer respectively extend to the two third end surfaces. At least one of the two third end surfaces is connected to the second end surface by means of a chamfered surface, thereby reducing the sharpness of a pointed corner between the second end surface and the third end surface, thus reducing the risk of a short-circuit failure caused by the sharp corner between the second end surface and the third end surface piercing a separator when the battery cell undergoes a mechanical drop test or is in a drop condition, and improving the safety of the battery cell during the mechanical drop test and improving the pass rate of the drop test of the battery cell.

Description

Battery cell and electric device Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411371380X, filed on September 29, 2024, entitled “Battery cell and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery cell and an electric device. BACKGROUND

[0003] With the rapid development of new energy technology, battery cells have been widely used in electronic devices, electric vehicles, electric two-wheel vehicles, electric tools and other fields. As the application of battery cells becomes more and more widespread, higher requirements are placed on the safety of battery cells. SUMMARY

[0004] The embodiments of the present application provide a battery cell and an electric device to improve the safety performance of the battery cell.

[0005] In a first aspect, the embodiments of the present application provide a battery cell, which includes an electrode assembly, the electrode assembly including a first pole piece, the first pole piece including a first main body and a first tab, the first main body including a first active material layer, the first main body having opposite first and second end faces along a width direction of the first pole piece, the first tab being connected to the first end face, one end of the first active material layer extending to the second end face, the first main body having opposite two third end faces along a length direction of the first pole piece, two ends of the first active material layer extending to the two third end faces respectively; and wherein at least one of the two third end faces is connected to the second end face by a chamfered face.

[0006] In one or more optional embodiments above, at least one of the two third end faces is connected to the second end face by a chamfered face, which can reduce the sharpness of the sharp corner between the second end face and the third end face, reduce the risk of the sharp corner between the second end face and the third end face piercing the separator, thereby reducing the risk of short circuit failure of the battery cell due to the sharp corner between the second end face and the third end face piercing the separator during the drop mechanical test of the battery cell, improving the safety of the drop mechanical test of the battery cell and increasing the pass rate of the drop test of the battery cell. At least one of the two third end faces being connected to the second end face by a chamfered face can also reduce the risk of short circuit of the battery cell due to the sharp corner between the second end face and the third end face piercing the separator when the battery cell is in a drop working condition, thereby improving the safety performance of the battery cell.

[0007] In some embodiments of the first aspect of the present application, the chamfered face includes at least one inclined surface.

[0008] In one or more optional embodiments of the above, the chamfered surface comprises at least one bevel, which not only helps to reduce the sharpness between the second end surface and the third end surface, but also makes the chamfered surface easier to form.

[0009] In some embodiments of the first aspect of the application, the chamfered surface comprises one bevel, a first rounded surface and a second rounded surface, the bevel is connected to the second end surface through the first rounded surface, and the bevel is connected to the third end surface through the second rounded surface.

[0010] In one or more optional embodiments of the above, the bevel is connected to the second end surface through the first rounded surface, and the bevel is connected to the third end surface through the second rounded surface, which avoids the formation of sharp corners between the bevel and the second end surface and between the bevel and the third end surface, reduces the risk of the sharp corners piercing the separator, reduces the risk of the battery short circuit caused by the sharp corners between the second end surface and the third end surface piercing the separator, improves the safety performance of the battery in the mechanical drop test, improves the pass rate of the battery drop test, and improves the safety performance of the battery in the drop working condition.

[0011] In some embodiments of the first aspect of the application, the chamfered surface comprises a plurality of bevels, and two adjacent bevels are arranged at an obtuse angle.

[0012] In one or more optional embodiments of the above, the chamfered surface comprises a plurality of bevels, i.e. multiple chamfering processes are performed between the second end surface and the third end surface, which further reduces the sharpness of the sharp corners between the second end surface and the third end surface, further reduces the risk of short circuit caused by the risk of the sharp corners piercing the separator, and thus further improves the safety performance of the battery in the mechanical drop test, improves the pass rate of the battery drop test, and improves the safety performance of the battery in the drop working condition.

[0013] In some embodiments of the first aspect of the application, the chamfered surface further comprises a first rounded surface and a second rounded surface, one bevel is connected to the second end surface through the first rounded surface, and another bevel is connected to the third end surface through the second rounded surface.

[0014] In one or more optional embodiments of the above, one bevel is connected to the second end surface through the first rounded surface, and one bevel is connected to the third end surface through the second rounded surface, which avoids the formation of sharp corners between the bevel and the second end surface and between the bevel and the third end surface, reduces the risk of the sharp corners piercing the separator, reduces the risk of the battery short circuit caused by the sharp corners between the second end surface and the third end surface piercing the separator, improves the safety performance of the battery in the mechanical drop test, improves the pass rate of the battery drop test, and improves the safety performance of the battery in the drop working condition.

[0015] In some embodiments of the first aspect of the application, the chamfered surface further comprises a third rounded surface, and the two adjacent bevel surfaces are connected by the third rounded surface.

[0016] In one or more optional embodiments above, the two adjacent bevel surfaces are connected by a third rounded surface, which avoids the formation of a sharp corner between the two adjacent bevel surfaces, reduces the risk of the battery cell short circuiting due to the sharp corner between the second end surface and the third end surface piercing the separator, and improves the safety performance of the battery cell in the drop mechanical test, the pass rate of the battery cell drop test, and the safety performance of the battery cell in the drop working condition.

[0017] In some embodiments of the first aspect of the application, the radius of the first rounded surface is R1, the radius of the second rounded surface is R2, and the radius of the third rounded surface is R3, and 0.6≤R3 / R1≤1.5 and 0.6≤R3 / R2≤1.5.

[0018] In one or more optional embodiments above, by limiting the ratio of the radius of the third rounded surface to the radius of the first rounded surface to 0.6≤R3 / R1≤1.5, the difference between the radius of the third rounded surface and the radius of the first rounded surface can be controlled within a reasonable range, so that the difference between the radius of the third rounded surface and the radius of the first rounded surface is not too large or too small, reducing the risk of the first tab tearing due to uneven stress during the charging and discharging process of the battery cell caused by the large or small difference between the radius of the first rounded surface and the radius of the third rounded surface, thereby improving the safety performance of the battery cell. By limiting the ratio of the radius of the third rounded surface to the radius of the second rounded surface to 0.6≤R3 / R2≤1.5, the difference between the radius of the third rounded surface and the radius of the second rounded surface can be controlled within a reasonable range, so that the difference between the radius of the third rounded surface and the radius of the second rounded surface is not too large or too small, reducing the risk of the first tab tearing due to uneven stress during the charging and discharging process of the battery cell caused by the large or small difference between the radius of the second rounded surface and the radius of the third rounded surface, thereby improving the safety performance of the battery cell.

[0019] In some embodiments of the first aspect of the application, the radius of the first rounded surface is R1, the radius of the second rounded surface is R2, and the radius of the third rounded surface is R3, and 0.2mm≤R1≤3mm, 0.2mm≤R2≤3mm, and 0.2mm≤R3≤3mm.

[0020] In one or more optional embodiments above, R1 is greater than or equal to 0.2 mm, which is conducive to reducing the processing difficulty of the first rounded surface and improving the manufacturability and practicability of the battery cell. R2 is greater than or equal to 0.2 mm, which is conducive to reducing the processing difficulty of the second rounded surface and improving the manufacturability and practicability of the battery cell. R3 is greater than or equal to 0.2 mm, which is conducive to reducing the processing difficulty of the third rounded surface and improving the manufacturability and practicability of the battery cell. R1 is less than or equal to 3 mm, which reduces the loss of energy density caused by processing the first rounded surface. R2 is less than or equal to 3 mm, which reduces the loss of energy density caused by processing the second rounded surface. R3 is less than or equal to 3 mm, which reduces the loss of energy density caused by processing the third rounded surface.

[0021] In some embodiments of the first aspect of the present application, the angle between the bevel and the second end face is greater than or equal to 151° and less than or equal to 178°.

[0022] In one or more optional embodiments above, the angle between the bevel and the second end face is greater than or equal to 151°, so that the sharpness of the included angle between the bevel and the second end face is smaller, thereby reducing the risk of short circuit failure caused by the included angle between the second end face and the third end face piercing the separator during the drop mechanical test of the battery cell, improving the safety of the drop mechanical test of the battery cell, improving the drop test pass rate of the battery cell, and improving the safety performance of the battery cell. The angle between the bevel and the second end face is less than or equal to 178°, which reduces the processing difficulty and improves the manufacturability of the battery cell.

[0023] In some embodiments of the first aspect of the present application, the angle between the bevel and the second end face is greater than or equal to 160° and less than or equal to 170°.

[0024] In one or more optional embodiments above, the angle between the bevel and the second end face is greater than or equal to 160°, so that the sharpness of the included angle between the bevel and the second end face is smaller, thereby further reducing the risk of short circuit failure caused by the included angle between the second end face and the third end face piercing the separator during the drop mechanical test of the battery cell, improving the safety of the drop mechanical test of the battery cell, improving the drop test pass rate of the battery cell, and improving the safety performance of the battery cell. The angle between the bevel and the second end face is less than or equal to 170°, which further reduces the processing difficulty and improves the manufacturability of the battery cell.

[0025] In some embodiments of the first aspect of the present application, the chamfer surface includes a plurality of bevels, and two adjacent bevels are arranged at an obtuse angle. The ratio of the supplementary angle of the angle between one of the two adjacent bevels close to the third end face and the second end face to the supplementary angle of the angle between one of the two adjacent bevels close to the second end face and the second end face is greater than or equal to 1.05 and less than or equal to 1.5.

[0026] In one or more optional embodiments above, a ratio of a supplementary angle of one of the two adjacent bevels close to the third end face to an angle of the second end face to a supplementary angle of one of the two adjacent bevels close to the second end face is greater than or equal to 1.05, which reduces the processing difficulty of the cutting tool, facilitates the realization of variable cutting, thereby reducing the processing difficulty of the first pole piece and improving the manufacturability of the battery cell. The ratio of the supplementary angle of one of the two adjacent bevels close to the third end face to the angle of the second end face to the supplementary angle of one of the two adjacent bevels close to the second end face is less than or equal to 1.5, which reduces the sharpness of the included angle between the bevel and the second end face, reduces the risk of the included angle between the bevel and the second end face piercing the isolation film to cause short circuit failure, improves the safety of the battery cell in the drop mechanical test and improves the drop test pass rate of the battery cell. It can also reduce the risk of the sharp angle between the bevel and the second end face piercing the isolation film to cause short circuit of the battery cell when the battery cell is in a drop working condition, and improve the safety performance of the battery cell.

[0027] In some embodiments of the first aspect of the application, a ratio of a supplementary angle of one of the two adjacent bevels close to the third end face to an angle of the second end face to a supplementary angle of one of the two adjacent bevels close to the second end face is greater than or equal to 1.1 and less than or equal to 1.3.

[0028] In one or more optional embodiments above, a ratio of a supplementary angle of one of the two adjacent bevels close to the third end face to an angle of the second end face to a supplementary angle of one of the two adjacent bevels close to the second end face is greater than or equal to 1.1, which further reduces the processing difficulty of the cutting tool, facilitates the realization of variable cutting, thereby further reducing the processing difficulty of the first pole piece and further improving the manufacturability of the battery cell. The ratio of the supplementary angle of one of the two adjacent bevels close to the third end face to the angle of the second end face to the supplementary angle of one of the two adjacent bevels close to the second end face is less than or equal to 1.3, which further reduces the sharpness of the included angle between the bevel and the second end face, further reduces the risk of the included angle between the bevel and the second end face piercing the isolation film to cause short circuit failure, further improves the safety of the battery cell in the drop mechanical test and improves the drop test pass rate of the battery cell. It can also reduce the risk of the sharp angle between the bevel and the second end face piercing the isolation film to cause short circuit of the battery cell when the battery cell is in a drop working condition, and improve the safety performance of the battery cell.

[0029] In some embodiments of the first aspect of the application, the number of bevels is less than or equal to 3.

[0030] In one or more optional embodiments above, the number of bevels is less than or equal to 3, which alleviates the problem that too many bevels in the manufacturing process cause interference during the working process of the winding cutter, thereby causing the cutting precision to be unable to be guaranteed.

[0031] In some embodiments of the first aspect of the application, the chamfer surface intersects the third end surface at a first position, and the distance between the first position and the second end surface along the width direction of the first pole piece is L1, 1 mm≤L1≤5 mm.

[0032] In one or more optional embodiments above, L1≥1 mm, which reduces the risk of debris produced during chamfering being easily rolled into the battery cell and reduces the difficulty of chamfering, and L1≤5 mm, which reduces the capacity loss caused by processing the chamfer surface, thereby reducing the loss of energy density and ensuring product competitiveness.

[0033] In some embodiments of the first aspect of the application, 2 mm≤L1≤3.5 mm.

[0034] In one or more optional embodiments above, L1≥2 mm, which further reduces the risk of debris produced during chamfering being easily rolled into the battery cell and further reduces the difficulty of chamfering, and L1≤3.5 mm, which further reduces the capacity loss caused by processing the chamfer surface, thereby further reducing the loss of energy density and ensuring product competitiveness.

[0035] In some embodiments of the first aspect of the application, the chamfer surface intersects the third end surface at a first position, and the distance between the first position and the second end surface along the width direction of the first pole piece is L1, and the size of the first active material layer is L, 0.01≤L1 / L≤0.2.

[0036] In one or more optional embodiments above, L1 / L≥0.01, which, in the case of a multi-segment chamfer surface, reduces the difficulty of multi-segment cutting processing and reduces the loss of battery cell capacity. L1 / L≤0.2, which reduces the loss of energy density when processing the chamfer surface and ensures higher competitiveness of the product.

[0037] In some embodiments of the first aspect of the application, 0.03≤L1 / L≤0.1.

[0038] In one or more optional embodiments above, L1 / L≥0.03, which, in the case of a multi-segment chamfer surface, further reduces the difficulty of multi-segment cutting processing and thereby reduces the loss of battery cell capacity. L1 / L≤0.1, which further reduces the loss of energy density when processing the chamfer surface and ensures higher competitiveness of the product.

[0039] In some embodiments of the first aspect of the application, each of the third end surfaces is connected to the second end surface by one of the chamfer surfaces.

[0040] In the one or more optional embodiment modes above, each third end surface is connected to the second end surface by a chamfered surface, the sharpness of the sharp corner between the second end surface and each third end surface is smaller, the risk of the sharp corner between the second end surface and the third end surface piercing the separation film is reduced, the risk of short circuit failure of the battery cell due to the sharp corner between the second end surface and the third end surface piercing the separation film during the drop mechanical test of the battery cell is reduced, the safety of the drop mechanical test of the battery cell is improved, and the drop test pass rate of the battery cell is improved. The connection of each third end surface to the second end surface by a chamfered surface can also reduce the risk of short circuit of the battery cell due to the sharp corner between the second end surface and the third end surface piercing the separation film when the battery cell is in a drop working condition, and improve the safety performance of the battery cell.

[0041] In some embodiments of the first aspect of the application, the electrode assembly has a winding structure, the first tab is a positive electrode tab, in the winding direction of the electrode assembly, one of the two third end surfaces is a winding end of the first tab, and the other of the two third end surfaces is a winding start end of the first tab, and the winding end is connected to the second end surface by one chamfered surface.

[0042] In the one or more optional embodiment modes above, the first tab is a positive electrode tab, the winding end of the positive electrode tab is connected to the second end surface by one chamfered surface, the sharpness of the sharp corner between the second end surface and the third end surface is smaller, the risk of the sharp corner between the second end surface and the third end surface piercing the separation film after the electrode assembly expands to contact the shell is reduced, the risk of short circuit failure of the battery cell due to the sharp corner between the second end surface and the third end surface piercing the separation film is reduced, the safety performance of the battery cell is improved. The connection of the winding end of the positive electrode tab to the second end surface by one chamfered surface can also reduce the risk of short circuit failure of the battery cell due to the sharp corner between the second end surface and the third end surface piercing the separation film during the drop mechanical test of the battery cell, improve the safety of the drop mechanical test of the battery cell, and improve the drop test pass rate of the battery cell. The connection of the winding end of the positive electrode tab to the second end surface by one chamfered surface can also reduce the risk of short circuit of the battery cell due to the sharp corner between the second end surface and the third end surface piercing the separation film when the battery cell is in a drop working condition, and improve the safety performance of the battery cell.

[0043] In some embodiments of the first aspect of the application, the battery cell is a cylindrical battery cell.

[0044] In one or more optional embodiments above, the electric core is a cylindrical electric core. By connecting at least one of the third end faces of the first pole piece of the cylindrical electric core to the second end face through a chamfered face, the sharpness of the sharp corner between the second end face and the third end face can be reduced, and the risk of the sharp corner between the second end face and the third end face piercing the separator can be reduced, thereby reducing the risk of short circuit failure of the cylindrical electric core due to the sharp corner between the second end face and the third end face piercing the separator during the drop mechanical test, improving the safety of the drop mechanical test of the cylindrical electric core, and improving the pass rate of the drop test of the cylindrical electric core. Connecting at least one of the two third end faces to the second end face through a chamfered face can also reduce the risk of short circuit of the cylindrical electric core due to the sharp corner between the second end face and the third end face piercing the separator when the cylindrical electric core is in a drop working condition, and improve the safety performance of the cylindrical electric core.

[0045] In a second aspect, the embodiments of the present application provide a power consuming device, which comprises the electric core provided in any of the above embodiments.

[0046] In one or more optional embodiments above, the electric core provided in any of the above embodiments has good safety, which is beneficial to improving the power consumption safety of the power consuming device powered by the electric core. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the 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.

[0048] FIG. 1 is an exploded view of a cylindrical electric core provided by an embodiment of the present application;

[0049] FIG. 2 is a structural schematic view of an electrode assembly provided by an embodiment of the present application;

[0050] FIG. 3 is a structural schematic view of a first pole piece provided by some embodiments of the present application;

[0051] FIG. 4 is a structural schematic view of a first pole piece provided by another embodiment of the present application;

[0052] FIG. 5 is a structural schematic view of a first pole piece provided by still another embodiment of the present application;

[0053] FIG. 6 is a structural schematic view of a first pole piece provided by yet another embodiment of the present application;

[0054] FIG. 7 is a structural schematic view of a first pole piece provided by still another embodiment of the present application;

[0055] FIG. 8 is a structural schematic view of a first pole piece provided by yet another embodiment of the present application;

[0056] FIG. 9 is a structural schematic diagram of a first tab according to still another embodiment of the present application;

[0057] FIG. 10 is a structural schematic diagram of a first tab according to yet another embodiment of the present application;

[0058] FIG. 11 is a structural schematic diagram of a first tab according to still another embodiment of the present application;

[0059] FIG. 12 is a structural schematic diagram of a first tab according to yet another embodiment of the present application;

[0060] FIG. 13 is a structural schematic diagram of a first tab according to still another embodiment of the present application.

[0061] FIG. 13 is a structural schematic diagram of a first tab according to still another embodiment of the present application. DETAILED DESCRIPTION

[0062] So that the objects, technical solutions and advantages of the embodiments of the present application are more apparent, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0063] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0064] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0065] It should be noted that similar reference numbers and letters refer to similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0066] In the description of the embodiments of the present application, it should be noted that the indicated position or positional relationship is based on the position or positional relationship shown in the drawings, or the position or positional relationship commonly understood by those skilled in the art, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular position, be constructed and operated in a particular position, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0067] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "set", "mount", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. 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.

[0068] At present, from the development of market situation, the application of battery cell is more and more extensive. Battery cell is widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as electric tools, unmanned aerial vehicles, energy storage equipment and many other fields. With the continuous expansion of the application field of battery cell, the demand for battery cell is also increasing, and the safety requirement of battery cell is also increasing.

[0069] The electrode assembly of the battery cell includes a positive electrode sheet and a negative electrode sheet. Along the length direction of the positive electrode sheet, the opposite ends of the positive electrode sheet are the cutting positions in the production process of the positive electrode sheet. Along the length direction of the negative electrode sheet, the opposite ends of the negative electrode sheet are the cutting positions in the production process of the negative electrode sheet. The end face of the positive electrode sheet in the width direction and the end face of the cutting position of the positive electrode sheet form a right-angle sharp corner, and the end face of the negative electrode sheet in the width direction and the end face of the cutting position of the negative electrode sheet form a right-angle sharp corner. The right-angle sharp corner is easy to pierce the isolation film and cause short circuit failure of the battery cell. Especially when the battery cell is in drop test and drop working condition, the right-angle sharp corner pierces the isolation film and causes short circuit failure of the battery cell, which increases the risk of the battery cell. The safety performance of the battery cell is reduced.

[0070] Based on the above considerations, in order to alleviate the problem of reduced safety of the battery cell caused by the sharp corners of the cutting end face and the end face in the width direction of the pole piece piercing the isolation film, the embodiment of the present application provides a battery cell, which comprises an electrode assembly, and the electrode assembly comprises a first pole piece, the first pole piece comprises a first main body and a first tab, the first main body comprises a first active material layer, along the width direction of the first pole piece, the first main body has opposite first and second end faces, the first tab is connected to the first end face, one end of the first active material layer extends to the second end face, and along the length direction of the first pole piece, the first main body has two opposite third end faces, and two ends of the first active material layer extend to the two third end faces respectively; wherein at least one of the two third end faces is connected to the second end face by a chamfered face.

[0071] At least one of the two third end faces is connected to the second end face by a chamfered face, which can reduce the sharpness of the sharp corners between the second end face and the third end face, reduce the risk of the sharp corners between the second end face and the third end face piercing the isolation film, thereby reducing the risk of short circuit failure of the battery cell caused by the sharp corners between the second end face and the third end face piercing the isolation film during the drop mechanical test, improving the safety of the battery cell drop mechanical test and improving the pass rate of the battery cell drop test. At least one of the two third end faces is connected to the second end face by a chamfered face, which can also reduce the risk of short circuit of the battery cell caused by the sharp corners between the second end face and the third end face piercing the isolation film when the battery cell is in the drop working condition, and improve the safety performance of the battery cell.

[0072] The battery cell disclosed in the embodiment of the present application can be used in electric two-wheeled vehicles, power tools, unmanned aerial vehicles, energy storage devices and other electric devices, but is not limited to this. The battery cell disclosed in the embodiment of the present application can also be used as a power supply system of an electric device, which is beneficial to improve the safety performance of the battery cell.

[0073] The embodiment of the present application provides a power device using a battery cell as a power supply. The power device can be, but is not limited to, an electronic device, a power tool, an electric vehicle, an unmanned aerial vehicle and an energy storage device. The electronic device can include a mobile phone, a tablet, a notebook computer and the like. The power tool can include a power drill, a power saw and the like. The electric vehicle can include an electric car, an electric motorcycle and an electric bicycle.

[0074] As shown in FIG. 1 and FIG. 2, the embodiment of the present application provides a battery cell 100, which comprises a shell 10 and an electrode assembly 20; the electrode assembly 20 is contained in the shell 10.

[0075] The shell 10 forms a containing space. The containing space can be used to contain the electrode assembly 20, electrolyte and the like. The shell 10 can be a hard shell 11, such as a steel shell or an aluminum shell, to form a steel shell battery cell or an aluminum shell battery cell. The shell 10 can also be formed of a relatively soft material, such as an aluminum plastic film or a steel plastic film, to form a soft package battery cell.

[0076] As shown in FIG. 1, the outer shell 10 can include a shell body 11 and a cover body 12. The shell body 11 is a hollow structure with at least one open end, and the cover body 12 is used to cover the open end of the shell body 11, so that the cover body 12 and the shell body 11 together form the outer shell 10 with a containing space.

[0077] The electrode assembly 20 includes a first electrode tab 21, a second electrode tab 22, and a separator 23. The first electrode tab 21 and the second electrode tab 22 are opposite in polarity, that is, one of the first electrode tab 21 and the second electrode tab 22 is a positive electrode tab, and the other of the first electrode tab 21 and the second electrode tab 22 is a negative electrode tab.

[0078] The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer, and at least one side of the positive electrode current collector is provided with the positive electrode active material layer. For a lithium ion battery, the material of the positive electrode current collector can be aluminum. The positive electrode active material layer can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The positive electrode current collector can be a composite current collector or a non-composite current collector.

[0079] The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer, and at least one side of the negative electrode current collector is provided with the negative electrode active material layer. For a lithium ion battery, the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The negative electrode current collector can be a composite current collector or a non-composite current collector.

[0080] The separator 23 is used to insulate and separate the first electrode tab 21 and the second electrode tab 22, and to reduce the risk of short circuit of the battery 100. The material of the separator 23 can include PP (polypropylene), PE (polyethylene), or the like.

[0081] The electrode assembly 20 can be a laminated structure or a wound structure.

[0082] In an embodiment in which the electrode assembly 20 is a laminated structure, the first electrode tab 21, the separator 23, and the second electrode tab 22 are stacked in a certain order for one or more times.

[0083] In an embodiment in which the electrode assembly 20 is a wound structure, the first electrode tab 21, the separator 23, the second electrode tab 22, and another separator 23 are stacked in a certain order, and then wound to form an electrode assembly with a wound structure; or the separator 23, the first electrode tab 21, another separator 23, and the second electrode tab 22 are stacked in a certain order, and then wound to form an electrode assembly with a wound structure. The wound electrode assembly can be a flat wound electrode assembly or a cylindrical electrode assembly.

[0084] In the embodiment where the electrode assembly 20 is in a cylindrical structure, the battery cell 100 can be a cylindrical battery cell 100. When the battery cell 100 is a cylindrical battery cell 100, by connecting at least one of the third end faces 2115 of the first tab 21 of the cylindrical battery cell 100 with the second end face 2114 through the chamfered face 2116, the sharpness of the sharp corner between the second end face 2114 and the third end face 2115 can be reduced, and the risk of the sharp corner between the second end face 2114 and the third end face 2115 piercing the separator 23 can be reduced, thereby reducing the risk of short circuit failure of the cylindrical battery cell 100 due to the sharp corner between the second end face 2114 and the third end face 2115 piercing the separator 23 during the drop mechanical test, improving the safety of the cylindrical battery cell 100 during the drop mechanical test, and improving the pass rate of the cylindrical battery cell 100 during the drop test. Connecting at least one of the two third end faces 2115 with the second end face 2114 through the chamfered face 2116 can also reduce the risk of short circuit of the cylindrical battery cell 100 due to the sharp corner between the second end face 2114 and the third end face 2115 piercing the separator 23 when the cylindrical battery cell 100 is in a drop working condition, and improve the safety performance of the cylindrical battery cell 100. The case where the battery cell 100 is a cylindrical battery cell 100 is shown in FIG. 1, and the case where the electrode assembly 20 is in a cylindrical structure is shown in FIG. 2.

[0085] As shown in FIGS. 3 and 4, in some embodiments, the first tab 21 includes a first body 211 and a first tab 212, and the first body 211 includes a first active material layer 2111.

[0086] The first body 211 includes a first current collector 2112 and a first active material layer 2111, and the first current collector 2112 is provided with the first active material layer 2111 on at least one side in the thickness direction Z of the first tab.

[0087] In the width direction X of the first tab, the first active material layer 2111 extends to the second end face 2114. Understandably, in the width direction X of the first tab, one end of the first active material layer 2111 and one end of the first current collector 2112 are flush together to form the second end face 2114 of the first body 211.

[0088] In the length direction Y of the first tab, both ends of the first active material layer 2111 extend to the two third end faces 2115. Understandably, in the length direction Y of the first tab, the opposite two end faces of the first active material layer 2111 are flush with the opposite two end faces of the first current collector 2112, thereby forming the opposite two third end faces 2115 of the first body 211 at the two ends in the length direction Y of the first tab.

[0089] In the embodiment where the first tab 21 is a positive electrode tab, the first active material layer 2111 is a positive electrode active material layer, the first current collector 2112 is a positive electrode current collector, and the first current collector 2112 and the first active material layer 2111 together form a first body 211 of the first tab 21. Along the length direction Y of the first tab, the two opposite end faces of the first active material layer 2111 are flush with the two opposite end faces of the first current collector 2112, thereby forming two opposite third end faces 2115 at the two ends along the length direction Y of the first tab.

[0090] As shown in FIG. 3, in some embodiments, along the width direction X of the first tab, the first current collector 2112 includes a first region 21121 covered by the first active material layer 2111 and a second region 21122 not covered by the first active material layer 2111, and the first region 21121 and the second region 21122 are connected. Along the width direction X of the first tab, the first tab 212 is connected to one end of the second region 21122 away from the first region 21121, and the one end of the second region 21122 away from the first region 21121 forms a first end face 2113 of the first body 211 along the width direction X of the first tab. The one end of the second region 21122 away from the first region 21121 and the one end of the first active material layer 2111 away from the first region 21121 are flush together to form a second end face 2114 of the first body 211 along the width direction X of the first tab.

[0091] As shown in FIGS. 4-6, in another embodiment, along the width direction X of the first tab, one end of the first current collector 2112 is flush with one end of the first active material layer 2111 to form a first end face 2113 of the first body 211, the other end of the first current collector 2112 is flush with the other end of the first active material layer 2111 to form a second end face 2114 of the first body 211, and the first tab 212 is connected to one end of the first current collector 2112 located at the first end face 2113.

[0092] It should be noted that, in the embodiment where the electrode assembly 20 is a stacked structure, the width direction X of the first tab, the length direction Y of the first tab, and the thickness direction Z of the first tab can be perpendicular to each other. In the embodiment where the electrode assembly 20 is a wound structure, the width direction X of the first tab is parallel to the extension direction of the winding axis of the electrode assembly 20, and the length direction Y of the first tab corresponds to the winding direction K of the electrode assembly 20.

[0093] In the embodiment where the first tab 21 is a negative electrode tab, the first active material layer 2111 is a negative electrode active material layer, and the first current collector 2112 is a negative electrode current collector. The first current collector 2112 and the first active material layer 2111 together form a first body 211 of the first tab 21. Along the length direction Y of the first tab, the two opposite end faces of the first active material layer 2111 are flush with the two opposite end faces of the first current collector 2112, thereby forming two opposite third end faces 2115 at the two ends along the length direction Y of the first tab. Along the width direction X of the first tab, one end of the first current collector 2112 is flush with one end of the first active material layer 2111 to form a first end face 2113 of the first body 211, and the other end of the first current collector 2112 is flush with the other end of the first active material layer 2111 to form a second end face 2114 of the first body 211. The first tab 21 further comprises a first tab lug 212 connected to the first current collector 2112 at the end of the first end face 2113.

[0094] In some embodiments, the first tab lug 212 can be a split tab protruding from the first end face 2113 and having a dimension in the length direction Y of the first tab smaller than that of the first current collector 2112, as shown in FIGS. 3 and 4. In other embodiments, the first tab lug 212 can also be a full tab protruding from the first end face 2113 and having a dimension in the length direction Y of the first tab equal to that of the first current collector 2112, as shown in FIGS. 5 and 6.

[0095] As shown in FIGS. 5 and 6, in some embodiments, at least one of the two third end faces 2115 is connected to the second end face 2114 by a chamfered face 2116.

[0096] As shown in FIG. 5, only one third end face 2115 can be connected to the second end face 2114 by one chamfered face 2116, which is advantageous for reducing capacity loss and improving energy density.

[0097] As shown in FIG. 6, each third end surface 2115 and the second end surface 2114 can also be connected by a chamfer surface 2116. Each third end surface 2115 is connected to the second end surface 2114 by a chamfer surface 2116. The sharpness of the sharp corner between the second end surface 2114 and each third end surface 2115 is reduced, which reduces the risk of the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, thereby reducing the risk of short circuit failure of the battery cell 100 due to the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, improving the safety of the drop mechanical test of the battery cell 100 and increasing the pass rate of the drop test of the battery cell 100. The connection of each third end surface 2115 to the second end surface 2114 by a chamfer surface 2116 also reduces the risk of short circuit of the battery cell 100 due to the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, thereby improving the safety performance of the battery cell 100.

[0098] At least one of the two third end surfaces 2115 is connected to the second end surface 2114 by a chamfer surface 2116, which reduces the sharpness of the sharp corner between the second end surface 2114 and the third end surface 2115, thereby reducing the risk of the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, thereby reducing the risk of short circuit failure of the battery cell 100 due to the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, improving the safety of the drop mechanical test of the battery cell 100 and increasing the pass rate of the drop test of the battery cell 100. The connection of at least one of the two third end surfaces 2115 to the second end surface 2114 by a chamfer surface 2116 also reduces the risk of short circuit of the battery cell 100 due to the sharp corner between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, thereby improving the safety performance of the battery cell 100.

[0099] As shown in FIG. 2, in the embodiment in which the electrode assembly 20 has a jelly-roll structure, the first tab 21 is a positive electrode tab. In the winding direction K of the electrode assembly 20, one of the two third end surfaces 2115 is a winding end 2115' of the first tab 21, and the other of the two third end surfaces 2115 is a winding start end 2115" of the first tab 21. The winding end 2115' is connected to the second end surface 2114 by a chamfer surface 2116.

[0100] The first tab 21 is a positive electrode tab. The winding end 2115' of the positive electrode tab is connected to the second end face 2114 through a chamfer face 2116. The sharpness of the sharp angle between the second end face 2114 and the third end face 2115 is smaller, thereby reducing the risk that the sharp angle between the second end face 2114 and the third end face 2115 pierces the separator 23 to cause short circuit failure of the battery cell 100 after the electrode assembly 20 expands to contact the shell 10, improving the safety performance of the battery cell 100. The winding end 2115' of the positive electrode tab is connected to the second end face 2114 through a chamfer face 2116, which can also reduce the risk that the sharp angle between the second end face 2114 and the third end face 2115 pierces the separator 23 to cause short circuit failure of the battery cell 100 during the drop mechanical test, improving the safety of the battery cell 100 during the drop mechanical test and improving the pass rate of the drop test of the battery cell 100. The winding end 2115' of the positive electrode tab is connected to the second end face 2114 through a chamfer face 2116, which can also reduce the risk that the sharp angle between the second end face 2114 and the third end face 2115 pierces the separator 23 to cause short circuit of the battery cell 100 when the battery cell 100 is in a drop working condition, improving the safety performance of the battery cell 100.

[0101] In the embodiment in which each third end face 2115 is connected to the second end face 2114 through a chamfer face 2116, i.e., the winding start end 2115" and the winding end 2115' of the positive electrode tab are connected to the second end face 2114 through a chamfer face 2116, respectively.

[0102] As shown in FIGS. 5 and 7, in some embodiments, the chamfer face 2116 includes at least one inclined face 21161. The chamfer face 2116 includes at least one inclined face 21161, which not only helps to reduce the sharpness between the second end face 2114 and the third end face 2115, but also makes the forming of the chamfer face 2116 easier, facilitating the manufacturing of the battery cell 100.

[0103] The chamfer face 2116 includes at least one inclined face 21161, and the first tab 21 is subjected to at least one chamfering process. Each inclined face 21161 is arranged at an obtuse angle with the second end face 2114, and each inclined face 21161 is arranged at an obtuse angle with the third end face 2115.

[0104] As shown in FIG. 5, the chamfer surface 2116 can include one bevel surface 21161. As shown in FIG. 6, the chamfer surface 2116 can also include multiple bevel surfaces 21161. In the embodiment in which the chamfer surface 2116 includes multiple bevel surfaces 21161, the multiple bevel surfaces 21161 are arranged in sequence in the direction from the second end surface 2114 to the third end surface 2115. Adjacent two bevel surfaces 21161 are arranged at an obtuse angle. The chamfer surface 2116 includes multiple bevel surfaces 21161, i.e., multiple chamfering processes are performed between the second end surface 2114 and the third end surface 2115, further reducing the sharpness of the sharp corner between the second end surface 2114 and the third end surface 2115, further reducing the risk of the sharp corner piercing the isolation film 23 to cause short circuit, thereby further improving the safety performance of the battery cell 100 in the drop mechanical test, improving the drop test pass rate of the battery cell 100, and improving the safety performance of the battery cell 100 in the drop working condition.

[0105] For example, in some embodiments, the number of bevel surfaces 21161 is less than or equal to 3. That is, the number of bevel surfaces 21161 can be one, two, or three. The number of bevel surfaces 21161 being less than or equal to 3 alleviates the problem of too many beveling times in the manufacturing process causing interference in the working process of the winding cutter, thereby causing the cutting precision to be unable to be guaranteed. The case in which the number of bevel surfaces 21161 is two is shown in FIG. 7.

[0106] As shown in FIG. 7, in some embodiments, the angle between the bevel surface 21161 and the second end surface 2114 is greater than or equal to 151° and less than or equal to 178°.

[0107] In other words, the supplementary angle of the angle between the bevel surface 21161 and the second end surface 2114 is greater than or equal to 2° and less than or equal to 29°.

[0108] As shown in FIG. 7, the angles between the two bevel surfaces 21161 and the second end surface 2114 are T1 and T2 respectively, and 151°≤T1≤178° and 151°≤T2≤178°.

[0109] For example, the angle between the bevel surface 21161 and the second end surface 2114 can be 151°, 155°, 158°, 160°, 163°, 165°, 168°, 170°, 173°, 175°, 178°, etc.

[0110] The angle between the inclined surface 21161 and the second end surface 2114 is greater than or equal to 151°, so that the sharpness of the included angle between the inclined surface 21161 and the second end surface 2114 is smaller, thereby reducing the risk of short circuit failure caused by the included angle between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, improving the safety of the drop mechanical test of the battery cell 100, improving the drop test pass rate of the battery cell 100, and improving the safety performance of the battery cell 100. The angle between the inclined surface 21161 and the second end surface 2114 is less than or equal to 178°, which reduces the processing difficulty and improves the manufacturability of the battery cell 100.

[0111] Further, the angle between the inclined surface 21161 and the second end surface 2114 is greater than or equal to 160° and less than or equal to 170°.

[0112] As shown in FIG. 7, the angles between the two inclined surfaces 21161 and the second end surface 2114 are T1 and T2 respectively, so that 160°≤T1≤170° and 160°≤T2≤170°.

[0113] For example, the angle between the inclined surface 21161 and the second end surface 2114 can be 160°, 161°, 162°, 163°, 164°, 166°, 167°, 168°, 169°, 170°, etc.

[0114] The angle between the inclined surface 21161 and the second end surface 2114 is greater than or equal to 160°, so that the sharpness of the included angle between the inclined surface 21161 and the second end surface 2114 is smaller, thereby further reducing the risk of short circuit failure caused by the included angle between the second end surface 2114 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test of the battery cell 100, improving the safety of the drop mechanical test of the battery cell 100, improving the drop test pass rate of the battery cell 100, and improving the safety performance of the battery cell 100. The angle between the inclined surface 21161 and the second end surface 2114 is less than or equal to 170°, which further reduces the processing difficulty and improves the manufacturability of the battery cell 100.

[0115] In some embodiments, the chamfer surface 2116 includes a plurality of inclined surfaces 21161, and adjacent two inclined surfaces 21161 are arranged at an obtuse angle; the ratio of the supplementary angle of the angle between one of the adjacent two inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114 to the supplementary angle of the angle between the other of the adjacent two inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114 is greater than or equal to 1.05 and less than or equal to 1.5.

[0116] As shown in FIG. 7, the supplementary angles of the angles between the two adjacent inclined surfaces 21161 and the second end surface 2114 are T11 and T21, respectively, T11 is the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114, and T21 is the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114, and 1.05≤T11 / T21≤1.5.

[0117] The ratio of the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114 to the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114 can be 1.05, 1.1, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, etc.

[0118] The ratio of the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114 to the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114 is greater than or equal to 1.05, which reduces the processing difficulty of the cutting tool, facilitates the realization of variable cutting, thereby reducing the processing difficulty of the first pole piece 21 and improving the manufacturability of the battery cell 100. The ratio of the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114 to the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114 is less than or equal to 1.5, which reduces the sharpness of the included angle between the inclined surface 21161 and the second end surface 2114, reduces the risk of short circuit failure caused by the included angle between the inclined surface 21161 and the second end surface 2114 piercing the separator 23, improves the safety of the battery cell 100 in the mechanical drop test, and improves the drop test pass rate of the battery cell 100. It can also reduce the risk of short circuit of the battery cell 100 caused by the sharp angle between the inclined surface 21161 and the second end surface 2114 piercing the separator 23 when the battery cell 100 is in a drop working condition, and improve the safety performance of the battery cell 100.

[0119] Further, the ratio of the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 and the second end surface 2114 to the supplementary angle of the angle between one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 and the second end surface 2114 is greater than or equal to 1.1 and less than or equal to 1.3.

[0120] As shown in FIG. 7, 1.1≤T11 / T21≤1.3.

[0121] The ratio of the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 to the second end surface 2114 to the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 to the second end surface 2114 can be 1.1, 1.13, 1.17, 1.18, 1.21, 1.22, 1.23, 1.27, 1.28, 1.3, etc.

[0122] The ratio of the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 to the second end surface 2114 to the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 to the second end surface 2114 is greater than or equal to 1.1, further reducing the processing difficulty of the cutting tool, facilitating variable cutting, thereby further reducing the processing difficulty of the first pole piece 21 and further improving the manufacturability of the battery cell 100. The ratio of the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the third end surface 2115 to the second end surface 2114 to the supplementary angle of one of the two adjacent inclined surfaces 21161 close to the second end surface 2114 to the second end surface 2114 is less than or equal to 1.3, further reducing the sharpness of the included angle between the inclined surface 21161 and the second end surface 2114, further reducing the risk of the included angle between the inclined surface 21161 and the second end surface 2114 piercing the isolation film 23 to cause short circuit failure, further improving the safety of the battery cell 100 in the mechanical drop test and improving the drop test pass rate of the battery cell 100. It can also reduce the risk of the battery cell 100 short circuiting due to the sharp angle between the inclined surface 21161 and the second end surface 2114 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, and improve the safety performance of the battery cell 100.

[0123] In the embodiment in which the chamfer surface 2116 includes one inclined surface 21161, as shown in FIG. 7, the inclined surface 21161 can be directly connected to the second end surface 2114, and the inclined surface 21161 can be directly connected to the third end surface 2115, making the process of the chamfer surface 2116 simpler.

[0124] In the embodiment in which the chamfer surface 2116 includes one inclined surface 21161, the inclined surface 21161 can be indirectly connected to the second end surface 2114, and the inclined surface 21161 can be indirectly connected to the third end surface 2115. As shown in FIG. 8, the chamfer surface 2116 includes one inclined surface 21161, a first rounded corner surface 21162, and a second rounded corner surface 21163. The inclined surface 21161 is connected to the second end surface 2114 through the first rounded corner surface 21162, and the inclined surface 21161 is connected to the third end surface 2115 through the second rounded corner surface 21163.

[0125] The bevel 21161 and the second end face 2114 are indirectly connected through the first fillet face 21162, and the bevel 21161 and the second end face 2114 are smoothly transitioned. The bevel 21161 and the third end face 2115 are indirectly connected through the second fillet face 21163, and the bevel 21161 and the third end face 2115 are smoothly transitioned.

[0126] The bevel 21161 and the second end face 2114 are connected through the first fillet face 21162, and the bevel 21161 and the third end face 2115 are connected through the second fillet face 21163, avoiding the formation of sharp corners between the bevel 21161 and the second end face 2114 and between the bevel 21161 and the third end face 2115, reducing the risk of the sharp corners piercing the isolation film 23, reducing the risk of the second end face 2114 and the third end face 2115 piercing the isolation film 23 to cause the battery cell 100 to short circuit, improving the safety performance of the battery cell 100 in the drop mechanical test, improving the drop test pass rate of the battery cell 100, and improving the safety performance of the battery cell 100 in the drop working condition.

[0127] In the embodiment in which the chamfer face 2116 includes a plurality of bevels 21161, one of the plurality of bevels 21161 can be directly connected to the second end face 2114, another of the plurality of bevels 21161 can be directly connected to the third end face 2115, and two adjacent bevels 21161 can also be directly connected, so that the process of the chamfer face 2116 is simpler.

[0128] In the embodiment in which the chamfer face 2116 includes a plurality of bevels 21161, one of the plurality of bevels 21161 can be indirectly connected to the second end face 2114, and one of the plurality of bevels 21161 can be indirectly connected to the third end face 2115. As shown in FIG. 9, the chamfer face 2116 further includes a first fillet face 21162 and a second fillet face 21163, one bevel 21161 is connected to the second end face 2114 through the first fillet face 21162, and another bevel 21161 is connected to the third end face 2115 through the second fillet face 21163.

[0129] One bevel 21161 is indirectly connected to the second end face 2114 through the first fillet face 21162, and the bevel 21161 and the second end face 2114 are smoothly transitioned. Another bevel 21161 is indirectly connected to the third end face 2115 through the second fillet face 21163, and the bevel 21161 and the third end face 2115 are smoothly transitioned.

[0130] One bevel 21161 is connected with the second end face 2114 through a first fillet surface 21162, and one bevel 21161 is connected with the third end face 2115 through a second fillet surface 21163, so as to avoid the formation of sharp corners between the bevel 21161 and the second end face 2114 and between the bevel 21161 and the third end face 2115, reduce the risk of the sharp corners piercing the isolation film 23, reduce the risk of the sharp corners between the second end face 2114 and the third end face 2115 piercing the isolation film 23 to cause the short circuit of the battery cell 100, improve the safety performance of the battery cell 100 in the mechanical drop test, improve the drop test pass rate of the battery cell 100, and improve the safety performance of the battery cell 100 in the drop working condition.

[0131] Please continue to refer to FIG. 9. In the embodiment in which the chamfer surface 2116 includes a plurality of bevels 21161, the chamfer surface 2116 further includes a third fillet surface 211164, and two adjacent bevels 21161 are connected through the third fillet surface 211164.

[0132] The two adjacent bevels 21161 are indirectly connected through the third fillet surface 211164, so that the two adjacent bevels 21161 are smoothly connected.

[0133] The two adjacent bevels 21161 are connected through the third fillet surface 211164, so as to avoid the formation of sharp corners between the two adjacent bevels 21161, reduce the risk of the sharp corners between the second end face 2114 and the third end face 2115 piercing the isolation film 23 to cause the short circuit of the battery cell 100, improve the safety performance of the battery cell 100 in the mechanical drop test, improve the drop test pass rate of the battery cell 100, and improve the safety performance of the battery cell 100 in the drop working condition.

[0134] The radius of the first fillet surface 21162, the radius of the second fillet surface 21163, and the radius of the third fillet surface 211164 can be the same or different.

[0135] As shown in FIGS. 8 and 9, in some embodiments, the radius of the first fillet surface 21162 is R1, the radius of the third fillet surface 211164 is R3, and 0.6≤R3 / R1≤1.5.

[0136] For example, R3 / R1 can be 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 / 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, etc.

[0137] By limiting the ratio of the radius of the third rounded surface 211164 and the radius of the first rounded surface 21162 to 0.6≤R3 / R1≤1.5, the difference between the radius of the third rounded surface 211164 and the radius of the first rounded surface 21162 can be controlled within a reasonable range, so that the difference between the radius of the third rounded surface 211164 and the radius of the first rounded surface 21162 is not too large or too small, reducing the risk of tearing of the first tab 21 due to uneven stress of the first tab 21 during charging and discharging of the battery cell 100 caused by too large or too small difference between the radius of the first rounded surface 21162 and the radius of the third rounded surface 211164, thereby improving the safety performance of the battery cell 100.

[0138] Please continue to refer to FIGS. 8 and 9, in some embodiments, the radius of the second rounded surface 21163 is R2, the radius of the third rounded surface 211164 is R3, and 0.6≤R3 / R2≤1.5.

[0139] For example, R3 / R2 can be 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 / 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, etc.

[0140] By limiting the ratio of the radius of the third rounded surface 211164 and the radius of the second rounded surface 21163 to 0.6≤R3 / R2≤1.5, the difference between the radius of the third rounded surface 211164 and the radius of the second rounded surface 21163 can be controlled within a reasonable range, so that the difference between the radius of the third rounded surface 211164 and the radius of the second rounded surface 21163 is not too large or too small, reducing the risk of tearing of the first tab 21 due to uneven stress of the first tab 21 during charging and discharging of the battery cell 100 caused by too large or too small difference between the radius of the second rounded surface 21163 and the radius of the third rounded surface 211164, thereby improving the safety performance of the battery cell 100.

[0141] Specifically, the radius of the first rounded surface 21162 is R1, and 0.2mm≤R1≤3mm. R1≥0.2mm is conducive to reducing the processing difficulty of the first rounded surface 21162 and improving the manufacturability and practicality of the battery cell 100. R1≤3mm reduces the loss of energy density caused by processing the first rounded surface 21162.

[0142] For example, R1 can be 0.2mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.2mm, 2.5mm, 2.7mm, 2.9mm, 3mm, etc.

[0143] In some embodiments, the radius of the second fillet surface 21163 is R2, and 0.2mm≤R2≤3mm. R2≥0.2mm is conducive to reducing the processing difficulty of the second fillet surface 21163, improving the manufacturability and practicability of the battery cell 100. R2≤3mm reduces the loss of energy density caused by processing the second fillet surface 21163.

[0144] For example, R2 can be 0.2mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.2mm, 2.5mm, 2.7mm, 2.9mm, 3mm, etc.

[0145] In some embodiments, the radius of the third fillet surface 211164 is R3, and 0.2mm≤R3≤3mm. R3≥0.2mm is conducive to reducing the processing difficulty of the third fillet surface 211164, improving the manufacturability and practicability of the battery cell 100. R3≤3mm reduces the loss of energy density caused by processing the third fillet surface 211164.

[0146] For example, R3 can be 0.2mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.2mm, 2.5mm, 2.7mm, 2.9mm, 3mm, etc.

[0147] As shown in FIGS. 7-9, in some embodiments, the chamfer surface 2116 intersects the third end surface 2115 at a first position Q1, and the distance between the first position Q1 and the second end surface 2114 along the width direction X of the first pole piece is L1, and 1mm≤L1≤5mm.

[0148] In embodiments in which the chamfer surface 2116 includes at least one inclined surface 21161, if the inclined surface 21161 is directly connected to the third end surface 2115, the first position Q1 is the position where the inclined surface 21161 intersects the third end surface 2115.

[0149] In embodiments in which the inclined surface 21161 is connected to the third end surface 2115 through the second fillet surface 21163, the first position Q1 can be the position where the second fillet surface 21163 is tangent to the third end surface 2115.

[0150] For example, L1 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0151] 1mm≤L1, the risk of debris generated when chamfering being easily rolled into the battery cell 100 is reduced, and the difficulty of chamfering is reduced, L1≤5mm, the capacity loss generated by processing the chamfer surface 2116 is reduced, thereby reducing the loss of energy density, and ensuring the competitiveness of the product.

[0152] Further, 2mm≤L1≤3.5mm.

[0153] Exemplarily, L1may be 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, etc.

[0154] L1≥2mm, the risk of debris generated when chamfering being easily rolled into the battery cell 100 is further reduced, and the difficulty of chamfering is further reduced, L1≤3.5mm, the capacity loss generated by processing the chamfer surface 2116 is further reduced, thereby further reducing the loss of energy density, and ensuring the competitiveness of the product.

[0155] In some embodiments, the chamfer surface 2116 intersects the third end surface 2115 at a first position Q1, the distance between the first position Q1 and the second end surface 2114 along the width direction X of the first tab is L1, and the size of the first active material layer 2111 is L, 0.01≤L1 / L≤0.2.

[0156] Exemplarily, L1 / Lmay be 0.01, 0.03, 0.05, 0.07, 0.09, 0.1, 0.13, 0.15, 0.17, 0.19, 0.2, etc.

[0157] L1 / L≥0.01, in the case that the chamfer surface 2116 is a multi-segment surface, the difficulty of multi-segment cutting processing is reduced, and the loss of the battery cell 100 is reduced. L1 / L≤0.2, the energy density loss when processing the chamfer surface 2116 is reduced, and the competitiveness of the product is ensured.

[0158] Further, 0.03≤L1 / L≤0.1.

[0159] Exemplarily, L1 / Lmay be 0.03, 0.35, 0.04, 0.45, 0.05, 0.55, 0.06, 0.65, 0.7, 0.75, 0.08, 0.85, 0.09, 0.95, 0.1, etc.

[0160] L1 / L≥0.03, in the case that the chamfer surface 2116 is a multi-segment surface, the difficulty of multi-segment cutting processing is further reduced, thereby reducing the loss of the battery cell 100. L1 / L≤0.1, the energy density loss when processing the chamfer surface 2116 is further reduced, and the competitiveness of the product is ensured.

[0161] As shown in FIG. 10 and FIG. 11, in the embodiment in which the first tab 212 is in a slitting structure, one of the two third end faces 2115 and the first end face 2113 can be connected by a chamfered face 2116, which can reduce the sharpness of the sharp corner between the first end face 2113 and the third end face 2115, reduce the risk of the sharp corner between the first end face 2113 and the third end face 2115 piercing the isolation film 23, thereby reducing the risk of short circuit failure of the battery cell 100 due to the sharp corner between the first end face 2113 and the third end face 2115 piercing the isolation film 23 during the drop mechanical test, improving the safety of the battery cell 100 during the drop mechanical test and improving the pass rate of the battery cell 100 drop test. At least one of the two third end faces 2115 and the first end face 2113 is connected by a chamfered face 2116, which can also reduce the risk of short circuit of the battery cell 100 due to the sharp corner between the first end face 2113 and the third end face 2115 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, thereby improving the safety performance of the battery cell 100.

[0162] In the embodiment in which the first current collector 2112 includes a first region 21121 coated with a first active material layer 2111 and a second region 21122 not coated with an active material layer, the chamfered face 2116 connecting the first end face 2113 and the third end face 2115 can be located entirely in the second region 21122. The chamfered face 2116 connecting the first end face 2113 and the third end face 2115 can also be partially located in the second region 21122 and partially located in the first region 21121. The chamfered face 2116 connecting the first end face 2113 and the third end face 2115 is partially located in the second region 21122 and partially located in the first region 21121 is shown in FIG. 9.

[0163] As shown in FIG. 12 and FIG. 13, in the embodiment in which the first tab 212 is a full tab structure, along the width direction X of the first tab, the first tab 212 has a fourth end surface 2121 facing away from the first end surface 2113, and along the length direction Y of the first tab, the first tab 212 has two opposite fifth end surfaces 2122 flush with the two third end surfaces 2115. As shown in FIG. 12, at least one of the two fifth end surfaces 2122 is connected to the fourth end surface 2121 by a chamfer surface 2116, which can reduce the sharpness of the sharp corner between the fourth end surface 2121 and the fifth end surface 2122, and reduce the risk of the sharp corner between the fourth end surface 2121 and the fifth end surface 2122 piercing the isolation film 23, thereby reducing the risk of short circuit failure of the battery cell 100 due to the sharp corner between the fourth end surface 2121 and the fifth end surface 2122 piercing the isolation film 23 during the drop mechanical test, improving the safety of the battery cell 100 in the drop mechanical test, and improving the pass rate of the battery cell 100 in the drop test. The connection of at least one of the two fifth end surfaces 2122 to the fourth end surface 2121 by the chamfer surface 2116 can also reduce the risk of short circuit of the battery cell 100 due to the sharp corner between the fourth end surface 2121 and the fifth end surface 2122 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, and improve the safety performance of the battery cell 100.

[0164] As shown in FIG. 13, at least one of the two third end surfaces 2115 is connected to the fourth end surface 2121 by a chamfer surface 2116, which can reduce the sharpness of the sharp corner between the fourth end surface 2121 and the third end surface 2115, and reduce the risk of the sharp corner between the fourth end surface 2121 and the third end surface 2115 piercing the isolation film 23, thereby reducing the risk of short circuit failure of the battery cell 100 due to the sharp corner between the fourth end surface 2121 and the third end surface 2115 piercing the isolation film 23 during the drop mechanical test, improving the safety of the battery cell 100 in the drop mechanical test, and improving the pass rate of the battery cell 100 in the drop test. The connection of at least one of the two third end surfaces 2115 to the fourth end surface 2121 by the chamfer surface 2116 can also reduce the risk of short circuit of the battery cell 100 due to the sharp corner between the fourth end surface 2121 and the third end surface 2115 piercing the isolation film 23 when the battery cell 100 is in a drop working condition, and improve the safety performance of the battery cell 100.

[0165] The embodiments of the present application also provide a power consumption device, which includes the battery cell 100 provided by any of the above embodiments.

[0166] The battery cell 100 provided by any of the above embodiments has good safety, which is conducive to improving the power consumption safety of the power consumption device powered by the battery cell 100.

[0167] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. Those skilled in the art can make various modifications and variations to the present application.

Claims

1. An electric core, comprising: an electrode assembly including a first tab, the first tab including a first body and a first tab ear, the first body including a first active material layer, the first body having opposite first and second end faces along a width direction of the first tab, the first tab ear being connected to the first end face, one end of the first active material layer extending to the second end face, the first body having opposite two third end faces along a length direction of the first tab, two ends of the first active material layer extending to the two third end faces respectively; wherein at least one of the two third end faces is connected to the second end face by a chamfered face.

2. The electric cell of claim 1, wherein, The chamfered face includes at least one bevel.

3. The electric cell of claim 2, wherein, The chamfered face includes one bevel, a first rounded face and a second rounded face, the bevel being connected to the second end face by the first rounded face, the bevel being connected to the third end face by the second rounded face.

4. The electric cell of claim 2, wherein, The chamfered face includes a plurality of bevels, two adjacent bevels being arranged at an obtuse angle.

5. The electric cell of claim 4, wherein, The chamfered face further includes a first rounded face and a second rounded face, one bevel being connected to the second end face by the first rounded face, another bevel being connected to the third end face by the second rounded face.

6. The electric cell of claim 5, wherein, The chamfered face further includes a third rounded face, two adjacent bevels being connected by the third rounded face.

7. The electric cell of claim 6, wherein, A radius of the first rounded face is R1, a radius of the second rounded face is R2, and a radius of the third rounded face is R3, 0.6≤R3 / R1≤1.5, and 0.6≤R3 / R2≤1.

5.

8. The electric cell of claim 6, wherein, A radius of the first rounded face is R1, a radius of the second rounded face is R2, and a radius of the third rounded face is R3, 0.2mm≤R1≤3mm, 0.2mm≤R2≤3mm, and 0.2mm≤R3≤3mm.

9. The electric cell of claim 2, wherein, An angle between the bevel and the second end face is greater than or equal to 151° and less than or equal to 178°.

10. The electric cell of claim 9, wherein, An angle between the bevel and the second end face is greater than or equal to 160° and less than or equal to 170°.

11. The electric cell of claim 2, wherein, The chamfered face includes a plurality of bevels, two adjacent bevels being arranged at an obtuse angle. A ratio of a supplementary angle of one of the two adjacent bevels close to the third end face to an angle of the second end face to a supplementary angle of the other of the two adjacent bevels close to the second end face is greater than or equal to 1.05 and less than or equal to 1.

5.

12. The electric cell of claim 11, wherein, A ratio of a supplementary angle of one of the two adjacent bevels close to the third end face to an angle of the second end face to a supplementary angle of the other of the two adjacent bevels close to the second end face is greater than or equal to 1.1 and less than or equal to 1.

3.

13. The electrically core of claim 2, wherein, The number of the bevels is less than or equal to 3.

14. The electrically core of claim 1, wherein, The chamfered face intersects the third end face at a first position, a distance between the first position and the second end face along the width direction of the first tab is L1, 1mm≤L1≤5mm.

15. The electric cell of claim 14, wherein, 2mm≤L1≤3.5mm.

16. The electrically core of claim 1, wherein, The chamfer surface intersects the third end surface at a first position, and the distance between the first position and the second end surface is L1 along the width direction of the first tab, and the size of the first active material layer is L, and 0.01≤L1 / L≤0.

2.

17. The electric cell of claim 16, wherein, 0.03≤L1 / L≤0.

1.

18. The electrically core of claim 1, wherein, Each of the third end surfaces is connected to the second end surface by one chamfer surface.

19. The electrically core of claim 1, wherein, The electrode assembly is in a wound structure, the first tab is a positive electrode tab, and along the winding direction of the electrode assembly, one of the two third end surfaces is a winding end tab of the first tab, and the other of the two third end surfaces is a winding start tab of the first tab, and the winding end tab is connected to the second end surface by one chamfer surface.

20. The electrically core of claim 1, wherein, The battery cell is a cylindrical battery cell.

21. An electrical device comprising the battery cell according to any one of claims 1-20.

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