Battery cell, electrode assembly, battery device and electric device

Abstract

The utility model provides a battery monomer, an electrode assembly, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly, and the electrode assembly is arranged in the shell. The electrode assembly comprises a solid electrolyte layer and a plurality of pole pieces, the solid electrolyte layer is arranged between every two adjacent pole pieces in the first direction, each pole piece comprises an active substance layer, and in every two adjacent pole pieces, the polarities of the active substance layers facing the solid electrolyte layer located between every two adjacent pole pieces are opposite. And in the first direction, four corners of the two pole pieces which are farthest from each other are provided with chamfering structures. The four corners of the two pole pieces which are farthest from each other are provided with the chamfering structures, so that the risk that the four corners of the two pole pieces which are farthest from each other pierce the packaging bag in the isostatic pressing process can be reduced, and the yield of the single batteries can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular, to a battery monomer, an electrode assembly, a battery device and a power utilization device. BACKGROUND

[0002] Batteries are widely used in the field of new energy, for example, electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. The development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, the yield of the battery also needs to be considered. However, the yield of the battery needs to be further improved at present. CONTENT OF THE UTILITY MODEL

[0003] The embodiments of the present application provide a battery monomer, an electrode assembly, a battery device and a power utilization device, which can improve the yield of the battery.

[0004] In a first aspect, the embodiments of the present application provide a battery monomer, which comprises a shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly comprises a solid electrolyte layer and a plurality of pole pieces, along a first direction, the solid electrolyte layer is arranged between two adjacent pole pieces, the pole piece comprises an active material layer, the polarity of the active material layer facing the solid electrolyte layer between the two adjacent pole pieces is opposite; along the first direction, four corners of the two pole pieces farthest apart are provided with chamfer structures.

[0005] In the above technical solution, the plurality of pole pieces and the solid electrolyte layer are arranged in a stack along the first direction, that is, the electrode assembly is a stacked electrode assembly. For the stacked electrode assembly, during the isostatic pressing process, the pole pieces at both ends of the electrode assembly are most likely to pierce the packaging bag along the first direction. In the embodiments of the present application, the two pole pieces farthest apart are the pole pieces at both ends of the electrode assembly. By providing the four corners of the two pole pieces farthest apart with chamfer structures, it is beneficial to reduce the risk of the four corners of the two pole pieces farthest apart piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer. In addition, by providing the four corners of the two pole pieces farthest apart with chamfer structures, it is also beneficial to reduce the risk of scratching between the pole pieces and the shell, reduce the risk of damage between the pole pieces and the shell, and improve the reliability of the battery monomer.

[0006] As an optional technical solution of the embodiment of the application, the plurality of pole pieces include a first pole piece and a second pole piece, the first pole piece and the second pole piece are opposite in polarity, the first pole piece, the solid-state electrolyte layer and the second pole piece are stacked in the first direction, and the solid-state electrolyte layer is arranged between the first pole piece and the second pole piece; wherein the first pole piece is a plurality of, along the first direction, the two first pole pieces farthest apart are the pole pieces located at both ends of the electrode assembly, and the four corners of the two first pole pieces farthest apart are provided with chamfer structures.

[0007] In the above technical solution, the electrode assembly includes a first pole piece, a solid-state electrolyte layer and a second pole piece stacked, so that the electrode assembly is simple and convenient to manufacture, and has low cost. The two first pole pieces farthest apart are the pole pieces located at both ends of the electrode assembly, and by providing the four corners of the two first pole pieces farthest apart with chamfer structures, it is beneficial to reduce the risk of the four corners of the two first pole pieces farthest apart piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer. In addition, by providing the four corners of the two first pole pieces farthest apart with chamfer structures, it is also beneficial to reduce the risk of scratching between the first pole piece and the shell, reduce the risk of damage between the first pole piece and the shell, and improve the reliability of the battery monomer.

[0008] As an optional technical solution of the embodiment of the application, the four corners of each first pole piece are provided with the chamfer structure.

[0009] In the above technical solution, by providing the four corners of each first pole piece with chamfer structures, on the one hand, it is beneficial to reduce the risk of the four corners of the plurality of first pole pieces piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer. On the other hand, it is beneficial to reduce the risk of scratching between the four corners of the plurality of first pole pieces and the shell, reduce the risk of damage between the plurality of first pole pieces and the shell, and improve the reliability of the battery monomer.

[0010] As an optional technical solution of the embodiment of the application, the second pole piece is a plurality of, along the first direction, the four corners of the two second pole pieces farthest apart are provided with the chamfer structure.

[0011] In the technical solution, along the first direction, the two second pole pieces farthest apart are relatively close to the two ends of the electrode assembly, and in the isostatic pressing process, the four corners of the two second pole pieces farthest apart are relatively easy to pierce the packaging bag. In the embodiment of the present application, by arranging the chamfer structure on the four corners of the two second pole pieces farthest apart, the risk of the four corners of the two second pole pieces farthest apart piercing the packaging bag is reduced, and the yield of the battery monomer is improved. In addition, by arranging the chamfer structure on the four corners of the two second pole pieces farthest apart, the risk of the four corners of the two second pole pieces farthest apart scratching the shell is reduced, the risk of damage to the second pole piece and the shell is reduced, and the reliability of the battery monomer is improved.

[0012] As an optional technical solution of the embodiment of the present application, the chamfer structure is arranged on the four corners of each second pole piece.

[0013] In the technical solution, by arranging the chamfer structure on the four corners of each second pole piece, on the one hand, the risk of the four corners of the plurality of second pole pieces piercing the packaging bag in the isostatic pressing process is reduced, and the yield of the battery monomer is improved. On the other hand, the risk of the four corners of the plurality of second pole pieces scratching the shell is reduced, the risk of damage to the plurality of second pole pieces and the shell is reduced, and the reliability of the battery monomer is improved.

[0014] As an optional technical solution of the embodiment of the present application, the chamfer structure is a round corner, and the first pole piece and the second pole piece are a plurality of, the round corner is arranged on the four corners of each first pole piece, and the round corner is arranged on the four corners of each second pole piece.

[0015] In the technical solution, when the chamfer structure is a round corner, the transition is smoother, and new sharp corners are not easy to be generated. By arranging the round corner on the four corners of each first pole piece, the risk of the four corners of the plurality of first pole pieces piercing the packaging bag in the isostatic pressing process is further reduced, and the yield of the battery monomer is improved. Moreover, by arranging the round corner on the four corners of each first pole piece, the risk of the four corners of the plurality of first pole pieces scratching the shell is further reduced, the risk of damage to the plurality of first pole pieces and the shell is further reduced, and the reliability of the battery monomer is improved. Similarly, by arranging the round corner on the four corners of each second pole piece, the risk of the four corners of the plurality of second pole pieces piercing the packaging bag in the isostatic pressing process is further reduced, and the yield of the battery monomer is improved. Moreover, by arranging the round corner on the four corners of each second pole piece, the risk of the four corners of the plurality of second pole pieces scratching the shell is further reduced, the risk of damage to the plurality of second pole pieces and the shell is further reduced, and the reliability of the battery monomer is improved.

[0016] As an optional technical solution of the embodiment of the application, the first pole piece is a negative pole piece, the second pole piece is a positive pole piece, the radii of the rounded corners of the plurality of first pole pieces are equal, the radii of the rounded corners of the plurality of second pole pieces are equal, and the radius of the rounded corner of the first pole piece is less than or equal to the radius of the rounded corner of the second pole piece.

[0017] In the above technical solution, the radii of the rounded corners of the plurality of first pole pieces are equal, the radii of the rounded corners of the plurality of second pole pieces are equal, which is beneficial to simplify the manufacturing and reduce the manufacturing cost of the battery monomer. When the first pole piece is a negative pole piece, the second pole piece is a positive pole piece, and the radius of the rounded corner of the first pole piece is less than or equal to the radius of the rounded corner of the second pole piece, it is beneficial to make the first pole piece exceed the second pole piece, and it is beneficial to reduce the risk of metal ion precipitation.

[0018] As an optional technical solution of the embodiment of the application, the first pole piece is a negative pole piece, the second pole piece is a positive pole piece, the length of the first pole piece is greater than the length of the second pole piece, the width of the first pole piece is greater than the width of the second pole piece, and the thickness direction of the first pole piece is parallel to the first direction.

[0019] In the above technical solution, when the first pole piece is a negative pole piece and the second pole piece is a positive pole piece, by making the length of the first pole piece greater than the length of the second pole piece and the width of the first pole piece greater than the width of the second pole piece, it is beneficial to reduce the assembly difficulty and realize the overhang design, and it is beneficial to reduce the risk of metal ion precipitation.

[0020] As an optional technical solution of the embodiment of the application, the number of the first pole pieces is odd, the number of the second pole pieces is even, and the radius of the rounded corner of the middle first pole piece gradually increases to the radius of the rounded corner of the first pole piece at both ends.

[0021] In the above technical solution, in order to realize the overhang design, the first pole piece will exceed the second pole piece in the length direction and the width direction, so that the first pole piece is more likely to pierce the packaging bag than the second pole piece during the isostatic pressing process. When the number of the first pole pieces is odd and the number of the second pole pieces is even, by gradually increasing the radius of the rounded corner of the middle first pole piece to the radius of the rounded corner of the first pole piece at both ends, the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, thereby further reducing the risk of the plurality of first pole pieces piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer.

[0022] As an optional technical solution of the embodiment of the present application, along the first direction, the first pole piece located at the middle position is a first middle pole piece, and a plurality of the second pole pieces are arranged on both sides of the first middle pole piece; in the plurality of the second pole pieces located on the same side of the first middle pole piece, the radius of the fillet of the second pole piece closest to the first middle pole piece gradually increases to the radius of the fillet of the second pole piece farthest from the first middle pole piece.

[0023] In the above technical solution, by gradually increasing the radius of the fillet of the second pole piece closest to the first middle pole piece to the radius of the fillet of the second pole piece farthest from the first middle pole piece in the second pole pieces located on the same side of the first middle pole piece, the change trend of the fillet of the plurality of first pole pieces is adapted, the overhang design is realized, and the area of the second pole piece is large, which is beneficial to improve the energy density and reliability of the battery monomer.

[0024] As an optional technical solution of the embodiment of the present application, the radius of the fillet of the second pole piece is equal to the radius of the fillet of the first pole piece adjacent to the second pole piece and located on the side of the second pole piece away from the first middle pole piece.

[0025] In the above technical solution, by equalizing the radius of the fillet of the second pole piece to the radius of the fillet of the first pole piece adjacent to the second pole piece and located on the side of the second pole piece away from the first middle pole piece, the overhang design is realized, and the area of the second pole piece is large, which is beneficial to improve the energy density and reliability of the battery monomer.

[0026] As an optional technical solution of the embodiment of the present application, the first pole pieces located on both sides of the first middle pole piece are symmetrically arranged about the first middle pole piece; and / or the second pole pieces located on both sides of the first middle pole piece are symmetrically arranged about the first middle pole piece.

[0027] In the above technical solution, by symmetrically arranging the first pole pieces located on both sides of the first middle pole piece about the first middle pole piece, the radius of the fillet of the two symmetrically arranged first pole pieces is equal, and in the manufacturing of the fillet, the two symmetrically arranged first pole pieces can be cut together, which is beneficial to simplify the manufacturing and reduce the manufacturing cost of the battery monomer. By symmetrically arranging the second pole pieces located on both sides of the first middle pole piece about the first middle pole piece, the radius of the fillet of the two symmetrically arranged second pole pieces is equal, and in the manufacturing of the fillet, the two symmetrically arranged second pole pieces can be cut together, which is beneficial to simplify the manufacturing and reduce the manufacturing cost of the battery monomer.

[0028] As an optional technical solution of the embodiment of the present application, the number of the first pole pieces is even, the number of the second pole pieces is odd, the second pole piece located at the middle position is a second middle pole piece in the first direction, and a plurality of the first pole pieces are arranged on both sides of the second middle pole piece; in the plurality of the first pole pieces located on the same side of the second middle pole piece, the radius of the fillet of the first pole piece closest to the second middle pole piece gradually increases to the radius of the fillet of the first pole piece farthest from the second middle pole piece.

[0029] In the above technical solution, in order to realize the overhang design, the first pole piece exceeds the second pole piece in the length direction and the width direction, so that the first pole piece is more likely to scratch the shell than the second pole piece. When the number of the first pole pieces is even and the number of the second pole pieces is odd, in the plurality of the first pole pieces located on the same side of the second middle pole piece, the radius of the fillet of the first pole piece closest to the second middle pole piece gradually increases to the radius of the fillet of the first pole piece farthest from the second middle pole piece, so that the adjacent two corners of the electrode assembly in the first direction form a spherical transition, thereby further reducing the risk of the plurality of the first pole pieces piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer.

[0030] As an optional technical solution of the embodiment of the present application, the radius of the fillet of the second pole piece at the middle gradually increases to the radius of the fillet of the second pole piece at both ends.

[0031] In the above technical solution, by gradually increasing the radius of the fillet of the second pole piece at the middle to the radius of the fillet of the second pole piece at both ends, the change trend of the fillet of the plurality of the first pole pieces is adapted, the overhang design is realized, and the area of the second pole piece is large, which is beneficial to improve the energy density and reliability of the battery monomer.

[0032] As an optional technical solution of the embodiment of the present application, the radius of the fillet of the second pole piece is equal to the radius of the fillet of the first pole piece adjacent to the second pole piece and located on the side of the second pole piece away from the second middle pole piece.

[0033] In the above technical solution, by making the radius of the fillet of the second pole piece equal to the radius of the fillet of the first pole piece adjacent to the second pole piece and located on the side of the second pole piece away from the second middle pole piece, the overhang design is realized, and the area of the second pole piece is large, which is beneficial to improve the energy density and reliability of the battery monomer.

[0034] As an optional technical solution of the embodiment of the present application, the first pole pieces located on both sides of the second intermediate pole piece are symmetrically arranged about the second intermediate pole piece; and / or the second pole pieces located on both sides of the second intermediate pole piece are symmetrically arranged about the second intermediate pole piece.

[0035] In the above technical solution, by symmetrically arranging the first pole pieces located on both sides of the first intermediate pole piece about the second intermediate pole piece, the radii of the round corners of the two symmetrically arranged first pole pieces are equal, and when the round corners are manufactured, the two symmetrically arranged first pole pieces can be cut together to form the round corners, which is beneficial to simplify the manufacturing process and reduce the manufacturing cost of the battery monomer. By symmetrically arranging the second pole pieces located on both sides of the second intermediate pole piece about the second intermediate pole piece, the radii of the round corners of the two symmetrically arranged second pole pieces are equal, and when the round corners are manufactured, the two symmetrically arranged second pole pieces can be cut together to form the round corners, which is beneficial to simplify the manufacturing process and reduce the manufacturing cost of the battery monomer.

[0036] As an optional technical solution of the embodiment of the present application, the four corners of the solid-state electrolyte layer are provided with chamfer structures.

[0037] In the above technical solution, by providing the four corners of the solid-state electrolyte layer with chamfer structures, the risk of the four corners of the solid-state electrolyte layer piercing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer is improved. In addition, by providing the four corners of the solid-state electrolyte layer with chamfer structures, the risk of scratching between the solid-state electrolyte layer and the shell is reduced, the risk of damage to the solid-state electrolyte layer and the shell is reduced, and the reliability of the battery monomer is improved.

[0038] As an optional technical solution of the embodiment of the present application, the chamfer structure is a round corner, the solid-state electrolyte layer is connected to the first pole piece, and the radius of the round corner of the solid-state electrolyte layer is equal to the radius of the round corner of the first pole piece corresponding to the round corner.

[0039] In the above technical solution, by connecting the solid-state electrolyte layer to the first pole piece, it is more simple and convenient to stack the first pole piece, the solid-state electrolyte layer and the second pole piece in the first direction. By connecting the solid-state electrolyte layer to the first pole piece, the solid-state electrolyte layer can stably separate the first pole piece and the second pole piece, and is convenient for ion transmission, which is beneficial to reduce the internal resistance of the battery monomer. By making the radius of the round corner of the solid-state electrolyte layer equal to the radius of the round corner of the first pole piece corresponding to the round corner, the solid-state electrolyte layer covers the first pole piece as much as possible, reduces the risk of short circuit caused by the contact between the first pole piece and the second pole piece, and improves the reliability of the battery monomer.

[0040] As an optional technical solution of the embodiment of the present application, the pole piece comprises a current collector, a first active material layer and a second active material layer, the polarities of the first active material layer and the second active material layer are opposite, and the first active material layer and the second active material layer are arranged on two sides of the current collector respectively; along the first direction, four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart are each provided with the chamfer structure.

[0041] In the above technical solution, by making the pole piece comprise a current collector, a first active material layer and a second active material layer, and the polarities of the first active material layer and the second active material layer being opposite, it is beneficial to make the battery monomer have a higher energy density. By making the four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart each be provided with the chamfer structure, it is beneficial to reduce the risk of piercing the packaging bag during the isostatic pressing process, and to improve the yield of the battery monomer. In addition, by making the four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart each be provided with the chamfer structure, it is also beneficial to reduce the risk of scratching between the pole pieces and the shell, to reduce the risk of damage between the pole pieces and the shell, and to improve the reliability of the battery monomer.

[0042] As an optional technical solution of the embodiment of the present application, the chamfer structure is a round corner, and each of the four corners of each pole piece is provided with the round corner.

[0043] In the above technical solution, when the chamfer structure is a round corner, the transition is smoother and new sharp corners are less likely to be generated. By making each of the four corners of each pole piece be provided with a round corner, it is more beneficial to reduce the risk of the four corners of the plurality of pole pieces piercing the packaging bag during the isostatic pressing process, to improve the yield of the battery monomer. And, by making each of the four corners of each pole piece be provided with a round corner, it is also more beneficial to reduce the risk of scratching between the four corners of the plurality of pole pieces and the shell, to reduce the risk of damage between the plurality of pole pieces and the shell, and to improve the reliability of the battery monomer.

[0044] As an optional technical solution of the embodiment of the present application, the number of pole pieces is odd, and the radius of the round corner of the middle pole piece gradually increases to the radius of the round corner of the pole piece at both ends.

[0045] In the above technical solution, when the number of pole pieces is odd, by making the radius of the round corner of the middle pole piece gradually increase to the radius of the round corner of the pole piece at both ends, the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, thereby further reducing the risk of the plurality of pole pieces piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer.

[0046] As an optional technical solution of the embodiment of the application, the number of the pole pieces is even, the solid electrolyte layer located at the middle position is an intermediate layer along the first direction, and a plurality of the pole pieces are arranged on both sides of the intermediate layer; in the plurality of the pole pieces located on the same side of the intermediate layer, the radius of the fillet of the pole piece closest to the intermediate layer gradually increases to the radius of the fillet of the pole piece farthest from the intermediate layer.

[0047] In the above technical solution, when the number of the pole pieces is even, in the plurality of the pole pieces located on the same side of the intermediate layer, the radius of the fillet of the pole piece closest to the intermediate layer gradually increases to the radius of the fillet of the pole piece farthest from the intermediate layer, so that the two adjacent corners of the electrode assembly along the first direction form a spherical transition, thereby further reducing the risk of the plurality of the pole pieces piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer.

[0048] As an optional technical solution of the embodiment of the application, the chamfer structure is a fillet.

[0049] In the above technical solution, when the chamfer structure is a fillet, the transition is smoother, and new sharp corners are less likely to be generated, which is more conducive to reducing the risk of the four corners of the two pole pieces farthest apart piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer.

[0050] As an optional technical solution of the embodiment of the application, the radius of the fillet is R, and 1mm≤R≤10mm is satisfied.

[0051] In the above technical solution, when R≥1mm, the radius of the fillet is large, the transition is smoother, and the transition effect is better, which is conducive to reducing the risk of the first pole piece piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer. When R≤10mm, the radius of the fillet is not too large, which is conducive to reducing the volume of the electrode assembly and facilitating the improvement of the energy density of the battery monomer. Therefore, when 1mm≤R≤10mm, the yield and the energy density of the battery monomer can be considered.

[0052] As an optional technical solution of the embodiment of the application, 1mm≤R≤5mm.

[0053] In the above technical solution, when R≥1mm, the radius of the fillet is large, the transition is smoother, and the transition effect is better, which is conducive to reducing the risk of the first pole piece piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer. When R≤5mm, the radius of the fillet is not too large, which is more conducive to reducing the volume of the electrode assembly and facilitating the improvement of the energy density of the battery monomer. Therefore, when 1mm≤R≤5mm, the yield and the energy density of the battery monomer can be considered.

[0054] As an optional technical solution of the embodiment of the application, the shell is a soft shell.

[0055] In the above technical solution, when the shell is a soft shell, by arranging the chamfer structure on the four corners of the first pole piece and / or the second pole piece, the risk of the first pole piece and / or the second pole piece piercing the shell is reduced, and the reliability of the battery monomer is improved.

[0056] As an optional technical solution of the embodiment of the application, the soft shell is an aluminum plastic film.

[0057] In the above technical solution, the aluminum plastic film is used to manufacture the shell, which is simple and convenient to manufacture and has low cost.

[0058] In a second aspect, the embodiment of the application also provides an electrode assembly, which comprises a solid-state electrolyte layer and a plurality of pole pieces. In a first direction, the solid-state electrolyte layer is arranged between two adjacent pole pieces. The pole piece comprises an active material layer. In two adjacent pole pieces, the polarity of the active material layer facing the solid-state electrolyte layer between the two adjacent pole pieces is opposite. In the first direction, the four corners of the two farthest pole pieces are each provided with a chamfer structure.

[0059] As an optional technical solution of the embodiment of the application, the plurality of pole pieces comprises a first pole piece and a second pole piece, and the polarity of the first pole piece and the second pole piece is opposite. In the first direction, the first pole piece, the solid-state electrolyte layer and the second pole piece are arranged in layers, and the solid-state electrolyte layer is arranged between the first pole piece and the second pole piece. The first pole piece is a plurality of pole pieces. In the first direction, the two farthest first pole pieces are the pole pieces at the two ends of the electrode assembly, and the four corners of the two farthest first pole pieces are each provided with a chamfer structure.

[0060] In the above technical solution, the electrode assembly comprises a first pole piece, a solid-state electrolyte layer and a second pole piece arranged in layers. In this way, the electrode assembly is simple and convenient to manufacture and has low cost. The two farthest first pole pieces are the pole pieces at the two ends of the electrode assembly. By arranging the chamfer structure on the four corners of the two farthest first pole pieces, the risk of the four corners of the two farthest first pole pieces piercing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer is improved. In addition, by arranging the chamfer structure on the four corners of the two farthest first pole pieces, the risk of the first pole piece scratching the shell is reduced, the risk of the first pole piece damaging the shell is reduced, and the reliability of the battery monomer is improved.

[0061] As an optional technical solution of the embodiment of the application, the chamfer structure is a round corner, and the first pole piece and the second pole piece are both a plurality of, each of the four corners of each first pole piece is provided with the round corner, and each of the four corners of each second pole piece is provided with the round corner.

[0062] In the above technical solution, when the chamfer structure is a round corner, the transition is smoother, and new sharp corners are not easy to be generated. By providing each of the four corners of each first pole piece with a round corner, it is more conducive to reducing the risk of the four corners of the plurality of first pole pieces piercing the packaging bag in the isostatic pressing process, and is conducive to improving the yield of the battery monomer. Moreover, by providing each of the four corners of each first pole piece with a round corner, it is also more conducive to reducing the risk of the four corners of the plurality of first pole pieces scratching the shell, and is more conducive to reducing the risk of damage to the plurality of first pole pieces and the shell, and is conducive to improving the reliability of the battery monomer. Similarly, by providing each of the four corners of each second pole piece with a round corner, it is more conducive to reducing the risk of the four corners of the plurality of second pole pieces piercing the packaging bag in the isostatic pressing process, and is conducive to improving the yield of the battery monomer. Moreover, by providing each of the four corners of each second pole piece with a round corner, it is also more conducive to reducing the risk of the four corners of the plurality of second pole pieces scratching the shell, and is more conducive to reducing the risk of damage to the plurality of second pole pieces and the shell, and is conducive to improving the reliability of the battery monomer.

[0063] As an optional technical solution of the embodiment of the application, the first pole piece is a negative pole piece, the second pole piece is a positive pole piece, the length of the first pole piece is greater than the length of the second pole piece, the width of the first pole piece is greater than the width of the second pole piece, and the thickness direction of the first pole piece is parallel to the first direction.

[0064] In the above technical solution, when the first pole piece is a negative pole piece and the second pole piece is a positive pole piece, by making the length of the first pole piece greater than the length of the second pole piece and the width of the first pole piece greater than the width of the second pole piece, it is conducive to reducing the assembly difficulty and realizing the overhang design, and is conducive to reducing the risk of metal ion precipitation.

[0065] As an optional technical solution of the embodiment of the application, the number of the first pole pieces is odd, the number of the second pole pieces is even, and the radius of the round corner of the middle first pole piece gradually increases to the radius of the round corner of the first pole piece at both ends.

[0066] In the technical solution, in order to realize the overhang design, the first tab exceeds the second tab in the length direction and the width direction, so that the first tab is more likely to pierce the packaging bag than the second tab during the isostatic pressing process. When the number of the first tabs is odd and the number of the second tabs is even, the radius of the fillet of the middle first tab gradually increases to the radius of the fillet of the first tab at both ends, so that the adjacent two corners of the electrode assembly in the first direction form a spherical transition, thereby further reducing the risk of the multiple first tabs piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery cell.

[0067] As an optional technical solution of the embodiment, the number of the first tabs is even, and the number of the second tabs is odd. Along the first direction, the second tab located at the middle position is a second middle tab, and a plurality of the first tabs are arranged on both sides of the second middle tab. Among the plurality of the first tabs located on the same side of the second middle tab, the radius of the fillet of the first tab closest to the second middle tab gradually increases to the radius of the fillet of the first tab farthest from the second middle tab.

[0068] In the technical solution, in order to realize the overhang design, the first tab exceeds the second tab in the length direction and the width direction, so that the first tab is more likely to pierce the packaging bag than the second tab during the isostatic pressing process. When the number of the first tabs is odd and the number of the second tabs is even, the radius of the fillet of the middle first tab gradually increases to the radius of the fillet of the first tab at both ends, so that the adjacent two corners of the electrode assembly in the first direction form a spherical transition, thereby further reducing the risk of the multiple first tabs piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery cell.

[0069] As an optional technical solution of the embodiment, the tab includes a current collector, a first active material layer and a second active material layer, the polarities of the first active material layer and the second active material layer are opposite, and the first active material layer and the second active material layer are arranged on both sides of the current collector. Along the first direction, four corners of at least one of the current collector, the first active material layer and the second active material layer of the two tabs farthest apart are provided with the chamfer structure.

[0070] In the technical scheme, by arranging the pole piece to include the current collector, the first active material layer and the second active material layer, and by arranging the first active material layer and the second active material layer to have opposite polarities, the battery monomer has a higher energy density. By arranging the four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart to be provided with the chamfer structure, the risk of piercing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer is improved. In addition, by arranging the four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart to be provided with the chamfer structure, the risk of scratching the shell by the pole pieces is reduced, the risk of damage to the shell by the pole pieces is reduced, and the reliability of the battery monomer is improved.

[0071] As an optional technical scheme of the embodiment of the application, the chamfer structure is a round corner, and each of the four corners of each pole piece is provided with the round corner.

[0072] In the technical scheme, when the chamfer structure is a round corner, the transition is smoother, and new sharp corners are less likely to be generated. By arranging each of the four corners of each pole piece to be provided with the round corner, the risk of piercing the packaging bag by the four corners of the plurality of pole pieces during the isostatic pressing process is further reduced, and the yield of the battery monomer is improved. In addition, by arranging each of the four corners of each pole piece to be provided with the round corner, the risk of scratching the shell by the four corners of the plurality of pole pieces is further reduced, the risk of damage to the shell by the plurality of pole pieces is further reduced, and the reliability of the battery monomer is improved.

[0073] As an optional technical scheme of the embodiment of the application, the number of pole pieces is odd, and the radius of the round corner of the pole piece in the middle gradually increases to the radius of the round corner of the pole piece at both ends.

[0074] In the technical scheme, when the number of pole pieces is odd, by arranging the radius of the round corner of the pole piece in the middle to gradually increase to the radius of the round corner of the pole piece at both ends, the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, so that the risk of piercing the packaging bag by the plurality of pole pieces during the isostatic pressing process is further reduced, and the yield of the battery monomer is improved.

[0075] As an optional technical scheme of the embodiment of the application, the number of pole pieces is even, and along the first direction, the solid-state electrolyte layer in the middle position is an intermediate layer, and a plurality of pole pieces are arranged on both sides of the intermediate layer; in the plurality of pole pieces on the same side of the intermediate layer, the radius of the round corner of the pole piece closest to the intermediate layer gradually increases to the radius of the round corner of the pole piece farthest from the intermediate layer.

[0076] In the technical solution, when the number of the pole pieces is even, in the plurality of pole pieces on the same side of the middle layer, the radius of the fillet of the pole piece closest to the middle layer gradually increases to the radius of the fillet of the pole piece farthest from the middle layer, so that the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, thereby further reducing the risk of the plurality of first pole pieces piercing the packaging bag during the isostatic pressing process, and facilitating improvement of the yield of the battery monomer.

[0077] In a third aspect, the embodiments of the present application further provide an electrode assembly manufacturing method, which comprises: providing a plurality of pole pieces; providing a solid-state electrolyte layer; stacking the plurality of pole pieces and the solid-state electrolyte layer along a first direction, so that the solid-state electrolyte layer is arranged between adjacent two pole pieces along the first direction, to form an electrode assembly blank, the pole piece comprises an active material layer, the polarity of the active material layer facing the solid-state electrolyte layer between the adjacent two pole pieces is opposite, and four corners of the two pole pieces farthest apart along the first direction are provided with chamfer structures; loading the electrode assembly blank into a packaging bag; and performing isostatic pressing treatment on the electrode assembly blank loaded into the packaging bag.

[0078] As an optional technical solution of the embodiments of the present application, the plurality of pole pieces comprises first pole pieces and second pole pieces, the polarity of the first pole pieces and the second pole pieces is opposite; the providing a plurality of pole pieces comprises: providing the first pole pieces; and providing the second pole pieces; the providing the first pole pieces comprises: providing a plurality of first pole piece blanks; chamfering four corners of at least two first pole piece blanks to form the chamfer structure; in the electrode assembly blank, the first pole pieces, the solid-state electrolyte layer and the second pole pieces are stacked along the first direction, the solid-state electrolyte layer is arranged between the first pole pieces and the second pole pieces along the first direction, and four corners of the two first pole pieces farthest apart along the first direction are provided with chamfer structures.

[0079] In the technical solution, by chamfering the four corners of the first pole piece blank, the four corners of the first pole piece are provided with the chamfer structure.

[0080] As an optional technical solution of the embodiments of the present application, the chamfering four corners of at least two first pole piece blanks comprises: rounding the four corners of each first pole piece blank; and in the electrode assembly blank, the four corners of each first pole piece are provided with the fillet.

[0081] In the above technical solution, the four corners of each first pole piece blank are chamfered, so that the chamfer structure is a round corner. When the chamfer structure is a round corner, the transition is smoother, and new sharp corners are less likely to occur, which is more conducive to reducing the risk of the four corners of the first pole piece piercing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery monomer.

[0082] As an optional technical solution of the embodiment of the present application, in the step of chamfering the four corners of each first pole piece blank, the radii of the round corners of the plurality of first pole piece blanks are different; in the electrode assembly blank, when the number of first pole pieces is odd and the number of second pole pieces is even, the radius of the round corner of the middle first pole piece gradually increases to the radius of the round corner of the first pole piece at both ends; when the number of first pole pieces is even and the number of second pole pieces is odd, along the first direction, the second middle pole piece is located at the middle position, and a plurality of first pole pieces are arranged on both sides of the second middle pole piece, and the radius of the round corner of the first pole piece closest to the second middle pole piece gradually increases to the radius of the round corner of the first pole piece farthest from the second middle pole piece among the plurality of first pole pieces on the same side of the second middle pole piece.

[0083] In the above technical solution, in order to realize the overhang design, the first pole piece will exceed the second pole piece in the length direction and the width direction, so that the first pole piece is more likely to pierce the packaging bag relative to the second pole piece during the isostatic pressing process. When the number of first pole pieces is odd and the number of second pole pieces is even, by gradually increasing the radius of the round corner of the middle first pole piece to the radius of the round corner of the first pole piece at both ends, the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, thereby further reducing the risk of the plurality of first pole pieces piercing the packaging bag during the isostatic pressing process, and being conducive to improving the yield of the battery monomer. When the number of first pole pieces is even and the number of second pole pieces is odd, the radius of the round corner of the first pole piece closest to the second middle pole piece gradually increases to the radius of the round corner of the first pole piece farthest from the second middle pole piece among the plurality of first pole pieces on the same side of the second middle pole piece, so that the adjacent two corner portions of the electrode assembly along the first direction form a spherical transition portion, thereby further reducing the risk of the plurality of first pole pieces piercing the packaging bag during the isostatic pressing process, and being conducive to improving the yield of the battery monomer.

[0084] As an optional technical solution of the embodiment of the present application, the providing the second pole piece comprises: providing a plurality of second pole piece blanks; chamfering the four corners of at least two second pole piece blanks to form the chamfer structure; in the electrode assembly blank, the four corners of the two second pole pieces farthest apart along the first direction are provided with the chamfer structure.

[0085] In the technical solution, the four corners of the second pole piece blank are chamfered, so that the four corners of the second pole piece are provided with chamfered structures. In the first direction, the two second pole pieces farthest apart are closer to the two ends of the electrode assembly. In the isostatic pressing process, the four corners of the two second pole pieces farthest apart are relatively easy to pierce the packaging bag. In the embodiment of the present application, by providing the four corners of the two second pole pieces farthest apart with chamfered structures, the risk of the four corners of the two second pole pieces farthest apart piercing the packaging bag is reduced, and the yield of the battery monomer is improved. In addition, by providing the four corners of the two second pole pieces farthest apart with chamfered structures, the risk of the four corners of the two second pole pieces farthest apart scratching the shell is reduced, the risk of damage to the second pole piece and the shell is reduced, and the reliability of the battery monomer is improved.

[0086] In a fourth aspect, the embodiments of the present application also provide a battery device, which comprises the battery monomer described above.

[0087] In a fifth aspect, the embodiments of the present application also provide a power utilization device, which comprises the battery monomer described above, and the battery monomer is used to provide electric energy for the power utilization device. BRIEF DESCRIPTION OF DRAWINGS

[0088] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. 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.

[0089] Figure 1 The structural schematic diagram of the vehicle is provided for some embodiments of the present application;

[0090] Figure 2 The exploded view of the battery device is provided for some embodiments of the present application;

[0091] Figure 3 The exploded view of the battery monomer is provided for some embodiments of the present application;

[0092] Figure 4 The top view schematic diagram of the electrode assembly is provided for some embodiments of the present application;

[0093] Figure 5 The side view schematic diagram of the electrode assembly is provided for some embodiments of the present application;

[0094] Figure 6 The side view schematic diagram of the electrode assembly is provided for some embodiments of the present application;

[0095] Figure 7 A side view schematic of an electrode assembly according to yet some embodiments of the present application;

[0096] Figure 8 A side view schematic of an electrode assembly according to still some embodiments of the present application;

[0097] Figure 9 A structural schematic of an electrode assembly according to some embodiments of the present application;

[0098] Figure 10 A side view schematic of an electrode assembly according to further some embodiments of the present application;

[0099] Figure 11 A side view schematic of an electrode assembly according to yet some other embodiments of the present application;

[0100] Figure 12 A side view schematic of an electrode assembly according to still some other embodiments of the present application;

[0101] Figure 13 A side view schematic of an electrode assembly according to yet some further embodiments of the present application;

[0102] Figure 14 A schematic block diagram of a method of manufacturing an electrode assembly according to some embodiments of the present application;

[0103] Figure 15 A schematic block diagram of a method of manufacturing an electrode assembly according to some other embodiments of the present application;

[0104] Figure 16 A schematic block diagram of a method of manufacturing an electrode assembly according to yet some embodiments of the present application;

[0105] Figure 17 A schematic block diagram of a method of manufacturing an electrode assembly according to still some embodiments of the present application.

[0106] FIG. 10: A box; 11: A first portion; 12: A second portion; 20: A battery cell; 21: An outer shell; 211: A shell; 212: An end cap; 22: An electrode assembly; 221: A tab; 2211: A first tab; 22111: A first intermediate tab; 2212: A second tab; 22121: A second intermediate tab; 2213: A current collector; 2214: A first active material layer; 2215: A second active material layer; 223: A solid-state electrolyte layer; 2231: An intermediate layer; 224: A tab; 23: A chamfer structure; 231: A rounded corner; 30: A method of manufacturing an electrode assembly; 100: A battery device; 200: A controller; 300: A motor; 1000: A vehicle. DETAILED DESCRIPTION

[0107] 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.

[0108] 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.

[0109] In the present application, the phrase "embodiments" means that the specific features, structures or properties described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiments, nor is it necessarily mutually exclusive or alternative embodiments.

[0110] 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 integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the 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.

[0111] 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.

[0112] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the 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.

[0113] As used herein, the term "plurality" means two or more (including two).

[0114] In embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be used continuously by activating the active material through charging after discharging the battery cell.

[0115] The battery cell generally includes an electrode assembly. The electrode assembly includes a cathode, an anode, and a separator. During charging and discharging of the battery cell, active ions are inserted and extracted between the cathode and the anode. The separator is disposed between the cathode and the anode, and can reduce the risk of short circuiting between the cathode and the anode, while allowing the active ions to pass through.

[0116] In some embodiments, the cathode can be a cathode tab, which can include a cathode current collector and a cathode active material disposed on at least one surface of the cathode current collector.

[0117] As an example, the cathode current collector has two surfaces opposite in the thickness direction thereof, and the cathode active material is disposed on either one or both of the two surfaces of the cathode current collector.

[0118] As an example, the cathode current collector can be a metal foil or a composite current collector. For example, as a metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0119] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material of a battery cell can also be used. These positive electrode active materials can be used alone only one or two or more of them can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04(also referred to as LFP for short)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2(also referred to as NCM 333 for short), LiNi 0.5 Co 0.2 Mn 0.3 O2(also referred to as NCM 523 for short), LiNi 0.5 Co 0.25 Mn 0.25 O2(also referred to as NCM 211 for short), LiNi 0.6 Co 0.2 Mn 0.2 O2(also referred to as NCM 622 for short), LiNi 0.8 Co 0.1 Mn 0.1 O2(also referred to as NCM 811 for short), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), and modified compounds thereof, and the like.

[0120] In some embodiments, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or the like. When the foamed metal is used as the positive electrode, the foamed metal surface can not be provided with a positive electrode active material, or of course can be provided with a positive electrode active material. As an example, the foamed metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0121] In some embodiments, the negative electrode can be a negative electrode tab, and the negative electrode tab can include a negative electrode current collector.

[0122] As an example, the negative current collector has two surfaces opposite in the thickness direction thereof, and the negative active material is provided on either one or both of the two surfaces of the negative current collector.

[0123] As an example, the negative active material can employ a negative active material for a battery cell known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative active material for a battery cell can also be used. These negative active materials can be used alone or in combination of two or more.

[0124] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0125] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0126] The solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0127] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, cellulose, etc.

[0128] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0129] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0130] In some embodiments, the electrode assembly is a stacked structure.

[0131] As an example, a plurality of positive electrode tabs and a plurality of negative electrode tabs can be alternately stacked.

[0132] As an example, the separators can be provided in plurality, each provided between any adjacent positive electrode tab or negative electrode tab.

[0133] In some embodiments, the electrode assembly is provided with tabs, which can conduct current out of the electrode assembly. The tabs include positive electrode tabs and negative electrode tabs.

[0134] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and electrolyte. The housing can be a steel case, an aluminum case, a plastic case (such as polypropylene), a composite metal case (such as a copper-aluminum composite case), or an aluminum-plastic film, etc.

[0135] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0136] In some embodiments, the 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 formed by arranging and fixing a plurality of battery cells into an independent module.

[0137] As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0138] In some embodiments, the battery apparatus can be a battery pack, which can include a box and one or more battery cell assemblies housed in the box.

[0139] As an example, the battery cell assembly can be a battery module, which can be housed in the box by fixing the battery module in the box.

[0140] As an example, the battery cell assembly can also be housed in the box by directly fixing a plurality of battery cells in the box.

[0141] As an example, the box can include a first part and a second part. The first part and the second part are buckled so that a closed space is formed inside the box to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first part can be a top cover or a bottom plate.

[0142] 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 with the frame, so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0143] As an example, the box can be part of a chassis structure of a vehicle. For example, the top cover of the box can become at least part of the floor of the vehicle, or the frame of the box can become at least part of the cross beam and the longitudinal beam of the vehicle.

[0144] In some embodiments, the battery device refers to an energy storage device, and the energy storage device includes a box, at least one side of the box is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0145] At present, from the development of market situation, the application of battery is more and more widely. The battery is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0146] The development of battery technology needs to consider many design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, the yield of the battery also needs to be considered. However, the yield of the battery needs to be further improved at present.

[0147] The solid-state battery has the characteristics of high energy density, and using the solid-state battery in new energy vehicles will significantly improve the endurance of new energy vehicles. In the manufacturing process of the solid-state battery, the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet need to be subjected to isostatic pressing treatment to compact them. During the isostatic pressing treatment, the packaging bag packaging the positive electrode sheet, the solid-state electrolyte layer and the negative electrode sheet arranged in layers is placed in the hydraulic oil, and the hydraulic oil is then pressurized to realize the isostatic pressing treatment. However, during the isostatic pressing process, the packaging bag is easily pierced by the electrode sheet, so that the electrode sheet is damaged under the action of hydraulic pressure, resulting in short circuit and lapping of the electrode assembly. Therefore, the yield of the battery needs to be further improved.

[0148] In view of this, the battery monomer provided by the embodiments of the present application includes a shell and an electrode assembly, and the electrode assembly is arranged in the shell. The electrode assembly includes a solid-state electrolyte layer and a plurality of electrode sheets. In the first direction, the solid-state electrolyte layer is arranged between two adjacent electrode sheets, and the active material layer of the electrode sheet facing the solid-state electrolyte layer between the two adjacent electrode sheets has opposite polarity. In the first direction, the four corners of the two electrode sheets farthest apart are provided with chamfered structures.

[0149] The plurality of pole pieces and the solid electrolyte layer are arranged in a stacked manner along the first direction, that is, the electrode assembly is a stacked electrode assembly. For the stacked electrode assembly, during the isostatic pressing process, the pole pieces located at the two ends of the electrode assembly are most likely to pierce the packaging bag along the first direction. In the embodiments of the present application, the two pole pieces farthest apart are the pole pieces located at the two ends of the electrode assembly. By providing the four corners of the two pole pieces farthest apart with chamfered structures, it is beneficial to reduce the risk of the four corners of the two pole pieces farthest apart piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer. In addition, by providing the four corners of the two pole pieces farthest apart with chamfered structures, it is also beneficial to reduce the risk of scratching between the pole pieces and the shell, reduce the risk of damage between the pole pieces and the shell, and improve the reliability of the battery monomer.

[0150] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery monomers and battery devices, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, the spacecraft includes airplanes, rockets, space shuttles and spaceships, etc.

[0151] The following embodiments are described for convenience with the electric device being a vehicle as an example.

[0152] Please refer to Figure 1 , Figure 1 The structural schematic diagram of the vehicle 1000 provided in some embodiments of the present application is shown. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom, head or tail 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 the operating power supply of the vehicle 1000.

[0153] The vehicle 1000 can also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0154] In some embodiments of the present application, the battery device 100 can not only be used as the operating power supply of the vehicle 1000, but also be used as the driving power supply of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0155] Please refer to Figure 2 , Figure 2 The exploded view of the battery device 100 provided in some embodiments of the present application is shown. The battery device 100 can include a box 10 and a battery monomer 20, and the box 10 is used to accommodate the battery monomer 20.

[0156] The box 10 has an enclosed space inside for accommodating the battery cell 20. The box 10 can have various structures. In some embodiments, the box 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 being coupled to each other. The first part 11 and the second part 12 can have various shapes, such as a cuboid, a cylinder, etc. The first part 11 can be a hollow structure with one side open, and the second part 12 can also be a hollow structure with one side open, the open side of the second part 12 being coupled to the open side of the first part 11 to form the box 10 with the enclosed space. Alternatively, the first part 11 can be a hollow structure with one side open, and the second part 12 can be a plate structure, the second part 12 being coupled to the open side of the first part 11 to form the box 10 with the enclosed space.

[0157] In the battery device 100, the battery cell 20 can be one or multiple. If the battery cell 20 is multiple, the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection, where the mixed connection means that the multiple battery cells 20 are connected in series and in parallel. The multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules can be connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box 10. Alternatively, all the battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and the whole formed by the battery cells 20 is accommodated in the box 10.

[0158] In some embodiments, the battery device 100 can further include a current collecting component, and the multiple battery cells 20 can be electrically connected through the current collecting component to achieve the series connection, the parallel connection, or the mixed connection of the multiple battery cells 20. The current collecting component can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0159] Please refer to Figure 3 , Figure 4 and Figure 5 , Figure 3 the exploded view of the battery cell 20 provided in some embodiments of the present application. Figure 4 the top view of the electrode assembly 22 provided in some embodiments of the present application. Figure 5A side view schematic diagram of an electrode assembly 22 is provided for some embodiments of the present application. Embodiments of the present application provide a battery cell 20, which includes a housing 21 and an electrode assembly 22, the electrode assembly 22 is disposed in the housing 21. The electrode assembly 22 includes a solid-state electrolyte layer 223 and a plurality of electrode sheets 221, along a first direction, the solid-state electrolyte layer 223 is disposed between two adjacent electrode sheets 221, the electrode sheet 221 includes an active material layer, the polarity of the active material layers of the two adjacent electrode sheets 221 facing the solid-state electrolyte layer 223 between the two adjacent electrode sheets 221 is opposite. Along the first direction, the four corners of the two electrode sheets 221 farthest apart are provided with chamfered structures 23.

[0160] The battery cell 20 refers to the smallest unit that constitutes the battery device 100.

[0161] In some embodiments, the housing 21 can include a shell 211 and an end cover 212, the shell 211 has an opening, and the end cover 212 seals the opening of the shell 211. Here, sealing refers to covering or closing, which can be sealed or unsealed.

[0162] The end cover 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 212 can be adapted to the shape of the shell 211 to fit the shell 211. Optionally, the end cover 212 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 212 is not easily deformed when subjected to extrusion and collision, so that the battery cell 20 can have higher structural strength and reliability performance can also be improved. The material of the end cover 212 can include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0163] The shell 211 is a component for fitting the end cover 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, electrolyte and other components. The shell 211 and the end cover 212 can be independent components, an opening can be provided on the shell 211, and the end cover 212 is covered on the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 212 and the shell 211 can also be integrated, specifically, the end cover 212 and the shell 211 can form a common joint surface before other components enter the shell, and when it is necessary to seal the inside of the shell 211, the end cover 212 is covered on the shell 211. The shell 211 can be of various shapes and sizes, such as rectangular, cylindrical, hexagonal, etc. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the shell 211 can include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0164] In the embodiment in which the housing 211 has an opening formed at one end, one end cover 212 can be provided correspondingly. In the embodiment in which the housing 211 has openings formed at opposite two ends, two end covers 212 can be provided correspondingly, and the two end covers 212 respectively close the two openings of the housing 211, and the two end covers 212 and the housing 211 together define a receiving space for accommodating the electrode assembly 22.

[0165] When the electrode assembly 22 includes a solid-state electrolyte layer 223, the electrode assembly 22 is a solid-state electrode assembly. The solid-state electrolyte layer 223 is arranged between the two adjacent electrode sheets 221, and simultaneously plays a role of transmitting ions and isolating the positive and negative electrodes.

[0166] The first direction is the stacking direction of the plurality of electrode sheets 221 and the solid-state electrolyte layer 223. Please refer to Figure 5 , the first direction is the X direction shown in the figure.

[0167] The solid-state electrolyte layer 223 includes a polymer solid-state electrolyte layer, an inorganic solid-state electrolyte layer, and a composite solid-state electrolyte layer.

[0168] As an example, the polymer solid-state electrolyte layer can be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single-ion polymer, polyionic liquid-lithium salt, cellulose, etc.

[0169] As an example, the inorganic solid-state electrolyte layer can include one or more of oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorus sulfur, sulfide silver germanium), amorphous sulfide), halide solid electrolyte, nitride solid electrolyte, and hydride solid electrolyte.

[0170] As an example, the composite solid-state electrolyte layer is formed by adding inorganic solid-state electrolyte fillers to the polymer solid-state electrolyte.

[0171] The "polarity of the active material layer of one of the two adjacent electrode sheets 221 facing the solid-state electrolyte layer 223 between the two adjacent electrode sheets 221 is opposite to that of the other electrode sheet 221" means that the polarity of the active material layer of one of the two adjacent electrode sheets 221 facing the solid-state electrolyte layer 223 between the two adjacent electrode sheets 221 is opposite to that of the other electrode sheet 221, in other words, the active material layer of one of the two adjacent electrode sheets 221 facing the solid-state electrolyte layer 223 between the two adjacent electrode sheets 221 is a positive active material layer, and the active material layer of the other electrode sheet 221 facing the solid-state electrolyte layer 223 between the two adjacent electrode sheets 221 is a negative active material layer.

[0172] In some embodiments, the plurality of pole pieces 221 includes positive pole pieces and negative pole pieces, and the positive pole pieces, the solid-state electrolyte layer 223 and the negative pole pieces are stacked to form the electrode assembly 22. The positive pole pieces and the negative pole pieces have portions with active materials constituting a main body of the electrode assembly 22, and portions without active materials of the positive pole pieces and the negative pole pieces each constituting a tab 224. The positive pole tab and the negative pole tab can be located together at one end of the main body or at two ends of the main body respectively.

[0173] In other embodiments, the pole piece 221 includes a current collector 2213, a positive active material layer and a negative active material layer, and the positive active material layer and the negative active material layer are respectively arranged on both sides of the current collector 2213. The solid-state electrolyte layer 223 and the plurality of pole pieces 221 are stacked to form the electrode assembly 22.

[0174] The electrode assembly 22 can include two pole pieces 221, three pole pieces 221, a first pole piece 2211 or more pole pieces 221.

[0175] Please refer to Figure 5 In the first direction, the two pole pieces 221 farthest apart are the pole pieces 221 located at the two ends of the electrode assembly 22, that is, the two pole pieces 221 farthest apart are the two pole pieces 221 located at the outermost sides of the electrode assembly 22.

[0176] In the first direction, the four corners of the two pole pieces 221 farthest apart are provided with chamfer structures 23, that is, the four corners of the two pole pieces 221 located at the two ends of the electrode assembly 22 are provided with chamfer structures 23, or the four corners of the two pole pieces 221 located at the outermost sides of the electrode assembly 22 are provided with chamfer structures 23, and the chamfer structures 23 can be round corners 231 or bevels.

[0177] The chamfer structures 23 of the four corners of the pole piece 221 can be the same or different, for example, some of the chamfer structures 23 of the four corners of the pole piece 221 are round corners 231, and some of the chamfer structures 23 of the four corners of the pole piece 221 are bevels. Please refer to Figure 4 and Figure 5 In the embodiments shown in the drawings, the chamfer structures 23 of the four corners of the pole piece 221 are the same.

[0178] The plurality of pole pieces 221 and the solid-state electrolyte layer 223 are stacked along the first direction, that is, the electrode assembly 22 is a stacked electrode assembly. For the stacked electrode assembly, during the isostatic pressing process, the pole pieces 221 located at the two ends of the electrode assembly 22 are most likely to pierce the packaging bag along the first direction. In the embodiment of the present application, the two pole pieces 221 farthest apart are the pole pieces 221 located at the two ends of the electrode assembly 22. By providing the four corners of the two pole pieces 221 farthest apart with chamfer structures 23, it is beneficial to reduce the risk of the four corners of the two pole pieces 221 farthest apart piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. In addition, by providing the four corners of the two pole pieces 221 farthest apart with chamfer structures 23, it is also beneficial to reduce the risk of scratching between the pole pieces 221 and the shell 21, reduce the risk of damage between the pole pieces 221 and the shell 21, and improve the reliability of the battery monomer 20.

[0179] Please refer to Figure 3 , Figure 4 and Figure 5 In some embodiments, the plurality of pole pieces 221 includes a first pole piece 2211 and a second pole piece 2212, and the polarities of the first pole piece 2211 and the second pole piece 2212 are opposite. The first pole piece 2211, the solid-state electrolyte layer 223, and the second pole piece 2212 are stacked along the first direction, and the solid-state electrolyte layer 223 is arranged between the first pole piece 2211 and the second pole piece 2212. Among them, the first pole pieces 2211 are multiple, and the two first pole pieces 2211 farthest apart are the pole pieces 221 located at the two ends of the electrode assembly 22 along the first direction. The four corners of the two first pole pieces 221 farthest apart are provided with chamfer structures 23.

[0180] One of the first pole piece 2211 and the second pole piece 2212 is a positive pole piece, and the other of the first pole piece 2211 and the second pole piece 2212 is a negative pole piece. For example, when the first pole piece 2211 is a positive pole piece, the second pole piece 2212 is a negative pole piece. For another example, when the first pole piece 2211 is a positive pole piece, the second pole piece 2212 is a negative pole piece.

[0181] The electrode assembly 22 can include two first pole pieces 2211, three first pole pieces 2211, four first pole pieces 2211, or more first pole pieces 2211.

[0182] Please refer to Figure 5 The two first pole pieces 2211 farthest apart are the pole pieces 221 located at the two ends of the electrode assembly 22 along the first direction, that is, the two first pole pieces 2211 farthest apart are the two pole pieces 221 located at the outermost side of the electrode assembly 22.

[0183] In the first direction, the four corners of the two first pole pieces 2211 farthest apart are each provided with a chamfer structure 23. The chamfer structure 23 can be a round corner 231 or an oblique corner.

[0184] The chamfer structures 23 of the four corners of the first pole pieces 2211 can be the same or different. For example, among the four corners of the first pole pieces 2211, some chamfer structures 23 are round corners 231 and some chamfer structures 23 are oblique corners. Please refer to Figure 4 and Figure 5 In the embodiment shown in the figure, the chamfer structures 23 of the four corners of the first pole pieces 2211 are the same.

[0185] The electrode assembly 22 includes the first pole pieces 2211, the solid-state electrolyte layer 223, and the second pole pieces 2212 stacked together. In this way, the electrode assembly 22 is simple and convenient to manufacture and has a low cost. By providing the chamfer structures 23 on the four corners of the two first pole pieces 2211 farthest apart, it is beneficial to reduce the risk of the four corners of the two first pole pieces 2211 farthest apart puncturing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. In addition, by providing the chamfer structures 23 on the four corners of the two first pole pieces 2211 farthest apart, it is also beneficial to reduce the risk of the first pole pieces 2211 scratching the outer shell 21, reduce the risk of damage to the first pole pieces 2211 and the outer shell 21, and improve the reliability of the battery monomer 20.

[0186] Please refer to Figure 6 , Figure 6 A side view schematic diagram of the electrode assembly 22 provided by some embodiments of the present application. In some embodiments, the four corners of each first pole piece 2211 are provided with a chamfer structure 23.

[0187] “Each first pole piece 2211 has a chamfer structure 23 on the four corners” means that all first pole pieces 2211 have chamfer structures 23 on the four corners.

[0188] The chamfer structures 23 of the four corners of one first pole piece 2211 can be the same as the chamfer structures 23 of the four corners of another first pole piece 2211. For example, the chamfer structures 23 of the four corners of one first pole piece 2211 and the chamfer structures 23 of the four corners of another first pole piece 2211 are all round corners 231 or all oblique corners. The chamfer structures 23 of the four corners of one first pole piece 2211 can also be different from the chamfer structures 23 of the four corners of another first pole piece 2211. For example, the chamfer structures 23 of the four corners of one first pole piece 2211 are round corners 231, and the chamfer structures 23 of the four corners of another first pole piece 2211 are oblique corners. Please refer to Figure 6In the embodiment shown in the figure, the chamfer structure 23 of the four corners of one first tab 2211 is the same as the chamfer structure 23 of the four corners of another first tab 2211.

[0189] By providing the four corners of each first tab 2211 with a chamfer structure 23, on the one hand, it is beneficial to reduce the risk of the four corners of the plurality of first tabs 2211 puncturing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. On the other hand, it is beneficial to reduce the risk of the four corners of the plurality of first tabs 2211 scratching the shell 21, and it is beneficial to reduce the risk of damage to the plurality of first tabs 2211 and the shell 21, and it is beneficial to improve the reliability of the battery monomer 20.

[0190] Please refer to Figure 7 , Figure 7 A side view schematic diagram of the electrode assembly 22 provided for some embodiments of the present application. In some embodiments, the second tab 2212 is a plurality, and the four corners of the two second tabs 2212 farthest apart along the first direction are each provided with a chamfer structure 23.

[0191] The electrode assembly 22 can include two second tabs 2212, three second tabs 2212, four second tabs 2212, or more second tabs 2212.

[0192] Please refer to Figure 7 , the two second tabs 2212 farthest apart along the first direction are relatively close to the two ends of the electrode assembly 22.

[0193] The chamfer structure 23 of the four corners of the second tab 2212 can be the same or different, for example, some of the chamfer structures 23 of the four corners of the second tab 2212 are round corners 231, and some of the chamfer structures 23 are bevels. Please refer to Figure 7 In the embodiment shown in the figure, the chamfer structure 23 of the four corners of the second tab 2212 is the same.

[0194] The two second tabs 2212 farthest apart along the first direction are relatively close to the two ends of the electrode assembly 22, and the four corners of the two second tabs 2212 farthest apart are relatively easy to puncture the packaging bag during the isostatic pressing process. In the embodiments of the present application, by providing the four corners of the two second tabs 2212 farthest apart with a chamfer structure 23, it is beneficial to reduce the risk of the four corners of the two second tabs 2212 farthest apart puncturing the packaging bag, and it is beneficial to improve the yield of the battery monomer 20. In addition, by providing the four corners of the two second tabs 2212 farthest apart with a chamfer structure 23, it is beneficial to reduce the risk of the four corners of the two second tabs 2212 farthest apart scratching the shell 21, and it is beneficial to reduce the risk of damage to the second tab 2212 and the shell 21, and it is beneficial to improve the reliability of the battery monomer 20.

[0195] Please refer to Figure 8 , Figure 8 A side view schematic diagram of the electrode assembly 22 is provided for some embodiments of the present application. In some embodiments, the four corners of each second tab 2212 are provided with a chamfer structure 23.

[0196] The "four corners of each second tab 2212 are provided with a chamfer structure 23" means that the four corners of all second tabs 2212 are provided with a chamfer structure 23.

[0197] The chamfer structure 23 of the four corners of one second tab 2212 can be the same as the chamfer structure 23 of the four corners of another second tab 2212, for example, the chamfer structure 23 of the four corners of one second tab 2212 and the chamfer structure 23 of the four corners of another second tab 2212 are both round corners 231 or both bevels. The chamfer structure 23 of the four corners of one second tab 2212 can also be different from the chamfer structure 23 of the four corners of another second tab 2212, for example, the chamfer structure 23 of the four corners of one second tab 2212 is a round corner 231, and the chamfer structure 23 of the four corners of another second tab 2212 is a bevel. Please refer to Figure 8 In the embodiments shown in the figure, the chamfer structure 23 of the four corners of one second tab 2212 is the same as the chamfer structure 23 of the four corners of another second tab 2212.

[0198] By providing the four corners of each second tab 2212 with a chamfer structure 23, on the one hand, it is beneficial to reduce the risk of the four corners of the plurality of second tabs 2212 piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. On the other hand, it is beneficial to reduce the risk of the four corners of the plurality of second tabs 2212 scratching the shell 21, it is beneficial to reduce the risk of damage to the plurality of second tabs 2212 and the shell 21, and it is beneficial to improve the reliability of the battery monomer 20.

[0199] Please refer to Figure 8 In some embodiments, the chamfer structure 23 is a round corner 231. The first tab 2211 and the second tab 2212 are both a plurality. The four corners of each first tab 2211 are provided with a round corner 231, and the four corners of each second tab 2212 are provided with a round corner 231.

[0200] All the four corners of the first tab 2211 are provided with a round corner 231, and all the four corners of the second tab 2212 are provided with a round corner 231.

[0201] The radius of the round corner 231 of the four corners of one first tab 2211 can be equal, and the radius of the round corner 231 of the four corners of one first tab 2211 can also be unequal. Please refer toFigure 8 In the embodiment shown in the figures, the radii of the rounded corners 231 of the four corners of one first pole piece 2211 can be equal.

[0202] The radii of the rounded corners 231 of the four corners of one second pole piece 2212 can be equal, and the radii of the rounded corners 231 of the four corners of one second pole piece 2212 can also be unequal. Please refer to Figure 8 In the embodiment shown in the figures, the radii of the rounded corners 231 of the four corners of one second pole piece 2212 can be equal.

[0203] The radii of the rounded corners 231 of the four corners of one first pole piece 2211 can be equal to the radii of the rounded corners 231 of the four corners of another first pole piece 2211, and the radii of the rounded corners 231 of the four corners of one first pole piece 2211 can also be unequal to the radii of the rounded corners 231 of the four corners of another first pole piece 2211. Please refer to Figure 8 In the embodiment shown in the figures, the radii of the rounded corners 231 of the four corners of one first pole piece 2211 can be equal to the radii of the rounded corners 231 of the four corners of another first pole piece 2211.

[0204] The radii of the rounded corners 231 of the four corners of one second pole piece 2212 can be equal to the radii of the rounded corners 231 of the four corners of another second pole piece 2212, and the radii of the rounded corners 231 of the four corners of one second pole piece 2212 can also be unequal to the radii of the rounded corners 231 of the four corners of another second pole piece 2212. Please refer to Figure 8 In the embodiment shown in the figures, the radii of the rounded corners 231 of the four corners of one second pole piece 2212 can be equal to the radii of the rounded corners 231 of the four corners of another second pole piece 2212.

[0205] When the chamfer structure 23 is a round corner 231, the transition is smoother, and it is not easy to produce a new sharp corner. By providing the four corners of each first pole piece 2211 with a round corner 231, it is more conducive to reducing the risk of the four corners of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and it is conducive to improving the yield of the battery monomer 20. Moreover, by providing the four corners of each first pole piece 2211 with a round corner 231, it is also more conducive to reducing the risk of the four corners of the plurality of first pole pieces 2211 scratching the shell 21, and it is more conducive to reducing the risk of damage to the plurality of first pole pieces 2211 and the shell 21, and it is conducive to improving the reliability of the battery monomer 20. Similarly, by providing the four corners of each second pole piece 2212 with a round corner 231, it is more conducive to reducing the risk of the four corners of the plurality of second pole pieces 2212 piercing the packaging bag during the isostatic pressing process, and it is conducive to improving the yield of the battery monomer 20. Moreover, by providing the four corners of each second pole piece 2212 with a round corner 231, it is also more conducive to reducing the risk of the four corners of the plurality of second pole pieces 2212 scratching the shell 21, and it is more conducive to reducing the risk of damage to the plurality of second pole pieces 2212 and the shell 21, and it is conducive to improving the reliability of the battery monomer 20.

[0206] Please refer to Figure 8 In some embodiments, the first pole piece 2211 is a negative pole piece, and the second pole piece 2212 is a positive pole piece. The radii of the round corners 231 of the plurality of first pole pieces 2211 are equal, the radii of the round corners 231 of the plurality of second pole pieces 2212 are equal, and the radius of the round corner 231 of the first pole piece 2211 is less than or equal to the radius of the round corner 231 of the second pole piece 2212.

[0207] The radii of the round corners 231 of all the first pole pieces 2211 are equal, the radii of the round corners 231 of all the second pole pieces 2212 are equal, and the radius of the round corner 231 of the first pole piece 2211 is less than or equal to the radius of the round corner 231 of the second pole piece 2212.

[0208] The radii of the round corners 231 of the plurality of first pole pieces 2211 are equal, the radii of the round corners 231 of the plurality of second pole pieces 2212 are equal, which is conducive to simplifying the manufacturing and reducing the manufacturing cost of the battery monomer 20. When the first pole piece 2211 is a negative pole piece, the second pole piece 2212 is a positive pole piece, and the radius of the round corner 231 of the first pole piece 2211 is less than or equal to the radius of the round corner 231 of the second pole piece 2212, it is conducive to making the first pole piece 2211 protrude from the second pole piece 2212, and it is conducive to reducing the risk of metal ion precipitation.

[0209] Please refer to Figure 9 and Figure 10 , Figure 9 The structural schematic diagram of the electrode assembly 22 provided by some embodiments of the present application is shown. Figure 10A side view schematic diagram of an electrode assembly 22 is provided for some embodiments of the present application. In some embodiments, the first electrode tab 2211 is a negative electrode tab, and the second electrode tab 2212 is a positive electrode tab. The length of the first electrode tab 2211 is greater than the length of the second electrode tab 2212, and the width of the first electrode tab 2211 is greater than the width of the second electrode tab 2212. The thickness direction of the first electrode tab 2211 is parallel to the first direction.

[0210] The length of the first electrode tab 2211 is greater than the length of the second electrode tab 2212, and along the length direction of the first electrode tab 2211, both ends of the first electrode tab 2211 exceed the second electrode tab 2212. The width of the first electrode tab 2211 is greater than the width of the second electrode tab 2212, and along the width direction of the first electrode tab 2211, both ends of the first electrode tab 2211 exceed the second electrode tab 2212.

[0211] When the first electrode tab 2211 is a negative electrode tab and the second electrode tab 2212 is a positive electrode tab, by making the length of the first electrode tab 2211 greater than the length of the second electrode tab 2212 and the width of the first electrode tab 2211 greater than the width of the second electrode tab 2212, it is beneficial to reduce the assembly difficulty and realize the overhang design, which is beneficial to reduce the risk of metal ion precipitation.

[0212] Please refer to Figure 9 and Figure 10 In some embodiments, the number of first electrode tabs 2211 is odd, and the number of second electrode tabs 2212 is even. The radius of the fillet 231 of the first electrode tab 2211 in the middle gradually increases to the radius of the fillet 231 of the first electrode tab 2211 at both ends.

[0213] The number of first electrode tabs 2211 is odd, and the number of second electrode tabs 2212 is even. The number of first electrode tabs 2211 is one more than the number of second electrode tabs 2212. For example, when the number of first electrode tabs 2211 is 7, the number of second electrode tabs 2212 can be 6.

[0214] Along the first direction, the radius of the fillet 231 of the first electrode tab 2211 in the middle is the smallest, and the radius of the fillet 231 of the first electrode tab 2211 at both ends is the largest. The radius of the fillet 231 of the first electrode tab 2211 gradually increases from the middle to both ends, in other words, the radius of the fillet 231 of the first electrode tab 2211 close to the middle is smaller than the radius of the fillet 231 of the first electrode tab 2211 away from the middle.

[0215] In order to realize the overhang design, the first pole piece 2211 protrudes out of the second pole piece 2212 in the length direction and the width direction, so that the first pole piece 2211 is more likely to pierce the packaging bag than the second pole piece 2212 during the isostatic pressing process. When the number of the first pole pieces 2211 is odd and the number of the second pole pieces 2212 is even, the radius of the fillet 231 of the middle first pole piece 2211 gradually increases to the radius of the fillet 231 of the first pole piece 2211 at both ends, so that the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0216] Please refer to Figure 9 and Figure 10 In some embodiments, along the first direction, the first pole piece 2211 located in the middle position is a first intermediate pole piece 22111, and a plurality of second pole pieces 2212 are arranged on both sides of the first intermediate pole piece 22111. In the plurality of second pole pieces 2212 located on the same side of the first intermediate pole piece 22111, the radius of the fillet 231 of the second pole piece 2212 closest to the first intermediate pole piece 22111 gradually increases to the radius of the fillet 231 of the second pole piece 2212 farthest from the first intermediate pole piece 22111.

[0217] When the number of the first pole pieces 2211 is odd, the first pole piece 2211 located in the middle position along the first direction is a first intermediate pole piece 22111. Along the first direction, a plurality of second pole pieces 2212 are arranged on both sides of the first intermediate pole piece 22111.

[0218] In the plurality of second pole pieces 2212 located on the same side of the first intermediate pole piece 22111, the farther the second pole piece 2212 is from the first intermediate pole piece 22111, the larger the radius of the fillet 231 of the second pole piece 2212. Along the first direction, the radius of the fillet 231 of the second pole piece 2212 closest to the first intermediate pole piece 22111 is the smallest, and the radius of the fillet 231 of the second pole piece 2212 farthest from the first intermediate pole piece 22111 is the largest.

[0219] By gradually increasing the radius of the fillet 231 of the second pole piece 2212 closest to the first intermediate pole piece 22111 to the radius of the fillet 231 of the second pole piece 2212 farthest from the first intermediate pole piece 22111 in the plurality of second pole pieces 2212 located on the same side of the first intermediate pole piece 22111, the trend of the radius of the fillet 231 of the plurality of first pole pieces 2211 is adapted, the overhang design is realized, and the area of the second pole piece 2212 is larger, which is beneficial to improve the energy density and reliability of the battery monomer 20.

[0220] Please refer toFigure 9 and Figure 10 In some embodiments, the radius of the rounded corner 231 of the second tab 2212 is equal to the radius of the rounded corner 231 of the first tab 2211 adjacent to the second tab 2212 and on the side of the second tab 2212 away from the first intermediate tab 22111.

[0221] The radius of the rounded corner 231 of the second tab 2212 is a first radius, and the radius of the rounded corner 231 of the first tab 2211 adjacent to the second tab 2212 and on the side of the second tab 2212 away from the first intermediate tab 22111 is a second radius, the first radius is equal to the second radius.

[0222] Please refer to Figure 10 In the first direction, the radius of the rounded corner 231 of the first tab 2211 on the outermost side of the electrode assembly 22 is equal to the radius of the rounded corner 231 of the second tab 2212 adjacent thereto. The radius of the rounded corner 231 of the second tab 2212 adjacent to the first intermediate tab 22111 is equal to the radius of the rounded corner 231 of the first tab 2211 adjacent to the first intermediate tab 22111.

[0223] By making the radius of the rounded corner 231 of the second tab 2212 equal to the radius of the rounded corner 231 of the first tab 2211 adjacent to the second tab 2212 and on the side of the second tab 2212 away from the first intermediate tab 22111, it is beneficial to achieve the overhang design while making the area of the second tab 2212 larger, which is beneficial to improve the energy density and reliability of the battery monomer 20.

[0224] Please refer to Figure 9 and Figure 10 In some embodiments, the first tabs 2211 on both sides of the first intermediate tab 22111 are symmetrically arranged about the first intermediate tab 22111. And / or the second tabs 2212 on both sides of the first intermediate tab 22111 are symmetrically arranged about the first intermediate tab 22111.

[0225] In the first direction, a plurality of first tabs 2211 are symmetrically arranged on both sides of the first intermediate tab 22111, and a plurality of second tabs 2212 are symmetrically arranged on both sides of the first intermediate tab 22111.

[0226] It should be noted that "symmetrically" here means approximately symmetrically, not completely symmetrically.

[0227] By symmetrically arranging the first pole pieces 2211 on both sides of the first intermediate pole piece 22111 about the first intermediate pole piece 22111, the radii of the rounded corners 231 of the two symmetrically arranged first pole pieces 2211 are equal, and in the manufacture of the rounded corners 231, the two symmetrically arranged first pole pieces 2211 can be cut together to facilitate the manufacturing process and reduce the manufacturing cost of the battery monomer 20. By symmetrically arranging the second pole pieces 2212 on both sides of the first intermediate pole piece 22111 about the first intermediate pole piece 22111, the radii of the rounded corners 231 of the two symmetrically arranged second pole pieces 2212 are equal, and in the manufacture of the rounded corners 231, the two symmetrically arranged second pole pieces 2212 can be cut together to facilitate the manufacturing process and reduce the manufacturing cost of the battery monomer 20.

[0228] Please refer to Figure 11 , Figure 11 A side view schematic diagram of the electrode assembly 22 provided by some embodiments of the present application is shown. In some embodiments, the number of first pole pieces 2211 is even, and the number of second pole pieces 2212 is odd. Along the first direction, the second pole piece 2212 located in the middle position is the second intermediate pole piece 22121, and a plurality of first pole pieces 2211 are arranged on both sides of the second intermediate pole piece 22121. Among the plurality of first pole pieces 2211 located on the same side of the second intermediate pole piece 22121, the radius of the rounded corner 231 of the first pole piece 2211 closest to the second intermediate pole piece 22121 gradually increases to the radius of the rounded corner 231 of the first pole piece 2211 farthest from the second intermediate pole piece 22121.

[0229] The number of first pole pieces 2211 is even, the number of second pole pieces 2212 is odd, and the number of first pole pieces 2211 is one more than the number of second pole pieces 2212. For example, when the number of first pole pieces 2211 is 6, the number of second pole pieces 2212 can be 5.

[0230] When the number of second pole pieces 2212 is odd, the second pole piece 2212 located in the middle position along the first direction is the second intermediate pole piece 22121. Along the first direction, a plurality of first pole pieces 2211 are arranged on both sides of the second intermediate pole piece 22121.

[0231] Among the plurality of first pole pieces 2211 located on the same side of the second intermediate pole piece 22121, the farther the first pole piece 2211 is from the second intermediate pole piece 22121, the larger the radius of the rounded corner 231 of the first pole piece 2211. Along the first direction, the radius of the rounded corner 231 of the first pole piece 2211 closest to the second intermediate pole piece 22121 is the smallest, and the radius of the rounded corner 231 of the first pole piece 2211 farthest from the second intermediate pole piece 22121 is the largest.

[0232] To realize the overhang design, the first tab 2211 protrudes out of the second tab 2212 in both length and width directions, so the first tab 2211 is more likely to scratch the shell 21 than the second tab 2212. When the number of the first tabs 2211 is even and the number of the second tabs 2212 is odd, among the first tabs 2211 on the same side of the second middle tab 22121, the radius of the fillet 231 of the first tab 2211 closest to the second middle tab 22121 gradually increases to the radius of the fillet 231 of the first tab 2211 farthest from the second middle tab 22121, so that the two adjacent corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the first tabs 2211 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0233] Please refer to Figure 11 In some embodiments, the radius of the fillet 231 of the middle second tab 2212 gradually increases to the radius of the fillet 231 of the second tab 2212 at both ends.

[0234] In the first direction, the radius of the fillet 231 of the middle second tab 2212 is the smallest, that is, the radius of the fillet 231 of the second middle tab 22121 is the smallest among the radii of the fillets 231 of the plurality of second tabs 2212, and the radius of the fillet 231 of the second tab 2212 at both ends is the largest. The radius of the fillet 231 of the second tab 2212 gradually increases from the middle to both ends. In other words, the radius of the fillet 231 of the second tab 2212 close to the second middle tab 22121 is smaller than the radius of the fillet 231 of the second tab 2212 far from the second middle tab 22121.

[0235] By gradually increasing the radius of the fillet 231 of the middle second tab 2212 to the radius of the fillet 231 of the second tab 2212 at both ends, the trend of the radius of the fillet 231 of the plurality of first tabs 2211 is adapted, the overhang design is realized, and the area of the second tab 2212 is large, which is beneficial to improve the energy density and reliability of the battery monomer 20.

[0236] Please refer to Figure 11 In some embodiments, the radius of the fillet 231 of the second tab 2212 is equal to the radius of the fillet 231 of the first tab 2211 adjacent to the second tab 2212 and located on the side of the second tab 2212 away from the second middle tab 22121.

[0237] The radius of the rounded corner 231 of the second tab 2212 is a first radius, and the radius of the rounded corner 231 of the first tab 2211 adjacent to the second tab 2212 and located on a side of the second tab 2212 away from the first intermediate tab 22111 is a second radius, and the first radius is equal to the second radius.

[0238] Please refer to Figure 11 In the first direction, the radius of the rounded corner 231 of the first tab 2211 located at the outermost side of the electrode assembly 22 is equal to the radius of the rounded corner 231 of the second tab 2212 adjacent thereto. The radius of the rounded corner 231 of the first tab 2211 adjacent to the second intermediate tab 22121 is equal to the radius of the rounded corner 231 of the second intermediate tab 22121.

[0239] By equalizing the radius of the rounded corner 231 of the second tab 2212 to the radius of the rounded corner 231 of the first tab 2211 adjacent to the second tab 2212 and located on a side of the second tab 2212 away from the second intermediate tab 22121, it is beneficial to achieve the overhang design while making the area of the second tab 2212 larger, which is beneficial to improve the energy density and reliability of the battery monomer 20.

[0240] Please refer to Figure 11 In some embodiments, the first tabs 2211 located on both sides of the second intermediate tab 22121 are symmetrically arranged about the second intermediate tab 22121. And / or the second tabs 2212 located on both sides of the second intermediate tab 22121 are symmetrically arranged about the second intermediate tab 22121.

[0241] When the number of second tabs 2212 is odd, in the first direction, a plurality of first tabs 2211 are symmetrically arranged on both sides of the second intermediate tab 22121, and a plurality of second tabs 2212 are symmetrically arranged on both sides of the second intermediate tab 22121.

[0242] It should be noted that here "symmetric" means approximately symmetric, not completely symmetric.

[0243] By symmetrically arranging the first pole piece 2211 located on both sides of the first intermediate pole piece 22111 about the second intermediate pole piece 22121, the radii of the rounded corners 231 of the two symmetrically arranged first pole pieces 2211 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged first pole pieces 2211 can be cut together to form the rounded corners 231, which is beneficial to simplify the manufacturing process and reduce the manufacturing cost of the battery monomer 20. By symmetrically arranging the second pole piece 2212 located on both sides of the second intermediate pole piece 22121 about the second intermediate pole piece 22121, the radii of the rounded corners 231 of the two symmetrically arranged second pole pieces 2212 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged second pole pieces 2212 can be cut together to form the rounded corners 231, which is beneficial to simplify the manufacturing process and reduce the manufacturing cost of the battery monomer 20.

[0244] Please refer to Figure 11 In some embodiments, the four corners of the solid-state electrolyte layer 223 are provided with chamfer structures 23.

[0245] The chamfer structures 23 of the four corners of the solid-state electrolyte layer 223 can be the same or different, for example, some of the chamfer structures 23 are rounded corners 231, and some of the chamfer structures 23 are bevels. Please refer to Figure 11 In the embodiments shown in the drawings, the chamfer structures 23 of the four corners of the solid-state electrolyte layer 223 are the same.

[0246] By providing the four corners of the solid-state electrolyte layer 223 with chamfer structures 23, it is beneficial to reduce the risk of the four corners of the solid-state electrolyte layer 223 piercing the packaging bag during the isostatic pressing process, and to improve the yield of the battery monomer 20. In addition, by providing the four corners of the solid-state electrolyte layer 223 with chamfer structures 23, it is beneficial to reduce the risk of scratching between the solid-state electrolyte layer 223 and the shell 21, and to reduce the risk of damage to the solid-state electrolyte layer 223 and the shell 21, thereby improving the reliability of the battery monomer 20.

[0247] Please refer to Figure 11 In some embodiments, the chamfer structure 23 is a rounded corner 231, the solid-state electrolyte layer 223 is connected to the first pole piece 2211, and the radius of the rounded corner 231 of the solid-state electrolyte layer 223 is equal to the radius of the rounded corner 231 of the first pole piece 2211 corresponding thereto.

[0248] The first pole piece 2211 includes a first current collector and a first active material layer 2214, and the first active material layer 2214 is arranged on at least one side of the first current collector in the first direction. The solid-state electrolyte layer 223 can be arranged on the side of the first active material layer 2214 away from the first current collector.

[0249] In some embodiments, the solid-state electrolyte layer 223 is coated on the side of the first active material layer 2214 facing away from the first current collector.

[0250] The radius of the rounded corner 231 of the solid-state electrolyte layer 223 is equal to the radius of the rounded corner 231 of the first pole piece 2211 corresponding thereto. During manufacturing, since the solid-state electrolyte layer 223 is connected to the first pole piece 2211, the solid-state electrolyte layer 223 and the first pole piece 2211 can be chamfered together.

[0251] By connecting the solid-state electrolyte layer 223 to the first pole piece 2211, it is more simple and convenient to stack the first pole piece 2211, the solid-state electrolyte layer 223, and the second pole piece 2212 in the first direction. Moreover, connecting the solid-state electrolyte layer 223 to the first pole piece 2211 enables the solid-state electrolyte layer 223 to stably separate the first pole piece 2211 and the second pole piece 2212 and facilitate ion transmission, which is conducive to reducing the internal resistance of the battery monomer 20. By making the radius of the rounded corner 231 of the solid-state electrolyte layer 223 equal to the radius of the rounded corner 231 of the first pole piece 2211 corresponding thereto, the solid-state electrolyte layer 223 covers the first pole piece 2211 as much as possible, reducing the risk of short circuit caused by the contact between the first pole piece 2211 and the second pole piece 2212, and facilitating the improvement of the reliability of the battery monomer 20.

[0252] Please refer to Figure 12 , Figure 12 A side view schematic diagram of the electrode assembly 22 provided for another embodiment of the present application is shown. In some embodiments, the pole piece 221 includes a current collector 2213, a first active material layer 2214, and a second active material layer 2215, the polarities of the first active material layer 2214 and the second active material layer 2215 are opposite, and the first active material layer 2214 and the second active material layer 2215 are respectively arranged on both sides of the current collector 2213. In the first direction, the four corners of at least one of the current collector 2213, the first active material layer 2214, and the second active material layer 2215 of the two pole pieces 221 farthest apart are each provided with a chamfer structure 23.

[0253] The pole piece 221 is a bipolar pole piece, and the first active material layer 2214 and the second active material layer 2215 are respectively arranged on both sides of the current collector 2213, one of the first active material layer 2214 and the second active material layer 2215 is a positive active material layer, and the other of the first active material layer 2214 and the second active material layer 2215 is a negative active material layer.

[0254] The four corners of at least one of the current collectors 2213, the first active material layers 2214, and the second active material layers 2215 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the current collectors 2213 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the first active material layers 2214 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the second active material layers 2215 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the first active material layers 2214 and the current collectors 2213 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the second active material layers 2215 and the current collectors 2213 of the two most distant pole pieces 221 can be provided with chamfer structures 23. The four corners of the current collectors 2213, the first active material layers 2214, and the second active material layers 2215 of the two most distant pole pieces 221 can be provided with chamfer structures 23.

[0255] By including the current collectors 2213, the first active material layers 2214, and the second active material layers 2215 in the pole pieces 221, and by having opposite polarities of the first active material layers 2214 and the second active material layers 2215, the battery monomer 20 has a higher energy density. By providing the four corners of at least one of the current collectors 2213, the first active material layers 2214, and the second active material layers 2215 of the two most distant pole pieces 221 with chamfer structures 23, the risk of piercing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer 20 is improved. In addition, by providing the four corners of at least one of the current collectors 2213, the first active material layers 2214, and the second active material layers 2215 of the two most distant pole pieces 221 with chamfer structures 23, the risk of scratching the pole pieces 221 against the shell 21 is reduced, the risk of damage to the pole pieces 221 is reduced, and the reliability of the battery monomer 20 is improved.

[0256] Please refer to Figure 12 In some embodiments, the chamfer structures 23 are round corners 231, and each of the four corners of each pole piece 221 is provided with a round corner 231.

[0257] When the chamfer structure 23 is a round corner 231, the transition is smoother, and new sharp corners are less likely to occur. By providing each of the four corners of each pole piece 221 with a round corner 231, the risk of the four corners of the plurality of pole pieces 221 puncturing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer 20 is improved. Furthermore, by providing each of the four corners of each pole piece 221 with a round corner 231, the risk of the four corners of the plurality of pole pieces 221 scratching the shell 21 is reduced, the risk of damage to the plurality of pole pieces 221 and the shell 21 is reduced, and the reliability of the battery monomer 20 is improved.

[0258] Please refer to Figure 12 In some embodiments, the number of pole pieces 221 is odd, and the radius of the round corner 231 of the middle pole piece 221 gradually increases to the radius of the round corner 231 of the pole piece 221 at both ends.

[0259] Along the first direction, the radius of the round corner 231 of the middle pole piece 221 is the smallest, and the radius of the round corner 231 of the pole piece 221 at both ends is the largest. The radius of the round corner 231 of the pole piece 221 gradually increases from the middle to the both ends. In other words, the radius of the round corner 231 of the pole piece 221 close to the middle is smaller than the radius of the round corner 231 of the pole piece 221 away from the middle.

[0260] When the number of pole pieces 221 is odd, by gradually increasing the radius of the round corner 231 of the middle pole piece 221 to the radius of the round corner 231 of the pole piece 221 at both ends, the adjacent two corners of the electrode assembly 22 along the first direction form a spherical transition, thereby further reducing the risk of the plurality of pole pieces 221 puncturing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0261] Please refer to Figure 13 , Figure 13 A side view schematic diagram of the electrode assembly 22 provided by some embodiments of the present application is provided. In some embodiments, the number of pole pieces 221 is even. Along the first direction, the solid-state electrolyte layer 223 at the middle position is the middle layer 2231, and the middle layer 2231 is provided with a plurality of pole pieces 221 on both sides. Among the plurality of pole pieces 221 on the same side of the middle layer 2231, the radius of the round corner 231 of the pole piece 221 closest to the middle layer 2231 gradually increases to the radius of the round corner 231 of the pole piece 221 farthest from the middle layer 2231.

[0262] When the number of pole pieces 221 is even, the solid-state electrolyte layer 223 at the middle position along the first direction is the middle layer 2231. Along the first direction, the middle layer 2231 is provided with a plurality of pole pieces 221 on both sides.

[0263] In the plurality of pole pieces 221 on the same side of the intermediate layer 2231, the farther the pole piece 221 is from the intermediate layer 2231, the greater the radius of the fillet 231 of the pole piece 221. In the first direction, the radius of the fillet 231 of the pole piece 221 closest to the intermediate layer 2231 is the smallest, and the radius of the fillet 231 of the pole piece 221 farthest from the intermediate layer 2231 is the largest.

[0264] When the number of pole pieces 221 is even, in the plurality of pole pieces 221 on the same side of the intermediate layer 2231, the radius of the fillet 231 of the pole piece 221 closest to the intermediate layer 2231 gradually increases to the radius of the fillet 231 of the pole piece 221 farthest from the intermediate layer 2231, so that the two adjacent corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of pole pieces 221 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0265] In some embodiments, the chamfer structure 23 is a fillet 231.

[0266] When the chamfer structure 23 is a fillet 231, the transition is smoother and new sharp corners are less likely to occur, which is more conducive to reducing the risk of the four corners of the two pole pieces 221 farthest apart piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0267] Please refer again to Figure 4 In some embodiments, the radius of the fillet 231 is R, which satisfies: 1mm≤R≤10mm.

[0268] R represents the radius of the fillet 231. The radius of the fillet 231 can be: R=1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0269] When R≥1mm, the radius of the fillet 231 is large, the transition is smooth, the transition effect is good, which is conducive to reducing the risk of the first pole piece 2211 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20. When R≤10mm, the radius of the fillet 231 is not too large, which is conducive to reducing the volume of the electrode assembly 22 and improving the energy density of the battery monomer 20. Therefore, when 1mm≤R≤10mm, the yield and energy density of the battery monomer 20 can be considered.

[0270] Optionally, 1mm≤R≤5mm.

[0271] The radius of the fillet 231 can be: R=1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0272] When R≥1mm, the radius of the rounded corner 231 is large, the transition is smooth, the transition effect is good, which is conducive to reducing the risk of the first electrode tab 2211 piercing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery monomer 20. When R≤5mm, the radius of the rounded corner 231 is not too large, which is more conducive to reducing the volume of the electrode assembly 22, and is more conducive to improving the energy density of the battery monomer 20. Therefore, when 1mm≤R≤5mm, the yield and energy density of the battery monomer 20 can be considered at the same time.

[0273] In some embodiments, the shell 21 is a soft shell.

[0274] The shell 21 is a soft shell, that is, the material for manufacturing the shell 21 is relatively soft. For example, the shell 21 can be an aluminum plastic film, and the shell 21 can also be a heat-shrinkable film.

[0275] When the shell 21 is a soft shell, by providing the chamfer structure 23 on the four corners of the first electrode tab 2211 and / or the second electrode tab 2212, it is conducive to reducing the risk of the first electrode tab 2211 and / or the second electrode tab 2212 piercing the shell 21, and is conducive to improving the reliability of the battery monomer 20.

[0276] In some embodiments, the soft shell is an aluminum plastic film.

[0277] Using an aluminum plastic film to manufacture the shell 21 is simple and convenient, and has low cost.

[0278] Please refer to Figures 4 to 13 The present application also provides an electrode assembly 22, which comprises a solid electrolyte layer 223 and a plurality of electrode tabs 221. In the first direction, the solid electrolyte layer 223 is arranged between two adjacent electrode tabs 221. The electrode tab 221 comprises an active material layer. In the two adjacent electrode tabs 221, the polarity of the active material layer facing the solid electrolyte layer 223 between the two adjacent electrode tabs 221 is opposite. In the first direction, the four corners of the two electrode tabs 221 farthest apart are provided with chamfer structures 23.

[0279] In some embodiments, the plurality of pole pieces 221 includes a first pole piece 2211 and a second pole piece 2212, the first pole piece 2211 and the second pole piece 2212 are opposite in polarity. In the first direction, the first pole piece 2211, the solid-state electrolyte layer 223 and the second pole piece 2212 are stacked, and the solid-state electrolyte layer 223 is arranged between the first pole piece 2211 and the second pole piece 2212. Among them, the first pole piece 2211 is multiple, and the two first pole pieces 2211 farthest apart in the first direction are the pole pieces 221 located at the two ends of the electrode assembly 22, and the four corners of the two first pole pieces 2211 farthest apart are provided with chamfer structures 23. The electrode assembly 22 includes the first pole piece 2211, the solid-state electrolyte layer 223 and the second pole piece 2212 stacked, so that the electrode assembly 22 is simple and convenient to manufacture, and the cost is low. By providing the four corners of the two first pole pieces 2211 farthest apart with chamfer structures 23, it is beneficial to reduce the risk of the four corners of the two first pole pieces 2211 farthest apart piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. In addition, by providing the four corners of the two first pole pieces 2211 farthest apart with chamfer structures 23, it is also beneficial to reduce the risk of the first pole piece 2211 scratching the shell 21, beneficial to reduce the risk of damage to the first pole piece 2211 and the shell 21, and beneficial to improve the reliability of the battery monomer 20.

[0280] In some embodiments, the chamfer structure 23 is a round corner 231. The first pole piece 2211 and the second pole piece 2212 are multiple, each first pole piece 2211 has four corners provided with a round corner 231, and each second pole piece 2212 has four corners provided with a round corner 231. When the chamfer structure 23 is a round corner 231, the transition is smoother and new sharp corners are less likely to occur. By providing each first pole piece 2211 with a round corner 231 at its four corners, it is more beneficial to reduce the risk of the four corners of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. And, by providing each first pole piece 2211 with a round corner 231 at its four corners, it is also more beneficial to reduce the risk of the four corners of the plurality of first pole pieces 2211 scratching the shell 21, more beneficial to reduce the risk of damage to the plurality of first pole pieces 2211 and the shell 21, and beneficial to improve the reliability of the battery monomer 20. Similarly, by providing each second pole piece 2212 with a round corner 231 at its four corners, it is more beneficial to reduce the risk of the four corners of the plurality of second pole pieces 2212 piercing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of the battery monomer 20. And, by providing each second pole piece 2212 with a round corner 231 at its four corners, it is also more beneficial to reduce the risk of the four corners of the plurality of second pole pieces 2212 scratching the shell 21, more beneficial to reduce the risk of damage to the plurality of second pole pieces 2212 and the shell 21, and beneficial to improve the reliability of the battery monomer 20.

[0281] In some embodiments, the first tab 2211 is a negative electrode tab, the second tab 2212 is a positive electrode tab, the length of the first tab 2211 is greater than the length of the second tab 2212, and the width of the first tab 2211 is greater than the width of the second tab 2212. The thickness direction of the first tab 2211 is parallel to the first direction. When the first tab 2211 is a negative electrode tab and the second tab 2212 is a positive electrode tab, by making the length of the first tab 2211 greater than the length of the second tab 2212 and the width of the first tab 2211 greater than the width of the second tab 2212, it is beneficial to reduce the assembly difficulty and achieve overhang design, and it is beneficial to reduce the risk of metal ion precipitation.

[0282] In some embodiments, the number of the first tabs 2211 is odd, the number of the second tabs 2212 is even, and the radius of the fillet 231 of the middle first tab 2211 gradually increases to the radius of the fillet 231 of the first tab 2211 at both ends. In order to achieve overhang design, the first tab 2211 will exceed the second tab 2212 in the length direction and the width direction, so that the first tab 2211 is more likely to pierce the packaging bag relative to the second tab 2212 during isostatic pressing. When the number of the first tabs 2211 is odd and the number of the second tabs 2212 is even, by making the radius of the fillet 231 of the middle first tab 2211 gradually increase to the radius of the fillet 231 of the first tab 2211 at both ends, the adjacent two corners of the electrode assembly 22 along the first direction form a spherical transition, thereby further reducing the risk of multiple first tabs 2211 piercing the packaging bag during isostatic pressing, and it is beneficial to improve the yield of the battery monomer 20.

[0283] In some embodiments, the number of the first pole pieces 2211 is odd, and the number of the second pole pieces 2212 is even. In this case, the second pole piece 2212 located at the middle position in the first direction is a second middle pole piece 22121, and a plurality of first pole pieces 2211 are arranged on both sides of the second middle pole piece 22121. In the plurality of first pole pieces 2211 located on the same side of the second middle pole piece 22121, the radius of the fillet 231 of the first pole piece 2211 closest to the second middle pole piece 22121 gradually increases to the radius of the fillet 231 of the first pole piece 2211 farthest from the second middle pole piece 22121. In order to realize the overhang design, the first pole piece 2211 will protrude out of the second pole piece 2212 in the length direction and the width direction of the first pole piece 2211, so the first pole piece 2211 is more likely to scratch the shell 21 than the second pole piece 2212. When the number of the first pole pieces 2211 is odd and the number of the second pole pieces 2212 is even, the radius of the fillet 231 of the first pole piece 2211 closest to the second middle pole piece 22121 gradually increases to the radius of the fillet 231 of the first pole piece 2211 farthest from the second middle pole piece 22121 in the plurality of first pole pieces 2211 located on the same side of the second middle pole piece 22121, so that the two adjacent corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0284] In some embodiments, the pole piece 221 comprises a current collector 2213, a first active material layer 2214 and a second active material layer 2215, the first active material layer 2214 and the second active material layer 2215 are opposite in polarity, and the first active material layer 2214 and the second active material layer 2215 are arranged on both sides of the current collector 2213. In the first direction, the four corners of at least one of the current collector 2213, the first active material layer 2214 and the second active material layer 2215 of the two pole pieces 221 farthest apart are each provided with a chamfer structure 23. By making the pole piece 221 comprise the current collector 2213, the first active material layer 2214 and the second active material layer 2215, and the first active material layer 2214 and the second active material layer 2215 are opposite in polarity, it is beneficial to make the battery monomer 20 have higher energy density. By making the four corners of at least one of the current collector 2213, the first active material layer 2214 and the second active material layer 2215 of the two pole pieces 221 farthest apart be provided with a chamfer structure 23, it is beneficial to reduce the risk of piercing the packaging bag during the isostatic pressing process, and to improve the yield of the battery monomer 20. In addition, by making the four corners of at least one of the current collector 2213, the first active material layer 2214 and the second active material layer 2215 of the two pole pieces 221 farthest apart be provided with a chamfer structure 23, it is also beneficial to reduce the risk of scratching the pole piece 221 and the shell 21, reduce the risk of damage to the pole piece 221 and the shell 21, and improve the reliability of the battery monomer 20.

[0285] In some embodiments, the chamfer structure 23 is a round corner 231, and each of the four corners of each pole piece 221 is provided with a round corner 231. When the chamfer structure 23 is a round corner 231, the transition is smoother and new sharp corners are less likely to occur. By making each of the four corners of each pole piece 221 provided with a round corner 231, it is more beneficial to reduce the risk of the four corners of the plurality of pole pieces 221 piercing the packaging bag during the isostatic pressing process, and to improve the yield of the battery monomer 20. Furthermore, by making each of the four corners of each pole piece 221 provided with a round corner 231, it is also more beneficial to reduce the risk of the four corners of the plurality of pole pieces 221 scratching the shell 21, more beneficial to reduce the risk of damage to the plurality of pole pieces 221 and the shell 21, and beneficial to improve the reliability of the battery monomer 20.

[0286] In some embodiments, the number of pole pieces 221 is odd, and the radius of the round corner 231 of the middle pole piece 221 gradually increases to the radius of the round corner 231 of the pole piece 221 at both ends. When the number of pole pieces 221 is odd, by making the radius of the round corner 231 of the middle pole piece 221 gradually increase to the radius of the round corner 231 of the pole piece 221 at both ends, the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of pole pieces 221 piercing the packaging bag during the isostatic pressing process, and improving the yield of the battery monomer 20.

[0287] In some embodiments, the number of the plurality of pole pieces 221 is even. Along the first direction, the solid-state electrolyte layer 223 located in the middle position is the middle layer 2231, and a plurality of pole pieces 221 are arranged on both sides of the middle layer 2231. Among the plurality of pole pieces 221 located on the same side of the middle layer 2231, the radius of the fillet 231 of the pole piece 221 closest to the middle layer 2231 gradually increases to the radius of the fillet 231 of the pole piece 221 farthest from the middle layer 2231. When the number of the plurality of pole pieces 221 is even, among the plurality of pole pieces 221 located on the same side of the middle layer 2231, the radius of the fillet 231 of the pole piece 221 closest to the middle layer 2231 gradually increases to the radius of the fillet 231 of the pole piece 221 farthest from the middle layer 2231, so that the adjacent two corners of the electrode assembly 22 along the first direction form a spherical transition, thereby further reducing the risk of the plurality of pole pieces 221 piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer 20.

[0288] Please refer to Figure 14 , Figure 14 A schematic block diagram of the electrode assembly manufacturing method 30 provided by some embodiments of the present application is shown. The embodiments of the present application also provide an electrode assembly manufacturing method 30, which comprises:

[0289] Step S100: providing a plurality of pole pieces 221;

[0290] Step S300: providing a solid-state electrolyte layer 223;

[0291] Step S400: stacking the plurality of pole pieces 221 and the solid-state electrolyte layer 223 along a first direction, so that the solid-state electrolyte layer 223 is arranged between the adjacent two pole pieces 221 along the first direction, to form an electrode assembly blank, the pole piece 221 comprises an active material layer, the polarity of the active material layer facing the solid-state electrolyte layer 223 between the adjacent two pole pieces 221 is opposite, and along the first direction, the four corners of the two pole pieces 221 farthest apart are provided with a chamfer structure 23;

[0292] Step S500: loading the electrode assembly blank into a packaging bag;

[0293] Step S600: performing isostatic pressing treatment on the electrode assembly blank loaded into the packaging bag.

[0294] In step S100, a plurality of pole pieces 221 are provided, and the four corners of at least two pole pieces 221 in the plurality of pole pieces 221 are provided with a chamfer structure 23.

[0295] In step S400, when the plurality of pole pieces 221 and the solid-state electrolyte layer 223 are stacked along the first direction, in addition to the solid-state electrolyte layer 223 being arranged between two adjacent pole pieces 221 along the first direction, the two pole pieces 221 farthest apart are the pole pieces 221 at the two ends of the electrode assembly blank, and the four corners of the two pole pieces 221 farthest apart are each provided with a chamfer structure 23.

[0296] In step S500, the packaging bag has an open end of the accommodating cavity, and the electrode assembly blank can be loaded into the packaging bag from the open end of the packaging bag. The packaging bag can be an aluminum plastic film, a heat-shrinkable film, etc.

[0297] The isostatic pressing working principle is Pascal's law: "The pressure of a medium (liquid or gas) in a closed container can be transmitted equally in all directions". Through isostatic pressing, the densification of the electrode assembly 22 is facilitated, and the reliability and energy density of the battery cell 20 are improved.

[0298] In step S600, the packaging bag containing the electrode assembly blank can be placed in the hydraulic oil, and the hydraulic oil can be pressurized to achieve isostatic pressing.

[0299] Please refer to Figure 15 , Figure 15 A schematic block diagram of an electrode assembly manufacturing method 30 provided for other embodiments of the present application. In some embodiments, the plurality of pole pieces 221 includes a first pole piece 2211 and a second pole piece 2212, and the polarities of the first pole piece 2211 and the second pole piece 2212 are opposite. The plurality of pole pieces 221 is provided by:

[0300] The first pole piece 2211 is provided.

[0301] Step S200: providing a second pole piece 2212.

[0302] The first pole piece 2211 is provided by:

[0303] Step S110: providing a plurality of first pole piece blanks;

[0304] Step S120: chamfering the four corners of at least two first pole piece blanks to form a chamfer structure 23.

[0305] In the electrode assembly blank, along the first direction, the first pole piece 2211, the solid-state electrolyte layer 223, and the second pole piece 2212 are stacked, and the solid-state electrolyte layer 223 is arranged between the first pole piece 2211 and the second pole piece 2212. Along the first direction, the two first pole pieces 2211 farthest apart are the pole pieces 221 at the two ends of the electrode assembly 22, and the four corners of the two first pole pieces 2211 farthest apart are each provided with a chamfer structure 23.

[0306] The first tab blank is a tab structure after the first current collector is coated with the first active material layer 2214 and the slitting and die cutting are completed. For the first tab 2211 with the chamfer structure 23 at the four corners, the four corners of the first tab blank are chamfered to obtain the first tab 2211. For the first tab 2211 without the chamfer structure 23 at the four corners, the first tab blank is the first tab 2211.

[0307] By chamfering the four corners of the first tab blank, the four corners of the first tab 2211 are provided with the chamfer structure 23.

[0308] Please refer to Figure 16 , Figure 16 A schematic block diagram of the electrode assembly manufacturing method 30 provided for some embodiments of the present application. In some embodiments, chamfering the four corners of the at least two first tab blanks comprises:

[0309] Step S121: chamfering the four corners of each first tab blank;

[0310] In the electrode assembly blank, the four corners of each first tab 2211 are provided with the fillet 231.

[0311] By chamfering the four corners of each first tab blank, the four corners of each first tab 2211 are provided with the fillet 231. When the chamfer structure 23 is the fillet 231, the transition is smoother, and new sharp corners are less likely to occur, which is more conducive to reducing the risk of the four corners of the first tab 2211 piercing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery monomer 20.

[0312] In some embodiments, in the step of chamfering the four corners of each first tab blank, the radii of the fillets 231 of the plurality of first tab blanks are different. In the electrode assembly blank, when the number of first tabs 2211 is odd and the number of second tabs 2212 is even, the radius of the fillet 231 of the first tab 2211 in the middle gradually increases to the radius of the fillet 231 of the first tab 2211 at both ends. When the number of first tabs 2211 is even and the number of second tabs 2212 is odd, along the first direction, the second tab 2212 located in the middle position is a second middle tab 22121, and a plurality of first tabs 2211 are arranged on both sides of the second middle tab 22121. Among the plurality of first tabs 2211 on the same side of the second middle tab 22121, the radius of the fillet 231 of the first tab 2211 closest to the second middle tab 22121 gradually increases to the radius of the fillet 231 of the first tab 2211 farthest from the second middle tab 22121.

[0313] To realize the overhang design, the first tab 2211 protrudes out of the second tab 2212 in both the length direction and the width direction, so that the first tab 2211 is more likely to pierce the pouch during the isostatic pressing process. When the number of the first tabs 2211 is odd and the number of the second tabs 2212 is even, the radius of the fillet 231 of the middle first tab 2211 gradually increases to the radius of the fillet 231 of the first tab 2211 at both ends, so that the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the multiple first tabs 2211 piercing the pouch during the isostatic pressing process, and improving the yield of the battery cell 20. When the number of the first tabs 2211 is even and the number of the second tabs 2212 is odd, the radius of the fillet 231 of the first tab 2211 closest to the second middle tab 22121 gradually increases to the radius of the fillet 231 of the first tab 2211 farthest from the second middle tab 22121 among the multiple first tabs 2211 on the same side of the second middle tab 22121, so that the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the multiple first tabs 2211 piercing the pouch during the isostatic pressing process, and improving the yield of the battery cell 20.

[0314] Please refer to Figure 17 , Figure 17 A schematic block diagram of the electrode assembly manufacturing method 30 provided for some embodiments of the present application is shown. In some embodiments, the providing the second tab 2212 comprises:

[0315] Step S210: providing a plurality of second tab blanks;

[0316] Step S220: chamfering the four corners of at least two second tab blanks to form a chamfer structure 23;

[0317] In the electrode assembly blank, the four corners of the two second tabs 2212 farthest apart are provided with the chamfer structure 23 in the first direction.

[0318] The second tab 2212 comprises a second current collector and a second active material layer 2215, and the second active material layer 2215 is arranged on at least one side of the second current collector in the first direction.

[0319] The second tab blank is a tab structure after the second active material layer 2215 is coated on the second current collector, and the slitting and die cutting are completed. For the second tab 2212 with the chamfer structure 23 at the four corners, the four corners of the second tab blank are chamfered to obtain the second tab 2212. For the second tab 2212 without the chamfer structure 23 at the four corners, the second tab blank is the second tab 2212.

[0320] By chamfering the four corners of the second tab blank, the four corners of the second tab 2212 are provided with the chamfer structure 23. In the first direction, the two second tabs 2212 farthest apart are closer to the two ends of the electrode assembly 22, and in the isostatic pressing process, the four corners of the two second tabs 2212 farthest apart are relatively easy to pierce the packaging bag. In the embodiment of the present application, by providing the four corners of the two second tabs 2212 farthest apart with the chamfer structure 23, the risk of the four corners of the two second tabs 2212 farthest apart piercing the packaging bag is reduced, and the yield of the battery monomer 20 is improved. In addition, by providing the four corners of the two second tabs 2212 farthest apart with the chamfer structure 23, the risk of the four corners of the two second tabs 2212 farthest apart scratching the shell 21 is reduced, the risk of damage to the second tab 2212 and the shell 21 is reduced, and the reliability of the battery monomer 20 is improved.

[0321] The embodiment of the present application also provides a battery device 100, which comprises the battery monomer 20 described above.

[0322] The embodiment of the present application also provides a battery device 100, which comprises the battery monomer 20 described above.

[0323] According to some embodiments of the present application, please refer to Figures 3 to 13 .

[0324] The embodiment of the application provides a battery monomer 20, the battery monomer 20 includes a shell 21 and an electrode assembly 22, and the electrode assembly 22 is arranged in the shell 21. The electrode assembly 22 includes a first pole piece 2211, a second pole piece 2212 and a solid electrolyte layer 223, the polarities of the first pole piece 2211 and the second pole piece 2212 are opposite, the first pole piece 2211, the solid electrolyte layer 223 and the second pole piece 2212 are stacked along a first direction, and along the first direction, the solid electrolyte layer 223 is at least partially arranged between the first pole piece 2211 and the second pole piece 2212. Wherein the first pole piece 2211 is multiple, along the first direction, the two first pole pieces 2211 farthest apart are pole pieces 221 located at both ends of the electrode assembly 22, and the four corners of the two first pole pieces 2211 farthest apart are each provided with a chamfer structure 23. The first pole piece 2211, the solid electrolyte layer 223 and the second pole piece 2212 are stacked along the first direction, that is, the electrode assembly 22 is a laminated electrode assembly. For the laminated electrode assembly, during the isostatic pressing process, along the first direction, the pole pieces 221 located at both ends of the electrode assembly 22 are most likely to pierce the packaging bag, in the embodiment of the application, the two first pole pieces 2211 farthest apart are pole pieces 221 located at both ends of the electrode assembly 22, by making the four corners of the two first pole pieces 2211 farthest apart be provided with the chamfer structure 23, the risk of the four corners of the two first pole pieces 2211 farthest apart piercing the packaging bag during the isostatic pressing process is reduced, and the yield of the battery monomer 20 is improved. In addition, by making the four corners of the two first pole pieces 2211 farthest apart be provided with the chamfer structure 23, the risk of the first pole piece 2211 scratching the shell 21 is reduced, the risk of the first pole piece 2211 damaging the shell 21 is reduced, and the reliability of the battery monomer 20 is improved.

[0325] The chamfer structure 23 is a round corner 231. The first pole piece 2211 and the second pole piece 2212 are both multiple, each of the four corners of the first pole piece 2211 is provided with a round corner 231, and each of the four corners of the second pole piece 2212 is provided with a round corner 231. When the chamfer structure 23 is a round corner 231, the transition is smoother, and it is not easy to produce a new sharp corner, which is more conducive to reducing the risk of the four corners of the two first pole pieces 2211 farthest apart in the isostatic pressing process piercing the packaging bag, and is conducive to improving the yield of the battery monomer 20. By providing each of the four corners of the first pole piece 2211 with a round corner 231, it is more conducive to reducing the risk of the four corners of the multiple first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery monomer 20. And, by providing each of the four corners of the first pole piece 2211 with a round corner 231, it is also more conducive to reducing the risk of the four corners of the multiple first pole pieces 2211 scratching the shell 21, more conducive to reducing the risk of damage to the multiple first pole pieces 2211 and the shell 21, and conducive to improving the reliability of the battery monomer 20. Similarly, by providing each of the four corners of the second pole piece 2212 with a round corner 231, it is more conducive to reducing the risk of the four corners of the multiple second pole pieces 2212 piercing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery monomer 20. And, by providing each of the four corners of the second pole piece 2212 with a round corner 231, it is also more conducive to reducing the risk of the four corners of the multiple second pole pieces 2212 scratching the shell 21, more conducive to reducing the risk of damage to the multiple second pole pieces 2212 and the shell 21, and conducive to improving the reliability of the battery monomer 20.

[0326] The first pole piece 2211 is a negative pole piece, the second pole piece 2212 is a positive pole piece, the length of the first pole piece 2211 is greater than the length of the second pole piece 2212, the width of the first pole piece 2211 is greater than the width of the second pole piece 2212, and the thickness direction of the first pole piece 2211 is parallel to the first direction. When the first pole piece 2211 is a negative pole piece and the second pole piece 2212 is a positive pole piece, by making the length of the first pole piece 2211 greater than the length of the second pole piece 2212 and the width of the first pole piece 2211 greater than the width of the second pole piece 2212, it is conducive to reducing the assembly difficulty and realizing the overhang design, and is conducive to reducing the risk of metal ion precipitation.

[0327] In some embodiments, the number of the first pole pieces 2211 is odd, the number of the second pole pieces 2212 is even, and the radius of the fillet 231 of the first pole piece 2211 in the middle gradually increases to the radius of the fillet 231 of the first pole piece 2211 at both ends. When the number of the first pole pieces 2211 is odd and the number of the second pole pieces 2212 is even, by gradually increasing the radius of the fillet 231 of the first pole piece 2211 in the middle to the radius of the fillet 231 of the first pole piece 2211 at both ends, the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer 20.

[0328] In other embodiments, the number of the first pole pieces 2211 is even, the number of the second pole pieces 2212 is odd, and along the first direction, the second pole piece 2212 located in the middle position is a second middle pole piece 22121, and a plurality of first pole pieces 2211 are arranged on both sides of the second middle pole piece 22121; among the plurality of first pole pieces 2211 located on the same side of the second middle pole piece 22121, the radius of the fillet 231 of the first pole piece 2211 closest to the second middle pole piece 22121 gradually increases to the radius of the fillet 231 of the first pole piece 2211 farthest from the second middle pole piece 22121. When the number of the first pole pieces 2211 is even and the number of the second pole pieces 2212 is odd, among the plurality of first pole pieces 2211 located on the same side of the second middle pole piece 22121, the radius of the fillet 231 of the first pole piece 2211 closest to the second middle pole piece 22121 gradually increases to the radius of the fillet 231 of the first pole piece 2211 farthest from the second middle pole piece 22121, so that the adjacent two corners of the electrode assembly 22 in the first direction form a spherical transition, thereby further reducing the risk of the plurality of first pole pieces 2211 piercing the packaging bag during the isostatic pressing process, and facilitating the improvement of the yield of the battery monomer 20.

[0329] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized by, The application relates to a battery, comprising: a shell; an electrode assembly arranged in the shell, the electrode assembly comprising a solid electrolyte layer and a plurality of electrode sheets, the solid electrolyte layer being arranged between two adjacent electrode sheets in a first direction, the electrode sheets comprising active material layers, the polarities of the active material layers of two adjacent electrode sheets facing the solid electrolyte layer between the two adjacent electrode sheets being opposite; four corners of two electrode sheets farthest apart in the first direction are each provided with a chamfer structure.

2. The battery cell of claim 1, wherein, The plurality of electrode sheets comprises a first electrode sheet and a second electrode sheet, the polarities of the first electrode sheet and the second electrode sheet being opposite, the first electrode sheet, the solid electrolyte layer and the second electrode sheet being arranged in layers in the first direction, the solid electrolyte layer being arranged between the first electrode sheet and the second electrode sheet; wherein the first electrode sheet is a plurality, two first electrode sheets farthest apart in the first direction are electrode sheets at two ends of the electrode assembly, and four corners of the two first electrode sheets farthest apart are each provided with a chamfer structure.

3. The battery cell of claim 2, wherein, Four corners of each first electrode sheet are each provided with the chamfer structure.

4. The battery cell of claim 2, wherein, The second electrode sheet is a plurality, four corners of two second electrode sheets farthest apart in the first direction are each provided with the chamfer structure.

5. The battery cell of claim 4, wherein, Four corners of each second electrode sheet are each provided with the chamfer structure.

6. The battery cell of claim 2, wherein, The chamfer structure is a round corner, the first electrode sheet and the second electrode sheet are a plurality, four corners of each first electrode sheet are each provided with the round corner, and four corners of each second electrode sheet are each provided with the round corner.

7. The battery cell of claim 6, wherein, The first electrode sheet is a negative electrode sheet, the second electrode sheet is a positive electrode sheet, the radii of the round corners of the plurality of first electrode sheets are equal, the radii of the round corners of the plurality of second electrode sheets are equal, and the radius of the round corner of the first electrode sheet is less than or equal to the radius of the round corner of the second electrode sheet.

8. The battery cell of claim 6, wherein, The first electrode sheet is a negative electrode sheet, the second electrode sheet is a positive electrode sheet, the length of the first electrode sheet is greater than the length of the second electrode sheet, the width of the first electrode sheet is greater than the width of the second electrode sheet, and the thickness direction of the first electrode sheet is parallel to the first direction.

9. The battery cell of claim 8, wherein, The number of the first electrode sheets is odd, and the number of the second electrode sheets is even, the radius of the round corner of the first electrode sheet gradually increases from the first electrode sheet at the middle to the first electrode sheet at the two ends.

10. The battery cell of claim 9, wherein, In the first direction, the first electrode sheet at the middle is a first middle electrode sheet, and a plurality of second electrode sheets are arranged on both sides of the first middle electrode sheet; In the plurality of second electrode sheets on the same side of the first middle electrode sheet, the radius of the round corner of the second electrode sheet closest to the first middle electrode sheet gradually increases to the radius of the round corner of the second electrode sheet farthest from the first middle electrode sheet.

11. The battery cell of claim 10, wherein, The radius of the round corner of the second electrode sheet is equal to the radius of the round corner of the first electrode sheet adjacent to the second electrode sheet and located on the side of the second electrode sheet farthest from the first middle electrode sheet.

12. The battery cell of claim 10, wherein, The first electrode sheets on both sides of the first middle electrode sheet are symmetrically arranged about the first middle electrode sheet; and / or The second pole pieces located on both sides of the second intermediate pole piece are symmetrically arranged about the second intermediate pole piece.

13. The battery cell of claim 8, wherein the cathode comprises a lithium metal oxide. The number of the first pole pieces is even, the number of the second pole pieces is odd, along the first direction, the second pole piece located at the middle position is a second intermediate pole piece, and the second intermediate pole piece is provided with a plurality of first pole pieces on both sides thereof. Among the plurality of first pole pieces located on the same side of the second intermediate pole piece, the radius of the fillet of the first pole piece closest to the second intermediate pole piece gradually increases to the radius of the fillet of the first pole piece farthest from the second intermediate pole piece.

14. The battery cell of claim 13, wherein, The radius of the fillet of the second pole piece located at the middle gradually increases to the radius of the fillet of the second pole piece located at the two ends.

15. The battery cell of claim 14, wherein the cathode comprises a lithium metal oxide. The radius of the fillet of the second pole piece is equal to the radius of the fillet of the first pole piece adjacent to the second pole piece and located on the side of the second pole piece away from the second intermediate pole piece.

16. The battery cell according to claim 13, characterized in that, The first pole pieces located on both sides of the second intermediate pole piece are symmetrically arranged about the second intermediate pole piece; and / or The second pole pieces located on both sides of the second intermediate pole piece are symmetrically arranged about the second intermediate pole piece.

17. The battery cell of claim 6, wherein, The solid-state electrolyte layer is provided with a chamfer structure at four corners thereof.

18. The battery cell of claim 17, wherein, The solid-state electrolyte layer is connected to the first pole piece, and the radius of the fillet of the solid-state electrolyte layer is equal to the radius of the fillet of the first pole piece corresponding thereto.

19. The battery cell of claim 1, wherein, The pole piece comprises a current collector, a first active material layer and a second active material layer, the polarities of the first active material layer and the second active material layer are opposite, and the first active material layer and the second active material layer are respectively arranged on both sides of the current collector. Along the first direction, four corners of at least one of the current collector, the first active material layer and the second active material layer of the two pole pieces farthest apart are provided with the chamfer structure.

20. The battery cell of claim 19, wherein, The chamfer structure is a fillet, and each pole piece is provided with the fillet at four corners thereof.

21. The battery cell of claim 20, wherein, The number of the pole pieces is odd, and the radius of the fillet of the pole piece located at the middle gradually increases to the radius of the fillet of the pole piece located at the two ends.

22. The battery cell of claim 20, wherein the cathode comprises a lithium metal oxide. The number of the pole pieces is even, along the first direction, the solid-state electrolyte layer located at the middle position is an intermediate layer, and the intermediate layer is provided with a plurality of pole pieces on both sides thereof. Among the plurality of pole pieces located on the same side of the intermediate layer, the radius of the fillet of the pole piece closest to the intermediate layer gradually increases to the radius of the fillet of the pole piece farthest from the intermediate layer.

23. The battery cell of any one of claims 1-5, 19, wherein, The chamfer structure is a fillet.

24. The battery cell of claim 23, wherein the cathode comprises a lithium metal oxide. The radius of the fillet is R, and 1mm≤R≤10mm is satisfied.

25. The battery cell according to claim 24, characterized in that, 1mm≤R≤5mm.

26. The battery cell of any one of claims 1-22, wherein, The shell is a soft shell.

27. The battery cell of claim 26, wherein the cathode comprises a lithium metal oxide. The soft shell is an aluminum plastic film.

28. An electrode assembly, characterized by The solid-state electrolyte layer and a plurality of pole pieces are provided, along a first direction, the solid-state electrolyte layer is arranged between adjacent two pole pieces, the pole piece comprises an active material layer, among the adjacent two pole pieces, the polarities of the active material layers facing the solid-state electrolyte layer between the adjacent two pole pieces are opposite; Along the first direction, four corners of the two pole pieces farthest apart are provided with a chamfer structure.

29. The electrode assembly of claim 28, wherein, The plurality of pole pieces includes a first pole piece and a second pole piece, polarities of the first pole piece and the second pole piece are opposite, the first pole piece, the solid-state electrolyte layer and the second pole piece are stacked along the first direction, and the solid-state electrolyte layer is arranged between the first pole piece and the second pole piece. The first pole piece is a plurality, and the two farthest apart first pole pieces are the pole pieces at the two ends of the electrode assembly along the first direction.

30. The electrode assembly of claim 29, wherein, The chamfer structure is a round corner, and the first pole piece and the second pole piece are both a plurality, each of the four corners of each of the first pole pieces is provided with the round corner, and each of the four corners of each of the second pole pieces is provided with the round corner.

31. The electrode assembly of claim 30, wherein, The first pole piece is a negative pole piece, the second pole piece is a positive pole piece, the length of the first pole piece is greater than the length of the second pole piece, the width of the first pole piece is greater than the width of the second pole piece, and the thickness direction of the first pole piece is parallel to the first direction.

32. The electrode assembly of claim 31, wherein, The number of the first pole pieces is odd, the number of the second pole pieces is even, and the radius of the round corner of the first pole piece gradually increases from the middle to the two ends.

33. The electrode assembly of claim 31, wherein the conductive material is a conductive adhesive. The number of the first pole pieces is even, the number of the second pole pieces is odd, and the second middle pole piece is located at a middle position along the first direction. Among the plurality of first pole pieces on the same side of the second middle pole piece, the radius of the round corner of the first pole piece closest to the second middle pole piece gradually increases to the radius of the round corner of the first pole piece farthest from the second middle pole piece.

34. The electrode assembly of claim 28, wherein, The pole piece includes a current collector, a first active material layer and a second active material layer, polarities of the first active material layer and the second active material layer are opposite, and the first active material layer and the second active material layer are arranged on both sides of the current collector respectively. Along the first direction, the four corners of at least one of the current collector, the first active material layer and the second active material layer of the two farthest apart pole pieces are provided with the chamfer structure.

35. The electrode assembly of claim 34, wherein, The chamfer structure is a round corner, and the four corners of each of the pole pieces are provided with the round corner.

36. The electrode assembly of claim 35, wherein, The number of the pole pieces is odd, and the radius of the round corner of the pole piece gradually increases from the middle to the two ends.

37. The electrode assembly of claim 35, wherein, The number of the pole pieces is even, and the middle layer is located at a middle position along the first direction. Among the plurality of pole pieces on the same side of the middle layer, the radius of the round corner of the pole piece closest to the middle layer gradually increases to the radius of the round corner of the pole piece farthest from the middle layer.

38. A battery device, characterized by The battery cell according to any one of claims 1-27.

39. An electrical device, comprising: The battery cell according to any one of claims 1-27 is used to provide electric energy for the electric device.

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