Battery cell, electrode assembly and manufacturing method therefor, battery device and electric device

Abstract

Provided in the present application are a battery cell, an electrode assembly and a manufacturing method therefor, a battery device and an electric device. The battery cell comprises a casing and an electrode assembly, wherein the electrode assembly is arranged in the casing. The electrode assembly comprises a solid-state electrolyte layer and a plurality of electrode sheets. In a first direction, the solid-state electrolyte layer is arranged between two adjacent electrode sheets. Each electrode sheet comprises an active material layer, and among two adjacent electrode sheets, the polarities of the active material layers facing the solid-state electrolyte layer located between the two adjacent electrode sheets are opposite. In the first direction, the four corners of the two electrode sheets that are farthest apart from each other are each provided with a chamfered structure. The four corners of the two electrode sheets that are farthest apart from each other being each provided with a chamfered structure helps reduce the risk of said corners puncturing a packaging pouch during isostatic pressing, facilitating improvement to the yield of the battery cell.

Description

Battery cells, electrode assemblies and their manufacturing methods, battery devices and electrical devices Cross-references to related applications

[0001] This application claims priority to Chinese patent application filed on December 31, 2024, entitled “Battery cell, electrode assembly and method of manufacturing thereof, battery device and power device” (application number: 2024119972827), the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of batteries, and more specifically, to a battery cell, electrode assembly and manufacturing method thereof, battery device and power-consuming device. Background Technology

[0003] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as energy density, cycle life, discharge capacity, and charge / discharge rate. Additionally, battery yield rate also needs to be considered. However, the current battery yield rate needs further improvement. Summary of the Invention

[0004] This application provides a battery cell, electrode assembly and manufacturing method thereof, battery device and power device, which can improve the yield rate of batteries.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a casing and an electrode assembly, the electrode assembly being disposed within the casing, the electrode assembly including a solid electrolyte layer and a plurality of electrode plates, the solid electrolyte layer being disposed between two adjacent electrode plates along a first direction, the electrode plate including an active material layer, the polarity of the active material layer facing the solid electrolyte layer located between the two adjacent electrode plates being opposite; along the first direction, the four corners of the two electrode plates furthest apart are provided with a chamfer structure.

[0006] In the above technical solution, multiple electrode sheets and solid electrolyte layers are stacked along a first direction, that is, the electrode assembly is a stacked electrode assembly. For stacked electrode assemblies, during isostatic pressing, the electrode sheets located at both ends of the electrode assembly are most likely to puncture the packaging bag along the first direction. In this embodiment, the two electrode sheets furthest apart are located at both ends of the electrode assembly. By providing chamfered structures at the four corners of the two furthest electrode sheets, the risk of the four corners of the two furthest electrode sheets puncturing the packaging bag during isostatic pressing is reduced, which helps to improve the yield of the battery cell. In addition, by providing chamfered structures at the four corners of the two furthest electrode sheets, the risk of the electrode sheets rubbing against the casing is also reduced, which helps to reduce the risk of damage to the electrode sheets and the casing, and helps to improve the reliability of the battery cell.

[0007] As an optional technical solution in this application embodiment, the plurality of electrode sheets include a first electrode sheet and a second electrode sheet, the first electrode sheet and the second electrode sheet having opposite polarities, and the first electrode sheet, the solid electrolyte layer and the second electrode sheet being stacked along the first direction, the solid electrolyte layer being disposed between the first electrode sheet and the second electrode sheet; wherein, there are a plurality of first electrode sheets, and along the first direction, the two first electrode sheets farthest apart are the electrode sheets located at both ends of the electrode assembly, and the four corners of the two first electrode sheets farthest apart are provided with a chamfer structure.

[0008] In the above technical solution, the electrode assembly includes a first electrode, a solid electrolyte layer, and a second electrode stacked together. This simplifies the manufacturing process and reduces costs. The two first electrodes furthest apart are located at both ends of the electrode assembly. By providing chamfered corners to the four corners of these two farthest first electrodes, the risk of them puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield rate of the battery cells. Furthermore, chamfered corners on the four corners of the two farthest first electrodes also reduce the risk of scratches between the first electrodes and the casing, thus reducing the risk of damage to both and improving the reliability of the battery cells.

[0009] As an optional technical solution in this application embodiment, each of the four corners of the first electrode is provided with the chamfer structure.

[0010] In the above technical solution, by providing chamfered structures at all four corners of each first electrode, the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, it reduces the risk of the four corners of multiple first electrodes rubbing against the casing, thereby reducing the risk of damage to both the first electrodes and the casing and improving the reliability of the individual battery cells.

[0011] As an optional technical solution in this application embodiment, there are multiple second electrode sheets, and the four corners of the two second electrode sheets that are farthest apart along the first direction are provided with the chamfer structure.

[0012] In the above technical solution, along the first direction, the two second electrodes furthest apart are closer to the two ends of the electrode assembly. During isostatic pressing, the four corners of the two furthest second electrodes are relatively easy to puncture the packaging bag. In this embodiment, by providing chamfered structures at the four corners of the two furthest second electrodes, the risk of the four corners of the two furthest second electrodes puncturing the packaging bag is reduced, which helps to improve the yield of the battery cell. In addition, by providing chamfered structures at the four corners of the two furthest second electrodes, the risk of the four corners of the two furthest second electrodes rubbing against the casing is reduced, which helps to reduce the risk of damage to the second electrodes and the casing, and helps to improve the reliability of the battery cell.

[0013] As an optional technical solution in this application embodiment, each of the four corners of the second electrode is provided with the chamfer structure.

[0014] In the above technical solution, by providing chamfered structures at all four corners of each second electrode, the risk of multiple second electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, it reduces the risk of the four corners of multiple second electrodes rubbing against the casing, thereby reducing the risk of damage to both the second electrodes and the casing and improving the reliability of the individual battery cells.

[0015] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner, and there are multiple first pole pieces and multiple second pole pieces. Each of the four corners of the first pole piece is provided with the rounded corner, and each of the four corners of the second pole piece is provided with the rounded corner.

[0016] In the above technical solutions, when the chamfer structure is rounded, the transition is smoother and less prone to creating new sharp corners. By rounding all four corners of each first electrode, the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, rounding all four corners of each first electrode also reduces the risk of scratches between the corners of multiple first electrodes and the casing, further reducing the risk of damage to both the first electrodes and the casing, and ultimately improving the reliability of the individual battery cells. Similarly, by rounding all four corners of each second electrode, the risk of multiple second electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, rounding all four corners of each second electrode also reduces the risk of scratches between the corners of multiple second electrodes and the casing, further reducing the risk of damage to both the second electrodes and the casing, and ultimately improving the reliability of the individual battery cells.

[0017] As an optional technical solution in this application embodiment, the first electrode is a negative electrode, the second electrode is a positive electrode, the radii of the rounded corners of the plurality of first electrodes are equal, the radii of the rounded corners of the plurality of second electrodes are equal, and the radii of the rounded corners of the first electrodes are less than or equal to the radii of the rounded corners of the second electrodes.

[0018] In the above technical solution, the radii of the rounded corners of multiple first electrodes are equal, and the radii of the rounded corners of multiple second electrodes are equal, which simplifies manufacturing and reduces the manufacturing cost of individual battery cells. When the first electrode is a negative electrode and the second electrode is a positive electrode, and the radius of the rounded corner of the first electrode is less than or equal to the radius of the rounded corner of the second electrode, it is advantageous to make the first electrode extend beyond the second electrode, which helps to reduce the risk of metal ion precipitation.

[0019] As an optional technical solution in this application embodiment, the first electrode is a negative electrode, the second electrode is a positive electrode, the length of the first electrode is greater than the length of the second electrode, the width of the first electrode is greater than the width of the second electrode, and the thickness direction of the first electrode is parallel to the first direction.

[0020] In the above technical solution, when the first electrode is a negative electrode and the second electrode is a positive electrode, by making the length of the first electrode greater than the length of the second electrode and the width of the first electrode greater than the width of the second electrode, it is beneficial to reduce the assembly difficulty and realize the overhang design, which is beneficial to reduce the risk of metal ion precipitation.

[0021] As an optional technical solution in this application embodiment, the number of the first electrode plates is odd, the number of the second electrode plates is even, and the radius of the rounded corner of the middle first electrode plate gradually increases to the radius of the rounded corner of the first electrode plates at both ends.

[0022] In the above technical solution, to achieve the overhang design, the first electrode extends beyond the second electrode in both its length and width directions. Therefore, during isostatic pressing, the first electrode is more likely to puncture the packaging bag than the second electrode. When the number of first electrodes is odd and the number of second electrodes is even, by gradually increasing the radius of the rounded corners of the middle first electrode to the rounded corners of the first electrodes at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly along the first direction. This further reduces the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing, which is beneficial for improving the yield of individual battery cells.

[0023] As an optional technical solution in this application embodiment, along the first direction, the first electrode located in the middle position is the first intermediate electrode, and a plurality of second electrodes are provided on both sides of the first intermediate electrode; among the plurality of second electrodes located on the same side of the first intermediate electrode, the radius of the rounded corner of the second electrode closest to the first intermediate electrode gradually increases to the radius of the rounded corner of the second electrode furthest from the first intermediate electrode.

[0024] In the above technical solution, by gradually increasing the radius of the rounded corner of the second electrode closest to the first intermediate electrode to the radius of the rounded corner of the second electrode furthest from the first intermediate electrode on the same side of the first intermediate electrode, the changing trend of the rounded corners of multiple first electrodes is adapted. While realizing the overhang design, the area of ​​the second electrode is made larger, which is beneficial to improving the energy density and reliability of the battery cell.

[0025] As an optional technical solution in this application embodiment, the radius of the rounded corner of the second electrode is equal to the radius of the rounded corner of the first electrode that is adjacent to the second electrode and located on the side of the second electrode away from the first intermediate electrode.

[0026] In the above technical solution, by making the radius of the rounded corner of the second electrode equal to the radius of the rounded corner of the first electrode adjacent to the second electrode and located on the side of the second electrode away from the first intermediate electrode, it is beneficial to achieve the overhang design while making the area of ​​the second electrode larger, which is beneficial to improve the energy density and reliability of the battery cell.

[0027] As an optional technical solution in this application embodiment, the first electrode plates located on both sides of the first intermediate electrode plate are symmetrically arranged with respect to the first intermediate electrode plate; and / or the second electrode plates located on both sides of the first intermediate electrode plate are symmetrically arranged with respect to the first intermediate electrode plate.

[0028] In the above technical solution, by symmetrically arranging the first electrodes on both sides of the first intermediate electrode, the radii of the rounded corners of the two symmetrically arranged first electrodes are equal. During corner rounding, the two symmetrically arranged first electrodes can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell. Similarly, by symmetrically arranging the second electrodes on both sides of the first intermediate electrode, the radii of the rounded corners of the two symmetrically arranged second electrodes are equal. During corner rounding, the two symmetrically arranged second electrodes can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell.

[0029] As an optional technical solution in this application embodiment, the number of first electrodes is even, the number of second electrodes is odd, the second electrode located in the middle along the first direction is the second intermediate electrode, and multiple first electrodes are provided on both sides of the second intermediate electrode; among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

[0030] In the above technical solution, to achieve the overhang design, the first electrode extends beyond the second electrode in both length and width directions. Therefore, the first electrode is more prone to rubbing against the casing compared to the second electrode. When the number of first electrodes is even and the number of second electrodes is odd, among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode. This causes the electrode assembly to form a spherical transition section between two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing and improving the yield of the battery cell.

[0031] As an optional technical solution in this application embodiment, the radius of the rounded corner of the middle second electrode gradually increases to the radius of the rounded corner of the second electrode at both ends.

[0032] In the above technical solution, by gradually increasing the radius of the rounded corner of the middle second electrode to the rounded corner of the second electrode at both ends, the changing trend of the rounded corners of multiple first electrodes is adapted. While realizing the overhang design, the area of ​​the second electrode is made larger, which is beneficial to improving the energy density and reliability of the battery cell.

[0033] As an optional technical solution in this application embodiment, the radius of the rounded corner of the second electrode is equal to the radius of the rounded corner of the first electrode that is adjacent to the second electrode and located on the side of the second electrode away from the second intermediate electrode.

[0034] In the above technical solution, by making the radius of the rounded corner of the second electrode equal to the radius of the rounded corner of the first electrode adjacent to the second electrode and located on the side of the second electrode away from the second intermediate electrode, it is beneficial to achieve the overhang design while making the area of ​​the second electrode larger, which is beneficial to improving the energy density and reliability of the battery cell.

[0035] As an optional technical solution in this application embodiment, the first electrode plates located on both sides of the second intermediate electrode plate are symmetrically arranged with respect to the second intermediate electrode plate; and / or the second electrode plates located on both sides of the second intermediate electrode plate are symmetrically arranged with respect to the second intermediate electrode plate.

[0036] In the above technical solution, by symmetrically arranging the first electrodes on both sides of the first intermediate electrode with respect to the second intermediate electrode, the radii of the rounded corners of the two symmetrically arranged first electrodes are equal. During corner rounding, the two symmetrically arranged first electrodes can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell. Similarly, by symmetrically arranging the second electrodes on both sides of the second intermediate electrode with respect to the second intermediate electrode, the radii of the rounded corners of the two symmetrically arranged second electrodes are equal. During corner rounding, the two symmetrically arranged second electrodes can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell.

[0037] As an optional technical solution in this application embodiment, the four corners of the solid electrolyte layer are provided with chamfered structures.

[0038] In the above technical solution, by providing chamfered structures at all four corners of the solid electrolyte layer, the risk of the four corners of the solid electrolyte layer puncturing the packaging bag during isostatic pressing is reduced, which helps to improve the yield of battery cells. Furthermore, by providing chamfered structures at all four corners of the solid electrolyte layer, the risk of the solid electrolyte layer rubbing against the outer casing is reduced, thus reducing the risk of damage to both the solid electrolyte layer and the outer casing, and improving the reliability of the battery cells.

[0039] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner, the solid electrolyte layer is connected to the first electrode, and the radius of the rounded corner of the solid electrolyte layer is equal to the radius of the rounded corner of the corresponding first electrode.

[0040] In the above technical solution, by connecting the solid electrolyte layer to the first electrode, it is simpler and more convenient to stack the first electrode, the solid electrolyte layer, and the second electrode along the first direction. Furthermore, connecting the solid electrolyte layer to the first electrode allows it to stably separate the first and second electrodes and facilitates ion transport, which helps reduce the internal resistance of the battery cell. By making the radius of the rounded corners of the solid electrolyte layer equal to the radius of the rounded corners of its corresponding first electrode, the solid electrolyte layer covers the first electrode as much as possible, reducing the risk of short circuits caused by contact between the first and second electrodes and improving the reliability of the battery cell.

[0041] As an optional technical solution in this application embodiment, the electrode includes a current collector, a first active material layer and a second active material layer, the first active material layer and the second active material layer have opposite polarities, and the first active material layer and the second active material layer are respectively disposed on both sides of the current collector; along the first direction, at least one of the current collector, the first active material layer and the second active material layer of the two electrodes that are farthest apart are provided with the chamfer structure at all four corners.

[0042] In the above technical solution, by making the electrode include a current collector, a first active material layer, and a second active material layer, with the first and second active material layers having opposite polarities, it is beneficial to achieve a higher energy density in the battery cell. By providing chamfered structures at all four corners of the current collector, the first active material layer, and the second active material layer of the two farthest electrodes, the risk of puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield rate of the battery cell. Furthermore, by providing chamfered structures at all four corners of the current collector, the first active material layer, and the second active material layer of the two farthest electrodes, the risk of the electrode rubbing against the casing is also reduced, thus reducing the risk of damage to the electrode and casing and improving the reliability of the battery cell.

[0043] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner, and the four corners of each electrode are provided with the rounded corner.

[0044] In the above technical solution, when the chamfer structure is rounded, the transition is smoother and less likely to generate new sharp corners. By rounding all four corners of each electrode, the risk of multiple electrodes puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell. Furthermore, rounding all four corners of each electrode also reduces the risk of multiple electrodes rubbing against the casing, further reducing the risk of damage to both the electrodes and the casing, and ultimately improving the reliability of the battery cell.

[0045] As an optional technical solution in this application embodiment, the number of electrodes is odd, and the radius of the rounded corner of the middle electrode gradually increases from the radius of the rounded corner of the electrodes at both ends.

[0046] In the above technical solution, when the number of electrodes is odd, by gradually increasing the radius of the rounded corners of the middle electrode to the rounded corners of the electrodes at both ends, the electrode assembly forms a spherical transition part at two adjacent corners along the first direction, thereby further reducing the risk of multiple electrodes puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of battery cells.

[0047] As an optional technical solution in this application embodiment, the number of electrodes is even. Along the first direction, the solid electrolyte layer located in the middle position is the intermediate layer, and multiple electrodes are provided on both sides of the intermediate layer. Among the multiple electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer.

[0048] In the above technical solution, when the number of electrodes is even, among the multiple electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer, so that the electrode assembly forms a spherical transition part between two adjacent corners along the first direction, thereby further reducing the risk of multiple electrodes puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of battery cells.

[0049] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner.

[0050] In the above technical solution, when the chamfer structure is rounded, the transition is smoother and it is less likely to generate new sharp corners. This is more conducive to reducing the risk that the four corners of the two electrodes that are furthest apart during the isostatic pressing process will puncture the packaging bag, which is beneficial to improving the yield of battery cells.

[0051] As an optional technical solution in this application embodiment, the radius of the fillet is R, which satisfies: 1mm≤R≤10mm.

[0052] In the above technical solutions, when R ≥ 1mm, the radius of the fillet is relatively large, the transition is smoother, and the transition effect is better. This helps reduce the risk of the first electrode puncturing the packaging bag during isostatic pressing and improves the yield of individual battery cells. When R ≤ 10mm, the radius of the fillet is not too large, which helps reduce the volume of the electrode assembly and improves the energy density of individual battery cells. Therefore, when 1mm ≤ R ≤ 10mm, both the yield of individual battery cells and energy density can be balanced.

[0053] As an optional technical solution in this application embodiment, 1mm≤R≤5mm.

[0054] In the above technical solutions, when R ≥ 1mm, the radius of the fillet is relatively large, the transition is smoother, and the transition effect is better. This helps reduce the risk of the first electrode puncturing the packaging bag during isostatic pressing and improves the yield of individual battery cells. 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 improving the energy density of individual battery cells. Therefore, when 1mm ≤ R ≤ 5mm, it is possible to better balance the yield and energy density of individual battery cells.

[0055] As an optional technical solution in this application embodiment, the outer shell is a soft shell.

[0056] In the above technical solution, when the outer shell is a soft shell, setting chamfered structures at the four corners of the first electrode and / or the second electrode helps to reduce the risk of the first electrode and / or the second electrode piercing the outer shell, and helps to improve the reliability of the battery cell.

[0057] As an optional technical solution in this application embodiment, the soft shell is an aluminum-plastic film.

[0058] In the above technical solution, aluminum-plastic film is used to manufacture the outer shell, which is simple and convenient to manufacture and has a low cost.

[0059] Secondly, embodiments of this application also provide an electrode assembly, the electrode assembly including a solid electrolyte layer and a plurality of electrodes. Along a first direction, the solid electrolyte layer is disposed between two adjacent electrodes. Each electrode includes an active material layer. In the two adjacent electrodes, the active material layers facing the solid electrolyte layer located between the two adjacent electrodes have opposite polarities. Along the first direction, the four corners of the two electrodes that are furthest apart are provided with chamfer structures.

[0060] As an optional technical solution in this application embodiment, the plurality of electrode sheets include a first electrode sheet and a second electrode sheet, the first electrode sheet and the second electrode sheet having opposite polarities, and the first electrode sheet, the solid electrolyte layer and the second electrode sheet being stacked along the first direction, the solid electrolyte layer being disposed between the first electrode sheet and the second electrode sheet; wherein, there are a plurality of first electrode sheets, and along the first direction, the two first electrode sheets farthest apart are the electrode sheets located at both ends of the electrode assembly, and the four corners of the two first electrode sheets farthest apart are provided with a chamfer structure.

[0061] In the above technical solution, the electrode assembly includes a first electrode, a solid electrolyte layer, and a second electrode stacked together. This simplifies the manufacturing process and reduces costs. The two first electrodes furthest apart are located at both ends of the electrode assembly. By providing chamfered corners to the four corners of these two farthest first electrodes, the risk of them puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield rate of the battery cells. Furthermore, chamfered corners on the four corners of the two farthest first electrodes also reduce the risk of scratches between the first electrodes and the casing, thus reducing the risk of damage to both and improving the reliability of the battery cells.

[0062] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner, and there are multiple first pole pieces and multiple second pole pieces. Each of the four corners of the first pole piece is provided with the rounded corner, and each of the four corners of the second pole piece is provided with the rounded corner.

[0063] In the above technical solutions, when the chamfer structure is rounded, the transition is smoother and less prone to creating new sharp corners. By rounding all four corners of each first electrode, the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, rounding all four corners of each first electrode also reduces the risk of scratches between the corners of multiple first electrodes and the casing, further reducing the risk of damage to both the first electrodes and the casing, and ultimately improving the reliability of the individual battery cells. Similarly, by rounding all four corners of each second electrode, the risk of multiple second electrodes puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of individual battery cells. Furthermore, rounding all four corners of each second electrode also reduces the risk of scratches between the corners of multiple second electrodes and the casing, further reducing the risk of damage to both the second electrodes and the casing, and ultimately improving the reliability of the individual battery cells.

[0064] As an optional technical solution in this application embodiment, the first electrode is a negative electrode, the second electrode is a positive electrode, the length of the first electrode is greater than the length of the second electrode, the width of the first electrode is greater than the width of the second electrode, and the thickness direction of the first electrode is parallel to the first direction.

[0065] In the above technical solution, when the first electrode is a negative electrode and the second electrode is a positive electrode, by making the length of the first electrode greater than the length of the second electrode and the width of the first electrode greater than the width of the second electrode, it is beneficial to reduce the assembly difficulty and realize the overhang design, which is beneficial to reduce the risk of metal ion precipitation.

[0066] As an optional technical solution in this application embodiment, the number of the first electrode plates is odd, the number of the second electrode plates is even, and the radius of the rounded corner of the middle first electrode plate gradually increases to the radius of the rounded corner of the first electrode plates at both ends.

[0067] In the above technical solution, to achieve the overhang design, the first electrode extends beyond the second electrode in both its length and width directions. Therefore, during isostatic pressing, the first electrode is more likely to puncture the packaging bag than the second electrode. When the number of first electrodes is odd and the number of second electrodes is even, by gradually increasing the radius of the rounded corners of the middle first electrode to the rounded corners of the first electrodes at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly along the first direction. This further reduces the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing, which is beneficial for improving the yield of individual battery cells.

[0068] As an optional technical solution in this application embodiment, the number of first electrodes is even, the number of second electrodes is odd, the second electrode located in the middle along the first direction is the second intermediate electrode, and multiple first electrodes are provided on both sides of the second intermediate electrode; among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

[0069] In the above technical solution, to achieve the overhang design, the first electrode extends beyond the second electrode in both length and width directions. Therefore, the first electrode is more prone to rubbing against the casing compared to the second electrode. When the number of first electrodes is even and the number of second electrodes is odd, among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode. This causes the electrode assembly to form a spherical transition section between two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing and improving the yield of the battery cell.

[0070] As an optional technical solution in this application embodiment, the electrode includes a current collector, a first active material layer and a second active material layer, the first active material layer and the second active material layer have opposite polarities, and the first active material layer and the second active material layer are respectively disposed on both sides of the current collector; along the first direction, at least one of the current collector, the first active material layer and the second active material layer of the two electrodes that are farthest apart are provided with the chamfer structure at all four corners.

[0071] In the above technical solution, by making the electrode include a current collector, a first active material layer, and a second active material layer, with the first and second active material layers having opposite polarities, it is beneficial to achieve a higher energy density in the battery cell. By providing chamfered structures at all four corners of the current collector, the first active material layer, and the second active material layer of the two farthest electrodes, the risk of puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield rate of the battery cell. Furthermore, by providing chamfered structures at all four corners of the current collector, the first active material layer, and the second active material layer of the two farthest electrodes, the risk of the electrode rubbing against the casing is also reduced, thus reducing the risk of damage to the electrode and casing and improving the reliability of the battery cell.

[0072] As an optional technical solution in this application embodiment, the chamfer structure is a rounded corner, and the four corners of each electrode are provided with the rounded corner.

[0073] In the above technical solution, when the chamfer structure is rounded, the transition is smoother and less likely to generate new sharp corners. By rounding all four corners of each electrode, the risk of multiple electrodes puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell. Furthermore, rounding all four corners of each electrode also reduces the risk of multiple electrodes rubbing against the casing, further reducing the risk of damage to both the electrodes and the casing, and ultimately improving the reliability of the battery cell.

[0074] As an optional technical solution in this application embodiment, the number of electrodes is odd, and the radius of the rounded corner of the middle electrode gradually increases from the radius of the rounded corner of the electrodes at both ends.

[0075] In the above technical solution, when the number of electrodes is odd, by gradually increasing the radius of the rounded corners of the middle electrode to the rounded corners of the electrodes at both ends, the electrode assembly forms a spherical transition part at two adjacent corners along the first direction, thereby further reducing the risk of multiple electrodes puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of battery cells.

[0076] As an optional technical solution in this application embodiment, the number of electrodes is even. Along the first direction, the solid electrolyte layer located in the middle position is the intermediate layer, and multiple electrodes are provided on both sides of the intermediate layer. Among the multiple electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer.

[0077] In the above technical solution, when the number of electrodes is even, among the multiple electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer, so that the electrode assembly forms a spherical transition part between two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of battery cells.

[0078] Thirdly, embodiments of this application also provide an electrode assembly manufacturing method, the method comprising: providing a plurality of electrode sheets; providing a solid electrolyte layer; stacking the plurality of electrode sheets and the solid electrolyte layer along a first direction, such that the solid electrolyte layer is disposed between two adjacent electrode sheets along the first direction to form an electrode assembly blank, wherein the electrode sheets include an active material layer, and in two adjacent electrode sheets, the active material layer facing the solid electrolyte layer located between the two adjacent electrode sheets has opposite polarities, and the four corners of the two electrode sheets furthest apart along the first direction are provided with chamfer structures; placing the electrode assembly blank into a packaging bag; and performing isostatic pressing on the electrode assembly blank placed in the packaging bag.

[0079] As an optional technical solution in this application embodiment, the plurality of electrode sheets include a first electrode sheet and a second electrode sheet, the first electrode sheet and the second electrode sheet having opposite polarities; providing the plurality of electrode sheets includes: providing the first electrode sheet; providing the second electrode sheet; providing the first electrode sheet includes: providing a plurality of first electrode sheet blanks; chamfering the four corners of at least two of the first electrode sheet blanks to form the chamfered structure; in the electrode assembly blank, along the first direction, the first electrode sheet, the solid electrolyte layer and the second electrode sheet are stacked, the solid electrolyte layer is disposed between the first electrode sheet and the second electrode sheet, along the first direction, the two first electrode sheets farthest apart are the electrode sheets located at both ends of the electrode assembly, and the four corners of the two farthest first electrode sheets are provided with a chamfered structure.

[0080] In the above technical solution, the four corners of the first electrode blank are chamfered, so that the four corners of the first electrode are all provided with chamfered structures.

[0081] As an optional technical solution in this application embodiment, the chamfering process of the four corners of at least two first electrode blanks includes: rounding the four corners of each first electrode blank; in the electrode assembly blank, the four corners of each first electrode are provided with the rounded corners.

[0082] In the above technical solution, the four corners of each first electrode blank are rounded, and the chamfer structure is rounded. When the chamfer structure is rounded, the transition is smoother and it is less likely to generate new sharp corners. This is more conducive to reducing the risk of the four corners of the first electrode puncturing the packaging bag during the isostatic pressing process, and it is beneficial to improve the yield of battery cells.

[0083] As an optional technical solution in this application embodiment, in the step of rounding the four corners of each first electrode blank, the rounding radii of the multiple first electrode blanks are different; in the electrode assembly blank, when the number of first electrodes is odd and the number of second electrodes is even, the radius of the rounded corner of the middle first electrode gradually increases to the radius of the rounded corner of the first electrodes at both ends; when the number of first electrodes is even and the number of second electrodes is odd, along the first direction, the second electrode located in the middle position is the second intermediate electrode, and multiple first electrodes are provided on both sides of the second intermediate electrode. Among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

[0084] In the above technical solution, to achieve the overhang design, the first electrode extends beyond the second electrode in both its length and width directions. Therefore, during isostatic pressing, the first electrode is more likely to puncture the packaging bag than the second electrode. When the number of first electrodes is odd and the number of second electrodes is even, by gradually increasing the radius of the rounded corners of the middle first electrode to the rounded corners of the first electrodes at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly along the first direction. This further reduces the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing, which is beneficial for improving the yield of individual battery cells. When the number of first electrodes is even and the number of second electrodes is odd, among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode. This causes the electrode assembly to form a spherical transition section between two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrodes puncturing the packaging bag during isostatic pressing and improving the yield of battery cells.

[0085] As an optional technical solution in this application embodiment, providing the second electrode includes: providing a plurality of second electrode blanks; chamfering the four corners of at least two second electrode blanks to form the chamfered structure; in the electrode assembly blank, the four corners of the two second electrodes that are furthest apart along the first direction are provided with the chamfered structure.

[0086] In the above technical solution, the four corners of the second electrode blank are chamfered, resulting in a chamfered structure at each of the four corners of the second electrode. Along the first direction, the two second electrodes furthest apart are closer to the two ends of the electrode assembly. During isostatic pressing, the four corners of the two furthest second electrodes are relatively easy to puncture the packaging bag. In this embodiment, by providing chamfered structures at the four corners of the two furthest second electrodes, the risk of the four corners of the two furthest second electrodes puncturing the packaging bag is reduced, which helps improve the yield rate of the battery cell. Furthermore, by providing chamfered structures at the four corners of the two furthest second electrodes, the risk of the four corners of the two furthest second electrodes rubbing against the casing is reduced, which helps reduce the risk of damage to the second electrode and the casing, and helps improve the reliability of the battery cell.

[0087] Fourthly, embodiments of this application also provide a battery device, the battery device comprising the aforementioned battery cell.

[0088] Fifthly, embodiments of this application also provide an electrical device, the electrical device including the aforementioned battery cell, the battery cell being used to provide electrical energy to the electrical device. Attached Figure Description

[0089] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0090] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0091] Figure 2 is an exploded view of a battery device provided in some embodiments of this application;

[0092] Figure 3 is an exploded view of a single battery cell provided in some embodiments of this application;

[0093] Figure 4 is a top view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0094] Figure 5 is a side view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0095] Figure 6 is a side view schematic diagram of an electrode assembly provided in some other embodiments of this application;

[0096] Figure 7 is a side view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0097] Figure 8 is a side view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0098] Figure 9 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0099] Figure 10 is a side view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0100] Figure 11 is a side view schematic diagram of an electrode assembly provided in some other embodiments of this application;

[0101] Figure 12 is a side view of an electrode assembly provided in some other embodiments of this application;

[0102] Figure 13 is a side view schematic diagram of an electrode assembly provided in some other embodiments of this application;

[0103] Figure 14 is a schematic block diagram of an electrode assembly manufacturing method provided in some embodiments of this application;

[0104] Figure 15 is a schematic block diagram of an electrode assembly manufacturing method provided in some other embodiments of this application;

[0105] Figure 16 is a schematic block diagram of an electrode assembly manufacturing method provided in some embodiments of this application;

[0106] Figure 17 is a schematic block diagram of an electrode assembly manufacturing method provided in some embodiments of this application.

[0107] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Casing; 211-Shell; 212-End cap; 22-Electrode assembly; 221-Electrode; 2211-First electrode; 22111-First intermediate electrode; 2212-Second electrode; 22121-Second intermediate electrode; 2213-Current collector; 2214-First active material layer; 2215-Second active material layer; 223-Solid electrolyte layer; 2231-Intermediate layer; 224-Taper; 23-Chamfered structure; 231-Rounded corner; 30-Electrode assembly manufacturing method; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0108] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0109] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0110] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0111] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0112] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0113] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0114] In this application, "multiple" means two or more (including two).

[0115] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0116] A single battery cell typically includes an electrode assembly. The electrode assembly comprises a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0117] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0118] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0119] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors 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 substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0120] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0121] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0122] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0123] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0124] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0125] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0126] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0127] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0128] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0129] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0130] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0131] In some implementations, the electrode assembly is a stacked structure.

[0132] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0133] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0134] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0135] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0136] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0137] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0138] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0139] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0140] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0141] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0142] As an example, the enclosure may include a first part and a second part. The first and second parts are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting off; it can be sealed or not sealed. The first part may be a top cover or a bottom plate.

[0143] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0144] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0145] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0146] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0147] The development of battery technology requires consideration of multiple design factors, such as energy density, cycle life, discharge capacity, and charge / discharge rate. Additionally, battery yield must also be considered. However, current battery yield rates need further improvement.

[0148] Solid-state batteries, characterized by high energy density, will significantly improve the range of new energy vehicles. In the manufacturing process of solid-state batteries, the positive electrode, solid electrolyte layer, and negative electrode need to undergo isostatic pressing to compress them. During isostatic pressing, a packaging bag containing the stacked positive electrode, solid electrolyte layer, and negative electrode is placed in hydraulic oil, which is then pressurized to achieve isostatic pressing. However, during isostatic pressing, the packaging bag is easily punctured by the electrode, causing the electrode to break under hydraulic pressure and resulting in short circuits in the electrode assembly. Therefore, the yield rate of the battery needs further improvement.

[0149] Therefore, this application provides a battery cell, which includes a casing and an electrode assembly disposed within the casing. The electrode assembly includes a solid electrolyte layer and multiple electrode plates. Along a first direction, the solid electrolyte layer is disposed between two adjacent electrode plates. Each electrode plate includes an active material layer. In adjacent electrode plates, the active material layers facing the solid electrolyte layer between the two adjacent electrode plates have opposite polarities. Along the first direction, the four corners of the two farthest electrode plates are provided with chamfered structures.

[0150] Multiple electrodes and a solid electrolyte layer are stacked along a first direction, i.e., the electrode assembly is a stacked electrode assembly. For stacked electrode assemblies, during isostatic pressing, the electrodes located at both ends of the electrode assembly are most likely to puncture the packaging bag along the first direction. In this embodiment, the two electrodes furthest apart are located at both ends of the electrode assembly. By providing chamfered structures at all four corners of the two furthest electrodes, the risk of the four corners of the two furthest electrodes puncturing the packaging bag during isostatic pressing is reduced, which helps to improve the yield of the battery cell. In addition, by providing chamfered structures at all four corners of the two furthest electrodes, the risk of the electrodes rubbing against the casing is also reduced, which helps to reduce the risk of damage to the electrodes and the casing, and helps to improve the reliability of the battery cell.

[0151] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0152] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0153] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0154] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0155] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0156] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, with the housing 10 used to house the battery cells 20.

[0157] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, which are interlocked. The first part 11 and the second part 12 can have various shapes, such as cuboids or cylinders. The first part 11 can be a hollow structure open on one side, and the second part 12 can also be a hollow structure open on one side. The open side of the second part 12 interlocks with the open side of the first part 11, thus forming a housing 10 with an enclosed space. Alternatively, the first part 11 can be a hollow structure open on one side, and the second part 12 can be a plate-like structure, with the second part 12 interlocking with the open side of the first part 11, thus forming a housing 10 with an accommodating space.

[0158] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0159] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0160] Please refer to Figures 3, 4, and 5. Figure 3 is an exploded view of a battery cell 20 provided in some embodiments of this application. Figure 4 is a top view of an electrode assembly 22 provided in some embodiments of this application. Figure 5 is a side view of an electrode assembly 22 provided in some embodiments of this application. This application provides a battery cell 20, which includes a housing 21 and an electrode assembly 22, with the electrode assembly 22 disposed within the housing 21. The electrode assembly 22 includes a solid electrolyte layer 223 and multiple electrode plates 221. Along a first direction, the solid electrolyte layer 223 is disposed between two adjacent electrode plates 221. Each electrode plate 221 includes an active material layer. In two adjacent electrode plates 221, the active material layers facing the solid electrolyte layer 223 located between the two adjacent electrode plates 221 have opposite polarities. Along the first direction, chamfered structures 23 are provided at the four corners of the two farthest electrode plates 221.

[0161] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0162] In some embodiments, the housing 21 may include a housing 211 and an end cap 212, the housing 211 having an opening and the end cap 212 closing the opening of the housing 211. Here, "closing" refers to covering or shutting down, and can be either sealed or unsealed.

[0163] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 212 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0164] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0165] In an embodiment where the housing 211 has an opening at one end, one end cap 212 may be provided. In an embodiment where the housing 211 has openings at opposite ends, two end caps 212 may be provided, with the two end caps 212 respectively closing the two openings of the housing 211. The two end caps 212 and the housing 211 together define the receiving space for accommodating the electrode assembly 22.

[0166] If the electrode assembly 22 includes a solid electrolyte layer 223, then the electrode assembly 22 is a solid electrode assembly. The solid electrolyte layer 223 is disposed between two adjacent electrodes 221, and serves to both transport ions and isolate the positive and negative electrodes.

[0167] The first direction is the stacking direction of the multiple electrodes 221 and the solid electrolyte layer 223. Please refer to Figure 5, where the first direction is the X direction shown in the figure.

[0168] The solid electrolyte layer 223 includes a polymer solid electrolyte layer, an inorganic solid electrolyte layer, and a composite solid electrolyte layer.

[0169] As an example, the polymer solid electrolyte layer can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymer, polyionic liquid-lithium salt, cellulose, etc.

[0170] As an example, the inorganic solid electrolyte layer may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver germanium sulfide), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0171] As an example, a composite solid electrolyte layer is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0172] "In two adjacent electrodes 221, the polarity of the active material layer facing the solid electrolyte layer 223 between the two adjacent electrodes 221 is opposite." That is, in two adjacent electrodes 221, the polarity of the active material layer facing the solid electrolyte layer 223 between the two adjacent electrodes 221 of one electrode 221 is opposite to that of the active material layer facing the solid electrolyte layer 223 between the two adjacent electrodes 221 of the other electrode 221. In other words, in two adjacent electrodes 221, the active material layer facing the solid electrolyte layer 223 between the two adjacent electrodes of one electrode 221 is the positive electrode active material layer, and the active material layer facing the solid electrolyte layer 223 between the two adjacent electrodes of the other electrode 221 is the negative electrode active material layer.

[0173] In some embodiments, a plurality of electrodes 221 include positive and negative electrodes, and the positive electrode, solid electrolyte layer 223, and negative electrode are stacked to form an electrode assembly 22. The portions of the positive and negative electrodes having active material constitute the main body of the electrode assembly 22, and the portions of the positive and negative electrodes without active material each constitute a tab 224. The positive and negative tabs may be located together at one end of the main body or at opposite ends of the main body.

[0174] In other embodiments, the electrode 221 includes a current collector 2213, a positive active material layer, and a negative active material layer, with the positive and negative active material layers respectively disposed on both sides of the current collector 2213. The solid electrolyte layer 223 and multiple electrodes 221 are stacked to form an electrode assembly 22.

[0175] The electrode assembly 22 may include two electrodes 221, three electrodes 221, a first electrode 2211, or more electrodes 221.

[0176] Referring to Figure 5, along the first direction, the two pole pieces 221 that are furthest apart are the pole pieces 221 located at both ends of the electrode assembly 22, that is, the two pole pieces 221 that are furthest apart are the two pole pieces 221 located on the outermost side of the electrode assembly 22.

[0177] Along the first direction, the four corners of the two pole pieces 221 that are furthest apart are provided with chamfered structures 23. That is, the four corners of the two pole pieces 221 located at both ends of the electrode assembly 22 are provided with chamfered structures 23. Or, the four corners of the two pole pieces 221 located on the outermost side of the electrode assembly 22 are provided with chamfered structures 23. The chamfered structure 23 can be a rounded corner 231 or a beveled corner.

[0178] The chamfering structures 23 at the four corners of the electrode 221 can be the same or different. For example, some chamfering structures 23 at the four corners of the electrode 221 are rounded corners 231, while others are beveled corners. Please refer to Figures 4 and 5. In the embodiments shown in the figures, the chamfering structures 23 at the four corners of the electrode 221 are the same.

[0179] Multiple electrode sheets 221 and a solid electrolyte layer 223 are stacked along a first direction, meaning the electrode assembly 22 is a stacked electrode assembly. For stacked electrode assemblies, during isostatic pressing, the electrode sheets 221 located at both ends of the electrode assembly 22 are most likely to puncture the packaging bag along the first direction. In this embodiment, the two farthest electrode sheets 221 are located at both ends of the electrode assembly 22. By providing chamfered structures 23 at all four corners of the two farthest electrode sheets 221, the risk of the four corners of the two farthest electrode sheets 221 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. In addition, by providing chamfered structures 23 at all four corners of the two farthest electrode sheets 221, the risk of the electrode sheets 221 rubbing against the casing 21 is also reduced, which helps reduce the risk of damage to the electrode sheets 221 and the casing 21, and helps improve the reliability of the battery cell 20.

[0180] Referring to Figures 3, 4, and 5, in some embodiments, the plurality of electrode plates 221 include a first electrode plate 2211 and a second electrode plate 2212, with the first electrode plate 2211 and the second electrode plate 2212 having opposite polarities. Along a first direction, the first electrode plate 2211, the solid electrolyte layer 223, and the second electrode plate 2212 are stacked, with the solid electrolyte layer 223 disposed between the first electrode plate 2211 and the second electrode plate 2212. There are multiple first electrode plates 2211. Along the first direction, the two first electrode plates 2211 furthest apart are located at both ends of the electrode assembly 22, and each of the four corners of the two furthest first electrode plates 2211 has a chamfered structure 23.

[0181] One of the first electrode 2211 and the second electrode 2212 is the positive electrode, and the other is the negative electrode. For example, when the first electrode 2211 is the positive electrode, the second electrode 2212 is the negative electrode. Or, for instance, when the first electrode 2211 is the positive electrode, the second electrode 2212 is the negative electrode.

[0182] The electrode assembly 22 may include two first electrodes 2211, three first electrodes 2211, four first electrodes 2211, or more first electrodes 2211.

[0183] Referring to Figure 5, along the first direction, the two first electrodes 2211 that are furthest apart are the electrodes 221 at both ends of the electrode assembly 22, that is, the two first electrodes 2211 that are furthest apart are the two electrodes 221 on the outermost side of the electrode assembly 22.

[0184] Along the first direction, the four corners of the two farthest first pole pieces 2211 are provided with chamfer structures 23. The chamfer structures 23 can be rounded corners 231 or beveled corners.

[0185] The chamfer structures 23 at the four corners of the first electrode 2211 can be the same or different. For example, some chamfer structures 23 at the four corners of the first electrode 2211 are rounded corners 231, while others are beveled corners. Referring to Figures 4 and 5, in the embodiments shown in the figures, the chamfer structures 23 at the four corners of the first electrode 2211 are the same.

[0186] The electrode assembly 22 includes a first electrode 2211, a solid electrolyte layer 223, and a second electrode 2212 stacked together. This makes the electrode assembly 22 simple and convenient to manufacture, and reduces cost. By providing chamfered structures 23 at all four corners of the two farthest first electrodes 2211, the risk of the four corners of the two farthest first electrodes 2211 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, by providing chamfered structures 23 at all four corners of the two farthest first electrodes 2211, the risk of the first electrode 2211 rubbing against the casing 21 is also reduced, which helps reduce the risk of damage to the first electrode 2211 and the casing 21, and helps improve the reliability of the battery cell 20.

[0187] Please refer to Figure 6, which is a side view of the electrode assembly 22 provided in some other embodiments of this application. In some embodiments, each first electrode 2211 has a chamfered structure 23 at each of its four corners.

[0188] "Each first electrode 2211 has a chamfered structure 23 at each of its four corners" means that all the first electrodes 2211 have a chamfered structure 23 at each of their four corners.

[0189] The chamfered structures 23 at the four corners of one first electrode 2211 can be the same as those at the four corners of another first electrode 2211. For example, both the chamfered structures 23 at the four corners of one first electrode 2211 and the chamfered structures 23 at the four corners of another first electrode 2211 can be rounded corners 231 or both can be beveled corners. Alternatively, the chamfered structures 23 at the four corners of one first electrode 2211 can be different from those at the four corners of another first electrode 2211. For example, one first electrode 2211 can have rounded corners 231, while the other first electrode 2211 can have beveled corners. Referring to Figure 6, in the embodiment shown in the figure, the chamfered structures 23 at the four corners of one first electrode 2211 are the same as those at the four corners of another first electrode 2211.

[0190] By providing chamfered structures 23 at all four corners of each first electrode 2211, the risk of multiple first electrodes 2211 puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of the battery cell 20. Furthermore, it reduces the risk of the four corners of the multiple first electrodes 2211 rubbing against the casing 21, thereby reducing the risk of damage to both the first electrodes 2211 and the casing 21 and improving the reliability of the battery cell 20.

[0191] Please refer to Figure 7, which is a side view of the electrode assembly 22 provided in some embodiments of this application. In some embodiments, there are multiple second electrode plates 2212, and along the first direction, the four corners of the two second electrode plates 2212 that are furthest apart are provided with chamfered structures 23.

[0192] The electrode assembly 22 may include two second electrodes 2212, three second electrodes 2212, four second electrodes 2212, or more second electrodes 2212.

[0193] Referring to Figure 7, along the first direction, the two second electrodes 2212 that are furthest apart are located at both ends of the electrode assembly 22.

[0194] The chamfering structures 23 at the four corners of the second electrode 2212 can be the same or different. For example, some chamfering structures 23 at the four corners of the second electrode 2212 are rounded corners 231, while others are beveled corners. Referring to Figure 7, in the embodiment shown in the figure, the chamfering structures 23 at the four corners of the second electrode 2212 are the same.

[0195] Along the first direction, the two second electrode plates 2212 that are furthest apart are closer to the two ends of the electrode assembly 22. During isostatic pressing, the four corners of the two furthest second electrode plates 2212 are relatively easy to puncture the packaging bag. In this embodiment, by providing chamfered structures 23 at the four corners of the two furthest second electrode plates 2212, the risk of the four corners of the two furthest second electrode plates 2212 puncturing the packaging bag is reduced, which helps to improve the yield of the battery cell 20. In addition, by providing chamfered structures 23 at the four corners of the two furthest second electrode plates 2212, the risk of the four corners of the two furthest second electrode plates 2212 rubbing against the outer casing 21 is reduced, which helps to reduce the risk of damage to the second electrode plates 2212 and the outer casing 21, which helps to improve the reliability of the battery cell 20.

[0196] Please refer to Figure 8, which is a side view of the electrode assembly 22 provided in some embodiments of this application. In some embodiments, each second electrode 2212 has a chamfered structure 23 at each of its four corners.

[0197] "Each second electrode 2212 has a chamfered structure 23 at each of its four corners" means that all the second electrodes 2212 have a chamfered structure 23 at each of their four corners.

[0198] The chamfered structure 23 of the four corners of one second electrode 2212 can be the same as the chamfered structure 23 of the four corners of another second electrode 2212. For example, both the chamfered structure 23 of the four corners of one second electrode 2212 and the chamfered structure 23 of the four corners of another second electrode 2212 can be rounded corners 231 or both can be beveled corners. The chamfered structure 23 of the four corners of one second electrode 2212 can also be different from the chamfered structure 23 of the four corners of the other two first electrodes 2211. For example, the chamfered structure 23 of the four corners of one second electrode 2212 can be rounded corners 231, while the chamfered structure 23 of the four corners of the other second electrode 2212 can be beveled. Referring to Figure 8, in the embodiment shown in the figure, the chamfered structure 23 of the four corners of one second electrode 2212 is the same as the chamfered structure 23 of the four corners of another second electrode 2212.

[0199] By providing chamfered structures 23 at all four corners of each second electrode 2212, the risk of multiple second electrodes 2212 puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield of the battery cell 20. Furthermore, it reduces the risk of the four corners of the multiple second electrodes 2212 rubbing against the casing 21, thereby reducing the risk of damage to both the second electrodes 2212 and the casing 21 and improving the reliability of the battery cell 20.

[0200] Referring to Figure 8, in some embodiments, the chamfer structure 23 is a rounded corner 231. There are multiple first pole pieces 2211 and second pole pieces 2212. Each first pole piece 2211 has rounded corners 231 at all four corners, and each second pole piece 2212 has rounded corners 231 at all four corners.

[0201] All four corners of the first electrode 2211 are provided with rounded corners 231, and all four corners of the second electrode 2212 are provided with rounded corners 231.

[0202] The radii of the fillets 231 at the four corners of a first electrode 2211 can be equal, or they can be unequal. Referring to Figure 8, in the embodiment shown in the figure, the radii of the fillets 231 at the four corners of a first electrode 2211 are equal.

[0203] The radii of the fillets 231 at the four corners of a second electrode 2212 can be equal, or they can be unequal. Referring to Figure 8, in the embodiment shown in the figure, the radii of the fillets 231 at the four corners of a second electrode 2212 are equal.

[0204] The radii of the rounded corners 231 of the four corners of one first electrode 2211 can be equal to the radii of the rounded corners 231 of the four corners of another first electrode 2211, or the radii of the rounded corners 231 of the four corners of one first electrode 2211 can be unequal to the radii of the rounded corners 231 of the four corners of another first electrode 2211. Referring to Figure 8, in the embodiment shown in the figure, the radii of the rounded corners 231 of the four corners of one first electrode 2211 can be equal to the radii of the rounded corners 231 of the four corners of another first electrode 2211.

[0205] The radii of the rounded corners 231 of the four corners of one second electrode 2212 can be equal to the radii of the rounded corners 231 of the four corners of another second electrode 2212, or they can be unequal to the radii of the rounded corners 231 of the four corners of another second electrode 2212. Referring to Figure 8, in the embodiment shown in the figure, the radii of the rounded corners 231 of the four corners of one second electrode 2212 can be equal to the radii of the rounded corners 231 of the four corners of another second electrode 2212.

[0206] When the chamfer structure 23 is rounded 231, the transition is smoother and less prone to creating new sharp corners. By providing rounded corners 231 to all four corners of each first electrode 2211, the risk of multiple first electrode 2211 corners puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, providing rounded corners 231 to all four corners of each first electrode 2211 also reduces the risk of the four corners of multiple first electrode 2211 rubbing against the casing 21, further reducing the risk of damage to both the first electrode 2211 and the casing 21, thus improving the reliability of the battery cell 20. Similarly, by providing rounded corners 231 to all four corners of each second electrode 2212, the risk of multiple second electrode 2212 corners puncturing the packaging bag during isostatic pressing is further reduced, which helps improve the yield of the battery cell 20. Furthermore, the rounded corners 231 of each second electrode 2212 further reduce the risk of the four corners of the multiple second electrodes 2212 rubbing against the outer casing 21, thus reducing the risk of damage to the multiple second electrodes 2212 and the outer casing 21 and improving the reliability of the battery cell 20.

[0207] Referring to Figure 8, in some embodiments, the first electrode 2211 is the negative electrode, and the second electrode 2212 is the positive electrode. The radii of the fillets 231 of the plurality of first electrodes 2211 are equal, the radii of the fillets 231 of the plurality of second electrodes 2212 are equal, and the radius of the fillets 231 of the first electrodes 2211 is less than or equal to the radius of the fillets 231 of the second electrodes 2212.

[0208] All the first pole pieces 2211 have the same radius of ...

[0209] Having equal radii for the rounded corners 231 of multiple first electrodes 2211 and equal radii for the rounded corners 231 of multiple second electrodes 2212 simplifies manufacturing and reduces the manufacturing cost of the battery cell 20. When the first electrode 2211 is the negative electrode and the second electrode 2212 is the positive electrode, and the radius of the rounded corners 231 of the first electrode 2211 is less than or equal to the radius of the rounded corners 231 of the second electrode 2212, it is advantageous to have the first electrode 2211 extend beyond the second electrode 2212, which helps reduce the risk of metal ion precipitation.

[0210] Please refer to Figures 9 and 10. Figure 9 is a structural schematic diagram of the electrode assembly 22 provided in some embodiments of this application. Figure 10 is a side view schematic diagram of the electrode assembly 22 provided in other embodiments of this application. In some embodiments, the first electrode 2211 is a negative electrode, and the second electrode 2212 is a positive electrode. The length of the first electrode 2211 is greater than the length of the second electrode 2212, and the width of the first electrode 2211 is greater than the width of the second electrode 2212. The thickness direction of the first electrode 2211 is parallel to the first direction.

[0211] The length of the first electrode 2211 is greater than the length of the second electrode 2212. Along the length direction of the first electrode 2211, both ends of the first electrode 2211 extend beyond the second electrode 2212. The width of the first electrode 2211 is greater than the width of the second electrode 2212. Along the width direction of the first electrode 2211, both ends of the first electrode 2211 extend beyond the second electrode 2212.

[0212] When the first electrode 2211 is the negative electrode and the second electrode 2212 is the positive electrode, by making the length of the first electrode 2211 greater than the length of the second electrode 2212 and the width of the first electrode 2211 greater than the width of the second electrode 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.

[0213] Referring to Figures 9 and 10, in some embodiments, the number of first pole pieces 2211 is odd, the number of second pole pieces 2212 is even, and the radius of the rounded corner 231 of the middle first pole piece 2211 gradually increases from the radius of the rounded corner 231 of the first pole pieces 2211 at both ends.

[0214] The number of first electrode plates 2211 is odd, and the number of second electrode plates 2212 is even. The number of first electrode plates 2211 is one more than the number of second electrode plates 2212. For example, when there are 7 first electrode plates 2211, the number of second electrode plates 2212 can be 6.

[0215] Along the first direction, the radius of the rounded corner 231 of the first pole piece 2211 located in the middle is the smallest, and the radius of the rounded corner 231 of the first pole pieces 2211 located at both ends is the largest. The radius of the rounded corner 231 of the first pole piece 2211 gradually increases from the middle to both ends. In other words, the radius of the rounded corner 231 of the first pole piece 2211 closer to the middle is smaller than the radius of the rounded corner 231 of the first pole piece 2211 farther from the middle.

[0216] To achieve the overhang design, the first electrode 2211 extends beyond the second electrode 2212 in both length and width. Therefore, during isostatic pressing, the first electrode 2211 is more likely to puncture the packaging bag than the second electrode 2212. When the number of first electrodes 2211 is odd and the number of second electrodes 2212 is even, by gradually increasing the radius of the rounded corner 231 of the middle first electrode 2211 to the radius of the rounded corner 231 of the first electrodes 2211 at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly 22 along the first direction. This further reduces the risk of multiple first electrodes 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0217] Referring to Figures 9 and 10, in some embodiments, along the first direction, a first electrode 2211 located in the middle position is a first intermediate electrode 22111, and multiple second electrodes 2212 are provided on both sides of the first intermediate electrode 22111. Among the multiple second electrodes 2212 located on the same side of the first intermediate electrode 22111, the radius of the rounded corner 231 of the second electrode 2212 closest to the first intermediate electrode 22111 gradually increases to the radius of the rounded corner 231 of the second electrode 2212 furthest from the first intermediate electrode 22111.

[0218] When the number of first electrode plates 2211 is odd, the first electrode plate 2211 located in the middle along the first direction is the first intermediate electrode plate 22111. Along the first direction, multiple second electrode plates 2212 are respectively arranged on both sides of the first intermediate electrode plate 22111.

[0219] Among the multiple second electrodes 2212 located on the same side of the first intermediate electrode 22111, the radius of the rounded corner 231 of the second electrode 2212 farther away from the first intermediate electrode 22111 is larger. Along the first direction, the radius of the rounded corner 231 of the second electrode 2212 closest to the first intermediate electrode 22111 is the smallest, and the radius of the rounded corner 231 of the second electrode 2212 farthest from the first intermediate electrode 22111 is the largest.

[0220] By gradually increasing the radius of the rounded corner 231 of the second electrode 2212 located on the same side as the first intermediate electrode 22111, from the radius of the rounded corner 231 of the second electrode 2212 closest to the first intermediate electrode 22111 to the radius of the rounded corner 231 of the second electrode 2212 furthest from the first intermediate electrode 22111, the changing trend of the rounded corner 231 of multiple first electrodes 2211 is adapted. While realizing the overhang design, the area of ​​the second electrode 2212 is made larger, which is beneficial to improving the energy density and reliability of the battery cell 20.

[0221] Referring to Figures 9 and 10, in some embodiments, the radius of the fillet 231 of the second electrode 2212 is equal to the radius of the fillet 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the first intermediate electrode 22111.

[0222] The radius of the rounded corner 231 of the second electrode 2212 is the first radius, and the radius of the rounded corner 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the first intermediate electrode 22111, is the second radius. The first radius is equal to the second radius.

[0223] Referring to Figure 10, along the first direction, the radius of the rounded corner 231 of the outermost first electrode 2211 of the electrode assembly 22 is equal to the radius of the rounded corner 231 of the adjacent second electrode 2212. The radius of the rounded corner 231 of the second electrode 2212 adjacent to the first intermediate electrode 22111 is equal to the radius of the rounded corner 231 of the first electrode 2211 adjacent to the first intermediate electrode 22111.

[0224] By making the radius of the rounded corner 231 of the second electrode 2212 equal to the radius of the rounded corner 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the first intermediate electrode 22111, it is beneficial to achieve an overhang design while making the area of ​​the second electrode 2212 larger, which is beneficial to improving the energy density and reliability of the battery cell 20.

[0225] Referring to Figures 9 and 10, in some embodiments, the first electrode plates 2211 located on both sides of the first intermediate electrode plate 22111 are symmetrically arranged with respect to the first intermediate electrode plate 22111. And / or the second electrode plates 2212 located on both sides of the first intermediate electrode plate 22111 are symmetrically arranged with respect to the first intermediate electrode plate 22111.

[0226] Along the first direction, a plurality of first electrode plates 2211 are symmetrically arranged on both sides of the first intermediate electrode plate 22111, and a plurality of second electrode plates 2212 are symmetrically arranged on both sides of the first intermediate electrode plate 22111.

[0227] It should be noted that "symmetry" here refers to approximate symmetry, not perfect symmetry.

[0228] By symmetrically arranging the first electrode plates 2211 on both sides of the first intermediate electrode plate 22111, the radii of the rounded corners 231 of the two symmetrically arranged first electrode plates 2211 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged first electrode plates 2211 can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell 20. Similarly, by symmetrically arranging the second electrode plates 2212 on both sides of the first intermediate electrode plate 22111, the radii of the rounded corners 231 of the two symmetrically arranged second electrode plates 2212 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged second electrode plates 2212 can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell 20.

[0229] Please refer to Figure 11, which is a side view of an electrode assembly 22 provided in some other embodiments of this application. In some embodiments, the number of first electrode plates 2211 is even, and the number of second electrode plates 2212 is odd. Along the first direction, the second electrode plate 2212 located in the middle position is the second intermediate electrode plate 22121, and multiple first electrode plates 2211 are provided on both sides of the second intermediate electrode plate 22121. Among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121.

[0230] The number of first electrode plates 2211 is even, and the number of second electrode plates 2212 is odd. The number of first electrode plates 2211 is one more than the number of second electrode plates 2212. For example, when there are 6 first electrode plates 2211, the number of second electrode plates 2212 can be 5.

[0231] When the number of second electrode plates 2212 is odd, the second electrode plate 2212 located in the middle position along the first direction is the second intermediate electrode plate 22121. Along the first direction, multiple first electrode plates 2211 are respectively arranged on both sides of the second intermediate electrode plate 22121.

[0232] Among the multiple first electrodes 2211 located on the same side of the second intermediate electrode 22121, the radius of the rounded corner 231 of the first electrode 2211 farther away from the second intermediate electrode 22121 is larger. Along the first direction, the radius of the rounded corner 231 of the first electrode 2211 closest to the second intermediate electrode 22121 is the smallest, and the radius of the rounded corner 231 of the first electrode 2211 farthest from the second intermediate electrode 22121 is the largest.

[0233] To achieve the overhang design, the first electrode 2211 extends beyond the second electrode 2212 in both length and width directions. Therefore, the first electrode 2211 is more prone to rubbing against the casing 21 than the second electrode 2212. When the number of first electrodes 2211 is even and the number of second electrodes 2212 is odd, among the multiple first electrodes 2211 located on the same side of the second intermediate electrode 22121, the radius of the rounded corner 231 of the first electrode 2211 closest to the second intermediate electrode 22121 gradually increases to the radius of the rounded corner 231 of the first electrode 2211 furthest from the second intermediate electrode 22121. This causes the electrode assembly 22 to form a spherical transition portion between two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrodes 2211 puncturing the packaging bag during isostatic pressing and improving the yield of the battery cell 20.

[0234] Referring to Figure 11, in some embodiments, the radius of the rounded corner 231 of the middle second pole piece 2212 gradually increases to the radius of the rounded corner 231 of the second pole pieces 2212 at both ends.

[0235] Along the first direction, the radius of the rounded corner 231 of the second pole piece 2212 located in the middle is the smallest, meaning the radius of the rounded corner 231 of the second middle pole piece 2212 is the smallest among the multiple second pole pieces 2212. The radius of the rounded corner 231 of the second pole pieces 2212 located at both ends is the largest, and the radius of the rounded corner 231 of the second pole pieces 2212 gradually increases from the middle to both ends. In other words, the radius of the rounded corner 231 of the second pole piece 2212 closer to the second middle pole piece 22121 is smaller than the radius of the rounded corner 231 of the second pole piece 2212 farther from the second middle pole piece 22121.

[0236] By gradually increasing the radius of the rounded corner 231 of the middle second electrode 2212 to the rounded corner 231 of the two ends, the changing trend of the rounded corner 231 of multiple first electrodes 2211 is adapted. While realizing the overhang design, the area of ​​the second electrode 2212 is made larger, which is beneficial to improving the energy density and reliability of the battery cell 20.

[0237] Referring to Figure 11, in some embodiments, the radius of the fillet 231 of the second electrode 2212 is equal to the radius of the fillet 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the second intermediate electrode 22121.

[0238] The radius of the rounded corner 231 of the second electrode 2212 is the first radius, and the radius of the rounded corner 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the first intermediate electrode 22111, is the second radius. The first radius is equal to the second radius.

[0239] Referring to Figure 11, along the first direction, the radius of the rounded corner 231 of the outermost first electrode 2211 of the electrode assembly 22 is equal to the radius of the rounded corner 231 of the adjacent second electrode 2212. The radius of the rounded corner 231 of the first electrode 2211 adjacent to the second intermediate electrode 22121 is equal to the radius of the rounded corner 231 of the second intermediate electrode 22121.

[0240] By making the radius of the rounded corner 231 of the second electrode 2212 equal to the radius of the rounded corner 231 of the first electrode 2211, which is adjacent to the second electrode 2212 and located on the side of the second electrode 2212 away from the second intermediate electrode 22121, it is beneficial to achieve an overhang design while making the area of ​​the second electrode 2212 larger, which is beneficial to improving the energy density and reliability of the battery cell 20.

[0241] Referring to Figure 11, in some embodiments, the first electrodes 2211 located on both sides of the second intermediate electrode 22121 are symmetrically arranged with respect to the second intermediate electrode 22121. And / or the second electrodes 2212 located on both sides of the second intermediate electrode 22121 are symmetrically arranged with respect to the second intermediate electrode 22121.

[0242] When the number of second electrode plates 2212 is odd, along the first direction, multiple first electrode plates 2211 are symmetrically arranged on both sides of the second intermediate electrode plate 22121, and multiple second electrode plates 2212 are symmetrically arranged on both sides of the second intermediate electrode plate 22121.

[0243] It should be noted that "symmetry" here refers to approximate symmetry, not perfect symmetry.

[0244] By symmetrically arranging the first electrode plates 2211 on both sides of the first intermediate electrode plate 22111 with respect to the second intermediate electrode plate 22121, the radii of the rounded corners 231 of the two symmetrically arranged first electrode plates 2211 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged first electrode plates 2211 can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell 20. Similarly, by symmetrically arranging the second electrode plates 2212 on both sides of the second intermediate electrode plate 22121 with respect to the second intermediate electrode plate 22121, the radii of the rounded corners 231 of the two symmetrically arranged second electrode plates 2212 are equal. When manufacturing the rounded corners 231, the two symmetrically arranged second electrode plates 2212 can be cut together, which simplifies manufacturing and reduces the manufacturing cost of the battery cell 20.

[0245] Referring to Figure 11, in some embodiments, the four corners of the solid electrolyte layer 223 are provided with chamfered structures 23.

[0246] The chamfer structures 23 at the four corners of the solid electrolyte layer 223 can be the same or different. For example, some chamfer structures 23 of the solid electrolyte layer 223 are rounded corners 231, while others are beveled corners. Referring to Figure 11, in the embodiment shown in the figure, the chamfer structures 23 at the four corners of the solid electrolyte layer 223 are the same.

[0247] By providing chamfered structures 23 at all four corners of the solid electrolyte layer 223, the risk of the four corners of the solid electrolyte layer 223 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, by providing chamfered structures 23 at all four corners of the solid electrolyte layer 223, the risk of the solid electrolyte layer 223 rubbing against the outer casing 21 is reduced, thus reducing the risk of damage to both the solid electrolyte layer 223 and the outer casing 21, and improving the reliability of the battery cell 20.

[0248] Referring to Figure 11, in some embodiments, the chamfer structure 23 is a rounded corner 231, the solid electrolyte layer 223 is connected to the first electrode 2211, and the radius of the rounded corner 231 of the solid electrolyte layer 223 is equal to the radius of the rounded corner 231 of the corresponding first electrode 2211.

[0249] The first electrode 2211 includes a first current collector and a first active material layer 2214, the first active material layer 2214 being disposed along a first direction on at least one side of the first current collector. The solid electrolyte layer 223 may be disposed on the side of the first active material layer 2214 opposite to the first current collector.

[0250] In some embodiments, a solid electrolyte layer 223 is coated on the side of the first active material layer 2214 opposite to the first current collector.

[0251] The radius of the fillet 231 of the solid electrolyte layer 223 is equal to the radius of the fillet 231 of the corresponding first electrode 2211. During manufacturing, since the solid electrolyte layer 223 is connected to the first electrode 2211, the solid electrolyte layer 223 and the first electrode 2211 can be chamfered together.

[0252] By connecting the solid electrolyte layer 223 to the first electrode 2211, it is simpler and more convenient to stack the first electrode 2211, the solid electrolyte layer 223, and the second electrode 2212 along the first direction. Furthermore, connecting the solid electrolyte layer 223 to the first electrode 2211 allows the solid electrolyte layer 223 to stably separate the first electrode 2211 and the second electrode 2212, and facilitates ion transport, which helps reduce the internal resistance of the battery cell 20. By making the radius of the rounded corner 231 of the solid electrolyte layer 223 equal to the radius of the rounded corner 231 of its corresponding first electrode 2211, the solid electrolyte layer 223 covers the first electrode 2211 as much as possible, reducing the risk of short circuits due to contact between the first electrode 2211 and the second electrode 2212, thus improving the reliability of the battery cell 20.

[0253] Please refer to Figure 12, which is a side view of an electrode assembly 22 provided in some other embodiments of this application. In some embodiments, the electrode 221 includes 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 have opposite polarities and are respectively disposed on both sides of the current collector 2213. Along the first direction, at least one of the current collector 2213, the first active material layer 2214, and the second active material layer 2215 of the two electrodes 221 that are furthest apart has a chamfered structure 23 at each of its four corners.

[0254] The electrode 221 is a bipolar electrode. A first active material layer 2214 and a second active material layer 2215 are respectively disposed 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.

[0255] "At least one of the current collectors 2213 of the two farthest electrodes 221, the first active material layer 2214, and the second active material layer 2215 has chamfered structures 23 at all four corners" can mean that the current collectors 2213 of the two farthest electrodes 221 have chamfered structures 23 at all four corners, or that the first active material layer 2214 of the two farthest electrodes 221 has chamfered structures 23 at all four corners, or that the second active material layer 2215 of the two farthest electrodes 221 has chamfered structures 23 at all four corners. Each corner is provided with a chamfered structure 23. Alternatively, the four corners of the first active material layer 2214 and the current collector 2213 of the two farthest electrodes 221 can be provided with a chamfered structure 23. Alternatively, the four corners of the second active material layer 2215 and the current collector 2213 of the two farthest electrodes 221 can be provided with a chamfered structure 23. Alternatively, the four corners of the current collector 2213, the first active material layer 2214 and the second active material layer 2215 of the two farthest electrodes 221 can be provided with a chamfered structure 23.

[0256] By including a current collector 2213, a first active material layer 2214, and a second active material layer 2215 in the electrode 221, with the first active material layer 2214 and the second active material layer 2215 having opposite polarities, the battery cell 20 can achieve a higher energy density. By providing chamfered structures 23 at all 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 farthest electrodes 221, the risk of puncturing the packaging bag during isostatic pressing is reduced, thus improving the yield rate of the battery cell 20. Furthermore, by providing chamfered structures 23 at all 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 farthest electrodes 221, the risk of the electrode 221 rubbing against the casing 21 is reduced, thus reducing the risk of damage to both the electrode 221 and the casing 21, and improving the reliability of the battery cell 20.

[0257] Referring to Figure 12, in some embodiments, the chamfer structure 23 is a rounded corner 231, and each of the four corners of the electrode 221 is provided with a rounded corner 231.

[0258] When the chamfer structure 23 is rounded 231, the transition is smoother and less likely to produce new sharp corners. By providing rounded corners 231 to all four corners of each electrode 221, the risk of multiple electrode 221 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, providing rounded corners 231 to all four corners of each electrode 221 also reduces the risk of multiple electrode 221 scraping against the casing 21, further reducing the risk of damage to multiple electrode 221 and the casing 21, and improving the reliability of the battery cell 20.

[0259] Referring to Figure 12, in some embodiments, the number of electrodes 221 is odd, and the radius of the rounded corner 231 of the middle electrode 221 gradually increases to the radius of the rounded corner 231 of the electrodes at both ends.

[0260] Along the first direction, the radius of the rounded corner 231 of the middle electrode 221 is the smallest, and the radius of the rounded corner 231 of the two ends electrode 221 is the largest. The radius of the rounded corner 231 of the electrode 221 gradually increases from the middle to the two ends. In other words, the radius of the rounded corner 231 of the electrode 221 closer to the middle is smaller than the radius of the rounded corner 231 of the electrode 221 farther from the middle.

[0261] When the number of electrode sheets 221 is odd, by gradually increasing the radius of the rounded corner 231 of the middle electrode sheet 221 to the radius of the rounded corner 231 of the two end electrode sheets 221, the electrode assembly 22 forms a spherical transition part at two adjacent corners along the first direction, thereby further reducing the risk of multiple electrode sheets 221 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0262] Please refer to Figure 13, which is a side view of the electrode assembly 22 provided in some other embodiments of this application. In some embodiments, the number of electrodes 221 is even. Along the first direction, the solid electrolyte layer 223 located in the middle position is the intermediate layer 2231, and multiple electrodes 221 are provided on both sides of the intermediate layer 2231. Among the multiple electrodes 221 located on the same side of the intermediate layer 2231, the radius of the rounded corner 231 of the electrode 221 closest to the intermediate layer 2231 gradually increases to the radius of the rounded corner 231 of the electrode 221 furthest from the intermediate layer 2231.

[0263] When the number of electrodes 221 is even, the solid electrolyte layer 223 located in the middle along the first direction is the intermediate layer 2231. Along the first direction, multiple electrodes 221 are respectively disposed on both sides of the intermediate layer 2231.

[0264] Among the multiple electrodes 221 located on the same side of the intermediate layer 2231, the radius of the rounded corner 231 of the electrode 221 farther away from the intermediate layer 2231 is larger. Along the first direction, the radius of the rounded corner 231 of the electrode 221 closest to the intermediate layer 2231 is the smallest, and the radius of the rounded corner 231 of the electrode 221 farthest from the intermediate layer 2231 is the largest.

[0265] When the number of electrode sheets 221 is even, among the multiple electrode sheets 221 located on the same side of the intermediate layer 2231, the radius of the rounded corner 231 of the electrode sheet 221 closest to the intermediate layer 2231 gradually increases to the radius of the rounded corner 231 of the electrode sheet 221 furthest from the intermediate layer 2231. This causes the electrode assembly 22 to form a spherical transition part between two adjacent corners along the first direction, thereby further reducing the risk of multiple electrode sheets 221 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0266] In some embodiments, the chamfer structure 23 is a rounded corner 231.

[0267] When the chamfer structure 23 is rounded corner 231, the transition is smoother and it is less likely to generate new sharp corners. This is more conducive to reducing the risk that the four corners of the two electrodes 221 that are furthest apart during the isostatic pressing process will puncture the packaging bag, which is beneficial to improving the yield of the battery cell 20.

[0268] Please refer to Figure 4 again. In some embodiments, the radius of fillet 231 is R, which satisfies: 1mm≤R≤10mm.

[0269] R represents the radius of fillet 231. The radius of fillet 231 can be: R = 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0270] When R ≥ 1 mm, the radius of the fillet 231 is relatively large, resulting in a smoother transition and better transition effect. This helps reduce the risk of the first electrode 2211 puncturing the packaging bag during isostatic pressing, and improves the yield of the battery cell 20. When R ≤ 10 mm, the radius of the fillet 231 is not too large, which helps reduce the volume of the electrode assembly 22 and improves the energy density of the battery cell 20. Therefore, when 1 mm ≤ R ≤ 10 mm, both the yield and energy density of the battery cell 20 can be balanced.

[0271] Optionally, 1mm≤R≤5mm.

[0272] The radius of fillet 231 can be: R = 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0273] When R ≥ 1 mm, the radius of the fillet 231 is relatively large, resulting in a smoother transition and better transition effect. This helps reduce the risk of the first electrode 2211 puncturing the packaging bag during isostatic pressing, and improves the yield of the battery cell 20. When R ≤ 5 mm, the radius of the fillet 231 is not too large, which is more conducive to reducing the volume of the electrode assembly 22 and improving the energy density of the battery cell 20. Therefore, when 1 mm ≤ R ≤ 5 mm, it is possible to better balance the yield and energy density of the battery cell 20.

[0274] In some embodiments, the outer shell 21 is a soft shell.

[0275] The outer shell 21 is a soft shell, meaning that the material used to manufacture the outer shell 21 is relatively soft. For example, the outer shell 21 can be an aluminum-plastic film, or it can be a heat-shrink film.

[0276] When the outer shell 21 is a soft shell, by setting chamfered structures 23 at the four corners of the first electrode 2211 and / or the second electrode 2212, it is beneficial to reduce the risk of the first electrode 2211 and / or the second electrode 2212 puncturing the outer shell 21, and to improve the reliability of the battery cell 20.

[0277] In some embodiments, the soft shell is an aluminum-plastic film.

[0278] The outer shell 21 is made of aluminum-plastic film, which is simple and convenient to manufacture and has a low cost.

[0279] Referring to Figures 4 to 13, this embodiment of the application also provides an electrode assembly 22, which includes a solid electrolyte layer 223 and a plurality of electrode sheets 221. Along a first direction, the solid electrolyte layer 223 is disposed between two adjacent electrode sheets 221. Each electrode sheet 221 includes an active material layer. In two adjacent electrode sheets 221, the active material layers facing the solid electrolyte layer 223 located between the two adjacent electrode sheets 221 have opposite polarities. Along the first direction, the four corners of the two farthest electrode sheets 221 are provided with chamfered structures 23.

[0280] In some embodiments, the plurality of electrode plates 221 include a first electrode plate 2211 and a second electrode plate 2212, the first electrode plate 2211 and the second electrode plate 2212 having opposite polarities. Along a first direction, the first electrode plate 2211, the solid electrolyte layer 223, and the second electrode plate 2212 are stacked, with the solid electrolyte layer 223 disposed between the first electrode plate 2211 and the second electrode plate 2212. There are multiple first electrode plates 2211; along the first direction, the two first electrode plates 2211 furthest apart are located at both ends of the electrode assembly 22, and each of the four corners of the two furthest first electrode plates 2211 has a chamfered structure 23. The electrode assembly 22 includes the stacked first electrode plates 2211, the solid electrolyte layer 223, and the second electrode plates 2212, thus making the electrode assembly 22 simple and convenient to manufacture, and at a low cost. By providing chamfered structures 23 at all four corners of the two farthest first electrode sheets 2211, the risk of the four corners of the two farthest first electrode sheets 2211 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, by providing chamfered structures 23 at all four corners of the two farthest first electrode sheets 2211, the risk of the first electrode sheets 2211 rubbing against the casing 21 is also reduced, which helps reduce the risk of damage to the first electrode sheets 2211 and the casing 21, and helps improve the reliability of the battery cell 20.

[0281] In some embodiments, the chamfer structure 23 is a rounded corner 231. There are multiple first electrode sheets 2211 and second electrode sheets 2212, with each first electrode sheet 2211 and each second electrode sheet 2212 having rounded corners 231 at all four corners. When the chamfer structure 23 is a rounded corner 231, the transition is smoother and less prone to creating new sharp corners. By providing rounded corners 231 at all four corners of each first electrode sheet 2211, the risk of multiple first electrode sheets 2211 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, providing rounded corners 231 at all four corners of each first electrode sheet 2211 also reduces the risk of the multiple first electrode sheets 2211 rubbing against the casing 21, further reducing the risk of damage to both the multiple first electrode sheets 2211 and the casing 21, thus improving the reliability of the battery cell 20. Similarly, by providing rounded corners 231 at all four corners of each second electrode 2212, the risk of multiple second electrode 2212 puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, providing rounded corners 231 at all four corners of each second electrode 2212 also reduces the risk of the four corners of multiple second electrode 2212 rubbing against the casing 21, further reducing the risk of damage to both the multiple second electrode 2212 and the casing 21, thus improving the reliability of the battery cell 20.

[0282] In some embodiments, the first electrode 2211 is a negative electrode, and the second electrode 2212 is a positive electrode. The length of the first electrode 2211 is greater than the length of the second electrode 2212, and the width of the first electrode 2211 is greater than the width of the second electrode 2212. The thickness direction of the first electrode 2211 is parallel to a first direction. When the first electrode 2211 is a negative electrode and the second electrode 2212 is a positive electrode, by making the length of the first electrode 2211 greater than the length of the second electrode 2212, and the width of the first electrode 2211 greater than the width of the second electrode 2212, it is beneficial to reduce assembly difficulty, achieve an overhang design, and reduce the risk of metal ion precipitation.

[0283] In some embodiments, the number of first electrodes 2211 is odd, and the number of second electrodes 2212 is even. The radius of the rounded corner 231 of the middle first electrode 2211 gradually increases towards the rounded corner 231 of the first electrodes 2211 at both ends. To achieve an overhang design, the first electrode 2211 extends beyond the second electrode 2212 in both its length and width directions. Therefore, during isostatic pressing, the first electrode 2211 is more likely to puncture the packaging bag than the second electrode 2212. When the number of first electrode plates 2211 is odd and the number of second electrode plates 2212 is even, by gradually increasing the radius of the rounded corner 231 of the middle first electrode plate 2211 to the radius of the rounded corner 231 of the first electrode plates 2211 at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly 22 along the first direction. This further reduces the risk of multiple first electrode plates 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0284] In some embodiments, the number of first electrode plates 2211 is even, and the number of second electrode plates 2212 is odd. Along the first direction, the second electrode plate 2212 located in the middle position is the second intermediate electrode plate 22121, and multiple first electrode plates 2211 are provided on both sides of the second intermediate electrode plate 22121. Among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121. In order to achieve the overhang design, the first electrode plate 2211 extends beyond the second electrode plate 2212 in both its length and width directions. Therefore, the first electrode plate 2211 is more likely to rub against the outer casing 21 than the second electrode plate 2212. When the number of first electrode plates 2211 is even and the number of second electrode plates 2212 is odd, among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121. This causes the electrode assembly 22 to form a spherical transition portion at two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrode plates 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0285] In some embodiments, the electrode 221 includes 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 have opposite polarities and are respectively disposed on both sides of the current collector 2213. Along the first direction, at least one of the current collector 2213, the first active material layer 2214, and the second active material layer 2215 of the two electrodes 221 that are furthest apart has chamfered structures 23 at all four corners. By making the electrode 221 include a current collector 2213, a first active material layer 2214, and a second active material layer 2215, with the first active material layer 2214 and the second active material layer 2215 having opposite polarities, it is beneficial to make the battery cell 20 have a higher energy density. By providing chamfered structures 23 at all 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 farthest electrodes 221, the risk of puncturing the packaging bag during isostatic pressing is reduced, which helps improve the yield of the battery cell 20. Furthermore, by providing chamfered structures 23 at all 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 farthest electrodes 221, the risk of the electrodes 221 rubbing against the casing 21 is also reduced, which helps reduce the risk of damage to the electrodes 221 and the casing 21, and helps improve the reliability of the battery cell 20.

[0286] In some embodiments, the chamfer structure 23 is a rounded corner 231, and each electrode 221 has rounded corners 231 at all four corners. When the chamfer structure 23 is a rounded corner 231, the transition is smoother and it is less likely to generate new sharp corners. By providing rounded corners 231 at all four corners of each electrode 221, it is easier to reduce the risk of the four corners of multiple electrodes 221 puncturing the packaging bag during isostatic pressing, which helps to improve the yield of the battery cell 20. Furthermore, providing rounded corners 231 at all four corners of each electrode 221 also helps to reduce the risk of the four corners of multiple electrodes 221 rubbing against the casing 21, which helps to reduce the risk of damage to multiple electrodes 221 and the casing 21, and helps to improve the reliability of the battery cell 20.

[0287] In some embodiments, the number of electrodes 221 is odd, and the radius of the rounded corner 231 of the middle electrode 221 gradually increases from the radius of the rounded corner 231 of the electrodes at both ends. When the number of electrodes 221 is odd, by making the radius of the rounded corner 231 of the middle electrode 221 gradually increase from the radius of the rounded corner 231 of the electrodes at both ends, the electrode assembly 22 forms a spherical transition portion at two adjacent corners along the first direction, thereby further reducing the risk of multiple electrodes 221 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0288] In some embodiments, the number of electrodes 221 is even. Along the first direction, the solid electrolyte layer 223 located in the middle is an intermediate layer 2231, and multiple electrodes 221 are disposed on both sides of the intermediate layer 2231. Among the multiple electrodes 221 located on the same side of the intermediate layer 2231, the radius of the rounded corner 231 of the electrode 221 closest to the intermediate layer 2231 gradually increases to the radius of the rounded corner 231 of the electrode 221 furthest from the intermediate layer 2231. When the number of electrode sheets 221 is even, among the multiple electrode sheets 221 located on the same side of the intermediate layer 2231, the radius of the rounded corner 231 of the electrode sheet 221 closest to the intermediate layer 2231 gradually increases to the radius of the rounded corner 231 of the electrode sheet 221 furthest from the intermediate layer 2231. This causes the electrode assembly 22 to form a spherical transition part between two adjacent corners along the first direction, thereby further reducing the risk of multiple electrode sheets 221 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0289] Please refer to Figure 14, which is a schematic block diagram of an electrode assembly manufacturing method 30 provided in some embodiments of this application. This application also provides an electrode assembly manufacturing method 30, which includes:

[0290] Step S100: Provide multiple electrode plates 221;

[0291] Step S300: Provide a solid electrolyte layer 223;

[0292] Step S400: Multiple electrode sheets 221 and solid electrolyte layer 223 are stacked along the first direction, such that the solid electrolyte layer 223 is disposed between two adjacent electrode sheets 221 along the first direction to form an electrode assembly blank. The electrode sheet 221 includes an active material layer. In two adjacent electrode sheets 221, the polarity of the active material layer facing the solid electrolyte layer 223 located between the two adjacent electrode sheets 221 is opposite. Along the first direction, the four corners of the two electrode sheets 221 that are farthest apart are provided with chamfer structures 23.

[0293] Step S500: Pack the electrode assembly blank into a packaging bag;

[0294] Step S600: Perform isostatic pressing on the electrode assembly blank placed in the packaging bag.

[0295] In step S100, a plurality of electrode plates 221 are provided, and at least two of the electrode plates 221 have chamfered structures 23 at their four corners.

[0296] In step S400, when multiple electrode sheets 221 and solid electrolyte layer 223 are stacked along the first direction, in addition to the solid electrolyte layer 223 being disposed between two adjacent electrode sheets 221 along the first direction, the two electrode sheets 221 that are furthest apart are the electrode sheets 221 located at both ends of the electrode assembly blank, and the four corners of the two electrode sheets 221 that are furthest apart are provided with chamfered structures 23.

[0297] In step S500, the packaging bag has a receiving cavity with one end open, allowing the electrode assembly blank to be inserted into the packaging bag from the open end. The packaging bag can be aluminum-plastic film, heat-shrink film, etc.

[0298] The working principle of isostatic pressing is based on Pascal's law: "Pressure in a medium (liquid or gas) within a closed container is transmitted equally in all directions." Isostatic pressing facilitates the densification of the electrode assembly 22, thereby improving the reliability and energy density of the battery cell 20.

[0299] In step S600, the encapsulation bag containing the electrode assembly blank can be placed into the hydraulic oil, and then the hydraulic oil can be pressurized to achieve isostatic pressure treatment.

[0300] Please refer to Figure 15, which is a schematic block diagram of an electrode assembly manufacturing method 30 provided in some other embodiments of this application. In some embodiments, the plurality of electrode sheets 221 include a first electrode sheet 2211 and a second electrode sheet 2212, wherein the polarities of the first electrode sheet 2211 and the second electrode sheet 2212 are opposite. Providing the plurality of electrode sheets 221 includes:

[0301] Provide the first electrode 2211;

[0302] Step S200: Provide the second electrode 2212.

[0303] The first electrode 2211 includes:

[0304] Step S110: Provide multiple first electrode blanks;

[0305] Step S120: Chamfer the four corners of at least two first electrode blanks to form a chamfered structure 23.

[0306] In the electrode assembly blank, along the first direction, a first electrode 2211, a solid electrolyte layer 223, and a second electrode 2212 are stacked, with the solid electrolyte layer 223 disposed between the first electrode 2211 and the second electrode 2212. Along the first direction, the two first electrodes 2211 furthest apart are the electrodes 221 at both ends of the electrode assembly 22, and each of the four corners of the two furthest first electrodes 2211 has a chamfered structure 23.

[0307] The first electrode blank is the electrode structure after the first active material layer 2214 has been coated onto the first current collector and after slitting and die-cutting. For the first electrode 2211 with chamfered structures 23 at the four corners, the four corners of the first electrode blank are chamfered to obtain the first electrode 2211. For the first electrode 2211 without chamfered structures 23 at the four corners, the first electrode blank is the first electrode 2211.

[0308] By chamfering the four corners of the first electrode blank, the four corners of the first electrode 2211 are provided with chamfered structures 23.

[0309] Please refer to Figure 16, which is a schematic block diagram of an electrode assembly manufacturing method 30 provided in some embodiments of this application. In some embodiments, chamfering the four corners of at least two first electrode blanks includes:

[0310] Step S121: Round the four corners of each first electrode blank 231;

[0311] In the electrode assembly blank, each of the four corners of the first electrode 2211 is provided with a rounded corner 231.

[0312] The four corners of each first electrode blank are rounded 231, so that each first electrode 2211 has rounded corners 231 at all four corners. When the chamfer structure 23 is rounded corners 231, the transition is smoother and it is less likely to produce new sharp corners. This is more conducive to reducing the risk of the four corners of the first electrode 2211 puncturing the packaging bag during the isostatic pressing process, and is conducive to improving the yield of the battery cell 20.

[0313] In some embodiments, during the step of rounding the four corners 231 of each first electrode blank, the radii of the rounded corners 231 of the multiple first electrode blanks are different. In the electrode assembly blank, when the number of first electrodes 2211 is odd and the number of second electrodes 2212 is even, the radius of the rounded corner 231 of the middle first electrode 2211 gradually increases towards the radius of the rounded corner 231 of the first electrodes 2211 at both ends. When the number of first electrode plates 2211 is even and the number of second electrode plates 2212 is odd, along the first direction, the second electrode plate 2212 located in the middle position is the second intermediate electrode plate 22121. Multiple first electrode plates 2211 are provided on both sides of the second intermediate electrode plate 22121. Among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121.

[0314] To achieve the overhang design, the first electrode 2211 extends beyond the second electrode 2212 in both length and width. Therefore, during isostatic pressing, the first electrode 2211 is more likely to puncture the packaging bag than the second electrode 2212. When the number of first electrodes 2211 is odd and the number of second electrodes 2212 is even, by gradually increasing the radius of the rounded corner 231 of the middle first electrode 2211 to the radius of the rounded corner 231 of the first electrodes 2211 at both ends, a spherical transition portion is formed between two adjacent corners of the electrode assembly 22 along the first direction. This further reduces the risk of multiple first electrodes 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20. When the number of first electrode plates 2211 is even and the number of second electrode plates 2212 is odd, among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121. This causes the electrode assembly 22 to form a spherical transition portion at two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrode plates 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0315] Please refer to Figure 17, which is a schematic block diagram of an electrode assembly manufacturing method 30 provided in some embodiments of this application. In some embodiments, providing the second electrode 2212 includes:

[0316] Step S210: Provide multiple second electrode blanks;

[0317] Step S220: Chamfer the four corners of at least two second electrode blanks to form a chamfered structure 23;

[0318] In the electrode assembly blank, along the first direction, the four corners of the two second electrode plates 2212 that are furthest apart are provided with chamfered structures 23.

[0319] The second electrode 2212 includes a second current collector and a second active material layer 2215, the second active material layer 2215 being disposed along a first direction on at least one side of the second current collector.

[0320] The second electrode blank is the electrode structure after the second active material layer 2215 has been coated onto the second current collector and after slitting and die-cutting. For the second electrode 2212 with chamfered structures 23 at the four corners, the four corners of the second electrode blank are chamfered to obtain the second electrode 2212. For the second electrode 2212 without chamfered structures 23 at the four corners, the second electrode blank is the second electrode 2212.

[0321] By chamfering the four corners of the second electrode blank, each of the four corners of the second electrode 2212 is provided with a chamfered structure 23. Along the first direction, the two second electrodes 2212 furthest apart are closer to the two ends of the electrode assembly 22. During isostatic pressing, the four corners of the two furthest second electrodes 2212 are relatively easy to puncture the packaging bag. In this embodiment, by providing chamfered structures 23 at the four corners of the two furthest second electrodes 2212, the risk of the four corners of the two furthest second electrodes 2212 puncturing the packaging bag is reduced, which helps improve the yield of the battery cell 20. Furthermore, by providing chamfered structures 23 at the four corners of the two furthest second electrodes 2212, the risk of the four corners of the two furthest second electrodes 2212 rubbing against the outer casing 21 is reduced, which helps reduce the risk of damage to the second electrodes 2212 and the outer casing 21, and helps improve the reliability of the battery cell 20.

[0322] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0323] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0324] Please refer to Figures 3 to 13 for some embodiments of this application.

[0325] This application provides a battery cell 20, which includes a housing 21 and an electrode assembly 22 disposed within the housing 21. The electrode assembly 22 includes a first electrode 2211, a second electrode 2212, and a solid electrolyte layer 223. The first electrode 2211 and the second electrode 2212 have opposite polarities. The first electrode 2211, the solid electrolyte layer 223, and the second electrode 2212 are stacked along a first direction. Along the first direction, the solid electrolyte layer 223 is at least partially disposed between the first electrode 2211 and the second electrode 2212. There are multiple first electrodes 2211. Along the first direction, the two first electrodes 2211 furthest apart are located at both ends of the electrode assembly 22. Each of the four corners of the two furthest first electrodes 2211 has a chamfered structure 23. The first electrode 2211, the solid electrolyte layer 223, and the second electrode 2212 are stacked along the first direction, that is, the electrode assembly 22 is a stacked electrode assembly. For stacked electrode assemblies, during isostatic pressing, the electrodes 221 located at both ends of the electrode assembly 22 are most likely to puncture the packaging bag along the first direction. In this embodiment, the two first electrodes 2211 that are furthest apart are the electrodes 221 located at both ends of the electrode assembly 22. By providing chamfered structures 23 at the four corners of the two furthest first electrodes 2211, it is beneficial to reduce the risk of the four corners of the two furthest first electrodes 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20. In addition, by providing chamfered structures 23 at the four corners of the two farthest first electrode plates 2211, it is beneficial to reduce the risk of the first electrode plate 2211 rubbing against the outer casing 21, reduce the risk of damage to the first electrode plate 2211 and the outer casing 21, and improve the reliability of the battery cell 20.

[0326] The chamfer structure 23 has rounded corners 231. There are multiple first electrode sheets 2211 and second electrode sheets 2212. Each first electrode sheet 2211 and each second electrode sheet 2212 has rounded corners 231 at all four corners. When the chamfer structure 23 has rounded corners 231, the transition is smoother, less likely to generate new sharp corners, and it is more conducive to reducing the risk of the four corners of the two first electrode sheets 2211 furthest apart puncturing the packaging bag during the isostatic pressing process, thus improving the yield of the battery cell 20. By providing rounded corners 231 at all four corners of each first electrode sheet 2211, it is more conducive to reducing the risk of the four corners of multiple first electrode sheets 2211 puncturing the packaging bag during the isostatic pressing process, thus improving the yield of the battery cell 20. Furthermore, rounding the four corners of each first electrode 2211 with rounded corners 231 further reduces the risk of the four corners of the multiple first electrodes 2211 rubbing against the outer casing 21, thus reducing the risk of damage to both the multiple first electrodes 2211 and the outer casing 21, and improving the reliability of the battery cell 20. Similarly, rounding the four corners of each second electrode 2212 with rounded corners 231 further reduces the risk of the four corners of the multiple second electrodes 2212 puncturing the packaging bag during isostatic pressing, thus improving the yield of the battery cell 20. Furthermore, rounding the four corners of each second electrode 2212 with rounded corners 231 further reduces the risk of the four corners of the multiple second electrodes 2212 rubbing against the outer casing 21, thus reducing the risk of damage to both the multiple second electrodes 2212 and the outer casing 21, and improving the reliability of the battery cell 20.

[0327] The first electrode 2211 is the negative electrode, and the second electrode 2212 is the positive electrode. The length of the first electrode 2211 is greater than the length of the second electrode 2212, and the width of the first electrode 2211 is greater than the width of the second electrode 2212. The thickness direction of the first electrode 2211 is parallel to the first direction. When the first electrode 2211 is the negative electrode and the second electrode 2212 is the positive electrode, making the length and width of the first electrode 2211 greater than the length and width of the second electrode 2212 helps to reduce assembly difficulty, achieve an overhang design, and reduce the risk of metal ion precipitation.

[0328] In some embodiments, the number of first electrodes 2211 is odd, and the number of second electrodes 2212 is even. The radius of the rounded corner 231 of the middle first electrode 2211 gradually increases from the radius of the rounded corner 231 of the first electrodes 2211 at both ends. When the number of first electrodes 2211 is odd and the number of second electrodes 2212 is even, by making the radius of the rounded corner 231 of the middle first electrode 2211 gradually increase from the radius of the rounded corner 231 of the first electrodes 2211 at both ends, the electrode assembly 22 forms a spherical transition portion at two adjacent corners along the first direction. This further reduces the risk of multiple first electrodes 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0329] In other embodiments, the number of first electrode plates 2211 is even, and the number of second electrode plates 2212 is odd. Along the first direction, the second electrode plate 2212 located in the middle position is the second intermediate electrode plate 22121. Multiple first electrode plates 2211 are provided on both sides of the second intermediate electrode plate 22121. Among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121. When the number of first electrode plates 2211 is even and the number of second electrode plates 2212 is odd, among the multiple first electrode plates 2211 located on the same side of the second intermediate electrode plate 22121, the radius of the rounded corner 231 of the first electrode plate 2211 closest to the second intermediate electrode plate 22121 gradually increases to the radius of the rounded corner 231 of the first electrode plate 2211 furthest from the second intermediate electrode plate 22121. This causes the electrode assembly 22 to form a spherical transition portion at two adjacent corners along the first direction, thereby further reducing the risk of multiple first electrode plates 2211 puncturing the packaging bag during isostatic pressing, which is beneficial to improving the yield of the battery cell 20.

[0330] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, wherein, include: shell; An electrode assembly is disposed within the housing. The electrode assembly includes a solid electrolyte layer and a plurality of electrodes. Along a first direction, the solid electrolyte layer is disposed between two adjacent electrodes. Each electrode includes an active material layer. In two adjacent electrodes, the active material layers facing the solid electrolyte layer located between the two adjacent electrodes have opposite polarities. Along the first direction, the four corners of the two electrodes that are furthest apart are all provided with chamfered structures.

2. The battery cell according to claim 1, wherein, The plurality of electrodes include a first electrode and a second electrode, the first electrode and the second electrode having opposite polarities. Along the first direction, the first electrode, the solid electrolyte layer and the second electrode are stacked, and the solid electrolyte layer is disposed between the first electrode and the second electrode. There are multiple first electrodes. Along the first direction, the two first electrodes that are furthest apart are located at both ends of the electrode assembly. The four corners of the two first electrodes that are furthest apart are provided with chamfered structures.

3. The battery cell according to claim 2, wherein, Each of the four corners of the first electrode is provided with the chamfered structure.

4. The battery cell according to claim 2 or 3, wherein, There are multiple second electrodes, and the four corners of the two second electrodes that are furthest apart along the first direction are provided with the chamfered structure.

5. The battery cell according to claim 4, wherein, Each of the four corners of the second electrode is provided with the chamfered structure.

6. The battery cell according to any one of claims 2-5, wherein, The chamfered structure is a rounded corner. There are multiple first and second electrodes. Each of the four corners of the first electrode is provided with the rounded corner, and each of the four corners of the second electrode is provided with the rounded corner.

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

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

9. The battery cell according to claim 8, wherein, The number of first electrodes is odd, the number of second electrodes is even, and the radius of the rounded corner of the middle first electrode gradually increases from the radius of the rounded corner of the first electrodes at both ends.

10. The battery cell according to claim 9, wherein, Along the first direction, the first electrode located in the middle position is the first intermediate electrode, and multiple second electrodes are provided on both sides of the first intermediate electrode; Among the plurality of second electrodes located on the same side of the first intermediate electrode, the radius of the rounded corner of the second electrode closest to the first intermediate electrode gradually increases to the radius of the rounded corner of the second electrode furthest from the first intermediate electrode.

11. The battery cell according to claim 10, wherein, The radius of the rounded corner of the second electrode is equal to the radius of the rounded corner of the first electrode that is adjacent to the second electrode and located on the side of the second electrode away from the first intermediate electrode.

12. The battery cell according to claim 10 or 11, wherein, The first electrodes located on both sides of the first intermediate electrode are symmetrically arranged with respect to the first intermediate electrode; and / or The second electrodes located on both sides of the first intermediate electrode are symmetrically arranged with respect to the first intermediate electrode.

13. The battery cell according to claim 8, wherein, The number of first electrodes is even, the number of second electrodes is odd, and the second electrode located in the middle along the first direction is the second middle electrode. Multiple first electrodes are provided on both sides of the second middle electrode. Among the plurality of first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

14. The battery cell according to claim 13, wherein, The radius of the rounded corner of the middle second electrode gradually increases towards the radius of the rounded corner of the second electrodes at both ends.

15. The battery cell according to claim 14, wherein, The radius of the rounded corner of the second electrode is equal to the radius of the rounded corner of the first electrode that is adjacent to the second electrode and located on the side of the second electrode away from the second intermediate electrode.

16. The battery cell according to any one of claims 13-15, wherein, The first electrodes located on both sides of the second intermediate electrode are symmetrically arranged with respect to the second intermediate electrode; and / or The second electrodes located on both sides of the second intermediate electrode are symmetrically arranged with respect to the second intermediate electrode.

17. The battery cell according to any one of claims 6-16, wherein, The solid electrolyte layer has chamfered corners at all four corners.

18. The battery cell according to claim 17, wherein, The chamfered structure is a rounded corner, the solid electrolyte layer is connected to the first electrode, and the radius of the rounded corner of the solid electrolyte layer is equal to the radius of the rounded corner of the corresponding first electrode.

19. The battery cell according to any one of claims 1-18, wherein, The electrode includes a current collector, a first active material layer, and a second active material layer. The first active material layer and the second active material layer have opposite polarities and are respectively disposed on both sides of the current collector. Along the first direction, at least one of the current collectors, the first active material layer, and the second active material layer of the two electrodes that are furthest apart are provided with the chamfered structure at all four corners.

20. The battery cell according to claim 19, wherein, The chamfered structure is rounded, and each of the four corners of the electrode is provided with the rounded corners.

21. The battery cell according to claim 20, wherein, The number of electrodes is odd, and the radius of the rounded corner of the middle electrode gradually increases from the radius of the rounded corner of the electrodes at both ends.

22. The battery cell according to claim 20, wherein, The number of electrodes is even. Along the first direction, the solid electrolyte layer located in the middle position is the middle layer, and multiple electrodes are provided on both sides of the middle layer. Among the plurality of electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer.

23. The battery cell according to any one of claims 1-22, wherein, The chamfered structure is a rounded corner.

24. The battery cell according to claim 23, wherein, The radius of the fillet is R, which satisfies: 1mm≤R≤10mm.

25. The battery cell according to claim 24, wherein, 1mm≤R≤5mm.

26. The battery cell according to any one of claims 1-25, wherein, The outer shell is a soft shell.

27. The battery cell according to claim 26, wherein, The soft shell is made of aluminum-plastic film.

28. An electrode assembly, wherein, The device includes a solid electrolyte layer and multiple electrodes. Along a first direction, the solid electrolyte layer is disposed between two adjacent electrodes. Each electrode includes an active material layer. In the two adjacent electrodes, the active material layers facing the solid electrolyte layer located between the two adjacent electrodes have opposite polarities. Along the first direction, the four corners of the two electrodes that are furthest apart are all provided with chamfered structures.

29. The electrode assembly according to claim 28, wherein, The plurality of electrodes include a first electrode and a second electrode, the first electrode and the second electrode having opposite polarities. Along the first direction, the first electrode, the solid electrolyte layer and the second electrode are stacked, and the solid electrolyte layer is disposed between the first electrode and the second electrode. There are multiple first electrodes. Along the first direction, the two first electrodes that are furthest apart are located at both ends of the electrode assembly. The four corners of the two first electrodes that are furthest apart are provided with chamfered structures.

30. The electrode assembly according to claim 29, wherein, The chamfered structure is a rounded corner. There are multiple first and second electrodes. Each of the four corners of the first electrode is provided with the rounded corner, and each of the four corners of the second electrode is provided with the rounded corner.

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

32. The electrode assembly according to claim 31, wherein, The number of first electrodes is odd, the number of second electrodes is even, and the radius of the rounded corner of the middle first electrode gradually increases from the radius of the rounded corner of the first electrodes at both ends.

33. The electrode assembly according to claim 31, wherein, The number of first electrodes is even, the number of second electrodes is odd, and the second electrode located in the middle along the first direction is the second middle electrode. Multiple first electrodes are provided on both sides of the second middle electrode. Among the plurality of first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases to the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

34. The electrode assembly according to any one of claims 28-33, wherein, The electrode includes a current collector, a first active material layer, and a second active material layer. The first active material layer and the second active material layer have opposite polarities and are respectively disposed on both sides of the current collector. Along the first direction, at least one of the current collectors, the first active material layer, and the second active material layer of the two electrodes that are furthest apart are provided with the chamfered structure at all four corners.

35. The electrode assembly according to claim 34, wherein, The chamfered structure is rounded, and each of the four corners of the electrode is provided with the rounded corners.

36. The electrode assembly of claim 35, wherein, The number of electrodes is odd, and the radius of the rounded corner of the middle electrode gradually increases from the radius of the rounded corner of the electrodes at both ends.

37. The electrode assembly according to claim 35, wherein, The number of electrodes is even. Along the first direction, the solid electrolyte layer located in the middle position is the middle layer, and multiple electrodes are provided on both sides of the middle layer. Among the plurality of electrodes located on the same side of the intermediate layer, the radius of the rounded corner of the electrode closest to the intermediate layer gradually increases to the radius of the rounded corner of the electrode furthest from the intermediate layer.

38. A method for manufacturing an electrode assembly, wherein, include: Multiple electrode plates are available; Provide a solid electrolyte layer; Multiple electrodes and solid electrolyte layers are stacked along a first direction, such that the solid electrolyte layer is disposed between two adjacent electrodes along the first direction to form an electrode assembly blank. Each electrode includes an active material layer. In two adjacent electrodes, the active material layer facing the solid electrolyte layer located between the two adjacent electrodes has opposite polarities. Along the first direction, the four corners of the two electrodes that are furthest apart are provided with chamfer structures. The electrode assembly blank is placed into a packaging bag; The electrode assembly blank, which is placed in the packaging bag, is subjected to isostatic pressing.

39. The method for manufacturing an electrode assembly according to claim 38, wherein, The plurality of electrodes include a first electrode and a second electrode, wherein the first electrode and the second electrode have opposite polarities; The provision of multiple electrodes includes: providing a first electrode; providing a second electrode; The first electrode includes: Provide multiple first electrode blanks; The four corners of at least two first electrode blanks are chamfered to form the chamfered structure; In the electrode assembly blank, along the first direction, the first electrode, the solid electrolyte layer and the second electrode are stacked, the solid electrolyte layer is disposed between the first electrode and the second electrode, and along the first direction, the two first electrodes that are furthest apart are the electrodes located at both ends of the electrode assembly, and the four corners of the two first electrodes that are furthest apart are provided with a chamfer structure.

40. The method for manufacturing an electrode assembly according to claim 39, wherein, The chamfering process for the four corners of at least two first electrode blanks includes: The four corners of each first electrode blank are rounded. In the electrode assembly blank, each of the four corners of the first electrode sheet is provided with the rounded corners.

41. The method for manufacturing an electrode assembly according to claim 40, wherein, In the step of rounding the four corners of each first electrode blank, the rounding radii of the multiple first electrode blanks are different; In the electrode assembly blank, when the number of first electrodes is odd and the number of second electrodes is even, the radius of the rounded corner of the middle first electrode gradually increases from the radius of the rounded corner of the first electrodes at both ends; when the number of first electrodes is even and the number of second electrodes is odd, along the first direction, the second electrode located in the middle position is the second intermediate electrode, and multiple first electrodes are provided on both sides of the second intermediate electrode. Among the multiple first electrodes located on the same side of the second intermediate electrode, the radius of the rounded corner of the first electrode closest to the second intermediate electrode gradually increases from the radius of the rounded corner of the first electrode furthest from the second intermediate electrode.

42. The method for manufacturing an electrode assembly according to any one of claims 39-41, wherein, The provision of the second electrode includes: Multiple second electrode blanks are provided; The four corners of at least two second electrode blanks are chamfered to form the chamfered structure; In the electrode assembly blank, along the first direction, the four corners of the two second electrodes that are furthest apart are provided with the chamfered structure.

43. A battery device, wherein, Includes the battery cell according to any one of claims 1-27.

44. An electrical appliance, wherein, Includes a battery cell according to any one of claims 1-27, the battery cell being used to provide electrical energy to the electrical device.

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