Electrode assembly, battery and electric equipment

Abstract

The utility model provides an electrode assembly, a battery and electric equipment, and relates to the technical field of energy storage, the electrode assembly comprises a plurality of pole pieces and isolating membranes located between any adjacent pole pieces; at least part of the pole pieces are provided with protruding parts, in any three adjacent pole pieces with the protruding parts, the orthographic projection of the protruding part on one pole piece on the adjacent pole piece and the protruding part of the adjacent pole piece are arranged in a staggered mode, or the orthographic projection of the protruding part on one pole piece on the second adjacent pole piece and the orthographic projection of the protruding part on the other pole piece on the adjacent pole piece are arranged in a staggered mode. And the convex parts of the secondary adjacent pole pieces are arranged in a staggered manner. The expansion stress of the electrode assembly can be relieved, so that the risk of distortion and even breakage of the electrode assembly is reduced, the cycle life of the electrode assembly is prolonged, and the safety of the electrode assembly is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of energy storage, and in particular to an electrode assembly, a battery and an electric device. BACKGROUND

[0002] A battery is a device for converting chemical energy into electrical energy, which is widely used in new energy vehicles, energy storage power stations and other fields. The battery generally includes a shell, an electrode assembly and an electrolyte arranged in the shell. The electrode assembly includes a separator and two electrode plates oppositely arranged on both sides of the separator, and the polarities of the two electrode plates are opposite.

[0003] However, during the charging and discharging process of the battery, the two electrode plates are prone to volume expansion, which causes the electrode assembly to twist and deform or even break, affecting the cycle life and safety of the electrode assembly. CONTENT OF THE UTILITY MODEL

[0004] In view of the above problems, embodiments of the present application provide an electrode assembly, a battery and an electric device, which can alleviate the expansion stress of the electrode assembly, thereby reducing the risk of twisting and deforming or even breaking of the electrode assembly, and improving the cycle life and safety of the electrode assembly.

[0005] To achieve the above-mentioned purpose, embodiments of the present application provide the following technical solutions:

[0006] The first aspect of the embodiments of the present application provides an electrode assembly, comprising a plurality of electrode plates and a separator between any adjacent electrode plates;

[0007] At least part of the electrode plates is provided with a protruding part. In any three adjacent electrode plates with protruding parts, the protruding part on one of the electrode plates is arranged in a position offset from the protruding part on the adjacent electrode plate, or the protruding part on one of the electrode plates is arranged in a position offset from the protruding part on the second adjacent electrode plate.

[0008] In a possible implementation, the plurality of electrode plates includes a first electrode plate and a second electrode plate; at least one of the first electrode plate and the second electrode plate is provided with a protruding part;

[0009] Among the electrode plates provided with the protruding part, the protruding parts of at least two adjacent or second adjacent electrode plates are arranged in a position offset.

[0010] In a possible implementation, the first electrode plate and the second electrode plate are both provided with a protruding part;

[0011] The protruding parts of at least two adjacent electrode plates are arranged in a position offset.

[0012] In a possible implementation, the electrode assembly is formed by stacking and winding the first electrode sheet, the separator film, and the second electrode sheet.

[0013] In a possible implementation, the protrusions in at least two adjacent electrode sheets are staggered in a direction from the winding center of the electrode assembly to the winding edge.

[0014] In a possible implementation, the protrusions in any two adjacent electrode sheets are staggered.

[0015] In a possible implementation, in any two adjacent first electrode sheet and second electrode sheet, the protrusion of one of the first electrode sheets is aligned with the protrusion of the other first electrode sheet in the orthographic projection of the other first electrode sheet.

[0016] In a possible implementation, the electrode assembly comprises a curved section, the curved section comprising a plurality of layers of the first electrode sheet and a plurality of layers of the second electrode sheet, and at least part of the first electrode sheet and / or at least part of the second electrode sheet is provided with a protrusion.

[0017] In a possible implementation, the plurality of layers of the first electrode sheet and the plurality of layers of the second electrode sheet in the curved section are each provided with a protrusion.

[0018] In a possible implementation, the electrode assembly further comprises a straight section.

[0019] The curved section comprises a first curved section and a second curved section, and the first curved section and the second curved section are connected by the straight section.

[0020] In a possible implementation, the first curved section and the second curved section are symmetrically arranged relative to the vertical center line of the straight section.

[0021] In a possible implementation, one first electrode sheet, one second electrode sheet, and one separator film form a stack, and the electrode assembly is formed by winding a plurality of the stacks.

[0022] In a possible implementation, in a direction from the winding center of the electrode assembly to the winding edge, the number of protrusions in the plurality of stacks shows an increasing trend.

[0023] In a possible implementation, in the winding state, in the first electrode sheet and the second electrode sheet of each stack, the number of columns of the protrusions in the second electrode sheet and the number of columns of the protrusions in the first electrode sheet have a difference.

[0024] In a possible implementation, in the first and second pole pieces of each layer stack, the number of columns of the protrusions in the second pole piece and the number of columns of the protrusions in the first pole piece differ by one column.

[0025] In a possible implementation, in each layer stack, the number of protrusions of the first pole piece is equal to the number of protrusions of the second pole piece.

[0026] In a possible implementation, each protrusion includes a plurality of sub-protrusions; in the unfolded state, the plurality of sub-protrusions are arranged in sequence along the width direction of the pole piece.

[0027] In a possible implementation, the plurality of sub-protrusions are arranged in multiple rows and multiple columns on the pole piece.

[0028] In a possible implementation, any adjacent sub-protrusions are spaced apart and form a recess;

[0029] In a possible implementation, between the adjacent sub-protrusions and the recess, the maximum vertical distance between the top of the sub-protrusion and the bottom of the recess in the thickness direction of the pole piece is 0.02 mm to 0.04 mm.

[0030] In a possible implementation, along the winding direction, the maximum width of the sub-protrusion is 0.5 mm to 1.5 mm.

[0031] In a possible implementation, part of the first pole piece and the second pole piece protrudes in a direction away from the winding center of the electrode assembly to form the protrusion.

[0032] The second aspect of the embodiments of the present application provides a battery, which includes: a housing and the electrode assembly of the first aspect; the electrode assembly is arranged in the housing.

[0033] The third aspect of the embodiments of the present application provides a power consumption device, which includes a power consumption device and the battery of the second aspect, and the battery is electrically connected to the power consumption device to supply power to the power consumption device.

[0034] In the electrode assembly, the battery, and the power consumption device provided by the embodiments of the present application, at least part of the pole pieces is provided with protrusions, the protrusions can increase the distance between the pole pieces with protrusions and the adjacent separator, so that a buffer gap is formed between the pole pieces with protrusions and the adjacent separator, thus, the buffer gap can provide a buffer space for the expansion of the pole pieces during the charging and discharging process, thereby releasing the expansion stress of the pole pieces, preventing the electrode assembly from being twisted and deformed due to the expansion stress, and improving the cycle life and safety performance of the electrode assembly.

[0035] In addition, in any three adjacent and having protrusions pole pieces, the protrusions on one of the pole pieces are misaligned with the protrusions on the adjacent pole piece in orthographic projection, or the protrusions on one of the pole pieces are misaligned with the protrusions on the second adjacent pole piece in orthographic projection. In this way, the protrusions can be prevented from forming an overlap, thereby reducing the thickness of the electrode assembly and improving the energy density of the battery.

[0036] In addition to the technical problems solved by the embodiments of the present application, the technical features constituting the technical solutions, and the beneficial effects brought by the technical features, the other technical problems solved by the electrode assembly, the battery and the electric device provided by the embodiments of the present application, the other technical features included in the technical solutions, and the beneficial effects brought by the technical features will be further described in detail in the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0038] Figure 1 a schematic diagram of the electrode assembly provided by the embodiments of the present application;

[0039] Figure 2 a schematic diagram of the first pole piece provided by the embodiments of the present application;

[0040] Figure 3 a schematic diagram of the second pole piece provided by the embodiments of the present application;

[0041] Figure 4 a schematic diagram of the sub-protrusion provided by the embodiments of the present application.

[0042] Explanation of reference signs:

[0043] 100: electrode assembly;

[0044] 110: first pole piece; 120: second pole piece; 130: separator; 140: flat section; 150: curved section; 151: first curved section; 152: second curved section; 160: protrusion; 161: sub-protrusion. DETAILED DESCRIPTION

[0045] As described in the background section, electrode assemblies in related technologies are prone to twisting, deformation, and even breakage. The inventors have discovered that this problem arises because the electrode sheets expand in volume due to the delithiation or lithium insertion of the active material. This expansion inevitably leads to expansion stress between the electrode sheet and the separator, especially concentrated in the corner areas formed by the winding of the electrode assembly. This results in twisting, deformation, and even breakage of the electrode assembly, thus reducing its performance.

[0046] To address the aforementioned technical problems, embodiments of this application provide an electrode assembly, a battery, and an electrical device. At least a portion of the electrode sheets are provided with protrusions. These protrusions can increase the distance between the electrode sheet with the protrusions and its adjacent separator, thereby forming a buffer gap between the electrode sheet with the protrusions and its adjacent separator. Thus, during the charging and discharging process of the battery, the buffer gap can provide buffer space for the expansion of the electrode sheets, thereby releasing the expansion stress of the electrode sheets, preventing the electrode assembly from twisting and deforming due to expansion stress, and improving the cycle life and safety performance of the electrode assembly.

[0047] Furthermore, in any three adjacent electrodes with protrusions, the orthographic projection of the protrusion on one of the electrodes onto its adjacent electrode is offset from the protrusion of that adjacent electrode; or, the orthographic projection of the protrusion on one of the electrodes onto its next adjacent electrode is offset from the protrusion of that next adjacent electrode. This prevents the protrusions from overlapping, thereby reducing the thickness of the electrode assembly and increasing the energy density of the battery.

[0048] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0049] Please refer to the attached document. Figure 1 To be continued Figure 3 This application provides an electrode assembly 100, which can be applied to energy storage devices, such as batteries. It should be noted that the electrode assembly 100 in this embodiment can also be understood as an electrode core, which can be a cylindrical electrode core or an elliptical electrode core.

[0050] The electrode assembly 100 includes multiple electrodes and a separator 130 located between any adjacent electrodes. The separator 130 serves to insulate the first electrode 110 and the second electrode 120. The separator 130 can be made of polypropylene (PP) or polyethylene (PE), etc. It should be noted that in this embodiment, some of the electrodes are positive electrodes, and some are negative electrodes.

[0051] For example, the plurality of electrodes includes a first electrode 110 and a second electrode 120. The first electrode 110 and the second electrode 120 are respectively disposed on opposite sides of the separator 130. One of the first electrode 110 and the second electrode 120 is a negative electrode, and the other is a positive electrode. As an example, the first electrode 110 is a negative electrode, and the second electrode 120 is a positive electrode.

[0052] Both the first electrode 110 and the second electrode 120 include a current collector and an active material layer disposed on the current collector. It should be noted that the difference between the first electrode 110 and the second electrode 120 lies in the material of the active material layer. For example, when the first electrode 110 is a negative electrode, the active material layer may be made of silicon-carbon alloy. Silicon-carbon anode is a novel lithium-ion battery anode material, composed of silicon and carbon, and possesses advantages such as high specific capacity. When the second electrode 120 is a positive electrode, the active material layer may be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0053] At least some of the electrode sheets are provided with protrusions 160. In any three adjacent electrode sheets with protrusions 160, the orthographic projection of the protrusion 160 on one of the electrode sheets onto the adjacent electrode sheet is offset from the protrusion 160 on the adjacent electrode sheet. Alternatively, the orthographic projection of the protrusion 160 on one of the electrode sheets onto the next adjacent electrode sheet is offset from the protrusion 160 on the next adjacent electrode sheet.

[0054] It should be noted that when all the electrodes are provided with protrusions 160, in this embodiment, any three adjacent electrodes with protrusions 160 refer to any three adjacent electrodes. When some of the electrodes are provided with protrusions 160, in this embodiment, any three adjacent electrodes with protrusions 160 can refer to three discontinuous electrodes that have protrusions 160. (See attached diagram) Figure 1 Taking the structure shown as an example, from the center to the edge, the three pole pieces include, but are not limited to, the first pole piece, the third pole piece, and the sixth pole piece.

[0055] This creates a buffer gap between the electrode with protrusion 160 and its adjacent separator 130. During the charging and discharging process, the buffer gap provides space for the expansion of the electrode, thereby releasing the expansion stress of the electrode, preventing the electrode assembly from twisting and deforming due to expansion stress, and improving the cycle life and safety performance of the electrode assembly.

[0056] It needs to be understood that, with the appendix Figure 1 Taking the orientation shown as an example, in any three adjacent pole pieces, and along the stacking direction of any three adjacent pole pieces, the pole piece located on the innermost or bottommost layer is one of the pole pieces, the second pole piece is the adjacent pole piece, and the third pole piece is the next adjacent pole piece.

[0057] In this embodiment, among any three adjacent electrode sheets having protrusions 160, and along the stacking direction of any three adjacent electrode sheets, the protrusions 160 of the first electrode sheet and the protrusions 160 of the second electrode sheet are misaligned. In this case, the protrusions 160 of the first electrode sheet and the protrusions 160 of the third electrode sheet may or may not be misaligned. Alternatively, the protrusions 160 of the first electrode sheet and the protrusions 160 of the third electrode sheet are misaligned. In this case, the protrusions 160 of the first electrode sheet and the protrusions 160 of the second electrode sheet may or may not be misaligned.

[0058] This avoids the overlapping of protrusions 160, thereby reducing the thickness of electrode assembly 100 and increasing battery energy density.

[0059] To further describe the layout of the protrusion 160, it is advisable to divide the multiple electrode sheets into several parts. Exemplarily, the multiple electrode sheets include a first electrode sheet 110 and a second electrode sheet 120. It should be noted that in this embodiment, there are multiple first electrode sheets 110 and multiple second electrode sheets 120. At least one of the first electrode sheet 110 and the second electrode sheet 120 is provided with the protrusion 160. It should also be noted that the polarities of the first electrode sheet 110 and the second electrode sheet 120 are opposite.

[0060] In one example, one of the first electrode 110 and the second electrode 120 is provided with a protrusion 160. In another example, both the first electrode 110 and the second electrode 120 are provided with a protrusion 160.

[0061] In the electrode sheet with protrusions 160, at least some of the protrusions 160 of two adjacent or next-adjacent electrode sheets are staggered. For example, the protrusions 160 of some adjacent or next-adjacent electrode sheets are staggered. Or, for example, the protrusions 160 of all adjacent or next-adjacent electrode sheets are staggered.

[0062] It should be understood that when the protruding portions 160 of all adjacent pole pieces are arranged in a staggered manner, among any three adjacent pole pieces, the protruding portions 160 of the first pole piece and the third pole piece can be arranged in a staggered manner or not.

[0063] In this way, the number of buffer gaps formed between the pole pieces and the separator 130 can be increased as much as possible, and the formed buffer gaps are arranged in a staggered manner as much as possible, which can effectively disperse the layout of the buffer gaps, and further more effectively disperse and buffer the expansion stress; in addition, the thickness of the electrode assembly 100 can be reduced, and the energy density of the battery can be improved.

[0064] It should be noted that in this embodiment, the electrode assembly 100 can be a stacked structure or a wound structure. As an example, the electrode assembly 100 is formed by stacking and winding the first pole piece 110, the separator 130 and the second pole piece 120. In this way, the space can be utilized more effectively, so as to increase the mass or area of the active material of the pole piece, and further improve the energy density of the battery.

[0065] Along the direction from the winding center of the electrode assembly 100 to the winding edge, the protruding portions 160 in at least some adjacent two pole pieces after winding are arranged in a staggered manner. Among them, Figure 1 D1 can be understood as the direction from the winding center of the electrode assembly 100 to the winding edge.

[0066] As an example, the protruding portions 160 in some adjacent two pole pieces after winding are arranged in a staggered manner. As another example, along the direction from the winding center of the electrode assembly 100 to the winding edge, the protruding portions 160 in all any adjacent two pole pieces are arranged in a staggered manner.

[0067] It should be noted that on the premise of ensuring that the protruding portions 160 in any adjacent two pole pieces are arranged in a staggered manner, the protruding portions 160 of one pole piece and the pole piece adjacent to it can be arranged in an aligned manner or not.

[0068] Exemplarily, among any adjacent two first pole pieces 110 and the second pole piece 120, in other words, the second pole piece 120 is located between any adjacent two first pole pieces 110.

[0069] The orthographic projection of the protruding portion 160 of one first pole piece 110 on the other first pole piece 110 is aligned with the protruding portion 160 of the other first pole piece 110. In this way, on the premise of ensuring that the protruding portions 160 of the second pole piece 120 are staggered with the protruding portions 160 of both first pole pieces 110, the protruding portions 160 of the two first pole pieces 110 are arranged in an aligned manner, which helps to improve the structural compactness of the electrode assembly 100, thereby improving the energy density of the entire battery.

[0070] Please continue to refer to the appendix. Figure 1 The wound electrode assembly 100 includes a bent section 150. The bent section 150 includes multiple layers of first electrode 110 and multiple layers of second electrode 120, and at least a portion of the first electrode 110 and / or the second electrode 120 is provided with a protrusion 160.

[0071] As an example, in the bending section 150, both the multilayer first electrode 110 and the multilayer second electrode 120 are provided with protrusions 160. That is, at least the first electrode 110 and the second electrode 120 located on the bending section 150 are provided with protrusions 160. The protrusions 160 can be formed by a stamping process or by other methods. For example, the protrusions 160 can be formed by a rolling mechanism. For example, the rolling mechanism includes a first pressure roller and a second pressure roller. The surface of the first pressure roller is uniformly covered with protrusions, and the second pressure roller is smooth. When the first electrode 110 and the second electrode 120 pass through the rolling equipment, the protrusions 160 can be formed on the first electrode 110 and the second electrode 120.

[0072] Given that the tension force is greatest at the bending section 150 during the winding process, and consequently the expansion stress is greatest at the bending section 150, in this embodiment, protrusions 160 are provided on both the first electrode 110 and the second electrode 120 located at the bending section 150. The protrusions 160 increase the distance between the first electrode 110 and the separator 130, and between the second electrode 120 and the separator 130, thus forming buffer gaps between them. During charging and discharging, these buffer gaps provide space for the expansion of the first electrode 110 and the second electrode 120, thereby releasing the expansion stress of the first electrode 110 and the second electrode 120, preventing the electrode assembly 100 from twisting and deforming due to expansion stress, and improving the cycle life and safety performance of the electrode assembly 100.

[0073] The orthographic projection mentioned in this embodiment is the orthographic projection of the protrusion 160 on the first electrode 110 onto the second electrode 120 when the electrode assembly 100 is in a wound state.

[0074] It should be noted that the curved segment 150 in this embodiment can be configured according to the shape of the electrode assembly 100. As an example, the electrode assembly 100 is cylindrical, and the curved segment 150 can be any arc segment of the electrode assembly 100. As another example, the electrode assembly 100 is elliptical in shape. In this case, the electrode assembly 100 also includes a straight segment 140.

[0075] The curved section 150 includes a first curved section 151 and a second curved section 152. The two ends of the first curved section 151 and the second curved section 152 are respectively connected by a straight section 140, so that the electrode assembly 100 has an elongated oval shape. That is, there are two straight sections 140, one of which connects one end of the first curved section 151 and the second curved section 152, and the other straight section 140 connects the other end of the first curved section 151 and the second curved section 152.

[0076] In this embodiment, the electrode assembly 100 has a wound structure, which can ensure the stability and compactness of the internal structure of the battery, and is beneficial to improving the energy density and cycle life of the battery.

[0077] It should be understood that, in this embodiment, the protrusion 160 may be provided on the electrode in the curved section 150, or it may be provided in other ways. For example, the first electrode 110 and the second electrode 120 on both the straight section 140 and the curved section 150 are provided with the protrusion 160.

[0078] Wherein, when the electrode of the bending section 150 has a protrusion 160, at least a portion of the multilayer first electrode 110 and multilayer second electrode 120 located in the first bending section 151 are provided with the protrusion 160, and / or at least a portion of the multilayer first electrode 110 and multilayer second electrode 120 located in the second bending section 152 are provided with the protrusion 160.

[0079] The protrusion 160 can be provided only in the first bending section 151, only in the second bending section 152, or simultaneously in both bending sections 151 and 152. This arrangement allows for the rational design of the protrusion 160's position based on the application scenario of the electrode assembly 100. It helps provide buffer space for the expansion of the first electrode 110 and the second electrode 120 located in any bending section, thereby releasing the expansion stress of the first electrode 110 and the second electrode 120, preventing the electrode assembly 100 from twisting and deforming due to expansion stress, and improving the cycle life and safety performance of the electrode assembly 100.

[0080] In one example, a protrusion 160 is provided in part of the multilayer first electrode 110 and multilayer second electrode 120 of the first curved section 151, and a protrusion 160 is provided in part of the multilayer first electrode 110 and multilayer second electrode 120 of the second curved section 152.

[0081] In another example, protrusions 160 are partially provided in the multilayer first electrode 110 and multilayer second electrode 120 of the first curved section 151; protrusions 160 are provided in all of the multilayer first electrode 110 and multilayer second electrode 120 located in the second curved section 152. In this way, while providing a buffer gap between the first electrode 110 and the second electrode 120 to buffer expansion stress, the thickness of the electrode assembly 100 in the direction from the winding center to the winding edge is also reduced, thereby allowing the electrode assembly 100 to fit more tightly during winding, further improving the energy density of the battery. Furthermore, the placement of the protrusions 160 can be rationally set according to the number of layers of the first electrode 110 and the second electrode 120, improving the design flexibility of the electrode assembly 100.

[0082] In another example, both the multilayer first electrode 110 and the multilayer second electrode 120 of the first bending segment 151 and the second bending segment 152 are provided with protrusions 160; that is, all the multilayer first electrode 110 and the multilayer second electrode 120 of the first bending segment 151 are provided with protrusions 160, and all the multilayer first electrode 110 and the multilayer second electrode 120 of the second bending segment 152 are provided with protrusions 160.

[0083] In this way, the number of buffer gaps can be increased as much as possible, thereby better releasing the expansion stress of the first electrode 110 and the second electrode 120, preventing the electrode assembly 100 from twisting and deforming due to expansion stress, and improving the cycle life and safety performance of the electrode assembly 100.

[0084] It should be noted that the arrangement of the protrusions in the first curved segment 151 and the second curved segment 152 can be the same or different. In some possible embodiments, the first curved segment 151 and the second curved segment 152 are symmetrically arranged with respect to the vertical center line of the straight segment 140. In this embodiment, the vertical center line is a line passing through the center of the straight segment 140 and perpendicular to the thickness of the straight segment 140, in order to... Figure 1 Taking the indicated orientation as an example, the vertical center line is attached. Figure 1 The S-shaped structure simplifies the fabrication process of the first electrode 110 and the second electrode 120, and reduces their manufacturing costs.

[0085] In one possible implementation, a first electrode 110, a second electrode 120, and a separator 130 constitute a laminate; the electrode assembly is formed by winding multiple laminates.

[0086] In particular, along the direction from the winding center of the electrode assembly 100 to the winding edge, the number of protrusions 160 in the multiple laminates tends to increase.

[0087] Along the direction from the winding center of the electrode assembly 100 to the winding edge, the curvature of the electrode gradually increases. Therefore, more protrusions 160 are provided on the electrode that are further away from the winding center of the electrode assembly 100. This helps the protrusions 160 to effectively support the adjacent separator 130 and creates more buffer gaps between the electrode and the adjacent separator 130. This more effectively absorbs and buffers the expansion stress generated by the battery during charging and discharging, allowing the electrode to have a certain degree of freedom when expanding, thereby reducing stress concentration and preventing deformation and breakage of the electrode.

[0088] It should be noted that the increasing trend in this embodiment can be understood as the number of protrusions 160 on the electrode sheet closer to the winding center of the electrode assembly 100 being less, while the number of protrusions 160 on the electrode sheet farther from the winding center of the electrode assembly 100 being more. The increasing trend can be a gradual increase, showing a linear change; or it can be an overall increasing trend, but the number of protrusions 160 in some adjacent electrode sheets can be equal.

[0089] In some possible embodiments, the number of protrusions 160 in the multilayer first electrode 110 and the number of protrusions 160 in the multilayer second electrode 120 gradually increase along the direction from the winding center to the winding edge of the electrode assembly 100. This arrangement, while ensuring more buffer gaps are provided to effectively absorb and alleviate the expansion stress generated during battery charging and discharging, also makes the electrode assembly structure more stable. During battery charging and discharging, the relative movement between the electrode and the separator is reduced, avoiding material wear and cracking caused by friction and compression, thereby improving the structural stability and durability of the battery. It should be noted that the protrusions 160 are auxiliary... Figure 2 The component within the dashed box.

[0090] In one possible implementation, in the wound state, in each laminate, the number of columns of protrusions 160 in the second electrode 120 differs from the number of columns of protrusions 160 in the first electrode 110. For example, the difference between the number of columns of protrusions 160 in the second electrode 120 and the number of columns of protrusions 160 in the first electrode 110 is one column, two columns, or even more.

[0091] In one possible implementation, in each laminated first electrode 110 and second electrode 120, the difference between the number of columns of protrusions 160 in the second electrode 120 and the number of columns of protrusions 160 in the first electrode 110 is one column. For example, in each laminated first electrode 110 and second electrode 120, one of the first electrode 110 and the second electrode 120 has an odd number of columns of protrusions 160, and the other has an even number of columns of protrusions 160.

[0092] To facilitate the description of the number and layout of protrusions 160 in the first electrode 110 and the second electrode 120 of each laminate, this embodiment is described with the example of an odd number of columns of protrusions 160 in the first electrode 110 and an even number of columns of protrusions 160 in the second electrode 120.

[0093] Along the direction from the winding center to the winding edge of the electrode assembly 100, in the first laminate, the number of columns of protrusions 160 in the first electrode 110 is 1, and the number of columns of protrusions 160 in the second electrode 120 is 2.

[0094] In the second stacked body, the number of columns of protrusions in the first electrode 110 is 3, and the number of columns of protrusions in the second electrode 120 is 4.

[0095] In the third stack, the number of columns of protrusions 160 in the first electrode 110 is 5, and the number of columns of protrusions 160 in the second electrode 120 is 6.

[0096] In the fourth laminate, the first electrode 110 has 7 columns of protrusions 160, and the second electrode 120 has 8 columns of protrusions 160. And so on, with a difference between the number of columns of protrusions 160 in the second electrode 120 and the number of columns of protrusions 160 in the first electrode 110 in each laminate.

[0097] This configuration ensures that the orthographic projection of the protrusion 160 on the first electrode 110 onto the second electrode 120 is located between adjacent protrusions 160 on the second electrode 120. This results in the orthographic projection of the protrusion 160 on the first electrode 110 onto the second electrode 120 being misaligned with the protrusion 160 on the second electrode 120, thereby preventing the protrusion 160 on the first electrode 110 from overlapping with the protrusion 160 on the second electrode 120. This also prevents excessive increase in the thickness of the electrode assembly 100 and improves the energy density of the battery.

[0098] In order to ensure that the projection of the protrusion 160 on the first electrode 110 onto the second electrode 120 in the two curved sections of the electrode assembly 100 is offset from the projection of the protrusion 160 on the second electrode 120.

[0099] In this embodiment, along the direction away from the starting section of winding, i.e., attached Figure 2 From left to right, the protrusions 160 of the first electrode 110 are arranged in a row of 1, 1, 3, 3, 5, and 5 columns. This arrangement ensures that the number of protrusions 160 in the first curved section 151 and the second curved section 152 of the wound first electrode 110 is equal.

[0100] Along the direction away from the starting section of the winding, i.e., attached Figure 3From left to right, the protrusions 160 of the second electrode 120 are arranged in 2 rows, 2 rows, 4 rows, 4 rows, 6 rows, and 6 rows, which can ensure that the number of protrusions 160 in the first bending section 151 and the second bending section 152 of the wound second electrode 120 is equal.

[0101] In one possible implementation, in each laminate, the number of protrusions 160 of the first electrode 110 is equal to the number of protrusions 160 of the second electrode 120. This simplifies the fabrication process of the electrode assembly 100 and reduces manufacturing costs, provided that the protrusions 160 in two adjacent laminates are staggered.

[0102] It should be noted that the protrusion direction of the protrusion 160 of the first electrode 110 can be the same as or different from the protrusion direction of the protrusion 160 of the second electrode 120. For example, a portion of the first and second electrodes protrudes in a direction away from the winding center of the electrode assembly 100 to form the protrusion 160. This arrangement ensures that each layer of the separator 130 is supported by the protrusion 160, allowing a buffer gap to be formed between any adjacent electrode and the separator 130.

[0103] To ensure that more buffer clearance is provided, each protrusion 160 includes multiple sub-protrusions 161. Please refer to the appendix. Figure 3 and attached Figure 4 In the unfolded state, multiple sub-protrusions 161 are arranged sequentially along the width direction of the electrode sheet. It should be understood that the multiple sub-protrusions 161 can be arranged regularly or in other ways. For example, the multiple sub-protrusions 161 are arranged in multiple rows and columns on the electrode sheet, such as in two columns and multiple rows. The column direction is the width direction of the electrode sheet, and the row direction is the length direction of the electrode sheet.

[0104] Since the sub-protrusions 161 are usually prepared by a rolling process, while the extrusion electrode forms the sub-protrusions 161, the area between adjacent sub-protrusions 161 is also extruded in opposite directions. Therefore, any adjacent sub-protrusions 161 are spaced apart and form a recess.

[0105] Please refer to the attached document. Figure 4 The maximum vertical distance H between the top of the sub-protrusion 161 and the bottom of its adjacent recess in the thickness direction of the electrode sheet is 0.02 mm to 0.04 mm. Furthermore, the maximum width L of the sub-protrusion 161 along the winding direction is 0.5 mm to 1.5 mm. By setting the maximum vertical distance H and the maximum width L, this embodiment can improve the electrode sheet growth rate and yield, thereby further increasing the battery capacity and energy density.

[0106] Please refer to the attached document.Figure 4 , attached Figure 4 A sub-protrusion 161 is shown, where L is the maximum width of the sub-protrusion 161; H is the maximum vertical distance between the bottom of the sub-protrusion 161 and the top of its adjacent recess; and R is the radius of the circle containing the sub-protrusion 161. The following will use H = 0.03 mm and L = 1 mm as an example to explain in detail the changes in the growth rate and yield of the electrode assembly 100.

[0107] According to the definition of a Pythagorean theorem, we know that:

[0108]

[0109] According to the perfect square formula:

[0110]

[0111] After optimization, we can obtain:

[0112]

[0113] Taking H = 0.03 mm and L = 1 mm as an example, and substituting H = 0.03 mm and L = 1 mm into formula (3), we get R = 4.18 mm.

[0114] According to the cosine formula:

[0115]

[0116] Substituting L = 1 mm and R = 4.18 mm into formula (4), we get sinθ = 0.12

[0117] Then, using the inverse function, we get:

[0118] θ=sin -1 0.12 = 6.89°

[0119] Then the arc length C:

[0120]

[0121] Substituting π = 3.14, R = 4.18 mm, and θ = 6.89° into formula (5), we get C = 1.005.

[0122] According to the elongation formula:

[0123]

[0124] Right now:

[0125]

[0126] Substituting C = 1.005 and L = 1 into formula (6), we get N = 0.5%.

[0127] In other words, the thickness of the electrode at the location of the corresponding protrusion 160 increases by 0.5%. If the orthogonal projection of the protrusion on the first electrode onto the second electrode coincides with the protrusion on the second electrode, and the curved section 150 of the electrode assembly 100 includes m layers of electrode sheets, the growth rate G in the width direction of the electrode assembly 100 is m × 0.5%.

[0128] Accordingly, when the protrusions of the first electrode and the second electrode are misaligned in this embodiment, the growth rate K in the width direction of the electrode assembly 100 is as follows:

[0129]

[0130] Then, the yield rate in the width direction of the electrode assembly 100 is calculated using the following formula: The yield in the width direction of electrode assembly 100 can be obtained as 1 / 2.

[0131] The above calculations clearly show that when the protrusions 160 of the first electrode 110 and the second electrode 120 are misaligned, the growth rate and yield of the electrode assembly 100 in the width direction can be effectively reduced. This design optimizes the geometry of the electrode assembly 100, allowing the battery to accommodate more active material within a limited space, thereby increasing the battery's energy density.

[0132] In this embodiment, a winding system is typically used to wind the first electrode 110, the second electrode 120, and the separator 130 to form the electrode assembly 100. The winding system typically includes a first unwinding mechanism, a second unwinding mechanism, a third unwinding mechanism, a first membrane pressing mechanism, a second membrane pressing mechanism, a conveying mechanism, and a winding mechanism. The second unwinding mechanism is used to unwind the second electrode 120, and the third unwinding mechanism is used to unwind the separator 130.

[0133] The first unwinding mechanism unwinds the first electrode 110 and conveys it to the first pressing mechanism via a conveying mechanism. The first pressing mechanism rolls the first electrode 110 to form a protrusion 160 at a specific position on the first electrode 110. The first pressing mechanism typically includes a first pressure roller and a second pressure roller. The surface of the first pressure roller is uniformly covered with protrusions, while the surface of the second pressure roller is smooth. The gap between the first and second pressure rollers and the pressure of the pressure rollers are controlled by a servo motor, so that the surface of the first electrode 110 forms a certain height and an uneven shape when passing through the rollers.

[0134] The second unwinding mechanism is used to unwind the second electrode 120 and transport it to the second pressing mechanism via a conveying mechanism. The second pressing mechanism rolls the second electrode 120 to form a protrusion 160 at a specific position on the second electrode 120. It should be noted that the second pressing mechanism operates on the same principle as the first pressing mechanism, except that the arrangement of the protrusions on the first pressure roller is different. This embodiment will not elaborate further on this point.

[0135] After the membrane pressing process is completed, the conveying mechanism transports the first electrode 110, the second electrode 120 and the separator 130 to the winding mechanism for winding to form the electrode assembly 100.

[0136] It should be understood that the first unwinding mechanism, the second unwinding mechanism, the third unwinding mechanism, the conveying mechanism, and the winding mechanism are all existing technologies. For details, please refer to the relevant descriptions. This embodiment will not elaborate further here.

[0137] This application also provides a battery, which includes a casing and an electrode assembly 100, wherein the electrode assembly 100 is disposed within the casing. It should be noted that, in this example, an electrolyte is also disposed within the casing.

[0138] Given that the battery in this embodiment includes the electrode assembly 100 described in any of the above embodiments, the battery also includes the structure and beneficial effects of the electrode assembly 100, which will not be described in detail here.

[0139] This application also provides an electrical device, including an electrical device and a battery as described in any of the above embodiments, wherein the battery is used to provide electrical energy to the electrical device.

[0140] The electrical equipment in this embodiment can be a vehicle, such as a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle, and a new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. Accordingly, the electrical device can be the vehicle's drive mechanism or the vehicle's control system.

[0141] In addition, electrical equipment can also serve as other energy storage devices, such as mobile phones, portable devices, laptops, electric toys, power tools, ships, and spacecraft. Among these, spacecraft can include airplanes, rockets, space shuttles, or spacecraft.

[0142] Since the electrical device in this embodiment includes the battery described in any of the above embodiments, the electrical device includes a battery pack structure and beneficial effects, which will not be described in detail here.

[0143] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0144] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An electrode assembly, characterized in that, It includes multiple electrodes and a separator (130) located between any adjacent electrodes; At least some of the electrode sheets are provided with protrusions (160). In any three adjacent electrode sheets having protrusions (160), the orthographic projection of the protrusion (160) on one of the electrode sheets onto the adjacent electrode sheet is offset from the protrusion (160) of the adjacent electrode sheet. Alternatively, the orthographic projection of the protrusion (160) on one of the electrode sheets onto the next adjacent electrode sheet is offset from the protrusion (160) of the next adjacent electrode sheet.

2. The electrode assembly according to claim 1, characterized in that, The plurality of electrode plates include a first electrode plate (110) and a second electrode plate (120); at least one of the first electrode plate (110) and the second electrode plate (120) is provided with a protrusion (160); In the electrode sheet provided with the protrusion (160), at least some of the protrusions (160) of two adjacent or next-adjacent electrode sheets are misaligned.

3. The electrode assembly according to claim 2, characterized in that, Both the first electrode (110) and the second electrode (120) are provided with protrusions (160).

4. The electrode assembly according to claim 3, characterized in that, The electrode assembly (100) is formed by stacking and winding the first electrode (110), the insulating film (130), and the second electrode (120); Along the direction from the winding center of the electrode assembly to the winding edge, the protrusions (160) in at least two adjacent electrodes after winding are misaligned.

5. The electrode assembly according to claim 4, characterized in that, The protrusions (160) in any two adjacent electrodes are misaligned.

6. The electrode assembly according to claim 5, characterized in that, In any two adjacent first pole pieces (110) and second pole pieces (120), the protrusion (160) of one first pole piece (110) is aligned with the protrusion (160) of the other first pole piece (110) in the orthographic projection of the other first pole piece (110).

7. The electrode assembly according to any one of claims 4-6, characterized in that, The electrode assembly (100) includes a bent section (150), which includes multiple layers of first electrode (110) and multiple layers of second electrode (120), and at least a portion of the first electrode (110) and / or at least a portion of the second electrode (120) are provided with protrusions (160).

8. The electrode assembly according to claim 7, characterized in that, The curved section (150) has protrusions (160) in both the multilayer first electrode (110) and the multilayer second electrode (120).

9. The electrode assembly according to claim 7, characterized in that, The electrode assembly also includes a straight section (140); The curved segment (150) includes a first curved segment (151) and a second curved segment (152), which are connected by the straight segment (140).

10. The electrode assembly according to claim 9, characterized in that, The first curved segment (151) and the second curved segment (152) are symmetrically arranged with respect to the vertical center line of the straight segment (140).

11. The electrode assembly according to claim 7, characterized in that, A first electrode (110), a second electrode (120), and a separator (130) constitute a laminate; the electrode assembly is formed by winding multiple laminates.

12. The electrode assembly according to claim 11, characterized in that, Along the direction from the winding center of the electrode assembly (100) to the winding edge, the number of protrusions (160) in the plurality of stacks tends to increase.

13. The electrode assembly according to claim 12, characterized in that, In the wound state, in each of the first electrode (110) and the second electrode (120) of the laminate, the number of columns of the protrusions (160) in the second electrode (120) is different from the number of columns of the protrusions (160) in the first electrode (110).

14. The electrode assembly according to claim 13, characterized in that, In each laminate, the difference between the number of columns of the protrusions (160) in the second electrode (120) and the number of columns of the protrusions (160) in the first electrode (110) is one column.

15. The electrode assembly according to claim 12, characterized in that, In each of the laminates, the number of protrusions (160) of the first electrode (110) is equal to the number of protrusions (160) of the second electrode (120).

16. The electrode assembly according to any one of claims 12-15, characterized in that, Each of the protrusions (160) includes a plurality of sub-protrusions (161); in the unfolded state, the plurality of sub-protrusions (161) are arranged sequentially along the width direction of the electrode sheet.

17. The electrode assembly according to claim 16, characterized in that, Multiple sub-protrusions (161) are arranged in multiple rows and columns on the electrode sheet.

18. The electrode assembly according to claim 17, characterized in that, The sub-protrusions (161) are spaced apart and form recesses; Between adjacent sub-protrusions (161) and recesses, the maximum vertical distance between the top of the sub-protrusion (161) and the bottom of the recess in the thickness direction of the electrode sheet is 0.02 mm to 0.04 mm.

19. The electrode assembly according to claim 17, characterized in that, Along the winding direction, the maximum width of the sub-protrusion (161) is 0.5 mm to 1.5 mm.

20. The electrode assembly according to any one of claims 2-6, characterized in that, A portion of the first electrode (110) and the second electrode (120) protrudes in a direction away from the winding center of the electrode assembly (100) to form the protrusion (160).

21. A battery, characterized in that, It includes a housing and an electrode assembly (100) as described in any one of claims 1-20; the electrode assembly is disposed within the housing.

22. An electrical appliance, characterized in that, It includes an electrical device and the battery of claim 21, wherein the battery is electrically connected to the electrical device and is used to provide electrical energy to the electrical device.

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