Electrode assembly, battery cell, battery, electric device, manufacturing method and apparatus

Abstract

The invention discloses an electrode assembly which comprises a first pole piece, a second pole piece and a plurality of folding units, the first pole piece and the second pole piece are opposite in polarity, the folding units are stacked in the thickness direction, and each folding unit in the folding units is configured to be formed by folding a first isolation piece and a second isolation piece which are stacked in a folded mode. The first separator and the second separator are used for separating the first pole piece and the second pole piece; wherein the first pole piece is arranged between the first separator and the second separator, and the second pole piece is arranged on one side, far away from the first pole piece, of the first separator or the second separator. By adopting the electrode assembly structure, the production takt can be improved, and the production efficiency of mass production of the electrode assembly is improved, so that the comprehensive economic benefit of the electrode assembly is improved.

Description

[0001] This application is a divisional application of the invention patent application with the application date of October 27, 2021, the application number of 202111258104.9, and the name of "Electrode assembly, battery cell, battery, power utilization device, manufacturing method and equipment". TECHNICAL FIELD

[0002] The present application relates to the field of batteries, in particular to an electrode assembly, a battery cell, a battery, a power utilization device, a manufacturing method and equipment. BACKGROUND

[0003] With the development of economy, battery technology is widely used in various fields, especially in the field of transportation tools such as electric vehicles. Each battery cell in the battery includes at least one electrode assembly, and the structural diversity of the electrode assembly provides more choices for battery cells with different shapes or different use requirements, so that various different schemes for composing battery products can be more flexible. SUMMARY

[0004] The present application provides a battery cell, a battery, a power utilization device, a manufacturing method and equipment, which can make the structural design of the electrode assembly more flexible to adapt to battery products with different use requirements, and at the same time, can also speed up the production rhythm, which is beneficial to the mass production of battery products.

[0005] In a first aspect, the present application provides an electrode assembly, comprising:

[0006] a first pole piece and a second pole piece with opposite polarities; a plurality of folding units stacked in a thickness direction, each of the plurality of folding units is configured to be folded by a first separator and a second separator, and the first separator and the second separator are used to separate the first pole piece and the second pole piece; wherein the first pole piece is arranged between the first separator and the second separator, and the second pole piece is arranged on a side of the first separator or the second separator away from the first pole piece.

[0007] By adopting the above scheme, in each folding unit, the first separator and the second separator can be folded to separate several spaces for placing pole pieces, for example, the space between the first separator and the second separator can be divided into two spaces after folding, and when the first separator and the second separator are folded towards the direction of the first separator, another space for placing pole pieces can also be formed on the inner side of the first separator after folding. Compared with the traditional stacked electrode assembly, the number of actions required by the equipment to produce one electrode assembly can be reduced, the production rhythm can be accelerated, and the economic benefit of the electrode assembly can be improved.

[0008] In some embodiments, the folding unit comprises a folding plane, the folding unit comprises a first part and a second part on two sides of the folding plane respectively, at least part of the first pole piece is located in the first part, and another part of the first pole piece is located in the second part.

[0009] By adopting the above scheme, the first pole piece and the second pole piece with different polarities can be inserted into different spaces of the folding unit in an alternating order. For example, when the first separator and the second separator are folded towards the direction of the first separator, a space for placing a pole piece can be formed on the inner side of the first separator after folding, which can be used to place the second pole piece. The space between the first separator and the second separator can be divided into two spaces after folding, and the two spaces can be used to place the first pole pieces with the same polarity. In this way, the first pole piece and the second pole piece with opposite polarities can be prevented from contacting each other, and internal short circuit can be avoided.

[0010] In some embodiments, the first pole piece is provided with a blank current collector, and the folding plane passes through the blank current collector.

[0011] By adopting the above scheme, when the first pole piece is placed between the first separator and the second separator, the first pole piece can be folded at the same time as the first separator and the second separator. The region of the first pole piece close to the folding plane is provided as a blank current collector, which can reduce the probability of structural defects of the active material layer on the first pole piece due to extrusion or stretching when being bent, thereby improving the use safety of the electrode assembly.

[0012] In some embodiments, the first pole piece is provided in two parts.

[0013] By adopting the above scheme, the first pole piece can be provided in two parts, i.e., two first pole pieces can be placed between the same first separator and second separator, so that the first pole piece does not need to be bent, which can reduce the probability of pole piece defects of the first pole piece due to bending, thereby improving the use safety of the electrode assembly. In addition, the two first pole pieces provided in two parts are distributed on two sides of the second pole piece, which can be used to form electrochemical reaction units with the second pole piece respectively, thereby improving the cycle capability of the battery cell formed by the electrode assembly.

[0014] In some embodiments, the second pole piece is clamped between the first part and the second part.

[0015] By adopting the above scheme, the second pole piece can be clamped between the first part and the second part of the same folding unit, so that the first isolation piece or the second isolation piece after folding can completely cover the second pole piece from both sides of the second pole piece to isolate the second pole piece from the first pole piece. For example, when the folding unit is folded in a direction in which the first isolation piece points to the second isolation piece, the second pole piece can be located inside the second isolation piece, and the second isolation piece is arranged on both sides of the second pole piece to isolate the second pole piece from the first pole piece. Alternatively, when the folding unit is folded in a direction in which the second isolation piece points to the first isolation piece, the second pole piece can be located inside the first isolation piece, and the first isolation piece is arranged on both sides of the second pole piece to isolate the second pole piece from the first pole piece.

[0016] In some embodiments, the second pole piece is clamped between two adjacent folding units in the plurality of folding units.

[0017] By adopting the above scheme, when the plurality of folding units are stacked to form an electrode assembly, the outermost isolation piece in the stacking direction in each folding unit can be used to separate the first pole piece of the next outer layer from the second pole piece, so as to form more electrochemical units in the same electrode assembly.

[0018] In some embodiments, the folding directions of the two adjacent folding units in the plurality of folding units are different.

[0019] By adopting the above scheme, the thickness of the folding unit based on the folding structure can be non-uniform, and when the plurality of folding units are stacked, the non-uniform thickness will be further enlarged, which is easy to cause uneven stress distribution on the electrode assembly. By making the folding directions of the two adjacent folding units in the plurality of folding units different, the non-uniform thickness can be improved, so as to reduce the probability of uneven stress distribution on the electrode assembly.

[0020] In a second aspect, the present application provides a battery cell, comprising the battery cell provided in any of the embodiments of the first aspect.

[0021] In a third aspect, the embodiments of the present application provide a power consumption device, comprising the battery of the second aspect, and the battery is used to provide electric energy.

[0022] In a fourth aspect, the embodiments of the present application provide a manufacturing method of an electrode assembly, comprising:

[0023] providing a first isolation piece, a second isolation piece, and first and second pole pieces with opposite polarities;

[0024] stack the first pole piece, the second pole piece, the first isolation piece and the second isolation piece, wherein the first pole piece is placed between the first isolation piece and the second isolation piece, and the second pole piece is placed on a surface of the first isolation piece away from the second isolation piece;

[0025] fold the first isolation piece and the second isolation piece to obtain a folded unit.

[0026] In some embodiments, the manufacturing method further comprises stacking a plurality of folded units in a thickness direction to form an electrode assembly.

[0027] In a fifth aspect, the embodiments of the present application provide a manufacturing device of an electrode assembly, comprising:

[0028] a providing module configured to provide a first isolation piece, a second isolation piece, and a first pole piece and a second pole piece with opposite polarities;

[0029] a first stacking module configured to stack the first pole piece, the second pole piece, the first isolation piece and the second isolation piece, wherein the first pole piece is placed between the first isolation piece and the second isolation piece, and the second pole piece is placed on a surface of the first isolation piece away from the second isolation piece;

[0030] a folding module configured to fold the first isolation piece and the second isolation piece to obtain a folded unit.

[0031] In some embodiments, the manufacturing device further comprises a second stacking module configured to stack a plurality of folded units in a thickness direction to form an electrode assembly. BRIEF DESCRIPTION OF DRAWINGS

[0032] The features, advantages, and technical effects of the exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0033] Figure 1 a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0034] Figure 2 an exploded schematic diagram of a battery provided by some embodiments of the present application;

[0035] Figure 3 an exploded schematic diagram of a battery cell provided by some embodiments of the present application;

[0036] Figure 4 a structural schematic diagram of a battery provided by some embodiments of the present application; Figure 3 a top view of an electrode assembly;

[0037] Figure 5 a structural schematic diagram of a battery provided by some embodiments of the present application; Figure 4 a structural schematic diagram of a folded unit;

[0038] Figure 6 a position relationship diagram of a folded unit and a first pole piece provided by some embodiments of the present application;

[0039] Figure 7 is Figure 6 a partial enlarged view of G in the middle;

[0040] Figure 8 is Figure 6 another structural schematic view of G in the middle;

[0041] Figure 9 is Figure 6 still another structural schematic view of G in the middle;

[0042] Figure 10 a positional relationship diagram of the folding unit, the first pole piece and the second pole piece provided by some embodiments of the present application;

[0043] Figure 11 a positional relationship diagram of the folding unit and the second pole piece provided by some embodiments of the present application;

[0044] Figure 12 a structural schematic view of an electrode assembly provided by some other embodiments of the present application;

[0045] Figure 13 a manufacturing method of an electrode assembly provided by some embodiments of the present application;

[0046] Figure 14 a manufacturing device of an electrode assembly provided by some embodiments of the present application.

[0047] In the drawings, the drawings are not necessarily drawn according to the actual scale.

[0048] Reference Signs

[0049] 1 - vehicle;

[0050] 10 - battery, 20 - controller, 30 - motor;

[0051] 11 - box, 111 - first box part, 112 - second box part, 113 - accommodation space;

[0052] 12 - battery cell;

[0053] 400 - end cover;

[0054] 500 - electrode assembly;

[0055] 501 - first pole piece, 502 - second pole piece, 503 - first isolation piece, 503a - blank current collector, 504 - second isolation piece;

[0056] 50a - folding unit, 50a1 - first part, 50a2 - second part;

[0057] 600 - housing, 610 - opening

[0058] P - fold line,

[0059] L1 - first fold line, L2 - second fold line

[0060] X - thickness direction of the electrode assembly. DETAILED DESCRIPTION

[0061] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0063] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0064] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] The term "and / or" in the present application is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0066] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length, width and other dimensions of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0067] "Multiple" appearing in the present application means two or more (including two).

[0068] In the present application, the battery cell can include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The embodiments of the present application are not limited thereto. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft package battery cells, etc. The embodiments of the present application are not limited thereto.

[0069] The battery referred to in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application can include a battery module or a battery pack, etc. The battery generally includes a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cell.

[0070] The battery cell includes a shell, an end cover, an electrode assembly and an electrolyte, the end cover and the shell are sealed to form a containing space, and the electrode assembly and the electrolyte are placed in the containing space. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector; the positive electrode current collector includes a positive electrode current collecting part and a positive electrode protruding part protruding from the positive electrode current collecting part, the positive electrode current collecting part is coated with the positive electrode active material layer, at least part of the positive electrode protruding part is not coated with the positive electrode active material layer, and the positive electrode protruding part serves as a positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collecting part and a negative electrode protruding part protruding from the negative electrode current collecting part, the negative electrode current collecting part is coated with the negative electrode active material layer, at least part of the negative electrode protruding part is not coated with the negative electrode active material layer, and the negative electrode protruding part serves as a negative electrode tab. The material of the negative electrode current collector can be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that the fusing does not occur when passing a large current, the number of positive electrode tabs is multiple and they are stacked together, and the number of negative electrode tabs is multiple and they are stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene) or the like.

[0071] In the traditional structure of the laminated electrode assembly, a plurality of separators, a plurality of positive electrode sheets and a plurality of negative electrode sheets are stacked in the structure of separator-positive electrode sheet-separator-negative electrode sheet through multiple stacking operations; or one separator is folded multiple times to obtain a plurality of folding spaces separated in the thickness direction, and an electrode sheet is placed in each folding space, and different polarity electrode sheets are placed in adjacent folding spaces.

[0072] The production cycle of the electrode assembly refers to the time required to produce each electrode assembly, and the operation required to produce an electrode assembly is one of the key factors affecting the length of the production cycle. In the above-mentioned laminated electrode assembly, multiple stacking operations or multiple folding operations are required to form a multi-layer stacked structure, which will result in a longer production cycle for each electrode assembly, resulting in an increase in the production cost of the electrode assembly and affecting the economic benefit of the product.

[0073] Based on daily observation, the applicant finds that in a folding paper structure, the number of layers can be doubled by folding once, and in the case of a multi-layered insulation layer stack, folding the multi-layered insulation layer stack can obtain a plurality of separated spaces, and each separated space is arranged with insulation on both sides in the thickness direction. Based on the case that the first polar sheet and the second polar sheet with opposite polarities in the electrode assembly need to be arranged alternately, in the folding structure, the adjacent separated spaces can be used to arrange the first polar sheet and the second polar sheet with different polarities. Through this method, the applicant finds that only the polar sheets with the same polarity can be arranged in the two separated spaces formed by the same first insulation and second insulation, which can avoid the first polar sheet and the second polar sheet with different polarities being arranged in the two separated spaces formed by the same first insulation and second insulation, and further avoid the first polar sheet and the second polar sheet from being in contact at the folding position to cause short circuit.

[0074] However, the applicant also finds that when the plurality of first insulations and the plurality of second insulations form a multi-layered stack and are folded, on the one hand, the hardness of the stack after folding is large, and it is not easy to fold; on the other hand, after folding, the position close to the folding line is easy to form an arc-shaped bending to cause the thickness of the position to be large, which is easy to cause the thickness distribution of the electrode assembly to be uneven, thereby causing the stress distribution of the electrode assembly to be uneven.

[0075] Based on this, the applicant provides an electrode assembly, which includes a plurality of folding units stacked in the thickness direction, and each folding unit in the plurality of folding units is configured to be folded by a first insulation and a second insulation stacked to form. The space between the adjacent insulations in the plurality of folding units can be used to arrange the polar sheet to form the electrode assembly. This kind of electrode assembly can improve the production rhythm and speed up the production, and at the same time, it can also reduce the probability of uneven thickness of the electrode assembly caused by the folding structure, so as to reduce the probability of uneven stress distribution of the electrode assembly in use.

[0076] The electrode assembly described in the embodiments of the present application is suitable for battery monomers, batteries, and electric devices using batteries.

[0077] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or an extended range automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc. The embodiments of the present application do not specially limit the above electric devices.

[0078] The following embodiments are described by taking the electric device as a vehicle for example.

[0079] Figure 1 A structural schematic diagram of a vehicle is provided for some embodiments of the present application. As shown in the figure, the inside of the vehicle 1 is provided with a battery 10, which can be arranged at the bottom, head or tail of the vehicle 1. The battery 10 can be used for power supply of the vehicle 1, for example, the battery 10 can be used as the operating power supply of the vehicle 1. Figure 1

[0080] The vehicle 1 can further include a controller 20 and a motor 30, the controller 20 is used to control the battery 10 to supply power to the motor 30, for example, to meet the power demand of the vehicle 1 during starting, navigation and driving.

[0081] In some embodiments of the present application, the battery 10 can not only be used as the operating power supply of the vehicle 1, but also be used as the driving power supply of the vehicle 1, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1.

[0082] Figure 2 An exploded schematic diagram of the battery 10 is provided for some embodiments of the present application. As shown in the figure, the battery 10 includes a box body 11 and a battery cell 12, the battery cell 12 is contained in the box body 11. Figure 2

[0083] The box body 11 is used to contain the battery cell 12, and the box body 11 can be of various structures. In some embodiments, the box body 11 can include a first box body part 111 and a second box body part 112, the first box body part 111 and the second box body part 112 are mutually covered, and the first box body part 111 and the second box body part 112 jointly define a containing space 113 for containing the battery cell. The second box body part 112 can be a hollow structure with one end open, and the first box body part 111 is a plate-like structure, which is covered on the open side of the second box body part 112 to form the box body 11 with the containing space 113; or the first box body part 111 and the second box body part 112 can both be a hollow structure with one side open, and the open side of the first box body part 111 is covered on the open side of the second box body part 112 to form the box body 11 with the containing space 113. Of course, the first box body part 111 and the second box body part 112 can be of various shapes, such as a cylinder, a cuboid, etc.

[0084] In order to improve the sealing performance of the first box body part 111 and the second box body part 112 after being connected, a sealing member such as sealing glue, sealing ring, etc. can be arranged between the first box body part 111 and the second box body part 112.

[0085] ​​The first box body part 111 can also be referred to as an upper box cover, and the second box body part 112 can also be referred to as a lower box body, assuming that the first box body part 111 covers the top of the second box body part 112.

[0086] In the battery 10, the battery cells 12 are multiple. The multiple battery cells 12 can be connected in series, in parallel, or in a mixed manner, where the mixed manner means that the multiple battery cells 12 are connected in series and in parallel. The multiple battery cells 12 can be directly connected in series, in parallel, or in a mixed manner, and then the whole of the multiple battery cells 12 are accommodated in the box body 11; of course, the multiple battery cells 12 can be first connected in series, in parallel, or in a mixed manner to form a battery module (not shown in the figure), and then the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box body 11. The multiple battery cells 12 in the battery module can be electrically connected through a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 12 in the battery module.

[0087] Please refer to Figure 3 、 Figure 4 and Figure 5 , Figure 3 the explosion schematic diagram of the battery cell 12 provided for some embodiments of the present application, Figure 4 the top view of the electrode assembly 500 in Figure 3 , Figure 5 the structure schematic diagram of the folding unit 50a in Figure 4 .

[0088] The battery cell 12 includes an end cover 400 and a shell 600, the shell 600 has an opening 610, and the end cover 400 covers the opening 610 to close the shell 600 to form a closed space, and the electrode assembly 500 is placed in the closed space to form the battery cell 12. The above-mentioned electrode assembly 500 is a laminated electrode assembly 500, which includes first and second polar plates 501 and 502 with opposite polarities, and multiple folding units 50a stacked along a thickness direction X, each of the multiple folding units 50a is configured to be folded by first and second separators 503 and 504, and the first and second separators 503 and 504 are used to separate the first and second polar plates 501 and 502; wherein the first polar plate 501 is arranged between the first and second separators 503 and 504, and the second polar plate 502 is arranged on a side of the first or second separator 503 or 504 away from the first polar plate 501.

[0089] As Figure 4 and Figure 5As shown, the electrode assembly 500 includes a plurality of folded units 50a, each of which includes a first spacer 503 and a second spacer 504, and the first spacer 503 and the second spacer 504 are folded to obtain the folded unit 50a. The first spacer 503 and the second spacer 504 can only provide one space separated by the spacer after being stacked. After the first spacer 503 and the second spacer 504 are folded, three spaces separated by the spacer can be obtained. When the first spacer 503 and the second spacer 504 are not completely attached at the folding part, two spaces distributed between the first spacer 503 and the second spacer 504 and located on both sides of the folding part can form a communication structure at the folding part, so that the two spaces are not completely separated. Therefore, the first pole piece 501 and the second pole piece 502 of opposite polarity cannot be placed in the two spaces respectively, but the first pole piece 501 or the second pole piece 502 of the same polarity can be placed in the two spaces. A third space formed by the first spacer 503 or the second spacer 504 after being folded is distributed between the two spaces, as shown in Figure 5 When the first pole piece 501 is placed in the two spaces separated by the third space, the third space is used to place the second pole piece 502; otherwise, when the second pole piece 502 is placed in the two spaces, the third space is used to place the first pole piece 501. In this way, the structure of the first pole piece 501 and the second pole piece 502 placed alternately can be formed, and a plurality of first pole pieces 501 and second pole pieces 502 arranged oppositely and a plurality of electrochemical units can be obtained.

[0090] By using the electrode assembly 500 with the above structure, the same number of pole piece placement spaces can be obtained by fewer steps or actions, the production rhythm can be improved, the production efficiency of mass production of the electrode assembly 500 can be improved, and the overall economic benefit of the electrode assembly 500 can be improved.

[0091] Please refer to Figure 6 and Figure 7 , Figure 6 the position relationship diagram of the folded unit 50a and the first pole piece 501 provided in the embodiments of the present application, Figure 7 for Figure 6 the enlarged view of G in FIG. 5.

[0092] As shown in Figure 6 and Figure 7 , in some embodiments of the present application, the folded unit 50a includes a folding plane P, the folded unit 50a includes a first part 50a1 and a second part 50a2 on both sides of the folding plane P, at least part of the first pole piece 501 is located in the first part 50a1, and another part of the first pole piece 501 is located in the second part 50a2.

[0093] When the folding unit 50a is folded, the first partition 503 is folded along the first fold line L1, and the second partition is folded along the second fold line L2. The plane through which the first fold line L1 and the second fold line L2 pass is the folding plane P. The two sides of the folding unit 50a along the folding plane P are respectively the first part 50a1 and the second part 50a2. On both sides of the folding plane P, the first part 50a1 is formed by the first partition 503 and the second partition 504 forming a partition space; the second part 50a2 is also formed by the first partition 503 and the second partition 504 forming another partition space, and the first part 50a1 and the second part 50a2 sandwich to form a third partition space.

[0094] like Figure 7 As shown, in a folding unit 50a, the first electrode 501 can be formed by stacking it together with the first separator 503 and the second separator 504 and then folding them together. After folding, a portion of the first electrode 501 is distributed on both sides of the folding plane P. That is, the first electrode 501 is placed in the space between the first separator 503 and the second separator 504. After folding, the first separator 503 and the second separator 504 form two spaces distributed on both sides of the folding plane P, and a portion of the first electrode 501 is located in each of the two spaces. Optionally, the first electrode 501 here can be a negative electrode, which helps to provide more lithium intercalation space and reduce the probability of lithium plating caused by insufficient lithium intercalation.

[0095] By setting the first electrode 501 as one, after folding in the folding unit 50a, the first electrode 501 also has a folded structure, so that each part of the first electrode 501 is located in the two spaces formed by folding the first separator 503 and the second separator 504. The electrode assembly 500 with this structure can reduce the number of steps in production and increase the production cycle of the electrode assembly 500. Furthermore, this structure of the electrode assembly 500 can improve the economic efficiency of production and help the mass production of related products.

[0096] Please see Figure 8 , Figure 8 for Figure 6 Another structural diagram at point G.

[0097] like Figure 8 As shown, in some embodiments of this application, optionally, the first electrode 501 is provided with a blank current collector 503a, and the folded plane P passes through the blank current collector 503a.

[0098] Since the first tab 501 is folded at the intersection with the folding plane P, the active material on the surface of the blank current collector 503a at the folding position is prone to be peeled off due to excessive bending angle, which not only leads to the attenuation of the service life of the electrode assembly 500, but also causes the dust of the peeled material to corrode the metal shell, such as an aluminum shell, thereby causing a safety problem. In addition, when the first tab 501 is folded, the active material layer on the surface of the first tab 501 is prone to be cracked due to excessive bending angle, which causes lithium precipitation in the interior of the electrode assembly 500 and punctures the separator, thereby causing internal short circuit.

[0099] Based on this, the blank current collector 503a can be arranged on the first tab 501, that is, a part of the area is not coated with active material to keep the surface of the current collector exposed, and the folding plane P passes through the blank current collector 503a. Alternatively, one surface of the first tab 501 can be exposed to the blank current collector 503a. For example, the active material layer subjected to extrusion when the first tab 501 is bent is more prone to structural defects, while the active material layer subjected to stretching is not prone to structural defects, so the surface subjected to extrusion when bent can be exposed to the blank current collector 503a. Alternatively, the blank current collector 503a can also be exposed on both surfaces of the first tab 501, so that the active material layers arranged on both surfaces can be avoided from structural defects due to extrusion or stretching when bent.

[0100] Alternatively, the arrangement area of the blank current collector 503a can be adjusted according to the stress distribution of the first tab 501 when bent, and can be arranged to cover the folding line formed after the first tab 501 is folded along the folding plane P, so as to facilitate the bending of the first tab 501.

[0101] By arranging the blank current collector 503a on the first tab 501 and making the folding plane P pass through the blank current collector 503a, the third folding line (not shown in the figure) on the first tab 501 can be located on the blank current collector 503a, which can reduce the problem of active material peeling or cracking of the first tab 501 due to folding, thereby improving the safety of the electrode assembly 500.

[0102] Please refer to Figure 9 , Figure 9 for Figure 6 another structure diagram at G in FIG. 1.

[0103] As Figure 9 shown, in some embodiments of the present application, the first tab 501 is arranged separately.

[0104] The first pole piece 501 can be split, that is, two first pole pieces 501 can be placed between the same first isolation piece 503 and second isolation piece 504. The sizes of the two first pole pieces 501 can be the same or different, but the two first pole pieces 501 need to be separated from the second pole piece 502 via the first isolation piece 503 or the second isolation piece 504 to avoid internal short circuit. As shown in Figure 9 The space formed by folding the first isolation piece 503 and the second isolation piece 504 in half is divided into two by the folding plane P. The two first pole pieces 501 can be distributed in the spaces on both sides of the folding plane P. In this way, the first pole piece 501 does not need to be bent, which can reduce the probability of pole piece defects caused by bending of the first pole piece 501 and improve the use safety of the electrode assembly 500. Moreover, the two first pole pieces 501 arranged in a split manner are distributed on both sides of the second pole piece 502, which can be used to form electrochemical reaction units with the second pole piece 502 respectively, thereby improving the cycle capability of the battery monomer 12 formed by the electrode assembly 500.

[0105] Please refer to Figure 10 , Figure 10 the position relationship diagram of the folding unit 50a, the first pole piece 501 and the second pole piece 502 provided by some embodiments of the present application.

[0106] As shown in Figure 10 , in some embodiments, the second pole piece 502 is clamped between the first part 50a1 and the second part 50a2.

[0107] When the first isolation piece 503 and the second isolation piece 504 are folded in the direction in which the first isolation piece 503 points to the second isolation piece 504, the first isolation piece 503 covers the second isolation piece 504 from the outside, and the second isolation piece 504 covers the second pole piece 502 from the outside, so that the second pole piece 502 is clamped between the first part 50a1 and the second part 50a2. Alternatively, when the first isolation piece 503 and the second isolation piece 504 are folded in the direction in which the second isolation piece 504 points to the first isolation piece 503, the second isolation piece 504 covers the first isolation piece 503 from the outside, and the first isolation piece 503 covers the second pole piece 502 from the outside, so that the second pole piece 502 is clamped between the first part 50a1 and the second part 50a2. In this way, the first pole piece 501 and the second pole piece 502 arranged between the first isolation piece 503 and the second isolation piece 504 can be separated by the first isolation piece 503 or the second isolation piece 504, so as to avoid contact between the first pole piece 501 and the second pole piece 502 and form a structure in which the first pole piece 501 and the second pole piece 502 are alternately arranged.

[0108] Please refer to Figure 11 , Figure 11The positional relationship diagram of the folding unit 50a and the second pole piece 502 is provided for some embodiments of the present application.

[0109] As shown in the drawings, Figure 11 In some embodiments of the present application, the second pole piece 502 is arranged between two adjacent folding units 50a in the plurality of folding units 50a.

[0110] When the electrode assembly is formed by stacking the folding units 50a, the outermost layer of each folding unit 50a is the first or second spacer 503 or 504, and the next outer layer is the first pole piece 501. The second pole piece 502 is arranged between the adjacent folding units 50a. Thus, the first or second spacer 503 or 504 in the outermost layer of each folding unit 50a can be used to separate the first pole piece 501 in the next outer layer from the second pole piece 502. Alternatively, the size of the second pole piece 502 can be set according to the size of the first pole piece 501 in the next outer layer of the adjacent two folding units 50a, so as to form a structure in which the negative pole piece completely covers the positive pole piece in the thickness direction of the electrode assembly 500. In addition, the size of the first or second spacer 503 or 504 in the outermost layer of the adjacent two folding units 50a can be set according to the size of the first pole piece 501 and the second pole piece 502, so as to separate the first pole piece 501 from the second pole piece 502 and avoid contact short circuit.

[0111] At the same time, through the above structure, more electrochemical reaction units of the first pole piece 501-the first or second spacer 503 / 504-the second pole piece 502 can be formed, and the cycle capability of the electrode assembly 500 can be improved.

[0112] Please refer to Figure 12 , Figure 12 The structural schematic diagram of the electrode assembly 500 is provided for some other embodiments of the present application.

[0113] As shown in the drawings, Figure 12 In some embodiments of the present application, the folding directions of the adjacent two folding units 50a in the plurality of folding units 50a are different.

[0114] Since the spacer itself has a certain thickness, the first and second spacers 503 and 504 in the folding unit 50a are not easy to completely fit at the folding line and have an arc-shaped bending structure, so that the overall thickness of the folding unit 50a near the folding line is larger, and the overall thickness of the folding unit 50a far from the folding line is smaller than that near the folding line. The folding directions of the plurality of folding units 50a are directed to different directions when the electrode assembly 500 is formed, for example, Figure 12As shown, adjacent folding units 50a can be oriented in two opposite directions. This allows for a more uniform thickness distribution of the electrode assembly 500 when multiple folding units 50a are stacked, reducing the probability of uneven stress distribution when the electrode assembly 500 is under stress, thereby improving the mechanical properties of the electrode assembly 500.

[0115] like Figure 12 As shown, in some embodiments of this application, the electrode assembly 500 may include a plurality of folding units 50a stacked along the thickness direction X. Each folding unit 50a is configured to be formed by folding together a stacked first spacer 503 and a second spacer 504. Both the first spacer 503 and the second spacer 504 are used to separate the first electrode 501 and the second electrode 502. The first electrode 501 is disposed between the first spacer 503 and the second spacer 504, and the second electrode 502 is disposed on the side of the first spacer 503 or the second spacer 504 away from the first electrode 501. The folding directions of two adjacent folding units 50a may be opposite. The structure of the electrode assembly 500 provided in this embodiment requires fewer operations during production, which can shorten the total time required to produce one electrode assembly 500, increase the production cycle time, and thus improve the overall economic efficiency.

[0116] In some embodiments of this application, a battery cell 12 is also provided, which includes the electrode assembly 500 in any of the foregoing embodiments. The battery cell 12 formed by using the electrode assembly 500 structure can effectively improve its various performance characteristics.

[0117] In some embodiments of this application, a battery 10 is also provided, which includes at least one battery cell 12 as described in the foregoing embodiments.

[0118] In some embodiments of this application, an electrical device is also provided. The electrical device may be the vehicle 1 mentioned above, mobile phone, portable device, laptop, ship, spacecraft, electric toy and power tool, etc. Any device that operates using the battery 10 provided in the foregoing embodiments as a power source can be considered as the electrical device referred to in the embodiments of this application.

[0119] Please see Figure 13 , Figure 13 S is a method for manufacturing an electrode assembly provided in some embodiments of this application.

[0120] like Figure 13 As shown, the manufacturing method of this electrode assembly includes:

[0121] S1: providing a first separator, a second separator, and a first pole piece and a second pole piece with opposite polarities; S2: stacking the first pole piece, the second pole piece, the first separator, and the second separator, wherein the first pole piece is placed between the first separator and the second separator, and the second pole piece is placed on a surface of the first separator away from the second separator; and S3: folding the first separator and the second separator to obtain a folded unit.

[0122] In some embodiments of the present application, the method for manufacturing the electrode assembly can further include: stacking a plurality of folded units in a thickness direction to form the electrode assembly.

[0123] By using the method for manufacturing the electrode assembly in any of the foregoing embodiments, the production rhythm of the electrode assembly can be improved, the time required for producing the same number of electrode assemblies can be shortened, the production cost can be reduced, and the overall economic benefit of the product can be improved.

[0124] Please refer to Figure 14 , Figure 14 A manufacturing device for an electrode assembly is provided in some embodiments of the present application.

[0125] As shown in Figure 14 , the manufacturing device for the electrode assembly includes:

[0126] A providing module M1 is configured to provide a first separator, a second separator, and a first pole piece and a second pole piece with opposite polarities; a first stacking module M2 is configured to stack the first pole piece, the second pole piece, the first separator, and the second separator, wherein the first pole piece is placed between the first separator and the second separator, and the second pole piece is placed on a surface of the first separator away from the second separator; and a folding module M3 is configured to fold the first separator and the second separator to obtain a folded unit.

[0127] In some embodiments of the present application, the manufacturing device for the electrode assembly can further include:

[0128] A second stacking module (not shown in the figure) is configured to stack a plurality of folded units in a thickness direction to form the electrode assembly.

[0129] By using the manufacturing device for the electrode assembly in any of the foregoing embodiments, the production rhythm of the electrode assembly can be improved, the time required for producing the same number of electrode assemblies can be shortened, the production cost can be reduced, and the overall economic benefit of the product can be improved.

[0130] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0131] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An electrode assembly, characterized in that, include: First and second poles with opposite polarities; Multiple folding units are stacked along the thickness direction, each of the multiple folding units being configured to be formed by folding together a first spacer and a second spacer, the first spacer and the second spacer being used to separate the first electrode and the second electrode; The first electrode is disposed between the first separator and the second separator, and the second electrode is disposed on the side of the first separator or the second separator away from the first electrode.

2. The electrode assembly according to claim 1, characterized in that, The folding unit includes a folding plane, and the two sides of the folding plane are respectively a first part and a second part. At least a portion of the first electrode is located in the first part, and the other part of the first electrode is located in the second part.

3. The electrode assembly according to claim 2, characterized in that, The first electrode is provided with a blank current collector, and the folded plane passes through the blank current collector.

4. The electrode assembly according to claim 2, characterized in that, The first electrode is set separately.

5. The electrode assembly according to claim 2, characterized in that, The second electrode is sandwiched between the first part and the second part.

6. The electrode assembly according to claim 1, characterized in that, The second electrode is sandwiched between two adjacent folding units in the plurality of folding units.

7. The electrode assembly according to any one of claims 1-6, characterized in that, The folding directions of two adjacent folding units in the plurality of folding units are different.

8. A single battery cell, characterized in that, include: Electrode assembly as described in any one of claims 1-7; A housing for accommodating the electrode assembly.

9. A battery, characterized in that, The battery includes the battery cell as described in claim 8.

10. An electrical device, characterized in that, The electrical device includes the battery as described in claim 9, the battery being used to provide electrical energy.

11. A method for manufacturing an electrode assembly, characterized in that, include: Provides a first isolator, a second isolator, and first and second electrodes with opposite polarities; The first electrode, the second electrode, the first separator, and the second separator are stacked, wherein the first electrode is placed between the first separator and the second separator, and the second electrode is placed on the surface of the first separator away from the second separator. The first and second isolation components are folded in half to obtain a folded unit.

12. The manufacturing method according to claim 11, characterized in that, The method further includes stacking multiple folding units along the thickness direction to form the electrode assembly.

13. An apparatus for manufacturing an electrode assembly, characterized in that, The manufacturing equipment includes: A module is provided for providing a first isolator, a second isolator, and a first electrode and a second electrode with opposite polarities; The first stacking module is used to stack the first electrode, the second electrode, the first separator, and the second separator, wherein the first electrode is placed between the first separator and the second separator, and the second electrode is placed on the surface of the first separator away from the second separator. The folding module is used to fold the first separator and the second separator in half to obtain a folding unit.

14. The manufacturing equipment according to claim 13, characterized in that, The manufacturing equipment also includes a second stacking module for stacking multiple folding units along the thickness direction to form the electrode assembly.

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