Electrode assembly, battery and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to an electrode assembly, a battery and electric equipment, the electrode assembly comprises a pole piece and a diaphragm, along the thickness direction of the electrode assembly, the pole piece comprises a plurality of pole piece layers, the diaphragm comprises a plurality of diaphragm layers, the plurality of pole piece layers and the plurality of diaphragm layers are alternately stacked, and the plurality of diaphragm layers are alternately stacked. Each pole piece layer is provided with a first edge part; each diaphragm layer is provided with a second edge part corresponding to the first edge part, a gap is formed between the adjacent first edge part and second edge part, the gap is filled with a supporting piece, the supporting piece is provided with a metal-friendly surface and a plastic-friendly surface which are oppositely arranged, the metal-friendly surface is attached to the first edge part, and the plastic-friendly surface is attached to the second edge part. The plastic-friendly surface is attached to the second edge part; the first edge part of the pole piece layer and the second edge part of the diaphragm layer can achieve a better attaching effect through the supporting piece, so that bubbles or black spots on the first edge part are reduced, and the performance of the electrode assembly is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and specifically relates to an electrode assembly, a battery and an electrical device. Background Art

[0002] As a new type of secondary battery, lithium-ion battery has the advantages of high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and green environmental protection. It has broad application prospects in portable appliances, power tools, large-scale energy storage, electric transportation power supply, etc.

[0003] In batteries, the degree of interfacial adhesion between the battery pole piece and the diaphragm is crucial to shortening the ion migration path and exerting battery performance. Usually, due to the certain curvature of the battery pole piece, the edge of the battery pole piece and the diaphragm are not as well adhered to as the middle area of ​​the battery pole piece. This makes it easy for bubbles and black spots to appear on the edge of the battery pole piece, which in turn affects the performance of the battery cell. Utility Model Content

[0004] The purpose of the utility model is to provide an electrode assembly to address the deficiencies in the prior art, so as to solve the problem in the prior art that, due to the curvature of the electrode piece, the fit between the edge and the diaphragm is not as good as that in the middle area, resulting in bubbles or black spots on the edge of the battery electrode piece, affecting the performance of the battery cell.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An electrode assembly comprises a pole piece and a diaphragm. Along the thickness direction of the electrode assembly, the pole piece comprises a plurality of pole piece layers, and the diaphragm comprises a plurality of diaphragm layers. The plurality of pole piece layers and the plurality of diaphragm layers are alternately stacked, and each of the pole piece layers has a first edge portion; each of the diaphragm layers has a second edge portion corresponding to the first edge portion, and a gap is formed between adjacent first edge portions and second edge portions, and the gap is filled with a support member, and the support member has a metal-friendly surface and a plastic-friendly surface arranged opposite to each other, the metal-friendly surface is in contact with the first edge portion, and the plastic-friendly surface is in contact with the second edge portion.

[0007] Preferably, along the height direction of the electrode assembly, the first edge portion of at least one end of each of the electrode sheets is connected to a pole lug, and the support member corresponds to the position of the pole lug.

[0008] Preferably, the pole lug has a connecting portion, the connecting portion is formed by extending from an edge of the first edge portion in a direction away from the pole piece layer, and the supporting member partially covers the connecting portion.

[0009] Preferably, the support member is an insulating support member.

[0010] Preferably, the support member comprises a first adhesive layer and a second adhesive layer which are stacked, the metal-friendly surface is located in the first adhesive layer, and the plastic-friendly surface is located in the second adhesive layer.

[0011] Preferably, the support member further includes a reinforcement layer, and the reinforcement layer is arranged between the first adhesive layer and the second adhesive layer.

[0012] Preferably, each of the electrode layers includes a current collector layer and an active material layer. Along the height direction of the electrode assembly, the current collector layer includes a main body and the first edge portion arranged on at least one side of the main body, the active material layer is arranged on the main body, and the thickness of the support member is equal to the thickness of the active material layer.

[0013] Preferably, the width of the first edge portion and / or the width of the second edge portion is less than or equal to the width of the support member.

[0014] Another object of the utility model is: a battery, comprising a shell, a top cover and the electrode assembly as described above in the specification, wherein the top cover is arranged on the opening of the shell and a receiving cavity is formed between the top cover and the shell, and the electrode assembly is arranged in the receiving cavity.

[0015] Another object of the present invention is to provide an electrical device, comprising the battery described above in the specification.

[0016] The beneficial effect of the utility model lies in that the electrode assembly of the utility model, through the coordinated use of the pole piece layer, the diaphragm layer and the support member, the support member is arranged in the gap between the first edge portion of the adjacent pole piece layer and the second edge portion of the diaphragm layer, the surface of the support member that fits with the first edge portion is a metal-friendly surface, and the surface of the support member that fits with the second edge portion is a plastic-friendly surface, so that the first edge portion of the pole piece layer and the second edge portion of the diaphragm layer can achieve a better fitting effect through the support member, thereby reducing the problem of bubbles or black spots on the first edge portion and improving the performance of the electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0018] Figure 1 It is a structural schematic diagram of the electrode assembly of the utility model.

[0019] Figure 2 for Figure 1 Schematic diagram of the enlarged structure at point A in the middle.

[0020] Figure 3 It is a structural schematic diagram of the pole piece of the utility model.

[0021] The reference numerals are described as follows:

[0022] 100. Electrode assembly;

[0023] 10, pole piece; 11, pole piece layer; 111, current collector layer; 1111, main body; 1112, first edge portion; 112, active material layer;

[0024] 20. diaphragm; 21. diaphragm layer; 211. second edge portion;

[0025] 30. Support member; 31. First adhesive layer; 311. Metal-friendly surface; 32. Second adhesive layer; 321. Plastic-friendly surface; 33. Reinforcement layer;

[0026] 40. Tab; 41. Connecting portion; 42. Welding portion;

[0027] a. Thickness direction of the electrode assembly; b. Height direction of the electrode assembly. DETAILED DESCRIPTION

[0028] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0029] Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0030] In the utility model, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0031] In the utility model, "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the utility model, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0032] The following is combined with Figures 1 to 3 The utility model is further described in detail, but it is not intended to limit the utility model.

[0033] The electrical equipment of the embodiment of the utility model includes a battery. The electrical equipment may be a car, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The car may be a fuel car, a gas car, or a new energy car, and the new energy car may be a pure electric car, a hybrid car, or an extended-range car, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical equipment.

[0034] The battery of the embodiment of the utility model comprises a shell, a top cover and an electrode assembly 100. The top cover is arranged on the opening of the shell and forms a receiving cavity between the top cover and the shell. The electrode assembly 100 is arranged in the receiving cavity.

[0035] See also Figures 1 to 3 The electrode assembly 100 of the embodiment of the utility model includes a pole piece 10 and a diaphragm 20. Along the thickness direction a of the electrode assembly 100, the pole piece 10 includes a plurality of pole piece layers 11, and the diaphragm 20 includes a plurality of diaphragm layers 21. The plurality of pole piece layers 11 and the plurality of diaphragm layers 21 are alternately stacked, and each of the pole piece layers 11 has a first edge portion 1112; each of the diaphragm layers 21 has a second edge portion 211 corresponding to the first edge portion 1112, and a gap is formed between adjacent first edge portions 1112 and second edge portions 211, and the gap is filled with a support member 30, and the support member 30 has a metal-friendly surface 311 and a plastic-friendly surface 321 that are relatively arranged, and the metal-friendly surface 311 is in contact with the first edge portion 1112, and the plastic-friendly surface 321 is in contact with the second edge portion 211.

[0036] Compared with the prior art, the electrode assembly 100 of the embodiment of the utility model uses the pole piece layer 11, the diaphragm layer 21 and the support member 30 in coordination. The support member 30 is arranged in the gap between the first edge portion 1112 of the adjacent pole piece layer 11 and the second edge portion 211 of the diaphragm layer 21. The surface of the support member 30 that is bonded to the first edge portion 1112 is a metal-friendly surface 311, and the surface of the support member 30 that is bonded to the second edge portion 211 is a plastic-friendly surface 321, so that the first edge portion 1112 of the pole piece layer 11 and the second edge portion 211 of the diaphragm layer 21 can achieve a better bonding effect through the support member 30, thereby reducing the problem of bubbles or black spots in the first edge portion 1112 and improving the performance of the electrode assembly 100.

[0037] See also Figures 1-2 In some embodiments, along the height direction b of the electrode assembly 100, the first edge portion 1112 of at least one end of each of the pole sheet layers 11 is connected to a pole lug 40, and the support member 30 corresponds to the position of the pole lug 40. Generally, compared with the edge of the pole sheet layer 11 not connected to the pole lug 40, the edge of the pole sheet layer 11 connected to the pole lug 40 has a greater curvature and a worse fit with the diaphragm layer 21. Therefore, by arranging the support member 30 to correspond to the position of the pole lug 40, that is, arranging the support member 30 at one end of the pole sheet layer 11 connected to the pole lug 40, it is beneficial to further improve the fit between the pole sheet edge and the diaphragm edge.

[0038] See also Figures 2-3 In some embodiments, the pole tab 40 has a connecting portion 41, and the connecting portion 41 is formed by extending from the edge of the first edge portion 1112 in a direction away from the pole sheet layer 11, and the supporting member 30 partially covers the connecting portion 41. Through the setting of the connecting portion 41, the supporting member 30 partially covers the connecting portion 41, that is, the root of the pole tab 40 is covered by the supporting member 30, further strengthening the supporting effect of the pole tab 40, increasing the hardness of the pole tab 40, making the root of the pole tab 40 not easy to bend or inverted, and further making the pole tab 40 not easy to be folded and deformed, thereby preventing the electrode assembly 100 from short-circuiting due to the inverted insertion of the pole tab 40.

[0039] Furthermore, the width of the portion of the support member 30 covering the connection portion 41 is E, and the length of the tab 40 is H, which satisfies the relationship: 0≤E≤(HT), where T is 3-20 mm. When E=0, that is, the connection portion 41 of the tab 40 is not covered by the support member 30.

[0040] Furthermore, the tab 40 also has a welding portion 42 , which is connected to an end of the connecting portion 41 away from the electrode layer 11 . The tab 40 can be connected to a pole or a busbar of the battery through the welding portion 42 to ensure the performance of the battery.

[0041] Specifically, the welding portion 42 and the connecting portion 41 are formed integrally, that is, the welding portion 42 and the connecting portion 41 are one component.

[0042] In some embodiments, the support member 30 is an insulating support member 30. By setting the insulating support member 30, the insulating support member 30 has an insulating effect, which effectively prevents the first edge portions 1112 of the electrode layers 11 with opposite polarities from contacting each other and causing a short circuit in the electrode assembly 100.

[0043] See also Figure 2 In some embodiments, the support member 30 includes a first adhesive layer 31 and a second adhesive layer 32 that are stacked, the metal-friendly surface 311 is located in the first adhesive layer 31, and the plastic-friendly surface 321 is located in the second adhesive layer 32. Through the coordinated use of the first adhesive layer 31 and the second adhesive layer 32, the first edge portion 1112 is bonded to the metal-friendly surface 311 of the first adhesive layer 31, and the second edge portion 211 is bonded to the plastic-friendly surface 321 of the second adhesive layer 32, which effectively improves the bonding effect between the first edge portion 1112 and the second edge portion 211, and prevents the support member 30 from falling off.

[0044] Furthermore, the first adhesive layer 31 is metal-philic modified PP or metal-philic modified PE, and the second adhesive layer 32 is plastic-philic modified PP or plastic-philic modified PE.

[0045] In some embodiments, the support member 30 further includes a reinforcing layer 33, and the reinforcing layer 33 is disposed between the first adhesive layer 31 and the second adhesive layer 32. By disposing the reinforcing layer 33, the reinforcing layer 33 can improve the overall strength of the support member 30, thereby strengthening the lamination effect of the first edge portion 1112 and the second edge portion 211, and strengthening the support effect on the tab 40, increasing the hardness of the tab 40, making the root of the tab 40 not easy to bend or inverted, and further making the tab 40 not easy to be folded and deformed, thereby preventing the electrode assembly 100 from short-circuiting due to the inverted insertion of the tab 40.

[0046] Furthermore, the reinforcement layer 33 is aluminum oxide, boehmite (AlOOH), silicon oxide, calcium oxide, titanium dioxide, epoxy resin, silicone structural adhesive or polyethylene naphthalate film.

[0047] Furthermore, the thickness of the first adhesive layer 31 is J, the thickness of the reinforcing layer 33 is K, and the thickness of the second adhesive layer 32 is L, which satisfy the relationship: J:K:L=(1-2):(1-2):(1-2). For example, J:K:L=1:1:1, J:K:L=1:2:1, or J:K:L=2:1:2.

[0048] See also Figures 1 to 3In some embodiments, each of the pole sheet layers 11 includes a current collector layer 111 and an active material layer 112. Along the height direction b of the electrode assembly 100, the current collector layer 111 includes a main body 1111 and a first edge portion 1112 disposed on at least one side of the main body 1111. The active material layer 112 is disposed on the main body 1111. The thickness of the support member 30 is equal to the thickness of the active material layer 112. By setting the thickness of the support member 30, if the thickness of the support member 30 is less than or greater than the thickness of the active material layer 112, the pole sheet layer 11 located in the area where the support member 30 is located will be concave or convex, thereby causing the surface of the pole sheet layer 11 to be uneven, resulting in poor contact between the pole sheet layers 11 with opposite polarities, affecting the conductivity of the battery, and further affecting the charge and discharge performance of the battery. At the same time, it may also cause local concavities or convexities in the electrode assembly 100, thereby reducing the capacity of the battery. Therefore, when the thickness of the support member 30 is equal to the thickness of the active material layer 112 , the flatness of the electrode layer 11 is effectively guaranteed, thereby ensuring the consistency of the overall thickness of the electrode assembly 100 and improving the performance and safety of the battery.

[0049] See also Figures 2-3 In some embodiments, the width of the first edge portion 1112 and / or the width of the second edge portion 211 is less than or equal to the width of the support member 30. By setting the width of the support member 30, if the width of the first edge portion 1112 and / or the width of the second edge portion 211 is greater than the support member 30, part of the first edge portion 1112 and / or the second edge portion 211 cannot fit with the support member 30, thereby reducing the fitting effect between the support member 30 and the first edge portion 1112 and / or the second edge portion 211. At the same time, there is a certain distance between the support member 30 and the tab 40, and the support member 30 has a poor supporting effect on the tab 40, which makes the tab 40 prone to folding and deformation. Therefore, when the width of the first edge portion 1112 and / or the width of the second edge portion 211 is less than or equal to the width of the support member 30, the fitting effect between the support member 30 and the first edge portion 1112 and / or the second edge portion 211 can be ensured, and at the same time, the supporting effect on the pole ear 40 can be ensured, so that the pole ear 40 is not easy to fold and deform, thereby preventing the electrode assembly 100 from short-circuiting due to the inverted insertion of the pole ear 40.

[0050] Furthermore, the actual width of the portion of the support member 30 located at the pole ear 40 is D, and the designed width is F, satisfying the relationship D=F±S, wherein S is 0.1-0.5 mm.

[0051] Specifically, D satisfies the relationship: 0<D≤10mm.

[0052] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.

Claims

1. An electrode assembly, characterized in that: The invention comprises a pole piece (10) and a diaphragm (20), wherein along the thickness direction (a) of the electrode assembly (100), the pole piece (10) comprises a plurality of pole piece layers (11), the diaphragm (20) comprises a plurality of diaphragm layers (21), the plurality of pole piece layers (11) and the plurality of diaphragm layers (21) are alternately stacked, each of the pole piece layers (11) has a first edge portion (1112); each of the diaphragm layers (21) has a first edge portion (1112) and a second edge portion (1113) extending from the first edge portion (1114); 2) a corresponding second edge portion (211), a gap is formed between the adjacent first edge portion (1112) and the second edge portion (211), the gap is filled with a support member (30), the support member (30) has a metal-friendly surface (311) and a plastic-friendly surface (321) that are relatively arranged, the metal-friendly surface (311) is in contact with the first edge portion (1112), and the plastic-friendly surface (321) is in contact with the second edge portion (211).

2. The electrode assembly according to claim 1, characterized in that: Along the height direction (b) of the electrode assembly (100), the first edge portion (1112) of at least one end of each electrode layer (11) is connected to a pole lug (40), and the support member (30) corresponds to the position of the pole lug (40).

3. The electrode assembly according to claim 2, characterized in that: The pole lug (40) has a connecting portion (41), the connecting portion (41) extending from the edge of the first edge portion (1112) in a direction away from the pole piece layer (11), and the supporting member (30) partially covers the connecting portion (41).

4. The electrode assembly according to claim 1, characterized in that: The support member (30) is an insulating support member (30).

5. The electrode assembly according to any one of claims 1 to 4, characterized in that: The support member (30) comprises a first adhesive layer (31) and a second adhesive layer (32) which are stacked, the metal-friendly surface (311) being located on the first adhesive layer (31), and the plastic-friendly surface (321) being located on the second adhesive layer (32).

6. The electrode assembly according to claim 5, characterized in that: The support member (30) further comprises a reinforcement layer (33), wherein the reinforcement layer (33) is arranged between the first adhesive layer (31) and the second adhesive layer (32).

7. The electrode assembly according to claim 1, characterized in that: Each of the electrode sheets (11) comprises a current collector layer (111) and an active material layer (112); along the height direction (b) of the electrode assembly (100), the current collector layer (111) comprises a main body (1111) and the first edge portion (1112) arranged on at least one side of the main body (1111); the active material layer (112) is arranged on the main body (1111); and the thickness of the support member (30) is equal to the thickness of the active material layer (112).

8. The electrode assembly according to claim 1, characterized in that: The width of the first edge portion (1112) and / or the width of the second edge portion (211) is less than or equal to the width of the support member (30).

9. A battery, characterized in that: It comprises a shell, a top cover and the electrode assembly according to any one of claims 1 to 8, wherein the top cover is arranged on the opening of the shell and an accommodating cavity is formed between the top cover and the shell, and the electrode assembly (100) is arranged in the accommodating cavity.

10. An electrical equipment, characterized in that: A battery comprising the battery of claim 9.

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