Electrode assembly, battery cell, battery, and electric device

Abstract

The application relates to an electrode assembly, a battery monomer, a battery and a power utilization device, and belongs to the technical field of battery manufacturing. The electrode assembly comprises a pole piece and a diaphragm, the pole piece has a main body part and a pole lug, the main body part has opposite first and second edges in a first direction, and the pole lug is connected to the second edge; the diaphragm comprises a diaphragm body and a coating layer arranged on at least one side of the diaphragm body in the thickness direction, the diaphragm body has opposite first and second side edges in the first direction, the first side edge is arranged correspondingly to the first edge, and the coating layer is arranged at least on the first side edge of the diaphragm body to form a first coating layer area. The electrode assembly is simple in structure and has high energy density. The application further provides a battery monomer, a battery and a power utilization device, all of which comprise the electrode assembly.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and more specifically, to an electrode assembly, a battery cell, a battery, and an electrical device. Background Technology

[0002] In recent years, with the increasing market share of electric vehicles, the market for power batteries has also been expanding. The development of the industry has also placed higher demands on the performance of power batteries. Optimizing battery structure and improving energy density, while ensuring safety performance, is also a development direction.

[0003] Currently, the internal structure of a battery cell uses a bottom plate to insulate and isolate the electrode assembly and the bottom wall of the casing. If improvements can be made to this area to further simplify the structure of the battery cell, it will be possible to improve the structural compactness and energy density of the battery cell. Utility Model Content

[0004] Therefore, this application proposes an electrode assembly, a battery cell, a battery, and an electrical device, which have a simple structure and high energy density.

[0005] The electrode assembly of a first aspect of this application includes: an electrode sheet and a diaphragm. The electrode sheet includes a first electrode sheet and a second electrode sheet, and the diaphragm is located between the first electrode sheet and the second electrode sheet. The electrode sheet has a main body portion and an electrode tab. The main body portion has a first edge and a second edge opposite to each other along a first direction, and the electrode tab is connected to the second edge. The diaphragm includes a membrane body and a coating disposed on at least one side of the membrane body in the thickness direction. The membrane body has a first side edge and a second side edge opposite to each other along the first direction. The first side edge and the first edge are correspondingly disposed. The coating is disposed at least on the first side edge of the membrane body to form a first coating region.

[0006] Optionally, the dimension of the first coating area along the first direction is W1, satisfying:

[0007] 3mm≤W1≤5mm.

[0008] Optionally, the coating is further disposed on the second side of the membrane body to form a second coating area, which is correspondingly disposed at the connection between the tab and the main body.

[0009] Optionally, the dimension of the second coating area along the first direction is W2, and the dimension of the tab along the first direction is H, satisfying:

[0010] W2≤1 / 3H; and / or 3mm≤W2≤5mm.

[0011] Optionally, the first coating region and / or the second coating region are disposed on one side of the film body surface in the thickness direction, the coating thickness is D1, and the electrode sheet disposed on the same side as the coating has a thickness D, satisfying:

[0012] 1.3D≤D1≤1.6D.

[0013] Optionally, the distance between the first edge of the electrode and the first coating area on the same side is A1, and the distance between the second edge of the electrode and the second coating area on the same side is A2, satisfying:

[0014] 0mm≤A1≤2mm, 0mm≤A2≤2mm.

[0015] Optionally, the elastic modulus of the coating is E, satisfying:

[0016] 1 GPa ≤ E ≤ 3.5 GPa; and / or

[0017] The coating material is PVDF or PMM.

[0018] The battery cell of the second aspect of this application includes: a housing, including a bottom wall and a top wall disposed opposite to each other, the top wall being provided with electrode terminals; an electrode assembly of the first aspect of this application, housed inside the housing; a first edge disposed near the bottom wall, a second edge disposed near the top wall, and a tab electrically connected to the electrode terminals.

[0019] The battery of the third aspect embodiment of this application includes the battery cell of the second aspect embodiment of this application.

[0020] The electrical device according to the fourth aspect of this application includes the battery described in the third aspect of this application, the battery being used to provide electrical energy to the electrical device.

[0021] Compared with existing technologies, this solution has the following advantages:

[0022] The electrode assembly of this application embodiment has a coating on the first side of the membrane body of the diaphragm, forming a first coating area, which can insulate and isolate the electrode assembly and the bottom wall of the housing, eliminating the need for a traditional bottom support plate. This not only simplifies the structure of the battery cell but also improves the energy density of the battery cell.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in an embodiment of this application;

[0026] Figure 2 A schematic diagram (unfolded state) of one form of the electrode assembly provided in an embodiment of this application;

[0027] Figure 3 A schematic diagram of another form of the electrode assembly provided in the embodiments of this application (unfolded state);

[0028] Figure 4 A schematic diagram of the structure of the first coating region formed by the coating on one side of the diaphragm of the electrode assembly provided in the embodiments of this application;

[0029] Figure 5 A schematic diagram of the double-sided coating of the diaphragm of the electrode assembly provided in this application embodiment;

[0030] Figure 6 This is a schematic diagram of the structure of the second coating region formed by the coating on one side of the diaphragm of the electrode assembly provided in the embodiments of this application.

[0031] Icons: 100-Electrode assembly; 110-Electrode sheet; 111-First electrode sheet; 112-Second electrode sheet; 113-Main body; 114-Taper; 115-First edge; 116-Second edge; 120-Separator; 121-Membrane body; 1211-First surface; 1212-Second surface; 122-Coating; 123-First side; 124-Second side; 130-First coating area; 140-Second coating area; 200-Battery cell; 210-Housing; 211-Bottom wall; 212-Top wall; 213-Side wall; 220-Electrode terminal; Z-First direction; X-Second direction; Y-Third direction. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the battery cell 200 includes a housing 210, an electrode assembly 100, and electrode terminals 220. The housing 210 includes a bottom wall 211 and a top wall 212 disposed opposite to each other, and the top wall 212 is provided with electrode terminals 220. The electrode assembly 100 is housed inside the housing 210. The electrode assembly 100 includes an electrode 110 and a separator 120, with the separator 120 located between the first electrode 111 and the second electrode 112. The electrode 110 includes a main body 113 and a tab 114, and the electrode 110 also includes a first electrode 111 and a second electrode 112, one of which is a positive electrode and the other is a negative electrode.

[0035] The housing 210 has a square structure. Its length extends along a first direction Z, its width along a second direction X, and its thickness along a third direction Y. The first direction Z, the second direction X, and the third direction Y are arranged perpendicularly to each other. The housing 210 also includes a side wall 213, which connects to the bottom wall 211 and the top wall 212. Two electrode terminals 220 are provided, spaced apart along the second direction X on the top wall 212. These two electrode terminals are a positive electrode terminal and a negative electrode terminal, respectively. The positive electrode terminal is electrically connected to a positive electrode tab, and the negative electrode terminal is electrically connected to a negative electrode tab, enabling the battery cell 200 to output electrical energy.

[0036] like Figure 2 and Figure 4 As shown, the electrode assembly 100 of some embodiments of this application includes an electrode 110 and a diaphragm 120. The electrode 110 includes a first electrode 111 and a second electrode 112, and the diaphragm 120 is located between the first electrode 111 and the second electrode 112. The electrode 110 has a main body portion 113 and an electrode tab 114. The main body portion 113 has opposing first edges 115 and second edges 116 along a first direction Z, and the electrode tab 114 is connected to the second edge 116. The diaphragm 120 includes a membrane body 121 and a coating 122 disposed on at least one side in the thickness direction of the membrane body 121. The membrane body 121 has opposing first side edges 123 and second side edges 124 along the first direction Z. The first side edges 123 and the first edges 115 are correspondingly disposed. The coating 122 is disposed at least on the first side edge 123 of the membrane body 121, forming a first coating region 130.

[0037] The electrode assembly 100 can be a stacked structure, with the first electrode 111, the diaphragm 120 and the second electrode 112 stacked together; the electrode assembly 100 can also be a wound structure, with the first electrode 111, the diaphragm 120 and the second electrode 112 stacked together and wound to form the electrode assembly 100.

[0038] Both the electrode 110 and the membrane body 121 extend along the third direction Y. The membrane body 121 has a first surface 1211 and a second surface 1212 on its two sides along the third direction Y. One of the first surface 1211 and the second surface 1212 may have a coating 122, or both the first surface 1211 and the second surface 1212 may have a coating 122. The coating 122 may be provided only on the first side 123 of the membrane body 121, forming a first coating region 130; the coating 122 may also be provided on the second side 124 of the membrane body 121, forming a second coating region 140.

[0039] It is understandable that, in the unfolded state, the projection outline of the electrode 110 on the XZ plane falls inside the projection outline of the diaphragm 120. For the coating 122 disposed on the same side as the first electrode 111, the coating 122 is disposed outside the projection outline of the first electrode 111 on the diaphragm 120; for the coating 122 disposed on the same side as the second electrode 112, the coating 122 is disposed outside the projection outline of the second electrode 112 on the diaphragm 120.

[0040] The electrode assembly 100 of this application embodiment has a coating 122 on the first side 123 of the membrane body 121 of the diaphragm 120, forming a first coating area 130, which can insulate and isolate the electrode assembly 100 and the bottom wall 211 of the housing 210, eliminating the need for a traditional bottom support plate. This not only simplifies the structure of the battery cell 200, but also improves the energy density of the battery cell 200.

[0041] like Figure 2 As shown, in some embodiments of this application, the size of the first coating area 130 along the first direction Z is W1, which satisfies: 3mm≤W1≤5mm.

[0042] It is understandable that the dimension W1 of the first coating area 130 along the first direction Z refers to the dimension of the coating 122 provided on the first side 123 of the diaphragm 120 in the unfolded state.

[0043] By limiting the above parameters to the above range, it is possible to reliably insulate the bottom wall 211 of the isolation housing 210 from the electrode assembly 100, and also to improve the energy density of the battery cell 200.

[0044] like Figure 1 and Figure 2As shown, in some embodiments of this application, the coating 122 is also disposed on the second side 124 of the membrane body 121 to form a second coating area 140, which is correspondingly disposed at the connection between the tab 114 and the main body 113.

[0045] The tab 114 is integrally formed with the main body 113. In the second direction X, there may be two second coating areas 140, which are respectively provided with the positive tab and the negative tab. The second coating areas 140 may also extend continuously to the edge of the diaphragm 120 in the second direction X.

[0046] By setting the second coating area 140, the root of the tab 114 of the electrode sheet 110 can be insulated and protected, preventing the electrode assembly 100 from short-circuiting due to the tab 114 being inserted upside down, thus improving the safety performance of the battery cell 200.

[0047] like Figure 2 As shown, in some embodiments of this application, the second coating region 140 has a dimension of W2 along the first direction Z, and the tab 114 has a dimension of H along the first direction Z, satisfying: W2≤1 / 3H.

[0048] It is understandable that the dimension H of the tab 114 along the first direction Z refers to the dimension of the tab 114 before bending, and the dimension W2 of the second coating area 140 along the first direction Z refers to the dimension of the diaphragm 120 in the unfolded state.

[0049] In some other embodiments of this application, the following condition is satisfied: 3mm≤W2≤5mm.

[0050] By limiting the above parameters to the above range, the root of the tab 114 can be reliably insulated and protected, and the energy density of the battery cell 200 can be increased.

[0051] like Figure 3 As shown, in some embodiments of this application, the dimension of the bottom wall 211 along the second direction X is L, and the length of the first coating area 130 along the second direction X is L1, satisfying: 2 / 3L≤L1=L.

[0052] By limiting the above parameters to the above range, it is possible to reduce the amount of coating material used in coating 122 while reliably insulating the electrode assembly 100 from the bottom wall 211 and reducing the weight of the electrode assembly 100.

[0053] like Figure 4 As shown, in some embodiments of this application, the first coating region 130 and / or the second coating region 140 are disposed on one side surface of the membrane body 121 in the thickness direction, the thickness of the coating 122 is D1, and the thickness of the electrode 110 disposed on the same side as the coating 122 is D, satisfying: 1.3D≤D1≤1.6D.

[0054] For a membrane 120, the two sides of the membrane 120 are a first electrode 111 and a second electrode 112, respectively. The first surface 1211 of the membrane body 121 is disposed on the same side as the first electrode 111, and the second surface 1212 is disposed on the same side as the second electrode 112. The coating 122 is disposed on the first surface 1211 or the second surface 1212. The coating 122 is disposed on the first side 123 of the membrane body 121 to form a first coating area 130, or disposed on the second side 124 of the membrane body 121 to form a second coating area 140.

[0055] Taking the first coating region 130 disposed on the first surface 1211 as an example, the thickness of the first electrode 111 is D, the thickness of the coating 122 coated on the first surface 1211 is D1, the coating 122 is connected to the first electrode 111 on one side along the first direction Z, and extends to the edge of the membrane body 121 on the other side to form the first coating region 130.

[0056] By limiting the above parameters to the above range, the thickness of the coating 122 on the surface of the membrane body 121 can be guaranteed in the case of single-sided coating, and the thickness of the coating 122 is matched with the thickness of the electrode 110 on the same side, which can achieve both insulation protection and improve the energy density of the battery cell 200.

[0057] like Figure 5 As shown, in other embodiments, the first coating region 130 and / or the second coating region 140 are disposed on both sides of the membrane body 121 in the thickness direction, the thickness of the coating 122 is D2, and the thickness of the electrode 110 disposed on the same side as the coating 122 is D, satisfying: 0.6D≤D2≤0.8.

[0058] By limiting the above parameters to the above range, the total thickness of the coating 122 on both sides of the membrane body 121 can be guaranteed when coating on both sides, and the thickness of the coating 122 matches the thickness of the electrode 110 on the same side. This can not only provide reliable insulation and protection, but also improve the energy density of the battery cell 200.

[0059] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the distance between the first edge 115 of the electrode 110 and the first coating area 130 on the same side is A1, and the distance between the second edge 116 of the electrode 110 and the second coating area 140 on the same side is A2, satisfying: 0mm≤A1≤2mm, 0mm≤A2≤2mm.

[0060] That is, when the diaphragm 120 is in the unfolded state, there is a gap between the first edge 115 of the first electrode 111 and / or the second electrode 112 and the first coating area 130 on the same side, and the size of the gap is A1; and there is a gap between the second edge 116 of the first electrode 111 and / or the second electrode 112 and the second coating area 140 on the same side, and the size of the gap is A2.

[0061] like Figure 4 As shown, for example, a coating 122 is provided on the first surface 1211 of the membrane body 121, and is provided corresponding to the first edge 115 of the first electrode 111, forming a first coating region 130. The distance between the first edge 115 of the first electrode 111 and the first coating region 130 is A1; Figure 6 As shown, for example, the second surface 1212 of the membrane body 121 is provided with a coating 122, and is provided corresponding to the second edge 116 of the second electrode 112 to form a second coating area 140, and the distance between the second edge 116 of the second electrode 112 and the second coating area 140 is A2.

[0062] This configuration avoids reducing the effective area of ​​the electrode 110 due to the coating 122 adhering to its edges, thus ensuring that the original capacitance of the electrode assembly 100 is not reduced.

[0063] In other embodiments, coating 122 may also be attached to the edge of electrode 110 on the same side.

[0064] In some embodiments of this application, the elastic modulus of coating 122 is E, which satisfies: 1 GPa ≤ E ≤ 3.5 GPa.

[0065] In some other embodiments of this application, the coating 122 is made of PVDF or PMM.

[0066] This configuration allows the elastic modulus of coating 122 to be within a suitable range, making it easy to process and providing both vibration isolation and cushioning effects.

[0067] like Figure 1 As shown, in some embodiments of this application, the battery cell 200 includes a housing 210 and an electrode assembly 100. The electrode assembly 100 is housed inside the housing 210. A first edge 115 is disposed near the bottom wall 211, and a second edge 116 is disposed near the top wall 212. The tab 114 is electrically connected to the electrode terminal 220.

[0068] Due to the characteristics of the electrode assembly 100 in this application embodiment, the battery cell 200 in this application embodiment is not only simple in structure, but also has a high energy density.

[0069] The battery in some embodiments of this application includes a battery cell 200.

[0070] Some embodiments of this application include an electrical device comprising a battery according to embodiments of this application, the battery being used to provide electrical energy to the electrical device.

[0071] Electrical devices can include automobiles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Automobiles can be gasoline-powered, natural gas-powered, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0072] Due to the characteristics of the electrode assembly 100 in this application embodiment, the battery and power device in this application embodiment also have high energy density.

[0073] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0074] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electrode assembly (100), characterized in that, include: The electrode (110) includes a first electrode (111) and a second electrode (112), and the diaphragm (120) is located between the first electrode (111) and the second electrode (112). The electrode (110) has a main body (113) and an electrode tab (114). The main body (113) has a first edge (115) and a second edge (116) opposite each other along a first direction. The electrode tab (114) is connected to the second edge (116). The diaphragm (120) includes a membrane body (121) and a coating (122) disposed on at least one side of the membrane body (121) in the thickness direction. The membrane body (121) has a first side (123) and a second side (124) opposite to each other along the first direction. The first side (123) and the first edge (115) are disposed correspondingly. The coating (122) is disposed at least on the first side (123) of the membrane body (121) to form a first coating area (130).

2. The electrode assembly (100) according to claim 1, characterized in that, The first coating area (130) has a dimension W1 along the first direction, satisfying: 3mm≤W1≤5mm.

3. The electrode assembly (100) according to claim 1, characterized in that, The coating (122) is also provided on the second side (124) of the membrane body (121) to form a second coating area (140), which is correspondingly provided at the connection between the tab (114) and the main body (113).

4. The electrode assembly (100) according to claim 3, characterized in that, The second coating area (140) has a dimension of W2 along the first direction, and the tab (114) has a dimension of H along the first direction, satisfying: W2≤1 / 3H; and / or 3mm≤W2≤5mm.

5. The electrode assembly (100) according to claim 3, characterized in that, The first coating region (130) and / or the second coating region (140) are disposed on one side surface of the membrane body (121) in the thickness direction. The thickness of the coating (122) is D1, and the thickness of the electrode (110) disposed on the same side as the coating (122) is D, satisfying: 1.3D≤D1≤1.6D.

6. The electrode assembly (100) according to claim 3, characterized in that, The distance between the first edge (115) of the electrode (110) and the first coating area (130) on the same side is A1, and the distance between the second edge (116) of the electrode (110) and the second coating area (140) on the same side is A2, satisfying: 0mm≤A1≤2mm, 0mm≤A2≤2mm.

7. The electrode assembly (100) according to claim 1, characterized in that, The elastic modulus of the coating (122) is E, which satisfies: 1 GPa ≤ E ≤ 3.5 GPa; and / or The material of the coating (122) is PVDF or PMM.

8. A single battery cell (200), characterized in that, include: The housing (210) includes a bottom wall (211) and a top wall (212) disposed opposite to each other, wherein the top wall (212) is provided with electrode terminals (220); The electrode assembly (100) as described in any one of claims 1 to 7 is housed inside the housing (210); the first edge (115) is disposed near the bottom wall (211), the second edge (116) is disposed near the top wall (212), and the tab (114) is electrically connected to the electrode terminal (220).

9. A battery, characterized in that, Includes the battery cell (200) as described in claim 8.

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

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