Electrode assembly, battery and electronic device comprising the same

Abstract

This application discloses an electrode assembly formed by winding a stack. The stack includes a first conductive layer, a second conductive layer, and a first layer disposed between the first and second conductive layers and comprising an insulating material. The stack also includes a first surface, a first end, and a second end located opposite the first end. The stacking direction of the stack is defined as a first direction. Viewed along the first direction, the first surface has a first region located on one side of the first end and a second region located on the other side of the first end in a second direction perpendicular to the first direction. In the winding direction of the stack, the first region is closer to the first end than the second region. The first region includes a first area and a second area, the first area being covered by a second layer containing insulating material. The first region also includes a third end located on the first side of the first end in the second direction, the second area being located between the first end and the third end, and the second area being separate from the second layer.

Description

Technical Field

[0001] This application relates to the field of energy storage devices, and more particularly to an electrode assembly and a battery and electronic device including said electrode assembly. Background Technology

[0002] Currently, terminal devices that use electricity as their functional means are developing towards being mobile and portable. However, portable devices may suffer physical damage during use, such as impacts, squeezing, or drops, which can cause the adhesive layer fixing the tail of the battery cell to open, leading to cell failure. Summary of the Invention

[0003] One objective of this application is to provide an electrode assembly that reduces the risk of third-layer detachment.

[0004] This application provides an electrode assembly formed by winding a stack, the electrode assembly including a first metal plate electrically connected to the stack. The stack includes a first conductive layer, a second conductive layer, and a first layer disposed between the first and second conductive layers and comprising an insulating material. The stack also includes a first surface, a first end, and a second end located opposite the first end. A direction perpendicular to a surface of the first metal plate is defined as a first direction. Viewed along the first direction, the first surface has a first region located on a first side of the first end in a second direction perpendicular to the first direction, and a second region located on a second side of the first end. In the winding direction of the stack, the first region is closer to the first end than the second region. The first region includes a first area and a second area, the first area being covered by a second layer containing an insulating material, and the first region also includes a third end located on the first side of the first end in the second direction, the second area being located between the first end and the third end, and the second area being separate from the second layer.

[0005] This application improves adhesion and reduces the risk of the third layer detaching by providing a second region not covered by the second layer on a first region of the first surface of the electrode assembly. Furthermore, by providing the second region, the thickness of the stack is reduced, thus minimizing energy density loss.

[0006] According to some embodiments of this application, in the second direction, the second region is located between the first end and the first region.

[0007] According to some embodiments of this application, in a second direction, the second region extends from the first end.

[0008] According to some embodiments of this application, when viewed along a first direction, in a third direction perpendicular to the second direction, the first region has a fourth end and a fifth end located opposite the fourth end.

[0009] According to some embodiments of this application, in the third-party direction, the second region has a portion extending from the fourth end to the fifth end.

[0010] According to some embodiments of this application, in a third-party direction, the second region has a portion that is separate from the fourth or fifth end.

[0011] According to some embodiments of this application, the electrode assembly further includes a third layer containing insulating material, disposed on the first surface; viewed along a first direction, the third layer is connected to the first region and the second region, and has an overlap with the first end. By providing the third layer, the first end is secured to the first surface, reducing the risk of the stack being pushed apart by internal forces.

[0012] According to some embodiments of this application, when viewed along a first direction, the third layer and the second region have overlapping portions.

[0013] According to some embodiments of this application, the electrode assembly further includes a first metal plate connected to a first conductive layer, and when viewed along a first direction, the first metal plate has an overlapping portion with the fifth end.

[0014] According to some embodiments of this application, the third layer includes a sixth end located on one side of the third end in the second direction, and the second region includes a seventh end located on one side of the third end in the second direction, wherein a first distance from the sixth end to the third end is shorter than a second distance from the seventh end to the third end.

[0015] According to some embodiments of this application, when viewed along a first direction, in a third direction perpendicular to the second direction, the first region has a fourth end and a fifth end located opposite the fourth end.

[0016] According to some embodiments of this application, the third layer also includes an eighth end located on the side of the fourth end in the third direction and a ninth end located on the side of the fifth end, wherein the third distance from the eighth end to the fourth end is shorter than the fourth distance from the ninth end to the fifth end.

[0017] According to some embodiments of this application, the electrode assembly further includes a second surface located opposite the first surface in a first direction and a fourth layer extending from the first surface to the second surface through a fifth end. By providing the fourth layer, the stack can be further secured, reducing the risk of the stack opening due to internal forces and further reducing the risk of the third layer detaching.

[0018] According to some embodiments of this application, when viewed along a first direction, the third and fourth layers have overlapping portions in a third direction.

[0019] According to some embodiments of this application, when viewed along a first direction, at least a portion of the fourth layer has a portion connected to the first end.

[0020] According to some embodiments of this application, at least a portion of the fourth layer has a portion connected to the second region.

[0021] According to some embodiments of this application, the electrode assembly further includes a fifth layer disposed in the second region, and both sides of the fifth layer are provided with adhesive layers.

[0022] According to some embodiments of this application, the fifth layer is separate from the first end and the third layer.

[0023] According to some embodiments of this application, the electrode assembly further includes a second surface located opposite to the first surface in a first direction and a fourth layer extending from the first surface through a fifth end to the second surface, the fifth layer being separate from the fourth layer.

[0024] According to some embodiments of this application, in a second direction, a first region is disposed between a first end and a second region.

[0025] According to some embodiments of this application, the first surface further includes a second coating area covered by a second layer and separated from the first area, the second area being disposed in a second direction between the first area and the second coating area.

[0026] According to some embodiments of this application, the first conductive layer includes at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide phosphate, lithium-rich manganese-based materials, lithium nickel cobalt aluminum oxide, or lithium titanate.

[0027] According to some embodiments of this application, the second layer includes a ceramic material and an adhesive.

[0028] According to some embodiments of this application, the third layer includes a substrate and an adhesive layer disposed on the substrate.

[0029] According to some embodiments of this application, the substrate includes at least one of polyethylene terephthalate, polyimide, polyvinyl chloride, polypropylene, or polyethylene and combinations thereof, and the adhesive layer includes at least one of acrylate, polyurethane, rubber, or silicone.

[0030] A second aspect of this application also provides a battery including any of the above-described electrode components and a housing covering the electrode components, wherein a first metal plate extends from one end of the housing.

[0031] A third aspect of this application also provides an electronic device including the aforementioned battery. Attached Figure Description

[0032] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1A A top view of a battery provided according to an embodiment of this application;

[0034] Figure 1B for Figure 1A The diagram shows the structure of the battery before packaging.

[0035] Figure 2A A cross-sectional schematic diagram of an electrode assembly provided in an embodiment of this application;

[0036] Figure 2B for Figure 2A Enlarged view of section IIB shown;

[0037] Figure 2C for Figure 2A Enlarged view of IIC shown;

[0038] Figure 3 for Figure 2A Top view of the electrode assembly shown;

[0039] Figure 4 A top view of an electrode assembly provided in an embodiment of this application;

[0040] Figure 5 A top view of an electrode assembly provided in another embodiment of this application;

[0041] Figure 6 for Figure 2A A schematic cross-sectional view of the first conductive layer of the electrode assembly shown after unfolding.

[0042] Figure 7 for Figure 2A A schematic cross-sectional view of the unfolded second conductive layer of the electrode assembly shown.

[0043] Figure 8 A cross-sectional schematic diagram of the third layer provided in one embodiment of this application;

[0044] Figure 9 A top view of an electrode assembly provided according to an embodiment of this application;

[0045] Figure 10A A top view of an electrode assembly provided according to an embodiment of this application;

[0046] Figure 10B for Figure 10A A bottom view of the electrode assembly shown;

[0047] Figure 10C for Figure 10A Right side view of the electrode assembly shown;

[0048] Figure 11 for Figure 10A A reverse view of the electrode assembly shown;

[0049] Figure 12 A top view of an electrode assembly provided in one embodiment of this application;

[0050] Figure 13A A top view of an electrode assembly provided according to an embodiment of this application;

[0051] Figure 13B A top view of an electrode assembly provided according to an embodiment of this application;

[0052] Figure 14 A cross-sectional schematic diagram of the eighth layer provided in one embodiment of this application;

[0053] Figure 15 A top view of an electrode assembly provided according to an embodiment of this application;

[0054] Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0055] Figure 17 A top view of the electrode assembly provided in Comparative Example 1 of this application.

[0056] Explanation of main component symbols

[0057] Battery 100

[0058] Casing 20

[0059] First Metal Plate 101

[0060] Second metal plate 102

[0061] Stack 11

[0062] First conductive layer 111

[0063] Second conductive layer 112

[0064] First floor 113

[0065] Part 1 201

[0066] Part Two 202

[0067] 203 cubic meters of space

[0068] First surface 110

[0069] First end 11a

[0070] Second surface 120

[0071] First area 110a

[0072] Second Zone 110b

[0073] Zone 1, 21

[0074] Second District 22

[0075] Second floor 12

[0076] Third end 11c

[0077] First metal layer 111a

[0078] First conductive material layer 111b

[0079] Page 31a

[0080] Page 31b

[0081] 7th floor 17

[0082] Second metal layer 112a

[0083] Second conductive material layer 112b

[0084] Third floor 13

[0085] Substrate 131, 181

[0086] Adhesive layers 133, 183

[0087] 6th floor 16

[0088] Fourth end 11d

[0089] Fifth end 11e

[0090] Sixth end 11f

[0091] 11g at the seventh end

[0092] Eighth end 11h

[0093] Ninth end 11i

[0094] Tenth end 11j

[0095] Eleventh end 11k

[0096] 11m at the twelfth end

[0097] Thirteenth end 11n

[0098] Fourteenth end 11p

[0099] The fifteenth end 11r

[0100] Sixteenth end 11s

[0101] Seventeenth end 11t

[0102] Fourth layer 14a, 14b

[0103] Fifth floor 15

[0104] Eighth floor 18

[0105] District 3, 23

[0106] Electronic devices 200

[0107] Main body 210

[0108] First end 12a

[0109] Second end 12b

[0110] Third end 12c Detailed Implementation

[0111] The technical solutions in the embodiments of this application are described clearly and in detail below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0112] The embodiments of this application will be described in detail below. However, this application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to provide a thorough and detailed understanding of this application to those skilled in the art.

[0113] Additionally, for brevity and clarity, the dimensions or thicknesses of various components and layers may be enlarged in the accompanying drawings. Throughout the text, the same numerical values ​​refer to the same elements. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more of the associated enumerated items. Furthermore, it should be understood that when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intermediate element C and element A and element B may be indirectly connected to each other.

[0114] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".

[0115] The technical terms used herein are for the purpose of describing particular embodiments and are not intended to limit this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that the term "comprising," as used in this specification, means the presence of the described features, values, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.

[0116] Spatial terms, such as "above," may be used herein for convenience in describing the relationship between one element or feature and another element (or feature) or feature (or feature) illustrated in the figures. It should be understood that, in addition to the directions depicted in the figures, spatial terms are intended to include different orientations of the device or apparatus during use or operation. For example, if the device in the figure is flipped, an element described as "above" or "on" other elements or features would be oriented "below" or "under" other elements or features. Therefore, the exemplary term "above" can include both above and below orientations. It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0117] Please see Figure 1A and Figure 1B This application provides a battery 100, including an electrode assembly 10 and a housing 20 for housing the electrode assembly 10. A first metal plate 101 and a second metal plate 102 of the electrode assembly 10 extend from one end of the housing 20 to connect to external components. The first metal plate 101 and the second metal plate 102 are electrically connected to a stack 11, respectively. Please refer to the accompanying document. Figure 2A The electrode assembly 10 is formed by winding a stack 11. The stack 11 includes a first conductive layer 111, a second conductive layer 112, and a first layer 113 disposed between the first conductive layer 111 and the second conductive layer 112. The first conductive layer 111, the first layer 113, and the second conductive layer 112 are sequentially stacked along a first direction Z and then wound to form the electrode assembly 10. In this application, the first direction Z refers to a direction perpendicular to one surface of the first metal plate 101. Figure 2A In the process, the stack 11 is wound counterclockwise around the winding axis. Viewed along the first direction Z, the second conductive layer 112 is located on the outermost layer of the electrode assembly 10. The second conductive layer 112 can be the negative electrode, and the first conductive layer 111 can be the positive electrode.

[0118] The first layer 113 is used to prevent direct contact between the first conductive layer 111 and the second conductive layer 112, thereby reducing the risk of short circuits between the first conductive layer 111 and the second conductive layer 112. The first layer 113 contains an insulating material. The insulating material is selected from at least one of polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polymethyl methacrylate, or polyethylene glycol. The first layer 113 may be a separator membrane.

[0119] In some embodiments, at least a portion of the inner surface of the housing 20 facing the electrode assembly may be made of a conductive material to improve the mechanical strength of the housing 20. The housing 20 may be a metal housing, such as a steel or aluminum housing. In other embodiments, the housing 20 may also be a packaging bag encapsulated with an encapsulation film, i.e., the battery 100 is a pouch battery.

[0120] Please see Figure 1B In some embodiments, the housing 20 includes a first portion 201 and a second portion 202 disposed opposite to each other. In a first direction Z, the first portion 201 encloses at least a portion of the electrode assembly 10 and forms a receiving space 203, and the second portion 202 covers the electrode assembly 10 and seals the receiving space 203. The first portion 201 and the second portion 202 can be directly connected or indirectly connected via adhesives or the like to seal the receiving space 203. The first metal plate 101 and the stack 11 (see...) Figure 2A A first metal plate 101 is connected to the stack 11 and extends out of the housing 20 from the connection between the first part 201 and the second part 202. The first metal plate 101 can be used to connect the stack 11 to an external device. A second metal plate 102 is connected to the stack 11 and extends out of the housing 20 from the connection between the first part 201 and the second part 202. The second metal plate 102 can be used to connect the stack 11 to an external device. In this application, the third direction Y is the direction in which the first metal plate 101 or the second metal plate 102 protrudes from the stack 11, and also the direction in which the first metal plate 101 or the second metal plate 102 extends out of the housing 20. The second direction X refers to a direction perpendicular to both the first direction Z and the third direction Y.

[0121] Please refer to the following: Figure 2A , 2B and Figure 6The first conductive layer 111 includes a first metal layer 111a and a first conductive material layer 111b disposed on the first metal layer 111a. The first metal layer 111a includes a first surface 31a and a second surface 31b disposed opposite to each other. Both the first surface 31a and the second surface 31b include a region where the first conductive material layer 111b is disposed and a region away from the first conductive material layer 111b. The first metal layer 111a can be a current collector, which has the function of current collection, and can include at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations thereof. The first conductive material layer 111b has the function of an active layer, and can include at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide, lithium-rich manganese-based materials, lithium nickel cobalt aluminum oxide and combinations thereof. Viewed along the first direction Z, the first surface 31a of each first metal layer 111a is closer to the winding center of the electrode assembly 10 than the second surface 31b. In the fourth direction X', the first metal layer 111a includes a first end 12a and a second end 12b disposed opposite to each other, wherein the first end 12a serves as the ending end of the winding of the first conductive layer 111, and the second end 12b serves as the starting end of the winding of the first conductive layer 111. In this application, the fourth direction X' is perpendicular to the third direction Y, and it is the extension direction of the first conductive layer 111 before winding, and also the direction of extension from the first region 110a of the first surface 110 to the second region 110b.

[0122] Please refer to the following: Figure 2A , 2B and Figure 7The second conductive layer 112 includes a second metal layer 112a and a second conductive material layer 112b disposed on the second metal layer 112a. The second metal layer 112a includes a third surface 41a and a fourth surface 41b disposed opposite to each other. Both the third surface 41a and the fourth surface 41b include a region where the second conductive material layer 112b is disposed and a region away from the second conductive material layer 112b. The second metal layer 112a has a current-collecting function and may include at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe, Co, Cr, W, Mo, Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, Zn and combinations thereof. The second conductive material layer 112b has an active layer function and may be selected from at least one of graphite-based materials, alloy materials, lithium metal and alloys thereof. Graphite-based materials may be selected from at least one of artificial graphite and natural graphite; alloy materials may be selected from at least one of silicon, silicon oxide, tin, and titanium sulfide. The second metal plate 102 is welded to the third surface 41a in the region away from the first conductive material layer 111b. Viewed along the first direction Z, the fourth surface 41b is closer to the winding center of the electrode assembly 10 than the third surface 41a.

[0123] Please refer to the following: Figure 2A , 2C and Figure 7 In the fourth direction X', the second metal layer 112a includes a first end 11a and a second end 11b disposed opposite to each other. After the stack 11 is wound from the first direction Z to the second direction X to form the electrode assembly 10, the portion of the third surface 41a that is away from the second conductive material layer 112b constitutes the first surface 110 of the electrode assembly 10. The first surface 110 is a surface of the stack 11 in the first direction Z. The first end 11a is located on the first surface 110, and the second end 11b is located at the center of the electrode assembly 10, wherein the second end 11b serves as the starting end of the winding of the second conductive layer 112, and the first end 11a serves as the ending end of the winding of the second conductive layer 112. Viewed along the first direction Z, the first surface 110 includes a first region 110a located on the first side X1 of the first end 11a in the second direction X and a second region 110b located on the second side X2 of the first end 11a opposite to the first side X1 in the second direction X. In the winding direction of the stack 11 (i.e., in the fourth direction X' of the unfolded second conductive layer 112), the first region 110a is closer to the first end 11a than the second region 110b.

[0124] The electrode assembly 10 further includes a second layer 12. The second layer 12 covers the portion of the third surface 41a that is away from the first conductive material layer 111b. The stack 11 also includes a second surface 120 located opposite the first surface 110 in the first direction Z. The second layer 12 covers a portion of the first surface 110 and the second surface 120. The second layer 12 includes a ceramic material and a binder. The ceramic material includes at least one of Al2O3, TiO2, MgO, SiO2, ZrO2, CaO, or boehmite, and the binder may include polyvinylidene fluoride (PVDF). By providing the second layer 12, when the conductive layer of the electrode assembly 10 is broken due to external force or other factors, the first metal layer 111a does not come into contact with the second metal layer 112a, thereby reducing the risk of instantaneous high heat accumulation and improving safety.

[0125] The first region 110a also includes a first region 21 and a second region 22. The first region 21 is covered by the second layer 12, and the second region 22 is exposed outside the second layer 12 and separate from it. Please refer to the following: Figure 2A , 2C and Figure 3 The electrode assembly 10 further includes a third layer 13. The third layer 13 is disposed on the first surface 110. Viewed along the first direction Z, the third layer 13 is connected to the first region 110a and the second region 110b, and overlaps with the first end 11a. The third layer 13 contains an insulating material. See also... Figure 8 The third layer 13 includes a substrate 131 and an adhesive layer 133 disposed on the substrate 131. The substrate 131 includes at least one of polyethylene terephthalate, polyimide, polyvinyl chloride, polypropylene, or polyethylene, and combinations thereof. The adhesive layer 133 includes at least one of acrylate, polyurethane, rubber, and silicone. By providing the third layer 13, the first end 11a is secured to the first surface 110, reducing the risk of the electrode assembly 10 being forced open by internal forces.

[0126] The third layer 13 overlaps with the second region 22. The third layer 13 is attached to a portion of the second region 22, and there is an adhesive force between the third layer 13 and the second region 22, so that the third layer 13 can be bonded to the first surface 110, further reducing the risk that the electrode assembly 10 will be stretched open at the first end 11a due to internal forces.

[0127] Please refer to the following: Figure 2A , 2B and Figure 6A first metal plate 101 is soldered to the area of ​​the second surface 31b away from the first conductive material layer 111b. A solder mark (not shown) is formed between the first metal plate 101 and the second surface 31b. A seventh layer 17 is provided in the areas of both the first surface 31a and the second surface 31b away from the first conductive material layer 111b. Specifically, one seventh layer 17 is disposed on the second surface 31b and covers the solder mark on the first metal plate 101, while the other seventh layer 17 is disposed on the first surface 31a and covers the area on the first surface 31a opposite to the position of the solder mark on the first metal plate 101. This reduces the occurrence of solder burrs piercing the first layer 113 and reduces the risk of short circuit between the first conductive layer 111 and the second conductive layer 112. The seventh layer 17 contains an insulating material selected from at least one of polyethylene, polypropylene, phenolic resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, or polyurethane.

[0128] Please refer to the following: Figure 2A , 2B and Figure 7 The second metal plate 102 is soldered to the area of ​​the third surface 41a away from the first conductive material layer 111b. A sixth layer 16 is provided on both the third surface 41a and the fourth surface 41b in areas corresponding to the second metal plate 102. Specifically, one sixth layer 16 is provided on the third surface 41a and covers the solder marks on the second metal plate 102, while the other sixth layer 16 is provided on the fourth surface 41b and covers the area on the fourth surface 41b opposite to the solder marks on the second metal plate 102. This reduces the occurrence of solder burrs piercing the first layer 113 and reduces the risk of a short circuit between the first conductive layer 111 and the second conductive layer 112.

[0129] Please see Figure 3 Viewed along the first direction Z, the first surface 110 includes a third end 11c located on a first side X1 of the first end 11a in the second direction X, and a tenth end 11j located on a second side X2 of the first end 11a opposite to the first side X1 in the second direction X. The first end 11a extends along a third direction Y, and 11j extends along a third direction Y. A second region 22 is located between the first end 11a and the third end 11c. Specifically, in the second direction X, the second region 22 is located between the first end 11a and the first region 21, and the second region 22 extends from the first end 11a. Viewed along the first direction Z, in the third direction Y, the first surface 110 has a fourth end 11d and a fifth end 11e located opposite to the fourth end 11d. In the third direction Y, the fourth end 11d and the fifth end 11e are the edges of the stack. The second region 22 extends from the fourth end 11d to the fifth end 11e.

[0130] Viewed along the first direction Z, the third layer 13 includes a sixth end 11f located on the side of the third end 11c and extending in the third direction Y along the second direction X, and an eleventh end 11k located on the side of the tenth end 11j and extending in the third direction Y along the second direction X. The second region 22 includes a seventh end 11g located on the side of the third end 11c and extending in the third direction Y along the second direction X, and a twelfth end 11m located on the side of the tenth end 11j and extending in the third direction Y along the second direction X. In this embodiment, viewed along the first direction Z, the twelfth end 11m overlaps with the first end 11a. Viewed along the first direction Z, the third layer 13 overlaps with both the seventh end 11g and the eleventh end 11k. The first distance D1 from the sixth end 11f to the third end 11c is shorter than the second distance D2 from the seventh end 11g to the third end 11c, and the fifth distance D5 from the eleventh end 11k to the tenth end 11j is shorter than the sixth distance D6 from the twelfth end 11m to the tenth end 11j. By increasing the contact area between the third layer 13 and the second region 22, the adhesion between the third layer 13 and the second region 22 is improved; and the area of ​​the second region 22 exposed to the electrolyte is reduced, thereby reducing the amount of electrolyte remaining in the second region 22 and reducing the impact of the electrolyte remaining in the second region 22 on the shape of the encapsulation film when the electrode assembly is encapsulated with an encapsulation film. In this application, the third direction Y is perpendicular to the first direction Z and the second direction X, and is the extension direction of the first metal plate 101 or the second metal plate 102 itself.

[0131] Viewed along the first direction Z, the third layer 13 also includes an eighth end 11h located on the side of the fourth end 11d and extending along the first direction X in the third direction Y, and a ninth end 11i located on the side of the fifth end 11e and extending along the first direction X in the third direction Y. The third distance D3 from the eighth end 11h to the fourth end 11d is shorter than the fourth distance D4 from the ninth end 11i to the fifth end 11e. Viewed along the first direction Z, the second region 22 includes a thirteenth end 11n located on the side of the fourth end 11d and extending along the first direction X in the third direction Y, and a fourteenth end 11p located on the side of the fifth end 11e and extending along the first direction X in the third direction Y. The thirteenth end 11n has an overlapping portion with the fourth end 11d, and the fourteenth end 11p has an overlapping portion with the fifth end 11e.

[0132] Please see Figure 4In some embodiments, in the second direction X, the first region 21 is disposed between the second region 22 and the first end 11a, such that the second region 22 is separated from the first end 11a. Viewed along the first direction Z, the seventh end 11g of the second region 22 overlaps with the third end 11c of the first surface 110. The seventh distance D7 between the twelfth end 11m of the second region 22 and the third end 11c is longer than the first distance D1 between the sixth end 11f and the third end 11c of the third layer 13, thus further improving the adhesion between the third layer 13 and the electrode assembly 10.

[0133] Please see Figure 5 In some embodiments, the second region 22 is separated from the fourth end 11d and the fifth end 11e of the first surface 110. Viewed along the first direction Z, the eighth distance D8 between the thirteenth end 11n and the fourth end 11d of the second region 22 is shorter than the third distance D3 between the eighth end 11h and the fourth end 11d of the third layer 13, and the ninth distance D9 between the fourteenth end 11p and the fifth end 11e of the second region 22 is shorter than the fourth distance D4 between the ninth end 11i of the third layer 13. In other embodiments, the eighth distance D8 between the thirteenth end 11n and the fourth end 11d may be longer than the third distance D3 between the eighth end 11h and the fourth end 11d, and the ninth distance D9 between the fourteenth end 11p and the fifth end 11e may be longer than the fourth distance D4 between the ninth end 11i. This balances cost while maintaining good adhesion between the third layer 13 and the electrode assembly 10.

[0134] Please see Figure 9 In some embodiments, when viewed along the Z direction, in the first direction X, the third layer 13 partially overlaps with the second region 22, and the third layer 13 is separated from the first region 21 and the seventh end 11g. Specifically, the first distance D1 from the sixth end 11f to the third end 11c of the third layer 13 is longer than the second distance D2 from the seventh end 11g to the third end 11c of the second region 22. This reduces the adverse effect on the thickness of the stack 11 after the third layer 13 overlaps with the first region 21 in the first direction Z.

[0135] Please see Figure 15In some embodiments, the first surface 110 further includes a third region 23. The third region 23 is covered by the second layer 12 and is separate from the first region 21. Specifically, viewed along the first direction Z, in the second direction X, the second region 22 is disposed between the first region 21 and the third region 23, and the second distance D2 between the seventh end 11g and the third end 11c of the second region 22 and the seventh distance D7 between the twelfth end 11m and the third end 11c of the second region 22 are both shorter than the first distance D1 between the sixth end 11f and the third end 11c of the third layer 13. In other embodiments, the second distance D2 between the seventh end 11g and the third end 11c and the seventh distance D7 between the twelfth end 11m and the third end 11c may both be longer than the first distance D1 between the sixth end 11f and the third end 11c, or the first distance D1 between the sixth end 11f and the third end 11c may be less than the seventh distance D7 between the twelfth end 11m and the third end 11c and greater than the second distance D2 between the seventh end 11g and the third end 11c.

[0136] In some embodiments, the first surface 110 may further include a fourth region (not shown), which is exposed outside and separate from the second layer 12. Viewed along the first direction Z, in the second direction X, the second region 22 and the fourth region are located on either side of the first region 21 or the third region 23.

[0137] Please see Figure 10A , Figure 10B , Figure 10C and Figure 11 In some embodiments, the electrode assembly 10 further includes two fourth layers 14a and 14b. Both fourth layers 14a and 14b are disposed on the first surface 110 of the electrode assembly. Viewed along a third direction Y, in the first direction Z, the second surface 120 has a third end 12c opposite to the fifth end 11e. Viewed along the first direction Z, both fourth layers 14a and 14b extend from the fifth end 11e of the first surface 110 and the third end 12c of the second surface 120 to the second surface 120 of the electrode assembly. Viewed along a second direction X, both fourth layers 14a and 14b extend a predetermined distance from the fifth end 11e of the first surface 110 and the third end 12c of the second surface 120 in the third direction Y. Viewed along the third direction Y, in the first direction Z, both fourth layers 14a and 14b are configured from the fifth end 11e to the third end 12c. By incorporating fourth layers 14a and 14b, the electrode assembly can be further secured, reducing the risk of it opening due to internal forces and further mitigating the risk of the third layer 13 detaching. Both fourth layers 14a and 14b include insulating material selected from at least one of polyethylene, polypropylene, phenolic resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, or polyurethane.

[0138] Viewed along the first direction Z, in the third direction Y, the third layer 13 and the fourth layer 14b have overlapping portions and are disposed separately from the fourth layer 14a. Viewed along the first direction Z, the fourth layer 14b includes a fifteenth end 11r located on the side of the fifth end 11e in the third direction Y and extending in the first direction X. The tenth distance D10 between the fifteenth end 11r and the fifth end 11e is longer than the fourth distance D4 between the ninth end 11i and the fifth end 11e. Viewed along the first direction Z, the fourth layer 14b has overlapping portions with the second region 22, and the fourth layer 14a is disposed separately from the second region 22. The fourth layer 14b has a portion connected to the first end 11a. Viewed along the first direction Z, the fourth layer 14b includes a sixteenth end 11s located on the side of the third end 11c in the second direction X and extending in the third direction Y. The first distance D1 from the sixth end 11f to the third end 11c is longer than the eleventh distance D11 from the sixteenth end 11s to the third end 11c. By setting a fourth layer 14b that overlaps with the third layer 13, the risk of the edge of the third layer 13 warping or falling off due to electrolyte impact or friction with the housing 20 during a drop can be reduced.

[0139] Please see Figure 12 In some embodiments, the fourth layer 14b is separated from the third layer 13 in the third direction Y. When viewed along the first direction Z, the tenth distance D10 between the fifteenth end 11r and the fifth end 11e is shorter than the fourth distance D4 between the ninth end 11i and the fifth end 11e.

[0140] Please see Figure 13A In some embodiments, the electrode assembly 10 further includes an eighth layer 18 disposed in the second region 110b. Viewed along the first direction Z, the eighth layer 18 is disposed separately from the first end 11a, the third layer 13, and the two fourth layers 14a, 14b. The eighth layer 18 contains an insulating material, and the electrode assembly 10 is connected to the inner surface of the housing via the eighth layer 18 to secure the electrode assembly within the housing. Viewed along the first direction Z, the eighth layer 18 includes a seventeenth end 11t located on the side of the fifth end 11e in the third direction Y and extending along the second direction X. In this embodiment, in the second direction X, the ninth end 11i of the third layer 13 is flush with the seventeenth end 11t of the eighth layer 18. Viewed along the first direction Z, the twelfth distance D12 between the seventeenth end 11t and the fifth end 11e is longer than the tenth distance D10 between the fifteenth end 11r and the fifth end 11e.

[0141] Please see Figure 13BIn some embodiments, when viewed along the first direction Z, the eighth layer 18 overlaps with the fourth layer 14a in the third direction Y and is disposed separately from the fourth layer 14b. When viewed along the first direction Z, in the third direction Y, the first distance D1 from the sixth end 11f to the third end 11c is longer than the tenth distance D10 from the eleventh end 11k to the third end 11c; in the second direction X, the first distance D1 from the sixth end 11f to the third end 11c is longer than the eleventh distance D11 from the sixteenth end 11s to the third end 11c. In other embodiments, the eighth layer 18 may also overlap with the third layer 13 in the second direction X.

[0142] Please see Figure 14 The eighth layer 18 includes a substrate 181 and an adhesive layer 183 disposed on opposite surfaces of the substrate 181. The substrate 181 includes at least one of polyethylene terephthalate, polyimide, polyvinyl chloride, polypropylene, or polyethylene, and combinations thereof. The adhesive layer 183 includes at least one of acrylate, polyurethane, rubber, and silicone.

[0143] Please see Figure 16 Embodiments of this application also provide an electronic device 200, which includes a main body 210 and a battery 100. The battery 100 is housed within the main body 210. The electronic device 200 may be one of a mobile phone, a tablet, or an e-reader.

[0144] In this application, the electronic device 200 is taken as a mobile phone, with the battery 100 disposed inside the phone to provide power for the phone's use, and the main body 210 being the phone structure. It is understood that in other embodiments, the electronic device 200 may have other structures, not limited to the above-mentioned mobile phone, tablet, or e-reader.

[0145] This application improves adhesion and reduces the risk of the third layer detaching by providing a second region not covered by the second layer on a first region of the first surface of the electrode assembly. Furthermore, by providing the second region, the thickness of the stack is reduced, thus minimizing energy density loss.

[0146] The performance of the battery provided in this application will be described below through specific embodiments and comparative examples.

[0147] Example 1

[0148] Adopting such Figure 3 The electrode assembly 10 shown is installed in the housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. Among them, the first distance D1 from the sixth end 11f of the third layer 13 to the third end 11c of the first region 110a is shorter than the second distance D2 from the seventh end 11g of the second region 22 to the third end 11c.

[0149] Example 2

[0150] Adopting such Figure 9 The electrode assembly 10 shown is installed in the housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. Among them, the first distance D1 from the sixth end 11f of the third layer 13 to the third end 11c of the first region 110a is longer than the second distance D2 from the seventh end 11g of the second region 22 to the third end 11c.

[0151] Example 3

[0152] Adopting such Figure 12 The electrode assembly 10 shown is installed in a housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. The first distance D1 from the sixth end 11f of the third layer 13 to the third end 11c of the first region 110a is shorter than the second distance D2 from the seventh end 11g of the second region 22 to the third end 11c. The fourth layer 14 overlaps with the second region 22, and the third layer 13 and the fourth layer 14 are separated in the third direction Y.

[0153] Example 4

[0154] Adopting such Figure 10A and Figure 11 The electrode assembly 10 shown is installed in a housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. The first distance D1 from the sixth end 11f of the third layer 13 to the third end 11c of the first region 110a is shorter than the second distance D2 from the seventh end 11g of the second region 22 to the third end 11c. The fourth layer 14 overlaps with the second region 22, and the third layer 13 and the fourth layer 14 overlap in the third direction Y.

[0155] Example 5

[0156] Adopting such Figure 13A The electrode assembly 10 shown is installed in a housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. The first distance D1 from the sixth end 11f of the third layer 13 to the third end 11c of the first region 110a is shorter than the second distance D2 from the seventh end 11g of the second region 22 to the third end 11c. The fourth layer 14 overlaps with the second region 22. The third layer 13 and the fourth layer 14 are separated in the third direction Y, and the seventh layer 17 is separated from the first end 11a, the third layer 13, and the fourth layer 14.

[0157] Comparative Example 1

[0158] Adopting such Figure 17 The electrode assembly 10 shown is installed in the housing, and after liquid injection, encapsulation, and formation, a finished battery is obtained. Figure 17 The electrode assembly 10 shown is Figure 3The difference in the electrode assembly 10 shown is that the first region 110a does not include the second region 22.

[0159] Five samples of batteries from each of the examples and comparative examples were subjected to nail penetration and cycle testing. The test results are shown in Table 1.

[0160] Nail Penetration Test: Place the battery sample in a 25℃ constant temperature chamber and let it stand for 30 minutes to allow the battery to reach a constant temperature. Charge the battery at a constant current of 0.5C to the battery cutoff voltage, then charge it at a constant voltage of the cutoff voltage until the current reaches 0.025C. Transfer the fully charged battery to the nail penetration tester, maintaining the test environment temperature at 25℃±2℃. Drive a steel nail into the center of the battery at a speed of 150mm / s until it penetrates completely, hold for 10 minutes, and then withdraw the nail. The steel nail diameter is 2.45mm, the length is 45mm, and the tip length ranges from 2mm to 4.9mm. Observe whether the battery catches fire or explodes. If fire or explosion occurs, the nail penetration test is considered a failure. Record the success rate of the nail penetration test.

[0161] Cyclic testing: The battery sample was charged at room temperature with a current of 0.2C, and then discharged to the cutoff voltage. Next, the battery was charged at a constant current and voltage of 0.8C to the limiting voltage, and the appearance of the battery was observed for any abnormalities (such as increased local thickness). The battery was then subjected to 1000 cycles of charge-discharge at 0.8C / 1C, and the appearance of the battery after the cycles was observed for any abnormalities (such as increased local thickness). Finally, the battery was disassembled, and the third layer was observed to see if it had detached from the electrode assembly, and the interface of the second conductive layer was also observed. The deformation of the battery appearance, the detachment of the third layer, and the interface condition of the second conductive layer were statistically analyzed.

[0162] Table 1

[0163]

[0164] Note: X / 5 indicates the number of samples that passed the nail penetration test or had the third layer detach out out of the 5 tested samples.

[0165] X.

[0166] As can be seen from the test results in Table 1, compared with Examples 1-5 and Comparative Example 1, by setting a second area that is not covered by the second layer on the first area of ​​the first surface of the electrode assembly and directly connecting the third layer to the second area, the probability of deformation after cyclic testing is small, the probability of the third layer falling off is small, and the overall interface remains good, while ensuring the pass rate of the nail penetration test.

[0167] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.

Claims

1. An electrode assembly formed by winding a stack, the electrode assembly comprising a first metal plate electrically connected to the stack, the stack comprising a first conductive layer, a second conductive layer, and a first layer disposed between the first conductive layer and the second conductive layer and containing an insulating material, characterized in that, the stack further comprises a first surface, a first end portion, and a second end portion located on the opposite side of the first end portion; a first direction perpendicular to one surface of the first metal plate is defined as a first direction, and the first surface has, as viewed in the first direction, a first region located on a first side of the first end portion in a second direction perpendicular to the first direction, and a second region located on a second side of the first end portion; the first region is closer to the first end portion than the second region in a winding direction of the stack; the first region comprises a first area and a second area, the first area is covered with a second layer containing an insulating material, the first region further comprises a third end portion located on a first side of the first end portion in the second direction, the second area is located between the first end portion and the third end portion, and the second area is separated from the second layer; the second area is located between the first end portion and the first area in the second direction, and the second area extends from the first end portion; the first region has a fourth end portion and a fifth end portion located on the opposite side of the fourth end portion in a third direction perpendicular to the second direction, as viewed in the first direction; the electrode assembly further comprises a third layer containing an insulating material, the third layer is disposed on the first surface; the third layer is connected to the first region and the second region, and has an overlapping portion with the first end portion, as viewed in the first direction, the third layer has an overlapping portion with the second area, as viewed in the first direction; the electrode assembly further comprises a fifth layer provided on the second region, the fifth layer is provided with an adhesive layer on both surfaces, and the fifth layer is separated from the first end portion and the third layer; the second area has a portion extending from the fourth end portion to the fifth end portion in the third direction; the second area has a portion separated from the fourth end portion or the fifth end portion in the third direction; the third layer comprises a sixth end portion located on one side of the third end portion in the second direction, the second area comprises a seventh end portion located on one side of the third end portion in the second direction, a first distance from the sixth end portion to the third end portion is shorter than a second distance from the seventh end portion to the third end portion; the third layer further comprises an eighth end portion located on one side of the fourth end portion in the third direction, and a ninth end portion located on one side of the fifth end portion in the third direction, a third distance from the eighth end portion to the fourth end portion is shorter than a fourth distance from the ninth end portion to the fifth end portion; the electrode assembly further comprises a second surface located on the opposite side of the first surface in the first direction, and a fourth layer extending from the first surface to the second surface through the fifth end portion. ​ ​ ​ ​ ​ ​ ​ ​ 2. The electrode assembly of claim 1, wherein, ​ 3. The electrode assembly of claim 1, wherein, ​ 4. The electrode assembly of claim 1, wherein, ​ 5. The electrode assembly of claim 1, wherein, ​ 6. The electrode assembly of claim 1, wherein, ​ 7. The electrode assembly of claim 6, wherein, In the third direction, the third layer has an overlapping portion with the fourth layer as viewed in the first direction.

8. The electrode assembly of claim 6, wherein, At least a portion of the fourth layer has a portion connected to the first end portion.

9. The electrode assembly of claim 8, wherein, At least a portion of the fourth layer has a portion connected to the second region.

10. The electrode assembly of claim 4, wherein, The electrode assembly further includes a second surface opposite to the first surface in the first direction and a fourth layer extending from the first surface to the second surface through a fifth end portion, the fifth layer being apart from the fourth layer.

11. The electrode assembly of claim 1, wherein, In the second direction, the first region is disposed between the first end portion and the second region.

12. The electrode assembly of claim 1, wherein, The first surface further includes a second coated region covered by the second layer and apart from the first region, the second region being disposed between the first region and the second coated region in the second direction.

13. The electrode assembly of claim 1, wherein, The first conductive layer includes at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxyphosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminum oxide, or lithium titanate.

14. The electrode assembly of claim 1, wherein, The second layer includes a ceramic material and a binder.

15. The electrode assembly of claim 1, wherein, The third layer includes a substrate and an adhesive layer disposed on the substrate.

16. The electrode assembly of claim 15, wherein, The substrate includes at least one of polyethylene terephthalate, polyimide, polyvinyl chloride, polypropylene, or polyethylene, and combinations thereof, and the adhesive layer includes at least one of acrylate, polyurethane, rubber, or silicone.

17. A battery, characterized by The battery includes the electrode assembly according to any one of claims 1 to 16 and a case covering the electrode assembly, the first metal plate protruding from one end of the case.

18. An electronic device, comprising: The battery includes the electrode assembly according to claim 17.

Images