Electrode body, battery device and electronic device

Abstract

The present invention provides an electrode assembly, a battery device, and an electronic device. The electrode assembly includes a negative electrode sheet 12, a negative electrode tab 104, and a positive electrode sheet 11. The negative electrode sheet 12 includes a negative electrode current collector 102 and a negative electrode active material 106 attached to the negative electrode current collector 102. A negative electrode tab groove 111 is formed in the negative electrode active material 106. The negative electrode tab 104 is provided in the negative electrode tab groove 111. The positive electrode sheet 11 includes a positive electrode current collector 101 and a positive electrode active material 105 attached to the positive electrode current collector 101. A first groove 112 is formed in the positive electrode active material 105 so as to face the negative electrode tab groove 111, and a projection of the first groove 112 onto the negative electrode sheet 12 is located within the negative electrode tab groove 111.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on March 25, 2022, bearing application number 202220680683.X and titled "Electrode body, battery device and electronic device," the entire contents of which are incorporated herein by reference. The present invention relates to the technical field of power supply devices, and more particularly to electrode assemblies, battery devices, and electronic devices. [Background technology]

[0002] Lithium-ion batteries are secondary batteries characterized by high energy density, high specific power, good cycle characteristics, no memory effect, and no pollution. They are currently widely used in fields such as mobile phones, mobile laptops, hybrid vehicles, electric vehicles, and solar power generation systems. Lithium-ion batteries typically consist of an electrode assembly and a battery case. The electrode assembly is located within the battery case. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. The separator is located between the positive electrode sheet and the negative electrode sheet.

[0003] Positive and negative electrode sheets typically include a tab, a current collector, and a coating attached to the current collector. The portion of the current collector where the coating layer is not attached forms a blank area. The tab is welded to the blank area. The current collector with the exposed blank area typically has burrs. These burrs can penetrate the separator and come into contact with the coating on the other pole piece, easily causing a short circuit in the battery. Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, the most serious consequences are caused by a short circuit between the positive electrode current collector or positive electrode tab and a fully charged negative electrode active material, which causes the lithium ion battery to generate the most heat in a short period of time and is therefore most likely to explode.

[0005] Therefore, there is a need to provide a new technical solution to solve the above technical problems. [Means for solving the problem]

[0006] One object of the present application is to provide a new technical solution for an electrode assembly.

[0007] According to one aspect of the present disclosure, there is provided an electrode assembly, the electrode assembly including a negative electrode sheet, a negative electrode tab, and a positive electrode sheet. , separator Includes: The separator is located between the positive electrode sheet and the negative electrode sheet. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material attached to the negative electrode current collector, and the negative electrode active material has a negative electrode tab groove. Setting The negative electrode tab is provided in the negative electrode tab groove. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material attached to the positive electrode current collector. A first groove is formed in the positive electrode active material. The first groove and The negative electrode tab The grooves are arranged on opposite surfaces of the separator. The projection of the first groove onto the negative electrode sheet is groove Located inside.

[0009] Preferably, the negative electrode active material further has second grooves formed symmetrically to the negative electrode tab groove on both sides of the negative electrode current collector, and the positive electrode active material has a third groove formed opposite the second groove, with the projection of the third groove onto the negative electrode sheet positioned within the second groove.

[0010] Preferably, the electrode body further includes a first insulating adhesive layer, a second insulating adhesive layer, a third insulating adhesive layer, and a fourth insulating adhesive layer, wherein the first insulating adhesive layer is adhered to the groove bottom of the negative electrode tab groove and extends to the negative electrode active material on the side of the negative electrode tab groove, or the first insulating adhesive layer is adhered to the top surface of the negative electrode tab and extends to the negative electrode active material on the side of the negative electrode tab groove, the second insulating adhesive layer is adhered to the groove bottom of the negative electrode tab groove and extends to the positive electrode active material on the side of the negative electrode tab groove, the third insulating adhesive layer is adhered to the groove bottom of the second groove and extends to the negative electrode active material on the side of the second groove, and the fourth insulating adhesive layer is adhered to the groove bottom of the third groove and extends to the positive electrode active material on the side of the third groove.

[0011] Preferably, the first groove is a through groove including a first left groove wall and a first right groove wall, the second insulating adhesive layer includes a second left insulating adhesive layer provided on the first left groove wall and a second right insulating adhesive layer provided on the first right groove wall, the second left insulating adhesive layer and the second right insulating adhesive layer being arranged at opposing positions in the first groove and overlapping at the groove bottom, or the second left insulating adhesive layer and the second right insulating adhesive layer being arranged at opposing positions apart from each other at the groove bottom of the first groove, and / Or, the third groove is a through groove including a third left groove wall and a third right groove wall, the fourth insulating adhesive layer includes a fourth left insulating adhesive layer provided on the third left groove wall and a fourth right insulating adhesive layer provided on the third right groove wall, and the fourth left insulating adhesive layer and the fourth right insulating adhesive layer are arranged in opposing positions in the third groove and overlap at the groove bottom, or the fourth left insulating adhesive layer and the fourth right insulating adhesive layer are arranged apart from each other in opposing positions at the groove bottom of the third groove.

[0012] Preferably, the electrode assembly further includes a positive electrode tab, a positive electrode tab groove is formed in the positive electrode active material, the positive electrode tab is disposed in the positive electrode tab groove, and a fourth groove is formed in the negative electrode active material, the fourth groove is disposed opposite the positive electrode tab groove, and a projection of the positive electrode tab groove onto the negative electrode sheet is located within the fourth groove.

[0013] Preferably, the positive electrode active material further includes a fifth groove symmetrically disposed on both sides of the positive electrode current collector with respect to the positive electrode tab groove, and the negative electrode active material includes a sixth groove opposed to the fifth groove, the projection of the fifth groove onto the negative electrode sheet being located within the sixth groove.

[0014] Preferably, the electrode assembly further includes a fifth insulating adhesive layer, a sixth insulating adhesive layer, a seventh insulating adhesive layer, and an eighth insulating adhesive layer. The fifth insulating adhesive layer is adhered to the bottom of the positive electrode tab groove and extends to the positive electrode active material on the side of the positive electrode tab groove, or is adhered to the top surface of the positive electrode tab and extends to the positive electrode active material on the side of the positive electrode tab groove. The sixth insulating adhesive layer is adhered to the bottom of the fourth groove and extends to the negative electrode active material on the side of the fourth groove. The seventh insulating adhesive layer is adhered to the bottom of the fifth groove and extends to the positive electrode active material on the side of the fifth groove. The eighth insulating adhesive layer is adhered to the bottom of the sixth groove and extends to the negative electrode active material on the side of the sixth groove.

[0015] Preferably, the fourth groove is a through groove including a fourth left groove wall and a fourth right groove wall, and the sixth insulating adhesive layer includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall. The sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove and overlap at the groove bottom, or there is a gap between the sixth left insulating adhesive layer and the sixth right insulating adhesive layer at opposing positions in the groove bottom of the fourth groove. And / or the sixth groove is a through groove including a sixth left groove wall and a sixth right groove wall, and the eighth insulating adhesive layer includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall. The 8th left insulating adhesive layer and the 8th right insulating adhesive layer are arranged at opposing positions in the 6th groove and overlap at the groove bottom, or the 8th left insulating adhesive layer and the 8th right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the 6th groove.

[0016] Preferably, the central axes of the negative electrode tab groove, the first groove, the second groove, and the third groove are collinear.

[0017] Preferably, the central axes of the positive electrode tab groove, the fourth groove, the fifth groove, and the sixth groove are collinear.

[0018] According to a second aspect of the present disclosure, there is provided an electrode assembly. The electrode assembly includes a positive electrode sheet, a positive electrode tab, and a negative electrode sheet. , separator Includes: The separator is located between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material attached to the positive electrode current collector, and a positive electrode tab groove is formed in the positive electrode active material. The positive electrode tab is provided in the positive electrode tab groove. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material attached to the negative electrode current collector, and a fourth groove is formed in the negative electrode active material. The fourth groove and the positive electrode tab groove are disposed on opposite surfaces of the separator, The projection of the positive electrode tab groove onto the negative electrode sheet is located within the fourth groove.

[0019] Preferably, the positive active material further includes fifth grooves symmetrically disposed on both sides of the positive current collector with respect to the positive tab groove, and the negative active material includes a sixth groove opposed to the fifth groove, the fifth groove projecting onto the negative sheet being positioned within the sixth groove.

[0020] Preferably, the electrode body further includes a fifth insulating adhesive layer, a sixth insulating adhesive layer, a seventh insulating adhesive layer, and an eighth insulating adhesive layer, wherein the fifth insulating adhesive layer is adhered to the groove bottom of the positive electrode tab groove and extends to the positive electrode active material on the side of the positive electrode tab groove, or the fifth insulating adhesive layer is adhered to the upper surface of the positive electrode tab and extends to the positive electrode active material on the side of the positive electrode tab groove, the sixth insulating adhesive layer is adhered to the groove bottom of the fourth groove and extends to the negative electrode active material on the side of the fourth groove, the seventh insulating adhesive layer is adhered to the groove bottom of the fifth groove and extends to the positive electrode active material on the side of the fifth groove, and the eighth insulating adhesive layer is adhered to the groove bottom of the sixth groove and extends to the negative electrode active material on the side of the sixth groove.

[0021] Preferably, the fourth groove is a through groove including a fourth left groove wall and a fourth right groove wall, and the sixth insulating adhesive layer includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall. The sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove and overlap at the groove bottom, or the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions at the groove bottom of the fourth groove but spaced apart. And / or the sixth groove is a through groove including a sixth left groove wall and a sixth right groove wall, and the eighth insulating adhesive layer includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall. The 8th left insulating adhesive layer and the 8th right insulating adhesive layer are arranged at opposing positions in the 6th groove and overlap at the groove bottom, or the 8th left insulating adhesive layer and the 8th right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the 6th groove.

[0022] According to a third aspect of the present disclosure, there is provided an electrode assembly including a positive electrode sheet, a negative electrode sheet, and a separator, wherein the positive electrode sheet includes a positive electrode current collector and a positive electrode active material attached to the positive electrode current collector, the positive electrode current collector having at least one first recessed area to which the positive electrode active material is not attached, and a positive electrode tab is provided in at least one of the first recessed areas, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material attached to the negative electrode current collector, the negative electrode current collector having at least one second recessed area to which the negative electrode active material is not attached, and no negative electrode tab is provided in the second recessed area, the second recessed area being disposed opposite the first recessed area, and the separator is located between the positive electrode sheet and the negative electrode sheet.

[0023] Preferably, the projection of the first recessed region onto the negative electrode sheet is located within the range of the second recessed region, the area of ​​the second recessed region is larger than the area of ​​the first recessed region, and the area where burrs can occur in the first recessed region is located within the range of the second recessed region.

[0024] Preferably, the first recessed areas are provided symmetrically with respect to the positive electrode current collector, and the positive electrode tab is provided in one of the first recessed areas.

[0025] Preferably, the insulating material further comprises a first insulating adhesive layer, the first insulating adhesive layer being applied to at least one of the first recessed areas; and / or The substrate further includes a second insulating material adhesive layer, the second insulating material adhesive layer being applied to at least one of the second recessed areas.

[0026] Preferably, the bottom of the positive electrode groove in the positive electrode sheet is the first recessed area, and the first insulating material adhesive layer is fixed to the first recessed area and extends to the side of the positive electrode groove; and / or The bottom of the negative electrode groove in the negative electrode sheet is the second recessed region, and the second insulating material adhesive layer is fixed to the second recessed region and extends to the side of the negative electrode groove.

[0027] Preferably, the first insulating material adhesive layer covers the first recessed area; and / or The second insulating material adhesive layer covers the second recessed area.

[0028] Preferably, the side of the positive electrode groove has a plurality of surfaces, the first insulating material adhesive layer is disposed on each of the surfaces, and the first insulating material adhesive layers on different surfaces are disposed independently; and / or The negative electrode groove has a side portion with a plurality of surfaces, and the second insulating material adhesive layer is provided on each of the surfaces, and the second insulating material adhesive layers on different surfaces are provided independently.

[0029] Preferably, the portions of the first insulating material adhesive layers located in the first recessed areas are stacked, and / or The portions of the second insulating material adhesive layers located in the second recessed regions are stacked.

[0030] Preferably, the portions of the first insulating material adhesive layer located in the first recessed areas surround the sub-void areas; and / or The portions of the second insulating material adhesive layers located in the second recessed regions surround the sub-void regions.

[0031] Preferably, at least one of the first insulating material adhesive layer and the second insulating material adhesive layer is a single-sided tape, a high-temperature adhesive, or an insulating film; or At least one of the first insulating material adhesive layer and the second insulating material adhesive layer is a double-sided tape or a hot melt adhesive, and at least one of the first insulating material adhesive layer and the second insulating material adhesive layer includes a first adhesive surface and a second adhesive surface having different adhesive strengths, the first adhesive surface is adhered to the separator, and the adhesive strength of the first adhesive surface is greater than the adhesive strength of the second adhesive surface.

[0032] Preferably, the first recessed region penetrates the positive electrode sheet along the width direction, or The positive electrode active material has a notch formed on one side in the width direction of the positive electrode sheet, and the first recessed region is formed by the notch.

[0033] Preferably, the second recessed region penetrates the negative electrode sheet along the width direction, or The negative electrode active material has a notch formed on one side in the width direction of the negative electrode sheet, and the notch forms the second recessed region.

[0034] According to a fourth aspect of the present disclosure, there is provided an electrode assembly comprising a first electrode sheet, a first insulating adhesive, and a second insulating adhesive, the first electrode sheet comprising a current collector and an active material attached to a surface of the current collector, a groove formed on a surface of the active material, the groove comprising a bottom and first and second sidewalls arranged opposite each other, the active material not attached to the bottom of the groove, the first insulating adhesive bonded to the bottom and extending onto the active material of the first sidewall, and the second insulating adhesive bonded to the bottom and extending onto the active material of the second sidewall.

[0035] Preferably, the first insulating adhesive extends from the first sidewall portion to a surface of the active material. The second insulating adhesive extends from the second sidewall portion to the surface of the active material.

[0036] Preferably, the first insulating adhesive and the second insulating adhesive are provided so that their portions located at the bottom are stacked.

[0037] Preferably, the first insulating adhesive and the second insulating adhesive are spaced apart at portions located at the bottom.

[0038] Preferably, the bottom portion is provided with an electrode tab located in a region where the first insulating adhesive and the second insulating adhesive are spaced apart.

[0039] Preferably, the length of the portion of the first insulating adhesive that extends to the surface of the active material is 0.5 mm or more. The length of the portion of the second insulating adhesive that extends to the surface of the active material is 0.5 mm or more.

[0040] Preferably, the recessed groove is an open groove extending toward one side in the width direction of the current collector, and further includes a third side wall portion connected between the first side wall portion and the second side wall portion, and the third side wall portion faces an opening portion of the open groove. The electrode body further includes a third insulating adhesive, which is adhered to the bottom portion and extends onto the active material of the third sidewall portion.

[0041] Preferably, at least one of the first insulating adhesive and the second insulating adhesive is a single-sided tape, a high-temperature adhesive, an insulating film, a double-sided tape, or a hot-melt adhesive.

[0042] Preferably, the battery further includes a second electrode sheet and a separator, the separator being positioned between the first electrode sheet and the second electrode sheet, a tab groove being formed in the second electrode sheet, a tab being formed in the tab groove, the electrode body further including a third insulating adhesive covering the tab groove, and the recessed groove being formed opposite the tab groove.

[0043] According to a fifth aspect of the present disclosure, there is provided a battery device including the electrode assembly described above.

[0044] Preferably, the battery device further includes a case in which the electrode assembly is housed.

[0045] According to a sixth aspect of the present disclosure, there is provided an electronic device including the battery device described above.

[0046] In the embodiment of the present disclosure, the projection of the first groove formed in the positive electrode active material onto the negative electrode sheet is located within the negative electrode tab groove. Therefore, even if burrs or dendrites on the negative electrode tab groove and the first groove penetrate the separator and reach the other side of the separator, there is little chance of them coming into contact with the negative electrode active material on the negative electrode sheet. This installation method significantly reduces the risk of the electrode assembly generating excessive heat and ultimately exploding. This significantly improves the safety of the electrode assembly.

[0047] Other features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the invention, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0048] The drawings, which form a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. [Figure 1] 1 is a structural schematic diagram of an electrode body according to an embodiment of the first aspect of the present disclosure. [Figure 2] FIG. 2 is a top view of a positive electrode sheet according to an example of the first aspect of the present disclosure. [Figure 3] FIG. 2 is a side view of a positive electrode sheet according to an embodiment of the first aspect of the present disclosure. [Figure 4] FIG. 1 is a plan view of a negative electrode sheet according to an example of the first aspect of the present disclosure. [Figure 5] FIG. 2 is a side view of a negative electrode sheet according to an example of the first aspect of the present disclosure. [Figure 6] FIG. 2 is a structural schematic diagram of an electrode body according to an embodiment of the second aspect of the present disclosure. [Figure 7] FIG. 2 is a plan view of a positive electrode sheet according to an example of the second aspect of the present disclosure. [Figure 8] FIG. 2 is a side view of a positive electrode sheet according to an embodiment of the second aspect of the present disclosure. [Figure 9] FIG. 2 is a bottom view of a positive electrode sheet according to an embodiment of the second aspect of the present disclosure. [Figure 10] FIG. 2 is a top view of a negative electrode sheet according to an example of the second aspect of the present disclosure. [Figure 11]FIG. 2 is a side view of a negative electrode sheet according to an example of the second aspect of the present disclosure. [Figure 12] FIG. 2 is a bottom view of a negative electrode sheet according to an example of the second aspect of the present disclosure. [Figure 13] FIG. 2 is a partial view of an electrode assembly according to an embodiment of the second aspect of the present disclosure. [Figure 14] FIG. 10 is a structural schematic diagram of an electrode body according to an embodiment of the third aspect of the present disclosure. [Figure 15] FIG. 10 is a top view of a positive electrode sheet according to an example of the third aspect of the present disclosure. [Figure 16] FIG. 10 is a structural schematic diagram of a second type electrode body according to an embodiment of the third aspect of the present disclosure. [Figure 17] FIG. 10 is a side view of a positive electrode sheet according to an example of the third aspect of the present disclosure. [Figure 18] FIG. 10 is a structural schematic diagram of a third type of electrode body according to an embodiment of the third aspect of the present disclosure. [Figure 19] FIG. 10 is a structural schematic diagram of a fourth type electrode body according to an embodiment of the third aspect of the present disclosure. [Figure 20] FIG. 10 is a structural schematic diagram of a fifth type of electrode body according to an embodiment of the third aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0049] Various embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that the relative arrangement of components and steps, formulas and numerical values ​​described in these embodiments do not limit the scope of the present application unless specifically stated otherwise.

[0050] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting of the invention, its application, or uses.

[0051] Techniques and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and devices should be considered part of the specification.

[0052] In all examples shown and discussed herein, any specific values ​​should be construed as merely illustrative and not limiting, and therefore other example embodiments may have different values.

[0053] It should be noted that in the following drawings, the same reference numerals and letters indicate the same items, so that if an item is defined in one drawing, it does not need to be further explained in the following drawings.

[0054] (First aspect) According to one embodiment of the present disclosure, an electrode assembly is provided. As shown in FIG. 1 , the electrode assembly includes a negative electrode sheet 12, a negative electrode tab 104, and a positive electrode sheet 11. The negative electrode sheet 12 includes a negative electrode current collector 102 and a negative electrode active material 106 attached to the negative electrode current collector 102. A negative electrode tab groove 111 is formed in the negative electrode active material 106. The negative electrode tab 104 is disposed in the negative electrode tab groove 111. The positive electrode sheet 11 includes a positive electrode current collector 101 and a positive electrode active material 105 attached to the positive electrode current collector 101. The positive electrode active material 105 is provided with a first groove 112. The first groove 112 is disposed opposite the negative electrode tab groove 111. The projection of the first groove 112 on the negative electrode sheet 12 is located within the negative electrode tab groove 111.

[0055] The electrode assembly further includes a separator 107. The separator 107 is located between the positive electrode sheet 11 and the negative electrode sheet 12.

[0056] The electrode assembly has a wound structure or a laminated structure. The electrode assembly includes a negative electrode sheet 12 and a positive electrode sheet 11.

[0057] The negative electrode sheet 12 includes a negative electrode current collector 102 and a negative electrode active material 106 attached to the negative electrode current collector 102. The negative electrode current collector 102 may be a copper foil, or of course, may be any other suitable material, which is not limited here and can be selected by those skilled in the art according to actual needs.

[0058] The negative electrode active material 106 may be a graphite material, or of course, may be other suitable materials, which are not limited here and can be selected by those skilled in the art according to actual needs.

[0059] The negative electrode active material 106 has a negative electrode tab groove 111 formed therein. At the same time, the negative electrode tab 104 is provided in the negative electrode tab groove 111. The negative electrode tab 104 is provided in the negative electrode tab groove 111 by welding. Of course, other suitable connection methods may also be used, which are not limited herein and can be selected by those skilled in the art according to actual needs.

[0060] The positive electrode sheet 11 includes a positive electrode current collector 101 and a positive electrode active material 105 attached to the positive electrode current collector 101. The positive electrode current collector 101 may be an aluminum foil, or of course, may be any other suitable material, which is not limited here and can be selected by those skilled in the art according to actual needs.

[0061] The positive electrode active material 105 may be a lithium cobalt oxide material, or of course, may be other suitable materials, which are not limited here and can be selected by those skilled in the art according to actual needs.

[0062] A first groove 112 is formed in the positive electrode active material 105 , and the first groove 112 is disposed opposite the negative electrode tab groove 111 , and the projection of the first groove 112 onto the negative electrode sheet 12 is located within the negative electrode tab groove 111 .

[0063] Taking a lithium ion battery as an example, during the charge and discharge process, lithium ions are repeatedly absorbed and released between the positive and negative electrode sheets 12. During charging, lithium ions are released from the positive electrode active material 105 of the positive electrode sheet 11 and are absorbed into the negative electrode active material 106 of the negative electrode sheet 12 through the electrolyte and separator 107, at which point the negative electrode sheet 12 is in a lithium-rich state. Conversely, during discharging, lithium ions in the negative electrode active material 106 are released from the negative electrode sheet 12 and are absorbed into the positive electrode active material 105 of the positive electrode sheet 11 through the electrolyte and separator 107, creating a potential difference between the positive and negative electrode sheets 12.

[0064] During processing, burrs are likely to form on the edges of the negative electrode tab groove 111 and / or the edges of the first recessed groove 112. If the burrs come into contact with the negative electrode active material 106 after piercing the separator 107, the electrode body will generate intense heat and even explode.

[0065] In an embodiment of the present disclosure, as shown in FIGS. 4 and 5 , the first groove 112 formed in the positive electrode active material 105 is positioned opposite the position of the negative electrode tab groove 111 formed in the negative electrode active material 106, and the projection of the first groove 112 on the negative electrode sheet 12 is located within the negative electrode tab groove 111.

[0066] Furthermore, the projection of the first groove 112 onto the negative electrode sheet 12 is located within the groove of the negative electrode tab 104, i.e., the negative electrode tab groove 111 can completely include the first groove 112, and the size of the negative electrode tab groove 111 is larger than the size of the first groove 112.

[0067] After burrs, dendrites, and other materials in the negative electrode tab groove 111 and the first groove 112 break through the separator 107, the size of the negative electrode tab groove 111 is larger than the size of the first groove 112 and can completely contain the first groove 112. Therefore, even if burrs, dendrites, and other materials break through the separator 107 and reach the other side of the separator 107, they are unlikely to come into contact with the negative electrode active material 106 in the negative electrode sheet 12. This installation method significantly reduces the risk of the electrode assembly generating excessive heat and even exploding, significantly improving the safety of the electrode assembly.

[0068] Although a phenomenon occurs in which burrs and / or dendrites come into contact with the negative electrode tab groove 111, the amount of heat generated by this contact is small, and therefore the risk to the safety of the electrode assembly is small.

[0069] Forming the first groove 112 in the positive electrode sheet 11 and the negative electrode tab groove 111 in the negative electrode sheet 12 may be performed by laser cleaning, intermittent coating, or adhesive peeling, and is not limited thereto, and those skilled in the art may select a groove forming method according to actual needs.

[0070] In one example, a second groove 113 is further formed in the negative electrode active material 106. The second grooves 113 are formed on both sides of the negative electrode current collector 102, symmetrically to the negative electrode tab groove 111.

[0071] The positive electrode active material 105 has third grooves 114 formed therein. The third grooves 114 are formed opposite the second grooves 113. The projection of the third grooves 114 onto the negative electrode sheet 12 is located within the second grooves 113.

[0072] The negative electrode sheet 12 includes, for example, a negative electrode current collector 102 and a negative electrode active material attached to the negative electrode current collector 102. A negative electrode active material 106 is attached to both sides of the negative electrode current collector 102. A negative electrode tab groove 111 for attaching a negative electrode tab 104 is formed on a first side of the negative electrode current collector 102. A second groove 113 is formed on a second side of the negative electrode current collector 102. The second groove 113 and the negative electrode tab groove 111 are symmetrically formed on both sides of the negative electrode current collector 102. In this manner, the amount of negative electrode active material 106 removed from both sides of the negative electrode current collector 102 can be made equal, and the second groove 113 and the negative electrode tab groove 111 formed can be made smoother, thereby preventing the generation of more burrs and simplifying the process. At the same time, it ensures that a sufficient amount of negative electrode active material 106 is still retained on the negative electrode sheet 12, so that there is enough active material in the electrode body to react and ensure the energy density of the battery formed by later winding of the electrode body.

[0073] The positive electrode active material 105 has third grooves 114 formed therein. The third grooves 114 are formed opposite the second grooves 113. The projections of the third grooves 114 on the negative electrode sheet 12 are located within the second grooves 113.

[0074] The third groove 114 formed in the positive electrode active material 105 and the second groove 113 formed in the negative electrode active material 106 are arranged opposite each other, and the projection of the third groove 114 onto the negative electrode sheet 12 is located within the second groove 113.

[0075] Furthermore, the projection of the third groove 114 onto the negative electrode sheet 12 is located within the second groove 113, that is, the second groove 113 can completely include the third groove 114, and the size of the second groove 113 is larger than the size of the third groove 114.

[0076] Even if burrs, dendrites, and other materials on the second groove 113 and the third groove 114 break through the separator 107, the size of the second groove 113 is larger than the size of the third groove 114 and can completely contain the third groove 114. Therefore, even if burrs, dendrites, and other materials break through the separator 107 and reach the other side of the separator 107, they are unlikely to come into contact with the negative electrode active material 106 on the negative electrode sheet 12. This installation method significantly reduces the risk of excessive heat generation and even explosion of the electrode assembly, significantly improving the safety of the electrode assembly.

[0077] Although a phenomenon occurs in which burrs and / or dendrites come into contact with the negative electrode tab groove 111, the amount of heat generated by this contact is small, and therefore the risk to the safety of the electrode assembly is small.

[0078] In one example, the electrode assembly further includes a first insulating adhesive layer 121, a second insulating adhesive layer 122, a third insulating adhesive layer 123, and a fourth insulating adhesive layer 124. The first insulating adhesive layer 121 is adhered to the bottom of the negative electrode tab groove 111 and extends to the negative electrode active material 106 on the side of the negative electrode tab groove 111. The negative electrode tab groove includes a left groove wall and a right groove wall of the negative electrode tab groove. The first insulating adhesive layer 121 includes a first left insulating adhesive layer provided on the left groove wall of the negative electrode tab groove and a first right insulating adhesive layer provided on the right groove wall of the negative electrode tab groove. A gap exists between the first left insulating adhesive layer and the first right insulating adhesive layer at opposing positions on the groove bottom of the negative electrode tab groove. The negative electrode tab is provided between the first left insulating adhesive layer and the first right insulating adhesive layer. Alternatively, the first insulating adhesive layer 121 is adhered to the top surface of the negative electrode tab and extends to the negative electrode active material 106 on the side of the negative electrode tab groove.

[0079] The second insulating adhesive layer 122 is adhered to the bottom of the first groove 112 and extends to the positive electrode active material 105 on the side of the first groove 112. The third insulating adhesive layer 123 is adhered to the bottom of the second groove 113 and extends to the negative electrode active material 106 on the side of the second groove 113. The fourth insulating adhesive layer 124 is adhered to the bottom of the third groove 114 and extends to the positive electrode active material 105 on the side of the third groove 114.

[0080] In this example, an insulating adhesive layer is provided in each of the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114, and the insulating adhesive layer completely covers the grooves and extends to the active material on the sides of the grooves. Since neither the positive electrode current collector 101 nor the negative electrode current collector 102 is a porous material, the electrolyte infiltrates and coats the edge adhesive layer on the active material from the porous active material (e.g., the positive electrode active material 105, the negative electrode active material 106). Even if the adhesiveness of the insulating adhesive layer covering the active material is weak or lost, The portions of the insulating adhesive layer that still cover the grooves (e.g., the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114) are tightly bonded to the corresponding current collectors (e.g., the positive electrode current collector 101, the negative electrode current collector 102). This prevents the electrolyte from penetrating the insulating adhesive layer, and prevents radicals from the electrolyte from penetrating the insulating adhesive layer. As a result, the insulating adhesive properties of the grooves (e.g., the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114) can still maintain good adhesion.

[0081] Furthermore, the grooves (e.g., the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114) and the insulating adhesive layers covering the active materials (e.g., the positive electrode active material 105 and the negative electrode active material 106) are integrally connected. This prevents the insulating adhesive layers covering the active materials (e.g., the first insulating adhesive layer 121, the second insulating adhesive layer 122, the third insulating adhesive layer 123, and the fourth insulating adhesive layer 124) from shifting from their initial bonding positions. Therefore, the insulating adhesive layers covering the active materials (e.g., the first insulating adhesive layer 121, the second insulating adhesive layer 122, the third insulating adhesive layer 123, and the fourth insulating adhesive layer 124) still maintain their initial insulating properties, effectively reducing the risk of lithium deposition and improving the safety of the battery formed by winding the electrode assembly.

[0082] In one example, the first groove 112 is a through groove. The first groove 112 includes a first left groove wall and a first right groove wall. The second insulating adhesive layer 122 includes a second left insulating adhesive layer provided on the first left groove wall and a second right insulating adhesive layer provided on the first right groove wall.

[0083] The second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions in the first groove 112 and overlap at the groove bottom, or the second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the first groove 112.

[0084] In one example, the third groove 114 is a through groove. The third groove 114 includes a third left groove wall and a third right groove wall. The fourth insulating adhesive layer 124 includes a fourth left insulating adhesive layer 1241 provided on the third left groove wall and a fourth right insulating adhesive layer 1242 provided on the third right groove wall.

[0085] The fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are arranged in opposing positions in the third groove 114 and overlap at the groove bottom, or the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are arranged apart in opposing positions at the groove bottom of the third groove 114.

[0086] For example, the second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions in the first groove 112 and overlap at the groove bottom, and the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are arranged at opposing positions in the third groove 114 and overlap at the groove bottom.

[0087] In one example, the second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions in the first groove 112 and overlap at the groove bottom, and the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are arranged at opposing positions apart at the groove bottom of the third groove 114.

[0088] In one example, the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are spaced apart at opposing positions at the bottom of the third groove 114, and the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are arranged at opposing positions in the third groove 114 and overlap at the bottom of the groove.

[0089] In one example, the second left insulating adhesive layer and the second right insulating adhesive layer are spaced apart at opposing positions on the bottom of the first groove 112, and the fourth left insulating adhesive layer 1241 and the fourth right insulating adhesive layer 1242 are spaced apart at opposing positions on the bottom of the third groove 114.

[0090] Furthermore, by stacking the insulating adhesive layers on the left and right sides of the groove, the depression caused by the removal of the active material can be more effectively filled, improving the flatness of the electrode body, which is advantageous for pressure formation and reduces bending deformation of the battery.Furthermore, problems such as short circuits caused by bending deformation of the cell can be avoided, and ultimately the safety of the battery formed by winding the cell can be improved.

[0091] Furthermore, since the left and right insulating adhesive layers are stacked and disposed, the electrolyte can be prevented from penetrating from the porous active materials (e.g., the positive electrode active material 105, the negative electrode active material 106) into the insulating adhesive layers covering the active materials, which would otherwise weaken or lose the adhesive strength of the insulating adhesive layers covering the active materials. However, the portions of the insulating adhesive layers covering the grooves (e.g., the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114) are still tightly bonded to the corresponding current collectors (e.g., the positive electrode current collector 101, the negative electrode current collector 102). This prevents the electrolyte from penetrating the insulating adhesive layers, and prevents free radicals in the electrolyte from penetrating the insulating adhesive layers. As a result, the insulating adhesive layers located in the grooves (e.g., the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114) can still maintain good adhesive strength.

[0092] If one of the left and right insulating adhesive layers covering the grooves is infiltrated with electrolyte and the adhesive strength of the insulating adhesive layer is weakened or lost, or if the adhesive bonding mechanism of one of them becomes abnormal and the adhesive cloth is not attached properly, the remaining insulating adhesive layer on the other side can still maintain good adhesive performance, ensuring effective initial insulation and reducing the risk of lithium deposition.

[0093] Even if the adhesive strength of the insulating adhesive layer covering the active material is reduced or lost due to the infiltration of the electrolyte into both the left and right insulating adhesive layers covering the grooves, because the left and right insulating adhesive layers are installed in a stacked manner, the stacked insulating adhesive layers and the grooves are tightly adhered and good insulating effect can still be ensured. In addition, the double-layer installation of the stacked insulating adhesive layers further improves the insulating effect and greatly improves the safety of use of the battery formed by winding the electrode body.

[0094] Furthermore, if there is a gap between the left and right insulating adhesive layers at opposing positions at the bottom of the groove, the amount of insulating adhesive layer used can be reduced, and the thickness of the electrode body can also be reduced, provided that the insulating effect is guaranteed.

[0095] In addition, the provision of the insulating adhesive layer can also serve as a heat insulator, preventing contact between the fallen positive electrode active material 105 and the negative electrode current collector 102, or between the fallen negative electrode active material 106 and the positive electrode current collector 101, further reducing the risk of heat generation and explosion of the electrode body.

[0096] In one example, the electrode assembly further includes a positive electrode tab 103. A positive electrode tab groove 115 is formed in the positive electrode active material 105, the positive electrode tab 103 is disposed in the positive electrode tab groove 115, and a fourth groove 116 is formed in the negative electrode active material 106, the fourth groove 116 being disposed opposite the positive electrode tab groove 115, and the projection of the positive electrode tab groove 115 onto the negative electrode sheet is located within the fourth groove 116.

[0097] In one example, a fifth groove 117 is further formed in the positive electrode active material 105, and the fifth groove 117 is provided on both sides of the positive electrode current collector 101 symmetrically with the positive electrode tab groove 115. A sixth groove 118 is formed in the negative electrode active material 106, and the sixth groove 118 is disposed opposite the fifth groove 117, and the projection of the fifth groove 117 onto the negative electrode sheet 12 is located within the sixth groove 118.

[0098] In one example, the electrode assembly further includes a fifth insulating adhesive layer 125, a sixth insulating adhesive layer 126, a seventh insulating adhesive layer 127, and an eighth insulating adhesive layer 128. The fifth insulating adhesive layer 125 is adhered to the bottom of the positive electrode tab groove 115 and extends to the positive electrode active material 105 on the sides of the positive electrode tab groove 115, or the fifth insulating adhesive layer is adhered to the top surface of the positive electrode tab and extends to the positive electrode active material on the sides of the positive electrode tab groove. The sixth insulating adhesive layer 126 is adhered to the bottom of the fourth groove 116 and extends to the negative electrode active material 106 on the sides of the fourth groove 116. The seventh insulating adhesive layer 127 is adhered to the bottom of the fifth groove 117 and extends to the positive electrode active material 105 on the sides of the fifth groove 117. The eighth insulating adhesive layer 128 is adhered to the bottom of the sixth groove 118 and extends to the negative electrode active material 106 on the side of the sixth groove 118 .

[0099] In one example, the fourth groove 116 is a through groove including a fourth left groove wall and a fourth right groove wall, and the sixth insulating adhesive layer 126 includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall. The sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove 116 and overlap at the groove bottom, or the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions at the groove bottom of the fourth groove 116 but spaced apart. Alternatively, the sixth groove 118 is a through groove including a sixth left groove wall and a sixth right groove wall, and the eighth insulating adhesive layer 128 includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall. The eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions in the sixth groove 118 and overlap at the groove bottom, or the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the sixth groove 118.

[0100] In one example, the central axes of the negative electrode tab groove 111, the first groove 112, the second groove 113, and the third groove 114 are on the same straight line.

[0101] In one example, the central axes of the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118 are on the same straight line.

[0102] According to another embodiment of the present disclosure, an electrode assembly is provided. As shown in FIGS. 2 and 3 , the electrode assembly includes a positive electrode sheet 11, a positive electrode tab 103, and a negative electrode sheet 12. The positive electrode sheet 11 includes a positive electrode current collector 101 and a positive electrode active material 105 attached to the positive electrode current collector 101. A positive electrode tab groove 115 is formed in the positive electrode active material 105. The positive electrode tab 103 is disposed in the positive electrode tab groove 115. The negative electrode sheet 12 includes a negative electrode current collector 102 and a negative electrode active material 106 attached to the negative electrode current collector 102. A fourth groove 116 is formed in the negative electrode active material 106. The fourth groove 116 is disposed opposite the positive electrode tab groove 115. Furthermore, the projection of the positive electrode tab groove 115 onto the negative electrode sheet is located within the fourth groove 116.

[0103] In the embodiment of the present disclosure, the fourth groove 116 formed in the negative electrode active material 106 is positioned opposite the position of the positive electrode tab groove 115 formed in the positive electrode active material 105, and the projection of the positive electrode tab groove 115 onto the negative electrode sheet 12 is located within the fourth groove 116.

[0104] Furthermore, the projection of the positive electrode tab groove 115 onto the negative electrode sheet 12 is located within the fourth groove 116, that is, the fourth groove 116 can completely include the positive electrode tab groove 115, and the size of the fourth groove 116 is larger than the size of the positive electrode tab groove 115.

[0105] After burrs, dendrites, and other materials in the positive electrode tab groove 115 and the fourth groove 116 break through the separator 107, the fourth groove 116 is larger than the positive electrode tab groove 115 and can completely contain the positive electrode tab groove 115. Therefore, even if burrs, dendrites, and other materials break through the separator 107 and reach the other side of the separator 107, they are unlikely to come into contact with the negative electrode active material 106 in the negative electrode sheet 12. This installation method significantly reduces the risk of excessive heat generation and even explosion of the electrode assembly, significantly improving the safety of the electrode assembly.

[0106] Although a phenomenon occurs in which burrs and / or dendrites come into contact with the negative electrode tab groove 111, the amount of heat generated by this contact is small, and therefore the risk to the safety of the electrode assembly is small.

[0107] The fourth groove 116 may be formed in the negative electrode sheet 12, and the positive electrode tab groove 115 may be formed in the positive electrode sheet 11 by laser cleaning, intermittent application, or adhesive peeling. Of course, this is not a limitation, and those skilled in the art may select a groove forming method according to actual needs.

[0108] In one example, the positive electrode active material 105 further has a fifth groove 117 formed therein. The fifth groove 117 is provided on both sides of the positive electrode current collector 101 symmetrically with the positive electrode tab groove 115.

[0109] The negative electrode active material 106 has a sixth groove 118 formed therein. The sixth groove 118 is formed opposite the fifth groove 117. The projection of the fifth groove 117 onto the negative electrode sheet 12 is located within the sixth groove 118.

[0110] The positive electrode sheet 11 includes, for example, a positive electrode current collector 101 and a positive electrode active material attached to the positive electrode current collector 101. Positive electrode active material 105 is attached to both sides of the positive electrode current collector 101. A positive electrode tab groove 115 for attaching a positive electrode tab 103 is formed on a first side of the positive electrode current collector 101. A fifth groove 117 is formed on a second side of the positive electrode current collector 101. The fifth groove 117 and the positive electrode tab groove 115 are symmetrically formed on both sides of the positive electrode current collector 101. In this manner, the amount of positive electrode active material 105 removed from both sides of the positive electrode current collector 101 can be made equal, and the fifth groove 117 and the positive electrode tab groove 115 formed can be made smoother, thereby preventing the generation of more burrs and simplifying the process. At the same time, it ensures that a sufficient amount of positive electrode active material 105 is still retained in the positive electrode sheet 11, so that there is enough active material in the electrode body for reaction and ensures the energy density of the battery formed by later winding of the electrode body.

[0111] The negative electrode active material 106 has a sixth groove 118 formed therein. The sixth groove 118 is formed opposite the fifth groove 117. The projection of the fifth groove 117 onto the negative electrode sheet 12 is located within the sixth groove 118.

[0112] The sixth groove 118 formed in the negative electrode active material 106 and the fifth groove 117 formed in the positive electrode active material 105 are arranged opposite each other, and the projection of the fifth groove 117 on the negative electrode sheet 12 is located within the sixth groove 118.

[0113] Furthermore, the projection of the fifth groove 117 on the negative electrode sheet 12 is located within the sixth groove 118, that is, the sixth groove 118 can completely include the fifth groove 117, and the size of the sixth groove 118 is larger than the size of the fifth groove 117.

[0114] After burrs, dendrites, and other materials on the fifth groove 117 and the sixth groove 118 break through the separator 107, the sixth groove 118 is larger than the fifth groove 117 and can completely contain the fifth groove 117. Therefore, even if burrs, dendrites, and other materials break through the separator 107 and reach the other side of the separator 107, they are unlikely to come into contact with the negative electrode active material 106 on the negative electrode sheet 12. This installation method significantly reduces the risk of the electrode assembly overheating and even explosion, significantly improving the safety of the electrode assembly.

[0115] Although a phenomenon occurs in which burrs and / or dendrites come into contact with the negative electrode tab groove 111, the amount of heat generated by this contact is small, and therefore the risk to the safety of the electrode assembly is small.

[0116] In one example, the electrode body further includes a fifth insulating adhesive layer 125, a sixth insulating adhesive layer 126, a seventh insulating adhesive layer 127, and an eighth insulating adhesive layer 128. The fifth insulating adhesive layer 125 is adhered to the bottom of the positive electrode tab groove 115 and extends to the positive electrode active material 105 on the side of the positive electrode tab groove 115. Alternatively, the fifth insulating adhesive layer 125 is adhered to the top surface of the positive electrode tab and extends to the positive electrode active material 105 on the side of the positive electrode tab groove 115.

[0117] The sixth insulating adhesive layer 126 is adhered to the bottom of the fourth groove 116 and extends to the negative electrode active material 106 on the side of the fourth groove 116. The seventh insulating adhesive layer 127 is adhered to the bottom of the fifth groove 117 and extends to the positive electrode active material 105 on the side of the fifth groove 117. The eighth insulating adhesive layer 128 is adhered to the bottom of the sixth groove 118 and extends to the negative electrode active material 106 on the side of the sixth groove 118.

[0118] In this example, an insulating adhesive layer is provided in each of the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118, and the insulating adhesive layer completely covers the grooves and extends to the active material on the side of the grooves. Since neither the positive electrode current collector 101 nor the negative electrode current collector 102 is a porous material, even if the electrolyte penetrates from the porous active material (e.g., the positive electrode active material 105, the negative electrode active material 106) into the edge adhesive layer covering the active material, and the adhesiveness of the insulating adhesive layer covering the active material is weakened or lost, The portions of the insulating adhesive layer that still cover the grooves (e.g., the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118) are tightly bonded to the corresponding current collectors (e.g., the positive electrode current collector 101, the negative electrode current collector 102). This prevents the electrolyte from penetrating the insulating adhesive layer, and prevents radicals from the electrolyte from penetrating the insulating adhesive layer. As a result, the insulating adhesive layer located in the grooves (e.g., the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118) can still maintain good adhesion.

[0119] Furthermore, the grooves (e.g., the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118) and the insulating adhesive layers covering the active materials (e.g., the positive electrode active material 105 and the negative electrode active material 106) are integrally connected. This prevents the insulating adhesive layers covering the active materials (e.g., the fifth insulating adhesive layer 125, the sixth insulating adhesive layer 126, the seventh insulating adhesive layer 127, and the eighth insulating adhesive layer 128) from shifting from their initial bonding positions. Therefore, the insulating adhesive layers covering the active materials (e.g., the fifth insulating adhesive layer 125, the sixth insulating adhesive layer 126, the seventh insulating adhesive layer 127, and the eighth insulating adhesive layer 128) still maintain their initial insulating properties, effectively reducing the risk of lithium deposition and improving the safety of the battery formed by winding the electrode assembly.

[0120] In one example, the fourth groove 116 is a through groove. The fourth groove 116 includes a fourth left groove wall and a fourth right groove wall. The sixth insulating adhesive layer 126 includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall.

[0121] The sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove 116 and overlap at the groove bottom, or the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the fourth groove 116.

[0122] In one example, the sixth groove 118 is a through groove. The sixth groove 118 includes a sixth left groove wall and a sixth right groove wall. The eighth insulating adhesive layer 128 includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall.

[0123] The eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions in the sixth groove 118 and overlap at the groove bottom, or the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the sixth groove 118.

[0124] For example, the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove 116 and overlap at the groove bottom, and the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the sixth groove 118.

[0125] In one example, the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove 116 and overlap at the groove bottom, and the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions apart at the groove bottom of the sixth groove 118.

[0126] In one example, the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are spaced apart at opposing positions at the bottom of the fourth groove 116, and the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions at the bottom of the sixth groove 118 and overlap at the bottom of the groove. In one example, there is a gap between the sixth left insulating adhesive layer and the sixth right insulating adhesive layer at a position where they face each other at the bottom of the fourth groove 116, and there is a gap between the eighth left insulating adhesive layer and the eighth right insulating adhesive layer at a position where they face each other at the bottom of the sixth groove 118.

[0127] Furthermore, by stacking the insulating adhesive layers on the left and right sides of the groove, the depression caused by the removal of the active material can be more effectively filled, improving the flatness of the electrode body, which is advantageous for pressure formation and reduces bending deformation of the battery.Furthermore, problems such as short circuits caused by bending deformation of the cell can be avoided, and ultimately the safety of the battery formed by winding the cell can be improved.

[0128] Furthermore, the left and right insulating adhesive layers are stacked and installed, and thus the electrolyte may penetrate from the porous active materials (e.g., the positive electrode active material 105, the negative electrode active material 106) into the active materials to form the edge adhesive layers, which may weaken or lose the adhesive strength of the insulating adhesive layers covering the active materials. However, the portions of the insulating adhesive layers that still cover the grooves (e.g., the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118) are tightly bonded to the corresponding current collectors (e.g., the positive electrode current collector 101, the negative electrode current collector 102). This prevents the electrolyte from penetrating the insulating adhesive layers, and prevents free radicals in the electrolyte from penetrating the insulating adhesive layers. As a result, the insulating adhesive layers located in the grooves (e.g., the positive electrode tab groove 115, the fourth groove 116, the fifth groove 117, and the sixth groove 118) can still maintain good adhesive strength.

[0129] If one of the left and right insulating adhesive layers covering the grooves is infiltrated with electrolyte and the adhesive strength of the insulating adhesive layer is weakened or lost, or if the adhesive bonding mechanism of one of them becomes abnormal and the adhesive cloth is not attached properly, the remaining insulating adhesive layer on the other side can still maintain good adhesive performance, ensuring effective initial insulation and reducing the risk of lithium deposition.

[0130] Even if the adhesive strength of the insulating adhesive layer covering the active material is weakened or lost due to the infiltration of the electrolyte into the left and right insulating adhesive layers covering the grooves, because the left and right insulating adhesive layers are installed in a stacked manner, the stacked insulating adhesive layers and the grooves are tightly adhered and a good insulating effect can still be ensured. In addition, the double-layer installation of the stacked insulating adhesive layers further improves the insulating effect and greatly improves the safety of use of the battery formed by winding the electrode body.

[0131] Furthermore, if there is a gap between the left and right insulating adhesive layers at opposing positions at the bottom of the groove, the amount of insulating adhesive layer used can be reduced, and the thickness of the electrode body can also be reduced, provided that the insulating effect is guaranteed.

[0132] In addition, the provision of the insulating adhesive layer can also serve as a heat insulator, preventing contact between the fallen positive electrode active material 105 and the negative electrode current collector 102, or between the fallen negative electrode active material 106 and the positive electrode current collector 101, further reducing the risk of heat generation and explosion of the electrode body.

[0133] According to another embodiment of the present disclosure, there is provided a battery device, the battery device including the electrode assembly described above.

[0134] The battery device may be, but is not limited to, a lithium ion battery, a sodium ion battery, a nickel metal hydride battery, a nickel cadmium battery, etc. The battery device may be a soft pack battery or a prismatic battery.

[0135] The battery device includes a case and an electrode assembly. The electrode assembly is provided within the case. The battery device is characterized by excellent safety performance.

[0136] According to another embodiment of the present disclosure, there is provided an electronic device, the electronic device including the battery device described above.

[0137] For example, the electronic device may be a vehicle, a mobile phone, an earphone, an electronic pen, VR, AR, etc., and is not limited thereto, and those skilled in the art can select it according to their actual needs.

[0138] This electronic device is characterized by a high safety factor.

[0139] (Second aspect) According to one embodiment of the present disclosure, an electrode assembly is provided, which includes a positive electrode sheet A11, a negative electrode sheet A12, and a separator A107, as shown in Figure 6.

[0140] The positive electrode sheet A11 includes a positive electrode current collector A101 and a positive electrode active material A105 attached to the positive electrode current collector A101. The positive electrode current collector A101 has at least one first recessed region A111 to which no positive electrode active material A105 is attached. A positive electrode tab A103 is provided in at least one first recessed region A111, and as shown in FIG. 6, the positive electrode tab A103 is provided in the upper first recessed region A111. The lower first recessed region A111 does not have a positive electrode tab A103.

[0141] The negative electrode sheet A12 includes a negative electrode current collector A102 and a negative electrode active material A106 attached to the negative electrode current collector A102. The negative electrode current collector A102 has at least one second recessed region A113 to which the negative electrode active material A106 is not attached. The second recessed region A113 does not have a negative electrode tab A104. This prevents explosions caused by burrs or welds of the positive electrode current collector A101 or the positive electrode tab A103 in the first recessed region A111 piercing the separator and coming into contact with the negative electrode active material A106. The second recessed region A113 is located opposite the first recessed region A111. The separator is located between the positive electrode sheet A11 and the negative electrode sheet A12.

[0142] Specifically, the electrode assembly has a wound structure or a laminated structure. The positive electrode active material A105 includes a first active material. The negative electrode active material A106 includes a second active material. The first and second active materials are prepared as slurries and applied to corresponding current collectors. During charging and discharging, a conductive material migrates between the first and second active materials. Those skilled in the art can select the materials for the first and second active materials according to their actual needs.

[0143] The first recessed region A111 and the second recessed region A113 can be formed by laser cleaning, intermittent coating, or adhesive peeling. The positive electrode tab A103 is fixed to the first recessed region A111 by, for example, laser welding, ultrasonic welding, resistance welding, or conductive adhesion. The positive electrode tab A103 is made of a metal foil, metal wire, or the like.

[0144] For example, the first recessed region A111 may be located at 1 / 4 to 3 / 4 of the length from the beginning to the end of the first current collector, which can reduce ohmic impedance and improve the rapid charging performance of the battery device. Here, the length refers to the unfolded length of the first current collector. Of course, the location of the first recessed region A111 on the first current collector is not limited here and can be selected by those skilled in the art according to actual needs. In one example, the positive electrode sheet A11 has a positive electrode groove. The bottom of the positive electrode groove is the first recessed region A111. The negative electrode sheet A12 has a negative electrode groove pocket. The bottom of the negative electrode groove is the second recessed region A113.

[0145] For example, the cathode active material A105 can be removed from the cathode sheet A11 to form the cathode grooves, and the anode active material A106 can be removed from the anode sheet A12 to form the anode grooves by laser cleaning, intermittent coating, or peeling. The cathode current collector A101 and the anode current collector A102 serve as electrical conductors. Typically, the cathode current collector A101 and the anode current collector A102 are made of metal foil.

[0146] For example, the material of the metal foil material or metal wire material may be copper, aluminum, iron, platinum, gold, silver, lead, tin, or the like, but is not limited to these.

[0147] The first recessed region A111 and the second recessed region A113 are arranged opposite each other. For example, the first recessed region A111 is located on one side of the separator and faces the separator. The second recessed region A113 is located on the other side of the separator and faces the separator. The first recessed region A111 and the second recessed region A113 are separated by the separator. The separator serves as an insulator, preventing direct contact between the first recessed region A111 and the second recessed region A113, which could cause a short circuit.

[0148] Taking a lithium-ion battery as an example, the conductive material is lithium ions. The first active material is lithium manganese oxide, lithium cobalt oxide, lithium nickel-cobalt manganese oxide, or lithium iron phosphate. The positive electrode current collector A101 is aluminum foil. The second active material is graphite or silicon. The negative electrode current collector A102 is copper foil.

[0149] During charging and discharging, lithium ions travel back and forth between the positive and negative electrode sheets A12, absorbing and releasing them. During charging, lithium ions are released from the first active material of the positive electrode sheet A11, pass through the electrolyte and separator, and are absorbed into the second active material of the negative electrode sheet A12, at which point the negative electrode sheet A12 is in a lithium-rich state. During discharging, conversely, lithium ions in the second active material are released from the negative electrode sheet A12, pass through the electrolyte and separator, and are absorbed into the first active material of the positive electrode sheet A11, creating a potential difference between the positive and negative electrode sheets A12.

[0150] Of course, the specific components of the electrode body are not limited here, and those skilled in the art can select them according to actual needs.

[0151] Burrs are likely to form on the positive electrode foil material during processing. Burrs are likely to form on the edge of the first recessed region A111 and / or the edge of the positive electrode tab A103, and welding burrs are also likely to occur at the welded portion between the positive electrode tab A103 and the positive electrode current collector A101. If the burrs penetrate the separator and come into contact with the negative electrode active material A106, the electrode assembly will generate intense heat and eventually explode.

[0152] Furthermore, dendrites are formed in the first recessed region A111 and / or the positive electrode tab A103. If the dendrites penetrate the separator and then come into contact with the negative electrode active material A106, the electrode body will generate intense heat and eventually explode.

[0153] In the embodiment of the present disclosure, the first recessed region A111 and the second recessed region A113 are arranged opposite each other. This reduces the probability that burrs, dendrites, etc., from the first recessed region A111 and the positive electrode tab A103 will come into contact with the negative electrode active material A106 even if they penetrate the separator and reach the other side of the separator. This installation method significantly reduces the risk of intense heat generation and, ultimately, explosion of the electrode assembly, significantly improving the safety of the electrode assembly.

[0154] Although the phenomenon of burrs and / or dendrites coming into contact with the second recessed region A113 does occur, the amount of heat generated by this contact is very small, and therefore the risk to the safety of the electrode body is small.

[0155] In one example, as shown in FIG. 6, the electrode body further includes a first insulating material adhesive layer A121 and a second insulating material adhesive layer A123.

[0156] At least one first recessed area A111 is adhered by a first insulating material adhesive layer A121.

[0157] In one example, at least one second recessed area A113 is adhered by a second insulating material adhesive layer A123.

[0158] For example, the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 are adhesive layers having adhesive properties, and are fixed together by adhesion.

[0159] A first insulating material adhesive layer A121 may be adhered to the first recessed area A111, or a second insulating material adhesive layer A123 may be adhered to the second recessed area A113.

[0160] A first insulating material adhesive layer A121 may be adhered to the first recessed area A111, and a second insulating material adhesive layer A123 may be adhered to the second recessed area A113.

[0161] The first insulating material adhesive layer A121 may be adhered to the first recessed region A111 such that the first insulating material adhesive layer A121 completely covers the first recessed region A111 or partially covers the first recessed region A111. The first insulating material adhesive layer A121 may partially cover the first recessed region A111, or the first insulating material adhesive layer A121 may cover the edge positions of the first recessed region A111.

[0162] The second insulating material adhesive layer A123 may be adhered to the second recessed area A113 such that the second insulating material adhesive layer A123 completely covers the second recessed area A113 or partially covers the second recessed area A113. The second insulating material adhesive layer A123 may partially cover the second recessed area A113, or the second insulating material adhesive layer A123 may cover the edge positions of the second recessed area A113.

[0163] The first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 cover burrs and / or dendrites, thereby reducing the probability of the separator being punctured and further improving the safety of use of the electrode assembly.

[0164] 6, the projection of the negative electrode sheet A12 onto the first recessed region A111 is located within the range of the second recessed region A113, and the area of ​​the second recessed region A113 is larger than the area of ​​the first recessed region A111.

[0165] For example, the shape of the first recessed region A111 is similar to the shape of the second recessed region A113. The area of ​​the second recessed region A113 is larger than the area of ​​the first recessed region A111. Thus, the area where burrs may occur in the first recessed region A111 is located within the range of the second recessed region A113, i.e., outside the negative electrode active material A106. Therefore, even if burrs, dendrites, etc. of the first recessed region A111 and the positive electrode tab A103 penetrate the separator and reach the other side of the separator, the burrs, dendrites, etc. will not come into contact with the negative electrode active material A106. Therefore, the risk of the electrode assembly generating excessive heat and ultimately exploding is extremely low. The electrode assembly is extremely safe to use.

[0166] For example, the first recessed region A111 and the second recessed region A113 are rectangular, and the width and length of the second recessed region A113 are both larger than the width and length of the first recessed region A111, for example, by 1 mm or more on each side. The length is the dimension along the X-axis. This range effectively prevents burrs, dendrites, and the like from coming into contact with the negative electrode active material A106.

[0167] The area of ​​the first recessed region A111 where burrs or dendrites may occur is located within the range of the second recessed region A113. In other words, because it is located outside the negative electrode active material A106, even if burrs, dendrites, etc. of the first recessed region A111 and the positive electrode tab A103 penetrate the separator and reach the other side of the separator, the burrs, dendrites, etc. will not come into contact with the negative electrode active material A106. Therefore, the risk of the electrode assembly generating excessive heat and ultimately exploding is extremely low. This makes the electrode assembly extremely safe to use.

[0168] In one example, as shown in FIG. 13, the bottom of the positive electrode groove in the positive electrode sheet A11 is the first recessed area A111, and the first insulating material adhesive layer A121 is fixed to the first recessed area A111 and extends to the side of the positive electrode groove.

[0169] In one example, the bottom of the negative electrode groove in the negative electrode sheet A12 is the second recessed area A113, and the second insulating material adhesive layer A123 is fixed to the second recessed area A113 and extends to the side of the negative electrode groove.

[0170] In this example, a portion of the first insulating material adhesive layer A121 is located in the first recessed region A111, and another portion is located in the positive electrode active material A105.

[0171] In one example, a portion of the second insulating material adhesive layer A123 is located in the second recessed region A113, and another portion is located in the negative electrode active material A106.

[0172] Since neither the positive electrode current collector A101 nor the negative electrode current collector A102 is a porous material, even if the electrolyte penetrates from the porous active material (e.g., the negative electrode active material A106, the positive electrode active material A105) into the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 that cover the active material, and the adhesiveness of the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 that cover the active material is weakened or lost, the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 do not form a gap region (e.g., a first recess The portions covered with the blank areas (e.g., the first recessed area A111, the second recessed area A113) are tightly bonded to the corresponding current collectors (e.g., the positive electrode current collector A101, the negative electrode current collector A102), so that the electrolyte cannot penetrate into the insulating adhesive layer and the radicals of the electrolyte cannot penetrate into the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123. As a result, the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 located in the blank areas (e.g., the first recessed area A111, the second recessed area A113) can still maintain good adhesion.

[0173] Furthermore, the first recessed region A111 and the first insulating material adhesive layer A121 bonded to the positive electrode active material A105 are integrally connected. The second recessed region A113 and the second insulating material adhesive layer A123 bonded to the negative electrode active material A106 are integrally connected. This prevents the insulating adhesive layers covering the active materials (e.g., the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123) from shifting from their initial bonding positions. Therefore, the insulating adhesive layers covering the active materials (e.g., the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123) still maintain their initial insulating properties, effectively reducing the risk of lithium precipitation.

[0174] In one example, as shown in FIGS. 7-12, a first insulating material adhesive layer A121 covers the first recessed area A111.

[0175] In one example, the second insulating material adhesive layer A123 covers the second recessed area A113.

[0176] In this example, the insulating adhesive layer (e.g., the first insulating material adhesive layer A121, the second insulating material adhesive layer A123) effectively protects the first recessed region A111 and / or the second recessed region A113, and can prevent the electrolyte from excessively corroding the positive electrode current collector A101 and / or the negative electrode current collector A102.

[0177] In addition, the insulating adhesive layer (e.g., the first insulating material adhesive layer A121, the second insulating material adhesive layer A123) can also serve as a heat insulator, preventing the heat generated when welding the positive electrode tab A103 and the external element from diffusing to other parts of the electrode body.

[0178] Furthermore, the first recessed region A111 and the first insulating material adhesive layer A121 covering the positive electrode active material A105 are integrally connected, and the second recessed region A113 and the second insulating material adhesive layer A123 covering the negative electrode active material A106 are integrally connected, which prevents the detached positive electrode active material A105 from contacting the negative electrode current collector A102 or the detached negative electrode active material A106 from contacting the positive electrode current collector A101, further reducing the risk of heat generation and explosion of the electrode body.

[0179] In one example, as shown in FIGS. 7-12, the side of the positive electrode groove has multiple surfaces, the multiple surfaces surround the first recessed area A111, and each surface is provided with a first insulating material adhesive layer A121; and / or The negative electrode groove has a plurality of sides, which surround the second recessed area A113, and each side is provided with a second insulating material adhesive layer A123.

[0180] When the positive electrode groove penetrates the positive electrode active material along the width direction, i.e., when the first recessed region penetrates the positive electrode sheet along the width direction, the side of the positive electrode groove includes two opposing surfaces. When the positive electrode groove is a notch along the width direction of the positive electrode active material, i.e., when the first recessed region is a notch on one side along the width direction of the positive electrode active material, the side of the positive electrode groove includes three surfaces connected in sequence.

[0181] When the negative electrode groove penetrates the negative electrode active material along the width direction, i.e., when the second recessed region penetrates the negative electrode sheet along the width direction, the side of the negative electrode groove includes two opposing surfaces. When the negative electrode groove is a notch along the width direction of the negative electrode active material, i.e., when the second recessed region is a notch on one side along the width direction of the negative electrode active material, the side of the negative electrode groove includes three surfaces connected in sequence.

[0182] In this example, one insulating adhesive layer (e.g., the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123) may cover multiple surfaces. In this way, the insulating adhesive layer can cover burrs, dendrites, etc. in all directions. For example, the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 may have a U-shaped structure or an integral structure.

[0183] Different insulating adhesive layers (eg, first insulating material adhesive layer A121 or second insulating material adhesive layer A123) may cover different surfaces.

[0184] Since each surface is covered with an insulating adhesive layer (e.g., the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123), the insulating adhesive layer (e.g., the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123) can effectively isolate the active materials (e.g., the positive electrode active material A105, the negative electrode active material A106) on each surface, thereby reducing the risk of lithium precipitation.

[0185] In one example, as shown in FIG. 13, the first insulating material adhesive layers A121 on different surfaces are provided independently.

[0186] In one example, the second insulating material adhesive layers A123 on the different surfaces are provided independently.

[0187] For example, the positive electrode active material A105 has two sides parallel to the width direction. The region between the two sides is a first recessed region A111. A first insulating material adhesive layer A121 is provided on each of the two sides. The two first insulating material adhesive layers A121 are provided opposite each other. A portion of each first insulating material adhesive layer A121 is adhered to the positive electrode active material A105, and the other portion is adhered to the first recessed region A111.

[0188] The negative electrode active material A106 has two opposing surfaces parallel to the width direction, and the region between the two opposing surfaces is the second recessed region A113; that is, the two opposing surfaces are the sides of the negative electrode groove. A second insulating material adhesive layer A123 is provided on each of the two opposing surfaces. The two second insulating material adhesive layers A123 are provided opposite each other. A portion of each second insulating material adhesive layer A123 is adhered to the negative electrode active material A106, and the other portion is adhered to the second recessed region A113.

[0189] The positive electrode active material A105 has two opposing surfaces parallel to the width direction, and the region between the two opposing surfaces is a first recessed region A111; in other words, the two opposing surfaces are the sides of the positive electrode groove. A first insulating material adhesive layer A121 is provided on each of the two opposing surfaces. The two first insulating material adhesive layers A121 are provided opposite each other. A portion of each first insulating material adhesive layer A121 is adhered to the positive electrode active material A105, and the other portion is adhered to the first recessed region A111.

[0190] Of course, the sides of the positive electrode groove and the negative electrode groove are not limited to two sides, and those skilled in the art can select them according to actual needs.

[0191] In this example, the first insulating material adhesive layers A121 or second insulating material adhesive layers A123 on different sides are provided independently, so the first insulating material adhesive layers A121 or second insulating material adhesive layers A123 do not affect each other. Thus, even if some insulating adhesive layers fall off, it does not affect the function of the other insulating adhesive layers.

[0192] In one example, the portions of the multiple first insulating material adhesive layers A121 located in the first recessed areas A111 are stacked.

[0193] In one example, the portions of the plurality of second insulating material adhesive layers A123 located in the second recessed areas A113 are stacked.

[0194] In this example, the method of stacking multiple first insulating material adhesive layers A121 or multiple third insulating material adhesive layers A122 is shown in Figure 13. Multiple first insulating material adhesive layers A121 or multiple second insulating material adhesive layers A123 stacked together are less likely to be pierced by burrs, dendrites, etc. than a single first insulating material adhesive layer A121 or second insulating material adhesive layer A123. This can improve the safety of the electrode assembly when used.

[0195] Additionally, the first recessed region A111 and the second recessed region A113 are typically the bottoms of grooves. The thickness of the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123 is typically thin. The multi-layer insulating adhesive layer can fill the recessed grooves, thereby making the overall thickness of the positive electrode sheet A11 and / or the negative electrode sheet A12 more uniform and avoiding defects in the electrode assembly due to uneven thickness of the positive and negative electrode sheets A12 during manufacturing.

[0196] In one example, the portions of the plurality of first insulating material adhesive layers A121 located in the first recessed areas A111 surround the sub-void areas.

[0197] In one example, the portions of the plurality of second insulating material adhesive layers A123 located in the second recessed areas A113 surround the sub-void areas.

[0198] In this example, the sub-blank area is a portion of the first recessed area A111 or the second recessed area A113. This portion is not covered with the insulating adhesive layer. In this way, the amount of the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123 used can be reduced, thereby saving raw materials.

[0199] Furthermore, since the sub-blank areas are not covered with the insulating adhesive layer, the first current collector and the second current collector have better heat dissipation performance.

[0200] In one example, the first recessed areas A111 are provided symmetrically with respect to the positive electrode current collector A101, as shown in Figure 8. One of the first recessed areas A111 is provided with a positive electrode tab A103.

[0201] In this example, two symmetrically arranged first recessed areas A111 provide a space for welding the positive electrode tab A103, which is welded to one of the first recessed areas A111 by, for example, laser welding, resistance welding, or ultrasonic welding.

[0202] In this example, the two symmetrically arranged first recessed areas A111 provide a working space for resistance welding, laser welding, or ultrasonic welding of the positive electrode tab A103. The two first insulating material adhesive layers A121 prevent burrs in the two first recessed areas A111 from piercing the separator.

[0203] In one example, at least one of the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 is a single-sided tape, a high-temperature adhesive, or an insulating film.

[0204] In one example, at least one of the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 is a double-sided tape or a hot melt adhesive, and at least one of the first insulating material adhesive layer A121 and the second insulating material adhesive layer A123 includes a first adhesive surface and a second adhesive surface having different adhesive strengths, the first adhesive surface is adhered to a separator, and the adhesive strength of the first adhesive surface is greater than the adhesive strength of the second adhesive surface.

[0205] In this example, when the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123 is a single-sided tape, a high-temperature adhesive, or an insulating film, the first adhesive layer has only one adhesive surface, i.e., the surface that is adhered to the first recessed area A111 and the second recessed area A113. When the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123 is a double-sided tape or a hot-melt adhesive, the second adhesive surface has a weak adhesive surface that is adhered to the first recessed area A111 and the second recessed area A113.

[0206] Here, the high-temperature adhesive is an adhesive that maintains its viscosity even under high-temperature operation of the battery device, and the insulating film is an adhesive film formed by curing a liquid adhesive in the corresponding area using a coating and curing method.

[0207] For example, single-sided tapes, double-sided adhesives, high-temperature adhesives, or hot melt adhesives are adhesives based on polymer materials and coated with viscous components such as acrylic resin adhesives, SBR adhesives, SIS adhesives, etc. Those skilled in the art can select the materials for the base and viscous components according to actual needs.

[0208] Of course, the material of the first insulating material adhesive layer A121 or the second insulating material adhesive layer A123 is not limited to the above embodiment, and can be selected by those skilled in the art according to actual needs.

[0209] In one example, the first recessed region A111 penetrates the positive electrode sheet A11 in the width direction. In this example, the width direction is the Y-axis direction. The positive electrode groove may penetrate the positive electrode sheet A11 in the width direction. In this case, the side portion of the positive electrode groove includes two opposing surfaces.

[0210] In one example, the positive electrode active material A105 has a notch on one side in the width direction of the positive electrode sheet A11. The first recessed region A111 is formed by the notch. In this example, the positive electrode active material A105 has a notch on one side in the width direction of the positive electrode sheet A11, and the first recessed region A111 is formed by the notch. In other words, the positive electrode groove does not penetrate all the way through the positive electrode sheet A11. In this case, the side of the positive electrode groove includes three opposing surfaces.

[0211] As a result, provided that the positive electrode tab A103 can be properly installed in the first recessed area A111, some active material can still be retained around the first recessed area A111 formed in the positive electrode sheet A11, and the retained active material can still undergo a lithium ion transfer reaction, thereby improving the energy density of the electrode body.

[0212] In one example, the second recessed region A113 penetrates the negative electrode sheet A12 in the width direction. In this example, the negative electrode groove may penetrate the negative electrode sheet A12 in the width direction. In this case, the side of the negative electrode groove includes two opposing surfaces.

[0213] In one example, the negative electrode active material A106 has a notch on one side in the width direction of the negative electrode sheet A12. The second recessed region A113 is formed by the notch. In this example, the negative electrode active material A106 has a notch on one side in the width direction of the negative electrode sheet A12, and the second recessed region A113 is formed by the notch; that is, the negative electrode groove does not penetrate through the negative electrode sheet A12. In this case, the side of the negative electrode groove includes three opposing surfaces.

[0214] In this way, under the condition that the negative electrode tab A104 can be properly installed in the second recessed area A113, a portion of the active material can still be retained around the second recessed area A113 formed in the negative electrode sheet A12, and the lithium ions that have migrated can be absorbed, thereby reducing the risk of lithium precipitation.

[0215] In addition, some of the reserved active material can still undergo a lithium ion transfer reaction, improving the energy density of the electrode body.

[0216] According to the present disclosure, a battery device is provided. The battery device includes the electrode assembly described above. The battery device may be, but is not limited to, a lithium-ion battery, a sodium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, or the like. The battery device may also be a soft-pack battery or a prismatic battery.

[0217] The battery device includes a case and an electrode assembly. The electrode assembly is provided within the case. The battery device is characterized by excellent safety performance.

[0218] According to another embodiment of the present disclosure, there is provided an electronic device, the electronic device including the battery device described above.

[0219] For example, the electronic device may be a vehicle, a mobile phone, an earphone, an electronic pen, VR, AR, etc., and is not limited thereto, and those skilled in the art can select it according to their actual needs.

[0220] This electronic device is characterized by a high safety factor.

[0221] Example 1 As shown in Figures 7-12, this example provides a lithium-ion battery. The lithium-ion battery includes a positive electrode sheet A11, a negative electrode sheet A12, a separator A107, and an electrolyte. The positive electrode sheet A11 includes a positive electrode current collector A101, a positive electrode tab A103, a positive electrode active material A105, and a first recessed area A111. The positive electrode tab A103 is welded to the first recessed area A111.

[0222] The negative electrode sheet A12 includes a negative electrode current collector A102, a negative electrode tab A104, a negative electrode active material A106, and a third recessed region A112. The negative electrode tab A104 is welded to the third recessed region A112.

[0223] Neither the front nor the back of the first recessed region A111 nor the third recessed region A112 is coated with an active material, and the second recessed region A113 is provided at a position on the negative electrode sheet A12 corresponding to the first recessed region A111. The back of the second recessed region A113 is coated with the negative electrode active material A106.

[0224] The first insulating material adhesive layer A121 covers the first recessed region A111 and the surrounding positive electrode active material A105, and the third insulating material adhesive layer A122 covers the third recessed region A112 and the surrounding negative electrode active material A106.

[0225] The second insulating material adhesive layer A123 covers the second recessed region A113 and the surrounding negative electrode active material A106.

[0226] The length and width of the first recessed region A111 are smaller than the length and width of the second recessed region A113. The length is the dimension along the X axis, and the width is the dimension along the Y axis.

[0227] The length and width of the first insulating material adhesive layer A121 are greater than the length and width of the second insulating material adhesive layer A123. That is, to prevent lithium deposition, the length and width of the insulating adhesive layer on the positive electrode sheet A11 are greater than the insulating adhesive layer on the negative electrode sheet A12.

[0228] The following describes the manufacturing method of the lithium secondary battery of the present invention, taking a soft pack battery (model number: 466480, i.e., cell thickness 4.6 mm, width 64 mm, height 80 mm) as an example.

[0229] The positive electrode sheet was produced as follows.

[0230] Cathode active material LiCoO 2 The resulting mixture was mixed with a carbon nanotube (CNT) conductive agent, a PVDF binder, and NMP in a mass ratio of 100:0.5:0.7:28, and stirred to obtain a positive electrode slurry.

[0231] The positive electrode slurry was applied to an aluminum foil having a thickness of 9 μm to form a positive electrode active material A105. The surface density of the positive electrode active material A105 was 17.4 mg / cm. 2 It was.

[0232] The mixture was dried, tableted, and slit to obtain a positive electrode sheet A11 having a width of 73 mm and a length of 1120 mm.

[0233] Using a laser cleaning device, the positive electrode active material A105 is cleaned at a position 1 / 4 of the way down from the end of the positive electrode sheet A11 to form a first recessed region A111. The first recessed region A111 is 18 mm long and 10 mm wide.

[0234] The first recessed region A111 and its surrounding area are coated with a first insulating material adhesive layer A121. The first insulating material adhesive layer A121 is 24 mm long and 16 mm wide. The first insulating material adhesive layer A121 completely covers the first recessed region A111, partially covers the positive electrode active material, and covers one side by 3 mm.

[0235] The negative electrode sheet was produced as follows.

[0236] A negative electrode active material, graphite, a Super-P conductive agent, a CMC-Li binder, and deionized water are stirred in a mass ratio of 100:0.3:1.1:110 to obtain a negative electrode slurry.

[0237] The negative electrode slurry was applied to a copper foil having a thickness of 5 μm to form a negative electrode active material A106. The surface density of the negative electrode active material A106 was 9.6 mg / cm. 2 It was.

[0238] The mixture was dried, tableted, and then slit to obtain a negative electrode sheet A12 having a width of 74.5 mm and a length of 1040 mm.

[0239] A laser cleaning device is used to clean the third recessed region A112 at the central half position of the negative electrode sheet A12. The third recessed region A112 has a length of 20 mm and a width of 12 mm.

[0240] At a position on the negative electrode sheet A12 corresponding to the first recessed area A111, a second recessed area A113 having a length of 20 mm and a width of 12 mm is cleaned.

[0241] The third recessed region A112 and the surrounding negative electrode active material are covered with a third insulating material adhesive layer A122. The third insulating material adhesive layer A122 is 14 mm wide and 22 mm long, with one side of the cover material being 1 mm thick.

[0242] The second recessed regions A113 and the surrounding negative electrode active material are covered with a second insulating material adhesive layer A123. The second insulating material adhesive layer A123 is 14 mm wide and 22 mm long, with a 1 mm portion covering the negative electrode active material A106 in the width direction and a 2 mm portion covering the negative electrode active material A106 in the length direction. Two second recessed regions A113 are provided in the negative electrode sheet, and the second insulating material adhesive layer A123 is adhered to the two second recessed regions A113.

[0243] The electrolyte solution was prepared as follows.

[0244] EMC:DEC:EC:EP were uniformly mixed in a mass ratio of 30%:30%:30%:10%.

[0245] LiPF6 was added as a solute. The concentration of LiPF6 was 1M.

[0246] As additives, 2% by mass of adiponitrile and 1% by mass of 1,6-hexanetricarbonitrile were added, and the mixture was thoroughly dissolved to obtain an electrolyte solution.

[0247] The manufacturing process of a lithium battery is as follows.

[0248] The positive electrode sheet A11, the negative electrode sheet A12, and the separator A107 prepared above were wound in a winding device to prepare a winding core. The winding core was baked and dried, and then an electrolyte solution was injected into the core, which was then sealed and molded to prepare a final lithium battery.

[0249] This lithium-ion battery has a high safety factor.

[0250] Example 2 13, in this example, two independent second insulating material adhesive layers A123 are laminated in the second recessed area A113, which can fill the depression caused by the negative electrode groove after lamination, which is beneficial to the overall flatness of the electrode body and reduces bending deformation of the electrode body.

[0251] (Third aspect) According to one embodiment of the present disclosure, there is provided an electrode assembly for use in a battery device.

[0252] 14 and 15, the electrode assembly includes a first pole piece, a first insulating adhesive B124a, and a second insulating adhesive B124b. The first electrode sheet is a positive electrode sheet B11 or a negative electrode sheet B12.

[0253] The first electrode sheet includes a current collector and an active material attached to the surface of the current collector, and a groove (e.g., a fourth escape groove B114) including a bottom and opposing first and second side wall portions is provided on the surface of the active material, and the active material is not attached to the bottom of the groove (e.g., the fourth escape groove B114).

[0254] A first insulating adhesive B124a is adhered to the bottom and extends over the active material of the first sidewall.

[0255] A second insulating adhesive B124b is adhered to the bottom and extends over the active material of the second sidewall.

[0256] Specifically, the current collector is a metal foil material. The grooves (e.g., the fourth relief groove B114) can be formed by laser cleaning, intermittent coating, or adhesive peeling. The current collector is exposed at the bottom of the groove (e.g., the fourth relief groove B114). For example, the positive electrode current collector B101 is an aluminum foil, and the negative electrode current collector B102 is a copper foil.

[0257] The active material may be a positive electrode active material B105 or a negative electrode active material B106. Take an electrode body of a lithium-ion battery as an example. The positive electrode active material B105 includes lithium manganese oxide, lithium cobalt oxide, lithium nickel-cobalt manganese oxide, or lithium iron phosphate. The negative electrode active material B106 includes graphite or silicon. The first side wall portion and the second side wall portion are formed after the active material is removed. The first side wall portion and the second side wall portion may be provided opposite to each other or adjacent to each other.

[0258] Of course, the active material is not limited to the above examples, and those skilled in the art can select it according to their actual needs.

[0259] For example, as shown in Figure 14, the electrode assembly further includes a second electrode sheet and a separator B107. The separator B107 is located between the first electrode sheet and the second electrode sheet.

[0260] Taking the electrode assembly of a lithium-ion battery as an example, during the charge and discharge process, lithium ions travel back and forth between the positive and negative electrode sheets B12, storing and releasing them. During charging, lithium ions are released from the positive electrode active material B105 of the positive electrode sheet B11 and are absorbed into the negative electrode active material B106 of the negative electrode sheet B12 via the electrolyte and separator B107, making the negative electrode sheet B12 lithium-rich. During discharging, conversely, lithium ions in the negative electrode active material B106 are released from the negative electrode sheet B12 and are absorbed into the positive electrode active material B105 of the positive electrode sheet B11 via the electrolyte and separator B107, creating a potential difference between the positive and negative electrode sheets B12.

[0261] Of course, the specific components of the electrode body are not limited here, and those skilled in the art can select them according to actual needs.

[0262] In the embodiment of the present disclosure, the first insulating adhesive B124a is attached to the bottom and extends onto the active material of the first sidewall. The second insulating adhesive B124b is attached to the bottom and extends onto the active material of the second sidewall. The first insulating adhesive B124a and the second insulating adhesive B124b are spaced apart and fixed to the bottom. In this way, the first insulating adhesive B124a and the second insulating adhesive B124b can effectively cover the active material at the edge of the groove, thereby preventing the release of conductive material and the deposition of conductive material on the pole piece of the opposite polarity, such as lithium deposition.

[0263] In addition, the first insulating adhesive B124a and the second insulating adhesive B124b cover a portion of the current collector, preventing conductive materials, such as lithium ions, between the current collector and the pole piece of the other polarity from reaching the current collector, thereby preventing conductive materials, such as lithium, from being deposited on the current collector.

[0264] Furthermore, the first insulating adhesive B124a and the second insulating adhesive B124b cover the current collector, thereby shielding burrs on the current collector and preventing the burrs from penetrating the separator B107.

[0265] Furthermore, even if one of the first insulating adhesive B124a and the second insulating adhesive B124b falls off, the effect of the other insulating adhesive in preventing lithium deposition and preventing burrs from puncturing the separator B107 is not affected, thereby improving the safety of using the electrode body.

[0266] In one example, the electrode assembly further includes a second electrode sheet and a separator B107, as shown in Figure 14. The separator B107 is located between the first electrode sheet and the second electrode sheet.

[0267] In one example, as shown in FIG. 16, the first insulating adhesive B124a extends from the first sidewall portion to the surface of the active material, and the second insulating adhesive B124b extends from the second sidewall portion to the surface of the active material.

[0268] In this example, a portion of the first insulating adhesive B124a is located at the bottom of the groove (e.g., the fourth relief groove B114), and another portion is located on the active material, e.g., the positive electrode active material B105. A portion of the second insulating adhesive B124b is located at the bottom of the groove (e.g., the fourth relief groove B114), and another portion is located on the active material.

[0269] Since neither the positive electrode current collector B101 nor the negative electrode current collector B102 is a porous material, even if the electrolyte penetrates from the porous active material (for example, the negative electrode active material B106, the positive electrode active material B105) into the first insulating adhesive B124a and the second insulating adhesive B124b that cover the active material, and the adhesiveness of the first insulating adhesive B124a and the second insulating adhesive B124b that cover the active material is weakened or lost, the first insulating adhesive B124a and the second insulating adhesive B124b will not be affected. The portion covering the bottom of each of the insulating adhesives B124a and B124b is tightly bonded to the corresponding current collector (e.g., positive electrode current collector B101, negative electrode current collector B102), so that the electrolyte cannot penetrate the first insulating adhesive B124a and the second insulating adhesive B124b, and the radicals of the electrolyte cannot penetrate the first insulating adhesive B124a and the second insulating adhesive B124b, so that the first insulating adhesive B124a and the second insulating adhesive B124b located at the bottom can still maintain good adhesion.

[0270] Furthermore, the first insulating adhesive B124a that coats the bottom and the active material (e.g., negative electrode active material B106, positive electrode active material B105) is integrally bonded. The bottom and the second insulating adhesive B124b that coats the active material (e.g., negative electrode active material B106, positive electrode active material B105) are integrally connected. This prevents the first insulating adhesive B124a and second insulating adhesive B124b that coat the active material from shifting from their initial bonding positions. Therefore, the first insulating adhesive B124a and second insulating adhesive B124b that coat the active material still maintain their initial insulating properties, effectively reducing the risk of lithium precipitation.

[0271] In one example, as shown in FIGS. 14, 16, and 17, the first insulating adhesive B124a and the second insulating adhesive B124b are laminated on the portion located at the bottom.

[0272] In this example, the first insulating adhesive B124a and the second insulating adhesive B124b are laminated to effectively cover the bottom of the groove. The laminated installation method is more resistant to puncture by burrs, dendrites, etc. than a single first insulating adhesive B124a or second insulating adhesive B124b. This improves the safety of the electrode assembly when used.

[0273] Furthermore, the thickness of the first insulating adhesive B124a or the second insulating adhesive B124b is usually thin, and the multi-layer insulating adhesive can fill the grooves (e.g., the fourth relief groove B114) to make the overall thickness of the electrode sheet more uniform and avoid defects in the electrode assembly due to uneven thickness of the positive and negative electrode sheets B12 during the manufacturing process.

[0274] In addition, the first insulating adhesive B124a and the second insulating adhesive B124b, which are stacked and installed, can fill in the depressions caused by the grooves, which is beneficial to the overall flatness of the electrode body, reduces bending deformation of the electrode body, and can avoid problems such as short circuits caused by bending deformation of the electrode body, ultimately improving the safety of use of the battery formed by winding the electrode body.

[0275] Furthermore, the first insulating adhesive B124a and the second insulating adhesive B124b are disposed in layers in the recessed groove, thereby improving the overall flatness of the electrode body.

[0276] In one example, as shown in FIGS. 18, 19, and 20, the first insulating adhesive B124a and the second insulating adhesive B124b are spaced apart at the portion located at the bottom.

[0277] For example, when the active material attached to the surface of the current collector is relatively thin, the first insulating adhesive B124a and the second insulating adhesive B124b are separated at the bottom, there is no overlapping portion, and the height after the first insulating adhesive B124a and the second insulating adhesive B124b are stacked exceeds the height of the active material, thereby avoiding the problem of unevenness.

[0278] For example, a blank area is formed between the first insulating adhesive B124a and the second insulating adhesive B124b. This blank area is not covered with insulating paste. In this way, the amount of the first insulating adhesive B124a or the second insulating adhesive B124b used can be reduced, thereby saving raw materials.

[0279] Furthermore, the current collectors, for example, the positive electrode current collector B101 and the negative electrode current collector B102, are exposed in the blank areas, which allows the current collectors to have better heat dissipation performance.

[0280] In one example, as shown in FIG. 18, the bottom portion is provided with an electrode tab located in a region where the first insulating adhesive B124a and the second insulating adhesive B124b are spaced apart.

[0281] For example, the tab may be a positive electrode tab B103 or a negative electrode tab B104. The tab may be welded to the blank area by laser welding, resistance welding, or ultrasonic welding, or may be die-cut into the pole piece to form the tab. This method allows the space in the groove (e.g., the fourth relief groove B114) to be fully utilized.

[0282] In one example, the length of the portion of the first insulating adhesive B124a that extends onto the surface of the active material is 0.5 mm or more, and the length of the portion of the second insulating adhesive B124b that extends onto the surface of the active material is 0.5 mm or more.

[0283] Within this range, the first insulating adhesive B124a and the second insulating adhesive B124b can effectively protect the active material.

[0284] Furthermore, under the condition that the electrode sheet is the positive electrode sheet B11, this size range can effectively prevent the occurrence of the lithium deposition phenomenon in the negative electrode sheet B12.

[0285] In one example, as shown in FIG. 16, the groove (e.g., the fourth relief groove B114) is a through groove that runs along the width direction of the pole piece. The width direction is the Y-axis direction. For example, the bottom is rectangular. The first insulating adhesive B124a and the second insulating adhesive B124b are provided on two sides of the rectangle, respectively, and extend to the sidewalls and then to the surface of the active material. The first insulating adhesive B124a and the second insulating adhesive B124b are Z-shaped and symmetrical with respect to the central axis of the groove (e.g., the fourth relief groove B114).

[0286] In this example, the process of forming the groove (for example, the fourth relief groove B114) is simple, and when a tab needs to be welded, the bottom space is large, making it easy to weld the tab.

[0287] In one example, the groove is an open groove extending toward one widthwise side of the current collector, and further includes a third side wall portion connected between the first side wall portion and the second side wall portion. The third side wall portion faces the opening of the open groove.

[0288] The electrode body further includes a third insulating adhesive that is adhered to the bottom portion and extends onto the active material of the third sidewall portion.

[0289] In this example, the open groove is a non-through groove, which allows the first tab to be properly installed at the bottom, and allows some of the active material to be reserved around the bottom, allowing it to absorb the migrated lithium ions and reduce the risk of lithium deposition.

[0290] In addition, some of the reserved active material can still undergo a lithium ion transfer reaction, improving the energy density of the electrode body.

[0291] In one example, at least one of the first insulating adhesive B124a and the second insulating adhesive B124b is a single-sided tape, a high-temperature adhesive, an insulating film, a double-sided tape, or a hot-melt adhesive.

[0292] In this example, when the first insulating adhesive B124a and the second insulating adhesive B124b are single-sided tapes, high-temperature adhesives, or insulating films, only one side of the first adhesive layer has adhesive properties, i.e., the side that is attached to the bottom. When the first insulating adhesive B124a and the second insulating adhesive B124b are double-sided tapes or hot-melt adhesives, the second adhesive side has weak adhesive properties and is attached to the bottom. The first adhesive side has strong adhesive properties. The first adhesive side is used for bonding to the separator B107 of the battery device. The first insulating adhesive B124a and the second insulating adhesive B124b can effectively prevent lithium ions from passing through the separator B107, reducing the risk of lithium precipitation on the negative electrode sheet B12.

[0293] Here, the high-temperature adhesive is an adhesive that maintains its viscosity even under high-temperature operation of the battery device, and the insulating film is an adhesive film formed by curing a liquid adhesive in the corresponding area using a coating and curing method.

[0294] For example, single-sided tapes, double-sided adhesives, high-temperature adhesives, or hot melt adhesives are adhesives based on polymer materials and coated with viscous components such as acrylic resin adhesives, SBR adhesives, SIS adhesives, etc. Those skilled in the art can select the materials of the substrate and viscous components according to actual needs.

[0295] Of course, the material of the insulating adhesive is not limited to the above embodiment, and those skilled in the art can select it according to actual needs.

[0296] In one example, as shown in FIG. 14, a tab groove is provided in the second electrode sheet, a tab is provided in the tab groove, the electrode body further includes a third insulating adhesive covering the tab groove, and the recessed groove is provided opposite the tab groove.

[0297] In this example, when the second electrode sheet is a negative electrode sheet B12, the tab is a negative electrode tab B104. When the second electrode sheet is a positive electrode sheet B11, the electrode tab is a positive electrode tab B103. For example, as shown in FIG. 14, a negative electrode tab B104 is provided in a negative electrode tab groove B112a. The negative electrode tab groove B112a is coated with a third insulating adhesive B122a (corresponding to the first insulating adhesive layer 121 in the first embodiment). A groove, for example, a fourth relief groove B114, is provided in the negative electrode tab groove B112a. B112a The fourth escape groove B114 faces the separator B107. The first insulating adhesive B124a and the second insulating adhesive B124b are coated inside the fourth escape groove B114. The third insulating adhesive can cover the negative electrode tab groove B112a. This effectively prevents burrs on the negative electrode tab B104 from breaking through the separator B107.

[0298] Additionally, the third insulating adhesive 122a can effectively reduce lithium deposition in the negative electrode tab groove B112a.

[0299] Furthermore, even if a burr on the positive electrode sheet pierces the separator B107 and the third insulating adhesive 122a, the presence of the negative electrode tab groove B112a prevents the burr from coming into contact with the negative electrode active material, effectively preventing the electrode body from suddenly generating heat.

[0300] According to the present disclosure, a battery device is provided. The battery device includes the electrode assembly described above. The battery device may be, but is not limited to, a lithium-ion battery, a sodium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, or the like. The battery device may also be a soft-pack battery or a prismatic battery.

[0301] The battery device includes a case and an electrode assembly. The electrode assembly is provided within the case. The battery device is characterized by excellent safety performance.

[0302] According to another embodiment of the present disclosure, there is provided an electronic device, the electronic device including the battery device described above.

[0303] For example, the electronic device may be a vehicle, a mobile phone, an earphone, an electronic pen, VR, AR, etc., and is not limited thereto, and those skilled in the art can select it according to their actual needs.

[0304] This electronic device is characterized by a high safety factor.

[0305] Example 3 16, in this example, the negative electrode tab B104 is provided in one of the second relief grooves B112 (i.e., the negative electrode tab groove B112a), and a first insulating adhesive B124a and a second insulating adhesive B124b are provided on the two second relief grooves B112. The first insulating adhesive B124a and the second insulating adhesive B124b are adhered to the two fourth relief grooves B114 corresponding to the negative electrode tab B104 of the positive electrode sheet B11. The first insulating adhesive B124a and the second insulating adhesive B124b in each groove 112, 114 corresponding to the negative electrode tab B104 are installed by stacking them on the bottom.

[0306] The positive electrode tab B103 is provided in one of the first relief grooves B111. A first insulating adhesive B124a and a second insulating adhesive B124b are provided in the two first relief grooves B111. A first insulating adhesive B124a and a second insulating adhesive B124b are provided in two third relief grooves B113 corresponding to the positive electrode tab B103 of the negative electrode sheet B12. The first insulating adhesive B124a and the second insulating adhesive B124b in each groove B111, B113 corresponding to each positive electrode tab B103 are provided stacked on the bottom.

[0307] Example 4 18, in this example, the negative electrode tab B104 is provided in one of the second relief grooves B112 (i.e., the negative electrode tab groove B112a). A first insulating adhesive B124a and a second insulating adhesive B124b are provided on the two second relief grooves B112. The first insulating adhesive B124a and the second insulating adhesive B124b are adhered to the two fourth relief grooves B114 corresponding to the negative electrode tab B104 of the positive electrode sheet B11. The first insulating adhesive B124a and the second insulating adhesive B124b in each groove B112, B114 corresponding to the negative electrode tab B104 form a gap at the bottom.

[0308] The positive electrode tab B103 is provided in one of the first relief grooves B111. A first insulating adhesive B124a and a second insulating adhesive B124b are provided in the two first relief grooves B111. A first insulating adhesive B124a and a second insulating adhesive B124b are provided in two third relief grooves B113 corresponding to the positive electrode tab B103 of the negative electrode sheet B12. The first insulating adhesive B124a and the second insulating adhesive B124b in each groove B111, B113 corresponding to the negative electrode tab B104 form a gap at the bottom.

[0309] Example 5 Referring to FIG. 19, in this example, the negative electrode tab B104 is provided in one of the second relief grooves B112 (i.e., the negative electrode tab groove B112a). A third insulating adhesive B122a (corresponding to the first insulating adhesive layer 121 in the first embodiment) and an adhesive tape (corresponding to the third insulating adhesive layer 123 in the first embodiment) are provided in each of the two second relief grooves B112. A first insulating adhesive B124a and a second insulating adhesive B124b are adhered to the two fourth relief grooves B114 corresponding to the negative electrode tab B104 of the positive electrode sheet. The first insulating adhesive B124a and the second insulating adhesive B124b form a gap at the bottom.

[0310] The positive electrode tab B103 is provided in one of the first relief grooves B111. A third insulating adhesive 122a and an adhesive tape B122 (corresponding to the seventh insulating adhesive layer 127 in the first embodiment) are provided in each of the two first relief grooves B111. A first insulating adhesive B124a and a second insulating adhesive B124b are provided in the two third relief grooves B113 corresponding to the positive electrode tab B103 of the negative electrode sheet B12. The first insulating adhesive B124a and the second insulating adhesive B124b form a gap at their bottoms.

[0311] Example 6 Referring to FIG. 20, in this example, the negative electrode tab B104 is provided in one of the second relief grooves B112 (i.e., the negative electrode tab groove B112a). A third insulating adhesive B122a and a tape B122 (corresponding to the third insulating adhesive layer 123 in the first embodiment) are provided in each of the two second relief grooves B112. A first insulating adhesive B124a and a second insulating adhesive B124b are adhered to the two fourth relief grooves B114 corresponding to the negative electrode tab B104 of the positive electrode sheet. The first insulating adhesive B124a and the second insulating adhesive B124b form a gap at the bottom.

[0312] The positive electrode tab B103 is provided in one of the first relief grooves B111 (i.e., the positive electrode tab groove 111a). A third insulating adhesive B122a and a tape B121 (corresponding to the seventh insulating adhesive layer 127 in the first embodiment) are provided in the two first relief grooves B111. An adhesive tape B123 (corresponding to the eighth insulating adhesive layer 128 in the first embodiment) is provided in the two third relief grooves B113 corresponding to the positive electrode tab B103 of the negative electrode sheet B12.

[0313] The above embodiments have been focused on the differences between each embodiment, and the different optimization features between each embodiment, as long as they are not contradictory, can be combined to form a more preferred embodiment, and for the sake of brevity, the description will be omitted here.

[0314] Although some specific embodiments of the present application have been described in detail by using examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present application. Those skilled in the art should understand that modifications can be made to the above examples without departing from the scope and spirit of the present application. The scope of the present invention is defined by the claims. [Explanation of symbols]

[0315] Explanation of symbols in the first embodiment: 11 Positive electrode sheet 12 Negative electrode sheet 101 Positive electrode current collector 102 Negative electrode current collector 103 Positive electrode tab 104 Negative electrode tab 105 Cathode active material 106 Anode active material 107 Separator 111 Negative electrode tab groove 112 1st groove 113 Second groove 114 Third groove 115 Positive electrode tab groove 116 4th groove 117 5th groove 118 6th groove 121 First insulating adhesive layer 122 Second insulating adhesive layer 123 Third insulating adhesive layer 124 Fourth insulating adhesive layer 1241 4th left insulating adhesive layer 1242 4th right insulating adhesive layer 125 5th insulating adhesive layer 126 6th insulating adhesive layer 127 7th insulating adhesive layer 128 8th insulating adhesive layer Explanation of symbols in the second embodiment: A11 Positive electrode sheet A12 Negative electrode sheet A101 Positive electrode current collector A102 Negative electrode current collector A103 Positive electrode tab A104 negative electrode tab A105 Cathode active material A106 Anode active material A107 Separator A111: First recessed region (corresponding to the bottom of the positive electrode tab groove 115 and the bottom of the fifth recessed groove 117 in the first embodiment) A112: Third recessed region (corresponding to the bottom of the negative electrode tab groove 111 and the bottom of the second recessed groove 113 in the first embodiment) A113: Second recessed region (corresponding to the bottom of the fourth groove 116 and the bottom of the sixth groove 118 in the first embodiment) A121: First insulating material adhesive layer (corresponding to the fifth insulating adhesive layer 125 and the seventh insulating adhesive layer 127 of the first embodiment) A122: Third insulating material adhesive layer (corresponding to the first insulating adhesive layer 121 and the third insulating adhesive layer 123 in the first embodiment) A123: Second insulating material adhesive layer (corresponding to the sixth insulating adhesive layer 126 and the eighth insulating adhesive layer 128 in the first embodiment) Explanation of symbols in the third aspect: B11 Positive electrode sheet B12 negative electrode sheet B101 Positive electrode current collector B102 Negative electrode current collector B103 Positive electrode tab B104 Negative electrode tab B105 Cathode active material B106 Negative electrode active material B107 Separator B111: First relief groove (corresponding to the positive electrode tab groove 115 and the fifth groove 117 in the first embodiment) B112 Second relief groove (corresponding to the negative electrode tab groove 111 and the second groove 113 in the first embodiment) B112a Negative electrode tab groove B113: Third relief groove (corresponding to the fourth groove 116 and the sixth groove 118 in the first embodiment) B114: Fourth relief groove (corresponding to the first groove 112 and the third groove 114 in the first embodiment) B121 Tape B122 Tape B122a: Third insulating adhesive (corresponding to the first insulating adhesive layer 121 of the first embodiment) B123 Tape B124a: First insulating adhesive (corresponding to the fourth left insulating adhesive layer 1241 in the first embodiment) B124b Second insulating adhesive (first embodiment) 4th right insulating adhesive layer (equivalent to 1242)

Claims

1. An electrode assembly including a negative electrode sheet (12), a negative electrode tab (104), a positive electrode sheet (11), and a separator (107); the separator (107) is located between the positive electrode sheet (11) and the negative electrode sheet (12); The negative electrode sheet (12) includes a negative electrode current collector (102) and a negative electrode active material (106) attached to the negative electrode current collector (102), and a negative electrode tab groove (111) is formed on the negative electrode active material (106); The negative electrode tab (104) is disposed in the negative electrode tab groove (111), The positive electrode sheet (11) includes a positive electrode current collector (101) and a positive electrode active material (105) attached to the positive electrode current collector (101), and a first groove (112) is formed on the positive electrode active material (105). The first groove (112) and the negative electrode tab groove (111) are provided opposite to each other on the opposite surface of the separator (107), and the projection of the first groove (112) onto the negative electrode sheet (12) is located within the negative electrode tab groove (111). The electrode body is characterized by the above.

2. The negative electrode active material (106) further has a second groove (113), and the second groove (113) and the negative electrode tab groove (111) are symmetrically disposed on both sides of the negative electrode current collector (102); A third groove (114) is formed in the positive electrode active material (105), the third groove (114) is disposed opposite to the second groove (113), and the projection of the third groove (114) onto the negative electrode sheet (12) is located within the second groove (113).

2. The electrode assembly according to claim 1 .

3. The adhesive layer further includes a first insulating adhesive layer (121), a second insulating adhesive layer (122), a third insulating adhesive layer (123), and a fourth insulating adhesive layer (124). the first insulating adhesive layer (121) is adhered to the bottom of the negative electrode tab groove (111) and extends to the negative electrode active material (106) on the side of the negative electrode tab groove (111), or the first insulating adhesive layer (121) is adhered to the top surface of the negative electrode tab groove (104) and extends to the negative electrode active material (106) on the side of the negative electrode tab groove (111); the second insulating adhesive layer (122) is adhered to the bottom of the first groove and extends to the positive electrode active material (105) on the side of the first groove; the third insulating adhesive layer (123) is adhered to the bottom of the second groove (113) and extends to the negative electrode active material (106) on the side of the second groove (113); the fourth insulating adhesive layer (124) is adhered to the bottom of the third groove (114) and extends to the positive electrode active material (105) on the side of the third groove (114); 3. The electrode assembly according to claim 2, wherein:

4. the first groove is a through groove including a first left groove wall and a first right groove wall, and the second insulating adhesive layer (122) includes a second left insulating adhesive layer provided on the first left groove wall and a second right insulating adhesive layer provided on the first right groove wall, the second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions in the first groove and overlap at the groove bottom, or the second left insulating adhesive layer and the second right insulating adhesive layer are arranged at opposing positions apart from each other at the groove bottom of the first groove; and / or the third groove (114) is a through groove including a third left groove wall and a third right groove wall, and the fourth insulating adhesive layer (124) includes a fourth left insulating adhesive layer provided on the third left groove wall and a fourth right insulating adhesive layer provided on the third right groove wall, The fourth left insulating adhesive layer and the fourth right insulating adhesive layer are arranged at opposing positions in the third groove (114) and overlap at the groove bottom, or the fourth left insulating adhesive layer and the fourth right insulating adhesive layer are arranged at opposing positions apart from each other at the groove bottom of the third groove (114).

4. The electrode assembly according to claim 3.

5. The electrode body further includes a positive electrode tab (103), a positive electrode tab groove (115) is formed in the positive electrode active material (105), the positive electrode tab (103) is disposed in the positive electrode tab groove (115), and a fourth groove (116) is formed in the negative electrode active material (106), the fourth groove (116) is disposed opposite the positive electrode tab groove (115), and a projection of the positive electrode tab groove (115) onto the negative electrode sheet is located within the fourth groove (116).

2. The electrode assembly according to claim 1 .

6. The positive electrode active material (105) further has a fifth groove (117), and the fifth groove (117) and the positive electrode tab groove (115) are symmetrically provided on both sides of the positive electrode current collector (101), a sixth groove (118) is formed in the negative electrode active material (106), the sixth groove (118) is disposed opposite to the fifth groove (117), and the projection of the fifth groove (117) onto the negative electrode sheet (12) is located within the sixth groove (118); 6. The electrode assembly according to claim 5.

7. The electrode body further includes a fifth insulating adhesive layer (125), a sixth insulating adhesive layer (126), a seventh insulating adhesive layer (127), and an eighth insulating adhesive layer (128), the fifth insulating adhesive layer (125) is adhered to the bottom of the positive electrode tab groove (115) and extends to the positive electrode active material (105) on the side of the positive electrode tab groove (115), or the fifth insulating adhesive layer (125) is adhered to the top surface of the positive electrode tab groove (103) and extends to the positive electrode active material (105) on the side of the positive electrode tab groove (115); the sixth insulating adhesive layer (126) is adhered to the bottom of the fourth groove (116) and extends to the negative electrode active material (106) on the side of the fourth groove (116); the seventh insulating adhesive layer (127) is adhered to the bottom of the fifth groove (117) and extends to the positive electrode active material (105) on the side of the fifth groove (117); The eighth insulating adhesive layer (128) is adhered to the bottom of the sixth groove (118) and extends to the negative electrode active material (106) on the side of the sixth groove (118).

7. The electrode assembly according to claim 6.

8. the fourth groove (116) is a through groove including a fourth left groove wall and a fourth right groove wall, and the sixth insulating adhesive layer (126) includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall, the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions in the fourth groove (116) and overlap at the groove bottom, or the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions at the groove bottom of the fourth groove (116) and spaced apart, and / or the sixth groove (118) is a through groove including a sixth left groove wall and a sixth right groove wall, and the eighth insulating adhesive layer (128) includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall, The eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions in the sixth groove (118) and overlap at the groove bottom, or the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions apart from each other at the groove bottom of the sixth groove (118).

8. The electrode assembly according to claim 7.

9. The central axes of the negative electrode tab groove (111), the first groove (112), the second groove (113), and the third groove (114) are collinear.

3. The electrode assembly according to claim 2.

10. The central axes of the positive electrode tab groove (115), the fourth groove (116), the fifth groove (117), and the sixth groove (118) are collinear.

7. The electrode assembly according to claim 6.

11. a positive electrode sheet (11) including a positive electrode current collector (101) and a positive electrode active material (105) attached to the positive electrode current collector (101), wherein a positive electrode tab groove (115) is formed in the positive electrode active material (105); a positive electrode tab (103) provided in the positive electrode tab groove (115); a separator (107) positioned between the positive electrode sheet (11) and the negative electrode sheet (12); and a negative electrode sheet (12) including a negative electrode current collector (102) and a negative electrode active material (106) attached to the negative electrode current collector (102), wherein a fourth groove (116) is formed in the negative electrode active material (106), the fourth groove (116) and the positive electrode tab groove (115) are provided opposite to each other on the surface of the separator (107), and the projection of the positive electrode tab groove (115) onto the negative electrode sheet includes the negative electrode sheet (12) located within the fourth groove (116); The electrode body is characterized by the above.

12. The positive electrode active material (105) further has a fifth groove (117), and the fifth groove (117) and the positive electrode tab groove (115) are symmetrically provided on both sides of the positive electrode current collector (101), A sixth groove (118) is formed in the negative electrode active material (106), the sixth groove (118) is disposed opposite to the fifth groove (117), and the projection of the fifth groove (117) onto the negative electrode sheet (12) is located within the sixth groove (118). The electrode assembly according to claim 11 .

13. The electrode body further includes a fifth insulating adhesive layer (125), a sixth insulating adhesive layer (126), a seventh insulating adhesive layer (127), and an eighth insulating adhesive layer (128), the fifth insulating adhesive layer (125) is adhered to the bottom of the positive electrode tab groove (115) and extends to the positive electrode active material (105) on the side of the positive electrode tab groove (115), or the fifth insulating adhesive layer (125) is adhered to the upper surface of the positive electrode tab groove (103) and extends to the positive electrode active material (105) on the side of the positive electrode tab groove (115); the sixth insulating adhesive layer (126) is adhered to the bottom of the fourth groove (116) and extends to the negative electrode active material (106) on the side of the fourth groove (116); the seventh insulating adhesive layer (127) is adhered to the bottom of the fifth groove (117) and extends to the positive electrode active material (105) on the side of the fifth groove (117); the eighth insulating adhesive layer (128) is adhered to the bottom of the sixth groove (118) and extends to the negative electrode active material (106) on the side of the sixth groove (118); The electrode assembly according to claim 12,

14. the fourth groove (116) is a through groove including a fourth left groove wall and a fourth right groove wall, and the sixth insulating adhesive layer (126) includes a sixth left insulating adhesive layer provided on the fourth left groove wall and a sixth right insulating adhesive layer provided on the fourth right groove wall, the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions on the groove bottom of the fourth groove (116) and overlap at the groove bottom, or the sixth left insulating adhesive layer and the sixth right insulating adhesive layer are arranged at opposing positions on the groove bottom of the fourth groove (116) and spaced apart, and / or the sixth groove (118) is a through groove including a sixth left groove wall and a sixth right groove wall, and the eighth insulating adhesive layer (128) includes an eighth left insulating adhesive layer provided on the sixth left groove wall and an eighth right insulating adhesive layer provided on the sixth right groove wall, The eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions on the bottom of the sixth groove (118) and overlap at the groove bottom, or the eighth left insulating adhesive layer and the eighth right insulating adhesive layer are arranged at opposing positions on the bottom of the sixth groove (118) but spaced apart.

14. The electrode assembly according to claim 13.

15. The electrode assembly according to any one of claims 1 to 14 is provided. A battery device characterized by:

16. 16. The battery device according to claim 15, further comprising a case, the electrode assembly being housed in the case.

17. A battery device according to claim 15 is provided. An electronic device characterized by:

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