Battery, electrode assembly, and method of manufacturing the same

Abstract

The application provides a battery, an electrode assembly and a preparation method thereof, and comprises a first pole piece, a second pole piece and a diaphragm between the first pole piece and the second pole piece; the first pole piece comprises a first current collector, a first active material layer and a first insulating layer; the first active material layer is arranged on a main surface of the first current collector and extends to a tab surface of the first current collector to form a thinned area of the first active material layer; the first insulating layer is pasted and covers an intersection area of a tab of the first current collector and the first active material layer and a corner area where a main body of the first current collector is connected with the tab through an adhesive; the second pole piece comprises a second current collector and a second active material layer, and the second active material layer is arranged on a main surface of the second current collector. The application forms the insulating layer through pasting after die cutting, the selection range of the insulating material is wider, the product reliability is high, the risk of short circuit in the battery cell is low, and different design requirements can be achieved by using different insulating materials in different areas.

Description

Technical Field

[0001] This invention relates to the field of batteries, and in particular to a battery, an electrode assembly, and a method for preparing the same. Background Technology

[0002] A battery is a device that converts chemical energy into electrical energy. It contains an electrolyte solution and metal electrodes, forming a cup, tank, or other container or composite container that generates an electric current. The main performance parameters of a battery include electromotive force, capacity, specific energy, and resistance. Using batteries as an energy source provides a stable voltage, stable current, long-term stable power supply, and minimal susceptibility to external influences. Furthermore, batteries are simple in structure, portable, easy to charge and discharge, unaffected by external climate and temperature, and offer stable and reliable performance, playing a significant role in various aspects of modern life.

[0003] In battery modules, the first and second electrodes are insulated from each other by a separator. During assembly, the tabs can easily be pressed between the first and second electrodes, causing a short circuit. Existing technologies use coating to form an insulating layer on the tabs of the first electrode to avoid this problem. However, the coating process requires the bonding of the insulating coating and the current collector / active material during current collector production. The insulating material needs to be mixed with a solvent to maintain its fluidity during coating, and the solvent needs to be removed after coating to leave the insulating material in a solid form. Considering the limitations of the fluidity of the insulating material coating and the limitations of the active material coating process, the range of insulating materials available is significantly narrowed. Furthermore, the coating process is usually completed before the tabs are die-cut, meaning that burrs generated during the die-cutting process are not effectively protected, and there is still a risk that burrs on the first electrode will puncture the separator and electrically connect with the second electrode, causing a short circuit.

[0004] Therefore, how to solve the short circuit problem between the first and second electrodes while expanding the range of insulating materials, improving insulation performance, enhancing product reliability, reducing costs and short circuit risks has become one of the technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a battery, an electrode assembly and a method for preparing the same, to solve the problems of limited selection of insulating materials, high cost and poor reliability in the prior art.

[0006] To achieve the above and other related objectives, the present invention provides an electrode assembly, the electrode assembly comprising at least:

[0007] A first electrode, a second electrode, and a diaphragm, wherein the diaphragm is disposed between the first electrode and the second electrode;

[0008] The first electrode includes a first current collector, a first active material layer, and a first insulating layer; the first active material layer is disposed on the surface of the main body of the first current collector and extends to the surface of the tab of the first current collector to form a thinned area of ​​the first active material layer; the first insulating layer is adhered to and covers the junction area between the tab of the first current collector and the first active material layer, as well as the corner area where the main body of the first current collector and the tab are connected, by an adhesive.

[0009] The second electrode includes a second current collector and a second active material layer, wherein the second active material layer is disposed on the main surface of the second current collector.

[0010] Optionally, the second active material layer further extends to the tab surface of the second current collector, and the upper end face of the second active material layer is located between the upper end face of the first insulating layer and the upper end face of the first active material layer.

[0011] Optionally, the lower end face of the thinned area is lower than the upper end face of the body of the first current collector.

[0012] Alternatively, the lower end face of the first insulating layer is located within the thinned area.

[0013] Alternatively, the maximum distance from the outer surface of the first insulating layer to the first current collector is not greater than the maximum distance from the outer surface of the first active material layer to the first current collector.

[0014] Optionally, the material of the first insulating layer is ceramic, PET, or PP.

[0015] Alternatively, the surface of the first insulating layer may also be covered with a protective layer, the hardness of which is greater than that of the first insulating layer.

[0016] Alternatively, the first electrode may further include a second insulating layer, which is adhered to and covers the upper edge region of the body of the first current collector by an adhesive.

[0017] Alternatively, the material of the second insulating layer is PET or PP.

[0018] Alternatively, the adhesive is PVDF.

[0019] To achieve the above and other related objectives, the present invention also provides a battery, the battery comprising at least:

[0020] Housing assembly, electrode terminal assembly, electrolyte, and the aforementioned electrode assembly;

[0021] The electrode terminal assembly and the housing assembly form a receiving cavity, the electrolyte and the electrode assembly are contained within the receiving cavity, and the electrode assembly is electrically connected to the electrode terminal assembly.

[0022] To achieve the above and other related objectives, the present invention also provides a method for preparing an electrode assembly, wherein the method for preparing the electrode assembly includes at least the following steps:

[0023] 1) An electrode plate is provided, the electrode plate comprising a first current collector and a first active material layer, the first current collector having a body and a tab;

[0024] 2) The first insulating layer is attached to the junction area between the tab and the first active material layer of the first current collector and the corner area where the body of the first current collector is connected to the tab using an adhesive to form the first electrode.

[0025] 3) Provide a second electrode, the second electrode comprising a second current collector and a second active material layer;

[0026] 4) The first electrode, the diaphragm, and the second electrode are stacked in sequence to form an electrode assembly.

[0027] Optionally, the method of forming the electrode plate includes:

[0028] 11) Coat the surface of the first foil with the first active material, dry the first active material to form the first active material layer, and roll the first active material layer;

[0029] 12) The structure prepared in step 11) is cut into several first electrode units, and the first electrode units are die-cut to form the main body and electrode tabs to obtain the electrode plate.

[0030] Optionally, the method for forming the second electrode includes:

[0031] 31) Coat the second active material on the surface of the second foil, dry the second active material to form the second active material layer, and roll the second active material layer;

[0032] 32) The structure prepared in step 31) is cut into several second electrode units, and the second electrode units are die-cut to form a main body and an electrode tab to obtain the second electrode.

[0033] Optionally, step 4) further includes the step of winding the stacked first electrode, the diaphragm and the second electrode.

[0034] Alternatively, step 2) further includes: using an adhesive to attach the second insulating layer to the upper edge region of the body of the first current collector.

[0035] Alternatively, step 2) further includes: forming a protective layer on the surface of the first insulating layer, wherein the hardness of the protective layer is greater than that of the first insulating layer.

[0036] As described above, the battery, electrode assembly, and preparation method of the present invention have the following beneficial effects:

[0037] 1. The battery, electrode assembly and its preparation method of the present invention form an insulating layer by pasting after die-cutting, which is separate from the production process of the electrode plate. It can only consider its own processability and ignore the impact on the manufacturing of the electrode assembly. The range of insulating materials is wider and better insulation effect can be achieved.

[0038] 2. The battery, electrode assembly and its preparation method of the present invention are bonded after die-cutting. Even if burrs are generated during the die-cutting process, the burrs can be isolated and protected by bonding the insulating layer, so as not to affect the separator in subsequent use, thereby improving the reliability of the product and reducing the risk of short circuit in the cell.

[0039] 3. The battery, electrode assembly and its preparation method of the present invention cover the first insulating material layer in the junction area between the tab and the first active material layer of the first current collector and the corner area where the body of the first current collector connects to the tab, and cover the second insulating material layer in the upper edge area of ​​the body of the first current collector. Different insulating materials are used in different areas to achieve different design requirements. At the same time, for the upper edge area of ​​the body of the first current collector with fewer burrs, a material with lower wear resistance can be used, thereby reducing costs. Attached Figure Description

[0040] Figure 1 The diagram shown is a structural schematic of the electrode assembly of the present invention.

[0041] Figure 2 The diagram shown is a structural schematic of the first current collector of the present invention.

[0042] Figure 3 The diagram shown is a structural schematic of the electrode plate of the present invention.

[0043] Figure 4 The diagram shown is a structural schematic of the first electrode plate of the present invention.

[0044] Figure 5 This is a schematic diagram of another structure of the first electrode plate of the present invention.

[0045] Figure 6 The diagram shows the relative positions of the components of the electrode assembly of the present invention.

[0046] Figure 7The diagram shown is another structural schematic of the first electrode plate of the present invention.

[0047] Figure 8 The diagram shown is a structural schematic of the second electrode plate of the present invention.

[0048] Component designation explanation

[0049] 1 Electrode assembly

[0050] 11 First Electrode

[0051] 111 First Current Collector

[0052] 111a The main body of the first current collector

[0053] 111b First current collector tab

[0054] 112 First active substance layer

[0055] 113 First Insulation Layer

[0056] 114 Second Insulation Layer

[0057] 12 Second pole piece

[0058] 121 Second Current Collector

[0059] 121a Main body of the second current collector

[0060] 121b The tab of the second current collector

[0061] 122 Second active substance layer

[0062] 13. Diaphragm Detailed Implementation

[0063] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0064] Please see Figures 1 to 8 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0065] Example 1

[0066] like Figure 1 As shown, the present invention provides an electrode assembly 1, the electrode assembly 1 comprising:

[0067] First electrode 11, second electrode 12 and diaphragm 13.

[0068] like Figure 1 As shown, the first electrode 11 includes a first current collector 111, a first active material layer 112, and a first insulating layer 113. The first active material layer 112 is disposed on the surface of the body 111a of the first current collector and extends to the surface of the tab 111b of the first current collector to form a thinned area of ​​the first active material layer 112. The first insulating layer 113 is adhered to and covers the interface area between the tab 111b of the first current collector and the first active material layer 112, as well as the corner area where the body 111a of the first current collector and the tab 111b are connected, by an adhesive.

[0069] Specifically, such as Figure 2 As shown, the first current collector 111 includes a body 111a and a tab 111b, with the tab 111b protruding from the body 111a. In this embodiment, the body 111a is rectangular, and the tab 111b is an isosceles trapezoid. The corner where the base of the tab 111b connects to the body 111a is connected by an R-angle. As an example, the first current collector 111 is made of aluminum foil. In actual use, the material of the first current collector 111 can be selected according to actual needs.

[0070] Specifically, such as Figure 1 and Figure 3 As shown, the first active material layer 112 is coated on the surface of the main body 111a of the first current collector. Due to the fluidity of the first active material, the first active material overflows towards the tab 111b of the first current collector and forms a thinned area of ​​the first active material layer 112 after curing; as Figure 1 As shown, within the thinning region, the thickness of the first active material layer 112 decreases sequentially along the direction from the body 111a of the first electrode sheet towards the tab 111b. In this embodiment, the lower end face of the thinning region is lower than the upper end face of the body 111a of the first current collector.

[0071] It should be noted that, in actual use, the lower end face of the thinning area can be higher than or flush with the upper end face of the body 111a of the first collector, and the area of ​​the thinning area can be set according to actual needs.

[0072] Specifically, such as Figure 4 and Figure 5As shown, the first insulating layer 113 wraps around the interface between the tab 111b of the first current collector and the first active material layer 112, and also wraps around the corner area where the body 111a of the first current collector connects to the tab 111b, thereby achieving insulation protection. Even if the tab is inserted between the first electrode 11 and the second electrode 12, it can prevent short circuits caused by the electrical connection between the first electrode 11 and the second electrode 12. As a first example, such as Figure 4 As shown, the first insulating layer 113 has a trapezoidal structure, including a top edge, a bottom edge, and two arc-shaped sides. The two arc-shaped sides are arranged at the corner where the body 111a of the first current collector connects to the tab 111b. The top edge of the first insulating layer 113 is lower than the upper end surface of the tab 111b of the first current collector and higher than the boundary between the tab 111b and the first active material layer 112. The bottom edge of the first insulating layer 113 is lower than the upper end surface of the body 111a of the first current collector. In this embodiment, the bottom edge (lower end surface) of the first insulating layer 113 is located within the thinned area. Figure 6 As shown, when the lower end face of the thinned area is lower than the upper end face of the body 111a of the first current collector, by controlling the thickness of the first insulating layer 113, the maximum distance t1 from the outer side of the first insulating layer 113 to the first current collector 111 can be no greater than the maximum distance t2 from the outer side of the first active material layer 112 to the first current collector 111, thereby not affecting the overall thickness of the first electrode 11. As a second example, such as Figure 5 As shown, based on the first example, the bottom edge of the first insulating layer 113 is divided into three sections. The middle section is lower than the boundary between the tab 111b of the first current collector and the first active material layer 112, and higher than the upper end face of the body 111a of the first current collector. Compared with the first example, the second example can reduce the amount of insulating material used and reduce costs.

[0073] It should be noted that if the lower end face of the thinned area is higher than or flush with the upper end face of the body 111a of the first current collector, in order to cover the aforementioned boundary area and corner area, the bottom edge (lower end face) of the first insulating layer 113 is lower than the lower end face of the thinned area. In this case, the overall thickness of the first electrode 11 increases. In actual use, it can be set as needed and is not limited to this embodiment.

[0074] Specifically, the material of the first insulating layer 113 includes, but is not limited to, ceramic, PET (polyethylene glycol terephthalate), or PP (polypropylene). Any material capable of electrically insulating the first electrode 11 and the second electrode 12 and being resistant to electrolyte is applicable, and is not limited to this embodiment. Furthermore, to prevent burrs from damaging the first insulating layer 113 and improve reliability, the surface of the first insulating layer 113 is also covered with a protective layer (not shown in the figure), the hardness of which is greater than that of the first insulating layer 113. As an example, when the material of the first insulating layer 113 is PET or PP, a ceramic layer is sprayed onto the surface of the PET or PP layer to improve burr puncture resistance. In practical use, when the material of the first insulating layer 113 is ceramic, a protective layer with a hardness greater than that of ceramic may not be sprayed (ceramic has sufficient burr puncture resistance), or a protective layer with a hardness greater than that of ceramic may be sprayed to further improve burr puncture resistance.

[0075] It should be noted that the materials of the protective layer and the first insulating layer 113 can be selected according to actual needs and are not limited to this embodiment.

[0076] As another implementation of the present invention, such as Figure 7 As shown, the first electrode 11 further includes a second insulating layer 114, which is attached to and covers the upper edge region of the body 111a of the first current collector by an adhesive, and is used to provide insulation protection for the upper edge region of the body 111a of the first current collector. Figure 7 The structure of the first insulating layer 113 shown in the first example is only illustrated here, but it also applies to the structure of the first insulating layer 113 shown in the second example, and will not be described in detail here. The material of the second insulating layer 114 includes, but is not limited to, ceramic, PET, or PP; any material that can electrically insulate the first electrode 11 and the second electrode 12 is applicable, and is not limited to this embodiment. The upper edge region of the body 111a of the first current collector has relatively few burrs. As an example, the material of the second insulating layer 114 is PET or PP, which has relatively poor wear resistance but relatively low cost; in actual use, materials with higher cost and better wear resistance can be used, and are not limited to this embodiment.

[0077] It should be noted that the materials of the first insulating layer 113 and the second insulating layer 114 can be the same or different. Furthermore, different insulating materials can be used in different areas to achieve different design requirements, which will not be elaborated upon here.

[0078] Specifically, the first insulating layer 113 and the second insulating layer 114 are adhered to their respective positions using an adhesive. The adhesive includes, but is not limited to, PVDF (polyvinylidene difluoride). Any material that can adhere the insulating layer to the first current collector and the first active material layer and is resistant to the electrolyte is applicable, and is not limited to this embodiment.

[0079] like Figure 1 As shown, the second electrode 12 includes a second current collector 121 and a second active material layer 122. The second active material layer 122 covers the surface of the body 121a of the second current collector.

[0080] Specifically, such as Figure 8 As shown, the second current collector 121 includes a main body 121a and a tab 121b, with the tab 121b protruding from the main body 121a. In this embodiment, the main body 121a is rectangular, and the tab 121b is an isosceles trapezoid. The corner where the base of the tab 121b connects to the main body 121a is connected by an R-angle. As an example, the second current collector 121 is made of copper foil. In actual use, the material of the second current collector 121 can be selected according to actual needs.

[0081] Specifically, such as Figure 1 and Figure 8 As shown, the second active material layer 122 is coated on the surface of the body 121a of the second current collector. Due to the fluidity of the second active material, the second active material will overflow to the tab 121b of the second current collector and form a thinned area of ​​the second active material layer 122 after curing.

[0082] Specifically, the upper surface of the second active material layer 122 is located between the upper surface of the first insulating layer 113 and the upper surface of the first active material layer 112. For example... Figure 6 As shown, the distance h1 from the upper end face of the first insulating layer 113 to the upper end face of the first active material layer 112 is greater than the distance h2 from the upper end face of the second active material layer 122 to the upper end face of the first active material layer 112.

[0083] like Figure 1 As shown, the diaphragm 13 is disposed between the first electrode 11 and the second electrode 12.

[0084] Specifically, in this embodiment, the upper surface of the diaphragm 13 is higher than the upper surfaces of the first active material layer 112 and the second active material layer 122.

[0085] It should be noted that, in order to more accurately show the positions of the first insulating layer 113 and the second insulating layer 114, in Figure 4 , Figure 5 and Figure 7 In this process, the first insulating layer 113 and the second insulating layer 114 are semi-transparent. In practical applications, the area covered by the first insulating layer 113 and the second insulating layer 114 cannot display the underlying structure.

[0086] The electrode assembly 1 of this invention can significantly reduce the probability of burrs puncturing the separator during the die-cutting process, thereby reducing the risk of internal short circuits in the battery and improving safety and reliability. Furthermore, by selectively bonding materials in critical areas, the utilization rate of materials can be maximized, thus minimizing costs.

[0087] Example 2

[0088] This embodiment provides a battery, which includes: an electrode assembly 1, a housing assembly, an electrode terminal assembly, and an electrolyte. The electrode terminal assembly and the housing assembly form a receiving cavity, and the electrolyte and the electrode assembly 1 are housed within the receiving cavity. The electrode assembly 1 is electrically connected to the electrode terminal assembly.

[0089] Specifically, the electrode assembly 1 adopts the structure of Embodiment 1, which will not be described in detail here.

[0090] Specifically, in this embodiment, the battery is a secondary battery, also known as a rechargeable battery or a storage battery, which refers to a battery that can be recharged after discharge to activate its active materials and continue to be used. In actual use, the battery can also be a dry cell battery, and is not limited to this embodiment.

[0091] It should be noted that any materials and structures that can constitute a battery are applicable to the casing assembly, electrode terminal assembly and electrolyte of the present invention, which will not be described in detail here.

[0092] Example 3

[0093] like Figures 3-5 , Figures 7-8 As shown, this embodiment provides a method for preparing an electrode assembly, used to prepare electrode assembly 1 of Embodiment 1. The method for preparing the electrode assembly includes:

[0094] 1) An electrode plate is provided, the electrode plate comprising a first current collector and a first active material layer, the first current collector having a body and a tab.

[0095] Specifically, such as Figure 3As shown, the electrode plate includes a first current collector 111 and a first active material layer 112. The first current collector 111 includes a body 111a and a tab 111b, with the tab 111b protruding from the body 111a. The first active material layer 112 is disposed on the surface of the body 111a of the first current collector and extends to the surface of the tab 111b to form a thinned region of the first active material layer 112.

[0096] Specifically, the electrode plate is a pre-existing structure and can also be fabricated. In this embodiment, the electrode plate is formed through fabrication, and the fabrication method is as follows:

[0097] 11) A first active material is coated onto the surface of a first foil, and the first active material is dried to form the first active substance layer. The first active substance layer is then rolled. For example, the first foil is aluminum foil, and the first active material is lithium manganese oxide or lithium iron phosphate. The first active material is melted in a solvent and then coated onto the surface of the first foil (with the thickness gradually decreasing at the edges). The solvent is evaporated by drying, and the solidified first active material is retained to form the first active substance layer 112. The first active substance layer 112 is then rolled to make it more compact.

[0098] 12) The structure prepared in step 11) is slit to obtain several first electrode units. The first electrode units are then die-cut to form a main body and electrode tabs to obtain the electrode plate. The first foil is slit to obtain several first electrode units of the same size as the electrode. The first electrode units are then die-cut to obtain the main body region and electrode tab region.

[0099] 2) The first insulating layer 113 is attached to the junction area between the tab 111b of the first current collector and the first active material layer 112, and the corner area where the body 111a of the first current collector is connected to the tab 111b, to form the first electrode 11.

[0100] Specifically, such as Figure 4 or Figure 5 As shown, the first insulating layer 113 is attached to the junction area between the tab 111b of the first current collector and the first active material layer 112, and to the corner area where the body 111a of the first current collector connects to the tab 111b.

[0101] Specifically, as another implementation of the present invention, step 2) further includes: forming a protective layer on the surface of the first insulating layer 113, wherein the hardness of the protective layer is greater than that of the first insulating layer 113, thereby improving the resistance to burr penetration.

[0102] Specifically, as another implementation of the present invention, such as Figure 7 As shown, step 2) further includes: using an adhesive to attach the second insulating layer 114 to the upper edge region of the body 11a of the first current collector.

[0103] 3) Provide a second electrode 12, the second electrode 12 including a second current collector 121 and a second active material layer 122.

[0104] Specifically, such as Figure 8 As shown, the second electrode 12 includes a second current collector 121 and a second active material layer 122. The second current collector 122 includes a body 121a and a tab 121b, with the tab 121b protruding from the body 121a. The second active material layer 122 is disposed on the surface of the body 121a of the second current collector. In this embodiment, the second active material layer 122 further extends to the surface of the tab 121b of the second current collector to form a thinned region of the second active material layer 122.

[0105] Specifically, the second electrode 12 is a pre-existing structure and can also be fabricated. In this embodiment, the second electrode 12 is formed by fabrication, and the fabrication method is as follows:

[0106] 31) A second active material is coated onto the surface of the second foil, and the second active material is dried to form the second active material layer. The second active material layer is then rolled. For example, the second foil is a copper foil, and the second active material is graphite. The second active material is melted in a solvent and then coated onto the surface of the second foil (with the thickness gradually decreasing at the edges). The solvent is evaporated by drying, and the solidified second active material is retained to form the second active material layer 122. The second active material layer 122 is then rolled to make it more compact.

[0107] 32) The structure prepared in step 31) is slit to obtain several second electrode units. The second electrode units are then die-cut to form a main body and an electrode tab, thus obtaining the second electrode 12. The second foil is slit to obtain several second electrode units of the same size as the electrode, and then the second electrode units are die-cut to obtain the main body region and the electrode tab region.

[0108] It should be noted that any method capable of preparing the electrode plate and the second electrode 12 is applicable to the present invention and is not limited to this embodiment. The order in which the first electrode 11 and the second electrode 12 are obtained is not limited. The step numbers in the present invention are only used to distinguish each step and there is no absolute order.

[0109] 4) The first electrode 11, the diaphragm 13 and the second electrode 12 are stacked in sequence to form the electrode assembly 1.

[0110] Specifically, as an example, the electrode assembly 1 is obtained by stacking the first electrode 11, the diaphragm 13, and the second electrode 12, and the electrode assembly 1 is a stacked structure. As another example, step 4) further includes: after completing the stacking, winding the stacked first electrode 11, diaphragm 13, and second electrode 12 to make the electrode assembly 1 a wound structure. The cross-section of the electrode assembly 1 includes, but is not limited to, an ellipse, which will not be described in detail here.

[0111] This invention forms an insulating layer by bonding after die-cutting, detaching it from the electrode plate production process. This allows for consideration of its own processability while ignoring its impact on electrode assembly manufacturing. It also allows for a wider range of insulating material choices, achieving better insulation performance. Because the bonding process occurs after die-cutting, even if burrs are generated during the die-cutting process, the bonding insulating layer can isolate and protect them, preventing them from affecting the separator during subsequent use. This improves product reliability and reduces the risk of internal short circuits within the cell. Furthermore, a first insulating material layer is applied to the interface between the tab and the first active material layer of the first current collector, as well as the corner area where the body of the first current collector connects to the tab. A second insulating material layer is applied to the upper edge area of ​​the body of the first current collector. Different insulating materials are used in different areas to meet different design requirements. Additionally, for the upper edge area of ​​the body of the first current collector with fewer burrs, a material with lower wear resistance can be used, thereby reducing costs.

[0112] In summary, the present invention provides a battery, an electrode assembly, and a method for preparing the same, comprising: a first electrode, a second electrode, and a separator, wherein the separator is disposed between the first electrode and the second electrode; wherein the first electrode comprises a first current collector, a first active material layer, and a first insulating layer; the first active material layer is disposed on the surface of the main body of the first current collector and extends to the surface of the tab of the first current collector to form a thinned area of ​​the first active material layer; the first insulating layer is adhered to and covers the junction area between the tab of the first current collector and the first active material layer, and the corner area where the main body of the first current collector connects to the tab, by an adhesive; the second electrode comprises a second current collector and a second active material layer, wherein the second active material layer is disposed on the surface of the main body of the second current collector. This invention forms an insulating layer by bonding after die-cutting, allowing for consideration of its own processability while ignoring its impact on electrode assembly manufacturing. This also broadens the range of insulating materials that can be selected. Furthermore, the bonding process after die-cutting isolates and protects burrs even if they are generated during the die-cutting process, preventing them from affecting the separator during subsequent use. This improves product reliability and reduces the risk of internal short circuits within the cell. Different insulating materials can be used in different areas to meet varying design requirements. Additionally, a material with lower wear resistance can be used on the upper edge of the first current collector body, where burrs are less prevalent, further reducing costs. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and possesses high industrial applicability.

[0113] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An electrode assembly, characterized in that: The electrode assembly includes at least: A first electrode, a second electrode, and a diaphragm, wherein the diaphragm is disposed between the first electrode and the second electrode; The first electrode includes a first current collector, a first active material layer, and a first insulating layer. The first active material layer is disposed on the surface of the main body of the first current collector and extends to the surface of the tab of the first current collector to form a thinned area of ​​the first active material layer. The first insulating layer is adhered to and covers the junction area between the tab of the first current collector and the first active material layer, as well as the corner area where the main body of the first current collector connects to the tab, by an adhesive. The lower end face of the first insulating layer is located within the thinned area. The second electrode includes a second current collector and a second active material layer, wherein the second active material layer is disposed on the main surface of the second current collector.

2. The electrode assembly according to claim 1, characterized in that: The second active material layer also extends to the tab surface of the second current collector, and the upper end face of the second active material layer is located between the upper end face of the first insulating layer and the upper end face of the first active material layer.

3. The electrode assembly according to claim 1, characterized in that: The lower end face of the thinned area is lower than the upper end face of the main body of the first current collector.

4. The electrode assembly according to claim 3, characterized in that: The maximum distance from the outer surface of the first insulating layer to the first current collector is not greater than the maximum distance from the outer surface of the first active material layer to the first current collector.

5. The electrode assembly according to any one of claims 1-4, characterized in that: The first electrode also includes a second insulating layer, which is adhered to and covers the upper edge region of the body of the first current collector by an adhesive.

6. A battery, characterized in that, The battery includes at least: The housing assembly, the electrode terminal assembly, the electrolyte, and the electrode assembly as described in any one of claims 1-5; The electrode terminal assembly and the housing assembly form a receiving cavity, the electrolyte and the electrode assembly are contained within the receiving cavity, and the electrode assembly is electrically connected to the electrode terminal assembly.

7. A method for preparing an electrode assembly, used to prepare the electrode assembly as described in any one of claims 1-5, characterized in that, The method for preparing the electrode assembly includes at least the following: 1) An electrode plate is provided, the electrode plate comprising a first current collector and a first active material layer, the first current collector having a body and tabs; 2) The first insulating layer is attached to the junction area between the tab and the first active material layer of the first current collector and the corner area where the body of the first current collector is connected to the tab using an adhesive to form the first electrode. 3) A second electrode is provided, the second electrode comprising a second current collector and a second active material layer; 4) The first electrode, the diaphragm and the second electrode are stacked in sequence to form an electrode assembly.

8. The method for preparing the electrode assembly according to claim 7, characterized in that: Step 2) further includes: using an adhesive to attach the second insulating layer to the upper edge region of the body of the first current collector.

9. The method for preparing the electrode assembly according to claim 7 or 8, characterized in that: Step 2) further includes: forming a protective layer on the surface of the first insulating layer, wherein the hardness of the protective layer is greater than that of the first insulating layer.

Images