Pole piece structure, battery cell and battery

Abstract

This application discloses an electrode structure, a battery cell, and a battery. The electrode structure includes a current collector, a first coating layer, and a second coating layer. Along the thickness direction of the current collector, the first coating layer is disposed on at least one side of the current collector; and along the thickness direction of the current collector, the second coating layer and the first coating layer are located on the same side. Along the width direction of the current collector, the second coating layer is disposed on at least one side of the first coating layer. The static voltage of the second coating layer is lower than the static voltage of the first coating layer. In the electrode structure of this application embodiment, the static voltage of the second coating layer is lower than the static voltage of the first coating layer, thus reducing the oxidation potential at the interface between the active material and the tab, reducing the oxidation potential at the interface between the active material and the tab (enriched electrolyte), thereby greatly reducing the corrosion reaction rate, reducing the risk of corrosion fracture at the interface between the positive electrode active material and the tab, and improving the cycle performance of the battery.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to an electrode structure, a cell, and a battery. Background Technology

[0002] During the charging and discharging process, due to the change in electrode thickness, the electrolyte tends to accumulate at the junction of the tab and the active material. Since there is usually trace amount of water inside the battery, it reacts with the electrolyte to produce hydrofluoric acid, which preferentially corrodes at the junction of the positive electrode active material and the tab, affecting the battery's performance. Summary of the Invention

[0003] This application provides an electrode structure, a battery cell, and a battery to at least partially solve the above-mentioned technical problems.

[0004] To achieve the above objectives, according to a first aspect of this application, an electrode structure is provided, comprising: current collector; A first coating layer, along the thickness direction of the current collector, is disposed on at least one side of the current collector; and, The second coating layer is located on the same side as the first coating layer along the thickness direction of the current collector; the second coating layer is provided on at least one side of the first coating layer along the width direction of the current collector, and the first coating layer and the second coating layer are adjacent to each other. The static voltage of the second coating layer is less than that of the first coating layer.

[0005] In some embodiments, the difference between the static voltage of the second coating layer and the static voltage of the first coating layer is greater than or equal to 0.2V and less than or equal to 1V.

[0006] This avoids excessively large differences in static voltage at the interface between the first and second coating layers, resulting in a more uniform potential distribution across the entire electrode structure. This helps reduce the risk of local overcharging / over-discharging and thus improves cycle life.

[0007] Furthermore, by setting the difference in static voltage at the junction between the first coating layer and the second coating layer within 1V, it is possible to reduce local high current density and heat generation on the electrode structure, thereby avoiding mechanical damage to the current collector caused by thermal expansion.

[0008] In some embodiments, the first coating layer is provided on both opposite sides of the current collector along the thickness direction.

[0009] This allows the current collector to hold more active material in the same volume, and the double-sided coating structure makes the heating of the electrode structure more uniform, reducing the risk of thermal runaway.

[0010] In some embodiments, a second coating layer is provided on both sides of each first coating layer along the width direction of the current collector.

[0011] Thus, by setting a second coating layer on both sides of the first coating layer, and because the static voltage of the second coating layer is lower than that of the first coating layer, the oxidation potential at the interface between the active material layers can be reduced more effectively, greatly reducing the rate of corrosion reaction and thus reducing the risk of corrosion fracture at the interface between the active material and the tab.

[0012] In some embodiments, the thickness of one layer of the first coating layer is the same as the thickness of one layer of the second coating layer.

[0013] In this way, the height difference between the first coating layer and the second coating layer can be avoided, resulting in a smoother and flatter surface of the electrode structure, a more uniform current distribution within the electrode plane, and prevention of local overcharging / over-discharging.

[0014] Furthermore, the absence of a height difference between the first coating layer and the second coating layer can reduce the phenomenon of delamination or peeling between the first coating layer and the second coating layer, thereby improving the flexibility of the electrode sheet.

[0015] In some embodiments, the thickness of one layer of the first coating layer or one layer of the second coating layer is greater than and / or equal to 20 μm and less than or equal to 150 μm.

[0016] Thus, through the above settings, the thickness of the active coating area of ​​the electrode structure is moderate, thereby improving the heat dissipation performance of the electrode structure and reducing the risk of thermal runaway of the battery.

[0017] Furthermore, through the above configuration, the electrode structure can ensure performance while also increasing the load of active materials and improving the energy density of the battery structure.

[0018] In this embodiment, the thickness of the first coating layer or the second coating layer is 25 μm.

[0019] However, this design is not limited to this. In other embodiments, the thickness of the first coating layer or the second coating layer can be any one or any two of the following: 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, and 130 μm.

[0020] It should also be noted that, in this embodiment, the compaction of the first coating layer is 3.15 g / cm³. 3 The coating weight is 71g / m². 2 The thickness is 25µm, and the compaction of the second coating layer is 2.2g / cm. 3 The coating weight is 55g / m². 2 The thickness is 25um; and the first coating layer and the second coating layer have the same coating thickness after cold pressing.

[0021] In some embodiments, the width of each of the second coating layers is greater than or equal to 3 mm and less than or equal to 15 mm.

[0022] This avoids the second coating layer being too narrow, preventing trace amounts of moisture inside the battery from flowing to the junction of the first and second coating layers. This ensures that the oxidation potential at the interface between the current collector and the active material layer is reduced, thereby reducing the risk of corrosion and breakage at the interface between the active material and the tab.

[0023] This also prevents the second coating layer from being too wide, thus ensuring that the area of ​​the first coating layer is sufficient, thereby ensuring the energy density of the battery.

[0024] Specifically, in this embodiment, the width of each second coating layer is 5 mm.

[0025] However, this design is not limited to this. In other embodiments, the width of the second coating layer can be any one or any two of the following: 3 mm, 4 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, and 15 mm.

[0026] In some embodiments, the first coating layer is one of a ternary lithium layer, a lithium cobalt oxide layer, a lithium manganese oxide layer, and a lithium manganese iron phosphate layer; and / or, the second coating layer is one of a lithium iron phosphate layer and a lithium manganese iron phosphate layer.

[0027] Specifically, in this embodiment, the first coating layer is a ternary lithium layer, and the second coating layer is a lithium iron phosphate layer. Thus, the static voltage of the ternary lithium layer is between 4.3V and 4.4V, and the static voltage of the lithium iron phosphate layer is 3.55V.

[0028] This reduces the oxidation potential at the interface between the active material and the tab (where the electrolyte is enriched) from 4.3V~4.4V to 3.55V, thereby effectively reducing the rate of corrosion reaction in the battery and thus reducing the risk of corrosion and breakage at the interface between the positive electrode active material and the tab.

[0029] However, this design is not limited to this. In other embodiments, the first coating layer may also be lithium cobalt oxide, lithium manganese oxide, or lithium manganese iron phosphate.

[0030] In some embodiments, the static voltage of the first coating layer is greater than or equal to 4.2V and less than or equal to 4.5V; and / or, the static voltage of the second coating layer is less than or equal to 4.2V.

[0031] It should be noted that in this application, "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the related objects before and after it are in an "or" relationship.

[0032] Therefore, by adopting the electrode structure in this embodiment, since a second coating layer is provided in the edge region of the first coating layer, and the static voltage of the second coating layer is less than that of the first coating layer, the oxidation potential at the junction of the active material and the tab can be reduced, and the oxidation potential at the junction of the active material and the tab (enriched electrolyte) can be reduced, thereby greatly reducing the corrosion reaction rate, reducing the risk of corrosion fracture at the junction of the positive electrode active material and the tab, and improving the cycle performance of the battery.

[0033] According to a second aspect of this application, a battery cell is provided, which includes the electrode structure described above.

[0034] According to a third aspect of this application, a battery is provided, comprising a housing and the aforementioned battery cell, wherein the housing has a receiving cavity; and the battery cell is disposed in the receiving cavity.

[0035] In the electrode structure of this application embodiment, since a second coating layer is provided on one side of the first coating layer, when moisture remains at the junction between the edge of the active material layer (i.e., the first coating layer and the second coating layer) and the current collector, the static voltage of the second coating layer is less than that of the first coating layer, thereby making the difference in static voltage between the second coating layer and the current collector smaller. This reduces the oxidation potential at the junction between the edge of the current collector and the second coating layer, greatly reducing the rate of corrosion reaction and thus reducing the risk of corrosion and breakage at the junction of the active material and the electrode tab. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0038] Figure 1 This is a top view of a first structure of the electrode structure provided in an exemplary embodiment of this disclosure; Figure 2 This is a top view of a second structure of the electrode structure provided in an exemplary embodiment of this disclosure; Figure 3 This is a cross-sectional view of a second structure of the electrode structure provided in the exemplary embodiments of this disclosure; Figure 4 This is a top view of a conventional electrode structure; Figure 5 This is a cross-sectional view of a conventional electrode structure; Figure 6 This is a graph showing the ratio of the number of cycles to capacity retention in the electrode structure provided in the exemplary embodiments of this disclosure to that in a conventional electrode structure. Figure 7 This is a graph showing the ratio of the number of cycles to the DC resistance growth rate in the electrode structure provided in the exemplary embodiments of this disclosure to that in a conventional electrode structure. Figure 8 This is a disassembled diagram of the electrode structure provided in an exemplary embodiment of this disclosure; Figure 9 This is a disassembled diagram of a conventional electrode structure.

[0039] Explanation of reference numerals in the attached figures: 1. Electrode structure; 11. Current collector; 12. First coating layer; 13. Second coating layer. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0041] The following will explain the solution of this application with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0042] During the charging and discharging process of ternary lithium-ion batteries, due to the change in electrode thickness, the electrolyte distribution within the core exhibits a certain breathing effect. It tends to accumulate more easily at the interface between the tab and the active material. Since there are usually trace amounts of moisture inside the battery, it reacts with the electrolyte to produce hydrofluoric acid. Hydrofluoric acid will corrode the aluminum foil substrate of the positive electrode. Actual disassembly will reveal that the corrosion reaction occurs preferentially at the interface between the positive electrode active material and the tab, which can easily lead to corrosion and breakage at the interface, affecting the battery's lifespan.

[0043] This application provides an electrode structure 1, a battery cell, and a battery. Please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic diagram of the electrode structure 1 provided in an embodiment of this application.

[0044] An electrode structure 1 includes a current collector 11, a first coating layer 12, and a second coating layer 13. The first coating layer 12 is disposed on at least one side of the current collector 11 along the thickness direction of the current collector 11. The second coating layer 13 is located on the same side as the first coating layer along the thickness direction of the current collector 11. The second coating layer 13 is disposed on at least one side of the first coating layer 12 along the width direction of the current collector 11, and the first coating layer 12 and the second coating layer 13 are adjacent to each other. The static voltage of the second coating layer 13 is less than the static voltage of the first coating layer 12.

[0045] In the electrode structure 1 of this application embodiment, since a second coating layer 13 is provided on one side of the first coating layer 12, when moisture remains at the junction between the edge of the active material layer (i.e., the first coating layer 12 and the second coating layer 13) and the current collector 11, the static voltage of the second coating layer 13 is less than that of the first coating layer 12, thereby making the difference in static voltage between the second coating layer 13 and the current collector 11 smaller. This reduces the oxidation potential at the junction between the edge of the current collector 11 and the second coating layer 13, greatly reducing the rate of corrosion reaction and thus reducing the risk of corrosion and breakage at the junction of the active material and the electrode tab.

[0046] It should also be noted that since the first coating layer 12 and the second coating layer 13 are adjacent, moisture can be prevented from remaining in the gap between the first coating layer 12 and the second coating layer 13, thereby ensuring that the oxidation potential at the junction between the current collector 11 and the edge of the second coating layer 13 is reduced and the corrosion rate of the battery is slowed down.

[0047] In some embodiments, the difference between the static voltage of the second coating layer 13 and the static voltage of the first coating layer 12 is greater than or equal to 0.2V and less than or equal to 1V.

[0048] In this way, the difference in static voltage at the junction between the first coating layer 12 and the second coating layer 13 can be avoided, thereby making the potential distribution of the entire electrode structure 1 more uniform, which helps to reduce the risk of local overcharging / over-discharging and thus improve cycle life.

[0049] Furthermore, by setting the difference in static voltage at the junction between the first coating layer 12 and the second coating layer 13 within 1V, it is possible to reduce local high current density and heat generation on the electrode structure 1, thereby avoiding mechanical damage to the current collector 11 caused by thermal expansion.

[0050] In some embodiments, refer to Figure 2 and Figure 3 As shown, along the thickness direction of the current collector 11, the two opposite sides of the current collector 11 are provided with a first coating layer 12.

[0051] In this way, the current collector 11 can be loaded with more active material in the same volume, and the double-sided coating structure can make the heating of the electrode structure 1 more uniform and reduce the risk of thermal runaway.

[0052] In some embodiments, a second coating layer 13 is provided on both sides of each first coating layer 12 along the width direction of the current collector 11.

[0053] Thus, by providing second coating layers 13 on both sides of the first coating layer 12, and because the static voltage of the second coating layer 13 is lower than that of the first coating layer 12, the oxidation potential at the interface between the active material layers can be reduced more effectively, greatly reducing the rate of corrosion reaction and thus reducing the risk of corrosion fracture at the interface between the active material and the tab.

[0054] In some embodiments, the thickness of a first coating layer 12 is the same as the thickness of a second coating layer 13.

[0055] In this way, the height difference between the first coating layer 12 and the second coating layer 13 can be avoided, thereby making the surface of the electrode structure 1 smoother and making the current more evenly distributed in the electrode plane, avoiding local overcharging / over-discharging.

[0056] Furthermore, the absence of a height difference between the first coating layer 12 and the second coating layer 13 can reduce the phenomenon of delamination or peeling between the first coating layer 12 and the second coating layer 13, thereby improving the flexibility of the electrode sheet.

[0057] In some embodiments, the thickness of a first coating layer 12 or a second coating layer 13 is greater than and / or equal to 20 μm and less than or equal to 150 μm.

[0058] Thus, through the above settings, the thickness of the active coating area of ​​the electrode structure 1 is moderate, thereby improving the heat dissipation performance of the electrode structure 1 and reducing the risk of thermal runaway of the battery.

[0059] Furthermore, through the above configuration, the electrode structure 1 can ensure performance while also increasing the load of sufficient active material and improving the energy density of the battery structure.

[0060] In this embodiment, the thickness of the first coating layer 12 or the second coating layer 13 is 25 μm.

[0061] However, this design is not limited to this. In other embodiments, the thickness of the first coating layer 12 or the second coating layer 13 can be any one or any two of the following: 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, and 130 μm.

[0062] It should also be noted that, in this embodiment, the compaction of the first coating layer 12 is 3.15 g / cm³.3 The coating weight is 71g / m². 2 The thickness is 25 μm, and the compaction of the second coating layer 13 is 2.2 g / cm³. 3 The coating weight is 55g / m². 2 The thickness is 25um; and the first coating layer 12 and the second coating layer 13 have the same coating thickness after cold pressing.

[0063] In some embodiments, the width of each second coating layer 13 is greater than or equal to 3 mm and less than or equal to 15 mm.

[0064] In this way, the width of the second coating layer 13 is avoided from being too small, preventing trace amounts of moisture inside the battery from flowing to the junction of the first coating layer 12 and the second coating layer 13. This ensures that the oxidation potential at the junction between the current collector 11 and the active material layer can be reduced, thereby reducing the risk of corrosion and breakage at the junction of the active material and the tab.

[0065] In this way, the width of the second coating layer 13 can be avoided from being too large, thereby ensuring that the area of ​​the first coating layer 12 is sufficient, and thus ensuring the energy density of the battery.

[0066] Specifically, in this embodiment, the width of each second coating layer 13 is 5 mm.

[0067] However, this design is not limited to this. In other embodiments, the width of the second coating layer 13 can be any one or any two of the following: 3mm, 4mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, and 15mm.

[0068] In some embodiments, the first coating layer 12 is one of a ternary lithium layer, a lithium cobalt oxide layer, a lithium manganese oxide layer, and a lithium manganese iron phosphate layer; and / or, the second coating layer 13 is one of a lithium iron phosphate layer and a lithium manganese iron phosphate layer.

[0069] Specifically, in this embodiment, the first coating layer 12 is a ternary lithium layer, and the second coating layer 13 is a lithium iron phosphate layer. Thus, the static voltage of the first coating layer 12 is between 4.3V and 4.4V, and the static voltage of the lithium iron phosphate layer is 3.55V.

[0070] This reduces the oxidation potential at the interface between the active material and the tab (where the electrolyte is enriched) from 4.3V~4.4V to 3.55V, thereby effectively reducing the rate of corrosion reaction in the battery and thus reducing the risk of corrosion and breakage at the interface between the positive electrode active material and the tab.

[0071] However, this design is not limited to this. In other embodiments, the first coating layer 12 may also be lithium cobalt oxide, lithium manganese oxide, or lithium manganese iron phosphate.

[0072] It should also be noted that when the second coating layer 13 uses lithium manganese iron phosphate, the first coating layer 12 uses ternary lithium. That is, in order to ensure that the first coating layer 12 and the second coating layer 13 have a potential difference, the first coating layer 12 and the second coating layer 13 will not use lithium manganese iron phosphate material at the same time.

[0073] In some embodiments, the static voltage of the first coating layer 12 is greater than or equal to 4.2V and less than or equal to 4.4V; and / or, the static voltage of the second coating layer 13 is greater than or equal to 3.55V and less than 4.2V.

[0074] The static voltage comparison of the above materials is shown in the table below:

[0075] It should be noted that in this application, "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the related objects before and after it are in an "or" relationship.

[0076] To verify the improvement of battery performance by the electrode structure 1 in this embodiment, a comparative experiment was conducted between the electrode structure 1 in this embodiment and the conventional electrode structure 1. After both electrode structures 1 and conventional electrode structures 1 were fabricated into batteries, their cycle performance was tested. The number of cycles to 80% capacity retention and the degree of battery corrosion were compared. Figure 2 and Figure 3 This is a schematic diagram of electrode structure 1 in this experiment. Figure 4 and Figure 5 This is a schematic diagram of a conventional electrode structure 1; The experimental results are as follows: (Refer to...) Figure 6 As shown, when the battery cycle count is approximately 1000, the capacity retention rates of electrode structure 1 (i.e., the experimental group) and conventional electrode structure 1 (i.e., the control group) in this embodiment are not significantly different. However, when the battery cycle count is approximately 2000, the battery capacity retention rate of conventional electrode structure 1 has decreased to below 80%, while the battery capacity retention rate of electrode structure 1 in this embodiment remains above 85%. When the battery cycle count is approximately 4000, the battery capacity retention rate of electrode structure 1 in this embodiment only decreases to 80%. It can be seen that under the same conditions, the performance of electrode structure 1 in this embodiment is significantly improved, with more battery cycle counts and a longer lifespan.

[0077] Furthermore, referring to Figure 7As shown, when the battery cycle count is approximately 1000, the DC resistance growth rate of electrode structure 1 in this embodiment (i.e., the experimental group) and conventional electrode structure 1 (i.e., the control group) is not significantly different. However, when the battery cycle count is approximately 2000, the DC resistance growth rate of conventional electrode structure 1 has increased to over 20%, while the DC resistance growth rate of electrode structure 1 in this embodiment remains below 10%. When the battery cycle count is approximately 4000, the DC resistance growth rate of electrode structure 1 in this embodiment only increases to over 20%. It can be seen that under the same conditions, the performance of electrode structure 1 in this embodiment is significantly improved, resulting in more battery cycle counts and a longer lifespan.

[0078] At the same time, refer to Figure 8 and Figure 9 As shown, the two batteries were disassembled after the test. After disassembly, there was no obvious corrosion at the interface between the active material and the current collector 11 in the electrode structure 1 (i.e., the experimental group) in this embodiment, which indicates that the corrosion phenomenon has been significantly improved. However, there was obvious corrosion at the interface between the active material and the current collector 11 in the conventional electrode structure 1 (i.e., the control group), and the battery performance was greatly reduced.

[0079] Therefore, by adopting the electrode structure 1 in this embodiment, since a second coating layer 13 is provided in the edge region of the first coating layer 12, and the static voltage of the second coating layer 13 is less than that of the first coating layer 12, the oxidation potential at the junction of the active material and the tab can be reduced, and the oxidation potential at the junction of the active material and the tab (enriched electrolyte) can be reduced, thereby greatly reducing the corrosion reaction rate, reducing the risk of corrosion fracture at the junction of the positive electrode active material and the tab, and improving the cycle performance of the battery.

[0080] According to a second aspect of this application, a battery cell is provided, which includes the electrode structure 1 described above.

[0081] The cell has all the beneficial effects of the aforementioned electrode structure 1, which will not be repeated here.

[0082] According to a third aspect of this application, a battery is provided, which includes a housing and the aforementioned battery cell, wherein the housing has a receiving cavity; and the battery cell is disposed in the receiving cavity.

[0083] The battery possesses all the beneficial effects of the aforementioned battery cell, which will not be elaborated upon here.

[0084] The battery may include an outer packaging. This outer packaging is used to encapsulate the positive electrode, the negative electrode, and the electrolyte.

[0085] The outer packaging of the battery can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell; the outer packaging of the battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0086] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a battery case for encapsulating one or more battery cells. The battery case can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0087] The battery cell mentioned in the embodiments of this application may include an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The battery cell mainly relies on the movement of metal ions between the positive and negative electrode to operate. The positive electrode includes a positive current collector 11 and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector 11. The positive current collector 11 includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area. The positive electrode coating area is coated with the positive active material layer, while the positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery cell as an example, the material of the positive current collector 11 can be aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector 11 and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector 11. The negative electrode current collector 11 includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area. The negative electrode coating area is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector 11 can be copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0088] Currently, batteries are being used more and more widely. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of batteries continue to expand, the market demand for them is also constantly increasing.

[0089] The battery described in the embodiments of this application is used in electrical devices.

[0090] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0091] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0092] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery is installed inside the vehicle, which can be located at the bottom, front, or rear of the vehicle. The battery can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller is used to control the battery's power supply to the motor, for example, to meet the vehicle's power needs during starting, navigation, and driving.

[0093] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0094] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0095] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0096] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An electrode structure, characterized in that, include: Current collector(11); A first coating layer (12) is disposed on at least one side of the current collector (11) along the thickness direction of the current collector (11); and, The second coating layer (13) is located on the same side as the first coating layer along the thickness direction of the current collector (11); the first coating layer (12) is provided with the second coating layer (13) on at least one side along the width direction of the current collector (11), and the first coating layer (12) and the second coating layer (13) are adjacent to each other. The static voltage of the second coating layer (13) is less than that of the first coating layer (12).

2. The electrode structure according to claim 1, characterized in that, The difference between the static voltage of the second coating layer (13) and the static voltage of the first coating layer (12) is greater than or equal to 0.2V and less than or equal to 1V.

3. The electrode structure according to claim 1, characterized in that, Along the thickness direction of the current collector (11), the first coating layer (12) is provided on both opposite sides of the current collector (11).

4. The electrode structure according to claim 3, characterized in that, Along the width direction of the current collector (11), a second coating layer (13) is provided on both sides of each of the first coating layers (12).

5. The electrode structure according to any one of claims 1-4, characterized in that, The thickness of the first coating layer (12) is the same as the thickness of the second coating layer (13).

6. The electrode structure according to any one of claims 1-4, characterized in that, The thickness of one layer of the first coating layer (12) and / or one layer of the second coating layer (13) is greater than or equal to 20 μm and less than or equal to 150 μm.

7. The electrode structure according to any one of claims 1-4, characterized in that, The width of each second coating layer (13) is greater than or equal to 3 mm and less than or equal to 15 mm.

8. The electrode structure according to any one of claims 1-4, characterized in that, The first coating layer (12) is one of a ternary lithium layer, a lithium cobalt oxide layer, a lithium manganese oxide layer, and a lithium manganese iron phosphate layer; and / or, The second coating layer (13) is one of lithium iron phosphate layer and lithium manganese iron phosphate layer.

9. The electrode structure according to any one of claims 1-4, characterized in that, The static voltage of the first coating layer (12) is greater than or equal to 4.2V and less than or equal to 4.5V; and / or the static voltage of the second coating layer (13) is less than or equal to 4.2V.

10. A battery cell, characterized in that, Includes the electrode structure (1) as described in any one of claims 1-9.

11. A battery, characterized in that, include: A housing, the housing having a receiving cavity; and, The battery cell as claimed in claim 10, wherein the battery cell is disposed in the accommodating cavity.

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