Electrode plates and their manufacturing methods, secondary batteries, battery modules, battery packs, and power consumption devices

Abstract

The present application provides an electrode plate (6) and a manufacturing method thereof, a secondary battery (5), a battery module (4), a battery pack (1), and a power consuming device, the electrode plate (6) comprising a current collector (61) and an active material layer (62) provided on at least one surface of the current collector (61), the active material layer (62) comprising an active main material and a porous material, the active material layer (62) having pores (63) which may or may not penetrate the active material layer (62), a thickness of the active material layer (62) being x, a distance between ports at both ends of the pores (63) in a direction perpendicular to the active material layer (62) being y, and x and y satisfying the condition 0.1x≦y≦x.

Description

[Technical Field]

[0001] This application relates to the field of secondary batteries, and more specifically to electrode plates and methods for manufacturing the same, secondary batteries, battery modules, battery packs, and power consumption devices. [Background technology]

[0002] Rechargeable batteries, such as lithium-ion batteries, have advantages such as high energy density, good cycle performance, and high average output voltage, and are widely used as power sources in power-consuming devices. With the development of fields such as electric vehicles and large-scale energy storage equipment, higher energy density requirements for rechargeable batteries have been proposed. Conventional technology achieves relatively high energy density by increasing the coating weight of the electrode plates, but this generally lengthens the lithium-ion transmission path and causes deterioration of the electrochemical performance of the rechargeable battery. [Overview of the project] [Problems that the invention aims to solve]

[0003] Based on the above problems, this application provides an electrode plate and a method for manufacturing the same, a secondary battery, a battery module, a battery pack, and a power consumption device that can improve the rate characteristics of a secondary battery, reduce the impedance of the electrode plate, and improve the electrochemical performance of a secondary battery. [Means for solving the problem]

[0004] According to a first aspect, the present application provides an electrode plate, which is a electrode plate, Current collector and, Installed on at least one surface of the current collector, the active material layer comprises an active main material and a porous material, and includes a pore layer having pores, wherein the pores may or may not penetrate the active material layer, the thickness of the active material layer is x, the distance between the ports at both ends of the pores in a direction perpendicular to the active material layer is y, and x and y satisfy the condition 0.1x ≤ y ≤ x.

[0005] Regarding the above electrode plate, the active material layer contains a porous material. The active material layer has pore channels of a specific depth. The pore channels may or may not penetrate the active material layer. Since there are pore channels in the active material layer, it is beneficial for the liquid-phase transmission of the electrolyte and the shortening of the transmission path of lithium ions, thereby reducing the impedance of the electrode plate. Therefore, it is used in secondary batteries and can achieve both relatively high rate characteristics and relatively low impedance.

[0006] In some of these embodiments, the length along the inner wall of the pore channel between the ports at both ends of the pore channel is L, and L and y satisfy the condition L > y.

[0007] In some of these embodiments, the pore channel is a non-linear pore channel.

[0008] In some of these embodiments, the projection on the current collector inside the pore channel along the direction perpendicular to the active material layer does not overlap with the ports at both ends of the pore channel.

[0009] In some of these embodiments, the number of the pore channels is plural, the distance between two adjacent pore channels is d, and d ≤ 10x.

[0010] In some of these embodiments, the maximum diameter distribution of the pore channels is 1 μm to 50 μm.

[0011] In some of these embodiments, the porous material is a porous carbon material.

[0012] In some of these embodiments, the porous carbon material is at least one selected from hard carbon, biomass carbon, activated carbon, carbon fiber, and carbon aerogel.

[0013] In some of these embodiments, the Dv50 of the porous material is 1 μm to 100 μm.

[0014] In some of these embodiments, the Dv50 of the porous material is 1 μm to 20 μm.

[0015] In some of these embodiments, the specific surface area of the porous material in a carbon dioxide atmosphere ≧ 50 m 2 / g.

[0016] In some of these embodiments, the oil absorption value of the porous material ≧ 30 mL / 100 g, and the oil absorption value is measured by the Gardner-Coleman method.

[0017] In some of these embodiments, the ratio of the specific surface area of the electrode plate in a carbon dioxide atmosphere to the specific surface area of the electrode plate in a nitrogen gas atmosphere ≧ 3.

[0018] In some of these embodiments, in the active material layer, the mass percentage of the porous material is 0.1% to 20%.

[0019] In some of these embodiments, the electrode plate is a negative electrode plate.

[0020] In some of these embodiments, the active material layer includes a first sub-active layer and a second sub-active layer laminated on the current collector. The first sub-active layer is located between the current collector and the second sub-active layer. The first sub-active layer includes the porous material, the second sub-active layer includes the active main material, and the pore channels pass through the first sub-active layer and the second sub-active layer simultaneously and penetrate the second sub-active layer.

[0021] In some of these embodiments, the thickness ratio of the first sub-active layer to the second sub-active layer is (1 to 100):100.

[0022] In some of these embodiments, the thickness ratio of the first sub-active layer to the second sub-active layer is (5 to 50):100.

[0023] According to a second aspect, the present application provides a method for manufacturing an electrode plate, the method being, The step includes manufacturing an active material layer on at least one surface of the current collector, Here, the active material layer comprises an active main material and a porous material, the active material layer has pores, the pores may or may not penetrate the active material layer, the thickness of the active material layer is x, and the distance between the ports at both ends of the pores in a direction perpendicular to the active material layer is y, where x and y satisfy the condition 0.1x ≤ y ≤ x.

[0024] The above-described method for manufacturing electrode plates has a simple flow, relatively low manufacturing costs, facilitates mass production, and the resulting electrode plates have relatively good rate characteristics and relatively low impedance, resulting in good electrochemical performance.

[0025] In some of these embodiments, the step of manufacturing an active material layer on at least one surface of the current collector is: The porous material is pre-treated to adsorb gas onto it, The process involves manufacturing the aforementioned active main material and the aforementioned porous material into a slurry. This includes applying the slurry to at least one surface of the current collector.

[0026] In some of these embodiments, the step of manufacturing an active material layer on at least one surface of the current collector is: A first sub-active layer is manufactured on at least one surface of the current collector, wherein the first sub-active layer includes the porous material on which gas is adsorbed. The method involves manufacturing a second sub-active layer on the surface of the first sub-active layer away from the current collector, wherein the second sub-active layer contains the active main material.

[0027] In some of these embodiments, before the step of manufacturing the second sub-active layer on the surface of the first sub-active layer away from the current collector, The present invention further includes pre-treating the current collector from which the first sub-active layer has been manufactured, thereby adsorbing gas onto the porous material of the first sub-active layer.

[0028] According to a third aspect, the present application further provides a secondary battery comprising at least one electrode plate selected from those manufactured based on the above-described methods for manufacturing the electrode plate and the negative electrode plate.

[0029] According to a fourth aspect, the present application further provides a battery module which includes the above-mentioned secondary battery.

[0030] According to a fifth aspect, the present application further provides a battery pack which includes the above-mentioned battery module.

[0031] According to a sixth aspect, the present application further provides a power consumption device comprising at least one selected from the secondary battery, the battery module, and the battery pack described above.

[0032] Details of one or more embodiments of this application are proposed in the following drawings and description, and other features, purposes and advantages of this application will be apparent in the specification, drawings and claims. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram of the structure of an electrode plate according to one embodiment of this application. [Figure 2] This is a cross-sectional scanning electron microscope (SEM) image of an electrode plate according to one embodiment of this application. [Figure 3] This is a scanning electron microscope (SEM) image of the surface of an electrode plate according to one embodiment of this application. [Figure 4] This is a schematic diagram of the structure of an electrode plate in another embodiment of this application. [Figure 5] This is a schematic diagram of a secondary battery according to one embodiment of the present application. [Figure 6] Figure 5 is an exploded view of a secondary battery according to one embodiment of this application. [Figure 7] This is a schematic diagram of a battery module according to one embodiment of the present application. [Figure 8] This is a schematic diagram of a battery pack according to one embodiment of the present application. [Figure 9] Figure 8 is an exploded view of a battery pack according to one embodiment of this application. [Figure 10] This is a schematic diagram of a power consumption device powered by a secondary battery according to one embodiment of the present application. [Modes for carrying out the invention]

[0034] To better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, one or more drawings may be referenced. No additional details or examples used to illustrate the drawings should be intended to limit the scope of any one of the disclosed inventions, the embodiments and / or examples described herein, or the most preferred mode of these inventions as currently understood.

[0035] To facilitate understanding of this application, the application will be described more comprehensively below with reference to the relevant drawings. The drawings illustrate relatively preferred embodiments of this application. However, this application may be implemented in many different forms and is not limited to the embodiments described herein. Conversely, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosed content of this application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art relating to the present application. The terms used herein in the specification are solely for the purpose of describing specific embodiments and are not intended to limit the application. The term "and / or" as used herein includes any combination of one or more related listed items and all combinations thereof.

[0037] With the development of fields such as electric vehicles and large-scale energy storage equipment, higher demands are being made for the energy density of secondary batteries. Conventional technology achieves relatively high energy density by increasing the coating weight of the electrode plates. While increasing the coating weight of the electrode plates can increase the capacity and energy density of secondary batteries, it also affects the electrolyte penetration performance of the electrode plates, extending the lithium ion transmission path, thereby increasing the impedance of the electrode plates and causing a deterioration in the electrochemical performance of the secondary battery.

[0038] To improve the above problem, the internal resistance of the electrode plate is generally improved by increasing the porosity of the electrode plate through the creation of holes in the electrode plate. However, conventional methods such as mechanical hole creation result in the loss of a relatively large amount of active material, and the void structure obtained by hole creation due to the volatilization or decomposition of the porosizing agent is relatively unstable, and the residue may affect the electrical performance.

[0039] Through research, the inventors have discovered that by introducing a porous material into the electrode plate, the porous material, having a relatively large specific surface area, can easily adsorb gases. These adsorbed gases can then be desorbed during the manufacturing process of the electrode plate, forming a rich pore structure in the active material layer, thereby effectively improving the electrolyte permeability and lithium ion transmission of the electrode plate.

[0040] This application provides an electrode plate and a method for manufacturing the same, a secondary battery, a battery module, a battery pack, and a power consumption device using the electrode plate. Such a secondary battery can be applied to power consumption devices that use various batteries, such as mobile phones, portable devices, laptop computers, electric bicycles, electric toys, power tools, electric vehicles, ships, and aerospace vehicles, for example, aerospace vehicles include airplanes, rockets, space shuttles, and spacecraft.

[0041] Referring to Figure 1, one embodiment of the present application provides an electrode plate 6. The electrode plate 6 includes a current collector 61 and an active material layer 62.

[0042] The active material layer 62 is installed on at least one surface of the current collector 61, and the active material layer 62 comprises an active main material and a porous material, and the active material layer 62 has holes 63, which may or may not penetrate the active material layer 62, the thickness of the active material layer 62 is x, and the distance between the ports at both ends of the holes 63 in a direction perpendicular to the active material layer 62 is y, and x and y satisfy the condition 0.1x ≤ y ≤ x. Referring to Figure 2, it is a cross-sectional scanning electron microscope (SEM) image of an electrode plate 6 of one embodiment of the present application. As can be seen, the active material layer 62 of the electrode plate 6 has holes 63.

[0043] Regarding the electrode plate 6 described above, the active material layer 62 contains a porous material, and the active material layer 62 has pores 63 of a specific depth, which may or may not penetrate the active material layer 62. Because the active material layer 62 has pores 63, it is advantageous for shortening the liquid phase transmission of the electrolyte and the transmission path of lithium ions, thereby reducing the impedance of the electrode plate 6. Therefore, it can be used in secondary batteries to achieve both relatively high rate characteristics and relatively low impedance.

[0044] Specifically, the active main material is the active material in the electrode plate 6. If the electrode plate 6 is the positive electrode plate, the active main material is the positive electrode active material, and if the electrode plate 6 is the negative electrode plate, the active main material is the negative electrode active material.

[0045] In some of these embodiments, the length along the inner wall of the borehole 63 between the ports at both ends of the borehole 63 is L, and L and y satisfy the condition L > y. As can be seen, the distance between the ports at both ends of the borehole 63 does not have to be perpendicular to the surface of the negative electrode active material layer 62, or the borehole 63 is non-linear and exhibits a meandering distribution.

[0046] In some of these embodiments, the borehole 63 is a non-linear borehole 63. The non-linear borehole 63 has a longer transmission path, increases the specific surface area of ​​the electrode plate 6, further improves the electrolyte penetration of the electrode plate 6, and shortens the lithium-ion transmission path.

[0047] In some of these embodiments, none of the projections on the current collector 61 inside the holes 63, which are perpendicular to the active material layer 62, overlap with the ports at both ends of the holes 63. The projections on the current collector 61 inside the holes 63, which are perpendicular to the active material layer 62, do not completely overlap with the ports at both ends of the holes 63; that is, the holes 63 exhibit a meandering distribution, and the electrode plate 6 has a relatively rich hole 63 structure, which is advantageous for electrolyte infiltration and reduces the internal resistance of the electrode plate 6.

[0048] In some of these embodiments, the number of pores 63 is multiple, and the distance between two adjacent pores 63 is d, where d ≤ 10x. The pores 63 of the electrode plate 6 are distributed in a density range of ≤ 10x, ensuring that the electrode plate 6 has a relatively large number of pores 63, thereby ensuring electrolyte penetration and lithium ion transmission, and reducing the internal resistance of the electrode plate 6. Referring to Figure 3, it is a scanning electron microscope (SEM) image of the surface of an electrode plate 6 in one embodiment of the present application. As can be seen, there are multiple pore-like structures on the surface of the active material layer 62 of the electrode plate 6.

[0049] In some of these embodiments, the maximum diameter distribution of the pores 63 is 1 μm to 50 μm. When the maximum diameter distribution of the pores 63 of the electrode plate 6 is within the above range, it is advantageous for improving electrolyte penetration and lithium ion transmission and reducing the internal resistance of the electrode plate 6. The maximum diameter of the pores 63 refers to the major axis diameter of the pores on the electrode plate surface. Selectively, the maximum diameter distribution of the pores 63 is 1 μm to 10 μm, 10 μm to 20 μm, 20 μm to 30 μm, 30 μm to 40 μm, or 40 μm to 50 μm.

[0050] In some of these examples, the porous material is a porous carbon material.

[0051] In some of these embodiments, the porous carbon material is selected from at least one of hard carbon, biomass charcoal, activated carbon, carbon fiber, and carbon aerogel. The porous carbon material has a relatively large specific surface area and can be used in the electrode plate 6 to improve the porosity of the negative electrode plate. Furthermore, when adsorbed gas in the pores of the porous carbon material is desorbed, it can form a pore structure 63 in the electrode plate 6. In particular, when the electrode plate 6 is a negative electrode plate, the porous carbon material can also be used as a negative electrode active material to further improve the energy density of the negative electrode plate.

[0052] In some of these examples, the Dv50 of the porous material is between 1 μm and 100 μm. Dv50 refers to the particle size corresponding to 50% of the volume distribution. For example, Dv50 may be easily measured using a laser particle size analyzer, such as the Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK, referring to the GB / T 19077-2016 particle size distribution laser diffraction method. . Selection Selectively, the Dv50 of porous materials is 1 μm, 2 μm, 4 μm, 5 μm, 8 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm. Furthermore, the Dv50 of porous materials is between 1 μm and 20 μm.

[0053] In some of these examples, the specific surface area of ​​porous materials in a carbon dioxide atmosphere was ≥ 50 m². 2 The value is / g. Because porous materials have a relatively large specific surface area, they can adsorb gases, and the manufacturing process generates a rich pore structure 63 in the electrode plate 6, which is advantageous for improving the internal resistance of the electrode plate 6.

[0054] In some of these examples, the oil absorption value of the porous material is ≥ 30 mL / 100 g. The oil absorption value is measured by the Gardner-Coleman method, and the solvent used includes one of the following: dibutyl phthalate (DBP), dioctyl phthalate (DOP), linseed oil, deionized water, N-methylpyrrolidone, anhydrous ethanol, and acetone. When the oil absorption value of the porous material is within the above range, it is advantageous for the overflow of adsorbed gas from the porous material, for the formation of the pore structure 63 of the electrode plate 6, and further advantageous for improving the electrolyte permeability of the electrode plate 6 and improving the kinetic performance of the secondary battery.

[0055] In some of these embodiments, the ratio of the specific surface area of ​​the electrode plate 6 in a carbon dioxide atmosphere to the specific surface area of ​​the electrode plate 6 in a nitrogen gas atmosphere (BET CO2 / BET N2 (Abbreviated as ) ≥ 3. Since the molecular volume of carbon dioxide is relatively small compared to nitrogen gas molecules, and can be adsorbed in greater quantities in porous materials and the pores 63 of the electrode plate 6, the specific surface area of ​​the electrode plate 6 in carbon dioxide is measured to be relatively large, and the BET of the electrode plate 6 is adjusted. CO2 / BET N2 The BET of the electrode plate 6 is ≥3, and the electrode plate 6 has a relatively rich pore structure 63 and a relatively high porosity, which is advantageous in improving electrolyte penetration and lithium ion transmission and reducing the internal resistance of the electrode plate 6. Selectively, the BET of the electrode plate 6 CO2 / BET N2 The values ​​are ≥3, ≥5, ≥10, ≥15, or ≥20.

[0056] In some of these embodiments, the mass percentage of the porous material in the active material layer 62 is 0.1% to 20%. By controlling the mass percentage of the porous material to be within this range, appropriate pores 63 can be formed in the active material layer 62.

[0057] Referring to Figure 4, it is an electrode plate 6 of one embodiment of the present application. In some of these embodiments, the active material layer 62 includes a first sub-active layer 621 and a second sub-active layer 622 laminated on a current collector 61, the first sub-active layer 621 being located between the current collector 61 and the second sub-active layer 622, the first sub-active layer 621 containing a porous material, and the second sub-active layer 622 containing an active main material, and the pore passage 63 passing through both the first sub-active layer 621 and the second sub-active layer 622 simultaneously and penetrating the second sub-active layer 622. By placing the first sub-active layer 621 containing a porous material between the current collector 61 and the second sub-active layer 622, the second sub-active layer 622 can be penetrated through the pore passage 63, further improving the electrolyte permeability and lithium ion transmission of the electrode plate 6 and reducing the impedance of the electrode plate 6.

[0058] In some of these embodiments, the thickness ratio of the first sub-active layer 621 to the second sub-active layer 622 is (1~100):100. By controlling the thickness ratio of the first sub-active layer 621 to the second sub-active layer 622 to be within the above range, the electrode plate 6 has relatively abundant pores 63 and a relatively high porosity, the impedance of the electrode plate 6 is relatively low, and the rate characteristics are relatively good. Furthermore, the thickness ratio of the first sub-active layer 621 to the second sub-active layer 622 is (5~50):100.

[0059] Another embodiment of this application further provides a method for manufacturing an electrode plate, and this method is The step includes manufacturing an active material layer on at least one surface of the current collector, Here, the active material layer comprises an active main material and a porous material, the active material layer has pores, the pores may or may not penetrate the active material layer, the thickness of the active material layer is x, and the distance between the ports at both ends of the pores in a direction perpendicular to the active material layer is y, and x and y satisfy the condition 0.1x ≤ y ≤ x.

[0060] The above-described method for manufacturing electrode plates has a simple flow, relatively low manufacturing costs, facilitates mass production, and the resulting electrode plates have relatively good rate characteristics and relatively low impedance, resulting in good electrochemical performance.

[0061] In some of these embodiments, the step of manufacturing an active material layer on at least one surface of the current collector is: Pretreatment of a porous material to adsorb gas onto the porous material, The process involves manufacturing the active main material and porous material into a slurry, This includes applying the slurry to at least one surface of the current collector.

[0062] In the step of pre-treating a porous material to adsorb gas onto it, followed by completing the production of a slurry and applying it to produce an active material layer, the gas is desorbed from the porous material, thereby forming the pore structure of the electrode plate.

[0063] In some of these embodiments, the step of manufacturing an active material layer on at least one surface of the current collector is: A first sub-active layer is manufactured on at least one surface of the current collector, wherein the first sub-active layer includes a porous material on which gas is adsorbed. The method involves manufacturing a second sub-active layer on a surface of the first sub-active layer that is separated from the current collector, wherein the second sub-active layer contains an active main material.

[0064] In some of these embodiments, before the step of manufacturing a second sub-active layer on the surface of the first sub-active layer away from the current collector, The present invention further includes pre-treating the current collector from which the first sub-active layer has been manufactured, thereby adsorbing gas onto the porous material of the first sub-active layer.

[0065] In the step of pre-treating the first sub-active layer to adsorb gas onto the porous material and then producing the subsequent second sub-active layer, the gas desorbs from the first sub-active layer and overflows, forming pores that penetrate the second sub-active layer.

[0066] Furthermore, the secondary battery, battery module, battery pack, and power consumption device of this application will be described below with appropriate reference to the drawings.

[0067] One embodiment of this application provides a secondary battery.

[0068] Generally, a secondary battery includes a positive electrode plate, a negative electrode plate, an electrolyte, and a separator. During charging and discharging of the battery, active ions are intercepted and deintercepted as they reciprocate between the positive and negative electrode plates. The electrolyte acts as an ion conductor between the positive and negative electrode plates. The separator is placed between the positive and negative electrode plates and primarily serves to prevent short circuits between the positive and negative electrodes, while also allowing ions to pass through. In the embodiments of this application, the positive electrode plate and / or negative electrode plate in the secondary battery are electrode plates obtained by manufacturing according to the first embodiment described above or the manufacturing method described in the second embodiment described above.

[0069] positive electrode plate The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer placed on at least one surface of the positive electrode current collector, the positive electrode active material layer containing positive electrode active material.

[0070] For example, a positive electrode current collector has two opposing surfaces in its own thickness direction, and the positive electrode active material layer is placed on one or both of the two opposing surfaces of the positive electrode current collector.

[0071] In some of these embodiments, the positive electrode current collector may employ a metal foil sheet or a composite current collector. For example, it may be a metal foil sheet, and an aluminum foil may be employed. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer material substrate (such as substrates of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0072] In some of these embodiments, the positive electrode active material may employ a positive electrode active material known in the art for use in batteries. As an example, the positive electrode active material may include at least one of an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their modified compounds. However, this application is not limited to these materials, and conventional materials that can be used as other battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of the lithium transition metal oxide are lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which may be abbreviated as NCM 333 ), and LiNi 0.5 Co 0.2 Mn 0.3 O2 (which may be abbreviated as NCM 523 ), and LiNi 0.5 Co 0.25 Mn 0.25 O2 (which may be abbreviated as NCM 211 ), and LiNi 0.6 Co0.2 Mn 0.2 O2(NCM 622 (It may also be abbreviated as) and LiNi 0.8 Co 0.1 Mn 0.1 O2(NCM 811 (May be abbreviated as LiNi) and lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05 The material may include, but is not limited to, at least one of O2) and its modified compounds. Examples of lithium-containing phosphates with an olivine structure may include, but is not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), composite materials of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.

[0073] In some of these embodiments, the positive electrode active material layer further selectively includes an adhesive. For example, the adhesive may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0074] In some of these embodiments, the positive electrode active material layer further selectively contains a conductive agent. For example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0075] In some of these embodiments, the positive electrode plate may be manufactured by the following method: the components for manufacturing the positive electrode plate, such as a positive electrode active material, a conductive agent, an adhesive, and any other component, are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is applied onto a positive electrode current collector; and after processes such as drying and cold pressing, a positive electrode plate can be obtained.

[0076] Negative electrode plate The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer placed on at least one surface of the negative electrode current collector, the negative electrode active material layer containing a negative electrode active material.

[0077] For example, the negative electrode current collector has two opposing surfaces in its own thickness direction, and the negative electrode active material layer is placed on one or both of the two opposing surfaces of the negative electrode current collector.

[0078] In some of these embodiments, the negative electrode current collector may be a metal foil sheet or a composite current collector. For example, copper foil may be used as the metal foil sheet. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (such as copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys) on a polymer material substrate (for example, a substrate such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0079] In some of these embodiments, the negative electrode active material may be a negative electrode active material used in batteries known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicate compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, stancate compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used individually or in combination of two or more.

[0080] In some of these embodiments, the negative electrode active material layer further selectively comprises an adhesive. The adhesive may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0081] In some of these embodiments, the negative electrode active material layer further selectively contains a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0082] In some of these embodiments, the negative electrode active material layer further selectively contains other auxiliary agents, such as thickeners (e.g., sodium carboxymethylcellulose (CMC-Na)).

[0083] In some of these embodiments, the negative electrode plate may be manufactured by the following method: the components for manufacturing the negative electrode plate, such as a negative electrode active material, a conductive agent, an adhesive, and any other component, are dispersed in a solvent (e.g., deionized water) to form a negative electrode slurry; the negative electrode slurry is applied onto a negative electrode current collector; and after processes such as drying and cold pressing, the negative electrode plate can be obtained.

[0084] electrolyte The electrolyte plays a role in ion conduction between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, which can be selected according to the requirements. For example, the electrolyte may be a liquid, a gel, or an all-solid.

[0085] In some of these embodiments, an electrolyte solution is used as the electrolyte. The electrolyte solution contains an electrolyte salt and a solvent.

[0086] In some of these examples, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethylsulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0087] In some of these embodiments, the solvent may be selected from at least one of the following: ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfone, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone.

[0088] In some of these embodiments, the electrolyte further selectively includes additives. For example, the additives may include a negative electrode film-forming additive and a positive electrode film-forming additive, and may further include additives that can improve some of the battery's performance, such as additives that improve battery overcharge performance, or additives that improve battery high-temperature or low-temperature performance.

[0089] Separator In some of these embodiments, the secondary battery further includes a separator. This application does not particularly limit the type of separator, and any known porous separator having good chemical and mechanical stability may be selected.

[0090] In some of these embodiments, the material of the separator may be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multilayer composite film, and is not particularly limited. When the separator is a multilayer composite film, the materials of each layer may be the same or different, and is not particularly limited.

[0091] In some of these embodiments, the positive electrode plate, the negative electrode plate, and the separator may be manufactured into an electrode assembly by a winding process or a lamination process.

[0092] In some of these embodiments, the secondary battery may include an outer casing. This casing may be used to package the electrode assembly and electrolyte.

[0093] In some of these embodiments, the casing of the secondary battery may be a rigid case, such as a rigid plastic case, an aluminum case, or a steel case. The casing of the secondary battery may also be a pouch, such as a bag-shaped pouch. The material of the pouch may be plastic, and examples of plastics include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0094] This application does not particularly limit the shape of the secondary battery, which may be cylindrical, rectangular, or any other shape. For example, Figure 5 shows a secondary battery 5 with a rectangular structure as an example.

[0095] In some of these embodiments, referring to Figure 6, the casing may include a case 51 and a cover plate 53. Here, the case 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and side plates surround and form a housing cavity. The case 51 has an opening that communicates with the housing cavity, and the cover plate 53 can cover the opening, thereby sealing the housing cavity. The positive electrode plate, negative electrode plate and separator can form an electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is packaged in the housing cavity. The electrolyte is impregnated into the electrode assembly 52. ​​The number of electrode assemblies 52 included in the secondary battery 5 may be one or more, and a person skilled in the art can select according to the specific actual needs.

[0096] In some of these embodiments, the secondary batteries may be assembled into a battery module, and the number of secondary batteries included in the battery module may be one or more, and the specific number can be selected by a person skilled in the art depending on the application and capacity of the battery module.

[0097] Figure 7 shows an example of a battery module 4. Referring to Figure 7, in the battery module 4, the multiple secondary batteries 5 may be arranged in order along the longitudinal direction of the battery module 4. Of course, they may be arranged in any other manner. Furthermore, these multiple secondary batteries 5 may be fixed in place with fasteners.

[0098] Selectively, the battery module 4 may further include a housing having a housing space, in which a plurality of secondary batteries 5 are housed.

[0099] In some of these embodiments, the battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0100] Figures 8 and 9 show an example battery pack 1. Referring to Figures 8 and 9, the battery pack 1 may include a battery box and a plurality of battery modules 4 installed inside the battery box. The battery box includes an upper housing 2 and a lower housing 3, the upper housing 2 can cover the lower housing 3 and form a sealed space for housing the battery modules 4. The plurality of battery modules 4 may be arranged inside the battery box according to any arrangement.

[0101] Furthermore, this application provides a power consumption device comprising at least one of a secondary battery, battery module, or battery pack as described herein. The secondary battery, battery module, or battery pack may be used as a power source for the power consumption device or as an energy storage unit for the power consumption device. The power consumption device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0102] As a power consumption device, a secondary battery, battery module, or battery pack may be selected depending on the usage requirements.

[0103] Figure 10 shows an example of a power consumption device. This power consumption device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the demand for high power and high energy density of the secondary battery of this power consumption device, a battery pack or battery module may be used.

[0104] Other examples of devices may include mobile phones, tablet computers, and laptop computers. These devices generally require a thin design and may use rechargeable batteries as a power source.

[0105] Examples The following describes embodiments of this application. The embodiments described below are illustrative and are for interpretive purposes only, and should not be considered as limitations thereon. Unless otherwise specified, the embodiments are carried out in accordance with the techniques, conditions, or product specifications described in the literature in the art. Unless otherwise specified, the reagents or instruments used are all common commercially available products.

[0106] Example 1: The negative electrode plate in this embodiment is manufactured based on the following steps.

[0107] The negative electrode slurry is obtained by dispersing graphite as the negative electrode active material, hard carbon (Dv50, 4.6 μm) as a porous material, acetylene black as a conductive agent, SBR as an adhesive, and CMC as a dispersant in deionized water in a mass ratio of 95:2:1:1:1. The resulting negative electrode slurry is applied to copper foil, and after drying, it is cold-pressed and slit to obtain a negative electrode plate. The thickness of the negative electrode active material layer is 100 μm. During the drying and cold-pressing process, adsorbed gases in the porous material are desorbed and overflow, thereby forming a pore structure in the negative electrode active material layer.

[0108] Example 2: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the porous material in the negative electrode plate is activated carbon (Dv50 is 4.6 μm).

[0109] Example 3: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the porous material in the negative electrode plate is carbon fiber (Dv50 is 4.6 μm).

[0110] Example 4: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the porous material in the negative electrode plate is carbon aerogel (Dv50 is 4.6 μm).

[0111] Example 5: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the specific surface area of ​​the hard carbon is 125.6 m². 2 The condition is / g.

[0112] Example 6: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the specific surface area of ​​the hard carbon is 394.0 m². 2 The condition is / g.

[0113] Example 7: The difference between the negative electrode plate of this embodiment and that of Embodiment 1 is that the specific surface area of ​​the hard carbon is 968.7 m². 2 The condition is / g.

[0114] Refer to Table 1 for the type of porous material, oil absorption value, and specific surface area parameter of the negative electrode plates in Examples 1 to 7.

[0115] [Table 1]

[0116] Comparative Example 1: The difference between this comparative example and Example 1 is that the negative electrode plate does not contain porous material, and the negative electrode plate is manufactured based on the following steps: The negative electrode active material graphite, conductive agent acetylene black, adhesive SBR, and dispersant CMC are dispersed in deionized water in a mass ratio of 97:1:1:1, the resulting negative electrode slurry is applied onto copper foil, and after drying, it is cold-pressed and slit to obtain the negative electrode plate.

[0117] Example 8: The difference between this example and Example 1 is that the mass ratio of the negative electrode active material graphite, hard carbon, conductive agent acetylene black, adhesive SBR, and dispersant CMC is 96.9:0.1:1:1:1.

[0118] Example 9: The difference between this example and Example 1 is that the mass ratio of the negative electrode active material graphite, hard carbon, conductive agent acetylene black, adhesive SBR, and dispersant CMC is 87:10:1:1:1.

[0119] Example 10: The difference between this example and Example 1 is that the mass ratio of the negative electrode active material graphite, hard carbon, conductive agent acetylene black, adhesive SBR, and dispersant CMC is 77:20:1:1:1.

[0120] Refer to Table 2 for the compositional ratios of the negative electrode plates in Examples 1, 8-10.

[0121] [Table 2]

[0122] Examples 11-15 Hard carbon (Dv50 is 4.6 μm), conductive agent acetylene black, adhesive SBR, and dispersant CMC are dispersed in deionized water according to a certain mass ratio. The resulting first slurry is applied to a copper foil, dried, and cold-pressed to produce a first sub-active layer. The copper foil with the first sub-active layer is left to stand in a carbon dioxide atmosphere for 6 hours to allow carbon dioxide to be adsorbed onto the hard carbon. The negative electrode active material graphite, conductive agent acetylene black, adhesive SBR, and dispersant CMC are dispersed in deionized water according to a mass ratio of 97:1:1:1. The resulting second slurry is applied to the first sub-active layer to produce a second sub-active layer. After drying, it is cold-pressed and slit to obtain a negative electrode plate. During the drying and cold-pressing process, the adsorbed gas on the hard carbon desorbs and overflows, penetrating the second sub-active layer and thereby forming a pore structure in the negative electrode active material layer.

[0123] Refer to Table 3 for the hard carbon mass percentage, the composition ratio of the first sub-active layer, and the thickness ratio of the first sub-active layer to the second sub-active layer in the negative electrode plates of Examples 11 to 15.

[0124] [Table 3]

[0125] Manufacturing of positive electrode plates: Cathode active material LiNi 0.8 Co 0.1 Mn 0.1 O2, conductive agent acetylene black, and adhesive PVDF are mixed in a mass ratio of 96:2:2 and dispersed in NMP to obtain a slurry. This slurry is then applied to aluminum foil, and after drying, it is cold-pressed and slit to obtain a positive electrode plate.

[0126] Manufacturing of lithium-ion batteries: A bare cell is obtained by folding the positive electrode plate, polyethylene separator, and negative electrode plate in order. The bare cell is placed in an outer casing, and after drying, a 1M LiPF6 / EC:EMC:DEC (1:1:1) electrolyte is injected. A lithium-ion battery is then obtained through vacuum packaging, standing, chemical conversion, and molding processes. The amount of positive electrode active material used in all examples and comparative examples of lithium-ion batteries is the same, and the theoretical nominal capacity of the lithium-ion battery designed based on the amount of positive electrode active material used is 4.5Ah.

[0127] Test section: Specific surface area test: The specific surface area of ​​porous materials and negative electrode plates is obtained by measuring the isothermal adsorption / desorption curves of nitrogen gas / carbon dioxide in the material using a fully automated gas adsorption analyzer, and then calculating it using the multipoint Brunauer-Emmett-Teller method.

[0128] Oil absorption test: Oil absorption values ​​are determined using the Gardner-Coleman method, with dibutyl phthalate as the solvent.

[0129] Nominal capacity and rate characteristics test: At room temperature, a lithium-ion battery is charged to its upper voltage limit at a 1 / 3C rate, and then discharged to its lower voltage limit at 0.33C and 2C, respectively. The discharge capacity at the 0.33C rate is used as the nominal capacity reference set, and the capacity retention rate of the lithium-ion battery at the 2C rate is calculated.

[0130] DC internal resistance test: At room temperature, the lithium-ion battery is charged to its upper voltage limit at a rate of 1 / 3C to 100% SOC. Then, the lithium-ion battery is discharged to 50% SOC, left to stand for 5 minutes, and then discharged again at a rate of 4C for 10 seconds to obtain the DC internal resistance (DCR) of the lithium-ion battery at 50% SOC at room temperature.

[0131] SEM test of the negative electrode plate surface: By taking photographs of the surface of the negative electrode plate using a scanning electron microscope, the pore distribution and pore diameter of the negative electrode active material layer surface can be observed.

[0132] SEM test of the cross-section of the negative electrode plate: The negative electrode plate is sliced ​​perpendicular to the negative electrode active material layer, and a scanning electron microscope image is taken of the slice surface to observe the pore distribution in the negative electrode active material layer. hole route The distance between the ports at both ends of the borehole in a direction perpendicular to the negative electrode active material layer is y, and the length along the inner wall of the borehole between the ports at both ends of the borehole is L.

[0133] The test data for the negative electrode plates and lithium-ion batteries of Examples 1-15 and Comparative Example 1 are recorded in Table 4.

[0134] [Table 4]

[0135] As can be seen from the related data in Table 2, the BET of the negative electrode plates of Examples 1 to 15 compared to the negative electrode plate of Comparative Example 1. CO2 / BET N2 The specific surface area is within the range of 3 to 24, and the negative electrode plates of Examples 1 to 15 have a relatively large specific surface area and a relatively high porosity. The 0.33C nominal capacity of the lithium-ion batteries of Examples 1 to 15 is 3.8Ah to 4.6Ah, the 2C discharge capacity retention rate is 89.1% to 98.8%, and the DC internal resistance is 10.1 to 12.9 mohm, which is relatively high nominal capacity, relatively good rate characteristics, and relatively low DC internal resistance compared to the lithium-ion battery of Comparative Example 1.

[0136] As can be seen from Examples 5-7, the oil absorption value and specific surface area of ​​the porous material increased, and the BET of the negative electrode plate obtained by manufacturing was increased. CO2 / BET N2 The 0.33C nominal capacity of lithium-ion batteries also increases, the 2C discharge capacity retention rate decreases slightly, and the DC internal resistance decreases.

[0137] As can be seen from Examples 8-10, the porous material in the active material layer increases, and the BET of the negative electrode plate CO2 / BETN2 The 0.33C nominal capacity of lithium-ion batteries increases, the 2C discharge capacity retention rate decreases, and the DC internal resistance decreases.

[0138] Examples 11-15 control the composition ratio of the first sub-active layer, the mass percentage occupying the hard carbon active material layer, and the thickness ratio between the first and second sub-active layers. 11 The nominal capacity of lithium-ion batteries of type ~15 at 0.33C is 3.8Ah to 4.5Ah, the 2C discharge capacity retention rate is 91.2% to 98.2%, and the DC internal resistance is 10.2 to 12.9 mohm.

[0139] As described above, the technical features of the embodiments may be combined in any way, and for the sake of brevity, not all possible combinations of the technical features in the embodiments described above are described; however, as long as there is no inconsistency in these combinations of technical features, they should all be considered within the scope of this specification.

[0140] As stated above, the embodiments represent only a number of embodiments of this application, and their descriptions are relatively specific and detailed, but this should not be understood as limiting the scope of the patentable invention. It should be noted that, for those skilled in the art, several further modifications and improvements are possible without departing from the concept of this application, and all of these fall within the scope of protection of this application. Therefore, the scope of patent protection of this application should be determined by the attached claims. [Explanation of symbols]

[0141] 1. Battery pack, 2. Upper housing, 3. Lower housing, 4. Battery module, 5. Secondary battery, 51. Case, 52. Electrode assembly, 53. Cover plate, 6. Electrode plate, 61. Current collector, 62. Active material layer, 621. First sub-active layer, 622. Second sub-active layer, 63. Hole.

Claims

1. Electrode plates, Current collector and, Installed on at least one surface of the current collector, the active material layer comprises an active main material and a porous material, and includes a pore layer, wherein the pores penetrate or do not penetrate the active material layer, the thickness of the active material layer is x, the distance between the ports at both ends of the pores in a direction perpendicular to the active material layer is y, and x and y satisfy the condition 0.1x ≤ y ≤ x. The specific surface area of ​​the porous material in a carbon dioxide atmosphere is ≥ 50 m². ２ / g, An electrode plate characterized in that the ratio of the specific surface area of ​​the electrode plate in a carbon dioxide atmosphere to the specific surface area of ​​the electrode plate in a nitrogen gas atmosphere (specific surface area of ​​the electrode plate in a carbon dioxide atmosphere / specific surface area of ​​the electrode plate in a nitrogen gas atmosphere) ≥ 3.

2. The electrode plate according to claim 1, characterized in that the length along the inner wall of the hole between the ports at both ends of the hole is L, and L and y satisfy the condition L > y.

3. The electrode plate according to claim 1, characterized in that the aforementioned hole is a non-linear hole.

4. The electrode plate according to claim 1, characterized in that the projection on the current collector inside the hole, which is aligned perpendicular to the active material layer, does not overlap with the ports at both ends of the hole.

5. The electrode plate according to claim 1, characterized in that the number of holes is multiple, and the distance between two adjacent holes observed on the surface of the active material layer away from the current collector is d, where d ≤ 10x.

6. The electrode plate according to claim 1, characterized in that the maximum diameter distribution of the aforementioned holes is 1 μm to 50 μm.

7. The electrode plate according to claim 1, characterized in that the porous material is a porous carbon material.

8. The electrode plate according to claim 7, characterized in that the porous carbon material is selected from at least one of hard carbon, biomass charcoal, activated carbon, carbon fiber, and carbon aerogel.

9. The electrode plate according to claim 1, characterized in that the Dv50 of the porous material is 1 μm to 100 μm.

10. The electrode plate according to claim 1, characterized in that the Dv50 of the porous material is 1 μm to 20 μm.

11. The electrode plate according to claim 1, characterized in that the oil absorption value of the porous material is ≥ 30 mL / 100 g, and the oil absorption value is measured by the Gardner-Coleman method.

12. The electrode plate according to claim 1, characterized in that the ratio of the specific surface area of ​​the electrode plate in a carbon dioxide atmosphere to the specific surface area of ​​the electrode plate in a nitrogen gas atmosphere (specific surface area of ​​the electrode plate in a carbon dioxide atmosphere / specific surface area of ​​the electrode plate in a nitrogen gas atmosphere) ≥ 5.

13. The electrode plate according to claim 1, characterized in that the mass percentage of the porous material in the active material layer is 0.1% to 20%.

14. The electrode plate according to claim 1, characterized in that the electrode plate is a negative electrode plate.

15. The electrode plate according to claim 1, wherein the active material layer includes a first sub-active layer and a second sub-active layer laminated on the current collector, the first sub-active layer is located between the current collector and the second sub-active layer, the first sub-active layer includes the porous material, the second sub-active layer includes the active main material, and the pores pass through the first sub-active layer and the second sub-active layer simultaneously and penetrate the second sub-active layer.

16. The electrode plate according to claim 15, characterized in that the thickness ratio of the first sub-active layer to the second sub-active layer is (1 to 100):

100.

17. The electrode plate according to claim 15, characterized in that the thickness ratio of the first sub-active layer to the second sub-active layer is (5-50):

100.

18. A method for manufacturing electrode plates, The step includes manufacturing an active material layer on at least one surface of the current collector, Here, the active material layer comprises an active main material and a porous material, the active material layer has pores, the pores may or may not penetrate the active material layer, the thickness of the active material layer is x, the distance between the ports at both ends of the pores in a direction perpendicular to the active material layer is y, and x and y satisfy the condition 0.1x ≤ y ≤ x. The specific surface area of ​​the porous material in a carbon dioxide atmosphere is ≥ 50 m². ２ / g, A method for manufacturing an electrode plate, characterized by forming the pores by desorbing carbon dioxide adsorbed on the porous material.

19. The above step of manufacturing an active material layer on at least one surface of the current collector is: The porous material is used to adsorb carbon dioxide, The process involves manufacturing the aforementioned active main material and the aforementioned porous material into a slurry. The slurry is applied to at least one surface of the current collector, A method for manufacturing an electrode plate according to claim 18, characterized by comprising desorbing carbon dioxide from the porous material to form the pores.

20. The above step of manufacturing an active material layer on at least one surface of the current collector is: A first sub-active layer is manufactured on at least one surface of the current collector, wherein the first sub-active layer includes the porous material on which carbon dioxide is adsorbed. A second sub-active layer is manufactured on the surface of the first sub-active layer away from the current collector, wherein the second sub-active layer contains the active main material. A method for manufacturing an electrode plate according to claim 18, characterized by comprising desorbing carbon dioxide from the porous material to form the pores.

21. Before the step of manufacturing the second sub-active layer on the surface of the first sub-active layer away from the current collector, The method for manufacturing an electrode plate according to claim 20, further comprising adsorbing carbon dioxide onto the porous material of the first sub-active layer.

22. A secondary battery, characterized by including an electrode plate as described in any one of claims 1 to 17.

23. A battery module characterized by including a secondary battery as described in claim 22.

24. A battery pack, characterized by including the battery module described in claim 23.

25. A power consumption device characterized by including a secondary battery as described in claim 22.

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