Current collectors, electrode plates, secondary batteries, battery modules, battery packs, and electrical devices.

Abstract

This application provides a current collector, electrode sheet, secondary battery, battery module, battery pack, and electrical device. The current collector includes a substrate and an adsorption coating disposed on the substrate. The adsorption coating includes a binder and titanium carbide with a two-dimensional layered structure. The two-dimensional layered titanium carbide has multiple layers of stacked titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm ≤ H ≤ 5nm. The current collector, electrode sheet, secondary battery, battery module, battery pack, and electrical device of the embodiments of this application have a strong carbon dioxide adsorption capacity, which can improve the stability of the secondary battery during operation and extend its cycle life.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a current collector, electrode sheet, secondary battery, battery module, battery pack and power device. Background Technology

[0002] Lithium-ion batteries are widely used in electronic devices such as mobile phones, tablets, laptops, wind turbines, and solar power plants due to their advantages such as high energy density, long cycle life, and low environmental pollution.

[0003] Lithium-ion secondary batteries generate some gases during production and use, which can reduce the operating efficiency and safety of the batteries. Therefore, how to effectively reduce the content of harmful gases in secondary batteries is one of the key research areas in this field. Summary of the Invention

[0004] This application is made in view of the above-mentioned problems, and its purpose is to provide a current collector with a strong carbon dioxide adsorption capacity, which can improve the stability of secondary batteries during operation and extend their cycle life.

[0005] To achieve the above objectives, this application provides a current collector, electrode plates, a secondary battery, a battery module, a battery pack, and an electrical device.

[0006] The first aspect of this application provides a current collector, including a substrate and an adsorption coating disposed on the substrate. The adsorption coating includes an adhesive and titanium carbide having a two-dimensional layered structure. The two-dimensional layered titanium carbide has multiple layers of stacked titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm≤H≤5nm.

[0007] This application selects titanium carbide with a large interlayer spacing in a two-dimensional layered structure as an adsorbent. The two-dimensional layered structure of titanium carbide has a large adsorption space, thus improving the ability of the two-dimensional layered structure of titanium carbide in the adsorption coating to absorb carbon dioxide, thereby improving the stability and cycle life of the secondary battery.

[0008] In any implementation, the specific surface area A of the two-dimensional layered titanium carbide structure satisfies: 25m² 2 / g≤A≤35m 2 / g.

[0009] According to the embodiments of this application, the specific surface area of ​​titanium carbide with a two-dimensional layered structure increases with the increase of the interlayer spacing of the stacked titanium carbide nanosheets. When the interlayer spacing reaches 3nm≤H≤5nm, a large specific surface area and strong adsorption capacity can be guaranteed.

[0010] In any embodiment, the titanium carbide nanosheets contain multiple vacancies. These vacancies can bind to and accommodate carbon dioxide molecules, thereby enhancing the adsorption capacity of carbon dioxide gas.

[0011] In any embodiment, the cavity contains multiple active metal particles. These active metal particles can also bind to carbon dioxide gas, effectively enhancing the adsorption capacity of carbon dioxide gas.

[0012] In any embodiment, the surface of the titanium carbide nanosheets has multiple hydroxyl functional groups and / or multiple carboxylate functional groups. Therefore, the hydroxyl functional groups and / or multiple carboxylate functional groups can also bind to carbon dioxide molecules, further enhancing the adsorption capacity of the adsorption coating for carbon dioxide.

[0013] According to embodiments of this application, the adsorption coating comprises, by mass parts:

[0014] Adhesive: 100 parts;

[0015] Two-dimensional layered titanium carbide: 17.5–23.6 parts.

[0016] Therefore, by adding an appropriate proportion of binder, the adhesion effect of the adsorption coating can be guaranteed while the adsorption effect of titanium carbide can be ensured.

[0017] In any embodiment, the adsorption coating further includes a single layer of titanium carbide nanosheets. Optionally, multiple titanium carbide nanosheets are arranged in parallel orientation within the adsorption coating. Thus, by exfoliating the titanium carbide nanosheets to achieve partial parallel orientation, the specific surface area of ​​titanium carbide can be further increased, thereby enhancing the adsorption effect.

[0018] A second aspect of this application also provides a method for preparing a current collector, the method comprising: providing an adsorption coating slurry, the slurry comprising a binder, a dispersion medium and titanium carbide having a two-dimensional layered structure, the titanium carbide having a two-dimensional layered structure comprising multiple layers of titanium carbide nanosheets, the interlayer spacing H between adjacent titanium carbide nanosheets satisfying the range: 3nm≤H≤5nm;

[0019] An adsorption coating slurry is applied to at least a portion of the surface of a substrate and dried to form an adsorption coating.

[0020] Therefore, by selecting titanium carbide with a large interlayer spacing in its two-dimensional layered structure as an adsorbent, the titanium carbide with a two-dimensional layered structure has a large adsorption space, thus improving the ability of the titanium carbide with a two-dimensional layered structure in the adsorption coating to absorb carbon dioxide, thereby improving the stability and cycle life of the secondary battery.

[0021] A third aspect of this application provides an electrode sheet, comprising: a current collector as provided in the first aspect of this application; and an active material layer disposed on the surface of an adsorption coating, or disposed between a substrate and the adsorption material layer. In the above technical solutions, the placement of the active material layer does not affect the adsorption effect of the adsorption coating.

[0022] The fourth aspect of this application provides another electrode sheet, comprising: a substrate and an active material layer disposed on the substrate. The active material layer comprises: titanium carbide with a two-dimensional layered structure, an active material, and a binder. The two-dimensional layered titanium carbide has multiple layers of stacked titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm ≤ H ≤ 5nm. In the above technical solution, directly adding the adsorbent material to the active material layer can improve the manufacturing efficiency of the electrode sheet while ensuring the adsorption effect of carbon dioxide.

[0023] In any implementation, the specific surface area A of the two-dimensional layered titanium carbide structure satisfies: 25m² 2 / g≤A≤35m 2 / g.

[0024] In any embodiment, the titanium carbide nanosheets contain multiple cavities. These cavities can bind to and accommodate carbon dioxide molecules, thereby enhancing the adsorption capacity of carbon dioxide gas.

[0025] In any embodiment, the cavity contains multiple active metal particles. These active metal particles can also bind to carbon dioxide gas, effectively enhancing the adsorption capacity of carbon dioxide gas.

[0026] In any embodiment, the surface of the titanium carbide nanosheets has multiple hydroxyl functional groups and / or multiple carboxylate functional groups. Therefore, the hydroxyl functional groups and / or multiple carboxylate functional groups can also bind to carbon dioxide molecules, further enhancing the adsorption capacity of the active material layer for carbon dioxide.

[0027] In any embodiment, the active material layer comprises, by mass parts:

[0028] Adhesive, 100 parts;

[0029] Titanium carbide with a two-dimensional layered structure: 17.5–23.6 parts;

[0030] Active material, 3182–3318 parts.

[0031] In any embodiment, the active material layer further includes a single layer of titanium carbide nanosheets. Optionally, multiple titanium carbide nanosheets are arranged in a normal orientation along the thickness direction. The above technical solution, by peeling off some of the titanium carbide nanosheets, can further increase the specific surface area of ​​titanium carbide and improve the adsorption effect.

[0032] The fifth aspect of this application provides a method for preparing an electrode sheet, comprising:

[0033] An active material slurry is provided, comprising a binder, a dispersion medium, an active material, and titanium carbide with a two-dimensional layered structure. The titanium carbide with the two-dimensional layered structure has multiple layers of titanium carbide nanosheets stacked together, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies the range of 3nm≤H≤5nm.

[0034] The slurry is applied to at least a portion of the surface of the substrate and dried to form an active material layer.

[0035] In any embodiment, the raw materials of each component of the slurry are added in the following mass ratios:

[0036] Titanium carbide with a two-dimensional layered structure: 17.5–23.6 parts;

[0037] Adhesive: 100 parts;

[0038] Dispersion medium: 1136–1347 parts;

[0039] Active material: 3182-3318 parts.

[0040] In any embodiment, titanium carbide having a two-dimensional layered structure is prepared by the following steps:

[0041] Provides MAX phase titanium aluminum carbide;

[0042] MXene titanium carbide was obtained by etching MAX phase titanium aluminum carbide with hydrofluoric acid.

[0043] MXene titanium carbide was mixed with copper nitrate solution to obtain a mixed solution. The mixed solution was treated with dimethyl sulfoxide in ice water and dried to obtain titanium carbide with a two-dimensional layered structure.

[0044] Therefore, by adding dimethyl sulfoxide to expand the MXene titanium carbide layer structure, the interlayer spacing of the titanium carbide nanosheets was increased, effectively improving the specific surface area of ​​titanium carbide and enhancing its adsorption capacity for carbon dioxide. Furthermore, by adding copper nitrate solution, active copper ions were incorporated into the two-dimensional layered structure of titanium carbide, allowing the active metal ions to bind with carbon dioxide and improving the carbon dioxide absorption efficiency.

[0045] The sixth aspect of this application provides a secondary battery, including the electrode plates of the fourth or fifth aspect of this application.

[0046] A seventh aspect of this application provides a battery module, including the secondary battery of the sixth aspect of this application.

[0047] An eighth aspect of this application provides a battery pack that includes the battery module of the seventh aspect of this application.

[0048] The ninth aspect of this application provides an electrical device including at least one selected from the sixth aspect of this application, the seventh aspect of this application, or the eighth aspect of this application.

[0049] This application selects titanium carbide with a large interlayer spacing in a two-dimensional layered structure as an adsorbent. The two-dimensional layered structure of titanium carbide has a large adsorption space, thus improving the ability of the two-dimensional layered structure of titanium carbide in the adsorption coating to absorb carbon dioxide, thereby improving the stability and cycle life of the secondary battery. Attached Figure Description

[0050] Figure 1 This is a flowchart of one embodiment of the current collector preparation method according to this application.

[0051] Figure 2 This is a flowchart of one embodiment of the electrode preparation method according to this application.

[0052] Figure 3 This is a flowchart of one embodiment of the method for preparing two-dimensional layered titanium carbide according to this application.

[0053] Figure 4 This is a schematic diagram of a secondary battery according to one embodiment of this application.

[0054] Figure 5 This is an exploded view of a secondary battery according to one embodiment of this application.

[0055] Figure 6 This is a schematic diagram of a battery module according to one embodiment of this application.

[0056] Figure 7 This is a schematic diagram of a battery pack according to one embodiment of this application.

[0057] Figure 8 yes Figure 7 An exploded view of a battery pack according to one embodiment of this application is shown.

[0058] Figure 9 This is a schematic diagram of an electrical device that uses a secondary battery as a power source according to one embodiment of this application.

[0059] Figure 10 This is a scanning electron microscope image of titanium carbide from Comparative Example 1 of this application.

[0060] Figure 11 This is a scanning electron microscope image of a two-dimensional layered titanium carbide structure according to an embodiment of this application.

[0061] Figure 12 This is a scanning electron microscope image of a two-dimensional layered titanium carbide structure according to an embodiment of this application.

[0062] Figure 13 This is an XRD pattern of titanium carbide powder according to one embodiment of this application.

[0063] Figure 14 This is a scanning electron microscope image of titanium carbide nanosheets according to one embodiment of this application.

[0064] Figure 15 These are gas chromatography analysis chromatograms of the proportion of carbon dioxide adsorbed by titanium carbide in Examples 1-3 and Comparative Example 2 of this application.

[0065] Explanation of reference numerals in the attached figures:

[0066] 1 Battery pack; 2 Upper housing; 3 Lower housing; 4 Battery module; 5 Secondary battery; 51 Housing; 52 Electrode assembly; 53 Cover plate. Detailed Implementation

[0067] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the conductive paste, current collector, secondary battery, battery module, battery pack, and power supply device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for a full understanding of this application by those skilled in the art and are not intended to limit the subject matter of the claims.

[0068] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0069] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0070] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0071] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0072] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0073] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0074] During the production and use of lithium-ion batteries, chemical reactions occur, producing gases such as carbon monoxide, carbon dioxide, and hydrogen. Carbon dioxide is produced in relatively large quantities. Secondary batteries typically have a sealed internal structure. When the internal gas volume increases to a certain extent, it causes deformation of the battery casing, resulting in bulging. When bulging occurs, some electrode plates cannot be immersed in the electrolyte, leading to a decrease in electrode performance. Further expansion of the internal space can cause the pressure relief valve to open, resulting in battery failure. To avoid these situations, adsorption materials are needed to adsorb harmful gases inside the battery.

[0075] In related technologies, titanium carbide absorbents are used to absorb carbon dioxide gas inside secondary batteries. However, the interlayer spacing of the titanium carbide layers in these absorbents is small, typically 1 nm to 3 nm. This type of titanium carbide exhibits a three-dimensional aggregated structure with a small specific surface area, resulting in fewer carbon dioxide adsorption sites on the absorbent and poor adsorption efficiency. Furthermore, due to the limited number of adsorption sites, adjacent carbon dioxide molecules easily aggregate before and after chemical reactions, further reducing the specific surface area of ​​the absorbent. This leads to a decrease in the absorbent's carbon dioxide absorption efficiency, and it may even lose its activity, further shortening its adsorption lifetime. Moreover, this absorbent has fewer functional groups on its surface that can bind to carbon dioxide and fewer electrons on its molecular surface; therefore, the aforementioned absorbent has a poor carbon dioxide absorption efficiency.

[0076] To address the above problems, this invention develops a current collector with an adsorption coating. This application selects titanium carbide with a two-dimensional layered structure and large interlayer spacing as the adsorbent. The two-dimensional layered structure of titanium carbide has a large adsorption space, thus improving the ability of the two-dimensional layered structure of titanium carbide in the adsorption coating to absorb carbon dioxide, thereby improving the stability and cycle life of the secondary battery.

[0077] current collector

[0078] In a first aspect, this application proposes a current collector comprising a substrate and an adsorption coating disposed on the substrate. The adsorption coating comprises a binder and titanium carbide having a two-dimensional layered structure. The two-dimensional layered titanium carbide has multiple layers of stacked titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm≤H≤5nm.

[0079] The titanium carbide with a two-dimensional layered structure in this application includes multiple layers of stacked titanium carbide nanosheets. In the microstructure of these nanosheets, the distance between adjacent nanosheets varies, resulting in different structures. When the distance between the titanium carbide nanosheets is small, molecules easily aggregate, forming a structure closer to a three-dimensional shape. This structure results in a low specific surface area, which is unfavorable for the adsorption of carbon dioxide molecules, thus hindering its adsorption performance as a carbon dioxide adsorbent.

[0080] When the distance between two adjacent titanium carbide nanosheets reaches 3nm≤H≤5nm, titanium carbide molecules can form a two-dimensional layered structure similar to graphene. The surface of the titanium carbide layer can provide enough space to adsorb carbon dioxide molecules, thereby enhancing the ability of titanium carbide to adsorb carbon dioxide. Therefore, titanium carbide with the above structure can have a strong ability to adsorb carbon dioxide.

[0081] In some embodiments of this application, the substrate has two surfaces opposite each other in its own thickness direction, and the adsorption coating is disposed on either or both of the two opposite surfaces of the substrate.

[0082] In some embodiments of this application, the current collector includes a positive current collector and a negative current collector, and the positive current collector and the negative current collector use different substrates.

[0083] In some embodiments of this application, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material substrate 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 (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0084] In some embodiments of this application, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer material substrate 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 (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0085] In some embodiments of this application, 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).

[0086] This application selects titanium carbide with a large interlayer spacing in a two-dimensional layered structure as an adsorbent. The two-dimensional layered structure of titanium carbide has a large adsorption space, thus improving the ability of the two-dimensional layered structure of titanium carbide in the adsorption coating to absorb carbon dioxide, thereby improving the stability and cycle life of the secondary battery.

[0087] In some embodiments, the specific surface area A of the two-dimensional layered titanium carbide structure satisfies: 25m² 2 / g≤A≤5m 2 / g.

[0088] According to the embodiments of this application, the specific surface area of ​​titanium carbide with a two-dimensional layered structure increases with the increase of the interlayer spacing of the stacked titanium carbide nanosheets. When the interlayer spacing reaches 3nm≤H≤5nm, a large specific surface area and strong adsorption capacity can be guaranteed.

[0089] In some embodiments, the titanium carbide nanosheets contain multiple cavities. In the above technical solution, the cavities in the titanium carbide nanosheets can combine with the active metal, and the distance between adjacent metal particles is increased to limit the bonding between the metal particles. Even after carbon dioxide combines with the active metal, the metal particles will not agglomerate, and the adsorption effect of the adsorbent can be guaranteed.

[0090] In some embodiments, multiple active metal particles are incorporated into the cavity. These active metal particles exhibit strong binding activity with carbon dioxide gas, allowing the metal particles in the cavity to rapidly bind with carbon dioxide. This technical solution effectively enhances the adsorption capacity of carbon dioxide gas.

[0091] In some embodiments, the surface of the titanium carbide nanosheets has multiple hydroxyl functional groups and / or multiple carboxylate functional groups. The hydroxyl functional groups and / or multiple carboxylate functional groups in titanium carbide can also bind to carbon dioxide molecules, further enhancing the adsorption capacity of the adsorption coating for carbon dioxide.

[0092] In some embodiments, the adsorption coating comprises, by weight parts:

[0093] Adhesive: 100 parts;

[0094] Two-dimensional layered titanium carbide: 17.5–23.6 parts.

[0095] The above technical solution, by adding an appropriate proportion of binder, ensures both the adhesion effect of the adsorption coating and the air-drying efficiency, while also guaranteeing the gas adsorption effect of titanium carbide.

[0096] In some embodiments, the adsorption coating further includes a single layer of titanium carbide nanosheets; optionally, multiple titanium carbide nanosheets are arranged in parallel orientation in the adsorption coating. The above-described technical solution, by peeling off the titanium carbide nanosheets to achieve partial parallel orientation of the titanium carbide nanosheets, can further increase the specific surface area of ​​titanium carbide and improve the adsorption effect.

[0097] Preparation method of current collector

[0098] A second aspect of this application also provides a method for preparing a current collector. Figure 1 This is a flowchart of one embodiment of the current collector preparation method according to this application. The following will describe... Figure 1 An example of a current collector preparation method is shown.

[0099] like Figure 1 As shown, the method for preparing the current collector includes the following steps:

[0100] S11. Provide an adsorption coating slurry, the slurry including a binder, a dispersion medium and titanium carbide with a two-dimensional layered structure, the titanium carbide with the two-dimensional layered structure having multiple layers of titanium carbide nanosheets stacked together, the interlayer spacing H between adjacent titanium carbide nanosheets satisfying the range: 3nm≤H≤5nm.

[0101] S12. Apply the adsorption coating slurry to at least a portion of the surface of the substrate and dry it to form an adsorption coating.

[0102] According to an embodiment of the current collector preparation method of this application, a binder, a dispersion medium, and titanium carbide with a two-dimensional layered structure are first mixed to form a slurry, and then the slurry is coated onto a substrate to form a current collector. The above-mentioned method for preparing the positive electrode sheet is simple and has high manufacturability.

[0103] In the above embodiments, the slurry, by selecting titanium carbide with a two-dimensional layered structure of multilayered titanium carbide nanosheets, enhances the current collector's ability to adsorb carbon dioxide gas, thereby improving the stability and cycle life of the secondary battery.

[0104] Electrode plates

[0105] A third aspect of this application provides an electrode sheet comprising: a current collector as provided in the first aspect of this application; and an active material layer disposed on the surface of an adsorption coating, or disposed between a substrate and the adsorption material layer. In the above technical solutions, the placement of the active material layer does not affect the adsorption effect of the adsorption coating.

[0106] In some embodiments, the active material layer may optionally include a conductive agent. As an example, the conductive agent may include at least one selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. It is understood that the aforementioned conductive agents can be used in either the positive electrode active material layer or the negative electrode material layer, and this is not limited thereto.

[0107] A fourth aspect of this application provides another electrode sheet, comprising: a substrate and an active material layer disposed on the substrate, the active material layer comprising: titanium carbide having a two-dimensional layered structure, an active material and a binder, wherein the titanium carbide having a two-dimensional layered structure comprises multiple layers of titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm≤H≤5nm.

[0108] In the above technical solution, the adsorbent material is directly added to the slurry of the active material to form an active material layer with adsorption function. Subsequently, it is directly coated on the surface of the substrate to form an electrode sheet, which saves manufacturing process, improves the manufacturing efficiency of the electrode sheet, and ensures the adsorption effect of carbon dioxide.

[0109] In any implementation, the specific surface area A of the two-dimensional layered titanium carbide structure satisfies: 25m² 2 / g≤A≤35m 2 / g.

[0110] In any embodiment, the titanium carbide nanosheets contain multiple cavities. These cavities can bind to and accommodate carbon dioxide molecules, increasing the spacing between adjacent carbon dioxide molecules, restricting the binding of adjacent molecules, and enhancing the adsorption capacity of carbon dioxide gas.

[0111] In any embodiment, the cavity contains multiple active metal particles. These active metal particles can also bind to carbon dioxide gas, effectively enhancing the adsorption capacity of carbon dioxide gas.

[0112] In any embodiment, the surface of the titanium carbide nanosheets has multiple hydroxyl functional groups and / or multiple carboxylate functional groups. Therefore, the hydroxyl functional groups and / or multiple carboxylate functional groups can also bind to carbon dioxide molecules, further enhancing the adsorption capacity of the active material layer for carbon dioxide.

[0113] In any embodiment, the active material layer comprises, by mass parts:

[0114] Adhesive, 100 parts;

[0115] Titanium carbide with a two-dimensional layered structure: 17.5–23.6 parts;

[0116] Active material, 3182–3318 parts.

[0117] In some embodiments, the adhesive may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0118] In some embodiments, the active material is selected based on the electrode being prepared. The positive electrode uses a positive active material, and the negative electrode uses a negative active material.

[0119] In some embodiments of this application, the active material varies depending on the type of electrode being manufactured. Specifically, the positive electrode uses a positive active material, and the negative electrode uses a negative active material.

[0120] In some embodiments, the positive electrode active material may be a known positive electrode active material for batteries. As an example, the positive electrode active material may include at least one of the following materials: lithium phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Examples of lithium phosphates with an olivine structure include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0121] In some embodiments, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0122] In any embodiment, the active material layer further includes a single layer of titanium carbide nanosheets, and optionally, multiple titanium carbide nanosheets are arranged in a normal orientation along the thickness direction.

[0123] The above-mentioned technical solution, by peeling some titanium carbide nanosheets from the stacked titanium carbide structure, can further increase the surface space and interlayer space of the titanium carbide layer, improve the specific surface area of ​​the titanium carbide adsorbent, and enhance the adsorption effect.

[0124] Methods for preparing electrode sheets

[0125] A fifth aspect of this application provides a method for preparing an electrode sheet. Figure 2 This is a flowchart of one embodiment of the electrode preparation method according to this application. The following will describe... Figure 2An example of the electrode preparation method shown.

[0126] like Figure 2 As shown, the method for preparing the electrode sheet includes the following steps:

[0127] S1. Provide an active material slurry, the slurry including a binder, a dispersion medium, an active material and titanium carbide with a two-dimensional layered structure, the titanium carbide with the two-dimensional layered structure having multiple layers of titanium carbide nanosheets stacked together, the interlayer spacing H between adjacent titanium carbide nanosheets satisfying the range: 3nm≤H≤5nm;

[0128] S2. Apply the slurry to at least a portion of the surface of the substrate and dry it to form an active material layer.

[0129] In some embodiments, the adhesive may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0130] In some embodiments, the selection of active materials depends on the electrode being prepared. The positive electrode uses a positive active material, and the negative electrode uses a negative active material. The specific settings of the active materials can be selected based on the examples provided above, and will not be repeated here.

[0131] In some embodiments, exemplary, the dispersion medium during the preparation of the positive electrode sheet can be an organic solvent, such as N-methylpyrrolidone.

[0132] In some embodiments, exemplary, the dispersion medium during the preparation of the negative electrode sheet can be an aqueous solvent, such as deionized water.

[0133] In any embodiment, the raw materials of each component of the slurry are added in the following mass ratios:

[0134] Titanium carbide with a two-dimensional layered structure: 17.5–23.6 parts;

[0135] Adhesive: 100 parts;

[0136] Dispersion medium: 1136–1347 parts;

[0137] Active material: 3182-3318 parts.

[0138] In any implementation, such as Figure 3 As shown, titanium carbide with a two-dimensional layered structure in step S1 is prepared through the following steps:

[0139] S101 provides MAX phase titanium aluminum carbide;

[0140] S102. Use hydrofluoric acid to etch MAX phase titanium aluminum carbide to obtain MXene titanium carbide.

[0141] S103. Mix MXene titanium carbide with copper nitrate solution to obtain a mixed solution. Treat the mixed solution with dimethyl sulfoxide in ice water and dry it to obtain titanium carbide with a two-dimensional layered structure.

[0142] Therefore, by adding dimethyl sulfoxide to expand the MXene titanium carbide layer structure, the interlayer spacing of titanium carbide nanosheets is increased, effectively improving the specific surface area of ​​titanium carbide and enhancing its adsorption capacity for carbon dioxide.

[0143] The seventh aspect of this application provides a secondary battery, including the electrode plates of the fourth or fifth aspect of this application.

[0144] Typically, a secondary battery consists of a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active ions move back and forth between the positive and negative electrodes, inserting and releasing. The electrolyte acts as a conductor between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits while allowing ions to pass through.

[0145] In some embodiments of this application, the positive electrode may be the electrode sheet described in the third or fourth aspect of this application. Therefore, the foregoing description of embodiments of the electrode sheet according to this application is also applicable to the positive electrode sheet in a secondary battery, and the same content will not be repeated.

[0146] In some embodiments of this application, the negative electrode may be the electrode sheet described in the third or fourth aspect of this application. Therefore, the foregoing description of embodiments of the electrode sheets according to this application is also applicable to the positive electrode sheet in a secondary battery, and the same content will not be repeated.

[0147] In some embodiments, the negative electrode film may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0148] In some embodiments of this application, the electrolyte acts as a conductor of ions between the positive and negative electrode plates. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel-like, or entirely solid.

[0149] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0150] In some embodiments, the electrolyte salt may be selected from one or more of NaPF6, NaClO4, NaBF4, KPF6, KClO4, KBF4, LiPF6, LiClO4, LiBF4, Zn(PF6)2, Zn(ClO4)2, and Zn(BF4)2.

[0151] In some embodiments, the electrolyte salt may be selected from one or more of NaPF6, NaClO4, and NaBF4.

[0152] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0153] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0154] In some embodiments of this application, there are no particular restrictions on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0155] In some embodiments, the material of the separator can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0156] In some embodiments, the positive electrode, negative electrode, and separator can be fabricated into an electrode assembly by a winding process or a stacking process.

[0157] In some embodiments, the secondary battery may include an outer packaging. This outer packaging may be used to encapsulate the electrode assembly and electrolyte described above.

[0158] In some embodiments, the outer packaging of the secondary battery can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of the secondary battery can also be a soft pack, such as a pouch. The material of the soft pack can be plastic; examples of plastics include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0159] This application does not impose any particular limitation on the shape of the secondary battery; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 4 A square-structured secondary battery 5 is shown as an example.

[0160] In some implementations, refer to Figure 5 The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. A positive electrode, a negative electrode, and a separator can be formed into an electrode assembly 52 using a winding or stacking process. The electrode assembly 52 is encapsulated within the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The secondary battery 5 may contain one or more electrode assemblies 52, which can be selected by those skilled in the art according to specific practical needs.

[0161] In some implementations, the secondary batteries can be assembled into a battery module, and the number of secondary batteries contained in the battery module can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery module.

[0162] Figure 6 Battery module 4 is shown as an example. (See reference...) Figure 6 In battery module 4, multiple secondary batteries 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, these multiple secondary batteries 5 can be fixed in place using fasteners.

[0163] Optionally, the battery module 4 may also include a housing with a receiving space in which a plurality of secondary batteries 5 are received.

[0164] The aforementioned battery modules can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more, and the specific number can be selected by those skilled in the art based on the application and capacity of the battery pack.

[0165] Figures and Figure 8 Battery pack 1 is shown as an example. (See reference...) Figure 7 and Figure 8 The battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0166] In addition, this application also provides an electrical device, such as Figure 9As shown, the electrical device includes at least one of the secondary battery, battery module, or battery pack provided in this application. The secondary battery, battery module, or battery pack can be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical 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.

[0167] As the electrical device, a secondary battery, battery module, or battery pack can be selected according to its usage requirements.

[0168] Figure 9 An example electrical device is shown. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of the secondary battery for this device, a battery pack or battery module can be used.

[0169] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use a rechargeable battery as their power source.

[0170] Example

[0171] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting 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 this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0172] The current collector in this embodiment is prepared according to the following method.

[0173] Examples 1-3

[0174] 1. Preparation of titanium carbide with a two-dimensional layered structure.

[0175] 1.1 Take titanium aluminum carbide powder and titanium carbide powder, and mix them evenly in a 1:1 molar ratio. The titanium aluminum carbide powder was purchased from ThermoFisher.

[0176] 1.2 Add the above-mentioned uniformly mixed powder to a ball mill and ball mill for 1 day.

[0177] 1.3 The mixture was placed in an alumina boat and heated to 1350°C at a rate of 5°C / min under a continuous Ar gas flow, and held at this temperature for 1 hour to obtain loose sintered bricks.

[0178] 1.4 The obtained loose sintered bricks were ground with a titanium carbide coated milling head and sieved through a 400-mesh sieve to obtain powder with a particle size of <38μmTi3AlC2.

[0179] 1.5 Dissolve 1g of Ti3AlC2 powder with a particle size of <38μm in 30mL of hydrofluoric acid and keep it at 35℃ for 24 hours while stirring with a magnetic stirrer to obtain a blocky solid.

[0180] The resulting lumpy solid was washed several times with deionized water, centrifuged at 3500 rpm for 3 minutes each time, until the pH of the supernatant was above 6. A portion of the solid was taken, dried, and used as Comparative Example 1.

[0181] 1.7 Remove the solid and add copper nitrate solution to it. The specific amount to be added is shown in Table 1 below. Add 20 ml of ice-cold distilled water and mix well.

[0182] 1.8 Then add 50-100 ml of dimethyl sulfoxide and stir at 100-150 rpm (maximum speed) for 48 hours.

[0183] 1.9 Subsequently, the sample was filtered with 50 ml of ethanol for 30 minutes. The filtered sample was then placed in a vacuum drying oven, along with a beaker containing a small amount of ice. The oven was then dried overnight at a temperature of 0–5 degrees Celsius to obtain titanium carbide powder with a two-dimensional layered structure.

[0184] Table 1 shows the concentrations of copper nitrate solution added in Examples 1-3.

[0185] Concentration (mass concentration) of copper nitrate aqueous solution Corresponding absorption curve Example 1 3wt% A Example 2 5wt% B Example 3 10wt% C Comparative Example 1 / / Comparative Example 2 0 M

[0186] 2. Preparation of current collectors (Examples 1-3 and Comparative Examples 1-2)

[0187] 2.1 Titanium carbide powder with a two-dimensional layered structure was mixed uniformly with a binder, and the powders of Comparative Example 1 and Comparative Example 2 were also mixed uniformly with the binder. Polypropylene was selected as the binder to prepare an adsorbent slurry.

[0188] 2.2 Using aluminum foil as the substrate, the adsorbent slurry is coated on the surface of the aluminum foil, and then cold-pressed and dried to obtain the current collector.

[0189] 3. Testing Methods

[0190] 3.1 Titanium carbide powder samples were observed using a ZEISS Gemini SEM 300 scanning electron microscope at 10k magnification in backscattered electron mode.

[0191] 3.2 The adsorption coating material on the current collector was subjected to XRD test using an XRD diffractometer to obtain the XRD spectrum.

[0192] Please refer to Figures 10 to 13 , Figure 10 This is a scanning electron microscope image of titanium carbide from Comparative Example 1 of this application. Figure 11 and Figure 12 The image shows a scanning electron microscope (SEM) image of a two-dimensional layered titanium carbide structure prepared according to an embodiment of this application. Figure 13 The XRD pattern of the above-mentioned titanium carbide powder is shown, revealing the characteristic diffraction peaks of the layered structure material Ti3C.

[0193] Figure 10 The diagram shows a multilayer titanium carbide exhibiting an aggregated three-dimensional structure. In Comparative Example 1, the titanium carbide, without dimethyl sulfoxide expansion, exhibits an aggregated three-dimensional structure with small interlayer spacing, resulting in a small specific surface area and poor carbon dioxide adsorption performance.

[0194] Figure 11 The image shows that the crystal structure of titanium carbide exhibits a two-dimensional layered structure similar to graphene. Specifically, the two-dimensional layered titanium carbide structure comprises multiple stacked titanium carbide nanosheets. For example... Figure 12 As shown, the interlayer spacing H between adjacent titanium carbide nanosheets ranges from 3 nm to 5 nm. Figure 13 The XRD pattern of the above-mentioned titanium carbide powder shows the characteristic diffraction peaks of the layered structure material Ti3C. XRD patterns can be determined using methods and instruments known in the art. For example, XRD tests can be performed using an X'Pert Pro MPD X-ray diffractometer, where the radiation source for the XRD test is a Cu target, and the test parameters can be set as follows: tube voltage of 40 kV, tube current of 30 mA, scan rate of 8° / min, and 2θ range of 10°–80°.

[0195] By adding dimethyl sulfoxide to expand the above-mentioned titanium carbide layered structure, the interlayer spacing between adjacent titanium carbide nanolayers is increased, thereby enhancing the ability to adsorb carbon dioxide.

[0196] Furthermore, titanium carbide nanosheets can be exfoliated from the layered structure of titanium carbide by dispersing with ethanol, filtering, and then vacuum low-temperature drying. Figure 14 Titanium carbide nanosheets exfoliated from a layered titanium carbide structure are shown. When titanium carbide powder is uniformly mixed with a binder to form an adsorption coating, multiple titanium carbide nanosheets can be arranged in parallel orientation within the adsorption coating.

[0197] In the embodiments of this application, the current collector is selected as an adsorbent by using titanium carbide with a two-dimensional layered structure and a large interlayer spacing of titanium carbide nanosheets. The two-dimensional layered structure of titanium carbide has a large adsorption space, thus improving the ability of the two-dimensional layered structure of titanium carbide in the adsorption coating to absorb carbon dioxide, thereby improving the stability of the secondary battery operation and the cycle life.

[0198] In the current collector preparation process of this application embodiment, the Al layer in the middle of the layered compound Ti3AlC2 is etched with hydrofluoric acid, providing more vacancies while maintaining its overall structure. Simultaneously, by adding copper nitrate solution, active copper ions are introduced. These active metal ions can effectively capture free carbon dioxide, thus further enhancing the adsorbent's ability to adsorb carbon dioxide. Furthermore, by adding dimethyl sulfoxide to expand the aforementioned titanium carbide layered structure, the interlayer spacing between adjacent titanium carbide nanolayers is increased, releasing adsorption sites on the surface and between layers of Ti3C2, thereby further enhancing the titanium carbide's ability to adsorb carbon dioxide.

[0199] In some embodiments, such as Figure 14 As shown, electron microscopy also reveals sheet-like titanium carbide nanosheets within the aforementioned adsorption coating. These sheet-like titanium carbide nanosheets were peeled off from multilayered titanium carbide nanosheets using ethanol under vacuum and low temperature conditions. Multiple titanium carbide nanosheets are arranged in parallel orientation within the adsorption coating. This technical solution further increases the specific surface area of ​​titanium carbide and enhances its ability to adsorb carbon dioxide.

[0200] 3.3 Gas chromatography analysis of the differences in the adsorption effect of different concentrations of copper nitrate solution on carbon dioxide adsorption by the adsorbent.

[0201] The current collectors prepared in Examples 1 to 3 and Comparative Example 2 were placed in a sealed box, and the gas in the sealed box was heated.

[0202] The concentration of carbon dioxide in the blocked phase was monitored in real time using a gas chromatograph. The CO2 absorbance curve was obtained by calculating (initial CO2 concentration - real-time CO2 concentration) / initial CO2 concentration. Please refer to [reference needed]. Figure 14 Gas chromatographic analysis of the adsorption effect of titanium carbide adsorbent with different concentrations of copper nitrate.

[0203] like Figure 15 As shown, in Example 1, curve A represents the titanium carbide adsorbent with the addition of a 3 wt% copper nitrate solution. With increasing temperature, the adsorbent's ability to adsorb carbon dioxide increases, and the carbon dioxide adsorption capacity of Example 1 is higher than that of the comparative example and other examples. Adding 3 wt% copper nitrate solution can significantly improve the adsorption efficiency of titanium carbide.

[0204] In Example 2, curve B represents the titanium carbide adsorbent with 5 wt% copper nitrate solution added. As the temperature increases, the adsorbent's ability to adsorb carbon dioxide increases, and the carbon dioxide adsorption capacity of Example 2 is higher than that of the comparative example and Example 3. Adding 5 wt% copper nitrate solution also significantly improves the adsorption efficiency of titanium carbide.

[0205] In Example 3, curve C represents the titanium carbide adsorbent with a 10 wt% copper nitrate solution added. As the temperature increases, the adsorbent's ability to adsorb carbon dioxide increases, but the concentration of added copper nitrate is relatively high.

[0206] In Comparative Example 2, curve M represents the titanium carbide adsorbent without added active metal. With increasing temperature, the adsorbent's ability to adsorb carbon dioxide did not significantly improve, ultimately reaching an adsorption rate of only 0.03%, which is worse than the adsorption effect without added active metal. This is because when the Cu content is high, excess copper ions remain on the surface of the titanium carbide nanosheets. Under high temperature, the copper ions on the surface of the titanium carbide nanosheets and in the vacancies aggregate and enlarge, thereby disrupting the confinement effect of the vacancies and reducing the adsorption capacity of the titanium carbide nanosheets for carbon dioxide.

[0207] In summary, the above analysis shows that adding active metals can effectively enhance the ability of titanium carbide adsorbent to adsorb carbon dioxide, and adding a 3wt% copper nitrate solution can significantly improve the adsorption performance of titanium carbide.

[0208] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A current collector, characterized in that, The material includes a substrate and an adsorption coating disposed on the substrate. The adsorption coating includes an adhesive and titanium carbide having a two-dimensional layered structure. The two-dimensional layered titanium carbide has multiple layers of titanium carbide nanosheets stacked together, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies: 3nm≤H≤5nm.

2. The current collector according to claim 1, characterized in that, The specific surface area A of the two-dimensional layered titanium carbide structure satisfies: 25 m² / g ≤ A ≤ 35 m² / g.

3. The current collector according to claim 1, characterized in that, The titanium carbide nanosheets contain multiple vacancies.

4. The current collector according to claim 1, characterized in that, The surface of the titanium carbide nanosheets has multiple hydroxyl functional groups.

5. The current collector according to claim 1 or 2, characterized in that, The adsorption coating comprises, by mass parts: Adhesive: 100 parts; Two-dimensional layered titanium carbide: 17.5~23.6 parts.

6. The current collector according to claim 5, characterized in that, The adsorption coating also includes a single layer of titanium carbide nanosheets.

7. The current collector according to claim 6, characterized in that, Multiple titanium carbide nanosheets are arranged in parallel orientation in the adsorption coating.

8. A method for preparing a current collector, characterized in that, include: An adsorption coating slurry is provided, the slurry comprising a binder, a dispersion medium and titanium carbide having a two-dimensional layered structure, wherein the titanium carbide having a two-dimensional layered structure comprises multiple layers of titanium carbide nanosheets, and the interlayer spacing H between adjacent titanium carbide nanosheets satisfies the range of 3nm≤H≤5nm. The adsorption coating slurry is applied to at least a portion of the surface of the substrate and dried to form an adsorption coating.

9. An electrode sheet, characterized in that, include: The current collector as described in any one of claims 1 to 7; An active material layer is disposed on the surface of the adsorption coating.

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