Rolling resistant fluid and its use

Abstract

The application provides an anti-rolling current collector and application thereof. The provided current collector comprises an anti-rolling film layer and a metal layer, the metal layer is located on at least one surface of the anti-rolling film layer; the anti-rolling film layer is formed by a hydrogen bond cross-linking type photoresponsive polymer, a cross-linking agent and a polymer material melt. Also provided are a positive electrode sheet, a battery and an electric device.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more specifically to an anti-rolling current collector and its application. Background Technology

[0002] Composite current collectors are battery materials with a "sandwich" structure, consisting of an inner polymer layer, a middle conductive metal layer, and an outer corrosion-resistant material layer. The inner polymer layer serves as the positive electrode, the conductive metal layer as the negative electrode, and the outer corrosion-resistant material provides insulation and protection. The advantages of composite current collectors lie in their high energy density and good cycle life, while also providing sufficient overcharge protection, stable high-current discharge capability, and excellent safety performance. They can be widely used in high-performance battery applications, such as solar cells and lithium-ion batteries. Compared to traditional aluminum or copper foil, composite current collectors can reduce battery costs, increase energy density, and improve safety performance, thus being considered one of the best solutions for achieving high-energy-density batteries.

[0003] In the lithium-ion battery cell manufacturing process, a roll forming process is indispensable. Current roll forming technology results in differences in tension and elongation between the electrode coating and the composite current collector area. This leads to significant tensile stress in the composite current collector area after roll forming, causing wrinkling at the edges of the composite current collector. Consequently, this results in tab folding and poor cutting during subsequent production. To reduce edge wrinkling, most companies have modified the structural design of the roll forming equipment, but the solution has been unsatisfactory. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. The invention provides an anti-rolling pressure current collector and electrode sheet, a battery, and an electrical device. The provided anti-rolling pressure current collector incorporates an anti-rolling pressure thin film layer, in which a hydrogen-bonded cross-linked photoresponsive polymer can cross-link with a cross-linking agent to form a bonded polymer, thereby causing the polymer film to shrink and thus solving the problem of wrinkling at the electrode sheet edges.

[0005] Specifically, the present invention provides the following technical solution:

[0006] A first aspect of the invention provides an anti-rolling current collector, comprising an anti-rolling film layer and a metal layer, the metal layer being located on at least one surface of the anti-rolling film layer; the anti-rolling film layer comprising a hydrogen-bonded crosslinked photoresponsive polymer, a crosslinking agent, and a polymeric material.

[0007] The anti-rolling current collector provided by this invention features an anti-rolling film layer containing a hydrogen-bonded cross-linked photoresponsive polymer, a cross-linking agent, and a polymer material. These three materials form a shrinkable film. During rolling, heating and light exposure reduce stretching in the rolled portion, thus solving the edge wrinkling problem. Furthermore, the hydrogen-bonded cross-linked photoresponsive polymer forms a hydrogen-bonded network under ultraviolet light; breaking these hydrogen bonds softens and expands the polymer. Adding a heat-sensitive cross-linking agent triggers a cross-linking reaction upon heating, forming a three-dimensional network that intercalates the hydrogen-bonded polymer, causing the polymer film to shrink. Therefore, by controlling the conditions of ultraviolet light and the heat-sensitive cross-linking reaction, precise shrinkage of the polymer film can be achieved, thereby solving the edge wrinkling problem.

[0008] According to embodiments of the present invention, the anti-roller current collector described above may further include the following technical features:

[0009] According to an embodiment of the present invention, the mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymer material is (2.5-10):(2.5-10):(80-95). According to a preferred embodiment of the present invention, the mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymer material is (2.5-6):(2.5-6):(88-95).

[0010] According to an embodiment of the present invention, the hydrogen-bonded crosslinked photoresponsive polymer is a linear azobenzene polymer containing hydrogen bonds. According to an embodiment of the present invention, the hydrogen-bonded crosslinked photoresponsive polymer is obtained by addition polymerization of a diol containing an azophenyl group and a diisocyanate.

[0011] According to an embodiment of the present invention, the crosslinking agent is at least one selected from acrylic acid, bis(4-chlorophenoxy)glucose, diethylene glycol diacrylate, N,N'-methylenebisacrylamide, and phthaloyl dihydroxyethyl ester.

[0012] According to embodiments of the present invention, the polymeric material includes at least one selected from polypropylene, polyethylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene ether, polystyrene, and polyamide.

[0013] According to an embodiment of the present invention, the anti-rolling current collector further includes a substrate layer, and the anti-rolling film layer is located on at least one surface of the substrate layer.

[0014] According to an embodiment of the present invention, the thickness of the anti-rolling film layer is 1μm to 8μm; the thickness of the metal layer is 100nm to 1000nm.

[0015] According to an embodiment of the present invention, the anti-rolling film layer is formed by melting a hydrogen-bonded crosslinked photoresponsive polymer, a crosslinking agent, and a polymer material, and the anti-rolling film layer is prepared by the following method:

[0016] The hydrogen-bonded cross-linked photoresponsive polymer, cross-linking agent, and polymer material are mixed, heated and melted, and then extruded to obtain polymer slices.

[0017] The polymer slices are crystallized at a predetermined temperature and then dried. The dried polymer slices are then heated and melted, extruded and cast, and cooled to obtain polymer cast sheets.

[0018] The polymer casting is heated and subjected to longitudinal and transverse stretching and shaping to obtain the anti-rolling film layer.

[0019] According to an embodiment of the present invention, the temperature of the first heating and melting is 220 to 260 degrees Celsius.

[0020] According to an embodiment of the present invention, the predetermined temperature is 130 to 180 degrees Celsius.

[0021] According to an embodiment of the present invention, the second heating and melting temperature is 250 to 300 degrees Celsius.

[0022] According to an embodiment of the present invention, the longitudinal stretching temperature is 100 to 130 degrees Celsius, and the stretching ratio is 2:1 to 4:1.

[0023] According to an embodiment of the present invention, the temperature of the transverse stretching is 100 to 130 degrees Celsius, and the stretching ratio is 2:1 to 4:1.

[0024] According to an embodiment of the present invention, the metal layer is prepared by the following method:

[0025] The metal is melted and evaporated, and then cooled, so that the evaporated metal atoms are deposited on the surface of the anti-rolling film layer to obtain a metal layer.

[0026] According to an embodiment of the present invention, the melting and evaporation temperature is 1200–1800 degrees Celsius.

[0027] A second aspect of the present invention provides an electrode sheet comprising the anti-rolling current collector described in the first aspect above, and an active material layer attached to at least one surface of the anti-rolling current collector.

[0028] A third aspect of the present invention provides a battery comprising the electrode sheet described in the second aspect above.

[0029] A fourth aspect of the present invention provides an electrical device comprising the battery described above.

[0030] The beneficial effects achieved by this invention are as follows:

[0031] (1) Shrink film manufacturing was achieved through material composition optimization. Heating and light exposure during rolling reduced the stretching of the rolling part, thereby solving the problem of edge wrinkling.

[0032] (2) Hydrogen-bonded crosslinked photoresponsive polymers can form a hydrogen-bonded network under ultraviolet light. Breaking these hydrogen bonds causes the polymer to soften and expand. When a heat-sensitive crosslinking agent is added, these agents undergo a crosslinking reaction upon heating, forming a three-dimensional network that intercalates the hydrogen-bonded polymer, causing the polymer film to shrink. Therefore, by controlling the conditions of ultraviolet light and the heat-sensitive crosslinking reaction, precise shrinkage of the polymer film can be achieved, thereby solving the problem of edge wrinkling. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an anti-rolling current collector according to an embodiment of the present invention, wherein reference numeral 1 is the anti-rolling thin film layer and 2 is the metal layer.

[0034] Figure 2 This is a schematic diagram of an anti-rolling current collector according to an embodiment of the present invention, wherein 1 is the anti-rolling film layer, 2 is the metal layer, and 3 is the substrate layer. Detailed Implementation

[0035] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0036] A first aspect of the invention provides an anti-rolling current collector, comprising an anti-rolling film layer and a metal layer, the metal layer being located on at least one surface of the anti-rolling film layer; the anti-rolling film layer comprising a hydrogen-bonded crosslinked photoresponsive polymer, a crosslinking agent, and a polymeric material.

[0037] According to specific embodiments of the present invention, such as Figure 1 As shown, the metal layer is located on both sides of the anti-rolling film layer (located on the outer side of the anti-rolling film layer), where 1 is the anti-rolling film layer and 2 is the metal layer. According to a specific embodiment of the present invention, as... Figure 2 As shown, it further includes a substrate layer, the anti-rolling film layer is located on both sides of the substrate layer (located on the outside of the substrate layer), and the metal layer is located on both sides of the anti-rolling film layer (located on the outside of the anti-rolling film layer), wherein reference numeral 1 is the anti-rolling film layer, reference numeral 2 is the metal layer, and reference numeral 3 is the substrate layer.

[0038] The anti-rolling current collector provided by this invention features an anti-rolling film layer containing a hydrogen-bonded cross-linked photoresponsive polymer, a cross-linking agent, and a polymer material. These three materials form a shrinkable film. During rolling, heating and light exposure reduce stretching in the rolled portion, thus solving the edge wrinkling problem. Furthermore, the hydrogen-bonded cross-linked photoresponsive polymer forms a hydrogen-bonded network under ultraviolet light; breaking these hydrogen bonds softens and expands the polymer. Adding a heat-sensitive cross-linking agent triggers a cross-linking reaction upon heating, forming a three-dimensional network that intercalates the hydrogen-bonded polymer, causing the polymer film to shrink. Therefore, by controlling the conditions of ultraviolet light and the heat-sensitive cross-linking reaction, precise shrinkage of the polymer film can be achieved, thereby solving the edge wrinkling problem.

[0039] According to an embodiment, the mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymeric material is (2.5-10):(2.5-10):(80-95). According to a preferred embodiment of the invention, the mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymeric material is (2.5-6):(2.5-6):(88-95). According to a preferred embodiment, the mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymeric material is (3-5):(3-5):(90-94). For example, 5:5:90.

[0040] According to the embodiments, the hydrogen-bonded crosslinked photoresponsive polymer is a hydrogen-bonded linear azobenzene polymer. These hydrogen-bonded linear azobenzene polymers are linear backbone azobenzene liquid crystal polymers with high hydrogen bond crosslinking density, which can be synthesized by addition polymerization of azobenzene glycol and diisocyanate. This can be obtained by referring to the text of Chinese patent application number 202010686469.0 and publication number CN111875765B. This material is simple to synthesize, introducing a high density of hydrogen bonds into its linear structure, giving the material good crystallinity and liquid crystallization, ensuring good processability while improving its mechanical properties. Under ultraviolet light irradiation, the azobenzene groups inside this material undergo photoisomerization, lowering the glass transition temperature (Tg) of the material. Increasing the ultraviolet light intensity, the photothermal effect of azobenzene raises the temperature of the material, promoting dynamic exchange of hydrogen bonds within the material. By utilizing these two phase transitions as reversible phases and the high-temperature stable crystalline phase as the stationary phase, we can achieve precise, photo-controlled editing and restoration of permanent and temporary shapes simply by adjusting the light intensity. The advantage of this method lies in using the synergistic effect of the azobenzene polymer's photothermal effect and photoinduced Tg reduction to separate the overlapping reversible phase transition temperature zones, achieving multiple shape memories and restorations at lower temperatures. The lower shape restoration temperature also helps avoid thermal creep, and high shape fixation and restoration rates can be obtained even with only linear structures.

[0041] According to a specific embodiment, the hydrogen-bonded crosslinked photoresponsive polymer is a hydrogen-bonded linear azobenzene polymer PAB1-HDI(M n-GPC ~12000), or a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC These polymers (~18000) and their preparation methods are described in the Chinese patent application No. 202010686469.0 and publication No. CN111875765B. Those skilled in the art can cite them in this invention as needed.

[0042] According to specific embodiments, the crosslinking agent is at least one selected from acrylic acid, bis(4-chlorophenoxy)glucose, diethylene glycol diacrylate, N,N'-methylenebisacrylamide, and phthaloyl dihydroxyethyl ester. Acrylic acid is preferred.

[0043] According to specific embodiments, the polymer material includes at least one of polypropylene, polyethylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene ether, polystyrene, and polyamide.

[0044] According to a specific embodiment, the thickness of the anti-rolling film layer is 1μm to 8μm, for example, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm or 8μm. Preferably, it is 4μm to 8μm, for example, 4μm, 5μm, 6μm, 7μm or 8μm.

[0045] According to specific embodiments, the thickness of the metal layer is 100nm-1000nm, for example, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, or 1000nm. Preferably, it is 800-1000nm, for example, 800nm, 900nm, or 1000nm.

[0046] According to an embodiment of the present invention, the anti-rolling film layer is formed by melting a hydrogen-bonded crosslinked photoresponsive polymer, a crosslinking agent, and a polymer material, and the anti-rolling film layer is prepared by the following method:

[0047] The hydrogen-bonded cross-linked photoresponsive polymer, cross-linking agent, and polymer material are mixed, heated and melted, and then extruded to obtain polymer slices.

[0048] The polymer slices are crystallized at a predetermined temperature and then dried. The dried polymer slices are then heated and melted, extruded and cast, and cooled to obtain polymer cast sheets.

[0049] The polymer casting is heated and stretched longitudinally and laterally to obtain the anti-rolling film layer.

[0050] According to a specific embodiment, the temperature of the first heating and melting is 220–260 degrees Celsius. According to a preferred embodiment, the temperature of the first heating and melting is 240–250 degrees Celsius, for example, 245 degrees Celsius.

[0051] According to a specific embodiment, the predetermined temperature is 130–180 degrees Celsius. According to a preferred embodiment, the predetermined temperature is 140–160 degrees Celsius, for example, 150 degrees Celsius. The drying temperature is 150–170 degrees Celsius.

[0052] According to a specific embodiment, the second heating and melting temperature is 250–300 degrees Celsius. According to a preferred embodiment, the second heating and melting temperature is 260–280 degrees Celsius.

[0053] According to a specific embodiment, the temperature of the longitudinal stretching is 100 to 130 degrees Celsius (e.g., 110 degrees Celsius), and the stretching ratio is 2:1 to 4:1 (e.g., 3:1).

[0054] According to a specific embodiment, the temperature of the transverse stretching is 100 to 130 degrees Celsius (e.g., 110 degrees Celsius), and the stretching ratio is 2:1 to 4:1 (e.g., 3:1).

[0055] According to a specific embodiment, the metal layer is prepared by the following method:

[0056] The metal is melted and evaporated, and then cooled, so that the evaporated metal atoms are deposited on the surface of the anti-rolling film layer to obtain a metal layer.

[0057] According to a specific embodiment, the melting and evaporation temperature is 1200–1800 degrees Celsius. According to a specific embodiment, the melting and evaporation temperature is 1300–1500 degrees Celsius, for example, 1400 degrees Celsius.

[0058] A second aspect of the present invention provides an electrode sheet comprising the anti-rolling current collector described in the first aspect above, and an active material layer attached to at least one surface of the anti-rolling current collector.

[0059] A third aspect of the present invention provides a battery comprising the electrode sheet described in the second aspect above.

[0060] A fourth aspect of the present invention provides an electrical device comprising the battery described above.

[0061] The technical solution of the present invention will be described below through embodiments. It should be noted that these embodiments are only used to facilitate understanding by those skilled in the art and should not be regarded as a limitation on the scope of protection of the present invention. The reagents in the embodiments can all be commercially available or prepared by methods known in the art.

[0062] Example 1

[0063] Example 1 provides a method for preparing an anti-roller current collector, comprising the following steps:

[0064] S1. Prepare an anti-rolling-pressure thin film layer;

[0065] (1) Based on mass percentage, 90.0 wt% PET (polyethylene terephthalate), 5.0 wt% hydrogen-bonded crosslinked photoresponsive polymer (which is a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC ~18000), the polymer and its preparation method refer to CN111875765B), 5.0wt% acrylic acid, heated to 245℃ to melt, mixed, extruded, shaped and sliced ​​to obtain polymer slices;

[0066] (2) Place the polymer slices in a crystallizer, heat to 150°C, crystallize, keep warm for 40 minutes, transfer the polymer slices to a drying tower, heat to 155°C, dry for 140 minutes, heat the dried polymer slices to 270°C, melt and extrude, and then form a polymer casting by casting roller and water cooling.

[0067] (3) Heat the casting to 90°C, preheat for 10 seconds, then heat to 110°C and stretch longitudinally with a stretching ratio of 3:1. After the longitudinal stretching is completed, heat to 170°C, heat set for 10 seconds, then cool to 40°C and cool to form a longitudinally stretched casting.

[0068] (4) The longitudinally stretched casting sheet is heated to 90°C, preheated for 10s, then heated to 120°C, and longitudinally stretched with a stretching ratio of 3:1. After the longitudinal stretching is completed, the temperature is raised to 170°C, heat-set for 10s, and then cooled to 110°C to form a roll-press resistant film layer with a thickness of 6 micrometers.

[0069] S2. Prepare the reinforcing metal layer;

[0070] The anti-rolling film layer is placed in a vacuum evaporation chamber, and the high-purity aluminum wire in the metal evaporation chamber is melted and evaporated at a high temperature of 1400℃. The evaporated metal atoms are cooled by the cooling system in the vacuum coating chamber and deposited on both sides of the surface of the polymer substrate layer to form a metal layer with a thickness of 1000nm. After being removed, the anti-rolling current collector is obtained.

[0071] Example 2

[0072] Example 2 provides a method for preparing an anti-roller current collector, comprising the following steps:

[0073] S1. Prepare an anti-rolling-pressure thin film layer;

[0074] (1) Based on mass percentage, 94.0 wt% PET and 3.0 wt% hydrogen-bonded cross-linked photoresponsive polymer (which is a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC ~18000), the polymer and its preparation method refer to CN111875765B), 3.0wt% acrylic acid, heated to 245℃ to melt, mixed, extruded, shaped and sliced ​​to obtain polymer slices;

[0075] (2) Place the polymer slices in a crystallizer, heat to 150°C, crystallize, keep warm for 40 minutes, transfer the polymer slices to a drying tower, heat to 155°C, dry for 140 minutes, heat the dried polymer slices to 270°C, melt and extrude, and then form a polymer casting by casting roller and water cooling.

[0076] (3) Heat the casting to 90°C, preheat for 10 seconds, then heat to 110°C and stretch longitudinally with a stretching ratio of 3:1. After the longitudinal stretching is completed, heat to 170°C, heat set for 10 seconds, then cool to 40°C and cool to form a longitudinally stretched casting.

[0077] (4) The longitudinally stretched casting sheet is heated to 90°C, preheated for 10s, then heated to 120°C, and longitudinally stretched with a stretching ratio of 3:1. After the longitudinal stretching is completed, the temperature is raised to 170°C, heat-set for 10s, and then cooled to 110°C to form a roll-press resistant film layer with a thickness of 6 micrometers.

[0078] S2. Prepare the reinforcing metal layer;

[0079] The anti-rolling film layer is placed in a vacuum evaporation chamber, and the high-purity aluminum wire in the metal evaporation chamber is melted and evaporated at a high temperature of 1400℃. The evaporated metal atoms are cooled by the cooling system in the vacuum coating chamber and deposited on both sides of the surface of the polymer substrate layer to form a metal layer with a thickness of 1000nm. After being removed, the anti-rolling current collector is obtained.

[0080] Example 3

[0081] Example 3 provides a method for preparing an anti-roller current collector, comprising the following steps:

[0082] S1. Prepare an anti-rolling-pressure thin film layer;

[0083] (1) Based on mass percentage, 84.0 wt% PET and 8.0 wt% hydrogen-bonded cross-linked photoresponsive polymer (which is a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC ~18000), the polymer and its preparation method refer to CN111875765B), 8.0wt% acrylic acid, heated to 245℃ to melt, mixed, extruded, shaped and sliced ​​to obtain polymer slices;

[0084] (2) Place the polymer slices in a crystallizer, heat to 150°C, crystallize, keep warm for 40 minutes, transfer the polymer slices to a drying tower, heat to 155°C, dry for 140 minutes, heat the dried polymer slices to 270°C, melt and extrude, and then form a polymer casting by casting roller and water cooling.

[0085] (3) Heat the casting to 90°C, preheat for 10 seconds, then heat to 110°C and stretch longitudinally with a stretching ratio of 3:1. After the longitudinal stretching is completed, heat to 170°C, heat set for 10 seconds, then cool to 40°C and cool to form a longitudinally stretched casting.

[0086] (4) The longitudinally stretched casting sheet is heated to 90°C, preheated for 10s, then heated to 120°C, and longitudinally stretched with a stretching ratio of 3:1. After the longitudinal stretching is completed, the temperature is raised to 170°C, heat-set for 10s, and then cooled to 110°C to form a roll-press resistant film layer with a thickness of 6 micrometers.

[0087] S2. Prepare the reinforcing metal layer;

[0088] The anti-rolling film layer is placed in a vacuum evaporation chamber, and the high-purity aluminum wire in the metal evaporation chamber is melted and evaporated at a high temperature of 1400℃. The evaporated metal atoms are cooled by the cooling system in the vacuum coating chamber and deposited on both sides of the surface of the polymer substrate layer to form a metal layer with a thickness of 1000nm. After being removed, the anti-rolling current collector is obtained.

[0089] Comparative Example 1

[0090] Compared with the technical solution of Example 1, Comparative Example 1 does not add hydrogen-bonded crosslinked photoresponsive polymer and acrylic acid.

[0091] Comparative Example 2

[0092] Comparative Example 2 provides a method for preparing an anti-roller current collector, comprising the following steps:

[0093] S1. Prepare an anti-rolling-pressure thin film layer;

[0094] (1) Based on mass percentage, 98.0 wt% PET and 1.0 wt% hydrogen-bonded crosslinked photoresponsive polymer (which is a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC ~18000), the polymer and its preparation method refer to CN111875765B), 1.0wt% acrylic acid, heated to 245℃ to melt, mixed, extruded, shaped and sliced ​​to obtain polymer slices;

[0095] (2) Place the polymer slices in a crystallizer, heat to 150°C, crystallize, keep warm for 40 minutes, transfer the polymer slices to a drying tower, heat to 155°C, dry for 140 minutes, heat the dried polymer slices to 270°C, melt and extrude, and then form a polymer casting by casting roller and water cooling.

[0096] (3) Heat the casting to 90°C, preheat for 10 seconds, then heat to 110°C and stretch longitudinally with a stretching ratio of 3:1. After the longitudinal stretching is completed, heat to 170°C, heat set for 10 seconds, then cool to 40°C and cool to form a longitudinally stretched casting.

[0097] (4) The longitudinally stretched casting sheet is heated to 90°C, preheated for 10s, then heated to 120°C, and longitudinally stretched with a stretching ratio of 3:1. After the longitudinal stretching is completed, the temperature is raised to 170°C, heat-set for 10s, and then cooled to 110°C to form a roll-press resistant film layer with a thickness of 6 micrometers.

[0098] S2. Prepare the reinforcing metal layer;

[0099] The anti-rolling film layer is placed in a vacuum evaporation chamber, and the high-purity aluminum wire in the metal evaporation chamber is melted and evaporated at a high temperature of 1400℃. The evaporated metal atoms are cooled by the cooling system in the vacuum coating chamber and deposited on both sides of the surface of the polymer substrate layer to form a metal layer with a thickness of 1000nm. After being removed, the anti-rolling current collector is obtained.

[0100] Comparative Example 3

[0101] Comparative Example 3 provides a method for preparing an anti-roller current collector, comprising the following steps:

[0102] S1. Prepare an anti-rolling-pressure thin film layer;

[0103] (1) Based on mass percentage, 70.0 wt% PET and 15.0 wt% hydrogen-bonded cross-linked photoresponsive polymer (which is a hydrogen-bonded linear azobenzene polymer PAB2-IPDI (M n-GPC ~18000), the polymer and its preparation method refer to CN111875765B), 15.0wt% acrylic acid, heated to 245℃ to melt, mixed, extruded, shaped and sliced ​​to obtain polymer slices;

[0104] (2) Place the polymer slices in a crystallizer, heat to 150°C, crystallize, keep warm for 40 minutes, transfer the polymer slices to a drying tower, heat to 155°C, dry for 140 minutes, heat the dried polymer slices to 270°C, melt and extrude, and then form a polymer casting by casting roller and water cooling.

[0105] (3) Heat the casting to 90°C, preheat for 10 seconds, then heat to 110°C and stretch longitudinally with a stretching ratio of 3:1. After the longitudinal stretching is completed, heat to 170°C, heat set for 10 seconds, then cool to 40°C and cool to form a longitudinally stretched casting.

[0106] (4) The longitudinally stretched casting sheet is heated to 90°C, preheated for 10s, then heated to 120°C, and longitudinally stretched with a stretching ratio of 3:1. After the longitudinal stretching is completed, the temperature is raised to 170°C, heat-set for 10s, and then cooled to 110°C to form a roll-press resistant film layer with a thickness of 6 micrometers.

[0107] S2. Prepare the reinforcing metal layer;

[0108] The anti-rolling film layer is placed in a vacuum evaporation chamber, and the high-purity aluminum wire in the metal evaporation chamber is melted and evaporated at a high temperature of 1400℃. The evaporated metal atoms are cooled by the cooling system in the vacuum coating chamber and deposited on both sides of the surface of the polymer substrate layer to form a metal layer with a thickness of 1000nm. After being removed, the anti-rolling current collector is obtained.

[0109] Experimental example:

[0110] Tensile strength: Tensile strength was tested according to national standard GB / T 1040.3-2006.

[0111] Maximum deformation under rolling: 96g of active material NMC811, 2g of conductive agent carbon black, and 2g of binder PVDF were added to 80g of NMP and mixed evenly to obtain a ternary cathode slurry. The ternary cathode slurry was then uniformly coated onto the surface of the high-temperature resistant composite current collector obtained above, dried, and rolled (rolling pressure 60MPa) to obtain the cathode sheet. The material was laid flat on the experimental table, and the height of the section with the greatest bending was measured using a steel ruler.

[0112] Table 1

[0113]

[0114]

[0115] The data above show that, compared to Comparative Example 1, the positive electrode prepared with the hydrogen-bonded cross-linked photoresponsive polymer and acrylic acid anti-rolling current collector exhibits significantly higher tensile strength and a significantly lower maximum roll deformation. Compared to Comparative Examples 2 and 3, Examples 1-3, with the addition of appropriate amounts of hydrogen-bonded cross-linked photoresponsive polymer and acrylic acid, show significantly better tensile strength and lower maximum roll deformation than Comparative Examples 2 and 3.

[0116] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "implementation," "specific implementation," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0117] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A roller-pressure resistant current collector, characterized in that, It includes an anti-rolling film layer and a metal layer, wherein the metal layer is located on at least one surface of the anti-rolling film layer; the anti-rolling film layer comprises a hydrogen-bonded cross-linked photoresponsive polymer, a cross-linking agent, and a polymeric material. The hydrogen-bonded crosslinked photoresponsive polymer, the mass ratio of the crosslinking agent to the polymer material is (2.5-10):(2.5-10):(80-95); the hydrogen-bonded crosslinked photoresponsive polymer is a linear azobenzene polymer containing hydrogen bonds; the crosslinking agent is selected from at least one of acrylic acid, bis(4-chlorophenoxy)glucose, diethylene glycol diacrylate, N,N'-methylenebisacrylamide, and diethyl phthalate.

2. The anti-roller pressure current collector according to claim 1, characterized in that, The mass ratio of the hydrogen-bonded crosslinked photoresponsive polymer, the crosslinking agent, and the polymer material is (2.5-6):(2.5-6):(88-95).

3. The anti-roller pressure current collector according to claim 1, characterized in that, The hydrogen-bonded crosslinked photoresponsive polymer is obtained by addition polymerization of a diol containing an azophenyl group and a diisocyanate.

4. The anti-roller pressure current collector according to claim 1, characterized in that, The polymer material is selected from at least one of polypropylene, polyethylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene ether, polystyrene, and polyamide.

5. The anti-roller pressure current collector according to claim 1, characterized in that, It further includes a substrate layer, wherein the anti-rolling film layer is located on at least one surface of the substrate layer; The thickness of the anti-rolling film layer is 1μm~8μm; The thickness of the metal layer is 100nm-1000nm.

6. The anti-roller pressure current collector according to claim 1, characterized in that, The anti-rolling pressure film layer is formed by melting a hydrogen-bonded cross-linked photoresponsive polymer, a cross-linking agent, and a polymer material. The anti-rolling pressure film layer is prepared by the following method: The hydrogen-bonded cross-linked photoresponsive polymer, cross-linking agent, and polymer material are mixed, subjected to a first heating and melting process, and extruded to obtain polymer slices. The polymer slices are crystallized at a predetermined temperature and then dried. The dried polymer slices are then heated and melted, extruded and cast, and cooled to obtain polymer cast sheets. The polymer casting is heated and subjected to longitudinal and transverse stretching and shaping to obtain the anti-rolling film layer. The first heating and melting temperature is 220~260 degrees Celsius; The predetermined temperature is 130~180 degrees Celsius; The second heating and melting temperature is 250~300 degrees Celsius; The longitudinal stretching temperature is 100~130 degrees Celsius, and the stretching ratio is 2:1~4:1; The temperature for the transverse stretching is 100~130 degrees Celsius, and the stretching ratio is 2:1~4:

1.

7. The anti-roller pressure current collector according to claim 1, characterized in that, The metal layer is prepared by the following method: The metal is melted, evaporated, and cooled so that the evaporated metal atoms are deposited on the surface of the anti-rolling film layer to obtain a metal layer, wherein the metal layer is deposited on at least one surface of the anti-rolling film layer. The melting and evaporation temperature is 1200~1800 degrees Celsius.

8. An electrode sheet, characterized in that, It includes the anti-roll pressure current collector according to any one of claims 1 to 7, and an active material layer attached to at least one surface of the anti-roll pressure current collector.

9. A battery, characterized in that, Includes the electrode sheet as described in claim 8.

10. An electrical device, characterized in that, Includes the battery as described in claim 9.

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