Polymer binder containing beta crystal form nucleating agent as well as preparation method and application of polymer binder

Abstract

The invention discloses a polymer binder containing a beta crystal form nucleating agent as well as a preparation method and application of the polymer binder, and relates to the technical field of binder materials. The beta crystal form nucleating agent is added into the polyolefin adhesive, so that the beta crystal form crystallinity of polyolefin is improved. The unique crystal structure of the beta crystal form enables polyolefin to be fiberized more easily when the polyolefin is subjected to shear stress, so that the fiberizing capacity of the polyolefin is improved, the polyolefin can form a three-dimensional fiber net more easily, and the manufacturing difficulty of a dry-method electrode or a dry-method electrolyte membrane is greatly reduced. The polymer binder containing the beta crystal form nucleating agent provided by the invention can solve the lithiation side reaction problem of a traditional dry-method electrode binder PTFE and the problem of weak fibrosis capability of common non-fluorine binders polypropylene and polyethylene.

Description

Technical Field

[0001] This invention relates to the field of adhesive materials technology, and more specifically, to a polymer adhesive containing a β-crystal nucleating agent, its preparation method, and its application. Background Technology

[0002] Dry electrode fabrication is a novel electrode preparation technology. Instead of using liquid solvents to disperse active materials and conductive additives, dry electrode fabrication directly mixes solid powders of active materials, conductive agents, and binders together. In the dry electrode fabrication process, the active materials, conductive agents, and binders are first mixed together. During mixing, the high molecular weight binder powder is stretched into fibers. These mixtures are then pressed into thin sheets, which are finally hot-pressed onto the current collector of the battery to form the electrode.

[0003] Compared to traditional wet-coating electrode fabrication techniques, dry electrode technology offers unparalleled advantages in reducing battery costs and improving battery performance, making it considered the ideal process for semi-solid-state and all-solid-state batteries. Dry electrodes eliminate the need for liquid solvents, removing the solvent drying process and reducing energy requirements during battery production, resulting in a simpler and more environmentally friendly manufacturing process. Dry processes require less large equipment, thus reducing production line footprint and overall equipment capital investment and operating costs. More importantly, dry electrodes can achieve higher compaction density, leading to higher battery energy density; in the same volume, more energy can be stored, resulting in longer battery life.

[0004] Dry electrode fabrication using binder fibrosis is a promising electrode preparation process for mass production. Currently, polytetrafluoroethylene (PTFE) is the optimal binder choice for this method. When a shear load is applied to PTFE crystals, they undergo shape changes, specifically crystal slippage along the c-axis, forming a high aspect ratio nanofiber structure. Specifically, the PTFE dry electrode fabrication process involves mixing active materials with conductive additives (such as carbon black) and PTFE, and then subjecting the PTFE to fibrillation under shear force. The fibrils are only a few nanometers in diameter and tens of micrometers in length. These fibrils aggregate the active material and carbon black mixture by forming a three-dimensional network structure. This mixture is then rolled using rollers to form a film hundreds of micrometers thick. This film is further rolled to achieve the desired target thickness and porosity for the dry electrode.

[0005] However, the dry electrode process using PTFE binder fibers has a significant drawback: PTFE is unstable at low potentials and undergoes an irreversible reaction with lithium. Therefore, when PTFE is used in the dry electrode, lithiation occurs, consuming active lithium and reducing the electrode's reversible capacity, while also decreasing the adhesion between electrode particles and between the electrode and the current collector. Furthermore, when PTFE is used in the solid-state electrolyte membrane, during solid-state battery charging, the PTFE fibers in contact with the negative electrode in the solid-state electrolyte membrane are gradually reduced to amorphous carbon (as shown in Equation 1), leading to solid-state battery failure.

[0006] (Equation 1) To improve the low potential instability of PTFE binders, the following methods are currently available: (1) Use non-fibrous adhesives to partially replace PTFE, thereby reducing the amount of PTFE adhesive used.

[0007] For example, US patent 16366220 discloses a method of improving electrode film performance by mixing PTFE with non-fibrillated materials. Traditional non-fibrillated materials (such as PVDF and CMC) are ground into smaller particle sizes and then mixed with PTFE to form a novel binder. In Tesla's patent, the mass ratio of PVDF, CMC, and PTFE in the mixture is 1:1:2. Smaller particle sizes of the binder allow for a more uniform distribution of active materials in the electrode film, while also providing stronger adhesion. The addition of the non-fibrillated binder reduces the amount of PTFE used, thereby reducing PTFE's lithiation side reactions. However, due to the reduced amount of fibrous binder PTFE, the total amount of non-fibrillated binder plus fibrous binder PTFE is often greater than the amount of PTFE binder alone to achieve sufficient electrode particle bonding strength. This not only reduces the proportion of active materials within the electrode but also increases the resistance to electron and ion transport within the electrode due to the non-conductive nature of the binder, leading to increased electrode polarization and deteriorated rate performance.

[0008] Chinese patent CN202310865134.9 discloses a dry-process electrode film with low binder content, comprising an electrode film bonding network constructed from non-fibrous binder particles, fibrous binder, electrode active material particles, and a conductive agent. The fibrous binder interweaves to form a three-dimensional bonding network, within which the electrode active material particles and the conductive agent are dispersed. The non-fibrous binder particles are uniformly dispersed on the surfaces of the electrode active material particles and the conductive agent, forming dot-like bonds. The fibrous binder is selected from at least one of polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, polypropylene, polyethylene, ethylene-octene copolymer, and polyimide. When using fibrous binders such as PTFE and ethylene-tetrafluoroethylene copolymer, this patent still suffers from the problem of PTFE lithiation side reactions; while using ordinary non-fluorinated binders such as polypropylene, polyethylene, and ethylene-octene, these binders have weak fibrous capabilities and a weak ability to form a three-dimensional bonding network, significantly increasing the difficulty of the dry-process electrode manufacturing process.

[0009] (2) Another way to improve the low potential instability of PTFE binder is to coat the PTFE surface with a protective layer to block the reaction between PTFE and lithium.

[0010] For example, Tesla described a coating material using PTFE in another patent, US18067399, which incorporates electrical conductors (conductive carbon, carbon black, etc.) and particulate materials (powdered carbon materials) to passivate the adhesive by coating the PTFE surface with conductive carbon. The coating covers more than 90% of the PTFE particle surface, with a thickness ranging from 0.1 to 100 μm. This patent claims that after PTFE fibrillation, the coating remains attached to the particle surface due to intermolecular forces. The coating layer can enhance the conductivity of the active material, improve the stability of the adhesive, and inhibit the decomposition of materials such as electrolytes. However, after PTFE undergoes fibrillation, its aspect ratio increases sharply, and its specific surface area increases significantly, making it impossible for the coating layer to completely cover the fibers. Therefore, coating the PTFE adhesive itself cannot completely prevent the lithiation side reaction of PTFE.

[0011] Therefore, it is urgent to solve the problem of lithiumation side reaction in traditional dry electrode binder PTFE and the problem of weak fiberization ability of ordinary non-fluorinated binders polypropylene and polyethylene.

[0012] In view of this, the present invention is proposed. Summary of the Invention

[0013] The purpose of this invention is to provide a polymer binder containing a β-crystal nucleating agent, its preparation method, and its application, aiming to solve the problem of lithiumation side reaction in traditional dry electrode binder PTFE and the problem of weak fiberization ability in ordinary non-fluorinated binders such as polypropylene and polyethylene.

[0014] This invention is implemented as follows: In a first aspect, the present invention provides a polymer binder containing a β-crystal nucleating agent, comprising: a polyolefin binder and a β-crystal nucleating agent, wherein the mass ratio of the β-crystal nucleating agent to the polyolefin binder is (0.01-2.00):100.

[0015] In an optional embodiment, the mass ratio of the β-crystal nucleating agent to the polyolefin binder is (0.1-1.0):100, preferably (0.1-0.5):100.

[0016] In an optional embodiment, the β-crystal nucleating agent is an organic β-crystal nucleating agent or an inorganic β-crystal nucleating agent; Among them, the inorganic β-crystal nucleating agent is selected from at least one of calcium carbonate, calcium sulfate, calcium oxide, yttrium oxide, carbon black, nano-alumina, zeolite powder, porous silica and metal phosphate salt; The organic β-crystal nucleating agent is selected from at least one of the following: lanthanide light rare earth compound nucleating agents, quinacridone compound nucleating agents, aromatic amide compound nucleating agents, polycyclic aromatic hydrocarbon nucleating agents, organic acid nucleating agents, and sorbitol β-crystal nucleating agents; Preferably, the nucleating agent of lanthanide light rare earth compounds includes rare earth organic complexes formed by lanthanide rare earth elements and γ-crystalline quinacridone or tribenzodithiazine, and lanthanum hydrogenated benzoate; Preferably, the nucleating agent of the quinacridone compound includes γ-quinacridone, quinacridone derivatives, and a compound of quinacridone and a synergist. In the compound of quinacridone and a synergist, the mass ratio of the synergist to the quinacridone is (0.01-10):100. The synergist is selected from at least one of aluminum acrylonitrile, aluminum tert-butylbenzoate, aluminum benzoate, 2,2'-methylenebis(4,6-tert-butylphenol)phosphine aluminum salt, sodium succinate, sodium glutarate, and sodium hexanoate. Preferably, the nucleating agents of aromatic amide compounds include N,N"-dicyclohexyl terephthalamide and N,N"-dicyclohexyl-2,6-naphthalenediamide; Preferably, the nucleating agents of polycyclic aromatic hydrocarbons include phenanthrene, anthracene, 2-mercaptobenzimidazole, dithiazide, indigo ash, indigo brown, Ciba red, and Ciba blue; Preferably, the organic acid nucleating agents include aliphatic dicarboxylic acids and their salts, monocyclic carboxylic acid nucleating agents, and bicyclic carboxylic acid nucleating agents; more preferably, the organic acid nucleating agents include alkali metal salts of benzoate, aluminum salts of aromatic carboxylate, titanium salts of aromatic carboxylate, metal salts of hexahydrophthalic acid (HHPA), cyclic dicarboxylate, and β-crystalline nucleating agents of calcium stearate-pimelic acid complex; even more preferably, the organic acid nucleating agents include calcium phthalate, calcium pimelic acid and calcium octanoate, zinc phthalate, β-cyclodextrin maleic anhydride lanthanum complex, aluminum adipic acid, zinc adipic acid, aluminum phthalate, aluminum terephthalate, zinc terephthalate, and aluminum citrate; Preferably, the sorbitol β-crystal nucleating agents include dibenzyl sorbitol (DBS), methylbenzyl sorbitol (MDBS), and p-chlorobenzyl sorbitol (CDBS).

[0017] In an optional embodiment, the polyolefin binder is obtained by polymerizing one or more olefin monomers; Among them, olefin monomers include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, styrene, 4-methyl-1-pentene, and cyclic olefin monomers; Preferably, the polyolefin binder is selected from at least one of polyethylene, polypropylene, poly-1-butene, poly-1-pentene, poly-1-hexene, poly-1-octene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, polyethylene-vinyl acetate, polyethylene-acrylate, polyethylene-methacrylate, polyisobutylene, polycyclobutene, polycyclooctene, and poly-1,5-cyclooctadiene; Preferably, the weight-average molecular weight of the polyolefin adhesive is 5,000 to 6,000,000, more preferably 50,000 to 3,000,000, and even more preferably 50,000 to 2,000,000.

[0018] In a second aspect, the present invention provides a method for preparing a polymer binder containing a β-crystal nucleating agent according to any of the foregoing embodiments, comprising: preparing it using a first method or a second method; The first method includes the following steps: mixing an olefin monomer and a β-crystal nucleating agent, and preparing the product through a polymerization reaction; The second method includes the following steps: mixing and granulating a polyolefin and a β-crystal nucleating agent.

[0019] In an optional embodiment, the first method further includes: after the polymerization reaction is completed, performing solid-liquid separation, and washing and drying the obtained solid material; Preferably, the second method includes the steps of: mixing and melting the polyolefin and the β-crystal nucleating agent, and then extruding and granulating them.

[0020] Thirdly, the present invention provides the application of the polymer binder containing a β-crystal nucleating agent according to any of the foregoing embodiments or the polymer binder containing a β-crystal nucleating agent prepared by any of the foregoing embodiments in the preparation of dry electrodes or solid electrolyte membranes.

[0021] In an optional embodiment, the dry electrode is a dry positive electrode or a dry negative electrode, and the dry electrode may or may not contain a solid electrolyte. When the dry electrode does not contain a solid electrolyte, it comprises, by mass fraction: 90%-97% active material, 0.5%-5.0% conductive agent, and 0.5%-5% polymer binder containing a β-crystal nucleating agent; When the dry electrode contains a solid electrolyte, by mass fraction, the dry electrode comprises: 70%-97% active material, 5%-30% solid electrolyte, 0.5%-3.0% conductive agent, and 0.5%-3% polymer binder containing β-crystal nucleating agent; Preferably, the preparation process of the dry electrode includes: mixing and fiberizing the raw materials, and then rolling them through multiple stages to the target thickness or areal density to obtain a self-supporting sheet for the dry positive electrode or dry negative electrode; and hot-pressing the self-supporting sheet of the dry positive electrode or dry negative electrode with a current collector to obtain the dry positive electrode or dry negative electrode.

[0022] In an optional embodiment, the solid electrolyte membrane comprises, by mass fraction, 95.0%-99.5% solid electrolyte and 0.5%-5% polymer binder containing β-crystal nucleating agent; Preferably, the preparation process of the solid electrolyte membrane includes: mixing and fiberizing the raw materials, and then rolling them through multiple stages to the target thickness or areal density to obtain a dry electrolyte membrane; The dry electrolyte membrane is laminated and wound together with PET film or blank aluminum foil to obtain a dry electrolyte membrane protected by PET film or blank aluminum foil. Alternatively, the dry electrolyte membrane can be hot-pressed together with a dry positive electrode or a dry negative electrode to prepare a dry positive electrode-dry electrolyte membrane composite electrode or a dry negative electrode-dry electrolyte membrane composite electrode.

[0023] In an optional embodiment, the solid electrolyte is selected from at least one of sulfide solid electrolytes, halide solid electrolytes, halide oxide solid electrolytes, and anti-perovskite solid electrolytes. Preferably, the dry-process positive electrode containing solid electrolyte uses a halide solid electrolyte, a halide oxide solid electrolyte, or a sulfide solid electrolyte; the dry-process negative electrode containing solid electrolyte uses a sulfide solid electrolyte or an anti-perovskite solid electrolyte; and the dry-process solid electrolyte membrane uses a sulfide solid electrolyte, a halide solid electrolyte, or an anti-perovskite solid electrolyte.

[0024] This invention offers the following advantages: By adding a β-crystal nucleating agent to the polyolefin binder, the β-crystal crystallinity of the polyolefin is improved. The unique crystal structure of the β-crystal makes the polyolefin more prone to fibrosis under shear stress, thereby enhancing its fibrosis ability and making it easier to form a three-dimensional fiber network, significantly reducing the manufacturing difficulty of dry electrodes or dry electrolyte membranes. The polymer binder containing a β-crystal nucleating agent provided by this invention has the following advantages: (1) Since the β-crystalline polyolefin binder of the present invention is a non-fluorinated binder, it completely eliminates the use of fluorinated binders and avoids the problem of lithiation reaction of fluorinated binders at low potential. Therefore, the β-crystalline polyolefin binder of the present invention can not only be used for the preparation of dry cathode, but also for the preparation of dry anode and dry electrolyte membrane. It can also ensure that the prepared dry cathode, dry anode or dry electrolyte membrane maintains long-term stability, thereby improving the performance of the battery.

[0025] (2) Because the present invention adds a β-crystal nucleating agent to the polyolefin binder, the crystallinity of the β-crystal in the polyolefin is improved. The unique crystal structure of the β-crystal makes it easier for the polyolefin binder to form a three-dimensional fiber network when subjected to shear stress, so as to bond the active material, conductive agent and other components together to form an electrode, thereby greatly reducing the manufacturing difficulty of dry electrode or dry solid electrolyte membrane. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a diagram illustrating the process of fiberization of β-crystalline polyolefins. Figure 2 Here is a surface SEM image of the dry-process positive electrode roll sample containing solid electrolyte in Example 1; Figure 3 Here is a surface SEM image of the dry-process cathode roll sample containing solid electrolyte in Comparative Example 1. Figure 4 The image shows a surface SEM image of a dry-process cathode roll sample containing a solid electrolyte, prepared as Comparative Example 2. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0029] This invention provides a polymer adhesive containing a β-crystal nucleating agent, comprising: a polyolefin adhesive and a β-crystal nucleating agent, wherein the mass ratio of the β-crystal nucleating agent to the polyolefin adhesive is (0.01-2.00):100, preferably (0.1-1.0):100, and more preferably (0.1-0.5):100.

[0030] Specifically, the mass ratio of β-crystal nucleating agent to polyolefin binder can be 0.01:100, 0.05:100, 0.10:100, 0.20:100, 0.30:100, 0.40:100, 0.50:100, 0.80:100, 1.00:100, 1.30:100, 1.50:100, 1.80:100, 2.00:100, etc.

[0031] It should be noted that the polymer binder containing the β-crystal nucleating agent is a non-fluorinated binder, completely eliminating the use of fluorinated binders and avoiding the lithiation reaction problem of fluorinated binders at low potentials. Furthermore, the β-crystal polyolefin binder has high β-crystal crystallinity. Utilizing the unique crystal structure of the β-crystal form of polyolefins, the polyolefins are more prone to fibrosis under shear stress, thereby improving the fibrosis ability of polyolefins and making it easier to form three-dimensional fiber networks. This significantly reduces the manufacturing difficulty of dry electrodes or dry electrolyte membranes.

[0032] In some embodiments, the polyolefin binder is obtained by polymerization of one or more olefin monomers; wherein the olefin monomers include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, styrene, and 4-methyl-1-pentene, as well as certain cyclic olefins, which are semi-crystalline thermoplastic polymers polymerized or copolymerized individually. Further, the polyolefin binder is selected from at least one of polyethylene, polypropylene, poly-1-butene, poly-1-pentene, poly-1-hexene, poly-1-octene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, polyethylene-vinyl acetate, polyethylene-acrylate, polyethylene-methacrylate, polyisobutylene, polycyclobutene, polycyclooctene, and poly1,5-cyclooctadiene, and the polyolefin binder can be any one or more of the above. The weight-average molecular weight of the polyolefin binder is 5,000 to 6,000,000, more preferably 50,000 to 3,000,000, and even more preferably 50,000 to 2,000,000.

[0033] For example, polypropylene (PP) can form five crystal forms: α, β, γ, δ, and pseudo-hexagonal. Under normal conditions, the most stable α crystal form is dominant. By adding nucleating agents and improving processing conditions, PP with a dominant β crystal form can be obtained. The other crystal forms are the result of rapid cooling of the polymer melt and are almost impossible to produce in actual production. After adding a β crystal nucleating agent, the spherulites of the polyolefin become finer, transforming from the stable α crystal form to the metastable β crystal form, and the crystallinity of the β crystal form is improved.

[0034] When a β-nucleating agent is added to polyolefins, the molecular chains are induced to align in a β-crystalline manner during the cooling process of the polyolefin melt, forming a unique cross-hatching structure in β-crystalline polyolefins. Compared to α-crystalline polyolefins, metastable β-crystalline polyolefins undergo a crystal transformation under shear stress, changing from low density to high density, thus producing fibers, such as... Figure 1 As shown. Therefore, this characteristic of β-crystalline polyolefins allows polyolefins to replace fluorinated binders such as PTFE and can be used in the preparation of dry electrodes or dry solid electrolyte membranes.

[0035] In some embodiments, the β-crystal nucleating agent is an organic β-crystal nucleating agent or an inorganic β-crystal nucleating agent, and the specific type is not limited.

[0036] Among them, the inorganic β-crystal nucleating agent is selected from at least one of calcium carbonate, calcium sulfate, calcium oxide, yttrium oxide, carbon black, nano-alumina, zeolite powder, porous silica and metal phosphate salts, and the inorganic β-crystal nucleating agent can be any one or more of the above.

[0037] The organic β-crystalline nucleating agent is selected from at least one of the following: lanthanide light rare earth compound nucleating agents, quinacridone compound nucleating agents, aromatic amide compound nucleating agents, polycyclic aromatic hydrocarbon nucleating agents, organic acid nucleating agents, and sorbitol β-crystalline nucleating agents. The organic β-crystalline nucleating agent can be any one or more of these. The organic β-crystalline nucleating agent has a planar or near-planar structure.

[0038] Furthermore, the above-mentioned lanthanide light rare earth compound nucleating agents include rare earth organic complexes formed by lanthanide rare earth elements and γ-crystalline quinacridone or tribenzodithiazine, and lanthanum hydrogenated benzoate.

[0039] Furthermore, nucleating agents for quinacridone compounds include γ-quinacridone, quinacridone derivatives (such as Pigment Violet 19), and complexes of quinacridone and synergists. In the complexes of quinacridone and synergists, the mass ratio of synergist to quinacridone is (0.01-10):100, such as 0.01:100, 0.10:100, 0.50:100, 1.00:100, 2.00:100, 3.00:100, 4.00:100, 5.00:100, 6.00:100, 7.00:100, 8.00:100, 9.00:100, 10.00:100, etc. Synergists can include aluminum adipic acid, aluminum tert-butylbenzoate (Al-PTB-BA), aluminum benzoate, 2,2'-methylenebis(4,6-tert-butylphenol)phosphine aluminum salt, sodium succinate, sodium glutarate, sodium hexanoate, etc.

[0040] Furthermore, nucleating agents for aromatic amide compounds include N,N"-dicyclohexyl terephthalamide and N,N"-dicyclohexyl-2,6-naphthalenediamide.

[0041] Furthermore, nucleating agents for polycyclic aromatic hydrocarbons include phenanthrene, anthracene, 2-mercaptobenzimidazole, dithiazide, indigo ash, indigo brown, Ciba red, and Ciba blue; Further, the organic acid nucleating agents include aliphatic dicarboxylic acids and their salts, monocyclic carboxylic acid nucleating agents, and bicyclic carboxylic acid nucleating agents. Preferably, the organic acid nucleating agents include alkali metal salts of benzoate, aluminum salts of aromatic carboxylate, titanium salts of aromatic carboxylate, metal salts of hexahydrophthalic acid (HHPA), cyclic dicarboxylate, and β-crystalline nucleating agents such as calcium stearate-pimelic acid complexes; more preferably, the organic acid nucleating agents include calcium phthalate, calcium pimelic acid and calcium octanoate, zinc phthalate, β-cyclodextrin maleic anhydride lanthanum complex, aluminum adipic acid, zinc adipic acid, aluminum phthalate, aluminum terephthalate, zinc terephthalate, and aluminum citrate.

[0042] Furthermore, sorbitol β-crystal nucleating agents include dibenzyl sorbitol (DBS), methylbenzyl sorbitol (MDBS), and p-chlorobenzyl sorbitol (CDBS).

[0043] This invention also provides a method for preparing a polymer binder containing a β-crystal nucleating agent, comprising a first method and a second method, which can be used for preparation.

[0044] The first method includes the following steps: mixing olefin monomers and a β-crystalline nucleating agent, and preparing the mixture through a polymerization reaction. In actual operation, the β-crystalline nucleating agent is added to a polymerization reactor or slurry polymerization reactor containing olefin monomers, and then subjected to polymerization, filtration, washing, and drying.

[0045] The second method involves mixing and granulating a polyolefin and a β-nucleating agent. The polyolefin can be prepared in-house or sourced commercially. In practice, a dried β-nucleating agent is added during the external blending of the polyolefin during separation. The mixture is then mixed in a high-speed mixer and melted in a twin-screw extruder or internal mixer, followed by extrusion granulation.

[0046] This invention also provides the application of the polymer binder containing the β-crystal nucleating agent in the preparation of dry electrodes or solid electrolyte membranes. The dry electrode can be a dry positive electrode or a dry negative electrode, and may or may not contain a solid electrolyte.

[0047] When a polymer binder containing a β-crystal nucleating agent is used in the preparation of a dry electrode without a solid electrolyte, the dry electrode comprises, by mass fraction: 90%-97% active material, 0.5%-5.0% conductive agent, and 0.5%-5% polymer binder containing a β-crystal nucleating agent. Specifically, the active material can be either a positive or negative electrode active material, and its mass percentage can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, etc.; the conductive agent's mass percentage can be 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, etc.; and the polymer binder containing a β-crystal nucleating agent's mass percentage can be 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, etc.

[0048] When a polymer binder containing a β-crystal nucleating agent is used in the preparation of a dry electrode containing a solid electrolyte, the dry electrode comprises, by mass fraction: 70%-97% active material, 5%-30% solid electrolyte, 0.5%-3.0% conductive agent, and 0.5%-3% polymer binder containing a β-crystal nucleating agent. Specifically, the active material can be either a positive or negative electrode active material, and its mass percentage can be 70%, 75%, 80%, 85%, 90%, 95%, 97%, etc.; the solid electrolyte's mass percentage can be 5%, 10%, 15%, 20%, 25%, 30%, etc.; the conductive agent's mass percentage can be 0.5%, 1.0%, 2.0%, 3.0%, etc.; and the polymer binder containing a β-crystal nucleating agent's mass percentage can be 0.5%, 1.0%, 2.0%, 3.0%, etc.

[0049] Furthermore, the preparation process of dry electrodes (dry cathodes and dry anodes containing or without solid electrolytes) includes: mixing and fiberizing the various electrode components of the dry cathode and dry anode with a polyolefin binder containing a β-crystal nucleating agent, and then rolling them through multiple stages to the target thickness or areal density to obtain a self-supporting sheet of the dry cathode or dry anode; hot-pressing the self-supporting sheet of the dry cathode or dry anode with a current collector to obtain the dry cathode or dry anode.

[0050] When a polymer binder containing a β-crystal nucleating agent is used in the preparation of a dry solid electrolyte, the solid electrolyte membrane comprises, by mass fraction, 95.0%-99.5% solid electrolyte and 0.5%-5% polymer binder containing a β-crystal nucleating agent. Specifically, the mass percentage of solid electrolyte can be 95.0%, 95.5%, 96.0%, 96.5%, 97.0%, 97.5%, 98.0%, 98.5%, 99.0%, 99.5%, etc.; the mass percentage of polymer binder containing a β-crystal nucleating agent can be 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, etc.

[0051] Furthermore, the preparation process of the solid electrolyte membrane includes: mixing a solid electrolyte with a polymer binder containing a β-crystal nucleating agent, fiberizing the mixture, and then rolling it through multiple stages to achieve the target thickness or areal density to obtain a dry electrolyte membrane. Finally, the dry electrolyte membrane is laminated and wound with a PET film or blank aluminum foil to obtain a dry electrolyte membrane protected by a PET film or blank aluminum foil. Alternatively, in the final step, the electrolyte membrane is hot-pressed with the prepared dry positive or dry negative electrode to prepare a dry positive / dry electrolyte membrane composite electrode or a dry negative / dry electrolyte membrane composite electrode.

[0052] Furthermore, in the aforementioned dry-process positive electrode, dry-process negative electrode, or dry-process solid electrolyte membrane containing a solid electrolyte, the solid electrolyte used is selected from at least one of sulfide solid electrolytes, halide solid electrolytes, halide oxide solid electrolytes, and anti-perovskite solid electrolytes. The solid electrolyte can be any one or more of the above. Preferably, the dry-process positive electrode containing a solid electrolyte uses a halide solid electrolyte, a halide oxide solid electrolyte, or a sulfide solid electrolyte; the dry-process negative electrode containing a solid electrolyte uses a sulfide solid electrolyte or an anti-perovskite solid electrolyte; and the dry-process solid electrolyte membrane uses a sulfide solid electrolyte, a halide solid electrolyte, or an anti-perovskite solid electrolyte.

[0053] In some embodiments, the sulfide solid electrolyte comprises Li6PS5X, where X comprises any one or a combination of at least two of Cl, Br, or I. Preferably, the sulfide solid electrolyte further comprises Li7P2S8I, Li 5.3 PS4.3 ClBr 0.7 Li 6- n PS 5-n Cl 1+n (n=0.25, 0.375, 0.5, 0.55, 0.6), Li6PS 5-n O n Cl (0 < n ≤ 1.5), Li 5.3 PS 4.3 Br 1.7 Li6PS 5-n O n Br (0 < n ≤ 1.5), Li 5.35 Ca 0.1 PS 4.5 Cl 1.55 Li 9.88 GeP 1.96 Sb 0.04 S 11.88 Cl 0.12 Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li 6.6 Ge 0.6 P 0.4 S5Cl, Li 6.6 Ge 0.6 P 0.4 S5I, Li 6.6 Sb 0.4 Si 0.6 S5I, Li 6.5 Sb 0.5 Ge 0.5 S5I or (Li 5.69 Na 0.06 PS 4.75 Cl 1.25 One or more combinations of the above.

[0054] In some embodiments, the molecular formula of the halide solid electrolyte includes Li3M'X6 or Li2M”X4, where M' includes any one or at least two of Er, Yb, Al, Ga, In, Sc, Y, or La-Lu, wherein La-Lu includes any element between the two, M” includes any one or at least two of Mg, Al, Fe, Co, Ni, Mn, Cr, Ti, V, Zr, Cd, Zn, or In, and X includes any one or at least two of Cl, Br, or I. For example, it can be Li3InCl6, Li3YCl6, Li3ErCl6, Li3YbCl6, Li3InBr6, Li3ErI6, Li3AlCl6, Li3GaCl6, Li3ScCl6, Li3LaCl6, Li3LuCl6, Li2MgCl4, LiAlCl4, LiFeCl4, LiCoCl4, LiNiCl4, Li2MnCl4, LiCrCl4, LiTiCl4, LiVCl4, Li2ZrCl6, LiCdCl4, Li2ZnBr4, LiInBr4, or LiInI4, etc.

[0055] In some embodiments, the molecular formula of the above-mentioned halide electrolyte includes M a M b X c O d M includes Li or Na, M Includes any one or at least two of Al, Ti, Zr, V, Nb, or Ta; X includes any one or at least two of F, Cl, Br, or I; 0.4 ≤ a ≤ 3; 0 <b<2,0≤c≤6,0≤d≤1。

[0056] It should be noted that when M When M = Al, Ti, or Zr, a, b, c, and d satisfy a + 3b = c + 2d; when M When V, Nb, or Ta are equal to a, b, c, and d, a + 4b = c + 2d.

[0057] It should be noted that the halide oxide electrolyte can also be, for example, Li. 2x TaO x Cl5 (1.1≤x≤1.8) or Li3HfOCl4, or other halide oxide electrolytes, such as 0.13ZrO2-0.61NaCl-0.26Na2ZrCl6, Li 1.75 ZrCl 4.75 O 0.5 LiTaOCl4, LiNbOCl4, Li 2.5 ZrCl5.5 O 0.5 ZrO₂-2Li₂ZrCl₅F, ZrO₂-2Li₂ZrCl₆, or NaAlCl 2.5 O 0.75 wait.

[0058] Preferably, the molecular formula of the halogen-containing anti-perovskite solid electrolyte includes M3OX, where M includes Li or Na, and X includes any one or a combination of at least two of F, Cl, or Br. For example, it can be Li3OCl, Li3OBr, Na3OCl, or Na3OBr, etc.

[0059] It should be noted that halogen-containing anti-perovskite solid electrolytes can also be other types of anti-perovskite electrolytes, such as Li₂(OH)Cl, Li₂(OH)Br, Li 2.990 Ba 0.006 OCl, Li2(OH) 0.9 F 0.1 Cl、Li 1.16 (OH 1.84 Cl, LiOCl 0.5 Br 0.5 Li7O2Br3, Li3SCl 0.5 (BF4) 0.5 Li6OCl4, Li 6.5 OS 1.5 I 1.5 Li 25 O4S5I7, Na4OI2, Na 2.9 Sr 0.05 OBr 0.6 I 0.4 Na 25 O4S5I7, Na 2.99 Ba 0.005 OCl 1-x (OH) x Na3SI 0.5 (BCl4) 0.5 Na(SeO4)F 0.5 Cl 0.5 or Na3LiO5S 0.5 I2, etc.

[0060] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0061] Example 1 This embodiment provides a polymer binder containing a β-crystal nucleating agent, comprising: a polyolefin binder and a β-crystal nucleating agent. The polyolefin binder is polypropylene with a weight-average molecular weight of 1,000,000. The β-crystal nucleating agent is N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide, and the mass percentage of the β-crystal nucleating agent N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide in the polypropylene is 0.1% (i.e., the mass ratio of the β-crystal nucleating agent to the polyolefin binder is 0.1:100).

[0062] The preparation process of polymer binders containing β-crystalline nucleating agents includes: mixing polyolefin binders and β-crystalline nucleating agents in a high-speed mixer and melting them in a twin-screw extruder, followed by extrusion granulation. The temperature settings for each section of the twin-screw extruder are as follows: feeding section 150~160℃, melting section 180~190℃, mixing section 200~210℃, metering section 200~220℃, die head 200~210℃, and die 205~210℃.

[0063] This embodiment also provides the application of the polymer binder containing the above-mentioned β-crystal nucleating agent in the preparation of a dry cathode containing a solid electrolyte. The cathode material NCM811: solid electrolyte Li6PS5Cl: conductive agent CNT: polypropylene binder with N,N'-dicyclohexyl-2,6-naphthalenediamide as the β-crystal nucleating agent = 83%:13%:1%:3% by mass percentage is mixed uniformly by low-speed stirring (400 rpm, the same below), and then fiberized by high-speed stirring (4500 rpm, the same below) for 15 min to obtain a fibrous mixed powder. The fibrous mixed powder is continuously film-formed and thinned to 150 μm multiple times using a multi-stage differential speed roller press, and finally hot-pressed with carbon-coated aluminum foil to obtain a dry cathode roll without solid electrolyte.

[0064] The surface SEM image of the dry-process positive electrode roll sample containing solid electrolyte prepared in Example 1 is attached. Figure 2 As shown. From the appendix Figure 2 It can be seen that the electrode prepared in this embodiment contains polypropylene fibers with a distinct three-dimensional network structure.

[0065] Example 2 This embodiment provides a polymer binder containing a β-crystal nucleating agent, comprising: a polyolefin binder and a β-crystal nucleating agent. The polyolefin binder is an ethylene-propylene copolymer, commercially available as Dow VERSIFY™ 3000; the β-crystal nucleating agent is γ-quinacridone. The β-crystal nucleating agent γ-quinacridone accounts for 0.2% of the mass percentage in the ethylene-propylene copolymer.

[0066] The preparation method of the polymer binder containing β-crystal nucleating agent is as described in Example 1.

[0067] This embodiment also provides the application of the above-mentioned polymer binder containing β-crystal nucleating agent in the preparation of a dry-process cathode without solid electrolyte. The NCM811 cathode material, conductive agent SP, and polymer binder containing β-crystal nucleating agent are mixed at a low speed with a mass percentage of 95%:2%:3%, then stirred at a high speed to induce fibrosis, resulting in a fibrous mixed powder. The fibrous mixed powder is then continuously film-formed using a multi-roll differential speed roller press, reducing the film thickness to 160 μm. Finally, it is hot-pressed and laminated with carbon-coated aluminum foil to obtain a dry-process cathode roll without solid electrolyte.

[0068] Example 3 This embodiment provides a polymer binder containing a β-crystalline nucleating agent, comprising: a polyolefin binder and a β-crystalline nucleating agent. The polyolefin binder is an ethylene-propylene copolymer, commercially available as ExxonMobil Vistamaxx™ 6102FL; the β-crystalline nucleating agent is calcium pimerate and zinc phthalate (blended at a weight ratio of 8:2). The mass percentage of the β-crystalline nucleating agents calcium pimerate and zinc phthalate in the ethylene-propylene copolymer is 1.0%.

[0069] The preparation method of the polymer binder containing β-crystal nucleating agent is as described in Example 1.

[0070] This embodiment also provides the application of the polymer binder containing β-crystal nucleating agent in the preparation of a dry-process cathode without solid electrolyte. The NCM811 cathode material, conductive agent SP, and polymer binder containing β-crystal nucleating agent are mixed at low speed with a mass percentage of 95%:2%:3%, then stirred at high speed to induce fibrosis, resulting in a fibrous mixed powder. The fibrous mixed powder is then continuously film-formed using a multi-roll differential speed roller press, reducing the film thickness to 170 μm. Finally, it is hot-pressed and laminated with carbon-coated aluminum foil to obtain a dry-process cathode roll without solid electrolyte.

[0071] Example 4 This embodiment provides a polymer binder containing a β-crystal nucleating agent, comprising: a polyolefin binder and a β-crystal nucleating agent. The polyolefin binder is an ethylene-1-octene copolymer, commercially available as Dow Chemical INFUSE 9077; the β-crystal nucleating agent is lanthanum hydrogenated benzoate. The mass percentage of the β-crystal nucleating agent, lanthanum hydrogenated benzoate, in the ethylene-propylene copolymer is 0.5%.

[0072] The preparation method of the polymer binder containing β-crystal nucleating agent is as described in Example 1.

[0073] This embodiment also provides the application of the polymer binder containing the β-crystal nucleating agent in the preparation of dry solid electrolyte membranes. The sulfide solid electrolyte LPSC and the polymer binder containing the β-crystal nucleating agent are mixed at a mass percentage of 96% to 4% by low-speed stirring until homogeneous, and then subjected to high-speed stirring to fibrousize the mixture, resulting in a fibrous mixed powder. The fibrous mixed powder is then continuously rolled into a film using a multi-roll differential speed roller press, reducing the film thickness by 60 μm to obtain a self-supporting membrane roll of the dry solid electrolyte.

[0074] Example 5 This embodiment provides a polymer binder containing a β-crystalline nucleating agent, comprising: a polyolefin binder and a β-crystalline nucleating agent. The polyolefin binder is an ethylene-1-butene copolymer, commercially available as ExxonMobil EXACT high molecular weight POE9361; the β-crystalline nucleating agent is a sorbitol-based nucleating agent NP-828. The β-crystalline nucleating agent accounts for 0.2% of the mass percentage of the ethylene-1-butene copolymer.

[0075] The preparation method of the polymer binder containing β-crystal nucleating agent is as described in Example 1.

[0076] This embodiment also provides the application of the polymer binder containing β-crystal nucleating agent in the preparation of dry-process silicon-carbon anodes. The silicon-carbon anode material, conductive agent SP, and polymer binder containing β-crystal nucleating agent are mixed at a low speed to achieve uniformity, followed by high-speed stirring to induce fibrosis, resulting in a fibrous mixed powder. The fibrous mixed powder is then continuously film-formed using a multi-roll differential speed roller press, reducing the film thickness by 100 μm to obtain a dry-process silicon-carbon anode coil.

[0077] Comparative Example 1 This comparative example uses a β-nucleating agent-free polypropylene binder to prepare a dry-process cathode containing a solid electrolyte. The polypropylene has a molecular weight of 1,000,000. The cathode material NCM811, solid electrolyte Li6PS5Cl, conductive agent CNT, and β-nucleating agent-free polypropylene binder were mixed at low speed until homogeneous, followed by high-speed stirring to induce fibrosis, resulting in a fibrous mixed powder. The fibrous mixed powder was continuously film-formed using a multi-stage differential speed roller press, repeatedly thinning it to 150 μm. Finally, it was hot-pressed with carbon-coated aluminum foil to obtain a dry-process cathode roll containing a solid electrolyte.

[0078] The surface SEM image of the dry-process positive electrode roll sample containing solid electrolyte, prepared from polypropylene without β-crystal nucleating agent, is attached. Figure 3 As shown, from the appendix Figure 3 It can be seen that the electrode prepared in this comparative example contains only a small amount of polypropylene fibers, and the polypropylene fibers formed are relatively short and do not constitute a complete three-dimensional network structure.

[0079] The SEM images of the dry-process cathodes prepared in Example 1 and Comparative Example 1 show that adding a β-crystalline nucleating agent to polypropylene makes it easier for the polypropylene to be subjected to shear stress during the fiberization stage and the subsequent multi-roll continuous film formation stage, forming a polypropylene fiber network structure that binds various electrode material particles together, thereby reducing the manufacturing difficulty of the dry-process electrode. The results demonstrate that the β-crystalline nucleating agent-containing polyolefin binder of the present invention has outstanding advantages and significant effects.

[0080] Comparative Example 2 This comparative example uses the traditional fluorine-containing dry electrode binder PTFE. The only difference between this example and Example 1 is that the polymer binder containing β-crystal nucleating agent is replaced with an equal amount of polytetrafluoroethylene (PTFE).

[0081] The surface SEM images of the dry-process positive electrode roll sample containing solid electrolyte, prepared using the traditional fluorine-containing dry electrode binder PTFE, are attached. Figure 4 As shown. From the appendix Figure 4 It can be seen that the electrodes prepared in this comparative example contain typical PTFE fibers.

[0082] As can be seen from the SEM images of the dry-process cathodes prepared in Example 1 and Comparative Example 2, the β-crystalline nucleating agent-containing polyolefin binder of the present invention achieves a similar effect to the traditional dry-process electrode binder PTFE, both exhibiting good fibrosis and effectively bonding the electrode components together. This result further demonstrates that the β-crystalline nucleating agent-containing polymer binder of the present invention can replace the fluorinated dry-process electrode binder PTFE in the preparation of dry-process electrodes.

[0083] Comparative Example 3 This comparative example uses the traditional fluorine-containing dry electrode binder PTFE to prepare a dry solid electrolyte membrane. The only difference between this example and Example 4 is that the polymer binder containing β-crystal nucleating agent is replaced with an equal amount of polytetrafluoroethylene (PTFE).

[0084] Comparative Example 4 This comparative example uses the traditional fluorine-containing dry electrode binder PTFE to prepare a dry silicon-carbon anode. The only difference between this example and Example 5 is that the polymer binder containing β-crystal nucleating agent is replaced with an equal amount of polytetrafluoroethylene (PTFE).

[0085] Experimental Example 1 A 5Ah solid-state pouch cell was assembled using the dry-process positive electrode prepared in Example 1, the dry-process solid-state electrolyte membrane prepared in Example 4, and the silicon-carbon negative electrode prepared in Example 5. The effectiveness of the patented technology solution of this invention was demonstrated through charge-discharge cycle testing. The specific charge-discharge cycle test conditions were as follows: test temperature was 30℃, test stack voltage was 20MPa; the charging mode was CC-CV mode, first charging at 0.5C with a constant current to 4.2V, then charging at 4.2V with a constant voltage until the current was less than 0.05C; the discharging mode was CC mode, i.e., discharging at 0.5C with a constant current to 2.0V. After 300 charge-discharge cycles, the capacity retention rate of the battery was recorded.

[0086] Experimental Example 2 A 5Ah solid-state pouch cell was assembled using the dry-process positive electrode prepared in Example 1, the dry-process solid electrolyte membrane prepared in Example 4, and the silicon-carbon negative electrode prepared in Comparative Example 4. The test conditions were the same as in Example 1.

[0087] Experimental Example 3 A 5Ah solid-state pouch cell was assembled using the dry-process positive electrode prepared in Example 1, the dry-process solid electrolyte membrane prepared in Comparative Example 3, and the silicon-carbon negative electrode prepared in Example 5. The test conditions were the same as in Example 1.

[0088] Test Example 4 A 5Ah solid-state pouch cell was assembled using the dry-process positive electrode prepared in Example 1, the dry-process solid electrolyte membrane prepared in Comparative Example 3, and the silicon-carbon negative electrode prepared in Comparative Example 4. The test conditions were the same as in Example 1.

[0089] The performance of the dry electrode and dry solid electrolyte membrane prepared in the examples and comparative examples was tested using the above-mentioned test examples 1-4. The results are shown in Table 1: Table 1. Performance of the dry electrode and dry solid electrolyte membrane prepared in the examples and comparative examples.

[0090] The results of the above experiments show that Experiment 1 exhibits the highest initial efficiency and cycle capacity retention. Experiment 2, using the silicon-carbon anode prepared in Comparative Example 4, and Experiment 3, using the dry-process electrolyte membrane prepared in Comparative Example 3, both contain fluorinated binder PTFE. PTFE inevitably undergoes side reactions at low potentials, leading to a decrease in the battery's initial efficiency. Simultaneously, due to the breakage of PTFE fibers in the electrodes or solid electrolyte membrane during charge and discharge, the components in the electrodes or solid electrolyte membrane cannot bond together, resulting in poor interfacial contact and a significant decrease in cycle capacity retention. Experiment 4, with both the anode and solid electrolyte membrane containing PTFE, exhibits the worst initial efficiency and cycle performance.

[0091] The results of experiments 1-4 show that using polyolefin binders instead of fluorinated binders to prepare dry electrodes can achieve the same fiberization effect as PTFE, while avoiding the side reaction problems of PTFE at low potentials, thus improving the battery's initial efficiency and cycle performance. Therefore, the polymer binder containing β-crystal nucleating agents of this invention has outstanding technical advantages.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polymer binder containing a β-crystal nucleating agent, characterized in that, include: The mixture comprises a polyolefin binder and a β-crystal nucleating agent, wherein the mass ratio of the β-crystal nucleating agent to the polyolefin binder is (0.01-2.00):

100.

2. The polymer binder containing a β-crystalline nucleating agent according to claim 1, characterized in that, The mass ratio of the β-crystal nucleating agent to the polyolefin binder is (0.1-1.0):100, preferably (0.1-0.5):

100.

3. The polymer binder containing a β-crystalline nucleating agent according to claim 1 or 2, characterized in that, The β-crystal nucleating agent is an organic β-crystal nucleating agent or an inorganic β-crystal nucleating agent; The inorganic β-crystal nucleating agent is selected from at least one of calcium carbonate, calcium sulfate, calcium oxide, yttrium oxide, carbon black, nano-alumina, zeolite powder, porous silica, and metal phosphate salts. The organic β-crystal nucleating agent is selected from at least one of lanthanide light rare earth compound nucleating agents, quinacridone compound nucleating agents, aromatic amide compound nucleating agents, polycyclic aromatic hydrocarbon nucleating agents, organic acid nucleating agents, and sorbitol β-crystal nucleating agents; Preferably, the lanthanide light rare earth compound nucleating agent includes rare earth organic complexes formed by lanthanide rare earth elements and γ-crystalline quinacridone or tribenzodithiazine, and lanthanum hydrogenated benzoate; Preferably, the nucleating agent of the quinacridone compound includes γ-quinacridone, quinacridone derivatives, and a compound of quinacridone and a synergist, wherein the mass ratio of the synergist to the quinacridone in the compound of quinacridone and the synergist is (0.01-10):100, and the synergist is selected from at least one of aluminum acrylonitrile, aluminum tert-butylbenzoate, aluminum benzoate, 2,2'-methylenebis(4,6-tert-butylphenol)phosphine aluminum salt, sodium succinate, sodium glutarate, and sodium hexanoate; Preferably, the aromatic amide nucleating agent includes N,N'-dicyclohexyl terephthalamide and N,N'-dicyclohexyl-2,6-naphthalenediamide; Preferably, the nucleating agent of the polycyclic aromatic hydrocarbon includes phenanthrene, anthracene, 2-mercaptobenzimidazole, dithiazide, indigo ash, indigo brown, Ciba red, and Ciba blue; Preferably, the organic acid nucleating agent includes aliphatic dicarboxylic acids and their salts, monocyclic carboxylic acid nucleating agents, and bicyclic carboxylic acid nucleating agents; more preferably, the organic acid nucleating agent includes alkali metal salts of benzoate, aluminum salts of aromatic carboxylate, titanium salts of aromatic carboxylate, metal salts of hexahydrophthalic acid (HHPA), cyclic dicarboxylate, and β-crystal nucleating agents of calcium stearate-pimelic acid complex; even more preferably, the organic acid nucleating agent includes calcium phthalate, calcium pimelic acid and calcium octanoate, zinc phthalate, β-cyclodextrin maleic anhydride lanthanum complex, aluminum adipic acid, zinc adipic acid, aluminum phthalate, aluminum terephthalate, zinc terephthalate, and aluminum citrate; Preferably, the sorbitol β-crystal nucleating agent includes dibenzyl sorbitol (DBS), methylbenzyl sorbitol (MDBS), and p-chlorobenzyl sorbitol (CDBS).

4. The polymer binder containing a β-crystalline nucleating agent according to claim 1 or 2, characterized in that, The polyolefin binder is obtained by polymerizing one or more olefin monomers; The olefin monomers include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, styrene, 4-methyl-1-pentene, and cyclic olefin monomers; Preferably, the polyolefin binder is selected from at least one of polyethylene, polypropylene, poly-1-butene, poly-1-pentene, poly-1-hexene, poly-1-octene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, polyethylene-vinyl acetate, polyethylene-acrylate, polyethylene-methacrylate, polyisobutylene, polycyclobutene, polycyclooctene, and poly-1,5-cyclooctadiene; Preferably, the polyolefin adhesive has a weight-average molecular weight of 5,000 to 6,000,000, more preferably 50,000 to 3,000,000, and even more preferably 50,000 to 2,000,000.

5. A method for preparing a polymer binder containing a β-crystal nucleating agent as described in any one of claims 1-4, characterized in that, include: Prepared using either the first or the second method; The first method includes the following steps: mixing an olefin monomer and the β-crystal nucleating agent, and preparing the mixture via a polymerization reaction; The steps of the second method include: mixing and granulating the polyolefin and the β-crystal nucleating agent.

6. The preparation method according to claim 5, characterized in that, The steps of the first method further include: after the polymerization reaction is completed, performing solid-liquid separation, and washing and drying the obtained solid material; Preferably, the steps of the second method include: mixing and melting the polyolefin and the β-crystal nucleating agent, and then extruding and granulating them.

7. The use of the polymer binder containing a β-crystal nucleating agent as described in any one of claims 1-4 or the polymer binder containing a β-crystal nucleating agent prepared by the preparation method as described in any one of claims 5-6 in the preparation of dry electrodes or solid electrolyte membranes.

8. The application according to claim 7, characterized in that, The dry electrode is a dry positive electrode or a dry negative electrode, and the dry electrode may or may not contain a solid electrolyte. When the dry electrode does not contain a solid electrolyte, the dry electrode comprises, by mass fraction: 90%-97% active material, 0.5%-5.0% conductive agent, and 0.5%-5% polymer binder containing β-crystal nucleating agent; When the dry electrode contains a solid electrolyte, the dry electrode comprises, by mass fraction: 70%-97% active material, 5%-30% solid electrolyte, 0.5%-3.0% conductive agent, and 0.5%-3% polymer binder containing β-crystal nucleating agent; Preferably, the preparation process of the dry electrode includes: mixing and fiberizing the raw materials, and then rolling them through multiple stages to the target thickness or areal density to obtain a self-supporting sheet for the dry positive electrode or dry negative electrode; and hot-pressing the self-supporting sheet of the dry positive electrode or dry negative electrode with a current collector to obtain the dry positive electrode or dry negative electrode.

9. The application according to claim 7, characterized in that, The solid electrolyte membrane comprises, by mass fraction, 95.0%-99.5% solid electrolyte and 0.5%-5% polymer binder containing β-crystal nucleating agent; Preferably, the preparation process of the solid electrolyte membrane includes: mixing raw materials, fiberizing them, and then rolling them through multiple stages to achieve the target thickness or areal density to obtain a dry electrolyte membrane; The dry electrolyte membrane is laminated and wound together with a PET film or blank aluminum foil to obtain a dry electrolyte membrane protected by a PET film or blank aluminum foil. Alternatively, the dry electrolyte membrane can be hot-pressed together with a dry positive electrode or a dry negative electrode to prepare a dry positive electrode-dry electrolyte membrane composite electrode or a dry negative electrode-dry electrolyte membrane composite electrode.

10. The application according to claim 8 or 9, characterized in that, The solid electrolyte is selected from at least one of sulfide solid electrolytes, halide solid electrolytes, halide oxide solid electrolytes, and anti-perovskite solid electrolytes; Preferably, the dry-process positive electrode containing solid electrolyte uses a halide solid electrolyte, a halide oxide solid electrolyte, or a sulfide solid electrolyte; the dry-process negative electrode containing solid electrolyte uses a sulfide solid electrolyte or an anti-perovskite solid electrolyte; and the dry-process solid electrolyte membrane uses a sulfide solid electrolyte, a halide solid electrolyte, or an anti-perovskite solid electrolyte.

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