In-situ cured gel polymer electrolyte and applications thereof
Patent Information
- Application Number
- CN202611000576.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-07
- Publication Date
- 2026-09-15
AI Technical Summary
[0004]1）部分可聚合单体或聚合体系在首次循环过程中不能有效抑制电极/电解质界面副反应，导致首次不可逆容量较高、首次充放电效率仍然偏低；
[0026] (1) By introducing multifunctional compounds containing functional elements such as B, P, Si, S, W and Mo, they can participate in in-situ polymerization and cross-linking inside the battery, and actively participate in the construction of the electrode/electrolyte interface film, optimize the composition and microstructure of the interface film, effectively suppress irreversible side reactions such as electrolyte decomposition and active lithium loss during the first charge and discharge process, reduce irreversible capacity loss in the first cycle, and improve the first charge and discharge efficiency of the battery.
Smart Images
Figure CN122762818A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electrolyte technology for electrochemical energy storage devices, specifically to an in-situ cured gel polymer electrolyte and its applications. Background Technology
[0002] With the rapid development of portable electronic devices, electric vehicles, drones, and large-scale energy storage systems, secondary batteries are facing higher demands for energy density, cycle life, rate performance, and safety. Traditional liquid electrolytes possess high ionic conductivity and good electrode wettability, but they typically suffer from problems such as easy leakage, flammability, numerous interfacial side reactions, and insufficient safety. Especially in high-energy-density battery systems, continuous side reactions can easily occur between the electrolyte and highly active electrode materials, leading to increased initial irreversible capacity, decreased initial charge-discharge efficiency, increased interfacial impedance, and degraded cycle performance.
[0003] Gel polymer electrolytes combine the high ion conductivity of liquid electrolytes with the morphological stability of solid polymer electrolytes. Existing in-situ cured gel polymer electrolytes, through the injection of polymerizable precursors into the battery followed by polymerization or cross-linking reactions, can form a gel network in situ within the electrode and separator pores, exhibiting good interfacial contact and process compatibility. However, existing in-situ cured gel polymer electrolytes have the following drawbacks:
[0004] 1) Some polymerizable monomers or polymerizable systems cannot effectively suppress side reactions at the electrode / electrolyte interface during the first cycle, resulting in a high initial irreversible capacity and a still low initial charge-discharge efficiency;
[0005] 2) Gel networks with single linear polymerization or insufficient cross-linking often have limited mechanical strength and interfacial stability, and are prone to problems such as increased interfacial impedance, intensified battery polarization and decreased capacity retention during long-term cycling.
[0006] 3) During use, electrolyte leakage is likely to occur, and the thermal stability and mechanical integrity are not ideal, posing a safety risk. Summary of the Invention
[0007] To address the shortcomings of existing technologies, this application provides an in-situ cured gel polymer electrolyte, which solves the problems mentioned in the background art.
[0008] To achieve the above objectives, in a first aspect, embodiments of this application provide an in-situ cured gel polymer electrolyte, which is formed by in-situ curing and cross-linking a precursor composition inside a battery cavity;
[0009] The precursor composition includes a base electrolyte, a multifunctional compound, and an initiator;
[0010] The basic electrolyte comprises a metal salt and an organic solvent;
[0011] The molecule of the multifunctional compound contains at least one element selected from B, P, Si, S, W, and Mo, and the molecule of the multifunctional compound contains at least two polymerizable functional groups.
[0012] In conjunction with the first aspect, in one embodiment, the polymerizable functional group includes at least one selected from vinyl, allyl, acrylate, methacrylate, epoxy, alkynyl, mercapto, thioether, and alkoxysilyl groups.
[0013] In conjunction with the first aspect, in one embodiment, the multifunctional compound includes at least one of triallyl borate, triacrylate borate, triallyl phosphate, triallyl phosphite, tetraallyl silicate, vinyl silane compounds, allyl silane compounds, alkenyl sulfide compounds, alkenyl tungstate compounds, and alkenyl molybdate compounds.
[0014] In conjunction with the first aspect, in one embodiment, the content of the multifunctional compound in the precursor composition is 0.01-30 wt%.
[0015] In conjunction with the first aspect, in one embodiment, the precursor composition further includes a polythiol compound;
[0016] The multithiol compound contains at least two thiol groups, and the multithiol compound is used to undergo thiol-alkene addition reaction, free radical crosslinking reaction or click reaction with unsaturated bonds in multifunctional compounds to form a three-dimensional crosslinked gel polymer network.
[0017] The content of the polythiol compound in the precursor composition is 0.01-30 wt%.
[0018] In conjunction with the first aspect, in one embodiment, the multi-thiol compound includes at least one selected from pentaerythritol tetra-3-mercaptopropionate, pentaerythritol tetramercaptoacetate, trimethylolpropane tri-3-mercaptopropionate, trimethylolpropane trimercaptoacetate, ethylene glycol di-3-mercaptopropionate, polythiol compounds, and mercaptosilane compounds.
[0019] In conjunction with the first aspect, in one embodiment, the metal salt includes at least one selected from lithium salt, sodium salt, potassium salt, magnesium salt, and zinc salt; wherein the lithium salt includes at least one selected from LiPF6, LiBF4, LiFSI, LiTFSI, LiDFOB, LiBOB, and LiClO4.
[0020] The organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, fluoroethylene carbonate, ethyl acetate, propyl propionate, 1,3-dioxolane, and ethylene glycol dimethyl ether.
[0021] In conjunction with the first aspect, in one embodiment, the initiator includes at least one of a thermal initiator, a photoinitiator, and a redox initiator;
[0022] The thermal initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and dicumyl peroxide;
[0023] The photoinitiator includes at least one of 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, benzophenone, and benzoin ether photoinitiators.
[0024] Secondly, embodiments of this application provide an application of an in-situ cured gel polymer electrolyte as described in the first aspect in a solid-state-like battery, wherein the solid-state-like battery is one of a lithium-ion battery, a lithium metal battery, a sodium-ion battery, a potassium-ion battery, a magnesium-ion battery, and a zinc-ion battery.
[0025] Compared with the prior art, the advantages of this application are:
[0026] (1) By introducing multifunctional compounds containing functional elements such as B, P, Si, S, W and Mo, they can participate in in-situ polymerization and cross-linking inside the battery, and actively participate in the construction of the electrode / electrolyte interface film, optimize the composition and microstructure of the interface film, effectively suppress irreversible side reactions such as electrolyte decomposition and active lithium loss during the first charge and discharge process, reduce irreversible capacity loss in the first cycle, and improve the first charge and discharge efficiency of the battery.
[0027] (2) Introducing multi-thiol compounds, through mechanisms such as thiol-alkene addition, free radical crosslinking, and click reaction, to construct a uniform, dense, and highly flexible three-dimensional crosslinked gel network with multi-functional compounds. This network structure has strong stability and can maintain close contact between the electrolyte and the electrode for a long time, suppressing the problem of interface structure collapse and continuous impedance growth during cycling, effectively reducing electrode interface impedance, reducing battery working polarization, and improving battery charge and discharge response speed and rate performance.
[0028] (3) The three-dimensional cross-linked gel network effectively locks in the electrolyte, inhibits the migration, decomposition and loss of the electrolyte during long-term cycling, stabilizes the electrode interface structure, reduces the irreversible loss of active ions, alleviates the battery capacity decay rate, and extends the battery cycle life.
[0029] (4) It has excellent structural integrity and thermal stability. The cross-linked network can firmly bind the electrolyte, thereby reducing the safety risks caused by leakage of traditional liquid electrolyte. In addition, the dense three-dimensional network can improve the mechanical strength and heat resistance of the electrolyte, effectively avoiding the risk of thermal runaway and fire under abuse conditions such as puncture, extrusion, high temperature, and overcharging, thereby improving the safety and environmental adaptability of the battery. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 The table shows the results of the cyclic performance test in the embodiments of this application;
[0032] Figure 2 This is a comparison table of AC impedance tests in the embodiments of this application;
[0033] Figure 3 This is a sample state diagram after the needle puncture test in an embodiment of this application. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0035] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0037] In a first aspect, embodiments of this application provide an in-situ cured gel polymer electrolyte, which is formed by in-situ curing and cross-linking a precursor composition inside a battery cavity.
[0038] The precursor composition includes:
[0039] Multifunctional compounds: 0.01-30 wt%;
[0040] Initiator: 0.001-10 wt%;
[0041] The remaining amount of basic electrolyte.
[0042] In one embodiment, the molecule of the multifunctional compound contains at least one element selected from B, P, Si, S, W, and Mo, and the molecule of the multifunctional compound contains at least two polymerizable functional groups.
[0043] Multifunctional compounds include at least one of the following: triallyl borate, triacrylate borate, triallyl phosphate, triallyl phosphite, tetraallyl silicate, vinyl silane compounds, allyl silane compounds, alkenyl sulfide compounds, alkenyl tungstate compounds, and alkenyl molybdate compounds.
[0044] At this point, multifunctional compounds can participate in in-situ polymerization or cross-linking reactions to form a gel polymer network and participate in the construction of the electrode / electrolyte interface film, so as to reduce irreversible side reactions during the first charge and discharge process and improve the first charge and discharge efficiency of the battery.
[0045] As a preferred option, multifunctional compounds do not contain oxygen double bonds directly connected to the central atom, such as triallyl borate.
[0046] Based on this, the polymerizable functional groups include at least one of vinyl, allyl, acrylate, methacrylate, epoxy, alkynyl, mercapto, thioether, and alkoxysilyl groups.
[0047] Furthermore, the content of the multifunctional compound in the precursor composition is preferably 0.05-15 wt%.
[0048] Furthermore, the content of the multifunctional compound in the precursor composition is preferably 0.1-8 wt%.
[0049] In one embodiment, the initiator includes at least one of a thermal initiator, a photoinitiator, and a redox initiator;
[0050] Thermal initiators include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and dicumyl peroxide;
[0051] Photoinitiators include at least one of 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, benzophenone, and benzoin ether photoinitiators.
[0052] Furthermore, the initiator content in the precursor composition is preferably 0.01-5 wt%.
[0053] In one embodiment, the basic electrolyte comprises a metal salt and an organic solvent, wherein the metal salt comprises at least one of lithium salt, sodium salt, potassium salt, magnesium salt, and zinc salt; wherein the lithium salt comprises at least one of LiPF6, LiBF4, LiFSI, LiTFSI, LiDFOB, LiBOB, and LiClO4.
[0054] The organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, fluoroethylene carbonate, ethyl acetate, propyl propionate, 1,3-dioxolane, and ethylene glycol dimethyl ether.
[0055] In one embodiment, the precursor composition comprises, by weight, the following parts:
[0056] Multifunctional compounds: 0.01-30 wt%;
[0057] Initiator: 0.001-10 wt%;
[0058] Polythiol compounds: 0.01-30 wt%;
[0059] The remaining amount of basic electrolyte.
[0060] The multi-thiol compound contains at least two thiol groups, which can undergo thiol-alkene addition reactions, free radical crosslinking reactions, or click reactions with unsaturated bonds in multifunctional compounds to form a three-dimensional crosslinked gel polymer network. This three-dimensional crosslinked gel polymer network can reduce electrode / electrolyte interfacial impedance and battery polarization, improve cycle capacity retention, and enhance electrolyte leakage resistance and battery safety.
[0061] The aforementioned multi-thiol compounds include at least one of pentaerythritol tetra-3-mercaptopropionate, pentaerythritol tetramercaptoacetate, trimethylolpropane tri-3-mercaptopropionate, trimethylolpropane trimercaptoacetate, ethylene glycol di-3-mercaptopropionate, polythiol compounds, and mercaptosilane compounds.
[0062] Furthermore, the content of the polythiol compound in the precursor composition is preferably 0.05-15 wt%.
[0063] Furthermore, the content of the polythiol compound in the precursor composition is preferably 0.1-5 wt%.
[0064] Secondly, embodiments of this application provide an application of the in-situ cured gel polymer electrolyte as described above in a solid-state-like battery, wherein the solid-state-like battery is one of lithium-ion batteries, lithium metal batteries, sodium-ion batteries, potassium-ion batteries, magnesium-ion batteries, and zinc-ion batteries.
[0065] In application, the in-situ cured gel polymer electrolyte is placed between the positive and negative electrodes of the solid-state battery and comes into contact with the positive and / or negative electrodes to form an electrode / electrolyte interface film.
[0066] The following section describes the application of the in-situ cured gel polymer electrolyte provided in the first aspect in solid-state-like batteries, using specific preparation methods.
[0067] Example 1
[0068] Under argon protection, 0.15 g of N,N'-methylenebisacrylamide (as a gelling agent), 0.05 g of triallyl borate, and 0.003 g of azobisisobutyronitrile were dissolved in 10 g of basic electrolyte (1 M LiPF6 in an EC / EMC / FEC system), and stirred until homogeneous to obtain the precursor composition.
[0069] The precursor composition was injected into a lithium-ion battery with lithium cobalt oxide as the positive electrode and heated in an oven at 60°C for 6 hours to complete in-situ thermal polymerization.
[0070] Example 2
[0071] Under argon protection, 0.15 g of N,N'-methylenebisacrylamide, 0.05 g of triallyl borate, 0.05 g of pentaerythritol tetra-3-mercaptopropionate, and 0.003 g of azobisisobutyronitrile were dissolved in 10 g of basic electrolyte (1 M LiPF6 in an EC / EMC / FEC system), and stirred until homogeneous to obtain the precursor composition.
[0072] The precursor composition was injected into a lithium-ion battery with lithium cobalt oxide as the positive electrode and heated in an oven at 60°C for 6 hours to complete in-situ thermal polymerization.
[0073] Comparative Example 1
[0074] Under argon protection, 0.15 g of N,N'-methylenebisacrylamide and 0.003 g of azobisisobutyronitrile were dissolved in 10 g of basic electrolyte (1 M LiPF6 in an EC / EMC / FEC system), and stirred until homogeneous to obtain the precursor composition.
[0075] The precursor solution was injected into a lithium-ion battery with lithium cobalt oxide as the positive electrode, and then heated in a 60°C oven for 6 hours to complete in-situ thermal polymerization.
[0076] Performance testing
[0077] According to Examples 1, 2, and Comparative Example 1, after obtaining the corresponding samples, initial charge-discharge efficiency, cycle performance, AC impedance, and safety tests were performed. The results of the initial charge-discharge efficiency test are shown in Table 1.
[0078]
[0079] Table 1
[0080] As shown in Table 1, the batteries obtained from the multifunctional compounds have higher first charge-discharge efficiency, indicating that the gel polymer network of the multifunctional compounds in this application can effectively reduce irreversible capacity loss during the first charge-discharge process.
[0081] Reference Figure 1 The sample prepared in Example 1 retained 62.2% of its original value after 500 cycles at 1C at room temperature; the sample prepared in Example 2 retained 73.3% of its original value after 700 cycles at 1C at room temperature; and the sample prepared in Comparative Example 1 retained 73.7% of its original value after 278 cycles at 1C at room temperature. This demonstrates that the system containing crosslinking monomers, multifunctional compounds, and multithiol compounds exhibits superior cycling performance.
[0082] Reference Figure 2 The table shows the AC impedance test results of the samples prepared in Comparative Example 1, Example 1 and Example 2 after cycling at 1C for 5 and 100 cycles at room temperature. The impedance test results before and after cycling show that the interfacial impedance growth of the system containing polyfunctional compounds and polythiol compounds is suppressed.
[0083] Reference Figure 3 The image shows the sample state of Comparative Example 1, Example 1 and Example 2 after the needle penetration test. It can be seen that the samples prepared in Example 1 and Example 2 showed better stability in the safety test, indicating that the gel polymer network formed by in-situ curing can reduce the fluidity and leakage risk of electrolyte and improve the battery safety performance.
[0084] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0085] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.
[0086] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.
[0087] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.
[0088] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.
[0089] The above are merely specific embodiments of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the scope of the claims.
Claims
1. An in-situ cured gel polymer electrolyte, characterized in that, The in-situ cured gel polymer electrolyte is formed by in-situ curing and cross-linking of the precursor composition inside the battery cavity; The precursor composition includes a base electrolyte, a multifunctional compound, and an initiator; The basic electrolyte comprises a metal salt and an organic solvent; The molecule of the multifunctional compound contains at least one element selected from B, P, Si, S, W, and Mo, and the molecule of the multifunctional compound contains at least two polymerizable functional groups.
2. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The polymerizable functional group includes at least one selected from vinyl, allyl, acrylate, methacrylate, epoxy, alkynyl, mercapto, thioether, and alkoxysilyl groups.
3. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The multifunctional compounds include at least one of the following: triallyl borate, triacrylate borate, triallyl phosphate, triallyl phosphite, tetraallyl silicate, vinyl silane compounds, allyl silane compounds, alkenyl sulfide compounds, alkenyl tungstate compounds, and alkenyl molybdate compounds.
4. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The content of the multifunctional compound in the precursor composition is 0.01-30 wt%.
5. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The precursor composition also includes a polythiol compound; The multithiol compound contains at least two thiol groups, and the multithiol compound is used to undergo thiol-alkene addition reaction, free radical crosslinking reaction or click reaction with unsaturated bonds in multifunctional compounds to form a three-dimensional crosslinked gel polymer network. The content of the polythiol compound in the precursor composition is 0.01-30 wt%.
6. The in-situ cured gel polymer electrolyte according to claim 5, characterized in that, The multi-thiol compound includes at least one of pentaerythritol tetra-3-mercaptopropionate, pentaerythritol tetramercaptoacetate, trimethylolpropane tri-3-mercaptopropionate, trimethylolpropane trimercaptoacetate, ethylene glycol di-3-mercaptopropionate, polythiol compounds, and mercaptosilane compounds.
7. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The metal salt includes at least one of lithium salt, sodium salt, potassium salt, magnesium salt, and zinc salt; wherein the lithium salt includes at least one of LiPF6, LiBF4, LiFSI, LiTFSI, LiDFOB, LiBOB, and LiClO4. The organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, fluoroethylene carbonate, ethyl acetate, propyl propionate, 1,3-dioxolane, and ethylene glycol dimethyl ether.
8. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The initiator includes at least one of thermal initiator, photoinitiator, and redox initiator; The thermal initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, and dicumyl peroxide; The photoinitiator includes at least one of 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, benzophenone, and benzoin ether photoinitiators.
9. The in-situ cured gel polymer electrolyte according to claim 1, characterized in that, The initiator content in the precursor composition is 0.001-10 wt%.
10. The application of an in-situ cured gel polymer electrolyte as described in any one of claims 1-9 in a solid-state-like battery, wherein the solid-state-like battery is one of a lithium-ion battery, a lithium metal battery, a sodium-ion battery, a potassium-ion battery, a magnesium-ion battery, and a zinc-ion battery.