Organic electrolyte and preparation method thereof, electrolyte film layer and preparation method thereof, lithium ion solid-state battery, vehicle

Abstract

The application provides an organic electrolyte and a preparation method thereof, an electrolyte film layer and a preparation method thereof, a lithium ion solid-state battery and a vehicle, and relates to the technical field of lithium batteries. The organic electrolyte comprises a structure shown in formula I, wherein R1, R2 and R3 each independently comprise one of hydrogen, a substituted or unsubstituted C1-C5 alkyl, and R4 comprises at least one of a sulfonyl-containing group and an epoxy ether bond-containing group. In this way, the organic electrolyte has excellent electrochemical stability, so that it can match a high-voltage high-gram-capacity positive electrode, and the energy density of the lithium ion solid-state battery is improved.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, specifically to an organic electrolyte and its preparation method, an electrolyte membrane and its preparation method, a lithium-ion solid-state battery, and a vehicle. Background Technology

[0002] Compared to lithium-ion liquid batteries, lithium-ion solid-state batteries achieve lithium-ion transport through solid electrolytes. Therefore, lithium-ion solid-state batteries have advantages such as high safety, high energy density, high charging speed, and long lifespan.

[0003] PEO polymers, as common solid-state electrolytes, possess flexible molecular chains that allow for good adhesion and low interfacial resistance between the PEO polymer and the electrode interface. In particular, PEO polymers exhibit excellent compatibility with lithium metal anodes. However, PEO polymers have a relatively low electrochemical window and poor stability under high voltage, making them difficult to match with high-voltage, high-capacity cathodes, resulting in lower energy density in lithium-ion solid-state batteries.

[0004] Therefore, there is an urgent need to develop an organic electrolyte with excellent electrochemical stability so that it can be matched with a high-voltage, high-capacity cathode to improve the energy density of lithium-ion solid-state batteries. Summary of the Invention

[0005] This application provides an organic electrolyte and its preparation method, an electrolyte membrane and its preparation method, a lithium-ion solid-state battery, and a vehicle. Thus, the organic electrolyte exhibits excellent electrochemical stability, enabling it to be matched with a high-voltage, high-capacity cathode, thereby improving the energy density of the lithium-ion solid-state battery.

[0006] The technical solution of this application is as follows:

[0007] According to a first aspect of this application, an organic electrolyte is provided, comprising the structure shown in Formula I.

[0008]

[0009] In this formula, R1, R2, and R3 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups, and R4 includes at least one of a sulfonyl group and an epoxy ether group. For example, the value of n in Formula I can range from 10000 to 15000.

[0010] According to the aforementioned technical means, the organic electrolyte includes at least one of a sulfonyl group and an epoxy ether bond. Both the sulfonyl group and the epoxy ether bond are not easily oxidized or decomposed at high voltages, exhibiting good stability. This improves the electrochemical stability of the organic electrolyte, giving it a wide electrochemical window, allowing it to be matched with high-voltage, high-capacity cathodes and increasing the energy density of lithium-ion solid-state batteries. Furthermore, because the repeating units of the organic electrolyte contain ether-oxygen bonds, lithium ions undergo complexation and decomplexation processes with these bonds. Lithium ion migration is achieved through the movement of the organic electrolyte chain segments, resulting in superior ionic conductivity. The flexible molecular chains in the organic electrolyte also allow for good adhesion between the organic electrolyte and the electrode interface, as well as low interfacial resistance.

[0011] In one possible implementation, the sulfonyl group includes at least one of the following structures:

[0012]

[0013] Based on the above technical means, the above structures all have sulfonyl groups, which can improve the electrochemical stability of organic electrolytes, enabling organic electrolytes to be matched with high-voltage, high-capacity cathodes, resulting in higher energy density lithium-ion solid-state batteries.

[0014] In one possible implementation, the group containing the epoxy ether bond includes at least one of the following structures:

[0015]

[0016] Based on the above technical means, the above structures all have epoxy ether bonds, which can improve the electrochemical stability of organic electrolytes, enabling organic electrolytes to be matched with high-voltage, high-capacity cathodes, resulting in higher energy density lithium-ion solid-state batteries.

[0017] In one possible implementation, the polymer has an average molecular weight of 500,000 g / mol to 700,000 g / mol.

[0018] Based on the above-mentioned technical means, the average molecular weight of the organic electrolyte is controlled within the above-mentioned range, the organic electrolyte has a moderate average molecular weight, and the organic electrolyte has better ion transport effect and structural stability.

[0019] According to a second aspect provided in this application, a method for preparing an organic electrolyte is provided, comprising: subjecting a first organic compound and a second organic compound to a substitution reaction in the presence of an organic solvent to obtain an organic electrolyte;

[0020] The first organic compound includes the structure shown in Formula II:

[0021]

[0022] R1, R2, and R3 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups; the second organic compound includes at least one of sulfonyl halide and epoxy propane. For example, the value of n in Formula II can range from 10000 to 15000.

[0023] In one possible implementation, the first organic compound comprises polyethylene oxide. The average molecular weight of the polyethylene oxide can be from 500,000 g / mol to 700,000 g / mol.

[0024] In one possible implementation, the sulfonyl halide includes at least one of methylsulfonyl chloride, methylsulfonyl bromide, ethylsulfonyl chloride, propylsulfonyl chloride, phenylsulfonyl chloride, phenylsulfonyl bromide, and p-methylphenylsulfonyl chloride.

[0025] In one possible implementation, the epoxy halopropane includes at least one of epichlorohydrin, epibromopropane, methyl epichlorohydrin, and 1,2-epoxychlorobutane.

[0026] In one possible implementation, the molar ratio of the first organic compound to the second organic compound is 1:(1-3).

[0027] In one possible implementation, the substitution reaction is carried out at a temperature of 25°C to 35°C for 16 to 24 hours.

[0028] In one possible implementation, the above preparation method further includes purifying the organic electrolyte obtained from the substitution reaction to obtain a high-purity organic electrolyte.

[0029] According to a third aspect provided in this application, an electrolyte membrane layer is provided, comprising an inorganic electrolyte, a polymer, a lithium salt, and the aforementioned organic electrolyte, or an organic electrolyte prepared by the aforementioned method for preparing an organic electrolyte, wherein the polymer is coated on the surface of the inorganic electrolyte, the organic electrolyte is disposed on the surface of the polymer away from the inorganic electrolyte, and the lithium salt is disposed within the organic electrolyte; wherein the polymer comprises ether oxygen bonds and silane groups.

[0030] Based on the aforementioned technical methods, both the polymer and the organic electrolyte possess ether-oxygen bonds, resulting in good compatibility. The silane groups in the polymer can bond with certain elements (such as oxygen or sulfur) in the inorganic electrolyte, allowing the polymer to adsorb onto the surface of the inorganic electrolyte, thus providing excellent coating. This effectively inhibits direct contact between the inorganic and organic electrolytes, reducing phase separation and mitigating the risk of inorganic electrolyte aggregation. Ion transport between the inorganic and organic electrolytes occurs via the polymer, resulting in an excellent ion transport effect in the electrolyte membrane. Furthermore, the high voltage stability of the organic electrolyte contributes to the high voltage stability of the electrolyte membrane, enabling it to be matched with high-voltage, high-capacity cathodes, leading to higher energy density in lithium-ion solid-state batteries.

[0031] In one possible implementation, the polymer comprises the structure shown in Formula III.

[0032]

[0033] R5 contains hydrogen, or a substituted or unsubstituted C1-C5 alkyl group, while R6 and R7 each independently contain hydrogen or a silane group. For example, the value of m can range from 5 to 10.

[0034] Based on the above technical means, the polymer has both ether oxygen bonds and silane groups, which makes the polymer and organic electrolyte have good compatibility and the polymer and inorganic electrolyte have good bonding effect.

[0035] In one possible implementation, the polymer has an average molecular weight of 414 g / mol to 634 g / mol.

[0036] By using the above-mentioned technical means, the average molecular weight of the polymer is controlled within the above-mentioned range, and the polymer has better ion transport effect and mechanical properties.

[0037] In one possible implementation, the mass ratio of the mixture formed by the inorganic electrolyte, polymer, organic electrolyte, and lithium salt is 1:(0.05-0.1):(2-3). Since the lithium salt is disposed within the organic electrolyte, this approach can define the mixture formed by the organic electrolyte and the lithium salt.

[0038] Based on the above technical means, the mass ratio of the mixture formed by inorganic electrolyte, polymer, organic electrolyte and lithium salt is controlled within the above range. The proportion of polymer is moderate, and the polymer can achieve a good coating effect on inorganic electrolyte, so that the electrolyte membrane has excellent ion transport effect. The proportion of the mixture formed by organic electrolyte and lithium salt is moderate, and the electrolyte membrane has excellent high voltage stability.

[0039] In one possible implementation, in the mixture formed by the organic electrolyte and the lithium salt, the molar ratio of repeating units in the organic electrolyte to lithium ions in the lithium salt is (8-16):1. Wherein, the repeating units in the organic electrolyte are... R1 and R2 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups.

[0040] Based on the above technical means, the proportion of repeating units in the organic electrolyte is moderate, and the organic electrolyte has excellent electrochemical stability; the proportion of lithium ions in the lithium salt is moderate, and the energy density of the lithium-ion solid-state battery is high.

[0041] In one possible implementation, the electrolyte membrane layer is 50 to 100 micrometers in size.

[0042] Based on the above technical means, the electrolyte membrane layer has a moderate thickness and excellent mechanical properties and ion transport effect.

[0043] According to a fourth aspect provided in this application, a method for preparing an electrolyte membrane layer is provided, comprising: performing a first mixing treatment on an inorganic electrolyte and a polymer in an organic solvent to obtain a mixture; performing a second mixing treatment on the mixture, a lithium salt, and the aforementioned organic electrolyte, or an organic electrolyte prepared by the aforementioned method for preparing an organic electrolyte, to obtain an electrolyte membrane layer solution; and forming the electrolyte membrane layer solution on a substrate to obtain an electrolyte membrane layer.

[0044] In one possible implementation, the mass ratio of the mixture formed by the inorganic electrolyte, polymer, organic electrolyte and lithium salt is 1:(0.05-0.1):(2-3).

[0045] In one possible implementation, in the mixture formed by the organic electrolyte and the lithium salt, the molar ratio of repeating units in the organic electrolyte to lithium ions in the lithium salt is (8-16):1. Wherein, in the mixture formed by the organic electrolyte and the lithium salt, the mass ratio of the organic electrolyte to the lithium salt can be (5-8):(2-5).

[0046] According to the fifth aspect provided in this application, a lithium-ion solid-state battery is provided, comprising a positive electrode, a negative electrode, and the electrolyte film layer described above, or an electrolyte film layer prepared by the above method, wherein the electrolyte film layer is located between the positive electrode and the negative electrode.

[0047] According to the sixth aspect provided in this application, a vehicle is provided, including the aforementioned lithium-ion solid-state battery.

[0048] Therefore, the above-mentioned technical features of this application have the following beneficial effects:

[0049] (1) Organic electrolytes have excellent chemical stability.

[0050] Organic electrolytes include at least one of sulfonyl groups and epoxy ether groups. Both sulfonyl groups and epoxy ether groups are not easily oxidized or decomposed at high voltages, exhibiting good stability. Compared to polyethylene oxide, the organic electrolyte of this application replaces the hydroxyl groups in polyethylene oxide (hydroxyl groups are easily oxidized) with R4 groups (R4 groups include sulfonyl groups and epoxy ether groups), resulting in superior electrochemical stability and a wider electrochemical window, allowing it to be matched with high-voltage, high-capacity cathodes and improving the energy density of lithium-ion solid-state batteries.

[0051] (2) The electrolyte membrane layer has both excellent ion transport effect and chemical stability.

[0052] Because both polymers and organic electrolytes contain ether-oxygen bonds, they exhibit good compatibility. The silane groups in the polymer can form bonds with some elements (such as oxygen or sulfur) in the inorganic electrolyte, allowing the polymer to adsorb onto the surface of the inorganic electrolyte, resulting in superior coating performance. This effectively inhibits direct contact between the inorganic and organic electrolytes, reducing phase separation and mitigating the risk of inorganic electrolyte aggregation. Ion transport between the inorganic and organic electrolytes is facilitated by the polymer, resulting in excellent ion transport performance in the electrolyte membrane. Furthermore, the high voltage stability of organic electrolytes contributes to the high voltage stability of the electrolyte membrane, enabling it to be matched with high-voltage, high-capacity cathodes, leading to higher energy density in lithium-ion solid-state batteries.

[0053] (3) The preparation method is simple and easy to implement.

[0054] An organic polymer is prepared by substituting a first polymer with a sulfonyl halide and / or an epoxy propane halide. A mixture is obtained by first mixing an inorganic electrolyte and the polymer; then, the mixture, lithium salt, and organic electrolyte are subjected to a second mixing treatment to obtain an electrolyte membrane solution; the electrolyte membrane solution is then formed on a substrate to obtain an electrolyte membrane. In summary, the method for preparing the organic polymer and electrolyte membrane is simple, cost-effective, requires no complex pretreatment or post-treatment, and is easily industrialized.

[0055] It should be noted that the technical effects of any implementation method in the second aspect can be referred to the technical effects of the corresponding implementation method in the first aspect; the technical effects of any implementation method in the fourth to sixth aspects can be referred to the technical effects of the corresponding implementation method in the first or third aspect, and will not be repeated here.

[0056] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0057] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0058] Figure 1 This is a schematic diagram illustrating an electrolyte membrane layer according to an exemplary embodiment;

[0059] Figure 2 This is another schematic diagram of an electrolyte membrane layer according to an exemplary embodiment. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0061] In the specification of this application, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0062] Electric vehicles are a type of new energy vehicle, boasting advantages such as environmental friendliness, energy efficiency, and low operating costs. Batteries play a crucial role in electric vehicles, serving as the power source and directly affecting factors like driving range, charging time, and efficiency. Lithium-ion batteries, as environmentally friendly rechargeable batteries, offer advantages such as high energy density and long cycle life, and are widely used in the new energy vehicle sector. However, with the rapid development of new energy vehicles, consumer anxiety regarding vehicle range and battery safety is increasing, driving the development of lithium-ion batteries towards higher energy density and enhanced safety.

[0063] Lithium-ion batteries in electric vehicles are mainly divided into lithium-ion liquid batteries and lithium-ion solid batteries. Lithium-ion liquid batteries use electrolyte to achieve lithium-ion transfer between the positive and negative electrodes, while lithium-ion solid batteries use solid electrolyte to achieve lithium-ion transfer between the positive and negative electrodes. Compared with lithium-ion liquid batteries, lithium-ion solid batteries have advantages such as high safety and high energy density.

[0064] PEO polymers, as common solid-state electrolytes, possess flexible molecular chains that allow for good adhesion and low interfacial resistance between the PEO polymer and the electrode interface. In particular, PEO polymers exhibit excellent compatibility with lithium metal anodes. However, PEO polymers have a relatively low electrochemical window and poor stability under high voltage, making them difficult to match with high-voltage, high-capacity cathodes, resulting in lower energy density in lithium-ion solid-state batteries.

[0065] Based on this, this application proposes a vehicle, which can be a pure electric vehicle or a hybrid electric vehicle. To achieve the basic functions of the vehicle, it may include a body, chassis, battery system, and power system. Of course, the vehicle may also include other components; this is merely illustrative and does not limit the specific composition of the vehicle.

[0066] The vehicle body may include a frame, doors, and windows. The frame forms the overall external shape of the vehicle and creates a passenger space. Doors are rotatably connected to the frame, allowing the interior passenger space to be opened or closed. Windows are mounted on the doors or frame, facilitating passenger observation of the external environment. The chassis may include components such as a transmission system and a drive system. The drive system drives the wheels. Depending on the drive method, drive systems can be front-wheel drive, rear-wheel drive, or four-wheel drive. The transmission system transmits power generated by the power system to the wheels. The power system provides power to the vehicle, enabling it to perform basic driving functions. To supply power to the power system (such as an electric motor), the vehicle provided in this embodiment also includes a battery system, which includes lithium-ion solid-state batteries that provide electrical energy. The lithium-ion solid-state batteries can be connected to the vehicle's power system, allowing the battery pack's electrical energy to be transferred to the vehicle's power system for power supply.

[0067] As the above analysis shows, PEO polymers have poor stability under high voltage, making them difficult to match with high-voltage, high-capacity cathodes, resulting in low energy density in lithium-ion solid-state batteries. Therefore, this application provides an organic electrolyte to improve its stability under high voltage, enabling it to be matched with high-voltage, high-capacity cathodes and thus increasing the energy density of lithium-ion solid-state batteries.

[0068] Embodiments of this application provide an organic electrolyte comprising the structure shown in Formula I.

[0069]

[0070] In this formula, R1, R2, and R3 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups, and R4 includes at least one of a sulfonyl group and an epoxy ether group. In some possible embodiments, the value of n in Formula I can be in the range of 10,000 to 15,000. For example, the value of n can be in the range of 10,000, 12,000, 13,000, or 15,000.

[0071] In the aforementioned organic electrolyte, R4 in the structure shown in Formula I includes one or more groups containing sulfonyl groups and epoxy ether bonds. Both sulfonyl groups and epoxy ether bonds are not easily oxidized or decomposed at high voltages, exhibiting good stability. This enhances the electrochemical stability of the organic electrolyte, giving it a wide electrochemical window that allows it to be matched with high-voltage, high-capacity cathodes, thereby increasing the energy density of lithium-ion solid-state batteries. Furthermore, because the repeating units of the aforementioned organic electrolyte contain ether-oxygen bonds, lithium ions undergo complexation and decomplexation processes with these bonds. Lithium ion migration is achieved through the movement of the organic electrolyte chain segments, resulting in superior ionic conductivity. In addition, the organic electrolyte contains flexible molecular chains, ensuring good adhesion between the organic electrolyte and the electrode interface and resulting in low interfacial resistance.

[0072] For example, the sulfonyl group includes at least one of the following structures:

[0073]

[0074] Thus, all of the above structures have sulfonyl groups, which can improve the electrochemical stability of organic electrolytes, enabling organic electrolytes to be matched with high-voltage, high-capacity cathodes, resulting in higher energy density lithium-ion solid-state batteries.

[0075] As another example, groups containing epoxy ether bonds include at least one of the following structures:

[0076] Thus, the above structures all have epoxy ether bonds, which can improve the electrochemical stability of organic electrolytes, enabling organic electrolytes to be matched with high-voltage, high-capacity cathodes, resulting in higher energy density lithium-ion solid-state batteries.

[0077] In embodiments of this application, the term "C1-C5 alkyl" refers to a straight-chain or branched hydrocarbon chain group consisting only of carbon and hydrogen atoms, without unsaturation, having one to five carbon atoms, and attached to the rest of the molecule by single bonds. In embodiments of this application, the term "substituted" means that at least one hydrogen atom of the compound or chemical moiety is substituted by a substituent in another chemical moiety.

[0078] In some embodiments, the average molecular weight of the organic electrolyte is from 500,000 g / mol to 700,000 g / mol. For example, the molecular weight of the organic electrolyte can be 500,000 g / mol, 550,000 g / mol, 600,000 g / mol, 650,000 g / mol, 700,000 g / mol, or a value within a range consisting of any two of the above points.

[0079] By controlling the average molecular weight of the aforementioned organic electrolytes within the specified range, the organic electrolytes exhibit a suitable average molecular weight, resulting in superior ion transport performance and structural stability. Furthermore, this effectively mitigates the problems associated with excessively large average molecular weights, which can impair chain segment movement, hinder lithium-ion migration, and reduce ionic conductivity. Conversely, it effectively addresses the issues of excessively small average molecular weights, which can lead to reduced mechanical strength and poor structural stability.

[0080] Embodiments of this application provide a method for preparing an organic electrolyte, comprising: subjecting a first organic compound and a second organic compound to a substitution reaction in the presence of an organic solvent to obtain an organic electrolyte;

[0081] The first organic compound includes the structure shown in Formula II:

[0082] R1, R2, and R3 each independently contain hydrogen, or one of the substituted or unsubstituted C1-C5 alkyl groups; the second organic compound includes at least one of sulfonyl halides and epoxy halide propanes. For example, the value of n in Formula II can range from 10000 to 15000. For instance, the value of n can be 10000, 12000, 13000, or 15000.

[0083] The first and second organic compounds are dispersed in an organic solvent. Through functional group substitution, the H group in the weakly weak end group (-OH) of the first organic compound is replaced with a sulfonyl group or an epoxy ether bond in the second organic compound. The sulfonyl group and epoxy ether bond are not easily oxidized or decomposed at high voltages, exhibiting good stability. This results in an organic electrolyte with excellent high-voltage stability, allowing it to be matched with high-voltage, high-capacity cathodes, leading to high energy density in lithium-ion solid-state batteries. Furthermore, since the repeating units of the first organic compound contain ether-oxygen bonds, the repeating units of the prepared organic electrolyte also contain ether-oxygen bonds. Lithium ions undergo complexation and decomplexation processes with the ether-oxygen bonds in the organic electrolyte, and lithium ion migration is achieved through chain segment movement within the organic electrolyte, resulting in superior ionic conductivity.

[0084] In some embodiments, the first organic compound may be polyethylene oxide, and the substitution reaction between the polyethylene oxide and the second organic compound is shown below:

[0085]

[0086] Among them, R 4- X can represent a sulfonyl halide or an epoxy halide. Specifically, R4 represents the sulfonyl group in the sulfonyl halide or the epoxy ether bond in the epoxy halide, and X represents the halogen atom in the sulfonyl halide or the halogen atom in the epoxy halide.

[0087] In some embodiments, the method for preparing organic electrolytes may further include the following steps:

[0088] S100: Prepare the first organic solution.

[0089] In this step, a first organic compound is dispersed in a first organic solvent to obtain a solution of the first organic compound. In some possible embodiments, the first organic compound may be polyethylene oxide, which is dispersed in a first organic solvent to obtain a polyethylene oxide solution.

[0090] In some embodiments, polyethylene oxide is added to a dry mixing container filled with an inert atmosphere, followed by the addition of a first organic solvent. The mixture is then mixed to obtain a polyethylene oxide solution. In some possible embodiments, the inert gas may be one or more of nitrogen (N2) and argon (Ar). In some possible embodiments, the mixing container may be a flask. In some possible embodiments, the first organic solvent includes at least one of triethylamine solvent and anhydrous dichloromethane solvent.

[0091] In some embodiments, the average molecular weight of the polyethylene oxide is between 500,000 g / mol and 700,000 g / mol. For example, the molecular weight of the polyethylene oxide can be 500,000 g / mol, 550,000 g / mol, 600,000 g / mol, 650,000 g / mol, 700,000 g / mol, or a value within any two of the above ranges. By controlling the average molecular weight of the polyethylene oxide within the aforementioned range, the polyethylene oxide has a suitable average molecular weight, which results in a well-balanced average molecular weight for the prepared organic electrolyte, leading to superior ion transport performance and structural stability.

[0092] S200: In the presence of a second organic solvent, a solution of a first organic compound and a second organic compound undergo a substitution reaction to obtain a mixture containing an organic electrolyte. The second organic compound includes at least one of a sulfonyl halide and an epoxy propane halide.

[0093] In some embodiments, a second organic compound is first dispersed in a second organic solvent, and then a first organic compound solution is gradually added dropwise, and the mixture is stirred under an inert gas environment to obtain a mixture containing an organic electrolyte. In some possible embodiments, the second organic solvent includes at least one of triethylamine solvent and anhydrous dichloromethane solvent. In some possible embodiments, the inert gas forming the inert gas environment can be one or more of nitrogen (N2) and argon (Ar).

[0094] In some embodiments, the sulfonyl halide includes at least one of methylsulfonyl chloride, methylsulfonyl bromide, ethylsulfonyl chloride, propylsulfonyl chloride, phenylsulfonyl chloride, phenylsulfonyl bromide, and p-methylphenylsulfonyl chloride. Thus, the halogen atom in the sulfonyl halide can combine with the H in the weak end group (-OH) of the first organic compound (such as polyethylene oxide) to form a small molecule, and the sulfonyl group in the sulfonyl halide can replace the H in the weak end group (-OH) of the first organic compound (such as polyethylene oxide) to form an organic electrolyte having a sulfonyl group.

[0095] In some embodiments, the epoxy halide includes at least one selected from epichlorohydrin, epibromopropane, methylepoxychloropropane, and 1,2-epoxychlorobutane. Thus, the halogen atom in the epoxy halide can combine with the H atom in the weak end group (-OH) of the first organic compound (such as polyethylene oxide) to form a small molecule, and the epoxy ether bond in the epoxy halide can replace the H atom in the weak end group (-OH) of the first organic compound (such as polyethylene oxide) to form an organic electrolyte having epoxy ether bonds.

[0096] In some embodiments, the molar ratio of the first organic compound to the second organic compound is 1:(1-3), for example, the molar ratio of the first organic compound to the second organic compound can be 1:1, 1:1.5, 1:2, 1:2.5, or 1:3.

[0097] Preferably, the molar ratio of the first organic compound to the second organic compound is 1:(2.5-3). Controlling the molar ratio of the first organic compound to the second organic compound within the above range allows the second organic compound (such as sulfonyl halide or epoxy halide propane) to react fully without wasting the first organic compound (such as polyethylene oxide).

[0098] In some embodiments, the reaction temperature of the substitution reaction is 25°C to 35°C, and the reaction time is 16h to 24h. For example, the reaction temperature of the substitution reaction can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, or 35°C, and the reaction time can be 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, or 24h. Controlling the reaction temperature and time within the above ranges results in a higher degree of substitution reaction and a lower probability of side reactions. Furthermore, it helps mitigate the risk of excessively high reaction temperatures, which could lead to side reactions such as ring-opening of the first organic compound (e.g., polyethylene oxide).

[0099] S300: Purification of mixtures containing organic electrolytes to obtain high-purity organic electrolytes.

[0100] In this step, by purifying the mixture containing organic electrolytes obtained in step S200, impurities in the mixture can be removed to obtain a high-purity organic electrolyte. In some embodiments, the purification may include: filtering the mixture containing organic electrolytes obtained in step S200; washing the filtered organic electrolyte with a washing solution; and drying the washed organic electrolyte to obtain a high-purity organic electrolyte.

[0101] In some possible implementations, the mixture containing organic electrolytes prepared in step S200 is first filtered; then the filtered organic electrolyte is washed with diethyl ether, and after washing, the organic electrolyte is vacuum dried; then the vacuum-dried organic electrolyte is dissolved in dichloromethane, and the organic electrolyte is washed sequentially with hydrochloric acid solution, sodium bicarbonate solution, and deionized water; then the residual water on the washed organic electrolyte is removed with anhydrous sodium sulfate or anhydrous potassium carbonate; finally, the organic electrolyte is precipitated with diethyl ether and dried overnight at room temperature to obtain a high-purity organic electrolyte.

[0102] In some embodiments, the yield of the organic electrolyte prepared by the above method is 75% to 85%. The yield of the organic electrolyte is equal to the mass of the actual organic electrolyte obtained by the substitution reaction divided by the mass of the theoretical organic electrolyte obtained by the substitution reaction.

[0103] Polyethylene oxide (PEO) has a low ionic conductivity at room temperature (e.g., it can be 10). -7 S / cm to 10 -5The low rate capability of lithium-ion batteries (S / cm) makes it difficult to charge and discharge them at room temperature. Furthermore, the low electrochemical window of polyethylene oxide (PEO) (e.g., less than or equal to 4V) makes it difficult to match with high-voltage, high-capacity cathodes, resulting in lower energy density in lithium-ion batteries. To address these technical issues, in some cases, PEO can be modified to improve its ion transport performance. For example, mixing and heat-treating PEO, lithium carboxymethyl cellulose (CMC-Li), and lithium bisfluorosulfonyl imide (LiFSI) can reduce the crystallinity of PEO and enhance ion transport. However, this method suffers from poor high-voltage stability, hindering compatibility with high-voltage, high-capacity cathodes and hindering the development of high-energy-density lithium-ion solid-state batteries. In other cases, the overall electrochemical performance of polyethylene oxide (PEO) can be improved by mixing it with inorganic fillers. However, during the composite process of PEO and inorganic fillers, the inorganic fillers are prone to agglomeration, making it difficult to form an effective ion transport pathway between PEO and inorganic fillers, resulting in poor ion transport performance of lithium-ion solid-state batteries.

[0104] Embodiments of this application provide an electrolyte membrane layer comprising an inorganic electrolyte, a polymer, a lithium salt, and the aforementioned organic electrolyte, or an organic electrolyte prepared by the aforementioned method, wherein the polymer is coated on the surface of the inorganic electrolyte, the organic electrolyte is disposed on the surface of the polymer away from the inorganic electrolyte, and the lithium salt is disposed within the organic electrolyte; wherein the polymer comprises ether oxygen bonds and silane groups. In some possible embodiments, refer to... Figure 1 and Figure 2 The electrolyte membrane layer comprises lithium salt, polymer, inorganic electrolyte and organic electrolyte, wherein the polymer is wrapped around the surface of the inorganic electrolyte, the organic electrolyte is disposed on the side of the polymer away from the inorganic electrolyte, and the lithium salt is disposed within the organic electrolyte (for example, the lithium salt may be located within the molecular chain of the organic electrolyte).

[0105] The polymer contains ether-oxygen bonds, as do the repeating units in the organic electrolyte. Since both the polymer and the organic electrolyte possess ether-oxygen bonds, they exhibit good compatibility and excellent ion transport between them. Furthermore, the polymer contains silane groups, which can bond with certain elements in the inorganic electrolyte (such as oxygen or sulfur). The polymer can adsorb onto the surface of the inorganic electrolyte, resulting in superior coating and excellent ion transport between them. This effectively inhibits direct contact between the inorganic and organic electrolytes, reducing phase separation and the risk of inorganic electrolyte aggregation. Ion transport between the inorganic and organic electrolytes occurs via the polymer, thus the electrolyte membrane exhibits excellent ion transport performance.

[0106] Furthermore, since organic electrolytes include at least one of sulfonyl groups and epoxy ether groups, both sulfonyl groups and epoxy ether groups are not easily oxidized or decomposed at high voltages, exhibiting good stability. This allows organic electrolytes to possess high voltage stability, resulting in high voltage stability of the electrolyte membrane. The electrolyte membrane can then be matched with a high-voltage, high-capacity cathode, leading to higher energy density in lithium-ion solid-state batteries.

[0107] In some embodiments, the polymer comprises the structure shown in Formula III.

[0108]

[0109] In this design, R5 contains hydrogen or one of the substituted or unsubstituted C1-C5 alkyl groups, while R6 and R7 each independently contain one of the hydrogen or silane groups. For example, the value of m can range from 5 to 10. For instance, m can be 5, 6, 7, 8, 9, or 10. Thus, the polymer contains both ether oxygen bonds and silane groups, resulting in good compatibility between the polymer and the organic electrolyte, and good bonding between the polymer and the inorganic electrolyte.

[0110] Furthermore, R6 and R7 can both be silane groups, and the polymer structure can be 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS). This results in the polymer having at least three silane groups, which is beneficial for improving the bonding effect between the polymer and the inorganic electrolyte, and for enhancing the polymer's coating effect on the inorganic electrolyte.

[0111] In some embodiments, the average molecular weight of the polymer is between 414 g / mol and 634 g / mol. For example, the average molecular weight of the polymer can be 414 g / mol, 450 g / mol, 500 g / mol, 550 g / mol, 600 g / mol, or 634 g / mol. Controlling the average molecular weight of the polymer within the above range results in superior ion transport performance and mechanical properties. Furthermore, it can mitigate the effects of an excessively high average molecular weight, which leads to poor ion transport performance, and an excessively low average molecular weight, which leads to poor mechanical properties.

[0112] In some embodiments, the inorganic solid electrolyte includes at least one of oxide solid electrolytes and sulfide solid electrolytes. In some possible embodiments, the oxide solid electrolyte includes at least one of lithium aluminum titanium phosphate (LATP), lithium aluminum germanium phosphate (LAGP), lithium lanthanum zirconium oxide (LLZO), and lithium lanthanum zirconium tantalum oxide (LLZTO). In some possible embodiments, the sulfide solid electrolyte includes at least one of lithium germanium phosphorus sulfide (LGPS), lithium phosphorus sulfide chloride (LPSC), and lithium phosphorus sulfide (LPS).

[0113] In some embodiments, the mass ratio of the mixture formed by the inorganic electrolyte, polymer, organic electrolyte, and lithium salt is 1:(0.05-0.1):(2-3). For example, it can be 1:0.05:2, 1:0.075:2, 1:0.1:2, 1:0.05:2.5, or 1:0.05:3. Since the lithium salt is disposed within the organic electrolyte, this scheme can limit the mixture formed by the organic electrolyte and the lithium salt.

[0114] By controlling the mass ratio of the mixture formed by inorganic electrolyte, polymer, organic electrolyte, and lithium salt within the aforementioned range, a moderate polymer content is achieved, allowing for good coating of the inorganic electrolyte and resulting in excellent ion transport performance of the electrolyte membrane. Similarly, a moderate proportion of the mixture formed by the organic electrolyte and lithium salt contributes to excellent high voltage stability of the electrolyte membrane. Furthermore, controlling the mass ratio of inorganic electrolyte, polymer, and organic electrolyte within the aforementioned range mitigates the problem of excessive inorganic electrolyte content leading to poor polymer coating, reduced phase separation between the inorganic and organic electrolytes, and reduced inorganic electrolyte aggregation, resulting in higher ion transport performance of the electrolyte membrane. Since the ion transport performance of polymers is generally inferior to that of inorganic electrolytes, controlling the mass ratio of inorganic electrolyte, polymer, and organic electrolyte within the aforementioned range can alleviate the issue of excessive polymer content leading to poor ion transport performance of the electrolyte membrane.

[0115] In some embodiments, in the mixture formed by the organic electrolyte and the lithium salt, the molar ratio of repeating units in the organic electrolyte to lithium ions in the lithium salt is (8-16):1. Wherein, the repeating units in the organic electrolyte are... R1 and R2 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups.

[0116] Based on the above technical means, the proportion of repeating units in the organic electrolyte is moderate, and the organic electrolyte has excellent electrochemical stability; the proportion of lithium ions in the lithium salt is moderate, and the energy density of the lithium-ion solid-state battery is high.

[0117] In some embodiments, the electrolyte membrane layer is 50 to 100 micrometers thick; for example, the thickness of the electrolyte membrane layer can be 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, or 100 micrometers. This results in a moderate thickness of the electrolyte membrane layer, which exhibits superior mechanical properties and excellent ion transport performance.

[0118] Embodiments of this application provide a method for preparing an electrolyte membrane layer, comprising the following steps:

[0119] S10: The inorganic electrolyte and the polymer are first mixed in an organic solvent to obtain a mixture.

[0120] In this step, the inorganic electrolyte and polymer undergo a first mixing treatment, which enables bonding between some elements in the inorganic electrolyte (such as oxygen in oxide solid electrolytes or sulfur in sulfide solid electrolytes) and the polymer. The polymer can be adsorbed onto the surface of the inorganic electrolyte, exhibiting excellent encapsulation effect. In some possible embodiments, the organic solvent in step S10 can be acetonitrile.

[0121] In some embodiments, the temperature of the first mixing treatment is 50°C to 70°C, and the time of the first mixing treatment is 12h to 24h. For example, the temperature of the first mixing treatment can be 50°C, 55°C, 60°C, 65°C, or 70°C, and the time of the first mixing treatment can be 12h, 15h, 18h, 21h, or 24h. Controlling the temperature and time of the first mixing treatment within the above ranges results in a suitable temperature and time, leading to better bonding between some elements in the inorganic electrolyte and the polymer, and the polymer exhibiting excellent encapsulation effect on the inorganic electrolyte.

[0122] In some embodiments, the mass ratio of inorganic electrolyte to polymer is (10-20):1. For example, the mass ratio of inorganic electrolyte to polymer can be 10:1, 12:1, 14:1, 16:1, 18:1, or 20:1.

[0123] By controlling the feed ratio of the inorganic electrolyte and polymer within the aforementioned range, the bonding effect between some elements in the inorganic electrolyte (such as oxygen in oxide solid electrolytes or sulfur in sulfide solid electrolytes) and the polymer is better, and the polymer has an excellent encapsulation effect on the inorganic electrolyte. Furthermore, this method can mitigate the problem of excessive inorganic electrolyte content leading to poor polymer encapsulation, reduced phase separation between the inorganic and organic electrolytes, and reduced inorganic electrolyte aggregation, resulting in a higher ion transport efficiency for the electrolyte membrane. Since the ion transport efficiency of polymers is generally worse than that of inorganic electrolytes, controlling the mass ratio of inorganic electrolyte, polymer, and organic electrolyte within the aforementioned range can alleviate the problem of excessive polymer content negatively impacting ion transport in the electrolyte membrane.

[0124] S20: The mixture, lithium salt, and the organic electrolyte mentioned above, or the organic electrolyte prepared by the above method, are subjected to a second mixing treatment to obtain an electrolyte membrane solution.

[0125] In this step, the mixture, lithium salt, and the organic electrolyte mentioned above, or the organic electrolyte prepared by the above method, are subjected to a second mixing treatment, which can realize the composite of organic electrolyte and polymer, and the organic electrolyte and polymer have high compatibility.

[0126] In some embodiments, an organic electrolyte and a lithium salt are added to the mixture and slowly stirred to achieve a second mixing process. This slow stirring of the organic electrolyte, lithium salt, and mixture effectively prevents the formation of bubbles in the subsequently prepared electrolyte membrane. In some possible embodiments, the slow stirring time is 12 hours to 24 hours, for example, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, or 24 hours.

[0127] In some embodiments, the mass ratio of the mixture formed by the inorganic electrolyte, polymer, organic electrolyte, and lithium salt is 1:(0.05-0.1):(2-3). Furthermore, in the mixture formed by the organic electrolyte and lithium salt, the molar ratio of repeating units in the organic electrolyte to lithium ions in the lithium salt is (8-16):1. Wherein, the repeating units in the organic electrolyte are... R1 and R2 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups.

[0128] The mass ratio of the mixture formed by inorganic electrolyte, polymer, organic electrolyte and lithium salt is controlled within the above range. The proportion of polymer is moderate, which can achieve a good coating effect on inorganic electrolyte, so that the electrolyte membrane has excellent ion transport effect. The proportion of organic electrolyte and lithium salt is moderate, which can give the electrolyte membrane excellent high voltage stability.

[0129] In some embodiments, the lithium salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide (LITFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), and lithium tetrafluoroborate (LiBF4), preferably at least one of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) and lithium bis(fluorosulfonyl)imide (LiFSI).

[0130] S30: An electrolyte membrane solution is formed on a substrate to obtain an electrolyte membrane.

[0131] In this step, an electrolyte membrane solution is formed on a substrate, and after drying, an electrolyte membrane layer is obtained. In some possible embodiments, the electrolyte membrane solution is formed on the substrate by casting, and then vacuum dried to obtain the electrolyte membrane layer.

[0132] In some embodiments, the substrate may be a substrate with low adhesion. For example, the substrate may be a PET sheet, a glass sheet, or a metal sheet with a high surface smoothness.

[0133] In some embodiments, the vacuum drying temperature is 50°C to 70°C, and the vacuum drying time is 12h to 24h. For example, the vacuum drying temperature can be 50°C, 55°C, 60°C, 65°C, or 70°C, and the vacuum drying time can be 12h, 15h, 18h, 21h, or 24h. By controlling the vacuum drying temperature and time within the above ranges, the prepared electrolyte membrane layer has better uniformity, which is beneficial to improving the performance of the electrolyte membrane layer.

[0134] Embodiments of this application provide a lithium-ion solid-state battery, which includes a positive electrode, a negative electrode, and the aforementioned electrolyte film layer, with the electrolyte film layer located between the positive and negative electrode layers. Thus, the electrolyte film layer exhibits excellent ion transport performance and high voltage stability, resulting in a high energy density for the lithium-ion solid-state battery.

[0135] In some embodiments, the method for preparing the positive electrode sheet includes: dispersing the lithium salt and the aforementioned organic electrolyte in a solvent, then adding the positive electrode active material and a conductive agent to the solvent to form a positive electrode sheet slurry; and coating the positive electrode sheet slurry onto a positive electrode current collector to obtain the positive electrode sheet. In some possible embodiments, the positive electrode active material may be lithium nickel cobalt manganese oxide (NCM9055, NCM811). In some possible embodiments, the conductive agent may be conductive carbon black (Super P). In some possible embodiments, the solvent may be N,N-dimethylformamide (DMF). In some possible embodiments, the positive electrode current collector may be aluminum foil. In some possible embodiments, the mass ratio of the mixture formed by the positive electrode active material, the conductive agent, the organic electrolyte, and the lithium salt may be (60-80):(5-10):(10-30). 。

[0136] In some embodiments, the method for preparing the negative electrode sheet includes: bonding lithium metal onto a negative electrode current collector and rolling it to obtain the negative electrode sheet. In some possible embodiments, the negative electrode current collector may be copper foil.

[0137] In some embodiments, the method for preparing a lithium-ion solid-state battery is as follows: assembling a positive electrode sheet, an electrolyte film layer, and a negative electrode sheet in a stacked manner, performing hot pressing to ensure solid-solid interface bonding, sequentially welding positive electrode tabs and negative electrode tabs, and finally encapsulating to obtain a lithium-ion solid-state battery.

[0138] An embodiment of this application provides a vehicle that includes the lithium-ion solid-state battery described above. Thus, the lithium-ion solid-state battery has a high energy density, and the vehicle has a long service life.

[0139] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0140] Example 1

[0141] 1. Preparation of organic electrolytes.

[0142] (1-1) Polyethylene oxide was added to a dry flask filled with an inert Ar atmosphere. Then, 2 ml of triethylamine solvent and 50 ml of anhydrous dichloromethane solvent were added to the flask and mixed to dissolve the polyethylene oxide solution. The amount of polyethylene oxide used was 1.67 × 10⁻⁶. -5 mol (10g), the molecular weight of polyethylene oxide is 600,000g / mol;

[0143] (1-2) Phenylsulfonyl chloride was dissolved in anhydrous dichloromethane solvent, and the polyethylene oxide solution obtained in step (1-1) was gradually added dropwise to induce a substitution reaction. The mixture was stirred continuously for 17 h at room temperature (25℃) and under an inert Ar atmosphere to obtain a mixture containing an organic electrolyte; wherein the amount of phenylsulfonyl chloride used was 4.17 × 10⁻⁶. -5 The molar ratio of polyethylene oxide to phenylsulfonyl chloride is 1:2.5.

[0144] (1-3) The mixture containing organic electrolytes obtained in step (1-2) is filtered to remove solid by-reaction products. The filtered solution is then precipitated in diethyl ether to obtain organic electrolytes. The organic electrolytes are washed with diethyl ether and then vacuum dried. The vacuum-dried organic electrolytes are then dissolved in dichloromethane and washed successively with 0.1 mol / L hydrochloric acid, 5 wt% sodium bicarbonate aqueous solution, and deionized water. The residual water on the washed organic electrolytes is then removed with anhydrous sodium sulfate or anhydrous potassium carbonate. The purified organic electrolytes are precipitated again in diethyl ether and dried at room temperature overnight to obtain 7.5 g of organic electrolytes (yield approximately 75%).

[0145] 2. Preparation of electrolyte membrane layer.

[0146] (2-1) 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) and 0.5g of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) were mixed into 50mL of acetonitrile to obtain a mixture, wherein the mixing temperature was 60℃ and the mixing time was 12h.

[0147] (2-2) Add 7.1g of the organic electrolyte obtained in step (1-3) and 2.9g of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) to the mixture obtained in step (2-1), and stir slowly at 25°C for 24h to obtain an electrolyte membrane solution; wherein the molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 16:1;

[0148] (2-3) An electrolyte membrane solution is formed on a substrate by casting and then dried under vacuum to obtain an electrolyte membrane with a thickness of 80 micrometers. The drying temperature is 60℃ and the drying time is 12h.

[0149] 3. Preparation of lithium-ion solid-state batteries.

[0150] (3-1) Prepare the positive electrode sheet.

[0151] In N,N-dimethylformamide (DMF) solvent, a mixture of positive electrode active material NCM9055 (specific capacity 210 mAh / g), conductive carbon black (Super P), the organic electrolyte obtained in steps (1-3) (7.1 g), and lithium bis(trifluoromethanesulfonyl)imide (2.9 g) was mixed at a mass ratio of 80 g: 10 g: 10 g to obtain a positive electrode slurry with a solid content of 50 wt%. The positive electrode slurry was then coated onto a 12-micron-thick aluminum foil using a coating machine to obtain an areal density of 10 mg / cm³. 2 The positive electrode active layer is then dried at 110℃ for 5 minutes and then rolled to a compaction density of 3.6 g / cm³. 3 The positive electrode sheet with dimensions of 77mm*55mm*40um was obtained by cutting.

[0152] (3-2) Prepare the negative electrode sheet.

[0153] A 50µm thick lithium metal foil is bonded to a 6µm thick copper foil, and the two are combined using a physical rolling process. The resulting negative electrode sheet has dimensions of 79mm x 57mm x 56µm.

[0154] (3-3) The lithium-ion solid-state battery is assembled.

[0155] The positive electrode, electrolyte membrane (81mm*59mm), and negative electrode are assembled in a stacked manner (1 positive electrode + 1 electrolyte membrane + 1 negative electrode). The solid-solid interface is bonded by hot pressing at 50MPa. The positive and negative electrode tabs are then welded in sequence, and the battery is encapsulated with a 153um thick aluminum-plastic film to obtain an all-solid-state battery for electrical performance testing.

[0156] Example 2

[0157] The difference between Example 2 and Example 1 is:

[0158] 1. Preparation of organic electrolytes.

[0159] (1-1) The amount of polyethylene oxide used is 8.33 g, and the molecular weight is 500,000 g / mol;

[0160] (1-2) 4.17*10 -5 The phenylsulfonyl chloride was replaced by 4.67*10 mol. -5 The stirring time was changed from 17h to 20h for the addition of mol of p-methylphenylsulfonyl chloride; the molar ratio of polyethylene oxide to p-methylphenylsulfonyl chloride was 1:2.8.

[0161] (1-3) The organic electrolyte prepared was 6.5 g (yield of approximately 78%).

[0162] 2. Preparation of electrolyte membrane layer.

[0163] (2-1) Replace 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) with 5g of lithium lanthanum zirconium oxide (LLZO), and the mass of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.5g;

[0164] (2-2) The mass of the organic electrolyte is 5.51 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 4.49 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 8:1.

[0165] (2-3) The thickness of the electrolyte membrane is 50 micrometers.

[0166] Example 3

[0167] The difference between Example 3 and Example 1 is:

[0168] 1. Preparation of organic electrolytes.

[0169] (1-2) 4.17*10 -5 mol of phenylsulfonyl chloride was replaced with 5*10 -5 The stirring time was changed from 17h to 18h for the addition of mol of p-methylphenylsulfonyl chloride; the molar ratio of polyethylene oxide to p-methylphenylsulfonyl chloride was 1:3.

[0170] (1-3) The organic electrolyte prepared was 8.0 g (yield of about 80%).

[0171] 2. Preparation of electrolyte membrane layer.

[0172] (2-1) Replace 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) with 5g of lithium lanthanum zirconium tantalum oxide (LLZTO), and the mass of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.25g;

[0173] (2-2) The mass of the organic electrolyte is 6.48 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 3.52 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 12:1.

[0174] (2-3) The thickness of the electrolyte membrane is 100 micrometers.

[0175] Example 4

[0176] The difference between Example 4 and Example 1 is:

[0177] 1. Preparation of organic electrolytes.

[0178] (1-1) The amount of polyethylene oxide used is 11.67 g, and the molecular weight is 700,000 g / mol;

[0179] (1-2) 4.17*10 -5 The phenylsulfonyl chloride was replaced by 4.83*10 mol. -5 The stirring time was changed from 17h to 20h for the addition of mol of p-methylphenylsulfonyl chloride; the molar ratio of polyethylene oxide to p-methylphenylsulfonyl chloride was 1:2.9.

[0180] (1-3) The organic electrolyte prepared was 9.21 g (yield of approximately 79%).

[0181] 2. Preparation of electrolyte membrane layer.

[0182] (2-1) Replace 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) with 5g of lithium germanium phosphorus sulfur (LGPS), and the mass of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.5g;

[0183] (2-2) The mass of the organic electrolyte is 6.48 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 3.52 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 12:1.

[0184] Example 5

[0185] The difference between Example 5 and Example 1 is:

[0186] 1. Preparation of organic electrolytes.

[0187] (1-1) The amount of polyethylene oxide used is 8.33 g, and the molecular weight is 500,000 g / mol;

[0188] (1-2) 4.17*10 -5 mol of phenylsulfonyl chloride was replaced with 4*10 -5 The stirring time was changed from 17h to 20h for the addition of mol of p-methylphenylsulfonyl chloride; the molar ratio of polyethylene oxide to p-methylphenylsulfonyl chloride was 1:2.4.

[0189] (1-3) The organic electrolyte prepared was 6.25 g (yield of approximately 75%).

[0190] 2. Preparation of electrolyte membrane layer.

[0191] (2-1) Replace 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) with 5g of lithium phosphorus sulfur chloride (LPSC), and the mass of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.25g;

[0192] (2-2) The mass of the organic electrolyte is 6.48 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 3.52 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 12:1.

[0193] Example 6

[0194] The difference between Example 6 and Example 1 is:

[0195] 1. Preparation of organic electrolytes.

[0196] (1-2) 4.17*10 -5 The phenylsulfonyl chloride was replaced by 3.83*10 mol. -5 The stirring time was changed from 17h to 24h for the addition of epichlorohydrin; the molar ratio of polyethylene oxide to epichlorohydrin was 1:2.3.

[0197] (1-3) The organic electrolyte prepared was 7.5 g (yield of approximately 75%).

[0198] 2. Preparation of electrolyte membrane layer.

[0199] The mass of (2-1)3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.5 g;

[0200] (2-2) The mass of the organic electrolyte is 7.10 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 2.9 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 16:1.

[0201] Example 7

[0202] The difference between Example 7 and Example 1 is:

[0203] 1. Preparation of organic electrolytes.

[0204] (1-2) 4.17*10 -5 The phenylsulfonyl chloride was replaced by 4.17*10 mol. -5 The stirring time was changed from 17h to 22h for the addition of mol of epichlorohydrin; the molar ratio of polyethylene oxide to epichlorohydrin was 1:2.5.

[0205] (1-3) The organic electrolyte prepared was 7.5 g (yield of approximately 75%).

[0206] 2. Preparation of electrolyte membrane layer.

[0207] The mass of (2-1)3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) is 0.5 g;

[0208] (2-2) The mass of the organic electrolyte is 7.10 g, and the mass of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) is 2.9 g. The molar ratio of the repeating unit in the organic electrolyte to the lithium ions in the lithium bis(trifluoromethanesulfonyl)imide is 16:1.

[0209] Comparative Example 1

[0210] 1. Preparation of electrolyte membrane layer.

[0211] (1-1) 5g of lithium aluminum titanium phosphate solid electrolyte (LATP) and 0.5g of 3-[methoxy(polyethoxy)npropyl]trimethoxysilane (mPEO-TMS) were mixed into 50mL of acetonitrile to obtain a mixture, wherein the mixing temperature was 60℃ and the mixing time was 12h.

[0212] (1-2) 7.1 g of polyethylene oxide and 2.9 g of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) were added to the mixture obtained in step (1-1) at a molar ratio of 16:1 for the repeating unit in polyethylene oxide and the lithium ions in lithium bis(trifluoromethanesulfonyl)imide. The mixture was then slowly stirred at 25 °C for 24 h to obtain an electrolyte membrane solution.

[0213] (1-3) An electrolyte membrane solution is formed on a substrate by casting and then dried under vacuum to obtain an electrolyte membrane with a thickness of 80 micrometers. The drying temperature is 60℃ and the drying time is 12h.

[0214] 2. Preparation of lithium-ion solid-state batteries.

[0215] (2-1) Preparation of positive electrode sheet.

[0216] In N,N-dimethylformamide (DMF) solvent, a mixture of positive electrode active material NCM9055 (specific capacity 210 mAh / g), conductive carbon black (Super P), polyethylene oxide (7.1 g), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (2.9 g) was mixed at a mass ratio of 80 g: 10 g: 10 g to obtain a positive electrode slurry with a solid content of 50 wt%. The positive electrode slurry was then coated onto a 12-micron-thick aluminum foil using a coating machine to obtain an areal density of 10 mg / cm³. 2The positive electrode active layer is then dried at 110℃ for 5 minutes and then rolled to a compaction density of 3.6 g / cm³. 3 The positive electrode sheet with dimensions of 77mm*55mm*40um was obtained by cutting.

[0217] (2-2) Preparation of negative electrode sheet.

[0218] A 50µm thick lithium metal foil is bonded to a 6µm thick copper foil, and the two are combined using a physical rolling process. The resulting negative electrode sheet has dimensions of 79mm x 57mm x 56µm.

[0219] (2-3) The lithium-ion solid-state battery is assembled.

[0220] The positive electrode, electrolyte membrane (81mm*59mm), and negative electrode are assembled in a stacked manner (1 positive electrode + 1 electrolyte membrane + 1 negative electrode). The solid-solid interface is bonded by hot pressing at 50MPa. The positive and negative electrode tabs are then welded in sequence, and the battery is encapsulated with a 153um thick aluminum-plastic film to obtain an all-solid-state battery for electrical performance testing.

[0221] Comparative Example 2

[0222] 1. Preparation of electrolyte membrane layer.

[0223] (1) 5g of lithium titanium aluminum phosphate solid electrolyte (LATP), 7.1g of polyethylene oxide, and 2.9g of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) were mixed in 50mL of acetonitrile to obtain a mixture. The mixing temperature was 60℃ and the mixing time was 24h.

[0224] (2) An electrolyte membrane solution is formed on a substrate by casting and then dried under vacuum to obtain an electrolyte membrane with a thickness of 80 micrometers. The drying temperature is 60°C and the drying time is 12h.

[0225] 2. Preparation of lithium-ion solid-state batteries.

[0226] (2-1) Preparation of positive electrode sheet.

[0227] In N,N-dimethylformamide (DMF) solvent, a mixture of positive electrode active material NCM9055 (specific capacity 210 mAh / g), conductive carbon black (Super P), polyethylene oxide (7.1 g), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (2.9 g) was mixed at a mass ratio of 80 g: 10 g: 10 g to obtain a positive electrode slurry with a solid content of 50 wt%. The positive electrode slurry was then coated onto a 12-micron-thick aluminum foil using a coating machine to obtain an areal density of 10 mg / cm³. 2 The positive electrode active layer is then dried at 110℃ for 5 minutes and then rolled to a compaction density of 3.6 g / cm³. 3 The positive electrode sheet with dimensions of 77mm*55mm*40um was obtained by cutting.

[0228] (2-2) Preparation of negative electrode sheet.

[0229] A 50µm thick lithium metal foil is bonded to a 6µm thick copper foil, and the two are combined using a physical rolling process. The resulting negative electrode sheet has dimensions of 79mm x 57mm x 56µm.

[0230] (2-3) The lithium-ion solid-state battery is assembled.

[0231] The positive electrode, electrolyte membrane (81mm*59mm), and negative electrode are assembled in a stacked manner (1 positive electrode + 1 electrolyte membrane + 1 negative electrode). The solid-solid interface is bonded by hot pressing at 50MPa. The positive and negative electrode tabs are then welded in sequence, and the battery is encapsulated with a 153um thick aluminum-plastic film to obtain an all-solid-state battery for electrical performance testing.

[0232] Comparative Example 3

[0233] 1. Preparation of electrolyte membrane layer.

[0234] (1) 7.1g of polyethylene oxide and 2.9g of lithium bis(trifluoromethanesulfonyl)imide (LITFSI) were mixed in 50mL of acetonitrile to obtain a mixture, wherein the mixing temperature was 60℃ and the mixing time was 24h.

[0235] (2) An electrolyte membrane solution is formed on a substrate by casting and then dried under vacuum to obtain an electrolyte membrane with a thickness of 80 micrometers. The drying temperature is 60°C and the drying time is 12h.

[0236] 2. Preparation of lithium-ion solid-state batteries.

[0237] (2-1) Preparation of positive electrode sheet.

[0238] In N,N-dimethylformamide (DMF) solvent, a mixture of positive electrode active material NCM9055 (specific capacity 210 mAh / g), conductive carbon black (Super P), polyethylene oxide (7.1 g), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (2.9 g) was mixed at a mass ratio of 80 g: 10 g: 10 g to obtain a positive electrode slurry with a solid content of 50 wt%. The positive electrode slurry was then coated onto a 12-micron-thick aluminum foil using a coating machine to obtain an areal density of 10 mg / cm³. 2 The positive electrode active layer is then dried at 110℃ for 5 minutes and then rolled to a compaction density of 3.6 g / cm³. 3 The positive electrode sheet with dimensions of 77mm*55mm*40um was obtained by cutting.

[0239] (2-2) Preparation of negative electrode sheet.

[0240] A 50µm thick lithium metal foil is bonded to a 6µm thick copper foil, and the two are combined using a physical rolling process. The resulting negative electrode sheet has dimensions of 79mm x 57mm x 56µm.

[0241] (2-3) The lithium-ion solid-state battery is assembled.

[0242] The positive electrode, electrolyte membrane (81mm*59mm), and negative electrode are assembled in a stacked manner (1 positive electrode + 1 electrolyte membrane + 1 negative electrode). The solid-solid interface is bonded by hot pressing at 50MPa. The positive and negative electrode tabs are then welded in sequence, and the battery is encapsulated with a 153um thick aluminum-plastic film to obtain an all-solid-state battery for electrical performance testing.

[0243] Performance testing

[0244] (1) Method for testing the electrochemical window of the electrolyte membrane: Lithium sheet, composite electrolyte membrane, and stainless steel sheet were assembled into a button cell in the manner of negative electrode, electrolyte, and positive electrode. The Li|composite electrolyte membrane|SS button cell was tested by linear sweep voltammetry using an electrochemical workstation (Autolab PGSTAT3302N). The test voltage was 2.5-6V and the scan rate was 1mV / s.

[0245] (2) Method for testing the ionic conductivity of the electrolyte membrane: Stainless steel sheet, composite electrolyte, and stainless steel sheet are assembled into a button cell in the manner of negative electrode, electrolyte, and positive electrode. Electrochemical impedance spectroscopy is performed using an electrochemical workstation. The initial potential is set to 0V, the frequency range is 0.1Hz-5MHz, and the AC amplitude is 10mV.

[0246] (3) Method for testing the cycle performance of all-solid-state batteries: The clamping pressure of the all-solid-state battery is set to 0.2MPa, the temperature is set to 25℃, the voltage range is 2.5-4.2V, the charging regime is 1C constant current charging to 4.2V and constant voltage charging to 0.05C, the discharging regime is 1C constant current discharging to 2.5V, the charge and discharge cycle is 100 times, and the capacity retention rate is compared.

[0247] The key parameters for preparing the organic electrolyte and electrolyte membrane are shown in Table 1; the electrolyte membranes and lithium-ion solid batteries of each embodiment and comparative example were tested, and the test results are shown in Table 2.

[0248] Table 1

[0249]

[0250] Table 2

[0251]

[0252] Analyze the data in Tables 1 and 2:

[0253] The main differences between Examples 1-7 and Comparative Examples 1-3 are summarized as follows: Comparative Example 1 uses unmodified polyethylene oxide, and a polymer is disposed between the unmodified polyethylene oxide and the solid electrolyte; Comparative Example 2 uses unmodified polyethylene oxide, and no polymer is disposed between the unmodified polyethylene oxide and the solid electrolyte; Comparative Example 3 uses only unmodified polyethylene oxide and does not have a solid electrolyte.

[0254] Compared with Comparative Examples 1, 2, and 3, the electrolyte membrane prepared by the method provided in Examples 1-7 of this application has a wider electrochemical window and excellent ionic conductivity. Due to the improved electrochemical window of the electrolyte membrane, the electrolyte membrane can be adapted to high-voltage high-nickel ternary cathodes, which greatly improves the cycle capacity retention of the all-solid-state battery.

[0255] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. An organic electrolyte, characterized in that, The organic electrolyte comprises the structure shown in Formula I. Equation I; R1, R2, and R3 each independently contain one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups, R4 includes at least one of sulfonyl groups and epoxy ether groups, and n ranges from [10000, 15000]. The sulfonyl group includes at least one of the following structures: , , , and ; The group containing an epoxy ether bond includes at least one of the following structures: , and .

2. The organic electrolyte according to claim 1, characterized in that, The organic electrolyte has an average molecular weight of 500,000 g / mol to 700,000 g / mol.

3. A method for preparing organic electrolytes, characterized in that, include: In the presence of an organic solvent, a first organic compound and a second organic compound undergo a substitution reaction to obtain an organic electrolyte; The first organic compound comprises the structure shown in Formula II: Formula II; R1, R2, and R3 each independently contain hydrogen, or one of the substituted or unsubstituted C1-C5 alkyl groups; the second organic compound includes at least one of sulfonyl halide, epoxy halide, and 1,2-epoxychlorobutane, and n ranges from [10000, 15000]; the second organic compound satisfies at least one of the following conditions: the sulfonyl halide includes at least one of methylsulfonyl chloride, methylsulfonyl bromide, ethylsulfonyl chloride, propylsulfonyl chloride, phenylsulfonyl chloride, phenylsulfonyl bromide, and p-methylphenylsulfonyl chloride; the epoxy halide includes at least one of epichlorohydrin, epibromopropane, and methylepoxychloropropane.

4. The method according to claim 3, characterized in that, The first organic compound includes polyethylene oxide.

5. The method according to any one of claims 3-4, characterized in that, The substitution reaction satisfies at least one of the following conditions: The molar ratio of the first organic compound to the second organic compound is 1:(1-3); The substitution reaction is carried out at a temperature of 25°C to 35°C and for a duration of 16 h to 24 h.

6. An electrolyte membrane layer, characterized in that, The mixture includes inorganic electrolytes, polymers, lithium salts, and organic electrolytes as described in claim 1 or 2, or organic electrolytes prepared by the method of any one of claims 3-5, wherein the polymer coats the surface of the inorganic electrolyte, the organic electrolyte is disposed on the surface of the polymer away from the inorganic electrolyte, and the lithium salt is disposed within the organic electrolyte; wherein the polymer comprises the structure shown in Formula III. Formula III; R5 contains one of hydrogen, substituted or unsubstituted C1-C5 alkyl groups, and R6 and R7 each independently contain one of hydrogen or methoxy groups. The polymer has an average molecular weight of 414 g / mol to 634 g / mol.

7. The electrolyte membrane layer according to claim 6, characterized in that, The mass ratio of the mixture formed by the inorganic electrolyte, the polymer, the organic electrolyte and the lithium salt is 1:(0.05-0.1):(2-3).

8. The electrolyte membrane layer according to claim 6 or 7, characterized in that, In the mixture formed by the organic electrolyte and the lithium salt, the molar ratio of the repeating unit in the organic electrolyte to the lithium ion in the lithium salt is (8-16):

1.

9. The electrolyte membrane layer according to claim 6 or 7, characterized in that, The electrolyte membrane layer is 50 micrometers to 100 micrometers in size.

10. A method for preparing an electrolyte membrane layer, characterized in that, include: In an organic solvent, the inorganic electrolyte and the polymer are first mixed to obtain a mixture. The mixture, lithium salt, and organic electrolyte as described in claim 1 or 2, or organic electrolyte prepared by any one of claims 3-5, are subjected to a second mixing treatment to obtain an electrolyte membrane solution. The electrolyte membrane solution is formed on a substrate to obtain an electrolyte membrane.

11. A lithium-ion solid-state battery, characterized in that, It includes a positive electrode, a negative electrode, and an electrolyte membrane layer as described in any one of claims 6-9, or an electrolyte membrane layer prepared by the method of claim 10, wherein the electrolyte membrane layer is located between the positive electrode and the negative electrode.

12. A vehicle, characterized in that, Including the lithium-ion solid-state battery as described in claim 11.

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