Frame electrolyte structure, preparation method of electrolyte membrane, electrolyte membrane and battery

Abstract

The invention discloses a framework electrolyte structure, a preparation method of an electrolyte membrane, the electrolyte membrane and a battery. The framework electrolyte structure comprises a framework material, an organic molecule unit and an ion unit, the frame material is provided with a plurality of ordered channels with angstrom-level sizes; the organic molecule unit and the ion unit are both introduced into the ordered channel; the organic molecule unit is an organic molecule in a battery electrolyte; and the ion unit is metal battery ions. By means of the arrangement, the multiple bottleneck problems of poor interface stability, insufficient ionic conductivity, poor mechanical performance, low chemical stability and the like in the development process of the solid electrolyte can be solved.

Description

Technical Field

[0001] The present invention relates to the field of lithium ion batteries, and in particular to a frame electrolyte structure, a method for preparing an electrolyte membrane, an electrolyte membrane and a battery. Background Art

[0002] In today's energy-driven society, lithium-ion batteries, as a key energy storage device, are widely used in many fields such as electric vehicles, portable electronic devices, and large-scale energy storage systems. However, traditional lithium-ion batteries have encountered many bottlenecks in the process of technological development.

[0003] For example, the energy density of traditional lithium-ion batteries is limited and it is difficult to meet the growing energy demand. In addition, the use of liquid electrolytes brings safety risks, such as overheating and short circuits that may cause the battery to catch fire or explode. In addition, the cycle life and charge and discharge speed of lithium-ion batteries need to be improved.

[0004] In view of the above limitations of traditional lithium-ion batteries, solid-state batteries have emerged and are widely regarded as the core development direction of the next generation of battery technology. Solid-state batteries use solid electrolytes instead of traditional liquid electrolytes, which have the potential to significantly improve energy density and safety. At the same time, they are expected to significantly extend the cycle life of the battery and speed up the charging and discharging speed, thereby effectively overcoming many drawbacks of traditional lithium-ion batteries and opening up a new path for the development of high-performance batteries.

[0005] At present, the solid electrolytes used in solid-state batteries mainly include three categories: oxides, sulfides and polymer electrolytes. However, these three types of electrolytes face a series of thorny problems in their respective development processes.

[0006] Specifically, although oxide electrolytes have good chemical stability and relatively high electrical conductivity, their high preparation cost significantly increases the overall manufacturing cost of the battery. In addition, the interface contact problem between the oxide electrolyte and the electrode material has never been properly solved, which leads to an increase in the interface resistance and a decrease in the charge transfer efficiency during the charging and discharging process of the battery, which in turn causes fluctuations in battery performance and poor stability, greatly limiting its large-scale application.

[0007] Although sulfide electrolytes have high ionic conductivity and relatively excellent interface contact performance, they are extremely sensitive to environmental humidity and easily decompose in humid air, releasing toxic gases. This not only places strict requirements on the production and storage environment, increases the difficulty and cost of manufacturing and storage, but also poses potential safety risks during actual use.

[0008] Polymer electrolytes have good flexibility and can effectively solve the interface contact problem between electrolytes and electrode materials to a certain extent, but their room temperature ionic conductivity is low and cannot meet the ion transfer rate requirements for efficient battery operation at room temperature. At the same time, polymer electrolytes have poor thermal stability and are prone to degradation and performance degradation under high temperature conditions, which seriously affects the performance and cycle life of batteries under high temperature conditions.

[0009] Therefore, a framework electrolyte structure, a method for preparing an electrolyte membrane, an electrolyte membrane and a battery are needed to solve the above problems. Summary of the invention

[0010] The purpose of the present invention is to provide a framework electrolyte structure, a method for preparing an electrolyte membrane, an electrolyte membrane and a battery, so as to solve the multiple bottleneck problems faced by solid electrolytes in the development process, such as poor interface stability, insufficient ionic conductivity, poor mechanical properties and low chemical stability.

[0011] In order to solve the above technical problems, the present invention provides a framework electrolyte structure, including a framework material, an organic molecular unit and an ion unit;

[0012] The framework material has a plurality of ordered channels of angstrom size;

[0013] The organic molecular units and the ionic units are introduced into the ordered channels of the framework material;

[0014] The organic molecule unit is set as an organic molecule in the battery electrolyte;

[0015] The ion unit is configured as a metal battery ion.

[0016] Furthermore, the organic molecular unit and the framework material are bonded together through strong interaction;

[0017] The organic molecular unit and the ionic unit have a weak interaction to stabilize the ionic unit.

[0018] Furthermore, the strong interaction is an adsorption effect formed between the organic molecular unit and the active sites in the framework material, so that the organic molecular unit is fixed on the framework material;

[0019] The weak interaction is the electrostatic interaction formed between the negative charge sites in the organic molecular unit and the ionic unit, which stabilizes the ionic unit in the ordered channels of the framework material.

[0020] Furthermore, the size range of the ordered channels of the framework material is And the ordered channels of the frame material are arranged to have a regular pore structure.

[0021] Furthermore, the framework material is one or more of zeolite material, metal organic framework, and covalent organic framework.

[0022] Furthermore, the ion unit includes lithium ions, sodium ions, potassium ions or zinc ions.

[0023] Furthermore, the organic molecule unit is an organic molecule in a battery electrolyte solvent.

[0024] Furthermore, the organic molecular unit is at least one of ethylene carbonate, diethyl carbonate, polycarbonate, dimethyl carbonate, ethyl methyl carbonate, dioxolane or ethylene glycol dimethyl ether.

[0025] On the other hand, a method for preparing an electrolyte membrane is also proposed, comprising the following steps:

[0026] Providing a framework material powder having ordered channels, wherein the ordered channels have an angstrom-level size;

[0027] Physically compacting the framework material powder or preparing a membrane with a binder, and vacuum drying the membrane to obtain a raw molecular sieve membrane;

[0028] The organic molecular units and ionic units are introduced into the ordered channels of the original molecular sieve membrane by physical and chemical methods to obtain an electrolyte membrane.

[0029] Furthermore, the physicochemical method includes a vacuum-assisted liquid filling method or an electrochemical cycle activation method.

[0030] Furthermore, the vacuum liquid filling method comprises the following steps:

[0031] The original molecular sieve membrane is placed in an electrolyte, and a vacuum environment is formed by evacuating the electrolyte to promote the organic molecular units and the ion units to enter the ordered channels, thereby obtaining the electrolyte membrane.

[0032] Furthermore, the vacuum degree of the vacuum environment is>10 -2 Pa;

[0033] Furthermore, the electrochemical cycle activation method comprises the following steps:

[0034] Assembling the original molecular sieve membrane into a metal symmetric cell and immersing it in an electrolyte;

[0035] Applying a constant current to the metal symmetric battery to promote the organic molecular units and ion units to enter the ordered channels under the action of the electric field until the voltage of the metal symmetric battery tends to be stable, completing the activation of the original molecular sieve membrane, and obtaining the electrolyte membrane;

[0036] Furthermore, the constant current is 10μA-500μA.

[0037] Furthermore, the thickness of the original molecular sieve membrane is 50 μm-200 μm.

[0038] Furthermore, when the frame material powder is prepared into a film by physical compaction, the pressure range is 4t-15t.

[0039] Furthermore, when the frame material powder is prepared into a film by the binder, the binder accounts for 1wt%-1.5wt%, and the binder is set to be one or more of polytetrafluoroethylene and polyvinylidene fluoride.

[0040] On the other hand, the present invention further provides an electrolyte membrane, which is prepared by the method for preparing the electrolyte membrane described in the above embodiment.

[0041] In another aspect, the present invention further provides a battery, comprising an electrolyte membrane prepared by the method for preparing the electrolyte membrane described in the above embodiment.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] By setting up a framework electrolyte structure including a framework material with an ordered channel, an organic molecular unit and an ion unit, and introducing the organic molecular unit and the ion unit into the ordered channel, and setting the ordered channel as an angstrom-sized channel, this microstructure can provide good channel conditions for the rapid transmission of the ion unit, which is beneficial to the migration of the ion unit in the electrolyte. Compared with some traditional solid electrolytes, it can improve the transmission efficiency of the ion unit and achieve the purpose of improving the ionic conductivity.

[0044] In addition, compared with traditional liquid electrolytes, the framework electrolyte structure has better stability and mechanical strength, is not easy to leak, reduces safety hazards such as flammability, and improves the safety of the battery at high temperatures or under external impact.

[0045] Furthermore, the organic molecular units and the ionic units are stabilized through weak interactions (i.e., electrostatic interactions between negatively charged sites in the organic molecular units and the ionic units), so that the ionic units can be more stably and efficiently transported in the ordered channels, thereby helping to improve ionic conductivity.

[0046] Furthermore, the organic molecular units and the framework materials are bonded together through strong interactions (i.e., the adsorption effect formed by the organic molecular units and the active sites in the framework materials). This tight bonding helps to form a more stable interface between the electrolyte and the electrode materials. Therefore, when used in batteries, it can reduce interface resistance and reduce problems such as electrode material pulverization and electrolyte decomposition caused by interface instability, thereby improving interface compatibility and extending battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic structural diagram of a frame material of a frame electrolyte structure in Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic structural diagram of the framework electrolyte structure in Example 1 of the present invention;

[0049] Figure 3 The XRD diagram of the frame material and the prepared electrolyte membrane in the frame electrolyte structure in Example 2 of the present invention;

[0050] Figure 4 This is a constant current cycle curve diagram of the framework material in the framework electrolyte structure in Example 2 of the present invention when the electrochemical cycle is activated;

[0051] Figure 5 This is a comparative EIS graph of the original molecular sieve membrane before and after electrochemical activation in Example 2 of the present invention;

[0052] Figure 6 This is a constant voltage-current diagram when the original molecular sieve membrane is tested in Example 2 of the present invention;

[0053] Figure 7 The LSV diagram of the original molecular sieve membrane before and after electrochemical activation in Example 2 of the present invention;

[0054] Figure 8 This is a calculation diagram of the diffusion energy barrier of the original molecular sieve membrane after electrochemical activation in Example 2 of the present invention;

[0055] Fig. 9 This is a test diagram of the cycle performance when the original molecular sieve membrane in Example 2 of the present invention is assembled into a metal symmetric battery and activated;

[0056] Fig.10 This is a test diagram of the cycle performance of the metal solid-state battery prepared using the molecular sieve membrane in Example 4 of the present invention.

[0057] Figure numbers: 1. Framework material; 2. Ordered channel; 3. Organic molecular unit; 4. Ionic unit. DETAILED DESCRIPTION

[0058] The following will be described in more detail with reference to the schematic diagram of the present invention, the frame electrolyte structure, the method for preparing the electrolyte membrane, the electrolyte membrane and the battery, wherein the preferred embodiment of the present invention is shown, and it should be understood that the present invention described herein can be modified by those skilled in the art, and still achieve the advantageous effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art, and not as a limitation of the present invention.

[0059] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and are not in exact proportions, and are only used to facilitate and clearly assist in illustrating the purpose of the embodiments of the present invention.

[0060] Embodiment 1

[0061] like Figure 1 and Figure 2 As shown, this first embodiment proposes a framework electrolyte structure, including a framework material 1 , an organic molecule unit 3 and an ion unit 4 .

[0062] The framework material has a plurality of ordered channels 2, and the ordered channels 2 are arranged to be channels of angstrom-level size.

[0063] In this embodiment, the framework material 1 is one or more of a zeolite material, a metal organic framework, and a covalent organic framework, so as to form an ordered channel 2 of angstrom-level size.

[0064] The organic molecular units 3 and the ion units 4 are both introduced into the ordered channels 2 of the framework material 1, that is, the organic molecular units 3 and the ion units 4 can be evenly distributed in the ordered channels 2. Since the framework material 1 has good chemical stability and can maintain structural integrity under the battery working environment, it is effectively avoided that the framework material 1 decomposes and affects the electrolyte performance.

[0065] It should be noted that the organic molecule unit 3 is set as an organic molecule in the battery electrolyte. Specifically, the organic molecule unit 3 is an organic molecule in the battery electrolyte solvent, which is used to dissolve solutes and provide a migration medium for the ion unit 4.

[0066] In a specific example, the organic molecular unit 3 is at least one of ethylene carbonate, diethyl carbonate, polycarbonate, dimethyl carbonate, ethyl methyl carbonate, dioxolane, and ethylene glycol dimethyl ether.

[0067] It should also be noted that the ion unit 4 is configured as metal battery ions, specifically, lithium ions, sodium ions, potassium ions or zinc ions.

[0068] By setting up a framework electrolyte structure including a framework material 1 with an ordered channel 2, an organic molecular unit 3 and an ion unit 4, and introducing the organic molecular unit 3 and the ion unit 4 into the ordered channel 2, and setting the ordered channel 2 as an angstrom-sized channel, this microstructure can provide good channel conditions for the rapid transmission of the ion unit 4, which is beneficial to the migration of the ion unit 4 in the electrolyte. Compared with some traditional solid electrolytes, it can improve the transmission efficiency of the ion unit 4, thereby achieving the purpose of improving the ionic conductivity.

[0069] In addition, compared with traditional liquid electrolytes, the framework electrolyte structure has better stability and mechanical strength, is not easy to leak, reduces safety hazards such as flammability, and improves the safety of the battery at high temperatures or under external impact.

[0070] In one embodiment, the organic molecular unit 3 is combined with the framework material 1 through a strong interaction, ensuring the stable existence of the organic molecular unit 3 in the ordered channel 2 of the framework material 1. Even if the organic molecular unit 3 is disturbed by temperature changes, vibrations or other external forces during the operation of the battery, it can maintain its position and distribution in the channel to prevent it from moving or detaching at will, thereby maintaining the integrity and stability of the electrolyte structure and providing a stable environment for the transmission of the ion unit 4. In addition, this strong interaction is conducive to forming a stable and close contact at the interface between the electrolyte and the electrode material. The organic molecular unit 3 is tightly combined with the framework material 1, so that the electrolyte can better adapt to the microstructure of the electrode surface, reduce the gaps and defects at the interface, reduce the interface resistance, and improve the charge transfer efficiency, thereby improving the overall performance and cycle life of the battery.

[0071] The organic molecular unit 3 and the ionic unit 4 can stabilize the ionic unit 4 through weak interactions, thereby stabilizing the ionic state, promoting ionic migration, and achieving dynamic equilibrium.

[0072] Specifically, weak interactions (such as electrostatic interactions) can keep the ion units 4 in a relatively stable state in the ordered channels 2 of the framework material 1 without strongly binding them. This not only prevents the ion units 4 from being difficult to move due to being too tightly bound, but also prevents the ion units 4 from being too free and disorderly diffused, ensuring that the ion units 4 can be transported in an orderly and efficient manner in the ordered channels 2, helping to maintain a stable ion concentration gradient and achieving a continuous and stable ion conduction process.

[0073] Moreover, through the weak interaction between the organic molecular unit 3 and the ion unit 4, the ion unit 4 can obtain appropriate energy and direction guidance when passing through the ordered channel 2, that is, when the ions move under the action of the electric field, the organic molecular unit 3 can act as a "flexible buffer" to help the ion unit 4 overcome the local energy barriers that may exist in the ordered channel 2 through electrostatic attraction and repulsion, so that the ion unit 4 migrates more smoothly and the conductivity of the ion unit 4 is improved. Especially under conditions of low temperature or high current density, this promoting effect is more obvious, which is beneficial to improving the fast charging performance and low temperature performance of the battery.

[0074] In addition, weak interactions enable a dynamic balance to be formed between the ion unit 4 and the organic molecule unit 3. During the battery charging and discharging process, the ion concentration and electric field strength will change. This dynamic balance can adaptively adjust the distribution and transmission state of the ions, ensuring that the electrolyte always has good ionic conductivity, and can quickly respond to changes in the battery working state, thereby improving the battery's charging and discharging efficiency and stability.

[0075] It should be noted that the strong interaction is the adsorption effect formed between the organic molecular unit 3 and the active sites in the framework material 1 (such as Figure 2 The weak interaction is the electrostatic interaction between the negative charge sites in the organic molecular unit 3 and the ionic unit 4 (as indicated by the arrow A in the middle). Figure 2 As indicated by the arrow B in the middle, the ionic unit 4 is stabilized in the ordered channel 2 of the framework material 1 .

[0076] It should also be noted that the size range of the ordered channels 2 of the frame material 1 is Preferably, it can be By limiting the size of the ordered channel 2 to match the size of common lithium ions, sodium ions, potassium ions or zinc ions, the ion unit 4 can pass smoothly through it. For example, the diameter of a lithium ion is about Such a pore size can effectively prevent the ion unit 4 from being disorderly diffused due to the channel being too wide, or being blocked due to the channel being too narrow during the transmission process, thereby achieving rapid and orderly transmission of ions and helping to improve the ionic conductivity of the electrolyte.

[0077] In addition, the ordered channel 2 of the framework material 1 is configured to have a regular pore structure. By configuring the pore structure to be regular, the transmission path of the ion unit 4 is further optimized, and the collision and scattering of the ion unit 4 during the transmission process are reduced, and the energy loss of the ion unit 4 transmission is reduced, so that the ion unit 4 can migrate more efficiently in the electrolyte, thereby improving the charging and discharging efficiency of the battery.

[0078] Embodiment 2

[0079] In this second embodiment, a method for preparing an electrolyte membrane is proposed to prepare an electrolyte membrane with high ionic conductivity, good interface compatibility, high safety and good chemical stability, so as to solve the multiple bottleneck problems faced by solid electrolytes in the development process, such as poor interface stability, insufficient ionic conductivity, poor mechanical properties and low chemical stability.

[0080] In the second embodiment, a method for preparing an electrolyte membrane is proposed, which specifically includes the following steps:

[0081] Providing a powder of a framework material 1 having an ordered channel 2, wherein the ordered channel 2 has a size of angstrom level;

[0082] The powder of the framework material 1 is physically compacted or prepared into a film with a binder, and then vacuum dried to obtain a raw molecular sieve membrane;

[0083] The organic molecular units 3 and the ion units 4 are introduced into the ordered channels 2 of the original molecular sieve membrane by a physical and chemical method to obtain an electrolyte membrane.

[0084] The electrolyte membrane obtained by the above steps, by setting an ordered channel 2, can facilitate the migration of the ion unit 4 in the electrolyte. Compared with some traditional solid electrolytes, the transmission efficiency of the ion unit 4 can be improved, thereby achieving the purpose of improving the ion conductivity. And the framework material 1 is used as a supporting structure to provide good mechanical stability for the electrolyte membrane. And the strong interaction between the organic molecular unit 3 framework material 1 and the weak interaction between the ion unit 4 and the organic molecular unit 3 can provide good interface compatibility and high ion conductivity. Therefore, it can effectively solve the multiple bottleneck problems faced by solid electrolytes in the development process, such as poor interface stability, insufficient ion conductivity, poor mechanical properties and low chemical stability.

[0085] In this embodiment, the physicochemical method includes a vacuum-assisted liquid filling method or an electrochemical cycle activation method.

[0086] Specifically, the vacuum liquid filling method comprises the following steps:

[0087] The original molecular sieve membrane is placed in an electrolyte, and a vacuum environment is formed by evacuation to promote the organic molecular unit 3 and the ion unit 4 to enter the ordered channel 2, thereby obtaining the electrolyte membrane, and the vacuum degree of the vacuum environment is greater than 10 -2 Pa.

[0088] Create a vacuum environment by evacuating the vacuum (vacuum degree> 10 -2Pa), under this negative pressure environment, a large pressure difference is formed inside and outside the original molecular sieve membrane, so that the organic molecular unit 3 and the ion unit 4 can be effectively "sucked" into the ordered channel 2. This pressure difference-driven filling method can greatly improve the efficiency of the organic molecular unit 3 and the ion unit 4 entering the ordered channel 2, so that the ordered channel 2 can be fully filled in a shorter time, thereby improving the preparation efficiency of the electrolyte membrane.

[0089] In addition, the vacuum environment also helps the organic molecular units 3 and ion units 4 to be evenly distributed in the ordered channels 2 of the original molecular sieve membrane. Specifically, because in the vacuum state, the organic molecular units 3 and ion units 4 in the electrolyte are subjected to a uniform driving force and fill into various parts of the ordered channels 2, thus avoiding the uneven phenomenon caused by excessively high or low local concentrations.

[0090] In addition, the electrochemical cycle activation method comprises the following steps:

[0091] Assembling the original molecular sieve membrane into a metal symmetric cell and immersing it in an electrolyte;

[0092] A constant current is applied to the metal symmetric battery, and under the action of the electric field, the organic molecular unit 3 and the ion unit 4 are promoted to enter the ordered channel 2 until the voltage of the metal symmetric battery tends to be stable, the activation of the original molecular sieve membrane is completed, and the electrolyte membrane is obtained, wherein the constant current is 10μA-500μA.

[0093] By applying a constant current of 10μA-500μA to the metal symmetric battery, the organic molecular unit 3 and the ion unit 4 are forced to enter the ordered channel 2 under the action of the electric field, that is, under the action of the electric field, a guiding force can be provided to the organic molecular unit 3 and the ion unit 4, so that they can enter the channel in an orderly manner according to the direction of the electric field. Compared with other traditional methods, the electrochemical cycle activation method can more accurately control the entry process of the organic molecular unit 3 and the ion unit 4, avoiding the disordered accumulation or uneven distribution of substances in the channel.

[0094] In addition, during the whole process, the introduction of organic molecular units 3 and ion units 4 can be dynamically adjusted according to the change of battery voltage. For example, when the voltage tends to be stable, it means that the distribution of organic molecular units 3 and ion units 4 in the ordered channel 2 has reached a relatively balanced state, and the activation of the original molecular sieve membrane is completed at this time. This dynamic control can ensure that the quantity and state of the fillers in the ordered channel 2 are just right to achieve the best electrochemical performance.

[0095] In a further embodiment, the forming method of the original molecular sieve membrane is further defined.

[0096] Specifically, when the powder of the framework material 1 is prepared into a membrane by physical compaction, the pressure range is 4t-15t, and the thickness of the original molecular sieve membrane is 50μm-200μm.

[0097] In addition, when the powder of the framework material 1 is prepared into a film by the binder, the thickness of the original molecular sieve membrane is 50μm-200μm, and the proportion of the binder is 1wt%-1.5wt%, and the binder is set to one or more of polytetrafluoroethylene and polyvinylidene fluoride.

[0098] It should be noted that by limiting the thickness of the original molecular sieve membrane, a better balance can be achieved in physical properties. Specifically, when the thickness is lower than the set range, it may be insufficient in mechanical strength, that is, it is easy to break during the battery assembly process or when subjected to slight external pressure; and when the thickness is higher than the set range, it will increase the path length of the ion unit 4 transmission, resulting in a decrease in ionic conductivity. Therefore, by limiting the thickness of the original molecular sieve membrane, the original molecular sieve membrane can withstand a certain external force while effectively ensuring ionic conductivity.

[0099] like Figures 3 to 7 As shown, in a further embodiment, in order to further prove the effect of the electrolyte membrane prepared by the above method, a specific example is listed here, as shown below:

[0100] This example uses Based on the zeolite molecular sieve of size, ethylene carbonate, dimethyl carbonate and lithium hexafluorophosphate are introduced into In the ordered channel 2, the design and preparation of the framework electrolyte are realized, and the specific preparation method thereof comprises the following steps:

[0101] The ones used in this example The original powder of zeolite molecular sieve of size is a commercial product, so it needs to be nano-processed by high-energy ball milling, ethanol is added, and ball milling is performed for 1.5h, and then dried to obtain particles <1μm;

[0102] The ball-milled powder was heat treated at 450 °C for 6 h to remove the ethanol adsorbed on the Water molecules in the pores;

[0103] Go to a certain amount The original powder of zeolite molecular sieve of size was added with PTFE aqueous solution and ground to obtain a plasticine-like solid, and a molecular sieve membrane with a thickness of 300 μm was prepared by calendering method;

[0104] The molecular sieve membrane obtained above was vacuum dried at 100° C. for 24 h to obtain an original molecular sieve membrane;

[0105] The molecular sieve membrane is assembled into a metal symmetric cell and immersed in an electrolyte of ethylene carbonate (EC) / dimethyl carbonate (DMC) (VEC:VDMC=1:1) with sufficient 1 mol / L lithium hexafluorophosphate (LiPF6);

[0106] A current of 10 μA was applied and constant current cycling was performed until the voltage of the battery tended to be stable, and the entire activation process was completed to obtain an electrolyte membrane;

[0107] The electrolyte membrane is taken out and dried, and then assembled into a metal symmetrical battery. The positive electrode of the metal symmetrical battery is set to a lithium iron phosphate positive electrode, and a cycle performance test is performed.

[0108] It should be noted that the metal symmetric battery can be configured as a lithium metal symmetric battery, a sodium metal symmetric battery, a potassium metal symmetric battery or a zinc metal symmetric battery.

[0109] In this example, since lithium ions are used as ion units, the assembled metal symmetric battery is a lithium metal symmetric battery.

[0110] The electrolyte membrane prepared according to the above scheme and the characterization analysis of the lithium metal solid-state battery assembled based on the electrolyte membrane are as follows:

[0111] like Figure 3 As shown in Figure 2, after the electrolyte membrane was prepared, the XRD diffraction peak of the molecular sieve did not change significantly, indicating that its crystal structure still maintained its original The crystal structure of the zeolite molecular sieve powder of the same size indicates that the key structural features such as the arrangement of the internal atoms and the lattice parameters have not been destroyed. This structural stability enables the electrolyte membrane to provide stable and predictable performance in subsequent applications (such as being used as an electrolyte membrane in batteries, etc.).

[0112] like Figure 4 As shown in the figure, the voltage of the prepared original molecular sieve membrane increased from 0.074V to 0.283V and stabilized at 0.03V after 120 hours of cycling at a current density of 10 microamperes, proving that the activation process was completed and that ethylene carbonate (EC), dimethyl carbonate (DMC) and hexafluorophosphate (PF6-), lithium ions (Li+) had entered In the pores, an electrolyte membrane is obtained.

[0113] like Figure 5 As shown, compared with the original molecular sieve membrane before activation, the electrolyte membrane after electrochemical activation exhibits a room temperature ionic conductivity of 1.13x10-4S / cm, that is, the room temperature ionic conductivity is effectively improved.

[0114] like Figure 6As shown in the constant voltage test, the lithium ion migration number of the electrolyte membrane after electrochemical activation is 0.371, indicating that lithium ions account for a considerable proportion of the total ion current in the electrolyte membrane. A higher lithium ion migration number means that lithium ions can be more effectively transported in the electrolyte membrane, which is very beneficial for the fast charge and discharge performance of the battery. During the charging process, lithium ions can migrate more quickly from the positive electrode to the negative electrode, and can quickly return from the negative electrode to the positive electrode during discharge, thereby reducing the battery charging time and increasing the discharge power, meeting the needs of modern electronic devices and electric vehicles for fast charging and high power output.

[0115] like Figure 7 As shown, based on After activation, the molecular sieve membrane prepared from zeolite molecular sieve powder of certain size can reach a voltage window of 5V, which has a wide voltage stability window and stability compared to the liquid 1 mol / L lithium hexafluorophosphate ethylene carbonate / dimethyl carbonate electrolyte.

[0116] like Figure 8 As shown in the figure, the energy barrier for lithium ion migration in the molecular sieve membrane solid electrolyte after electrochemical activation is 0.179 eV, which means that the energy barrier that lithium ions need to overcome when migrating in the molecular sieve membrane of the solid electrolyte is smaller. This lower energy barrier can reduce the energy loss during lithium ion migration, allowing the battery to use electrical energy with higher efficiency during charging and discharging, which helps to improve the overall performance of the battery.

[0117] like Fig. 9 As shown, the lithium metal symmetric battery exhibits high stability at different current densities, demonstrating its interfacial stability to lithium metal and the good lithium ion migration kinetics of the prepared electrolyte membrane.

[0118] In summary, the electrolyte membrane prepared by the preparation method proposed in this embodiment, when applied to metal batteries, can effectively solve the multiple bottleneck problems faced by solid electrolytes in the development process, such as poor interface stability, insufficient ionic conductivity, poor mechanical properties and low chemical stability.

[0119] Embodiment 3

[0120] This embodiment 3 proposes an electrolyte membrane prepared by the preparation method described in embodiment 2. Figures 3 to 9 It can be seen from the information that the electrolyte membrane proposed in this embodiment, when applied to a metal battery, can achieve the purpose of improving interface stability, high ion conductivity, mechanical properties and chemical stability.

[0121] Embodiment 4

[0122] like Fig.10As shown, this fourth embodiment proposes a battery, including the electrolyte membrane proposed in the third embodiment, so that the prepared battery can achieve the purpose of improving interface stability, high ion conductivity, mechanical properties and chemical stability.

[0123] For details, please refer to Fig.10 , Fig.10 The activated molecular sieve membrane is used as the solid electrolyte and lithium iron phosphate is used as the positive electrode to construct a lithium metal solid-state battery. As can be seen from the figure, the battery formed by assembling the electrolyte membrane proposed in Example 3 has a 2C (1C = 160mAg -1 ) Under high current density, more than 120 mAh g can be obtained at room temperature -1 The specific capacity of the battery can be stably cycled for more than 450 cycles. This means that the battery life of the constructed lithium metal solid-state battery can be effectively improved to meet the application scenarios with high power requirements. In addition, since the battery can be stably cycled for more than 450 cycles, it means that the capacity decay rate of the battery is very slow during long-term use, achieving the purpose of maintaining relatively stable performance.

[0124] Accordingly, according to Figures 3 to 9 It can be seen that the prepared battery can also achieve the purpose of improving interface stability, high ionic conductivity and mechanical properties.

[0125] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A framework electrolyte structure, characterized in that: It includes framework materials, organic molecular units and ionic units; The framework material has a plurality of ordered channels of angstrom size; The organic molecular unit and the ionic unit are both introduced into the ordered channel; The organic molecule unit is an organic molecule in the battery electrolyte; The ion unit is a metal battery ion.

2. The framework electrolyte structure according to claim 1, characterized in that: The organic molecular unit and the framework material are combined with each other through strong interaction; The organic molecular unit and the ionic unit have a weak interaction to stabilize the ionic unit.

3. The framework electrolyte structure according to claim 2, characterized in that: The strong interaction is an adsorption effect formed between the organic molecular unit and the active sites in the framework material, so that the organic molecular unit is anchored on the framework material; The weak interaction is the electrostatic interaction formed between the negative charge sites in the organic molecular unit and the ionic unit, which stabilizes the ionic unit in the ordered channels of the framework material.

4. The framework electrolyte structure according to claim 1, characterized in that: The ordered channels of the framework material have a size range of And the ordered channels of the frame material are arranged to have a regular pore structure.

5. The framework electrolyte structure according to claim 1, characterized in that: The framework material is one or more of a zeolite material, a metal organic framework, and a covalent organic framework.

6. The framework electrolyte structure according to claim 1, characterized in that: The ion unit includes lithium ion, sodium ion, potassium ion or zinc ion.

7. The framework electrolyte structure according to claim 1, characterized in that: The organic molecule units are organic molecules in the battery electrolyte solvent.

8. The framework electrolyte structure according to claim 1 or 7, characterized in that: The organic molecular unit is at least one of ethylene carbonate, diethyl carbonate, polycarbonate, dimethyl carbonate, ethyl methyl carbonate, dioxolane or ethylene glycol dimethyl ether.

9. A method for preparing an electrolyte membrane, characterized in that: The steps include: Providing a framework material powder having ordered channels, wherein the ordered channels have an angstrom-level size; Physically compacting the framework material powder or preparing a membrane with a binder, and vacuum drying the membrane to obtain a raw molecular sieve membrane; The organic molecular units and ionic units are introduced into the ordered channels of the original molecular sieve membrane by physical and chemical methods to obtain an electrolyte membrane.

10. The method for preparing an electrolyte membrane according to claim 9, characterized in that: The physicochemical method includes a vacuum-assisted liquid filling method or an electrochemical cycle activation method.

11. The method for preparing an electrolyte membrane according to claim 10, wherein: The vacuum liquid filling method comprises the following steps: The original molecular sieve membrane is placed in an electrolyte, and a vacuum environment is formed by evacuating the electrolyte to promote the organic molecular units and the ion units to enter the ordered channels, thereby obtaining the electrolyte membrane.

12. The method for preparing an electrolyte membrane according to claim 11, characterized in that: The vacuum degree of the vacuum environment is>10 -2 Pa.

13. The method for preparing an electrolyte membrane according to claim 10, characterized in that: The electrochemical cycle activation method comprises the following steps: Assembling the original molecular sieve membrane into a metal symmetric cell and immersing it in an electrolyte; A constant current is applied to the metal symmetric battery, and under the action of the electric field, the organic molecular units and ion units are promoted to enter the ordered channels until the voltage of the metal symmetric battery tends to be stable, the activation of the original molecular sieve membrane is completed, and the electrolyte membrane is obtained.

14. The method for preparing an electrolyte membrane according to claim 13, wherein: The constant current is 10μA-500μA.

15. The method for preparing an electrolyte membrane according to claim 9, characterized in that: The thickness of the original molecular sieve membrane is 50 μm-200 μm.

16. The method for preparing an electrolyte membrane according to claim 9, wherein: When the frame material powder is prepared into a film by physical compaction, the pressure range is 4t-15t.

17. The method for preparing an electrolyte membrane according to claim 9, characterized in that: When the frame material powder is prepared into a film by the binder, the binder accounts for 1wt%-1.5wt%, and the binder is set to be one or more of polytetrafluoroethylene and polyvinylidene fluoride.

18. An electrolyte membrane, characterized in that: The electrolyte membrane is prepared by the method for preparing the electrolyte membrane as described in any one of claims 8 to 17.

19. A battery, characterized in that: Comprising the electrolyte membrane as claimed in claim 18.

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