Polymer solid-state electrolyte with pi-pi interaction and preparation method and application thereof

Abstract

The application provides a polymer solid-state electrolyte with pi-pi interaction and a preparation method thereof, and particularly relates to a high-molecular polyurea urethane with a polar group and a rigid benzene ring or naphthalene ring in a molecular chain and a preparation method thereof, which is prepared by first preparing an isocyanate-terminated prepolymer through addition polymerization reaction of a polyhydric alcohol and a diisocyanate, then blending with aromatic diamine through blending reaction, and finally preparing the high-molecular polyurea urethane with the polar group and the rigid benzene ring or naphthalene ring in the molecular chain through diamin chain extension reaction; the high-molecular polyurea urethane is combined with a lithium salt to be used as a polymer solid-state electrolyte, and the polymer solid-state electrolyte has a higher lithium ion migration number, excellent mechanical properties and a stable, LiF-rich solid-state electrolyte interphase (SEI) layer formed on the surface of lithium metal compared with a PEO-based solid-state electrolyte in the prior art.

Description

Technical Field

[0001] This invention relates to the field of polymer solid electrolyte technology, specifically to a polymer solid electrolyte with π-π interactions and its preparation method, particularly to a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain and its preparation method, and the application of this high molecular weight polyurethane in combination with lithium salt as a polymer solid electrolyte. Background Technology

[0002] The rapid development of wearable devices and electric vehicles necessitates rechargeable batteries with higher energy density. Lithium metal batteries, due to their high theoretical specific capacity (3860 mAh g / g), are a promising candidate. -1 Its low redox potential (-3.04V) makes it an ideal candidate battery for meeting this requirement. Compared to traditional lithium-ion batteries, developing lithium metal batteries using solid-state electrolytes provides a viable approach to achieving higher energy density and greater safety, thus meeting the stringent requirements for next-generation battery technology.

[0003] Solid-state electrolytes are a key component of solid-state lithium metal batteries, playing a crucial role in determining their overall performance. Generally, solid-state electrolytes can be classified into three main categories: inorganic solid-state electrolytes, polymer solid-state electrolytes, and composite solid-state electrolytes. Among polymer solid-state electrolytes, those based on polyethylene oxide (PEO) offer advantages such as good lithium salt solubility, processability, flexibility, and low cost. In 1978, Armand et al. first proposed a solid-state electrolyte with an ionic conductivity of 10... -4 The PEO-lithium salt polymer solid electrolyte (Fenton DE, Parker JM, Wright P V. Complexes of Alkaline Metal Ions with Poly(ethyleneoxide)[J].Polymer,1973,14(4):589-594.) can be used in lithium batteries at 40-60℃, and since then PEO-based solid electrolytes have been widely studied.

[0004] However, the inherent limitations of PEO polymer solid electrolytes still hinder their further development. For example, the low lithium-ion transfer number in PEO-based electrolytes increases polarization voltage and rapidly forms lithium dendrite nucleation sites during lithium deposition / stripping. Furthermore, PEO-based electrolytes form an unstable solid electrolyte interphase (SEI) layer upon contact with lithium metal, which gradually deteriorates during cycling. As cycling continues, the SEI layer thickens and evolves along with lithium dendrites, leading to increased internal resistance, rapid capacity decay, and potential short-circuit risks. To address these challenges, researchers have adopted strategies such as incorporating inorganic / organic fillers, modifying PEO substrates, optimizing lithium salts, and developing artificial SEI layers. Although some progress has been made in improving the performance of PEO-based solid electrolytes, challenges such as filler aggregation and complex pretreatment methods remain.

[0005] Therefore, it is necessary to design polymer solid electrolyte materials with optimized molecular structures to improve the performance of PEO-based electrolytes, enabling them to simultaneously possess considerable lithium-ion transference numbers, stronger mechanical strength, and the ability to form a stable SEI layer on lithium metal. This is beneficial for achieving high energy density and long cycle life in lithium metal batteries. Summary of the Invention

[0006] To address the problems raised by the prior art, this invention provides a polymer solid electrolyte with π-π interactions and its preparation method. The first objective is to provide a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain and its preparation method. The second objective is to utilize this high molecular weight polyurethane in combination with lithium salts as a polymer solid electrolyte. Compared with PEO-based solid electrolytes in the prior art, this polymer solid electrolyte has a higher lithium-ion transference number, excellent mechanical properties, and forms a stable, LiF-rich solid electrolyte interphase (SEI) layer on the lithium metal surface.

[0007] To achieve the above objectives, the present invention employs a technical solution consisting of the following technical measures.

[0008] In one aspect, the present invention provides a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain, the chemical structural formula of which is as follows:

[0009]

[0010] Among them, the polymeric polyurethane Mn = 1 × 10 4 ~1×10 6 g / mol, 0 < x ≤ 0.8;

[0011] R1 can be any of the following structures:

[0012]

[0013] R2 can be any of the following structures, where m = 10 to 200:

[0014]

[0015] R3 can be any of the following structures:

[0016]

[0017] R4 can be any of the following structures:

[0018]

[0019] In the above chemical structural formula, "---" indicates the position where the chemical bond is connected.

[0020] On the other hand, the present invention also provides a method for preparing the above-mentioned high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain. This method involves first preparing an isocyanate-terminated prepolymer by addition polymerization of a polymeric diol and a diisocyanate, then reacting it with an aromatic diamine, and finally undergoing a diamine chain extension reaction to obtain the high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain. It should be noted that those skilled in the art can derive the specific preparation steps based on the selection of raw materials and the reaction sequence shown above, and in particular, can balance the raw materials according to common knowledge in the art based on the specific chemical structural formulas described above. Therefore, the technical solutions provided below by the present invention do not imply the sole designation or limitation of the method for preparing the high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain.

[0021] This invention also provides a method for preparing a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain, comprising the following steps:

[0022] First, a prepolymer with isocyanate end-capped isocyanate is prepared by mixing a polymeric diol and a diisocyanate evenly and then reacting them at a temperature of 60-80°C for 3-12 hours. After the time is up, the reaction product is added to a diamine at a temperature of 20-30°C and reacted at a temperature of 0.5-2 hours to obtain a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0023] The aromatic diamine contains a benzene ring or a naphthalene ring in its chemical structure, and the diamine is a carbon straight-chain compound with amino groups at both ends;

[0024] The molar ratio of the polymeric diol, diisocyanate, aromatic diamine and diamine is 1:(1-6):(0.5-3):(1-3).

[0025] In this document, the polymeric diol is a polymer obtained by polymerizing monomers having two hydroxyl groups, such as any one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran ether glycol, with a molecular weight range of 600 to 10,000. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0026] In one preferred embodiment, the polymeric diol, as the flexible segment of polyurethane, is preferably polyethylene glycol with a molecular weight of approximately 4000.

[0027] In this document, the diisocyanate is a compound having two isocyanate groups, such as any one of diphenylmethane diisocyanate, 4,4-dicyclohexylmethane diisocyanate, isophorone diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0028] In one of the technical solutions, the diisocyanate is preferably 4,4-dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

[0029] In this document, the aromatic diamine contains a benzene ring or a naphthalene ring in its chemical structure, for example, any one of 1,5-diaminonaphthalene, 2,3-diaminonaphthalene, 1,8-diaminonaphthalene, o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0030] In this document, the diamine is a carbon straight-chain compound with amino groups at both ends, wherein the carbon straight chain is typically a C2-C6 carbon straight chain, such as any one of ethylenediamine, propylenediamine, butanediamine, pentanediamine, and hexamethylenediamine. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0031] In this document, the preparation of isocyanate-terminated prepolymers by uniformly mixing a polymeric diol and a diisocyanate followed by a prepolymerization reaction is described. The prepolymerization reaction of the polymeric diol and diisocyanate is a conventional addition polymerization reaction in the art, and its specific material ratios and reaction conditions follow the conventional prepolymerization reaction using the aforementioned compounds as raw materials. Those skilled in the art can directly refer to existing technologies / processes in the art for preparation. Generally, the specific polymeric diol can be determined first, and then a suitable prepolymerization reaction preparation process can be selected based on that specific polymeric diol.

[0032] To better illustrate the present invention and provide a reference technical solution, when the polymeric diol is polyethylene glycol, polyethylene glycol, diisocyanate, and catalyst are mixed evenly and then reacted at a reaction temperature of 60–80°C for 1–2 hours to prepare an isocyanate-terminated prepolymer. The catalyst used is a conventional catalyst used in prepolymerization reactions, such as dibutyltin dilaurate (DBTDL).

[0033] It should be noted that, based on common knowledge in the art, the preparation method of the above-mentioned high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain usually includes adding an organic solvent as a reaction medium, such as N,N-dimethylformamide, which can fully dissolve the raw materials and reaction products, and finally removing the solvent by separation and purification to obtain the high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain. In the above preparation method, the selection and amount of organic solvent usually do not significantly affect the reaction products and the characterization of the technical effects of the present invention; therefore, those skilled in the art can choose suitable organic solvents based on common knowledge in the art. Furthermore, conventional mechanical stirring is usually performed throughout the preparation process to accelerate the reaction rate and ensure complete reaction.

[0034] On the other hand, the high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain prepared above can be directly used as a component of polymer solid electrolytes and applied to the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0035] To better illustrate the present invention and provide a reference application, the present invention also provides a polymer solid electrolyte with π-π interactions, which is mainly composed of the following components in parts by mass:

[0036] 1-10 parts of high-molecular-weight polyurea-urethane with polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0037] One part lithium salt.

[0038] In this document, the lithium salt referred to is a selection of lithium salts commonly used in solid-state lithium metal batteries, such as lithium bis(trifluoromethanesulfonyl)imide.

[0039] It should be noted that, in the above-mentioned polymer solid electrolytes with π-π interactions, additives that have been disclosed or commercially available in this technical field can usually be added, depending on the solid metal battery to which they are adapted, to enhance performance, expand functionality, improve processability, etc.

[0040] On the other hand, the high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain prepared above can be directly used as one of the components of electrode binders and applied to the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0041] To better illustrate the present invention and provide a reference application method, the present invention also provides an electrode adhesive, which, by mass parts, is mainly composed of the following components:

[0042]

[0043] In the aforementioned electrode adhesive components, the organic solvent is selected from organic solvents commonly used in electrode adhesives, such as N,N-dimethylformamide.

[0044] In this document, the mixing, separation, purification, and drying processes all follow conventional principles in chemical processes, and those skilled in the art can perform the specific operations based on common knowledge.

[0045] The present invention has the following beneficial effects:

[0046] 1. The present invention provides a polymeric polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain. Comparative experiments have shown that as the content of rigid structure increases, the tensile strength and Young's modulus of the resulting polymer are improved to varying degrees. The improvement of Young's modulus is beneficial to suppressing dendrite growth in lithium metal batteries, thereby improving the cycle life of the battery.

[0047] 2. In the polymer solid electrolyte with π-π interaction prepared based on the high molecular weight polyurethane provided by the present invention, due to the large number of polar groups (urea bond and urethane bond) and the delocalized π electron cloud of the benzene ring in the base polymer, it can interact with lithium salt anions. On the one hand, it can anchor the anions and inhibit their migration, thereby increasing the lithium ion transference number. On the other hand, it can promote the dissociation of lithium salt anions, thereby promoting the formation of the solid electrolyte interphase layer (SEI) rich in lithium fluoride (LiF) and promoting the uniform deposition of lithium ions.

[0048] 3. The polymer solid electrolyte with π-π interactions provided by this invention, when tested as an electrolyte in a lithium-symmetric battery, exhibits performance at 0.1 mA / cm². -2 0.1mAhcm -2 It has been stably cycled for more than 3,000 hours at a current density, far exceeding that of PEO-based solid electrolytes, and its polarization voltage is also lower than that of PEO-based solid electrolytes.

[0049] 4. The polymer solid electrolyte with π-π interactions provided by this invention, when tested as an electrolyte in a LiFePO4 (LFP) half-cell, maintains a discharge specific capacity of 121 mAh g⁻¹ after 450 cycles at 0.2C. -1 The capacity retention rate is 83.6%, which is much higher than that of PEO-based solid electrolytes.

[0050] 5. The polymer solid electrolyte with π-π interaction provided by the present invention has been tested and found to have superior rate performance compared with ordinary PEO solid electrolyte when used as an electrolyte for LiFePO4 half-cells. Attached Figure Description

[0051] Figure 1 This is a schematic diagram illustrating the chemical structure and application of the high molecular weight polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain prepared by Example 1 of the present invention.

[0052] Figure 2 This is a line graph comparing the puncture resistance of the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of the present invention.

[0053] Figure 3 Linear graphs comparing the tensile properties of samples prepared in Example 1, Example 2, and Comparative Example 1, respectively, to verify the present invention.

[0054] Figure 4 Figure 1 shows a comparison of the flatness of the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention. Specifically, Figure 1(a) is an atomic force microscope image of the sample obtained in Example 1, Figure 1(b) is an atomic force microscope image of the comparative sample obtained in Comparative Example 1, and Figure 1(c) is an actual image of the polymer solid electrolyte membrane obtained in Example 1.

[0055] Figure 5 This is a comparison of the Arrhenius curves of the test films prepared in Verification Examples 2 and 3 of this invention. It includes the calculated activation energies and ionic conductivity at the corresponding temperatures for both films.

[0056] Figure 6 This is a comparison of Arrhenius curves for the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of the present invention. The curves include the calculated activation energies and ionic conductivity at the corresponding temperatures for both membranes.

[0057] Figure 7 The polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention were subjected to a 0.1 mA cm⁻¹ temperature. -2 and 0.1mAh cm -2 Comparison of symmetrical battery cycling under current density.

[0058] Figure 8 The lithium metal symmetric battery assembled using the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of this invention operates at 0.1 mA cm⁻¹. -2 Current density, 0.1 mAh / cm³ -2 The lithium sheet appearance after 50 cycles at the areal capacity. Among them, Figure (a) is the lithium sheet appearance obtained by disassembling the battery after the polymer solid electrolyte membrane prepared in Example 1 has been cycled in a symmetrical battery for 50 cycles; Figure (b) is the lithium sheet appearance obtained by disassembling the battery after the polymer solid electrolyte membrane prepared in Comparative Example 1 has been cycled in a symmetrical battery for 50 cycles.

[0059] Figure 9 The lithium metal symmetric battery assembled using the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of this invention operates at 0.1 mA cm⁻¹. -2 Current density, 0.1 mAh / cm³ -2 Scanning electron microscope (SEM) image of the lithium wafer surface after 50 cycles at the areal capacity.

[0060] Figure 10 This is a comparison curve of the long-cycle performance of the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of the present invention at 0.2C in a half-cell.

[0061] Figure 11 This is a comparison curve of the rate performance of LFP half-cells assembled with polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of the present invention.

[0062] Figure 12 The EIS curves of LFP half-cells assembled using the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention are shown in the initial and 50-cycle EIS curves. Detailed Implementation

[0063] To further understand the present invention, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims. Those skilled in the art can refer to the content of this document to appropriately improve the process parameters. In particular, it should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention. Although it is believed that those skilled in the art will fully understand the following terms, the following definitions are set forth to help illustrate the subject matter disclosed in the present invention.

[0064] In one aspect, the present invention provides a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain, the chemical structural formula of which is as follows:

[0065]

[0066] Among them, the polymeric polyurethane Mn = 1 × 10 4 ~1×10 6 g / mol, 0 < x ≤ 0.8;

[0067] R1 can be any of the following structures:

[0068]

[0069] R2 can be any of the following structures, where m = 10 to 200:

[0070]

[0071] R3 can be any of the following structures:

[0072]

[0073] R4 can be any of the following structures:

[0074]

[0075] In the above chemical structural formula, "---" indicates the position where the chemical bond is connected.

[0076] On the other hand, the present invention also provides a method for preparing the above-mentioned high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain. This method involves first preparing an isocyanate-terminated prepolymer by addition polymerization of a polymeric diol and a diisocyanate, then reacting it with an aromatic diamine, and finally undergoing a diamine chain extension reaction to obtain the high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain. It should be noted that those skilled in the art can derive the specific preparation steps based on the selection of raw materials and the reaction sequence shown above, and in particular, can balance the raw materials according to common knowledge in the art based on the specific chemical structural formulas described above. Therefore, the technical solutions provided below by the present invention do not imply the sole designation or limitation of the method for preparing the high molecular weight polyurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain.

[0077] This invention also provides a method for preparing a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in its molecular chain, comprising the following steps:

[0078] First, a prepolymer with isocyanate end-capped isocyanate is prepared by mixing a polymeric diol and a diisocyanate evenly and then reacting them at a temperature of 60-80°C for 3-12 hours. After the time is up, the reaction product is added to a diamine at a temperature of 20-30°C and reacted at a temperature of 0.5-2 hours to obtain a high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0079] The aromatic diamine contains a benzene ring or a naphthalene ring in its chemical structure, and the diamine is a carbon straight-chain compound with amino groups at both ends;

[0080] The molar ratio of the polymeric diol, diisocyanate, aromatic diamine and diamine is 1:(1-6):(0.5-3):(1-3).

[0081] In this document, the polymeric diol is a polymer obtained by polymerizing monomers having two hydroxyl groups. In one embodiment, it includes, for example, any one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran ether diol, with a molecular weight range of 600 to 10,000. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0082] In one preferred embodiment, the polymeric diol is used as a flexible segment of polyurethane, preferably polyethylene glycol with a molecular weight of about 4000.

[0083] In this document, the diisocyanate is a compound having two isocyanate groups, and in one embodiment, it includes, for example, any one of diphenylmethane diisocyanate, 4,4-dicyclohexylmethane diisocyanate, isophorone diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0084] In one embodiment, the diisocyanate is preferably 4,4-dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

[0085] In this document, the aromatic diamine contains a benzene ring or a naphthalene ring in its chemical structure. In one embodiment, for example, it may include any one of 1,5-diaminonaphthalene, 2,3-diaminonaphthalene, 1,8-diaminonaphthalene, o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0086] In this document, the diamine is a straight-chain carbon compound with amino groups at both ends, wherein the straight-chain carbon is typically a C2-C6 straight-chain. In one embodiment, it includes, for example, any one of ethylenediamine, propylenediamine, butanediamine, pentanediamine, and hexamethylenediamine. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0087] In this document, the preparation of isocyanate-terminated prepolymers by uniformly mixing a polymeric diol and a diisocyanate followed by a prepolymerization reaction is described. The prepolymerization reaction of the polymeric diol and diisocyanate is a conventional addition polymerization reaction in the art, and its specific material ratios and reaction conditions follow the conventional prepolymerization reaction using the aforementioned compounds as raw materials. Those skilled in the art can directly refer to existing technologies / processes in the art for preparation. Generally, the specific polymeric diol can be determined first, and then a suitable prepolymerization reaction preparation process can be selected based on that specific polymeric diol.

[0088] To better illustrate the present invention and provide a reference embodiment, when the polymeric diol is polyethylene glycol, polyethylene glycol, diisocyanate, and catalyst are mixed evenly and then reacted at a reaction temperature of 60–80°C for 1–2 hours to prepare an isocyanate-terminated prepolymer. The catalyst used is a conventional catalyst used in prepolymerization reactions, such as dibutyltin dilaurate (DBTDL).

[0089] It should be noted that, based on common knowledge in the art, the preparation method of the above-mentioned high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain usually includes the addition of an organic solvent as a reaction medium. In one embodiment, for example, N,N-dimethylformamide, which can fully dissolve the raw materials and reaction products, is added as a solvent, and the high molecular weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain is finally obtained by separation and purification to remove the solvent. In the above preparation method, the selection and amount of organic solvent usually do not have a significant impact on the reaction products and the characterization of the technical effect of the present invention. Therefore, those skilled in the art can choose a suitable organic solvent based on common knowledge in the art. In addition, conventional mechanical stirring is usually carried out during the entire preparation process to accelerate the reaction rate and ensure complete reaction.

[0090] In one embodiment, the molar ratio of the polymeric diol, diisocyanate, aromatic diamine, and diamine is 1:(1-6):(0.5-3):(1-3), wherein the molar ratio of the polymeric diol to the diisocyanate is 1:(1-6), for example 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, or... Any range or point value between them; the molar ratio of polymeric diol to aromatic diamine is 1:(0.5 to 3), 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any range or point value between them; the molar ratio of polymeric diol to diamine is 1:(1 to 3), for example 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any range or point value between them.

[0091] On the other hand, the high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain prepared above can be directly used as a component of polymer solid electrolytes and applied to the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0092] To better illustrate the present invention and provide a reference application, the present invention also provides a polymer solid electrolyte with π-π interactions, which is mainly composed of the following components in parts by mass:

[0093] 1-10 parts of high-molecular-weight polyurea-urethane with polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0094] One part lithium salt.

[0095] In this document, the lithium salt referred to is a selection of lithium salts commonly used in solid-state lithium metal batteries, such as lithium bis(trifluoromethanesulfonyl)imide.

[0096] It should be noted that, in the above-mentioned polymer solid electrolytes with π-π interactions, additives that have been disclosed or commercially available in this technical field can usually be added, depending on the solid metal battery to which they are adapted, to enhance performance, expand functionality, improve processability, etc.

[0097] In one embodiment, the polymeric polyurethane having polar groups and rigid benzene or naphthalene rings in the molecular chain is 1 to 10 parts, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or any range or point value between them.

[0098] On the other hand, the high-molecular-weight polyurethane with polar groups and rigid benzene or naphthalene rings in the molecular chain prepared above can be directly used as one of the components of electrode binders and applied to the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0099] To better illustrate the present invention and provide a reference application method, the present invention also provides an electrode adhesive, which, by mass parts, is mainly composed of the following components:

[0100]

[0101] In the aforementioned electrode adhesive components, the organic solvent is selected from organic solvents commonly used in electrode adhesives, such as N,N-dimethylformamide.

[0102] In one embodiment, the organic solvent is 27 to 126 parts, for example 27 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts, 110 parts, 115 parts, 120 parts, 125 parts, 126 parts, or any range or point value therebetween; the PVDF is 1 to 3 parts, for example 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, or any range or point value therebetween.

[0103] The present application will be further explained in detail below with reference to embodiments. However, those skilled in the art should understand that these embodiments are provided for illustrative purposes only and are not intended to limit the present application.

[0104] Example

[0105] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all commercially available conventional products. This application should not be construed as being limited to the specific embodiments described.

[0106] 1. Raw materials

[0107] Polyethylene glycol (PEG, analytical grade, Mn=4000), N,N-dimethylformamide (DMF, analytical grade), acetonitrile (analytical grade) and ethylenediamine (EDA, analytical grade) were purchased from Chengdu Kelong Chemical Reagent Co., Ltd.

[0108] Polyethylene oxide (PEO, RG, average Mv = ~5,000,000) and 1,5-diaminonaphthalene (DAN, purity 98%) were purchased from Adamas Reagents website.

[0109] Hexamethylene diisocyanate (HDI, 99% purity) was purchased from Aladdin Reagent Network.

[0110] Dibutyltin dilaurate (DBTDL, 95%) was purchased from Shanghai Titan Technology Co., Ltd.

[0111] Lithium iron phosphate (LFP) is from MTI Corporation.

[0112] Polyvinylidene fluoride (PVDF) was purchased from Zhengzhou Jinghong New Energy Technology Co., Ltd.

[0113] Lithium bis(trifluoromethanesulfonic acid)imide (LiTFSI, 99.9%) was purchased from Duoduo Reagent Network.

[0114] The conductive carbon black SuperP (99%) was purchased from Xinwei Technology Co., Ltd. (Shenzhen).

[0115] Before using DMF, first use The molecular sieve is dried for one week.

[0116] 2. Testing Methods

[0117] Puncture Experiment: The polymer solid electrolyte membrane prepared in this invention is cut into square sheets (1 cm), which are then fixed on the device of a servo-controlled electronic universal testing machine (RS-8000), and then compressed at a constant speed of 10 mm / min. -1 Record the external load generated on the sample.

[0118] Tensile test: In this invention, the prepared polymer solid electrolyte membrane was cut into tensile strips with a width of 4 mm, and then fixed on a dual-column benchtop testing machine (INS Tron general-purpose material testing machine 5967, USA) using a clamp. The tensile test was then conducted at a constant tensile speed of 50 mm / min. -1 Record the external load generated on the sample.

[0119] Atomic force microscopy (AFM) observation: AFM can observe surface morphology and physical properties, and can directly observe surface morphology and roughness at the nanometer level. In this invention, a polymer solid electrolyte precursor solution is dropped onto a smooth silicon wafer, and then the solvent is removed under vacuum and high temperature. The roughness of different polymer solid electrolyte surfaces is detected using the tapping mode of a Bruker atomic force microscope.

[0120] Constant current charge-discharge test: In this invention, the MIHW-200-160CH constant temperature test chamber from Shenzhen Xinwei Co., Ltd. was used to conduct constant current charge-discharge tests on the batteries at different cycle periods and charge-discharge rates. The current density of the symmetrical battery was 0.1 mA / cm². -2 0.1mAhcm -2 The standard specific capacity of LFP is 170 mAh g. -1The test voltage ranged from 2.5V to 3.8V, and the temperature was 60℃. Lithium-ion batteries based on different polymer solid electrolytes were assembled and tested to investigate the effect of the prepared polymer solid electrolytes on the electrochemical performance of lithium metal batteries.

[0121] Ionic conductivity testing: In this invention, a polymer solid electrolyte was sandwiched between two stainless steel plates. The ionic conductivity of the polymer solid electrolyte at different temperatures was measured using a Metrohm VIONIC electrochemical workstation, with a measurement frequency range of 1-10. 7 Hz.

[0122] Scanning Electron Microscopy (SEM) Testing: Scanning electron microscopy (SEM) uses a focused high-energy electron beam to scan the sample surface and analyzes the surface structure of the material by collecting the excited secondary electrons. In this invention, the sample was processed and studied using a JEM-F200 field emission transmission electron microscope from Nippon Electron Ltd. at an accelerating voltage of 5 kV.

[0123] Synthesis example 1

[0124] This synthetic example provides a method for preparing a high molecular weight polyurea urethane with polar groups and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0125] First, polyethylene glycol, dibutyltin dilaurate, and hexamethylene diisocyanate were dissolved in N,N-dimethylformamide and mixed evenly. The mixture was then reacted at 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution. Then, 1,5-diaminonaphthalene was added to the prepolymer solution at 70°C and the reaction was maintained for 12 hours. After the reaction time was reached, ethylenediamine was added to the reaction product at 25°C and the reaction was maintained for 2 hours. After the reaction time was reached, the solvent was removed by separation and purification to obtain a high molecular weight polyurethane with polar groups and rigid naphthalene rings in the molecular chain.

[0126] The molar ratio of polyethylene glycol, hexamethylene diisocyanate, 1,5-diaminonaphthalene, and ethylenediamine is 1:5:1.2:2.8;

[0127] The chemical structural formula of the prepared high-molecular-weight polyurea-urethane is as follows:

[0128]

[0129] Where x is approximately 0.3 after testing and calculation, and R1 is:

[0130]

[0131] R2 is:

[0132]

[0133] R3 is:

[0134]

[0135] R4 is:

[0136]

[0137] Synthesis example 2

[0138] This synthetic example provides a method for preparing a high molecular weight polyurea urethane with polar groups and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0139] First, polyethylene glycol, dibutyltin dilaurate, and hexamethylene diisocyanate were dissolved in N,N-dimethylformamide and mixed evenly. The mixture was then reacted at 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution. Then, 1,5-diaminonaphthalene was added to the prepolymer solution at 70°C and the reaction was maintained for 12 hours. After the reaction time was reached, ethylenediamine was added to the reaction product at 25°C and the reaction was maintained for 2 hours. After the reaction time was reached, the solvent was removed by separation and purification to obtain a high molecular weight polyurethane with polar groups and rigid naphthalene rings in the molecular chain.

[0140] The molar ratio of polyethylene glycol, hexamethylene diisocyanate, 1,5-diaminonaphthalene, and ethylenediamine is 1:5:0.8:3.2.

[0141] The chemical structural formula of the prepared high-molecular-weight polyurea-urethane is as follows:

[0142]

[0143] Where x is approximately 0.2 after testing and calculation, and R1 is:

[0144]

[0145] R2 is:

[0146]

[0147] R3 is:

[0148]

[0149] R4 is:

[0150]

[0151] Synthesis example 3

[0152] This synthetic example provides a method for preparing a high molecular weight polyurea urethane with polar groups and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0153] First, polyethylene glycol, dibutyltin dilaurate, and hexamethylene diisocyanate were dissolved in N,N-dimethylformamide and mixed evenly. The mixture was then reacted at 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution. Then, 1,5-diaminonaphthalene was added to the prepolymer solution at 70°C and the reaction was maintained for 12 hours. After the reaction time was reached, ethylenediamine was added to the reaction product at 25°C and the reaction was maintained for 2 hours. After the reaction time was reached, the solvent was removed by separation and purification to obtain a high molecular weight polyurethane with polar groups and rigid naphthalene rings in the molecular chain.

[0154] The molar ratio of polyethylene glycol, hexamethylene diisocyanate, 1,5-diaminonaphthalene, and ethylenediamine is 1:5:0.4:3.6;

[0155] The chemical structural formula of the prepared high-molecular-weight polyurea-urethane is as follows:

[0156]

[0157] Where x is approximately 0.1 after testing and calculation, and R1 is:

[0158]

[0159] R2 is:

[0160]

[0161] R3 is:

[0162]

[0163] R4 is:

[0164]

[0165] Synthesis example 4

[0166] This synthetic example provides a method for preparing a high molecular weight polyurea urethane with polar groups and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0167] First, polyethylene glycol, dibutyltin dilaurate, and 4,4-dicyclohexylmethane diisocyanate were dissolved in N,N-dimethylformamide and mixed evenly. The mixture was then reacted at 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution. Next, 1,5-diaminonaphthalene was added to the prepolymer solution at 70°C and the reaction was maintained for 12 hours. After the reaction time was reached, ethylenediamine was added to the reaction product at 25°C and the reaction was maintained for 2 hours. After the reaction time was reached, the solvent was removed by separation and purification to prepare a high molecular weight polyurethane with polar groups and rigid naphthalene rings in the molecular chain.

[0168] The molar ratio of polyethylene glycol, 4,4-dicyclohexylmethane diisocyanate, 1,5-diaminonaphthalene and ethylenediamine is 1:5:1.2:2.8;

[0169] The chemical structural formula of the prepared high-molecular-weight polyurea-urethane is as follows:

[0170]

[0171] Where x is approximately 0.3 after testing and calculation, and R1 is:

[0172]

[0173] R2 is:

[0174]

[0175] R3 is:

[0176]

[0177] R4 is:

[0178]

[0179] Synthesis example 5

[0180] This synthetic example provides a method for preparing a high molecular weight polyurethane with polar groups and rigid benzene rings in its molecular chain, comprising the following steps:

[0181] First, polyethylene glycol, dibutyltin dilaurate, and hexamethylene diisocyanate were dissolved in N,N-dimethylformamide and mixed evenly. The mixture was then reacted at 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution. Next, p-phenylenediamine was added to the prepolymer solution at 70°C and the reaction was maintained for 12 hours. After the reaction time was reached, ethylenediamine was added to the reaction product at 25°C and the reaction was maintained for 2 hours. After the reaction time was reached, the solvent was removed by separation and purification to obtain a high molecular weight polyurethane with polar groups and rigid benzene rings in the molecular chain.

[0182] The molar ratio of polyethylene glycol, hexamethylene diisocyanate, p-phenylenediamine, and ethylenediamine is 1:5:1.2:2.8;

[0183] The chemical structural formula of the prepared high-molecular-weight polyurea-urethane is as follows:

[0184]

[0185] Where x is approximately 0.3 after testing and calculation, and R1 is:

[0186]

[0187] R2 is:

[0188]

[0189] R3 is:

[0190]

[0191] R4 is:

[0192]

[0193] Example 1

[0194] This embodiment utilizes the high molecular weight polyurethane with polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 1, and adds lithium salt to prepare a polymer solid electrolyte with π-π interactions. The main steps include:

[0195] The high-molecular-weight polyurethane prepared in Synthesis Example 1 was mixed and dissolved evenly with LiTFSI in DMF. The solution was then poured into a Teflon mold as a polymer solid electrolyte precursor solution. After defoaming, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interactions, which was designated as DAN-LiTFSI-1. The membrane thickness was approximately 50 micrometers.

[0196] The mass ratio of the high molecular weight polyurethane to LiTFSI is 10:1.

[0197] Example 2

[0198] Example 2 is a sample prepared by replacing the lithium salt LiTFSI with LiFSI according to the steps of Example 1, and preparing a polymer solid electrolyte membrane with π-π interaction, denoted as DAN-LiFSI-1.

[0199] Example 3

[0200] Example 3 follows the steps of Example 1, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:2. A polymer solid electrolyte membrane with π-π interactions is prepared as a sample, denoted as DAN-LiTFSI-2.

[0201] Example 4

[0202] Example 4 was prepared according to the steps of Example 1, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:0.5, resulting in a polymer solid electrolyte membrane with π-π interactions, denoted as DAN-LiTFSI-3.

[0203] Example 5

[0204] This embodiment utilizes the polyurethane polymer with polar groups and rigid naphthalene rings in its molecular chain prepared in Synthesis Example 4, and adds lithium salt to prepare a polymer solid electrolyte with π-π interactions. The main steps include:

[0205] After the high-molecular-weight polyurethane prepared in Synthesis Example 2 was mixed and dissolved evenly with LiTFSI in DMF, the polymer solid electrolyte precursor solution was poured into a Teflon mold. After defoaming, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interactions, which was designated as HMDI-LiTFSI-1 and had a membrane thickness of approximately 50 micrometers.

[0206] The mass ratio of the high molecular weight polyurethane to LiTFSI is 10:1.

[0207] Example 6

[0208] Example 6 is a sample prepared by replacing the lithium salt LiTFSI with LiFSI according to the steps of Example 5, and preparing a polymer solid electrolyte membrane with π-π interaction, denoted as HMDI-LiFSI-1.

[0209] Example 7

[0210] Example 7 is prepared according to the steps of Example 5, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:2, to obtain a polymer solid electrolyte membrane with π-π interactions as a sample, denoted as HMDI-LiTFSI-2.

[0211] Example 8

[0212] Example 8 is a sample prepared by following the steps of Example 5, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:0.5, resulting in a polymer solid electrolyte membrane with π-π interactions, denoted as HMDI-LiTFSI-3.

[0213] Example 9

[0214] This embodiment utilizes the polyurethane polymer with polar groups and rigid benzene rings in its molecular chain prepared in Synthesis Example 5, and adds lithium salt to prepare a polymer solid electrolyte with π-π interactions. The main steps include:

[0215] After the high-molecular-weight polyurethane prepared in Synthesis Example 3 was mixed and dissolved evenly with LiTFSI in DMF, it was poured into a Teflon mold as a polymer solid electrolyte precursor solution. After defoaming, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interactions, which was designated as PDA-LiTFSI-1 and had a membrane thickness of approximately 50 micrometers.

[0216] The mass ratio of the high molecular weight polyurethane to LiTFSI is 10:1.

[0217] Example 10

[0218] Example 10 is a sample prepared by replacing the lithium salt LiTFSI with LiFSI according to the steps of Example 9, and the polymer solid electrolyte membrane with π-π interaction is denoted as PDA-LiFSI-1.

[0219] Example 11

[0220] Example 11 is prepared according to the steps of Example 9, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:2, to obtain a polymer solid electrolyte membrane with π-π interactions as a sample, denoted as PDA-LiTFSI-2.

[0221] Example 12

[0222] Example 12 was prepared according to the steps of Example 9, but with the mass ratio of the polymer polyurethane to LiTFSI being 10:0.5, resulting in a polymer solid electrolyte membrane with π-π interactions, denoted as PDA-LiTFSI-3.

[0223] Example 13

[0224] To improve ion conduction within the positive electrode, an LFP positive electrode was prepared using polyurethane polymer with polar groups and rigid benzene rings in its molecular chain, obtained from Synthesis Example 1, as one of the components of the electrode binder. The main steps included:

[0225] (1) The following raw materials are mixed evenly as an electrode binder by weight parts:

[0226]

[0227] (2) After thoroughly mixing the electrode adhesive from step (1) with LFP and conductive carbon black Super P in a mass ratio of 2:7:1, the mixture is scraped onto the surface of aluminum foil and dried under normal pressure and vacuum at 80°C to obtain the LFP positive electrode sheet.

[0228] Comparative Example 1

[0229] Comparative Example 1 is a polymer solid electrolyte prepared using PEO as a comparison, comprising the following steps:

[0230] PEO and LiTFSI were mixed and dissolved evenly in acetonitrile at the same molar ratio as in Example 1. The mixture was then poured into a Teflon mold, defoamed, and vacuumed at 80°C for 24 hours to remove the solvent, resulting in a PEO-based polymer solid electrolyte membrane, which was used as a control sample and designated as PEO-LiTFSI-1.

[0231] Verification Example 1

[0232] This verification example, designed to facilitate testing the mechanical properties of the polyurethane polymer with polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 1, mainly includes the following steps:

[0233] The high-molecular-weight polyurethane prepared in Synthesis Example 1 was mixed and dissolved evenly in DMF, and then poured into a Teflon mold as a test precursor solution. After defoaming, the solvent was removed by vacuuming at 80°C for 24 hours to obtain the test film as a sample, denoted as DAN-1, with a film thickness of approximately 50 micrometers.

[0234] Verification Example 2

[0235] This verification example, designed to facilitate testing the ionic conductivity of the polyurethane polymer with polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 2, mainly includes the following steps:

[0236] The high-molecular-weight polyurethane prepared in Synthesis Example 2 was mixed and dissolved evenly in DMF, and then poured into a Teflon mold as a test precursor solution. After defoaming, the solvent was removed by vacuuming at 80°C for 24 hours to obtain a test film as a sample. The film thickness was approximately 50 micrometers.

[0237] Verification Example 3

[0238] This verification example, designed to facilitate testing the ionic conductivity of the polyurethane polymer with polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 3, mainly includes the following steps:

[0239] The high-molecular-weight polyurethane prepared in Synthesis Example 3 was mixed and dissolved evenly in DMF, and then poured into a Teflon mold as a test precursor solution. After defoaming, the solvent was removed by vacuuming at 80°C for 24 hours to obtain a test film as a sample with a thickness of approximately 50 micrometers.

[0240] The polymer solid electrolytes prepared in Examples 1-12 and Comparative Example 1 were tested. These polymer solid electrolytes were used to replace the separator and electrolyte components in the assembly of lithium metal symmetric batteries and half-cells with LFP as the positive electrode. The battery casings included a positive electrode casing and a negative electrode casing, both made of 316 stainless steel. A lithium metal disc was placed in the negative electrode casing, followed by the prepared solid electrolyte film. Then, a lithium metal or LFP positive electrode sheet, a steel sheet, and a spring were sequentially placed on top, and the positive electrode casing was used for sealing. Specifically, a pressure-controlled electric button cell packaging machine was used to package the button half-cells.

[0241] 3. Test Results

[0242] Figure 1 This is a schematic diagram illustrating the chemical structure and application of the high molecular weight polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain prepared by Example 1 of the present invention.

[0243] Figure 2 It can be found that, compared with ordinary PEO solid electrolytes, polymer solid electrolytes with rigid naphthalene ring π-π stacking interactions have significantly improved puncture resistance. This helps to suppress the growth of lithium dendrites during lithium metal battery cycling, helps to avoid the risk of short circuit in the battery, and thus improves the cycle life of the battery.

[0244] pass Figure 3 The comparison reveals that, compared to ordinary PEO solid electrolytes, polymer solid electrolytes with rigid naphthalene ring π-π stacking interactions show significant improvements in both tensile strength and elongation at break. This indicates that the π-π stacking can significantly enhance the interaction force between chain segments, thereby increasing the toughness of the material and enabling it to better adapt to some volume changes during battery cycling.

[0245] Figure 4 Comparing the two AFM images reveals that the surface of the PEO solid electrolyte is rougher than that of the DAN-LiTFSI-1 solid electrolyte, exhibiting some bumps and pits. A smoother electrolyte surface facilitates better electrode-electrolyte interface contact, reduces interfacial impedance, and thus results in a more uniform lithium deposition and stripping process, contributing to improved battery performance. The DAN-LiTFSI-1 image shows a smooth, pale yellow, semi-transparent film.

[0246] The conductivity of DAN-LiTFSI-1 at 60℃ ranges from 1.23 × 10⁻⁶. -4 S cm -1 The conductivity of PEO is 9.8 × 10⁻⁶. -5 S cm -1 And according to the Arrhenius formula:

[0247]

[0248] Where A refers to the pre-factor, T represents the absolute temperature, and k b E represents the Boltzmann constant. a It is the activation energy. For example... Figure 6 As shown, the calculated activation energy of the DAN-LiTFSI-1 solid electrolyte is only 0.64 eV, lower than the 0.96 eV of the PEO solid electrolyte. This means that lithium-ion transport is easier in DAN-LiTFSI-1 compared to PEO. On one hand, this enhancement can be attributed to the disruption of molecular chain order by DAN in DAN-LiTFSI-1, thereby expanding the amorphous region and promoting the movement of PEG segments. On the other hand, the presence of polar groups (C=O) in DAN-LiTFSI-1 promotes interaction with lithium ions, enabling lithium ions to bind / dissociate, thus lowering the migration energy barrier and further promoting lithium-ion migration kinetics. Figure 5 The results show that the activation energy of the polymer solid electrolyte increases as the content of rigid naphthalene rings decreases.

[0249] Figure 7 The polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention were subjected to a 0.1 mA cm⁻¹ temperature. -2 and 0.1mAh cm -2 Cycling comparison of symmetrical batteries at current densities. The battery using DAN-LiTFSI-1 solid electrolyte achieved stable cycling for over 3000 hours with a low overpotential (<0.17V). In contrast, the battery using PEO-based electrolyte exhibited a higher overpotential and short-circuited after 270 hours. The enhanced lithium plating / stripping performance of the battery using DAN-LiTFSI-1 solid electrolyte can be attributed to three main factors. First, the excellent stability of the lithium metal-electrolyte interface plays a crucial role in maintaining a stable overpotential, thus extending cycle stability. Second, the high lithium-ion transference number promotes the formation of a stable electric field, which is essential for promoting uniform lithium deposition. Third, the π-π stacking interactions of the molecular chain segments within the DAN-LiTFSI-1 solid electrolyte produce favorable mechanical properties that help prevent lithium dendrites from penetrating the electrolyte membrane, thereby improving the battery's cycle life.

[0250] Figure 8 The lithium metal symmetric battery assembled using the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of this invention operates at 0.1 mA cm⁻¹. -2 Current density, 0.1 mAh / cm³ -2Optical images of the lithium sheet surface obtained after disassembling the battery at its areal capacity after 50 cycles. After 50 cycles, the lithium sheet using DAN-LiTFSI-1 solid electrolyte has a smooth lithium metal surface with a metallic luster, while the lithium sheet using PEO solid electrolyte shows black areas on its surface, indicating the formation of lithium dendrites in the PEO system.

[0251] Figure 9 The lithium metal symmetric battery assembled using the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of this invention was tested at 0.1 mA / cm². -2 Current density, 0.1 mAh / cm³ -2 SEM images of the lithium surface obtained after disassembling the battery at its areal capacity (50 cycles) show that the lithium surface using DAN-LiTFSI-1 exhibits a dense and smooth morphology, indicating that the DAN-LiTFSI-1 solid electrolyte can effectively induce uniform lithium deposition, thus forming a dense lithium deposition surface layer. Conversely, the lithium surface in the system using PEO solid electrolyte exhibits a distinct moss-like morphology with irregular dendritic structures, suggesting that the lithium deposition process is not uniform.

[0252] Figure 10 A comparison of the cycling data of lithium metal half-cells assembled with the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention and the LFP positive electrode prepared in Example 13 shows that the battery using DAN-LiTFSI-1 has an initial reversible specific capacity of 145 mAh g at a 0.2C rate. -1 (1C = 170mAh g) -1 The battery exhibited a capacity retention of 83.6% after 450 cycles, demonstrating stable cycling performance. Furthermore, the coulombic efficiency (CE) remained close to 100% throughout the cycling process, showcasing excellent interfacial stability between the electrolyte and electrodes. In contrast, the battery using a PEO solid electrolyte experienced a rapid capacity decline during cycling, retaining only 50% of its initial capacity after 260 cycles. The solid electrolyte membrane of DAN-LiTFSI-1 demonstrated superior full-cell cycling performance.

[0253] Figure 11 This paper compares the rate performance of LFP half-cells assembled from the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1 of this invention with those assembled from the LFP positive electrode prepared in Example 13. The test results show that the discharge specific capacities of the batteries using the DAN-LiTFSI-1 electrolyte are 147.6, 144.9, 141.6, 138.4, 135.1, and 100.5 mAh g⁻¹ when the current density changes from 0.1C to 1C. -1 When the current density returns to 0.1C, the battery's discharge specific capacity remains as high as 149.6 mAh g. -1The discharge specific capacities of batteries using PEO electrolyte were 141.8, 143.6, 139.9, 136.5, 131.2, and 37.6 mAh g, respectively. -1 The DAN-LiTFSI-1 solid electrolyte membrane exhibits superior rate performance.

[0254] Figure 12 The images show the initial and post-50-cycle electrochemical impedance spectroscopy (EIS) spectra of LFP half-cells assembled from the polymer solid electrolyte membranes prepared in Example 1 and Comparative Example 1, and the LFP cathode sheet prepared in Example 13. The cell using DAN-LiTFSI-1 had an interfacial resistance of 295.87 Ω before cycling, lower than the interfacial impedance (302.1 Ω) of the cell using PEO. Furthermore, the impedance of the cell using PEO increased significantly after 50 cycles, while the impedance spectrum change of the cell using DAN-LiTFSI-1 was negligible, indicating better interfacial stability during cycling. The results show that the significant cycling stability is mainly attributed to the superior electrode / electrolyte interface stability, improved lithium-ion transport kinetics, and excellent mechanical properties of the DAN-LiTFSI-1 solid electrolyte.

[0255] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A polymer solid-state electrolyte having π-π interaction, characterized by The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: ， wherein the polymeric polyurea urethane has Mn = 1 x 10 4 1 x 10 6 g / mol, 0 < x < 0.8; The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: 、 ； The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: 、 、 ； The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: 、 、 、 、 ； The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: 、 、 。 2. The polymer solid-state electrolyte of claim 1, wherein The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps:

3. The polymer solid-state electrolyte according to claim 2, wherein: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps:

4. The polymer solid-state electrolyte according to claim 2, wherein: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps:

5. The polymer solid-state electrolyte according to claim 2, wherein: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps:

6. The polymer solid-state electrolyte of claim 2, wherein: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps:

7. An electrode binder, characterized by The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings in the molecular chain is prepared by the following steps: The high molecular polyurea urethane with polar groups and rigid naphthalene rings

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