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

Abstract

The invention provides a polymer solid electrolyte with pi-pi interaction and a preparation method of the polymer solid electrolyte, and particularly relates to high-molecular polyurea urethane with polar groups and rigid benzene rings or naphthalene rings in molecular chains and a preparation method of the high-molecular polyurea urethane. The preparation method comprises the following steps: carrying out an addition polymerization reaction on polymeric dihydric alcohol and diisocyanate to prepare an isocyanate-terminated prepolymer, carrying out a blending reaction on the isocyanate-terminated prepolymer and aromatic diamine, and finally carrying out a diamine chain extension reaction to prepare the high-molecular polyurea urethane with a polar group and a rigid benzene ring or naphthalene ring in a molecular chain. According to the application of the combination of the high-molecular polyurea urethane and lithium salt as the polymer solid electrolyte, compared with a PEO-based solid electrolyte in the prior art, the polymer solid electrolyte has higher lithium ion transference number, excellent mechanical property and formation of a stable LiF-rich solid electrolyte interphase (SEI) layer on the surface of lithium metal.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer solid electrolytes, and relates to a polymer solid electrolyte with π-π interaction and a preparation method thereof, and specifically to a polymer polyureaurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain and a preparation method thereof, and to the application of the polymer polyureaurethane in combination with a lithium salt as a polymer solid electrolyte. Background Art

[0002] The rapid development of wearable devices and electric vehicles requires rechargeable batteries with higher energy density. Lithium metal batteries have high theoretical specific capacity (3860mAh g -1 ) and low redox potential (-3.04V) are considered to be ideal candidates to meet this need. The development of lithium metal batteries using solid electrolytes provides a viable approach to achieve higher energy density and improved safety compared to conventional lithium-ion batteries, thus meeting the stringent requirements for next-generation battery technology.

[0003] Solid electrolytes are a key component of solid-state lithium metal batteries and play a vital role in determining the overall performance of solid-state lithium metal batteries. Generally speaking, solid electrolytes can be divided into three categories: inorganic solid electrolytes, polymer solid electrolytes, and composite solid electrolytes. Among polymer solid electrolytes, solid electrolytes based on polyethylene oxide (PEO) have the advantages of good lithium salt solubility, processability, flexibility, and low cost. In 1978, Armand et al. first proposed a method with an ionic conductivity of 10 -4 PEO-lithium salt polymer solid electrolyte (Fenton DE, Parker JM, Wright PV. Complexes of Alkaline Metal Ions with Poly (ethylene oxide) [J]. Polymer, 1973, 14 (4): 589-594.) can be used in lithium batteries at 40-60 ° C. 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 of PEO-based electrolytes increases the polarization voltage and quickly forms lithium dendrite nucleation sites during lithium deposition / stripping. In addition, PEO-based electrolytes form an unstable solid electrolyte interphase (SEI) layer after contact with lithium metal, which gradually deteriorates during cycling. As the cycle continues, the SEI layer becomes thicker and evolves with lithium dendrites, resulting in increased internal resistance, rapid capacity decay, and potential short circuit risks. To address these challenges, researchers have chosen strategies such as adding 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, there are still challenges such as filler aggregation and complex pretreatment methods.

[0005] Therefore, it is necessary to design polymer solid electrolyte materials with optimized molecular structures to improve the performance of PEO-based electrolytes, so that they have considerable lithium ion migration numbers, stronger mechanical strength, and the ability to form a stable SEI layer on lithium metal, which is conducive to achieving high energy density and long cycle life of lithium metal batteries. Summary of the invention

[0006] In order to solve the problems raised by the above-mentioned prior art, the present invention provides a polymer solid electrolyte with π-π interaction and a preparation method thereof. The first invention purpose is to provide a polymer polyureaurethane with polar groups and rigid benzene rings or naphthalene rings in the molecular chain and a preparation method thereof. The second invention purpose is to utilize the polymer polyureaurethane in combination with a lithium salt as a polymer solid electrolyte. Compared with the PEO-based solid electrolyte in the prior art, the polymer solid electrolyte has a higher lithium ion migration number, excellent mechanical properties and forms a stable, LiF-rich solid electrolyte interphase (SEI) layer on the surface of lithium metal.

[0007] To achieve the above objectives, the present invention is implemented by adopting a technical solution consisting of the following technical measures.

[0008] In one aspect, the present invention provides a high molecular weight polyureaurethane having a polar group and a rigid benzene ring or naphthalene ring in the molecular chain, and the chemical structure thereof is as follows:

[0009]

[0010] Wherein, the polymer polyureaurethane Mn = 1×10 4 ~1×10 6 g / mol, 0<x≤0.8;

[0011] R 1 Any of the following structures:

[0012]

[0013] R 2 Any of the following structures, m=10-200:

[0014]

[0015] R 3 Any of the following structures:

[0016]

[0017] R 4 Any of the following structures:

[0018]

[0019] In the above chemical structural formula, “---” indicates the position where the chemical bonds are connected.

[0020] On the other hand, the present invention also provides a method for preparing the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the above-mentioned molecular chain, which is firstly to prepare an isocyanate-terminated prepolymer by polymerizing diols and diisocyanates through addition polymerization, and then to prepare the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the molecular chain through a diamine chain extension reaction after a blending reaction with aromatic diamines. It should be noted that those skilled in the art can obtain specific preparation steps according to the raw material selection and reaction sequence shown above, especially can balance the raw materials according to the common knowledge in the art through the above-mentioned specific chemical structure formula; therefore, the technical scheme provided by the present invention below does not mean the sole designation or limitation of the method for preparing the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0021] The present invention also provides a method for preparing a high molecular weight polyureaurethane having a polar group and a rigid benzene ring or a naphthalene ring in a molecular chain, comprising the following steps:

[0022] First, polymerized diol and diisocyanate are uniformly mixed and then subjected to prepolymerization reaction to obtain an isocyanate-terminated prepolymer; then, aromatic diamine is added to the prepolymer at a temperature of 60 to 80° C. and the prepolymer is kept warm for reaction for 3 to 12 hours. After the time is up, diamine is added to the reaction product at a temperature of 20 to 30° C. and the prepolymer is kept warm for reaction for 0.5 to 2 hours, so as to obtain a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain;

[0023] The chemical structure of the aromatic diamine contains a benzene ring or a naphthalene ring, 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] Herein, the polymeric diol is a polymer obtained by polymerization of a monomer having two hydroxyl groups, for example, any one of polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and the molecular weight of the polymeric diol is in the range of 600 to 10000. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0026] In one preferred technical solution, the polymeric diol as the flexible soft segment of polyureaurethane is preferably polyethylene glycol with a molecular weight of about 4000.

[0027] Herein, the diisocyanate is a compound having two isocyanate groups, 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.

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

[0029] Herein, the chemical structure of the aromatic diamine contains a benzene ring or a naphthalene ring, 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 article, the diamine is a carbon straight chain compound with amino groups at both ends, wherein the carbon straight chain is usually a carbon straight chain of C2 to C6, for example, any one of ethylenediamine, propylenediamine, butylenediamine, pentanediamine and hexamethylenediamine. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

[0031] In this article, the prepolymerization reaction of the polymerized diol and the diisocyanate after uniform mixing is carried out to prepare the isocyanate-terminated prepolymer, wherein the prepolymerization reaction of the polymerized diol and the diisocyanate is a conventional addition polymerization reaction in the art, and its specific material ratio, reaction conditions, etc. all follow the conventional prepolymerization reaction using the above compounds as raw materials, and those skilled in the art can directly refer to the existing technology / existing process in the art for preparation. Generally speaking, the specific polymerized diol can be determined first, and then a suitable prepolymerization reaction preparation process can be selected according to the specific polymerized diol.

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

[0033] It should be noted that in the preparation method of the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the above-mentioned molecular chain, based on the common knowledge in the art, it is generally further included to add an organic solvent as a reaction medium, for example, N,N-dimethylformamide that can fully dissolve the raw materials and the reaction product is added as a solvent, and finally the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain is prepared by removing the solvent through separation and purification. In the above-mentioned preparation method, the selection and addition amount of the organic solvent usually do not have a significant effect on the characterization of the reaction product and the technical effect of the present invention, so those skilled in the art can select a suitable organic solvent based on the common knowledge in the art. In addition, in order to speed up the reaction rate and ensure complete reaction during the entire preparation process, conventional mechanical stirring is usually accompanied.

[0034] On the other hand, the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain prepared as above can be directly used as one of the components of polymer solid electrolytes and used in the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0035] In order to better illustrate the present invention and provide a reference application mode, the present invention also provides a polymer solid electrolyte with π-π interaction, which is mainly composed of the following components by mass:

[0036] 1 to 10 parts of high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain,

[0037] 1 part of lithium salt.

[0038] Herein, the lithium salt is selected from lithium salts conventionally 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 electrolyte with π-π interaction, additives that have been disclosed or commercially available in the technical field can usually be added according to the solid-state metal battery to which it is adapted, so as to enhance performance / expand functions / improve processability, etc.

[0040] On the other hand, the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain prepared as above can be directly used as one of the components of electrode adhesives and used in the preparation of solid-state metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

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

[0042]

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

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

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

[0046] 1. The present invention provides a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain. Through comparative experiments, it is found that as the rigid structure content increases, the tensile strength and Young's modulus of the obtained polymer are improved to varying degrees. The improvement of Young's modulus is beneficial to inhibiting the growth of dendrites 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 polyureaurethane provided by the present invention, since the base polymer has a large number of polar groups (urea bonds and carbamate bonds) and the delocalized π electron cloud of the benzene ring, it can interact with the lithium salt anions. On the one hand, it can anchor the anions to inhibit their migration and thus increase the number of lithium ion migration. On the other hand, it can promote the dissociation of lithium salt anions, thereby promoting the formation of a 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 interaction provided by the present invention has been tested as an electrolyte for lithium symmetric batteries at 0.1 mA cm -2 , 0.1mAhcm -2 It can stably cycle for more than 3000 hours at a current density of , which is far higher than that of PEO-based solid electrolytes, and the polarization voltage is also lower than that of PEO-based solid electrolytes.

[0049] 4. The polymer solid electrolyte with π-π interaction provided by the present invention has been tested as LiFePO4 When the electrolyte of the half-cell (LFP) was used, the discharge capacity could still be maintained at 121 mAh g 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 as LiFePO 4 As the electrolyte of a half-cell, it has better rate performance than ordinary PEO solid electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The chemical structure and application diagram of the high molecular weight polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 1 of the present invention.

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

[0053] Figure 3 The tensile properties comparison line graphs of the samples prepared in Example 1, Example 1 and Comparative Example 1 are respectively used to verify the present invention.

[0054] Figure 4 The flatness comparison diagram of the polymer solid electrolyte membrane prepared in Example 1 of the present invention and Comparative Example 1. Among them, Figure (a) is an atomic force microscope image of the sample obtained in Example 1, Figure (b) is an atomic force microscope image of the comparative sample obtained in Comparative Example 1, and Figure (c) is a physical image of the polymer solid electrolyte membrane obtained in Example 1.

[0055] Figure 5 This is a comparison diagram of the Arrhenius curves of the test membranes prepared in Verification Example 2 and Verification Example 3 of the present invention, which includes the calculated activation energies of the two and the ionic conductivity at the corresponding temperature.

[0056] Figure 6 This is a comparison diagram of the Arrhenius curves of the polymer solid electrolyte membranes prepared in Example 1 of the present invention and Comparative Example 1, which includes the calculated activation energies of the two and the ionic conductivity at the corresponding temperatures.

[0057] Figure 7 The polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention was -2 and 0.1mAh cm -2 Comparison of symmetric battery cycles at different current densities.

[0058] Figure 8The lithium metal symmetric battery assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention is -2 Current density, 0.1mAhcm -2 Figure (a) shows the appearance of lithium sheets after 50 cycles of the polymer solid electrolyte membrane prepared in Example 1 in a symmetrical battery; Figure (b) shows the appearance of lithium sheets after 50 cycles of the polymer solid electrolyte membrane prepared in Comparative Example 1 in a symmetrical battery.

[0059] Fig. 9 The lithium metal symmetric battery assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention is -2 Current density, 0.1mAhcm -2 Scanning electron microscope (SEM) image of the lithium sheet surface after 50 cycles at full capacity.

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

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

[0062] Fig.12 The EIS curves of the LFP half-cell assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention at the initial stage and after 50 cycles are shown respectively. DETAILED DESCRIPTION

[0063] In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously change or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention. Although it is believed that those of ordinary skill in the art fully understand the following terms, the following definitions are still stated to help illustrate the subject matter disclosed by the present invention.

[0064] In one aspect, the present invention provides a high molecular weight polyureaurethane having a polar group and a rigid benzene ring or naphthalene ring in the molecular chain, and the chemical structure thereof is as follows:

[0065]

[0066] Wherein, the polymer polyureaurethane Mn = 1×10 4 ~1×10 6 g / mol, 0<x≤0.8;

[0067] R 1 Any of the following structures:

[0068]

[0069] R 2 Any of the following structures, m=10-200:

[0070]

[0071] R 3 Any of the following structures:

[0072]

[0073] R 4 Any of the following structures:

[0074]

[0075] In the above chemical structural formula, “---” indicates the position where the chemical bonds are connected.

[0076] On the other hand, the present invention also provides a method for preparing the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the above-mentioned molecular chain, which is firstly to prepare an isocyanate-terminated prepolymer by polymerizing diols and diisocyanates through addition polymerization, and then to prepare the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the molecular chain through a diamine chain extension reaction after a blending reaction with aromatic diamines. It should be noted that those skilled in the art can obtain specific preparation steps according to the raw material selection and reaction sequence shown above, especially can balance the raw materials according to the common knowledge in the art through the above-mentioned specific chemical structure formula; therefore, the technical scheme provided by the present invention below does not mean the sole designation or limitation of the method for preparing the polymer polyureaurethane having polar groups and rigid benzene or naphthalene rings in the molecular chain.

[0077] The present invention also provides a method for preparing a high molecular weight polyureaurethane having a polar group and a rigid benzene ring or a naphthalene ring in a molecular chain, comprising the following steps:

[0078] First, polymerized diol and diisocyanate are uniformly mixed and then subjected to prepolymerization reaction to obtain an isocyanate-terminated prepolymer; then, aromatic diamine is added to the prepolymer at a temperature of 60 to 80° C. and the prepolymer is kept warm for reaction for 3 to 12 hours. After the time is up, diamine is added to the reaction product at a temperature of 20 to 30° C. and the prepolymer is kept warm for reaction for 0.5 to 2 hours, so as to obtain a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain;

[0079] The chemical structure of the aromatic diamine contains a benzene ring or a naphthalene ring, 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] Herein, the polymeric diol is a polymer obtained by polymerization of a monomer having two hydroxyl groups, and in one embodiment, for example, includes any one of polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and the molecular weight of the polymeric diol ranges from 600 to 10000. 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 as the flexible soft segment of polyureaurethane is preferably polyethylene glycol with a molecular weight of about 4,000.

[0083] In this article, the diisocyanate is a compound having two isocyanate groups, and in one embodiment, for example, includes 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 article, the chemical structure of the aromatic diamine contains a benzene ring or a naphthalene ring. In one embodiment, for example, any one of 1,5-diaminonaphthalene, 2,3-diaminonaphthalene, 1,8-diaminonaphthalene, o-phenylenediamine, m-phenylenediamine and p-phenylenediamine is selected. Those skilled in the art can directly select commercially available conventional chemical raw material grade raw materials.

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

[0087] In this article, the prepolymerization reaction of the polymerized diol and the diisocyanate after uniform mixing is carried out to prepare the isocyanate-terminated prepolymer, wherein the prepolymerization reaction of the polymerized diol and the diisocyanate is a conventional addition polymerization reaction in the art, and its specific material ratio, reaction conditions, etc. all follow the conventional prepolymerization reaction using the above compounds as raw materials, and those skilled in the art can directly refer to the existing technology / existing process in the art for preparation. Generally speaking, the specific polymerized diol can be determined first, and then a suitable prepolymerization reaction preparation process can be selected according to the specific polymerized diol.

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

[0089] It should be noted that in the preparation method of the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the above-mentioned molecular chain, based on the common knowledge in the art, it is generally further included to add an organic solvent as a reaction medium, in one embodiment, for example, N, N-dimethylformamide that can fully dissolve the raw materials and the reaction product is added as a solvent, and finally the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain is prepared by removing the solvent through separation and purification. In the above-mentioned preparation method, the selection and addition amount of the organic solvent usually do not have a significant effect on the characterization of the reaction product and the technical effect of the present invention, so those skilled in the art can select a suitable organic solvent based on the common knowledge in the art. In addition, in order to speed up the reaction rate and ensure complete reaction during the entire preparation process, conventional mechanical stirring is usually accompanied.

[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 therebetween; the molar ratio of the polymeric diol to the aromatic diamine is 1:(0.5-3), 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any range or point value therebetween; the molar ratio of the polymeric diol to the diamine is 1:(1-3), for example 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any range or point value therebetween.

[0091] On the other hand, the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain prepared as above can be directly used as one of the components of polymer solid electrolytes and used in the preparation of solid metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

[0092] In order to better illustrate the present invention and provide a reference application mode, the present invention also provides a polymer solid electrolyte with π-π interaction, which is mainly composed of the following components by mass:

[0093] 1 to 10 parts of high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain,

[0094] 1 part of lithium salt.

[0095] Herein, the lithium salt is selected from lithium salts conventionally 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 electrolyte with π-π interaction, additives that have been disclosed or commercially available in the technical field can usually be added according to the solid-state metal battery to which it is adapted, so as to enhance performance / expand functions / improve processability, etc.

[0097] In one embodiment, the polymer polyureaurethane having polar groups and rigid benzene rings 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 therebetween.

[0098] On the other hand, the polymer polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain prepared as above can be directly used as one of the components of electrode adhesives and used in the preparation of solid-state metal batteries such as lithium metal batteries, sodium metal batteries, and potassium metal batteries.

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

[0100]

[0101] Among the above 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 invention will be further explained in detail with reference to the following examples. However, it should be understood by those skilled in the art that these examples are provided for illustrative purposes only and are not intended to limit the present invention.

[0104] Example

[0105] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. The specific conditions not specified in the examples are carried out according to the conditions recommended by normal conditions or manufacturers. The reagents used or the instruments not specified by the manufacturer are all conventional products that can be obtained commercially. The application should not be construed as being limited to the specific examples 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 = 5000000) and 1,5-diaminonaphthalene (DAN, purity 98%) were purchased from Adamas Reagent Network.

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

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

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

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

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

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

[0115] Before using DMF, Molecular sieve drying for one week.

[0116] 2. Test Method

[0117] Puncture test: The prepared polymer solid electrolyte membrane was cut into square sheets (1 cm), fixed on the device of a servo-controlled electronic universal material testing machine (RS-8000), and then compressed at a constant speed of 10 mm / min. -1 Record the applied load on the sample.

[0118] Tensile test: The prepared polymer solid electrolyte membrane was cut into 4 mm wide tensile specimens, and then fixed on a dual-column table test machine (INS Tron universal material testing machine 5967, USA) using a clamp, and then stretched at a constant speed of 50 mm / min. -1 Record the applied load on the sample.

[0119] Atomic force microscope observation: Atomic force microscope can observe surface morphology and physical properties, and can directly observe nano-level surface morphology, roughness, etc. The present invention drops the polymer solid electrolyte precursor solution on a smooth silicon wafer, then removes the solvent under vacuum and high temperature, and uses the tapping mode of the Bruker atomic force microscope to detect the roughness of the surfaces of different polymer solid electrolytes.

[0120] Constant current charge and discharge test: In the present invention, the MIHW-200-160CH constant temperature test box of Shenzhen Xinwei Company is used to perform constant current charge and discharge tests on the battery at different cycle periods and different charge and discharge rates. The current density of the symmetrical battery is 0.1 mA cm -2 , 0.1mAhcm -2 The standard specific capacity of LFP is 170 mAh g -1The test voltage was 2.5V to 3.8V and the temperature was 60°C. Lithium batteries based on different polymer solid electrolytes were assembled and tested to explore the effect of the prepared polymer solid electrolyte on the electrochemical performance of lithium metal batteries.

[0121] Ionic conductivity test: The present invention sandwiched the polymer solid electrolyte between two stainless steel plates and used the Metrohm VIONIC electrochemical workstation to measure the ionic conductivity of the polymer solid electrolyte at different temperatures. The measurement frequency range was 1-10 7 Hz.

[0122] Scanning electron microscope test: Scanning electron microscope (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. After the samples in the present invention were processed, they were studied using a JEOL JEM-F200 field emission transmission electron microscope at an accelerating voltage of 5 kV.

[0123] Synthesis example 1

[0124] This synthesis example provides a method for preparing a polymer polyureaurethane having a polar group and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0125] First, polyethylene glycol, dibutyltin dilaurate and hexamethylene diisocyanate are dissolved in N,N-dimethylformamide and mixed evenly, and reacted at a reaction temperature of 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution; then, 1,5-diaminonaphthalene is added to the prepolymer solution at a temperature of 70°C and kept warm for 12 hours. After the time is up, ethylenediamine is added to the reaction product at a temperature of 25°C and kept warm for 2 hours. After the time is up, the solvent is removed by separation and purification to prepare a high molecular weight polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain;

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

[0127] The obtained polymer polyureaurethane has the following chemical structure:

[0128]

[0129] Among them, x is about 0.3 after testing and calculation, R 1 for:

[0130]

[0131] R 2 for:

[0132]

[0133] R 3 for:

[0134]

[0135] R 4 for:

[0136]

[0137] Synthesis example 2

[0138] This synthesis example provides a method for preparing a polymer polyureaurethane having a polar group and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0139] First, polyethylene glycol, dibutyltin dilaurate and hexamethylene diisocyanate are dissolved in N,N-dimethylformamide and mixed evenly, and reacted at a reaction temperature of 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution; then, 1,5-diaminonaphthalene is added to the prepolymer solution at a temperature of 70°C and kept warm for 12 hours. After the time is up, ethylenediamine is added to the reaction product at a temperature of 25°C and kept warm for 2 hours. After the time is up, the solvent is removed by separation and purification to prepare a high molecular weight polyureaurethane having 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 obtained polymer polyureaurethane has the following chemical structure:

[0142]

[0143] Among them, x is about 0.2 after testing and calculation, R 1 for:

[0144]

[0145] R 2 for:

[0146]

[0147] R 3 for:

[0148]

[0149] R 4 for:

[0150]

[0151] Synthesis example 3

[0152] This synthesis example provides a method for preparing a polymer polyureaurethane having a polar group and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0153] First, polyethylene glycol, dibutyltin dilaurate and hexamethylene diisocyanate are dissolved in N,N-dimethylformamide and mixed evenly, and reacted at a reaction temperature of 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution; then, 1,5-diaminonaphthalene is added to the prepolymer solution at a temperature of 70°C and kept warm for 12 hours. After the time is up, ethylenediamine is added to the reaction product at a temperature of 25°C and kept warm for 2 hours. After the time is up, the solvent is removed by separation and purification to prepare a high molecular weight polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain;

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

[0155] The obtained polymer polyureaurethane has the following chemical structure:

[0156]

[0157] Among them, x is about 0.1 after testing and calculation, R 1 for:

[0158]

[0159] R 2 for:

[0160]

[0161] R 3 for:

[0162]

[0163] R 4 for:

[0164]

[0165] Synthesis example 4

[0166] This synthesis example provides a method for preparing a polymer polyureaurethane having a polar group and a rigid naphthalene ring in the molecular chain, comprising the following steps:

[0167] First, polyethylene glycol, dibutyltin dilaurate and 4,4-dicyclohexylmethane diisocyanate are dissolved in N,N-dimethylformamide and mixed evenly, and reacted at a reaction temperature of 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution; then, 1,5-diaminonaphthalene is added to the prepolymer solution at a temperature of 70°C and kept warm for reaction for 12 hours. After the time is up, ethylenediamine is added to the reaction product at a temperature of 25°C and kept warm for reaction for 2 hours. After the time is up, the solvent is removed by separation and purification to prepare a high molecular weight polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain;

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

[0169] The obtained polymer polyureaurethane has the following chemical structure:

[0170]

[0171] Among them, x is about 0.3 after testing and calculation, R 1 for:

[0172]

[0173] R 2 for:

[0174]

[0175] R 3 for:

[0176]

[0177] R 4 for:

[0178]

[0179] Synthesis example 5

[0180] This synthesis example provides a method for preparing a high molecular weight polyureaurethane having a polar group and a rigid benzene ring in the molecular chain, comprising the following steps:

[0181] First, polyethylene glycol, dibutyltin dilaurate and hexamethylene diisocyanate are dissolved in N,N-dimethylformamide and mixed evenly, and reacted at a reaction temperature of 80°C for 2 hours to prepare an isocyanate-terminated prepolymer solution; then, p-phenylenediamine is added to the prepolymer solution at a temperature of 70°C and the mixture is kept warm for 12 hours. After the time is up, ethylenediamine is added to the reaction product at a temperature of 25°C and the mixture is kept warm for 2 hours. After the time is up, the solvent is removed by separation and purification to prepare a high molecular weight polyureaurethane having 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 obtained polymer polyureaurethane has the following chemical structure:

[0184]

[0185] Among them, x is about 0.3 after testing and calculation, R 1 for:

[0186]

[0187] R 2 for:

[0188]

[0189] R 3 for:

[0190]

[0191] R 4 for:

[0192]

[0193] Example 1

[0194] This embodiment uses the polymer polyureaurethane having 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 interaction, which mainly includes the following steps:

[0195] The polymer polyureaurethane prepared in Synthesis Example 1 and LiTFSI were mixed and dissolved evenly in DMF, and then poured into a Teflon mold as a polymer solid electrolyte precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interaction as a sample, recorded as DAN-LiTFSI-1, and the membrane thickness was about 50 microns.

[0196] The mass ratio of the polymer polyureaurethane to LiTFSI is 10:1.

[0197] Example 2

[0198] Example 2 follows the steps of Example 1, but replaces the lithium salt LiTFSI with LiFSI to prepare a polymer solid electrolyte membrane with π-π interaction as a sample, which is recorded as DAN-LiFSI-1.

[0199] Example 3

[0200] Example 3 follows the steps of Example 1, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:2, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as DAN-LiTFSI-2.

[0201] Example 4

[0202] Example 4 follows the steps of Example 1, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:0.5, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as DAN-LiTFSI-3.

[0203] Example 5

[0204] This embodiment uses the polymer polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 4, and adds lithium salt to prepare a polymer solid electrolyte with π-π interaction, which mainly includes the following steps:

[0205] The polymer polyureaurethane prepared in Synthesis Example 2 was mixed and dissolved evenly with LiTFSI in DMF, and then poured into a Teflon mold as a polymer solid electrolyte precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interaction as a sample, recorded as HMDI-LiTFSI-1, with a membrane thickness of about 50 microns.

[0206] The mass ratio of the polymer polyureaurethane to LiTFSI is 10:1.

[0207] Example 6

[0208] Example 6 follows the steps of Example 5, but replaces the lithium salt LiTFSI with LiFSI to prepare a polymer solid electrolyte membrane with π-π interaction as a sample, which is recorded as HMDI-LiFSI-1.

[0209] Example 7

[0210] Example 7 follows the steps of Example 5, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:2, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as HMDI-LiTFSI-2.

[0211] Example 8

[0212] Example 8 follows the steps of Example 5, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:0.5, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as HMDI-LiTFSI-3.

[0213] Example 9

[0214] This embodiment uses the polymer polyureaurethane having polar groups and rigid benzene rings in the molecular chain prepared in Synthesis Example 5, and adds lithium salt to prepare a polymer solid electrolyte with π-π interaction, which mainly includes the following steps:

[0215] The polymer polyureaurethane prepared in Synthesis Example 3 and LiTFSI were mixed and dissolved evenly in DMF, and then poured into a Teflon mold as a polymer solid electrolyte precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a polymer solid electrolyte membrane with π-π interaction as a sample, denoted as PDA-LiTFSI-1, with a membrane thickness of about 50 microns.

[0216] The mass ratio of the polymer polyureaurethane to LiTFSI is 10:1.

[0217] Example 10

[0218] Example 10 follows the steps of Example 9, but replaces the lithium salt LiTFSI with LiFSI to prepare a polymer solid electrolyte membrane with π-π interaction as a sample, which is recorded as PDA-LiFSI-1.

[0219] Embodiment 11

[0220] Example 11 follows the steps of Example 9, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:2, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as PDA-LiTFSI-2.

[0221] Example 12

[0222] Example 12 follows the steps of Example 9, but the mass ratio of the polymer polyureaurethane to LiTFSI is 10:0.5, and a polymer solid electrolyte membrane with π-π interaction is prepared as a sample, which is recorded as PDA-LiTFSI-3.

[0223] Embodiment 13

[0224] In order to improve the ion conduction inside the positive electrode, the high molecular weight polyureaurethane having polar groups and rigid benzene rings in the molecular chain prepared in Synthesis Example 1 is used as one of the components of the electrode binder to prepare the LFP positive electrode, which mainly includes the following steps:

[0225] (1) The following raw materials are mixed uniformly by weight to form an electrode binder:

[0226]

[0227] (2) The electrode adhesive prepared in step (1) was fully mixed with LFP and conductive carbon black Super P in a mass ratio of 2:7:1, and then coated on the surface of aluminum foil, and dried at 80° C. under normal pressure and vacuum to obtain an LFP positive electrode sheet.

[0228] Comparative Example 1

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

[0230] PEO and LiTFSI were mixed and dissolved in acetonitrile in the same molar ratio as in Example 1, poured into a Teflon mold, and after degassing, the solvent was removed under vacuum at 80° C. for 24 hours to obtain a PEO-based polymer solid electrolyte membrane as a comparative sample, recorded as PEO-LiTFSI-1.

[0231] Verification Example 1

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

[0233] The high molecular weight polyureaurethane prepared in Synthesis Example 1 was mixed and dissolved in DMF evenly, and then poured into a Teflon mold as a test precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a test film as a sample, recorded as DAN-1, with a film thickness of about 50 microns.

[0234] Verification Example 2

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

[0236] The high molecular weight polyureaurethane prepared in Synthesis Example 2 was mixed and dissolved in DMF evenly, and then poured into a Teflon mold as a test precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a test film as a sample with a film thickness of about 50 microns.

[0237] Verification Example 3

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

[0239] The high molecular weight polyureaurethane prepared in Synthesis Example 3 was mixed and dissolved in DMF evenly, and then poured into a Teflon mold as a test precursor solution. After degassing, the solvent was removed under vacuum at 80°C for 24 hours to obtain a test film as a sample with a film thickness of about 50 microns.

[0240] The polymer solid electrolytes prepared in Examples 1 to 12 and Comparative Example 1 were tested, and the obtained polymer solid electrolytes were used as substitutes for the diaphragm and electrolyte components to assemble lithium metal symmetrical batteries and half-cells with LFP as the positive electrode. The battery shell includes a positive electrode shell and a negative electrode shell, both of which are made of 316 stainless steel. The lithium metal disc was placed in the negative electrode shell, and then padded with the prepared solid electrolyte film, and then padded with lithium metal or LFP positive electrode sheets, steel sheets and shrapnel in turn, and sealed with the positive electrode shell. Specifically, a pressure-controllable electric button battery packaging machine was used to package the button half-cell.

[0241] 3. Test results

[0242] Figure 1 The chemical structure and application diagram of the high molecular weight polyureaurethane having polar groups and rigid naphthalene rings in the molecular chain prepared in Synthesis Example 1 of the present invention.

[0243] Figure 2 It can be found that compared with ordinary PEO solid electrolytes, the puncture resistance of polymer solid electrolytes with rigid naphthalene ring π-π stacking interactions has been greatly improved, which helps to inhibit the growth of lithium dendrites during the cycle of lithium metal batteries, helps to avoid the risk of battery short circuit, and thus improve the cycle life of the battery.

[0244] pass Figure 3 By comparison, 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 tensile strength and elongation at break, indicating that its π-π stacking can significantly increase the interaction force between chain segments, thereby enhancing the toughness of the material and better adapting to some volume changes during battery cycling.

[0245] Figure 4 Comparing the two AFM images, it can be found that the surface of the PEO solid electrolyte is rougher than that of the DAN-LiTFSI-1 solid electrolyte, with certain protrusions and pits. A smoother electrolyte surface is conducive to good electrode electrolyte interface contact and reduces interface impedance, thereby making the lithium deposition and stripping process more uniform and helping to improve battery performance. The actual image of DAN-LiTFSI-1 shows a smooth, light yellow, translucent film.

[0246] The conductivity of DAN-LiTFSI-1 at 60 °C ranges from 1.23 × 10 -4 S cm -1 , while the conductivity of PEO is 9.8×10 -5 S cm -1 , and according to the Arrhenius formula:

[0247]

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

[0249] Figure 7 The polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention was -2 and 0.1mAh cm -2Comparison of symmetric battery cycles under current density. Batteries using DAN-LiTFSI-1 solid electrolyte can be stably cycled for more than 3000 hours with low overpotential (<0.17V). In contrast, batteries using PEO-based electrolytes showed higher overpotentials and short-circuited after 270 hours. The enhanced lithium plating / stripping performance of batteries 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 key role in maintaining a stable overpotential, thereby extending the cycle stability. Second, the high lithium ion migration number promotes the formation of a stable electric field, which is essential for promoting uniform deposition of lithium. Third, the π-π stacking interaction of the molecular segments inside the DAN-LiTFSI-1 solid electrolyte produces good mechanical properties, which helps prevent lithium dendrites from penetrating the electrolyte membrane, thereby improving the cycle life of the battery.

[0250] Figure 8 The lithium metal symmetric battery assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention is -2 Current density, 0.1mAhcm -2 Optical image of the surface of the lithium sheet obtained by disassembling the battery after 50 cycles at full capacity. After 50 cycles, the lithium metal surface of the lithium sheet using the DAN-LiTFSI-1 solid electrolyte is smooth and has a metallic luster, while the lithium surface using the PEO solid electrolyte has black areas, indicating that lithium dendrites have formed in the PEO system.

[0251] Fig. 9 The lithium metal symmetric battery assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention is -2 Current density, 0.1mAhcm -2 The SEM image of the lithium sheet surface obtained by disassembling the battery after 50 cycles at full capacity shows that the lithium surface using DAN-LiTFSI-1 presents a dense and flat morphology, indicating that the DAN-LiTFSI-1 solid electrolyte can effectively induce the uniform deposition of lithium, thereby forming a dense lithium deposition surface layer. In contrast, the lithium surface in the system using the PEO solid electrolyte presents a distinct moss-like morphology with an irregular dendritic structure, indicating that the lithium deposition process is not uniform.

[0252] Fig.10 The cycling data of the lithium metal half-cell assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 and the LFP positive electrode sheet prepared in Example 13 are compared. The test results show that the initial reversible specific capacity of the battery using DAN-LiTFSI-1 at a rate of 0.2C is 145 mAh g -1(1C = 170 mAh g -1 ), the capacity retention rate after 450 cycles was 83.6%, showing stable cycling performance. In addition, the Coulombic efficiency (CE) of the battery was close to 100% throughout the cycle, demonstrating excellent interfacial stability between the electrolyte and the electrode. In contrast, the capacity of the battery using PEO solid electrolyte dropped rapidly during the cycle, retaining only 50% of the initial capacity after 260 cycles. The solid electrolyte membrane of DAN-LiTFSI-1 showed excellent full-battery cycling performance.

[0253] Fig.11 The LFP half-cell rate performance of the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention and the LFP positive electrode sheet prepared in Example 13 is compared. The test results show that when the current density of the battery using the DAN-LiTFSI-1 electrolyte changes from 0.1C to 1C, the discharge specific capacity of the battery is 147.6, 144.9, 141.6, 138.4, 135.1 and 100.5 mAh g, respectively. -1 When the current density returned to 0.1C, the discharge capacity of the battery was still as high as 149.6 mAh g -1 The discharge specific capacities of batteries using PEO electrolytes are 141.8, 143.6, 139.9, 136.5, 131.2, and 37.6 mAh g -1 , DAN-LiTFSI-1 solid electrolyte membrane shows better rate performance.

[0254] Fig.12 The electrochemical impedance spectra of the LFP half-cell assembled with the polymer solid electrolyte membrane prepared in Example 1 and Comparative Example 1 of the present invention and the LFP positive electrode sheet prepared in Example 13 at the beginning and after 50 cycles, the interface resistance of the battery using DAN-LiTFSI-1 before the cycle is 295.87Ω, which is lower than the interface impedance of the battery using PEO (302.1Ω). In addition, the impedance of the battery using PEO increased significantly after 50 cycles. In contrast, the impedance spectrum change of the battery using DAN-LiTFSI-1 is negligible, indicating that it has better interface stability during the cycle. The results show that the significant cycle stability is mainly due to the superior electrode / electrolyte interface stability, improved lithium ion transfer kinetics and excellent mechanical properties of the DAN-LiTFSI-1 solid electrolyte.

[0255] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain, characterized in that The chemical structure is as follows: Wherein, the polymer polyureaurethane Mn = 1×10 4 ~1×10 6 g / mol, 0<x≤0.8; R1 is any of the following structures: R2 is any one of the following structures, m=10-200: R3 is any of the following structures: R4 is any of the following structures:

2. A method for preparing a high molecular weight polyureaurethane having a polar group and a rigid benzene ring or naphthalene ring in a molecular chain, characterized in that The following steps are involved: First, polymerized diol and diisocyanate are uniformly mixed and then subjected to prepolymerization reaction to obtain an isocyanate-terminated prepolymer; then, aromatic diamine is added to the prepolymer at a temperature of 60 to 80° C. and the prepolymer is kept warm for reaction for 3 to 12 hours. After the time is up, diamine is added to the reaction product at a temperature of 20 to 30° C. and the prepolymer is kept warm for reaction for 0.5 to 2 hours, so as to obtain a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain; The chemical structure of the aromatic diamine contains a benzene ring or a naphthalene ring, and the diamine is a carbon straight-chain compound with amino groups at both ends; The molar ratio of the polymeric diol, diisocyanate, aromatic diamine and diamine is 1:(1-6):(0.5-3):(1-3).

3. The preparation method according to claim 2, characterized in that: The polymeric diol is polyethylene glycol. Polyethylene glycol, diisocyanate and a catalyst are uniformly mixed and reacted at a reaction temperature of 60 to 80° C. for 1 to 2 hours to prepare an isocyanate-terminated prepolymer.

4. The preparation method according to claim 2, characterized in that: The diisocyanate is 4,4-dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

5. The preparation method according to claim 2, characterized in that: The aromatic diamine includes any one of 1,5-diaminonaphthalene, 2,3-diaminonaphthalene, 1,8-diaminonaphthalene, o-phenylenediamine, m-phenylenediamine and p-phenylenediamine.

6. The preparation method according to claim 2, characterized in that: The diamine includes any one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine and hexylenediamine.

7. Use of the high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain as claimed in claim 1 in polymer solid electrolytes.

8. A polymer solid electrolyte with π-π interaction, characterized in that The invention is a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain of claim 1, which is mainly composed of the following components by mass: 1 to 10 parts of high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain, 1 part of lithium salt.

9. Use of the high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain as claimed in claim 1 in electrode adhesives.

10. An electrode adhesive, characterized in that The invention is a high molecular weight polyureaurethane having polar groups and rigid benzene rings or naphthalene rings in the molecular chain of claim 1, which is mainly composed of the following components by mass:

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