Phosphorus monocyclic compound as well as preparation method and application thereof

Abstract

The invention discloses a phosphorus monocyclic compound as well as a preparation method and application thereof. The phosphorus monocyclic compound has the following structural formula, the two phosphorus atoms are bridged through oxygen atoms to form an annular basic structure, and the X group is located at the bridging position between the two phosphorus atoms; wherein the X group is a C1-C6 carbon chain group containing an alkylene group, a carbonyl group, a sulfinyl group, a sulfonyl group or a fluoroalkylene group; the A group is a saturated alkyl group, an unsaturated alkyl group, an aryl group or a silicon group; the group B is a saturated alkyl group, an unsaturated alkyl group, an aryl group or a silicon group; compared with a traditional phosphorus compound structure, the phosphorus compound has a remarkable difference, a new member is added for the phosphorus compound type, and the phosphorus compound is suitable for being used as an additive or a flame retardant or a catalyst of a lithium ion battery electrolyte or participating in drug molecule design, and has important theoretical significance and practical application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical synthesis, and particularly relates to a phosphorus-based monocyclic compound and a preparation method and application thereof. BACKGROUND

[0002] In many fields such as material science, organic synthesis and medicinal chemistry, cyclic compounds have always been the focus and hotspot of research. Cyclic phosphorus-based compounds have wide application prospects in flame retardants, catalysts, functional materials and the like due to the special chemical properties of phosphorus elements and the stability of cyclic structures.

[0003] In the field of flame retardants, although traditional halogen-based flame retardants have high flame retardant efficiency, they release toxic and harmful hydrogen halide gas during combustion, causing serious threats to the environment and human health. With increasingly stringent environmental requirements, their use is subject to many restrictions. Among non-halogen-based flame retardants, phosphorus-based flame retardants are of great concern due to their low smoke and low toxicity. However, existing phosphorus-based flame retardants still have deficiencies in terms of thermal stability, compatibility with matrix materials and the like, and are difficult to meet the needs of high-performance flame-retardant materials.

[0004] In the field of organic synthesis, efficient and highly selective catalysts are the key to realizing green and sustainable synthesis. The commonly used catalysts have low activity, poor selectivity and harsh reaction conditions in catalyzing certain specific reactions. Cyclic phosphorus-based compounds as potential new ligands or catalysts are expected to provide new solutions for organic synthesis reactions, but the existing cyclic phosphorus-based compounds have limited structure and performance, and cannot fully meet the diverse reaction needs.

[0005] In the field of medicinal chemistry, cyclic structures containing phosphorus have important value in drug molecule design, and can be used to regulate the biological activity, pharmacokinetic properties and the like of drugs. However, the known cyclic drug molecules containing phosphorus have relatively single structure type, and it is difficult to develop drugs with new action mechanisms and better efficacy.

[0006] Therefore, it is of important theoretical significance and practical application value to develop a new cyclic phosphorus-based compound. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a phosphorus-based monocyclic compound and a preparation method and application thereof, which is significantly different from the structure of traditional phosphorus-based compounds, adds a new member to the types of phosphorus-based compounds, is suitable for being used as an additive for lithium ion battery electrolyte or a flame retardant or a catalyst or participating in drug molecule design, and has important theoretical significance and practical application value.

[0008] The technical scheme adopted by the present application is as follows: A phosphorus-based monocyclic compound, comprising the following structural formula: The two phosphorus atoms are bridged by an oxygen atom to form a cyclic basic structure, and the X group is located in the bridging position between the two phosphorus atoms; wherein the X group is a C1-C6 carbon chain group containing an alkylene group, a carbonyl group, a sulfinyl group, a sulfonyl group, or a fluoroalkylene group; the A group is a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, or a silicon group; and the B group is a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, or a silicon group.

[0009] Preferably, the phosphorus-based monocyclic compound comprises the following structure: 、 、 、 、 Any one or a mixture of several.

[0010] Preferably, according to the above-mentioned method for preparing the phosphorus-based monocyclic compound, a phosphorus source as an initial raw material reacts with its corresponding ligand in an organic solvent environment, and the reaction product is post-treated to obtain the phosphorus-based monocyclic compound.

[0011] Preferably, the phosphorus source and the first ligand are dispersed in an organic solvent, the temperature is raised to a first temperature and a preliminary reaction is carried out for at least 5 hours. After the preliminary reaction is completed, a second ligand is added to continue the reaction to obtain a reaction product; and the reaction product is post-treated to obtain the phosphorus-based monocyclic compound.

[0012] Preferably, the phosphorus source includes any one of phosphoric acid H3PO4 and its metal salts, phosphorous acid H3PO3 and its metal salts, pyrophosphate H4P2O7 and its metal salts, pyrophosphoryl chloride POCl2O2PCl, pyrophosphorous acid H4P2O5 and its metal salts, and pyrophosphorous acid chloride POCl2OPCl, or a mixture of several of them.

[0013] Preferably, the first ligand includes any one of formaldehyde, paraformaldehyde, halogen-substituted or unsubstituted acetaldehyde, halogen-substituted or unsubstituted propionaldehyde, and halogenated alkanes; the second ligand is a silicon-based compound, including any one of alkyl silicon-based compounds, alkenyl silicon-based compounds, alkynyl silicon-based compounds, and aryl silicon-based compounds.

[0014] Preferably, the molar ratio of the ligand to the phosphorus source is 3-8 times, preferably 4-6 times; and / or the amount of the organic solvent added is 1.5-3 times, preferably 2-3 times, the molar amount of the corresponding ligand.

[0015] Preferably, the reaction solvent includes any one of ether organic solvents, carbonate organic solvents, carboxylate organic solvents, chlorinated hydrocarbons, alkanes, and nitrile organic solvents, or a mixture of several of them.

[0016] Preferably, the temperature of the reaction is controlled in the range of 30-150°C, preferably 50-120°C; the pressure of the reaction is controlled in the range of 0.1-5MPa, preferably 0.5-2MPa.

[0017] Preferably, the phosphorus-based cyclic compound is added to the electrolyte of a battery, or is used as a flame retardant or a catalyst or participates in the design of a drug molecule.

[0018] The phosphorus-based monocyclic compound provided in the application has a unique and novel cyclic structure, which is significantly different from the structure of traditional phosphorus-based compounds, and adds a new member to the category of phosphorus-based compounds. The phosphorus-based monocyclic compound is suitable for being used as an additive or a flame retardant or a catalyst or participating in the design of a drug molecule for a lithium ion battery electrolyte, and has important theoretical significance and practical application value. The application further provides a preparation method of the phosphorus-based monocyclic compound. A specific phosphorus source is directly subjected to a block synthesis reaction with a ligand having a target fragment to obtain a reaction product. After post-treatment of the reaction product, the target product is obtained. The reaction condition is mild, and the product has high purity and yield. DETAILED DESCRIPTION

[0019] The embodiment provides a phosphorus-based monocyclic compound, which has the following structural formula: Two phosphorus atoms are bridged by an oxygen atom to form a cyclic basic structure, an X group is located at a bridging position between the two phosphorus atoms, and an A group and a B group are respectively connected to specific positions of the phosphorus atoms; wherein the X group is a C1-C6 carbon chain group containing an alkylene group, a carbonyl group, a sulfinyl group, a sulfonyl group or a fluorinated alkylene group. Preferably, in the embodiment, the alkylene group refers to a divalent alkyl group; the carbonyl group is a functional group formed by connecting one carbon atom and one oxygen atom in a double bond (C = O); the sulfinyl group (S = O) is a group containing sulfur and sulfur and oxygen atoms connected by a double bond, and the sulfonyl group (-SO2-) is a divalent group in which a sulfur atom is connected to two oxygen atoms. It should be noted that when the X group is an alkylene group, it can be a straight chain or have a branched chain; the fluorinated alkylene group refers to the alkylene group described above, in which at least one hydrogen atom is replaced by a fluorine atom, or all hydrogen atoms are replaced by fluorine atoms. The substitution position and number of fluorine atoms are arbitrary, and the fluorinated alkylene group can be a straight chain or have a branched chain.

[0020] In the present embodiment, the A group is a saturated hydrocarbon group or an unsaturated hydrocarbon group or an aryl group or a silicon group; the B group is a saturated hydrocarbon group or an unsaturated hydrocarbon group or an aryl group or a silicon group; the specific connection mode of the phosphorus-based monocyclic compound proposed in the present application endows the compound with unique chemical activity and physical properties; for example, in the present embodiment, the saturated hydrocarbon group can be methyl-CH3 or n-butyl-CH2CH2CH2CH3; the unsaturated hydrocarbon group can be vinyl-CH=CH2 or allyl-CH2CH=CH2 or acetylenyl-C≡CH; the aryl group can be phenyl-C6H5 or naphthyl-C 10 H7; the silicon group can be trimethylsilyl-Si (CH3)3 or phenyldimethylsilyl-Si (CH3)2C6H5, etc.

[0021] Preferably, in the present embodiment, the phosphorus-based monocyclic compound comprises any one of the following structures or a mixture of several thereof: , , , ,

[0022] Preferably, the present embodiment proposes a preparation method of the phosphorus-based monocyclic compound as described above, in which a phosphorus source as an initial raw material is reacted with a corresponding ligand in an organic solvent environment, and the reaction product is subjected to post-treatment to obtain the phosphorus-based monocyclic compound.

[0023] Preferably, in the present embodiment, the phosphorus source and the first ligand are dispersed in an organic solvent, and the temperature is raised to a first temperature for a preliminary reaction of at least 5 hours; after the preliminary reaction is completed, the second ligand is added for continued reaction to obtain a reaction product; and the reaction product is subjected to post-treatment to obtain the phosphorus-based monocyclic compound. Preferably, the phosphorus source comprises any one of the following or a mixture of several thereof: phosphoric acid H3PO4 and metal salts thereof, phosphorous acid H3PO3 and metal salts thereof, pyrophosphoric acid H4P2O7 and metal salts thereof, phosphorous oxychloride POCl2O2PCl, pyrophosphorous acid H4P2O5 and metal salts thereof, and phosphorous oxychloride POCl2OPCl.

[0024] In the present embodiment, the selection of the ligand is optimized according to the reaction mechanism and the structure of the target product to promote the reaction and guide the generation of the target cyclic structure; preferably, in the present embodiment, the first ligand comprises any one of the following: formaldehyde, paraformaldehyde, halogen-substituted or unsubstituted acetaldehyde, halogen-substituted or unsubstituted propyl aldehyde, and halogenated alkanes; and the second ligand is a silicon compound, which comprises any one of the following: an alkyl silicon compound, an alkenyl silicon compound, an alkynyl silicon compound, and an aryl silicon compound.

[0025] ​Preferably, in the present embodiment, the molar ratio of the ligand to the phosphorus source is 3-8 times, preferably 4-6 times; and / or the amount of the organic solvent added is 1.5-3 times, preferably 2-3 times, of the corresponding molar amount of the ligand.

[0026] Preferably, in order to further facilitate the reaction efficiency, in the present embodiment, a catalyst can also be added to the reaction system, wherein the catalyst can be an acidic catalyst, a basic catalyst, and a phase transfer catalyst; wherein the acidic catalyst preferably uses sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, aluminum trichloride, boron trifluoride, phosphorus pentoxide, etc.; the basic catalyst preferably uses triethylamine, pyridine, 1,8-diazabicycloundec-7-ene, lithium diisopropylamide, etc.; and the phase transfer catalyst preferably uses crown ether, quaternary ammonium salt, DMSO, etc.

[0027] Preferably, in the present embodiment, the reaction solvent includes any one or a mixture of several of ether organic solvents, carbonate organic solvents, carboxylate organic solvents, chlorinated hydrocarbons, alkanes, nitrile organic solvents; for example, in the present embodiment, the ether organic solvent can be diethyl ether C2H5OC2H5or tetrahydrofuran C4H8O; the carbonate organic solvent can be dimethyl carbonate CH3OCOOCH3; the carboxylate organic solvent can be ethyl acetate CH3COOCH2CH3; the chlorinated hydrocarbon can be chloroform CHCl3or dichloromethane CH2Cl2; the alkane can be n-hexane C6H 14 or n-heptane C7H 16 ; and the nitrile can be acetonitrile.

[0028] Preferably, in the present embodiment, the reaction temperature is controlled in the range of 30-150℃, preferably 50-120℃; and the reaction pressure is controlled in the range of 0.1-5 MPa, preferably 0.5-2 MPa, to facilitate the formation of the target cyclic phosphorus compound.

[0029] In the present embodiment, the post-treatment referred to in the present application mainly refers to the process of fine separation (which can use a known separation process) and / or purification (which can use a known purification process) of the reaction product (which is in a mixture state) after the reaction, for example, first, the solid or liquid product is preliminarily separated by filtration to remove unreacted raw materials, by-products, and other impurities. Then, further purification is performed by extraction, crystallization, etc. to obtain a high-purity target cyclic phosphorus compound, which all belong to the conventional technical means that can be made by the person skilled in the art based on the content described in the present application; finally, the purity and structure of the final product are accurately characterized by a known analysis method such as nuclear magnetic resonance (NMR), to ensure that the target product meeting the requirements is obtained.

[0030] Preferably, the present embodiment also proposes an application of the phosphorus-based cyclic compound as described above, adding the phosphorus-based cyclic compound into the electrolyte of the battery; or using the phosphorus-based cyclic compound as a flame retardant or a catalyst or participating in the design of a drug molecule.

[0031] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0032] Based on the above-described embodiments, the present application further proposes the following specific embodiments: First of all, it should be noted that the reagent raw materials used in the following specific embodiments and comparative examples of the present application are as follows: The raw materials are all ordinary commercially available products unless otherwise specified.

[0033] The test methods used in the specific embodiments and comparative examples of the present application are as follows: NMR analysis is characterized by nuclear magnetic resonance NMR, and the spectrometer used is Bruker (Bruker Corporation) AVANCE II 400 MHz; It should be understood that the following specific embodiments are only used to illustrate the present application and not to limit the scope of the present application.

[0034] Example 1: A certain amount of pyrophosphoric acid, polyformaldehyde (as a first ligand) is dispersed in toluene, and phosphorus pentoxide is slowly added to catalyze the reaction. After the addition is completed, the temperature is raised to 50°C and the reaction is continued for 5 hours. After the reaction is completed, water is added to separate the phases, and the organic phase extract is dried and directly used for the next step reaction; Slowly add trimethylchlorosilane (as a second ligand) to the above organic phase extract to continue the reaction for 5 hours to obtain a reaction liquid; The molar ratio of polyformaldehyde (calculated as formaldehyde) to pyrophosphoric acid is 1.2:1, and the molar ratio of trimethylchlorosilane to pyrophosphoric acid is 2:1; The reaction liquid is rotary evaporated to a viscous state, added with ether to fully beat, filtered, and the filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound with the following structural formula: ; The phosphorus-based monocyclic compound obtained by the above synthesis is characterized by NMR (1H, 13C): 1 H NMR: δ 0.05(18H, s), 5.49 (2H, s); 13C NMR: δ 0.2 (6C, s), 93.6 (1C, s).

[0035] Example 2: A certain amount of potassium pyrophosphate, dibromofluoromethane (as the first ligand) is dispersed in dimethyl sulfoxide, and the temperature is raised to 70°C for a preliminary reaction of 18 hours. After the preliminary reaction is completed, the temperature is lowered to 50°C, and trimethylchlorosilane (as the second ligand) is slowly added dropwise into the reaction system for a continued reaction of 4 hours; wherein the molar ratio of dibromofluoromethane to potassium pyrophosphate is 2:1, and the molar ratio of trimethylchlorosilane to potassium pyrophosphate is 2:1; After the reaction is completed, the generated potassium salt is removed by filtration to obtain a filtrate; the filtrate is rotary evaporated to a viscous state and added with n-hexane to fully beat the pulp, filtered, and the filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound of the following structural formula: ; The phosphorus-based monocyclic compound synthesized as above is subjected to NMR (1H, 13C) characterization: 1 H NMR: δ 0.05(18H, s), 6.8 (H, s); 13 C NMR: δ 0.2 (6C, s), 100.5 (1C, s).

[0036] Example 3: A certain amount of potassium pyrophosphate, 1,1,1-trifluoro-2,2-dibromoethane (as the first ligand) is dispersed in dimethyl sulfoxide, and the temperature is raised to 100°C for a preliminary reaction of 12 hours. After the preliminary reaction is completed, the temperature is lowered to 50°C, and trimethylchlorosilane (as the second ligand) is slowly added dropwise into the reaction system for a continued reaction of 5 hours; wherein the molar ratio of 1,1,1-trifluoro-2,2-dibromoethane to potassium pyrophosphate is 2:1, and the molar ratio of trimethylchlorosilane to potassium pyrophosphate is 2:1; After the reaction is completed, the generated potassium salt is removed by filtration to obtain a filtrate; the filtrate is rotary evaporated to a viscous state and added with n-hexane to fully beat the pulp, filtered, and the filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound of the following structural formula: ; The phosphorus-based monocyclic compound synthesized as above is subjected to NMR (1H, 13C) characterization: 1 H NMR: δ 0.05(18H, s), 7.3 (H, s); 13 C NMR: δ 0.2(6C, s), 108 (1C, s),128( 1C, s)。

[0037] Example 4: A certain amount of potassium pyrophosphate, dibromomethane (as the first ligand) is dispersed in dimethyl sulfoxide, and the temperature is raised to 100°C for a preliminary reaction of 7 hours. After the preliminary reaction is completed, the temperature is lowered to 70°C, and triphenylchlorosilane (as the second ligand) is slowly added to the reaction system for continued reaction for 7 hours; wherein the molar ratio of dibromomethane to potassium pyrophosphate is 2:1, and the molar ratio of trimethylchlorosilane to potassium pyrophosphate is 2:1; After the reaction is completed, the generated potassium salt is filtered out to obtain a filtrate; the filtrate is rotary evaporated to a viscous state and added with ether for full beating, filtered, and the filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound of the following structural formula: ; The phosphorus-based monocyclic compound synthesized as above is subjected to NMR (1H, 13C) characterization: 1 H NMR: δ 5.68 (2H,s), 7.22-7.41 (30H, 7.28 (tt, J = 7.7, 1.4 Hz), 7.33 (dddd, J = 7.3, 1.6,1.4, 0.5 Hz), 7.34 (dddd, J = 7.7, 7.3, 1.5, 0.5 Hz)); 13 C NMR: δ 93.6 (1C, s),127.7 (12C, s), 130.1 (6C, s), 135.2 (12C, s), 135.5 (6C, s).

[0038] Example 5: A certain amount of potassium pyrophosphate is dispersed in acetonitrile, and a solid phosgene solution (the solid phosgene is specifically bis(trichloromethyl) carbonate, abbreviated as BTC) is slowly added, and the temperature is raised to 50°C for a preliminary reaction of 9 hours. After the preliminary reaction is completed, trimethylchlorosilane is slowly added at this temperature for continued reaction for 5 hours; wherein the molar ratio of solid phosgene to potassium pyrophosphate is 2:1, and the molar ratio of trimethylchlorosilane to potassium pyrophosphate is 2:1; After the reaction is completed, the generated potassium salt is filtered out to obtain a filtrate; the filtrate is rotary evaporated to a viscous state and added with ether for full beating, filtered, and the filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound of the following structural formula: ; The phosphorus-based monocyclic compound synthesized as above is subjected to NMR (13C, 31P) characterization: 13 C NMR: δ 0.2 (6C,s), 149.1 (1C, s); 31 P NMR: δ 3.58.

[0039] Example 6: A certain amount of pyrophosphorous acid, paraformaldehyde (first ligand) is dispersed in toluene, and phosphorus pentoxide is slowly added to catalyze the reaction. After the addition is completed, the temperature is raised to 50°C and the reaction is continued for 5 hours. After the reaction is completed, water is added to separate the phases, and the organic phase is extracted. The organic phase is dried and directly used in the next step; The above organic phase is slowly added to the above organic phase. The reaction is continued for 5 hours. The molar ratio of paraformaldehyde (calculated as formaldehyde) to pyrophosphorous acid is 1.2:1, and the molar ratio of trimethylchlorosilane to pyrophosphorous acid is 2:1. The reaction liquid is rotary evaporated to a viscous state, added with ether, and fully beaten. The filter cake is vacuum dried to obtain a phosphorus-based monocyclic compound with the following structure: ; The phosphorus-based monocyclic compound synthesized as above is characterized by NMR (1H, 13C): 1H NMR: δ -0.01 (18H, s), 5.31-5.54 (2H, 5.37 (d, J = 7.1 Hz), 5.48 (d, J = 7.1 Hz)); 13C NMR: δ 0.2 (6C, s), 93.6 (1C, s).

[0040] Comparative Example 1: The compound 5 provided in the prior patent application CN117276668A is used in this comparative example 1. .

[0041] Comparative Example 2: The ethoxy pentafluorocyclotriphosphazene used in the prior patent application CN105098245A is used in this comparative example 2.

[0042] The product purity and yield of Examples 1-6 are shown in Table 1 below:

[0043] As shown in Table 1 above, the reaction conditions proposed in this application are mild, and the product purity and yield are high.

[0044] In order to further verify the application effect achieved by Examples 1-6, the products provided by Examples 1-6 and Comparative Examples 1 and 2 are subjected to the following application comparison experiments: The soft pack batteries corresponding to Examples 1-6 and Comparative Example 1 are prepared according to the following steps: The electrolyte is prepared in a glove box under N2 atmosphere, and the water content of the organic solvent system is <10 ppm. The electrolyte includes: An organic solvent system with a mass fraction of 85.5%, specifically composed of diethyl carbonate DEC, ethyl methyl carbonate EMC and dimethyl carbonate DMC with a mass ratio of 1:1:1 (wt%); The lithium salt system is selected to be 1.0 mol·L -1 of lithium hexafluorophosphate LiPF6; The products provided by Examples 1-6 and Comparative Examples 1-2, respectively, are used, and the mass fraction of the product in the electrolyte is 1.2%; The rest are other additives, specifically composed of ethylene carbonate VC, lithium difluoro(oxalato)borate LiODFB and propanesulfonic acid inner ester PS = 2:1:1 (wt%); After the raw materials of the organic solvent system are mixed uniformly at a fixed ratio, they are frozen and cooled for 1.5-2 hours to obtain an organic solvent mixture. The lithium salt system is added and mixed uniformly. Finally, the products provided by Examples 1-6 and Comparative Examples 1 and 2, and other additives are added and mixed uniformly before use.

[0045] Preparation of the battery positive electrode: methylpyrrolidone NMP is used as the solvent, and 2% polyvinylidene fluoride PVDF is uniformly dispersed to obtain a mixture. Then 2% carbon nanotubes CNT are uniformly mixed, followed by the addition of 96% positive electrode active material (lithium cobaltate LiCoO2) and uniform mixing. After that, a coating machine is used to uniformly coat it on an aluminum foil, and after drying, rolling, cutting, a positive electrode sheet is prepared, with a surface density range of 350-450 g / cm 2 (double-sided); Preparation of the battery negative electrode: deionized water is used as the solvent, and 1% carboxymethyl cellulose CMC is uniformly dispersed to obtain a mixture. Then 2% conductive carbon black SP and 96% negative electrode active material (specifically, gas phase deposition silicon-carbon, material model SH-S02) are uniformly mixed, and finally 1% butyl rubber SBR is added and uniformly mixed. After mixing, a coating machine is used to uniformly coat it on a copper foil, and after drying, rolling, cutting, a negative electrode sheet is prepared, with a surface density range of 200-350 g / cm 2 (double-sided); In order to further prove the implementation effect, the present application also adds the following Comparative Example 3: Comparative Example 3: The rest of the technical solutions of this comparative example 3 are the same as those of Example 1, and the only difference is that the product in Example 1 is replaced by the additive lithium difluoro(oxalato)borate LiODFB.

[0046] Therefore, the soft package batteries corresponding to the electrolyte using the products provided by Examples 1-6 and Comparative Examples 1-3, respectively, as specific additives are obtained, and the electrolyte usage of each soft package battery is 25 g; then the performance of each soft package battery is compared and tested as follows: Three groups of each soft package battery of Examples 1-6 and Comparative Examples 1-3 were prepared, and each group was cycled for 200 cycles at 25℃, 45℃ and 60℃ respectively, wherein the charge and discharge conditions for each cycle test were as follows: the charge and discharge rate was 1C / 1C, and the voltage range was 2.5V-4.4V; The measured capacity retention rate of the lithium ion battery is shown in Table 2 below:

[0047] It should be particularly pointed out that the phosphorus-based monocyclic compound provided in the embodiment can also be applied as a flame retardant or a catalyst or involved in drug molecule design; Taking the phosphorus-based monocyclic compound provided in Example 1 of the embodiment as an example, the present application carried out the following performance comparison tests of flame retardant: The limiting oxygen index (LOI) test and the UL-94 vertical combustion test were carried out respectively to compare the performance difference of the phosphorus-based monocyclic compound provided in Example 1 of the embodiment and the traditional flame retardant, as follows: Limiting oxygen index (LOI) test: according to ASTM D2863 standard, polyurethane samples (size 100x10x4mm) containing 5wt% flame retardant were placed in an oxygen index instrument, the oxygen-nitrogen mixed gas ratio was adjusted, and the lowest oxygen concentration required for continuous combustion of the sample was recorded. The test results are shown in Table 3 below;

[0048] UL-94 vertical combustion test: according to UL-94 standard, the combustion test was carried out on 3.2mm thick samples (containing 5wt% flame retardant), and the afterflame time and the ignition of drippings were recorded. The test results are shown in Table 4 below:

[0049] Taking the phosphorus-based monocyclic compound provided in Example 1 of the embodiment as an example, the present application also carried out the following performance comparison tests of catalytic activity: Catalytic activity performance: the alkylation reaction of benzene and ethylene was selected as a probe reaction to compare the catalytic performance of the compound of the embodiment and the traditional Lewis acid catalyst (such as AlCl3). The test conditions were as follows: reaction temperature 80℃, catalyst loading 0.5mol%, reaction time 4h. The test method was as follows: the reaction products were analyzed by gas chromatography (GC), and the conversion rate of benzene and the selectivity of ethylbenzene (the target product was ethylbenzene, and the multi-alkylation side reaction needed to be inhibited) were calculated. The test results are shown in Table 5 below:

[0050] To further exert the effect of the phosphorus-based monocyclic compound on the lithium ion battery as proposed in the above embodiments, the present embodiment further proposes a lithium ion battery electrolyte based on the phosphorus-based monocyclic compound, which comprises an organic solvent system, a lithium salt system and an additive system; the organic solvent system is composed of a first organic solvent and a second organic solvent; the first organic solvent comprises at least one carboxylic acid ester, and the second organic solvent comprises at least one cyclic carbonate and at least one chain carbonate; the additive system comprises the phosphorus-based monocyclic compound as proposed in the above of the present embodiment; preferably, in the present embodiment, the mass fraction of the phosphorus-based monocyclic compound in the electrolyte of the lithium ion battery is 0.05-4%; more preferably, 0.1-2%. Preferably, in the present embodiment, the mass fraction of the first organic solvent in the electrolyte of the lithium ion battery is 2-15%; and the mass fraction of the second organic solvent in the electrolyte of the lithium ion battery is 65.5-87.9%.

[0051] Preferably, in the present embodiment, the carboxylic acid ester comprises methyl acetate and / or ethyl acetate and / or ethyl propionate and / or propyl propionate; the cyclic carbonate comprises fluoroethylene carbonate FEC and / or ethylene carbonate EC and / or propylene carbonate PC; and the chain carbonate comprises bis(2,2,2-trifluoroethyl) carbonate FEMC and / or ethyl methyl carbonate EMC and / or dimethyl carbonate DMC and / or diethyl carbonate DEC.

[0052] Preferably, in the present embodiment, the lithium salt system comprises any one or mixture of several of lithium hexafluorophosphate LiPF6, lithium bisfluorosulfonylimide LiFSI, lithium bis(trifluoromethylsulfonyl)imide LiTFSI, lithium bis(oxalato)borate LiBOB, lithium perchlorate LiClO4, lithium trifluoromethanesulfonate LiOTf and lithium tetrafluoroborate LiBF4.

[0053] Preferably, in the present embodiment, the concentration of the lithium salt system in the electrolyte of the ternary lithium ion battery is 0.8-1 mol·L -1 .

[0054] Preferably, in the present embodiment, the mass fraction of the additive system in the electrolyte of the ternary lithium ion battery is 0.2-5%; and the additive system further comprises at least two of lithium difluoro(oxalato)borate LiODFB, ethylene carbonate VC, vinylene sulfate DTD, propanesulfonic acid lactone PS and lithium difluorophosphate LiPO2F2.

[0055] Preferably, in the present embodiment, a preparation method of the above-mentioned lithium ion battery electrolyte based on phosphorus-based monocyclic compounds is adopted, raw materials of an organic solvent system are mixed to obtain an organic solvent mixture, the organic solvent mixture is frozen for 1-3 hours, a lithium salt system is added to the organic solvent mixture for mixing, and finally an additive system is added for mixing to obtain the electrolyte of the lithium ion battery.

[0056] The present embodiment also provides a ternary lithium ion battery adopting the above-mentioned electrolyte of the lithium ion battery based on phosphorus-based monocyclic compounds; a positive active material of the ternary lithium ion battery includes a ternary nickel-cobalt-manganese material (LiNi x Co y Mn 1-x-y O2, NCM); preferably, in the present embodiment, a negative active material of the ternary lithium ion battery includes graphite or a commonly known carbon-silicon composite material.

[0057] In order to further verify the implementation effect of the electrolyte of the ternary lithium ion battery provided in the above embodiments of the present application, the present application further provides the following embodiments and comparative examples: Embodiment 7: An electrolyte of a ternary lithium ion battery, comprising: 85.5% of an organic solvent system by mass fraction, specifically composed of fluoroethylene carbonate FEC: ethylene carbonate EC: ethyl methyl carbonate EMC: propyl propionate PP = 2:2:2:4 (wt%); 1.0 mol·L -1 of lithium hexafluorophosphate LiPF6 is selected as a lithium salt system; 1.2% of the product provided in Embodiment 1 by mass fraction; the rest is other additives, specifically composed of ethylene carbonate VC: lithium difluoro(oxalato)borate LiODFB: propanesulfonic acid inner ester PS = 2:1:1 (wt%); The electrolyte is prepared in a glove box in a N2 atmosphere, ensuring that the water content of the solvent system is <10 ppm. When preparing, first, the raw materials of the organic solvent system are mixed uniformly according to a fixed ratio, and then frozen for 1.5-2 hours to obtain an organic solvent mixture; the lithium salt system is added for uniform mixing, and finally the product provided in Embodiment 1 and other additives are added for uniform mixing.

[0058] Embodiment 8: The remaining technical solutions of Embodiment 8 are the same as those of Embodiment 7, except that in Embodiment 8, the product provided in Embodiment 2 is used to replace the product provided in Embodiment 1.

[0059] Embodiment 9: The remaining technical solutions of Embodiment 9 are the same as those of Embodiment 7, except that in Embodiment 9, the product provided in Embodiment 3 is used to replace the product provided in Embodiment 1.

[0060] Example 10: The remaining technical solutions of this Example 10 are the same as those of Example 7, except that in this Example 10, the product provided in Example 4 is used instead of the product provided in Example 1.

[0061] Example 11: The remaining technical solutions of this Example 11 are the same as those of Example 7, except that in this Example 11, the product provided in Example 5 is used instead of the product provided in Example 1.

[0062] Example 12: The remaining technical solutions of this Example 12 are the same as those of Example 7, except that in this Example 12, the product provided in Example 6 is used instead of the product provided in Example 1.

[0063] Comparative Example 4: The remaining technical solutions of this Comparative Example 4 are the same as those of Example 7, except that in this Comparative Example 4, the product provided in Comparative Example 1 is used instead of the product provided in Example 1.

[0064] Comparative Example 5: The remaining technical solutions of this Comparative Example 5 are the same as those of Example 7, except that in this Comparative Example 5, the product provided in Comparative Example 2 is used instead of the product provided in Example 1.

[0065] Comparative Example 6: The remaining technical solutions of this Comparative Example 6 are the same as those of Example 7, except that in this Comparative Example 6, the electrolyte provided in Comparative Example 3 is used.

[0066] Comparative Example 7: The remaining technical solutions of this Comparative Example 7 are the same as those of Example 7, except that in this Comparative Example 7, the organic solvent system is specifically composed of dimethyl carbonate DMC: ethyl methyl carbonate EMC: diethyl carbonate DEC = 1:1:1 (wt%).

[0067] Comparative Example 8: The remaining technical solutions of this Comparative Example 8 are the same as those of Example 7, except that in this Comparative Example 8, the organic solvent system is specifically composed of fluoroethylene carbonate FEC: ethylene carbonate EC: ethyl methyl carbonate EMC = 1:1:1 (wt%).

[0068] Comparative Example 9: The remaining technical solutions of this Comparative Example 9 are the same as those of Example 7, except that in this Comparative Example 9, the organic solvent system is specifically composed of propyl propionate PP: ethylene carbonate EC = 1:1 (wt%).

[0069] Comparative Example 10: The remaining technical solutions of this Comparative Example 10 are the same as those of Example 7, except that in this Comparative Example 10, the organic solvent system is specifically composed of propyl propionate PP: fluoroethylene carbonate FEC = 1:1 (wt%).

[0070] Then, the soft package batteries corresponding to Examples 7-12 and Comparative Examples 4-10 are respectively prepared according to the following steps: Preparation of the battery positive electrode: Using methyl pyrrolidone (NMP) as a solvent, 2% by mass of polyvinylidene fluoride (PVDF) is evenly dispersed to obtain a mixed solution. Then, 2% by mass of carbon nanotubes (CNT) are added and mixed evenly. Then, 96% by mass of positive electrode active material (using the ternary system NCM622) is added and mixed evenly. The mixture is then evenly coated on aluminum foil using a coating machine. After drying, roller pressing and cutting, the positive electrode sheet is made. Its surface density range is 350-450 g / cm 2 (double-sided); Preparation of the battery negative electrode: Using deionized water as the solvent, evenly disperse 1% by mass of carboxymethyl cellulose (CMC) to obtain a mixed solution. Then, add 2% by mass of conductive carbon black SP and 96% by mass of negative electrode active material (specifically, graphite) and mix them evenly. Finally, add 1% by mass of styrene-butadiene rubber (SBR) and mix them evenly. After mixing evenly, use a coating machine to evenly coat the mixture on copper foil, dry it, roll it, and cut it into negative electrode sheets. The surface density range of the negative electrode sheets is 200-350g / cm. 2 (double-sided); Therefore, the following NCM622||graphite soft-pack batteries were obtained by assembling the electrolytes containing the products provided in Examples 7-12 and Comparative Examples 4-10 as specific additives, respectively. The amount of electrolyte used in each soft-pack battery was 25g. The following performance comparison tests were then performed on each soft-pack battery: Three groups of soft-pack batteries corresponding to Examples 7-12 and Comparative Examples 4-10 were prepared. Each group was cycled for 200 cycles at 25°C, 45°C, and 60°C. The charge and discharge conditions used in each cycle test were: a charge and discharge rate of 1C / 1C and a voltage range of 2.5V-4.4V. The measured lithium-ion battery capacity retention rate is shown in Table 6 below:

[0071] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0072] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A phosphorus monocyclic compound, characterized in that Contains the following structural formula: Two phosphorus atoms are bridged by an oxygen atom to form a cyclic basic structure, and the X group is located in the bridging position between the two phosphorus atoms; wherein the X group is a C1-C6 carbon chain group containing an alkylene group, a carbonyl group, a sulfinyl group, a sulfonyl group, or a fluoroalkylene group; the A group is a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, or a silicon group; and the B group is a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, or a silicon group.

2. The phosphorus monocyclic compound according to claim 1, characterized in that The phosphorus-based monocyclic compound includes the following structure: 、 、 、 、 Any one or a mixture of several.

3. A method for preparing the phosphorus monocyclic compound according to claim 1 or 2, characterized in that: The phosphorus source as the initial raw material reacts with its corresponding ligand in an organic solvent environment, and the reaction product is post-treated to obtain the phosphorus-based monocyclic compound.

4. The method for preparing a phosphorus-based monocyclic compound according to claim 3, wherein: The phosphorus source and the first ligand are dispersed in an organic solvent, and the temperature is raised to a first temperature for a preliminary reaction for at least 5 hours. After the preliminary reaction is completed, a second ligand is added to continue the reaction to obtain a reaction product; and the reaction product is post-treated to obtain the phosphorus-based monocyclic compound.

5. The method for preparing a phosphorus monocyclic compound according to claim 3, wherein: The phosphorus source includes any one of phosphoric acid (H3PO4) and its metal salts, phosphorous acid (H3PO3) and its metal salts, pyrophosphoric acid (H4P2O7) and its metal salts, pyrophosphoryl chloride (POCl2O2PCl), pyrophosphorous acid (H4P2O5) and its metal salts, and pyrophosphorous acid chloride (POCl2OPCl) or a mixture of several of them.

6. The method for preparing a phosphorus-based monocyclic compound according to claim 5, wherein: The first ligand includes any one of formaldehyde, paraformaldehyde, halogen-substituted or unsubstituted acetaldehyde, halogen-substituted or unsubstituted propionaldehyde, and halogenated alkanes; the second ligand is a silicon-based compound, including any one of alkyl silicon-based compounds, alkenyl silicon-based compounds, alkynyl silicon-based compounds, and aryl silicon-based compounds.

7. The method for preparing a phosphorus monocyclic compound according to claim 3, wherein: The molar ratio of the ligand to the phosphorus source is 3-8 times, preferably 4-6 times; and / or the amount of the organic solvent added is 1.5-3 times, preferably 2-3 times, the molar amount of the corresponding ligand.

8. The method for preparing a phosphorus monocyclic compound according to claim 3, wherein: The reaction solvent includes any one of ether organic solvents, carbonate organic solvents, carboxylate organic solvents, chlorinated hydrocarbons, alkanes, and nitrile organic solvents, or a mixture of several of them.

9. The method for preparing a phosphorus monocyclic compound according to claim 3, wherein: The reaction temperature is controlled in the range of 30-150° C., preferably 50-120° C.; the reaction pressure is controlled in the range of 0.1 MPa-5 MPa, preferably 0.5-2 MPa.

10. Use of the phosphorus-based cyclic compound according to any one of claims 1-2, characterized in that: The phosphorus-based cyclic compound is added to the electrolyte of a battery; or the phosphorus-based cyclic compound is used as a flame retardant or catalyst or is involved in the design of drug molecules.

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