Application of phosphorus-based electrolyte additive, electrolyte and lithium battery

Abstract

The application belongs to the technical field of lithium battery electrolyte, and particularly relates to application of a phosphorus-based electrolyte additive, electrolyte and lithium ion battery. A non-aqueous electrolyte comprises an organic solvent, a lithium salt, other additives and at least one phosphorus-based lithium battery electrolyte additive as claimed in claims 1-3. The phosphorus-based electrolyte additive is applied to high-voltage lithium battery electrolyte, can effectively inhibit phase transition of positive electrode material to spinel and rock salt phase, form a thin, dense and protective solid-state electrolyte interface on the positive electrode surface, inhibit oxygen release from the positive electrode surface, avoid electrolyte decomposition, significantly improve battery rate performance, and improve battery cycle stability and coulomb efficiency.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery electrolyte technology, specifically relating to the application of a phosphorus-based electrolyte additive and the electrolyte and lithium battery. Background Technology

[0002] Lithium-ion batteries, as a type of rechargeable battery system with high energy density, long cycle life, and lightweight characteristics, have been widely used in mobile communication devices, portable computers, and electric vehicles. Their working principle is based on the reversible extraction / insertion mechanism of lithium ions between the positive and negative electrode active materials: during discharge, lithium ions are extracted from the negative electrode and migrate to the positive electrode via the electrolyte; during charging, the reverse migration occurs, thereby realizing the release and storage of electrochemical energy.

[0003] With the rapid development of the electric vehicle, drone, and mobile smart terminal industries, the market demand for high-energy-density lithium batteries is becoming increasingly urgent. Currently, the conventional technical approach involves modifying the surface of the cathode material with an oxide coating or preparing cathode materials of different shapes and structures. However, this process is complex, costly, and offers poor protection. Increasing the operating voltage of the cathode material to obtain higher capacity is another key technical approach to achieving high energy density, suitable for rapidly increasing the energy density of existing systems in the short to medium term (such as LCO batteries for consumer electronics). However, due to limitations in electrolyte stability, cycle life and safety performance become the biggest constraints, requiring the use of electrolyte additives. However, existing technologies have significant drawbacks in applications with high voltage systems of 4.53 V and above. Domestic and international patents have repeatedly reported poor compatibility between phosphorus-based electrolytes and high-voltage cathode materials. On the one hand, under high voltage, the cathode material undergoes deep delithiation, and changes in lattice volume lead to stress accumulation within the particles, generating microcracks and causing structural collapse, allowing the electrolyte to penetrate into the active material. On the other hand, highly oxidized transition metal ions catalyze electrolyte decomposition, while lattice oxygen evolution (O2 release) further exacerbates electrolyte oxidation, causing a surge in interfacial impedance. Furthermore, dissolved transition metal ions migrate to the negative electrode surface, leading to continuous damage and reconstruction of the solid electrolyte interphase (SEI) film, resulting in irreversible loss of active lithium. Ultimately, this leads to severe battery capacity decay, high-temperature performance degradation, and a significantly shortened cycle life.

[0004] Therefore, there is an urgent need to develop an additive suitable for high-voltage lithium battery electrolytes. Summary of the Invention

[0005] One of the technical objectives of this invention is to solve the technical problem that by adding phosphorus-based lithium battery electrolyte additives, the phase transition of the cathode material to spinel and rock salt phases can be effectively suppressed, a thin, dense, and protective solid electrolyte interface can be formed on the cathode surface, the release of oxygen from the cathode surface can be suppressed, the decomposition of the electrolyte can be avoided, and the cycle stability and coulombic efficiency of the battery can be improved.

[0006] The second technical objective of this invention is to provide a non-aqueous electrolyte that corresponds to one of the technical problems.

[0007] The third technical objective of this invention is to provide a lithium-ion battery corresponding to the second technical objective.

[0008] To achieve one of the above-mentioned technical objectives, the technical solution of the present invention is as follows: A phosphorus-based electrolyte additive is provided, the general structural formula of which is: (General Formula I) (General Formula II) (General Formula III) (General Formula IV) Wherein, R1 is 2-cyanoethyl or 3,3,3-trifluoropropyl; R2 and R3 are independently selected from any one of methyl, 2,2,2-trifluoroethyl, 2-propynyl, 2-cyanoethyl, trimethylsilyl, or vinyldimethylsilyl; R4 and R5 are independently selected from hydrogen atoms, substituted or unsubstituted C1-C atoms. 20 Alkyl, C2-C 20 alkenyl, C2-C 20 Alkyne group, substituted or unsubstituted C6-C 20 Aryl, C5-C 20 Heteroaryl groups (containing 1-4 N, O, S heteroatoms), substituted or unsubstituted C3-C 20 cycloalkyl, C3-C 20 Heterocyclic alkyl groups (containing 1-4 N, O, S heteroatoms), alkoxy-OR6, amino-NR7R8, acyl-C(=O)R9, ester-C(=O)OR 10 And other sensual groups, including R6-R 10 Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.; X, Y, and Z are independently selected from carbon atoms, oxygen atoms, sulfone-S(=O)2- or carbonyl-C(=O)-; m and n take values ​​of 0 or 1; When at least one of X, Y, and Z is a carbon atom, the carbon atom in the ring structure shown in general formulas III and IV can be further replaced by independent substituents, wherein the substituents are independently selected from hydrogen atoms, halogen atoms (F, Cl, Br, I), hydroxyl group -OH, cyano group -CN, nitro group -NO2, substituted or unsubstituted C1-C atoms. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Haloalkyl, amino-NR7R8, amide-C(=O)NR7R8, sulfonyl-S(=O)2R 11 etc., including R7, R8, R 11Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.; When there are at least two adjacent carbon atoms in X, Y, and Z, they can form a double bond, constituting an unsaturated ring structure.

[0009] As a further optimization of this technical solution, the phosphorus-based lithium battery electrolyte additives of structural formula III and structural formula IV are selected from at least one of the following structural formulas: (General Formula III-1) (General Formula III-2) (General Formula III-3) (General Formula III-4) (General Formula III-5) (General Formula IV-1) (General Formula IV-2) (General Formula IV-3) (General Formula IV-4), wherein R1 is 2-cyanoethyl or 3,3,3-trifluoropropyl; R 12 -R 15 Independently selected from hydrogen atoms, halogen atoms (F, Cl, Br, I), hydroxyl group -OH, cyano group -CN, nitro group -NO2, substituted or unsubstituted C1-C atoms. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Haloalkyl, amino-NR7R8, amide-C(=O)NR7R8, sulfonyl-S(=O)2R 11 etc., including R7, R8, R 11 Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.

[0010] As a further optimization of this technical solution, the phosphorus-based lithium battery electrolyte additives of general structural formulas I, II, III and IV are at least one of the following structural formulas:

[0011] .

[0012] To achieve the second of the above-mentioned technical objectives, the technical solution of the present invention is as follows: to provide a non-aqueous electrolyte comprising an organic solvent, a lithium salt, other additives, and one or more combinations of at least one phosphorus-based lithium battery electrolyte additive as described in claims 1 to 3.

[0013] As a further optimization of this technical solution, the other additives are selected from at least one of unsaturated carbonates, sulfates, sulfites, sulfonates, phosphates, phosphites, borates, anhydrides, polynitriles, phosphononitriles, or silanes; specifically, the other additives are selected from at least one of vinylene carbonate (VC), vinyl sulfate (DTD), vinyl disulfide (BESA), vinyl sulfite (ES), methanedisulfonate (MMDS), 1,3-propanesulfonate lactone (PS), 1,3-propenesulfonate lactone (PST), tris(trimethylsilyl)phosphate (TMSP), tris(trimethylsilyl)phosphite (TMSPi), tris(trimethylsilyl)borate (TMSB), succinic anhydride (SA), succinic anhydride (SN), adiponitrile (ADN), ethoxypentafluorocyclotriphosphonium (PFPN), tetravinylsilane (TVSi), or dimethyldivinylsilane (DMDV).

[0014] As a further optimization of this technical solution, lithium salts include lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6), lithium nitrate (LiNO3), lithium difluorooxalate borate (LiDFOB), lithium bis(oxalate borate) (LiBOB), lithium bis(oxalate difluorophosphate) (LiDFOP), lithium tetrafluorooxalate phosphate (LITFOP), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium perchlorate (LiClO). 4） At least one of the following inorganic and organic anionic lithium salts: lithium bis(trifluoromethanesulfonylimide) (LiTFSI), lithium 4,5-dicyano-2-trifluoromethyl-imidazolium (LiTDI), lithium trifluoromethanesulfonate (LiOTf), lithium nitrite (LiNO2), and lithium difluorophosphate (LiPO2F2).

[0015] As a further optimization of this technical solution, the organic solvent includes at least one of the following: dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), trifluoropropylene carbonate (TFPC), methyl acetate (MA), ethyl acetate (EA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), monofluoroethyl acetate (MFEA), difluoroethyl acetate (DFEA), trifluoroethyl acetate (TFEA), ethyl difluoroacetate (EDFA), ethyl trifluoroacetate (ETFA), butyl trifluoroacetate (BTFA), ethyl monofluoroacetate (EMFA), γ-butyrolactone (GBL), γ-valerolactone (GVL), etc., including chain carbonates or cyclic carbonates, fluorinated chain carbonates or fluorinated cyclic carbonates, chain carboxylic acid esters or cyclic carboxylic acid esters, fluorinated chain carboxylic acid esters or fluorinated cyclic carboxylic acid esters.

[0016] As a further optimization of this technical solution, the non-aqueous electrolyte contains phosphorus-based lithium battery electrolyte additives accounting for 0.5% to 20% of the total mass of the electrolyte; other additives accounting for 0.1% to 5% of the total mass of the non-aqueous electrolyte; lithium salt electrolyte accounting for 10% to 25% of the total mass of the non-aqueous electrolyte; and solvent accounting for 70% to 85% of the total mass of the non-aqueous electrolyte.

[0017] To achieve the third technical objective mentioned above, the technical solution of the present invention is as follows: a lithium-ion battery is provided, comprising a positive electrode material, a separator and a negative electrode material, and further comprising a non-aqueous electrolyte containing phosphorus-based lithium battery electrolyte additives as described in any one of claims 4 to 8.

[0018] As a further optimization of this technical solution, an active material for the positive electrode of a lithium-ion battery is LiNi. x Co y M （1-x-y） O2, lithium iron phosphate, lithium manganese iron phosphate, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel manganese oxide, and lithium nickel manganese oxide, wherein M is Mn or Al, 1≥x≥0.6, 0≤y≤0.4, and 1-xy≥0; the negative electrode active material is selected from at least one of carbon-based materials, silicon-based materials, and lithium metal materials.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1) This invention provides a series of phosphorus-based compounds that are compatible with high-energy-density cathode materials. These compounds are used as additives for high-voltage lithium battery electrolytes. They can effectively suppress the phase transition of cathode materials to spinel and rock salt phases, form a thin, dense, and protective solid electrolyte interface on the cathode surface, suppress the release of oxygen from the cathode surface, avoid electrolyte decomposition, significantly improve battery rate performance, and improve battery cycle stability and coulombic efficiency. 2) This invention combines organic solvents, lithium salts and phosphorus-based additives in the electrolyte of high-voltage lithium batteries in a specific way and further optimizes the ratio and concentration, so that the electrolyte of this invention can have excellent compatibility with the positive and negative electrodes, while significantly improving the cycle performance and coulombic efficiency of lithium batteries. 3) The high-voltage electrolyte of the present invention for lithium batteries is an electrolyte system with good film-forming performance, good rate performance, wide electrochemical window, and improved electrolyte safety, and has broad application prospects in lithium batteries. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 The electrolyte prepared in Example 1 is shown as a 25°C cycle life curve in a 1Ah LiCoO2 / AG soft-pack battery. Figure 2 The electrolyte prepared in Example 2 is shown in a 25°C rate cycling diagram in a 1.5Ah LiFePO4 / AG pouch cell. Figure 3 The electrolyte prepared in Example 3 was used in a LiNi electrolyte with a capacity of 1 Ah. 0.8 Co 0.1 Mn 0.1 Cycle life curve at 25℃ for O2 / AG soft-pack batteries; Figure 4 The figure shows the cycle life curve of the electrolyte prepared in Example 4 at 25°C in a 1Ah LiCoO2 / AG soft-pack battery. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Unless otherwise specified, all materials or reagents used in this invention are derived from commercial products.

[0025] Example 1 A high-voltage electrolyte for lithium batteries, containing phosphorus-based additives, is prepared as follows: First, prepare a solution of LiPF6, EC, DEC, PP, FEC and HTCN in a mass ratio of 15:25:10:40:6:2. Then, slowly add bis(vinyldimethylsilyl)(2-cyanoethyl)phosphonate (Formula 1) so that bis(vinyldimethylsilyl)(2-cyanoethyl)phosphonate accounts for 1% of the total mass of the electrolyte. Mix evenly until completely dissolved to obtain a phosphorus-based electrolyte for lithium batteries. Figure 1The figure shows the cycle life curve of the electrolyte prepared in Example 1 at 25°C in a 1Ah LiCoO2 / AG pouch cell. As can be seen from the figure, after 300 cycles at a charging cutoff voltage of 4.55V, the capacity retention of the electrolyte is approximately 94%, and the average coulombic efficiency is close to 100%.

[0026] Example 2 A high-voltage electrolyte for lithium batteries, containing phosphorus-based additives, is prepared as follows: A certain amount of LiPF6 is slowly dissolved in EC, DMC and EMC in a volume ratio of 1:1:1 to make the concentration of LiPF6 1 mol / L. Then, 5% by mass of fluoroethylene carbonate is added and mixed until completely dissolved. Then, bis(vinyldimethylsilyl)(2-cyanoethyl)phosphonate (Formula 1) is slowly added to make it account for 1% of the total mass of the electrolyte, thus obtaining the phosphorus-based electrolyte for lithium batteries. Figure 2 The figure shows the rate cycling curve of the electrolyte prepared in Example 2 at 25°C in a 1.5Ah LiFePO4 / AG pouch cell. The cycle rates are 0.1C for cycles 1-2, 0.5C for cycles 3-7, 1C for cycles 8-12, 2C for cycles 13-17, 3C for cycles 18-22, and 0.5C for cycles 23-27.

[0027] Example 3 A high-voltage electrolyte for lithium batteries, containing phosphorus-based additives, is prepared as follows: A certain amount of LiPF6 is slowly dissolved in EC, DEC and EMC in a volume ratio of 1:1:1 to make the concentration of LiPF6 1 mol / L. Then, 5%, 3% and 2% by mass of fluoroethylene carbonate, vinylene carbonate and LiPO2F2 are added and mixed until completely dissolved. Then, bis(2,2,2-trifluoroethyl)(2-cyanoethyl)phosphonate (Formula 14) is slowly added to make it account for 1% of the total mass of the electrolyte, thus obtaining the phosphorus-based electrolyte for lithium batteries. Figure 3 The electrolyte prepared for the example was used in a LiNi electrolyte with a capacity of 1 Ah. 0.8 Co 0.1 Mn 0.1 Cycle life curve at 25℃ for O2 / AG pouch cells. The graph shows that after 2000 cycles at a 4.5V charge cutoff voltage, the capacity retention of the electrolyte is approximately 80%, and the average coulombic efficiency is close to 100%.

[0028] Example 4 A high-voltage electrolyte for lithium batteries, containing phosphorus-based additives, is prepared as follows: First, prepare a solution of LiPF6, EC, DEC, PP, FEC and HTCN in a mass ratio of 15:25:10:40:6:2. Then, slowly add methyl bis(2-cyanoethyl)phosphonate (Formula 11) to make it account for 1% of the total mass of the electrolyte. Mix well until completely dissolved to obtain the phosphorus-based electrolyte for lithium batteries. Figure 4 The figure shows the cycle life curve of the electrolyte prepared for this example in a 1Ah LiCoO2 / AG pouch cell at 25°C. As can be seen from the figure, after 900 cycles at a charging cutoff voltage of 4.55V, the capacity retention of the electrolyte is approximately 86%, and the average coulombic efficiency is close to 100%.

[0029] In summary, this invention combines organic solvents, lithium salts, and phosphorus-based additives in the electrolyte of high-voltage lithium batteries in a specific way and further optimizes the ratio and concentration, so that the electrolyte of this invention can have excellent compatibility with the positive and negative electrodes, while significantly improving the cycle performance and coulombic efficiency of lithium batteries.

[0030] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. The above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phosphorus-based lithium battery electrolyte additive, characterized in that, The general structural formula of the phosphorus-based lithium battery electrolyte additive is: (General Formula I) (General Formula II) (General Formula III) (General Formula IV) Wherein, R1 is 2-cyanoethyl or 3,3,3-trifluoropropyl; R2 and R3 are independently selected from any one of methyl, 2,2,2-trifluoroethyl, 2-propynyl, 2-cyanoethyl, trimethylsilyl, or vinyldimethylsilyl; R4 and R5 are independently selected from hydrogen atoms, substituted or unsubstituted C1-C atoms. 20 Alkyl, C2-C 20 alkenyl, C2-C 20 Alkyne group, substituted or unsubstituted C6-C 20 Aryl, C5-C 20 Heteroaryl groups (containing 1-4 N, O, S heteroatoms), substituted or unsubstituted C3-C 20 cycloalkyl, C3-C 20 Heterocyclic alkyl groups (containing 1-4 N, O, S heteroatoms), alkoxy-OR6, amino-NR7R8, acyl-C(=O)R9, ester-C(=O)OR 10 And other sensual groups, including R6-R 10 Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.; X, Y, and Z are independently selected from carbon atoms, oxygen atoms, sulfone-S(=O)2- or carbonyl-C(=O)-; m and n take values ​​of 0 or 1; When at least one of X, Y, and Z is a carbon atom, the carbon atom in the ring structure shown in general formulas III and IV can be further replaced by independent substituents, wherein the substituents are independently selected from hydrogen atoms, halogen atoms (F, Cl, Br, I), hydroxyl group -OH, cyano group -CN, nitro group -NO2, substituted or unsubstituted C1-C atoms. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Haloalkyl, amino-NR7R8, amide-C(=O)NR7R8, sulfonyl-S(=O)2R 11 etc., including R7, R8, R 11 Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.; When there are at least two adjacent carbon atoms in X, Y, and Z, they can form a double bond, constituting an unsaturated ring structure.

2. The phosphorus-based lithium battery electrolyte additive according to claim 1, characterized in that, The phosphorus-based lithium battery electrolyte additives of general structural formulas III and IV are selected from at least one of the following general structural formulas: (General Formula III-1) (General Formula III-2) (General Formula III-3) (General Formula III-4) (General Formula III-5) (General Formula IV-1) (General Formula IV-2) (General Formula IV-3) (General Formula IV-4), wherein R1 is 2-cyanoethyl or 3,3,3-trifluoropropyl; R 12 -R 15 Independently selected from hydrogen atoms, halogen atoms (F, Cl, Br, I), hydroxyl group -OH, cyano group -CN, nitro group -NO2, substituted or unsubstituted C1-C atoms. 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Haloalkyl, amino-NR7R8, amide-C(=O)NR7R8, sulfonyl-S(=O)2R 11 etc., including R7, R8, R 11 Independently selected from hydrogen, C1-C 10 Alkyl, aryl, etc.

3. The phosphorus-based lithium battery electrolyte additive according to claim 1, characterized in that, The phosphorus-based lithium battery electrolyte additives of general structural formulas I, II, III, and IV are at least one of the following structural formulas: ； 。 4. A non-aqueous electrolyte, characterized in that, It comprises one or more combinations of organic solvents, lithium salts, other additives, and at least one phosphorus-based lithium battery electrolyte additive as described in claims 1 to 3.

5. The non-aqueous electrolyte according to claim 4, characterized in that, The other additives are selected from at least one of unsaturated carbonates, sulfates, sulfites, sulfonates, phosphates, phosphites, borates, anhydrides, polynitriles, phosphononitriles, or silanes; specifically, the other additives are selected from at least one of vinylene carbonate (VC), vinyl sulfate (DTD), vinyl disulfide (BESA), vinyl sulfite (ES), methylene disulfonate (MMDS), 1,3-propanesulfonyl lactone (PS), 1,3-propenesulfonyl lactone (PST), tris(trimethylsilyl) phosphate (TMSP), tris(trimethylsilyl) phosphite (TMSPi), tris(trimethylsilyl) borate (TMSB), succinic anhydride (SA), succinic anhydride (SN), adiponitrile (ADN), ethoxypentafluorocyclotriphosphazene (PFPN), tetravinylsilane (TVSi), or dimethyldivinylsilane (DMDV).

6. The non-aqueous electrolyte according to claim 4, characterized in that, The lithium salts include at least one of the following inorganic and organic anionic lithium salts: lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6), lithium nitrate (LiNO3), lithium difluorooxalate borate (LiDFOB), lithium bis(oxalate borate) (LiBOB), lithium bis(oxalate difluorophosphate) (LiDFOP), lithium tetrafluorooxalate phosphate (LiTFOP), lithium bis(fluorosulfonyl)imide (LiFSI), lithium perchlorate (LiClO4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium 4,5-dicyano-2-trifluoromethyl-imidazolium (LiTDI), lithium trifluoromethanesulfonate (LiOTf), lithium nitrite (LiNO2), and lithium difluorophosphate (LiPO2F2).

7. The non-aqueous electrolyte according to claim 4, characterized in that, The organic solvent includes at least one of the following: dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), trifluoropropylene carbonate (TFPC), methyl acetate (MA), ethyl acetate (EA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), monofluoroethyl acetate (MFEA), difluoroethyl acetate (DFEA), trifluoroethyl acetate (TFEA), ethyl difluoroacetate (EDFA), ethyl trifluoroacetate (ETFA), butyl trifluoroacetate (BTFA), ethyl monofluoroacetate (EMFA), γ-butyrolactone (GBL), γ-valerolactone (GVL), etc., including chain carbonates or cyclic carbonates, fluorinated chain carbonates or fluorinated cyclic carbonates, chain carboxylic acid esters or cyclic carboxylic acid esters, fluorinated chain carboxylic acid esters or fluorinated cyclic carboxylic acid esters.

8. The non-aqueous electrolyte according to claim 4, characterized in that, The non-aqueous electrolyte contains phosphorus-based lithium battery electrolyte additives at a mass of 0.5% to 20% of the total mass of the non-aqueous electrolyte; other additives at a mass of 0.1% to 5% of the total mass of the non-aqueous electrolyte; lithium salt electrolyte at a mass of 10% to 25% of the total mass of the non-aqueous electrolyte; and solvent at a mass of 70% to 85% of the total mass of the non-aqueous electrolyte.

9. A lithium-ion battery comprising a positive electrode material, a separator, and a negative electrode material, characterized in that, It also includes the non-aqueous electrolyte of the phosphorus-based lithium battery electrolyte additive as described in any one of claims 4 to 8.

10. A lithium-ion battery according to claim 9, characterized in that, The active material of the positive electrode is LiNi. x Co y M （1-x-y） O2, lithium iron phosphate, lithium manganese iron phosphate, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel manganese oxide, and lithium nickel manganese oxide, wherein M is Mn or Al, 1≥x≥0.6, 0≤y≤0.4, and 1-xy≥0; the negative electrode active material is selected from at least one of carbon-based materials, silicon-based materials, and lithium metal materials.

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