Phosphoric acid compound-containing secondary battery additive and application thereof
By using phosphoric acid compound additives in non-aqueous secondary ion batteries, the problem of controlling water acid content is solved, battery performance and safety are improved, manufacturing costs are reduced, and the goal of green manufacturing is achieved.
Patent Information
- Application Number
- CN202510784021.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-09-16
AI Technical Summary
In the existing non-aqueous secondary ion battery manufacturing process, it is difficult to control the water acid content, which leads to battery performance degradation and safety hazards, and strict dehumidification equipment increases manufacturing costs.
Phosphoric acid compounds are used as additives and added to the positive electrode, negative electrode slurry or electrolyte of the battery, or coated on the separator. They inhibit side reactions by combining with water molecules and thus improve the battery cycle life.
It effectively inhibits the occurrence of side reactions in batteries, improves battery cycle life and performance, reduces manufacturing costs, and complies with the concept of green manufacturing.
Smart Images
Figure CN120646792A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of non-aqueous secondary ion batteries, and particularly relates to a secondary battery additive containing a phosphoric acid compound and application thereof. Background Art
[0002] With the rapid development of science and technology and the growing demand for clean energy, non-aqueous secondary ion batteries, as a highly efficient energy storage device, have shown great potential for application in numerous fields. However, in the manufacturing process of non-aqueous secondary ion batteries, a key issue has long plagued the industry: the control of aqueous acid content.
[0003] In traditional non-aqueous secondary ion battery manufacturing, strict control of environmental humidity is required for both electrolyte configuration and positive and negative electrode preparation. This is because the water-acid content within the battery directly impacts its performance and lifespan. High water-acid content can lead to a series of side reactions within the battery, such as electrolyte decomposition and electrode material corrosion. These side reactions not only reduce the battery's energy density and cycle stability but can also cause safety issues such as flatulence, short circuits, and even fire and explosion.
[0004] To reduce the acid content in batteries, the current common practice is to equip battery manufacturing plants with expensive dehumidification equipment to maintain extremely low humidity. While this approach can ensure battery quality to a certain extent, it significantly increases manufacturing costs. The purchase, operation, and maintenance of dehumidification equipment require significant capital investment, and the dehumidification process itself consumes significant energy, which contradicts the current concept of green manufacturing.
[0005] Therefore, developing a method to effectively control the water acid content in non-aqueous secondary ion batteries without relying on stringent environmental control conditions has become a pressing technical challenge in the field of non-aqueous secondary ion batteries and a key breakthrough in driving the industry towards low-cost, high-performance development. The additive of the present invention was developed based on this technological background, aiming to bring innovative solutions to the non-aqueous secondary ion battery manufacturing process, reduce environmental control costs, and enhance the overall performance and market competitiveness of the batteries. Summary of the Invention
[0006] In order to solve the technical problems existing in the prior art, the present invention provides a secondary battery additive containing a phosphoric acid compound, the structural formula of the additive is as follows:
[0007]
[0008] Furthermore, when the structural formula of the additive is chain-like, the value of n is an integer ranging from 1 to 8; the R3 structure is: -OR4; R1 is a working ion of the secondary battery, or other alkali metal or transition metal cation having additive function, or one of the following structures: R2 is a working ion of the secondary battery, or other alkali metal or transition metal cations having an additive function; R4 is a working ion of the secondary battery, or other alkali metal or transition metal cations having an additive function, or one of the following structures:
[0009] Furthermore, when the structural formula of the additive is cyclic, the value of n is an integer ranging from 3 to 10; R1 and R3 are connected; wherein R2 is a working ion of a secondary ion battery, or other alkali metal or transition metal cation having additive function.
[0010] The present invention also provides a method for using the above-mentioned phosphoric acid compound secondary battery additive, wherein the additive is directly added to the positive electrode slurry, negative electrode slurry or electrolyte; or directly coated on the separator, or directly added to the battery in other forms.
[0011] Furthermore, the amount of the additive added to the battery, calculated based on the capacity of the battery, is such that the content (g) of the additive is 0.1 to 10% of the battery capacity (Ah).
[0012] Furthermore, when the additive is added to the positive electrode or negative electrode slurry, it is necessary to add it to the slurry before coating and stir it thoroughly.
[0013] Furthermore, when the additive is added to the separator, the dispersant or excellent solvent of the additive needs to be evenly impregnated into the inside of the separator or coated on the surface of the separator and then fully dried.
[0014] The present invention also provides a non-aqueous secondary ion battery containing the above-mentioned phosphoric acid compound secondary battery additive.
[0015] Beneficial effects: The additive of the present invention contains phosphate groups, which can effectively combine with water molecules in the battery, inhibit the occurrence of side reactions in the battery, and improve the battery cycle life. DETAILED DESCRIPTION
[0016] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and comparative examples.
[0017] Comparative Example 1, Examples 1-6
[0018] Electrolyte Preparation: Mix 20 g of ethylene carbonate, 60 g of ethyl methyl carbonate, 1 g of lithium tetrafluoroborate, and 19 g of lithium hexafluorophosphate to prepare a base electrolyte. Add X g of the additives to the electrolyte and stir until uniform. The resulting electrolyte is ready for use.
[0019] Preparation of the positive electrode: Weigh 95g of the positive electrode active material LiNi5Co2Mn3O2, take 3g of conductive carbon black, 1.9g of polyvinylidene fluoride and 0.1g of dispersant, and then add Yg of the additives. The above four substances are evenly mixed to obtain a positive electrode mixture. Next, N-methylpyrrolidone is gradually added to the positive electrode mixture and fully dispersed to obtain a positive electrode mixture slurry. Subsequently, a suitable coating process is used to evenly apply the obtained positive electrode mixture slurry to aluminum foil, and the positive electrode is dried to remove volatile substances such as solvents. After drying is completed, the dried positive electrode collector is processed and formed using a stamping process to finally obtain the desired positive electrode sheet.
[0020] Preparation of the negative electrode: First, 96g of graphite powder, 1g of conductive agent Super P, 3g of binder (the mass ratio of sodium carboxymethyl cellulose CMC to styrene-butadiene rubber SBR is 1:1) and an appropriate amount of deionized water are added to a stirring device, and then Z g of the additives are added. By fully stirring, the components are evenly mixed to prepare a negative electrode slurry with excellent dispersibility. Subsequently, the prepared negative electrode slurry is evenly coated on the surface of the copper foil to form a uniform coating. After coating, the copper foil coated with the slurry is placed in a drying device for drying to remove moisture from the coating and ensure that the slurry is firmly attached to the copper foil. Finally, the dried negative electrode is processed using a stamping process to obtain a negative electrode sheet with a certain size and shape.
[0021] Battery Assembly: Assemble CR2032 button cells in air. Use the positive electrode sheet produced in the above steps as the positive electrode, the negative electrode sheet as the negative electrode, and the electrolyte prepared in the above steps as the battery electrolyte. Assemble the positive and negative electrodes, separator, and button cell housing. After assembly, let the battery rest for 24 hours to obtain a button cell.
[0022] Examples 1-6 and Comparative Example 1 all used the above process, wherein the types of additives and the values of X, Y, and Z are shown in the following table:
[0023]
[0024] Comparative Example 2, Examples 7-12
[0025] Electrolyte Preparation: Mix 40 g of ethylene carbonate, 40 g of dimethyl carbonate, and 20 g of sodium hexafluorophosphate to prepare a base electrolyte. Add X g of the additives to the electrolyte and stir until uniform to obtain an electrolyte for later use.
[0026] Preparation of the positive electrode: First, accurately weigh 95g of the positive electrode active material NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, 3g of conductive carbon black, 1.9g of polyvinylidene fluoride, 0.1g of dispersant, and Yg of additive were mixed to form a positive electrode mixture. Next, N-methylpyrrolidone was gradually added and thoroughly dispersed to form a positive electrode mixture slurry. The slurry was then evenly coated onto aluminum foil and dried to remove volatile substances such as the solvent. Finally, the desired positive electrode sheet was obtained by stamping.
[0027] To prepare the negative electrode, 96g of coconut shell hard carbon powder, 1g of conductive agent Super P, 3g of binder (CMC to SBR ratio of 1:1 by mass), and an appropriate amount of deionized water were added to a stirring apparatus. Zg of additive was then added and stirred thoroughly until uniformly dispersed to prepare the negative electrode slurry. The slurry was then evenly coated on the surface of copper foil and dried to remove moisture and ensure firm adhesion. Finally, the dried negative electrode was processed using a stamping process to obtain a negative electrode sheet of the desired size and shape.
[0028] Battery Assembly: Assemble CR2032 button cells in air. Use the positive electrode sheet produced in the above steps as the positive electrode, the negative electrode sheet as the negative electrode, and the electrolyte prepared in the above steps as the battery electrolyte. Assemble the positive and negative electrodes, separator, and button cell housing. After assembly, let the battery rest for 24 hours to obtain a button cell.
[0029] Examples 7-12 and Comparative Example 2 all used the above process, wherein the types of additives and the values of X, Y, and Z are shown in the following table:
[0030]
[0031] Comparative Example 3, Examples 13-18
[0032] Preparation of electrolyte: Mix 40 g of ethylene carbonate, 40 g of dimethyl carbonate, and 20 g of potassium perchlorate to prepare a base electrolyte. Add X g of the additives to the electrolyte and stir until uniform to obtain an electrolyte for later use.
[0033] Preparation of positive electrode: First, accurately weigh 95g of positive electrode active material K 0.65 Fe 0.5 Mn 0.5O2, 3g of conductive carbon black, 1.9g of polyvinylidene fluoride, 0.1g of dispersant, and Yg of additive were mixed to form a positive electrode mixture. Next, N-methylpyrrolidone was gradually added and thoroughly dispersed to form a positive electrode mixture slurry. The slurry was then evenly coated onto aluminum foil and dried to remove volatile substances such as the solvent. Finally, the desired positive electrode sheet was obtained by stamping.
[0034] To prepare the negative electrode, 96g of coconut shell hard carbon powder, 1g of conductive agent Super P, 3g of binder (CMC to SBR ratio of 1:1 by mass), and an appropriate amount of deionized water were added to a stirring apparatus. Zg of additive was then added and stirred thoroughly until uniformly dispersed to prepare the negative electrode slurry. The slurry was then evenly coated on the surface of copper foil and dried to remove moisture and ensure firm adhesion. Finally, the dried negative electrode was processed using a stamping process to obtain a negative electrode sheet of the desired size and shape.
[0035] Battery Assembly: Assemble CR2032 button cells in air. Use the positive electrode sheet produced in the above steps as the positive electrode, the negative electrode sheet as the negative electrode, and the electrolyte prepared in the above steps as the battery electrolyte. Assemble the positive and negative electrodes, separator, and button cell housing. After assembly, let the battery rest for 24 hours to obtain a button cell.
[0036] Examples 13-18 and Comparative Example 3 all used the above process, wherein the types of additives and the values of X, Y, and Z are shown in the following table:
[0037]
[0038]
[0039] Battery performance test:
[0040] The charge and discharge capacity and capacity retention were measured using a BlueDian battery tester. First, a 0.1C charge and discharge cycle was performed at room temperature. Subsequently, a 0.5C charge and 2C discharge cycle was performed 100 times at 55°C.
[0041] Capacity retention [%] = (discharge capacity at the 100th cycle / discharge capacity at the 1st cycle) × 100%
[0042] example Capacity retention rate Comparative Example 1 65％ Example 1 85％ Example 2 83％ Example 3 81％ Example 4 84％ Example 5 82％ Example 6 79％
[0043] example Capacity retention rate Comparative Example 2 68％ Example 7 81％ Example 8 80％ Example 9 82％ Example 10 86％ Example 11 80％ Example 12 88％
[0044]
[0045]
[0046] It can be seen from the data shown in the above table that, compared with the comparative example without adding the additive of the present invention, Examples 1-18 of the present invention all achieved significantly increased capacity retention rates.
[0047] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A secondary battery additive containing a phosphoric acid compound, characterized in that: The structural formula of the additive is as follows:
2. The phosphoric acid compound secondary battery additive according to claim 1, characterized in that: When the structural formula of the additive is chain-like, the value of n is an integer ranging from 1 to 8; the structure of R3 is: -OR4; R1 is a working ion of a secondary ion battery, or other alkali metal or transition metal cation having additive function, or one of the following structures: R2 is a working ion of a secondary ion battery, or may be other alkali metal or transition metal cations having an additive function; R4 is a working ion of a secondary ion battery, or may be other alkali metal or transition metal cations having an additive function, or may be one of the following structures:
3. The phosphoric acid compound secondary battery additive according to claim 1, characterized in that: When the structural formula of the additive is cyclic, the value of n is an integer ranging from 3 to 10; R1 and R3 are connected; wherein R2 is a working ion of a secondary ion battery, or other alkali metal or transition metal cation having additive function.
4. The method for using a phosphoric acid compound secondary battery additive according to any one of claims 1 to 3, wherein: The additive is directly added to the positive electrode slurry, the negative electrode slurry or the electrolyte; or directly coated on the separator, or directly added to the battery in other forms.
5. The method for using the phosphoric acid compound secondary battery additive according to claim 4, wherein: The amount of the additive added to the battery is calculated based on the capacity of the battery, and the content (g) of the additive is 0.1 to 10% of the battery capacity (Ah).
6. The method for using the phosphoric acid compound secondary battery additive according to claim 5, wherein: When the additive is added to the positive electrode or negative electrode slurry, it is necessary to add it to the slurry before coating and stir it thoroughly.
7. The method for using the phosphoric acid compound secondary battery additive according to claim 6, wherein: When the additive is added to the separator, the dispersant or excellent solvent of the additive needs to be evenly impregnated into the inside of the separator or coated on the surface of the separator, and then fully dried.
8. A non-aqueous secondary ion battery, characterized in that: A secondary battery additive containing a phosphoric acid compound according to any one of claims 1 to 3.