Lithium battery charging and discharging acceleration method based on lithium battery electrolyte proportion adjustment

Abstract

The invention discloses a lithium battery charging and discharging acceleration method based on lithium battery electrolyte proportion adjustment, and relates to the technical field of battery charging and discharging, and the method comprises the following steps: establishing an influence model of the proportion of solvent types on the lithium ion diffusion rate, establishing an influence model of the proportion of the solvent types on the electrolyte-electrode interface film, and calculating the lithium ion diffusion rate according to the influence model; establishing an influence model of the lithium ion diffusion rate on the charging and discharging speed; calculating to obtain a first speed increasing coefficient for adjusting the component proportion of the solvent type with high dielectric constant and the solvent type with low viscosity; calculating to obtain a second speed increasing coefficient for adjusting the component proportion of the solvent type with high dielectric constant and the solvent type with low viscosity; and calculating to obtain a charge-discharge estimated value of the solvent type ratio adjustment scheme. By establishing various models and calculating to obtain the charge and discharge estimated value of the solvent type ratio adjustment scheme, the charge and discharge predicted speed is further obtained, the required scheme can be screened out according to the charge and discharge predicted speed, and targeted regulation and control are carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging and discharging, and specifically relates to a method for accelerating the charging and discharging of a lithium battery based on adjusting the electrolyte ratio of the lithium battery. Background Art

[0002] The electrolyte of a lithium battery, as an indispensable component thereof, plays a key role in conducting lithium ions inside the battery and has a profound impact on the overall performance and lifespan of the battery. The electrolyte is usually prepared from organic solvents, electrolytes, and various additives. The ratio of the organic solvents has a great influence on the charging and discharging speed of the lithium battery. The electrolyte usually adopts a mixture of a solvent with a high dielectric constant and a solvent with a low viscosity. The solvent with a high dielectric constant helps to increase the diffusion rate of lithium ions, thereby increasing the charging and discharging speed, while the solvent with a low viscosity can react to form an electrolyte-electrode interface film, and the electrolyte-electrode interface film can prevent the occurrence of reactions unrelated to charging and discharging, thereby reducing the influence on the charging and discharging speed.

[0003] However, the prior art has insufficient estimation of the specific influence of the ratio of the solvent with a high dielectric constant and the solvent with a low viscosity on the charging and discharging speed, resulting in difficulty in determining a more accurate regulation scheme when accelerating the charging and discharging. Summary of the Invention

[0004] To solve the above technical problems, a method for accelerating the charging and discharging of a lithium battery based on adjusting the electrolyte ratio of the lithium battery is provided, and the present technical solution solves the problems raised in the above background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for accelerating the charging and discharging of a lithium battery based on adjusting the electrolyte ratio of the lithium battery, comprising:

[0007] Obtaining the actual charging and discharging speed of the electrolyte, obtaining the actual component composition of the electrolyte, the actual component composition being the type of electrolyte and the first component ratio, the type of solvent with a high dielectric constant and the second component ratio, the type of solvent with a low viscosity and the third component ratio respectively, and the types of solvents used in the electrolyte being a mixture of EC, PC, DEC, DMC, EMC or EP;

[0008] Obtaining the target charging and discharging speed after the charging and discharging of the electrolyte is improved, and when adjusting the ratio, only adjusting the component ratios of the types of solvents with a high dielectric constant and the types of solvents with a low viscosity;

[0009] Establishing an influence model of the ratio of the types of solvents on the diffusion rate of lithium ions, establishing an influence model of the ratio of the types of solvents on the formation of the electrolyte-electrode interface film, and establishing an influence model of the diffusion rate of lithium ions on the charging and discharging speed, wherein the electrolyte-electrode interface film is used to maintain the stability of the lithium battery;

[0010] Based on the influence model of the proportion of solvent types on the lithium-ion diffusion rate, the first speed increase coefficient for adjusting the composition proportions of the solvent types with high dielectric constant and low viscosity is calculated;

[0011] Based on the influence model of the proportion of solvent types on the formation of the electrolyte-electrode interface film, the second speed increase coefficient for adjusting the composition proportions of the solvent types with high dielectric constant and low viscosity is calculated;

[0012] Form at least one solvent type proportion adjustment plan;

[0013] Based on the influence model of the lithium-ion diffusion rate on the charge and discharge speed, the first speed increase coefficient and the second speed increase coefficient, the charge and discharge prediction value of the solvent type proportion adjustment plan is calculated;

[0014] Based on the charge and discharge prediction value, select the target solvent type proportion adjustment plan, and perform proportion adjustment according to the parameters in the target solvent type proportion adjustment plan.

[0015] Preferably, the establishment of the influence model of the proportion of solvent types on the lithium-ion diffusion rate includes the following steps:

[0016] Subtract the first component proportion of the electrolyte type from 1 to obtain the adjustable proportion;

[0017] Obtain the value range of the proportion of solvent types, and equally divide the value range of the proportion of solvent types to obtain at least one sampling point;

[0018] Under preset conditions, obtain the lithium-ion conditional diffusion rate, and the preset conditions are: the proportion of the electrolyte type is equal to the first component proportion, the proportion of the solvent type is the value at the sampling point, and the proportion of EC is the adjustable proportion minus the value at the sampling point;

[0019] Pair the value at the sampling point with the lithium-ion conditional diffusion rate and fit to obtain the first influence fitting function, and pair the first influence fitting function with the solvent type, where the value at the sampling point is the independent variable and the lithium-ion conditional diffusion rate is the dependent variable.

[0020] Preferably, the establishment of the influence model of the proportion of solvent types on the formation of the electrolyte-electrode interface film includes the following steps:

[0021] Obtain the value range of the proportion of solvent types, and equally divide the value range of the proportion of solvent types to obtain at least one sampling point;

[0022] Under preset conditions, obtain the permeability of the electrolyte-electrode interface film. The preset conditions are: the proportion of the electrolyte type is equal to the proportion of the first component, the proportion of the solvent type is the value at the sampling point, and the proportion of EC is the adjustable proportion minus the value at the sampling point;

[0023] Pair and fit the value at the sampling point with the permeability of the electrolyte-electrode interface film to obtain a second influence fitting function, and pair the second influence fitting function with the solvent type, where the value at the sampling point is the independent variable and the permeability of the electrolyte-electrode interface film is the dependent variable.

[0024] Preferably, the establishment of the influence model of the lithium ion diffusion rate on the charge and discharge speed includes the following steps:

[0025] Obtain the value range of the lithium ion diffusion rate, and equally divide the value range of the lithium ion diffusion rate to obtain at least one sampling point;

[0026] Under the condition that the lithium ion diffusion rate is equal to the value at the sampling point, obtain the charge and discharge condition speed;

[0027] Pair and fit the value at the sampling point with the charge and discharge condition speed to obtain a third influence fitting function, where the value at the sampling point is the independent variable and the charge and discharge condition speed is the dependent variable.

[0028] Preferably, the calculation of the first speed increase coefficient for adjusting the component proportions of the high dielectric constant solvent type and the low viscosity solvent type includes the following steps:

[0029] Set a reference ratio, which is any positive number less than the proportion of the second component;

[0030] Subtract the reference ratio from the proportion of the second component to obtain a reference downward proportion, and add the proportion of the third component to the reference ratio to obtain a reference upward proportion;

[0031] Substitute the proportion of the second component into the first influence fitting function corresponding to the high dielectric constant solvent type to obtain a first reference value;

[0032] Substitute the proportion of the third component into the first influence fitting function corresponding to the low viscosity solvent type to obtain a second reference value;

[0033] Substitute the reference downward proportion into the first influence fitting function corresponding to the high dielectric constant solvent type to obtain a first increase value;

[0034] Substitute the reference upward proportion into the first influence fitting function corresponding to the low viscosity solvent type to obtain a second increase value;

[0035] Use the first speed increase formula to calculate the first speed increase coefficient;

[0036] The first speed increase formula is as follows:

[0037]

[0038] Among them, A is the first speed increase coefficient, b is the proportion of baseline reduction, B is the first increase value, c is the proportion of baseline increase, C is the second increase value, d is the proportion of the second component, D is the first baseline value, e is the proportion of the third component, and E is the second baseline value.

[0039] Preferably, the second speed increase coefficient for adjusting the component proportions of the solvent types with high dielectric constant and low viscosity obtained by calculation includes the following steps:

[0040] Substitute the proportion of the second component into the second influence fitting function corresponding to the solvent type with high dielectric constant to obtain the first sample value;

[0041] Substitute the proportion of the third component into the second influence fitting function corresponding to the solvent type with low viscosity to obtain the second sample value;

[0042] Substitute the proportion of baseline reduction into the second influence fitting function corresponding to the solvent type with high dielectric constant to obtain the first regulation value;

[0043] Substitute the proportion of baseline increase into the second influence fitting function corresponding to the solvent type with low viscosity to obtain the second regulation value;

[0044] Use the second speed regulation formula to calculate the second speed regulation coefficient;

[0045] The second speed regulation formula is as follows:

[0046]

[0047] Among them, F is the second speed increase coefficient, g is the proportion of baseline reduction, G is the first regulation value, h is the proportion of baseline increase, H is the second regulation value, i is the proportion of the second component, I is the first sample value, j is the proportion of the third component, and J is the second sample value.

[0048] Preferably, the formation of at least one solvent type ratio adjustment plan includes the following steps:

[0049] Taking the adjustable ratio and 0 as endpoints, form a to-be-regulated interval, and evenly take at least one identification point in the to-be-regulated interval;

[0050] Subtract the value at the identification point from the adjustable ratio to obtain the identification symmetry value;

[0051] Form a solvent type ratio adjustment plan. In the solvent type ratio adjustment plan, take the value at the identification point as the proportion of the solvent type with high dielectric constant, and take the identification symmetry value as the proportion of the solvent type with low viscosity.

[0052] Preferably, the charge and discharge prediction value for calculating the solvent type ratio adjustment plan includes the following steps:

[0053] Subtract the proportion of the second component from the proportion of the solvent type with a high dielectric constant in the solvent type ratio adjustment plan to obtain a proportion adjustment value;

[0054] Substitute the actual charge and discharge rate into the third influence fitting function to inversely solve the actual lithium ion diffusion rate;

[0055] Use the lithium ion diffusion prediction formula to calculate the predicted lithium ion diffusion rate;

[0056] Substitute the predicted lithium ion diffusion rate into the third influence fitting function to obtain the charge and discharge prediction value;

[0057] The lithium ion diffusion prediction formula is as follows:

[0058]

[0059] Among them, K is the predicted lithium ion diffusion rate, L is the actual lithium ion diffusion rate, p is the proportion adjustment value, and M is the reference ratio.

[0060] Preferably, the selection of the target solvent type ratio adjustment plan based on the charge and discharge prediction value includes the following steps:

[0061] Select the solvent type ratio adjustment plan with a charge and discharge prediction value consistent with the target charge and discharge rate as the preliminary plan;

[0062] When there are multiple preliminary plans, select the preliminary plan with the smallest proportion adjustment value as the target solvent type ratio adjustment plan. When the number of preliminary plans is 1, use the preliminary plan as the target solvent type ratio adjustment plan.

[0063] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0064] By establishing an influence model of the proportion of solvent types on the lithium ion diffusion rate, establishing an influence model of the proportion of solvent types on the formation of the electrolyte-electrode interface film, establishing an influence model of the lithium ion diffusion rate on the charge and discharge rate, and calculating the charge and discharge prediction value of the solvent type ratio adjustment plan, the charge and discharge rate of the solvent type ratio adjustment plan can be predicted. During the prediction, the lithium ion diffusion situation and the formation situation of the electrolyte-electrode interface film are considered, and the combined influence of the two on the charge and discharge rate is considered, so as to more accurately obtain the predicted charge and discharge rate. Therefore, the required plan can be screened based on this for targeted regulation. Description of the Drawings

[0065] Figure 1Schematic flow chart of the lithium battery charge and discharge acceleration method based on the adjustment of the lithium battery electrolyte ratio according to the present invention;

[0066] Figure 2 Schematic flow chart of the method for establishing the influence model of the proportion of solvent types on the lithium ion diffusion rate according to the present invention;

[0067] Figure 3 Schematic flow chart of the method for establishing the influence model of the proportion of solvent types on the formation of the electrolyte-electrode interface film according to the present invention;

[0068] Figure 4 Schematic flow chart of the method for establishing the influence model of the lithium ion diffusion rate on the charge and discharge speed according to the present invention;

[0069] Figure 5 Schematic flow chart of the method for calculating the first speed increase coefficient for adjusting the component proportions of the solvent types with high dielectric constant and low viscosity according to the present invention;

[0070] Figure 6 Schematic flow chart of the method for calculating the second speed increase coefficient for adjusting the component proportions of the solvent types with high dielectric constant and low viscosity according to the present invention;

[0071] Figure 7 Schematic flow chart of the method for forming at least one solvent type ratio adjustment scheme according to the present invention;

[0072] Figure 8 Schematic flow chart of the method for calculating the charge and discharge prediction value of the solvent type ratio adjustment scheme according to the present invention;

[0073] Figure 9 Schematic flow chart of the method for selecting the target solvent type ratio adjustment scheme based on the charge and discharge prediction value according to the present invention. Detailed implementation manners

[0074] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0075] Refer to Figure 1 As shown, a lithium battery charge and discharge acceleration method based on the adjustment of the lithium battery electrolyte ratio includes:

[0076] Obtain the actual charge and discharge speed of the electrolyte, obtain the actual component composition of the electrolyte, and the actual component composition is respectively the type of electrolyte and the first component ratio, the type of solvent with high dielectric constant and the second component ratio, the type of solvent with low viscosity and the third component ratio. The solvent types used in the electrolyte are a mixture of EC, PC, DEC, DMC, EMC or EP;

[0077] Obtain the target charge-discharge speed after the charge-discharge improvement of the electrolyte. When adjusting the formulation, only adjust the composition ratios of the solvents with high dielectric constants and the solvents with low viscosities;

[0078] Establish an influence model of the composition ratio of the solvent types on the lithium-ion diffusion rate, establish an influence model of the composition ratio of the solvent types on the formation of the electrolyte-electrode interface film, and establish an influence model of the lithium-ion diffusion rate on the charge-discharge speed. Among them, the electrolyte-electrode interface film is used to maintain the stability of the lithium battery;

[0079] Based on the influence model of the composition ratio of the solvent types on the lithium-ion diffusion rate, calculate the first speed increase coefficient for adjusting the composition ratios of the solvents with high dielectric constants and the solvents with low viscosities;

[0080] Based on the influence model of the composition ratio of the solvent types on the formation of the electrolyte-electrode interface film, calculate the second speed increase coefficient for adjusting the composition ratios of the solvents with high dielectric constants and the solvents with low viscosities;

[0081] Form at least one solvent type formulation adjustment plan;

[0082] Based on the influence model of the lithium-ion diffusion rate on the charge-discharge speed, the first speed increase coefficient, and the second speed increase coefficient, calculate the charge-discharge prediction value of the solvent type formulation adjustment plan;

[0083] Based on the charge-discharge prediction value, select the target solvent type formulation adjustment plan, and perform formulation adjustment according to the parameters in the target solvent type formulation adjustment plan.

[0084] Solvent types and melting points: The types and melting points of the solvents in the electrolyte have a direct impact on the lithium-ion diffusion rate. Chain and cyclic carbonates and carboxylates are commonly used solvents, and their melting points and viscosities directly affect the lithium-ion diffusion rate. The lower the melting point and the smaller the viscosity, the higher the self-diffusion coefficient of lithium ions, thus improving the fast-charging performance. Therefore, different types of solvent types will result in different lithium-ion diffusion rates. Thus, establish an influence model of the composition ratio of the solvent types on the lithium-ion diffusion rate;

[0085] Solvation energy: The high ionic conductivity of the electrolyte requires the solvent to have a high lithium-ion solvation energy, while the formation of an inorganic electrolyte-electrode interface film requires a low lithium-ion solvation energy. Therefore, when designing the electrolyte, a balance needs to be found between the two to achieve high ionic conductivity and a stable interface film;

[0086] There needs to be a certain distance and isolation between the positive and negative electrodes of the lithium battery to prevent direct contact between them. At this time, a special material such as an electrolyte separator is required;

[0087] The electrolyte-electrode interface film is a material with a unique pore structure and chemical properties. It can separate the electrolyte between the positive and negative electrodes, preventing the direct contact or short circuit between the positive and negative electrodes. Due to the good barrier performance and chemical corrosion resistance of the electrolyte diaphragm, it can protect the ion transfer and electrochemical reactions between the positive and negative electrodes;

[0088] Therefore, it is necessary to predict the permeability of the electrolyte-electrode interface film to obtain its influence on the charge and discharge speed. The greater the permeability, the faster the charge and discharge speed;

[0089] Concentration: Increasing the concentration of the electrolyte can significantly increase the self-diffusion coefficient of lithium ions, providing a wider channel for lithium ions and thus accelerating the charge and discharge speed. However, changing the lithium ion concentration of the electrolyte has a greater impact, and the generated heat is difficult to control, making it difficult to ensure absolute safety. In addition, the increase in lithium ions will also lead to uncontrollable costs. Therefore, in this solution, only the solvent ratio is adjusted;

[0090] Among EC, PC, DEC, DMC, EMC, and EP, there are solvent types with high dielectric constants and solvent types with low viscosities. Therefore, they can be used as the actual components of the electrolyte.

[0091] Refer to Figure 2 As shown, establishing the influence model of the proportion of solvent types on the lithium ion diffusion rate includes the following steps:

[0092] Subtract the first component proportion of the electrolyte type to obtain the adjustable proportion;

[0093] Obtain the value range of the proportion of solvent types, and equally divide the value range of the proportion of solvent types to obtain at least one sampling point;

[0094] Under the preset conditions, obtain the conditional diffusion rate of lithium ions. The preset conditions are: the proportion of the electrolyte type is equal to the first component proportion, the proportion of the solvent type is the value at the sampling point, and the proportion of EC is the adjustable proportion minus the value at the sampling point;

[0095] Pair and fit the value at the sampling point with the conditional diffusion rate of lithium ions to obtain the first influence fitting function, and pair the first influence fitting function with the solvent type. Among them, the value at the sampling point is the independent variable, and the conditional diffusion rate of lithium ions is the dependent variable.

[0096] Since different solvent types are used, the lithium ion diffusion rate will also be correspondingly different. To obtain the influence of the proportion of solvent types on the lithium ion diffusion rate, it is necessary to control the consistency of the test conditions. In the preset conditions, the proportion of the tested solvent type is regulated, and the other solvents participating in the mixture are fixed as EC, so the test conditions are all the same. Here, the tested solvent type may also be EC.

[0097] Reference Figure 3 As shown in FIG. 1 , establishing a model for the influence of the proportion of solvent types on the formation of electrolyte-electrode interface film includes the following steps:

[0098] Obtaining a value range of the proportion of solvent types, dividing the value range of the proportion of solvent types at equal intervals, and obtaining at least one sampling point;

[0099] Under the preset conditions, the permeability of the electrolyte-electrode interface film is obtained. The preset conditions are: the proportion of the electrolyte type is equal to the proportion of the first component, the proportion of the solvent type is the value at the sampling point, and the EC proportion is the adjustable proportion minus the value at the sampling point;

[0100] The value at the sampling point is paired and fitted with the permeability of the electrolyte-electrode interface film to obtain the second influence fitting function, and the second influence fitting function is paired with the solvent type, wherein the value at the sampling point is the independent variable and the permeability of the electrolyte-electrode interface film is the dependent variable.

[0101] Due to the different types of solvents used, the formation of the electrolyte-electrode interface film will also be different accordingly. In order to obtain the influence of the proportion of solvent types on the electrolyte-electrode interface film, it is necessary to control the consistency of the test conditions. In the preset conditions, the proportion of the tested solvent type is adjusted, and the other solvent involved in the mixture is fixed to EC, then the test conditions are consistent. Here, the tested solvent type may also be EC, thus, the permeability of the electrolyte-electrode interface film can be estimated. On the one hand, the electrolyte-electrode interface film protects the operation of the lithium battery. On the other hand, its permeability will also affect the diffusion rate of lithium ions, and then affect the charge and discharge speed. Therefore, it is necessary to evaluate the formation of the electrolyte-electrode interface film.

[0102] Reference Figure 4 As shown, establishing a model for the influence of lithium ion diffusion rate on charge and discharge speed includes the following steps:

[0103] Obtaining a value range of the lithium ion diffusion rate, dividing the value range of the lithium ion diffusion rate at equal intervals to obtain at least one sampling point;

[0104] Under the condition that the lithium ion diffusion rate is equal to the value at the sampling point, the charging and discharging condition speed is obtained;

[0105] The value at the sampling point is paired with the charging and discharging condition speed and fitted to obtain a third influencing fitting function, wherein the value at the sampling point is an independent variable and the charging and discharging condition speed is a dependent variable.

[0106] The lithium-ion diffusion rate is positively correlated with the charge and discharge speed. However, the functional relationship between the two may not be a direct proportional function. As the lithium-ion diffusion rate further increases, the charge and discharge speed may not increase significantly. Therefore, in order to predict the functional relationship between the two, the obtained test data is fitted.

[0107] Refer to Figure 5 As shown, calculating the first speed increase coefficient for adjusting the composition ratios of the solvent types with high dielectric constants and the solvent types with low viscosities includes the following steps:

[0108] Set a reference ratio, which is any positive number less than the second component ratio;

[0109] Subtract the reference ratio from the second component ratio to obtain the reference downward adjustment ratio, and add the third component ratio to the reference ratio to obtain the reference upward adjustment ratio;

[0110] Substitute the second component ratio into the first influence fitting function corresponding to the solvent type with a high dielectric constant to obtain the first reference value;

[0111] Substitute the third component ratio into the first influence fitting function corresponding to the solvent type with a low viscosity to obtain the second reference value;

[0112] Substitute the reference downward adjustment ratio into the first influence fitting function corresponding to the solvent type with a high dielectric constant to obtain the first increase value;

[0113] Substitute the reference upward adjustment ratio into the first influence fitting function corresponding to the solvent type with a low viscosity to obtain the second increase value;

[0114] Use the first speed increase formula to calculate the first speed increase coefficient;

[0115] The first speed increase formula is as follows:

[0116]

[0117] Where A is the first speed increase coefficient, b is the reference downward adjustment ratio, B is the first increase value, c is the reference upward adjustment ratio, C is the second increase value, d is the second component ratio, D is the first reference value, e is the third component, and E is the second reference value.

[0118] There are no special requirements for setting the reference ratio. Since the change in the charge and discharge rate caused by the ratio adjustment of the solvent types with high dielectric constant and the solvent types with low viscosity shows a certain proportional relationship, therefore, for the case where the adjustment range is the reference ratio, the first speed increase coefficient is obtained. Subsequently, in order to calculate the influence generated by the adjusted ratio, the product of the ratio of the adjusted ratio to the reference ratio and the first speed increase coefficient can be used to estimate the influence generated by the adjusted ratio, without the need to recalculate various influences, thereby simplifying the calculation process. The situation for the second speed increase coefficient is similar. The first speed increase coefficient corresponds to the influence of the solvent type on the lithium ion diffusion rate, and the second speed increase coefficient corresponds to the influence of the electrolyte-electrode interface film on the lithium ion diffusion rate. Because the permeability of the electrolyte-electrode interface film can be used as a weight to multiply with the lithium ion diffusion rate to obtain the effective lithium ion diffusion rate under the influence of the electrolyte-electrode interface film.

[0119] Refer to Figure 6 As shown, calculating the second speed increase coefficient for the adjustment of the composition ratio of the solvent types with high dielectric constant and the solvent types with low viscosity includes the following steps:

[0120] Substitute the second composition ratio into the second influence fitting function corresponding to the solvent type with high dielectric constant to obtain the first sample value;

[0121] Substitute the third composition ratio into the second influence fitting function corresponding to the solvent type with low viscosity to obtain the second sample value;

[0122] Substitute the reference downward adjustment ratio into the second influence fitting function corresponding to the solvent type with high dielectric constant to obtain the first adjustment value;

[0123] Substitute the reference upward adjustment ratio into the second influence fitting function corresponding to the solvent type with low viscosity to obtain the second adjustment value;

[0124] Use the second speed adjustment formula to calculate the second speed adjustment coefficient;

[0125] The second speed adjustment formula is as follows:

[0126]

[0127] Where F is the second speed increase coefficient, g is the reference downward adjustment ratio, G is the first adjustment value, h is the reference upward adjustment ratio, H is the second adjustment value, i is the second composition ratio, I is the first sample value, j is the third composition ratio, and J is the second sample value.

[0128] Refer to Figure 7 As shown, forming at least one solvent type ratio adjustment plan includes the following steps:

[0129] Taking the adjustable ratio and 0 as endpoints, a to-be-regulated interval is formed, and at least one identification point is evenly selected in the to-be-regulated interval;

[0130] Subtracting the value at the identification point from the adjustable ratio to obtain an identification symmetry value;

[0131] A solvent type ratio adjustment plan is formed. In the solvent type ratio adjustment plan, the value at the identification point is used as the ratio of the solvent type with a high dielectric constant, and the identification symmetry value is used as the ratio of the solvent type with a low viscosity.

[0132] Refer to Figure 8 As shown, calculating the charge-discharge prediction value of the solvent type ratio adjustment plan includes the following steps:

[0133] Subtracting the ratio of the second component from the ratio of the solvent type with a high dielectric constant in the solvent type ratio adjustment plan to obtain a ratio adjustment value;

[0134] Substituting the actual charge-discharge rate into the third influence fitting function and inversely solving to obtain the actual lithium ion diffusion rate;

[0135] Using the lithium ion diffusion prediction formula to calculate the predicted lithium ion diffusion rate;

[0136] Substituting the predicted lithium ion diffusion rate into the third influence fitting function to obtain the charge-discharge prediction value;

[0137] The lithium ion diffusion prediction formula is as follows:

[0138]

[0139] Wherein, K is the predicted lithium ion diffusion rate, L is the actual lithium ion diffusion rate, p is the ratio adjustment value, and M is the reference ratio.

[0140] Due to the change in the ratio, the actual lithium ion diffusion rate will also change. According to the third influence fitting function, the corresponding charge-discharge rate can be calculated from the lithium ion diffusion rate. However, due to the change in the lithium ion diffusion rate, it is necessary to determine the changed lithium ion diffusion rate. Since the influences caused by the regulation are the direct influence of the solvent and the indirect influence of the electrolyte-electrode interface film respectively, when considering, the two need to be combined, so the coefficients are multiplied. Thus, the comprehensive influence on the actual lithium ion diffusion rate can be obtained, and then the predicted lithium ion diffusion rate can be obtained.

[0141] Refer to Figure 9 As shown, based on the charge-discharge prediction value, selecting the target solvent type ratio adjustment plan includes the following steps:

[0142] Select the solvent type ratio adjustment plan with the charge-discharge prediction value consistent with the target charge-discharge rate as the preliminary plan;

[0143] When there are multiple alternative solutions, select the alternative solution with the smallest proportion adjustment value as the target solvent type ratio adjustment solution. When the number of alternative solutions is 1, use the alternative solution as the target solvent type ratio adjustment solution.

[0144] The purpose of selecting the alternative solution with the smallest proportion adjustment value is to control the adjustment range. The greater the adjustment range, the longer the time consumed. Therefore, for the sake of regulation efficiency, select the alternative solution with the smallest proportion adjustment value as the target solvent type ratio adjustment solution.

[0145] Furthermore, this solution also proposes a storage medium with a computer-readable program stored thereon. When the computer-readable program is called, it executes the above-mentioned lithium battery charge and discharge acceleration method based on the adjustment of the lithium battery electrolyte ratio.

[0146] It can be understood that the storage medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid-state drive (SSD).

[0147] In summary, the advantages of the present invention are as follows: By establishing an influence model of the proportion of solvent types on the lithium ion diffusion rate, an influence model of the proportion of solvent types on the formation of the electrolyte-electrode interface film, an influence model of the lithium ion diffusion rate on the charge and discharge speed, and calculating the charge and discharge pre-estimation value of the solvent type ratio adjustment solution, the charge and discharge speed of the solvent type ratio adjustment solution can be estimated. During the prediction, the lithium ion diffusion situation and the formation situation of the electrolyte-electrode interface film are considered, and the influence of both on the charge and discharge speed is synthesized, so as to more accurately obtain the predicted charge and discharge speed. Thus, the required solution can be screened based on this and targeted regulation can be carried out.

[0148] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A lithium battery charging and discharging acceleration method based on lithium battery electrolyte ratio adjustment, characterized in that: include: Obtaining the actual charge and discharge speed of the electrolyte, and obtaining the actual composition of the electrolyte, the actual composition is the type of electrolyte and the proportion of the first component, the type of solvent with a high dielectric constant and the proportion of the second component, the type of solvent with a low viscosity and the proportion of the third component, and the type of solvent used in the electrolyte is a mixture of EC, PC, DEC, DMC, EMC or EP; Obtain the target charge and discharge speed after the charge and discharge of the electrolyte is improved, and when adjusting the ratio, only adjust the proportion of the solvent type with a high dielectric constant and the solvent type with a low viscosity; Establish a model for the influence of the proportion of solvent types on the diffusion rate of lithium ions, establish a model for the influence of the proportion of solvent types on the formation of electrolyte-electrode interface film, and establish a model for the influence of lithium ion diffusion rate on charge and discharge speed, among which the electrolyte-electrode interface film is used to maintain the stability of lithium batteries; Based on the model of the influence of the proportion of solvent types on the lithium ion diffusion rate, the first speed improvement coefficient adjusted by the proportion of high dielectric constant solvent types and low viscosity solvent types is calculated; Based on the model of the influence of the proportion of solvent types on the formation of the electrolyte-electrode interface film, the second speed improvement coefficient adjusted by the proportion of high dielectric constant solvent types and low viscosity solvent types is calculated; Forming at least one solvent type ratio adjustment plan; Based on the influence model of lithium ion diffusion rate on charge and discharge speed, the first speed improvement coefficient and the second speed improvement coefficient, the charge and discharge estimated value of the solvent type ratio adjustment scheme is calculated; Based on the charge and discharge estimation, a target solvent type ratio adjustment scheme is selected, and the ratio is adjusted according to the parameters in the target solvent type ratio adjustment scheme.

2. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 1, characterized in that: The establishment of a model for the influence of the proportion of solvent types on the lithium ion diffusion rate comprises the following steps: 1 minus the first component ratio of the electrolyte type to obtain the adjustable ratio; Obtaining a value range of the proportion of solvent types, dividing the value range of the proportion of solvent types at equal intervals, and obtaining at least one sampling point; Under the preset conditions, the lithium ion conditional diffusion rate is obtained. The preset conditions are: the proportion of the electrolyte type is equal to the proportion of the first component, the proportion of the solvent type is the value at the sampling point, and the EC proportion is the adjustable proportion minus the value at the sampling point; The value at the sampling point is paired and fitted with the lithium ion conditional diffusion rate to obtain the first influence fitting function, and the first influence fitting function is paired with the solvent type, wherein the value at the sampling point is the independent variable and the lithium ion conditional diffusion rate is the dependent variable.

3. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 2, characterized in that: The establishment of a model for the influence of the proportion of solvent types on the formation of electrolyte-electrode interface film comprises the following steps: Obtaining a value range of the proportion of solvent types, dividing the value range of the proportion of solvent types at equal intervals, and obtaining at least one sampling point; Under the preset conditions, the permeability of the electrolyte-electrode interface film is obtained. The preset conditions are: the proportion of the electrolyte type is equal to the proportion of the first component, the proportion of the solvent type is the value at the sampling point, and the EC proportion is the adjustable proportion minus the value at the sampling point; The value at the sampling point is paired and fitted with the permeability of the electrolyte-electrode interface film to obtain the second influence fitting function, and the second influence fitting function is paired with the solvent type, wherein the value at the sampling point is the independent variable and the permeability of the electrolyte-electrode interface film is the dependent variable.

4. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 3, characterized in that: The establishment of the influence model of lithium ion diffusion rate on charge and discharge speed comprises the following steps: Obtaining a value range of the lithium ion diffusion rate, dividing the value range of the lithium ion diffusion rate at equal intervals to obtain at least one sampling point; Under the condition that the lithium ion diffusion rate is equal to the value at the sampling point, the charging and discharging condition speed is obtained; The value at the sampling point is paired with the charging and discharging condition speed and fitted to obtain a third influencing fitting function, wherein the value at the sampling point is an independent variable and the charging and discharging condition speed is a dependent variable.

5. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 4, characterized in that: The step of calculating the first speed improvement coefficient for adjusting the proportion of the solvent type with a high dielectric constant and the solvent type with a low viscosity comprises the following steps: Set the base ratio, which is any positive number less than the proportion of the second component; Subtract the proportion of the second component from the benchmark proportion to obtain the benchmark downward adjustment proportion, and add the proportion of the third component to the benchmark proportion to obtain the benchmark upward adjustment proportion; Substituting the proportion of the second component into the first influence fitting function corresponding to the type of solvent with a high dielectric constant to obtain a first reference value; Substituting the proportion of the third component into the first influence fitting function corresponding to the low-viscosity solvent type to obtain a second reference value; Substituting the baseline reduction ratio into the first impact fitting function corresponding to the solvent type with a high dielectric constant, a first improvement value is obtained; Substituting the baseline increase ratio into the first impact fitting function corresponding to the low-viscosity solvent type to obtain a second increase value; Use the first speed improvement formula to calculate the first speed improvement coefficient; The first speed improvement formula is as follows: Among them, A is the first speed improvement coefficient, b is the benchmark downward adjustment ratio, B is the first improvement value, c is the benchmark upward adjustment ratio, C is the second improvement value, d is the second component ratio, D is the first benchmark value, e is the third component ratio, and E is the second benchmark value.

6. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 5, characterized in that: The step of calculating the second speed improvement coefficient for adjusting the proportion of the solvent type with a high dielectric constant and the solvent type with a low viscosity comprises the following steps: Substituting the second component ratio into the second influence fitting function corresponding to the solvent type with a high dielectric constant to obtain a first sample value; Substituting the proportion of the third component into the second influence fitting function corresponding to the low-viscosity solvent type to obtain a second sample value; Substituting the baseline reduction ratio into the second impact fitting function corresponding to the solvent type with a high dielectric constant to obtain a first regulation value; Substituting the baseline upward adjustment ratio into the second impact fitting function corresponding to the low-viscosity solvent type to obtain a second adjustment value; Use the second speed control formula to calculate the second speed control coefficient; The second speed control formula is as follows: Among them, F is the second speed improvement coefficient, g is the benchmark downward adjustment ratio, G is the first regulation value, h is the benchmark upward adjustment ratio, H is the second regulation value, i is the second component ratio, I is the first sample value, j is the third component ratio, and J is the second sample value.

7. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 6, characterized in that: The forming of at least one solvent type ratio adjustment scheme comprises the following steps: The adjustable proportion and 0 are used as endpoints to form a range to be regulated, and at least one identification point is evenly selected in the range to be regulated; Subtract the adjustable proportion from the value at the identification point to obtain the identification symmetry value; A solvent type ratio adjustment scheme is formed, in which the value at the identification point is used as the proportion of the solvent type with a high dielectric constant, and the identification symmetry value is used as the proportion of the solvent type with a low viscosity.

8. A lithium battery charge and discharge acceleration method based on lithium battery electrolyte ratio adjustment according to claim 7, characterized in that: The calculation to obtain the estimated charge and discharge value of the solvent type ratio adjustment scheme comprises the following steps: The proportion of the solvent type with a high dielectric constant in the solvent type ratio adjustment scheme is subtracted from the proportion of the second component to obtain a proportion adjustment value; Substitute the actual charge and discharge speed into the third impact fitting function and inversely solve to obtain the actual lithium ion diffusion rate; Using the lithium ion diffusion prediction formula, the estimated lithium ion diffusion rate is calculated; Substituting the estimated lithium ion diffusion rate into the third impact fitting function to obtain the charge and discharge estimated value; The lithium ion diffusion prediction formula is as follows: Among them, K is the estimated lithium ion diffusion rate, L is the actual lithium ion diffusion rate, p is the proportion adjustment value, and M is the benchmark proportion.

9. A lithium battery charging and discharging acceleration method based on lithium battery electrolyte ratio adjustment according to claim 8, characterized in that: The method of selecting a target solvent type and ratio adjustment scheme based on the charge and discharge estimation comprises the following steps: Select a solvent type ratio adjustment plan whose charge and discharge estimate is consistent with the target charge and discharge speed as a preliminary plan; When there are multiple preliminary plans, the preliminary plan with the smallest proportion adjustment value is selected as the target solvent type ratio adjustment plan. When the number of preliminary plans is 1, the preliminary plan is used as the target solvent type ratio adjustment plan.

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