Battery cell infiltration method, medium and program product

Abstract

The invention discloses a battery cell infiltration method, a medium and a program product. The battery cell infiltration method comprises the following steps: calculating recoverable waste heat quantity of a formation process; calculating the optimal dynamic viscosity of cell infiltration, and looking up the table to obtain the optimal temperature corresponding to the optimal dynamic viscosity; calculating the total heat required for heating a certain mass of electrolyte to the optimal temperature; and if the recoverable waste heat quantity is greater than the total heat quantity, a control instruction is sent to an infiltration mechanism, so that the infiltration mechanism heats the electrolyte to the optimal temperature by utilizing the recoverable waste heat quantity, and the heated electrolyte is injected into the battery cell for infiltration. The waste heat of the formation workshop is fully utilized, the electrolyte heating cost is reduced, meanwhile, the dynamic viscosity of the electrolyte can be effectively reduced, and the infiltration effect is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery manufacturing, and in particular relates to a battery cell impregnation method, a medium and a program product. Background Art

[0002] In the lithium-ion battery manufacturing process, cell impregnation is one of the key steps that determine battery performance. The electrolyte needs to fully penetrate into the pores of the electrode sheet to achieve effective ion conduction. The traditional impregnation method currently used in the industry mainly includes the following steps: first, preheat the electrolyte (usually using an electric heater or steam heating method to heat the electrolyte to 40-60°C), then inject the preheated electrolyte into the battery cell shell, and promote the diffusion of the electrolyte through vacuum negative pressure or static method. However, the existing technology has the following significant defects:

[0003] (1) High energy consumption and uncontrollable costs: Electrolyte preheating mainly relies on external electricity or steam heat. For example, a single soaking of a certain type of battery cell requires heating the electrolyte to 50°C. Based on a daily production of 100,000 battery cells, the annual power consumption of the heating process alone can reach over one million kWh. The waste heat (including reaction heat, Joule heat, equipment heat dissipation, etc.) generated by the battery formation process (especially the high-temperature aging stage) is usually discharged directly through the cooling system without forming thermal coupling with the soaking process, resulting in double energy waste.

[0004] (2) Rough control of electrolyte viscosity: Existing technologies mostly use fixed temperature range heating, and do not dynamically optimize the electrolyte dynamic viscosity based on the battery cell structural parameters (such as electrode porosity and winding radius). At the same time, although the electrolyte dynamic viscosity is positively correlated with temperature, electrolyte volatilization caused by excessively high temperature should be avoided. Therefore, it is necessary to give a precise value for the control of electrolyte temperature, and the error should be within a reasonable range.

[0005] Therefore, there is an urgent need to develop a battery cell wetting method that can accurately match the formation waste heat with the electrolyte heating requirements and improve the wetting effect through viscosity optimization, so as to solve the technical bottlenecks of energy waste, high cost and uneven wetting in the existing technology. Summary of the Invention

[0006] In response to the above problems, the present invention proposes a battery cell wetting method, medium and program product, which recovers the waste heat generated in the battery formation process and uses it to heat the electrolyte, thereby reducing the dynamic viscosity of the electrolyte, thereby improving the wetting effect of the electrolyte on the electrode sheet, and further improving the overall performance of the battery.

[0007] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0008] In a first aspect, the present invention provides a battery cell impregnation method, comprising:

[0009] Calculate the recoverable waste heat of the formation process;

[0010] Calculate the optimal dynamic viscosity of the battery cell and find the optimal temperature corresponding to the optimal dynamic viscosity by looking up the table;

[0011] Calculating the total amount of heat required to heat a certain mass of electrolyte to the optimal temperature;

[0012] If the recoverable waste heat is greater than the total heat, a control instruction is sent to the infiltration mechanism, so that the infiltration mechanism uses the recoverable waste heat to heat the electrolyte to the optimal temperature and injects the heated electrolyte into the battery cell for infiltration.

[0013] In the above scheme, the waste heat generated in the battery formation process is recovered and used to heat the electrolyte, thereby reducing the dynamic viscosity of the electrolyte, thereby improving the wetting effect of the electrolyte on the electrode sheet, and thus improving the overall performance of the battery.

[0014] In combination with the first aspect, optionally, the calculation formula for the recoverable waste heat is:

[0015] ,

[0016] in:

[0017] ,

[0018] Where, To recover waste heat, is the total heat generated by the battery formation process, is the recovery coefficient, is the heat of reaction, is the Joule heat of the ohmic internal resistance, is the polarization heat, is the side reaction heat, It is the heat load of the forming cabinet itself.

[0019] In the above scheme, for the formation process, it is proposed that the total heat generated by the battery formation process includes reaction heat, Joule heat of ohmic internal resistance, polarization heat, side reaction heat and the heat load of the formation cabinet itself, and a specific calculation formula for recoverable waste heat is provided to facilitate the accurate calculation of recoverable waste heat. Due to the limitation of the second law of thermodynamics, the total heat generated by the formation process cannot be fully used for electrolyte heating. Recoverable waste heat Generally accounts for the total heat generated by the battery formation process 30%-50%. The value range is 30%-50%. Polarization heat refers to the phenomenon of polarization on the electrode surface when current flows through a lithium battery. The average terminal voltage of the battery differs from the open circuit voltage. The heat generated by this voltage drop is the battery's polarization heat. Polarization heat is closely related to the type of battery electrode material, ambient temperature, and charge and discharge depth. It can be calculated by referring to the D•Bernadi formula. Side reaction heat This refers to the heat generated by the chemical changes in the positive and negative electrode materials caused by a small amount of self-discharge during the charge and discharge process of lithium batteries. This heat accounts for a small proportion of the total heat generated in the battery formation process and can be ignored.

[0020] In combination with the first aspect, optionally, the reaction heat The calculation formula is:

[0021] ,

[0022] in,

[0023] ,

[0024] Where, is the electrochemical energy of the battery; It refers to the energy released during the actual use of the battery after the battery is charged; is the battery voltage, is the charge of the battery.

[0025] The above scheme provides a specific formula for calculating the heat of reaction, facilitating accurate calculation. Reaction heat refers to the heat generated by the electrochemical reaction of ions inserting and deinserting between the two electrodes during charging and discharging of a lithium battery. Under reversible conditions, this heat is negative during charging and positive during discharging.

[0026] In combination with the first aspect, optionally, the Joule heat of the ohmic internal resistance The calculation formula is:

[0027] ,

[0028] Where, is the charge and discharge current, is the ohmic internal resistance; is the charge and discharge time.

[0029] The above scheme provides a specific formula for calculating the Joule heat of ohmic internal resistance, facilitating accurate calculation of this Joule heat. This Joule heat refers to the heat generated over a period of time by the ohmic resistance of the battery's internal materials during charging and discharging. This heat is a scalar quantity and therefore remains positive throughout the charging and discharging process.

[0030] In combination with the first aspect, optionally, the heat load of the formation cabinet itself The calculation formula is:

[0031] ,

[0032] Where, is the total electrical energy input to the forming cabinet, is the cabinet heating rate.

[0033] In the above scheme, a specific calculation formula for the heat load of the forming cabinet itself is provided, which is convenient for accurately calculating the heat load of the forming cabinet itself. Refers to the heat emitted by the high-power control box, battery, high-current cables, positive and negative probes, and internal fans of the forming cabinet when it is unloaded or fully loaded.

[0034] In combination with the first aspect, optionally, the calculation formula for the optimal dynamic viscosity is:

[0035] ,

[0036] Where, is the optimal dynamic viscosity, is the electrolyte wetting height, is the aspiration time; is the form radius of the battery cell; is the surface tension of the electrolyte; is the contact angle.

[0037] The above scheme provides a specific calculation formula for the optimal dynamic viscosity, which facilitates accurate calculation of the optimal dynamic viscosity. To improve the wetting effect, the dynamic viscosity should be as low as possible. To this end, the viscosity of the electrolyte needs to be reduced by temperature.

[0038] In combination with the first aspect, optionally, the parameters in the table include different dynamic viscosities and temperatures corresponding to different dynamic viscosities.

[0039] The above scheme provides a specific form of the table, which is generated through experimental data during the specific implementation process. Specifically, an empirical formula similar to the Power Law model can be used to fit the relationship between dynamic viscosity and factors such as temperature and concentration:

[0040] ,

[0041] A and B are empirical constants, typically derived from experimental data. Calculations then create a table that correlates temperature and dynamic viscosity for each electrolyte. By looking up the table, we can determine the dynamic viscosity at different temperatures and find the optimal temperature for achieving the most suitable dynamic viscosity.

[0042] In combination with the first aspect, optionally, the calculation formula for the total calories is:

[0043] ,

[0044] in,

[0045] ,

[0046] Where, is the total calories, is the specific heat capacity, is the mass of the electrolyte, is the temperature difference, For the optimal temperature, is the initial temperature of the electrolyte.

[0047] In the above scheme, a calculation formula for the total heat is given, which facilitates the accurate calculation of the total heat required to heat a certain mass of electrolyte to the injection temperature.

[0048] In a second aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the battery cell wetting method described in any one of the first aspects.

[0049] In a third aspect, the present invention provides a computer program product, comprising a computer program / instruction, which, when executed by a processor, implements the battery cell wetting method described in any one of the first aspects.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention recovers the waste heat generated in the battery formation process and uses it to heat the electrolyte to reduce the dynamic viscosity of the electrolyte, thereby improving the electrolyte's wetting effect on the electrode sheet and further improving the overall performance of the battery.

[0052] The present invention reduces energy consumption, improves production efficiency, and lowers battery manufacturing costs through reasonable heat recovery and dynamic viscosity control. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0054] Figure 1 The present invention is an embodiment of the present invention of the battery cell impregnation method process schematic. DETAILED DESCRIPTION

[0055] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] Example 1

[0058] An embodiment of the present invention provides a battery cell impregnation method, comprising the following steps:

[0059] (1) Calculate the recoverable waste heat of the formation process;

[0060] (2) Calculate the optimal dynamic viscosity of the battery cell and find the optimal temperature corresponding to the optimal dynamic viscosity by looking up the table;

[0061] (3) Calculate the total amount of heat required to heat a certain mass of electrolyte to the optimal temperature;

[0062] (4) If the recoverable waste heat is greater than the total heat, a control instruction is sent to the infiltration mechanism, so that the infiltration mechanism uses the recoverable waste heat to heat the electrolyte to the optimal temperature and injects the heated electrolyte into the battery cell for infiltration.

[0063] In the above scheme, the waste heat generated in the battery formation process is recovered and used to heat the electrolyte, thereby reducing the dynamic viscosity of the electrolyte, thereby improving the wetting effect of the electrolyte on the electrode sheet, and thus improving the overall performance of the battery.

[0064] In a specific implementation of the embodiment of the present invention, the calculation formula for the recoverable waste heat is:

[0065] ,

[0066] in:

[0067] ,

[0068] Where, To recover waste heat, is the total heat generated by the battery formation process, is the recovery coefficient, is the heat of reaction, is the Joule heat of the ohmic internal resistance, is the polarization heat, is the side reaction heat, It is the heat load of the forming cabinet itself.

[0069] In the above scheme, for the battery formation process, it is proposed that the total heat generated by the battery formation process includes reaction heat, Joule heat of ohmic internal resistance, polarization heat, side reaction heat and the heat load of the formation cabinet itself, and a specific calculation formula for recoverable waste heat is provided to facilitate the accurate calculation of recoverable waste heat. Due to the limitation of the second law of thermodynamics, the total heat generated by the formation process cannot be fully used for electrolyte heating. Recoverable waste heat Generally accounts for the total heat generated by the battery formation process 30%-50% of The value range is generally 30%-50%. When a lithium battery has current flowing through it, polarization occurs on the electrode surface. The average terminal voltage of the battery is different from the open circuit voltage. The heat generated by this voltage drop is the polarization heat of the battery. It is closely related to the type of battery electrode material, ambient temperature, and charge / discharge depth, and can be calculated by referring to the D•Bernadi formula. Refers to the heat generated by the chemical changes in the positive and negative electrode materials caused by a small amount of self-discharge during the charge and discharge process of the lithium battery. It accounts for a small proportion of the total heat generated in the battery formation process and can generally be ignored.

[0070] In a specific embodiment of the present invention, the reaction heat The calculation formula is:

[0071] ,

[0072] in,

[0073] ,

[0074] Where, is the electrochemical energy of the battery; It refers to the energy released during the actual use of the battery after the battery is charged; is the battery voltage, is the charge of the battery.

[0075] The above scheme provides a specific formula for calculating the heat of reaction, facilitating accurate calculation. Reaction heat refers to the heat generated by the electrochemical reaction of ions inserting and deinserting between the two electrodes during charging and discharging of a lithium battery. Under reversible conditions, this heat is negative during charging and positive during discharging.

[0076] In a specific embodiment of the present invention, the Joule heat of the ohmic internal resistance The calculation formula is:

[0077] ,

[0078] Where, is the charge and discharge current, is the ohmic internal resistance; is the charge and discharge time.

[0079] The above scheme provides a specific formula for calculating the Joule heat of ohmic internal resistance, facilitating accurate calculation of this Joule heat. This Joule heat refers to the heat generated over a period of time by the ohmic resistance of the battery's internal materials during charging and discharging. This heat is a scalar quantity and therefore remains positive throughout the charging and discharging process.

[0080] In a specific implementation of the embodiment of the present invention, the heat load of the formation cabinet itself is The calculation formula is:

[0081] ,

[0082] Where, is the total electrical energy input to the forming cabinet, is the cabinet heating rate.

[0083] In the above scheme, a specific calculation formula for the heat load of the forming cabinet itself is provided, which is convenient for accurately calculating the heat load of the forming cabinet itself. Refers to the heat emitted by the high-power control box, battery, high-current cables, positive and negative probes, and internal fans of the forming cabinet when it is unloaded or fully loaded.

[0084] In a specific implementation of the embodiment of the present invention, the calculation formula of the optimal dynamic viscosity is:

[0085] ,

[0086] Where, is the optimal dynamic viscosity, is the electrolyte wetting height, is the aspiration time; is the form radius of the battery cell; is the surface tension of the electrolyte; is the contact angle.

[0087] The above scheme provides a specific calculation formula for the optimal dynamic viscosity, which facilitates accurate calculation of the optimal dynamic viscosity. To improve the wetting effect, the dynamic viscosity should be as low as possible. To this end, the viscosity of the electrolyte needs to be reduced by temperature.

[0088] In a specific implementation of the embodiment of the present invention, the parameters in the table include different dynamic viscosities and temperatures corresponding to different dynamic viscosities.

[0089] The above scheme provides a specific form of the table, which is generated through experimental data during the specific implementation process. Specifically, an empirical formula similar to the Power Law model can be used to fit the relationship between dynamic viscosity and factors such as temperature and concentration:

[0090] ,

[0091] A and B are empirical constants, typically derived from experimental data. Calculations then create a table that correlates temperature and dynamic viscosity for each electrolyte. By looking up the table, we can determine the dynamic viscosity at different temperatures and find the optimal temperature for achieving the most suitable dynamic viscosity.

[0092] In a specific implementation of the embodiment of the present invention, the calculation formula of the total heat is:

[0093] ,

[0094] in,

[0095] ,

[0096] Where, is the total calories, is the specific heat capacity, is the mass of the electrolyte, is the temperature difference, For the optimal temperature, is the initial temperature of the electrolyte.

[0097] In the above scheme, a calculation formula for the total heat is given, which facilitates the accurate calculation of the total heat required to heat a certain mass of electrolyte to the injection temperature.

[0098] The following combination Figure 1 The cell impregnation method in the embodiment of the present invention is described in detail.

[0099] The present invention provides a battery cell impregnation method that utilizes waste heat from the battery formation process to heat the electrolyte, reducing its dynamic viscosity, thereby improving its wetting effect on the electrode sheet and, in turn, enhancing the overall battery performance. Furthermore, through rational heat recovery and dynamic viscosity control, energy consumption is reduced, production efficiency is improved, and battery manufacturing costs are lowered.

[0100] like Figure 1 As shown, the cell infiltration method specifically includes the following steps:

[0101] S1. Calculate the recoverable waste heat of the formation process .

[0102] The total heat generated by the lithium-ion battery formation process Includes: including reaction heat , Joule heating of ohmic internal resistance , polarization heat , side reaction heat , the heat load of the forming cabinet itself Total calories The unit is joule (J).

[0103] The reaction heat Refers to the heat generated by the electrochemical reaction of the ions in the process of embedding and detaching between the two electrodes when the lithium battery is charged and discharged. Under reversible conditions, this part of the heat is negative during charging and positive during discharging. The calculation steps are:

[0104] The first step is to calculate the electrochemical energy of the battery. The electrochemical energy of the battery is equal to the product of the battery voltage and the battery charge:

[0105] ;

[0106] in: is the electrochemical energy of the battery, in joules (J); It is the voltage of the battery, measured in volts (V), usually the nominal voltage of the battery, such as 3.6V. It is the charge of the battery, which can be converted into coulombs (C) through the battery's capacity (mAh).

[0107] Step 2: Calorie calculation:

[0108] During the battery formation process, part of the electrical energy generated by discharge is converted into heat, and the other part is used for chemical reactions. It can be estimated by the following formula:

[0109] ;

[0110] It refers to the energy released during actual use of the battery after the battery is charged.

[0111] Joule heating of ohmic internal resistance , refers to the heat generated by the ohmic resistance of the internal materials of a lithium-ion battery during charging and discharging due to the action of current over a period of time. This heat is a scalar quantity and is therefore positive during the charging and discharging process. It can be calculated using the following formula:

[0112] ;

[0113] in, is the charge and discharge current, in amperes (A); is the ohmic internal resistance, the unit is ohm (Ω); is the charge and discharge time in seconds (s).

[0114] Polarization heat Polarization heat refers to the polarization phenomenon that occurs on the electrode surface when current flows through a lithium battery. This difference between the battery's average terminal voltage and the open-circuit voltage creates heat called polarization heat. Polarization heat is closely related to factors such as the battery's electrode material, ambient temperature, and charge / discharge depth. It can be calculated using the D·Bernadi formula.

[0115] Side reaction heat , refers to the heat generated by the chemical changes in the positive and negative electrode materials caused by the self-discharge of a small amount of lithium batteries during the charging and discharging process. It accounts for a small proportion of the total heat generated in the battery formation process and can generally be ignored.

[0116] The above, except for the heat load of the cabinet itself In addition, the heat generated during the battery formation process can also be calculated according to the following formula:

[0117] ;

[0118] Where, It is an empirical coefficient, usually between 0.1-0.2; is the capacity of a single battery cell (unit: mAh or Ah); It is the number of battery cells.

[0119] Thermal load of the forming cabinet itself , refers to the heat emitted by the high-power control box, battery, high-current cables, positive and negative probes and internal fans when the forming cabinet is empty or fully loaded. It can be calculated according to the following formula:

[0120] ;

[0121] Where, is the total electrical energy input to the forming cabinet, is the cabinet heating rate, when no-load, The value ranges from 10% to 30%. When fully loaded, The value ranges from 5% to 15%.

[0122] The total heat generated by the above battery formation process is:

[0123] ;

[0124] Due to the limitation of the second law of thermodynamics, the total heat generated in the formation process cannot be fully used for heating the electrolyte. The formation process can recover the waste heat. It generally accounts for 30%-50% of the total heat generated in the formation process.

[0125] S2. Use the Lucas-Washburn permeation model to calculate the optimal dynamic viscosity for cell wetting (i.e., the optimal dynamic viscosity). Find the optimal temperature corresponding to this dynamic viscosity from a table, which is the electrolyte injection temperature.

[0126] According to the Lucas-Washburn permeability model, the calculation formula is as follows:

[0127] ;

[0128] in, is the optimal dynamic viscosity, is the electrolyte wetting height, is the aspiration time; is the form radius of the battery cell; is the surface tension of the electrolyte; is the contact angle.

[0129] To improve the wetting effect, the dynamic viscosity should be as low as possible, so the viscosity of the electrolyte needs to be reduced by temperature. For lithium battery electrolytes, considering the complexity of components such as solvents and electrolytes, it is often necessary to obtain the viscosity relationship through experimental data. An empirical formula similar to the Power Law model can be used to fit the relationship between viscosity and factors such as temperature and concentration:

[0130] ,

[0131] A and B are empirical constants, typically derived from experimental data. After calculation, a table can be created that correlates temperature and dynamic viscosity for each electrolyte. By looking up the table, the dynamic viscosity at different temperatures can be determined, allowing the optimal temperature to be found, resulting in the most suitable dynamic viscosity for the electrolyte.

[0132] S3. Using the recovered waste heat to heat the electrolyte to the injection temperature;

[0133] Using the specific heat capacity formula:

[0134] ,

[0135] in,

[0136] ,

[0137] Where, is the total heat, in joules (J); is the specific heat capacity, in J / kg; m is the mass, in kg; ΔT is the temperature difference, in °C. For the optimal temperature, is the initial temperature of the electrolyte.

[0138] S4. Inject the heated electrolyte into the battery cell to soak it.

[0139] Implementation method one:

[0140] This embodiment utilizes waste heat recovery from the battery formation process to heat the electrolyte to the optimal injection temperature. The electrolyte's dynamic viscosity is then calculated to optimize the cell's wetting effect. This example details the relationship between the electrolyte's dynamic viscosity and temperature, derived through calculations and experiments, and calculates the optimal heating temperature, thereby reducing battery manufacturing costs and improving battery performance.

[0141] Specific steps:

[0142] S1. Calculate the amount of waste heat that can be recovered during the chemical process

[0143] The capacity of a certain type of lithium battery is 3000mAh, and the total formation process takes 1000s for a single cell. The following data was used in the calculation:

[0144] Electrochemical energy of batteries ;

[0145] Battery voltage U=3.6V;

[0146] Battery charge ;

[0147] Therefore, the electrochemical energy of the battery is:

[0148] ;

[0149] Effective energy ;

[0150] Reaction heat The calculation of is as follows:

[0151] Reaction heat ;

[0152] Furthermore, the Joule heat of the ohmic internal resistance is calculated :

[0153] ;

[0154] Charge and discharge current I=2A, battery internal resistance R=0.05Ω, charging time =1800s,

[0155] ;

[0156] Polarization heat and side reaction heat The proportion is small, so it is ignored in this implementation and no detailed calculation is required.

[0157] Heat load of forming cabinet , the input power is 500W, the cabinet heating rate =10%,

[0158] ;

[0159] In summary, the total heat generated by this type of lithium battery during the formation process is:

[0160] ;

[0161] The waste heat that can be recovered is The total heat generated by the lithium battery during the formation process 30% of

[0162] Right now:

[0163] ;

[0164] S2. Calculate the optimal dynamic viscosity of the electrolyte.

[0165] According to the process documents and material properties, the following parameters are obtained:

[0166] The electrolyte used is a 1 mol / l sodium sulfate solution, and the relationship between its viscosity and temperature is shown in Table 1. The optimal infiltration height H of the lithium battery electrolyte is 210.5 mm; the absorption time t is 1650 s; the cell radius is 0.02mm; the surface tension δ of the electrolyte is 0.005N / m; the contact angle between the electrolyte and the electrode is 45°.

[0167] Calculation is based on the Lucas-Washburn permeability model:

[0168] =1.32mpa / s;

[0169] When the calculation shows that the dynamic viscosity of the electrolyte should reach 1.32 mPa·s, the optimal temperature of the electrolyte is 44°C according to Table 1. Experiments show that the dynamic viscosity of the electrolyte at this temperature matches the table and is determined to be the appropriate value.

[0170] S3. Use waste heat to heat the electrolyte to the injection temperature

[0171] The initial temperature of the electrolyte measured on site is 20°C. The electrolyte injection temperature needs to be above 44°C. The waste heat available for the formation process is 16080J. The mass of the electrolyte used for immersion is 0.1kg. The specific heat capacity of the electrolyte is c=3.5 J / g·°C. The heat required to heat the electrolyte to 44°C can be calculated using the specific heat capacity formula:

[0172] =8400J<16080J;

[0173] Calculations show that the heat required to heat the electrolyte to the set injection temperature is far less than the available waste heat generated by the formation process, allowing the electrolyte to be heated to the set injection temperature using the waste heat from the formation process. Furthermore, without considering the impact of other lithium battery performance factors, as shown in Table 1, as the electrolyte temperature is further increased, the electrolyte viscosity is further reduced, and the time required for infiltration is further shortened, thus reducing the production cost of the lithium battery.

[0174] Table 1

[0175]

[0176] S4. Inject the heated electrolyte into the battery cell to soak it.

[0177] The heated electrolyte is injected into the battery cell, and the heated liquid is used to penetrate into the electrode sheet, ultimately improving the battery's wetting effect and enhancing the battery's overall performance.

[0178] Implementation Method 2

[0179] By simplifying the calculation steps, an empirical model is used to approximate the heat generated during the battery formation process, reducing the computational complexity. By directly using the experimentally derived relationship between electrolyte and temperature, the optimal electrolyte injection temperature can be quickly selected.

[0180] Specific steps:

[0181] S1. Calculate the amount of waste heat that can be recovered during the chemical process

[0182] The capacity of a certain type of lithium battery is 3Ah, and the total heat generated during the battery formation process is 3000J. Here, we simplify the heat calculation and directly assume that the waste heat that can be recovered is 40% of the total heat, that is:

[0183] = 0.40×30000 J= 12000 J;

[0184] S2. Simplified viscosity calculation

[0185] In this embodiment, the electrolyte used is a mixture of 1 mol / l sodium sulfate solution and 2 mol / l lithium hexafluorophosphate.

[0186] The optimal infiltration height H of the lithium battery electrolyte is 345 mm; the absorption time t is 5500s; the cell radius is 0.01mm; the surface tension δ of the electrolyte is 0.005N / m; the contact angle between the electrolyte and the electrode is 0°.

[0187] Calculation is based on the Lucas-Washburn permeability model:

[0188] ;

[0189] When the calculation shows that the dynamic viscosity of the electrolyte should reach 1.16 mPa·s, in order to simplify the calculation, the empirical formula of the dynamic viscosity of the electrolyte and temperature obtained from the experiment is used:

[0190] According to the experimental data, A = 0.1 and B = -0.67 are set, and the calculated result is 40°C. At the same time, it can be further verified by looking up Table 2 that when the electrolyte temperature is 40°C, the dynamic viscosity is close to about 1.1 mPa·s.

[0191] S3. Use waste heat to heat the electrolyte to the injection temperature

[0192] The initial temperature of the electrolyte measured on site is 20°C. The electrolyte injection temperature needs to be above 40°C. The waste heat available in the formation process is 12,000 J. The mass of the electrolyte used for immersion is 0.1 kg. The specific heat capacity of the electrolyte is c = 2.8 J / g·°C. The heat required to heat the electrolyte to 40°C can be calculated using the specific heat capacity formula:

[0193] =5600J<12000J

[0194] Calculations show that the heat required to heat the electrolyte to the set injection temperature is far less than the available waste heat generated by the formation process, allowing the electrolyte to be heated to the set injection temperature using the waste heat from the formation process. Furthermore, without considering the impact of other lithium battery performance factors, as shown in Table 2, as the electrolyte temperature is further increased, the electrolyte viscosity is further reduced, and the time required for infiltration is further shortened, thus reducing the production cost of the lithium battery.

[0195] Table 2

[0196]

[0197] S4. Inject the heated electrolyte into the battery cell to soak it

[0198] The heated electrolyte is injected into the battery cell. After using heat to reduce the viscosity, the electrolyte can better penetrate the electrode sheet and improve the wetting effect.

[0199] Example 2

[0200] In an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the battery cell wetting method described in any one of the embodiments 1 is implemented.

[0201] Example 3

[0202] A computer program product is provided in an embodiment of the present invention, including a computer program / instruction, which implements the battery cell wetting method described in any one of Embodiment 1 when executed by a processor.

[0203] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0204] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0205] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0206] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0207] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

[0208] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A battery cell infiltration method, characterized in that: include: Calculate the recoverable waste heat of the formation process; Calculate the optimal dynamic viscosity of the battery cell and find the optimal temperature corresponding to the optimal dynamic viscosity by looking up the table; Calculating the total amount of heat required to heat a certain mass of electrolyte to the optimal temperature; If the recoverable waste heat is greater than the total heat, a control instruction is sent to the infiltration mechanism, so that the infiltration mechanism uses the recoverable waste heat to heat the electrolyte to the optimal temperature and injects the heated electrolyte into the battery cell for infiltration.

2. A battery cell impregnation method according to claim 1, characterized in that: The calculation formula for the recoverable waste heat is: ， in: ， Where, To recover waste heat, is the total heat generated by the battery formation process, is the recovery coefficient, is the heat of reaction, is the Joule heat of the ohmic internal resistance, is the polarization heat, is the side reaction heat, It is the heat load of the forming cabinet itself.

3. A battery cell impregnation method according to claim 2, characterized in that: The reaction heat The calculation formula is: ， in, ， Where, is the electrochemical energy of the battery; It refers to the energy released during the actual use of the battery after the battery is charged; is the battery voltage, is the charge of the battery.

4. A battery cell impregnation method according to claim 2, characterized in that: Joule heating of the ohmic internal resistance The calculation formula is: ， Where, is the charge and discharge current, is the ohmic internal resistance; is the charge and discharge time.

5. A battery cell impregnation method according to claim 2, characterized in that: The thermal load of the forming cabinet itself The calculation formula is: ， Where, is the total electrical energy input to the forming cabinet, is the cabinet heating rate.

6. A battery cell impregnation method according to claim 1, characterized in that: The calculation formula of the optimal dynamic viscosity is: ， Where, is the optimal dynamic viscosity, is the electrolyte wetting height, is the aspiration time; is the form radius of the battery cell; is the surface tension of the electrolyte; is the contact angle.

7. A battery core impregnation method according to claim 1, characterized in that: The parameters in the table include different dynamic viscosities and temperatures corresponding to different dynamic viscosities.

8. A battery cell impregnation method according to claim 1, characterized in that: The calculation formula of the total heat is: ， in, ， Where, is the total calories, is the specific heat capacity, is the mass of the electrolyte, is the temperature difference, For the optimal temperature, is the initial temperature of the electrolyte.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the battery cell impregnation method according to any one of claims 1 to 8 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the battery cell impregnation method according to any one of claims 1 to 8 is implemented.

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