1. A method for predicting the service life of a lead storage battery is characterized by comprising the following steps:

(1) taking a plurality of lead storage batteries to be detected with the same model, performing a plurality of charge-discharge cycles, and sampling and detecting beta-PbO in the positive plate of the lead storage battery in the charge-discharge cycle process₂Crystal size of (a), number of charge-discharge cycles for sampled lead-acid batteries and beta-PbO in positive plate₂The crystal size of the lead-free lithium battery is subjected to linear fitting to obtain the charge-discharge cycle number-beta-PbO₂Crystal size relationship;

(2) the number of charge-discharge cycles obtained according to step (1) -beta-PbO₂The crystal size relation is calculated to obtain beta-PbO₂Has a crystal size ofThe corresponding number of charge-discharge cycles is used as the service life of the lead storage battery of the model.

2. The method for predicting the life of a lead-acid battery according to claim 1, wherein the lead-acid battery to be detected in the step (1) is subjected to 50 to 100 charge-discharge cycles.

3. The method for predicting the life of a lead-acid battery according to claim 1, wherein the sampling is performed at least 2 to 3 times during the charge-discharge cycle.

4. A method of predicting the life of a lead acid battery as in claim 3, wherein 50 charge and discharge cycles are performed every two sampling intervals.

5. The method for predicting the life of a lead-acid battery according to claim 1, wherein the lead-acid battery to be tested in the step (1) is sampled at 0 times and 50 times of the charge-discharge cycle through 50 cycles of the charge-discharge cycle, respectively.

6. The method for predicting the life of a lead acid battery as set forth in claim 1, wherein the charging in the step (1)The discharge cycle process is as follows: constant pressure first 2.45V/grid current limiting 0.5C₂Charging for 4h with A, and charging with 0.5C₂The current of A is discharged to 1.70V/grid.

7. The method for predicting the life of a lead storage battery according to claim 1, wherein in the step (1), the positive plate of the lead storage battery is washed with water and then dried, and the active material in the middle of the dried positive plate is ground into powder to be subjected to XRD test.

8. The method for predicting life of lead storage battery according to claim 7, wherein β -PbO₂The crystal size calculation process of (1), comprising the steps of:

(1) measurement of beta-PbO by XRD measurement₂A half-peak width B of the characteristic peak at θ of 25.4 degrees;

(2) calculating beta-PbO by using Sherle formula D ═ K lambda/Bcos theta₂K0.89, θ 25.4, λ 0.154056nm, to give a crystal of (a)Calculating the crystal size D by taking the half-peak width B of a plurality of characteristic peaks to obtain beta-PbO₂Average value of crystal size of

(3) Taking beta-PbO₂Average value of crystal sizeLinearly fitting with the number of charge-discharge cycles to obtain the number of charge-discharge cycles-beta-PbO₂Crystal size relationship;

(4) when beta-PbO₂Average of crystal sizeNumber of charge-discharge cycles-beta-PbO₂The number of charge-discharge cycles corresponding to the crystal size relationship is the life of the lead-acid battery.

Background

With the development of economy, the energy sources such as coal, petroleum and the like are seriously in short supply, and the development and the utilization of new energy sources become a necessary way for the sustainable development of various countries in the world. Therefore, the research on electromotive force has become the mainstream direction of research, and the development level of battery as the core component of electromotive force product directly affects the development of electromotive force industry. Only the power battery with mature technology, low cost and high safety can lead the electric products to be widely developed, and on one hand, the power battery with high performance and long service life should be developed; on the other hand, a power battery life evaluation method and a life model should be established, and the battery life should be scientifically evaluated and predicted.

In addition to the demand for higher capacity of the battery, the demand for longer life of the battery, that is, the number of times the battery can be charged and discharged, is also increasing. The traditional method for predicting the service life of the battery is realized by charging and discharging the battery for many times. The time required by one cycle test is about 10 hours, and 500 cycles require more than 5000 hours, namely more than 200 days, which brings certain difficulty to the progress of scientific research and the introduction of research and development batteries into mass production. Therefore, a test method for rapidly predicting the battery life is urgently needed.

Patent document (CN112034353A) discloses a battery life prediction method and system. The method comprises the following steps: calculating a predicted battery life value after the first actual service time of the battery according to the first life prediction curve and first working condition information, wherein the first working condition information comprises at least one of the first actual charging and discharging multiplying power, the first actual discharging total capacity, the first actual service temperature, the first actual charge state and the first actual service time of the battery; determining a first life correction factor according to the actual battery life value and the predicted battery life value after the first low-grade service time; and generating a second life prediction curve according to the first life correction coefficient and the first life prediction curve, and determining a life prediction result of the battery after the first actual service time according to the second life prediction curve.

Patent literature (CN111722115A) discloses a method and a system for predicting the life of a power battery, wherein the method for predicting the life of the power battery is implemented based on a time series model and transfer learning, and the method is based on a transfer learning mode, and obtains a third life curve by using life test data of the power battery, and then obtains a life deviation curve by using a first life curve obtained by actual battery sample data and the third life curve; and finally, the third life curve is subjected to superposition correction by using the life deviation curve to obtain a predicted life curve of the power battery, so that the aim of obtaining the corresponding relation between the service life of the power battery and the actual use in the complete life cycle of the power battery on the basis of limited actual battery sample data is fulfilled.

The two methods need to build an effective battery system model, however, a battery system model needs to consider a large number of parameters, the model becomes complicated due to the increase of the parameters, and the building of a battery equivalent model also becomes complicated.

Disclosure of Invention

The invention discloses a method for predicting the service life of a lead storage battery, and aims to provide a method for rapidly predicting the service life of the lead storage battery.

A method for predicting the service life of a lead storage battery comprises the following steps:

(1) taking a plurality of lead storage batteries to be detected with the same modelAfter a plurality of charging and discharging cycles, sampling and detecting the beta-PbO in the positive plate of the lead storage battery in the charging and discharging cycle process₂Crystal size of (a), number of charge-discharge cycles for sampled lead-acid batteries and beta-PbO in positive plate₂The crystal size of the lead-free lithium battery is subjected to linear fitting to obtain the charge-discharge cycle number-beta-PbO₂Crystal size relationship;

(2) the number of charge-discharge cycles obtained according to step (1) -beta-PbO₂The crystal size relation is calculated to obtain beta-PbO₂Has a crystal size ofThe corresponding number of charge-discharge cycles is used as the service life of the lead storage battery of the model.

And (2) performing 50-100 times of charge-discharge circulation on the lead storage battery to be detected in the step (1).

Sampling is carried out at least 2-3 times in the charging and discharging circulation process, and 50 charging and discharging circulations are carried out at intervals of sampling time every two times.

And (2) sampling the lead storage battery to be detected in the step (1) after 50 times of charge-discharge cycles, wherein the sampling is carried out when the charge-discharge cycles are 0 time and 50 times respectively.

The charge-discharge cycle process in the step (1) is as follows: constant pressure first 2.45V/grid current limiting 0.5C₂Charging for 4h with A, and charging with 0.5C₂The current of A is discharged to 1.70V/grid.

In the step (1), the positive plate of the lead storage battery is washed by water and then dried, and the active substance in the middle of the dried positive plate is ground into powder for XRD test.

β-PbO₂The crystal size calculation process of (1), comprising the steps of:

(1) measurement of beta-PbO by XRD measurement₂A half-peak width B of the characteristic peak at θ of 25.4 degrees;

(2) calculating beta-PbO by using Sherle formula D ═ K lambda/Bcos theta₂K0.89, θ 25.4, λ 0.154056nm, to give a crystal of (a)Calculating the crystal size D by taking the half-peak width B of a plurality of characteristic peaks to obtain beta-PbO₂Average value of crystal size of

(3) Taking beta-PbO₂Average value of crystal sizeLinearly fitting with the number of charge-discharge cycles to obtain the number of charge-discharge cycles-beta-PbO₂Crystal size relationship;

(4) when beta-PbO₂Average of crystal sizeNumber of charge-discharge cycles-beta-PbO₂The number of charge-discharge cycles corresponding to the crystal size relationship is the life of the lead-acid battery.

Analysis of big anatomical data of the power battery after circulation shows that the power battery is subjected to circulation, and beta-PbO₂Crystal size of (b) and beta-PbO in the positive plate₂Has a good linear relationship between the crystal size of the lead storage battery and the cycle number of the lead storage battery. beta-PbO in the positive plate at the end of life of the lead storage battery₂Tends to be constant in crystal size

By fitting beta-PbO of lead storage battery₂The crystal size of the lead storage battery and a linear equation corresponding to 50-100 times of lead storage battery circulation are obtained, and the charge-discharge cycle number-beta-PbO of the lead storage battery is obtained₂Crystal size relationship. By lead accumulator beta-PbO₂Value of crystal sizeAnd predicting the service life of the lead storage battery according to the corresponding cycle times.

Compared with the prior art, the invention has the following advantages:

the method has strong universality, shortens the testing period of the cycle life of the lead storage battery, and provides a good technical means for research and development and production control.

Drawings

FIG. 1 shows the number of charge-discharge cycles- β -PbO of the battery of example 1₂Crystal size relationship.

FIG. 2 shows the number of charge-discharge cycles-beta-PbO of the battery of example 2₂Crystal size relationship.

FIG. 3 shows the number of charge-discharge cycles- β -PbO of the batteries of examples 3-5₂Crystal size relationship.

Detailed Description

Example 1

Theta values and beta-PbO values at 0 cycle, 50 cycles and 100 cycles for different types of lead storage batteries₂Counting the half-peak width by using the theta value and the beta-PbO₂The half-peak width was substituted into the scherrer equation to calculate the corresponding crystal size and the results are shown in table 1.

TABLE 1 different types of lead-acid batteries with different cycles of beta-PbO₂Crystal size and related parameters

Meanwhile, the beta-PbO is detected when the lead storage batteries of different types are in cyclic failure₂The crystal parameters and dimensions of (a) and the experimental data are shown in table 2.

TABLE 2 beta-PbO corresponding to failure of different types of lead-acid batteries₂Crystal size and related parameters

As shown in Table 2, it was found from the table that beta-PbO was generated when the lead storage battery failed cyclically₂Crystal size substantially tends to

The corresponding data in tables 1 and 2 were curve fitted and plotted to give figure 1. The results show that the cycle number and beta-PbO₂Crystal size has a highly linear relationship, goodness of fit R²And the fitting degree of the linear equation to the observed value is good as being close to 1. While the failure endpoint of the fitted curve tends to

Therefore, the beta-PbO of the lead storage battery can be fitted₂The crystal size and a linear equation corresponding to 50-100 times of cycle of the lead storage battery are obtained to obtain the charge-discharge cycle number-beta-PbO of the lead storage battery₂Crystal size relationship. By lead accumulator beta-PbO₂Value of crystal sizeAnd predicting the service life of the lead storage battery according to the corresponding cycle times.

Example 2

Taking a small and compact 20Ah lead storage battery, forming and then dissecting to obtain a positive plate; washing the positive plate with water, drying, grinding the active substance in the middle of the positive plate into powder, and testing beta-PbO in the active substance by XRD₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂Taking the half-peak width B of the 3-time characteristic peak to calculate the crystal size D to obtain the beta-PbO₂Average value of crystal size ofAs the corresponding crystal size at 0 cycles.

Dividing small-density 20Ah lead storage batteries into 4 groups, and performing cyclic charge and discharge, wherein the cyclic charge and discharge process is as follows: charging for 4 hours at a constant voltage of 14.7V and a current of 10A, discharging to 10.2V at a current of 10A, recording as a cycle, respectively cycling for 50 times, 100 times, 200 times and stopping the cycle test when the service life of the battery is over, and disassembling the battery to obtain a positive plate; is to obtainWashing the plate with water, drying, grinding the active substance in the middle of the positive plate into powder, and testing beta-PbO in the active substance by XRD₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂Taking the half-peak width B of the 3-time characteristic peak under the condition of different cycle times to calculate the crystal size D to obtain the beta-PbO₂Average value of crystal size ofCorresponding beta-PbO of different times of battery circulation₂The crystal sizes are shown in table 3.

TABLE 3 beta-PbO corresponding to different times of cycling of small-density 20Ah batteries₂Crystal size and related parameters

Taking beta-PbO₂Average value of crystal sizeLinearly fitting with the charge-discharge cycle number to obtain the charge-discharge cycle number-beta-PbO of the lead storage battery₂The size of the crystal is related by the linear equation of

Y＝0.581X+425 (1)，

Y is beta-PbO₂The average value of crystal size, X is the number of cycles.

Goodness of fit R of the above-described Linear equation (1)²0.9992, close to 1, illustrates that the linear equation fits well to the observed values. The experimental data in table 3 were plotted to obtain fig. 2.

Example 3

Based on the mass of the lead powder, the lead powder is prepared by0.1 percent of fiber, 0.1 percent of stannous sulfate, 0.1 percent of antimony trioxide, 10 percent of water and 4.5 percent of water with the density of 1.4g/cm³Uniformly mixing and pasting the sulfuric acid to obtain positive lead paste, and coating the obtained positive lead paste on a positive grid with the model of 6-DZF-20 to obtain a positive plate;

based on the mass of the lead powder, 9.5 percent of water with the density of 1.4g/cm³4.7% of sulfuric acid, 0.2% of lignin, 0.1% of humic acid, 0.2% of acetylene black, 0.7% of barium sulfate and 0.1% of fiber are uniformly mixed, paste mixing is carried out, and the obtained negative lead paste is coated on a negative grid with the model of 6-DZF-20 to obtain a negative plate;

and assembling the positive plate and the negative plate into a lead storage battery with the model of 6-DZF-20.

The temperature of the electrolyte is 0-10 ℃, and the density is 1.25g/cm³And adding 200mL of electrolyte into a sulfuric acid solution containing 1% of sodium sulfate in a single cell, placing the mixture in a water bath at the temperature of 25-40 ℃, and standing for 0.5-1 h. And (3) placing the battery after standing in a water bath at 25-40 ℃, firstly charging for 48h by using 3.6A current, then charging for 2h by using 1.2A current, absorbing acid, adding a safety valve, and sealing to obtain a finished product battery with the model of 6-DZF-20.

Taking the formed battery for dissection to obtain a positive plate; washing the positive plate with water, drying, grinding the active substance in the middle of the positive plate into powder, and testing beta-PbO in the active substance by XRD₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂Taking the half-peak width B of the 3-time characteristic peak to calculate the crystal size D to obtain the beta-PbO₂Average value of crystal size ofAs the corresponding crystal size at 0 cycles. The test results are shown in Table 4.

Taking the formed battery to perform charge and discharge circularly, wherein the charge and discharge process is as follows: charging for 4 hours at constant voltage of 14.7V under current of 10A, discharging to 10.2V at current of 10A, recording as a cycle, stopping charging and discharging for 50 times, disassembling, and collecting the positive electrodeWashing the plate with water, drying, grinding the active substance in the middle of the positive plate into powder, and testing beta-PbO in the active substance by XRD₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂Taking the half-peak width B of the 3-time characteristic peak to calculate the crystal size D to obtain the beta-PbO₂Average value of crystal size ofAs the corresponding crystal size at 50 cycles. The test results are shown in Table 4.

Example 4

Based on the mass of the lead powder, the lead powder comprises 0.1 percent of fiber, 0.1 percent of stannous sulfate, 0.1 percent of antimony trioxide, 10 percent of water and 4.5 percent of water with the density of 1.4g/cm³Uniformly mixing and pasting the sulfuric acid to obtain positive lead paste, and coating the obtained positive lead paste on a positive grid with the model of 6-DZF-20 to obtain a positive plate;

based on the mass of the lead powder, 9.5 percent of water with the density of 1.4g/cm³4.7% of sulfuric acid, 0.2% of lignin, 0.1% of humic acid, 0.2% of acetylene black, 0.7% of barium sulfate and 0.1% of fiber are uniformly mixed, paste mixing is carried out, and the obtained negative lead paste is coated on a negative grid with the model of 6-DZF-20 to obtain a negative plate;

and assembling the positive plate and the negative plate into a lead storage battery with the model of 6-DZF-20.

The temperature of the electrolyte is 0-10 ℃, and the density is 1.25g/cm³And adding 200mL of electrolyte into a sulfuric acid solution containing 1% of sodium sulfate in a single cell, placing the mixture in a water bath at the temperature of 25-40 ℃, and standing for 0.5-1 h. And (3) placing the battery after standing in a water bath at 25-40 ℃, firstly charging for 48h by using 3.6A current, then charging for 2h by using 1.2A current, absorbing acid, adding a safety valve, and sealing to obtain a finished product battery with the model of 6-DZF-20.

Taking the formed battery to perform charge and discharge circularly, wherein the charge and discharge process is as follows: charging for 4 hours at constant voltage of 14.7V and current limited by 10A, discharging to 10.2V at current of 10A, recording as a cycle, stopping charging and discharging for 100 times, and thenThe positive plate is disassembled, the positive plate is washed by water and then dried, active substances in the middle of the dried positive plate are taken and ground into powder, and XRD is used for testing beta-PbO in the active substances₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂Taking the half-peak width B of the 3-time characteristic peak to calculate the crystal size D to obtain the beta-PbO₂Average value of crystal size ofAs the corresponding crystal size at 100 cycles. The test results are shown in Table 4.

TABLE 4 beta-PbO corresponding to 6-DZF-20 battery cycle at different times₂Crystal size and related parameters

As can be seen from Table 4, the lead storage battery has beta-PbO with an increase in the number of cycles₂The crystal size is increased.

Example 5

Taking the beta-PbO in example 3 and example 4₂Average value of crystal sizeLinear fitting is carried out with the number of charge-discharge cycles to obtain the number of charge-discharge cycles-beta-PbO₂The crystal size is related, resulting in the linear equation:

Y＝0.810X+332 (2)，

y is beta-PbO₂The average value of crystal size, X is the number of cycles.

Goodness of fit R of the above-described linear equation (2)²0.9876, close to 1, for explanationThe linear equation fits well to the observed values.

β-PbO₂Taking crystal sizeThe cycle life of the lead storage battery obtained by using a linear equation is 330 times; the experimental data in table 4 were plotted to obtain fig. 3.

Example 6

A cycle test was carried out on 3 batteries of the type 6-DZF-20 formed in example 3, and the charging and discharging processes were as follows: charging for 4 hours at constant voltage of 14.7V and current limited by 10A, discharging to 10.2V at current of 10A, recording as a cycle until the battery is invalid, disassembling, washing the positive plate with water, drying, grinding active substances in the middle of the dried positive plate into powder, and testing beta-PbO in the active substances by XRD₂The half-peak width B of the characteristic peak with the angle theta of 25.4 degrees is expressed by the formulaCalculation of beta-PbO₂And taking the half-peak width B of the characteristic peak of the crystal size D to calculate the crystal size D as the corresponding crystal size when the circulation fails. The test results are shown in Table 5.

The average cycle life of the above batteries was 328 times, which substantially coincided with 330 times predicted in example 5, and the error was only 0.6%.

TABLE 5 beta-PbO corresponding to 6-DZF-20 battery failure₂Crystal size and related parameters

As can be seen from Table 5, when the battery of type 6-DZF-20 failed, β -PbO₂The crystal size tends to be constantThe maximum error does not exceed 1.8 percent, and the maximum error is not excluded from being caused by accidental factors.