Internal formation process of AGM battery and AGM start-stop battery

Abstract

The present application discloses an in - formation process for an AGM battery and an AGM start - stop battery, which is applied to an AGM battery with a thickness of d mm of the AGM separator, where 1 ≤ d ≤ 2; the in - formation process includes the following steps: S1. Add dilute sulfuric acid to the battery as the electrolyte; S2. Constant - current charge for 14 h to reach a charge capacity of 70 Ah; S3. Stand still for 0.5 h; S4. Charge at I A for T1 h, stand still for M h, discharge at I A for T2 h, stand still for M h, and repeat the above charging and discharging steps N times to reach a charge capacity of 70 Ah; where 12 ≤ I ≤ 25, 8 / 60 ≤ T1 ≤ 20 / 60, 2 / 60 ≤ T2 ≤ 4 / 60; S5. Absorb acid; S6. Repeat S4 once. By adopting the above technical solution, it is possible to reduce the formation time while ensuring that the active components of the positive and negative electrodes inside the battery will not be reduced and the comprehensive performance of the battery will not be reduced.

Description

Technical Field

[0001] This application relates to the technical field of lead-acid batteries, especially the internal formation process of AGM batteries and AGM start-stop batteries. Background Art

[0002] The lead-acid batteries used in automobiles have relatively high requirements for their electrical performance, especially start-stop batteries; generally, AGM lead-acid batteries are selected.

[0003] The currently adopted internal formation process is generally divided into stage constant current charging or multi-step charge and discharge, but the charging and discharging currents are very small. Because when internal formation is carried out with a large current, the current reception of the battery plates is restricted, and the current will act on the electrolyte, electrolyzing the electrolyte and releasing a large amount of gas. Therefore, the existing technology generally requires more than 48 hours for internal formation. How to shorten the formation time of the battery and improve the production efficiency of the battery is an urgent problem to be solved. Summary of the Invention

[0004] In order to solve at least one of the above technical problems and develop an efficient internal formation process for AGM lead-acid batteries, this application provides an internal formation process for AGM batteries and AGM start-stop batteries.

[0005] On the one hand, an internal formation process for AGM batteries provided by this application is applied to AGM batteries with an AGM separator thickness of d mm, where 1 ≤ d ≤ 2; the internal formation process includes the following steps:

[0006] S1. Add dilute sulfuric acid to the battery as the electrolyte;

[0007] S2. Constant current charge for 14 hours to reach a charge capacity of 70 Ah;

[0008] S3. Stand for 0.5 hour;

[0009] S4. Charge at I A for T1 hours, stand for M hours, discharge at I A for T2 hours, stand for M hours, and repeat the above charge and discharge steps N times to reach a charge capacity of 70 Ah; where 12 ≤ I ≤ 25, 8 / 60 ≤ T1 ≤ 20 / 60, 2 / 60 ≤ T2 ≤ 4 / 60;

[0010] S5. Absorb acid;

[0011] S6. Repeat S4.

[0012] By adopting the above technical solution, while reducing the formation time, it can ensure that the active components of the positive and negative electrodes inside the battery do not decrease, and the comprehensive performance of the battery does not decrease.

[0013] Optionally, in S4, 5 ≤ M / (T1 + T2) ≤ 12.

[0014] By adopting the above technical solution, while reducing the formation time, it can effectively improve the active components of the positive and negative electrodes inside the storage battery and enhance the comprehensive performance of the storage battery.

[0015] Optionally, in S4, when 1 ≤ d ≤ 1.4, 8 ≤ M / (T1 + T2) ≤ 12; when 1.4 ≤ d ≤ 2, 5 ≤ M / (T1 + T2) ≤ 8.

[0016] By adopting the above technical solution, for the separator thickness in the range of 1 - 1.4 mm and 1.4 - 2 mm, different current magnitudes, charging time, discharging time, interval time, and number of cycles are adjusted to reduce the internal formation process time while also enhancing the comprehensive performance of the storage battery.

[0017] Optionally, in S4, 4.5 ≤ T1 / T2 ≤ 5.5.

[0018] Optionally, in S1, the concentration of the dilute sulfuric acid is 35%.

[0019] Optionally, in S1, the temperature of the dilute sulfuric acid is 10°C.

[0020] In a second aspect, the present application provides an AGM storage battery prepared by the above internal formation process.

[0021] By adopting the above technical solution, the comprehensive performance of the prepared storage battery can meet the AGM storage battery standard.

[0022] In summary, the present application includes at least one of the following beneficial technical effects:

[0023] 1. According to the thickness of the AGM separator being in the range of 1 - 2 mm, the present application formulates a corresponding internal formation process to reduce the formation time and ensure the stable comprehensive performance of the prepared storage battery;

[0024] 2. By limiting the charging and discharging current, multiple charging and discharging, and the interval time in the second-step charging and discharging and the third-step charging and discharging, the present application reduces the corresponding charging and discharging time, thereby reducing the total time-consuming of the internal formation process and ensuring the comprehensive performance of the prepared storage battery. Specific Embodiments

[0025] The following embodiments further illustrate the present application in detail.

[0026] The present application designs an internal formation process for an AGM storage battery, which is applied to an AGM storage battery with a separator thickness of d mm, where 1 ≤ d ≤ 2; the internal formation process includes the following steps:

[0027] S1. Add dilute sulfuric acid to the storage battery as the electrolyte;

[0028] S2. Constant current charge for 14 h to reach a charge capacity of 70 Ah;

[0029] S3. Stand still for 0.5 h;

[0030] S4. Charge at IA for T1 h, stand still for M h, discharge at IA for T2 h, stand still for M h, and repeat the above charge and discharge steps N times to reach a charge capacity of 70 Ah; where 12 ≤ I ≤ 25, 8 / 60 ≤ T1 ≤ 20 / 60, 2 / 60 ≤ T2 ≤ 4 / 60;

[0031] S5. Acid absorption;

[0032] S6. Repeat S4.

[0033] In the existing internal formation process, the time consumption is generally more than 48 h and the formation efficiency is relatively low. At present, there are also means to reduce the formation time by increasing the charge and discharge current. However, when charging and discharging at a large current, the gas evolution amount will increase, delaying the diffusion of sulfuric acid and water in the lead paste pores. The gas will also discharge the sulfuric acid liquid out of the lead paste pores, reducing the charging efficiency. Therefore, there are great restrictions in the application of the internal formation process and the effect is not good.

[0034] The applicant found that in an AGM battery, the pore diameter and thickness of the glass fiber AGM separator have a great influence on the absorption and recombination of hydrogen and oxygen generated into water. Since the pore diameter of the separator has a great influence on the battery performance and is not easy to expand, the applicant studied the thickness of the separator.

[0035] On this basis, the applicant found that when forming according to the above internal formation process, the formation time can be effectively reduced, and the performance of the prepared battery will not decrease significantly, and even has an improvement.

[0036] In the above technical solution, optionally, in S4, 5 ≤ M / (T1 + T2) ≤ 12.

[0037] The applicant analyzed and found that when increasing the charge and discharge current to reduce the internal formation process time and improve the efficiency, with the change of the single charge and discharge and the interval time, the influence on the performance of the prepared battery is relatively large. Therefore, the applicant further studied and found that when the single charge and discharge and the interval time satisfy 5 ≤ M / (T1 + T2) ≤ 12, the performance of the prepared battery is relatively excellent.

[0038] In the above technical solution, optionally, in S4, when 1 ≤ d ≤ 1.4, 8 ≤ M / (T1 + T2) ≤ 12; when 1.4 ≤ d ≤ 2, 5 ≤ M / (T1 + T2) ≤ 8.

[0039] The applicant analyzed and found that as the thickness of the separator changes, the impact of charge-discharge and interval time adjustment on the comprehensive performance of the prepared storage battery fluctuates. Moreover, within the ranges above and below 1.4 for the thickness of the separator, the fluctuations with the adjustment of charge-discharge and interval time are different. Therefore, on this basis, the applicant further studied and found that when 1 ≤ d ≤ 1.4 and 8 ≤ M / (T1 + T2) ≤ 12; when 1.4 ≤ d ≤ 2 and 5 ≤ M / (T1 + T2) ≤ 8, the prepared storage battery has better comprehensive performance.

[0040] Unless otherwise specified, the main raw materials in the following embodiments of this application are all purchased from commercially available products.

[0041] Dilute sulfuric acid: The concentration of dilute sulfuric acid is 35%. When adding, the temperature of dilute sulfuric acid is 10°C.

[0042] AGM separator: The density is 155 g / (m 2 *mm) Specific embodiments

[0044] Example 1

[0045] The thickness of the AGM separator in this example is 1 mm.

[0046] The internal formation process in this example includes the following steps: adding dilute sulfuric acid as the electrolyte to the storage battery; constant current charging for 14 h to reach a charging power of 70 Ah; standing for 0.5 h; charging at 12 A for 10 min, standing for 1 min, discharging at 12 A for 2 min, standing for 1 min, and repeating the above charge-discharge steps 44 times with a charging power of 70.4 Ah; vacuum acid suction; charging at 12 A for 10 min, standing for 1 min, discharging at 12 A for 2 min, standing for 1 min, and repeating the above charge-discharge steps 44 times with a charging power of 70.4 Ah. The total charging power input in the internal formation process of this example is 210.8 Ah, and it takes a total of 2102 min, approximately 35 h.

[0047] This example also provides a lead-acid storage battery prepared using the above internal formation process.

[0048] Example 2

[0049] The thickness of the AGM separator in this example is 1.2 mm.

[0050] The internal formation process of this embodiment includes the following steps: adding dilute sulfuric acid to the storage battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing still for 0.5 h; charging at 16 A for 18 min, standing still for 2.2 min, discharging at 16 A for 4 min, standing still for 2.2 min, repeating the above charge and discharge steps 19 times, and the charging capacity is 70.9 Ah; vacuum acid suction; charging at 16 A for 18 min, standing still for 2.2 min, discharging at 16 A for 4 min, standing still for 2.2 min, repeating the above charge and discharge steps 19 times, and the charging capacity is 70.9 Ah. The total charge input in the internal formation process of this embodiment is 211.8 Ah, and the total time consumed is 1873.2 min, approximately 31 h.

[0051] This embodiment also provides a lead-acid storage battery prepared by using the above internal formation process.

[0052] Example 3

[0053] The thickness of the AGM separator in this embodiment is 1.4 mm.

[0054] The internal formation process of this embodiment includes the following steps: adding dilute sulfuric acid to the storage battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing still for 0.5 h; charging at 25 A for 20 min, standing still for 3 min, discharging at 25 A for 4 min, standing still for 3 min, repeating the above charge and discharge steps 11 times, and the charging capacity is 73.3 Ah; vacuum acid suction; charging at 25 A for 20 min, standing still for 3 min, discharging at 25 A for 4 min, standing still for 3 min, repeating the above charge and discharge steps 11 times, and the charging capacity is 73.3 Ah. The total charge input in the internal formation process of this embodiment is 219.9 Ah, and the total time consumed is 1530 min, which is 25.5 h.

[0055] This embodiment also provides a lead-acid storage battery prepared by using the above internal formation process.

[0056] Example 4

[0057] The thickness of the AGM separator in this embodiment is 1.6 mm.

[0058] The internal formation process of this embodiment includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h until the charging capacity reaches 70 Ah; standing still for 0.5 h; charging at 22 A for 15 min, standing still for 2.6 min, discharging at 22 A for 3 min, standing still for 2.6 min, repeating the above charge and discharge steps 16 times, and the charging capacity is 70.4 Ah; vacuum acid suction; charging at 22 A for 15 min, standing still for 2.6 min, discharging at 22 A for 3 min, standing still for 2.6 min, repeating the above charge and discharge steps 16 times, and the charging capacity is 70.4 Ah. The total charge input in the internal formation process of this embodiment is 210.8 Ah, and the total time consumed is 1612.4 min, approximately 27 h.

[0059] This embodiment also provides a lead-acid battery prepared by using the above internal formation process.

[0060] Example 5

[0061] The thickness of the AGM separator in this embodiment is 1.8 mm.

[0062] The internal formation process of this embodiment includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h until the charging capacity reaches 70 Ah; standing still for 0.5 h; charging at 20 A for 11 min, standing still for 2.2 min, discharging at 20 A for 2 min, standing still for 2.2 min, repeating the above charge and discharge steps 24 times, and the charging capacity is 72 Ah; vacuum acid suction; charging at 20 A for 11 min, standing still for 2.2 min, discharging at 20 A for 2 min, standing still for 2.2 min, repeating the above charge and discharge steps 24 times, and the charging capacity is 72 Ah. The total charge input in the internal formation process of this embodiment is 214 Ah, and the total time consumed is 1705.2 min, approximately 28 h.

[0063] This embodiment also provides a lead-acid battery prepared by using the above internal formation process.

[0064] Example 6

[0065] The thickness of the AGM separator in this embodiment is 2 mm.

[0066] The internal formation process of this embodiment includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h until the charging capacity reaches 70 Ah; standing still for 0.5 h; charging at 18 A for 8 min, standing still for 2 min, discharging at 18 A for 2 min, standing still for 2 min, repeating the above charge and discharge steps 39 times, and the charging capacity is 70.2 Ah; vacuum acid suction; charging at 18 A for 8 min, standing still for 2 min, discharging at 18 A for 2 min, standing still for 2 min, repeating the above charge and discharge steps 39 times, and the charging capacity is 70.2 Ah. The total charge input in the internal formation process of this embodiment is 210.4 Ah, and the total time consumed is 1962 min, approximately 33 h.

[0067] This embodiment also provides a lead-acid battery prepared by using the above internal forming process.

[0068] Comparative Example 1

[0069] The thickness of the AGM separator in this comparative example is 1 mm.

[0070] The internal forming process of this comparative example includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing for 0.5 h;

[0071] Charging at 2 A for 2 h, discharging at 4 A for 3 h, discharging at 5 A for 6 h, discharging at 6 A for 4 h, with a charging capacity of 70 Ah;

[0072] Discharging at 10 A for 0.5 h, with a discharging capacity of 5 Ah;

[0073] Charging at 7 A for 0.5 h, discharging at 6 A for 1.5 h, with a charging capacity of 10.5 Ah;

[0074] Discharging at 10 A for 0.5 h, with a discharging capacity of 5 Ah;

[0075] Charging at 7 A for 2 h, discharging at 6 A for 4 h, discharging at 5 A for 3 h, discharging at 4 A for 2 h, discharging at 3 A for 3 h, with a charging capacity of 70 Ah;

[0076] The total charging capacity of the internal forming process in this comparative example is 210.5 Ah, and the total time consumed is 46.5 h.

[0077] This comparative example also provides a lead-acid battery prepared by using the above internal forming process.

[0078] Comparative Example 2

[0079] The thickness of the AGM separator in this comparative example is 1.4 mm.

[0080] The internal forming process of this comparative example includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing for 0.5 h;

[0081] Charging at 2 A for 2 h, discharging at 4 A for 3 h, discharging at 5 A for 6 h, discharging at 6 A for 4 h, with a charging capacity of 70 Ah;

[0082] Discharging at 10 A for 0.5 h, with a discharging capacity of 5 Ah;

[0083] Charging at 7 A for 0.5 h, discharging at 6 A for 1.5 h, with a charging capacity of 10.5 Ah;

[0084] Discharging at 10 A for 0.5 h, with a discharging capacity of 5 Ah;

[0085] Charge at 7 A for 2 h, discharge at 6 A for 4 h, discharge at 5 A for 3 h, discharge at 4 A for 2 h, discharge at 3 A for 3 h, and the charged amount is 70 Ah;

[0086] The total charged amount in the internal formation process of this comparative example is 210.5 Ah, and the total time taken is 46.5 h.

[0087] This comparative example also provides a lead-acid battery prepared by using the above internal formation process.

[0088] Comparative Example 3

[0089] The thickness of the AGM separator in this comparative example is 2 mm.

[0090] The internal formation process of this comparative example includes the following steps: Add dilute sulfuric acid to the battery as the electrolyte; Constant current charge for 14 h until the charged amount reaches 70 Ah; Stand still for 0.5 h;

[0091] Charge at 2 A for 2 h, discharge at 4 A for 3 h, discharge at 5 A for 6 h, discharge at 6 A for 4 h, and the charged amount is 70 Ah;

[0092] Discharge at 10 A for 0.5 h, and the discharged amount is 5 Ah;

[0093] Charge at 7 A for 0.5 h, discharge at 6 A for 1.5 h, and the charged amount is 10.5 Ah;

[0094] Discharge at 10 A for 0.5 h, and the discharged amount is 5 Ah;

[0095] Charge at 7 A for 2 h, discharge at 6 A for 4 h, discharge at 5 A for 3 h, discharge at 4 A for 2 h, discharge at 3 A for 3 h, and the charged amount is 70 Ah;

[0096] The total charged amount in the internal formation process of this comparative example is 210.5 Ah, and the total time taken is 46.5 h.

[0097] This comparative example also provides a lead-acid battery prepared by using the above internal formation process.

[0098] Select several batteries from Examples 1-6 and Comparative Examples 1-3 for the following experiments. For each group of experiments, select five batteries in each example or comparative example as a group, and the experimental results are averaged. Conduct a 45 °C 60% DOD cycle life detection test. The detection results are shown in Table 1.

[0099] Table 1 Detection performance of Examples 1-6 and Comparative Examples 1-3

[0100]

[0101] From Examples 1-6, Comparative Examples 1-3, and Table 1, it can be seen that the internal formation process of the present application can effectively improve the active components of the positive and negative electrodes, comprehensively improve the performance of the lead-acid battery, enabling the lead-acid battery to reach more than 2000 cycles at 45°C with 60% DOD, which is higher than less than 1850 cycles in Comparative Examples 1-3. Thus, it can be seen that the performance of the lead-acid battery prepared by the internal formation process of the present application is not lower than that of the lead-acid battery prepared by the existing internal formation process, and is even stronger in terms of comprehensive performance.

[0102] On this basis, the internal formation process of Examples 1-6 takes 25.5 - 35h, saving more than 25% of the time compared to the 46.5h of the internal formation process in Comparative Examples 1-3. On the premise of ensuring the effect of the internal formation process, the efficiency of the internal formation process is improved.

[0103] Referring to Example 1 and Comparative Example 1, Example 3 and Comparative Example 2, Example 6 and Comparative Example 3, and the corresponding performance parameters in Table 1, it can be seen that when the thickness of the AGM separator in the battery is the same, the internal formation process adopted in the present application can ensure that the performance of the battery does not decrease, and on the premise of different degrees of improvement, the time of the internal formation process is greatly reduced, thereby improving the efficiency of the internal formation process.

[0104] Referring to Examples 1-6 and the corresponding performance parameters in Table 1, it can be seen that when the present application's internal formation process is for AGM separators of different thicknesses, by adjusting the current magnitude, charging time, discharging time, interval time, and number of cycles in the second-step charging, while reducing the internal formation process time, the performance of the battery is ensured not to decrease. For this reason, the applicant made Comparative Examples 4-6.

[0105] Comparative Example 4

[0106] The thickness of the AGM separator in this comparative example is 1mm.

[0107] The internal formation process of this comparative example includes the following steps: adding dilute sulfuric acid as the electrolyte to the battery; constant current charging for 14h to reach a charging capacity of 70Ah; standing for 0.5h; charging at 25A for 20min, standing for 3min, discharging at 25A for 4min, standing for 3min, repeating the above charge and discharge steps 11 times, with a charging capacity of 73.3Ah; vacuum acid suction; charging at 25A for 20min, standing for 3min, discharging at 25A for 4min, standing for 3min, repeating the above charge and discharge steps 11 times, with a charging capacity of 73.3Ah. The total charge input in the internal formation process of this comparative example is 219.9Ah, and it takes a total of 1530min, which is 25.5h.

[0108] This comparative example also provides a lead-acid battery prepared using the above internal formation process.

[0109] Comparative Example 5

[0110] The thickness of the AGM separator in this comparative example is 1.4 mm.

[0111] The internal formation process of this comparative example includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing for 0.5 h; charging at 18 A for 8 min, standing for 2 min, discharging at 18 A for 2 min, standing for 2 min, repeating the above charge and discharge steps 39 times, with a charging capacity of 70.2 Ah; vacuum acid suction; charging at 18 A for 8 min, standing for 2 min, discharging at 18 A for 2 min, standing for 2 min, repeating the above charge and discharge steps 39 times, with a charging capacity of 70.2 Ah. The total charge input in the internal formation process of this comparative example is 210.4 Ah, and the total time consumed is 1962 min, approximately 33 h.

[0112] This comparative example also provides a lead-acid battery prepared by using the above internal formation process.

[0113] Comparative Example 6

[0114] The thickness of the AGM separator in this comparative example is 2 mm.

[0115] The internal formation process of this comparative example includes the following steps: adding dilute sulfuric acid to the battery as the electrolyte; constant current charging for 14 h to reach a charging capacity of 70 Ah; standing for 0.5 h; charging at 12 A for 10 min, standing for 1 min, discharging at 12 A for 2 min, standing for 1 min, repeating the above charge and discharge steps 44 times, with a charging capacity of 70.4 Ah; vacuum acid suction; charging at 12 A for 10 min, standing for 1 min, discharging at 12 A for 2 min, standing for 1 min, repeating the above charge and discharge steps 44 times, with a charging capacity of 70.4 Ah. The total charge input in the internal formation process of this comparative example is 210.8 Ah, and the total time consumed is 2102 min, approximately 35 h.

[0116] This comparative example also provides a lead-acid battery prepared by using the above internal formation process.

[0117] A 45°C 60% DOD cycle life detection test was carried out. The detection results are shown in Table 2.

[0118] Table 2 Detection Performance of Comparative Examples 4 - 6

[0119]

[0120]

[0121] Referring to Example 1, Comparative Example 1 and Comparative Example 4, Example 3, Comparative Example 2 and Comparative Example 5, Example 6, Comparative Example 3 and Comparative Example 6, and the corresponding performance parameters in Table 2, it can be seen that in the internal formation process of the present application, when 1≤d≤1.4, 8≤M / (T1+T2)≤12; when 1.4≤d≤2, 5≤M / (T1+T2)≤8. The internal formation process in Examples 1, 3, and 6 corresponding thereto takes a shorter time, and the comprehensive performance of the prepared storage battery is better; however, when 1≤d≤1.4, 5≤M / (T1+T2)≤8; when 1.4≤d≤2, 8≤M / (T1+T2)≤12, the internal formation process in Comparative Examples 4-6 corresponding thereto takes a shorter time, but the comprehensive performance of the corresponding prepared storage battery shows varying degrees of decline compared to Comparative Examples 1-3. Therefore, adjusting the charging time, discharging time, and interval time in the second and third charging and discharging processes in the present application according to the thickness of the AGM separator is a very important index in the internal formation process of the present application and has a greater impact on the performance of the prepared storage battery. When the performance requirements of the prepared storage battery are not high, the process parameters with shorter time consumption in Example 3 can be selected to reduce the internal formation process time and improve the efficiency. However, when pursuing the balance between performance and efficiency, it is more appropriate to stipulate the charging and discharging and interval times according to the AGM separator thickness d according to the standard: 1≤d≤1.4, 8≤M / (T1+T2)≤12; when 1.4≤d≤2, 5≤M / (T1+T2)≤8.

[0122] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. An internal formation process for an AGM battery, characterized in that, An AGM battery with a thickness of d mm applied to an AGM separator, where 1 ≤ d ≤ 2; the internal formation process includes the following steps: S1. Add dilute sulfuric acid to the battery as the electrolyte; S2. Constant current charge for 14 h to reach a charge capacity of 70 Ah; S3. Stand still for 0.5 h; S4. Charge with IA for T1 h, let it stand for M h, discharge with IA for T2 h, let it stand for M h, and repeat the above charging and discharging steps N times to reach a charging capacity of 70 Ah; where 12 ≤ I ≤ 25, 8 / 60 ≤ T1 ≤ 20 / 60, 2 / 60 ≤ T2 ≤ 4 / 60; S5. Absorb acid; S6. Repeat S4 once; Among them, in S4, 5 ≤ M / (T1 + T2) ≤ 12.

2. The internal formation process according to claim 1, characterized in that: In S4, when 1 ≤ d ≤ 1.4, 8 ≤ M / (T1 + T2) ≤ 12; When 1.4 ≤ d ≤ 2, 5 ≤ M / (T1 + T2) ≤ 8.

3. The internal formation process according to claim 1, characterized in that: In S4, 4.5 ≤ T1 / T2 ≤ 5.

5.

4. The internal formation process according to claim 1, characterized in that: In S1, the concentration of the dilute sulfuric acid is 35%.

5. The internal formation process according to claim 1, characterized in that: In S1, the temperature of the dilute sulfuric acid is 10°C.

6. An AGM battery, characterized in that, Prepared by the internal formation process according to any one of claims 1-3.

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