A method of formation charging of a lead storage battery

Abstract

The application discloses a lead storage battery charging formation method and relates to the field of lead storage battery charging formation. The method comprises the following steps: (1) large-current intermittent pulse charging; (2) multi-stage variable-current constant-current charging; (3) lead storage battery constant-current discharging; (4) large-current constant-current charging; (5) high-frequency positive and negative pulse charging; (6) multiple circulation of steps (3)-(5); (7) trickle charging the battery to voltage stability and then carrying out acid extraction to complete the battery formation. The charging process disclosed by the application can reduce the battery electrolyte temperature in the formation process, improve the electrical performance of the storage battery, improve the consistency of the storage battery and improve the matching stability of the battery. Further, the premature capacity decline caused by the inconsistency of the battery in the use process of the storage battery is reduced, and the return rate of the lead-acid storage battery is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of charging formation of lead-acid batteries, in particular to a method for charging formation of lead-acid batteries. BACKGROUND

[0002] Lead-acid batteries are widely used in social production and life due to their low price, cheap raw materials and good safety. Lead-acid batteries mainly include positive and negative plates, separators, electrolyte (sulfuric acid), etc. In use, lead-acid batteries need to be connected in series / parallel to improve the capacity or voltage of the lead-acid battery pack, so the consistency of the batteries in the whole group has a great influence on the durability of the batteries. Therefore, the consistency of the batteries needs to be paid attention to in the production of lead-acid batteries to increase the consistency of the whole group of lead-acid batteries.

[0003] Degree formation is a key link in the production process of lead-acid batteries and has a great influence on the performance of the batteries. At present, battery manufacturers generally use internal formation process. This process mode can avoid the shortcomings of long charging time, high power consumption, acid mist precipitation and large amount of acid and water consumption for cleaning of the plates in external formation process. This not only saves a large amount of water resources, but also avoids pollution to the environment. However, since the internal formation process is to directly assemble the green plates into batteries and then form them to obtain finished batteries, the quality control is more difficult than that in the external formation process.

[0004] The patent with authorization number CN108899592B discloses a power type lead-acid battery internal formation charging method, which uses different constant current values in different charging stages. The internal formation charging time is shortened and the battery charging power conversion efficiency is improved through two acid adding methods. The patent document with authorization number CN109659638B discloses a power type lead-acid battery large current formation process, which includes a standing stage and a formation stage. The whole process is carried out in a water bath not higher than 10℃, and the temperature in the battery is detected to be not higher than 70℃. The pulse principle is used for cyclic charging and discharging to reduce the polarization of the battery formation process. Shallow discharging is beneficial to the re-conversion of active substances, so as to realize the advantages of high formation quality, low energy consumption, high production efficiency and low cost.

[0005] The patent document with publication number CN107331902A discloses a lead-acid storage pulse internal formation process. The process first charges the storage battery under a constant current system with a small current; then charges the storage battery with intermittent pulse charging, positive pulse and positive and negative pulse current while assisting with constant current discharge to 1.8V / single cell; finally, charges the storage battery with a small current of 0.05C3 to complete the acid extraction and end the battery formation. The patent document with authorization number CN107591580B discloses a four-stage formation process of a lead-acid storage battery. The first stage: charge to 2.75-2.9V / single cell and discharge to 1.67-2V / single cell; the second stage: positive and negative pulse formation charging to 2.75-2.9V / single cell and discharging to 1.67-2V / single cell, and repeating the process 4 times; the third stage: positive and negative pulse formation charging of the storage battery with a current of 0.5C, 0.3C and 0.2C, and discharging to 1.67-2V / single cell; the fourth stage: 0.3A charging to the stable voltage of the storage battery.

[0006] In the prior art, under the charging and discharging system of constant current, the efficient formation of the battery is realized by the change formation process such as secondary acid addition or by lower formation water bath and multiple charging and discharging, which increases the complexity and control cost of the process to a certain extent. The mixed process of constant current and pulse current system has a long rising and falling time of the pulse current and a long intermittent time of positive and negative pulses, and the duty ratio is low. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a lead storage battery charging formation method, which improves the electrical performance of the storage battery, enhances the consistency of the storage battery and improves the matching stability of the battery.

[0008] The specific technical solutions of the present application are as follows:

[0009] The present application provides a lead storage battery formation charging method, which comprises the following steps:

[0010] (1) Large current intermittent pulse charging:

[0011] 10-20mA / cm 2 The positive pulse current charges the lead storage battery for 0.2h-0.5h;

[0012] (2) Multi-stage variable current constant current charging:

[0013] (2.1) 3.0-4.5mA / cm 2 The current charges the lead storage battery for 0.3h-0.5h;

[0014] (2.2) 8.0-10mA / cm 2The current charges the lead storage battery for 2-3 hours;

[0015] (2.3) The current is 10-12 mA / cm 2 The current charges the lead storage battery for 6-7 hours;

[0016] (2.4) When the temperature of the electrolyte in the lead storage battery is greater than 42℃, the positive and negative pulse charging is used, the positive pulse current is 11-13 mA / cm 2 , the time is 1000-1500 ms, the rising edge time and the falling edge time are 30-50 ms, the negative pulse current is 11-13 mA / cm 2 , the positive and negative pulse interval is 50-100 ms, and the charging time is 1-1.5 hours;

[0017] (3) The lead storage battery is discharged with constant current:

[0018] The constant current is 13-14 mA / cm 2 , and the discharging time is 0.4-2.1 hours;

[0019] (4) Large current constant current charging:

[0020] After step (3) is finished, the lead storage battery is charged with large current, the charging current is 13-14 mA / cm 2 , and the charging time is 1.5-2 hours;

[0021] (5) High frequency positive and negative pulse charging:

[0022] After step (4) is finished, the lead storage battery is charged with positive and negative pulse,

[0023] (5.1) The positive pulse charging current is 10-14 mA / cm 2 , the positive pulse time is 1000-1500 ms, the rising edge time and the falling edge time of the positive pulse are 30-50 ms, the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 50-80 ms, the positive and negative pulse interval is 50-80 ms, and the charging time is 1.0-1 hour;

[0024] (5.2) The positive pulse charging current is 8-11 mA / cm 2 , the positive pulse time is 1000-1200 ms, the rising edge time and the falling edge time of the positive pulse are 30-50 ms, the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 80-120 ms, the positive and negative pulse interval is 50-80 ms, and the charging time is 1-3 hours;

[0025] (5.3) The positive pulse charging current is 8-10 mA / cm 2, the positive pulse time is 1000-1200 ms, the rising edge time and the falling edge time of the positive pulse are 30-50 ms respectively, and the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 100-150 ms, the interval between the positive pulse and the negative pulse is 50-80 ms, and the charging time is 1-2 h;

[0026] (6) repeating steps (3)-(5) for multiple times;

[0027] (7) charging the lead storage battery at a charging current of 1-1.5 mA / cm 2 , and then performing acid extraction on the lead storage battery, and completing the formation of the lead storage battery.

[0028] The method for forming and charging the lead storage battery further comprises adding acid, adding the formation electrolyte into the inner formation dry battery, and transferring the inner formation battery filled with the formation electrolyte into a cooling water tank with cooling circulating water within 2 min, the temperature of the cooling circulating water is 18±2℃, and the standing time is ≥25 min.

[0029] Preferably, the temperature of the cooling water tank in the inner formation process is maintained at 38±2℃. The temperature of the electrolyte in the lead storage battery in the inner formation process is not higher than 52℃.

[0030] Preferably, in step (5), any 2-3 steps in steps (5.1)-(5.3) are adopted for charging. Selecting any 2-3 steps for charging can increase the capacity of the battery and the low-temperature performance of the battery.

[0031] Preferably, in step (6), steps (3)-(5) are repeated for 4-5 times. When steps (3)-(5) are repeated for 4-5 times, the capacity performance of the battery is best.

[0032] Specifically, the last discharge capacity of the lead storage battery is ≥1C, the discharge voltage is ≤10.4V per battery, the actual voltage value of each battery is recorded when the average discharge voltage is 10.4V per battery, and the voltage value is used for battery grading and grouping. When the battery voltage is <9.9V, it is recorded as a low-voltage battery (unqualified battery, 11th grade), and then the remaining batteries are graded according to the battery voltage from low to high, and each 0.1V is a grade, and the batteries are recorded as 0-10th grade, and the qualified rate of the battery formation is calculated accordingly.

[0033] The discharge capacity C of the lead storage battery is the 2hr rated capacity of the lead storage battery.

[0034] Preferably, in step (1), the conditions of the positive pulse are as follows: the time is 1500 ms, the rising edge time is 50 ms, the falling edge time is 50 ms, and the pulse interval is 500 ms.

[0035] The acid extraction time in step (7) is less than or equal to 1 hour.

[0036] The application also provides a lead storage battery prepared by the method for formation charging of the lead storage battery.

[0037] Compared with the prior art, the application has the beneficial effects of:

[0038] (1) The charging formation method of the application adopts multi-step charge-discharge formation. In the initial formation, high current density current is used for charging to form a large number of active material microcrystals at the junction of the grid rib and the lead paste, thereby improving the conversion efficiency of the active material in the subsequent charge formation.

[0039] (2) The constant current charging process is used for the supplement charging because the battery has high charge receiving capacity in the early formation and after the discharge of the storage battery, which can improve the charging efficiency of the battery.

[0040] (3) The intermittent positive and negative pulse charging formation is used for the later charging, which can reduce the electrochemical polarization and concentration polarization during formation, thereby improving the formation efficiency.

[0041] (4) The application of multiple constant current discharges and negative pulse current can reduce the internal temperature rise of the storage battery and avoid the performance degradation of the negative organic expander.

[0042] (5) The application of high current density positive and negative pulse current can promote the conversion of inactive lead paste to PbO2 and Pb with electrochemical activity, thereby improving the consistency of the storage battery after formation. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The application is 6-DZF-20.3 battery capacity detection file distribution.

[0044] Figure 2 The application is 6-DZF-20.3 battery cycle test battery pressure difference curve. DETAILED DESCRIPTION

[0045] The application will be further described below with specific examples, but the scope of the application is not limited thereto.

[0046] Example 1

[0047] 1, 6-DZF-20.3 battery treatment before charging is as follows:

[0048] The battery acid temperature is 9±1℃, and the acid density is 1.245g / ml. The battery is filled with liquid by using a vacuum acid filling machine, and the vacuum degree is 0.07Mpa. The vacuum is extracted for 5 times. After filling the liquid, the battery is transferred to a cooling water tank within 2 minutes for cooling, the water bath temperature is controlled at 18±2℃, and the water bath time is 25 minutes.

[0049] Then the battery is transferred to the formation tank, and the circulating water is injected, the water temperature is controlled at 38±2℃, and the battery is charged after being connected to the charging device.

[0050] 2. The 6-DZF-20.3 battery is charged and formed by using the multi-stage constant current charging process, and the battery charging process is shown in Table 1.

[0051] Table 1

[0052]

[0053] After the above process is completed, the charging current is adjusted to 0.6mA / cm 2 , and after 2h, the residual electrolyte in the battery is extracted by negative pressure, the charging device is turned off after the acid extraction is completed, and the whole process is completed. Then the battery is cleaned and sealed.

[0054] Example 2

[0055] 1. The 6-DZF-20.3 battery is treated before charging as described in Example 1;

[0056] 2. The 6-DZF-20.3 battery is charged and formed by using the multi-stage constant current charging and intermittent positive and negative pulse charging method, and the battery charging process is shown in Table 2.

[0057] Table 2

[0058]

[0059]

[0060] Finally, the trickle charging step is run for 2h, and the residual electrolyte in the battery is extracted by negative pressure, the charging device is turned off after the acid extraction is completed, and the whole process is completed. Then the battery is cleaned and sealed.

[0061] Example 3

[0062] 1. The 6-DZF-20.3 battery is treated before charging as described in Example 1;

[0063] 2. The 6-DZF-20.3 battery is charged and formed by using the multi-stage constant current charging and intermittent positive and negative pulse charging method, and the battery charging process is shown in Table 3.

[0064] Table 3

[0065]

[0066]

[0067]

[0068] Finally, the trickle charging step, after running 2h, the negative pressure extraction of residual electrolyte in the battery, after the acid extraction is completed, the charging device is closed, the whole process is finished. Then the battery is cleaned and the cover is completed.

[0069] Test Example 1

[0070] After the battery formation is finished, the actual voltage value of each battery is recorded when the average voltage of the battery is 10.4V in the last discharge, when the battery voltage is <9.9V, it is recorded as a low voltage battery (unqualified battery, 11th grade), then the remaining batteries are divided into 0-10 grades according to the battery voltage from low to high, and the qualified rate of battery formation is calculated according to the above.

[0071] Figure 1 The distribution curve of the proportion of batteries in each grade in Examples 1-3 is shown in the figure. As can be seen from the figure, the proportion of low-grade (unqualified battery) in Example 1 is 3.98%, the proportion of low-grade battery in Example 2 is 3.08%, and the proportion of low-grade battery in Example 3 is 1.0%. In addition, it is found that the distribution of batteries in Example 2 and Example 3 is concentrated in the middle grade.

[0072] Finally, the batteries under different formation processes are selected in the same grade to form 48V battery group, and the life test is carried out according to the following charge and discharge system, and the pressure difference change trend of the battery group is tracked during the battery cycle life test.

[0073] Battery test method:

[0074] 1. Place the battery in a test environment of 25±2℃ for 8h;

[0075] 2. Connect the series-connected battery group with the charge and discharge test equipment;

[0076] 3. Constant current discharge: control the discharge current to 10A, the discharge termination voltage to 10.5V per cell, and record the discharge capacity of the battery group and the discharge cutoff voltage of the single battery;

[0077] 4. Constant voltage and current limiting charging: control the charging current to 9A, the voltage limit to 14.8V per cell, and the charging time to 4.5h;

[0078] 5. Rest: after the battery is charged, rest for 0.5h;

[0079] 6. Steps 3-5 are a charge and discharge cycle, which is recorded as 1 cycle. In the test, the battery is continuously repeated for 3-5 steps, and when the discharge capacity of the battery group is less than 16.24Ah for three times in a row, the battery life is considered to be terminated, and the cycle life test is completed.

[0080] Figure 2 The battery voltage differential curves of the batteries in Examples 1-3 were tested according to the above-mentioned assembly and testing method. In use, due to the difference between each battery, the voltage difference gradually increases at the end of discharge, and a higher voltage difference will cause the discharge capacity of the battery to decrease, resulting in battery failure. Therefore, the voltage consistency of the battery during cycling, i.e., the voltage difference at the end of discharge, directly affects the cycling performance of the battery.

[0081] As can be seen from the figure, the voltage difference of the battery pack in Example 1 was stable at about 0.3V before 300 cycles, then gradually increased, reached 0.5V after 340 cycles, 1.0V after 358 cycles, and then sharply increased to 2.0V after 20 more cycles. The discharge capacity of the battery reached 16.24Ah after 20 cycles, and the battery failed after 414 cycles.

[0082] The voltage difference of the battery pack in Example 2 was stable at about 0.3V before 350 cycles, then gradually increased, reached 0.5V after 410 cycles, and then sharply increased to 2.0V after 10 more cycles. The discharge capacity of the battery reached 16.24Ah after 29 cycles, and the battery failed after 447 cycles.

[0083] The voltage difference of the battery pack in Example 3 was stable at about 0.3V before 410 cycles, then gradually increased, reached 0.5V after 430 cycles, and then increased to 1.0V after 20 more cycles. Then, the voltage difference of the battery increased to 2.0V at 520 cycles, and the discharge capacity of the battery reached 16.24Ah after 26 cycles. The battery failed after 546 cycles.

[0084] As can be seen from the above, the battery packs in Examples 2 and 3 have better voltage difference than the battery pack in Example 1, and the number of cycles is also higher than that of the battery pack in Example 1 (comparative example), reaching 33 and 132 times, respectively.

Claims

1. A method of formation charging of a lead storage battery, characterized by, The method comprises the following steps: (1) large current intermittent pulse charging: with 10-20 mA / cm 2 positive pulse current for 0.2-0.5 h; (2) multi-stage variable current constant current charging: (2.1) charging the lead storage battery with 3.0 to 4.5 mA / cm 2 current for 0.3 to 0.5 hours; (2.2) 8.0-10 mA / cm 2 The lead accumulator is charged with a current of 8.0-10 mA / cm2for 2-3 h. (2.3) 10-12 mA / cm 2 The lead accumulator is charged with a current of 6-7 hours. (2.4) When the temperature of the electrolyte in the lead storage battery is greater than 42℃, the positive and negative pulse charging is used, the positive pulse current is 11-13 mA / cm 2 , the time is 1000-1500 ms, the rising edge time and the falling edge time are 30-50 ms, the negative pulse current is 11-13 mA / cm 2 , the interval between the positive and negative pulses is 50-100 ms, and the charging time is 1-1.5 h; (3) constant current discharging of the lead-acid battery: at a constant current of 13-14 mA / cm 2 Discharge was performed for 0.4-2.1 h; (4) large current constant current charging: After step (3) is completed, the lead storage battery is charged with a large current, the charging current being 13-14 mA / cm 2 , and the charging time being 1.5-2 h. (5) high frequency positive and negative pulse charging: After step (4), the lead-acid battery is subjected to positive and negative pulse charging, (5.1) the positive pulse charging current is 10-14 mA / cm 2 , the positive pulse time is 1000-1500 ms, the rising time and the falling time of the positive pulse are 30-50 ms, the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 50-80 ms, the interval between the positive pulse and the negative pulse is 50-80 ms, and the charging time is 1.0-1 h; (5.2) the positive pulse charging current is 8-11 mA / cm 2 , the positive pulse time is 1000-1200 ms, the rising time and the falling time of the positive pulse are 30-50 ms, the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 80-120 ms, the interval between the positive pulse and the negative pulse is 50-80 ms, and the charging time is 1-3 h; (5.3) the positive pulse charging current is 8-10 mA / cm 2 , the positive pulse time is 1000-1200 ms, the rising time and the falling time of the positive pulse are 30-50 ms, the negative pulse current is 12-14 mA / cm 2 , the negative pulse time is 100-150 ms, the interval between the positive pulse and the negative pulse is 50-80 ms, and the charging time is 1-2 h; (6) multiple cycles of steps (3)-(5); (7) The lead storage battery is trickle charged at a current of 1 to 1.5 mA / cm 2 The lead storage battery is trickle charged to a voltage of 16.5 to 16.75 V / cell, and then the lead storage battery is subjected to acid extraction, and formation of the lead storage battery is completed.

2. The method of formation charging a lead storage battery of claim 1 wherein, The method further comprises adding acid, adding formation electrolyte into the inner formation dry battery, and transferring the inner formation battery filled with the formation electrolyte into a cooling water tank with cooling circulating water within 2 min, wherein the cooling circulating water has a temperature of 18±2℃, and the standing time is ≥25 min.

3. The method of formation charging a lead storage battery of claim 2 wherein, The temperature of the cooling water tank in the inner formation process is maintained at 38±2℃.

4. The method of formation charging a lead storage battery of claim 2 wherein, The temperature of the electrolyte inside the lead-acid battery in the inner formation process is not higher than 52℃.

5. The method of formation charging a lead storage battery of claim 1 wherein, In step (5), any 2-3 steps of steps (5.1)-(5.3) are adopted for charging.

6. The method of formation charging a lead storage battery of claim 1 wherein, In step (6), steps (3)-(5) are cycled 4-5 times.

7. The method of formation charging a lead storage battery of claim 1 wherein, The last discharge capacity of the lead-acid battery is ≥1C, the discharge voltage is ≤10.4V per battery, and the actual voltage value of each battery is recorded as the average discharge voltage of 10.4V per battery, which is used for battery grading and grouping.

8. The method of formation charging a lead storage battery of claim 7 wherein, The discharge capacity C of the lead-acid battery is the 2hr rated capacity of the lead-acid battery.

9. The method of formation charging a lead storage battery of claim 1 wherein, In step (1), the conditions of the positive pulse are: time 1500ms, rising edge time 50ms, falling edge time 50ms, and pulse interval 500ms; In step (7), the acid extraction time is ≤1h.

10. A lead storage battery characterized by The lead-acid battery is prepared by the method for formation charging of the lead-acid battery according to any one of claims 1-9.

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