Formation charging method for lead storage battery

Abstract

The invention 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) carrying out large-current intermittent pulse charging; (2) multi-stage variable current and constant current charging; (3) performing constant-current discharge on the lead storage battery; (4) carrying out large-current constant-current charging; (5) charging with high-frequency positive and negative pulses; (6) circulating the steps (3)-(5) for multiple times; and (7) carrying out trickle charging on the battery until the voltage is stable, and then carrying out acid extraction to finish battery formation. By adopting the charging process disclosed by the invention, the temperature of the electrolyte of the battery can be reduced in the formation process, the electrical property of the storage battery is improved, the consistency of the storage battery is improved, and the matching stability of the battery is improved. And therefore, the premature capacity decline caused by inconsistency of the batteries in the use process of the storage batteries is reduced, and the return rate of the lead-acid storage batteries is reduced.

Description

Technical Field

[0001] The invention relates to the field of lead-acid battery charging and formation, and in particular to a lead-acid battery charging and formation method. Background Art

[0002] Lead-acid batteries are widely used in social production and life because of their low price, cheap and easy-to-obtain raw materials, and good safety. Lead-acid batteries are mainly composed of positive and negative plates, separators, electrolytes (sulfuric acid), etc. Lead-acid batteries need to be used in series / parallel to increase the capacity or voltage of the lead-acid battery group. Therefore, the consistency of the battery in the use of the entire battery group also has a great impact on the durability of the battery. Therefore, it is necessary to pay attention to the consistency of the battery in the production of batteries to increase the consistency of the entire battery group.

[0003] As a key link in the production process of lead-acid batteries, the degree of formation has a great impact on battery performance. At present, battery manufacturers generally adopt the internal formation process, which can avoid the shortcomings of the external formation process, such as long charging time, high power consumption, acid mist precipitation, and large amounts of acid and water consumed in the cleaning of the plates. This not only saves a lot of water resources, but also avoids pollution to the environment. However, since the internal formation process directly assembles the green plates into batteries and then forms them to obtain finished batteries, the difficulty of quality control is greater than that of the external formation process.

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

[0005] Patent document with announcement number CN10733 1902A discloses a lead-acid battery internal pulse formation process, in which the battery is first charged with a small current under a constant current system; then, the battery is charged with intermittent pulse charging, positive pulse and positive and negative pulse currents while being assisted by constant current discharge to 1.8V / cell; finally, the battery is charged with a small current of 0.05C3 to complete acid extraction and end battery formation. The patent document with authorization number CN107591580B discloses a four-stage formation process for lead-acid batteries. The first stage: charging until the battery voltage reaches 2.75-2.9V / cell, and discharging to 1.67-2V / cell; the second stage: positive and negative pulse formation charging until the battery voltage reaches 2.75-2.9V / cell, and discharging to 1.67-2V / cell, and repeating the process 4 times; the third stage: positive and negative pulse formation charging of the battery with currents of 0.5C, 0.3C, and 0.2C, and discharging to 1.67-2V / cell; the fourth stage: 0.3A charging until the battery voltage stabilizes.

[0006] In the prior art, under the constant current charge and discharge system, the efficient formation of the battery is achieved by changing the process flow such as secondary acid addition or by a lower formation water bath and multiple charge and discharge, which increases the complexity of the process and the control cost to a certain extent. The hybrid process using constant current and pulse current mode has a longer current rising and falling edge time and positive and negative pulse interval time in the pulse mode, and a lower duty cycle. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a method for charging and forming a lead-acid battery, which improves the electrical performance of the battery, enhances the consistency of the battery, and improves the stability of the battery assembly.

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

[0009] The present invention provides a method for forming and charging a lead storage battery, comprising the following steps:

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

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

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

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

[0014] (2.2) Using 8.0~10mA / cm 2The current charges the lead-acid battery for 2h to 3h;

[0015] (2.3) Using 10~12mA / cm 2 The current charges the lead-acid battery for 6h to 7h;

[0016] (2.4) When the internal electrolyte temperature of the lead-acid battery is greater than 42°C, positive and negative pulse charging is used, with the positive pulse current of 11 to 13 mA / cm 2 , time 1000~1500ms, rising edge time and falling edge time are 30~50ms respectively, negative pulse current 11~13mA / cm 2 , positive and negative pulse interval is 50-100ms, charging time is 1-1.5h;

[0017] (3) Lead-acid battery discharges at a constant current:

[0018] With constant current 13~14mA / cm 2 Discharge for 0.4 to 2.1 hours;

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

[0020] After step (3) is completed, the lead-acid battery is charged with a large current, and the charging current is 13-14 mA / cm 2 , charge for 1.5 to 2 hours;

[0021] (5) Charging with high frequency positive and negative pulses:

[0022] After step (4) is completed, the lead-acid battery is charged with positive and negative pulses.

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

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

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

[0026] (6) Repeating steps (3) to (5) multiple times;

[0027] (7) Charge the lead-acid battery at a current of 1 to 1.5 mA / cm 2 Trickle charge is performed until the voltage reaches 16.5-16.75V / battery, and then the lead-acid battery is acid-extracted to complete the formation of the lead-acid battery.

[0028] The lead storage battery formation charging method of the present invention also includes adding acid, adding a formation electrolyte into an internal formation dry cell, transferring the internal formation cell filled with the formation electrolyte into a cooling water tank with cooling circulating water within 2 minutes, wherein the temperature of the cooling circulating water is 18±2° C., and the standing time is ≥25 minutes.

[0029] Preferably, the temperature of the cooling water tank is maintained at 38±2° C. during the internal formation process. The temperature of the electrolyte inside the lead-acid battery is not higher than 52° C. during the internal formation process.

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

[0031] Preferably, in step (6), steps (3) to (5) are cycled 4 to 5 times. When steps (3) to (5) are cycled 4 to 5 times, the battery capacity performance is optimal.

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

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

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

[0035] In step (7), the acid extraction time is ≤ 1 h.

[0036] The present invention also provides a lead-acid battery, which is prepared by the lead-acid battery formation charging method.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The charging formation method of the present invention adopts a multi-step charging and discharging formation. In the initial stage of formation, a high current density current is used for charging, and a large number of active material microcrystals are formed at the junction of the grid ribs and the lead paste, thereby improving the conversion efficiency of the active material in the subsequent charging formation;

[0039] (2) In the early stage of formation and after the battery is discharged, the battery's charge acceptance capacity is high, so the constant current charging process is used for supplementary power, which can improve the battery charging efficiency;

[0040] (3) The later stage of charging adopts intermittent positive and negative pulse charging, which can reduce electrochemical polarization and concentration polarization during formation, thereby improving the formation efficiency;

[0041] (4) The present invention adopts multiple constant current discharges and negative pulse currents, which can reduce the internal temperature rise of the battery and avoid the performance degradation of the negative electrode organic expansion agent;

[0042] (5) The present invention adopts positive and negative pulse currents with high current density, which can promote the conversion of inactive lead paste into electrochemically active PbO2 and Pb, thereby improving the consistency of the battery after formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the capacity inspection gear distribution of the 6-DZF-20.3 battery of the present invention.

[0044] Figure 2 This is the battery pressure difference curve in the 6-DZF-20.3 battery cycle test of the present invention. DETAILED DESCRIPTION

[0045] The present invention is further described below with reference to specific embodiments, but the scope of the present invention is not limited thereto.

[0046] Example 1

[0047] 1. The pre-charging treatment of 6-DZF-20.3 battery is as follows:

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

[0049] Then transfer the battery to the formation water tank, inject circulating water, control the water temperature at 38±2℃, and charge the battery after connecting it to the charging equipment.

[0050] 2. The 6-DZF-20.3 battery is charged and formed using a multi-stage constant current charging formation process. 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 After running for 2 hours, the residual electrolyte in the battery is extracted by negative pressure. After the acid extraction is completed, the charging equipment is turned off and the entire process operation is completed. The battery is then cleaned and capped.

[0054] Example 2

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

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

[0057] Table 2

[0058]

[0059]

[0060] Finally, the trickle charging process runs for 2 hours and then negative pressure is used to extract the residual electrolyte in the battery. After the acid extraction is completed, the charging equipment is turned off and the entire process is completed. The battery is then cleaned and capped.

[0061] Example 3

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

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

[0064] Table 3

[0065]

[0066]

[0067]

[0068] Finally, the trickle charging process runs for 2 hours and then negative pressure is used to extract the residual electrolyte in the battery. After the acid extraction is completed, the charging equipment is turned off and the entire process is completed. The battery is then cleaned and capped.

[0069] Test Example 1

[0070] After the battery formation is completed, when the average battery voltage in the last discharge is 10.4V, the actual voltage value of each battery is recorded. When the battery voltage is less than 9.9V, it is recorded as a low-voltage battery (unqualified battery, 11 grades). Then the remaining batteries are divided into grades from low to high according to the battery voltage, with each grade of 0.1V, and recorded as 0 to 10 grades respectively, and the qualified rate of the battery formation is calculated accordingly.

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

[0072] Finally, 4 batteries were selected from the same gear under different formation processes to form a 48V battery for the whole group cycle life test according to the following charge and discharge system, and the voltage difference change trend of the battery group was tracked during the battery cycle life test.

[0073] Battery testing method:

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

[0075] 2. Use a series battery pack to connect to the charge and discharge test equipment;

[0076] 3. Constant current discharge: control the discharge current to 10A, the discharge end voltage to 10.5V / battery, and record the discharge capacity of the battery pack and the discharge end voltage of a single battery;

[0077] 4. Constant voltage and current limiting charging: the charging current is controlled to 9A, the voltage limit is 14.8V / pcs, and the charging time is 4.5h;

[0078] 5. Standstill: After the battery is charged, let it stand for 0.5 hours;

[0079] 6. Steps 3 to 5 constitute a charge and discharge cycle, which is recorded as 1 cycle. During the test, the battery continuously repeats steps 3 to 5. When the discharge capacity of the battery pack is lower than 16.24Ah for three consecutive times, the battery life is considered to have expired and the cycle life test is over.

[0080] Figure 2 The voltage difference curve of the battery in the cycle life test of the battery in Examples 1 to 3 according to the above grouping and testing method. When the battery pack is in use, due to the differences of each battery, the voltage difference will gradually increase at the end of discharge. A higher voltage difference will cause the battery discharge capacity to decay and cause battery failure. Therefore, the battery voltage consistency during the cycle, that is, the voltage difference at the end of discharge, directly affects the battery cycle performance.

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

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

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

[0084] From the above, it can be seen that the battery packs of Examples 2 and 3 are better than the battery pack of Example 1 in maintaining the battery pressure difference. Correspondingly, the number of battery cycles is also higher than that of the battery pack of Example 1 (comparative example), reaching 33 times and 132 times respectively.

Claims

1. A method for forming and charging a lead-acid battery, characterized in that: The following steps are involved: (1) High current intermittent pulse charging: Use 10~20mA / cm 2 The positive pulse current charges the lead-acid battery for 0.2h to 0.5h; (2) Multi-stage variable current constant current charging: (2.1) Using 3.0~4.5mA / cm 2 The current charges the lead-acid battery for 0.3h to 0.5h; (2.2) Using 8.0~10mA / cm 2 The current charges the lead-acid battery for 2h to 3h; (2.3) Using 10~12mA / cm 2 The current charges the lead-acid battery for 6h to 7h; (2.4) When the internal electrolyte temperature of the lead-acid battery is greater than 42°C, positive and negative pulse charging is used, with the positive pulse current of 11 to 13 mA / cm 2 , time 1000~1500ms, rising edge time and falling edge time are 30~50ms respectively, negative pulse current 11~13mA / cm 2 , positive and negative pulse interval is 50-100ms, charging time is 1-1.5h; (3) Lead-acid battery discharges at a constant current: With constant current 13~14mA / cm 2 Discharge for 0.4 to 2.1 hours; (4) High current constant current charging: After step (3) is completed, the lead-acid battery is charged with a large current, and the charging current is 13-14 mA / cm 2 , charge for 1.5 to 2 hours; (5) Charging with high frequency positive and negative pulses: After step (4) is completed, the lead-acid battery is charged with positive and negative pulses. (5.1) Positive pulse charging current is 10~14mA / cm 2 The positive pulse time is 1000-1500ms, the rising edge time and falling edge time of the positive pulse are 30-50ms respectively, and the negative pulse current is 12-14mA / cm 2 , negative pulse time 50~80ms, positive and negative pulse interval 50~80ms, charging 1.0~1h; (5.2) Positive pulse charging current is 8~11mA / cm 2 The positive pulse time is 1000-1200ms, the rising edge time and falling edge time of the positive pulse are 30-50ms respectively, and the negative pulse current is 12-14mA / cm 2 , negative pulse time 80 ~ 120ms, positive and negative pulse interval 50 ~ 80ms, charging 1 ~ 3h; (5.3) Positive pulse charging current is 8~10mA / cm 2 The positive pulse time is 1 000-1200ms, the rising edge time and falling edge time of the positive pulse are 30-50ms respectively, and the negative pulse current is 12-14mA / cm 2 , negative pulse time 100 ~ 150ms, positive and negative pulse interval 50 ~ 80ms, charging 1 ~ 2h; (6) Repeating steps (3) to (5) multiple times; (7) Charge the lead-acid battery at a current of 1 to 1.5 mA / cm 2 Trickle charge is performed until the voltage reaches 16.5-16.75V / battery, and then the lead-acid battery is acid-extracted to complete the formation of the lead-acid battery.

2. The method for forming and charging a lead-acid battery according to claim 1, wherein: It also includes adding acid, adding the formation electrolyte into the internal formation dry battery, transferring the internal formation battery filled with the formation electrolyte into a cooling water tank with cooling circulating water within 2 minutes, the temperature of the cooling circulating water is 18±2℃, and the standing time is ≥25 minutes.

3. The method for forming and charging a lead-acid battery according to claim 2, wherein: The temperature of the cooling water tank was maintained at 38±2℃ during the internalization process.

4. The method for forming and charging a lead-acid battery according to claim 2, wherein: During the internal formation process, the electrolyte temperature inside the lead-acid battery is not higher than 52°C.

5. The method for forming and charging a lead-acid battery according to claim 1, characterized in that: In step (5), charging is performed using any 2 to 3 steps from steps (5.1) to (5.3).

6. The method for forming and charging a lead-acid battery according to claim 1, characterized in that: In step (6), steps (3) to (5) are repeated 4 to 5 times.

7. The method for forming and charging a lead-acid battery according to claim 1, characterized in that: The last discharge capacity of the lead-acid battery is ≥1C, and the discharge voltage is ≤10.4V / battery. When the average discharge voltage is 10.4V / battery, the actual voltage value of each battery is recorded and used for battery grading and grouping.

8. The method for forming and charging a lead-acid battery according to claim 7, characterized in that: The discharge capacity C of the lead-acid battery is the rated capacity of the lead-acid battery for 2 hr.

9. The method for forming and charging a lead-acid battery according to claim 1, characterized in that: In step (1), the conditions of the positive pulse are: time 1500ms, rising edge time 50ms, falling edge time 50ms, pulse interval 500ms; In step (7), the acid extraction time is ≤ 1 h.

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

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