Storage battery container formation charging and matching method

Abstract

The invention discloses a storage battery container formation charging and matching method, and belongs to the technical field of storage battery production. According to the container formation charging and matching process method for the storage battery, through three times of discharge capacity detection, grading is carried out according to the discharge termination voltage value in the same range, and grading and matching are carried out in the specified floating charge voltage value range, so that the online discharge one-time qualified rate and the capacity online matching qualified rate of all the batteries can be ensured; the battery screening accuracy, stability and performance consistency are improved, and the cycle period and the service life of the battery are prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of battery production, and in particular relates to a method for internal formation charging and assembly of batteries. Background Art

[0002] Lead-acid battery is a widely used chemical power source, which has the advantages of good reversibility, stable voltage characteristics, long service life, wide application range, abundant raw materials, renewable use, and low cost. In recent years, with the enhancement of environmental awareness and the increasing severity of energy problems, lead-acid batteries play an extremely important role as a power source in electric vehicle systems.

[0003] The battery electrochemical conversion technology and battery formation charging and discharging process methods involved in the factory battery manufacturing process directly affect the performance characteristics of the finished battery, such as capacity, charging acceptance, and discharge efficiency. In order to achieve the replacement battery formation charging and discharging capacity, improve production efficiency, and reduce energy consumption, optimizing the battery formation charging process and screening the battery for performance consistency are of great significance to the later battery life and reducing the battery return rate.

[0004] However, due to the manufacturers' large-scale assembly line production and fierce competition in the industry, the production efficiency has been improved to reduce manufacturing costs, resulting in a significant decline in the consistency of battery performance, which in turn affects the battery's riding mileage and increases the return rate of products in the market.

[0005] How to improve the consistency of battery performance and group matching is one of the keys to improving the consistency and service life of battery packs.

[0006] For example, the invention with publication number CN11 1416164A discloses a method for internally forming and grouping batteries, in which the battery is discharged to below 10.3V per battery during capacity inspection and discharge; during grouping, the discharge time required for each battery to be discharged to 10.3V after capacity inspection is reviewed, and the batteries are divided into grades according to the discharge time, and several batteries in the same grade are grouped together, thereby basically ensuring that the capacity of all batteries can be fully discharged to the end and thus be screened out, thereby increasing the screening range, and improving the one-time discharge pass rate and the grouping rate.

[0007] For another example, the invention with publication number CN1 06972212A discloses a method for internal formation and grouping of lead-acid batteries. In the capacity inspection discharge stage of the internal formation, the battery is first discharged at a timed or constant voltage with a current of 1 to 3C amperes, and the termination voltage value is recorded as voltage 1; then the battery is discharged at a current of 0.5C amperes to an average voltage of 10.2 to 10.5V, and the termination voltage value is recorded as voltage 2. The capacity released in the capacity inspection discharge stage is controlled at 1.0 to 1.1C ampere-hours; after the internal formation is completed, the battery is offline, and the open circuit voltage is detected after standing still; unqualified batteries are eliminated with voltage 1 as an indicator, and then grouped with voltage 2, and the difference in the open circuit voltage of the batteries in the same group must be ensured to be no more than 20mV. However, the grading method in the above-mentioned prior art is still relatively rough, and the difference between different batteries in the same group is still relatively large. Summary of the invention

[0008] The present invention aims at the deficiencies in the prior art, and provides a battery internal formation charging and grouping method to improve battery formation charging efficiency and performance consistency.

[0009] The present invention adopts three-time discharge process capacity test, and divides the grades according to the battery discharge termination voltage value range; and adopts the battery formation floating charge online voltage value range to classify the grades; combining the above two processes, meeting the above battery discharge termination voltage value range conditions, and meeting the battery formation floating charge online voltage value range, the final battery classification and matching can be established, the existing common open circuit voltage value classification process method is cancelled, the matching accuracy is improved, and the operating staff is saved.

[0010] The specific technical solutions of the present invention are as follows:

[0011] The present invention provides a method for internal formation charging and assembly of a storage battery, comprising the following steps:

[0012] (1) performing internal charge and discharge on the battery, wherein the internal steps include six-step discharge and twenty-step charge, and the discharge adopts constant current discharge;

[0013] (2) Classification:

[0014] After the third step of discharge, the first grading is performed according to the extreme difference of the discharge termination voltage.

[0015] After the fourth step of discharge, the second grading is performed according to the extreme difference of the discharge termination voltage.

[0016] After the fifth step of discharge, the third grading is performed according to the extreme difference of the discharge termination voltage;

[0017] (3) After the three gradings in step (2), the batteries at the same level are subjected to constant current float charging, the average circuit voltage is set, and the fourth grading is performed according to the voltage value of the battery after the constant current float charging, and the grouping is performed according to the fourth grading result.

[0018] Preferably, in step (2), the first gear division is divided into gears V1 to V6:

[0019] V1: 0~0.04V;

[0020] V2: 0.05~0.08V;

[0021] V3: 0.09~0.12V;

[0022] V4: 0.13~0.16V;

[0023] V5: 0.17~0.20V;

[0024] V6: 0.21V and above;

[0025] The second classification is divided into V1~V6 gears:

[0026] V1: 0~0.03V;

[0027] V2: 0.04~0.06V;

[0028] V3: 0.07~0.09V;

[0029] V4: 0.10~0.12V;

[0030] V5: 0.13~0.15V;

[0031] V6: 0.16V and above;

[0032] The third classification is divided into V1~V6 gears:

[0033] V1: 0~0.02V;

[0034] V2: 0.03~0.05V;

[0035] V3: 0.06~0.08V;

[0036] V4: 0.09~0.11V;

[0037] V5: 0.12~0.14V;

[0038] V6: 0.15V and above.

[0039] According to the above allocation, the battery with the same discharge termination voltage range for three times can be grouped together for the last time. The computer control program can automatically record the three discharge capacity, voltage and range classification of each single battery in the same circuit.

[0040] Preferably, in step (3), the constant current float charge step is: float charge with a constant current of 0.02C2A, when the average loop voltage is 16.3-16.6V, use a negative pressure vacuum of -0.085Mpa to start extracting free acid from each battery, and the acid extraction time for each same loop is controlled to be completed within 5 minutes.

[0041] Furthermore, after the battery capacity is tested and classified, the battery recharge process is carried out. In the acid extraction process (floating charge stage), the battery voltage value during floating charge is used to classify the battery again (the fourth classification), and the battery is grouped for the last time. If the battery meets the conditions, it can be directly offline. The existing offline open circuit voltage grouping process of the battery is cancelled.

[0042] The fourth classification is divided into A1~A8:

[0043] A1: 16.22~16.23V:

[0044] A2: 16.24~16.25V;

[0045] A3: 16.26~16.27V;

[0046] A4: 16.28~16.29V;

[0047] A5: 16.30~16.31 V;

[0048] A6: 16.32~16.33V;

[0049] A7: 16.34~16.35V;

[0050] A8: 16.36V and above.

[0051] Furthermore, in step (3), the batteries that do not meet the grouping conditions are finally concentrated and discharged and charged for one cycle before being grouped again;

[0052] The process of one cycle of discharge and charge: first discharge at a constant current of 0.5C2A, with a voltage limit of 10.1V / cell; then recharge at a constant current of 0.3C2A, with a voltage limit of 14.8V / cell; and discharge again at a constant current of 0.5C2A, with a voltage limit of 10.1V / cell.

[0053] When the batteries are paired again, the batteries that still do not meet the pairing conditions will be downgraded or scrapped.

[0054] Preferably, in step (3), after the battery is assembled, it is taken off the assembly line and left to stand for 1 to 2 hours before being covered with a rubber safety cap. If the open circuit voltage of the battery is between 13.15 and 13.25 V, the rubber safety cap should be covered for 1 to 2 hours; if the open circuit voltage of the battery is 13.26 V or above, the rubber safety cap should be covered for 2 to 3 hours.

[0055] Specifically, in step (1), the specific operation steps of the internalization charge and discharge process are: each circuit is composed of 18 to 30 batteries connected in series, and the internalization steps include six steps of discharge and twenty steps of charge;

[0056] First charge: charge at a constant current of 0.04C2A for 20 minutes;

[0057] Second charge: charge at a constant current of 0.1C2A for 20 minutes;

[0058] Three-charge: charge at constant current 0.15C2A for 0.5h;

[0059] Four-charge: charge at constant current 0.2C2A for 0.5h;

[0060] Five-charge: charge at constant current 0.3C2A for 3.0h;

[0061] Sixth charge: charge at a constant current of 0.35C2A for 6.5h;

[0062] First discharge: discharge at a constant current of 0.5C2A for 30 minutes;

[0063] Seventh charge: charge at a constant current of 0.4C2A for 1.5h;

[0064] Eight-charge: charge at constant current 0.4C2A for 2.0h;

[0065] Second discharge: discharge at a constant current of 0.5C2A for 45 minutes;

[0066] Nine-charge: charge at a constant current of 0.4C2A for 1.5h;

[0067] Ten-charge: charge at a constant current of 0.36C2A for 2.5h;

[0068] Third discharge: discharge at a constant current of 0.5C2A for 55min;

[0069] Eleven-charge: charge at constant current 0.4C2A for 2.0h;

[0070] Twelve-charge: charge at a constant current of 0.36C2A for 3.0h;

[0071] Fourth discharge: discharge at a constant current of 0.50C2A for 1h10min;

[0072] Thirteenth charge: charge at constant current 0.4C2A for 3.0h;

[0073] Fourteen-charge: charge at a constant current of 0.36C2A for 3.0h;

[0074] Fifteenth charge: charge at constant current 0.3C2A for 3.0h;

[0075] Fifth discharge: discharge at a constant current of 0.50C2A for 1h40min;

[0076] Sixth discharge: discharge at a constant current of 0.50C2A to 10.1V / pc;

[0077] Sixteen-charge: charge at a constant current of 0.40C2A for 2.5h;

[0078] Seventeen-time charging: charge at a constant current of 0.40C2A for 1.0h;

[0079] 18-hour charge: charge at a constant current of 0.30C2A for 1.0h;

[0080] Nineteenth charge: charge at a constant current of 0.12C2A for 30 minutes;

[0081] Twenty charge: charge at constant current 0.02C2A for 3.0h;

[0082] Finish.

[0083] Among them, C2 is the 2-hour rate rated capacity.

[0084] Beneficial effects of the present invention:

[0085] The internal formation charging and grouping process method of the storage battery of the present invention divides the battery into grades with the same range of discharge termination voltage values ​​through three discharge capacity tests, and specifies the graded grouping method within the range of floating charge voltage values, thereby ensuring the one-time qualified rate of online discharge and the qualified rate of online capacity grouping of all batteries, improving the accuracy, stability and performance consistency of battery screening, and extending the cycle life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 The figure is a cycle life curve diagram of the battery assembled according to the battery formation charge and discharge process in Example 1.

[0087] Figure 2 The cycle life curve of the battery assembled by the battery formation charge and discharge process in Comparative Example 1 is shown. DETAILED DESCRIPTION

[0088] Example 1

[0089] The internalization charge and discharge process parameters of 1000 lead-acid batteries of model 6-DZF-22 are shown in Table 1.

[0090] Table 1

[0091]

[0092]

[0093] As shown in Table 1, the battery formation process is divided into charging process and discharging process stages. The first charging process is steps 1 to 6, and the first discharging process is step 7; the second charging process is steps 8 to 9, and the second discharging process is step 10; the third charging process is steps 11 to 12, and the third discharging process is step 13, which are classified as capacity detection 1 discharge and termination voltage value; the fourth charging process is steps 14 to 15, and the fourth discharging process is step 16, which are classified as capacity detection 2 discharges and termination voltage value; the fifth charging process is steps 17 to 19, and the fifth discharging process is steps 20 to 21, which are classified as capacity detection 3 discharges and termination voltage value.

[0094] Results: 1000 batteries tested once, voltage values ​​were classified into extreme values:

[0095]

[0096] The extreme difference of the voltage values ​​of the battery capacity test twice:

[0097]

[0098] The extreme difference of voltage values ​​of battery capacity detection 3 times:

[0099]

[0100] According to the above three capacity test termination voltage results, the computer software is combined to automatically screen and record. The floating charge stage acid extraction process in the formation process is continued in sequence. The following is the voltage value screened at the same time after the battery is floated for 1.5 hours (acid can only be extracted after 1.5 hours) and is divided into grades.

[0101] Specific steps: The formation process proceeds to step 26 in Table 1. According to the process requirements, the current is 0.44A. When the time is 1.6h and the average loop voltage is 16.4V, the entire loop battery is extracted cleanly using a negative pressure vacuum of -0.085Mpa. The acid extraction time is controlled within 5min. After the acid extraction process is completed, the charging process continues to run for the remaining time.

[0102] Battery float charge voltage value classification:

[0103]

[0104] After comprehensive analysis, 980 batteries out of the entire batch of 1,000 batteries were qualified for grouping, with a grouping rate of 98.0%.

[0105] Example 2

[0106] The internalization charge and discharge process parameters of 1000 lead-acid batteries of model 6-DZF-20 are shown in Table 2.

[0107] Table 2

[0108]

[0109]

[0110] As shown in Table 2, the battery formation process is divided into charging process and discharging process stages. The first charging process is steps 1 to 6, and the first discharging process is step 7; the second charging process is steps 8 to 9, and the second discharging process is step 10; the third charging process is steps 11 to 12, and the third discharging process is step 13, which are classified as capacity detection 1 discharge and termination voltage value; the fourth charging process is steps 14 to 15, and the fourth discharging process is step 16, which are classified as capacity detection 2 discharges and termination voltage value; the fifth charging process is steps 17 to 19, and the fifth discharging process is steps 20 to 21, which are classified as capacity detection 3 discharges and termination voltage value.

[0111] Results: 1000 batteries tested once, voltage values ​​were classified into extreme values:

[0112]

[0113] The extreme difference of the voltage values ​​of the battery capacity test twice:

[0114]

[0115] The extreme difference of voltage values ​​of battery capacity detection 3 times:

[0116]

[0117] According to the above three capacity test termination voltage results, the computer software is used for automatic screening and recording. The acid extraction process in the floating charge stage of the formation process is carried out in sequence. The following is the voltage value screened at the same time after the battery is floated for 1.5 hours.

[0118] Specific steps: The formation process proceeds to step 26 in Table 2. According to the process requirements, the current is 0.40A, the time is 1.6h, and the average loop voltage is 16.5V. The entire loop battery is extracted cleanly using a negative pressure vacuum of -0.085Mpa. The acid extraction time is controlled within 5min. After the acid extraction process is completed, the charging process continues to run for the remaining time.

[0119] Battery float charge voltage value classification:

[0120]

[0121] After comprehensive analysis, 989 batteries out of the entire batch of 1,000 batteries were qualified for grouping, with a grouping rate of 98.9%.

[0122] Comparative Example 1

[0123] The internalization charge and discharge process parameters of 1000 lead-acid batteries of model 6-DZF-20 are shown in Table 3.

[0124] Table 3

[0125] stage program Current A Voltage Time h: min Remark 1 Charge 0.8 0：20 2 Charge 2.0 0：20 3 Charge 3.0 0：30 4 Charge 4.0 0：30 5 Charge 6.0 3：00 6 Charge 7.0 6：30 7 Discharge -11 0：30 8 Charge 8.0 1：30 9 Charge 8.0 2：00 10 Discharge -11 0：45 11 Charge 8.0 1：30 12 Charge 7.0 2：30 13 Discharge -11 1：10 14 Charge 8.0 3：00 15 Charge 7.0 3：00 16 Charge 6.0 3：00 17 Discharge -11 1：40 18 Discharge -11 10V / pcs 18 19 Charge 8.0 2：30 20 Charge 8.0 1：00 21 Charge 2.40 0：30 22 Charge 0.40 3：00 23 Finish

[0126] As shown in Table 3, the battery formation process is divided into charging process and discharging process stages. The first charging process is steps 1 to 6, and the first discharging process is step 7; the second charging process is steps 8 to 9, and the second discharging process is step 10; the third charging process is steps 11 to 12, and the third discharging process is step 13; the fourth charging process is steps 14 to 16; the fourth discharging process is steps 17 to 18, which serves as the first online capacity screening and matching process; and the fifth charging process is steps 19 to 22.

[0127] The results of the 1000 battery capacity test were as follows:

[0128]

[0129] The batteries are divided into different levels according to the offline production line, and then the open circuit voltage matching is carried out for the second time after the batteries are left to stand. The voltage standard is: the voltage difference of 4-pack batteries is ≤0.02V, and the voltage difference of 6-pack batteries is ≤0.03V.

[0130] Comprehensive analysis shows that for the whole batch of 1,000 batteries, the X and Y grades are unqualified, and from grade 0 to grade 5, 930 are qualified for grouping, with a grouping rate of 93.0%.

[0131] Comparative Example 2

[0132] The internalization charge and discharge process parameters of 1000 lead-acid batteries of model 6-DZF-22 are shown in Table 4.

[0133] Table 4

[0134]

[0135]

[0136] As shown in Table 4, the battery formation process is divided into charging process and discharging process stages. The first charging process is steps 1 to 6, and the first discharging process is step 7; the second charging process is steps 8 to 9, and the second discharging process is step 10; the third charging process is steps 11 to 12, and the third discharging process is step 13; the fourth charging process is steps 14 to 16; the fourth discharging process is steps 17 to 18, which serves as the first online capacity screening and matching process; and the fifth charging process is steps 19 to 22.

[0137] The results of the 1000 battery capacity test were as follows:

[0138]

[0139] The batteries are divided into different levels according to the offline production line, and then the open circuit voltage matching is carried out for the second time after the batteries are left to stand. The voltage standard is: the voltage difference of 4-pack batteries is ≤0.02V, and the voltage difference of 6-pack batteries is ≤0.03V.

[0140] Comprehensive analysis shows that for the whole batch of 1,000 batteries, the X and Y grades are unqualified, and from grade 0 to grade 5, 914 batteries are qualified for grouping, with a grouping rate of 91.4%.

[0141] Test Example 1

[0142] 1. The comparison table of the qualifying rates of the embodiments and the comparative examples is shown in Table 5:

[0143] Table 5

[0144]

[0145] It can be seen from the data that the charging and matching process of the present invention ensures the one-time qualified rate of online discharge and the qualified rate of online capacity matching of all batteries.

[0146] 2. Cycle life

[0147] The test method of the cycle life of the present invention is:

[0148] Step 1: Discharge at a constant current of 0.5C2A, and the end voltage is 10.5V / single;

[0149] Step 2: Constant current 0.5C2A charging, voltage limit 14.8V / single, charging time 4h30min;

[0150] Step 3: Let stand for 30 minutes;

[0151] The above is a cyclic process.

[0152] The battery cycle life curves of the battery formation charge and discharge process of Example 1 and Comparative Example 1 are shown as follows: Figure 1 and Figure 2As shown in the results, it can be seen that the cycle life of the paired battery in the embodiment can reach more than 596 times, while the cycle life of the paired battery in the comparative example is less than 505 times. This shows that the formation charge and discharge process matching of the present invention improves the accuracy, stability and performance consistency of battery screening and prolongs the cycle life of the battery.

Claims

1. A method for internal charging and assembly of batteries, It is characterized in that The following steps are involved: (1) performing internal charge and discharge on the battery, wherein the internal steps include six-step discharge and twenty-step charge, and the discharge adopts constant current discharge; (2) Classification: After the third step of discharge, the first grading is performed according to the extreme difference of the discharge termination voltage. After the fourth step of discharge, the second grading is performed according to the extreme difference of the discharge termination voltage. After the fifth step of discharge, the third grading is performed according to the extreme difference of the discharge termination voltage; (3) After the three gradings in step (2), the batteries at the same level are subjected to constant current float charging, the average circuit voltage is set, and the fourth grading is performed according to the voltage value of the battery after the constant current float charging, and the grouping is performed according to the fourth grading result.

2. The method for internal formation, charging and assembly of batteries according to claim 1, It is characterized in that In step (2), the first gear is divided into V1 to V6 gears: V1: 0~0.04V; V2: 0.05~0.08V; V3: 0.09~0.12V; V4: 0.13~0.16V; V5: 0.17~0.20V; V6: 0.21V and above; The second classification is divided into V1~V6 gears: V1: 0~0.03V; V2: 0.04~0.06V; V3: 0.07~0.09V; V4: 0.10~0.12V; V5: 0.13~0.15V; V6: 0.16V and above; The third classification is divided into V1~V6 gears: V1: 0~0.02V; V2: 0.03~0.05V; V3: 0.06~0.08V; V4: 0.09~0.11V; V5: 0.12~0.14V; V6: 0.15V and above.

3. The method for internal formation, charging and assembly of batteries according to claim 1, It is characterized in that In step (3), the constant current floating charge step is: 2 Float charge, when the average circuit voltage is 16.3 ~ 16.6V, use negative pressure vacuum -0.085Mpa to start extracting free acid from each battery, and the acid extraction time for each same circuit is controlled within 5 minutes.

4. The method for internal formation, charging and assembly of batteries according to claim 3, It is characterized in that The fourth classification is divided into A1~A8: A1: 16.22~16.23V; A2: 16.24~16.25V; A3: 16.26~16.27V; A4: 16.28~16.29V; A5: 16.30~16.31V: A6: 16.32~16.33V; A7: 16.34~16.35V; A8: 16.36V and above.

5. The battery internal formation charging and assembly method according to claim 1, It is characterized in that In step (3), the batteries that do not meet the grouping conditions are finally put into groups after a discharge and charge cycle, and then grouped again; The process of discharging and charging for one cycle: first charge at a constant current of 0.5C 2 A discharge, voltage limit 10.1V / pcs; then constant current 0.3C 2 A recharge, voltage limit 14.8V / pcs; then recharge at constant current 0.5C 2 A discharge, voltage limit 10.1V / pcs.

6. The method for internal formation, charging and assembly of batteries according to claim 5, It is characterized in that When the batteries are paired again, the batteries that still do not meet the pairing conditions will be downgraded or scrapped.

7. The method for internal formation, charging and assembly of batteries according to claim 1, It is characterized in that In step (3), after the assembly is completed, the battery is taken off the production line, left to stand for 1 to 2 hours, and then covered with a battery rubber safety cap.

8. The method for internal formation, charging and assembly of batteries according to claim 7, It is characterized in that When the open circuit voltage of the battery is between 13.15 and 13.25 V, cover the battery with the rubber safety cap for 1 to 2 hours. When the open circuit voltage of the battery is 13.26 V and above, cover the battery with the rubber safety cap for 2 to 3 hours.

9. The battery internal formation charging and assembly method according to claim 1, It is characterized in that In step (1), the specific operation steps of the internalization charge and discharge process are as follows: each circuit is composed of 18 to 30 batteries connected in series, and the internalization steps include six steps of discharge and twenty steps of charge; First charge: constant current 0.04C 2 A is charged for 20 minutes; Second charge: constant current 0.1C 2 A is charged for 20 minutes; Three-charge: constant current 0.15C 2 A is charged for 0.5h; Four-charge: constant current 0.2C 2 A is charged for 0.5h; Five-charge: constant current 0.3C 2 A charging 3.0h; Sixth charge: constant current 0.35C 2 A charging 6.5h; First discharge: constant current 0.5C 2 A discharges for 30 minutes; Seventh charge: constant current 0.4C 2 A charging 1.5h; Eight-charge: constant current 0.4C 2 A charging 2.0h; Second discharge: constant current 0.5C 2 A discharges for 45 minutes; Nine-charge: constant current 0.4C 2 A charging 1.5h; Ten times charge: constant current 0.36C 2 A charging 2.5h; Three discharges: constant current 0.5C 2 A discharges for 55 minutes; Eleven-time charging: constant current 0.4C 2 A charging 2.0h; 12-hour charge: constant current 0.36C 2 A charging 3.0h; Four discharge: constant current 0.50C 2 A discharges for 1h10min; Thirteenth charge: constant current 0.4C 2 A charging 3.0h; 14-hour charge: constant current 0.36C 2 A charging 3.0h; 15-minute charge: constant current 0.3C 2 A charging 3.0h; Fifth discharge: constant current 0.50C 2 A discharges for 1h40min; Sixth discharge: constant current 0.50C 2 A discharge to 10.1V / pcs; Sixteen-hour charge: constant current 0.40C 2 A charging 2.5h; 17-hour charge: constant current 0.40C 2 A charging 1.0h; 18-hour charge: constant current 0.30C 2 A charging 1.0h; 19-hour charge: constant current 0.12C 2 A charging for 30 minutes; 20-second charge: constant current 0.02C 2 A charging 3.0h; Finish.

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