Charging and discharging process for rapidly repairing interface barrier layer of lead-acid storage battery

Abstract

The invention relates to a charging and discharging process for rapidly repairing an interface barrier layer of a lead-acid storage battery. The charging and discharging process comprises the following steps: (1) detecting initial capacity and internal resistance; (2) identifying and screening peak voltage; (3) adaptive deep discharge repair; and (4) recovering the capacity, charging and the like. According to the charging and discharging process, peak voltage rapid identification is combined with an adaptive deep discharging technology, the problem of repairing the interface barrier layer of the lead-acid storage battery is efficiently solved, and the effect is remarkable; the repairing efficiency is greatly improved, the repairing effect is stable and thorough, and the energy consumption is obviously reduced. The process disclosed by the invention is suitable for various valve-regulated lead-acid storage batteries, does not need chemical additives, has no potential safety hazard, can be realized by modifying existing equipment, is simple to operate and is convenient for large-scale popularization.

Description

Technical Field

[0001] This invention relates to the field of lead-acid battery fault repair, specifically to the repair technology of the interface barrier layer of lead-acid batteries. Background Technology

[0002] Lead-acid batteries are highly susceptible to early capacity decay during actual use due to factors such as usage habits and storage conditions. The formation of an electrode interface barrier layer is one of the core causes of this problem. Specifically, if the battery is over-discharged or under-charged during cycling, or if it is left idle for extended periods during off-seasons or inventory periods, a high-resistivity, dense lead sulfate layer (i.e., the interface barrier layer) will gradually form on the plates (the interface between the grid and the active material). This barrier layer is a typical manifestation of early capacity loss in lead-acid batteries (PCL-1 effect). The presence of the interface barrier layer significantly increases the battery's internal resistance, hindering ion migration and electrochemical reactions between the electrodes and the electrolyte. This directly leads to a significant decrease in battery capacity, poorer charge acceptance, and reduced charge / discharge efficiency. In severe cases, it can even cause premature battery failure, not only reducing the user experience but also increasing replacement costs and wasting resources.

[0003] Existing repair technologies mainly include low-current long-term charging repair, pulse charging repair, and chemical additive repair. These technologies generally suffer from drawbacks such as long repair cycles, high energy consumption, unstable repair results, incomplete repair, and high secondary return rates. They struggle to balance repair efficiency, effectiveness, and economic viability, failing to meet the industry's demand for efficient recycling and repair of lead-acid batteries. Therefore, developing a repair technology that can quickly identify interface barrier layers, accurately adapt repair parameters, completely remove barrier layers, and consume low energy is of significant practical importance and economic value for extending the lifespan of lead-acid batteries, reducing user costs, and improving resource utilization. Summary of the Invention

[0004] To overcome the above deficiencies, this invention provides a charging and discharging process for rapidly repairing the interface barrier layer of lead-acid batteries.

[0005] This invention provides a charging and discharging process for rapidly repairing the interface barrier layer of lead-acid batteries, characterized by comprising the following steps: (1) Initial capacity and internal resistance test: The lead-acid battery was discharged to 1.75V / cell using a 2-hour rate current, and the battery capacity and internal resistance data were recorded after 2 hours. (2) Peak voltage identification and screening: The battery is charged with a charging current of (1C2~2C2)A for 1~5 minutes. Voltage data during the charging process is collected at a recording interval of 0.1 seconds. The location of high resistance is identified based on the characteristics of the voltage curve, and the batteries to be repaired that have high resistance originating from the electrode interface are screened out. (3) Adaptive deep discharge repair: Based on the density of the interface barrier layer identified in step (2), match the corresponding discharge parameters. The discharge parameters include discharge current and discharge termination voltage. The discharge current is (0.05C2~0.5C2)A, and the discharge termination voltage is 1V~1.75V / cell. The higher the density of the interface barrier layer and the greater the resistance, the smaller the discharge current and the lower the discharge termination voltage. (4) Capacity recovery charging: The battery repaired in step (3) is fully charged using the conventional vehicle charging mode to complete the interface barrier layer repair and battery capacity recovery.

[0006] Furthermore, the charging current in step (2) is 2 C2A, and the charging time is 3~5 minutes.

[0007] Furthermore, the rules for determining the discharge current in step (3) are as follows: when the density of the interface barrier layer is light, the peak part of the corresponding peak voltage characteristic curve is arc-shaped without sharp peaks, the discharge current is (0.3C2~0.5C2)A, and the discharge termination voltage is 1.5~1.75V / cell; when the density of the interface barrier layer is moderate, the peak part of the corresponding peak voltage characteristic curve is weakly sharp, the discharge current is (0.15C2~0.3C2)A, and the discharge termination voltage is 1.2~1.5V / cell; when the density of the interface barrier layer is heavy, the peak part of the corresponding peak voltage characteristic curve is sharp, the discharge current is (0.05C2~0.15C2)A, and the discharge termination voltage is 1~1.2V / cell.

[0008] Furthermore, the conventional vehicle charging mode described in step (4) includes three stages of charging: the first stage is to charge at a constant current of (0.5C2~1C2)A to the battery voltage of 14.4V; the second stage is to charge at a constant current of (0.25C2~0.5C2)A to the battery voltage of 14.8V; the third stage is to charge at a current-limited rate of ≤0.2C2A and a constant voltage of 14.8V until the charging current is less than 0.5A or the charging time exceeds 3 hours, and then charge at a current-limited rate of 0.15C2A and a constant voltage of 13.8V for 2 hours.

[0009] Furthermore, after the fully charged battery is left to stand for 2 hours, when the battery open circuit voltage is ≤13.7V, repeat the charging process of step (4) once.

[0010] Furthermore, the lead-acid battery is a valve-regulated sealed lead-acid battery, including the 6-DZF series, 6-EVF series automotive batteries, and starved lead-acid batteries for UPS backup power.

[0011] Furthermore, in step (2), the state of the interface barrier layer is identified by the fluctuation amplitude of the voltage curve: when the peak value of the peak voltage characteristic curve is sharp, it is determined to be a battery with high resistance originating from the electrode interface; when the peak value of the peak voltage characteristic curve is a weakly sharp, rounded peak, it is determined to be a battery with moderate resistance originating from the electrode interface; when the peak value of the peak voltage characteristic curve is a weakly sharp, rounded peak, it is determined to be a battery with moderate resistance originating from the electrode interface; when the peak voltage characteristic curve is sharp, it is determined to be a battery with high resistance originating from the electrode interface. When the peak of the characteristic curve is arc-shaped without sharp peaks, there is no electrode interface problem, and it is judged to be a normal battery.

[0012] The targeted solution provided by this invention has the following beneficial effects: 1. The charging and discharging process of this invention combines rapid peak voltage identification with adaptive deep discharge technology to efficiently solve the problem of repairing the interface barrier layer of lead-acid batteries, with significant results.

[0013] 2. The repair efficiency is greatly improved. The state of the barrier layer can be accurately identified in 1 to 5 minutes with a high current of (1C2~2C2)A. It can be completely removed in only 1 to 2 charge and discharge cycles. The cycle is shortened by more than 80% compared with traditional low current technology and by 50% compared with pulse technology, which is suitable for batch repair needs.

[0014] 3. The repair effect is stable and thorough. The discharge current (0.05C2~0.5C2) and the termination voltage of 1V~1.75V / cell are dynamically matched according to the density of the barrier layer. After repair, the battery capacity reaches more than 95% of the rated capacity after 2 hours, the internal resistance is significantly reduced, and the cycle life is extended by 30%.

[0015] 4. Energy consumption is significantly reduced. A single 6-DZF-20Ah battery can save 1.5 to 2 kWh, and repairing 100,000 batteries annually can save 150,000 to 200,000 kWh of electricity. Secondary returns are completely eliminated, reducing economic losses by 1.3 yuan per battery, and reducing losses by more than 130,000 yuan per year for repairing 100,000 batteries.

[0016] The process of this invention is applicable to various valve-regulated lead-acid batteries, requires no chemical additives, poses no safety hazards, can be implemented by modifying existing equipment, is simple to operate, and is easy to promote on a large scale. Attached Figure Description

[0017] Figure 1 This is a cycle life curve of the 6-DZF-22 battery of this invention under 2-hour rate and 100% depth of discharge (DOD) conditions.

[0018] Figure 2 This is a peak voltage characteristic curve of the 6-DZF-20 battery with a heavy electrode interface barrier layer.

[0019] Figure 3 This is a peak voltage characteristic curve of a 6-DZF-20 battery with a medium electrode interface barrier layer.

[0020] Figure 4 This is a peak voltage characteristic curve of a 6-DZF-20 battery with a normal electrode interface barrier layer. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides a charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery, comprising the following steps: (1) Initial capacity and internal resistance test: The lead-acid battery was discharged to 1.75V / cell using a 2-hour rate current, and the battery capacity and internal resistance data were recorded after 2 hours. (2) Peak voltage identification and screening: The battery is charged with a charging current of (1C2~2C2)A for 1~5 minutes. Voltage data during the charging process is collected at a recording interval of 0.1 seconds. The location of high resistance is identified based on the characteristics of the voltage curve, and the batteries to be repaired that have high resistance originating from the electrode interface are screened out. (3) Adaptive deep discharge repair: Based on the density of the interface barrier layer identified in step (2), match the corresponding discharge parameters. The discharge parameters include discharge current and discharge termination voltage. The discharge current is (0.05C2~0.5C2)A, and the discharge termination voltage is 1V~1.75V / cell. The higher the density of the interface barrier layer and the greater the resistance, the smaller the discharge current and the lower the discharge termination voltage. (4) Capacity recovery charging: The battery repaired in step (3) is fully charged using the conventional vehicle charging mode to complete the interface barrier layer repair and battery capacity recovery.

[0023] Furthermore, the charging current in step (2) is 2 C2A, and the charging time is 3~5 minutes.

[0024] Furthermore, the rules for determining the discharge current in step (3) are as follows: when the density of the interface barrier layer is light, the peak part of the corresponding peak voltage characteristic curve is arc-shaped without sharp peaks, the discharge current is (0.3C2~0.5C2)A, and the discharge termination voltage is 1.5~1.75V / cell; when the density of the interface barrier layer is moderate, the peak part of the corresponding peak voltage characteristic curve is weakly sharp, the discharge current is (0.15C2~0.3C2)A, and the discharge termination voltage is 1.2~1.5V / cell; when the density of the interface barrier layer is heavy, the peak part of the corresponding peak voltage characteristic curve is sharp, the discharge current is (0.05C2~0.15C2)A, and the discharge termination voltage is 1~1.2V / cell.

[0025] Furthermore, the conventional vehicle charging mode described in step (4) includes three stages of charging: the first stage is to charge at a constant current of (0.5C2~1C2)A to the battery voltage of 14.4V; the second stage is to charge at a constant current of (0.25C2~0.5C2)A to the battery voltage of 14.8V; the third stage is to charge at a current-limited rate of ≤0.2C2A and a constant voltage of 14.8V until the charging current is less than 0.5A or the charging time exceeds 3 hours, and then charge at a current-limited rate of 0.15C2A and a constant voltage of 13.8V for 2 hours.

[0026] Furthermore, after the fully charged battery is left to stand for 2 hours, when the battery open circuit voltage is ≤13.7V, repeat the charging process of step (4) once.

[0027] Furthermore, the lead-acid battery is a valve-regulated sealed lead-acid battery, including the 6-DZF series, 6-EVF series automotive batteries, and starved lead-acid batteries for UPS backup power.

[0028] Furthermore, in step (2), the state of the interface barrier layer is identified by the fluctuation amplitude of the voltage curve: when the peak value of the peak voltage characteristic curve is sharp, it is determined that the high resistance originates from the electrode interface of the battery to be repaired (e.g., Figure 2 When the peak voltage characteristic curve exhibits a weak, sharp, arc-shaped peak (e.g.) Figure 3 The battery is identified as having moderate resistance originating from the electrode interface and is to be repaired; when the peak voltage characteristic curve has a rounded peak without sharp peaks (e.g. Figure 4 ), The absence of an electrode interface issue indicates that the battery is functioning normally.

[0029] This invention uses a charging current of (1C2~2C2)A to charge the battery for 1~5 minutes, and collects voltage data during the charging process at 0.1-second recording intervals; the location of high resistance is determined by the instantaneous fluctuation value of the voltage curve. The specific algorithm and threshold calibration method are as follows: Core Algorithm: ① Data preprocessing: For the acquired voltage sequence {U1, U2, U3, ..., U...}, n (n is the number of sampling points, n = charging time / 0.1s) Outlier removal is performed using the 3σ criterion: the mean μ and standard deviation σ of the voltage sequence are calculated, and outliers |Uᵢ - μ| > 3σ are removed, resulting in the preprocessed effective voltage sequence {U'1, U'2, ..., U' m (m≤n); ② Fluctuation value calculation: according to the formula ΔUᵢ = |U'ᵢ +1 - U'ᵢ| Calculate the absolute value of the voltage difference between two adjacent valid sampling points (i.e., the instantaneous fluctuation value), and obtain the fluctuation value sequence {ΔU1,ΔU2,...,ΔU...} m-1}; ③ Judgment rule: Statistical fluctuation value series with values ​​≥ threshold ΔU th The number of fluctuations, if the value of a single fluctuation is ≥ ΔU th If the cumulative number of fluctuations within 1 minute is ≥3, the battery is determined to be a high-resistance battery originating from the electrode interface and requiring repair; the threshold ΔU th =50mV.

[0030] Threshold calibration method: ① Preparation of standard samples: Select 3 to 5 brand new lead-acid batteries (without interface barrier layer) of the same model and specifications as standard samples, numbered S1 to S5; ② Benchmark fluctuation value test: Charge the standard samples according to the parameters in step 2 (charging current 1C2~2C2 A, charging time 3 minutes, sampling 0.1 seconds), and calculate the maximum instantaneous fluctuation value ΔU of each standard sample according to the core algorithm described above. max (S); ③ Threshold determination: Take twice the maximum fluctuation value of all standard samples as the threshold ΔU. th That is, ΔU th =2×max {ΔU max (S1), ΔU max (S2),...,ΔU max (S5)}; According to actual measurements, the maximum fluctuation value of the standard samples of 6-DZF series, 6-EVF series and UPS starved lead-acid batteries is ≤25mV, so a unified threshold ΔU is set. th =50mV, covering the identification needs of various target batteries; ④ Threshold verification: Select 3-5 known faulty batteries with interface barrier layers and test them according to the above method. If the fluctuation value is ≥50mV and the fluctuation value of known normal aged batteries without barrier layers (only active material decay, no dense lead sulfate layer) is <50mV, the threshold verification is completed.

[0031] Optimal parameters: charging current 2C2A, charging time 3~5 minutes (balancing recognition accuracy and battery safety). Equipment requirements: The charging power supply must support instantaneous high current output (response time ≤ 10ms), the data acquisition unit sampling frequency ≥ 10Hz, and the voltage measurement resolution ≥ 1Mv. Example

[0032] Two 6-DZF-22Ah lead-acid batteries returned from the market were selected, with serial numbers J20241120-1# and J20241120-2# respectively. This group of batteries had been used for 10 months and were returned due to low capacity and difficulty in charging. After testing, it was confirmed that there was a significant interface barrier layer.

[0033] The repair process steps in this embodiment are as follows: Pre-treatment discharge: Discharge each battery separately using a constant current of 11A (0.5C2, i.e., 2-hour rate current) until the voltage of a single cell drops to 1.75V (total voltage 10.5V), then stop discharging; Peak voltage identification and screening: The pre-treated batteries were charged with a constant current of 22A (1C2) for 3 minutes, and the battery voltage data was recorded every 0.1 seconds; through voltage change curve analysis, it was confirmed that the high resistance of both batteries occurred at the electrode interface and were included in the scope of repair. Deep discharge repair: Based on the peak voltage data, the interface barrier layer of the two batteries is of medium density. The discharge current is matched with 11A (0.5C2) and discharged to a single cell voltage of 1.75V (total voltage of 10.5V) to complete the deep discharge repair. Capacity restoration charging: a. Charge the battery at a constant current of 11A (0.5C2) until the total battery voltage reaches 14.40V; b. Switch to constant current 5.5A (0.25C2) charging until the battery total voltage reaches 14.80V; c. Charge using current-limited constant-voltage mode: current limit 4.4A (0.2C2), constant voltage 14.8V, continue charging until the current is less than 0.5A or the charging time exceeds 3 hours; d. Allow to stand until the battery voltage drops below 13.7V; e. Charge for 2 hours using a constant voltage of 13.8V and a current limit of 3A (0.15C2); Example

[0034] Three 6-DZF-20Ah lead-acid batteries, numbered A1, A2, and A3, were selected from the market. They had been in use for 8 months and were returned due to capacity decay after long-term storage. The interface barrier layer was found to be highly dense.

[0035] The repair process steps are as follows: Pre-treatment discharge: constant current 10A (0.5C2) discharge to total voltage 10.5V (1.75V / cell); Peak voltage identification and screening: Constant current 20A (1C2) charging for 4 minutes, voltage data is recorded once every 0.1 seconds. It was confirmed that all 3 batteries had high electrode interface resistance and were included in the repair. Deep discharge repair: Due to the high density of the barrier layer, a matching discharge current of 2A (0.1C2) is used to discharge to a total voltage of 6V (1V / cell), completing the repair. Capacity recovery charging: The standard vehicle charging mode is used (constant current 10A charging to 14.4V, then constant current 5A charging to 14.8V, then current-limited 4A constant voltage 14.8V charging until the current ≤0.5A, followed by resting and then constant voltage 13.8V charging for 2 hours) to complete capacity recovery. Repair effect verification 1. Example 1: Performance data comparison before and after repair

[0036] Example 2: Comparison of data before and after repair

[0037] Verification results: After repair, the battery capacity reached more than 95% of the rated capacity within 2 hours, and the internal resistance dropped to below 15mΩ; after 300 cycles, the capacity retention rate was ≥90%, far exceeding the existing technology (60%~70% for pulse repair method), completely solving the problem of secondary returns.

[0038] Compared with existing technologies:

[0039] This invention is the first to combine peak voltage instantaneous fluctuation identification technology (including standardized threshold calibration method) with internal resistance graded adaptation deep discharge, solving the problem of incomplete repair caused by the "blind repair" of existing technologies; through 1C2~2C2 A high current short-time charging + 0.1 second-level data acquisition + algorithm screening, it achieves rapid and accurate positioning of the blocking layer, breaking through the bottleneck of low efficiency of traditional small current identification and fuzzy identification of pulse technology.

[0040] The repair cycle of this invention is shortened by more than 60% compared with traditional low-current technology and by 50% compared with pulse technology, making it suitable for batch repair needs.

[0041] This invention can save 1.5 to 2 kWh of electricity per 6-DZF-20Ah battery, and can save 150,000 to 200,000 kWh of electricity by repairing 100,000 batteries per year; the secondary return rate is reduced to less than 1%, the return loss per battery is reduced by 1.3 yuan, and the annual loss is reduced by more than 130,000 yuan.

[0042] This invention requires no chemical additives and avoids battery damage through safety measures such as temperature monitoring and voltage limiting; it is applicable to various valve-regulated sealed lead-acid batteries and can be implemented by modifying existing equipment, making it easy to promote on a large scale.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery, characterized in that, Includes the following steps: (1) Initial capacity and internal resistance test: The lead-acid battery was discharged to 1.75V / cell using a 2-hour rate current, and the battery capacity and internal resistance data were recorded after 2 hours. (2) Peak voltage identification and screening: The battery is charged with a charging current of (1C2~2C2)A for 1~5 minutes. Voltage data during the charging process is collected at a recording interval of 0.1 seconds. The location of high resistance is identified based on the characteristics of the voltage curve, and the batteries to be repaired that have high resistance originating from the electrode interface are screened out. (3) Adaptive deep discharge repair: Based on the density of the interface barrier layer identified in step (2), match the corresponding discharge parameters. The discharge parameters include discharge current and discharge termination voltage. The discharge current is (0.05C2~0.5C2)A, and the discharge termination voltage is 1V~1.75V / cell. The higher the density of the interface barrier layer and the greater the resistance, the smaller the discharge current and the lower the discharge termination voltage. (4) Capacity recovery charging: The battery repaired in step (3) is fully charged using the conventional vehicle charging mode to complete the interface barrier layer repair and battery capacity recovery.

2. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to claim 1, characterized in that: The charging current in step (2) is 2 C2A, and the charging time is 3~5 minutes.

3. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to claim 1, characterized in that: The rules for determining the discharge current in step (3) are as follows: when the density of the interface barrier layer is slightly high, the peak value of the corresponding peak voltage characteristic curve is arc-shaped without sharp peaks, the discharge current is (0.3C2~0.5C2)A, and the discharge termination voltage is 1.5~1.75V / cell; when the density of the interface barrier layer is moderate, the peak value of the corresponding peak voltage characteristic curve is weakly sharp, the discharge current is (0.15C2~0.3C2)A, and the discharge termination voltage is 1.2~1.5V / cell; when the density of the interface barrier layer is high, the peak value of the corresponding peak voltage characteristic curve is sharp, the discharge current is (0.05C2~0.15C2)A, and the discharge termination voltage is 1~1.2V / cell.

4. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to claim 1, characterized in that: The conventional vehicle charging mode described in step (4) includes three stages of charging: the first stage is to charge at a constant current of (0.5C2~1C2)A to the battery voltage of 14.4V; the second stage is to charge at a constant current of (0.25C2~0.5C2)A to the battery voltage of 14.8V; the third stage is to charge at a current-limited rate of ≤0.2C2A and a constant voltage of 14.8V until the charging current is less than 0.5A or the charging time exceeds 3 hours, and then charge at a current-limited rate of 0.15C2A and a constant voltage of 13.8V for 2 hours.

5. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to claim 1, characterized in that: After charging is completed in step (4), a static verification step is also included: let the fully charged battery stand for 2 hours. When the battery open circuit voltage is ≤13.7V, repeat the charging process of step (4) once.

6. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to any one of claims 1-5, characterized in that: The lead-acid battery is a valve-regulated sealed lead-acid battery, including the 6-DZF series, 6-EVF series automotive batteries, and starved lead-acid batteries for UPS backup power.

7. The charging and discharging process for rapidly repairing the interface barrier layer of a lead-acid battery according to any one of claims 1-5, characterized in that: In step (2), the state of the interface barrier layer is identified by the fluctuation amplitude of the voltage curve: when the peak value of the peak voltage characteristic curve is sharp, it is determined to be a battery with high resistance originating from the electrode interface that needs to be repaired; when the peak value of the peak voltage characteristic curve is a weak sharp arc-shaped peak, it is determined to be a battery with moderate resistance originating from the electrode interface. When there is no sharp peak, there is no electrode interface problem and it is determined to be a normal battery.

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