Battery cell depolarization method and system based on charge pre-compensation

Abstract

The invention discloses a cell depolarization method and system based on charge pre-compensation, and the method comprises the steps: obtaining the voltage change rate of a target cell according to a preset sampling duration, and determining the polarization state of the target cell according to the voltage change rate; matching a symmetric bidirectional constant-amplitude pulse operation parameter and an asymmetric bidirectional constant-amplitude pulse operation parameter corresponding to the polarization state; performing pre-compensation charging and discharging on the target battery cell according to the asymmetric bidirectional constant-amplitude pulse operation parameters to obtain a pre-compensation battery cell; and performing depolarization operation on the pre-compensation battery cell according to the symmetric bidirectional constant-amplitude pulse operation parameters and the asymmetric bidirectional constant-amplitude pulse operation parameters to obtain a depolarized battery cell which is used for improving the depolarization effect of the battery cell.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage devices, and in particular to a cell depolarization method and system based on charge precompensation. Background Technology

[0002] Lithium-ion batteries have advantages such as high energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight, and are widely used in consumer electronics. However, during use, with operations such as fast charging or high-rate discharging, severe concentration polarization and electrochemical polarization occur within the battery cells. These polarization phenomena not only cause voltage lag but also easily lead to adverse effects such as capacity decay and reduced cycle life.

[0003] Existing technologies achieve cell depolarization through natural placement or pulse charging / discharging. However, natural placement typically requires the cell to be left to stand for 5-10 hours to achieve depolarization, which is too time-consuming and cannot meet practical charging needs. While pulse charging / discharging can accelerate depolarization, it cannot adapt to different types of polarization phenomena, resulting in poor depolarization performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this application discloses a cell depolarization method and system based on charge pre-compensation, which is used to improve the depolarization effect of the cell.

[0005] To achieve the above objectives, this application proposes a cell depolarization method based on charge pre-compensation, comprising:

[0006] The voltage change rate of the target cell is obtained according to a preset sampling duration, and the polarization state of the target cell is determined according to the voltage change rate.

[0007] Match the symmetrical bidirectional constant amplitude pulse operation parameters and the asymmetric bidirectional constant amplitude pulse operation parameters corresponding to the polarization state;

[0008] The target battery cell is pre-compensated by charging and discharging according to the asymmetric bidirectional equal amplitude pulse operation parameters to obtain a pre-compensated battery cell.

[0009] The pre-compensated cell is depolarized according to the symmetrical bidirectional equal-amplitude pulse operation parameters and the asymmetrical bidirectional equal-amplitude pulse operation parameters to obtain a depolarized cell.

[0010] This application discloses a cell depolarization method based on charge pre-compensation. This method dynamically identifies the cell's polarization state and selects different pulse parameter combinations for each polarization state to improve the depolarization effect. Specifically, the voltage change rate of the target cell is obtained based on a preset sampling duration, enabling real-time identification of the cell's polarization degree and timely depolarization. Next, symmetrical and asymmetrical bidirectional equal-amplitude pulse parameters corresponding to the polarization state are matched to eliminate different types of polarization phenomena, thereby improving the depolarization effect. Furthermore, pre-compensation charging and discharging of the cell is performed according to asymmetrical pulse parameters to address charge accumulation caused by asymmetrical pulses, improving the subsequent pulse-based depolarization effect. Finally, a composite depolarization operation is performed by combining symmetrical and asymmetrical pulses. The high-frequency characteristics of the symmetrical pulses accelerate ion migration, while the low-frequency characteristics of the asymmetrical pulses eliminate concentration polarization, further enhancing the cell depolarization effect.

[0011] In some implementations, the step of acquiring the voltage change rate of the target cell according to a preset sampling duration and determining the polarization state of the target cell based on the voltage change rate includes:

[0012] The first voltage of the target battery cell at the first sampling time and the second voltage at the second sampling time are obtained according to the preset sampling duration.

[0013] The voltage change rate of the target battery cell is obtained based on the first voltage, the second voltage, and the sampling duration.

[0014] When the absolute value of the voltage change rate is greater than or equal to a preset change rate threshold and the voltage conversion rate is positive, the target cell is determined to be in a post-discharge polarization state.

[0015] The above embodiments achieve accurate identification of the cell polarization state through the voltage change rate. Specifically, continuous voltage data is acquired by setting a fixed sampling period, and the voltage change rate is obtained by difference calculation. This ensures the temporal correlation of data acquisition and avoids misjudgment caused by instantaneous fluctuations. By setting an absolute value threshold and dual judgment conditions of positive and negative polarity, normal voltage fluctuations and polarization phenomena can be effectively distinguished. In particular, when the voltage change rate shows a positive increase and exceeds the threshold, it is accurately determined to be a polarization accumulation state after discharge. Based on the determination of the polarization accumulation state, an accurate state identification basis is provided for subsequent matching of corresponding asymmetric pulse parameters, thereby improving the cell depolarization effect.

[0016] In some implementations, the step of acquiring the voltage change rate of the target cell according to a preset sampling duration and determining the polarization state of the target cell based on the voltage change rate includes:

[0017] When the absolute value of the voltage change rate is greater than or equal to a preset change rate threshold and the voltage change rate is negative, the target cell is determined to be in a post-charging polarization state.

[0018] The above-described implementation identifies the polarization state after charging by utilizing the polarity characteristics of the voltage change rate, thus achieving accurate determination of the polarization type. Specifically, while the previous implementation already provided the characteristic of a positive voltage change rate to determine if the target cell is in a post-discharge polarization state, this implementation combines the characteristic of a negative voltage change rate to explicitly determine post-charging polarization. This provides a basis for subsequent matching of corresponding asymmetric pulse parameters, thereby improving the targeting of the depolarization operation and enhancing the cell depolarization effect.

[0019] In some embodiments, the matching of the symmetric bidirectional constant-amplitude pulse operating parameters and the asymmetric bidirectional constant-amplitude pulse operating parameters corresponding to the polarization state includes:

[0020] Match the absolute value with the corresponding pulse frequency, pulse amplitude, and pulse application duration; wherein, the pulse frequency includes symmetrical pulse frequency and asymmetrical pulse frequency; the pulse amplitude includes symmetrical pulse amplitude and asymmetrical pulse amplitude; the pulse application duration includes symmetrical pulse application duration and asymmetrical pulse application duration; the symmetrical pulse frequency is higher than the asymmetrical pulse frequency;

[0021] When the target cell is in a post-discharge polarization state, a preset charging bias pulse duty cycle is obtained; wherein, the proportion of positive pulses in the charging bias pulse duty cycle is greater than the proportion of negative pulses.

[0022] The symmetrical bidirectional constant amplitude pulse operation parameters corresponding to the target cell are obtained based on the symmetrical pulse frequency, the symmetrical pulse amplitude, the symmetrical pulse application duration, and the preset symmetrical pulse duty cycle; wherein, the proportion of positive pulses in the symmetrical pulse duty cycle is equal to the proportion of negative pulses.

[0023] The charging bias asymmetric bidirectional equal amplitude pulse operation parameters corresponding to the target cell are obtained based on the asymmetric pulse frequency, the asymmetric pulse amplitude, the asymmetric pulse application duration, and the charging bias pulse duty cycle.

[0024] The above implementation establishes a dynamic matching mechanism between pulse parameters and polarization state, designing specific symmetrical and asymmetrical pulse depolarization strategies for the post-discharge polarization state. First, the pulse frequency, amplitude, and duration are correlated using absolute value parameters. High-frequency pulses are used to eliminate electrochemical polarization, while low-frequency pulses are used to eliminate concentration polarization. Specifically, when post-discharge polarization is detected in the cell, an asymmetrical duty cycle with a larger proportion of positive pulses should be used in the low-frequency asymmetrical bidirectional equal-amplitude pulses to preferentially neutralize excess negative charge generated during discharge through positive charge injection. The symmetrical pulse parameters are designed with an equal duty cycle to ensure the balance of charge exchange during basic depolarization. By combining high-frequency symmetrical pulses with low-frequency asymmetrical pulses, electrochemical and concentration polarization can be rapidly eliminated, improving the depolarization effect.

[0025] In some embodiments, the matching of the symmetric bidirectional constant-amplitude pulse operating parameters and the asymmetric bidirectional constant-amplitude pulse operating parameters corresponding to the polarization state includes:

[0026] When the target cell is in a charged polarized state, a preset discharge bias pulse duty cycle is obtained; wherein, the proportion of positive pulses in the discharge bias pulse duty cycle is less than the proportion of negative pulses;

[0027] The discharge bias asymmetric bidirectional equal amplitude pulse operation parameters corresponding to the target cell are obtained based on the asymmetric pulse frequency, asymmetric pulse amplitude, asymmetric pulse application duration, and the discharge bias pulse duty cycle.

[0028] The above implementation addresses the unique characteristics of the battery cell in its post-charging polarized state by adjusting the duty cycle relationship of positive and negative pulses to construct asymmetric pulse parameters that match the polarization state. First, when the battery cell is in its post-charging polarized state, excessive positive charge accumulates internally. At this time, a discharge bias pulse duty cycle with a smaller proportion of positive pulses than negative pulses is used. By enhancing the duration or intensity of the negative pulses, excess charge is preferentially released. Second, by combining parameters such as asymmetric pulse frequency, amplitude, and application duration, an asymmetric bidirectional equal-amplitude pulse with specific timing characteristics is formed. This ensures efficient charge release while avoiding over-discharge that could damage the battery cell. Through this combination of asymmetric parameters, precise compensation can be made for the charge distribution imbalance caused by charging polarization, improving the depolarization effect of the battery cell.

[0029] In some embodiments, the step of performing pre-compensated charge-discharge on the target cell according to the asymmetric bidirectional constant amplitude pulse operation parameters to obtain a pre-compensated cell includes:

[0030] Based on the asymmetric pulse amplitude, the asymmetric pulse application duration, and the charging bias pulse duty cycle, the charging amount corresponding to the charging bias asymmetric bidirectional equal amplitude pulse operation parameters is obtained.

[0031] Based on the asymmetric pulse amplitude, the asymmetric pulse application duration, and the discharge bias pulse duty cycle, the discharge quantity corresponding to the discharge bias asymmetric bidirectional equal amplitude pulse operation parameters is obtained.

[0032] The target cell is discharged or charged according to the amount of charge, to obtain a pre-compensated cell after discharge or charging.

[0033] The above implementation method establishes a quantitative relationship between asymmetric pulse parameters and charge compensation, achieving precise charge pre-compensation for different polarization states. Specifically, by combining the asymmetric pulse amplitude, asymmetric pulse application duration, and asymmetric pulse duty cycles with different biases, the required charge compensation for the polarization state after discharge can be accurately quantified. Similarly, by combining the asymmetric pulse amplitude, asymmetric pulse application duration, and discharge bias pulse duty cycle, the required discharge compensation for the polarization state after charging can be accurately obtained. Furthermore, by dynamically adjusting the compensation direction through polarization direction, the pre-compensation amount and polarization charge amount form an inverse cancellation relationship, effectively eliminating the polarization charge accumulated inside the cell and improving the cell's depolarization effect.

[0034] In some embodiments, the step of performing a depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal-amplitude pulse operation parameters and the asymmetrical bidirectional equal-amplitude pulse operation parameters to obtain a depolarized cell includes:

[0035] A symmetrical bidirectional equal-amplitude pulse containing both positive and negative pulses is generated based on the symmetrical pulse frequency, symmetrical pulse amplitude, and symmetrical pulse duty cycle.

[0036] The pre-compensated battery cell is charged and discharged according to the symmetrical pulse application duration and the symmetrical bidirectional equal amplitude pulse to obtain the initial depolarized battery cell.

[0037] Based on the asymmetric pulse frequency, asymmetric pulse amplitude, and discharge bias pulse duty cycle, a discharge bias asymmetric bidirectional equal amplitude pulse containing positive and negative pulses is generated.

[0038] The initial depolarized cell is charged and discharged according to the asymmetric pulse application duration and the discharge bias asymmetric bidirectional equal amplitude pulse to obtain a depolarized cell.

[0039] The above implementation achieves multi-dimensional depolarization by applying symmetrical bidirectional equal-amplitude pulses and asymmetrical bidirectional equal-amplitude pulses in stages. First, a high-frequency symmetrical pulse is used to quickly break the accumulation of polarization charge. Simultaneously, the balancing characteristic of the symmetrical pulse prevents secondary charge accumulation. By limiting the application duration of the symmetrical pulse, the action time of the high-frequency pulse is precisely controlled to prevent overprocessing. Then, a low-frequency asymmetrical bidirectional equal-amplitude pulse is applied, utilizing the continuous oscillation characteristic of the low-frequency pulse to thoroughly eliminate residual polarization. Through the combination of high-frequency symmetrical bidirectional equal-amplitude pulses and low-frequency asymmetrical bidirectional equal-amplitude pulses, both depolarization speed and processing depth are ensured, overcoming the limitation of a single pulse mode being unable to adapt to different polarization stages.

[0040] In some embodiments, the step of performing a depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal-amplitude pulse operation parameters and the asymmetrical bidirectional equal-amplitude pulse operation parameters to obtain a depolarized cell includes:

[0041] A charging bias asymmetric bidirectional equal-amplitude pulse containing both positive and negative pulses is generated based on the asymmetric pulse frequency, asymmetric pulse amplitude, and charging bias pulse duty cycle.

[0042] The initial depolarized cell is charged and discharged according to the asymmetric pulse application duration and the charging bias asymmetric bidirectional equal amplitude pulse to obtain the depolarized cell.

[0043] The above implementation method improves the cell depolarization effect by matching the characteristic parameters of the polarization state after charging and constructing an asymmetric pulse waveform using a discharge bias pulse duty cycle with a higher proportion of negative pulses.

[0044] In some embodiments, the step of performing a depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal-amplitude pulse operation parameters and the asymmetrical bidirectional equal-amplitude pulse operation parameters to obtain a depolarized cell further includes:

[0045] The third voltage of the depolarized cell at the third sampling time and the fourth voltage at the fourth sampling time are obtained according to the sampling duration.

[0046] The depolarization voltage change rate of the depolarized cell is obtained based on the third voltage, the fourth voltage, and the sampling duration.

[0047] When the absolute value of the depolarization voltage change rate is less than the change rate threshold, the depolarization operation of the target cell is completed.

[0048] The above implementation method establishes a closed-loop judgment mechanism to achieve precise control by dynamically monitoring the voltage change characteristics during the depolarization process. Specifically, the polarization phenomenon is determined to be eliminated only when the voltage conversion rate of the depolarized cell is determined to be lower than a threshold. This avoids the over-processing or under-processing problems that may exist in traditional fixed-duration processing methods, and the real-time feedback mechanism ensures that the depolarization operation automatically terminates when the optimal effect is achieved, thus improving processing efficiency while ensuring processing effect.

[0049] On the other hand, the present invention discloses a cell depolarization system based on charge pre-compensation, including a polarization identification module, a pulse adjustment module, a pre-compensation module and a depolarization module;

[0050] The polarization identification module is used to obtain the voltage change rate of the target cell according to a preset sampling time, and to determine the polarization state of the target cell according to the voltage change rate.

[0051] The pulse adjustment module is used to match the symmetrical bidirectional constant amplitude pulse operation parameters and the asymmetrical bidirectional constant amplitude pulse operation parameters corresponding to the polarization state.

[0052] The pre-compensation module is used to pre-compensate the target cell for charging and discharging according to the asymmetric bidirectional equal amplitude pulse operation parameters to obtain a pre-compensated cell.

[0053] The depolarization module is used to perform depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal amplitude pulse operation parameters and the asymmetrical bidirectional equal amplitude pulse operation parameters to obtain a depolarized cell.

[0054] This invention discloses a cell depolarization system based on charge pre-compensation. This system dynamically identifies the cell's polarization state and selects different pulse parameter combinations for each polarization state to improve depolarization effectiveness. Specifically, the voltage change rate of the target cell is obtained based on a preset sampling duration, enabling real-time identification of the cell's polarization level and timely depolarization. Next, symmetrical and asymmetrical bidirectional equal-amplitude pulse parameters corresponding to the polarization state are matched to eliminate different types of polarization phenomena, thereby improving the depolarization effect. Furthermore, pre-compensation charging and discharging of the cell is performed based on asymmetrical pulse parameters to address charge accumulation caused by asymmetrical pulses, improving the effectiveness of subsequent pulse-based depolarization. Finally, a composite depolarization operation is performed by combining symmetrical and asymmetrical pulses. Symmetrical high-frequency pulses eliminate electrochemical polarization, while asymmetrical pulses eliminate concentration polarization, further enhancing the cell depolarization effect. Attached Figure Description

[0055] The embodiments described in this application are not limited to the accompanying drawings, which are only some of the embodiments described herein. Those skilled in the art can obtain drawings of other embodiments based on the content of this application.

[0056] Figure 1 A schematic flowchart of the cell depolarization method based on charge pre-compensation provided in this application;

[0057] Figure 2 A schematic diagram of the cell depolarization system based on charge pre-compensation provided in this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The embodiments of this application may omit unnecessary detailed descriptions. For example, detailed descriptions of well-known matters and repeated descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0059] In this application, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in a range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly, encompassing not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified. In the detailed description and claims, a list of items connected by the terms “one of,” “among,” “one of,” or other similar terms may mean any of the listed items. For example, if items A and B are listed, the phrase “one of A and B” means only A or only B. In another instance, if items A, B, and C are listed, the phrase “one of A, B, and C” means only A; only B; or only C. In the following description, all figures disclosed in this application are approximate values, regardless of whether the terms “about” or “approximate” are used in conjunction. These can vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a numerical range with a lower limit (RL) and an upper limit (RU) is disclosed, any value falling within that range is specifically disclosed. Specifically, the following value within this range is specifically disclosed: R = RL + k * (RU - RL), where k is a variable with a 1% increment from 1% to 100%, i.e., k is 1%, 2%, ..., or 100%. Furthermore, any numerical range defined by the two R values ​​as defined above is also specifically disclosed. Throughout this specification, references to “implementation,” “partial implementation,” “one implementation,” “another implementation,” “specific implementation,” or “partial implementation” mean that at least one implementation or embodiment in this application includes the specific features, structures, materials, or properties described in that implementation or embodiment. In this application, numerical ranges are considered continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value, or with other lower or upper limits, to form an unspecified range.

[0060] Reference Figure 1To address the technical problem of the inability to quickly and accurately depolarize battery cells in existing technologies, this application provides an embodiment of a battery cell depolarization method based on charge pre-compensation. This method eliminates charge accumulation during depolarization by pre-compensating the battery cell and eliminates different polarization phenomena by setting symmetrical and asymmetrical bidirectional equal-amplitude pulses, thereby improving the depolarization effect and efficiency. Specifically, the method includes:

[0061] Step 101: Obtain the voltage change rate of the target cell according to the preset sampling duration, and determine the polarization state of the target cell according to the voltage change rate;

[0062] Step 102: Match the symmetrical bidirectional constant amplitude pulse operation parameters and the asymmetrical bidirectional constant amplitude pulse operation parameters corresponding to the polarization state;

[0063] Step 103: Perform pre-compensation charge and discharge on the target cell according to the asymmetric bidirectional constant amplitude pulse operation parameters to obtain a pre-compensated cell;

[0064] Step 104: Perform depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal amplitude pulse operation parameters and the asymmetrical bidirectional equal amplitude pulse operation parameters to obtain a depolarized cell.

[0065] In this embodiment, the sampling duration is the time difference between two adjacent sampling moments when the battery cell's voltage is acquired. By using this sampling duration to perform intermittent voltage acquisition of the battery cell, sampling errors caused by voltage fluctuations are avoided, thereby ensuring the accuracy of battery cell polarization identification. Battery cell polarization refers to the phenomenon where the actual operating voltage of the battery cell deviates from its theoretical equilibrium voltage during charging and discharging. Battery cell polarization typically includes electrochemical polarization and concentration polarization. Electrochemical polarization is the voltage shift caused by the need to overcome energy barriers during charging and discharging through electrochemical reactions. Concentration polarization refers to the voltage change caused by reactants being consumed on the electrode surface and not being replenished from the solution, or by products accumulating on the electrode surface and not dispersing, resulting in a difference in concentration between the electrode surface and the solution. In the technique of depolarizing the battery cell using pulses, symmetrical bidirectional equal-amplitude pulses refer to charging and discharging waveforms with equal positive and negative pulse amplitudes and the same duty cycle, which can be implemented using a high-frequency square wave generator. Asymmetric bidirectional equal-amplitude pulses refer to charging and discharging waveforms where the positive and negative pulse amplitudes are equal but the duty cycles are different. This can be achieved by adjusting the pulse width ratio using a programmable pulse controller. Pre-compensated charging and discharging refers to the operation of adjusting the charge amount of the battery cell according to the polarization state. This can be achieved by achieving charge balance through the difference in the positive and negative proportions of asymmetric pulses.

[0066] In this embodiment, the above steps improve the depolarization effect of the battery cell by dynamically identifying its polarization state and selecting different pulse parameter combinations for each polarization state. Specifically, by acquiring the voltage change rate of the target battery cell based on a preset sampling duration, the polarization degree of the battery cell can be identified in real time, allowing for timely depolarization. Next, by matching symmetrical and asymmetrical bidirectional equal-amplitude pulse parameters corresponding to the polarization state, different types of polarization phenomena are eliminated, thereby improving the depolarization effect. Furthermore, the battery cell undergoes pre-compensation charging and discharging based on asymmetrical pulse parameters to address charge accumulation caused by asymmetrical pulses, improving the subsequent depolarization effect based on the pulses. Finally, a composite depolarization operation is performed by combining symmetrical and asymmetrical pulses. The high-frequency characteristics of the symmetrical pulses accelerate ion migration, while the low-frequency characteristics of the asymmetrical pulses eliminate concentration polarization, thereby improving the battery cell depolarization effect.

[0067] In this embodiment, step 101 includes:

[0068] Step 1011: Obtain the first voltage of the target cell at the first sampling time and the second voltage at the second sampling time according to the preset sampling duration.

[0069] Step 1012: Obtain the voltage change rate of the target cell based on the first voltage, the second voltage, and the sampling duration.

[0070] Step 1013: When the absolute value of the voltage change rate is greater than or equal to the preset change rate threshold and the voltage conversion rate is positive, it is determined that the target cell is in a post-discharge polarization state.

[0071] Step 1014: When the absolute value of the voltage change rate is greater than or equal to a preset change rate threshold and the voltage change rate is negative, it is determined that the target cell is in a post-charging polarization state.

[0072] Specifically, in this embodiment, the voltage change rate refers to the numerical value of voltage change per unit time, which can be calculated by dividing the difference between two consecutive voltage sampling values ​​by the sampling duration. When acquiring voltage data according to a preset sampling duration, a timed trigger method can be used to acquire the first open-circuit voltage of the battery cell at a consecutive first sampling moment and the second open-circuit voltage at a second sampling moment. The voltage difference between the first and second open-circuit voltages and the time difference between the first and second sampling moments are used to determine the voltage conversion rate of the target battery cell. In this embodiment, the change rate threshold is a pre-set critical value used to distinguish between normal voltage fluctuations and polarization states. It can be determined through experimental calibration or historical data analysis and is used to filter out minor voltage changes caused by non-polarization factors.

[0073] Specifically, during cell operation, voltage sampling is periodically triggered, for example, the open-circuit voltage is sampled every 60 seconds, and voltage data from two adjacent sampling points are continuously recorded. The open-circuit voltage value at the next moment is subtracted from the open-circuit voltage value at the previous moment, and then divided by the sampling interval to obtain the voltage change rate. When the absolute value of this change rate exceeds a preset threshold and is positive, it indicates that the ion concentration distribution inside the cell is unbalanced after discharge, causing the voltage to show a continuous upward trend; this is determined to be a post-discharge polarization state. After the charging operation is completed, a lithium-ion concentration gradient will form on the surface of the positive electrode active material inside the cell, causing the open-circuit voltage to gradually decrease over time. If the absolute value of the change rate exceeds a preset threshold and is negative, it indicates that the cell is in a post-charging polarization state. For example, when the change rate threshold is 4 × 10⁻⁶... -7 If the calculated voltage change rate is greater than the threshold value and is positive at V / s, the cell is determined to be in a discharged polarized state. If the calculated voltage change rate is greater than the threshold value and is negative, the cell is determined to be in a charged polarized state.

[0074] In this embodiment, the above steps achieve accurate identification of the cell polarization state through the voltage change rate. Specifically, continuous voltage data is acquired by setting a fixed sampling period, and the voltage change rate is obtained by difference calculation, which ensures the temporal correlation of data acquisition and avoids misjudgment caused by instantaneous fluctuations. By setting an absolute value threshold and dual judgment conditions of positive and negative polarity, normal voltage fluctuations and polarization phenomena can be effectively distinguished. In particular, when the voltage change rate shows a positive increase and exceeds the threshold, it is accurately determined to be a polarization accumulation state after discharge. Based on the determination of the polarization accumulation state, an accurate state identification basis is provided for subsequent matching of corresponding asymmetric pulse parameters, thereby improving the cell depolarization effect.

[0075] In this embodiment, step 102 includes:

[0076] Step 1021: Match the pulse frequency, pulse amplitude, and pulse application duration corresponding to the absolute value; wherein, the pulse frequency includes symmetrical pulse frequency and asymmetrical pulse frequency; the pulse amplitude includes symmetrical pulse amplitude and asymmetrical pulse amplitude; the pulse application duration includes symmetrical pulse application duration and asymmetrical pulse application duration; the symmetrical pulse frequency is higher than the asymmetrical pulse frequency;

[0077] Step 1022: When the target cell is in a post-discharge polarization state, obtain a preset charging bias pulse duty cycle; wherein, the proportion of positive pulses in the charging bias pulse duty cycle is greater than the proportion of negative pulses;

[0078] Step 1023: When the target cell is in a charged polarized state, obtain a preset discharge bias pulse duty cycle; wherein, the proportion of positive pulses in the discharge bias pulse duty cycle is less than the proportion of negative pulses;

[0079] Step 1024: Obtain the symmetrical bidirectional constant amplitude pulse operation parameters corresponding to the target cell based on the symmetrical pulse frequency, the symmetrical pulse amplitude, the symmetrical pulse application duration, and the preset symmetrical pulse duty cycle; wherein, the proportion of positive pulses in the symmetrical pulse duty cycle is equal to the proportion of negative pulses;

[0080] Step 1025: Obtain the charging bias asymmetric bidirectional equal amplitude pulse operation parameters corresponding to the target cell based on the asymmetric pulse frequency, the asymmetric pulse amplitude, the asymmetric pulse application duration, and the charging bias pulse duty cycle;

[0081] Step 1026: Obtain the discharge bias asymmetric bidirectional equal amplitude pulse operation parameters corresponding to the target cell based on the asymmetric pulse frequency, asymmetric pulse amplitude, asymmetric pulse application duration, and the discharge bias pulse duty cycle.

[0082] Specifically, in this embodiment, pulse frequency refers to the number of pulses applied per unit time, which can be achieved by adjusting the oscillation period of the pulse generator. Symmetrical high-frequency pulses are used to eliminate electrochemical polarization, while asymmetric pulses are used to eliminate concentration polarization. Pulse amplitude refers to the voltage amplitude of a single pulse, which can be achieved by adjusting the power supply output power. Different amplitudes correspond to different disturbance intensity requirements. Pulse application duration refers to the length of time a specific pulse pattern is continuously applied. Pulse duty cycle refers to the ratio of the duration of positive and negative pulses within the period, which can be achieved by adjusting the duty cycle parameter of the pulse waveform generator. The asymmetric duty cycle design can specifically compensate for charge imbalances under specific polarization states.

[0083] Specifically, when the absolute value of the voltage change rate reaches a threshold and is positive, the cell is determined to be in a post-discharge polarization state. At this time, electrochemical polarization is eliminated using a high-frequency symmetrical pulse, while concentration polarization is eliminated using a low-frequency asymmetrical pulse with a larger proportion of positive pulses. Preferably, to ensure the high-frequency requirements of the symmetrical bidirectional equal-amplitude pulse operating parameters, the symmetrical pulse frequency can be set in the range of 50 to 200 Hz, and the symmetrical pulse amplitude can be set in the range of ±1C to ±3C. Here, C refers to the cell capacity. To ensure the high-frequency requirements of the asymmetrical bidirectional equal-amplitude pulse operating parameters, the asymmetrical pulse frequency can be set in the range of 0.1 to 1 Hz, and the asymmetrical pulse amplitude can be set in the range of ±0.2C to ±0.8C.

[0084] During the symmetrical pulse phase, a 50% equal duty cycle is used, meaning the ratio of positive pulses for charging to negative pulses for discharging is 1:1, allowing for bidirectional charging and discharging of the cell through the switching of positive and negative pulses. In the asymmetric compensation phase, an asymmetric pulse duty cycle is used where either the positive pulse ratio is higher than the negative pulse ratio, or vice versa, to eliminate concentration polarization by increasing the amount of positive charge injection or by increasing the amount of negative charge. To further improve the depolarization effect of the cell, the duration of the asymmetric pulse application can be set to be longer than that of the symmetrical pulse application. Preferably, the duration of the symmetrical pulse application is 5 to 30 seconds, while the duration of the asymmetric pulse application is 1 to 5 minutes.

[0085] In this embodiment, the above steps establish a dynamic matching mechanism between pulse parameters and polarization state, designing specific symmetrical pulse depolarization strategies and asymmetric pulse depolarization strategies for the post-discharge polarization state. First, the pulse frequency, amplitude, and duration are correlated using absolute value parameters to eliminate electrochemical polarization using symmetrical high-frequency pulses and concentration polarization using asymmetric pulses. Specifically, when post-discharge polarization is detected, an asymmetric duty cycle with a larger proportion of positive pulses is used to eliminate concentration polarization. The symmetrical pulse parameters are designed with an equal duty cycle to ensure the balance of charge exchange during basic depolarization. By combining high-frequency symmetrical pulses with low-frequency asymmetric pulses, electrochemical and concentration polarization are quickly eliminated, improving the depolarization effect. Specifically, considering the special characteristics of the post-charging polarization state, asymmetric pulse parameters matching the polarization state are constructed by adjusting the duty cycle relationship between positive and negative pulses. First, when the battery cell is in a post-charge polarized state, there is an excessive accumulation of positive charge inside. At this time, a discharge bias pulse duty cycle with a lower proportion of positive pulses than negative pulses is used. By enhancing the duration or intensity of the negative pulses, the excess charge is preferentially released. Second, by combining parameters such as asymmetric pulse frequency, amplitude, and application duration, an asymmetric bidirectional equal-amplitude pulse with specific timing characteristics is formed. Through this combination of asymmetric parameters, precise compensation can be made for the charge distribution imbalance caused by charging polarization, improving the depolarization effect of the battery cell.

[0086] In this embodiment, step 103 includes:

[0087] Step 1031: Based on the asymmetric pulse amplitude, the asymmetric pulse application duration, and the charging bias pulse duty cycle, obtain the charging amount corresponding to the charging bias asymmetric bidirectional equal amplitude pulse operation parameters.

[0088] Step 1032: Based on the asymmetric pulse amplitude, the asymmetric pulse application duration, and the discharge bias pulse duty cycle, obtain the discharge quantity corresponding to the discharge bias asymmetric bidirectional equal amplitude pulse operation parameters;

[0089] Step 1033: Discharge the target cell according to the charging amount or charge the target cell according to the discharging amount to obtain a pre-compensated cell after discharge or charging.

[0090] Specifically, in this embodiment, the asymmetric pulse amplitude refers to the voltage amplitude applied across the battery cell, which determines the intensity of charge transfer per unit time. The asymmetric pulse duration refers to the length of time the pulse acts, which affects the total amount of charge transferred. The asymmetric pulse duty cycle is the ratio of the positive pulse duration to the pulse period, which can be achieved by adjusting the ratio of positive to negative pulse times using pulse width modulation technology. This parameter is used to control the charge compensation direction in the polarized state after discharge. The discharge bias pulse duty cycle is the ratio of the negative pulse duration to the pulse period, which can be achieved by adjusting the ratio of positive to negative pulse times using reverse pulse width modulation technology. This parameter is used to control the charge compensation direction in the polarized state after charging.

[0091] Specifically, the total pulse charge is obtained by multiplying the asymmetric pulse amplitude by the asymmetric pulse net duration (for discharge-biased pulses, net duration = total discharge duration - total charging duration; for charging-biased pulses, net duration = total charging duration - total discharge duration). This total charge is the amount of charging or discharging that needs compensation, or the charge compensation required for a discharge pulse = (discharge pulse percentage - charging pulse percentage) / (discharge pulse percentage + charging pulse percentage) * total pulse duration * pulse amplitude. By precisely calculating the charge amount, a corresponding charge compensation operation is performed on the battery cell, quantitatively neutralizing the polarization charge accumulated inside the cell.

[0092] In this embodiment, the above steps establish a quantitative relationship between asymmetric pulse parameters and charge compensation, thereby achieving precise charge pre-compensation for different polarization states. Specifically, by combining the asymmetric pulse amplitude, asymmetric pulse application duration, and asymmetric pulse duty cycle, the amount of charge required to compensate for the polarization state after discharge can be accurately quantified. Similarly, by combining the asymmetric pulse amplitude, asymmetric pulse application duration, and asymmetric pulse duty cycle, the amount of discharge or charge required to compensate for different polarization states can be accurately obtained. Furthermore, by dynamically adjusting the compensation direction through the polarization direction, it is ensured that the pre-compensation amount and the polarization charge amount form an inverse cancellation relationship, effectively eliminating the polarization charge accumulated inside the cell and improving the depolarization effect of the cell.

[0093] In this embodiment, step 104 includes:

[0094] Step 1041: Generate a symmetrical bidirectional constant amplitude pulse containing positive and negative pulses according to the symmetrical pulse frequency, symmetrical pulse amplitude and symmetrical pulse duty cycle; charge and discharge the pre-compensated cell according to the symmetrical pulse application duration and the symmetrical bidirectional constant amplitude pulse to obtain the initial depolarized cell.

[0095] Step 1042: Generate a discharge bias asymmetric bidirectional constant amplitude pulse containing positive and negative pulses based on the asymmetric pulse frequency, asymmetric pulse amplitude, and discharge bias pulse duty cycle; charge and discharge the initial depolarized cell according to the asymmetric pulse application duration and the discharge bias asymmetric bidirectional constant amplitude pulse to obtain a depolarized cell.

[0096] Step 1043: Generate a charging bias asymmetric bidirectional equal amplitude pulse containing positive and negative pulses based on the asymmetric pulse frequency, asymmetric pulse amplitude, and charging bias pulse duty cycle; charge and discharge the initial depolarized cell based on the asymmetric pulse application duration and the charging bias asymmetric bidirectional equal amplitude pulse to obtain the depolarized cell.

[0097] Step 1044: Obtain the third voltage of the depolarized cell at the third sampling time and the fourth voltage at the fourth sampling time according to the sampling duration; obtain the depolarization voltage change rate of the depolarized cell according to the third voltage, the fourth voltage and the sampling duration; when the absolute value of the depolarization voltage change rate is less than the change rate threshold, complete the depolarization operation of the target cell.

[0098] Specifically, in this embodiment, based on the pre-compensated battery cell, a high-frequency symmetrical bidirectional equal-amplitude pulse is first applied. For example, a symmetrical pulse with a pulse frequency of 50 Hz and a pulse amplitude of 1C is used for an application duration of 15 seconds. The positive pulse of the high-frequency symmetrical bidirectional equal-amplitude pulse is used to charge the battery cell, and the negative pulse of the high-frequency symmetrical bidirectional equal-amplitude pulse is used to discharge the battery cell. By switching between the discharge and charging operations, the charge within the battery cell migrates rapidly, thereby disrupting the stable state of polarization charge formation. At the same time, the alternating positive and negative action of the symmetrical pulse maintains charge balance. Subsequently, a low-frequency asymmetrical bidirectional equal-amplitude pulse is applied. For example, an asymmetrical pulse with a pulse frequency of 1 Hz and a pulse amplitude of 0.5C is used for a continuous oscillation treatment of the battery cell for an application duration of 100 seconds. The longer application time of the low-frequency pulse allows the polarization charge to gradually diffuse while maintaining symmetry to avoid new charge accumulation. The combined application of the two-stage parameter differences—high-frequency pulses eliminating electrochemical polarization and low-frequency pulses eliminating concentration polarization—improves the depolarization effect of the battery cell.

[0099] Next, during the depolarization operation, the cell's voltage data is periodically collected, for example, every 60 seconds. The voltage difference between the third and fourth sampling times is divided by the sampling duration to obtain the depolarization voltage change rate. When the absolute value of this change rate is lower than a preset threshold, it indicates that the polarization phenomenon inside the cell has stabilized, and the depolarization operation is immediately terminated.

[0100] In this embodiment, the above steps achieve multi-dimensional depolarization by applying symmetrical bidirectional equal-amplitude pulses and asymmetrical bidirectional equal-amplitude pulses in stages. First, high-frequency symmetrical pulses are used to quickly break the accumulation of polarization charge. Simultaneously, the balancing characteristics of the symmetrical pulses prevent secondary charge accumulation. By limiting the application duration of the symmetrical pulses, the duration of the high-frequency pulses is precisely controlled to prevent overprocessing. Next, the process switches to low-frequency asymmetrical bidirectional equal-amplitude pulses, utilizing the continuous oscillation characteristics of the low-frequency pulses to thoroughly eliminate residual polarization. Then, through the high-frequency symmetrical bidirectional equal-amplitude pulses and the low-frequency asymmetrical bidirectional equal-amplitude pulses, both depolarization speed and processing depth are ensured, overcoming the limitation of a single pulse mode being unable to adapt to different polarization stages. A closed-loop judgment mechanism is established by dynamically monitoring the voltage change characteristics during the depolarization process to achieve precise control. Specifically, the polarization phenomenon is determined to be eliminated only when the voltage conversion rate of the depolarized cell is below a threshold. This avoids the overprocessing or underprocessing problems that may exist in traditional fixed-duration processing methods, and the real-time feedback mechanism ensures that the depolarization operation automatically terminates when the optimal effect is achieved, thus improving processing efficiency while ensuring processing effectiveness.

[0101] Preferably, in this embodiment one, refer to Figure 1 The cell depolarization method described above first takes 15 minutes in Implementation 1 to charge the cell's state of charge to +0.5% of the current state of charge using a constant current of 0.02C for pre-charge compensation. Then, the high-frequency pulse parameters are set to 100Hz, ±2C, and a charge / discharge ratio of 1:1, lasting for 20 seconds; the low-frequency pulse parameters are set to 0.5Hz, ±0.5C, and a charge / discharge ratio of 1:1.3, lasting for 276 seconds. At this point, the net discharge corresponding to the low-frequency pulse is approximately 0. 0.5% SOC; In Implementation Method 2, the cell's state of charge is charged to the current state of charge +0.5% for 30 minutes using a constant current of 0.01C to perform pre-charge compensation: then the high-frequency pulse parameters are set to 50Hz, ±1C, and a charge / discharge ratio of 1:1, lasting for 30 seconds; the low-frequency pulse parameters are set to 0.2Hz, ±0.3C, and a charge / discharge ratio of 1:1.2, lasting for 11 minutes, at which time the net discharge corresponding to the low-frequency pulse is ≈0.5% SOC.

[0102] In Comparative Example 1, the polarization voltage decay was monitored by allowing the battery cell to rest for 5 hours. In Comparative Example 2, a single pulse of 0.1Hz, ±0.5C was directly applied to the battery cell for 2 hours. The performance data of Embodiment 1, Embodiment 2, Comparative Example 1, and Comparative Example 2 are shown in the table below:

[0103]

[0104] As shown in the table above, this application, through pre-compensation and multi-frequency pulse synergy, significantly outperforms the comparative example in both depolarization speed (10 times faster than natural shelving) and SOC stability (5 times better than the single pulse method).

[0105] On the other hand, refer to Figure 2 This embodiment provides a cell depolarization system based on charge pre-compensation, including a polarization identification module 201, a pulse adjustment module 202, a pre-compensation module 203, and a depolarization module 204.

[0106] The polarization identification module 201 is used to obtain the voltage change rate of the target cell according to a preset sampling time, and determine the polarization state of the target cell according to the voltage change rate.

[0107] The pulse adjustment module 202 is used to match the symmetrical bidirectional constant amplitude pulse operation parameters and the asymmetrical bidirectional constant amplitude pulse operation parameters corresponding to the polarization state.

[0108] The pre-compensation module 203 is used to pre-compensate the target cell by charging and discharging according to the asymmetric bidirectional equal amplitude pulse operation parameters to obtain a pre-compensated cell.

[0109] The depolarization module 204 is used to perform a depolarization operation on the pre-compensated cell according to the symmetrical bidirectional equal amplitude pulse operation parameters and the asymmetrical bidirectional equal amplitude pulse operation parameters to obtain a depolarized cell.

[0110] The cell depolarization method and system based on charge pre-compensation provided in this embodiment significantly reduces depolarization time and improves depolarization efficiency by performing depolarization operations based on pulses. Specifically, it employs a coupled design of charge pre-compensation and pulses to achieve zero charge state drift in the cell through pre-compensated charging / discharging, solving the charge accumulation problem and improving depolarization performance. During depolarization, high-frequency symmetrical equal-amplitude bidirectional pulses can target electrochemical polarization, while low-frequency asymmetric equal-amplitude bidirectional pulses can target concentration polarization, resulting in a significant improvement in overall depolarization performance. Before depolarization, pulse parameters are automatically optimized based on the real-time cell state, ensuring compatibility with different cell systems and improving depolarization effectiveness. Furthermore, in other embodiments, parameter templates can be pre-set, allowing automatic execution of the depolarization process simply by selecting a preset parameter template based on the test type. Compared to the cumbersome operation of traditional static methods requiring manual judgment of stable state and frequent data recording, this method avoids human judgment errors through built-in real-time polarization monitoring and automatic termination mechanisms.

[0111] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method of depolarization of a battery cell based on charge pre-compensation, characterized in that, The method comprises the following steps: obtaining a voltage change rate of the target battery according to a preset sampling duration, and determining a polarization state of the target battery according to the voltage change rate; matching symmetric bidirectional equal-amplitude pulse operation parameters and asymmetric bidirectional equal-amplitude pulse operation parameters corresponding to the polarization state; performing pre-compensation charging and discharging on the target battery according to the asymmetric bidirectional equal-amplitude pulse operation parameters, to obtain a pre-compensation battery; performing depolarization operation on the pre-compensation battery according to the symmetric bidirectional equal-amplitude pulse operation parameters and the asymmetric bidirectional equal-amplitude pulse operation parameters, to obtain a depolarization battery.

2. The charge pre-compensated cell depolarization method of claim 1, wherein, The method comprises the following steps: obtaining a first voltage of the target battery at a first sampling time and a second voltage of the target battery at a second sampling time according to a preset sampling duration; obtaining a voltage change rate of the target battery according to the first voltage, the second voltage and the sampling duration; when the absolute value of the voltage change rate is greater than or equal to a preset change rate threshold and the voltage change rate is positive, determining that the target battery is in a post-discharge polarization state.

3. The charge pre-compensated cell depolarization method of claim 2, wherein, The method comprises the following steps: when the absolute value of the voltage change rate is greater than or equal to a preset change rate threshold and the voltage change rate is negative, determining that the target battery is in a post-charge polarization state.

4. The charge pre-compensated cell depolarization method of claim 2, wherein, The method comprises the following steps: matching pulse frequency, pulse amplitude and pulse application duration corresponding to the absolute value; wherein the pulse frequency comprises symmetric pulse frequency and asymmetric pulse frequency; the pulse amplitude comprises symmetric pulse amplitude and asymmetric pulse amplitude; the pulse application duration comprises symmetric pulse application duration and asymmetric pulse application duration; the symmetric pulse frequency is higher than the asymmetric pulse frequency; when the target battery is in a post-discharge polarization state, obtaining a preset charge bias pulse duty cycle; wherein the proportion of positive pulses in the charge bias pulse duty cycle is greater than the proportion of negative pulses; obtaining symmetric bidirectional equal-amplitude pulse operation parameters corresponding to the target battery according to the symmetric pulse frequency, the symmetric pulse amplitude, the symmetric pulse application duration and a preset symmetric pulse duty cycle; wherein the proportion of positive pulses in the symmetric pulse duty cycle is equal to the proportion of negative pulses; obtaining charge bias asymmetric bidirectional equal-amplitude pulse operation parameters corresponding to the target battery according to the asymmetric pulse frequency, the asymmetric pulse amplitude, the asymmetric pulse application duration and the charge bias pulse duty cycle.

5. The charge pre-compensated cell depolarization method of claim 4, wherein, The method comprises the following steps: when the target battery is in a post-charge polarization state, obtaining a preset discharge bias pulse duty cycle; wherein the proportion of positive pulses in the discharge bias pulse duty cycle is less than the proportion of negative pulses. The asymmetric pulse frequency, the asymmetric pulse amplitude, the asymmetric pulse application duration, and the discharge-biased pulse duty cycle are used to obtain the discharge-biased asymmetric bidirectional equal-amplitude pulse operation parameter corresponding to the target battery.

6. The charge pre-compensated cell depolarization method according to any one of claims 4-5, wherein, The pre-compensation charging and discharging of the target battery according to the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a pre-compensation battery includes: According to the asymmetric pulse amplitude, the asymmetric pulse application duration, and the charge-biased pulse duty cycle, a charge amount corresponding to the charge-biased asymmetric bidirectional equal-amplitude pulse operation parameter is obtained. According to the asymmetric pulse amplitude, the asymmetric pulse application duration, and the discharge-biased pulse duty cycle, a discharge amount corresponding to the discharge-biased asymmetric bidirectional equal-amplitude pulse operation parameter is obtained. The target battery is discharged according to the charge amount or charged according to the discharge amount to obtain a pre-compensation battery after discharging or charging.

7. The charge pre-compensated cell depolarization method of claim 4, wherein, The depolarization operation of the pre-compensation battery according to the symmetric bidirectional equal-amplitude pulse operation parameter and the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a depolarization battery includes: The symmetric bidirectional equal-amplitude pulse containing positive and negative pulses is generated according to the symmetric pulse frequency, the symmetric pulse amplitude, and the symmetric pulse duty cycle. The pre-compensation battery is charged and discharged according to the symmetric pulse application duration and the symmetric bidirectional equal-amplitude pulse to obtain an initial depolarization battery. The discharge-biased asymmetric bidirectional equal-amplitude pulse containing positive and negative pulses is generated according to the asymmetric pulse frequency, the asymmetric pulse amplitude, and the discharge-biased pulse duty cycle. The initial depolarization battery is charged and discharged according to the asymmetric pulse application duration and the discharge-biased asymmetric bidirectional equal-amplitude pulse to obtain a depolarization battery.

8. The charge pre-compensated cell depolarization method of claim 5, wherein, The depolarization operation of the pre-compensation battery according to the symmetric bidirectional equal-amplitude pulse operation parameter and the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a depolarization battery includes: The charge-biased asymmetric bidirectional equal-amplitude pulse containing positive and negative pulses is generated according to the asymmetric pulse frequency, the asymmetric pulse amplitude, and the charge-biased pulse duty cycle. The initial depolarization battery is charged and discharged according to the asymmetric pulse application duration and the charge-biased asymmetric bidirectional equal-amplitude pulse to obtain a depolarization battery.

9. The charge pre-compensated cell depolarization method of claim 2, wherein, The depolarization operation of the pre-compensation battery according to the symmetric bidirectional equal-amplitude pulse operation parameter and the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a depolarization battery further includes: The third voltage of the depolarization battery at a third sampling time and the fourth voltage of the depolarization battery at a fourth sampling time are obtained according to the sampling duration. The depolarization voltage change rate of the depolarization battery is obtained according to the third voltage, the fourth voltage, and the sampling duration. When the absolute value of the depolarization voltage change rate is less than the change rate threshold, the depolarization operation of the target battery is completed.

10. A cell depolarization system based on charge pre-compensation, characterized in that, The polarization identification module is used to obtain the voltage change rate of the target battery according to a preset sampling duration, and determine the polarization state of the target battery according to the voltage change rate. ​ The pulse adjustment module is configured to match the symmetric bidirectional equal-amplitude pulse operation parameter and the asymmetric bidirectional equal-amplitude pulse operation parameter corresponding to the polarization state; The pre-compensation module is configured to pre-compensate the target battery cell according to the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a pre-compensated battery cell; The depolarization module is configured to perform depolarization operation on the pre-compensated battery cell according to the symmetric bidirectional equal-amplitude pulse operation parameter and the asymmetric bidirectional equal-amplitude pulse operation parameter to obtain a depolarized battery cell.

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