Battery step charging method, device, equipment and readable storage medium

Abstract

The application relates to a battery step charging method, device, equipment and readable storage medium. The method comprises the following steps: periodically charging a battery in a first stage, charging the battery for a first preset time in each period according to a first step charging current corresponding to each period, the first step charging current in the current period being greater than that in the last period before the battery voltage reaches a first preset charging cutoff voltage; after the battery voltage reaches the first preset charging cutoff voltage, periodically charging the battery in a second stage, charging the battery for a second preset time in each period according to a second step charging current corresponding to each period, the second step charging current in the current period being less than that in the last period before the battery voltage reaches a second preset charging cutoff voltage, so that the charging polarization phenomenon is controlled, the damage to the battery is reduced, and the charging rate of the battery is ensured.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and in particular to a battery stepped charging method, apparatus, device, and readable storage medium. Background Technology

[0002] Currently, the most widely used charging technology is constant current / constant voltage (DCV) charging, which involves charging the battery with a constant current to the cutoff voltage, and then charging it with a constant voltage at the cutoff voltage. However, due to the inherent internal resistance of the battery, DCV charging causes continuous accumulation of battery polarization, which affects the charging speed. Battery polarization refers to the phenomenon where current flowing through the battery causes it to deviate from its equilibrium electrode potential. Therefore, during constant current charging, the accumulation of battery polarization becomes increasingly severe, thus reducing the charging speed. Therefore, controlling and eliminating polarization is crucial for achieving fast and efficient battery charging.

[0003] In related technologies, the charging limiting current remains unchanged throughout the entire lifespan, meaning the limiting current is constant throughout the entire lifespan. However, batteries degrade, so a suitable limiting current in the early stages of a battery's lifespan may not be suitable in the later stages. Therefore, using a constant limiting current for charging throughout the entire lifespan will most likely damage the battery. Summary of the Invention

[0004] This application provides a battery stepped charging method, apparatus, device, and readable storage medium to solve the problem of battery damage caused by using a constant limiting current for charging throughout the entire life cycle in related technologies.

[0005] In one aspect, a battery stepped charging method is provided, comprising the following steps:

[0006] The battery is charged in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first stage of charging, the battery is charged for a first preset time according to the first step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first step charging current of the current cycle is greater than the first step charging current of the previous cycle.

[0007] Once the battery voltage reaches the first preset charging cutoff voltage, the battery is charged in the second stage according to the cycle. In each cycle of the second stage charging, the battery is charged for a second preset duration according to the second step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second step charging current of the current cycle is less than the second step charging current of the previous cycle.

[0008] In some embodiments, the battery stepped charging method includes:

[0009] When the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, the preset charging duration of the i-th cycle, the battery state of charge at the start of the i-th cycle, and the ambient temperature are substituted into the first calculation formula to obtain the first step charging current corresponding to the i-th cycle. The first calculation formula is as follows:

[0010]

[0011] Among them, I 1i Let be the first-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A1 and B1 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C1 is the SOC coefficient, D1 is the temperature coefficient, E1 and F1 are the time coefficients, SOC1 is the battery state of charge at the start of the i-th cycle, SOC0 is the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the ratio of battery capacity to nominal capacity, and e is the natural constant.

[0012] In some embodiments, when the state of charge of the battery at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage, the charging amount of the i-th cycle is greater than the charging amount of the (i-1)-th cycle.

[0013] In some embodiments, the battery stepped charging method includes:

[0014] When the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature are substituted into the second calculation formula to obtain the second-step charging current corresponding to the i-th cycle. The second calculation formula is as follows:

[0015]

[0016] Among them, I 2iLet be the second-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A2 and B2 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C2 and D2 are the SOC coefficients, E2 is the temperature coefficient, F2 and G2 are the time coefficients, SOC2 is the battery state of charge at the start of the i-th cycle, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, H2 is the SOH health coefficient, SOH is the ratio of battery capacity to nominal capacity, and e represents the natural constant.

[0017] In some embodiments, when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the charging amount of the i-th cycle is less than the charging amount of the (i-1)-th cycle.

[0018] Secondly, a battery stepped charging device is provided, comprising:

[0019] The first-stage charging module is used to charge the battery in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first-stage charging, the battery is charged for a first preset duration according to the first-step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first-step charging current of the current cycle is greater than the first-step charging current of the previous cycle.

[0020] The second-stage charging module is used to charge the battery in the second stage according to the cycle after the battery voltage reaches the first preset charging cutoff voltage. In each cycle of the second-stage charging, the battery is charged for a second preset duration according to the second-step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second-step charging current of the current cycle is less than the second-step charging current of the previous cycle.

[0021] In some embodiments, the battery stepped charging device further includes:

[0022] The first current determination module is used to determine the first step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a first calculation formula when the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage. The first calculation formula is as follows:

[0023]

[0024] Among them, I 1i Let be the first-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A1 and B1 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C1 is the SOC coefficient, D1 is the temperature coefficient, E1 and F1 are the time coefficients, SOC1 is the battery state of charge at the start of the i-th cycle, SOC0 is the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the ratio of battery capacity to nominal capacity, and e is the natural constant.

[0025] In some embodiments, the battery stepped charging device further includes:

[0026] The second current determination module is used to determine the second step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a second calculation formula when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage. The second calculation formula is as follows:

[0027]

[0028] Among them, I 2i Let be the second-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A2 and B2 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C2 and D2 are the SOC coefficients, E2 is the temperature coefficient, F2 and G2 are the time coefficients, SOC2 is the battery state of charge at the start of the i-th cycle, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, H2 is the SOH health coefficient, SOH is the ratio of battery capacity to nominal capacity, and e represents the natural constant.

[0029] Thirdly, a battery stepped charging device is provided, comprising: a memory and a processor, wherein the memory stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the aforementioned battery stepped charging method.

[0030] Fourthly, a computer-readable storage medium is provided, the computer storage medium storing a computer program that, when executed by a processor, implements the aforementioned battery step-charging method.

[0031] This application provides a battery stepped charging method, apparatus, device, and readable storage medium, including a first stage of charging the battery in cycles, wherein the number of cycles is an integer greater than or equal to 2. In each cycle of the first stage charging, the battery is charged for a first preset duration according to a first stepped charging current corresponding to that cycle. Before the battery voltage reaches a first preset charging cutoff voltage, the first stepped charging current of the current cycle is greater than the first stepped charging current of the previous cycle. After the battery voltage reaches the first preset charging cutoff voltage, a second stage of charging is performed, in which each cycle of the second stage charging is charged for a second preset duration according to a second stepped charging current corresponding to that cycle. Before the battery voltage reaches a second preset charging cutoff voltage, the second stepped charging current of the current cycle is less than the second stepped charging current of the previous cycle. Through this application, the battery is charged in stages and cycles, with the charging current gradually increasing in the first stage and gradually decreasing in the second stage, thus controlling charging polarization and suppressing side reactions, reducing damage to the battery, and ensuring the overall charging rate of the battery. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic flowchart of a battery stepped charging method provided in an embodiment of this application;

[0034] Figure 2 This is a schematic diagram of the structure of a battery stepped charging device provided in an embodiment of this application;

[0035] Figure 3 This is a schematic diagram of a battery stepped charging device provided in an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] This application provides a battery stepped charging method, apparatus, device, and readable storage medium, which can solve the problem of battery damage caused by using a constant limiting current for charging throughout the entire life cycle in related technologies.

[0038] Figure 1 This application provides a battery stepped charging method, which includes the following steps:

[0039] Step S10: Charge the battery in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first stage of charging, the battery is charged for a first preset time according to the first step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first step charging current of the current cycle is greater than the first step charging current of the previous cycle.

[0040] As an example, in this embodiment, the number of cycles is an integer greater than or equal to 2, which can be set according to actual needs, and the duration of each cycle can be set according to actual needs.

[0041] The preset charging cutoff voltage is positively correlated with the battery's SOC state, and its specific value can be set according to the actual battery system and system control requirements. Before the battery voltage reaches the first preset charging cutoff voltage, the battery charging is in the first stage. In the first stage, each cycle charges the battery for a first preset duration according to the first step charging current corresponding to each cycle (or it can be a step charging power, which can be determined according to actual needs and is not limited here). In the first stage, the battery's SOC at the beginning of each cycle is lower than the maximum SOC corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage. Therefore, in this embodiment, the first step charging current of the current cycle will be greater than the first step charging current of the previous cycle. The first preset duration can be set according to actual needs; for example, the first preset duration can be between 1 second and 600 seconds.

[0042] Furthermore, battery cascading charging methods include:

[0043] When the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, the preset charging duration of the i-th cycle, the battery state of charge at the start of the i-th cycle, and the ambient temperature are substituted into the first calculation formula to obtain the first step charging current corresponding to the i-th cycle. The first calculation formula is as follows:

[0044]

[0045] Among them, I1i Let A1 be the first-step charging current corresponding to the i-th cycle, where i is an integer and 1 ≤ i ≤ N, and N is the number of cycles. A1 and B1 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C1 is the SOC coefficient, D1 is the temperature coefficient, E1 and F1 are the time coefficients, SOC1 is the battery state of charge at the start of the i-th cycle, SOC0 is the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the battery health state, i.e., the ratio of battery capacity to nominal capacity, and e is the natural constant. The battery's current handling capacity can be determined based on the rate charging test current, and the specific values ​​of A1, B1, and D1 can be derived through fitting calculations.

[0046] In this exemplary embodiment, the battery state of charge (SOC) at the start of the i-th cycle is compared with the maximum SOC corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage. When the SOC at the start of the i-th cycle is lower than the maximum SOC corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, the first-step charging current corresponding to the i-th cycle is determined based on the battery capacity, nominal capacity, minimum SOC corresponding to the second lithium intercalation platform of the negative electrode graphite, the preset charging duration of the i-th cycle, the battery SOC at the start of the i-th cycle, and the ambient temperature. Specifically, the battery capacity, nominal capacity, minimum SOC corresponding to the second lithium intercalation platform of the negative electrode graphite, the preset charging duration of the i-th cycle, the battery SOC at the start of the i-th cycle, and the ambient temperature are substituted into the first calculation formula to obtain the first-step charging current corresponding to the i-th cycle. The first calculation formula is:

[0047]

[0048] Among them, I 1i Let A1 be the first-step charging current corresponding to the i-th cycle, B1 be the material chemical reaction rate coefficient corresponding to the ambient temperature at the start of the i-th cycle, C1 be the SOC coefficient, D1 be the temperature coefficient, E1 be the time coefficient, SOC1 be the battery state of charge at the start of the i-th cycle, SOC0 be the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R be the molar gas constant, T be the ambient temperature at the start of the i-th cycle, t be the preset charging duration of the i-th cycle, SOH be the battery health state, i.e., the ratio of battery capacity to nominal capacity, and e be the natural constant.

[0049] It should be noted that the above is only an illustrative explanation of the first calculation formula. Based on the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, the duration of the preset charging in the i-th cycle, the battery state of charge at the start of the i-th cycle, and the ambient temperature, the first step charging current corresponding to the i-th cycle can also be calculated by other formulas. The principle followed is that when the battery state of charge is lower than the maximum state of charge corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, the first step charging current corresponding to the next cycle is greater than the first step charging current corresponding to the previous cycle.

[0050] In this embodiment, when the battery's state of charge (SOC) at the start of the i-th cycle is lower than the maximum SOC corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, it indicates that the battery's charging capacity is weak. Therefore, the first-stage charging current is set based on the principle that the first-stage charging current in the subsequent cycle is greater than the first-stage charging current in the previous cycle, which can prevent lithium plating in the low SOC segment and ensure charging speed. In addition, since the charging current change in the first stage in this embodiment fully considers the SOH change and its impact throughout the battery's entire service life, it can further ensure the safe use of the battery and prevent battery abuse.

[0051] Furthermore, when the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage, the charging amount in the i-th cycle is greater than the charging amount in the (i-1)-th cycle.

[0052] As an example, in this embodiment, after determining that the state of charge of the battery at the beginning of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage, the charging capacity of the i-th cycle is determined according to the first step charging current at the beginning of the i-th cycle, and the charging capacity of the i-th cycle is greater than the charging capacity of the (i-1)-th cycle.

[0053] Step S20: When the battery voltage reaches the first preset charging cutoff voltage, the battery is charged in the second stage according to the cycle. In each cycle of the second stage charging, the battery is charged for a second preset duration according to the second step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second step charging current of the current cycle is less than the second step charging current of the previous cycle.

[0054] As an example, in this embodiment, the number of cycles is an integer greater than or equal to 2, and can be set according to actual needs. The duration of each cycle can also be set according to actual needs.

[0055] Before the battery voltage reaches the first preset charging cutoff voltage but before reaching the second preset charging cutoff voltage, the battery charging is in the second stage. In the second stage, the battery is charged for a second preset duration according to the second-step charging current corresponding to each cycle. Furthermore, in the second stage, the battery's state of charge at the beginning of each cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage. Therefore, in this embodiment, the second-step charging current of the current cycle will be less than the second-step charging current of the previous cycle. The second preset duration can be set according to actual needs; for example, the second preset duration can be between 1 second and 600 seconds.

[0056] Furthermore, battery cascading charging methods include:

[0057] When the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature are substituted into the second calculation formula to obtain the second-step charging current corresponding to the i-th cycle. The second calculation formula is as follows:

[0058]

[0059] Among them, I 2i Let A1 be the second-step charging current corresponding to the i-th cycle, where i is an integer and 1 ≤ i ≤ N, and N is the number of cycles. A2 and B2 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C2 and D2 are the SOC coefficients, E2 is the temperature coefficient, F2 and G2 are the time coefficients, SOC2 is the battery state of charge at the start of the i-th cycle, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, H2 is the SOH health coefficient, and SOH is the ratio of battery capacity to nominal capacity; e represents the natural constant. The battery's current-carrying capacity can be determined based on the rate-charging test current, and the specific values ​​of A1 and B1 can be derived through fitting calculations.

[0060] In this exemplary embodiment, the battery state of charge (SOC) at the start of the i-th cycle is compared to the minimum SOC corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the second stage. When the SOC at the start of the i-th cycle is higher than the minimum SOC corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the second stage, the second-step charging current corresponding to the i-th cycle is determined based on the battery capacity, nominal capacity, the preset charging duration of the i-th cycle, the battery SOC at the start of the i-th cycle, and the ambient temperature. Specifically, the battery capacity, nominal capacity, the preset charging duration of the i-th cycle, the battery SOC at the start of the i-th cycle, and the ambient temperature are substituted into the second calculation formula to obtain the second-step charging current corresponding to the i-th cycle. The second calculation formula is:

[0061]

[0062] Among them, I 2i Here, i is the second-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A2 and B2 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C2 and D2 are the SOC coefficients, E2 is the temperature coefficient, F2 and G2 are the time coefficients, SOC2 is the battery state of charge at the start of the i-th cycle, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, H2 is the SOH health coefficient, where SOH is the battery health state, i.e., the ratio of battery capacity to nominal capacity; e represents the natural constant.

[0063] It should be noted that the above is only an illustrative explanation of the second calculation formula. Based on the battery capacity, nominal capacity, the duration of the preset charging in the i-th cycle, the battery state of charge at the start of the i-th cycle, and the ambient temperature, the second-stage charging current corresponding to the i-th cycle can also be calculated using other formulas. The principle followed is that when the battery state of charge is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the second-stage charging current corresponding to the next cycle is less than the second-stage charging current corresponding to the previous cycle.

[0064] In this embodiment, considering that the battery's charging capacity gradually decreases as the battery's state of charge increases, this approach effectively avoids lithium plating caused by the decrease in charging capacity after battery capacity decays. Furthermore, since the charging current variation in the second stage of this embodiment fully considers the changes and impacts of SOH throughout the battery's entire lifespan, it further ensures the safe use of the battery and prevents battery abuse.

[0065] Furthermore, when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the charging amount in the i-th cycle is less than the charging amount in the (i-1)-th cycle.

[0066] As an example, in this embodiment, after determining that the state of charge of the battery at the beginning of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the charging capacity of the i-th cycle is determined according to the second step charging current at the beginning of the i-th cycle, and the charging capacity of the i-th cycle is less than the charging capacity of the (i-1)-th cycle.

[0067] Therefore, this embodiment demonstrates that by charging the battery in stages and according to cycles, and by gradually increasing the charging current in the first stage and gradually decreasing the charging current in the second stage, the battery is protected from crystallization and damage to the positive electrode structure. In other words, the battery is rapidly charged with a larger current and charged with a smaller current to keep the charging polarization phenomenon within a certain range. This achieves control over the charging polarization phenomenon, thereby reducing capacity decay during battery charging, suppressing side reactions, reducing damage to the battery, and ensuring the overall charging rate of the battery.

[0068] See Figure 2 As shown in the figure, this application embodiment also provides a battery stepped charging device, including:

[0069] The first-stage charging module is used to charge the battery in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first-stage charging, the battery is charged for a first preset duration according to the first-step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first-step charging current of the current cycle is greater than the first-step charging current of the previous cycle.

[0070] The second-stage charging module is used to charge the battery in the second stage according to the cycle after the battery voltage reaches the first preset charging cutoff voltage. In each cycle of the second-stage charging, the battery is charged for a second preset duration according to the second-step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second-step charging current of the current cycle is less than the second-step charging current of the previous cycle.

[0071] Furthermore, the battery stepped charging device also includes:

[0072] The first current determination module is used to determine the first step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a first calculation formula when the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage. The first calculation formula is as follows:

[0073]

[0074] Among them, I 1i Let be the first-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A1 and B1 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C1 is the SOC coefficient, D1 is the temperature coefficient, E1 and F1 are the time coefficients, SOC1 is the battery state of charge at the start of the i-th cycle, SOC0 is the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the ratio of battery capacity to nominal capacity, and e is the natural constant.

[0075] Furthermore, when the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage, the charging amount in the i-th cycle is greater than the charging amount in the (i-1)-th cycle.

[0076] Furthermore, the battery stepped charging device also includes:

[0077] The second current determination module is used to determine the second step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a second calculation formula when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage. The second calculation formula is as follows:

[0078]

[0079] Among them, I 2iLet be the second-step charging current corresponding to the i-th cycle, where i is an integer and 1≤i≤N, and N is the number of cycles. A2 and B2 are the material chemical reaction rate coefficients corresponding to the ambient temperature at the start of the i-th cycle. C2 and D2 are the SOC coefficients, E2 is the temperature coefficient, F2 and G2 are the time coefficients, SOC2 is the battery state of charge at the start of the i-th cycle, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, H2 is the SOH health coefficient, SOH is the ratio of battery capacity to nominal capacity, and e represents the natural constant.

[0080] Furthermore, when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the charging amount in the i-th cycle is less than the charging amount in the (i-1)-th cycle.

[0081] It should be noted that those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the device and each unit described above can be referred to the corresponding process in the aforementioned battery stepped charging method embodiments, and will not be repeated here.

[0082] The apparatus provided in the above embodiments can be implemented as a computer program, which can be used in, for example... Figure 3 The battery cascading charging device shown is in operation.

[0083] This application also provides a battery stepped charging device, including: a memory, a processor, and a network interface connected via a system bus. The memory stores at least one instruction, which is loaded and executed by the processor to implement all or part of the steps of the aforementioned battery stepped charging method.

[0084] The network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0085] A processor can be a CPU, or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor, or any conventional processor. The processor is the control center of a computer device, connecting all parts of the computer device through various interfaces and lines.

[0086] Memory can be used to store computer programs and / or modules. The processor performs various functions of the computer device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can primarily include a program storage area and a data storage area. The program storage area can store the operating system, application programs required for at least one function (such as video playback, image playback, etc.), etc.; the data storage area can store data created based on the use of the mobile phone (such as video data, image data, etc.). Furthermore, memory can include high-speed random access memory (RAM), and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMedia Cards (SMC), Secure Digital Cards (SD cards), Flash Cards, at least one disk storage device, flash memory devices, or other volatile solid-state storage devices.

[0087] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements all or part of the steps of the aforementioned battery stepped charging method.

[0088] The embodiments of this application can implement all or part of the aforementioned processes, or they can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various methods described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0089] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, servers, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0090] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0091] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0092] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A battery stepped charging method, characterized in that, Includes the following steps: The battery is charged in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first stage of charging, the battery is charged for a first preset time according to the first step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first step charging current of the current cycle is greater than the first step charging current of the previous cycle. When the battery voltage reaches the first preset charging cutoff voltage, the battery is charged in the second stage according to the cycle. In each cycle of the second stage charging, the battery is charged for a second preset duration according to the second step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second step charging current of the current cycle is less than the second step charging current of the previous cycle. The battery stepped charging method includes: When the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the second lithium intercalation platform of the negative electrode graphite in the first stage, the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, the preset charging duration of the i-th cycle, the battery state of charge at the start of the i-th cycle, and the ambient temperature are substituted into the first calculation formula to obtain the first step charging current corresponding to the i-th cycle. The first calculation formula is as follows: in, Let be the first-step charging current corresponding to the i-th cycle, where i is an integer, 1≤i≤N, and N is the number of cycles. and The material chemical reaction rate coefficient is the environmental temperature at the start of the i-th cycle. The SOC coefficient, For temperature coefficient, and For time coefficient, Let be the battery state of charge at the start of the i-th cycle. denoted as the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the ratio of battery capacity to nominal capacity, and e is the natural constant. The battery stepped charging method includes: When the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature are substituted into the second calculation formula to obtain the second-step charging current corresponding to the i-th cycle. The second calculation formula is as follows: in, Let be the second-step charging current corresponding to the i-th cycle, where i is an integer, 1≤i≤N, and N is the number of cycles. and The material chemical reaction rate coefficient is the environmental temperature at the start of the i-th cycle. and The SOC coefficient, For temperature coefficient, and For time coefficient, Let R be the battery state of charge at the start of the i-th cycle, R be the molar gas constant, T be the ambient temperature at the start of the i-th cycle, and t be the preset charging duration of the i-th cycle. SOH is the health coefficient, where SOH is the ratio of battery capacity to nominal capacity; e represents the natural constant.

2. The battery stepped charging method as described in claim 1, characterized in that: When the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage, the charging amount in the i-th cycle is greater than the charging amount in the (i-1)-th cycle.

3. The battery stepped charging method as described in claim 1, characterized in that: When the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage, the charging amount in the i-th cycle is less than the charging amount in the (i-1)-th cycle.

4. A battery stepped charging device, characterized in that, include: The first-stage charging module is used to charge the battery in the first stage according to the cycle. The number of cycles is an integer greater than or equal to 2. In each cycle of the first-stage charging, the battery is charged for a first preset duration according to the first-step charging current corresponding to each cycle. Before the battery voltage reaches the first preset charging cutoff voltage, the first-step charging current of the current cycle is greater than the first-step charging current of the previous cycle. The second-stage charging module is used to charge the battery in the second stage according to the cycle after the battery voltage reaches the first preset charging cutoff voltage. In each cycle of the second-stage charging, the battery is charged for a second preset duration according to the second-step charging current corresponding to each cycle. Before the battery voltage reaches the second preset charging cutoff voltage, the second-step charging current of the current cycle is less than the second-step charging current of the previous cycle. The battery stepped charging device further includes: The first current determination module is used to determine the first step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a first calculation formula when the battery state of charge at the start of the i-th cycle is lower than the maximum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the first stage. The first calculation formula is as follows: in, Let be the first-step charging current corresponding to the i-th cycle, where i is an integer, 1≤i≤N, and N is the number of cycles. and The material chemical reaction rate coefficient is the environmental temperature at the start of the i-th cycle. The SOC coefficient, For temperature coefficient, and For time coefficient, Let be the battery state of charge at the start of the i-th cycle. denoted as the minimum state of charge corresponding to the second lithium intercalation platform of the negative electrode graphite, R is the molar gas constant, T is the ambient temperature at the start of the i-th cycle, t is the preset charging duration of the i-th cycle, SOH is the ratio of battery capacity to nominal capacity, and e is the natural constant. The battery stepped charging device also includes: The second current determination module is used to determine the second step charging current corresponding to the i-th cycle by substituting the battery capacity, nominal capacity, preset charging duration of the i-th cycle, battery state of charge at the start of the i-th cycle, and ambient temperature into a second calculation formula when the battery state of charge at the start of the i-th cycle is higher than the minimum state of charge corresponding to the lowest point of the negative electrode graphite second lithium intercalation platform in the second stage. The second calculation formula is as follows: in, Let be the second-step charging current corresponding to the i-th cycle, where i is an integer, 1≤i≤N, and N is the number of cycles. and The material chemical reaction rate coefficient is the environmental temperature at the start of the i-th cycle. and The SOC coefficient, For temperature coefficient, and For time coefficient, Let R be the battery state of charge at the start of the i-th cycle, R be the molar gas constant, T be the ambient temperature at the start of the i-th cycle, and t be the preset charging duration of the i-th cycle. SOH is the health coefficient, where SOH is the ratio of battery capacity to nominal capacity; e represents the natural constant.

5. A battery tiered charging device, characterized in that, include: A memory and a processor, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the battery stepped charging method according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program that, when executed by a processor, implements the battery step-charging method according to any one of claims 1 to 3.

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