Battery charging control method, device and charging equipment

Abstract

The application provides a battery charging control method and device and a charging equipment, and relates to the technical field of battery charging. In the charging process, the state parameters of a battery to be charged are acquired. The real aging degree of the battery under the current temperature environment can be determined based on the internal resistance data and the temperature data in the current state parameters. Then, the target charging rate is determined in combination with the current state of charge of the battery. The corresponding charging parameters can be determined according to the state of the battery. With the change of the aging degree and the temperature environment, the charging rate that matches the current state of the battery and is within the charging safety boundary can be determined. The safe charging can be ensured under different aging degrees and different temperature environments, and the fast charging capacity of the battery under the current state can be fully released.

Description

Technical Field

[0001] This invention relates to the field of battery charging technology, and in particular to a battery charging control method, apparatus, and charging equipment. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density, long cycle life, and low self-discharge rate, have become the mainstream energy storage device in the current new energy field. With the rapid popularization of new energy vehicles, smart terminals, and energy storage systems, users are placing higher demands on the charging speed of lithium-ion batteries, making fast charging technology a core research and development direction for the industry.

[0003] Currently, the mainstream lithium-ion battery charging method in the industry is the traditional three-stage charging, namely constant current pre-charging, constant current fast charging, and constant voltage float charging. This charging method uses pre-set fixed current and voltage values ​​for segmented control throughout the charging cycle. The switching between each stage is based on whether the terminal voltage reaches a preset threshold, and the charging parameters are not adjusted according to changes in battery state during the charging process. As batteries continuously degrade and age during use, their internal resistance gradually increases and their capacity continuously decreases. The fixed parameters are no longer the optimal parameters for an aged battery under safe conditions. Therefore, in order to cover safety redundancy throughout the entire life cycle, the current value setting of this method tends to be conservative, resulting in low charging efficiency.

[0004] Meanwhile, the polarization effect intensifies during fast charging, and the anode potential easily drops below the lithium plating potential during high-current charging, triggering lithium plating. The polarization effect is further aggravated at low temperatures, increasing the risk of lithium plating. Therefore, fixed-parameter charging methods cannot simultaneously achieve both charging efficiency and safety throughout the entire lifecycle and under all temperature conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a battery charging control method, device, and charging equipment that can not only ensure safe charging under different aging levels and different temperature environments, but also fully release the fast charging capability of the battery in its current state.

[0006] In a first aspect, embodiments of the present invention provide a battery charging control method, wherein the method includes: acquiring state parameters of the battery to be charged during the charging process; wherein the state parameters include: internal resistance data, temperature data, and the current state of charge of the battery to be charged; determining the degree of aging of the battery to be charged based on the temperature data and internal resistance data; determining a target charging rate of the battery to be charged within a preset charging safety boundary based on the degree of aging, temperature data, and the current state of charge of the battery to be charged; and charging the battery to be charged based on the target charging rate.

[0007] In conjunction with the first aspect, the present invention also provides a first implementation of the first aspect, wherein the step of determining the degree of aging of the battery to be recharged based on temperature data and internal resistance data includes: obtaining an aging degree comparison table of the battery to be recharged based on the temperature data; determining the degree of aging of the battery to be recharged based on the internal resistance range corresponding to the internal resistance data in the aging degree comparison table; wherein the aging degree comparison table includes the internal resistance range of the battery to be recharged under different aging degrees.

[0008] In conjunction with the first aspect, this embodiment of the invention also provides a second implementation of the first aspect, wherein the step of determining the target charging rate of the battery to be charged within a preset charging safety boundary based on the degree of aging, temperature data, and the current state of charge of the battery to be charged includes: obtaining a charging capacity boundary table corresponding to the degree of aging based on the temperature data; querying the upper limit of the charging rate corresponding to the current state of charge in the charging capacity boundary table as the target charging rate.

[0009] In conjunction with the first aspect, the present invention also provides a third implementation of the first aspect, wherein each state of charge in the charging capability boundary table corresponds to an upper limit of the charging rate, and the upper limit of the charging rate is the charging rate corresponding to the lithium potential of the anode of the battery to be charged reaching a preset lithium plating safety threshold in the corresponding state of charge.

[0010] In conjunction with the first aspect, this invention also provides a fourth implementation of the first aspect, wherein the method further includes: acquiring pre-conducted test data; wherein the process of acquiring the test data includes: performing charging tests at different charging rates on batteries of the same type to be charged under different states of charge, monitoring the anode-to-lithium potential of the same type of battery at the corresponding state of charge and charging rate; verifying lithium plating on the tested batteries of the same type to determine the lithium plating safety threshold; and finding the charging rate corresponding to the anode-to-lithium potential reaching the lithium plating safety threshold under different states of charge in the test data, as the upper limit of the charging rate for the corresponding state of charge.

[0011] In conjunction with the first aspect, this invention also provides a fifth implementation of the first aspect, wherein the step of acquiring the state parameters of the battery to be charged during the charging process includes: acquiring the charging current, charging voltage, and temperature data of the battery under the current ambient temperature of the battery during the charging process according to a preset sampling frequency; determining the internal resistance data of the battery during the charging process based on the charging current and charging voltage; and determining the current state of charge based on the charging voltage and the current polarization voltage of the battery.

[0012] In conjunction with the first aspect, this invention also provides a sixth implementation of the first aspect, wherein the step of determining the current state of charge (SOC) based on the charging voltage and the current polarization voltage of the battery to be charged includes: determining the open-circuit voltage based on the charging voltage and the current polarization voltage; determining the SOC-open-circuit voltage mapping relationship based on the aging degree of the battery to be charged; and querying the SOC corresponding to the open-circuit voltage in the SOC-open-circuit voltage mapping relationship as the current SOC of the battery to be charged.

[0013] In conjunction with the first aspect, the present invention also provides a seventh implementation of the first aspect, wherein the method further includes: when any monitoring parameter among the battery temperature, polarization voltage, charging voltage and internal resistance data of the battery to be charged exceeds the corresponding preset threshold range, performing a safety control operation corresponding to the monitoring parameter.

[0014] In conjunction with the first aspect, this invention also provides an eighth embodiment of the first aspect, wherein the step of charging the battery to be charged based on a target charging rate includes: determining the current charging stage of the battery to be charged based on the current state of charge; determining the charging current coefficient corresponding to the battery to be charged based on the charging stage; determining the target charging current corresponding to the charging stage based on the target charging rate and the charging current coefficient, and charging the battery to be charged with the target charging current.

[0015] Secondly, embodiments of the present invention provide a battery charging control device, wherein the device includes: a data acquisition module, used to acquire state parameters of the battery to be charged during the charging process; wherein the state parameters include: internal resistance data, temperature data, and the current state of charge of the battery to be charged; an aging degree determination module, used to determine the aging degree of the battery to be charged based on the temperature data and internal resistance data; a data processing module, used to determine a target charging rate of the battery to be charged within a preset charging safety boundary based on the aging degree, temperature data, and the current state of charge of the battery to be charged; and an execution module, used to charge the battery to be charged based on the target charging rate.

[0016] Thirdly, embodiments of the present invention provide a charging device, which is configured with the battery charging control device of the above embodiments for executing the battery charging control method of any of the above embodiments.

[0017] The embodiments of the present invention have the following beneficial effects: The embodiments of the present invention provide a battery charging control method, device and charging equipment. During the charging process, the state parameters of the battery to be charged are acquired. Based on the internal resistance data and temperature data in the current state parameters, the actual aging degree of the battery under the current temperature environment can be determined. Then, combined with the current state of charge of the battery, the target charging rate is determined. The corresponding charging parameters can be determined according to the battery's own state. As the aging degree and temperature environment change, a charging rate that matches the current state of the battery and is within the charging safety boundary can be determined. This not only ensures safe charging under different aging degrees and different temperature environments, but also fully releases the fast charging capability of the battery under the current state.

[0018] Other features and advantages of the invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 A flowchart of a battery charging control method provided in an embodiment of the present invention; Figure 2 A flowchart of another battery charging control method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a battery charging control device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] To facilitate understanding, a battery charging control method provided in an embodiment of the present invention will first be described, referring to... Figure 1 The method includes the following steps: Step S102: During the charging process of the battery to be charged, acquire the state parameters of the battery to be charged.

[0025] The battery to be charged represents an energy storage device that requires charging. In one embodiment, it can be a single lithium-ion battery cell, a battery module, or a battery pack, and can be applied to electric vehicles, energy storage systems, or portable electronic devices. In a specific implementation, after the charging gun is connected to the vehicle's charging port or the charging circuit is turned on, the battery management system (BMS) is awakened and starts the charging process, subsequently entering the stage of monitoring and collecting status parameters.

[0026] State parameters characterize the real-time operating condition information of the battery at the current moment. In one implementation, these include internal resistance data, temperature data, and the current state of charge (SOC). Internal resistance data characterizes the combined resistance to ion and electron conduction within the battery, reflecting the current degree of degradation and polarization. It can be calculated in real-time using the ratio of current change to corresponding voltage change (ΔV / ΔI) during charging, or obtained by measuring AC internal resistance through an injected AC signal. Temperature data characterizes the battery's thermal state under its current environment. It can be acquired by temperature sensors (such as NTC thermistors) placed on the battery surface or inside the battery pack, reflecting the impact of ambient temperature on battery dynamic performance. The state of charge (SOC) characterizes the percentage of the battery's current remaining charge relative to its rated capacity. It can be determined using the ampere-hour integration method combined with open-circuit voltage correction, or obtained through estimation methods such as Kalman filtering, reflecting the battery's current position in the charging process.

[0027] In summary, by collecting state parameters during the battery charging process, the embodiments of the present invention can determine the charging parameters based on the current actual state of the battery, thus avoiding the accelerated lifespan degradation caused by the accumulation of battery wear due to fixed-parameter charging methods.

[0028] Step S104: Determine the degree of aging of the battery to be charged based on the temperature data and internal resistance data.

[0029] The degree of aging is used to characterize the irreversible performance degradation of a battery due to long-term use, reflecting the battery's current lifespan and load-bearing capacity. During cyclic charging and discharging, the internal material structure of a battery gradually degrades, active materials decrease, and internal resistance gradually increases. The battery's tolerance to charging rates decreases as aging progresses. Simultaneously, battery internal resistance is affected by temperature. At low temperatures, the electrolyte ionic conductivity decreases, and internal resistance also increases. At high temperatures, although the ionic conductivity increases, temporarily reducing internal resistance, excessively high temperatures accelerate side reactions, and prolonged exposure to high temperatures will exacerbate the irreversible aging process. Therefore, based on internal resistance and temperature data, the degree of aging corresponding to the battery's actual loss state under current conditions can be determined.

[0030] Batteries with different aging levels exhibit varying tolerance to charging rates. Batteries with milder aging have lower internal resistance and smaller polarization voltage differences during charging, allowing them to be charged at higher rates without easily exceeding safety limits. Batteries with more severe aging have significantly increased internal resistance, resulting in a larger polarization voltage difference at the same charging current, thus reducing their tolerance to charging rates and necessitating a corresponding reduction in charging rate to avoid safety risks. For example, a new car's battery has its internal resistance at the factory setting, allowing for safe charging at a higher rate. However, after the same car has traveled tens of thousands of kilometers, the battery's internal resistance increases; if charged at the same rate, the polarization voltage difference increases, raising the safety risk. In summary, this invention determines the battery's aging level using temperature and internal resistance data, enabling charging control to understand the battery's true load-bearing capacity under current temperature conditions. This ensures that the determined charging rate remains within the battery's current tolerance range, helping to mitigate battery lifespan degradation during subsequent use.

[0031] Step S106: Based on the degree of aging, temperature data, and the current state of charge of the battery to be charged, determine the target charging rate of the battery to be charged within the preset charging safety boundary.

[0032] The charging safety boundary refers to the physical limit within which a battery will not enter an unsafe operating region during charging. Within this boundary, the battery can operate safely without triggering safety risks. The target charging rate refers to the charging rate used to charge the battery under the current conditions, usually expressed in C (C-rate).

[0033] After determining the degree of aging, the controller has learned the battery's current carrying capacity. Based on this, this embodiment of the invention further combines temperature data and the current state of charge (SOC) to determine the final target charging rate. Specifically, the lower the temperature, the lower the electrolyte ionic conductivity, and the lower the battery's tolerance to charging rates; the higher the SOC, the narrower the acceptable charging current. For example, the same battery can withstand a high charging rate at room temperature, but its tolerance decreases significantly at low temperatures; the same battery can charge quickly in the low SOC range, but as the SOC increases, the charging rate needs to be gradually reduced. This embodiment of the invention determines the target charging rate based on the degree of aging, temperature data, and SOC, so that the charging parameters can not only be adjusted according to changes in battery aging and temperature environment, but also naturally narrow as the SOC increases during charging.

[0034] Step S108: Charge the battery to be charged based on the target charging rate.

[0035] Once the target charging rate is determined, it can be converted into a charging current command by the controller and sent to the charger, which then charges the battery according to that current value. The charging rate characterizes the relative speed of charging within the battery's rated capacity. For example, for a battery with a rated capacity of 100Ah, if the target charging rate is 0.5C, the corresponding charging current is 50A; if the target charging rate is 1C, the corresponding charging current is 100A, theoretically allowing the battery to be fully charged in one hour. The higher the target charging rate, the more energy is charged into the battery per unit time, and the faster the charging speed.

[0036] In one implementation, the battery management system (BMS) and charger can exchange information via a controller area network (CLAN) bus. The BMS sends the current demand value corresponding to the target charging rate to the charger via the CAN bus. Upon receiving the demand, the charger adjusts its output current to the target value. In another implementation, the BMS can also transmit current commands via hard-wired signals. During charging, the BMS continuously monitors the actual charging current. When there is a deviation between the actual current and the target current, closed-loop adjustment is used to ensure the actual current follows the target value. As the charging process progresses, the battery's state of charge (SOC) continuously increases. The BMS re-determines the target charging rate based on the updated SOC and sends the updated current command to the charger, which continuously adjusts the charging current accordingly. In the low SOC range, the battery charges rapidly at a higher rate. As the SOC increases, the target charging rate gradually decreases, and the charging current naturally narrows.

[0037] In summary, the embodiments of the present invention charge the battery to be charged based on a target charging rate. The target charging rate is determined according to the battery state within the charging safety boundary and is automatically adjusted as the state of charge increases. This allows the charging process to maintain a high charging speed as much as possible without exceeding the safety boundary.

[0038] Furthermore, based on the above embodiments, this invention also provides another battery charging control method, referring to... Figure 2 The method includes the following steps: Step S202: During the charging process of the battery to be charged, acquire the state parameters of the battery to be charged.

[0039] In one implementation, the state parameters of the battery to be charged can be determined by the following steps: 1) Acquire the charging current, charging voltage, and temperature data of the battery under the current ambient temperature of the battery during the charging process according to the preset sampling frequency.

[0040] The sampling frequency characterizes the number of times various parameters of the charging process are collected per unit time. In one implementation, the sampling frequency can be once every 10ms, meaning that a set of charging current, charging voltage, and temperature data is collected and updated every 10ms. During the charging process, continuously acquiring charging current, charging voltage, and temperature data according to the preset sampling frequency allows for obtaining continuous state information of the battery over time. Specifically, the charging current characterizes the amount of charge passing through the battery per unit time, i.e., the real-time current value injected into the battery through the charging circuit, which can be obtained by a current sensor (such as a Hall sensor or shunt resistor) installed in the charging circuit. The magnitude of the charging current directly determines the amount of charge injected into the battery per unit time. The charging voltage characterizes the real-time terminal voltage measured at the positive and negative terminals of the battery, which can be obtained through a voltage sampling circuit. The temperature data characterizes the thermal state of the environment in which the battery is located during the current charging process. In one embodiment, the temperature data can be ambient temperature, i.e., the temperature of the external environment where the battery is located, which can be obtained by a temperature sensor located on the outside of the battery pack or the vehicle. In another embodiment, the temperature data can also be the battery surface temperature, i.e., the actual temperature of the battery itself, which can be obtained by a temperature sensor located on the battery surface. In yet another embodiment, the temperature data can also be the internal temperature of the battery pack, i.e., the ambient temperature inside the battery pack, which can be obtained by a temperature sensor located inside the battery pack. Ambient temperature reflects the background temperature of the external environment where the battery is located, while battery surface temperature and internal battery pack temperature are supplemented by the effects of battery self-heating and the heat generated by equipment inside the battery pack. In one embodiment, ambient temperature can be used as the temperature data; in another embodiment, battery surface temperature or internal battery pack temperature can also be collected as the temperature data.

[0041] In real-world charging scenarios, ambient temperatures during outdoor charging in winter can drop as low as -10°C, causing the battery's temperature to decrease accordingly. In such cases, collecting ambient temperature or battery surface temperature data can reflect the impact of low temperatures on the battery's thermal state. For example, lower battery temperature leads to a decrease in electrolyte ionic conductivity and an increase in internal resistance. Conversely, during high-temperature charging in summer, the battery generates its own heat during high-current charging, and its surface temperature may be several degrees Celsius higher than the ambient temperature. In these situations, collecting battery surface temperature or the internal temperature of the battery pack can reflect the battery's actual thermal state.

[0042] 2) Based on the charging current and charging voltage, determine the internal resistance data of the battery to be charged during the charging process.

[0043] The magnitude of the charging current affects the battery's polarization and terminal voltage response, while the charging voltage reflects the battery's state response under the current current. During charging, changes in the charging current will cause corresponding changes in the battery's terminal voltage. An increase in current raises the terminal voltage, while a decrease in current lowers it; the magnitude of this change is directly related to the battery's internal resistance.

[0044] In one implementation, a brief current pulse or current step can be applied during charging, and the voltage difference before and after the current change can be recorded. Dividing the voltage difference (ΔV / ΔI) by the voltage difference yields the DC internal resistance at the current state. For example, when the charging current jumps from 50A to 100A, the terminal voltage rises accordingly from 3.6V to 3.65V, a voltage change of 0.05V and a current change of 50A. Therefore, the internal resistance is 0.05V / 50A = 1mΩ. Internal resistance data characterizes the combined resistance to ion and electron conduction within the battery. Its value gradually increases with battery aging and fluctuates with battery temperature changes, reflecting the current degree of battery degradation.

[0045] 3) Determine the current state of charge based on the charging voltage and the current polarization voltage of the battery to be charged.

[0046] Polarization voltage characterizes the voltage components generated during charging due to electrochemical polarization and concentration polarization, reflecting the degree to which the battery deviates from its equilibrium potential. Charging voltage can be represented by the real-time terminal voltage measured at the positive and negative terminals of the battery, reflecting the overall voltage response of the battery under the current charging current. Combining polarization voltage and charging voltage yields a voltage value unaffected by polarization effects, which has a stable correlation with the state of charge (SOC). In this embodiment of the invention, the corresponding charging parameters are determined by assessing the aging state of the battery to be charged. The data monitored during charging is correlated with the current aging degree of the battery; therefore, the correlation between this voltage value and the SOC can be determined based on the current aging degree.

[0047] In one implementation, the mapping relationship between the current voltage and the state of charge (SOC) can be determined based on the corresponding aging level of the battery to be recharged. By querying the SOC corresponding to the voltage value, the actual SOC of the battery at the current aging level (i.e., the current SOC) can be determined. The voltage value can be an open-circuit voltage unaffected by polarization effects, and the corresponding mapping relationship can be pre-calibrated and stored in the form of a SOC-open-circuit voltage lookup table.

[0048] In one implementation, the state-of-charge (SOC)-voltage mapping relationship corresponding to different aging levels can be pre-defined and stored in the battery management system in the form of a lookup table. Table 1 exemplarily shows the voltage values ​​corresponding to each SOC point when charging at different charging rates under a certain aging level (such as a brand new battery state).

[0049] Table 1. SOC-OCV Comparison Table for Different Charging Rates:

[0050] As shown in Table 1, at the same SOC, the higher the charging rate, the more significant the polarization effect, and the higher the terminal voltage. This voltage-SOC relationship shifts overall with the increasing degree of battery aging; the more severe the aging, the lower the voltage value at the same SOC. Therefore, during charging, the corresponding SOC-voltage lookup table can be selected based on the current aging level. By looking up the corresponding SOC in the selected table for the voltage value obtained after removing the polarization effect, the actual state of charge of the battery at the current aging level can be obtained.

[0051] In practical applications, if a brand new battery has a state of charge (SOC) of 60% at an open-circuit voltage of 3.6V, the same battery may have a SOC of 55% at the same open-circuit voltage of 3.6V after a certain period of use. Therefore, determining the corresponding mapping relationship based on the degree of aging can accurately determine the battery's state of charge in the current charging process.

[0052] Furthermore, this embodiment of the invention also performs risk management and parameter correction during the charging process. Specifically, this embodiment continuously monitors the battery temperature, polarization voltage, charging voltage, and internal resistance data at a preset sampling frequency during charging, with each parameter corresponding to a preset threshold range. When any of the monitored parameters (battery temperature, polarization voltage, charging voltage, and internal resistance) exceeds the corresponding preset threshold range, a safety control operation corresponding to that monitored parameter is executed.

[0053] In one implementation, the type of safety control operation is determined based on the triggered monitoring parameters and may include at least one of the following: When the battery temperature exceeds the temperature threshold range, a current-reducing and cooling operation is performed. For example, the battery temperature is monitored in real time throughout the charging process. When the battery temperature exceeds a first temperature (e.g., 50°C), the charging current is immediately reduced (e.g., 50%) to buffer the cooling. After the temperature drops below a second temperature (e.g., 40°C), normal fast charging parameters are restored. When the polarization voltage exceeds the polarization threshold range, a polarization compensation operation is performed. For example, when an excessive polarization voltage is detected and there is a risk of lithium plating, polarization compensation parameters are superimposed in real time to fine-tune the charging current and voltage and eliminate the polarization effect. When the charging voltage exceeds the voltage threshold range or the internal resistance data exceeds the internal resistance threshold range, a charging pause operation can be performed. For example, when a fault state such as an abnormal voltage surge or a sudden change in internal resistance occurs, charging is immediately paused and a fault warning is output to ensure charging safety. The above-mentioned safety control operations can be selected and executed one by one according to the actual monitored anomaly type, or they can be executed in combination. For example, when both temperature exceedance and polarization exceedance occur at the same time, current reduction and cooling operations and polarization compensation operations can be executed simultaneously.

[0054] In one implementation, the aforementioned safety control operations are achieved by the battery management system (BMS) sending corresponding control commands to the charger. For example, the BMS can send current reduction commands, compensation parameters, or pause commands to the charger via a CAN bus or hard-wired signal, and the charger responds and performs the corresponding current or voltage adjustment. In another implementation, when the BMS detects abnormal parameters exceeding the threshold range, it can also directly disconnect the relays or contactors in the charging circuit to achieve hardware-level safety protection without relying on communication with the charger, thus ensuring charging safety even in cases of communication failure or charger unresponsiveness.

[0055] In summary, by continuously monitoring battery temperature, polarization voltage, charging voltage, and internal resistance data during the charging process, and executing corresponding safety control operations when any parameter exceeds the corresponding threshold, the embodiments of the present invention can enable the charging process to have real-time proactive multi-dimensional safety protection capabilities.

[0056] Step S204: Determine the degree of aging of the battery to be charged based on the temperature data and internal resistance data.

[0057] Based on the above embodiments, an aging degree comparison table of the battery to be recharged can be obtained according to temperature data; the aging degree of the battery to be recharged can be determined according to the internal resistance range corresponding to the internal resistance data in the aging degree comparison table; wherein, the aging degree comparison table includes the internal resistance range of the battery to be recharged under different aging degrees. Temperature data characterizes the actual thermal state of the battery during the current charging process, reflecting the degree of influence of the temperature environment on the battery's internal resistance. According to the temperature data, an internal resistance reference standard can be determined at the current temperature state. Obtaining an aging degree comparison table at the corresponding temperature allows the measured internal resistance to be compared under the same temperature reference, avoiding the misjudgment of increased internal resistance caused by low temperature as accelerated aging, and also avoiding the concealment of the true aging degree by decreased internal resistance at high temperature. In the aging degree comparison table, different temperatures correspond to different internal resistance ranges, and at the same temperature, the more severe the aging degree, the higher the internal resistance; at the same aging degree, the lower the temperature, the higher the internal resistance. In one implementation, the degree of aging can be characterized by a percentage change relative to the factory condition. For example, an increase of 0%-10% in internal resistance compared to the factory value corresponds to a brand new condition, an increase of 10%-30% corresponds to mild aging, an increase of 30%-60% corresponds to moderate aging, and an increase of more than 60% corresponds to severe aging.

[0058] In one implementation, battery aging can be categorized based on internal resistance. Batteries from the same batch are selected and aged from a fresh state to the end of their lifespan, with changes in internal resistance recorded. An aging degree comparison table is then created for the entire lifespan to determine the internal resistance range corresponding to different aging degrees. Each temperature can correspond to a separate aging degree comparison table. For example, internal resistance ranges corresponding to different aging degrees can be marked at temperatures such as -10℃, 0℃, 10℃, 25℃, and 45℃, forming comparison tables for multiple temperatures. Within the same temperature comparison table, the more severe the aging degree, the higher the corresponding internal resistance range. Between different temperatures, the lower the temperature, the higher the internal resistance value corresponding to the same aging degree. During charging, the current temperature data can be used as an index to select the aging degree comparison table for that temperature. The measured internal resistance falls within the specified range in the table; the aging degree corresponding to this range is the current aging degree of the battery. In one implementation, the aging degree comparison table for each temperature can refer to the format shown in Table 2. Table 2 exemplarily shows the internal resistance range corresponding to different aging degrees for a certain battery model at 25℃. Similarly, comparison tables can be marked for other temperatures.

[0059] Table 2. DC internal resistance (mΩ) of individual cells at different lifespan states at 25℃:

[0060] In summary, the embodiments of the present invention determine the corresponding aging degree comparison table through temperature data, and compare the measured internal resistance with the standard internal resistance range under the same temperature reference, which can accurately identify the aging degree corresponding to the actual loss state of the battery under the current temperature environment.

[0061] Step S206: Based on the temperature data, obtain the charging capacity boundary table corresponding to the degree of aging.

[0062] A charging capacity boundary table is a pre-calibrated reference data used to determine the maximum allowable charging rate under the current state. In one implementation, this table can be pre-constructed by: conducting charging tests at different rates on batteries of the same type to be charged under different states of charge, monitoring the anode-to-lithium potential of the same type of battery at the corresponding state of charge and charging rate; verifying lithium plating on the tested batteries of the same type to determine the lithium plating safety threshold; and finding the charging rate corresponding to the anode-to-lithium potential reaching the lithium plating safety threshold under different states of charge in the test data, which serves as the upper limit of the charging rate for the corresponding state of charge. This establishes a correspondence between the state of charge and the upper limit of the charging rate for batteries of corresponding aging levels under corresponding temperature conditions.

[0063] In one implementation, the battery charging ambient temperature can be categorized. For battery samples with different aging levels, charging tests are conducted under different temperature conditions. The batteries are assembled into a three-electrode configuration and charged at different rates at different temperatures. Simultaneously, the anode-to-lithium potential and dynamic state of charge (SOC) of the three electrodes are monitored, and a table of anode-to-lithium potentials under different temperatures, rates, and dynamic SOCs is plotted. After categorizing the anode-to-lithium potentials, the charged battery samples are disassembled, and lithium plating at the anode interface is verified to determine the true lithium plating anode potential. Anode-to-lithium potential curves are fitted for all temperatures, rates, and different dynamic SOCs. Based on the true lithium plating anode potentials, the charging rates at different charge levels in the curves are confirmed, thereby determining the upper limit of the charging rate corresponding to each aging level, temperature condition, and state of charge, forming a charging capacity boundary table.

[0064] In one embodiment, Table 3 exemplarily shows the anode-to-lithium potential values ​​corresponding to different states of charge at different charging rates under a certain degree of aging (e.g., brand new battery state) and a temperature of 25°C.

[0065] Table 3. Lithium potential at different SOCs (mV) when fresh batteries are charged at different rates at 25°C:

[0066] As shown in Table 3, at the same SOC, the higher the charging rate, the lower the anode-to-lithium potential (closer to the lithium plating safety threshold); conversely, at the same charging rate, the higher the SOC, the lower the anode-to-lithium potential. When the anode-to-lithium potential drops to the preset lithium plating safety threshold, that charging rate becomes the upper limit of the charging rate at that SOC. For example, in Table 3, when the SOC is 10%, the anode-to-lithium potential corresponding to 4.0C is 96mV, far exceeding the lithium plating safety threshold. However, when the SOC rises to 35%, the anode-to-lithium potential corresponding to 4.0C drops to -1mV, exceeding the lithium plating safety threshold. Therefore, under these aging conditions and temperature conditions, 4.0C charging cannot be used in the high SOC range, and the upper limit must be determined based on the charging rate corresponding to the lithium plating boundary. At different aging levels, the anode-to-lithium potential corresponding to the same SOC and charging rate differs; the more severe the aging, the lower the anode-to-lithium potential, and the narrower the corresponding upper limit of the charging rate. Tables 4 and 5 show the anode-to-lithium potential values ​​corresponding to different aging levels, which are used to show the upper limit of the charging rate under the corresponding aging level, so as to determine the corresponding charging capacity boundary.

[0067] Table 4. At 25℃, with the state of life decayed to 85%, the anode-to-lithium potential (mV) at different SOC charging rates is as follows:

[0068] Table 5. At 25℃, with the state of life decayed to 65%, the anode-to-lithium potential (mV) at different SOC charging rates is as follows:

[0069] Step S208: Query the upper limit of the charging rate corresponding to the current state of charge in the charging capacity boundary table, and use it as the target charging rate.

[0070] In the charging capacity boundary table, each state of charge (SOC) corresponds to an upper limit for the charging rate. This upper limit represents the charging rate required when the battery's anode-to-lithium potential reaches a preset lithium plating safety threshold under the corresponding SOC. After obtaining the charging capacity boundary table corresponding to the current aging level and temperature, the upper limit for the charging rate corresponding to the current SOC can be retrieved from the table using the current SOC as an index, serving as the target charging rate. This target charging rate is the maximum usable rate that, under the combined constraints of the current aging level, current temperature, and current SOC, just barely exceeds the lithium plating safety boundary. The charging rate is higher in the low SOC range, and automatically decreases as the SOC increases, allowing the charging process to be performed at the highest possible rate within the safety boundary.

[0071] In summary, by obtaining the charging capability boundary table corresponding to the degree of aging and querying the upper limit of the current SOC as the target charging rate, the embodiment of the present invention can make the charging rate subject to the joint constraints of the degree of aging, temperature conditions and state of charge, and charge at the maximum rate allowed in the current state within the safety boundary, and automatically narrow the rate as the SOC increases.

[0072] Step S210: Charge the battery to be charged based on the target charging rate.

[0073] In one implementation, the current charging stage of the battery to be charged can be determined based on the current state of charge; the charging current coefficient corresponding to the battery to be charged can be determined based on the charging stage; and the target charging current corresponding to the charging stage can be determined based on the target charging rate and the charging current coefficient, so as to charge the battery to be charged with the target charging current.

[0074] Specifically, the charging process can be divided into multiple charging stages based on the battery's real-time SOC range, temperature range, and aging level. In one embodiment, the charging stages may include a pre-charge activation stage, a fast charging stage, a voltage stabilization and replenishment stage, and a trickle-down stage, which are connected sequentially. The pre-charge activation stage corresponds to the SOC range from 0% to a first threshold. During this stage, the lithium-ion activity inside the battery is low, and charging can be performed with a smaller current coefficient to avoid lithium plating damage caused by high current at low SOC. The fast charging stage corresponds to the SOC range from the first threshold to the second threshold. This stage is the battery's efficient fast charging range, and charging is performed with a larger current coefficient to shorten the charging time. The voltage stabilization and replenishment stage corresponds to the SOC range from the second threshold to the third threshold. This stage switches to a constant voltage charging mode, and the charging current gradually decreases as the SOC increases. The trickle-down stage corresponds to the SOC range from the third threshold to full charge, and charging is performed with a very small current coefficient to replenish the battery's internal charge and balance the voltage difference between individual cells. In one embodiment, the first threshold corresponds to an SOC of 20%, the second threshold corresponds to an SOC of 80%, and the third threshold corresponds to an SOC of 95%.

[0075] Each charging stage corresponds to a different charging current coefficient. This coefficient can be used to adjust the target charging rate based on the differences in current tolerance at each stage. Specifically, at low SOC, the battery's internal lithium-ion activity is low and the anode potential baseline is low, making it highly susceptible to lithium plating damage from high-current charging. Therefore, a lower current coefficient (e.g., 30%) can be set for the pre-charge activation stage. In the intermediate SOC range, the battery has the strongest tolerance to charging rates, and can be charged to its maximum capacity to shorten charging time, provided safety limits allow. A higher current coefficient (e.g., 100%) can be set for the fast charging stage. During the voltage stabilization and replenishment stage, the battery switches to constant voltage mode, and the current gradually decreases as SOC increases; no coefficient needs to be set. Furthermore, in the high SOC range, the anode potential has dropped to a low level, and high-current charging can easily exceed the lithium plating boundary. Therefore, a minimum current coefficient (e.g., 10%) can be set for the trickle-charging termination stage to complete the process with minimal current. For example, for a brand new battery at room temperature (25°C), assuming a target charging rate of 1.5C, if it is currently in the pre-charge activation stage (SOC of 10%), and the pre-charge current coefficient for this stage is 0.2, then the actual charging current is the target charging rate of 1.5C multiplied by 0.2, which is 0.3C. When the SOC enters the fast charging stage (SOC of 30%), the current coefficient for this stage is 1.0, so the actual charging current is the target charging rate of 1.5C multiplied by 1.0, which is 1.5C. When the SOC enters the trickle charging stage (SOC of 96%), the current coefficient for this stage is 0.1, so the actual charging current is the target charging rate of 1.5C multiplied by 0.1, which is 0.15C. The current coefficients for each stage of the same battery at different temperatures can be adjusted according to temperature conditions. For example, in low-temperature environments, the current coefficient of the fast charging stage decreases, and the current coefficients of the pre-charge and trickle charging stages also narrow accordingly. This charging process can be adapted to the target charging rate based on the charging stage and current operating conditions.

[0076] In summary, this invention, by collecting state parameters during battery charging, can determine charging parameters based on the battery's current actual state and continuously adjust them as the state changes. This avoids the use of the same current value after battery state changes, thus reducing lifespan loss caused by mismatch between charging parameters and battery state. Furthermore, by determining the battery's aging level using temperature and internal resistance data, charging control can understand the battery's true carrying capacity under current temperature conditions, ensuring the determined charging rate is within the battery's current tolerance range, which helps slow down battery lifespan degradation in subsequent use. Moreover, by jointly determining the target charging rate based on aging level, temperature data, and state of charge, the charging parameters not only adjust with changes in battery aging and temperature environment but also naturally narrow as the state of charge increases during charging, achieving adaptive changes in the charging rate throughout the entire lifespan and under all temperature conditions.

[0077] Within the aforementioned logical framework, the battery can obtain charging parameters matching its current state under different operating conditions. For example, in one embodiment, a brand-new ternary lithium battery at room temperature using the method of this invention can be charged at a 1.5C rate, reducing the overall charging time by 35% compared to the traditional three-stage charging (e.g., from 70 minutes to 45 minutes), significantly improving charging efficiency. For mildly aged lithium iron phosphate batteries at 0°C, the method of this invention can accelerate charging by 28% compared to traditional low-temperature fast charging, with no lithium plating or battery damage throughout the process. For severely aged lithium iron phosphate batteries at 0°C, the method of this invention can accelerate charging by 22% compared to traditional low-temperature fast charging, also with no lithium plating or damage. In contrast, a control group charged at a fixed 1C rate at 0°C showed slight, moderate, and severe lithium plating in mildly, moderately, and severely aged batteries, respectively. The degree of lithium plating increased progressively with the degree of aging, severely compromising charging safety. The above comparative results verify the effectiveness of this invention in suppressing lithium plating risk and ensuring charging safety through adaptive adjustment of the charging rate.

[0078] In summary, this invention is compatible with mainstream lithium-ion batteries such as ternary lithium and lithium iron phosphate, and can withstand various battery conditions, including brand new, slightly aged, and heavily aged batteries. It can also adapt to complex high and low temperature environments and can be widely applied in various charging scenarios such as new energy vehicles, energy storage systems, and portable devices. Furthermore, through a real-time sampling and adaptive adjustment mechanism, the charging parameters dynamically and adaptively adjust according to the battery state, requiring no manual intervention. This results in high control precision, strong stability, and ease of engineering implementation.

[0079] In summary, the embodiments of the present invention can achieve safe, efficient and fast charging of batteries under corresponding aging conditions, temperature data and state of charge. While improving charging speed, it can effectively suppress safety risks such as lithium plating and overheating, thereby extending battery cycle life.

[0080] Based on the above system embodiments, this invention also provides a battery charging control device, referring to... Figure 3 The device includes: a data acquisition module 10, used to acquire state parameters of the battery to be charged during the charging process; wherein the state parameters include: internal resistance data, temperature data, and the current state of charge of the battery to be charged; an aging degree determination module 20, used to determine the aging degree of the battery to be charged based on the temperature data and internal resistance data; a data processing module 30, used to determine the target charging rate of the battery to be charged within a preset charging safety boundary based on the aging degree, temperature data, and the current state of charge of the battery to be charged; and an execution module 40, used to charge the battery to be charged based on the target charging rate. The battery charging control device provided in this embodiment of the invention has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0081] Furthermore, this embodiment of the invention also provides a charging device equipped with the aforementioned battery charging control device, used to execute the battery charging control method of any of the above embodiments. The charging device provided by this embodiment of the invention has the same implementation principle and technical effects as the foregoing method embodiments. For the sake of brevity, any parts not mentioned in the charging device embodiment section can be referred to the corresponding content in the foregoing method embodiments.

[0082] This invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described... Figures 1-2 The steps of any of the methods shown. Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the above-described steps. Figures 1-2 The steps of any of the methods shown. Embodiments of the present invention also provide a structural schematic diagram of an electronic device, such as... Figure 4 The diagram shows the structure of the electronic device, which includes a processor 101 and a memory 100. The memory 100 stores computer-executable instructions that can be executed by the processor 101. The processor 101 executes the computer-executable instructions to implement the above-mentioned... Figures 1-2 Any of the methods shown.

[0083] exist Figure 4In the illustrated embodiment, the electronic device further includes a bus 102 and a communication interface 103, wherein the processor 101, the communication interface 103, and the memory 100 are connected via the bus 102. The memory 100 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk drive. Communication between this system network element and at least one other network element is achieved through at least one communication interface 103 (which can be wired or wireless), using the Internet, wide area network, local area network, metropolitan area network, etc. Bus 102 can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, or an AMBA (Advanced Microcontroller Bus Architecture) bus. AMBA defines three types of buses: APB (Advanced Peripheral Bus), AHB (Advanced High-performance Bus), and AXI (Advanced eXtensible Interface). Bus 102 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4The diagram uses only a single double-headed arrow, but this does not imply a single bus or a single type of bus. Processor 101 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 101 or by instructions in software form. Processor 101 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor 101 reads information from the memory and, in conjunction with its hardware, completes the aforementioned tasks. Figures 1-2 Any of the methods shown.

[0084] The computer program product of the battery charging control method, apparatus, and charging device provided in this invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. Specific implementations can be found in the method embodiments and will not be repeated here. Those skilled in the art will understand that, for convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the preceding method embodiments, and will not be repeated here. If the function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Finally, it should be noted that the above embodiments are merely specific implementations of this invention, used to illustrate the technical solutions of this invention, and not to limit it. The scope of protection of this invention is not limited thereto. Although this invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in this invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this invention, and should all be covered within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A battery charging control method, characterized in that, The method includes: During the charging process of the battery to be charged, the state parameters of the battery to be charged are acquired; wherein, the state parameters include: internal resistance data, temperature data and the current state of charge of the battery to be charged; The degree of aging of the battery to be charged is determined based on the temperature data and the internal resistance data. Based on the degree of aging, the temperature data, and the current state of charge of the battery to be charged, a target charging rate for the battery to be charged within a preset charging safety boundary is determined; wherein, the current state of charge is determined based on the mapping relationship between the current voltage and the state of charge of the battery to be charged, and the mapping relationship is determined according to the current degree of aging of the battery to be charged. The battery to be charged is charged based on the target charging rate.

2. The method according to claim 1, characterized in that, The step of determining the degree of aging of the battery to be recharged based on the temperature data and the internal resistance data includes: Based on the temperature data, obtain a table comparing the aging degree of the battery to be charged; The aging degree of the battery to be recharged is determined based on the internal resistance range corresponding to the internal resistance data in the aging degree comparison table; wherein, the aging degree comparison table includes the internal resistance range of the battery to be recharged under different aging degrees.

3. The method according to claim 1, characterized in that, The step of determining the target charging rate of the battery to be charged within a preset charging safety boundary based on the aging degree, the temperature data, and the current state of charge of the battery to be charged includes: Based on the temperature data, obtain the charging capacity boundary table corresponding to the degree of aging; The upper limit of the charging rate corresponding to the current state of charge is queried in the charging capacity boundary table and used as the target charging rate.

4. The method according to claim 3, characterized in that, Each state of charge in the charging capacity boundary table corresponds to an upper limit of the charging rate. The upper limit of the charging rate is the charging rate corresponding to the lithium potential of the anode of the battery to be charged reaching a preset lithium plating safety threshold in the corresponding state of charge.

5. The method according to claim 4, characterized in that, The method further includes: Acquire pre-conducted test data; wherein, the process of acquiring the test data includes: performing charging tests at different charging rates on the same type of battery to be charged under different states of charge, and monitoring the anode-to-lithium potential of the same type of battery at the corresponding states of charge and charging rates; Lithium plating was verified on the tested batteries of the same type to determine the lithium plating safety threshold; The charging rate corresponding to the lithium potential of the anode reaching the lithium plating safety threshold under different charging states is found in the test data and used as the upper limit of the charging rate for the corresponding charging state.

6. The method according to claim 1, characterized in that, The steps for acquiring the state parameters of the battery to be charged during the charging process include: The charging current and charging voltage of the battery to be charged during the charging process, as well as the temperature data of the battery to be charged under the current ambient temperature, are obtained according to a preset sampling frequency. Based on the charging current and the charging voltage, the internal resistance data of the battery to be charged during the charging process is determined; The current state of charge is determined based on the charging voltage and the current polarization voltage of the battery to be charged.

7. The method according to claim 6, characterized in that, The step of determining the current state of charge based on the charging voltage and the current polarization voltage of the battery to be charged includes: The open-circuit voltage is determined based on the charging voltage and the current polarization voltage; The state of charge-open circuit voltage mapping relationship is determined based on the aging degree of the battery to be charged. The state of charge corresponding to the open circuit voltage is queried in the state of charge-open circuit voltage mapping relationship and used as the current state of charge of the battery to be charged.

8. The method according to claim 6, characterized in that, The method further includes: When any of the monitoring parameters of the battery temperature, polarization voltage, charging voltage, and internal resistance of the battery to be charged exceeds the corresponding preset threshold range, the safety control operation corresponding to the monitoring parameter is executed.

9. The method according to claim 1, characterized in that, The step of charging the battery to be charged based on the target charging rate includes: Based on the current state of charge, determine the current charging stage of the battery to be charged; Based on the charging stage, determine the charging current coefficient corresponding to the battery to be charged; Based on the target charging rate and the charging current coefficient, the target charging current corresponding to the charging stage is determined, and the battery to be charged is charged with the target charging current.

10. A battery charging control device, characterized in that, The device includes: The data acquisition module is used to acquire the state parameters of the battery to be charged during the charging process; wherein, the state parameters include: internal resistance data, temperature data and the current state of charge of the battery to be charged; An aging degree determination module is used to determine the aging degree of the battery to be charged based on the temperature data and the internal resistance data. The data processing module is used to determine the target charging rate of the battery to be charged within a preset charging safety boundary based on the aging degree, the temperature data, and the current state of charge of the battery to be charged; wherein the current state of charge is determined based on the mapping relationship between the current voltage and the state of charge of the battery to be charged, and the mapping relationship is determined according to the current aging degree of the battery to be charged. An execution module is used to charge the battery to be charged based on the target charging rate.

11. A charging device, characterized in that, The charging device is equipped with the battery charging control device as described in claim 10, for executing the battery charging control method as described in any one of claims 1-9.

Images