Battery charging method, battery management system, battery device and electric device

Abstract

The application discloses a battery charging method, a battery management system, a battery device and an electric device, and relates to the technical field of batteries. The battery management system comprises a first connecting end connected with a positive electrode of a battery, a second connecting end connected with a negative electrode of the battery, a heating device, a switching device, a sampling device and a controller; the heating device is connected in series between the first connecting end and the second connecting end; the switching device is connected in series with the heating device; the sampling device is connected with the battery and is used for acquiring battery information of the battery, wherein the battery information comprises a battery temperature and a battery voltage; the controller is connected with control ends of the heating device and the switching device, is used for determining a remaining battery capacity based on the battery voltage, and is used for controlling the switching device to be closed and heating the battery by controlling the heating device to adjust a charging current size of the battery in response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining battery capacity. The application is beneficial to improving the battery charging rate at low temperatures.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to battery charging methods, battery management systems, battery devices, and electric equipment. Background Technology

[0002] With the development of battery technology, lithium-ion batteries have been widely used due to their large capacity, long range, light weight, low price, and high safety, and can be applied to electric vehicles, mobile terminals and other devices.

[0003] However, lithium-ion batteries experience increased polarization at low temperatures, resulting in lower charging rates and slower charging speeds. The charging time for lithium-ion batteries can typically last for several hours, causing inconvenience to users.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] In view of the above problems, this application provides a battery charging method, a battery management system, a battery device, and an electric device, aiming to improve the battery charging rate at low temperatures.

[0006] In a first aspect, this application provides a battery management system, which includes a first connection terminal, a second connection terminal, a heating device, a switching device, a sampling device, and a controller;

[0007] The first connection terminal is used to connect to the positive terminal of the battery, and the second connection terminal is used to connect to the negative terminal of the battery; the heating device is connected in series between the first connection terminal and the second connection terminal; the switching device is connected in series with the heating device.

[0008] The sampling device is connected to the battery and is used to acquire battery information, including battery temperature and battery voltage.

[0009] The controller is connected to the control terminals of the heating device and the switching device, and is used to determine the remaining battery power based on the battery voltage; in response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller controls the switching device to close, and controls the heating device to heat the battery, thereby adjusting the charging current of the battery.

[0010] In the technical solution of this application embodiment, the heating device is connected to the positive and negative terminals of the battery by controlling the closing of the switching device, so that the heating device heats the battery. At the same time, the temperature rise of the battery is accelerated under the intervention of the heating device. The charging current of the battery can also change with the working state of the heating device. Thus, the heating device is used to disturb the charging current of the battery, eliminate polarization, and improve charging efficiency.

[0011] In some embodiments, the heating device is a positive temperature coefficient thermistor.

[0012] In the technical solution of this application embodiment, the working characteristics of a positive temperature coefficient thermistor are used to disturb the charging current of the battery, eliminate polarization, and improve charging efficiency.

[0013] In some embodiments, the controller is used to:

[0014] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following:

[0015] The battery is charged using the first charging current;

[0016] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0017] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0018] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0019] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

[0020] The embodiments of this application employ a low-temperature strategy to charge the battery, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0021] In some embodiments, the controller is further configured to:

[0022] Get battery temperature and remaining battery power;

[0023] The value of the first charging current is determined based on the obtained battery temperature and remaining battery power.

[0024] The controller is also used for:

[0025] Get battery temperature and remaining battery power;

[0026] The first preset duration is determined based on the obtained battery temperature and remaining battery power.

[0027] In some embodiments, the controller is further configured to:

[0028] Reacquire battery temperature and remaining battery power;

[0029] In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than a preset remaining charge, the charging current is determined based on the battery temperature and the remaining battery charge.

[0030] In this embodiment of the application, when the battery is charged using a low-temperature strategy, the charging current is dynamically adjusted, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0031] In some embodiments, the controller is further configured to:

[0032] Reacquire battery temperature and remaining charge;

[0033] In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery capacity being lower than a preset remaining capacity, the low-temperature charging strategy of the battery is adjusted or the current low-temperature charging strategy is maintained based on the battery temperature and the remaining battery capacity; wherein the low-temperature charging strategy includes at least one of the following:

[0034] The battery is charged using the first charging current;

[0035] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0036] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0037] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0038] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

[0039] The embodiments of this application dynamically adjust the low-temperature strategy to charge the battery, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0040] In some embodiments, the controller is used to:

[0041] In response to a battery temperature below a preset temperature threshold and a remaining battery capacity not below a preset remaining capacity, a low-temperature charging strategy is employed to charge the battery; wherein the low-temperature charging strategy includes:

[0042] The battery is charged with a first charging current, and the anode potential of the battery is detected.

[0043] When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold.

[0044] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current;

[0045] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0046] According to the embodiment of this application, the charging current is adjusted in real time based on the temperature rise. After the charging current is increased, the heat of the heating device can also be further increased, thereby increasing the temperature rise. The two work together to improve the charging efficiency.

[0047] In some embodiments, the controller is further configured to:

[0048] Reacquire battery temperature and remaining charge;

[0049] The charging request current and the closed / open state of the switching device are determined based on the battery temperature and the remaining battery power.

[0050] The system sends a charging request current to the external charging device based on the determined magnitude of the charging request current, and / or adjusts the closed / open state of the switching device.

[0051] The embodiments of this application dynamically adjust the charging current of the battery and the working state of the heating device, thereby improving charging efficiency and reducing energy consumption caused by the operation of the heating device.

[0052] In some embodiments, the controller is used to:

[0053] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge not being lower than a preset remaining charge, the charging request current of the battery is determined;

[0054] The charging request current is sent to the external charging device according to the determined charging request current magnitude.

[0055] The embodiments of this application employ a low-temperature strategy to charge the battery, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0056] In some embodiments, the controller is used to:

[0057] In response to the battery temperature not being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the actual charging request current of the battery is determined based on the remaining battery power, and the actual charging request current is sent to the external charging device.

[0058] Secondly, this application provides a battery management system, which includes a first connection terminal, a second connection terminal, a heating device, a switching device, a sampling device, and a controller;

[0059] The first connection terminal is used to connect to the positive terminal of the battery, and the second connection terminal is used to connect to the negative terminal of the battery; the switching device is connected in parallel with the battery;

[0060] The sampling device is connected to the battery and is used to acquire battery information, including battery temperature and battery voltage.

[0061] The controller is connected to the control terminals of the heating device and the switching device, and is used to determine the remaining battery power based on the battery voltage; in response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller controls the switching device to close / open at a preset frequency to adjust the charging current of the battery.

[0062] In this embodiment, in response to the battery temperature falling below a preset temperature threshold and the remaining battery charge falling below a preset remaining charge, a switching device is controlled to close / open at a preset frequency to control the heating device to operate and heat the battery. Furthermore, the changing state of the switching device (closed / open) controls the charging current of the disturbed battery. This application helps to balance battery charging efficiency and lithium plating risk in low-temperature environments.

[0063] In some embodiments, the heating device includes at least one of a heating wire, a heating film, and a heating plate.

[0064] The controller is used for:

[0065] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following:

[0066] The battery is charged using the first charging current;

[0067] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0068] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0069] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0070] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

[0071] In some embodiments, the controller is used to:

[0072] In response to a battery temperature falling below a preset temperature threshold and the remaining battery capacity falling below a preset remaining capacity, a low-temperature charging strategy is employed to charge the battery; wherein the low-temperature charging strategy includes:

[0073] The battery is charged with a first charging current, and the anode potential of the battery is detected.

[0074] When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold.

[0075] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current;

[0076] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0077] Thirdly, this application provides a battery charging method, implemented based on the battery management system described above, the battery charging method comprising:

[0078] Get battery temperature and remaining battery power;

[0079] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge being lower than a preset remaining charge, the switching device in the battery management system is controlled to close, and the battery is heated by controlling the heating device to adjust the charging current of the battery.

[0080] In the technical solution of this application embodiment, the heating device is connected to the positive and negative terminals of the battery by controlling the closing of the switching device, so that the heating device heats the battery. At the same time, the temperature rise of the battery is accelerated under the intervention of the heating device. The charging current of the battery can also change with the working state of the heating device. Thus, the heating device is used to disturb the charging current of the battery, eliminate polarization, and improve charging efficiency.

[0081] In some embodiments, the heating device is a positive temperature coefficient thermistor, and the method further includes:

[0082] When the battery temperature is lower than a preset temperature threshold and the remaining battery power is lower than a preset remaining power, the switching device in the battery management system is controlled to close, and the battery is heated by controlling the thermistor to adjust the charging current of the battery.

[0083] In the technical solution of this application embodiment, the working characteristics of a positive temperature coefficient thermistor are used to disturb the charging current of the battery, eliminate polarization, and improve charging efficiency.

[0084] In some embodiments, the method further includes:

[0085] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following:

[0086] The battery is charged using the first charging current;

[0087] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0088] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0089] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0090] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

[0091] The embodiments of this application employ a low-temperature strategy to charge the battery, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0092] In some embodiments, the first charging current is determined using the following steps:

[0093] Get battery temperature and remaining battery power;

[0094] The value of the first charging current is determined based on the obtained battery temperature and remaining charge.

[0095] In some embodiments, the first preset duration is determined using the following steps:

[0096] Get battery temperature and remaining power;

[0097] The first preset duration is determined based on the obtained battery temperature and remaining power.

[0098] In some embodiments, the method further includes:

[0099] Reacquire battery temperature and remaining battery power;

[0100] In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than the preset temperature threshold, the charging current of the battery is determined based on the battery temperature and the remaining battery charge.

[0101] The battery is charged according to the determined charging current, and then the process returns to the step of re-acquiring the battery temperature and remaining charge.

[0102] In this embodiment of the application, when the battery is charged using a low-temperature strategy, the charging current is dynamically adjusted, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0103] In some embodiments, the method further includes:

[0104] Reacquire battery temperature and remaining charge;

[0105] In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than the preset temperature threshold, the low-temperature charging strategy of the battery is adjusted or the current low-temperature charging strategy is maintained based on the battery temperature and the remaining battery charge.

[0106] The battery is charged according to the determined low-temperature charging strategy, and the process returns to the step of re-acquiring the battery temperature and remaining charge; wherein the low-temperature charging strategy includes at least one of the following:

[0107] The battery is charged using the first charging current;

[0108] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0109] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0110] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0111] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

[0112] The embodiments of this application dynamically adjust the low-temperature strategy to charge the battery, which helps to balance charging demand and lithium plating risk, thereby improving charging efficiency and shortening charging time.

[0113] In some embodiments, the method further includes:

[0114] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy, which includes the following steps:

[0115] The battery is charged with a first charging current, and the anode potential of the battery is detected.

[0116] When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold.

[0117] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current;

[0118] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0119] According to the embodiment of this application, the charging current is adjusted in real time based on the temperature rise. After the charging current is increased, the heat of the heating device can also be further increased, thereby increasing the temperature rise. The two work together to improve the charging efficiency.

[0120] In some embodiments, the method further includes:

[0121] Reacquire battery temperature and remaining battery power;

[0122] The charging request current and the closed / open state of the switching device are determined based on the reacquired battery temperature and the remaining battery power.

[0123] Based on the determined magnitude of the charging request current, a charging request current is sent to the external charging device, and / or the closed / open state of the switching device is adjusted, and the process returns to the step of re-acquiring the battery temperature and remaining charge.

[0124] The embodiments of this application dynamically adjust the charging current of the battery and the working state of the heating device, thereby improving charging efficiency and reducing energy consumption caused by the operation of the heating device.

[0125] Secondly, this application provides an electric device that includes the battery device described above.

[0126] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0127] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0128] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0129] Figure 1 Structural schematic diagrams of some embodiments of the vehicle provided in this application;

[0130] Figure 2 Exploded structural diagrams of some embodiments of the battery provided in this application;

[0131] Figure 3An exploded structural diagram of some embodiments of the battery cell provided in this application;

[0132] Figure 4 Circuit diagrams of some embodiments of the battery management system provided in this application;

[0133] Figure 5 A flowchart illustrating the first embodiment of the charging method provided in this application;

[0134] Figure 6 A flowchart illustrating the second embodiment of the charging method provided in this application;

[0135] Figure 7 A flowchart illustrating the third embodiment of the charging method provided in this application;

[0136] Figure 8 A flowchart illustrating the fourth embodiment of the charging method provided in this application;

[0137] Figure 9 A flowchart illustrating the fifth embodiment of the charging method provided in this application;

[0138] Figure 10 This is a flowchart illustrating the sixth embodiment of the charging method provided in this application.

[0139] The reference numerals in the detailed embodiments are as follows:

[0140] 1000 vehicles;

[0141] Battery 100, controller 200, motor 300;

[0142] Box 10, Part 11, Part 2 12;

[0143] Battery cell 20, end cap 21, electrode terminal 21a, housing 22, cell assembly 23, tab 23a;

[0144] First connection terminal BAT+, second connection terminal BAT-, heating device 30, controller 40, sampling device 50, switching device SW.

[0145] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0146] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0147] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0148] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0149] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0150] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0151] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0152] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0153] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0154] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0155] To meet diverse power demands, battery devices can include multiple individual battery cells, which can be connected in series, parallel, or a combination of both. Optionally, multiple battery cells can first be connected in series, parallel, or a combination to form a battery module, and then these battery modules can be connected in series, parallel, or a combination to form a battery. In other words, multiple battery cells can directly form a battery, or they can first be assembled into battery modules, and then the battery modules can be assembled into a battery. The battery is then further installed in electrical equipment to provide power to the equipment.

[0156] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, discharge capacity, charge / discharge rate, and other performance parameters. In addition, battery safety performance also needs to be considered.

[0157] In lithium-ion batteries, energy storage and discharge are achieved through the migration of lithium ions between the positive and negative electrodes. During charging, lithium ions are extracted from the positive electrode and then inserted into the negative electrode. However, the migration of lithium ions between the positive and negative electrodes is greatly affected by temperature, especially in low-temperature environments. Due to deteriorating kinetic conditions at the positive and negative electrodes, as well as increased electrolyte viscosity and decreased conductivity, the lithium insertion capacity of the negative electrode may be insufficient to cope with the rapid extraction of lithium ions during fast charging. Consequently, some lithium ions will precipitate on the surface of the negative electrode, forming metallic lithium, a phenomenon known as lithium plating. This phenomenon is more likely to occur during high-rate, low-temperature charging because high-rate charging means a larger charging current, requiring the negative electrode to insert more lithium ions more quickly. If the capacity and structure of the negative electrode cannot meet this demand, the lithium ions extracted from the positive electrode cannot be inserted into the negative electrode in time. The process of forming metallic lithium on the surface of the negative electrode leads to lithium plating, which in turn induces lithium dendrite formation. The lithium deposited on the negative electrode surface often exists in the form of dendrites. After the dendrites grow to a certain extent, they can easily pierce the separator between the positive and negative electrodes, causing a short circuit in the battery cell and seriously affecting the battery's safety performance. In mild cases, it reduces battery life; in severe cases, it causes internal short circuits leading to thermal runaway.

[0158] Based on the above considerations, and to address the lithium plating problem that easily occurs when batteries are charged at high rates and low temperatures, a battery charging method was designed after in-depth research. This method utilizes a heating device to provide a disturbance current during battery cell charging, causing pulse changes in the battery's charging current. Specifically, the heating device is connected in parallel with the battery cell. When the battery is in a low-temperature environment, the heating device is activated. Utilizing the thermistor characteristics of the heating device, the current flowing through it is altered, thereby changing the current of the battery cell connected in parallel. For example, when the battery is in a low-temperature environment and heating is required, the heating device is activated, meaning the electrical energy output from the battery management system is supplied to the heating device, applying a voltage across its terminals. The heating device automatically heats up after being powered on, thus heating the battery. After a certain period, the resistance of the heating device enters a transition region, meaning its resistance jumps from a small value to a large value, causing the current flowing through the heating device to decrease rapidly. Since the heating device and the battery cell are connected in parallel, when the current flowing through the heating device decreases, the current flowing through the battery cell increases. The heating temperature of the heating element decreases as the current flowing through it decreases, and it does not continue to rise. After a period of time, the resistance of the heating element decreases, causing the current flowing through it to increase, while the current flowing through the battery cell decreases. This process repeats, causing the battery to be charged with a fluctuating current, rather than maintaining a high value or only being able to be charged with a low current. The embodiments of this application can...

[0159] When the heating element is connected in parallel with the battery, in environments where the battery temperature is low, a high current can be used to charge the battery while simultaneously heating it, thus raising its temperature. Since the current flowing through the heating element changes with the resistance due to temperature variations, the disturbance current generated by the heating element can be used to switch the current flowing through the battery between higher and lower currents based on the temperature of the heating element. This allows the battery to be charged using a pulsed current method.

[0160] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0161] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0162] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0163] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0164] Please refer to Figure 2 , Figure 2This is an exploded view of a battery 100 provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0165] The battery can be a power battery, such as a lithium-ion battery, lithium metal battery, lithium-sulfur battery, sodium lithium-ion battery, lithium-air battery, etc. In terms of scale, the power battery can be a single battery cell, or a battery module or battery device, and is not limited thereto. The battery cell can be cylindrical, flat, cuboid, or other shapes, and this application embodiment is not limited in this regard. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and this application embodiment is not limited in this regard either.

[0166] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0167] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0168] Please refer to Figure 3 , Figure 3This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit that makes up a battery. Figure 3 The battery cell 20 includes an end cap 21, a housing 22, a cell assembly 23, and other functional components.

[0169] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with cell assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0170] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the cell assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the cell assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0171] The cell assembly 23 is the component in the battery cell 100 where the electrochemical reaction occurs. The casing 22 may contain one or more cell assemblies 23. The cell assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the cell assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab 23a. The battery mainly relies on the movement of metal ions, such as lithium ions, between the positive and negative electrode sheets to operate. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the positive current collector without the positive active material layer protrudes beyond the positive current collector with the positive active material layer coated on it, serving as the positive tab. Taking a lithium-ion battery as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode current collector without the negative electrode active material layer protrudes beyond the one coated with the negative electrode active material layer. The negative electrode current collector without the negative electrode active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. The positive and negative electrode tabs can be located together at one end of the main body or at opposite ends of the main body. During the charging and discharging process of the battery, the positive and negative electrode active materials react with the electrolyte, and the tab 23a connects to the electrode terminals to form a current loop.

[0172] This application provides a battery management system, referring to... Figure 4 , Figure 4 This is a circuit diagram of an embodiment of the battery management system of this application.

[0173] The battery management system includes a first connection terminal BAT+, a second connection terminal BAT-, a heating device 30, a switching device SW, a sampling device 50, and a controller 40;

[0174] The first connection terminal BAT+ is used to connect to the positive terminal of the battery, and the second connection terminal BAT- is used to connect to the negative terminal of the battery; the heating device 30 is connected in series between the first connection terminal BAT+ and the second connection terminal BAT-; the switching device SW is connected in parallel with the heating device 30.

[0175] The sampling device 50 is connected to the battery and is used to acquire battery information, including battery temperature and battery voltage.

[0176] The controller 40 is connected to the control terminal of the heating device 30 and the switching device SW. It is used to determine the remaining battery power based on the battery voltage. In response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller 40 controls the switching device SW to close and controls the heating device 30 to heat the battery and adjust the charging current of the battery.

[0177] In this embodiment, battery information may include battery temperature, battery voltage, battery current, and remaining battery charge (SOC). The sampling device 50 can be implemented using a temperature sensor, voltage detection circuit, etc. The battery temperature can be obtained by a temperature sensor installed in the battery cell, such as a PTC (Positive Temperature Coefficient) thermistor. The battery temperature can be the real-time temperature of one battery in the battery pack, the average real-time temperature of multiple battery packs, the internal temperature of the battery pack, the casing temperature of the battery pack, or the real-time temperature of the external environment of the battery pack. The remaining battery charge (SOC) can be estimated by detecting the battery voltage using a voltage detection circuit installed in the battery cell.

[0178] The controller 40 can be implemented using a BMU (Battery Management Unit), which can perform battery system charging and discharging control, thermal management control, etc. The controller 40 can also be implemented using an MCU (Microcontroller Unit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), SOC (System on Chip), etc., without limitation.

[0179] The first connection terminal BAT+ is connected to the positive terminal of the battery, and the second connection terminal BAT- is connected to the negative terminal of the battery. The heating device 30 and the switching device SW are connected in series between the first connection terminal BAT+ and the second connection terminal BAT-, so that when the switching device SW is closed, the heating device 30 and the battery form a parallel circuit.

[0180] When the battery is connected to the charging device, the charging device can be connected to the battery via a wire and to the BMS via a communication line, enabling communication between the battery and the charging device. The communication line facilitates information exchange between the charging device and the BMS. For example, this communication line may include, but is not limited to, a Controller Area Network (CAN) communication bus or a daisy-chain communication bus. Besides communicating with the BMS via a communication line, the charging device can also communicate with the BMS via a wireless network. This application does not specifically limit the type of wired or wireless communication between the charging device and the BMS.

[0181] The preset temperature threshold can be set to a value that affects battery charging efficiency, or a value at which the battery cannot start charging normally. Battery charging performance is poor at low temperatures, leading to increased charging time. Furthermore, as the remaining battery charge increases, the anode (negative electrode) potential is more likely to fall below 0V, gradually reducing the lithium intercalation space at the anode and increasing lithium ion accumulation on the negative electrode surface, thus making lithium metal deposition more likely, i.e., increasing the risk of lithium plating. Therefore, in this embodiment, when the remaining battery charge is lower than a preset remaining charge and the battery temperature is lower than the preset temperature threshold, a corresponding low-temperature charging strategy can be used to charge the battery. Optionally, the low-temperature charging strategy can specifically involve using a charging current, charging frequency, charging duration, and charging voltage adapted to the battery temperature and remaining charge.

[0182] In this embodiment, the heating device 30 can be implemented using a PTC thermistor. Optionally, the PTC thermistor can be attached to the outer wall of the battery cell. Whether the heating device 30 is activated can be determined based on the battery temperature and remaining charge. For example, certain temperature thresholds and remaining charge thresholds can be set. When the battery temperature is below a certain temperature threshold and the remaining charge is below a certain remaining charge threshold, the heating device 30 is activated. Furthermore, when the heating device 30 is activated, the power, operating current, operating voltage supplied to the heating device 30, as well as the operating frequency and total operating time, can also be determined based on the real-time battery temperature and battery charge, and implemented by controlling the opening / closing frequency and degree of the switching device SW.

[0183] When the controller 40 needs to control the operation of the heating device 30, it can close the switch SW to connect the heating device 30 to both ends of the battery, i.e., in parallel with the battery. The electrical energy output from the charging device drives the heating device 30 to heat the battery. When the heating device 30 does not need to be operated, the controller 40 opens the switch SW to disconnect the heating device 30 from the battery management system, thus stopping the heating of the battery. It can be understood that because the heating device 30 is connected in parallel with the battery, the current flowing through the battery is reduced due to the current diversion from the heating device 30. When the heating device 30 is not operating, it is disconnected from the battery, and all the current output from the heating device flows through the battery, increasing the current flowing through the battery. This process repeats. With the intervention of the heating device 30, even if the output current of the charging device and the charging current output by the battery management system remain constant, the charging current of the battery can also vary, for example, through pulsed disturbance current charging.

[0184] Understandably, the PTC thermistor is electrically connected in parallel with the battery cell. When it's necessary to control the PTC thermistor's operation, the switch SW is closed to connect the PTC thermistor to the charging device. The electrical energy output from the charging device then drives the PTC thermistor to heat the battery. When it's not necessary to control the PTC thermistor's operation, the switch SW is opened to disconnect the PTC thermistor from the battery management system, thus stopping the heating of the battery.

[0185] During operation, the PTC thermistor is connected in parallel with the battery. The current output from the charging device to the battery is partially diverted by the PTC thermistor. According to the operating characteristics of the PTC thermistor, the current flowing through the PTC thermistor changes with the temperature of the PTC thermistor. This indirectly disturbs the magnitude of the charging current flowing through the battery, so that the battery charging current can change with the temperature of the PTC thermistor, thereby providing a disturbance current for battery charging.

[0186] Specifically, when the PTC thermistor is activated for heating, its resistance is relatively low, resulting in a larger current flowing through it. This leads to a stronger heating effect on the battery, effectively raising its temperature. Due to the current shunting effect of the PTC thermistor, the battery's charging current is relatively low, reducing the risk of lithium plating. As the temperature rises and reaches the PTC thermistor's home temperature, its resistance gradually increases, causing the current flowing through it to gradually decrease. This reduces the current shunting ratio to the battery, allowing the charging current to gradually increase and improving charging efficiency. After a certain period, the surface temperature of the PTC thermistor decreases, and its resistance gradually decreases, again increasing the current shunting ratio to the battery, which further helps reduce the risk of lithium plating. In this way, with the cooperation of the PTC thermistor, without adjusting the output current of the charging device or the charging current set by the battery management system, there is no need to repeatedly control the switching device SW to open / close or control the conduction level of the switching device SW. By changing the working characteristics of the PTC thermistor, the charging current flowing through the battery can be changed, and the battery can also be charged in a variable, such as pulse, form.

[0187] In practical applications, a PTC thermistor is used to charge the battery with a perturbation current. The normal charging current is a constant current. The PTC thermistor is connected in parallel with the battery. By adjusting the resistance of the PTC thermistor during the heating process, the change in the battery charging current is controlled. The conventional battery charging current is a constant current, denoted as A. The current flowing through the PTC thermistor is an alternating current of varying magnitudes, denoted as ±B. After the PTC thermistor is activated, the resistance of the PTC changes with temperature, and the combined current value is A±B. The frequency of the change of A±B can be adjusted according to the magnitude of the current flowing through the PTC thermistor. In some embodiments, the frequency of change can be set to 0.1S.

[0188] In one embodiment, the controller 40 is used to:

[0189] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following:

[0190] The battery is charged using the first charging current;

[0191] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0192] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0193] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0194] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after charging is stopped; wherein the first charging current is greater than the second charging current.

[0195] In this embodiment, the controller in the battery management system can send a charging request to an external charging device according to a low-temperature charging strategy. The charging device can output charging power according to the charging requirements of the battery management system to charge the battery. For example, the charging device can output a voltage and current corresponding to the charging request voltage and charging request current sent by the battery management system. Optionally, the charging device in this embodiment can be a charging pile, also known as a charger. The charging pile here can be, for example, a regular charging pile, a supercharging pile, or a charging pile supporting vehicle-to-grid (V2G) mode.

[0196] First charging strategy: Charge with the first charging current;

[0197] Under this charging strategy, the magnitude of the charging current output to the battery can be changed by controlling whether the heating device 30 is connected in parallel with the battery. When the heating device 30 is not working, that is, when the heating device 30 is disconnected from the battery, the entire first charging current is output to the battery, thus charging the battery with the first charging current. This can meet the battery's charging efficiency during the charging process, and the larger first charging current can also cause the battery temperature to rise rapidly, achieving the purpose of heating the battery. When the battery reaches the lithium plating critical state, or the polarization value reaches the preset polarization threshold, the heating device 30 can be controlled to start working. With the heating device 30 acting in parallel, the first charging current is shunted by the heating device 30, thereby achieving a smaller charging current to continue charging the battery. The smaller charging current results in lower charging efficiency, reduces battery polarization, and keeps the anode potential at a preset value, such as 0V, or above 0V, or below 0V but close to 0V. The operation of the heating device 30 is controlled by charging with a high current for a period of time. When the battery polarization suddenly increases, a period of charging with a low current is used to reduce the polarization, ensuring that the anode potential remains above or near 0V. By switching the heating device 30 on and off, the first charging current alternates between shunt and non-shunt charging, thus keeping the first charging current output to the battery constant while reducing the duration of the alternating charging. This process is repeated until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset level. This charging strategy reduces polarization, increases the charging rate, and shortens the charging time. The first charging current can be the maximum charging current when the battery generates polarization or reaches a preset polarization value. The first preset duration can be the duration during which the battery generates polarization or reaches a preset polarization value when charged with the first charging current. The reduced charging current can be the maximum charging current when the battery depolarizes or the polarization value drops to a preset polarization value. The second preset duration can be the duration during which the battery depolarizes or the polarization value drops to a preset polarization value when charged with the second charging current.

[0198] The second charging strategy is to alternately charge the battery with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0199] This charging strategy employs a larger initial charging current to charge the battery. This ensures efficient charging during the process and also rapidly raises the battery temperature, effectively heating it. Once the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, a smaller second charging current is used to continue charging. This second charging current, being smaller and less efficient, reduces battery polarization, maintaining the anode potential at a preset value, such as 0V, above 0V, or near 0V. After a period of high-current charging, when battery polarization suddenly increases, a period of low-current charging is applied to reduce polarization, keeping the anode potential consistently above or near 0V. The first and second charging currents are alternated for corresponding durations, repeating this process until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current required to generate polarization or reach the preset polarization value. The first preset duration can be the duration during which the battery generates polarization or the polarization value reaches a preset polarization value when charged with the first charging current. The second charging current can be the maximum charging current when the battery depolarizes or the polarization value drops to the preset polarization value. The second preset duration can be the duration during which the battery depolarizes or the polarization value drops to the preset polarization value when charged with the second charging current.

[0200] The third charging strategy is to charge the battery with the first charging current for a first preset time, then stop charging for a second preset time and alternately charge the battery.

[0201] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, charging is stopped for a period to eliminate polarization, maintaining the anode potential at a preset value, such as 0V, above 0V, or near 0V. The specific setting can be adjusted based on battery and ambient temperatures, and is not limited here. After a period of high-current charging, if battery polarization suddenly increases, charging is stopped for a period to eliminate polarization, ensuring the anode potential remains above or near 0V. Charging with the initial charging current, alternating between charging and stopping for corresponding durations, is repeated until the battery's remaining capacity reaches a preset remaining capacity and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The initial charging current can be the critical current value at which polarization occurs or the maximum charging current when the polarization value reaches the preset polarization value. The first preset duration can be the duration during which the battery reaches a critical polarization value or a preset polarization value when charged with the first charging current. The second preset duration can be the duration during which the polarization de-polarizes or the polarization value drops to a preset polarization value.

[0202] The fourth charging strategy is to charge the battery with the first charging current for a first preset time, and then discharge the battery with the first discharging current for a second preset time, alternating between charging and discharging the battery.

[0203] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, the battery is controlled to discharge to the loads in the battery management system. During discharge, the concentration of reactants on the anode surface decreases, while the high-concentration substances in the middle diffuse towards the vicinity of the electrode. This eliminates battery polarization, keeping the anode potential at a preset value, such as 0V, above 0V, or below 0V but close to 0V. The specific setting can be adjusted based on battery temperature and ambient temperature, and is not limited here. After a period of high-current charging, when the battery polarization suddenly increases, it is discharged for a period of time to eliminate polarization, keeping the anode potential consistently above 0V or below 0V but close to 0V. Charging with the first charging current and discharging with the first discharging current, alternating between charging and stopping for corresponding durations, is repeated until the remaining battery capacity reaches a preset remaining capacity and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current when the battery generates polarization or the polarization value reaches a preset polarization value. The first preset duration can be the duration for which the battery generates polarization or the polarization value reaches the preset polarization value when charged with the first charging current. The first discharging current can be set to be relatively small so that it eliminates polarization without affecting the internal energy consumption of the battery. The second preset duration can be the duration for the polarization to dissipate or for the polarization value to drop to the preset polarization value.

[0204] The fifth charging strategy involves alternating between charging the battery with a first charging current for a first preset time, charging with a second charging current for a second preset time, and stopping charging for a third preset time; wherein the first charging current is greater than the second charging current.

[0205] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, a smaller initial charging current is used. This balances charging efficiency and slows down polarization. During the charging process with the second current and the charging process itself, the reactant concentration on the anode surface decreases, while the high-concentration material diffuses towards the electrode, thus eliminating battery polarization and maintaining the anode potential at a preset value, such as 0V, above 0V, or below 0V but close to 0V. The specific setting can be adjusted based on battery temperature and ambient temperature, and is not limited here. Charging with a large current for a period, followed by charging with a small current for a period when battery polarization suddenly increases, balances charging efficiency. Charging is then stopped for a period to eliminate the polarization generated by the first and second charging currents, ensuring the anode potential remains at 0V, or below 0V but close to 0V. The battery is first charged with a first charging current and a second charging current, then charging is paused for a period of time. This alternating period of high charging current, low current, and paused charging continues until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset level. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current at which polarization occurs or the polarization value reaches a preset value. The first preset duration can be the critical value at which polarization occurs when the battery is charged with the first charging current, or the duration at which the polarization value reaches the preset value. The second charging current can be set to a value that alleviates polarization without reducing charging efficiency. The second preset duration can be the duration at which polarization dissipates or the polarization value decreases to the preset value.

[0206] By adopting the above-mentioned alternating current charging strategy, setting a high current + low current (positive value) + charging off mode or a high current + charging off strategy, and a high current charging + low current discharging strategy, the battery polarization increases suddenly under a high current for a short period of time, and decreases under a low current, so that the anode potential is always kept above or near 0V. Therefore, the charging rate is maximized and the charging time is shortened.

[0207] In the above embodiments, the first charging current can be much larger than the second charging current. In specific embodiments, the first charging current and the second charging current can be represented by a rate C. Here, C represents a rate unit relative to the nominal capacity of the lithium-ion battery. For example, if the nominal capacity of the lithium-ion battery is 1000mAh, when the lithium-ion battery is charged at a charging rate of 0.5C, the charging current is 500mA.

[0208] In the above embodiments, the low-temperature charging strategy can be implemented simultaneously with the steps of controlling the heating device 30 to be connected to the positive and negative terminals of the battery, enabling the heating device 30 to operate, heating the battery, and providing a disturbance current to the battery. During this process, the battery charging current will change with the operation of the heating device 30, and will also change due to the current changes in the charging strategy. Furthermore, as the current in the charging strategy changes, when the heating device 30 uses a PTC for heating, the operating characteristics of the PTC will also change due to the current changes in the charging strategy. For example, when the battery is charged using alternating large and small currents, the pulse duty cycle of the disturbance current provided by the PTC will also change accordingly. In some embodiments, the battery can be charged first using the low-temperature charging strategy, and then the heating device 30 can be used to heat the battery. Alternatively, the heating device 30 can be used to heat the battery first, using the disturbance current provided by the heating device 30 to balance the charging rate and the risk of lithium plating. After a certain period of time, the battery can be charged again using the low-temperature charging strategy based on the battery capacity and battery temperature. That is, after controlling the heating device 30 to be connected to the positive and negative terminals of the battery to make the heating device 30 work, heat the battery, and provide a disturbance current to the battery, the low-temperature charging strategy of the battery can be determined based on the battery capacity and battery temperature. In this embodiment, the disturbance charging rate can be adjusted in real time according to the temperature rise. After the charging rate is increased, the heat generation of the PTC is further increased, thereby increasing the temperature rise, and the two work together to promote the charging. In this way, it is beneficial to improve the charging rate and shorten the charging time.

[0209] Optionally, the controller 40 can obtain the first charging current and the first preset duration in the following ways:

[0210] Get battery temperature and remaining battery power;

[0211] The value of the first charging current is determined based on the obtained battery temperature and remaining battery power.

[0212] Get battery temperature and remaining battery power;

[0213] The first preset duration is determined based on the obtained battery temperature and remaining battery power.

[0214] It is understandable that the battery's environment, ambient temperature, and pre-charging temperature all affect the charging process. The rate of temperature change during charging also varies, as does the remaining battery charge. Furthermore, the battery's remaining charge before charging depends on its usage. Correspondingly, the first charging current value will vary depending on the battery temperature and remaining charge. Therefore, in this embodiment, the first charging current value can be set based on the battery temperature and the rate of temperature change in its environment. Specifically, it can be set according to the season, geographical location, daytime temperature variations, and nighttime temperature variations. For example, the first charging current value can be set differently in winter and summer, during the day and at night, at higher and lower latitudes, and at higher and lower altitudes. The first charging current value can also be set differently based on the remaining battery charge. For instance, at the same temperature, a higher remaining charge requires a higher first charging current, while a higher remaining charge requires a lower first charging current. The first charging current value is adjusted and determined based on actual conditions. Setting the first preset charging time too long can easily lead to lithium plating due to prolonged high-current charging, while setting it too short can easily affect charging efficiency. Therefore, the specific first preset charging time can be set according to the battery temperature and remaining battery capacity in actual application. This ensures that each temperature range and remaining capacity range corresponds to a first charging current and a first preset charging time, which helps to balance charging demand and the risk of lithium plating, thereby improving charging efficiency and shortening charging time.

[0215] In one embodiment, the controller 40 is further configured to:

[0216] Reacquire battery temperature and remaining charge;

[0217] In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery capacity being lower than a preset remaining capacity, the low-temperature charging strategy of the battery is adjusted or the current low-temperature charging strategy is maintained based on the battery temperature and the remaining battery capacity; wherein the low-temperature charging strategy includes at least one of the following:

[0218] The battery is charged using the first charging current;

[0219] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0220] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0221] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0222] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after charging is stopped; wherein the first charging current is greater than the second charging current.

[0223] In this embodiment, during battery charging, the low-temperature battery charging strategy is not limited to one of the five strategies. It can switch between or maintain the current low-temperature charging strategy based on the dynamic changes in battery temperature and remaining battery capacity. At the beginning of charging, when the battery temperature is low, any one of the five low-temperature charging strategies can be selected. In the middle stage of charging, either the first or second low-temperature charging strategy can be selected. In the later stage of charging, the first low-temperature charging strategy can be selected, or the low-temperature charging strategy can be exited and a constant current charging strategy can be adopted. This dynamic adjustment of the charging strategy balances charging efficiency and the risk of lithium plating.

[0224] In one embodiment, the controller 40 is used to:

[0225] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity not being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein, the low-temperature charging strategy includes:

[0226] The battery is charged with a first charging current, and the anode potential of the battery is detected.

[0227] When the anode potential is less than or equal to the preset potential threshold, stop charging the battery until the anode potential is greater than the preset potential threshold.

[0228] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current.

[0229] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0230] In this embodiment, the controller 40 sends a charging request current to the external charging device according to the low-temperature charging strategy, so that the external charging device provides a corresponding charging current to the battery. The preset potential threshold can be set to a value corresponding to the lithium plating critical value, or the preset potential threshold can be set to a value slightly larger than the value corresponding to the lithium plating critical value. When charging the battery, the battery can be charged with a first charging current. During the charging process, the potential of the battery anode is detected in real time. Once the anode potential reaches the preset potential threshold, the charging of the battery is stopped and a timer starts. When the timer reaches a third preset duration, the battery is charged again. This process is repeated until the battery is fully charged, or the battery temperature reaches a preset temperature, or the remaining battery capacity reaches a preset remaining capacity. The third preset duration can be the time for depolarization or the polarization value to drop to a preset polarization value. In practical applications, the third preset duration can be set to 1-5 seconds. Of course, in other embodiments, different values ​​are set according to the battery type, usage status, ambient temperature, etc., and no limitation is made here.

[0231] In one embodiment, the controller 40 is further configured to:

[0232] Reacquire battery temperature and remaining charge;

[0233] The charging request current and the closed / open state of the switching device SW are determined based on the battery temperature and remaining battery power.

[0234] Send a charging request current to an external charging device according to the determined charging request current magnitude, so that the external charging device provides a corresponding charging current to the battery, and / or adjust the closed / open state of the switching device SW.

[0235] Understandably, during charging, the battery's charge level changes as the charging time increases. Furthermore, the heating effect of the heating device 30 and the battery's own charging process generate heat, causing the battery temperature to vary with the charging time. Correspondingly, the specific charging current can be adjusted accordingly, ensuring that each temperature range and remaining charge range corresponds to a specific charging current to balance charging demand and lithium plating risk. As the battery temperature rises and the remaining charge increases, the operating state of the heating device 30 can also be adjusted. For example, when either the battery temperature or the remaining charge, or both, reach a certain threshold, the power of the heating device 30 can be reduced, or the operating time and frequency of the heating device 30 can be adjusted. When either the battery temperature or the remaining charge, or both, reach another threshold, and the battery exhibits good charging performance, the heating device 30 can be shut down.

[0236] In practical applications, the battery temperature (e.g., cell surface temperature) and remaining battery capacity can be re-detected at regular intervals (e.g., 10-30 seconds). Combined with the charging window diagram, the charging current value corresponding to the battery temperature / SOC level can be used for charging. Referring to Table 1 below, for example, at -10℃ / 50% SOC, the charging rate is 0.22C. After 10 seconds of perturbation pulse current charging, the temperature rises to 0℃, and the charging rate increases to 0.49C. After another 10 seconds, the temperature further increases to 10℃, and the charging rate increases to 0.96C. Therefore, the charging rate gradually increases, and the charging time is significantly shortened, which is beneficial for improving charging efficiency. Furthermore, when using PTC to heat the battery, the perturbation charging rate is adjusted in real time according to the temperature rise. After the charging rate increases, the heat generation of the PTC further increases, thereby increasing the temperature rise. These two factors work together to further improve charging efficiency.

[0237] Table 1

[0238]

[0239] In one embodiment, the controller 40 is used to:

[0240] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge not being lower than a preset remaining charge, the charging request current of the battery is determined.

[0241] The charging request current is sent to the external charging device according to the determined charging request current magnitude.

[0242] It should be noted that as the remaining battery charge increases, the anode (negative electrode) potential is more likely to fall below 0V, gradually reducing the lithium intercalation space at the anode. This leads to increased lithium ion accumulation on the negative electrode surface, making lithium metal deposition more likely, thus increasing the risk of lithium plating. Therefore, for safety reasons, low-temperature charging strategies are not suitable for situations with high remaining charge, such as when the battery's SOC is less than 80%, requiring alternative charging strategies. In other words, even when the battery temperature is low, if the remaining charge is not lower than a preset threshold, the battery may not need to be charged, or a conventional charging strategy may be used. The specific decision to charge the battery, including the charging current and voltage, can be determined based on the remaining charge, battery temperature, and other factors. When using a conventional charging strategy, the charging process can include a constant current charging stage and a constant voltage charging stage. For example, the constant current value, cutoff current value, and cutoff voltage can all be set to certain values. The specific charging process can be: first, constant current charging is performed; once the voltage reaches the lithium-ion battery's cutoff voltage, charging is continued at a constant voltage until the cutoff current is reached. During this process, the heating device 30 can be controlled to heat the battery until the battery temperature reaches a preset threshold or the SOC reaches a high value. Then, the heating device 30 can be stopped or controlled to stop working. In this way, while improving charging efficiency, the energy consumption caused by the operation of the heating device 30 can be reduced.

[0243] In one embodiment, in response to the battery temperature not being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the actual charging request current of the battery is determined based on the remaining battery power, and the actual charging request current is sent to an external charging device.

[0244] In this embodiment, when the battery temperature is not lower than a preset temperature threshold, there is no need to heat the battery. Simultaneously, when the remaining battery power is detected to be less than the remaining power threshold, an actual charging request current is sent to the external charging device so that the external charging device provides a corresponding charging current to the battery. When it is determined that the battery needs charging, a conventional charging strategy can be used to charge the battery. The conventional charging strategy can refer to the above embodiment and will not be repeated here.

[0245] This application also provides a battery management system, as described above. Figure 4 The battery management system includes a first connection terminal BAT+, a second connection terminal BAT-, a heating device 30, a switching device SW, a sampling device, and a controller 40.

[0246] The first connection terminal BAT+ is used to connect to the positive terminal of the battery, and the second connection terminal BAT- is used to connect to the negative terminal of the battery; the switching device SW is connected in parallel with the battery.

[0247] A sampling device, connected to the battery, is used to acquire battery information, including battery temperature and battery voltage.

[0248] The controller 40 is connected to the control terminal of the heating device 30 and the switching device SW, and is used to determine the remaining battery power based on the battery voltage; in response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller controls the switching device SW to close / open at a preset frequency to adjust the charging current of the battery.

[0249] The heating device 30 includes at least one of a heating wire, a heating film, and a heating plate.

[0250] In this embodiment, the heating device 30 may include a heating element, a heating wire, a heating film, etc. Optionally, the heating element, heating film, etc., may be attached to the outer wall of the battery cell, and the heating wire may be wound around the outer peripheral wall of the battery cell. Whether the heating device 30 is activated can be determined based on the battery temperature and remaining charge. For example, certain temperature thresholds and remaining charge thresholds can be set, and the heating device 30 is activated when the battery temperature is below a certain temperature threshold and the remaining charge is below a certain remaining charge threshold. Furthermore, after the heating device 30 is activated, the power, operating current, operating voltage supplied to the heating device 30, the operating frequency controlling the operation of the heating device 30, and the total operating time can also be determined based on the real-time battery temperature and battery charge.

[0251] In practical applications, the controller 40 controls whether the heating device 30 operates by setting a switch SW in the working circuit of the heating device 30. The switching of the switch SW on / off controls the operation. When the heating device 30 needs to operate, the controller 40 can close the switch SW to connect the heating device 30 to the charging device, using the electrical energy output from the charging device to drive the heating device 30 and heat the battery. When the heating device 30 does not need to operate, the controller 40 controls the switch SW to open, disconnecting the heating device 30 from the battery management system and stopping battery heating. Simultaneously, when the controller 40 is controlling the heating device 30, it can output pulse signals to the switch SW to control the switch SW to turn on / off at a certain frequency, thus controlling the heating device 30 to operate / not operate at a certain frequency. When the heating device 30 is working, since it is connected in parallel with the battery, the current flowing through the battery is reduced due to the current diversion from the heating device 30. When the heating device 30 is not working, it is disconnected from the battery, and all the current output from the heating device flows through the battery, increasing the current flowing through the battery. This process repeats, and with the intervention of the heating device 30, the battery can be charged with varying currents, such as pulsed disturbance currents, even when the output current of the charging device and the charging current output by the battery manager remain constant. Furthermore, by adjusting the conduction level, frequency, and duration of the switching device SW, the charging current flowing through the battery can be adjusted, thereby reducing the risk of lithium plating during battery charging.

[0252] Optionally, the power, frequency, and total operating time of the heating device 30 controlled by the controller 40 can be set to be inversely proportional to the battery temperature and remaining battery power. That is, the higher the battery temperature and the more remaining battery power, the lower the power, frequency, and total operating time of the heating device 30. Conversely, the lower the battery temperature and the less remaining battery power, the higher the power, frequency, and operating time of the heating device 30. Optionally, the power, frequency, and total operating time of the heating device 30 can be steplessly adjusted based on the battery temperature and battery power. Alternatively, different temperature thresholds and remaining battery power thresholds can be set, each corresponding to a power level, frequency range, and total operating time. The operating parameters of the heating device 30 are adjusted once each time the battery temperature reaches a certain temperature threshold or the remaining battery power reaches a certain remaining battery power threshold.

[0253] Optionally, the controller charges the battery using a low-temperature charging strategy when the battery temperature is below a preset temperature threshold and the remaining battery capacity is below a preset remaining capacity; wherein the low-temperature charging strategy includes at least one of the following:

[0254] The battery is charged using the first charging current;

[0255] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0256] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0257] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0258] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after charging is stopped; wherein the first charging current is greater than the second charging current.

[0259] In this embodiment, when the battery temperature is below a preset temperature threshold and the remaining battery power is detected to be less than the remaining power threshold, a low-temperature charging strategy is determined to charge the battery. The low-temperature charging strategy can be referred to in the above embodiment, and will not be repeated here.

[0260] Optionally, when the battery temperature is below a preset temperature threshold and the remaining battery capacity is not lower than a preset remaining capacity, the controller sends a low-temperature charging strategy to the external charging device, so that the external charging device provides a corresponding charging current to the battery; wherein, the low-temperature charging strategy includes:

[0261] The battery is charged with a first charging current, and the anode potential of the battery is detected.

[0262] When the anode potential is less than or equal to the preset potential threshold, stop charging the battery until the anode potential is greater than the preset potential threshold.

[0263] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current.

[0264] Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0265] In this embodiment, when the battery temperature is below a preset temperature threshold and the remaining battery power is detected to be less than the remaining power threshold, a low-temperature charging strategy is determined to charge the battery. The low-temperature charging strategy can be referred to in the above embodiment, and will not be repeated here.

[0266] This application also provides a battery charging method, referring to... Figure 5 , Figure 5 This is a flowchart illustrating the first embodiment of the battery charging method of this application. It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone; or an electronic device capable of performing the above functions, or a battery management system (BMS) in a battery device. This application uses a BMS as an example to describe this embodiment and the following embodiments. To intelligently manage and maintain the battery, prevent overcharging and over-discharging, and extend the battery's lifespan, the BMS can implement functions such as charge / discharge management, high-voltage control, battery protection, battery data collection, and battery status evaluation. Optionally, the BMS can be integrated with the battery in the same device or apparatus; alternatively, the battery management system can be installed as an independent device or apparatus outside the battery.

[0267] When the battery is connected to an external charging device, the charging device can be connected to the battery via a wire and to the BMS via a communication line, enabling communication between the battery and the charging device. The communication line facilitates information exchange between the charging device and the BMS. For example, this communication line may include, but is not limited to, a Controller Area Network (CAN) communication bus or a daisy-chain communication bus. Besides communicating with the BMS via a communication line, the charging device can also communicate with the BMS via a wireless network. This application does not specifically limit the type of wired or wireless communication between the charging device and the BMS.

[0268] The battery device sends a charging request to the charging device, which can output charging power according to the charging requirements of the BMS to charge the battery. For example, the charging device can output voltage and current according to the required voltage and charging request current sent by the BMS. Optionally, the charging device in this embodiment can be a charging pile, also known as a charger. The charging pile here can be, for example, a regular charging pile, a supercharging pile, or a charging pile that supports vehicle-to-grid (V2G) mode.

[0269] Reference Figure 5 In this embodiment, the battery charging method includes steps S10 to S20:

[0270] Step S10: Obtain battery temperature and remaining battery power;

[0271] In this embodiment, the battery temperature can be obtained through sampling devices such as temperature sensors installed in the battery cell, including PTC thermistors. The battery temperature can be the real-time temperature of one battery in the battery pack, the average real-time temperature of multiple battery packs, the internal temperature of the battery pack, the casing temperature of the battery pack, or the real-time temperature of the external environment of the battery pack. Battery information can include battery voltage, battery current, and remaining charge (State of Charge, SOC), which can be obtained through sampling devices such as current sensors and voltage detection circuits installed in the battery cell.

[0272] Step S20: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge being lower than a preset remaining charge, the switching device in the battery management system is controlled to close, and the battery is heated by controlling the heating device to adjust the charging current of the battery.

[0273] In this embodiment, the preset temperature threshold can be set to a value that affects battery charging efficiency, or a value at which the battery cannot start charging normally. Battery charging performance is poor at low temperatures, leading to increased charging time. Furthermore, as the remaining battery charge increases, the anode (negative electrode) potential is more likely to fall below 0V, gradually reducing the lithium intercalation space at the anode and increasing lithium ion accumulation on the negative electrode surface, thus making lithium metal deposition more likely, i.e., increasing the risk of lithium plating. Therefore, the low-temperature charging condition in this embodiment can also be set to whether the remaining battery charge is lower than a preset remaining charge. When the remaining battery charge is lower than the preset remaining charge and the battery temperature is lower than the preset temperature threshold, a corresponding low-temperature charging strategy can be used to charge the battery. Optionally, the low-temperature charging strategy can specifically involve using a charging current, charging frequency, charging duration, and charging voltage adapted to the battery temperature and remaining charge.

[0274] In this embodiment, the heating device may include a PTC thermistor, a heating element, a heating wire, a heating film, etc. Optionally, the PTC thermistor, heating element, heating film, etc., may be attached to the outer wall of the battery cell, and the heating wire may be wound around the outer peripheral wall of the battery cell. Whether the heating device is activated can be determined based on the battery temperature and remaining charge. For example, certain temperature thresholds and remaining charge thresholds can be set, and the heating device is activated when the battery temperature is below a certain temperature threshold and the remaining charge is below a certain remaining charge threshold. Furthermore, after the heating device is activated, the power, operating current, operating voltage supplied to the heating device, the operating frequency controlling the heating device's operation, and the total operating time can also be determined based on the real-time battery temperature and battery charge.

[0275] In practical applications, the operation of the heating element can be controlled by setting a switch in its working circuit. The switching on / off state of the switch controls whether the heating element is working. When operation is needed, the switch is closed to connect the heating element to the charging device, allowing the electrical energy output from the charging device to drive the heating element and heat the battery. When operation is not needed, the switch is opened to disconnect the heating element from the battery management system, thus stopping battery heating. Simultaneously, when controlling the heating element's operation, a pulse signal is output to the switch to control its on / off state at a specific frequency, allowing the heating element to operate at a certain frequency. When the heating element is working, because it is connected in parallel with the battery, the current flowing through the battery is reduced due to the current diverted by the heating element. When the heating element is not working, it is disconnected from the battery, and all the current output from the heating device flows through the battery, increasing the current flowing through the battery. This process is repeated, and with the intervention of the heating device, the battery can be charged using varying currents, such as pulsed disturbance currents, while maintaining constant output currents from both the charging device and the battery manager. Furthermore, by adjusting the conduction level, frequency, and duration of the switching devices, the magnitude of the charging current flowing through the battery can be adjusted, thereby reducing the risk of lithium plating during battery charging.

[0276] Optionally, the power, frequency, and total operating time of the heating device can be set to be inversely proportional to the battery temperature and remaining battery power. That is, the higher the battery temperature and the more remaining battery power, the lower the power, frequency, and total operating time of the heating device. Conversely, the lower the battery temperature and the less remaining battery power, the higher the power, frequency, and operating time of the heating device. Optionally, the power, frequency, and total operating time of the heating device can be steplessly adjusted based on the battery temperature and battery power. Alternatively, different temperature thresholds and remaining battery power thresholds can be set, each corresponding to a power level, frequency range, and total operating time. The operating parameters of the heating device are adjusted once each time the battery temperature reaches a certain temperature threshold or the remaining battery power reaches a certain remaining battery power threshold.

[0277] In this embodiment, the heating device can be implemented using a PTC (Positive Temperature Coefficient) thermistor, which is electrically connected in parallel with the battery cell. The method also includes:

[0278] In response to the battery temperature falling below a preset temperature threshold and the remaining battery charge falling below a preset remaining charge, the system controls the switching device in the battery management system to close, and controls the thermistor to heat the battery, thereby adjusting the battery charging current. Specifically, when it is necessary to control the PTC thermistor, the switching device can be closed to connect the PTC thermistor to the charging device, and the electrical energy output from the charging device drives the PTC thermistor to work, thus heating the battery. When it is not necessary to control the PTC thermistor, the switching device is opened to disconnect the PTC thermistor from the battery management system, thereby stopping the heating of the battery.

[0279] It is understandable that when a PTC thermistor is connected in parallel with a battery during operation, part of the current output from the charging device to the battery is diverted by the PTC thermistor. According to the operating characteristics of the PTC thermistor, the current flowing through the PTC thermistor will change with the temperature of the PTC thermistor. This can indirectly disturb the magnitude of the charging current flowing through the battery, so that the battery charging current can change with the temperature of the PTC thermistor, thereby providing a disturbance current for battery charging.

[0280] Specifically, when the PTC thermistor starts heating, its resistance is low, resulting in a large current flowing through it. This leads to a strong heating effect on the battery, effectively raising its temperature. Due to the current shunting effect of the PTC thermistor, the battery's charging current is low, reducing the risk of lithium plating. As the temperature rises and reaches the PTC thermistor's home temperature, its resistance gradually increases, causing the current flowing through it to gradually decrease. This reduces the current shunting ratio to the battery, allowing the charging current to gradually increase and improving charging efficiency. After a certain period, the surface temperature of the PTC thermistor decreases, and its resistance gradually decreases, again increasing the current shunting ratio to the battery, which further helps reduce the risk of lithium plating. In this way, with the cooperation of the PTC thermistor, without adjusting the output current of the charging device or the charging current set by the battery management system, there is no need to repeatedly control the switching devices to open / close or control the conduction level of the switching devices. By changing the working characteristics of the PTC thermistor, the charging current flowing through the battery can be changed, and the battery can also be charged in a variable, such as pulse, manner.

[0281] In practical applications, a PTC thermistor is used to charge the battery with a perturbation current. The normal charging current is a constant current. The PTC thermistor is connected in parallel with the battery. By adjusting the resistance of the PTC thermistor during the heating process, the change in the battery charging current is controlled. The conventional battery charging current is a constant current, denoted as A. The current flowing through the PTC is an alternating current of varying magnitudes, denoted as ±B. After the PTC is activated, the resistance of the PTC changes with temperature. The combined current value is A±B. The frequency of the change of A±B can be adjusted according to the magnitude of the current flowing through the PTC. In some embodiments, the frequency of change can be set to 0.1S.

[0282] Reference Figure 6 In one embodiment, the method further includes:

[0283] Step S30: If the battery temperature is lower than a preset temperature threshold and the remaining battery capacity is lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following:

[0284] First charging strategy: Charge with the first charging current;

[0285] Under this charging strategy, the magnitude of the charging current output to the battery can be changed by controlling whether the heating device is connected in parallel with the battery. When the heating device is not working, i.e., when the parallel connection between the heating device and the battery is disconnected, the entire first charging current is output to the battery, thus charging the battery using the first charging current. This satisfies the battery's charging efficiency during the charging process, and the larger first charging current can also cause the battery temperature to rise rapidly, achieving the purpose of heating the battery. When the battery reaches the lithium plating critical state, or the polarization value reaches the preset polarization threshold, the heating device can be controlled to start working. With the heating device connected in parallel, the first charging current is diverted by the heating device, thereby achieving a smaller charging current to continue charging the battery. The smaller charging current results in lower charging efficiency, reduces battery polarization, and keeps the anode potential at a preset value, such as 0V, or above 0V, or below 0V but close to 0V. By controlling whether the heating device is working or not, a period of high-current charging is used, followed by a period of low-current charging when the battery polarization suddenly increases, reducing polarization and keeping the anode potential always above or near 0V. By switching the heating device between working and non-working, the first charging current alternates between shunt and non-shunt states, thus keeping the first charging current output to the battery constant while reducing the duration of the alternating charging. This process is repeated until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset level. This charging strategy reduces polarization, increases the charging rate, and shortens the charging time. The first charging current can be the maximum charging current when the battery generates polarization or reaches a preset polarization value. The first preset duration can be the duration during which the battery generates polarization or reaches a preset polarization value when charged with the first charging current. The reduced charging current can be the maximum charging current when the battery depolarizes or the polarization value drops to a preset polarization value. The second preset duration can be the duration during which the battery depolarizes or the polarization value drops to a preset polarization value when charged with the second charging current.

[0286] The second charging strategy is to alternately charge the battery with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0287] This charging strategy employs a larger initial charging current to charge the battery. This ensures efficient charging during the process and also rapidly raises the battery temperature, effectively heating it. Once the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, a smaller second charging current is used to continue charging. This second charging current, being smaller and less efficient, reduces battery polarization, maintaining the anode potential at a preset value, such as 0V, above 0V, or near 0V. After a period of high-current charging, when battery polarization suddenly increases, a period of low-current charging is applied to reduce polarization, keeping the anode potential consistently above or near 0V. The first and second charging currents are alternated for corresponding durations, repeating this process until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current required to generate polarization or reach the preset polarization value. The first preset duration can be the duration during which the battery generates polarization or the polarization value reaches a preset polarization value when charged with the first charging current. The second charging current can be the maximum charging current when the battery depolarizes or the polarization value drops to the preset polarization value. The second preset duration can be the duration during which the battery depolarizes or the polarization value drops to the preset polarization value when charged with the second charging current.

[0288] The third charging strategy is to charge the battery with the first charging current for a first preset time, then stop charging for a second preset time and alternately charge the battery.

[0289] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, charging is stopped for a period to eliminate polarization, maintaining the anode potential at a preset value, such as 0V, above 0V, or near 0V. The specific setting can be adjusted based on battery and ambient temperatures, and is not limited here. After a period of high-current charging, if battery polarization suddenly increases, charging is stopped for a period to eliminate polarization, ensuring the anode potential remains above or near 0V. Charging with the initial charging current, alternating between charging and stopping for corresponding durations, is repeated until the battery's remaining capacity reaches a preset remaining capacity and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The initial charging current can be the critical current value at which polarization occurs or the maximum charging current when the polarization value reaches the preset polarization value. The first preset duration can be the duration during which the battery reaches a critical polarization value or a preset polarization value when charged with the first charging current. The second preset duration can be the duration during which the polarization de-polarizes or the polarization value drops to a preset polarization value.

[0290] The fourth charging strategy is to charge the battery with the first charging current for a first preset time, and then discharge the battery with the first discharging current for a second preset time, alternating between charging and discharging the battery.

[0291] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, the battery is controlled to discharge to the loads in the battery management system. During discharge, the concentration of reactants on the anode surface decreases, while the high-concentration substances in the middle diffuse towards the vicinity of the electrode. This eliminates battery polarization, keeping the anode potential at a preset value, such as 0V, above 0V, or below 0V but close to 0V. The specific setting can be adjusted based on battery temperature and ambient temperature, and is not limited here. After a period of high-current charging, when the battery polarization suddenly increases, it is discharged for a period of time to eliminate polarization, keeping the anode potential consistently above 0V or below 0V but close to 0V. Charging with the first charging current and discharging with the first discharging current, alternating between charging and stopping for corresponding durations, is repeated until the remaining battery capacity reaches a preset remaining capacity and / or the battery temperature reaches a preset temperature. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current when the battery generates polarization or the polarization value reaches a preset polarization value. The first preset duration can be the duration for which the battery generates polarization or the polarization value reaches the preset polarization value when charged with the first charging current. The first discharging current can be set to be relatively small so that it eliminates polarization without affecting the internal energy consumption of the battery. The second preset duration can be the duration for the polarization to dissipate or for the polarization value to drop to the preset polarization value.

[0292] The fifth charging strategy involves alternating between charging the battery with a first charging current for a first preset time, charging with a second charging current for a second preset time, and stopping charging for a third preset time; wherein the first charging current is greater than the second charging current.

[0293] Under this charging strategy, using a larger initial charging current ensures charging efficiency and allows the battery temperature to rise rapidly, effectively heating the battery. When the battery reaches the critical lithium plating state or the polarization value reaches a preset polarization threshold, a smaller initial charging current is used. This balances charging efficiency and slows down polarization. During the charging process with the second current and the charging process itself, the reactant concentration on the anode surface decreases, while the high-concentration material diffuses towards the electrode, thus eliminating battery polarization and maintaining the anode potential at a preset value, such as 0V, above 0V, or below 0V but close to 0V. The specific setting can be adjusted based on battery temperature and ambient temperature, and is not limited here. Charging with a large current for a period, followed by charging with a small current for a period when battery polarization suddenly increases, balances charging efficiency. Charging is then stopped for a period to eliminate the polarization generated by the first and second charging currents, ensuring the anode potential remains at 0V, or below 0V but close to 0V. The battery is first charged with a first charging current and a second charging current, then charging is paused for a period of time. This alternating period of high charging current, low current, and paused charging continues until the battery's remaining capacity reaches a preset level and / or the battery temperature reaches a preset level. This charging strategy reduces polarization, increases the charging rate, and shortens charging time. The first charging current can be the maximum charging current at which polarization occurs or the polarization value reaches a preset value. The first preset duration can be the critical value at which polarization occurs when the battery is charged with the first charging current, or the duration at which the polarization value reaches the preset value. The second charging current can be set to a value that alleviates polarization without reducing charging efficiency. The second preset duration can be the duration at which polarization dissipates or the polarization value decreases to the preset value.

[0294] By adopting the above-mentioned alternating current charging strategy, setting a high current + low current (positive value) + charging off mode or a high current + charging off strategy, and a high current charging + low current discharging strategy, the battery polarization increases suddenly under a high current for a short period of time, and decreases under a low current, so that the anode potential is always kept above or near 0V. Therefore, the charging rate is maximized and the charging time is shortened.

[0295] In the above embodiments, the first charging current can be much larger than the second charging current. In specific embodiments, the first charging current and the second charging current can be represented by a rate C. Here, C represents a rate unit relative to the nominal capacity of the lithium-ion battery. For example, if the nominal capacity of the lithium-ion battery is 1000mAh, when the lithium-ion battery is charged at a charging rate of 0.5C, the charging current is 500mA.

[0296] In the above embodiments, the low-temperature charging strategy can be implemented simultaneously with the control of the heating device. During this process, the battery charging current changes with the operation of the heating device and also with the current changes in the charging strategy. Furthermore, as the current in the charging strategy changes, the operating characteristics of the PTC (Power Transmitter) will also change due to the current changes in the heating device. For example, when the battery is charged using alternating high and low currents, the pulse duty cycle of the disturbance current provided by the PTC will also change. In some embodiments, the battery can be charged first using the low-temperature charging strategy, and then the battery can be heated by the control of the heating device. Alternatively, the battery can be heated first by the control of the heating device, using the disturbance current provided by the heating device to balance the charging rate and the risk of lithium plating. After a certain period of time, the battery can be charged again using the low-temperature charging strategy based on the battery capacity and battery temperature. That is, after controlling the heating device to be connected to the positive and negative terminals of the battery to make the heating device work, heat the battery, and provide a disturbance current to the battery, the low-temperature charging strategy of the battery can be determined based on the battery capacity and battery temperature. In this embodiment, the disturbance charging rate can be adjusted in real time according to the temperature rise. After the charging rate is increased, the heat generation of the PTC is further increased, thereby increasing the temperature rise, and the two work together to promote the charging. In this way, it is beneficial to improve the charging rate and shorten the charging time.

[0297] Optionally, obtaining the first charging current and the first preset duration using the following steps further includes:

[0298] Get battery temperature and remaining battery power;

[0299] The value of the first charging current is determined based on the obtained battery temperature and remaining battery power.

[0300] The first preset duration is determined based on the obtained battery temperature and remaining battery power.

[0301] It is understandable that the battery's environment, ambient temperature, and pre-charging temperature all affect the charging process. The rate of temperature change during charging also varies, as does the remaining battery charge. Furthermore, the battery's remaining charge before charging depends on its usage. Correspondingly, the first charging current value will vary depending on the battery temperature and remaining charge. Therefore, in this embodiment, the first charging current value can be set based on the battery temperature and the rate of temperature change in its environment. Specifically, it can be set according to the season, geographical location, daytime temperature variations, and nighttime temperature variations. For example, the first charging current value can be set differently in winter and summer, during the day and at night, at higher and lower latitudes, and at higher and lower altitudes. The first charging current value can also be set differently based on the remaining battery charge. For instance, at the same temperature, a higher remaining charge requires a higher first charging current, while a higher remaining charge requires a lower first charging current. The first charging current value is adjusted and determined based on actual conditions. Setting the first preset charging time too long can easily lead to lithium plating due to prolonged high-current charging, while setting it too short can easily affect charging efficiency. Therefore, the specific first preset charging time can be set according to the battery temperature and remaining battery capacity in actual application. This ensures that each temperature range and remaining capacity range corresponds to a first charging current and a first preset charging time, which helps to balance charging demand and the risk of lithium plating, thereby improving charging efficiency and shortening charging time.

[0302] Reference Figure 7 In one embodiment, the method further includes:

[0303] Step S40: Reacquire battery temperature and remaining battery power;

[0304] Step S50: In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired battery remaining power being lower than a preset remaining power, the charging current of the battery is determined based on the battery temperature and the battery remaining power.

[0305] Step S60: Charge the battery according to the determined charging current, and return to the step of re-acquiring the battery temperature and remaining battery power.

[0306] In this embodiment, after starting to charge the battery using any of the low-temperature charging strategies, the current magnitude in the low-temperature charging strategy can be adjusted according to changes in the remaining battery capacity and battery temperature. Taking the first strategy as an example, during the charging process, the current charging status can be determined by acquiring the battery temperature and remaining battery capacity. In the initial stage of charging, the first charging current can be set relatively small. As the battery temperature rises and the remaining battery capacity increases, the first charging current can increase accordingly, allowing different charging current values ​​to be used to charge the battery at corresponding battery temperatures / SOC levels. For example, at -10℃ / 50% SOC, the charging rate is 0.22C. After 10 seconds of perturbation pulse current charging, the temperature rises to 0℃, and the SOC increases to 60%, so the charging rate can increase to 0.43C. After another 10 seconds, the temperature further increases to 10℃, and the SOC increases to 70%, so the charging rate can increase to 0.68C. As the charging rate gradually increases, the charging time is significantly shortened, which is beneficial for improving charging efficiency.

[0307] Reference Figure 8 In one embodiment, the method further includes:

[0308] Step S40: Reacquire battery temperature and remaining battery power;

[0309] Step S70: In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired battery remaining power being lower than a preset remaining power, adjust the low-temperature charging strategy of the battery or maintain the current low-temperature charging strategy based on the battery temperature and the battery remaining power.

[0310] Step S80: Charge the battery according to the determined low-temperature charging strategy, and return to the step of re-acquiring the battery temperature and remaining battery capacity; wherein, the low-temperature charging strategy includes at least one of the following:

[0311] The battery is charged using the first charging current;

[0312] The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current.

[0313] After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately.

[0314] After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time.

[0315] The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after charging is stopped; wherein the first charging current is greater than the second charging current.

[0316] In this embodiment, during battery charging, the low-temperature battery charging strategy is not limited to one of the five strategies. It can switch between or maintain the current low-temperature charging strategy based on the dynamic changes in battery temperature and remaining battery capacity. At the beginning of charging, when the battery temperature is low, any one of the third to fifth low-temperature charging strategies can be selected. In the middle stage of charging, either the first or second low-temperature charging strategy can be selected. In the later stage of charging, the first low-temperature charging strategy can be selected, or the low-temperature charging strategy can be exited and a constant current charging strategy can be adopted. In this way, the charging strategy is dynamically adjusted to balance charging efficiency and the risk of lithium plating.

[0317] Reference Figure 9 In one embodiment, the method further includes:

[0318] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy, which includes the following steps:

[0319] Step S90: Charge the battery with the first charging current and detect the anode potential of the battery;

[0320] Step S101: When the anode potential is less than or equal to a preset potential threshold, stop charging the battery for a third preset time, and then charge the battery with the first charging current.

[0321] In this embodiment, the preset potential threshold can be set to a value corresponding to the lithium plating critical value, or it can be set to a value slightly larger than the lithium plating critical value. When charging the battery, charging can begin with a first charging current. During the charging process, the potential of the battery anode is monitored in real time. Once the anode potential reaches the preset potential threshold, charging stops and a timer begins. When the timer reaches a third preset duration, charging resumes, and this process is repeated until the battery is fully charged, or the battery temperature reaches a preset temperature, or the remaining battery capacity reaches a preset remaining capacity. The third preset duration can be the time required for depolarization or for the polarization value to drop to a preset polarization value. In practical applications, the third preset duration can be set to 1-5 seconds. Of course, in other embodiments, different values ​​are set depending on the battery type, usage status, ambient temperature, etc., and no limitation is imposed here.

[0322] Alternatively, in step S102, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current.

[0323] In this embodiment, when the anode potential reaches a preset potential threshold, the charging current for the battery is reduced, i.e., the battery is charged with a second charging current, thereby eliminating polarization under low-current charging. During this process, the anode potential is monitored in real time, and the battery is charged with alternating first and second charging currents based on the changes in the anode potential. This process is repeated until the battery is fully charged, or the battery temperature reaches a preset temperature, or the remaining battery capacity reaches a preset remaining capacity.

[0324] Alternatively, in step S103, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

[0325] In this embodiment, when the anode potential reaches a preset potential threshold, battery charging is stopped, and a discharge circuit is formed between the internal load in the battery manager and the battery. The battery is then discharged with a first discharge current, thereby eliminating polarization under low-current discharge. During this process, the anode potential is monitored in real time, and the battery is charged with an alternating first charging current and discharged with a first discharging current based on the changes in the anode potential. This process is repeated until the battery is fully charged, or the battery temperature reaches a preset temperature, or the remaining battery capacity reaches a preset remaining capacity. In a specific embodiment, the final current value can be A±B+C, where C is a constant value determined by the actual anode potential. The value of C varies with battery temperature / SOC to ensure that the anode potential remains near 0V at different charging rates. The value of C can be preset based on experimental results. Adopting the above low-temperature charging strategy helps improve charging efficiency and shorten charging time, thereby balancing charging demand and lithium plating risk.

[0326] Reference Figure 10 In some embodiments, the method further includes:

[0327] Step S105: Reacquire battery temperature and remaining battery power;

[0328] Step S106: Determine the charging current of the battery and the closing / opening of the switching device based on the battery temperature and the remaining battery power.

[0329] Step S107: Charge the battery according to the determined current magnitude, and / or adjust the closing / opening of the switching device, and return to the step of re-acquiring the battery temperature and remaining battery power.

[0330] Understandably, during charging, the battery's charge level changes as charging time increases. Furthermore, the heating element and the battery itself generate heat during charging, causing the battery temperature to fluctuate with charging duration. Correspondingly, the specific charging current can be adjusted to correspond to each temperature range and remaining charge range, balancing charging demand and lithium plating risk. As the battery temperature rises and the remaining charge increases, the heating element's operation can also be adjusted. For example, when either the battery temperature or the remaining charge reaches a certain threshold, or both, the heating element's power can be reduced, or its operating time and frequency can be adjusted. Conversely, when either the battery temperature or the remaining charge reaches another threshold, indicating good charging performance, the heating element can be shut down.

[0331] In practical applications, the battery temperature (e.g., cell surface temperature) and remaining battery capacity can be re-detected at regular intervals (e.g., 10-30 seconds). Combined with the charging window diagram, the charging current value corresponding to the battery temperature / SOC level can be used for charging. Referring to Table 1 below, for example, at -10℃ / 50% SOC, the charging rate is 0.22C. After 10 seconds of perturbation pulse current charging, the temperature rises to 0℃, and the charging rate increases to 0.49C. After another 10 seconds, the temperature further increases to 10℃, and the charging rate increases to 0.96C. Therefore, the charging rate gradually increases, and the charging time is significantly shortened, which is beneficial for improving charging efficiency. Furthermore, when using PTC to heat the battery, the perturbation charging rate is adjusted in real time according to the temperature rise. After the charging rate increases, the heat generation of the PTC further increases, thereby increasing the temperature rise. These two factors work together to further improve charging efficiency.

[0332] Table 1

[0333]

[0334] In some embodiments, after step S10, the steps of obtaining the battery temperature and the remaining battery power, the method further includes:

[0335] In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge not being lower than a preset remaining charge, the charging request current of the battery is determined.

[0336] The charging request current is sent to the external charging device according to the determined charging request current magnitude.

[0337] It should be noted that as the remaining battery charge increases, the anode (negative electrode) potential is more likely to fall below 0V, gradually reducing the lithium intercalation space at the anode. This leads to increased lithium ion accumulation on the negative electrode surface, making lithium metal deposition more likely, thus increasing the risk of lithium plating. Therefore, for safety reasons, low-temperature charging strategies are not suitable when the remaining battery charge is high, such as when the battery's state of charge (SOC) is less than 80%. In such cases, other charging strategies are required. That is, when the battery temperature is low and the remaining battery charge is not lower than a preset remaining charge, the battery may not need to be charged, or a conventional charging strategy may be used. The specific decision to charge the battery, as well as the charging current and voltage, can be determined based on the remaining battery charge and battery temperature. When using a conventional charging strategy, the battery charging process can include a constant current charging stage and a constant voltage charging stage. For example, the constant current value, cutoff current value, and cutoff voltage can all be set to certain values. The specific charging process can be: first, constant current charging is performed, and when the voltage reaches the lithium-ion battery's cutoff voltage, constant voltage charging is then performed until the cutoff current is reached. During this process, the heating device can heat the battery until the battery temperature reaches a preset threshold or the SOC reaches a high value. Then, the heating device can be stopped or controlled to stop working, which can improve charging efficiency and reduce the energy consumption caused by the operation of the heating device.

[0338] In some embodiments, the method further includes:

[0339] In response to the battery temperature not being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the actual charging request current of the battery is determined based on the remaining battery power, and the actual charging request current is sent to the external charging device.

[0340] In this embodiment, when the battery temperature is not lower than a preset temperature threshold, there is no need to heat the battery. Simultaneously, when the remaining battery power is detected to be less than the remaining power threshold, indicating that the battery needs charging, a conventional charging strategy can be used to charge the battery. The conventional charging strategy can refer to the above embodiment and will not be repeated here.

[0341] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processor 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0342] The battery management system provided in this application, employing the battery charging method described in the above embodiments, can solve the technical problem of lithium plating easily when charging lithium batteries in low-temperature environments. Compared with the prior art, the beneficial effects of the battery management system provided in this application are the same as those of the battery charging method provided in the above embodiments, and other technical features in this battery management system are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0343] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0344] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0345] This application also provides a battery device, the battery device package including a battery, a heating element and a battery management system as described above.

[0346] This application also provides an electric device that includes the battery device described above.

[0347] In the embodiments of this application, the electric device can be an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc.

[0348] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the battery charging method in the above embodiments.

[0349] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0350] The aforementioned computer-readable storage medium may be included in the battery management system; or it may exist independently and not be assembled into the battery management system.

[0351] The aforementioned computer-readable storage medium carries one or more programs that, when executed by the battery management system, enable the battery management system to perform the aforementioned battery charging method.

[0352] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof. These programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, and C++—and conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0353] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0354] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0355] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described battery charging method, which can solve the technical problem of lithium plating easily when charging lithium batteries in low-temperature environments. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the battery charging method provided in the above embodiments, and will not be repeated here.

[0356] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the battery charging method described above.

[0357] The computer program product provided in this application can solve the technical problem of lithium plating easily when charging lithium batteries in low-temperature environments. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the battery charging method provided in the above embodiments, and will not be repeated here.

[0358] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery management system, characterized in that, The battery management system includes a first connection terminal, a second connection terminal, a heating device, a switching device, a sampling device, and a controller; The first connection terminal is used to connect to the positive terminal of the battery, and the second connection terminal is used to connect to the negative terminal of the battery; the heating device is connected in series between the first connection terminal and the second connection terminal; the switching device is connected in series with the heating device. The sampling device is connected to the battery and is used to acquire battery information, including battery temperature and battery voltage. The controller is connected to the control terminals of the heating device and the switching device, and is used to determine the remaining battery power based on the battery voltage; in response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller controls the switching device to close, and controls the heating device to heat the battery, thereby adjusting the charging current of the battery.

2. The battery management system as described in claim 1, characterized in that, The heating device is a positive temperature coefficient thermistor.

3. The battery management system as described in claim 1, characterized in that, The controller is used for: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following: The battery is charged using the first charging current; The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current. After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately. After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time. The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

4. The battery management system as described in claim 3, characterized in that, The controller is also used for: Get battery temperature and remaining battery power; The value of the first charging current is determined based on the obtained battery temperature and remaining battery power.

5. The battery management system as described in claim 3, characterized in that, The controller is also used for: Get battery temperature and remaining battery power; The first preset duration is determined based on the obtained battery temperature and remaining battery power.

6. The battery management system as described in claim 3, characterized in that, The controller is also used for: Reacquire battery temperature and remaining battery power; In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than a preset remaining charge, the charging current is determined based on the battery temperature and the remaining battery charge.

7. The battery management system according to any one of claims 3 to 6, characterized in that, The controller is also used for: Reacquire battery temperature and remaining charge; In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery capacity being lower than a preset remaining capacity, the low-temperature charging strategy of the battery is adjusted or the current low-temperature charging strategy is maintained based on the battery temperature and the remaining battery capacity; wherein the low-temperature charging strategy includes at least one of the following: The battery is charged using the first charging current; The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current. After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately. After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time. The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

8. The battery management system as described in claim 1, characterized in that, The controller is used for: In response to a battery temperature below a preset temperature threshold and a remaining battery capacity not below a preset remaining capacity, a low-temperature charging strategy is employed to charge the battery; wherein the low-temperature charging strategy includes: The battery is charged with a first charging current, and the anode potential of the battery is detected. When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold. Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current; Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

9. The battery management system according to any one of claims 1 to 8, characterized in that, The controller is also used for: Reacquire battery temperature and remaining charge; The charging request current and the closed / open state of the switching device are determined based on the battery temperature and the remaining battery power. The system sends a charging request current to the external charging device based on the determined magnitude of the charging request current, and / or adjusts the closed / open state of the switching device.

10. The battery management system according to any one of claims 1 to 9, characterized in that, The controller is used for: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge not being lower than a preset remaining charge, the charging request current of the battery is determined; The charging request current is sent to the external charging device according to the determined charging request current magnitude.

11. The battery management system according to any one of claims 1 to 9, characterized in that, The controller is used for: In response to the battery temperature not being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the actual charging request current of the battery is determined based on the remaining battery power, and the actual charging request current is sent to the external charging device.

12. A battery management system, characterized in that, The battery management system includes a first connection terminal, a second connection terminal, a heating device, a switching device, a sampling device, and a controller; The first connection terminal is used to connect to the positive terminal of the battery, and the second connection terminal is used to connect to the negative terminal of the battery; the switching device is connected in parallel with the battery; The sampling device is connected to the battery and is used to acquire battery information, including battery temperature and battery voltage. The controller is connected to the control terminals of the heating device and the switching device, and is used to determine the remaining battery power based on the battery voltage; in response to the battery temperature being lower than a preset temperature threshold and the remaining battery power being lower than a preset remaining power, the controller controls the switching device to close / open at a preset frequency to adjust the charging current of the battery.

13. The battery management system as described in claim 12, characterized in that, The heating device includes at least one of heating wire, heating film, and heating plate.

14. The battery management system as described in claim 12, characterized in that, The controller is used for: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following: The battery is charged using the first charging current; The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current. After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately. After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time. The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

15. The battery management system as described in claim 12, characterized in that, The controller charges the battery using a low-temperature charging strategy when the battery temperature is below a preset temperature threshold and the remaining battery power is not lower than a preset remaining power; wherein the low-temperature charging strategy includes: The battery is charged with a first charging current, and the anode potential of the battery is detected. When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold. Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current; Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

16. A battery charging method, characterized in that, Based on the battery management system as described in any one of claims 1 to 11, the battery charging method includes: Get battery temperature and remaining battery power; In response to the battery temperature being lower than a preset temperature threshold and the remaining battery charge being lower than a preset remaining charge, the switching device in the battery management system is controlled to close, and the battery is heated by controlling the heating device to adjust the charging current of the battery.

17. The battery charging method as described in claim 16, characterized in that, The heating device is a positive temperature coefficient thermistor, and the method further includes: When the battery temperature is lower than a preset temperature threshold and the remaining battery power is lower than a preset remaining power, the switching device in the battery management system is controlled to close, and the battery is heated by controlling the positive temperature coefficient thermistor to adjust the charging current of the battery.

18. The battery charging method as described in claim 16, characterized in that, The method further includes: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy; wherein the low-temperature charging strategy includes at least one of the following: The battery is charged using the first charging current; The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current. After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately. After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time. The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

19. The battery charging method as described in claim 18, characterized in that, The first charging current is determined using the following steps: Get battery temperature and remaining battery power; The value of the first charging current is determined based on the obtained battery temperature and remaining charge.

20. The battery charging method as described in claim 18, characterized in that, The first preset duration is determined using the following steps: Get battery temperature and remaining battery power; The first preset duration is determined based on the obtained battery temperature and remaining power.

21. The battery charging method as described in claim 18, characterized in that, The method further includes: Reacquire battery temperature and remaining battery power; In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than the preset temperature threshold, the charging current of the battery is determined based on the battery temperature and the remaining battery charge. The battery is charged according to the determined charging current, and then the process returns to the step of re-acquiring the battery temperature and remaining charge.

22. The battery charging method according to any one of claims 18 to 21, characterized in that, The method further includes: Reacquire battery temperature and remaining battery power; In response to the reacquired battery temperature being lower than a preset temperature threshold and the reacquired remaining battery charge being lower than the preset temperature threshold, the low-temperature charging strategy of the battery is adjusted or the current low-temperature charging strategy is maintained based on the battery temperature and the remaining battery charge. The battery is charged according to the determined low-temperature charging strategy, and the process returns to the step of re-acquiring the battery temperature and remaining charge; wherein the low-temperature charging strategy includes at least one of the following: The battery is charged using the first charging current; The battery is charged alternately with a first charging current for a first preset time and a second charging current for a second preset time; wherein the first charging current is greater than the second charging current. After charging with the first charging current for a first preset time, charging is stopped for a second preset time, and the battery is charged alternately. After charging the battery with the first charging current for a first preset time, the battery is alternately charged and discharged with the first discharging current for a second preset time. The battery is charged alternately with a first charging current for a first preset time, a second charging current for a second preset time, and a third preset time after which charging is stopped; wherein the first charging current is greater than the second charging current.

23. The battery charging method as described in claim 16, characterized in that, The method further includes: In response to the battery temperature being lower than a preset temperature threshold and the remaining battery capacity being lower than a preset remaining capacity, the battery is charged using a low-temperature charging strategy, which includes the following steps: The battery is charged with a first charging current, and the anode potential of the battery is detected. When the anode potential is less than or equal to a preset potential threshold, charging of the battery is stopped until the anode potential is greater than the preset potential threshold. Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is charged with a second preset charging current until the anode potential is greater than the preset potential threshold; wherein, the first charging current is greater than the second charging current; Alternatively, when the anode potential is less than or equal to a preset potential threshold, the battery is discharged with a first preset discharge current until the anode potential is greater than the preset potential threshold.

24. The battery charging method according to any one of claims 16 to 23, characterized in that, The method further includes: Reacquire battery temperature and remaining battery power; The charging request current and the closed / open state of the switching device are determined based on the reacquired battery temperature and the remaining battery power. Based on the determined magnitude of the charging request current, a charging request current is sent to the external charging device, and / or the closed / open state of the switching device is adjusted, and the process returns to the step of re-acquiring the battery temperature and remaining charge.

25. A battery device, characterized in that, The battery device includes a battery and a battery management system as described in claims 1 to 15.

26. An electric device, characterized in that, The electric device includes the battery device as described in claim 25.

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