Battery system, charging control device, and charging method of battery pack

Abstract

The invention discloses a battery system, a charging control device and a charging method of a battery pack, the battery system comprises the battery pack of at least one battery cell, a temperature sensor, a battery management system and a heating device, a positive active material of the battery cell comprises lithium-containing transition metal phosphate, and a negative active material of the battery cell comprises lithium-containing transition metal phosphate. The lithium-containing transition metal phosphate at least comprises a manganese element; the temperature sensor is used for obtaining the temperature of the battery monomer; the battery management system is used for acquiring a first state parameter of the single battery before and / or in the charging process of the single battery; wherein the first state parameter of the single battery is used for generating a control instruction for the heating device; the control instruction is used for controlling the heating device to heat the battery monomers.

Description

Battery system, charging control device, and battery pack charging method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present disclosure is based on Chinese patent applications with application number PCT / CN2023 / 081452, application date March 14, 2023, and application name “Charging method, device, battery pack, electronic device and computer-readable storage medium”, and application number PCT / CN2023 / 124545, application date October 13, 2023, and application name “Battery, charging device, charging method, battery management system and electrical equipment”, and claims the priority of the above two Chinese patent applications. The entire contents of the Chinese patent applications are hereby introduced into the present disclosure as a reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery system, a charging control device, and a charging method for a battery pack. Background Art

[0004] With the advancement of the times, electric vehicles (EVs) have enormous market potential due to their environmental friendliness, low noise levels, and low operating costs. They can effectively promote energy conservation and emission reduction, contributing to social development and progress. Battery technology is a crucial factor in the development of EVs. Therefore, improving battery charging performance has become a pressing issue.

[0005] Summary of the Invention

[0006] In view of this, embodiments of the present application provide at least a battery system, a charging control device, and a charging method for a battery pack.

[0007] The technical solution of the embodiment of the present application is implemented as follows:

[0008] In a first aspect, an embodiment of the present application provides a battery system, comprising: a battery pack comprising at least one battery cell, a temperature sensor, a battery management system, and a heating device, wherein: the battery cell comprises a positive electrode plate; the positive electrode plate comprises a positive electrode collector and a positive electrode active material layer arranged on at least one side of the positive electrode collector, the positive electrode active material layer comprises a positive electrode active material; the positive electrode active material comprises a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate comprises a manganese element; the temperature sensor is used to obtain the temperature of the battery cell; the battery management system is used to obtain a first state parameter of the battery cell before and / or during charging of the battery cell; wherein: the first state parameter of the battery cell is used to generate a control instruction for the heating device; the control instruction is used to control the heating device to heat the battery cell.

[0009] In an embodiment of the present application, a control instruction for the heating device is generated by obtaining the first state parameter and the second state parameter of the battery cell before and / or during charging of the battery cell; the heating device is then controlled by the control instruction so that the temperature of the first period during the charging process of the battery cell is within a temperature range. In this way, by controlling the heating device, the temperature of the charging platform corresponding to the manganese element is within the temperature range during the charging process of the battery cell, thereby reducing the polarization of the positive electrode active material itself, increasing the delithiation depth of the positive electrode active material of the battery, and thus increasing the capacity of the battery. At the same time, the temperature of the battery cell within the temperature range helps to increase the diffusion rate and delithiation rate of lithium ions, thereby shortening the charging time of the battery cell, making it easier to meet the needs of fast charging, and thus improving the user's charging experience.

[0010] In some embodiments, the battery management system is further used to: obtain the second state parameter of the battery cell before and / or during charging of the battery cell; determine the control instruction based on the first state parameter of the battery cell; and send the control instruction to the heating device so that the temperature of the first time period during the charging process of the battery cell is within a temperature range; wherein, the first time period is a time period in which the second state parameter of the battery cell meets the conditions.

[0011] In an embodiment of the present application, a battery management system within the battery system can determine a control instruction based on a first state parameter and control the heating device based on the control instruction. This information exchange between the battery management system and the heating device, both within the battery system, can improve the efficiency of controlling the temperature of the battery cells. Furthermore, by detecting the first state parameter of the battery and determining the control instruction for controlling the battery temperature, the battery temperature can be effectively regulated while minimizing the impact on the battery charging process and reducing unnecessary power consumption.

[0012] In some embodiments, the first time period is the time period when the battery cell enters the charging platform corresponding to the manganese element; the battery management system is used to obtain the first state parameter of the battery cell before the battery cell enters the first time period and during the first time period; the control instruction is used to control the heating device so that the temperature of the battery cell in the first time period is within the temperature range.

[0013] In the embodiment of the present application, the battery management system can obtain the first state parameter of the battery cell not only before the battery cell enters the first period, but also during the first period. In this way, different heating methods can be used when obtaining the first state parameter at different periods, thereby improving the flexibility of controlling the battery cell temperature.

[0014] In some embodiments, the battery cell charging process also includes a second time period; the second time period is the time period when the battery cell enters the charging platform corresponding to the iron element; the battery management system is used to obtain the first state parameter of the battery cell during the first time period and the second time period; the control instruction is used to control the heating device so that the temperature of the battery cell before entering the first time period and during the first time period is within the temperature range.

[0015] In an embodiment of the present application, the battery management system can also pre-acquire the first state parameter of the battery cell when the battery cell enters the charging platform corresponding to the iron element, so that a heating method with a lower heating rate can be adopted. In this way, the temperature of the battery cell is within the temperature range when it enters the charging platform corresponding to the manganese element, and the power consumption can be reduced, thereby saving energy consumption.

[0016] In some embodiments, the first state parameter of the battery cell includes the temperature of the battery cell, and the battery management system is further used to obtain the temperature of the battery cell based on the temperature sensor before or during charging of the battery cell; the start indication information is generated when the temperature of the battery cell is less than or equal to a first temperature threshold, wherein the first temperature threshold is less than or equal to the upper limit temperature of the temperature range; the shutdown indication information is generated when the temperature of the battery cell is greater than or equal to a second temperature threshold, wherein the second temperature threshold is greater than or equal to the first temperature threshold, and the first temperature threshold is greater than or equal to the lower limit temperature of the temperature range; the first retention information is generated when the temperature of the battery cell is within the temperature range and the heating device is in the on state; the second retention information is generated when the temperature of the battery cell is within the temperature range and the heating device is in the off state.

[0017] In the embodiment of the present application, when the battery cells are at different temperatures, control instructions corresponding to the temperature of the battery cells can be generated, so that the temperature of the first period during the charging process of the battery cells can be accurately kept within the temperature range.

[0018] In some embodiments, the first state parameter of the battery cell includes one of the following: the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell; the battery management system is also used to obtain the first state parameter of the battery cell during the charging process of the battery cell; wherein, the turn-on indication information is generated when the first state parameter of the battery cell is less than or equal to a first threshold value; the turn-off indication information is generated when the first state parameter of the battery cell is greater than or equal to a second threshold value.

[0019] When the turn-on indication information and the turn-off indication information are directed to the same heating device, the first threshold is less than the second threshold; when the turn-on indication information and the turn-off indication information are not directed to the same heating device, the first threshold may be less than or equal to the second threshold, or the first threshold may be greater than the second threshold.

[0020] The value of the first threshold is related to at least one of the following factors: a heating rate of the heating device, a temperature of the battery cell, and a state parameter value of the battery cell when the battery cell is in the first time period.

[0021] In the embodiment of the present application, because the first state parameter of the battery cell includes the state parameter of the battery cell when it is in the first time period; therefore, when the first state parameter of the battery cell is less than or equal to the first threshold value, it can be determined that the battery cell has not entered the first time period. At this time, the heating device can be turned on in advance, so that when the battery cell enters the first time period, the temperature of the battery cell can be within the temperature range.

[0022] In some embodiments, the first state parameter of the battery cell includes the state of charge of the battery cell, and the battery management system is further used to obtain the state of charge of the battery cell during charging of the battery cell; the turn-on indication information is generated when the SOC of the battery cell is less than or equal to a first SOC threshold; the turn-off indication information is generated when the SOC of the battery cell is greater than or equal to a second SOC threshold; wherein the second SOC threshold is greater than the first SOC threshold; the first SOC threshold is determined based on the molar proportion of iron element in the iron and manganese elements of the positive electrode active material, and / or the molar proportion of manganese element.

[0023] In the embodiment of the present application, because the first SOC threshold is determined based on the molar ratio of the iron element and / or the molar ratio of the manganese element in the iron-manganese elements of the positive electrode active material, the first SOC threshold can accurately determine whether the battery cell has entered the charging platform corresponding to the manganese element during the charging process. Therefore, when the battery cell has not entered the charging platform corresponding to the manganese element, the heating device is pre-activated, so that when the battery cell enters the charging platform corresponding to the manganese element, the temperature of the battery cell can be within the temperature range.

[0024] In some embodiments, the first SOC threshold is related to the SOC of the battery in a fully charged state and the molar ratio of the iron element or the manganese element.

[0025] In an embodiment of the present application, the above-mentioned first SOC threshold can be determined based on the molar ratio of iron or manganese in the iron-manganese elements of the positive electrode active material, so that the temperature of the battery can be controlled when the battery reaches the charging platform corresponding to the Mn element, thereby effectively improving the charging performance of the battery and reducing unnecessary power consumption.

[0026] In some embodiments, the first state parameter of the battery cell also includes the temperature of the battery cell; the turn-on indication information is generated when the temperature of the battery cell is less than or equal to a first temperature threshold, and the SOC of the battery cell is less than or equal to a first SOC threshold; the first temperature threshold is less than or equal to the upper limit temperature of the temperature range; the turn-off indication information is generated when the temperature of the battery cell is greater than or equal to a second temperature threshold, and / or the SOC of the battery cell is greater than or equal to a second SOC threshold; wherein the second temperature threshold is greater than or equal to the first temperature threshold, and the first temperature threshold is greater than or equal to the lower limit temperature of the temperature range.

[0027] In the embodiment of the present application, the heating device can be turned on when the battery cell has not entered the first period and the battery cell temperature is low, and the heating device can be turned off when the battery cell enters the first period and / or when the battery cell temperature is high. In this way, the timing of controlling the heating device can be accurately determined based on the battery cell temperature and the battery cell SOC.

[0028] In some embodiments, the temperature range includes: 30°C to 60°C.

[0029] In the embodiment of the present application, if the temperature of the battery cell is low, the charging capacity of the battery cell cannot be effectively improved, and if the temperature of the battery cell is high, it may cause other damage to the battery cell. Therefore, in this implementation, the temperature of the battery cell is controlled between 30°C and 60°C, which can increase the charging capacity of the battery without causing additional damage to the battery.

[0030] In some embodiments, the battery management system is used to obtain a first state parameter of the battery cell before the charging process; based on the first state parameter of the battery cell, determine a control instruction for the heating device, and send the control instruction to the heating device; the battery management system is also used to control the battery cell to enter the charging process when the temperature of the battery cell is within the temperature range.

[0031] In an embodiment of the present application, the battery management system may send a control instruction to the heating device before the battery charging process to control the temperature of the battery cell through the heating device, thereby minimizing the impact of the heating process on the charging process.

[0032] In some embodiments, the heating device is electrically connected to the battery cell, the control instruction includes start-up indication information, and the heating device is used to respond to the start-up indication information and provide a pulse current to the battery cell to cause the battery cell to generate heat when the pulse current passes through the battery cell.

[0033] In the embodiments of the present application, pulse heating can be used to heat the battery. A heating device is electrically connected to the battery cells. In response to a power-on instruction from the battery management system, the heating device provides a pulse current to the battery. As the pulse current passes through the battery, the battery generates heat due to its own internal resistance, achieving self-heating. This heating method eliminates the need for additional hardware heating structures, reducing the structural complexity of the battery.

[0034] In some embodiments, the heating device includes a charging device for charging the battery; the charging device is configured to charge the battery based on the pulse current in response to the start-up indication information.

[0035] In the embodiment of the present application, the battery is charged based on a pulse current by a charging device other than the battery cell, thereby achieving pulse heating of the battery cell. In this way, the power of the battery cell does not need to be consumed during the heating process.

[0036] In some embodiments, the heating device includes a motor in the electrical device where the battery pack is located, and the motor includes a winding and a control circuit connected between the winding and the battery; the battery management system is also used to send the control instruction to the controller in the electrical device; the controller in the electrical device is used to respond to the start indication information in the control instruction and control the control circuit so that the motor charges the battery cell based on the pulse current.

[0037] In the embodiment of the present application, the heat generated by the working loss of the motor in the electrical equipment can be used to heat the battery cells without consuming additional electrical energy.

[0038] In some embodiments, the heating device includes a heating circuit, which includes an energy storage element and a switching module; the switching module is used to respond to the start indication information in the control instruction to form a circuit for the energy storage element to charge the battery cell, and a circuit for the battery to discharge the energy storage element, so that the energy storage element charges the battery cell based on the pulse current.

[0039] In an embodiment of the present application, an additional heating circuit is used to heat the battery cells. When the electrical equipment, such as a vehicle, has not yet been connected to the charging device, or the motor of the electrical equipment is working, the vehicle can be heated in advance, which greatly saves the user's time.

[0040] In some embodiments, the heating device is disposed outside the shell of the battery pack; the heating device is used to generate heat in response to the start indication information in the control instruction to transfer heat to the battery cell through the battery shell to achieve heating of the battery cell.

[0041] In the embodiments of the present application, external heating can also be used to heat the battery cells. A heating device is provided on the outside of the battery pack housing. The heating device generates heat in response to the start-up instruction information of the battery management system. The heat is then transferred between the heating device and the battery cells to heat the battery cells. This heating method can be performed during the battery charging process, that is, the battery cells can be heated simultaneously during the charging process without affecting the charging process of the battery cells.

[0042] In some embodiments, the battery management system is further used to determine a target heating method for heating the battery cell from at least two heating methods based on the temperature of the battery cell; or, based on the temperature rise rate of the battery cell and the temperature of the battery cell under different heating methods, determine a target heating method for heating the battery cell from at least two heating methods; the battery management system is further used to send the control instruction to the corresponding heating device based on the target heating method; wherein the at least two heating methods include: a first heating method for heating the battery cell based on a pulse current, and a second heating method for heating the battery cell by heat transfer.

[0043] In the embodiment of the present application, since different heating methods correspond to different temperature ranges with optimal heating efficiency, a suitable heating method can be selected according to the temperature of the battery cell to improve the heating efficiency.

[0044] In some embodiments, the battery management system is used to: determine the temperature difference between the temperature of the battery cell and the lower limit of the temperature range; when the temperature difference is greater than a third temperature threshold, determine that the target heating method is the first heating method; when the temperature difference is less than or equal to the third temperature threshold, determine that the target heating method is the second heating method.

[0045] In the embodiment of the present application, when the temperature of the battery cell is low, a first heating method with a higher heating rate can be used to heat the battery cell; when the temperature of the battery cell is high, a second heating method with a lower heating rate can be used to heat the battery cell. In this way, selecting the appropriate heating method based on the temperature of the battery cell can improve heating efficiency.

[0046] In some embodiments, the battery management system is used to: determine the temperature difference between the temperature of the battery cell and the lower limit of the temperature range, and the duration of time the battery cell enters the first time period; based on the size relationship between the temperature difference and the third temperature threshold, and the size relationship between the duration of time the battery cell enters the first time period and the second time threshold, determine a target heating method for heating the battery cell from at least two heating methods; wherein, when the temperature difference is greater than the third temperature threshold, and the duration of time the battery cell enters the first time period is greater than the second time threshold, the target heating method is the heating method with a higher temperature rise rate corresponding to the first heating method and the second heating method; when the temperature difference is less than or equal to the third temperature threshold, and or and the required time is less than or equal to the second time threshold, the target heating method is the heating method with a lower temperature rise rate corresponding to the first heating method and the second heating method.

[0047] In the embodiment of the present application, if the battery cell temperature is relatively low and the battery cell has been in the first period for a long time, a heating method with a higher heating rate is required; if the battery cell temperature is relatively high and the battery cell has been in the first period for a short time, a heating method with a lower heating rate can be used. In this way, by selecting the appropriate heating method based on the battery cell temperature and the length of time the battery cell has been in the first period, heating efficiency can be improved.

[0048] In some embodiments, the battery management system is also used to: send charging parameters to a charging device, the charging parameters including information of constant current and constant voltage, so that the charging device charges the battery based on the constant current, and when the battery cell is charged to a voltage greater than or equal to the voltage threshold based on the constant current, the battery is charged based on the constant voltage until the battery reaches a fully charged state; wherein the constant voltage is: the voltage of the battery cell when entering the first time period.

[0049] In the embodiment of the present application, the battery can be charged by a constant current followed by a constant voltage charging method, which improves the charging rate while further increasing the charging capacity of the battery.

[0050] In a second aspect, an embodiment of the present application provides a charging control device, which is used to control a heating device to heat a battery cell; the battery system includes a battery pack, a temperature sensor, a battery management system and the heating device; the battery pack includes at least one battery cell, wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode collector and a positive electrode active material layer arranged on at least one side of the positive electrode collector, and the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes manganese; the charging control device includes: a controller, which is used to obtain a first state parameter of the battery cell from the battery management system before and / or during charging of the battery cell; based on the first state parameter of the battery cell, a control instruction for the heating device is generated, and the control instruction is used to control the heating device to heat the battery cell.

[0051] In a third aspect, an embodiment of the present application provides a charging method for a battery pack, which is applied to a battery management system; the battery system comprises: a battery pack, a temperature sensor, a heating device and the battery management system; the battery pack comprises at least one battery cell, wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell comprises a positive electrode collector and a positive electrode active material layer arranged on at least one side of the positive electrode collector, and the positive electrode active material layer comprises a positive electrode active material; the positive electrode active material comprises a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate comprises at least manganese element; the method comprises: before and / or during charging the battery cell, obtaining a first state parameter of the battery cell; based on the first state parameter, generating a control instruction for the heating device; sending the control instruction to the heating device; the control instruction is used to control the heating device to heat the battery cell.

[0052] In a fourth aspect, an embodiment of the present application provides a charging method for a battery pack, wherein the battery pack includes at least one battery cell; the battery pack is located in a battery system; the battery system also includes a temperature sensor and a battery management system; wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode collector and a positive electrode active material layer arranged on at least one side of the positive electrode collector, and the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese element; the charging method for the battery pack is applied to a charging control device; the method includes: before and / or during charging the battery cell, obtaining a first state parameter of the battery cell from the battery management system; based on the first state parameter of the battery cell, generating a control instruction for a heating device, and the control instruction is used to control the heating device to heat the battery cell.

[0053] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the technical solutions of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0055] FIG1 is a schematic diagram of the composition of a battery system provided in an embodiment of the present application;

[0056] FIG2 is a schematic diagram of a charging curve of a battery cell provided in an embodiment of the present application;

[0057] FIG3 is a schematic diagram of a curve showing the relationship between the charging capacity and temperature of a battery according to an embodiment of the present application;

[0058] FIG4 is a schematic diagram of a curve showing the relationship between the discharge capacity and temperature of a battery according to an embodiment of the present application;

[0059] FIG5 is a first schematic diagram of a heating device provided in an embodiment of the present application;

[0060] FIG6 is a second schematic diagram of a heating device provided in an embodiment of the present application;

[0061] FIG7 is a first schematic diagram of a charging control device provided in an embodiment of the present application;

[0062] FIG8 is a second schematic diagram of a charging control device provided in an embodiment of the present application;

[0063] FIG9 is a first schematic diagram of a flow chart of a method for charging a battery pack according to an embodiment of the present application;

[0064] FIG10 is a second schematic diagram of a flow chart of a method for charging a battery pack according to an embodiment of the present application;

[0065] FIG11 is a third schematic diagram of a flow chart of a method for charging a battery pack according to an embodiment of the present application;

[0066] FIG12 is a fourth schematic diagram of a flow chart of a method for charging a battery pack according to an embodiment of the present application;

[0067] FIG13 is a fifth flowchart of a method for charging a battery pack according to an embodiment of the present application;

[0068] FIG14 is a sixth schematic diagram of the implementation flow of a battery pack charging method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions of this application are further elaborated in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0070] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0071] The terms "first / second / third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first / second / third" can be interchanged with a specific order or sequence where permitted so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing this application only and are not intended to limit this application.

[0073] Currently, new energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in a variety of fields such as aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0074] In the disclosed embodiments, the battery may be a battery cell. A battery cell refers to a basic unit that can realize the mutual conversion between chemical energy and electrical energy, and can be used to make a battery module or battery pack, thereby being used to supply power to electrical devices. The battery cell may be a secondary battery, which refers to a battery cell that can be recharged to activate the active material after the battery cell is discharged and continue to be used. Among them, the lithium manganese iron phosphate battery in the battery cell has a higher voltage platform than the lithium iron phosphate battery, and the energy density can be about 15% higher than that of the lithium iron phosphate battery. It has the safety and low cost of the lithium iron phosphate battery, which makes the lithium manganese iron phosphate battery widely used in the current market.

[0075] However, while lithium iron phosphate batteries offer the advantage of high energy density, the slow delithiation rate of the positive electrode active material in the positive electrode plates of lithium iron phosphate batteries leads to low charging rates, which inconveniences users. Furthermore, the low delithiation depth of the lithium iron phosphate (LiMnP) in the positive electrode active material of lithium iron phosphate batteries prevents the full utilization of the battery's capacity.

[0076] In order to solve the technical problems of low charging rate of lithium iron manganese phosphate batteries and inability to fully utilize the capacity of lithium iron manganese phosphate batteries, an embodiment of the present application provides a battery system 10. As shown in FIG1 , the battery system 10 includes a battery pack 101, a temperature sensor 102, a battery management system 103, and a heating device 104. The battery pack 101 includes at least one battery cell 1011.

[0077] The battery cell 1011 includes a positive electrode sheet, a negative electrode sheet, a separator disposed between the positive electrode sheet and the negative electrode sheet, and an electrolyte including a lithium salt; the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese;

[0078] The temperature sensor 102 is used to obtain the temperature of the battery cell;

[0079] The battery management system 103 is configured to obtain a first state parameter of the battery cell 1011 before and / or during charging of the battery cell 1011; wherein:

[0080] The first state parameter of the battery cell 1011 is used to generate a control instruction for the heating device;

[0081] The control instruction is used to control the heating device to heat the battery cell;

[0082] In some embodiments, the battery management system 103 is used to obtain the second state parameter of the battery cell 1011 before charging and / or during the charging process of the battery cell 1011; the control instruction is used to control the heating device so that the temperature of the first time period during the charging process of the battery cell 1011 is within a temperature range; here, the temperature range can be preset; the first time period is the time period in which the second state parameter of the battery cell meets the conditions.

[0083] During the implementation, at a certain moment t1, the first state parameter and the second state parameter may be the same instantaneous value of the battery cell. For example, the instantaneous value may be a voltage value of 1 (3.6V), a state of charge (SOC) value of the battery cell (35%), etc. Since the second state parameter cannot be a temperature value, when the first state parameter only includes temperature, at a certain moment, the second state parameter and the first state parameter are not the same instantaneous value.

[0084] In the embodiments of the present application, the electrolyte may be liquid, gel, or solid. In some embodiments, the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0085] In the embodiment of the present application, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0086] In some embodiments, the positive electrode active material layer may further optionally include a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0087] In some embodiments, the positive electrode active material layer may further include a conductive agent. For example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0088] In some embodiments, the positive electrode sheet can be prepared by the following method: the components for preparing the positive electrode active material layer, such as lithium-containing transition metal phosphate, conductive agent, binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0089] Here, a temperature sensor is a sensor that can sense temperature and convert it into a usable output signal. In some embodiments, the temperature sensor can directly collect the temperature of the battery cells. For example, the temperature sensor can be a thermistor sensor or a thermocouple sensor. In this way, the temperature sensor in the battery pack can detect the temperature of the battery cells in real time. In other embodiments, the temperature sensor can also collect the temperature of other components in direct contact with the battery pack, and use the temperature of other components in direct contact with the battery pack as the temperature of the battery cells.

[0090] In some embodiments, when the battery pack is used in an electric vehicle, the number of battery cells in the battery pack is greater than or equal to 20, and the temperature sensor can collect the temperature of each battery cell. For example, the number of battery cells can be 96 or 100.

[0091] In an embodiment of the present application, a battery management system (BMS) is configured to obtain a first state parameter and a second state parameter of a battery cell in real time before and / or during charging of the battery cell by a charging device.

[0092] Among them, before the charging device charges the battery cell refers to the preset time range before the charging device charges the battery cell; the process of the charging device charging the battery cell refers to the process between the electric energy of the charging device entering the battery cell and the battery cell being fully charged.

[0093] Here, the first state parameter and the second state parameter are used to characterize the real-time state of the battery cell. Exemplarily, the first state parameter includes at least one of the following: battery cell temperature, battery cell state of charge, battery cell charging time, battery cell voltage, and battery cell current; and the second state parameter includes at least one of the following: battery cell state of charge, battery cell charging time, battery cell voltage, and battery cell current.

[0094] In an embodiment of the present application, the first state parameter is used to generate a control instruction for the heating device. The control instruction is used to control the heating device so that the temperature of the battery cell is within a preset temperature range during a first period of time during the charging process of the battery cell. The first period is the period during which the second state parameter of the battery cell meets a condition.

[0095] Here, the heating device can be located inside the battery pack, outside the battery pack, or outside the battery system. The heating device can be controlled to heat the battery cell, maintain the current state of the heating device, or turn off the heating device. The second state parameter of the battery cell meeting the conditions can indicate that the battery cell has entered the charging platform corresponding to the manganese element. Exemplarily, the above-mentioned control instructions include one or more of the following: a first hold information for indicating that the heating device is kept on; a second hold information for indicating that the heating device is kept off; a turn-on indication information for indicating that the heating device is turned on; and a turn-off indication information for indicating that the heating device is turned off. Among them, the charging platform refers to, for example, the stage in the charging process where the electrochemical reaction reaches a state of equilibrium, and the battery potential in the charging platform fluctuates less with the state of charge, or in other words, the battery potential in the charging platform remains relatively stable.

[0096] In some embodiments, the control instruction includes operating parameters of the heating device, so that the heating device heats the battery cell based on the operating parameters in the control instruction.

[0097] It is understandable that although battery cells that use lithium-containing transition metal phosphates containing at least manganese as positive electrode active materials have advantages such as high energy density and large capacity, the capacity of the battery cells is difficult to fully utilize due to the low delithiation depth of the lithium-containing transition metal phosphates. In addition, the delithiation rate of the lithium-containing transition metal phosphates is slow, resulting in a low charging rate for the battery cells, thereby affecting the charging performance of the battery cells. Among them, the slow delithiation rate of the lithium-containing transition metal phosphates is mainly due to the difficulty of lithium ions to escape from the battery cells after reaching the charging platform corresponding to the manganese element. Charging the battery when the battery cells are within a preset temperature range can eliminate the polarization effect of the material itself, increase the delithiation depth of the lithium iron manganese phosphate in the lithium iron manganese phosphate battery, and thus increase the capacity of the lithium iron manganese phosphate battery. At the same time, high temperature helps to accelerate the diffusion rate and delithiation rate of lithium ions, thereby reducing the charging time of the lithium iron manganese phosphate battery and meeting the demand for fast charging.

[0098] Therefore, by controlling the heating device through control instructions, the temperature of the first period during the battery cell charging process can be kept within a preset temperature range, that is, the temperature of the charging platform corresponding to the manganese element during the battery cell charging process can be kept within a preset temperature range. This can increase the delithiation depth of the lithium iron manganese phosphate in the lithium iron manganese phosphate battery, as well as the diffusion rate and delithiation rate of lithium ions, thereby increasing the capacity of the lithium iron manganese phosphate battery and reducing the charging time of the lithium iron manganese phosphate battery.

[0099] In some embodiments, the entity that generates the control instructions for controlling the heating device may include one of the following: a battery management system and a controller of a charging control device; and the entity that controls the heating device to heat the battery cells based on the control instructions may include one of the following: a battery management system and a controller of a charging control device. The charging control device may be a control device on an electrical device (e.g., a vehicle) or a control device on a charging device (e.g., a charging station).

[0100] In an embodiment of the present application, a control instruction for the heating device is generated by obtaining the first state parameter and the second state parameter of the battery cell before and / or during charging of the battery cell; the heating device is then controlled by the control instruction so that the temperature of the first period during the charging process of the battery cell is within a preset temperature range. In this way, by controlling the heating device, the temperature of the charging platform corresponding to the manganese element during the charging process of the battery cell is within a preset temperature range, thereby reducing the polarization of the positive electrode active material itself, increasing the delithiation depth of the positive electrode active material of the battery, and thus increasing the capacity of the battery. At the same time, the temperature of the battery cell within the preset temperature range helps to increase the diffusion rate and delithiation rate of lithium ions, thereby shortening the charging time of the battery cell, making it easier to meet the needs of fast charging, and thus improving the user's charging experience.

[0101] In some embodiments, the battery management system is further used to determine a control instruction based on a first state parameter of the battery cell; and send the control instruction to the heating device so that the temperature of the first period during the charging process of the battery cell is within a preset temperature range.

[0102] In the embodiment of the present application, the execution entities for generating control instructions and controlling the heating device are both the battery management system.

[0103] In some embodiments, the battery management system is used to determine a control instruction based on a first state parameter of the battery cell; and send the control instruction to a controller of a charging control device; the controller of the charging control device is used to send a control instruction to a heating device so that the temperature of the first time period during the charging process of the battery cell is within a preset temperature range.

[0104] In the embodiment of the present application, the execution entity for generating the control instructions is the battery management system, and the execution entity for controlling the heating device is the controller of the charging control device. The charging control device can be the control device of the power-consuming device (such as a vehicle) or the control device of the charging device (such as a charging station).

[0105] In some embodiments, the battery management system is used to send the first state parameter of the battery cell to the controller of the charging control device; the controller of the charging control device is used to determine the control instruction based on the first state parameter of the battery cell and send the control instruction to the battery management system; the battery management system is used to control the heating device in response to the control instruction so that the temperature of the first time period during the charging process of the battery cell is within a preset temperature range.

[0106] In the embodiment of the present application, the controller of the charging control device is the executor for generating the control instructions, and the battery management system is the executor for controlling the heating device. The charging control device can be the control device of the power-consuming device (such as a vehicle) or the control device of the charging device (such as a charging station).

[0107] In some embodiments, the battery management system is used to send the first state parameter of the battery cell to the controller of the charging control device; the controller of the charging control device is used to determine the control instruction based on the first state parameter of the battery cell and send the control instruction to the heating device so that the temperature of the first time period during the charging process of the battery cell is within a preset temperature range.

[0108] In the embodiment of the present application, the execution entity for generating the control instructions is the battery management system, and the execution entity for controlling the heating device is the controller of the charging control device. The charging control device can be the control device of the power-consuming device (such as a vehicle) or the control device of the charging device (such as a charging station).

[0109] In some embodiments, the battery management system is configured to identify, based on the second state parameter of the battery cell, that the battery cell has entered a charging platform corresponding to the manganese element.

[0110] Correspondingly, the first period is when the battery cell enters the charging platform corresponding to the manganese element. The charging process of the battery cell also includes a second period, which is when the battery cell enters the charging platform corresponding to the iron element.

[0111] As the second state parameter of the battery cell continues to change, it enters the charging platform corresponding to the iron element and the charging platform corresponding to the manganese element in sequence. Because, during the charging process of the battery cell, the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell have an overall trend of gradually increasing, at this time, the state parameter thresholds such as the instantaneous state of charge, instantaneous charging time, instantaneous voltage, and instantaneous current of the battery cell when entering the charging platform corresponding to the manganese element can be predetermined. Then, based on the magnitude relationship between the second state parameter and the corresponding state parameter threshold, it can be determined whether the battery cell has entered the charging platform corresponding to the manganese element. That is, when the second state parameter is less than the state parameter threshold (which can be recorded as the third threshold), it is determined that the battery cell has not entered the charging platform corresponding to the manganese element; when the second state parameter is greater than or equal to the above-mentioned state parameter threshold (which can be recorded as the third threshold), it is determined that the battery cell has entered the charging platform corresponding to the manganese element. The third threshold is known. When the second state parameter includes SOC, the third threshold is the SOC threshold, and the third threshold corresponds to the molar ratio of iron and manganese elements. When the second state parameter includes voltage, the third threshold is a voltage threshold, which corresponds to the voltage at the charging platform of the Mn element teammate; when the second state parameter includes charging time, the third threshold is a charging time threshold, which corresponds to the time of passing through the charging platform corresponding to the Fe element and entering the charging platform corresponding to the Mn element.

[0112] In some embodiments, charging the battery cells using a charging method appropriate for the cell type can improve the charging rate. For example, when the lithium-containing transition metal phosphate in the battery cells includes manganese and iron, a charging method of first constant current charging and then constant voltage charging can be used. This involves first charging the battery cells with a preset constant current. When the battery cell voltage reaches a preset constant voltage, constant voltage charging is performed using the preset constant voltage. When the molar ratio of iron to manganese in the lithium-containing transition metal phosphate is 4:6, the preset constant current is 0.3C and the preset constant voltage is 4.1V.

[0113] As shown in Figure 2, charging curve 20 is a charging curve for a battery cell comprising a lithium-containing transition metal phosphate, wherein the molar ratio of iron to manganese is 4:6. The horizontal axis of charging curve 20 represents the battery cell's state of charge (SOC / %), and the vertical axis represents the battery cell's voltage (Voltage / V). As can be seen from Figure 2, the voltage platform of charging curve 20 exhibits a two-step pattern. That is, when the battery cell's state of charge is approximately 40% and the battery cell's voltage is approximately 4V, the battery cell moves from voltage platform 201, corresponding to the lower voltage of iron, to voltage platform 202, corresponding to the higher voltage of manganese. Therefore, 40% can be used as the state parameter threshold corresponding to the battery cell's state of charge, and 4V can be used as the state parameter threshold corresponding to the battery cell's voltage. When the battery cell's state of charge is greater than or equal to 40%, and / or the battery cell's voltage is greater than or equal to 4V, the battery cell is determined to have entered the charging platform corresponding to the manganese element. In addition, when the state of charge of the battery cell is 40% and the voltage of the battery cell is 4V, the instantaneous charging time of the battery cell can be determined as the state parameter threshold corresponding to the charging time of the battery cell. When the charging time of the battery cell is greater than or equal to the instantaneous charging time, it is determined that the battery cell enters the charging platform corresponding to the manganese element.

[0114] In some embodiments, when the lithium-containing transition metal phosphate includes iron and manganese, a state parameter of a battery cell when it enters a charging platform corresponding to manganese after passing through a charging platform corresponding to iron is used as a first threshold. The battery management system is configured to determine that the battery cell has not entered the first time period if a second state parameter of the battery cell is less than the first threshold; and to determine that the battery cell has entered the first time period if the second state parameter of the battery cell is greater than or equal to the first threshold. The first threshold may be at least one of the state parameter thresholds corresponding to the battery cell's state of charge, the battery cell's charging duration, the battery cell's voltage, and the battery cell's current.

[0115] In the embodiment of the present application, the first threshold value can be determined based on the molar ratio of the iron element in the iron-manganese element of the positive electrode active material, and / or the molar ratio of the manganese element. The molar ratio of the iron element in the iron-manganese element is equal to the ratio of the molar content of the iron element to the total molar content of the iron and manganese elements, and the molar ratio of the manganese element in the iron-manganese element is equal to the ratio of the molar content of the manganese element to the total molar content of the iron and manganese elements.

[0116] For example, when the lithium-containing transition metal phosphate includes iron and manganese, and the molar ratio of iron to manganese is 4:6, the molar proportion of iron is 0.4, and the molar proportion of manganese is 0.6. When the second state parameter is the state of charge of the battery cell, the first threshold value may be a state of charge threshold value, such as 40%. When the molar ratio of iron to manganese is 3:7, the molar proportion of iron is 0.3, and the molar proportion of manganese is 0.7. When the second state parameter is the state of charge of the battery cell, the first threshold value may be a state of charge threshold value, such as 30%. When the first threshold value is a voltage threshold value, a charging time threshold value, and a current threshold value, the voltage threshold value, the charging time threshold value, and the current threshold value may be the voltage, charging time, and current corresponding to the state of charge of the battery cell at the above-mentioned state of charge threshold value, respectively.

[0117] In some embodiments, the molar fraction of the iron element may be greater than zero and less than or equal to 1. In some embodiments, the molar fraction of the iron element may be greater than or equal to 0.01 and less than or equal to 0.6.

[0118] In some embodiments, the molar fraction of iron in the iron-manganese element may be less than the molar fraction of manganese. For example, the molar fraction of iron may be between 0.001 and 0.5, such as 0.001, 0.002, 0.003, 0.004, 0.005, 0.007, 0.008, 0.009, 0.01, 0.02, 0.05, 0.07, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.49, 0.5, and the like.

[0119] In some embodiments, the molar ratio of iron in the iron-manganese element may also be slightly greater than the molar ratio of manganese. For example, the molar ratio of iron in the iron-manganese element may be between 0.5 and 0.6, such as the molar ratio of iron in the iron-manganese element is equal to 0.51, 0.52, 0.55, 0.57, 0.58, 0.59, 0.6, and the like.

[0120] In some embodiments, the state of charge of the battery cell and the voltage of the battery cell can also be combined to determine whether the battery cell has entered the charging platform corresponding to the manganese element, that is, when the state of charge of the battery cell is greater than or equal to the state of charge threshold, such as 40%, and the state of charge of the battery cell is greater than or equal to the voltage threshold, such as 4V, it is determined that the battery cell has entered the charging platform corresponding to the manganese element.

[0121] It's understandable that to increase the rate of lithium delithiation after reaching the manganese-related charging platform, high-temperature charging at the Mn-related charging platform is necessary. Generally, charging at temperatures above 30°C is considered high-temperature charging. This means that the temperature of the battery cells at the Mn-related charging platform must be kept within a preset temperature range during the charging process. To achieve this, it's necessary to pre-acquire the first state parameters of the battery cells to generate control instructions for controlling the heating device. The timing of acquiring the first state parameters of the battery cells is related to the heating method's heating rate and the duration of the heating method's heat retention.

[0122] The temperature difference between the current temperature of the battery cell and the optimal temperature (generally between 40 and 45 degrees), the heating rate of the heating method, and the insulation time of the heating method will affect the time when the heating device is turned on. In other words, any method that can keep the temperature of the charging platform corresponding to the Mn element under high temperature conditions is acceptable. Example 1: Assuming that the insulation time of a certain heating method is long, then the high temperature environment can be maintained for a long time in advance, such as before receiving the charging instruction, or before the charging platform corresponding to the Fe element, or during the charging platform corresponding to the Fe element, the heating device is turned on for heating; after maintaining a certain heating time, it is possible to turn off the heating device before entering the charging platform corresponding to the Mn element. In this way, the charging platform corresponding to the Mn element can adopt a high-temperature charging method. Example 2: Assuming that the insulation time of a certain heating method is long, then the high temperature environment can be maintained for a long time in advance. Example 3: If the temperature difference is small and the heating rate of the heating method is particularly fast, then the heating device can be turned on when entering the charging platform corresponding to the Mn element.

[0123] In some embodiments, the above-mentioned heating device can use different heating methods to heat the battery cells. For example, the different heating methods can include at least a first heating method for heating the battery cells based on pulse current, and a second heating method for heating the battery cells by heat transfer. In the embodiment of the present application, there can be multiple heating devices, and different heating devices use different heating methods; in other embodiments, there can also be one heating device, and the heating device can have different heating methods. The embodiment of the present application does not limit the number of heating devices.

[0124] It's understandable that the first heating method involves pulse heating, which utilizes the short duration of high-power electrical pulses to transfer pulse energy to microscopic particles within a substance, achieving rapid heat transfer. Therefore, the first heating method achieves a higher heating rate than the second heating method, which heats the battery cells via heat transfer. In other words, if multiple heating devices are used, the heating rate of the first heating method is higher than that of the second heating method.

[0125] Therefore, based on the heating methods with different heating rates of the heating device, the first state parameters of the battery cell can be obtained at different times. For example, before charging the battery cell, the first state parameter is obtained. At this time, the time from the battery cell to entering the first time period is long. In order to reduce energy consumption, the heating device can adopt the second heating method with a lower heating rate, which can also make the temperature of the battery cell in the first time period fall within the preset temperature range. Of course, the heating device can also adopt the first heating method with a higher heating rate. The first state parameter is obtained at the initial stage of charging the battery cell. Since the battery cell has not yet entered the first time period, the second heating method with a lower heating rate can also be adopted. The first state parameter is obtained during the process of the battery cell entering the first time period. In order to make the temperature of the battery cell in the first time period fall within the preset temperature range as soon as possible, the heating device can adopt the first heating method with a higher heating rate.

[0126] In some embodiments, the battery management system is configured to obtain a first state parameter of the battery cell before and during the first period. Here, "before" the battery cell enters the first period may be before the charging gun of the charging device is inserted into the charging port of the vehicle; "before" the battery cell enters the first period may also be after the battery cell begins charging but enters a period other than the first period; for example, when the lithium-containing transition metal phosphate also includes iron, the battery cell enters the second period when the charging platform corresponding to the iron element is in the case where the lithium-containing transition metal phosphate also includes iron.

[0127] In an embodiment of the present application, the first state parameter of the battery cell can be obtained before the battery cell enters the first time period and during the first time period, so that the heating device is controlled based on the first state parameter so that the temperature of the battery cell in the first time period is within a preset temperature range.

[0128] In some embodiments, the lithium-containing transition metal phosphate also includes iron elements; the battery cell charging process also includes a second time period; the second time period is the time period when the battery cell enters the charging platform corresponding to the iron element; the battery management system is used to obtain the first state parameter of the battery cell during the first time period and the second time period; the control instruction is used to control the heating device so that the temperature of the battery cell before entering the first time period and during the first time period is within a preset temperature range.

[0129] In the embodiment of the present application, the first state parameter may be acquired in the second period before the first period, so that the temperature of the battery cell before entering the first period and during the first period is within a preset temperature range.

[0130] In some embodiments, the above-mentioned control instructions include one or more of the following: first keeping information for indicating that the heating device is kept turned on; second keeping information for indicating that the heating device is kept turned off; turning-on indication information for indicating that the heating device is turned on; and turning-off indication information for indicating that the heating device is turned off.

[0131] In an embodiment of the present application, when the first state parameter of a battery cell includes the temperature of the battery cell, the battery management system is used to determine whether the temperature of the battery cell is within a temperature range. If it is within the temperature range, it indicates that the current temperature of the battery cell can also ensure that the temperature of the charging platform corresponding to the manganese element during the charging process of the battery cell is within a preset temperature range when the heating device does not heat the battery cell (i.e., the heating device maintains its current state). Therefore, the control instruction generated based on the temperature of the battery cell can be used to instruct the heating device to maintain its current state. That is, when the current state of the heating device is on, the control instruction is a first maintenance information for instructing the heating device to remain on; when the current state of the heating device is off, the control instruction is a second maintenance information for instructing the heating device to remain on.

[0132] Therefore, when the temperature of the battery cell is within the temperature range and the heating device is in the on state, the first retention information may be generated; when the temperature of the battery cell is within the temperature range and the heating device is in the off state, the second retention information may be generated.

[0133] In some embodiments, if the temperature of a battery cell is less than or equal to a first temperature threshold, it indicates that the temperature of the battery cell is low. In order to ensure that the temperature of the charging platform corresponding to the manganese element is within a temperature range during charging of the battery cell, it is necessary to activate the heating device to heat the battery cell, i.e., generate activation indication information for instructing the activation of the heating device. The first temperature threshold is less than or equal to the upper limit of the temperature range. In other words, even if the temperature of the battery cell is already within the temperature range, activation indication information can still be generated to heat the battery cell.

[0134] In some embodiments, if the temperature of a battery cell is greater than or equal to a second temperature threshold, it indicates that the temperature of the battery cell is high. In order to ensure that the temperature of the charging platform corresponding to the manganese element is within a temperature range during charging of the battery cell, the heating device needs to be turned off to reduce the temperature of the battery cell, that is, shutdown indication information is generated to instruct the heating device to turn off. The second temperature threshold is greater than or equal to the upper limit temperature of the temperature range.

[0135] In some embodiments, when the first state parameter of a battery cell includes one of the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell, the control instruction is generated based on the magnitude relationship between the first state parameter and the first threshold value. For example, when the control instruction includes turn-on instruction information, the turn-on instruction information is generated when the first state parameter of the battery cell is less than or equal to the first threshold value; when the control instruction includes turn-off instruction information, the turn-off instruction information is generated when the first state parameter of the battery cell is greater than or equal to the second threshold value.

[0136] When the turn-on indication information and the turn-off indication information are directed to the same heating device, the first threshold is less than the second threshold; when the turn-on indication information and the turn-off indication information are not directed to the same heating device, the first threshold may be less than or equal to the second threshold, or the first threshold may be greater than the second threshold.

[0137] The value of the first threshold is related to at least one of the following factors: a heating rate of the heating device, a temperature of the battery cell, and a state parameter value of the battery cell when the battery cell is in the first time period.

[0138] Example 1: When the first state parameter of the battery cell is the SOC of the battery cell, the battery management system is further configured to obtain the SOC of the battery cell during charging of the battery cell; wherein the start-up indication information is generated when the SOC of the battery cell is less than or equal to a first threshold value (i.e., the first SOC threshold value); and the shutdown indication information is generated when the SOC of the battery cell is greater than or equal to a second threshold value (i.e., the second SOC threshold value). When the start-up indication information and the shutdown indication information are for the same heating device, the first SOC threshold value is less than the second SOC threshold value; and the value of the first SOC threshold value is related to at least one of the following factors: the heating rate of the heating device, the temperature of the battery cell, and the state parameter value of the battery cell when it is in the first time period.

[0139] Example 2: When the first state parameter of the battery cell is the voltage of the battery cell, the battery management system is further configured to obtain the voltage of the battery cell during charging of the battery cell; wherein the activation indication information is generated when the voltage of the battery cell is less than or equal to a first threshold value (i.e., the first voltage threshold value); and the deactivation indication information is generated when the voltage of the battery cell is greater than or equal to a second threshold value (i.e., the second voltage threshold value). When the activation indication information and the deactivation indication information are for the same heating device, the first voltage threshold value is less than the second voltage threshold value; and the value of the first voltage threshold value is related to at least one of the following factors: the heating rate of the heating device, the temperature of the battery cell, and the state parameter value of the battery cell when it is in the first time period.

[0140] Example 3: When the first state parameter of the battery cell is the charging time of the battery cell, the battery management system is further used to obtain the charging time of the battery cell during the charging process of the battery cell; wherein, the start indication information is generated when the charging time of the battery cell is less than or equal to a first threshold value (i.e., the first charging time threshold value); and the shutdown indication information is generated when the charging time of the battery cell is greater than or equal to a second threshold value (i.e., the second charging time threshold value). When the start indication information and the shutdown indication information are for the same heating device, the first charging time threshold value is less than the second charging time threshold value; the value of the first charging time threshold value is related to at least one of the following factors: the heating rate of the heating device, the temperature of the battery cell, and the state parameter value of the battery cell when it is in the first time period.

[0141] Here, the first threshold value includes the state parameter of the battery cell when it is in the first time period. Therefore, when the first state parameter of the battery cell is less than or equal to the first threshold value, it means that the battery cell has not started charging, or the battery cell has started charging but the battery cell is in the charging platform corresponding to the iron element and has not entered the charging platform corresponding to the manganese element. At this time, an on indication information for indicating that the heating device is turned on can be generated to heat the temperature of the battery cell in advance. When the battery cell enters the charging platform corresponding to the manganese element, the temperature of the battery cell can be within a preset temperature range, thereby increasing the charging speed and improving the battery capacity.

[0142] Here, the second threshold value may be a state parameter corresponding to when the battery cell is nearing the end of charging. When the first state parameter of the battery cell is greater than or equal to the second threshold value, it indicates that the battery cell has completed or is about to complete charging. At this time, shut-off indication information instructing the heating device to shut down may be generated to control the heating device to stop heating the battery cell.

[0143] In some embodiments, when the first state parameter of the battery cell includes the state of charge of the battery cell, the battery management system is further configured to obtain the state of charge of the battery cell during charging of the battery cell; wherein the on indication information is generated when the state of charge (SOC) of the battery cell is less than or equal to a first SOC threshold; and the off indication information is generated when the SOC of the battery cell is greater than or equal to a second SOC threshold; and the second SOC threshold is greater than the first SOC threshold;

[0144] Here, the first SOC threshold is determined based on the molar fraction of iron in the iron-manganese elements of the positive electrode active material, and / or the molar fraction of manganese. For example, when the transition metals in the lithium-containing transition metal phosphate of the positive electrode active material are iron and manganese, the molar fraction of iron in the iron-manganese elements is equal to the ratio of the molar content of iron to the total molar content of iron and manganese. When the molar fraction of iron is 0.3 and the molar fraction of manganese is 0.7, the first SOC threshold may be 30%.

[0145] In some embodiments, the first SOC threshold is related to the SOC of the battery cell in a fully charged state and the molar fraction of the iron element or the manganese element. For example, the first SOC threshold may be the product of the SOC of the battery cell in a fully charged state and the molar fraction of the iron element or the manganese element. It is understood that the SOC of the battery in a fully charged state is 1, so the first SOC threshold is the molar fraction of the iron element or the molar fraction of the manganese element.

[0146] It is understandable that a battery cell including positive electrode active materials containing iron and manganese elements will sequentially experience a charging platform corresponding to the iron element and a charging platform corresponding to the manganese element during the charging process. Since the direct current resistance (DCR) of the battery 120 in the charging platform corresponding to the manganese element is 1.5-2 times the DCR in the charging platform corresponding to the iron element, it is difficult for the battery cell to release lithium ions after reaching the charging platform corresponding to the manganese element. When the SOC of the battery cell is greater than or equal to the first SOC threshold, it has passed the charging platform corresponding to the iron element and entered the charging platform corresponding to the manganese element. At this time, controlling the temperature of the battery cell can significantly improve the depth of lithium desorption in the charging platform corresponding to the manganese element, thereby increasing the charging capacity of the battery cell, while having little impact on the charging process of the battery cell and reducing unnecessary power consumption.

[0147] Therefore, when the state of charge of a single battery cell is less than or equal to the first SOC threshold, it indicates that the battery cell has not entered the charging platform corresponding to the manganese element and is in the uncharged or early charging state. At this time, an on-indication message can be generated to control the heating device to heat the battery cell. In this way, the battery cell can be preheated, so that when the battery cell enters the charging platform corresponding to the manganese element, the temperature of the battery cell is within a preset temperature range.

[0148] In an embodiment of the present application, when the SOC of the battery cell is greater than or equal to the second SOC threshold, it indicates that the charging process of the battery cell has ended or is about to end. At this time, a shutdown indication information indicating that the heating device is turned off can be generated to control the heating device to stop heating the battery cell.

[0149] In some embodiments, when the first state parameter of the battery cell also includes the temperature of the battery cell and the SOC of the battery cell, the above-mentioned turn-on indication information is generated when the temperature of the battery cell is less than or equal to the first temperature threshold, and the SOC of the battery cell is less than or equal to the first SOC threshold; the above-mentioned turn-off indication information is generated when the temperature of the battery cell is greater than or equal to the second temperature threshold, and / or the SOC of the battery cell is greater than or equal to the second SOC threshold; wherein the first temperature threshold is less than or equal to the upper limit temperature of the temperature range, the second temperature threshold is greater than or equal to the first temperature threshold, and the first temperature threshold is greater than or equal to the lower limit temperature of the temperature range.

[0150] It can be understood that if the temperature of the battery cell is less than or equal to the first temperature threshold, it means that the temperature of the battery cell is low and the battery cell needs to be heated by a heating device. If the SOC of the battery cell is less than or equal to the first SOC threshold, it means that the battery cell is in the initial stage of charging and has not entered the charging platform of the manganese element. Therefore, when the temperature of the battery cell is low and the battery cell is in the initial stage of charging, an on indication information can be generated to control the heating device to heat the battery cell.

[0151] It can be understood that if the temperature of the battery cell is greater than or equal to the second temperature threshold, it means that the temperature of the battery cell is relatively high; if the SOC of the battery cell is greater than or equal to the second SOC threshold, it means that the battery cell is at the end of charging. Therefore, when the temperature of the battery cell is relatively high and the battery cell is at the end of charging, a shutdown indication information can be generated to control the heating device to stop heating the battery cell.

[0152] In some embodiments, when the first state parameter of the battery cell also includes the charging time of the battery cell, the battery management system is also used to obtain the charging time of the battery cell during the charging process of the battery cell; the start indication information is generated when the charging time of the battery cell is less than or equal to the first time threshold; the value of the first time threshold is greater than 0 and less than the maximum charging time of the battery cell; the shutdown indication information is generated when the charging time of the battery cell is greater than or equal to the second time threshold; the second time threshold is less than the maximum charging time of the battery cell.

[0153] Here, the first time threshold can be determined based on the time corresponding to when the battery cell enters the charging platform corresponding to the manganese element. For example, the time corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first time threshold, or the time shorter than the time corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first time threshold.

[0154] In an embodiment of the present application, the battery management system can obtain the charging duration of the battery cells in real time during the charging process. When the charging duration is less than or equal to a first duration threshold, it indicates that the battery is in the early stage of charging. At this time, the battery cells can be heated, and an on-state indication is generated. Correspondingly, when the charging duration is greater than or equal to a second duration threshold, it indicates that the battery is in the late stage of charging. At this time, the battery cells can be stopped from being heated, and an off-state indication is generated.

[0155] For example, the maximum charging time of the battery cell is 15 minutes, and the time corresponding to when the battery cell enters the charging platform corresponding to the manganese element is 5 minutes. Then, the start indication information can be generated when the charging time is less than or equal to 5 minutes.

[0156] In some embodiments, when the first state parameter of the battery cell includes the voltage of the battery cell, the battery management system is also used to obtain the voltage of the battery cell during charging of the battery cell; the turn-on indication information is generated when the voltage of the battery cell is less than or equal to the first voltage threshold; the turn-off indication information is generated when the voltage of the battery cell is greater than or equal to the second voltage threshold; the second voltage threshold is greater than the first voltage threshold.

[0157] Here, the first voltage threshold can be determined based on the voltage corresponding to when the battery cell enters the charging platform corresponding to the manganese element. For example, the voltage corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first voltage threshold, or a voltage lower than the voltage corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first voltage threshold.

[0158] In an embodiment of the present application, the battery management system can obtain the voltage of a battery cell in real time during the charging process. When the voltage is less than or equal to a first voltage threshold, it indicates that the battery is in the early stages of charging. At this time, the battery cell can be heated, i.e., a start indication information is generated. Correspondingly, when the charging duration is greater than or equal to a second voltage threshold, it indicates that the battery is in the late stages of charging. At this time, the battery cell heating can be stopped, i.e., a shutdown indication information is generated.

[0159] In some embodiments, when the first state parameter of the battery cell includes the current of the battery cell, the battery management system is also used to obtain the current of the battery cell during charging of the battery cell; the turn-on indication information is generated when the current of the battery cell is less than or equal to the first current threshold; the turn-off indication information is generated when the current of the battery cell is greater than or equal to the second current threshold; the second current threshold is greater than the first current threshold.

[0160] Here, the first current threshold can be determined based on the current corresponding to when the battery cell enters the charging platform corresponding to the manganese element. For example, the current corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first current threshold, or the current less than the current corresponding to when the battery cell enters the charging platform corresponding to the manganese element can be determined as the first current threshold.

[0161] In an embodiment of the present application, the battery management system can obtain the current of the battery cell in real time during the charging process of the battery cell. When the current is less than or equal to a first current threshold, it indicates that the battery is in the early stage of charging. At this time, the battery cell can be heated, and an on-state indication information is generated. Correspondingly, when the charging time is greater than or equal to a second current threshold, it indicates that the battery is in the late stage of charging. At this time, the battery cell heating can be stopped, and an off-state indication information is generated.

[0162] In some embodiments, the temperature range includes 30°C to a safety temperature threshold of the battery pack; the safety temperature threshold is a temperature that can cause a safety event in the battery pack; the safety event includes at least one of the following: thermal runaway and a reduction in the number of battery cycles. Exemplarily, the temperature range includes at least one of the following: 30°C to 60°C, 30°C to 55°C, 30°C to 50°C, 30°C to 45°C, 30°C to 40°C, 40°C to 50°C, and 40°C to 45°C.

[0163] Understandably, lower battery cell temperatures will not effectively improve the battery cell's charge capacity, while higher battery cell temperatures may cause other damage to the battery pack. Therefore, it is necessary to control the battery cell temperature within a preset temperature range to increase the battery cell's charge capacity while minimizing damage to the cell.

[0164] The preset temperature range is described in detail below with reference to FIG3 and FIG4 .

[0165] In the embodiment of the present application, the capacity of the battery cell at different temperatures can be tested to obtain Figures 3 and 4, where Figures 3 and 4 respectively show how the charging capacity and discharging capacity of the battery cell change with temperature.

[0166] Among them, the positive electrode active material, binder and conductive agent of the positive electrode sheet of the battery cell used for testing and the corresponding mass ratio are 97.3% LiFe 0.4 Mn 0.6 PO4+2.2%PVDF+0.5%SP, compacted density is 2.35g / cm 3 The negative electrode active material, binder, dispersant and conductive agent of the negative electrode sheet of the battery cell and their corresponding mass ratio are 96.5% graphite + 1.3% SBR + 1.1% CMC + 0.4% SP, and the compacted density is 1.65g / cm 3 The electrolyte for the battery cell is prepared using appropriate solvents, additives, and lithium salts in appropriate proportions. For example, ethylene carbonate, dimethyl carbonate, and 1,2-propylene glycol carbonate are mixed in a volume ratio of 1:1:1, and then LiPF6 is uniformly dissolved in the above solution to obtain an electrolyte. The concentration of LiPF6 in the electrolyte is 1 mol / L.

[0167] As an example, during the test, the battery cell is placed in a constant temperature oven at 25°C and left to stand for 2 hours, then discharged to 2.5V at 0.33C, and then discharged to 2.0V at 0.02C. After standing for 2 hours, it is charged to 4.3V at 0.33C, and then charged at a constant voltage to a cutoff current of 0.05C. This step can obtain the charging capacity at 25°C; after standing for 2 hours, it is discharged to 2.0V at 0.33C. This step can obtain the discharge capacity at 25°C.

[0168] By varying the temperature of the constant-temperature oven, the corresponding charge and discharge capacities were obtained for each temperature. The charge and discharge capacities corresponding to these temperatures were plotted to produce the charge and discharge capacity test results shown in Figures 3 and 4.

[0169] As shown in Table 1, at 25°C, i.e., room temperature, the charge capacity of the battery cell is 0.119Ah, and the discharge capacity is 0.119Ah; at 40°C, the charge capacity of the battery cell is 0.131Ah, and the discharge capacity is 0.132Ah; at 50°C, the charge capacity of the battery cell is 0.132Ah, and the discharge capacity is 0.130Ah; at 60°C, the charge capacity of the battery cell is 0.134Ah, and the discharge capacity is 0.133Ah; at 70°C, the charge capacity of the battery cell is 0.137Ah, and the discharge capacity is 0.136Ah; at 80°C, the charge capacity of the battery cell is 0.139Ah, and the discharge capacity is 0.139Ah.

[0170] Table 1

[0171] As can be seen from Figures 3 and 4, as the charging temperature of the battery cell increases, the charging capacity and discharge capacity of the battery cell tend to increase as a whole, with a certain drop between 45°C and 50°C. It can be understood that the higher the temperature of the battery cell, the higher the charging capacity and discharge capacity of the battery cell, and the lower the temperature of the battery cell, the lower the probability of thermal runaway and other conditions in the battery cell. In order to increase the charging capacity and reduce the failure rate of the battery cell, it is necessary to control the temperature of the battery cell to be within the preset temperature range. The temperature range is set to 40°C to 50°C. In some embodiments, when the temperature range is 40°C to 45°C, it can not only improve the charging capacity and discharge capacity of the battery cell and meet conventional charging requirements, but also will not increase the damage caused by high temperature to the battery pack or even the entire vehicle.

[0172] In some embodiments, the battery management system is used to obtain a first state parameter of the battery cell before the charging process; based on the first state parameter of the battery cell, determine a control instruction for the heating device, and send the control instruction to the heating device; the battery management system is also used to control the battery cell to enter the charging process when the temperature of the battery cell is within the temperature range.

[0173] In an embodiment of the present application, the first state parameter may be the temperature of a battery cell. When the temperature of the battery cell is less than or equal to a first temperature threshold, a control instruction including start-up instruction information is generated and sent to a heating device. The heating device may heat the battery cell in response to the start-up instruction information. Furthermore, when the acquired temperature of the battery cell is within a temperature range, the battery management system controls the battery cell to enter a charging process. Specifically, when there are multiple battery cells and the temperatures of all of the multiple battery cells are less than or equal to the first temperature threshold, the heating device may be controlled to heat the multiple battery cells in parallel. When all of the multiple battery cells are within the temperature range, the multiple battery cells are controlled to enter a charging process.

[0174] In some embodiments, when the temperature of a battery cell is greater than or equal to a second temperature threshold, a control instruction including shutdown instruction information is generated and sent to the heating device. The heating device may stop heating the battery cell in response to the shutdown instruction information. Because the current temperature of the battery cell is relatively high, even if the heating device stops heating the battery cell, the battery cell temperature will still be within the temperature range. Therefore, when the battery cell temperature is within the temperature range, the battery management system controls the battery cell to enter the charging process.

[0175] In some embodiments, the heating device is electrically connected to the battery cell, and the control instruction includes start-up indication information; the heating device is used to respond to the start-up indication information and provide a pulse current to the battery cell to cause the battery cell to generate heat when the pulse current passes through the battery cell.

[0176] In the embodiment of the present application, when the pulse current passes through the battery cell, the battery cell can generate heat due to its own internal resistance, thereby achieving self-heating of the battery cell. This heating method does not require the installation of additional hardware heating structure, which can reduce the structural complexity of the battery cell.

[0177] In some embodiments, the heating device includes a motor in the electrical device where the battery pack is located, and the motor includes a winding and a control circuit connected between the winding and the battery pack; the battery management system is also used to send the control instruction to the controller in the electrical device; the controller in the electrical device is used to respond to the start indication information in the control instruction and control the control circuit so that the motor charges the battery cell based on the pulse current.

[0178] Here, the electric device may be a vehicle, and the controller in the electric device may be a vehicle control unit (VCU) in the vehicle.

[0179] In the embodiment of the present application, the controller in the electrical device responds to the start-up instruction information in the control command and controls the control circuit to cause the motor to charge the battery cells based on the pulse current. In this way, the heat generated by the operating loss of the motor in the electrical device can be used to heat the battery cells without consuming additional electricity.

[0180] Figure 5 shows a schematic circuit diagram of a heating device. As shown in Figure 5, the heating device includes a motor in the electrical device where the battery pack is located. The motor includes a winding 132 and a control circuit 131 connected between the winding 132 and the battery pack.

[0181] Here, the control circuit 131 can be implemented by an inverter in the drive system of the motor, which can be implemented, for example, by using bridge arm switches of an insulated gate bipolar transistor (IGBT), namely switch A1, switch A2, switch B1, switch B2, switch C1 and switch C2 shown in Figure 5.

[0182] Figure 5 takes a three-phase motor as an example, which includes three-phase windings, namely winding 1321, winding 1322 and winding 1323. Accordingly, the control circuit 131 is a three-phase bridge arm circuit, including three bridge arms respectively connected to the three windings, namely the bridge arm where switch A1 and switch A2 are located, the bridge arm where switch B1 and switch B2 are located, and the bridge arm where switch C1 and switch C2 are located.

[0183] During the heating process, the switches in the control circuit 131 are controlled separately based on the corresponding timing, so that the current directions of different loops formed between the battery pack 101, the switch, and the winding 132 are different, thereby generating a pulse current, and then alternately charging and discharging the battery cells, and heating the battery cells in the process.

[0184] In some embodiments, the heating device includes a heating circuit, which includes an energy storage element and a switching module; the switching module is used to respond to the start indication information in the control instruction to form a circuit for the energy storage element to charge the battery cell, and a circuit for the battery to discharge the energy storage element, so that the energy storage element charges the battery cell based on the pulse current.

[0185] For example, as shown in FIG6 , the heating circuit 130 includes a switch module 133 and an energy storage element 134 . The switch module 133 includes a bridge arm circuit formed by switches D1, D2, E1, and E2, wherein switches D1 and D2 are located in one bridge arm, and switches E1 and E2 are located in another bridge arm. Switches D1, D2, E1, and E2 can, for example, be IGBTs. The energy storage element 134 can, for example, include an inductor, a capacitor, or a combination of an inductor and a capacitor. FIG8 uses an inductor L as an example. One end of the inductor L is connected between switches D1 and D2, and the other end is connected between switches E1 and E2.

[0186] During the heating process, by controlling the switches in the switch module, a circuit is formed for the battery cell to discharge to the energy storage element, and a circuit is formed for the energy storage element to charge to the battery cell, thereby forming a pulse current, alternately charging and discharging the battery cell, and heating the battery cell in the process.

[0187] In an embodiment of the present application, an additional heating circuit is used to heat the battery cells. When the electrical equipment, such as a vehicle, has not yet been connected to the charging device, or the motor of the electrical equipment is working, the battery cells can be heated in advance, saving the user's time.

[0188] In some embodiments, the heating device is disposed outside the battery pack housing; the heating device is configured to generate heat in response to the start-up indication information in the control instruction, so as to transfer heat to the battery cell through the battery pack housing to heat the battery cell.

[0189] In the embodiment of the present application, the heating device provided on the outside of the battery pack shell can generate heat during the charging process of the battery cell, that is, it can heat the battery cell simultaneously during the charging process of the battery cell without affecting the charging process of the battery cell.

[0190] In some embodiments, the heating device includes a control circuit and a heating film, the heating film includes a conductive layer, and an insulating layer located between the conductive layer and the shell; wherein the control circuit is used to respond to the start-up indication information and provide a pulse current to the conductive layer; the conductive layer is used to generate heat during the passage of the pulse current and transfer the heat to the battery cell; the insulating layer is used to electrically isolate the conductive layer from the battery.

[0191] In the embodiment of the present application, the control circuit may be the control circuit in the embodiment of FIG. 5 .

[0192] In some embodiments, the heating device may include an energy storage unit, and the control circuit is configured to control the energy storage unit to provide a pulsed current to the conductive layer in response to the start-up indication information. The conductive layer includes a resistive heating element, such as a metal heating wire, which generates heat when energized, so that the conductive layer can transfer the heat to the battery cell.

[0193] Here, the heating film can be attached to the surface of the battery cell by adhesive material, for example. The heat generated can be transferred to the interior of the battery cell through the contact between the heating film and the surface of the battery cell. It has the advantages of simple heating structure and can be integrated into the battery system.

[0194] In some embodiments, the heating device includes a control unit, a heating component and a heat-conducting component, wherein the heat-conducting component contains a heat-conducting medium; the control unit is used to provide a pulse current to the heating component in response to the start-up indication information; the heating component is used to generate heat during the passage of the current pulse, and the heat-conducting medium in the heat-conducting component is used to transfer the heat generated by the heating component to the battery cell.

[0195] In the embodiments of the present application, the heat-generating component may be an active heating device, such as a positive temperature coefficient (PTC) heater or a high volgate heater (HVH). The heat-conducting component may be, for example, a water-cooled component, and the heat-conducting medium in the heat-conducting component may be a liquid. Alternatively, the heat-conducting component may reuse the water-cooled plate of the battery cell. The heat generated by the heat-generating component is transferred to the liquid in the water-cooled plate, which then heats or insulates the battery cell.

[0196] In some embodiments, the heating device can also be a passive heating device, which includes a heat pump and a heat circulation pipe arranged around the battery pack. The heat circulation pipe is connected to the heat pump. The heat pump is used to control the inflow and outflow of the liquid in the heat circulation pipe in response to the start instruction information in the control instruction, so as to heat the battery cell through the liquid in the process. The heat source of the heat pump can be derived from the heat generated by the battery cell during operation. The hot liquid in the heat circulation pipe exchanges heat after passing through the heat pump. For example, the temperature of the liquid entering the heat circulation pipe from the heat pump is higher, while the temperature of the liquid flowing out of the heat circulation pipe to the heat pump is lower. In this way, during the circulation of the liquid, heat is brought to the battery cell through the liquid.

[0197] In some embodiments, the heat pump is provided with a control valve. The battery management system can determine the opening of the control valve based on the difference between the temperature of the battery cell and a first temperature threshold to adjust the temperature of the liquid entering the heat circulation pipe. For example, the greater the difference between the temperature of the battery cell and the first temperature threshold, the greater the opening of the control valve, and the higher the temperature of the liquid entering the heat circulation pipe. Conversely, the smaller the difference between the temperature of the battery cell and the first temperature threshold, the smaller the opening of the control valve, and the relatively lower the temperature of the liquid entering the heat circulation pipe.

[0198] In some embodiments, the battery management system is further configured to determine a target heating method for heating the battery cell from at least two heating methods based on the temperature of the battery cell; and the battery management system is further configured to send the control instruction to the corresponding heating device based on the target heating method. The at least two heating methods include: a first heating method for heating the battery cell based on a pulse current, and a second heating method for heating the battery cell by heat transfer.

[0199] It is understandable that since different heating methods are applied in different scenarios, such as different heating efficiencies and the ambient temperatures of the battery cells, a suitable heating method can be selected according to the temperature of the battery cells to improve the heating efficiency and shorten the time it takes for the battery cells to reach the preset temperature range.

[0200] In some embodiments, the battery management system is also used to determine the temperature difference between the temperature of the battery cell and the lower limit of the temperature range; when the temperature difference is greater than a third temperature threshold, the target heating method is determined to be the first heating method; when the temperature difference is less than or equal to the third temperature threshold, the target heating method is determined to be the second heating method.

[0201] In an embodiment of the present application, when the temperature difference between the temperature of the battery cell and the lower limit of the temperature range is greater than the third temperature threshold, it means that the gap between the current temperature of the battery cell and the temperature range is large. In order to improve the heating efficiency and make the battery cell enter the temperature range as soon as possible, a heating method with higher heating efficiency can be selected from at least two heating methods, that is, a first heating method based on pulse current to heat the battery can be used; when the temperature difference is less than or equal to the third temperature threshold, it means that the gap between the current temperature of the battery cell and the temperature range is small. Even if a heating method with lower heating efficiency is used, the battery cell can be within the temperature range when entering the first time period. In order to reduce energy consumption, a second heating method of heating the battery through heat transfer can be used.

[0202] In some embodiments, the battery management system is further configured to determine a target heating method for heating the battery cell from at least two heating methods based on the temperature rise rate of the battery cell and the temperature of the battery cell under different heating methods.

[0203] It is understood that when the temperature of a battery cell changes, its internal resistance will also change, and this change in internal resistance will affect the temperature rise rate of the battery cell under different heating methods. Therefore, it is necessary to determine the target heating method based on the temperature rise rate of the battery cell under different heating methods and the temperature of the battery cell.

[0204] In some embodiments, the battery management system is further configured to:

[0205] determining a temperature difference between the temperature of the battery cell and a lower limit of the temperature range, and a time required for the battery cell to enter a platform corresponding to the manganese element;

[0206] Based on the size relationship between the temperature difference and the third temperature threshold, and the size relationship between the duration of the battery cell entering the first period and the second duration threshold, a target heating method for heating the battery cell is determined from at least two heating methods.

[0207] Here, when the temperature difference is greater than the third temperature threshold, and the time for the battery cell to enter the first time period is greater than the second time threshold, the target heating method is determined to be the heating method with a higher temperature rise rate between the first heating method and the second heating method; when the temperature difference is less than or equal to the third temperature threshold, and / or the required time is less than or equal to the second time threshold, the target heating method is determined to be the heating method with a lower temperature rise rate between the first heating method and the second heating method.

[0208] In the embodiment of the present application, when the temperature difference is greater than the third temperature threshold, it indicates that the gap between the current temperature of the battery cell and the temperature range is large. When the time the battery cell has entered the first time period is greater than the second time threshold, it indicates that the battery cell has been in the first time period (the charging platform corresponding to the manganese element) for a long time. Therefore, it is necessary to make the battery cell enter the temperature range as soon as possible, that is, the target heating method is determined to be the heating method with a higher temperature rise rate between the first heating method and the second heating method. When the temperature difference is less than or equal to the third temperature threshold, it indicates that the gap between the current temperature of the battery cell and the temperature range is small. When the time the battery cell has entered the first time period is less than or equal to the second time threshold, it indicates that the battery cell has been in the first time period (the charging platform corresponding to the manganese element) for a short time. In order to reduce energy consumption, the target heating method can be determined to be the heating method with a lower temperature rise rate between the first heating method and the second heating method.

[0209] In some embodiments, the battery management system is further configured to: send charging parameters to a charging device, the charging parameters including constant current and constant voltage information, so that the charging device charges the battery based on the constant current, and when the battery cell is charged based on the constant current to a voltage greater than or equal to the voltage threshold, the battery is charged based on the constant voltage until the battery reaches a fully charged state;

[0210] In an embodiment of the present application, the battery management system sends information including a constant current and a constant voltage to the charging device, so that the charging device can first perform constant current charging on the battery cell, and then, when the battery cell is charged to a preset voltage threshold, perform constant voltage charging on the battery cell. The constant voltage for constant voltage charging of the battery cell is the voltage of the battery cell when entering the first time period. The charging device can be a common charging pile, a super charging pile, a charging pile that supports vehicle to grid (V2G) mode, a charger, or other charging device for charging and / or discharging the battery. The embodiment of the present application does not limit the specific type and specific application scenario of the charging device.

[0211] In some embodiments, when the SOC of a battery cell is greater than or equal to a certain threshold, the battery cell can be charged with a constant current based on a first constant current until a voltage threshold is reached, and then the battery can be charged with a constant voltage based on a first constant voltage until it reaches a fully charged state; or, when the SOC of a battery cell is less than the threshold, the battery cell can be charged with a second constant current until its SOC reaches the threshold, and then the battery cell can be charged with a constant current based on the first constant current until it reaches a voltage threshold, and then the battery can be charged with a constant voltage based on the first constant voltage until it reaches a fully charged state.

[0212] For example, the first constant current used in the constant current charging stage may be between 0.01C and 0.1C, and / or the first constant voltage used in the constant voltage charging stage may be between 3.95V and 4.35V.

[0213] In some embodiments, based on the total molar amount of manganese and iron in the lithium-containing transition metal phosphate, the molar proportion of manganese is greater than or equal to 10% and less than or equal to 90%; the molar proportion of iron is greater than or equal to 10% and less than or equal to 90%.

[0214] In some embodiments, based on the total molar amount of manganese and iron in the lithium-containing transition metal phosphate, the molar proportion of manganese is greater than or equal to 60% and less than or equal to 80%; the molar proportion of iron is greater than or equal to 20% and less than or equal to 40%.

[0215] It is understandable that in lithium-containing transition metal phosphates, manganese and iron elements have a suitable molar ratio, which improves the energy density while improving the problem of manganese dissolution.

[0216] In some embodiments, the lithium-containing transition metal phosphate includes Li x Mn y1 Fe y2 P z1 O a1 Q b , wherein Q includes at least one of Zn, Al, Na, K, Ti, V, Mg, Nb, Mo, W, B, S, Si, N, F, Cl, and Br; 0.8≤x≤1.2, 0.1≤y1≤0.9, 0.1≤y2≤0.9, 0.9≤z≤1, 3.5≤a≤4, and 0≤b≤0.2.

[0217] It should be noted that the above chemical formula is not limited to the class of substances represented by the chemical formula, but also includes substances formed after further modification of this class of substances. Modification includes doping, coating, etc. The chemical formula is measured before the lithium-containing transition metal phosphate is added to the positive electrode slurry. After the battery cell is formed and cycled, the molar number of each element in the chemical formula, such as Li and O, may fluctuate.

[0218] In some embodiments, the positive electrode active material further includes a ternary material and / or a lithium iron phosphate material.

[0219] It is understandable that, based on the requirements of energy density, ternary materials can be further mixed into the positive electrode active material; and / or, based on the requirements of cycle life, lithium iron phosphate materials can be mixed.

[0220] In some embodiments, based on the total mass of the positive electrode active material, the mass proportion of the lithium-containing transition metal phosphate is greater than or equal to 25%;

[0221] In some embodiments, based on the total mass of the positive electrode active material, the mass proportion of the lithium-containing transition metal phosphate is greater than or equal to 65%.

[0222] It should be noted that among the positive electrode active materials, lithium-containing transition metal phosphates that include at least manganese elements have a higher mass proportion, thereby taking into account both safety characteristics and energy density.

[0223] In some embodiments, embodiments of the present application further provide a charging control device for charging a battery pack, wherein the battery pack includes at least one battery cell, a temperature sensor, and a battery management system, wherein: the temperature sensor is used to detect the temperature of the battery cell;

[0224] The positive electrode plate of the battery cell includes a positive electrode current collector and a positive electrode active material layer arranged on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese.

[0225] LiMn compound 0.80 Fe 0.20 PO4 as an example, for the compound LiMn 0.80 Fe 0.20 The preparation method of PO4 is described below. The preparation method may include the following steps.

[0226] In step S1 , Fe-doped manganese oxalate is prepared.

[0227] For example, 919.4 g of manganese carbonate and 231.7 g of ferrous carbonate can be added to a mixer and thoroughly mixed for 6 hours. The resulting mixture is then transferred to a reactor, 5 L of deionized water and 1260.6 g of oxalic acid dihydrate are added, and the mixture is heated to 80° C. and stirred at 500 rpm for 6 hours to mix uniformly, until the reaction terminates and no bubbles are generated, to obtain an Fe-doped manganese oxalate suspension. The suspension is then filtered, dried at 120° C., and sand-milled to obtain ferromanganese oxalate particles with a particle size of 100 nm.

[0228] In step S2, LiMn is prepared 0.80 Fe 0.20 PO4.

[0229] For example, the manganese oxalate iron (C2O4Mn 0.80 Fe 0.201791.4 g of nitric acid (calculated as nitric acid 2H2O), 369.4 g of lithium carbonate, and 1150.1 g of ammonium dihydrogen phosphate were added to 20 L of deionized water and stirred thoroughly. The mixture was uniformly mixed and reacted at 80°C for 10 hours to obtain a slurry. The slurry was transferred to a spray dryer for spray drying and granulation, and then dried at 250°C to obtain a powder. The powder was sintered in a roller kiln at 700°C for 4 hours in a protective atmosphere such as 90% nitrogen and 10% hydrogen.

[0230] In some embodiments, the lithium-containing transition metal phosphate has the formula Li 1+t Mn 1-c Fe c P 1-z R z O4, wherein t is any value in the range of -0.100 to 0.100, c is any value in the range of 0.001 to 0.500, z is any value in the range of 0.001 to 0.100, and R includes one or more elements selected from B, S, Si and N.

[0231] The values ​​of t, c, and z are configured so that the entire compound remains electrically neutral. Optionally, the ratio of c to 1-c can be 1:10 to 1:1, further 1:4 to 1:1, where c represents the sum of the stoichiometric amounts of the Mn-site doping elements Fe. Optionally, the ratio of z to 1-z can be 1:9 to 1:999, further 1:499 to 1:249, where z represents the sum of the stoichiometric amounts of the P-site doping elements R.

[0232] For example, the compound Li 1+t Mn 1-c Fe c P 1-z R z The preparation method of O4 may include the following steps.

[0233] In step S1, a manganese source, an iron source, and an acid are dissolved in a solvent and stirred to generate a suspension of a manganese salt doped with elemental Fe. The suspension is filtered and a filter cake is dried to obtain a manganese salt doped with elemental Fe.

[0234] In step S2, a lithium source, a phosphorus source, a source of element R, a solvent, and the manganese salt doped with element Fe obtained in step S1 are added to a reaction container, ground and mixed to obtain a slurry.

[0235] In step S3, the slurry obtained in step S2 is transferred to a spray drying device for spray drying and granulation to obtain granules.

[0236] In step S4, the particles obtained in step S3 are sintered to obtain a positive electrode active material.

[0237] The manganese source is, for example, a manganese-containing substance that can be used to prepare lithium manganese phosphate, including but not limited to one or a combination of elemental manganese, manganese dioxide, manganese phosphate, manganese oxalate, and manganese carbonate. The iron source is, for example, selected from at least one of elemental iron, oxides, phosphates, oxalates, carbonates, and sulfates. The acid is, for example, selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and organic acids, such as oxalic acid. The source of element R is, for example, selected from at least one of element R sulfates, borates, nitrates, and silicates.

[0238] Compound Li 1.001 Mn 0.999 Fe 0.001 P 0.999 Si 0.001 For example, O4 can be prepared by:

[0239] In step S1 , Fe-doped manganese oxalate is prepared.

[0240] For example, 1148.2 g of manganese carbonate and 1.2 g of ferrous carbonate were added to a mixer and thoroughly mixed for 1 hour. The resulting mixture was then transferred to a reactor, 5 L of deionized water and 1260.6 g of oxalic acid dihydrate were added, and the mixture was heated to 80° C. and stirred at 500 rpm for 6 hours to mix uniformly until the reaction terminated and no bubbles were generated, thereby obtaining an Fe-doped manganese oxalate suspension. The suspension was then filtered, dried at 120° C., and sand-milled to obtain ferromanganese oxalate particles with a particle size of 100 nm.

[0241] Step S2: Preparation of Li 1.001 Mn 0.999 Fe 0.001 P 0.999 Si 0.001 O4.

[0242] Take the manganese oxalate iron (C2O4Mn 0.999 Fe 0.001 1789.6 g of nitric acid (calculated as nitric acid, 2H2O), 369.8 g of lithium carbonate, 1148.9 g of ammonium dihydrogen phosphate, and 0.8 g of silicic acid were added to 20 L of deionized water, stirred thoroughly, and uniformly mixed at 80°C for 10 hours to obtain a slurry. The slurry was transferred to a spray dryer for spray drying and granulation, and then dried at 250°C to obtain a powder. The powder was sintered in a roller kiln at 700°C for 4 hours in a protective atmosphere, such as 90% nitrogen and 10% hydrogen.

[0243] In some embodiments of the present application, the lithium-containing transition metal phosphate has the following chemical formula:

[0244] Li1+w C m Mn 1-u Fe u P 1-a R a O 4-n D n ;

[0245] Wherein, C includes one or more elements selected from Zn, Al, Na, K, Mg, Nb, Mo and W, R includes one or more elements selected from B, S, Si and N, D includes one or more elements selected from S, F, Cl and Br, w is any value in the range of -0.100 to 0.100, u is any value in the range of 0.001 to 0.500, a is any value in the range of 0.001 to 0.100, n is any value in the range of 0.001 to 0.1, and m is any value in the range of 0.9 to 1.1.

[0246] Similarly, the values ​​of w, u, a, and m described above are configured so that the entire compound remains electrically neutral.

[0247] For example, the compound Li 1+w C m Mn 1-u Fe u P 1-a R a O 4-n D n The preparation method may include the following steps.

[0248] In step S1, a manganese source, an iron source, and an acid are dissolved in a solvent and stirred to generate a suspension of a manganese salt doped with elemental Fe. The suspension is filtered and a filter cake is dried to obtain a manganese salt doped with elemental Fe.

[0249] In step S2, a lithium source, a phosphorus source, a source of element C, a source of element R, a source of element D, a solvent, and the manganese salt doped with element Fe obtained in step S1 are added to a reaction container, ground and mixed to obtain a slurry.

[0250] In step S3, the slurry obtained in step S2 is transferred to a spray drying device for spray drying and granulation to obtain granules.

[0251] In step S4, the particles obtained in step S3 are sintered to obtain a positive electrode active material.

[0252] The source of element C is, for example, selected from at least one of a simple substance, oxide, phosphate, oxalate, carbonate, and sulfate of element C. The manganese source is, for example, a manganese-containing substance that can be used to prepare lithium manganese phosphate, including but not limited to one or a combination of simple manganese, manganese dioxide, manganese phosphate, manganese oxalate, and manganese carbonate. The iron source is, for example, selected from at least one of a simple substance, oxide, phosphate, oxalate, carbonate, and sulfate of iron. The acid is, for example, selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and an organic acid, and may be, for example, oxalic acid. The source of element R is, for example, selected from at least one of a sulfate, borate, nitrate, and silicate of element R. The source of element D is, for example, selected from at least one of a simple substance and an ammonium salt of element D.

[0253] If the value of x is too small, the lithium content of the entire system will be reduced, affecting the gram capacity of the material. The y value will limit the total amount of all doping elements. If y is too small, that is, the doping amount is too little, the doping element will not work. If y exceeds 0.5, it will cause the Mn content in the system to be less, affecting the voltage platform of the material. The R element is doped in the position of P. Since the PO tetrahedron is relatively stable, and a large z value will affect the stability of the material, the a value is limited to 0.001 to 0.100. More specifically, w is any value in the range of -0.100 to 0.100, u is any value in the range of 0.001 to 0.500, a is any value in the range of 0.001 to 0.100, n is any value in the range of 0.001 to 0.1, and m is any value in the range of 0.9 to 1.1. For example, the 1+x is selected from the range of 0.9 to 1.1, for example, 0.97, 0.977, 0.984, 0.988, 0.99, 0.991, 0.992, 0.993, 0.994, 0.995, 0.996, 0.997, 0.998, 1.01, the x is selected from the range of 0.001 to 0.1, for example, 0.001, 0.005, the y is selected from the range of 0.001 to 0.5, for example, 0.001 , 0.005, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.34, 0.345, 0.349, 0.35, 0.4, the z is selected from the range of 0.001 to 0.1, for example, 0.001, 0.005, 0.08, 0.1, the n is selected from the range of 0.001 to 0.1, for example, 0.001, 0.005, 0.08, 0.1, and the positive electrode active material is electrically neutral.

[0254] Unless otherwise specified, in the above chemical formula, when a doping site has two or more elements, the above numerical ranges for w, u, a, or m are not only limited to the stoichiometric number of each element as the site, but also to the sum of the stoichiometric numbers of the elements as the site. For example, in a doping site with the chemical formula Li 1+w Mn 1-u Fe u P 1-a R a In the case of a compound containing O4, if R is two or more elements R1, R2, ..., Rn, the stoichiometric numbers z1, z2, ..., zn of R1, R2, ..., Rn must each fall within the numerical range specified for z in this application, and the sum of z1, z2, ..., zn must also fall within this numerical range. Similarly, for the case where C is two or more elements, the numerical range of the stoichiometric number of C also has the above meaning.

[0255] In some embodiments, the present application also provides a charging control device, which is used to control a heating device to heat a battery cell; the battery system further includes a battery pack, a temperature sensor, and a battery management system; the battery pack includes at least one battery cell, wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode current collector and a positive electrode active material layer provided on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes manganese; as shown in Figure 7, the charging control device 70 includes:

[0256] The controller 701 is used to obtain a first state parameter of the battery cell from the battery management system before and / or during charging of the battery cell; and generate a control instruction for the heating device based on the first state parameter of the battery cell, wherein the control instruction is used to control the heating device to heat the battery cell.

[0257] In the embodiment of the present application, the charging control device may be a control device on a vehicle, or a control device of a charging device (such as a charging pile).

[0258] In some embodiments, the controller of the charging control device is configured to send the control instruction to the heating device so that the temperature of the battery cell in the first period during the charging process is within a preset temperature range.

[0259] In some embodiments, the controller of the charging control device is configured to:

[0260] generating a start indication message when the temperature of the battery cell is less than or equal to a first temperature threshold; the first temperature threshold is less than or equal to an upper limit temperature of the temperature range;

[0261] generating shutdown indication information when the temperature of the battery cell is greater than or equal to a second temperature threshold; the second temperature threshold is greater than or equal to a first temperature threshold, and the first temperature threshold is greater than or equal to a lower limit temperature of the temperature range;

[0262] generating first holding information when the temperature of the battery cell is within the temperature range and the heating device is in an on state;

[0263] The second holding information is generated when the temperature of the battery cell is within the temperature range and the heating device is in an off state.

[0264] In some embodiments, when the first state parameter of the battery cell includes one of the following: a state of charge of the battery cell, a charging time of the battery cell, a voltage of the battery cell, and a current of the battery cell, the controller of the charging control device is configured to perform at least one of the following:

[0265] generating start indication information when a first state parameter of the battery cell is less than or equal to a first threshold;

[0266] Generate shutdown indication information when the first state parameter of the battery cell is greater than or equal to the second threshold; the value of the first threshold is related to the first state parameter of the battery cell; the first state parameter of the battery cell includes: the state parameter of the battery cell when it is in the first time period.

[0267] In some embodiments, the first state parameter of the battery cell includes a state of charge of the battery cell; and the controller of the charging control device is configured to:

[0268] generating start indication information when the SOC of the battery cell is less than or equal to a first SOC threshold;

[0269] Generate shutdown indication information when the SOC of the battery cell is greater than or equal to a second SOC threshold; the second SOC threshold is greater than the first SOC threshold; the first SOC threshold is determined based on the molar ratio of iron element in the iron and manganese elements of the positive electrode active material, and / or the molar ratio of manganese element.

[0270] In some embodiments, as shown in FIG8 , the charging control device 70 includes a charging device 702 , which further includes:

[0271] A charging module is used to charge at least one battery cell in the battery pack.

[0272] In the embodiment of the present application, the controller of the charging control device can control the charging module to charge at least one battery cell in the battery pack.

[0273] In some embodiments, the controller is used to determine whether the charging device is reserved or occupied; if it is determined that the charging device is reserved or occupied, generate a charging rejection instruction; if the control module determines that the charging device is not reserved or occupied, generate a charging permission instruction, wherein the charging permission instruction is used to indicate that the charging device is not reserved or occupied; send the charging rejection instruction or the charging permission instruction to the battery management system; receive the charging reservation instruction sent by the battery management system based on the charging permission instruction, wherein the charging reservation instruction is used to request a reservation for the charging device; and, in response to the charging reservation instruction, send a charging instruction to the battery management system.

[0274] In an embodiment of the present application, after the battery management system receives the charging permission instruction, the battery management system can send a charging reservation instruction to the controller in response to the charging permission instruction; after the controller receives the charging reservation instruction, it can send a charging instruction to the battery management system in response to the charging reservation instruction, thereby completing the occupation of the charging device. After that, after the battery management system sends a feedback message generated based on the charging instruction to the controller, the controller can control the charging module to charge at least one battery cell in the battery pack.

[0275] In some embodiments, as shown in FIG9 , an embodiment of the present application further provides a method for charging a battery pack, which is applied to a battery management system in the battery system; the battery system further includes: a battery pack, a temperature sensor, and a heating device; the battery pack includes at least one battery cell, wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode current collector and a positive electrode active material layer provided on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese; the method for charging the battery pack can be implemented by steps S901 to S903:

[0276] Step S901 : Before charging the battery cell and / or during charging, obtaining a first state parameter of the battery cell.

[0277] Here, the first state parameter and the second state parameter are used to characterize the real-time state of the battery cell. Exemplarily, the first state parameter includes at least one of the following: battery cell temperature, battery cell state of charge, battery cell charging time, battery cell voltage, and battery cell current; and the second state parameter includes at least one of the following: battery cell state of charge, battery cell charging time, battery cell voltage, and battery cell current.

[0278] Step S902: Generate a control instruction for the heating device based on the first state parameter.

[0279] Step S903: sending the control instruction to the heating device; the control instruction is used to control the heating device to heat the battery cell;

[0280] In some embodiments, it also includes: obtaining the second state parameter of the battery cell before and / or during charging of the battery cell; the control instruction is used to control the heating device so that the temperature of the first time period during the charging process of the battery cell is within a preset temperature range; the first time period is the time period in which the second state parameter of the battery cell meets the conditions.

[0281] Here, the battery cell may include a first period and a second period during the charging process. For example, when the lithium-containing transition metal phosphate includes manganese and iron elements, the second period is a charging platform corresponding to the iron element, and the first period is a charging platform corresponding to the manganese element. In an embodiment of the present application, the battery management system can control the heating device to increase the delithiation depth of the lithium iron manganese phosphate when the battery cell reaches the charging platform corresponding to the manganese element, thereby increasing the capacity of the lithium iron manganese phosphate battery.

[0282] In an embodiment of the present application, the battery management system in the battery pack can generate a control instruction based on the first state parameter used to characterize the real-time state of the battery cell and send the control instruction to the heating device. The heating device can heat the battery cell in response to the control instruction so that the temperature of the first period of time during the charging process of the battery cell is within a preset temperature range. This reduces the polarization of the positive electrode active material itself, increases the delithiation depth of the positive electrode active material of the battery, and thus increases the capacity of the battery. At the same time, the temperature of the battery cell within the preset temperature range helps to increase the diffusion rate and delithiation rate of lithium ions, thereby shortening the charging time of the battery cell, making it easier to meet the needs of fast charging, and thus improving the user's charging experience.

[0283] In some embodiments, as shown in FIG10 , the battery pack charging method may also be implemented through step S1001:

[0284] Step S1001 : identifying a first time period in a process of charging a battery cell based on a second state parameter of the battery cell.

[0285] It is understood that during the charging process of a battery cell, the second state parameter has an overall trend of gradually increasing. Therefore, a state parameter threshold for when the battery cell enters the first period during the charging process can be predetermined. Then, by acquiring the second state parameter of the battery cell during the charging process in real time and comparing the magnitude relationship between the second state parameter and the state parameter threshold, it can be determined whether the battery cell has entered the first period during the charging process.

[0286] In some embodiments, the second state parameter of the battery includes one of the following: the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell; as shown in FIG10 , the above step S1001 can be implemented through steps S10011 and S10012:

[0287] Step S10011: when the second state parameter of the battery cell is less than a first threshold, determining that the battery cell has not entered the first time period;

[0288] Among them, the first period represents the charging platform corresponding to the manganese element.

[0289] Step S10012: determining that the battery cell enters a first time period when the second state parameter of the battery cell is greater than or equal to a first threshold;

[0290] Here, the first threshold value of the battery cell includes: the state parameter of the battery cell when it enters the first period of the battery cell charging process. The first threshold value may include the state parameter threshold values ​​corresponding to the charge state of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell, respectively.

[0291] In some embodiments, the first state parameter of the battery cell includes the temperature of the battery cell; as shown in FIG11 , the above step S902 can also be implemented through steps S1101 to S1104:

[0292] Step S1101 : generating the start-up indication information when the temperature of the battery cell is less than or equal to a first temperature threshold; wherein the first temperature threshold is less than or equal to an upper limit temperature of the temperature range.

[0293] Step S1102 , generating the shutdown indication information when the temperature of the battery cell is greater than or equal to a second temperature threshold; wherein the second temperature threshold is greater than or equal to a first temperature threshold, and the first temperature threshold is greater than or equal to the lower limit temperature of the temperature range.

[0294] Step S1103 : generating the first retention information when the temperature of the battery cell is within the temperature range and the heating device is in an on state.

[0295] Step S1104 : generating the second retention information when the temperature of the battery cell is within the temperature range and the heating device is in an off state.

[0296] In an embodiment of the present application, different control instructions can be obtained by proportionally comparing the temperature of the battery cell obtained in real time with the upper and lower temperature limits of the temperature range, so that the heating device performs actions that are consistent with the current temperature of the battery cell, thereby ensuring that the temperature of the battery cell is within the temperature range when entering the manganese element charging platform.

[0297] In some embodiments, as shown in FIG12 , an embodiment of the present application further provides a method for charging a battery pack, wherein the battery pack includes at least one battery cell; the battery pack is located in a battery system; the battery system further includes a temperature sensor and a battery management system; the battery pack includes at least one battery cell, wherein: the temperature sensor is used to detect the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode current collector and a positive electrode active material layer provided on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese; the heating method is applied to a controller of a charging control device; the method for charging the battery pack can be implemented by steps S1201 and S1202:

[0298] Step S1201 : Before charging the battery cell and / or during charging, obtaining a first state parameter and a second state parameter of the battery cell from the battery management system.

[0299] In an embodiment of the present application, the battery management system of the battery pack can send the acquired first state parameter and second state parameter to the controller of the charging control device, so that the controller of the charging control device can obtain the first state parameter and second state parameter before and / or during charging of the battery cell.

[0300] Step S1202 : Based on the first state parameter of the battery cell, generate a control instruction for the heating device so that the temperature of the first period during the charging process of the battery cell is within a preset temperature range; the first period is the period during which the second state parameter of the battery cell meets the condition.

[0301] In the embodiment of the present application, after generating a control instruction, the controller of the charging control device may send the control instruction to the heating device, thereby completing the control of the heating device.

[0302] In some embodiments, as shown in FIG13 , the present application also provides a method for charging a battery pack. The method may be implemented through steps S1301 to S1304:

[0303] Step S1301 : Before or during charging of a battery cell, the battery management system obtains a first state parameter and a second state parameter of the battery cell.

[0304] Step S1302 : The battery management system determines a control instruction for the heating device based on a first state parameter of the battery cell.

[0305] Step S1303: The battery management system sends a control instruction to the controller of the charging control device.

[0306] Step S1304 : The controller of the charging control device sends a control instruction to the heating device so that the temperature of the battery cell in the first period of the charging process is within a preset temperature range.

[0307] The first time period is a time period during which the second state parameter of the battery cell meets the condition.

[0308] In some embodiments, as shown in FIG14 , the present application also provides a method for charging a battery pack. The method may be implemented through steps S1401 to S1405:

[0309] Step S1401 : Before or during charging of a battery cell, the battery management system obtains a first state parameter and a second state parameter of the battery cell.

[0310] Step S1402: The battery management system sends a first state parameter to a controller of the charging control device.

[0311] Step S1403 : The controller of the charging control device determines a control instruction for the heating device based on the first state parameter of the battery cell.

[0312] Step S1404: The controller of the charging control device sends a control instruction to the battery management system.

[0313] In step S1405 , the battery management system sends a control instruction to the heating device so that the temperature of the battery cell in the first period of the charging process is within a preset temperature range.

[0314] The first time period is a time period in which the second state parameter of the battery cell meets the condition.

[0315] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned steps / processes does not mean the order of execution, and the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0316] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0317] The above is only an implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A battery system, characterized in that: include: A battery pack comprising at least one battery cell, a temperature sensor, a battery management system and a heating device, wherein: The battery cell comprises a positive electrode sheet; the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one side of the positive electrode current collector, and the positive electrode active material layer comprises a positive electrode active material; The positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes a manganese element; The temperature sensor is used to obtain the temperature of the battery cell; The battery management system is used to obtain a first state parameter of the battery cell before and / or during charging of the battery cell; wherein: The first state parameter of the battery cell is used to generate a control instruction for the heating device; The control instruction is used to control the heating device to heat the battery cell.

2. The battery system according to claim 1, characterized in that: The battery management system is further used to: obtain a second state parameter of the battery cell before and / or during charging of the battery cell; Determining the control instruction based on the first state parameter of the battery cell; The control instruction is sent to the heating device so that the temperature of the first time period during the charging process of the battery cell is within the temperature range; wherein the first time period is a time period in which the second state parameter of the battery cell meets a condition.

3. The battery system according to claim 1 or 2, characterized in that: The control instructions include one or more of the following: first keeping information for instructing to keep the heating device turned on; second keeping information for instructing to keep the heating device turned off; Turn-on indication information for indicating that the heating device is turned on; Shutdown indication information for indicating that the heating device is shut down; The control instructions include operating parameters of the heating device.

4. The battery system according to any one of claims 1 to 3, characterized in that: The first time period is the time period when the battery cell enters the charging platform corresponding to the manganese element; The battery management system is used to obtain a first state parameter of the battery cell before the battery cell enters the first time period and during the first time period; The control instruction is used to control the heating device so that the temperature of the battery cell in the first time period is within a temperature range.

5. The battery system according to claim 4, characterized in that: The lithium-containing transition metal phosphate also includes iron.

6. The battery system according to claim 5, characterized in that: The process of charging the battery cell also includes a second period; the second period is the period when the battery cell enters the charging platform corresponding to the iron element; The battery management system is used for obtaining a first state parameter of the battery cell during the first time period and the second time period; The control instruction is used to control the heating device so that the temperature of the battery cell before entering the first period and during the first period is within a temperature range.

7. The battery system according to any one of claims 1 to 6, characterized in that: The first state parameter of the battery cell includes one or more of the following: temperature of the battery cell, state of charge of the battery cell, charging time of the battery cell, voltage of the battery cell, and current of the battery cell.

8. The battery system according to claim 7, characterized in that: The first state parameter of the battery cell includes the temperature of the battery cell, The battery management system is also used to charge the battery cells before or during charging, based on the temperature A temperature sensor is used to obtain the temperature of the battery cell; The start indication information is generated when the temperature of the battery cell is less than or equal to a first temperature threshold, wherein the first temperature threshold is less than or equal to an upper limit temperature of the temperature range; The shutdown indication information is generated when the temperature of the battery cell is greater than or equal to a second temperature threshold, wherein the second temperature threshold is greater than or equal to a first temperature threshold, and the first temperature threshold is greater than or equal to a lower limit temperature of the temperature range; The first retention information is generated when the temperature of the battery cell is within the temperature range and the heating device is in an on state; The second retention information is generated when the temperature of the battery cell is within the temperature range and the heating device is in an off state.

9. The battery system according to claim 7, characterized in that: The first state parameter of the battery cell includes one of the following: the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell; The battery management system is also used to obtain the first state parameter of the battery cell during the charging process of the battery cell; wherein, The on indication information is generated when the first state parameter of the battery cell is less than or equal to a first threshold; the off indication information is generated when the first state parameter of the battery cell is greater than or equal to a second threshold; When the turn-on indication information and the turn-off indication information are for the same heating device, the first threshold is less than the second threshold; the value of the first threshold is related to at least one of the following factors: the heating rate of the heating device, the temperature of the battery cell, and the state parameter value of the battery cell when it is in the first time period.

10. The battery system according to claim 9, characterized in that: The first state parameter of the battery cell includes the state of charge of the battery cell, and the battery management system is further used to obtain the state of charge of the battery cell during the charging process of the battery cell; The on indication information is generated when the SOC of the battery cell is less than or equal to a first SOC threshold; the off indication information is generated when the SOC of the battery cell is greater than or equal to a second SOC threshold; wherein the second SOC threshold is greater than the first SOC threshold; The first SOC threshold is determined based on the molar ratio of the iron element in the iron and manganese elements of the positive electrode active material and / or the molar ratio of the manganese element.

11. The battery system according to claim 10, characterized in that: The first SOC threshold is related to the SOC of the battery in a fully charged state and the molar ratio of the iron element or the manganese element.

12. The battery system according to claim 10 or 11, characterized in that: The first state parameter of the battery cell also includes the temperature of the battery cell; The activation indication information is generated when the temperature of the battery cell is less than or equal to a first temperature threshold and the SOC of the battery cell is less than or equal to a first SOC threshold; the first temperature threshold is less than or equal to an upper limit temperature of the temperature range; The shutdown indication information is generated when the temperature of the battery cell is greater than or equal to a second temperature threshold, and / or the SOC of the battery cell is greater than or equal to a second SOC threshold; The second temperature threshold is greater than or equal to the first temperature threshold, and the first temperature threshold is greater than or equal to the lower limit temperature of the temperature range.

13. The battery system according to any one of claims 1 to 12, characterized in that: The temperature range includes an optimal temperature, which is between 40°C and 45°C.

14. The battery system according to any one of claims 1 to 13, characterized in that: It is characterized in that The temperature range includes: 30°C to 60°C.

15. The battery system according to any one of claims 1 to 14, characterized in that: The battery management system is used to obtain a first state parameter of the battery cell before the charging process; determine a control instruction for the heating device based on the first state parameter of the battery cell, and send the control instruction to the heating device; The battery management system is further used to control the battery cell to enter the charging process when the temperature of the battery cell is within the temperature range.

16. The battery system according to any one of claims 1 to 15, characterized in that: The heating device is electrically connected to the battery cell, and the control instruction includes start-up instruction information. The heating device is used for providing a pulse current to the battery cell in response to the start-up indication information, so as to make the battery cell generate heat when the pulse current passes through the battery cell.

17. The battery system according to claim 16, characterized in that: The heating device comprises a charging device for charging the battery; The charging device is used to charge the battery based on the pulse current in response to the start-up indication information.

18. The battery system according to claim 16 or 17, characterized in that: The heating device includes a motor in the electrical equipment where the battery pack is located, and the motor includes a winding and a control circuit connected between the winding and the battery; The battery management system is further used to send the control instruction to the controller in the power-consuming device; The controller in the electrical device is used to respond to the start indication information in the control instruction and control the control circuit so that the motor charges the battery cell based on the pulse current.

19. The battery system according to any one of claims 16 to 18, characterized in that: The heating device comprises a heating circuit, and the heating circuit comprises an energy storage element and a switch module; The switch module is used to respond to the opening indication information in the control instruction to form a circuit for the energy storage element to charge the battery cell and a circuit for the battery to discharge the energy storage element, so that the energy storage element charges the battery cell based on the pulse current.

20. The battery system according to any one of claims 1 to 19, characterized in that: The heating device is arranged outside the housing of the battery pack; The heating device is used to generate heat in response to the start-up indication information in the control instruction, so as to transfer heat to the battery cell through the battery housing to heat the battery cell.

21. The battery system according to claim 20, characterized in that: The heating device comprises a control circuit and a heating film, wherein the heating film comprises a conductive layer and an insulating layer located between the conductive layer and the housing; wherein, The control circuit is used to provide a pulse current to the conductive layer in response to the start-up indication information; The conductive layer is used to generate heat during the passage of the pulse current and transfer the heat to the battery cell; The insulating layer is used to electrically isolate the conductive layer from the battery.

22. The battery system according to claim 20, characterized in that: The heating device comprises a control unit, a heat-generating component and a heat-conducting component, wherein the heat-conducting component contains a heat-conducting medium; The control unit is used to provide a pulse current to the heating component in response to the start-up indication information; The heat generating component is used to generate heat during the passage of the current pulse, and the heat conducting medium in the heat conducting component is used to transfer the heat generated by the heat generating component to the battery cell.

23. The battery system according to claim 20, characterized in that: The heating device comprises a heat circulation pipe arranged around the battery cell, and the heat circulation pipe is connected to a heat pump; The heat pump is used to control the conduction in the heat circulation pipeline in response to the start indication information in the control instruction. The hot liquid flows in and out in a cycle so as to heat the battery cells through the heat-conducting liquid.

24. The battery system according to any one of claims 1 to 23, characterized in that: The battery management system is further used to determine, based on the temperature of the battery cell, a target heating mode for heating the battery cell from at least two heating modes; or, based on the temperature rise rate of the battery cell and the temperature of the battery cell under different heating modes, determine, from at least two heating modes, a target heating mode for heating the battery cell; The battery management system is further configured to send the control instruction to the corresponding heating device based on the target heating mode; The at least two heating methods include: a first heating method for heating the battery cell based on a pulse current, and a second heating method for heating the battery cell by heat transfer.

25. The battery system according to claim 24, characterized in that: The battery management system is used for: determining a temperature difference between the temperature of the battery cell and a lower limit of the temperature range; When the temperature difference is greater than a third temperature threshold, the target heating mode is determined to be the first heating mode; when the temperature difference is less than or equal to the third temperature threshold, the target heating mode is determined to be the second heating mode.

26. The battery system according to claim 25, characterized in that: The battery management system is used for: Determining a temperature difference between the temperature of the battery cell and a lower limit of the temperature range, and a duration for the battery cell to enter a first period; Based on the magnitude relationship between the temperature difference and the third temperature threshold, and the magnitude relationship between the duration of the battery cell entering the first time period and the second duration threshold, determining a target heating mode for heating the battery cell from at least two heating modes; Wherein, when the temperature difference is greater than the third temperature threshold, and the duration of the battery cell entering the first time period is greater than the second duration threshold, the target heating method is the heating method with a higher temperature rise rate corresponding to the first heating method and the second heating method; When the temperature difference is less than or equal to the third temperature threshold, and / or the duration of the battery cell entering the first time period is less than or equal to the second time threshold, the target heating method is the heating method with a lower temperature rise rate between the first heating method and the second heating method.

27. The battery system according to any one of claims 1 to 26, characterized in that: The battery management system is also used for: Sending charging parameters to a charging device, wherein the charging parameters include information of a constant current and a constant voltage, so that the charging device charges the battery based on the constant current, and when the battery cell is charged to a voltage greater than or equal to the voltage threshold based on the constant current, the battery is charged based on the constant voltage until the battery reaches a fully charged state; The constant voltage is: the voltage of the battery cell when entering the first time period.

28. The battery pack according to claim 5, characterized in that: Based on the total molar ratio of manganese and iron in the lithium-containing transition metal phosphate, the molar ratio of manganese is greater than or equal to 10% and less than or equal to 90%; the molar ratio of iron is greater than or equal to 10% and less than or equal to 90%.

29. The battery system according to claim 5, characterized in that: Based on the total molar amount of manganese and iron in the lithium-containing transition metal phosphate, the molar proportion of manganese is greater than or equal to 60% and less than or equal to 80%; the molar proportion of iron is greater than or equal to 20% and less than or equal to 40%.

30. The battery system according to claim 5, characterized in that: The lithium-containing transition metal phosphate includes LixMny1Fey2Pz1Oa1Qb, wherein Q includes Zn, Al, Na, At least one of K, Ti, V, Mg, Nb, Mo, W, B, S, Si, N, F, Cl, and Br; 0.8≤x≤1.2, 0.1≤y1≤0.9, 0.1≤y2≤0.9, 0.9≤z1≤1, 3.5≤a1≤4, and 0≤b≤0.

2.

31. The battery system according to any one of claims 1 to 30, characterized in that: The positive electrode active material further includes a ternary material and / or a lithium iron phosphate material.

32. The battery system according to claim 5, characterized in that: Based on the total mass of the positive electrode active material, the mass proportion of the lithium-containing transition metal phosphate is greater than or equal to 25%.

33. The battery pack according to claim 5, characterized in that: Based on the total mass of the positive electrode active material, the mass proportion of the lithium-containing transition metal phosphate is greater than or equal to 65%.

34. A charging control device, characterized in that: The charging control device is used to control the heating device to heat the battery cell; the battery system includes a battery pack, a temperature sensor, a battery management system and the heating device; the battery pack includes at least one battery cell, wherein: the temperature sensor is used to obtain the temperature of the battery cell; The positive electrode plate of the battery cell comprises a positive electrode current collector and a positive electrode active material layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode active material layer comprises a positive electrode active material; the positive electrode active material comprises a lithium-containing transition metal phosphate, wherein the lithium-containing transition metal phosphate comprises a manganese element; The charging control device comprises: The controller is used to obtain the first state parameter of the battery cell from the battery management system before and / or during charging of the battery cell; based on the first state parameter of the battery cell, generate a control instruction for the heating device, wherein the control instruction is used to control the heating device to heat the battery cell.

35. The charging control device according to claim 34, characterized in that: The charging control device includes a charging device, and the charging device also includes: A charging module is used to charge at least one battery cell in the battery pack.

36. The charging control device according to claim 34 or 35, characterized in that: The controller is used to determine whether the charging device is reserved or occupied; If it is determined that the charging device is reserved or occupied, generating a charging rejection instruction; When the control module determines that the charging device is not reserved or occupied, generating a charging permission instruction, wherein the charging permission instruction is used to indicate that the charging device is not reserved or occupied; Sending the charge rejection instruction or the charge permission instruction to the battery management system; The controller is further configured to receive a charging reservation instruction sent by a battery management system based on the charging permission instruction, wherein the charging reservation instruction is used to request a reservation for the charging device; and, in response to the charging reservation instruction, send a charging instruction to the battery management system.

37. A method for charging a battery pack, characterized in that: Applied to a battery management system; the battery system comprises: a battery pack, a temperature sensor, a heating device and the battery management system; the battery pack comprises at least one battery cell; wherein the temperature sensor is used to obtain the temperature of the battery cell; The positive electrode sheet of the battery cell includes a positive electrode current collector and a positive electrode active material layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, wherein the lithium-containing transition metal phosphate includes at least a manganese element; the method includes: Before charging the battery cell and / or during charging, obtaining a first state parameter of the battery cell; generating a control instruction for a heating device based on the first state parameter; The control instruction is sent to the heating device; the control instruction is used to control the heating device to heat the battery cell.

38. The method according to claim 37, characterized in that The control instructions include one or more of the following: first keeping information for instructing to keep the heating device turned on; second keeping information for instructing to keep the heating device turned off; Turn-on indication information for indicating that the heating device is turned on; Shutdown indication information for indicating that the heating device is shut down; The control instructions include operating parameters of the heating device; The method further comprises: Before charging the battery cell and / or during charging, obtaining a second state parameter of the battery cell; The control instruction is used to control the heating device so that the temperature of the first time period during the charging process of the battery cell is within the temperature range; wherein the first time period is a time period in which the second state parameter of the battery cell meets a condition.

39. The method according to claim 38, characterized in that in, The second state parameter of the battery includes one of the following: the state of charge of the battery cell, the charging time of the battery cell, the voltage of the battery cell, and the current of the battery cell; The method further comprises: When the second state parameter of the battery cell is less than the first threshold value, determining that the battery cell has not entered the first time period; When the second state parameter of the battery cell is greater than or equal to a first threshold, determining that the battery cell enters a first time period; The first threshold value of the battery cell includes: a state parameter of the battery cell when the battery cell enters a first period in a process of charging the battery cell.

40. The method according to any one of claims 37 to 39, characterized in that The first state parameter of the battery cell includes one or more of the following: temperature of the battery cell, state of charge of the battery cell, charging time of the battery cell, voltage of the battery cell, and current of the battery cell.

41. The method according to claim 40, characterized in that The first state parameter of the battery cell includes the temperature of the battery cell; and generating a control instruction for the heating device based on the first state parameter includes: When the temperature of the battery cell is less than or equal to a first temperature threshold, generating the start indication information; wherein the first temperature threshold is less than or equal to an upper limit temperature of the temperature range; generating the shutdown indication information when the temperature of the battery cell is greater than or equal to a second temperature threshold; wherein the second temperature threshold is greater than or equal to a first temperature threshold, and the first temperature threshold is greater than or equal to a lower limit temperature of the temperature range; generating the first retention information when the temperature of the battery cell is within the temperature range and the heating device is in an on state; The second retention information is generated when the temperature of the battery cell is within the temperature range and the heating device is in an off state.

42. A method for charging a battery pack, characterized in that: The battery pack includes at least one battery cell; the battery pack is located in a battery system; the battery system also includes a temperature sensor and a battery management system; wherein: the temperature sensor is used to obtain the temperature of the battery cell; the positive electrode plate of the battery cell includes a positive electrode current collector and a positive electrode active material layer disposed on at least one side of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material; the positive electrode active material includes a lithium-containing transition metal phosphate, and the lithium-containing transition metal phosphate includes at least manganese; the charging method of the battery pack is applied to a charging control device; the method includes: Before and / or during charging of the battery cell, obtaining a first state parameter of the battery cell from the battery management system; Based on the first state parameter of the battery cell, a control instruction for the heating device is generated, wherein the control The instruction is used to control the heating device to heat the battery cell.

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