Heated film structure, battery device, battery system, and battery heating control method

Abstract

The application provides a heating film structure, a battery device, a battery system and a battery heating control method. The heating film is integrated with the module buffer pad, so that the heating film can avoid the risk of deformation and tearing during the heating process due to the elasticity of the module buffer pad. The heating film can be subsequently pasted with the battery cell, which can effectively avoid the risk of deformation and tearing caused by the expansion of the battery cell or the cooling plate. The elasticity of the module buffer pad enables the heating film to be closely attached to the battery cell, effectively avoiding the risk of dry burning. In addition, the module buffer pad and the heating film are integrated, so that the heat of the heating film can act on the battery cell pasted with the heating film. The temperature of the battery cell rises faster at low temperature, which can effectively and quickly improve the low temperature performance of the battery system. At the same time, the battery heating control method can accurately control whether the battery is heated, prevent the risk of thermal runaway, and effectively reduce the cost.

Description

Technical Field

[0001] This application relates to the field of battery heating technology, and more specifically, to a heating film structure, a battery device, a battery system, and a battery heating control method. Background Technology

[0002] Current power batteries experience a significant decrease in usable capacity under low-temperature conditions, resulting in a substantial loss in vehicle range compared to normal temperatures. Additionally, under low-temperature conditions, cell breakage can occur during charging, inducing internal short circuits and leading to cell thermal runaway. Therefore, when a battery is in low-temperature conditions, it is generally necessary to first warm up the battery. After warming up, the cell temperature is read to the verification temperature before charging the battery.

[0003] Currently, heating films are widely used to heat batteries. The heating film's position relative to the battery cell and its adhesion method relative to other components of the battery system vary. However, improper placement of the heating film can easily lead to the risk of dry burning. Furthermore, using heating films makes it difficult to precisely heat the battery to a predetermined temperature. Therefore, there is an urgent need for a heating film adhesion solution that can precisely control battery heating, prevent thermal runaway risks, and improve charging efficiency. Summary of the Invention

[0004] The purpose of this application is to address the shortcomings of the prior art by providing a heating film structure, a battery device, a battery system, and a battery heating control method to avoid the risk of dry burning of the heating film and prevent the risk of thermal runaway.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: In a first aspect, embodiments of this application provide a heating film structure, including: a module buffer pad, a first heating film, and a second heating film; One side of the first heating film is integrated and pasted with one side of the module buffer pad, and the other side of the first heating film is used to paste the battery cell. One side of the second heating film is integrated and bonded to the other side of the module buffer pad; the other side of the second heating film is used to bond the battery cell. The first heating film and the second heating film are used to heat the attached battery cell.

[0006] Optionally, the first heating film and the second heating film each include: a heating resistance wire and an insulating layer; One side of the insulating layer is adhered to one side of the module buffer pad; The heating resistance wire is attached to the other side of the insulating layer; The heating resistance wire includes a top section and a bottom section connected to each other, and the distance between the top section and the bottom section is greater than a preset distance.

[0007] Optionally, the other side of the insulating layer includes a fracture structure along the extension direction of the heating resistance wire, and the fracture structure is disposed in the gap between the heating resistance wires.

[0008] Optional features also include: multiple connectors; One end of each connector is connected to the end of the heating resistance wire in each heating film.

[0009] Optionally, it also includes: a first tape and a second tape; One side of the first tape is adhered to one side of the module buffer pad; One side of the second tape is adhered to the other side of the module buffer pad; Both the second side of the first tape and the second tape are used to adhere to the battery cell. The third side of both the first tape and the third side of the second tape are used for bonding with the battery cell.

[0010] Secondly, embodiments of this application also provide a battery device, including: a plurality of battery cells, wherein a heating film structure as described in the first aspect is disposed between two adjacent battery cells.

[0011] Thirdly, embodiments of this application also provide a battery system, including: at least one battery device as described in the second aspect, a cooling plate, and a housing, wherein the cooling plate is in close contact with each of the battery devices, and each of the battery devices and the cooling plate are located within the housing.

[0012] Fourthly, embodiments of this application also provide a battery heating control method, applied to a battery management system, for heating and controlling each cell in the battery system described in the third aspect, the method comprising: The second temperature of the cooling plate in the battery system, the third temperature of the housing, the current information and voltage information of the battery cell during charging are obtained. The expected temperature difference of the battery cell is determined based on the second temperature, the third temperature, the attribute information of the battery cell, the attribute information of the cooling plate, the attribute information of the air inside the casing, the current information and voltage information of the battery cell during charging, and the coefficients predetermined during the calibration stage. Based on the initial temperature of the battery cell before heating and the expected temperature difference, the expected temperature of the battery cell at the current moment is determined. Based on the expected temperature and the preset target temperature, determine whether to stop heating. If so, stop heating each cell in the battery system.

[0013] Optionally, determining the expected temperature difference of the battery cell based on the second temperature, the third temperature, the property information of the cooling plate, the property information of the air inside the casing, and coefficients predetermined during the calibration phase includes: Based on the second temperature, the temperature of the cooling plate at the previous moment of the current moment, the third temperature, and the temperature inside the box at the previous moment of the current moment, determine the third temperature difference inside the box and the second temperature difference of the cooling plate. The heat of the coolant in the cooling plate is determined based on the second temperature difference, the property information of the cooling plate, and a predetermined coefficient. The amount of heat dissipated by the air is determined based on the third temperature difference, the property information of the air inside the chamber, a predetermined coefficient, and the heating time. The amount of heat input to the heating film is determined based on the heating time, the current information during the charging of the battery cell, and the resistance value of the heating resistance wire. The amount of heat added during the charging process of the battery cell is determined based on the current information, voltage information, heating time, and a predetermined coefficient. The expected temperature difference of the battery cell is determined based on the heat of the coolant in the cooling plate, the heat dissipated by the air, the heat input by the heating film, the heat added during the charging process of the battery cell, the attribute information of the battery cell, and a predetermined coefficient.

[0014] Optionally, determining the third temperature difference within the housing and the second temperature difference of the cooling plate based on the second temperature, the temperature of the cooling plate at the previous moment, the third temperature, and the temperature inside the housing at the previous moment includes: A second temperature difference value for the cooling plate is determined based on the second temperature and the initial temperature of the cooling plate. The third temperature difference inside the box is determined based on the third temperature and the temperature inside the box at the previous time.

[0015] Fifthly, embodiments of this application also provide an electronic device, including: a processor, a storage medium, and a bus, wherein the storage medium stores program instructions executable by the processor, and when the application runs, the processor communicates with the storage medium via the bus, and the processor executes the program instructions to perform the steps of the battery heating control method described in the fourth aspect above.

[0016] Sixthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which is read and executes the steps of the battery heating control method described in the fourth aspect above.

[0017] The beneficial effects of this application are: This application provides a heating film structure, battery device, battery system, and battery heating control method. By integrating the heating film with a module buffer pad, the elasticity of the module buffer pad prevents the heating film from deforming and tearing during heating. Furthermore, since the heating film can be subsequently bonded to the battery cell, compared to existing methods of bonding the heating film to the battery cell or cooling plate, this effectively avoids the risk of deformation and tearing caused by the expansion of the battery cell or cooling plate. The elasticity of the module buffer pad ensures a tight fit between the heating film and the battery cell, effectively preventing the risk of dry burning. In addition, the integration of the module buffer pad and the heating film allows all the heat from the heating film to be applied to the battery cell bonded to it, resulting in a faster temperature rise of the battery cell at low temperatures and effectively improving the low-temperature performance of the battery system.

[0018] Meanwhile, by determining whether to stop heating based on the expected temperature and the preset target temperature at each moment, there is no need to place temperature detection devices on the heating film structure, and it can accurately control whether the battery is heated, prevent the risk of thermal runaway, and effectively reduce costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a heating film structure provided in an embodiment of this application; Figure 2 A schematic diagram of a battery device provided in an embodiment of this application; Figure 3 A schematic flowchart illustrating a battery heating control method provided in an embodiment of this application; Figure 4 A schematic flowchart of another battery heating control method provided in an embodiment of this application; Figure 5 This is a structural block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0022] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0023] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0024] Figure 1 This is a schematic diagram of a heating film structure provided in an embodiment of this application, as shown below. Figure 1 As shown, the heating film structure may include a module buffer pad 1, a first heating film 2, and a second heating film 3.

[0025] In this design, one side of the first heating film 2 is integrated and adhered to one side of the module buffer pad 1, and the other side of the first heating film 2 is used to adhere the battery cell, specifically as follows: Figure 2 The second heating film 3 is attached to the battery cell 9 as shown; one side of the second heating film 3 is integrated and attached to the other side of the module buffer pad 1, and the other side of the second heating film 3 can be used to attach the battery cell, specifically, as shown in... Figure 2 The battery cell 10 is attached as shown.

[0026] Among them, the first heating film 2 is as follows Figure 1 The front view shows a structural diagram, with the second heating film 3 as shown. Figure 1 The structure not shown on the back side is the same as that of the first heating film 2 and the second heating film 3.

[0027] Optionally, the module cushioning pad 1 can be an elastic foam, which can be configured as a curved surface or a flat surface. For example, if it is a curved surface, the module cushioning pad 1 can include two curved surfaces on both sides, and a heating film can be integrated and pasted on the two curved surfaces of the module cushioning pad 1. Figure 1 As shown, a first heating film 2 is integrated and adhered to one side of the module buffer pad 1, and a second heating film 3 is integrated and adhered to the other side of the module buffer pad 1. Since the other side of the first heating film 2 is used to adhere the battery cell, and the second heating film 3 is used to adhere the battery cell, the module buffer pad 1 is positioned in the gap between the two battery cells, specifically as follows: Figure 2 As shown, the module buffer pad 1 is located between the battery cell 10 and the battery cell 9.

[0028] Optionally, the heating film and the module buffer pad 1 can be integrated into one unit. After the module buffer pad 1 and the heating film are integrated, they are located in the gap between the two battery cells. Then, the length, width and thickness of the module buffer pad 1 and the heating film can be adjusted according to the size of the side of the battery cell. The thickness of the module buffer pad 1 can be set based on the gap between the two battery cells. If the thickness between the two battery cells increases, the thickness of the module buffer pad 1 will also increase; if the thickness between the two battery cells decreases, the thickness of the module buffer pad 1 will also decrease.

[0029] For example, the thickness of the heating film can be, for instance, 0.35 mm, which is much smaller than the arrangement gap between the cells, thus satisfying any type of battery system.

[0030] Optionally, the heating film can be adhered to the battery cell using the elastic foam of the module buffer pad 1. When the battery cell expands, the module buffer pad 1 is compressed, and the heating film moves with the module buffer pad 1. When the battery cell is in a low-temperature normal state, the outer dimensions of the foam of the module buffer pad 1 are larger than the elastic foam of the module buffer pad 1. Since the elastic foam of the module buffer pad 1 has a certain amount of compression, the adhesion between the heating film and the battery cell can be guaranteed, avoiding the risk of dry burning.

[0031] In this embodiment, by integrating the heating film and the module buffer pad, the elasticity of the module buffer pad prevents the heating film from deforming and tearing during heating. Furthermore, since the heating film can be subsequently bonded to the battery cell, compared to existing methods of bonding the heating film to the battery cell or cooling plate, this effectively avoids the risk of deformation and tearing caused by the expansion of the battery cell or cooling plate. The elasticity of the module buffer pad ensures a tight fit between the heating film and the battery cell, effectively preventing the risk of dry burning. Additionally, the integration of the module buffer pad and the heating film allows all the heat from the heating film to be applied to the battery cell bonded to it, resulting in a faster temperature rise of the battery cell at low temperatures and effectively improving the low-temperature performance of the battery system.

[0032] Continue to refer to Figure 1 ,like Figure 1As shown, the first heating film 2 and the second heating film 3 may each include a heating resistance wire 4 and an insulating layer 5.

[0033] In this process, one side of the insulating layer 5 is pasted to one side of the module buffer pad 1, and the heating resistance wire 4 is pasted to the other side of the insulating layer 5. The heating resistance wire 4 may include a top section and a bottom section that are connected to each other. The distance between the top section and the bottom section is greater than a preset distance, which makes the heating resistance wire have gaps.

[0034] In this embodiment, by setting gaps between the heating resistance wires, the heating film is prevented from being torn when the module buffer pad deforms.

[0035] Continue to refer to Figure 1 ,like Figure 1 As shown, the other side of the insulating layer 5 includes a fracture structure along the extension direction of the heating resistance wire, and the fracture structure is disposed in the gap between the heating resistance wires. The fracture structure is as follows: Figure 1 The diamond-shaped structure shown in the horizontal direction can effectively prevent the insulation layer of the heating film from tearing due to deformation during the deformation of the module buffer pad 1 by setting a fracture structure, thus effectively ensuring the strength of the module buffer pad.

[0036] Continue to refer to Figure 1 The first heating film 2 and the second heating film 3 each also include multiple connectors, specifically, such as... Figure 1 The connector 6 in the middle has one end connected to the end of the heating resistance wire in each heating film, and the other end of each connector can be connected to other circuits or connected in series with the connectors of other heating films. It can be connected in series with the connectors of other heating films to make the heating film connected in series with other heating films. Specifically, the connector can be set as a wire structure or other structures, which is not limited in this embodiment.

[0037] Continue to refer to Figure 1 The heating film structure may further include a first adhesive tape 7 and a second adhesive tape 8. One side of the first adhesive tape 7 can be adhered to one side of the module buffer pad 1, specifically, as shown below. Figure 1 As shown, the first adhesive tape 7 is pasted onto both sides of the upper side of the module buffer pad 1; one side of the second adhesive tape 8 is pasted onto the other side of the module buffer pad, specifically, as shown... Figure 1 As shown, the second adhesive tape 8 is pasted on both sides of the lower side of the module buffer pad 1. Then, the second side of both the first adhesive tape 7 and the second side of the second adhesive tape 8 can be pasted to the battery cell. Specifically, as shown... Figure 2 As shown, the second side of both the first adhesive tape 7 and the second side of the second adhesive tape 8 can be adhered to the battery cell 9. The third side of both the first adhesive tape 7 and the third side of the second adhesive tape 8 can also be adhered to the battery cell. Specifically, as shown... Figure 2As shown, the third side of the first tape 7 and the third side of the second tape 8 can both be adhered to the battery cell 10.

[0038] In this embodiment, the battery cells are bonded together with adhesive tape, which can both fix the heating film and effectively connect the battery cells. When multiple battery cells are connected to the heating film structure, the battery device can be arranged.

[0039] Optionally, to more clearly demonstrate the manufacturing process of the heating film structure of this application, the following exemplary embodiment will be used for illustration. Specifically, for example, a square-shell battery cell can be selected, and the dimensions of the large side surface of the cell can be measured. For example, the large side surface dimensions can be set to be 300mm long and 100mm high. Based on the length and height dimensions of the battery cell's side surface, a single module buffer pad can be set to be 280mm long and 80mm high. The upper and lower sides of the module buffer pad can be adhered with 10mm tape. Then, the dimensions of the heating film are 260mm long and 60mm high. Based on the length and height dimensions of the heating film, two rows of heating resistance wires can be selected. In the center of the heating film resistance wires, a section with a length of 230mm and a width of 5-10mm is set in the middle of the insulation layer. The cracked section is used to absorb the deformation caused by temperature changes in the battery cell. The module buffer pad is set to be 280mm long and 80mm high. The heating film and the module buffer pad are assembled together by adhesive or thermoforming. Tape is pasted in the 10mm area around the perimeter. This completes the prototype of the heating film structure. The heating film structure of this application is pasted between each battery cell. At the same time, the heating films are connected in series through connectors. Two heating films on both sides of a single heating film can be connected. The connectors are connected to other heating film structures to form a series structure and connect to the power supply.

[0040] Optionally, this embodiment also provides a battery device, which may include multiple battery cells, with a heating film structure as described in the above specific embodiment disposed between two adjacent battery cells.

[0041] Optionally, this embodiment also provides a battery system, which may include the battery devices, cooling plates, and housings described in the above specific embodiments, wherein the cooling plates are in close contact with each battery device, and each battery device and the cooling plates are located inside the housing.

[0042] Optionally, when the heating film in the heating film structure heats the battery cell, the heating film temperature state is heat input, that is, heat is input to each battery cell. At low temperatures, each battery cell in the battery system conducts heat with the cooling plate, housing, and air, and at this time, each battery cell is in a heat output state. The heat input and heat output of the battery cell reach equilibrium, but the actual temperature of the heating film is higher than the final temperature reached by the battery cell. This is because there are heat conduction losses between the components in the battery system, and there is a temperature delay between heat input and the temperature rise of the battery cell. Therefore, this application provides a battery heating control method that can accurately control battery heating and prevent the risk of thermal runaway. The battery heating control method will be explained below through specific embodiments.

[0043] Figure 3 This is a flowchart illustrating a battery heating control method provided in an embodiment of this application. This method is applied to a battery management system and can be used to control the heating of each cell in the battery system described in the specific embodiments above. Figure 3 As shown, the method may include: S101. Acquire the second temperature of the cooling plate in the battery system, the third temperature of the casing, the current information and voltage information during cell charging at preset time intervals.

[0044] Optionally, the Battery Management System (BMS) can read the cell temperature in the battery system at preset time intervals, for example, t1; the second temperature of the cooling plate, for example, t2; the third temperature of the casing, for example, t3; and the current information during cell charging. Specifically, this current information may include, for example, the instantaneous current during the cell charging time period, for example, Is, as well as the heating film resistance R and the heating film current I; and the voltage information may include, for example, the cell charging voltage U.

[0045] For example, if the battery is heated for 5 minutes, the first temperature of the battery cell, the second temperature of the cooling plate, the third temperature of the casing, the current information and voltage information of the battery cell during charging can be read at the current moment after the battery is heated for 5 minutes.

[0046] Optionally, before obtaining the second temperature of the cooling plate, the third temperature of the housing, the current information and voltage information during cell charging in the battery system, the energy Q1 required for the temperature rise of the cell can be initially estimated based on the initial temperature and target temperature of the cell before heating. Specifically, Q1 = k1 * c1 * m1 * Δt1. Energy can then be input to the cell based on the estimated energy to heat the cell. During the heating process, the second temperature of the cooling plate, the third temperature of the housing, the current information and voltage information during cell charging can be obtained at various times.

[0047] S102. Based on the second temperature, the third temperature, the cell's attribute information, the cooling plate's attribute information, the air inside the casing's attribute information, the cell's charging current information, voltage information, and the coefficients predetermined during the calibration phase, determine the expected temperature difference of the cell.

[0048] The battery cell's attribute information may include, for example, the battery cell's specific heat capacity c1 and battery cell mass m1; the cooling plate's attribute information may include, for example, the cooling liquid's specific heat capacity c2 and the cooling plate's mass m2; and the air inside the enclosure may include, for example, the air's specific heat capacity c3 and the air's mass m3.

[0049] The coefficients predetermined during the calibration phase may include, for example, the cell thermal coefficient k1 corresponding to the increase in static temperature of the cell, the cooling plate thermal coefficient k2, the air thermal coefficient k3 during air heat dissipation, the heat dissipation rate ε, and the cell thermal coefficient k5 during the cell charging process.

[0050] For example, the expected temperature difference of the battery cells after 5 minutes of battery heating can be determined based on the first temperature, second temperature, third temperature at the current moment after the battery has been heated for 5 minutes, the current information and voltage information during cell charging, the attribute information of the battery cells, the attribute information of the cooling plate, the attribute information of the air inside the box, and the coefficients predetermined during the calibration stage.

[0051] S103. Determine the expected temperature of the battery cell at the current moment based on the initial temperature of the battery cell before heating and the expected temperature difference.

[0052] Specifically, the difference between the initial temperature of the battery before heating and the expected temperature is added together to obtain the expected temperature of the cell at the current moment.

[0053] For example, if the current time refers to the time 5 minutes after the battery has been heated, the expected temperature at the current time can be obtained based on the expected temperature difference calculated in S102 above and the initial temperature before heating. Specifically, if the initial temperature of the battery before heating is -20℃, and the expected temperature difference calculated in S102 after 5 minutes of heating is 10℃, then the expected temperature of the battery cell at the current time is -10℃.

[0054] S104. Based on the expected temperature and the preset target temperature, determine whether the expected temperature is greater than or equal to the preset target temperature.

[0055] If yes, stop heating; otherwise, return to execute S101 as described above. Specifically, if the expected temperature at the current moment is less than the preset target temperature, heating can continue and S101 can be executed again by pressing return; if the expected temperature at the current moment is greater than or equal to the preset target temperature, heating can be stopped.

[0056] In this embodiment, the heating cell is heated based on the heating film structure of this application, which can effectively improve the heating rate. The heating can be stopped by determining whether to stop the heating based on the expected temperature and the preset target temperature at each time. There is no need to arrange temperature detection devices on the heating film structure. Furthermore, it can accurately control whether the battery is heated, prevent the risk of thermal runaway, and effectively reduce costs.

[0057] Figure 4 A schematic flowchart of another battery heating control method provided in this application embodiment is shown below. Figure 4 As shown, in step S102 above, determining the expected temperature difference of the battery cell based on the first temperature, the second temperature, the third temperature, the cell's attribute information, the cooling plate's attribute information, the air's attribute information inside the casing, the cell's charging current information, voltage information, and coefficients predetermined during the calibration phase can include: S201. Based on the second temperature, the temperature of the cooling plate at the previous moment, the third temperature, and the temperature inside the chamber at the previous moment, determine the second temperature difference of the cooling plate and the third temperature difference inside the chamber.

[0058] Here, the previous moment before the current moment refers to the moment before the current moment within a preset time interval. For example, if data is acquired every 5 minutes and the current moment is the 10th minute, then the previous moment before the current moment refers to the 5th minute.

[0059] The second temperature difference refers to the temperature change of the cooling plate at the current moment compared to the previous moment, Δt2; the third temperature difference refers to the temperature change of the air inside the chamber at the current moment compared to the previous moment, Δt3.

[0060] S202. Determine the heat of the coolant in the cooling plate based on the second temperature difference, the attribute information of the cooling plate, and a predetermined coefficient.

[0061] The predetermined coefficient refers to the cooling plate thermal coefficient k2.

[0062] Specifically, the heat of the coolant in the cooling plate is Q2 = k2 * c2 * m2 * Δt2.

[0063] S203. Determine the amount of heat dissipated by the air based on the third temperature difference, the property information of the air inside the chamber, the predetermined coefficient, and the heating time.

[0064] The predetermined coefficients refer to the air heat coefficient k3 and the heat dissipation rate ε, and the heating time is ΔT. Since the battery continuously dissipates heat and is placed inside the box where the air is sealed, the temperature of the box does not change much over a short period of time. Therefore, the heat exchange rate can be considered constant and only related to time.

[0065] Specifically, the heat lost by the air is the heat loss ΔQ = k3*c3*m3*Δt3 + ε*ΔT.

[0066] S204. Determine the heat input to the heating film based on the heating time, the current information during battery charging, and the resistance value of the heating resistance wire.

[0067] Specifically, the heat input to the heating film is Q3 = I²*R*△T.

[0068] S205. Based on the current information, voltage information, heating time, and predetermined coefficients during cell charging, determine the heat increase during the cell charging process.

[0069] The predetermined coefficient refers to the cell heat coefficient k5 during the cell charging process.

[0070] Specifically, the heat generated during the charging process of the battery cell is Q4 = k5 * ∫I s *U*△T.

[0071] S206. Determine the expected temperature difference of the battery cell based on the heat of the coolant in the cooling plate, the heat dissipated by the air, the heat input by the heating film, the heat added during the charging process of the battery cell, the attribute information of the battery cell, and a predetermined coefficient.

[0072] The predetermined coefficient refers to the cell thermal coefficient k1 corresponding to the increase in static temperature of the cell, and the cell attribute information refers to the cell specific heat capacity c1 and the cell mass m1, which determines the expected temperature difference of the cell.

[0073] Specifically, it can be calculated using the following formula (a).

[0074] I²*R*△T+ k5*∫I s *U*△T= k1*c1*m1*△t1+ k2*c2*m2*△t2+ k3*c3*m3*△t3+ε*△T Formula (I) Optionally, the above formula (i) is the specific form of Q3+ Q4= Q1+ Q2+△Q, where Q1 refers to the heat corresponding to the increase in the static temperature of the battery cell.

[0075] Optionally, in S201 above, determining the first temperature difference of the battery cell, the second temperature difference of the cooling plate, and the third temperature difference of the housing based on the first temperature, the temperature of the battery cell at the previous moment, the second temperature, the temperature of the cooling plate at the previous moment, the third temperature, and the temperature inside the housing at the previous moment can include: Optionally, the second temperature difference of the cooling plate is determined based on the second temperature and the temperature of the cooling plate at the previous moment. Specifically, the difference between the second temperature and the temperature at the previous moment is calculated and used as the second temperature difference of the cooling plate.

[0076] Optionally, the third temperature difference within the chamber can be determined based on the third temperature and the temperature inside the chamber at the previous moment. Specifically, the difference between the third temperature and the temperature at the previous moment is calculated and used as the third temperature difference within the chamber.

[0077] Optionally, the process for determining the coefficients predetermined during the calibration phase is as follows: Optionally, when the heating film heats up, the flow of liquid inside the cooling plate is stopped, placing the battery in a static state. This calibration phase can refer to pre-determining coefficients through experiments.

[0078] Specifically, when placing the battery device and cooling plate in a temperature test chamber, the specific heat capacity of the battery cell can be set as c1, the specific heat capacity of the coolant in the cooling plate as c2, and the specific heat capacity of the air as c3. Based on these parameters, the mass of the battery cell (m1), the mass of the cooling plate (m2), and the mass of the air (m3) can be obtained. The initial temperature of the temperature test chamber can be set to -20℃, and the initial temperatures of the battery cell (t1), the cooling plate (t2), and the test chamber (t3) can be read. The heating module is then heated. After a heating period of ΔT, the heating film resistance (R), heating film current (I), battery charging current (Is), and battery charging voltage (U) can be read, thus obtaining a set of data for the heating period of ΔT. The temperature of the battery cell, the temperature of the cooling plate, and the temperature inside the test chamber, as well as the heating film resistance (R), heating film current (I), battery charging current (Is), and battery charging voltage (U), are read periodically until the battery cell temperature meets the target temperature requirement, at which point heating is stopped. This allows us to obtain a set of data corresponding to multiple moments. In other words, at each moment, we can read the temperature of the battery cell, the temperature of the cooling plate, and the temperature inside the experimental chamber, as well as the heating film resistance R, heating film current I, battery charging current Is, and battery charging voltage U. Based on the battery cell temperature at each moment and the battery cell temperature at the previous moment, we can obtain the temperature difference between the battery cell, the cooling plate, and the experimental chamber. We can then substitute the data at each moment into formula (I) to obtain formula (I) corresponding to multiple different moments. Through multiple solutions and linear fitting of the temperature detection points from the initial temperature to the target temperature, we can obtain the coefficients in formula (I), specifically k1, k2, k3, k5, and ε.

[0079] Figure 5 This is a structural block diagram of an electronic device 400 provided in an embodiment of this application. This electronic device may, for example, include the aforementioned battery management system. Figure 5 As shown, the electronic device may include: a processor 401 and a memory 402.

[0080] Optionally, a bus 403 may also be included, wherein the memory 402 is used to store machine-readable instructions executable by the processor 401. When the electronic device 400 is running, the processor 401 and the memory 402 communicate via the bus 403. When the machine-readable instructions are executed by the processor 401, the method steps in the above method embodiments are performed.

[0081] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the method steps described in the battery heating control method embodiments.

[0082] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces; the indirect coupling or communication connection of devices or modules can be electrical, mechanical, or other forms.

[0083] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0084] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A battery heating control method, characterized in that, This invention is applied to a battery management system for heating control of individual battery cells within the system. The battery system includes at least one battery device, each comprising multiple battery cells. A heating film structure is disposed between adjacent battery cells. The heating film structure includes: a module buffer pad, a first heating film, and a second heating film. One side of the first heating film is integrated and adhered to one side of the module buffer pad, and the other side of the first heating film is used to adhere the battery cells. One side of the second heating film is integrated and adhered to the other side of the module buffer pad, and the other side of the second heating film is used to adhere the battery cells. The first heating film and the second heating film are respectively used to heat the adhered battery cells. The method includes: The second temperature of the cooling plate in the battery system, the third temperature of the housing, the current information and voltage information of the battery cell during charging are obtained. The expected temperature difference of the battery cell is determined based on the second temperature, the third temperature, the attribute information of the battery cell, the attribute information of the cooling plate, the attribute information of the air inside the casing, the current information and voltage information of the battery cell during charging, and the coefficients predetermined during the calibration stage. Based on the initial temperature of the battery cell before heating and the expected temperature difference, the expected temperature of the battery cell at the current moment is determined. Based on the expected temperature and the preset target temperature, determine whether to stop heating. If so, stop heating each cell in the battery system.

2. The battery heating control method according to claim 1, characterized in that, The step of determining the expected temperature difference of the battery cell based on the second temperature, the third temperature, the attribute information of the battery cell, the attribute information of the cooling plate, the attribute information of the air inside the casing, the current information and voltage information of the battery cell during charging, and coefficients predetermined during the calibration phase, includes: Based on the second temperature, the temperature of the cooling plate at the previous moment of the current moment, the third temperature, and the temperature inside the box at the previous moment of the current moment, determine the third temperature difference inside the box and the second temperature difference of the cooling plate. The heat of the coolant in the cooling plate is determined based on the second temperature difference, the property information of the cooling plate, and a predetermined coefficient. The amount of heat dissipated by the air is determined based on the third temperature difference, the property information of the air inside the chamber, a predetermined coefficient, and the heating time. The amount of heat input to the heating film is determined based on the heating time, the current information during the charging of the battery cell, and the resistance value of the heating resistance wire. The amount of heat added during the charging process of the battery cell is determined based on the current information, voltage information, heating time, and a predetermined coefficient. The expected temperature difference of the battery cell is determined based on the heat of the coolant in the cooling plate, the heat dissipated by the air, the heat input by the heating film, the heat added during the charging process of the battery cell, the attribute information of the battery cell, and a predetermined coefficient.

3. The battery heating control method according to claim 2, characterized in that, The step of determining the third temperature difference within the housing and the second temperature difference of the cooling plate based on the second temperature, the temperature of the cooling plate at the previous moment, the third temperature, and the temperature inside the housing at the previous moment includes: The second temperature difference of the cooling plate is determined based on the second temperature and the temperature of the cooling plate at the previous moment at the current moment; The third temperature difference inside the box is determined based on the third temperature and the temperature inside the box at the previous time.

4. The battery heating control method according to claim 1, characterized in that, The first heating film and the second heating film each include: a heating resistance wire and an insulating layer; One side of the insulating layer is adhered to one side of the module buffer pad; The heating resistance wire is attached to the other side of the insulating layer; The heating resistance wire includes a top section and a bottom section connected to each other. The distance between the top section and the bottom section is greater than a preset distance, and the preset distance causes gaps to exist between the heating resistance wires.

5. The battery heating control method according to claim 4, characterized in that, The other side of the insulating layer includes a fracture structure along the extension direction of the heating resistance wire, and the fracture structure is disposed in the gap between the heating resistance wires.

6. The battery heating control method according to claim 5, characterized in that, Also includes: Multiple connectors; One end of each connector is connected to the end of the heating resistance wire in each heating film.

7. The battery heating control method according to claim 1, characterized in that, Also includes: First tape and second tape; One side of the first tape is adhered to one side of the module buffer pad; One side of the second tape is adhered to the other side of the module buffer pad; Both the second side of the first tape and the second tape are used to adhere to the battery cell. The third side of both the first tape and the third side of the second tape are used for bonding with the battery cell.

8. A battery device, characterized in that, include: Multiple battery cells, each of which is heated by the battery heating control method according to any one of claims 1-7.

9. A battery system, characterized in that, include: At least one battery device, a cooling plate, and a housing, wherein the cooling plate is in close contact with each of the battery devices, each of the battery devices and the cooling plate are located inside the housing, and each cell in each of the battery devices is heated by the battery heating control method according to any one of claims 1-7.

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