Battery core heating method, device, storage medium and electronic device

Abstract

The present application relates to a method, device, storage medium and electronic device for heating a battery cell. The method comprises: obtaining the current temperature of a battery cell of a power battery; when the current temperature of the battery cell is lower than the target temperature, determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid; injecting the circulating liquid into the liquid cooling plate according to the liquid temperature; heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature. The present application solves the technical problem that the heating process is uncontrollable during the heating of the battery cell of a power battery.

Description

Technical Field

[0001] The present application relates to the field of power batteries, and in particular to a battery cell heating method, device, storage medium and electronic device. Background Art

[0002] In the prior art, due to the requirements of lightweight batteries and cost, the capacity of a single battery cell increases while the volume also becomes larger. The structure of the battery cell determines that the thermal conductivity of the battery cell itself is not high. During the external heating process, the heat is transferred from the side of the battery cell to the center of the battery cell. The heating speed is uncontrollable. If the heating speed is too high, uneven temperature is likely to occur. If the heating speed is too slow, it will affect consumers' usage needs.

[0003] That is to say, in the prior art, there is a technical problem that the heating process is uncontrollable during the heating of the battery cells of the power battery. Summary of the invention

[0004] The present application provides a battery cell heating method, device, storage medium and electronic device to solve the technical problem of uncontrollable heating process during heating of the battery cell of a power battery.

[0005] In a first aspect, the present application provides a battery cell heating method, comprising: obtaining a current temperature of a battery cell of a power battery; when the current temperature of the battery cell is lower than a target temperature, determining a heating power of a heating film according to a power curve of the battery cell, and determining a liquid temperature of a circulating liquid in a liquid cooling plate according to a temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records a relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records a relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid; injecting circulating liquid into the liquid cooling plate according to the liquid temperature; heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature.

[0006] In a second aspect, the present application provides a battery cell heating device, comprising: an acquisition module for acquiring the current temperature of a battery cell of a power battery; a determination module for determining the heating power of a heating film according to a power curve of the battery cell when the current temperature of the battery cell is lower than a target temperature, and determining the liquid temperature of a circulating liquid in a liquid cooling plate according to a temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid; an injection module for injecting circulating liquid into the liquid cooling plate according to the liquid temperature; a heating module for heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature.

[0007] As an optional example, the above-mentioned device also includes: a detection module, which is used to detect the current temperature of the above-mentioned battery cell once every predetermined period of time during the process of heating the above-mentioned heating film according to the above-mentioned heating power until the current temperature of the above-mentioned battery cell is equal to the above-mentioned target temperature; determine the temperature difference between the current temperature of the above-mentioned battery cell detected at the current time and the current temperature of the above-mentioned battery cell detected at the last time; when the above-mentioned temperature difference is less than the allowable temperature difference, increase the above-mentioned heating power, and when the above-mentioned temperature difference is greater than the allowable temperature difference, reduce the above-mentioned heating power, wherein the above-mentioned allowable temperature difference is determined according to a temperature difference curve, and the above-mentioned temperature difference curve records the relationship between the current temperature of the above-mentioned battery cell and the above-mentioned allowable temperature difference.

[0008] As an optional example, the determination module includes: an acquisition unit for acquiring the changed heating power according to the power curve of the battery cell when the current temperature of the battery cell changes, and determining the changed liquid temperature according to the circulating liquid temperature curve.

[0009] As an optional example, the above-mentioned device also includes: a testing module, which is used to obtain the internal temperature gradient of the test battery cell at different heating powers and different liquid temperatures of the circulating liquid before determining the heating power of the heating film according to the power curve of the above-mentioned battery cell and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the circulating liquid temperature curve of the above-mentioned battery cell; determine the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient according to the variation amplitude of the above-mentioned internal temperature gradient; generate the above-mentioned power curve and the above-mentioned circulating liquid temperature curve according to the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient.

[0010] As an optional example, the above-mentioned test module includes: a test unit, used to determine the current heating power of the heating film used in the above-mentioned internal temperature gradient and the current liquid temperature of the recyclable liquid when, in any of the above-mentioned internal temperature gradients, including a temperature section in which the current temperature of the above-mentioned battery cell rises steadily; determine the above-mentioned current heating power and the above-mentioned current liquid temperature as the heating power and liquid temperature corresponding to the above-mentioned temperature section; determine the above-mentioned current heating power and the above-mentioned current liquid temperature in each temperature section of the above-mentioned internal temperature gradient to obtain the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient.

[0011] As an optional example, the above-mentioned test module includes: a processing unit, used to arrange the above-mentioned temperature segments in order from small to large temperature as one of the horizontal coordinates or vertical coordinates of the above-mentioned power curve and the above-mentioned circulating liquid temperature curve; using the above-mentioned current heating power and the above-mentioned current liquid temperature corresponding to each of the above-mentioned temperature segments as the other of the horizontal coordinates or vertical coordinates of the above-mentioned power curve and the above-mentioned circulating liquid temperature curve to obtain the above-mentioned power curve and the above-mentioned circulating liquid temperature curve.

[0012] As an optional example, the above-mentioned device also includes: a generating module, which is used to determine the allowable temperature difference for the test cell at different current temperatures of the test cell before detecting the current temperature of the test cell once every predetermined period of time, so as to obtain a temperature difference curve, wherein the above-mentioned allowable temperature difference is the temperature increased per unit time when the test cell is at the above-mentioned current temperature, using standard power heating and providing standard liquid temperature of the recyclable liquid.

[0013] In a third aspect, the present application provides a battery cell heating device, comprising: a heating film, used to cover the surface of the battery cell to heat the battery cell; a heating film temperature sensor, in contact with the heating film, used to measure the temperature of the heating film; a battery cell temperature sensor, in contact with the battery cell, used to measure the temperature of the battery cell; a start-stop device, connected to the heating film temperature sensor and the battery cell temperature sensor, used to start or stop the heating of the heating film.

[0014] In a fourth aspect, the present application provides an electronic device comprising: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor connected to the at least one bus; and at least one memory connected to the at least one bus, wherein the memory stores a computer program, and the processor is configured to implement any one of the above-mentioned battery cell heating methods when executing the computer program.

[0015] In a fifth aspect, the present application further provides a computer storage medium storing computer executable instructions, wherein the computer executable instructions are used to execute any of the above-mentioned methods for heating a battery cell in the present application.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages over the prior art: the solution provided by the embodiment of the present application, by acquiring the current temperature of the battery cell of the power battery; when the current temperature of the above battery cell is lower than the target temperature, the heating power of the heating film is determined according to the power curve of the above battery cell, and the liquid temperature of the circulating liquid in the liquid cooling plate is determined according to the temperature curve of the circulating liquid of the above battery cell, wherein the heating film is attached to one side of the above battery cell, the above liquid cooling plate is in contact with the above battery cell, the above power curve records the relationship between the current temperature of the above battery cell and the heating power of the heating film, and the above circulating liquid temperature curve records the relationship between the current temperature of the above battery cell and the liquid temperature of the circulating liquid; the circulating liquid is injected into the above liquid cooling plate according to the above liquid temperature; the above heating film is heated according to the above heating power until the current temperature of the above battery cell is equal to the above target temperature, so that the liquid temperature and heating power of the circulating liquid can be controlled according to the current temperature of the battery cell of the power battery, so as to achieve controllable heating of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0020] Figure 1 A flow chart of a battery cell heating method provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of a battery cell heating provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of an internal temperature gradient curve of a battery core heating method provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of an internal temperature gradient curve of another battery core heating method provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of a power curve of a battery core heating method provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of a temperature difference curve of a battery core heating method provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of the structure of a battery core heating device provided in an embodiment of the present application;

[0027] Figure 8 A schematic structural diagram of another battery core heating device provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of temperature collection provided in an embodiment of the present application;

[0029] Fig.10 A schematic diagram of a liquid cooling plate provided in an embodiment of the present application;

[0030] Fig.11 A flow chart of a battery cell heating method provided in an embodiment of the present application;

[0031] Fig.12 A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0034] In order to solve the technical problem of uncontrollable heating process during heating of power battery cells in the prior art, the present application provides a cell heating method that can achieve the purpose of controllable heating of the cell.

[0035] Figure 1 This is a flow chart of a battery cell heating method provided in an embodiment of the present application. Figure 1 As shown, the above-mentioned battery cell heating method includes:

[0036] S102, obtaining the current temperature of the battery cell of the power battery;

[0037] S104, when the current temperature of the battery cell is lower than the target temperature, determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid;

[0038] S106, injecting a circulatory liquid into the liquid cooling plate according to the liquid temperature;

[0039] S108 , heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature.

[0040] The power battery in this embodiment can be a battery that provides power to cars, electric cars, hybrid cars, or extended-range vehicles, and the battery includes battery cells.

[0041] Figure 2 It is a schematic diagram of heating a battery cell according to this embodiment. Figure 2 In the process, multiple cells are arranged side by side, and gaps can be set between the cells. The heating film is attached to the sides of the multiple cells, and a liquid cooling plate is set at the bottom of the cells. It should be noted that Figure 2 For example only, the heating film can be attached to other positions of the battery cell to ensure a larger contact area, and the liquid cooling plate can also be set to other shapes, such as an embeddable shape, where one side of the battery cell is embedded in the liquid cooling plate. The heating film does not contact the liquid cooling plate.

[0042] There is a heating wire on the heating film, which is in contact with the battery cell and can heat the battery cell through the heating wire. In addition, a heating film temperature sensor is provided on the heating film to obtain the real-time temperature of the heating film.

[0043] A battery cell temperature sensor may be provided on the battery cell to obtain the real-time temperature of the battery cell.

[0044] The battery cell temperature sensor can be arranged on the surface of the battery cell, and there can be multiple of them. The heating film temperature sensor can be arranged on the heating wire of the heating film, or in the non-heating wire area of ​​the heating film, and there can be multiple of them.

[0045] The battery management system (BMS) can obtain the current temperature of the battery cell detected by the battery cell temperature sensor, and can also obtain the current temperature of the heating film detected by the heating film temperature sensor. It controls the heating power of the heating film and the temperature of the circulating liquid in the liquid cooling plate according to the current temperature of the battery cell. The temperature of the heating film is monitored by the heating film temperature sensor, and the temperature of the battery cell is monitored by the battery cell temperature sensor. The heating power and the temperature of the circulating liquid in the liquid cooling plate are adjusted according to the monitoring results to achieve controllable heating of the battery cell temperature.

[0046] When the temperature of the battery cell reaches the target temperature, the heating film can be stopped and the recyclable liquid in the liquid cooling plate can be discharged, or the heating film can be controlled to heat slowly to ensure that the battery cell temperature does not drop below the target temperature.

[0047] In this embodiment, a target temperature may be set. The target temperature is a temperature that the battery cell needs to reach or exceed. For example, it may be a temperature that the battery cell should not be lower than when the power battery is started or working.

[0048] If the temperature of the battery cell is lower than the target temperature, the battery cell needs to be heated. At this time, the heating power of the heating wire and the liquid temperature of the circulating liquid in the liquid cooling plate can be determined. The heating power is determined according to the power curve, which records the relationship between the current temperature of the battery cell and the heating power. In other words, different current temperatures of the battery cell can correspond to different heating powers. The liquid temperature of the circulating liquid is determined according to the circulating liquid temperature curve, which records the relationship between the liquid temperature of the circulating liquid and the current temperature of the battery cell. In other words, different current temperatures of the battery cell can correspond to different liquid temperatures.

[0049] After the heating power and the liquid temperature are determined by the two curves, heating is performed according to the heating power and circulating liquid is provided according to the liquid temperature to heat the battery cell until the current temperature of the battery cell is greater than or equal to the target temperature.

[0050] The solution provided by the embodiment of the present application obtains the current temperature of the battery cell of the power battery; when the current temperature of the above-mentioned battery cell is lower than the target temperature, determines the heating power of the heating film according to the power curve of the above-mentioned battery cell, and determines the liquid temperature of the circulating liquid in the liquid cooling plate according to the temperature curve of the circulating liquid of the above-mentioned battery cell, wherein the above-mentioned heating film is attached to one side of the above-mentioned battery cell, the above-mentioned liquid cooling plate is in contact with the above-mentioned battery cell, the above-mentioned power curve records the relationship between the current temperature of the above-mentioned battery cell and the heating power of the above-mentioned heating film, and the above-mentioned circulating liquid temperature curve records the relationship between the current temperature of the above-mentioned battery cell and the liquid temperature of the above-mentioned circulating liquid; injects the circulating liquid into the above-mentioned liquid cooling plate according to the above-mentioned liquid temperature; heats the above-mentioned heating film according to the above-mentioned heating power until the current temperature of the above-mentioned battery cell is equal to the above-mentioned target temperature, so that the liquid temperature and the heating power of the circulating liquid can be controlled according to the current temperature of the battery cell of the power battery, so as to achieve controllable heating of the battery cell.

[0051] As an optional example, in the process of heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature, the method further includes: detecting the current temperature of the battery cell once every predetermined time period; determining the temperature difference between the current temperature of the battery cell detected currently and the current temperature of the battery cell detected last time; when the temperature difference is less than the allowable temperature difference, increasing the heating power, and when the temperature difference is greater than the allowable temperature difference, reducing the heating power, wherein the allowable temperature difference is determined according to a temperature difference curve, and the temperature difference curve records the relationship between the current temperature of the battery cell and the allowable temperature difference.

[0052] In this embodiment, the process of heating the battery cell is a dynamically controlled process. The heating power used and the liquid temperature of the recyclable liquid are determined according to the current temperature of the battery cell. If the current temperature of the battery cell changes, the heating power used and the liquid temperature of the recyclable liquid will also change accordingly. For example, when the heating starts, the current temperature of the battery cell is x degrees Celsius, the heating power used is a1, and the liquid temperature of the recyclable liquid is b1. After heating, the current temperature of the battery cell changes to y degrees Celsius, then the corresponding heating power is adjusted to a2, and the liquid temperature of the recyclable liquid is adjusted to b2. In other words, the heating power and the liquid temperature of the recyclable liquid can be changed flexibly.

[0053] After the battery cell starts to be heated, the current temperature of the battery cell can be obtained once every predetermined time, and then the difference between the two current temperatures is the temperature difference. For example, after the heating starts, the temperature difference between the current temperature detected for the first time and the current temperature detected for the second time is 10 degrees Celsius, and the temperature difference between the current temperature detected for the second time and the current temperature detected for the third time is 20 degrees Celsius. The temperature difference can be compared with the allowable temperature difference. For example, if the allowable temperature difference is 15 degrees Celsius, the heating power should be increased when the temperature difference is 10 degrees Celsius for the second time, and the heating power should be reduced when the temperature difference is 20 degrees Celsius for the third time. The heating power is controlled by allowing the temperature difference to prevent the heating rate during the heating process of the battery cell from being too fast or too slow, and to maintain an average and stable level.

[0054] The allowable temperature difference is determined based on the temperature difference curve. The temperature difference curve can record the relationship between the current temperature of the battery cell and the allowable temperature difference. If the current temperature is different, the allowable temperature difference will be different.

[0055] As an optional example, when the current temperature of the battery cell is lower than the target temperature, the heating power of the heating film is determined according to the power curve of the battery cell, and the liquid temperature of the circulating liquid in the liquid cooling plate is determined according to the temperature curve of the circulating liquid of the battery cell, including: when the current temperature of the battery cell changes, the heating power after the change is obtained according to the power curve of the battery cell, and the liquid temperature after the change is determined according to the temperature curve of the circulating liquid.

[0056] In this embodiment, during the heating process of the battery cell, the heating power and the liquid temperature of the recyclable liquid are dynamically adjusted according to the current temperature of the battery cell. When the temperature of the battery cell rises, the heating power to be used and the liquid temperature of the recyclable liquid are determined according to the increased temperature of the battery cell. For example, when the heating starts, the current temperature of the battery cell is x degrees Celsius, the heating power used is a1, and the liquid temperature of the recyclable liquid is b1. After heating, the current temperature of the battery cell changes to y degrees Celsius, then the corresponding heating power is adjusted to a2, and the liquid temperature of the recyclable liquid is adjusted to b2. In other words, the heating power and the liquid temperature of the recyclable liquid can be flexibly changed.

[0057] As an optional example, before determining the heating power of the heating film according to the power curve of the above-mentioned battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the circulating liquid temperature curve of the above-mentioned battery cell, the above-mentioned method also includes: obtaining the internal temperature gradient of the test battery cell at different heating powers and different liquid temperatures of the circulating liquid; determining the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient according to the variation amplitude of the above-mentioned internal temperature gradient; generating the above-mentioned power curve and the above-mentioned circulating liquid temperature curve according to the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient.

[0058] This embodiment provides a method for obtaining a power curve and a circulating fluid temperature curve. In one method example, the two curves can be manually set according to empirical values. In another method example, the two curves can be determined based on test data obtained by performing a heating test on a test cell.

[0059] For example, in the case of using test cells to determine the curve, there can be multiple test cells, and the multiple test cells can be divided into multiple groups. Each group of test cells is heated using a heating power and a liquid temperature of the circulatory liquid. For example, the first group is heated using heating power 1 and liquid temperature 1, the second group is heated using heating power 1 and liquid temperature 2, the third group is heated using heating power 2 and liquid temperature 1, and the fourth group is heated using heating power 2 and liquid temperature 2. Then, for each group of cells, an internal temperature gradient can be obtained, and the internal temperature gradient is a curve of the change in the internal temperature of the cell at the heating power and liquid temperature. If the internal temperature gradients in a group of cells are different, the dissimilar curves are removed, and the remaining similar curves are averaged into an internal temperature gradient curve. For example, Figure 3 As shown, Figure 3 2 are exemplary internal temperature gradient curves of two groups of battery cells. Due to the different heating power and the liquid temperature of the circulatory liquid, the internal temperature gradients of the two groups of battery cells are different. The internal temperature gradient curve of the first group of battery cells is stable at first and then increases, while the internal temperature gradient curve of the second group of battery cells increases at first and then stabilizes ( Figure 3 for example only).

[0060] The change range of the cell temperature is the value of the change of the current temperature of the cell per unit time. For example, the change range of the first group of cells is small at first and then increases, while the change range of the second group of cells is large at first and then small.

[0061] As an optional example, the above-mentioned determination of the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient according to the variation amplitude of the above-mentioned internal temperature gradient includes: in any one of the above-mentioned internal temperature gradients, including a temperature segment in which the current temperature of the above-mentioned battery cell rises steadily, determining the current heating power of the heating film used for the above-mentioned internal temperature gradient and the current liquid temperature of the circulating liquid; determining the above-mentioned current heating power and the above-mentioned current liquid temperature as the heating power and liquid temperature corresponding to the above-mentioned temperature segment; determining the above-mentioned current heating power and the above-mentioned current liquid temperature in each temperature segment of the above-mentioned internal temperature gradient to obtain the heating power and liquid temperature corresponding to the above-mentioned internal temperature gradient.

[0062] Optional, continue combining Figure 3 Example, combined with Figure 4Description. In the internal gradient curve of the first group of battery cells, the current temperature 1 to the current temperature 2 rises smoothly, and in the internal gradient curve of the second group of battery cells, the current temperature 3 to the current temperature 4 rises smoothly. Therefore, it can be obtained that under the conditions of the heating power and liquid temperature of the first group of battery cells, the current temperature 1 to the current temperature 2 rises smoothly, and under the conditions of the heating power and liquid temperature of the second group of battery cells, the current temperature 3 to the current temperature 4 rises smoothly. Through the internal temperature gradients of multiple groups of battery cells, it is possible to obtain the temperature segments in which the current temperature of the battery cells rises smoothly from the beginning of heating to the temperature reaching the target temperature, and each temperature segment corresponds to a current heating power and a current liquid temperature. For example, Figure 4 The temperature segments from current temperature 1 to current temperature 2 and from current temperature 3 to current temperature 4 can be combined with multiple temperature segments obtained from other groups of cells, and the multiple temperature segments cover the entire process from the start of heating to the target temperature of the cell. It can be obtained that in the process of heating the cell, the heating power and the liquid temperature used in each temperature segment can promote the temperature of the cell to rise steadily.

[0063] As an optional example, generating the power curve and the circulatable liquid temperature curve according to the heating power and the liquid temperature corresponding to the internal temperature gradient includes:

[0064] Arrange the above-mentioned temperature segments in order from small to large temperature as one of the horizontal coordinates or vertical coordinates of the above-mentioned power curve and the above-mentioned circulating liquid temperature curve; use the above-mentioned current heating power and the above-mentioned current liquid temperature corresponding to each of the above-mentioned temperature segments as the other of the horizontal coordinates or vertical coordinates of the above-mentioned power curve and the above-mentioned circulating liquid temperature curve to obtain the above-mentioned power curve and the above-mentioned circulating liquid temperature curve.

[0065] In this embodiment, continue to combine Figure 3 , 4 Example explanation. After multiple temperature segments have been obtained, and the current liquid temperature and current heating power of each temperature segment are known. Therefore, the temperature segments of the current temperature can be sorted in order from small to large temperature, as one coordinate of the horizontal and vertical coordinates, and the current heating power is used as another coordinate, that is, the power curve is obtained. If the current liquid temperature is used as another coordinate, the circulating liquid temperature curve can be obtained. For example, Figure 5 is an exemplary power curve, such as Figure 5 As shown, the appropriate heating power can be determined according to the battery core temperature, and the heating power can make the battery core temperature rise steadily. The temperature curve of the circulating fluid will not be described in detail.

[0066] As an optional example, before detecting the current temperature of the battery cell once every predetermined period of time, the method further includes: determining the allowable temperature difference for the test cell at different current temperatures of the test cell to obtain the temperature difference curve, wherein the allowable temperature difference is the temperature that is increased per unit time when the test cell is at the current temperature and uses standard power heating and provides standard liquid temperature of the recyclable liquid.

[0067] In this embodiment, the temperature difference curve of the allowable temperature difference can be set manually. That is, the rising speed of the current temperature of the battery cell is set manually. If it exceeds the set rising speed, it means that the temperature rising speed is too fast. If it is less than the set rising speed, it means that the temperature rising speed is too slow. The allowable temperature difference can also be a temperature range. For example, Figure 6 Schematic diagram of the temperature difference curve between the battery cell temperature and the allowable temperature difference (temperature rise).

[0068] Figure 7 This is a schematic diagram of the structure of a battery core heating device provided in an embodiment of the present application. Figure 7 As shown, the above-mentioned battery core heating device includes:

[0069] An acquisition module 702 is used to acquire the current temperature of the battery cell of the power battery;

[0070] The determination module 704 is used to determine the heating power of the heating film according to the power curve of the battery cell when the current temperature of the battery cell is lower than the target temperature, and to determine the liquid temperature of the circulatory liquid in the liquid cooling plate according to the temperature curve of the circulatory liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulatory liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulatory liquid;

[0071] An injection module 706, for injecting a circulatory liquid into the liquid cooling plate according to the temperature of the liquid;

[0072] The heating module 708 is used to heat the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature.

[0073] like Figure 8 This is a schematic diagram of the structure of a battery core heating device provided in an embodiment of the present application. Figure 8 As shown, the above-mentioned battery core heating device includes:

[0074] The heating film 802 is used to cover the surface of the battery cell and heat the battery cell;

[0075] A heating film temperature sensor 804 is in contact with the heating film and is used to measure the temperature of the heating film;

[0076] The battery cell temperature sensor 806 is in contact with the battery cell and is used to measure the temperature of the battery cell;

[0077] The start-stop device 808 is connected to the heating film temperature sensor and the battery cell temperature sensor, and is used to start the heating of the heating film or terminate the heating of the heating film.

[0078] The above-mentioned start-stop device 808 is the above-mentioned BMS.

[0079] Fig. 9 It is a schematic diagram of temperature acquisition. As Fig. 9 shown, temperature sensors are installed on the battery cell tab and the side heating film, and the temperature sensors can transmit the temperatures of the heating film and the battery cell to the BMS in real time.

[0080] Fig.10 It is a schematic diagram of the liquid cooling plate of this embodiment. In the battery box, there is a liquid cooling plate at the bottom of the battery. The liquid cooling plate is provided with a water inlet and a water outlet, and the water inlet and the water outlet are respectively connected to the water outlet and the water inlet of the liquid cooling / heating unit to form a coolant (heating liquid) circulation loop. The BMS acquires the battery cell temperature in real time through the temperature sensor on the battery cell tab. The BMS stores the power curve, the temperature rise curve, and the recyclable liquid temperature curve. The operation of the heating film and the liquid cooling unit is controlled according to the three curves based on the real-time battery cell temperature.

[0081] Fig.11 It is a flowchart of this embodiment.

[0082] When the BMS receives the system start signal and reads the real-time battery cell temperature T_electricity in real time, and determines that T_electricity < T (T is the target temperature), it starts the heating of the heating film according to the power set by the battery cell temperature and the power curve, and controls the outlet water temperature of the liquid cooling unit according to the recyclable liquid temperature curve.

[0083] After the heating system runs for an interval of △t time, the battery cell temperature T_electricity2 is acquired in real time, and compared with the temperature T_electricity1 in the previous △t time, and △T_electricity = T_electricity2 - T_electricity1 is calculated. According to the temperature rise curve, the allowable temperature rise T_allow at the current temperature is determined:

[0084] When △T_electricity < T_allow, the heating power of the heating film is increased at a certain gradient until △T_electricity = T_allow;

[0085] When △T_electricity > T_allow, the heating power of the heating film is decreased at a certain gradient until △T_electricity = T_allow;

[0086] Read the real-time battery cell temperature T_electricity in real time, and when it is determined that T_electricity = T, stop the heating of the heating system.

[0087] The power curve is the maximum allowable heating power under different temperature conditions obtained by testing the battery cell under the condition of ensuring the temperature gradient inside the battery cell. In other words, it is the maximum power to ensure that the temperature of the battery cell is in a stable rising state. The temperature rise curve can be obtained by comprehensively considering the heat transfer efficiency inside the battery cell on the basis of the battery cell temperature and power curve, by testing the temperature rise and the temperature difference inside the battery cell under different heating rate conditions. Its purpose is to ensure the uniform temperature inside the battery cell by controlling the real-time temperature rise of the battery cell, and to prevent excessive temperature difference caused by too fast heating or too slow heating, which affects the heating efficiency.

[0088] The temperature curve of the circulating liquid can also be determined by experimental testing to ensure that the water inlet temperature of the liquid cooling plate and the real-time temperature curve of the battery cell are at different ambient temperatures under the condition of internal temperature difference of the battery cell.

[0089] Through this embodiment, not only the uniformity of the temperature inside the battery cell is improved, the heating power under different temperature conditions is optimized, and the relationship between the battery cell temperature and the heating power is reasonably adjusted. The temperature difference is small and the high power is used for rapid heating, and the temperature difference is large and the low power is used for heating. The time for the heat inside the battery cell to gradually diffuse with the temperature gradient is ensured, and the uniformity of the temperature inside the battery cell is effectively improved. In addition, the risk of thermal runaway can be reduced: according to the heat transfer law inside the battery cell, the temperature gradient inside the battery cell is ensured while heating, and the collected temperature is ensured to be basically consistent with the internal temperature of the battery cell, so as to prevent the battery cell from working at a high rate when the internal temperature is too low, which may damage the battery cell or even cause thermal runaway. Finally, the heating time is shortened and the heating efficiency is improved: the heating mode is optimized to ensure that the battery cell always maintains the maximum heating rate within a reasonable temperature range.

[0090] For other examples of this embodiment, please refer to the above examples and will not be described in detail here.

[0091] like Fig.12 As shown, an embodiment of the present application provides an electronic device, including a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0092] Memory 113, used for storing computer programs;

[0093] In one embodiment of the present application, the processor 111 is used to implement the battery cell heating method provided by any one of the aforementioned method embodiments when executing the program stored in the memory 113 .

[0094] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, a battery cell heating method as provided in any of the aforementioned method embodiments is implemented.

[0095] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0096] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0097] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0098] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for heating a battery core, characterized in that: include: Get the current temperature of the power battery cell; When the current temperature of the battery cell is lower than the target temperature, the heating power of the heating film is determined according to the power curve of the battery cell, and the liquid temperature of the circulating liquid in the liquid cooling plate is determined according to the temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid; injecting a circulatory liquid into the liquid cooling plate according to the temperature of the liquid; heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature; Wherein, before determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the circulating liquid temperature curve of the battery cell, the method further includes: obtaining the internal temperature gradient of the test battery cell at different heating powers and different liquid temperatures of the circulating liquid, wherein the internal temperature gradient is a curve of the change of the internal temperature of the battery cell over time at the heating power and the liquid temperature; determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the variation amplitude of the internal temperature gradient, wherein the variation amplitude is the value of the change of the current temperature of the battery cell in unit time; generating the power curve and the circulating liquid temperature curve according to the heating power and liquid temperature corresponding to the internal temperature gradient; Among them, determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the change amplitude of the internal temperature gradient includes: in any one of the internal temperature gradients, including a temperature segment in which the current temperature of the battery cell rises steadily, determining the current heating power of the heating film used by the internal temperature gradient and the current liquid temperature of the circulating liquid; determining the current heating power and the current liquid temperature as the heating power and liquid temperature corresponding to the temperature segment; determining the current heating power and the current liquid temperature of each temperature segment of the internal temperature gradient to obtain the heating power and liquid temperature corresponding to the internal temperature gradient.

2. The method according to claim 1, characterized in that In the process of heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature, the method further includes: Detecting the current temperature of the battery cell once at a predetermined time interval; Determine a temperature difference between a current temperature of the battery cell detected at a current time and a current temperature of the battery cell detected at a previous time; When the temperature difference is less than the allowable temperature difference, the heating power is increased, and when the temperature difference is greater than the allowable temperature difference, the heating power is reduced, wherein the allowable temperature difference is determined according to a temperature difference curve, and the temperature difference curve records the relationship between the current temperature of the battery cell and the allowable temperature difference.

3. The method according to claim 1, characterized in that When the current temperature of the battery cell is less than the target temperature, determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the temperature curve of the circulating liquid of the battery cell includes: When the current temperature of the battery cell changes, the changed heating power is acquired according to the power curve of the battery cell, and the changed liquid temperature is determined according to the temperature curve of the circulatable liquid.

4. The method according to claim 1, characterized in that The generating the power curve and the circulatable liquid temperature curve according to the heating power and the liquid temperature corresponding to the internal temperature gradient comprises: Arrange the temperature segments in order of temperature from small to large, and use them as one of the abscissas or ordinates of the power curve and the circulatable fluid temperature curve; The current heating power and the current liquid temperature corresponding to each temperature segment are used as the other of the abscissa or ordinate of the power curve and the circulatable liquid temperature curve to obtain the power curve and the circulatable liquid temperature curve.

5. The method according to claim 2, characterized in that: Before detecting the current temperature of the battery cell once every predetermined time period, the method further includes: Determine an allowable temperature difference for a test cell at different current temperatures of the test cell, wherein the allowable temperature difference is the temperature that the test cell increases in unit time at the current temperature when standard power is used for heating and a standard liquid temperature of a circulatory fluid is provided.

6. A battery core heating device, characterized in that: include: An acquisition module is used to obtain the current temperature of the battery cell of the power battery; a determination module, configured to determine the heating power of the heating film according to the power curve of the battery cell when the current temperature of the battery cell is lower than the target temperature, and to determine the liquid temperature of the circulatory liquid in the liquid cooling plate according to the temperature curve of the circulatory liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulatory liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulatory liquid; an injection module, used for injecting a circulatory liquid into the liquid cooling plate according to the temperature of the liquid; a heating module, used for heating the heating film according to the heating power until the current temperature of the battery cell is equal to the target temperature; Wherein, before determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the circulating liquid temperature curve of the battery cell, it also includes: obtaining the internal temperature gradient of the test battery cell at different heating powers and different liquid temperatures of the circulating liquid, the internal temperature gradient being a curve of the change of the internal temperature of the battery cell over time at the heating power and the liquid temperature; determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the variation amplitude of the internal temperature gradient, the variation amplitude being the value of the change of the current temperature of the battery cell in unit time; generating the power curve and the circulating liquid temperature curve according to the heating power and liquid temperature corresponding to the internal temperature gradient; Among them, determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the change amplitude of the internal temperature gradient includes: in any one of the internal temperature gradients, including a temperature segment in which the current temperature of the battery cell rises steadily, determining the current heating power of the heating film used by the internal temperature gradient and the current liquid temperature of the circulating liquid; determining the current heating power and the current liquid temperature as the heating power and liquid temperature corresponding to the temperature segment; determining the current heating power and the current liquid temperature of each temperature segment of the internal temperature gradient to obtain the heating power and liquid temperature corresponding to the internal temperature gradient.

7. A battery core heating device, characterized in that: include: A heating film, used to cover the surface of the battery cell and heat the battery cell; A heating film temperature sensor, in contact with the heating film, and used to measure the temperature of the heating film; A battery cell temperature sensor, in contact with the battery cell and used to measure the temperature of the battery cell; A start-stop device, connected to the heating film temperature sensor and the battery core temperature sensor, for starting or stopping heating of the heating film; Wherein, the device is also used to obtain the current temperature of the battery cell of the power battery; when the current temperature of the battery cell is lower than the target temperature, the heating power of the heating film is determined according to the power curve of the battery cell, and the liquid temperature of the circulating liquid in the liquid cooling plate is determined according to the temperature curve of the circulating liquid of the battery cell, wherein the heating film is attached to one side of the battery cell, the liquid cooling plate is in contact with the battery cell, the power curve records the relationship between the current temperature of the battery cell and the heating power of the heating film, and the circulating liquid temperature curve records the relationship between the current temperature of the battery cell and the liquid temperature of the circulating liquid; the circulating liquid is injected into the liquid cooling plate according to the liquid temperature; the heating film is heated according to the heating power until the current temperature of the battery cell is equal to the target temperature; Wherein, before determining the heating power of the heating film according to the power curve of the battery cell, and determining the liquid temperature of the circulating liquid in the liquid cooling plate according to the circulating liquid temperature curve of the battery cell, it also includes: obtaining the internal temperature gradient of the test battery cell at different heating powers and different liquid temperatures of the circulating liquid, the internal temperature gradient being a curve of the change of the internal temperature of the battery cell over time at the heating power and the liquid temperature; determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the variation amplitude of the internal temperature gradient, the variation amplitude being the value of the change of the current temperature of the battery cell in unit time; generating the power curve and the circulating liquid temperature curve according to the heating power and liquid temperature corresponding to the internal temperature gradient; Among them, determining the heating power and liquid temperature corresponding to the internal temperature gradient according to the change amplitude of the internal temperature gradient includes: in any one of the internal temperature gradients, including a temperature segment in which the current temperature of the battery cell rises steadily, determining the current heating power of the heating film used by the internal temperature gradient and the current liquid temperature of the circulating liquid; determining the current heating power and the current liquid temperature as the heating power and liquid temperature corresponding to the temperature segment; determining the current heating power and the current liquid temperature of each temperature segment of the internal temperature gradient to obtain the heating power and liquid temperature corresponding to the internal temperature gradient.

8. An electronic device, characterized in that: include: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor coupled to the at least one bus; At least one memory connected to the at least one bus, wherein a computer program is stored in the memory, and when the processor executes the computer program, the battery cell heating method described in any one of claims 1 to 5 is implemented.

9. A computer-readable storage medium, wherein the storage medium stores computer-executable instructions, wherein the computer-executable instructions are used to execute the battery cell heating method described in any one of claims 1 to 5 of the present application.

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