Battery heating circuit and method, circuit board and electronic equipment

Abstract

The invention provides a battery heating circuit and method, a circuit board and electronic equipment. The heating circuit comprises a battery, a control module, a first heating device and a second heating device; the control module is used for acquiring a health state parameter of the battery, and controlling the second heating device to heat the battery under the condition that the health state parameter is higher than a preset health state parameter threshold value; under the condition that the health state parameter is lower than the preset health state parameter threshold value, controlling the first heating device to heat the battery; compared with the prior art, the battery heating efficiency is improved on the premise of ensuring the safety of the battery.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a battery heating circuit, method, circuit board and electronic equipment. Background Art

[0002] Lithium-ion batteries are commonly used devices in the energy storage field, but in low temperature environments, the performance of lithium-ion batteries will be greatly reduced. Low temperature environments will also affect the life of lithium-ion batteries and even damage the batteries. Therefore, lithium-ion batteries need to be heated when they are working.

[0003] In the related art, an external heating module, such as a heating wire, is installed on the lithium-ion battery to provide heat to the lithium-ion battery through heat radiation from the external heating module to ensure that the lithium-ion battery is at a suitable operating temperature.

[0004] However, the efficiency of heating lithium-ion batteries through external heating modules is low, and it takes a long time to achieve the desired heating effect. Summary of the invention

[0005] The present application aims to provide a battery heating circuit, method, circuit board and electronic device to solve the problem of low heating efficiency in related technologies while ensuring battery safety.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] In a first aspect, an embodiment of the present application provides a heating circuit for a battery, the heating circuit comprising: a battery, a control module, a first heating device, and a second heating device;

[0008] The battery is electrically connected to the first heating device and the second heating device respectively, and the control module is electrically connected to the first heating device and the second heating device respectively; the first heating device is used to heat the battery by heat radiation or heat conduction; the second heating device is used to heat the battery by current pulse;

[0009] The control module is used to obtain a health state parameter of the battery, wherein the health state parameter of the battery is obtained by calculating a ratio of a current discharge capacity of the battery to an initial discharge capacity of the battery;

[0010] The control module is further configured to control the second heating device to heat the battery when the health state parameter is higher than a preset health state parameter threshold;

[0011] When the health state parameter is lower than the preset health state parameter threshold, the first heating device is controlled to heat the battery.

[0012] Optionally, a first switch module is provided between the battery and the first heating device; a second switch module is provided between the battery and the second heating device;

[0013] The control module is also used for:

[0014] When the health state parameter is higher than the preset health state parameter threshold, controlling the second switch module to conduct the second heating device and the battery, so that the second heating device heats the battery;

[0015] When the health state parameter is lower than the preset health state parameter threshold, the first switch module is controlled to conduct the first heating device and the battery, so that the first heating device heats the battery.

[0016] Optionally, the control module is also used to control the second heating device and the first heating device to heat the battery simultaneously when the health status parameter is higher than a set health status parameter threshold and the temperature of the battery is continuously lower than a preset ideal temperature within a preset period.

[0017] Optionally, the second heating device comprises: a bridge arm converter, a winding, and an energy storage element;

[0018] The first end of the bridge arm converter is electrically connected to the first polarity end of the battery, and the second end of the bridge arm converter is electrically connected to the second polarity end of the battery; one end of the winding is electrically connected to one end of the energy storage element, the other end of the winding is connected to the bridge arm converter, and the other end of the energy storage element is electrically connected to the second end of the bridge arm converter;

[0019] The bridge arm converter is used to receive a control instruction from a control module when the second heating device is connected to the battery, execute conversion between multiple preset states according to the control instruction, and regulate the charging and discharging between the battery and the energy storage element; when the energy storage element is discharged, the second heating device heats the battery.

[0020] Optionally, the bridge arm converter includes a first bridge arm switch and a second bridge arm switch; the first end of the bridge arm converter includes the first end of the first bridge arm switch, and the second end of the bridge arm converter includes the second end of the second bridge arm switch;

[0021] The first end of the first bridge arm switch is electrically connected to the first polarity end of the battery, the second end of the first bridge arm switch is electrically connected to the first end of the second bridge arm switch and one end of the winding, and the second end of the second bridge arm switch is electrically connected to the second polarity end of the battery and the other end of the energy storage element;

[0022] The multiple preset states include: a first preset state indicating that the first bridge arm switch is turned on and the second bridge arm switch is turned off, and a second preset state indicating that the first bridge arm switch is turned off and the second bridge arm switch is turned on;

[0023] The control module is further configured to, when the second heating device is connected to the battery, cyclically execute the following steps:

[0024] Controlling the bridge arm converter to enter a first preset state to charge the energy storage element;

[0025] When the capacity information of the energy storage element indicates that the current capacity of the energy storage element exceeds a preset capacity threshold, controlling the bridge arm converter to enter a second preset state from the first preset state;

[0026] When the current information of the winding indicates that the current of the winding is zero, the bridge arm converter is controlled to enter the first preset state from the second preset state to discharge the energy storage element until the voltage information of the energy storage element indicates that the current voltage of the energy storage element is equal to the voltage of the battery.

[0027] Optionally, the first heating device includes a heating resistor, and the heating resistor includes one or more of a heating block and a heating film; the heating block has a heating surface, and at least one of the heating surfaces directly or indirectly contacts the battery; the heating film is directly or indirectly coated on the outside of the battery.

[0028] Optionally, the first bridge arm switch and the second bridge arm switch include any one of an insulated gate bipolar transistor and an insulated gate field effect transistor.

[0029] In a second aspect, an embodiment of the present application provides a battery heating method, which is applied to the battery heating circuit as described in the first aspect, and the method includes:

[0030] Acquiring a health state parameter of the battery through a control module, wherein the health state parameter is determined according to a ratio of a current discharge capacity of the battery to an initial discharge capacity of the battery;

[0031] When the health state parameter is higher than a set health state parameter threshold, controlling the second heating device to heat the battery;

[0032] When the health state parameter is lower than the set health state parameter threshold, controlling the first heating device to heat the battery;

[0033] When the health state parameter is higher than a set health state parameter threshold and the temperature of the battery is continuously lower than a preset ideal temperature within a preset period, the second heating device and the first heating device are controlled to heat the battery simultaneously.

[0034] In a third aspect, the present application provides a battery heating circuit board, wherein the circuit board comprises the heating circuit as described in the first aspect.

[0035] In a fourth aspect, the present application provides an electronic device, comprising the circuit board as described in the third aspect.

[0036] In an embodiment of the present application, a second heating device is added in addition to the first heating device of the battery. By judging the relationship between the health status parameter of the battery and the preset health status parameter threshold, a scheme of turning on different circuits in different states and performing heating through different circuits is implemented; on the one hand, when the battery is in a good health state, the second heating device is used to heat the battery, and the current pulse generated by the second heating device can quickly generate a large amount of Joule heat, thereby improving the efficiency of heating the battery; on the other hand, when the battery is in a poor health state, the first heating device is used to heat the battery, thereby avoiding the second heating device causing the battery in a poor health state to heat up rapidly and cause thermal runaway, thereby ensuring the safety of the battery; compared with the scheme in the related art, the present application achieves an improvement in the battery heating efficiency while ensuring the safety of battery heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below.

[0038] Figure 1 It is a structural schematic diagram of a battery heating circuit provided in an embodiment of the present application;

[0039] Figure 2 is a specific structural schematic diagram of a battery heating circuit provided in an embodiment of the present application;

[0040] Figure 3a , Figure 3b , Figure 3c , Figure 3d They are schematic diagrams of current flow directions in four stages when the second heating device provided by the embodiment of the present application is connected to the battery;

[0041] Figure 4 It is a flowchart of the steps of the battery heating method provided in an embodiment of the present application.

[0042] Reference numerals:

[0043] 10 -battery; 20 -control module; 30 -first heating device; 40 -second heating device; 50 -first switch module; 60 -second switch module; 31 -heating resistor; 41 -bridge arm converter; 42 -winding; 43 -energy storage element; 411 -first bridge arm switch; 412 -second bridge arm switch. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of this application.

[0045] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0046] Reference Figure 1 , is a structural schematic diagram of a battery heating circuit provided in an embodiment of the present application, the heating circuit comprising: a battery 10, a control module 20, a first heating device 30, and a second heating device 40; the battery 10 is electrically connected to the first heating device 30 and the second heating device 40 respectively, and the control module 20 is electrically connected to the first heating device 30 and the second heating device respectively; the first heating device 30 is used to heat the battery 10 by heat radiation or heat conduction; the second heating device 40 is used to heat the battery 10 by current pulses; the control module 20 is used to obtain a health state parameter of the battery 10, and the health state parameter of the battery 10 is obtained by calculating the ratio of the current discharge capacity of the battery 10 to the initial discharge capacity of the battery 10; the control module 20 is also used to control the second heating device 40 to heat the battery 10 when the health state parameter is higher than a preset health state parameter threshold; and control the first heating device 30 to heat the battery 10 when the health state parameter is lower than the preset health state parameter threshold.

[0047] The battery heating circuit provided in the present application is first equipped with a first heating device 30. The first heating device 30 may include a basic heating circuit that generates heat through the thermal effect of electric current, and then transfers the heat to the battery through thermal radiation or heat conduction to achieve a battery heating effect; in the battery heating circuit of the present application, at least one second heating device 40 is connected in parallel to the first heating device 30, and the first heating device 30 or the second heating device 40 is turned on and off by the control module 20 to achieve a variety of heating methods. The present application can select a heating method by the health status parameter of the battery 10. The health status parameter of the battery 10 characterizes the health of the battery 10; it can be defined and calculated by the discharge capacity of the battery 10. Specifically, the health status (State of Health, SOH) parameter can be calculated according to the following formula:

[0048]

[0049] The discharge capacity of the battery 10 can be obtained by calculating the integral value of the current generated by the battery 10 during the process of discharging the voltage of the battery 10 to the set cut-off voltage; the initial discharge capacity refers to the discharge capacity of the battery 10 when it leaves the factory or is put into use for the first time; the SOH reflects the remaining life of the battery. As the battery 10 is used for a longer time, its internal resistance will gradually increase, the SOH will gradually decrease, the remaining life of the battery will decrease, and the available capacity will gradually decrease.

[0050] In addition to using discharge capacity to define and calculate SOH, SOH can also be defined and calculated by changes in the battery's internal resistance or the number of battery discharge cycles.

[0051] In the embodiment of the present application, the first heating device 30 and the second heating device 40 are electrically connected to the control module 20. The control module 20 can obtain the health status parameter of the battery and select the heating mode of the heating circuit according to the set health status parameter threshold:

[0052] When the health status parameter is higher than the preset health status parameter threshold, the second heating device 40 is controlled to heat the battery 10; when the health status parameter is higher than the preset health status parameter threshold, it indicates that the battery 10 has a good health status, and its internal resistance is close to the factory condition of the battery 10. In this regard, the second heating device can be used to heat the battery 10; the second heating device may include a pulse charging and discharging circuit that generates current pulses; when the second heating device 40 performs high-frequency pulse charging and discharging, it will generate a large current pulse, so that a large Joule heat is generated inside the battery 10 in a short time, so as to achieve the effect of heating the battery 10. Compared with the first heating device 30, the second heating device 40 has a higher heating efficiency.

[0053] When the health status parameter is lower than the preset health status parameter threshold, the first heating device 30 is controlled to heat the battery 10; when the health status parameter is lower than the preset health status parameter threshold, it indicates that the battery 10 has a poor health status, and its internal resistance is significantly greater than the factory condition of the battery 10. In this regard, the first heating device can be used to heat the battery 10; because the second heating device 40 will generate a large current pulse when performing high-frequency pulse charging and discharging, causing a large Joule heat to be generated inside the battery 10 in a short time, if the internal resistance of the battery 10 is large, the Joule heat accumulates inside the battery 10. If the battery 10 lacks a means of immediate heat dissipation, the temperature of the battery 10 will exceed the safety threshold in a short time, causing thermal runaway. Therefore, when the health status parameter of the battery 10 is low, the safer first heating device 30 can be used.

[0054] Exemplarily, the control module 20 may be a battery management system (BMS).

[0055] Exemplarily, the battery 10 may be a lithium-ion battery. In this case, when the health status parameter is higher than a preset health status parameter threshold, the second heating device 40 is controlled to heat the battery 10. This can also avoid the occurrence of lithium plating in the lithium-ion battery, thereby improving the heating efficiency of the battery 10 and extending the service life of the battery 10.

[0056] Exemplarily, the battery 10 may include a single cell, a battery module or a battery pack; in terms of application scenarios, the battery 10 may be used in commercial energy storage or household energy storage. For example, it may be used as a backup power source for household power supply to power household appliances.

[0057] Exemplarily, the preset health status parameter threshold can be set to 85%. If the health status parameter obtained by the control module 20 is 95%, the second heating device 40 is controlled to heat the battery 10; if the health status parameter obtained by the control module 20 is 75%, the first heating device 30 is controlled to heat the battery 10.

[0058] In an embodiment of the present application, a second heating device is added in addition to the first heating device of the battery. By judging the relationship between the health status parameter of the battery and the preset health status parameter threshold, a scheme of turning on different circuits in different states and performing heating through different circuits is implemented; on the one hand, when the battery is in a good health state, the second heating device is used to heat the battery, and the current pulse generated by the second heating device can quickly generate a large amount of Joule heat, thereby improving the efficiency of heating the battery; on the other hand, when the battery is in a poor health state, the first heating device is used to heat the battery, thereby avoiding the second heating device causing the battery in a poor health state to heat up rapidly and cause thermal runaway, thereby ensuring the safety of the battery; compared with the scheme in the related art, the present application achieves an improvement in the battery heating efficiency while ensuring the safety of battery heating.

[0059] Optional, see Figure 2 , is a specific structural diagram of the heating circuit of the battery 10 provided in an embodiment of the present application, wherein a first switch module 50 is provided between the battery 10 and the first heating device 30; a second switch module 60 is provided between the battery 10 and the second heating device 40; the control module 20 is also used for: when the health status parameter of the battery 10 is higher than the preset health status parameter setting threshold, controlling the second switch module 60 to connect the second heating device 40 and the battery 10, so that the second heating device 40 heats the battery 10; when the health status parameter of the battery 10 is lower than the preset health status parameter setting threshold, controlling the first switch module 50 to connect the first heating device 30 and the battery 10, so that the first heating device 30 heats the battery 10.

[0060] In the embodiment of the present application, the control module 20 can control the connection or disconnection between the battery 10 and the first heating device 30 through the first switch module 50. When the first heating device 30 and the battery 10 are connected, the current passes through the first heating device 30 to generate Joule heat, and the Joule heat is radiated to the surface of the battery 10 in the form of thermal radiation to achieve heating of the battery 10; the control module 20 can also control the connection or disconnection between the battery 10 and the pulse charging circuit through the second switch module 60. When the second heating device 40 and the battery 10 are connected, the second heating device 40 will generate a current pulse flowing to the battery 10. The current pulse flows through the inside of the battery 10 and can generate Joule heat to achieve heating of the battery 10; the control module 20 can switch the closing or opening of the first switch module 50 and the second switch module 60 according to the relationship between the health status parameter and the preset health status parameter threshold, so as to achieve the connection between the battery 10 and the first heating device 30 or the second heating device 40, so as to achieve different heating methods for the battery 10.

[0061] For example, the first switch module 50 and the second switch module 60 may both adopt single-control switches, or a single-control double-control switch may be used to replace the first switch module 50 and the second switch module 60 .

[0062] Optionally, the control module 20 is also used to control the second heating device 40 and the first heating device 30 to heat the battery 10 simultaneously when the health status parameter is higher than a set health status parameter threshold and the temperature of the battery 10 is continuously lower than a preset ideal temperature within a preset period.

[0063] In the embodiment of the present application, the battery 10 can be heated by only one of the second heating device 40 and the first heating device 30, or the second heating device 40 and the first heating device 30 can be selected to heat the battery 10 at the same time; the control module 20 can control the second heating device 40 and the first heating device 30 to heat the battery 10 at the same time when the health state parameter is higher than the set health state parameter threshold and the temperature of the battery 10 is continuously lower than the preset ideal temperature within a preset period; if the heating of the battery 10 by the second heating device 40 does not achieve the expected effect, the first heating device 30 can be controlled to heat the battery 10 at the same time to enhance the heating effect of the battery 10. The fact that the heating of the battery 10 by the second heating device 40 does not achieve the expected effect can be characterized by the fact that the temperature of the battery 10 is continuously lower than the preset ideal temperature within a preset period. The preset ideal temperature can refer to the temperature of the battery 10 when it is normally charged and discharged.

[0064] Exemplarily, the preset ideal temperature may include 0-45°C; the preset period may be preset according to user needs, and exemplary, the preset period may be set to several minutes to tens of minutes, such as 2 minutes, 5 minutes, 1 hour.

[0065] Exemplarily, the health status parameter threshold can be set to 85%, the preset ideal temperature can be 25°C, the preset period can be 5 minutes, and the health status parameter obtained by the control module 20 is 90%. The second heating device 40 is first turned on to heat the battery 10. Within 5 minutes after turning on the second heating device 40, if the temperature of the battery 10 still does not reach 25°C, then after 5 minutes, the first heating device 30 is turned on, and the battery 10 is heated by the first heating device 30 and the second heating device 40 at the same time.

[0066] Optional, see Figure 1The second heating device 40 includes: a bridge arm converter 41, a winding 42, and an energy storage element 43; the first end of the bridge arm converter 41 is electrically connected to the first polarity end of the battery 10, and the second end of the bridge arm converter 41 is electrically connected to the second polarity end of the battery 10; one end of the winding 42 is electrically connected to one end of the energy storage element 43, the other end of the winding 42 is connected to the bridge arm converter 41, and the other end of the energy storage element 43 is electrically connected to the second end of the bridge arm converter 41; the bridge arm converter 41 is used to receive a control instruction from the control module 20 when the second heating device 40 is connected to the battery 10, execute conversion between multiple preset states according to the control instruction, and regulate the charge and discharge between the battery 10 and the energy storage element 43; when the energy storage element 43 is discharged, the second heating device 40 heats the battery 10.

[0067] The circuit structure of the second heating device 40 can be as follows: Figure 1 As shown, the basic second heating device 40 can be formed by the bridge arm converter 41, the winding 42, and the energy storage element 43. In the second heating device 40, the winding 42 can be connected in series with the energy storage element 43, and further form a loop with a part of the bridge arm converter 41; the bridge arm converter 41 can be switched in multiple states according to the control instruction of the control module 20, and by switching the state of the bridge arm converter 41, the winding 42 and the energy storage element 43 can form a loop with the battery 10, or only the winding 42 and the energy storage element 43 can form a loop; when the second heating device 40 is connected to the battery 10, switching the state of the bridge arm converter 41 can make the energy storage element 43 and the winding 42 store energy or release energy, thereby generating current pulses of different directions between the energy storage element 43 and the battery 10, that is, the energy storage element 43 can receive charge from the battery 10, and can also discharge to the battery 10; in the process of the energy storage element 43 discharging to the battery 10, the current pulse generates Joule heat inside the battery 10, so as to achieve the effect of heating the battery 10.

[0068] The winding 42 is a component for electromagnetic conversion, which can realize energy conversion and storage; when the current in the loop passes through the winding 42, the winding 42 generates a magnetic field, converts electrical energy into magnetic energy and stores it, and when the loop is disconnected, the winding 42 releases the stored magnetic energy in the form of current to maintain the flow of current; in the embodiment of the present application, the winding 42 can release energy to the battery 10 or the energy storage element 43, and can also store energy from the battery 10 or the energy storage element 43. The energy storage element 43 is a component for storing electrical energy. In the embodiment of the present application, the energy storage element 43 can receive electrical energy from the battery 10 or the winding 42, and can also transmit electrical energy to the winding 42 or the battery 10 in the form of current.

[0069] Exemplarily, the energy storage element 43 may be a parallel plate capacitor, wherein one plate of the parallel plate capacitor is electrically connected to the winding 42 , and the other plate is electrically connected to the bridge arm converter 41 .

[0070] Optional, reference Figure 2 The bridge arm converter 41 includes a first bridge arm switch 411 and a second bridge arm switch 412; the first end of the bridge arm converter 41 includes the first end of the first bridge arm switch 411, and the second end of the bridge arm converter 41 includes the second end of the second bridge arm switch 412; the first end of the first bridge arm switch 411 is electrically connected to the first polarity end of the battery 10, the second end of the first bridge arm switch 411 is electrically connected to the first end of the second bridge arm switch 412 and one end of the winding 42, and the second end of the second bridge arm switch 412 is electrically connected to the second polarity end of the battery 10 and the other end of the energy storage element 43; the multiple preset states include: a first preset state representing that the first bridge arm switch 411 is turned on and the second bridge arm switch 412 is turned off, a first preset state representing that the first bridge arm switch 41 1 is disconnected, and the second bridge arm switch 412 is turned on; the control module 20 is also used for, when the second heating device 40 is turned on with the battery 10, cyclically executing the following steps: controlling the bridge arm converter 41 to enter the first preset state to charge the energy storage element 43; when the capacity information of the energy storage element 43 indicates that the current capacity of the energy storage element 43 exceeds the preset capacity threshold, controlling the bridge arm converter 41 to enter the second preset state from the first preset state; when the current information of the winding 42 indicates that the current of the winding 42 is zero, controlling the bridge arm converter 41 to enter the first preset state from the second preset state to discharge the energy storage element 43, until the voltage information of the energy storage element 43 indicates that the current voltage of the energy storage element 43 is equal to the voltage of the battery 10.

[0071] Specifically, the bridge arm converter 41 can be divided into a first bridge arm switch 411 and a second bridge arm switch 412 . The first bridge arm switch 411 and the second bridge arm switch 412 can receive control instructions from the control module 20 to execute closing or opening. In the loop formed by the bridge arm converter 41, the battery 10, the winding 42, and the energy storage element 43, when the first bridge arm switch 411 is closed, the current can flow from the first end of the first bridge arm switch 411 to the second end of the first bridge arm switch 411, and when the first bridge arm switch 411 is disconnected, the current can flow from the second end of the first bridge arm switch 411 to the first end of the first bridge arm switch 411; when the second bridge arm switch 412 is closed, the current can flow from the second end of the second bridge arm switch 412 to the second end of the second bridge arm switch 412, and when the second bridge arm switch 412 is disconnected, the current can flow from the second end of the second bridge arm switch 412 to the first end of the second bridge arm switch 412; in the above loop, the first end of the first bridge arm switch 411 is electrically connected to the positive electrode of the battery 10, the second end of the second bridge arm switch 412 is electrically connected to the negative electrode of the battery 10, and the second end of the first bridge arm switch 411 is electrically connected to the first end of the second bridge arm switch 412.

[0072] Combined with reference Figure 3a-3d The control module 20 can realize the charging and discharging of the energy storage element 43 and the winding 42 in the second heating device 40 by controlling the second heating device 40 to cyclically execute the following steps:

[0073] S1: Control the bridge arm converter 41 to enter a first preset state, that is, control the first bridge arm switch 411 to be turned on, and control the second bridge arm switch 412 to be turned off, so that the energy storage element 43 is charged.

[0074] At this time, the battery 10, the first bridge arm switch 411, the winding 42, and the energy storage element 43 form a complete circuit. The battery 10 discharges, the winding 42 stores electrical energy, and the energy storage element 43 charges. At this time, the current in the circuit flows as follows: Figure 3a shown.

[0075] S2: When the capacity information of the energy storage element 43 indicates that the current capacity of the energy storage element 43 exceeds the preset capacity threshold, the bridge arm converter 41 is controlled to enter the second preset state from the first preset state, that is, the first bridge arm switch 411 is controlled to be disconnected, and the second bridge arm switch 412 is controlled to be turned on.

[0076] The current capacity is used to represent the percentage of the ratio of the energy currently stored in the energy storage element 43 to the maximum energy stored in the energy storage element 43. The energy stored in the energy storage element 43 can be obtained through the control module 20; the preset capacity threshold represents the optimal energy storage state for energy release of the energy storage element 43.

[0077] Exemplarily, the preset capacity threshold may be 90%. When the energy stored in the energy storage element 43 reaches 90% of the maximum storage energy of the energy storage element, the first bridge arm switch 411 is controlled to be disconnected, and the second bridge arm switch 412 is controlled to be closed and turned on.

[0078] At this time, the second bridge arm switch 412, the winding 42, and the energy storage element 43 form a complete loop. Specifically, after executing step S2, the complete loop will enter the following states in sequence:

[0079] A1: The winding 42 releases energy, which flows to the energy storage element 43 in the form of current, so that the energy storage element 43 receives energy from the winding 42 and continues to charge.

[0080] A2: The current flowing through the winding 42 drops to zero, and the energy of the winding 42 is completely released; the current flow direction in state A1 and state A2 is as follows Figure 3b shown.

[0081] A3: The energy storage element 43 discharges, causing the winding 42 to store energy. The current flow direction in state A3 is as follows: Figure 3c shown.

[0082] When the current flowing through the winding 42 is detected to drop to zero again in the loop composed of the second bridge arm switch 412, the winding 42, and the energy storage element 43, step S3 is executed: the bridge arm converter 41 is controlled to enter the first preset state from the second preset state, so that the energy storage element 43 discharges until the voltage information of the energy storage element 43 indicates that the current voltage of the energy storage element 43 is equal to the voltage of the battery 10.

[0083] When the bridge arm converter 41 enters the first preset state from the second preset state, that is, the first bridge arm switch 411 is turned on and the second bridge arm switch 412 is turned off, the battery 10, the first bridge arm switch 411, the winding 42, and the energy storage element 43 form a complete loop again, and the energy storage element 43 continues to discharge. At the same time, the winding 42 releases energy and flows to the positive electrode of the battery 10 in the form of current, so that the energy storage element 43 discharges and charges the battery 10. At this time, the current in the loop flows as follows: Figure 3d As shown; charging the battery 10 can heat the battery 10.

[0084] The above Figure 2 , Figure 3a-3d The pulse charge and discharge circuit used as an example is only an optional implementation of the second heating device 40 in the embodiment of the present application. The embodiment of the present application does not make further restrictions on the variation or expansion of the second heating device 40.

[0085] Optionally, the first heating device 30 includes a heating resistor 31, and the heating resistor 31 includes one or more of a heating block and a heating film; the heating block has a heating surface, and at least one heating surface directly or indirectly contacts the battery 10; the heating film is directly or indirectly coated on the outside of the battery 10.

[0086] The first heating device 30 can heat the battery 10 by generating Joule heat through the heating resistor 31. The heating resistor 31 can be set as a heating block with multiple surfaces, at least one of which is in direct or indirect contact with the battery 10 to conduct heat or radiate heat to the battery 10. The heating resistor 31 can also be set as a heating film, which is directly or indirectly coated on the outside of the battery 10 through the heating film to conduct heat or radiate heat to the battery 10. The heating block is easier to obtain and has a lower cost, while the heating film has a larger direct or indirect contact area with the battery 10 and has a better heating effect.

[0087] The above Figure 2 The first heating device 30 taken as an example is only an optional implementation scheme provided in the embodiment of the present application. The embodiment of the present application does not make further restrictions on the variation or expansion of the first heating device 30.

[0088] Optionally, the first bridge arm switch 411 and the second bridge arm switch 412 include any one of an insulated gate bipolar transistor and an insulated gate field effect transistor.

[0089] Exemplarily, the first bridge arm switch 411 and the second bridge arm switch 412 may be implemented by an insulated gate bipolar transistor (IGBT) or an insulated gate field effect transistor (MOS). Figure 2 , Figure 3a-3d The implementation of using IGBT to implement the first bridge arm switch 411 and the second bridge arm switch 412 is merely given as an example.

[0090] In summary, in the embodiment of the present application, a second heating device is added in addition to the first heating device of the battery, and by judging the relationship between the health status parameter of the battery and the preset health status parameter threshold, a scheme of turning on different circuits in different states and performing heating through different circuits is realized; on the one hand, when the battery is in a good health state, the second heating device is used to heat the battery, and the current pulse generated by the second heating device can quickly generate a large amount of Joule heat, thereby improving the efficiency of heating the battery; on the other hand, when the battery is in a poor health state, the first heating device is used to heat the battery, thereby avoiding the second heating device causing the battery in a poor health state to heat up rapidly and cause thermal runaway, thereby ensuring the safety of the battery; compared with the scheme in the related art, the present application achieves an improvement in the battery heating efficiency while ensuring the safety of battery heating.

[0091] refer to Figure 4 The present application also provides a battery heating method, which is applied to the aforementioned battery heating circuit. The heating method includes:

[0092] Step 101: Acquire a health state parameter of a battery through a control module, wherein the health state parameter is determined according to a ratio of a current discharge capacity of the battery to an initial discharge capacity of the battery.

[0093] The control module needs to obtain the health status parameters of the battery. Through the SOH calculation formula mentioned above, the control module can obtain the health status parameters of the battery, so as to judge the health status of the battery according to the health status parameters, and select different heating methods according to the different health status of the battery.

[0094] Step 102: When the health status parameter is higher than a set health status parameter threshold, control the second heating device to heat the battery.

[0095] When the health status parameter is higher than the set health status parameter threshold, that is, when the health status parameter indicates that the battery is in a good health state, a second heating device is used to heat the battery. The high-frequency current pulse of the second heating device can quickly heat up the battery, thereby improving the heating efficiency of the battery.

[0096] Step 103: When the health status parameter is lower than the set health status parameter threshold, control the first heating device to heat the battery.

[0097] When the health status parameter is lower than the set health status parameter threshold, that is, when the health status parameter indicates that the health status of the battery is poor, the first heating device is used to heat the battery. For the battery in poor health status, its internal resistance value is increased compared with when it leaves the factory. The first heating device is used to heat the battery from the outside of the battery, which is less affected by the internal resistance value and can safely heat the battery, avoiding thermal runaway that may occur when the second heating device is used.

[0098] Step 104: When the health status parameter is higher than a set health status parameter threshold and the temperature of the battery is continuously lower than a preset ideal temperature within a preset period, control the second heating device and the first heating device to heat the battery simultaneously.

[0099] When using the second heating device to heat the battery, if the heating effect of the second heating device on the battery cannot reach the expected, the first heating device can be started again, and the battery can be heated by the second heating device and the first heating device at the same time to enhance the heating effect of the heating circuit on the battery, wherein the heating effect of the second heating device on the battery can be determined by whether the temperature of the battery exceeds the preset ideal temperature within a preset period.

[0100] In summary, in the embodiment of the present application, a second heating device is added in addition to the first heating device of the battery, and by judging the relationship between the health status parameter of the battery and the preset health status parameter threshold, a scheme of turning on different circuits in different states and performing heating through different circuits is realized; on the one hand, when the battery is in a good health state, the second heating device is used to heat the battery, and the current pulse generated by the second heating device can quickly generate a large amount of Joule heat, thereby improving the efficiency of heating the battery. When the effect of heating the battery using the second heating device cannot meet the expectations, the second heating device and the first heating device are simultaneously used to heat the battery to enhance the heating effect of the heating circuit; on the other hand, when the battery is in a poor health state, the first heating device is used to heat the battery, thereby avoiding the second heating device causing the battery in a poor health state to heat up rapidly and cause thermal runaway, thereby ensuring the safety of the battery; compared with the scheme in the related art, the present application selects targeted heating modes according to different health states of the battery, thereby improving the battery heating efficiency while ensuring the safety of battery heating.

[0101] An embodiment of the present application further provides a battery heating circuit board, comprising the battery heating circuit as described above.

[0102] The specific implementation process of the battery heating circuit in the battery heating circuit board is similar to the implementation process of the battery heating circuit described above, and will not be repeated here.

[0103] An embodiment of the present application also provides an electronic device, comprising at least one battery heating circuit board as described above.

[0104] The battery heating circuit in the battery heating circuit board in the electronic device is similar to the implementation process of the battery heating circuit mentioned above, which will not be repeated here.

[0105] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0106] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A battery heating circuit, characterized in that: The heating circuit comprises: a battery (10), a control module (20), a first heating device (30), and a second heating device (40); The battery (10) is electrically connected to the first heating device (30) and the second heating device (40), respectively; the control module (20) is electrically connected to the first heating device (30) and the second heating device (40), respectively; the first heating device (30) is used to heat the battery (10) by heat radiation or heat conduction; the second heating device (40) is used to heat the battery (10) by current pulses; The control module (20) is used to obtain a health state parameter of the battery (10), wherein the health state parameter of the battery (10) is obtained by calculating a ratio of a current discharge capacity of the battery (10) to an initial discharge capacity of the battery (10); The control module (20) is further used to control the second heating device (40) to heat the battery (10) when the health state parameter is higher than a preset health state parameter threshold; When the health state parameter is lower than the preset health state parameter threshold, the first heating device (30) is controlled to heat the battery (10).

2. The heating circuit according to claim 1, characterized in that: A first switch module (50) is provided between the battery (10) and the first heating device (30); and a second switch module (60) is provided between the battery (10) and the second heating device (40); The control module (20) is also used for: When the health state parameter is higher than the preset health state parameter threshold, controlling the second switch module (60) to conduct the second heating device (40) and the battery (10), so that the second heating device (40) heats the battery (10); When the health state parameter is lower than the preset health state parameter threshold, the first switch module (50) is controlled to conduct the first heating device (30) and the battery (10), so that the first heating device (30) heats the battery (10).

3. The heating circuit according to claim 1, characterized in that: The control module (20) is also used to control the second heating device (40) and the first heating device (30) to heat the battery (10) simultaneously when the health state parameter is higher than a set health state parameter threshold and the temperature of the battery (10) is continuously lower than a preset ideal temperature within a preset period.

4. The heating circuit according to claim 1, characterized in that: The second heating device (40) comprises: a bridge arm converter (41), a winding (42), and an energy storage element (43); The first end of the bridge arm converter (41) is electrically connected to the first polarity end of the battery (10), and the second end of the bridge arm converter (41) is electrically connected to the second polarity end of the battery (10); one end of the winding (42) is electrically connected to one end of the energy storage element (43), the other end of the winding (42) is connected to the bridge arm converter (41), and the other end of the energy storage element (43) is electrically connected to the second end of the bridge arm converter (41); The bridge arm converter (41) is used to receive a control instruction from a control module when the second heating device (40) is connected to the battery (10), and to perform conversion between a plurality of preset states according to the control instruction, thereby regulating the charge and discharge between the battery (10) and the energy storage element (43); and to achieve heating of the battery (10) by the second heating device (40) when the energy storage element (43) is discharged.

5. The heating circuit according to claim 4, characterized in that: The bridge arm converter (41) comprises a first bridge arm switch (411) and a second bridge arm switch (412); the first end of the bridge arm converter comprises the first end of the first bridge arm switch (411), and the second end of the bridge arm converter comprises the second end of the second bridge arm switch (412); The first end of the first bridge arm switch (411) is electrically connected to the first polarity end of the battery (10), the second end of the first bridge arm switch (411) is electrically connected to the first end of the second bridge arm switch (412) and one end of the winding (42), and the second end of the second bridge arm switch (412) is electrically connected to the second polarity end of the battery (10) and the other end of the energy storage element (43); The multiple preset states include: a first preset state indicating that the first bridge arm switch (411) is turned on and the second bridge arm switch (412) is turned off, and a second preset state indicating that the first bridge arm switch (411) is turned off and the second bridge arm switch (412) is turned on; The control module (20) is further configured to, when the second heating device (40) is connected to the battery (10), cyclically execute the following steps: Controlling the bridge arm converter (41) to enter a first preset state so that the energy storage element (43) is charged; When the capacity information of the energy storage element (43) indicates that the current capacity of the energy storage element (43) exceeds a preset capacity threshold, controlling the bridge arm converter (41) to enter a second preset state from the first preset state; When the current information of the winding (42) indicates that the current of the winding (42) is zero, the bridge arm converter (41) is controlled to enter the first preset state from the second preset state, so that the energy storage element (43) discharges until the voltage information of the energy storage element (43) indicates that the current voltage of the energy storage element (43) is equal to the voltage of the battery.

6. The heating circuit according to claim 1, characterized in that: The first heating device (30) comprises a heating resistor (31), and the heating resistor (31) comprises one or more of a heating block and a heating film; the heating block has a heating surface, and at least one of the heating surfaces directly or indirectly contacts the battery (10); the heating film is directly or indirectly coated on the outside of the battery (10).

7. The heating circuit according to claim 5, characterized in that: The first bridge arm switch (411) and the second bridge arm switch (412) include any one of an insulated gate bipolar transistor and an insulated gate field effect transistor.

8. A battery heating method, applied to the battery heating circuit according to any one of claims 1 to 7, characterized in that: The method comprises: Acquiring a health state parameter of the battery through a control module, wherein the health state parameter is determined according to a ratio of a current discharge capacity of the battery to an initial discharge capacity of the battery; When the health state parameter is higher than a set health state parameter threshold, controlling the second heating device to heat the battery; When the health state parameter is lower than the set health state parameter threshold, controlling the first heating device to heat the battery; When the health state parameter is higher than a set health state parameter threshold and the temperature of the battery is continuously lower than a preset ideal temperature within a preset period, the second heating device and the first heating device are controlled to heat the battery simultaneously.

9. A battery heating circuit board, characterized in that: The circuit board comprises the heating circuit according to any one of claims 1 to 7.

10. An electronic device, characterized in that: Comprising the circuit board as claimed in claim 9.

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