A lithium battery control device and control method

Abstract

The embodiment of the present application discloses a kind of lithium battery control device and control method, wherein lithium battery control device includes, liquid lithium battery loop, solid-state lithium battery loop, voltage sensor and control part;Liquid lithium battery loop and solid-state lithium battery loop are in parallel;Liquid lithium battery loop includes liquid lithium battery pack and first control switch;Liquid lithium battery pack and first control switch are in series;Solid-state lithium battery loop includes solid-state lithium battery pack, second control switch and current-limiting resistor;Solid-state lithium battery pack, second control switch and current-limiting resistor are in series;Solid-state lithium battery loop further includes third control switch;Second control switch and current-limiting resistor are in parallel with third control switch;The embodiment of the present application solves the problem that battery pack voltage is not matched when liquid lithium battery pack and solid-state lithium battery pack are used together, while realizing that the life of liquid lithium battery pack and solid-state lithium battery pack is nearly consistent.

Description

Technical Field

[0001] The present invention relates to rechargeable battery technology, and more particularly to a lithium battery control device and control method. Background Technology

[0002] Solid-state lithium battery technology is an advanced battery technology. Unlike commonly used liquid lithium batteries, solid-state lithium batteries use solid electrodes and solid electrolytes. Compared to liquid lithium batteries, solid-state lithium batteries have advantages such as better safety and higher energy density, with an energy density more than three times that of liquid batteries. However, current solid-state lithium batteries still have some shortcomings, such as poor power performance and short cycle life. In some applications, lithium batteries are required to have both high energy density and high power density, and it is difficult to meet the requirements of high energy and high power using only one type of lithium battery.

[0003] Therefore, solid-state batteries and liquid batteries are now commonly used together to form battery packs that combine the high power characteristics of liquid batteries and the high energy characteristics of solid-state batteries.

[0004] However, the battery packs constructed using the above methods have some problems. The two types of batteries have significantly different performance parameters, such as voltage range and charge / discharge rates. For example, the voltage range of a single liquid ternary lithium battery cell is generally 2.7V-4.2V, with a cycle life of up to 1500 cycles at room temperature and a rated discharge rate of 3-5C. Currently, the voltage range of a single solid-state lithium battery cell is generally 2.5V-4.7V, with a cycle life of around 500 cycles and a rated discharge rate of 1-2C. Directly connecting them in parallel can easily lead to battery voltage mismatch and shortened battery life. Summary of the Invention

[0005] This invention provides a lithium battery control device and control method to solve the problems of battery voltage mismatch and shortened battery life when liquid lithium batteries and solid lithium batteries are used together.

[0006] In a first aspect, embodiments of the present invention provide a lithium battery control device, comprising:

[0007] Liquid lithium battery circuit, solid lithium battery circuit, and control unit; liquid lithium battery circuit and solid lithium battery circuit are connected in parallel;

[0008] The liquid lithium battery circuit includes a liquid lithium battery pack and a first control switch; the liquid lithium battery pack and the first control switch are connected in series.

[0009] The solid-state lithium battery circuit includes a solid-state lithium battery pack, a second control switch, and a current-limiting resistor; the solid-state lithium battery pack, the second control switch, and the current-limiting resistor are connected in series; the solid-state lithium battery circuit also includes a third control switch; the second control switch and the current-limiting resistor are connected in parallel with the third control switch;

[0010] The voltage sensor is configured to acquire the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack.

[0011] The control unit is configured to control the on-off of the first control switch, the second control switch and the third control switch in response to the discharge instruction or the charge instruction and according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack.

[0012] Optionally, the lithium battery control device further comprises a cell equalizer, and the voltage sensor is further configured to acquire the current voltage of each cell of the liquid lithium battery pack and the current voltage of each cell of the solid lithium battery pack; the cell equalizer is configured to control the voltage difference of each cell of the liquid lithium battery pack to be less than a first threshold value and control the voltage difference of each cell of the solid lithium battery pack to be less than a second threshold value during the discharging process.

[0013] Optionally, the lithium battery control device further comprises a current sensor configured to detect the current value of the liquid lithium battery loop and / or the current value of the solid lithium battery loop and transmit the current value to the control unit; the control unit is configured to control the on-off of the first control switch, the second control switch and the third control switch according to the current value of the liquid lithium battery loop and / or the current value of the solid lithium battery loop.

[0014] Optionally, the voltage sensor is further configured to acquire the output voltage of the lithium battery control device and transmit the output voltage to the control unit; the control unit is configured to alarm when the output voltage exceeds a threshold voltage range and / or control the on-off of the first control switch, the second control switch and the third control switch.

[0015] Optionally, the lithium battery control device further comprises a switch state sensor configured to detect the switch state of the first control switch, the second control switch or the third control switch and transmit the switch state to the control unit; the control unit is configured to alarm when the control state of the first control switch, the second control switch or the third control switch is inconsistent with the state perceived by the switch state sensor.

[0016] In a second aspect, the embodiments of the present application further provide a lithium battery control method, which is suitable for the lithium battery control device of any one of the above-mentioned devices, and the method comprises the following steps:

[0017] acquiring a discharge instruction or a charge instruction;

[0018] acquiring the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack;

[0019] controlling the on-off of the first control switch, the second control switch and the third control switch in response to the discharge instruction or the charge instruction and according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack.

[0020] Optionally, in response to the discharging instruction or the charging instruction, and according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack, the on-off of the first control switch, the second control switch and the third control switch is controlled, including:

[0021] In response to the discharging instruction, the size relationship between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is judged.

[0022] If the current voltage value of the liquid lithium battery pack is less than or equal to the current voltage value of the solid lithium battery pack, the first control switch and the second control switch are controlled to be turned on, and the third control switch is controlled to be turned off.

[0023] If the current voltage value of the liquid lithium battery pack is greater than the current voltage value of the solid lithium battery pack, the second control switch and the third control switch are controlled to be turned off, and the first control switch is controlled to be turned on.

[0024] Optionally, in the discharging process, further including:

[0025] If the current voltage value of the liquid lithium battery pack is less than the discharging cut-off voltage of the liquid lithium battery pack, or the current voltage value of the solid lithium battery pack is less than the discharging cut-off voltage of the solid lithium battery pack, the first control switch, the second control switch and the third control switch are controlled to be turned off.

[0026] Optionally, in response to the discharging instruction or the charging instruction, and according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack, the on-off of the first control switch, the second control switch and the third control switch is controlled, including:

[0027] In response to the charging instruction, it is judged whether the absolute value of the difference between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is less than or equal to a preset threshold value;

[0028] If yes, the first control switch and the third control switch are controlled to be turned on, and the second control switch is controlled to be turned off; otherwise, it is judged whether the current voltage value of the liquid lithium battery pack is greater than the current voltage value of the solid lithium battery pack;

[0029] If yes, the first control switch and the second control switch are controlled to be turned off, and the third control switch is controlled to be turned on; otherwise, the second control switch and the third control switch are controlled to be turned off, and the first control switch is controlled to be turned on.

[0030] Optionally, in the charging process, further including:

[0031] If the current voltage value of the liquid lithium battery pack reaches the rated voltage of the liquid lithium battery pack, the first control switch is controlled to be turned off;

[0032] Or, if the current voltage value of the solid-state lithium battery reaches the rated voltage of the solid-state lithium battery, the third control switch is controlled to be turned off.

[0033] The embodiment of the present application reduces the discharge current of the solid-state lithium battery by connecting a current-limiting resistor in series when the solid-state lithium battery is discharged, and bears the voltage difference between the solid-state lithium battery pack and the liquid-state lithium battery pack. Further, the discharge depth of the solid-state lithium battery pack is limited, and the cycle number of the solid-state lithium battery pack is reduced. The service life of the solid-state lithium battery pack is close to that of the liquid-state lithium battery pack. The control unit can switch the lithium battery control device between charging and discharging states by controlling the first control switch, the second control switch and the third control switch. The present device can determine the charging and discharging states of the solid-state lithium battery pack and the liquid-state lithium battery pack according to the current voltage values of the solid-state lithium battery pack and the liquid-state lithium battery pack obtained by the voltage sensor, and further control the first control switch, the second control switch and the third control switch to be turned on or turned off, thereby protecting the device. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A general structure schematic diagram of a lithium battery control device provided by the embodiment of the present application is provided;

[0035] Figure 2 A general flow schematic diagram of a lithium battery control method provided by the embodiment of the present application is provided;

[0036] Figure 3 A partial flow schematic diagram of a lithium battery control method provided by the embodiment of the present application is provided; BRIEF DESCRIPTION OF DRAWINGS:

[0038] 1-liquid-state lithium battery pack, 2-solid-state lithium battery pack, 3-current sensor, 4-first control switch, 5-second control switch, 6-third control switch, 7-current-limiting resistor, 8-liquid-state lithium battery circuit, 9-solid-state lithium battery circuit DETAILED DESCRIPTION

[0039] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0040] The embodiment of the present application provides a lithium battery control device, Figure 1 A structure schematic diagram of a lithium battery control device provided by the embodiment of the present application is provided, referring to Figure 1The lithium battery control device comprises a liquid lithium battery circuit 8, a solid lithium battery circuit 9, and a control unit (not shown in the figure); the liquid lithium battery circuit 8 and the solid lithium battery circuit 9 are connected in parallel; the liquid lithium battery circuit 8 comprises a liquid lithium battery pack 1 and a first control switch 4; the liquid lithium battery pack 1 and the first control switch 4 are connected in series; the solid lithium battery circuit 9 comprises a solid lithium battery pack 2, a second control switch 5, and a current-limiting resistor 7; the solid lithium battery pack 2, the second control switch 5, and the current-limiting resistor 7 are connected in series; the solid lithium battery circuit 9 further comprises a third control switch 6; the second control switch 5, the current-limiting resistor 7, and the third control switch 6 are connected in parallel; a voltage sensor (not shown in the figure); the voltage sensor is used to obtain the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2; the control unit is used to control the on-off of the first control switch 4, the second control switch 5, and the third control switch 6 in response to a discharge instruction or a charge instruction and according to the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2.

[0041] The liquid lithium battery pack 1 and the solid lithium battery pack 2 can each comprise a single battery, and the single batteries can be connected in series, connected in parallel, or connected in series-parallel. The first control switch 4, the second control switch 5, and the third control switch 6 are devices for controlling the conduction or disconnection of the circuits in which they are located, for example, can be relays, MOS tubes, IGBT tubes, and the like, and the embodiments of the present application do not limit the specific types of the control switches.

[0042] The current-limiting resistor 7 is a resistor for limiting the current of the solid lithium battery circuit 9, which can be a fixed resistor or a variable resistor. The resistance value thereof can be determined according to the actual application scenario. When the current-limiting resistor 7 is a variable resistor, it can be a positive temperature coefficient resistor (PTC resistor). When the current flowing through the positive temperature coefficient resistor is high, the positive temperature coefficient resistor generates more heat, causing the resistance value of the positive temperature coefficient resistor to increase. Since the voltage is constant, the current flowing through the circuit is inversely proportional to the resistance of the circuit, so the current flowing through the positive temperature coefficient resistor decreases, forming a negative feedback regulation of the current of the solid lithium battery circuit 9, and obtaining a smaller and stable current of the solid lithium battery circuit 9. The current-limiting resistor 7 can also be other devices other than the above-mentioned devices, and the specific solutions will be described in detail below.

[0043] The current-limiting resistor 7 reduces the output current of the solid lithium battery circuit 9 by increasing the total resistance of the solid lithium battery circuit 9, thereby reducing the discharge depth of the solid lithium battery pack 2, delaying the decay rate of the solid lithium battery pack 2, and enabling the solid lithium battery pack 2 to have a service life basically the same as that of the liquid lithium battery pack 1.

[0044] The voltage sensor is a device for obtaining the current voltage value of the liquid lithium battery pack 1 and the solid lithium battery pack 2, for example, can be a device for determining the current voltage value of the liquid lithium battery pack 1 and the solid lithium battery pack 2 by measuring the output port voltage of the liquid lithium battery pack 1 and the solid lithium battery pack 2, or can be a device for determining the current voltage value of the liquid lithium battery pack 1 and the solid lithium battery pack 2 by measuring the single battery voltage of the liquid lithium battery pack 1 and the solid lithium battery pack 2 and calculating. The embodiments of the present application do not limit the specific type, working principle and model of the voltage sensor.

[0045] The control unit is a device for controlling the on-off of the first control switch 4, the second control switch 5 and the third control switch 6 according to the discharge instruction or the charge instruction, and the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2. Any device that can have the above functions can be used as the control unit in the embodiments of the present application, for example, can be a battery management system. The control logic of the control unit can be various, and one of them will be introduced as follows: when the control unit receives the discharge instruction, the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2 are obtained, and when the above voltage values are in the discharge voltage range, the control unit controls the first control switch 4 and the second control switch 5 to be closed; when the control unit receives the charge instruction, the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2 are obtained, and when the above voltage values are in the charge voltage range, the control unit controls the first control switch 4 and the third control switch 6 to be closed. The discharge voltage range and the charge voltage range can be determined according to actual needs.

[0046] In other embodiments, the lithium battery control device further comprises a single battery equalizer (not shown in the figure); the voltage sensor is further used to obtain the current voltage of each single battery of the liquid lithium battery pack 1 and the current voltage of each single battery of the solid lithium battery pack 2; the single battery equalizer is used to control the voltage difference of each single battery of the liquid lithium battery pack 1 to be less than a first threshold value and the voltage difference of each single battery of the solid lithium battery pack 2 to be less than a second threshold value during discharging.

[0047] The single battery equalizer is a device for controlling the voltage between each group of single batteries within a certain range. Any device that has the above functions can be used as the single battery equalizer, and the embodiments of the present application do not limit the specific type, model and working method of the single battery equalizer. For the sake of simplicity, one of the single battery equalizers and its working principle will be described below taking the solid lithium battery pack 2 as an example.

[0048] The monomer battery equalizer can be a load consumption equalizer. The load consumption equalizer is parallelly connected with a circuit formed by a discharge resistor and a control switch in series on each monomer battery, and the control switch of the load consumption equalizer can be controlled by the monomer battery equalizer or the control unit. The working principle is that the control unit determines the lowest voltage in the monomer battery collected by the voltage sensor, and adds a second threshold value to the lowest voltage to obtain the highest normal voltage. The monomer battery whose voltage exceeds the highest normal voltage is confirmed, and the control switch of the monomer battery is closed to discharge until the voltage of the monomer battery reaches the highest normal voltage, and the control switch is disconnected to stop discharging. The second threshold value can be set according to actual needs. The load consumption equalizer has the characteristics of simple structure and simple control logic, and is especially suitable for the solid-state lithium battery pack 2 or the liquid-state lithium battery pack 1 with more monomer batteries.

[0049] In other embodiments, the lithium battery control device further comprises a current sensor 3 for detecting the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 and transmitting to the control unit; the control unit controls the on-off of the first control switch 4, the second control switch 5 and the third control switch 6 according to the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9.

[0050] The current sensor 3 is a device for detecting the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 and transmitting to the control unit. The type of current sensor 3 is various, such as electronic current transformer and electromagnetic current transformer, etc. The working principle or specific model of the embodiment of the present application is not limited. The working principle of the current sensor 3 can be that, in the discharging process, the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 is detected, when the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 exceeds the preset alarm threshold value, the control unit alarms and requests the external control device connected with the device to reduce the output power; when the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 exceeds the preset disconnection threshold value within a certain time, the battery circuit with the current value exceeding the preset disconnection threshold value is disconnected by the control unit, and forced power-off is performed. In the charging process, when the current sensor 3 detects that the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 exceeds the alarm threshold value, the control unit sends an alarm instruction through the external communication interface, requests the external control device connected with the device to reduce the charging power; when the current value of the liquid-state lithium battery circuit 8 and / or the current value of the solid-state lithium battery circuit 9 exceeds the preset disconnection threshold value, the battery circuit with the current value exceeding the preset disconnection threshold value is disconnected by the control unit, and forced power-off is performed. The alarm threshold value and the disconnection threshold value in the charging and discharging process can be set according to actual needs. It can be seen that the current sensor 3 improves the safety of the device.

[0051] On this basis, the current-limiting resistor 7 can also be a digital potentiometer, which can be controlled by the control unit to change the resistance value according to the current size of the solid-state lithium battery circuit 9. The mapping relationship between the resistance value of the digital potentiometer and the current size of the solid-state lithium battery circuit 9 can be determined according to the actual application scenario.

[0052] In some other embodiments, the voltage sensor of the lithium battery control device is also used to obtain the output voltage of the lithium battery control device and transmit it to the control unit. The control unit is used to alarm when the output voltage exceeds the threshold voltage range, and / or control the on-off of the first control switch 4, the second control switch 5 and the third control switch 6.

[0053] Among them, the voltage sensor can also obtain the output voltage of the lithium battery control device. The voltage sensor can obtain the output voltage of the device by directly detecting the voltage at the output end of the device, or by detecting the voltage of the single battery in the liquid lithium battery pack 1 and calculating the output voltage of the device. The calculation method needs to be determined according to the connection relationship between the single batteries during actual use. In the discharge state, when the output voltage is lower than the lowest discharge voltage of the threshold voltage range or higher than the highest discharge voltage of the threshold voltage range, the control unit can alarm to the external control device connected to the device through the communication port. The control unit can also disconnect the circuit whose output voltage is lower than the lowest discharge voltage of the threshold voltage range or higher than the highest discharge voltage of the threshold voltage range, or disconnect all circuits by disconnecting the first control switch 4, the second control switch 5 and the third control switch 6, to ensure the safety of the device. The lowest discharge voltage and the highest discharge voltage of the threshold voltage range can be determined according to actual needs.

[0054] In some other embodiments, the lithium battery control device further comprises a switch state sensor (not shown in the figure), which is used to detect the switch state of the first control switch 4, the second control switch 5 or the third control switch 6 and send it to the control unit. The control unit is used to alarm when the control state of the first control switch 4, the second control switch 5 or the third control switch 6 is inconsistent with the state perceived by the switch state sensor.

[0055] Wherein, the switch state sensor is a sensor for detecting the switch state of the first control switch 4, the second control switch 5 or the third control switch 6, and the structure of the embodiment of the present application is not limited. When the control switch is a relay, the switch state sensor can be a feedback device in the relay. The switch state of the relay is transmitted to the control part by the auxiliary contact of the relay feedback device, and whether the switch state of the relay is consistent with the switch state of the issued command is detected by the control part. When the control switch is a MOS tube or an IGBT tube, a voltage detection device can be arranged at both ends of the source and the drain as a sensor of the switch state, and whether the voltage at both ends of the source and the drain is consistent is compared by the control part. If consistent, the control switch is in a normal state, and if inconsistent, the control switch is in an abnormal state. If in the abnormal state, the control part alarms the external control device connected to the device. Thus, the actual state of the device can be confirmed, and the alarm can be given in time to eliminate the hidden danger as soon as possible.

[0056] In other embodiments, the lithium battery control device further comprises a single battery temperature sensor (not shown in the figure), which is a sensor for detecting the temperature of the single battery of the liquid lithium battery pack 1 and / or the solid lithium battery pack 2, and can transmit the collected temperature information to the control part. When there is a single battery with a current temperature higher than the alarm temperature threshold in the single battery, the control part alarms the external control device connected to the device. When there is a single battery with a current temperature higher than the power-off temperature threshold in the single battery, the control part controls the first control switch 4, the second control switch 5 and the third control switch 6 to be disconnected. Wherein, the alarm temperature threshold and the power-off temperature threshold can be determined according to the actual application scene.

[0057] In other embodiments, the lithium battery control device further comprises an insulation monitoring module (not shown in the figure), which can be any existing module, such as JYJC-32, JYJC-64 or IM-32EA, etc. It can also be an auxiliary function module of an existing battery management system. The insulation monitoring module can monitor the insulation of the bus of the lithium battery control device in real time. When the insulation resistance of the bus of the lithium battery control device is lower than the preset insulation resistance, the control part alarms the external control device connected to the device. Wherein, the preset insulation resistance can be determined according to the actual use scene.

[0058] On the other hand, the embodiment of the present application discloses a lithium battery control method suitable for any of the above lithium battery control devices, Figure 2 The overall flowchart of the lithium battery control method provided by the embodiment of the present application is shown in the figure; Figure 2 The method comprises:

[0059] S110: obtaining a discharge command or a charge command;

[0060] S120: obtaining the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2;

[0061] S130: in response to the discharge instruction or the charge instruction, and according to the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2, controlling the on-off of the first control switch 4, the second control switch 5 and the third control switch 6.

[0062] The discharge instruction or the charge instruction can be provided by an external control device connected to the device. In response to the discharge instruction or the charge instruction, and according to the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2, the method of controlling the on-off of the first control switch 4, the second control switch 5 and the third control switch 6 can have various forms. One form is that according to the obtained discharge instruction, the first control switch 4 and the second control switch 5 are closed; and according to the obtained charge instruction, the first control switch 4 and the third control switch 6 are closed. This control method is simple and can reduce the operation pressure of the control part.

[0063] In other embodiments, in response to the discharge instruction or the charge instruction, and according to the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2, the method of controlling the on-off of the first control switch 4, the second control switch 5 and the third control switch 6 includes:

[0064] In response to the discharge instruction, judging the size relationship between the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2;

[0065] If the current voltage value of the liquid lithium battery pack 1 is less than or equal to the current voltage value of the solid lithium battery pack 2, the first control switch 4 and the second control switch 5 are controlled to be turned on, and the third control switch 6 is turned off.

[0066] If the current voltage value of the liquid lithium battery pack 1 is greater than the current voltage value of the solid lithium battery pack 2, the second control switch 5 and the third control switch 6 are controlled to be turned off, and the first control switch 4 is turned on.

[0067] The embodiment of the application can turn off the control switch of the solid lithium battery circuit 9 when the current voltage value of the liquid lithium battery pack 1 is greater than the current voltage value of the solid lithium battery pack 2, until the current voltage value of the liquid lithium battery pack 1 is equal to the current voltage value of the solid lithium battery pack 2. This avoids the current of the liquid lithium battery pack 1 from flowing back to the solid lithium battery pack 2, and further avoids the increase of the charge-discharge cycle times of the solid lithium battery pack 2, which leads to the reduction of the service life of the solid lithium battery pack 2.

[0068] In other embodiments, the discharge process further includes:

[0069] If the current voltage value of the liquid lithium battery pack 1 is less than the discharge cut-off voltage of the liquid lithium battery pack 1, or the current voltage value of the solid lithium battery pack 2 is less than the discharge cut-off voltage of the solid lithium battery pack 2, the first control switch 4, the second control switch 5 and the third control switch 6 are controlled to be turned off.

[0070] The embodiment of the present application can consider that the discharge of the device is completed when the discharge of any one of the solid lithium battery pack 2 and the liquid lithium battery pack 1 is completed. Since the discharge completion voltage of the solid lithium battery pack 2 is generally lower than the discharge completion voltage of the liquid lithium battery pack 1, and due to the voltage division effect of the current limiting resistor 7, the current voltage value of the solid lithium battery pack 2 should be higher than the current voltage value of the liquid lithium battery pack 1 after the first control switch 4 and the second control switch 5 are turned on for a period of time, so under normal circumstances, when the liquid lithium battery pack 1 completes the discharge, the solid lithium battery pack 2 still has power. Therefore, the embodiment can better reduce the discharge depth of the solid lithium battery pack 2, so that the service life of the solid lithium battery pack 2 is closer to the service life of the liquid lithium battery pack 1.

[0071] In other embodiments, referring to Figure 3 , in response to the discharge instruction or the charge instruction, and according to the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2, the on-off of the first control switch 4, the second control switch 5 and the third control switch 6 is controlled, including:

[0072] In response to the charge instruction, it is judged whether the absolute value of the difference between the current voltage value of the liquid lithium battery pack 1 and the current voltage value of the solid lithium battery pack 2 is less than or equal to a preset threshold value;

[0073] If yes, the first control switch 4 and the third control switch 6 are controlled to be turned on, and the second control switch 5 is controlled to be turned off; otherwise, it is judged whether the current voltage value of the liquid lithium battery pack 1 is greater than the current voltage value of the solid lithium battery pack 2;

[0074] If yes, the first control switch 4 and the second control switch 5 are controlled to be turned off, and the third control switch 6 is controlled to be turned on; otherwise, the second control switch 5 and the third control switch are controlled to be turned off, and the first control switch 4 is controlled to be turned on.

[0075] The embodiment of the present application separately charges the battery pack with low voltage when the voltage difference between the two battery packs is too high until the voltages of the two battery packs are equal, and then the two battery packs are charged in parallel. Or after the battery pack with low voltage is fully charged, the other battery pack is charged. This avoids damaging the battery pack due to the excessively high charging voltage.

[0076] In other embodiments, the charging process further includes:

[0077] If the current voltage value of the liquid lithium battery pack 1 reaches the rated voltage of the liquid lithium battery pack 1, the first control switch 4 is controlled to be turned off;

[0078] Alternatively, if the current voltage value of the solid-state lithium battery pack 2 reaches the rated voltage of the solid-state lithium battery pack 2, the third control switch 6 is controlled to be turned off.

[0079] The embodiment of the present application turns off the corresponding control switch after charging of any battery pack is completed, thereby avoiding overcharging of the battery pack and affecting the service life of the battery pack.

[0080] It should be noted that the above only describes the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, mutual combinations and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and more other equivalent embodiments can be included without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A lithium battery control device, characterized in that, include: A liquid lithium battery circuit, a solid lithium battery circuit, and a control unit; the liquid lithium battery circuit and the solid lithium battery circuit are connected in parallel; The liquid lithium battery circuit includes a liquid lithium battery pack and a first control switch; the liquid lithium battery pack and the first control switch are connected in series. The solid-state lithium battery circuit includes a solid-state lithium battery pack, a second control switch, and a current-limiting resistor; the solid-state lithium battery pack, the second control switch, and the current-limiting resistor are connected in series; the solid-state lithium battery circuit also includes a third control switch; the second control switch and the current-limiting resistor are connected in parallel with the third control switch; Voltage sensor; the voltage sensor is used to acquire the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack; The control unit is used to respond to a discharge command or a charge command, and to control the on / off state of the first control switch, the second control switch and the third control switch according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack. The step of responding to a discharge command or a charge command, and controlling the on / off state of the first control switch, the second control switch, and the third control switch according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack, includes: In response to a discharge command, the relationship between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is determined. If the current voltage value of the liquid lithium battery pack is less than or equal to the current voltage value of the solid lithium battery pack, then the first control switch and the second control switch are turned on, and the third control switch is turned off. If the current voltage value of the liquid lithium battery pack is greater than the current voltage value of the solid lithium battery pack, then the second control switch and the third control switch are turned off, and the first control switch is turned on. In response to a charging command, determine whether the absolute value of the difference between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is less than or equal to a preset threshold. If so, then control the first control switch and the third control switch to be turned on, and control the second control switch to be turned off; otherwise, determine whether the current voltage value of the liquid lithium battery pack is greater than the current voltage value of the solid lithium battery pack. If so, the first control switch and the second control switch are turned off, and the third control switch is turned on; otherwise, the second control switch and the third control switch are turned off, and the first control switch is turned on.

2. The lithium battery control device according to claim 1, characterized in that, It also includes a single-cell equalizer; the voltage sensor is also used to acquire the current voltage of each single cell in the liquid lithium battery pack and the current voltage of each single cell in the solid lithium battery pack; the single-cell equalizer is used to control the voltage difference between each single cell in the liquid lithium battery pack to be less than a first threshold and to control the voltage difference between each single cell in the solid lithium battery pack to be less than a second threshold during discharge.

3. The lithium battery control device according to claim 1, characterized in that, It also includes a current sensor, which is used to detect the current value of the liquid lithium battery circuit and / or the current value of the solid lithium battery circuit and transmit it to the control unit; the control unit controls the on / off state of the first control switch, the second control switch and the third control switch according to the current value of the liquid lithium battery circuit and / or the current value of the solid lithium battery circuit.

4. The lithium battery control device according to claim 1, characterized in that, The voltage sensor is also used to acquire the output voltage of the lithium battery control device and transmit it to the control unit; the control unit is used to issue an alarm when the output voltage exceeds the threshold voltage range, and / or control the on / off state of the first control switch, the second control switch and the third control switch.

5. The lithium battery control device according to claim 1, characterized in that, It also includes a switch status sensor, which is used to detect the switch status of the first control switch, the second control switch or the third control switch and send it to the control unit. The control unit is used to issue an alarm when the control status of the first control switch, the second control switch or the third control switch is inconsistent with the status sensed by the switch status sensor.

6. A lithium battery control method, characterized in that, The method, applicable to any one of claims 1-5, comprises: Obtain a discharge or charge command; Obtain the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack; In response to the discharge command or the charge command, and based on the current voltage values ​​of the liquid lithium battery pack and the solid lithium battery pack, the first control switch, the second control switch, and the third control switch are controlled to open and close.

7. The method according to claim 6, characterized in that, The step of responding to a discharge command or a charge command, and controlling the on / off state of the first control switch, the second control switch, and the third control switch according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack, includes: In response to a discharge command, the relationship between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is determined. If the current voltage value of the liquid lithium battery pack is less than or equal to the current voltage value of the solid lithium battery pack, then the first control switch and the second control switch are turned on, and the third control switch is turned off. If the current voltage of the liquid lithium battery pack is greater than the current voltage of the solid lithium battery pack, then the second control switch and the third control switch are turned off, and the first control switch is turned on.

8. The method according to claim 6, characterized in that, The discharge process also includes: If the current voltage of the liquid lithium battery pack is less than the discharge cutoff voltage of the liquid lithium battery pack, or the current voltage of the solid lithium battery pack is less than the discharge cutoff voltage of the solid lithium battery pack, then the first control switch, the second control switch, and the third control switch are controlled to disconnect.

9. The method according to claim 6, characterized in that, The step of responding to a discharge command or a charge command, and controlling the on / off state of the first control switch, the second control switch, and the third control switch according to the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack, includes: In response to a charging command, determine whether the absolute value of the difference between the current voltage value of the liquid lithium battery pack and the current voltage value of the solid lithium battery pack is less than or equal to a preset threshold. If so, then control the first control switch and the third control switch to be turned on, and control the second control switch to be turned off; otherwise, determine whether the current voltage value of the liquid lithium battery pack is greater than the current voltage value of the solid lithium battery pack. If so, the first control switch and the second control switch are turned off, and the third control switch is turned on; otherwise, the second control switch and the third control switch are turned off, and the first control switch is turned on.

10. The method according to claim 6, characterized in that, The charging process also includes: If the current voltage of the liquid lithium battery pack reaches the rated voltage of the liquid lithium battery pack, then the first control switch is turned off. Alternatively, if the current voltage of the solid-state lithium battery pack reaches the rated voltage of the solid-state lithium battery pack, the third control switch is turned off.

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