Battery and charge-discharge control method of battery

Abstract

This invention discloses a battery and a charging / discharging control method for the battery. The battery includes a cell pack, a thermal management system, and a charging / discharging management system. The cell pack includes at least three different types of cells, arranged in at least three nested layers. From the innermost to the outermost layer of the cell pack, the energy density of each type of cell gradually decreases, while the discharge capacity of each type of cell gradually increases within a preset temperature range. The charging / discharging management system controls the discharge of the corresponding type of cell based on the temperature and operating conditions of the cell pack during discharge, and also controls the operation of the thermal management system. During charging, the charging / discharging management system controls the charging power of each type of cell based on the temperature and charging mode of the cell pack, and also controls the operation of the thermal management system. This invention can improve the battery's low-temperature performance, energy density, charging speed, and safety.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery and a method for controlling the charging and discharging of the battery. Background Technology

[0002] With the rapid development of electric vehicles and energy storage systems, the performance requirements for battery packs are increasing.

[0003] Currently, the industry generally uses cells with a single chemical system to construct battery packs, such as ternary lithium batteries, lithium iron phosphate batteries, or sodium-ion batteries. Among them, ternary lithium batteries have a high energy density, but their cost and safety are insufficient; lithium iron phosphate batteries have a lower cost and better safety, but their energy density and low-temperature performance are poor; sodium-ion batteries have advantages in cost and low-temperature performance, but their energy density is relatively low. Using any type of cell alone makes it difficult to simultaneously achieve multiple goals such as high energy density, excellent safety, good low-temperature performance, and low cost, which restricts further improvement in the overall performance of battery packs. Summary of the Invention

[0004] This invention provides a battery and a method for controlling the charging and discharging of the battery, in order to improve the low-temperature performance, energy density, charging speed and safety of the battery.

[0005] In a first aspect, embodiments of the present invention provide a battery, the battery comprising a cell pack, a thermal management system, and a charge / discharge management system; The battery cell assembly includes at least three different types of battery cells, and the battery cells of each type are arranged in at least three nested layers; wherein, from the innermost layer to the outermost layer of the battery cell assembly, the energy density of each type of battery cell gradually decreases, and the discharge capability of each type of battery cell gradually increases within a preset temperature range. The thermal management system is located on one side of the battery cell assembly, and the thermal management system is used to control the temperature of the battery cell assembly. The charge / discharge management system is connected to the battery cell assembly and the thermal management system respectively. When the battery cell assembly is discharging, the charge / discharge management system controls the corresponding type of battery cell to discharge according to the temperature and operating conditions of the battery cell assembly, and controls the thermal management system to work. When the battery cell assembly is charging, the charge / discharge management system controls the charging power of each type of battery cell according to the temperature and charging mode of the battery cell assembly, and controls the thermal management system to work.

[0006] Optionally, at least three different types of battery cells include a first battery cell, a second battery cell, and a third battery cell, wherein the first battery cell is nested within the second battery cell, and both the first battery cell and the second battery cell are nested within the third battery cell, wherein the first battery cell is located in the innermost layer of the battery cell group, and the third battery cell is located in the outermost layer of the battery cell group; The energy density of the first battery cell is greater than the first energy density, the energy density of the second battery cell is greater than the second energy density, and the energy density of the third battery cell is greater than the third energy density. The first energy density is greater than the second energy density, and the second energy density is greater than the third energy density. The charge / discharge rate of the first battery cell within the preset temperature range is greater than the first charge / discharge rate, the charge / discharge rate of the second battery cell within the preset temperature range is greater than the second charge / discharge rate, and the discharge / charge / discharge rate of the third battery cell within the preset temperature range is greater than the third charge / discharge rate. The first charge / discharge rate is less than the second charge / discharge rate, and the second charge / discharge rate is less than or equal to the third charge / discharge rate.

[0007] Optionally, the charge / discharge management system is connected to the first battery cell, the second battery cell, and the third battery cell; The charge-discharge management system is used to control the corresponding cells to discharge according to the remaining charge of each cell and the discharge power of the cell group when the cell group is discharging; the charge-discharge management system is also used to control the thermal management system to cool the corresponding cells if the temperature of the cell group is higher than the preset cooling temperature when the cell group is discharging. The charge and discharge management system is used to control the charging of the corresponding cells according to the remaining power of each cell, the discharge power of the cell group and the temperature of the cell group when the cell group is being charged, and to control the thermal management system to cool the corresponding cells.

[0008] Optionally, the thermal management system includes a first circulation pipeline, a second circulation pipeline, a first heater, a second heater, a circulating water pump, a heat exchanger, and a solenoid three-way valve; The outlet of the circulating water pump is connected to the first end of the heat exchanger via a pipe, and the second end of the heat exchanger is connected to the inlet of the electromagnetic three-way valve via a pipe; the heat exchanger is used to control the temperature of the circulating liquid. The first heater is located at the inlet end of the first circulation pipeline, the first outlet of the electromagnetic three-way valve is connected to the inlet end of the first circulation pipeline, the outlet end of the first circulation pipeline is connected to the first inlet end of the circulating water pump, the first circulation pipeline is located on one side of the battery cell assembly, and the vertical projection of the first circulation pipeline on the battery cell assembly is located within at least one type of battery cell; the first circulation pipeline is used to heat or cool the corresponding battery cell through the circulating liquid. The second heater is located at the inlet end of the second circulation pipeline, the second outlet of the electromagnetic three-way valve is connected to the inlet end of the second circulation pipeline, the outlet end of the second circulation pipeline is connected to the second inlet end of the circulation pump, the second circulation pipeline is located on one side of the battery cell assembly, and the vertical projection of the second circulation pipeline on the battery cell assembly is located within at least two types of battery cells; the second circulation pipeline is used to heat or cool the corresponding battery cell through the circulating liquid.

[0009] Optionally, the electromagnetic three-way valve includes a valve body and a valve core; The inlet, the first outlet, and the second outlet are all located on the valve body, and the inlet is located between the first outlet and the second outlet. The inlet and the first outlet and the inlet and the second outlet are all spaced at a preset distance. The valve core is located at the center of the valve body. The valve core is used to control the connection between the water inlet and the first water outlet or / and the second water outlet by rotation, and to control the flow rate between the water inlet and the first water outlet or / and the second water outlet.

[0010] Optionally, the electromagnetic three-way valve further includes a servo motor, which is coaxially connected to the valve core; The servo motor is connected to the charging and discharging management system, and the charging and discharging management system is also used to send a control signal to the servo motor according to the temperature of the battery pack, so as to control the servo motor to rotate. The servo motor is used to control the rotation angle of the valve core by rotation, so as to control the connection or partial connection between the water inlet and the first water outlet, and the connection or partial connection between the water inlet and the second water outlet.

[0011] Optionally, the valve core includes a first interval point, a second interval point, and a third interval point, wherein the distances between the first interval point, the second interval point, and the third interval point are all the same; The central angle formed by the inlet and the first outlet with the center of the valve body is less than 120°, and the central angle formed by the inlet and the second outlet with the center of the valve body is less than 120°.

[0012] Optionally, the charging modes of the battery pack include at least a first fast charging mode and a second fast charging mode; The charging and discharging management system is also used to control the charging power of the inner layer of the battery cell to 0 when the temperature of the battery cell group is lower than the first preset temperature when the battery cell group is in the first fast charging mode, and to control the first circulation pipeline to be turned on and the first heater to be turned on to heat the outermost layer of the battery cell group. The charging and discharging management system is further configured to, when the battery cell assembly is in the first fast charging mode, control the first circulation pipeline to close, the first heater to turn off heating, and control the charging power of the inner battery cell to be 0 if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature; if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, and the temperature of the inner battery cell of the battery cell assembly is less than the second preset temperature, control the first heater to turn off heating, the second heater to turn on heating, control both the first circulation pipeline and the second circulation pipeline to open, and control the charging power of the inner battery cell of the battery cell assembly to be 0; wherein, the first preset temperature is less than the second preset temperature; The charging and discharging management system is also used to control the charging power of the inner layer of the battery cell to 0 when the temperature of the battery cell group is lower than the first preset temperature when the battery cell group is in the second fast charging mode, and to control both the first heater and the second heater to turn on for heating, and both the first circulation pipeline and the second circulation pipeline to open.

[0013] Secondly, embodiments of the present invention also provide a battery charging and discharging control method, the battery charging and discharging control method being used to control the charging and discharging of the battery described in any embodiment of the present invention, the battery charging and discharging control method comprising: When the battery cell assembly is discharging, the corresponding type of battery cell is controlled to discharge according to the temperature and operating conditions of the battery cell assembly, and the thermal management system is controlled to work. During the charging of the battery cell assembly, the charging power of each type of battery cell is controlled according to the temperature and charging mode of the battery cell assembly, and the thermal management system is also controlled to operate.

[0014] Optionally, the battery cell includes a first battery cell, a second battery cell, and a third battery cell. During battery cell group discharge, the corresponding type of battery cell is controlled to discharge according to the temperature and operating conditions of the battery cell group, and the thermal management system is controlled to operate, including: When discharging the battery pack within a first temperature range, if the remaining charge of the third battery cell and the second battery cell is greater than the first remaining charge, the third battery cell and the second battery cell are controlled to discharge. When the remaining power of the third battery cell and the second battery cell is less than or equal to the first remaining power, the first battery cell, the third battery cell, and the second battery cell are all controlled to discharge. When the battery cell group is controlled to discharge within the first temperature range, and the discharge power of the battery cell group is greater than the first discharge power and less than the second discharge power, the third battery cell and the second battery cell are controlled to discharge; the charge and discharge management system is further configured to control the first battery cell, the third battery cell and the second battery cell to discharge when the battery cell group is controlled to discharge within the first temperature range and the discharge power of the battery cell group is greater than the second discharge power. When the remaining charge of the second battery cell is less than the second remaining charge, the second battery cell is controlled to stop discharging; when the remaining charge of the third battery cell is less than the third remaining charge, the third battery cell is controlled to stop discharging; wherein, the first remaining charge is greater than the second remaining charge, and the second remaining charge is greater than the third remaining charge; The charging modes of the battery cell assembly include at least a first fast charging mode and a second fast charging mode. During charging, the charging power of each type of battery cell is controlled according to the temperature of the battery cell assembly and the charging mode, and the thermal management system is controlled to operate, including: When the battery cell assembly is in the first fast charging mode, if the temperature of the battery cell assembly is lower than the first preset temperature, the charging power of the inner layer of the battery cell assembly is controlled to be 0, and the first circulation pipeline is controlled to be turned on, and the first heater is turned on to heat the outermost layer of the battery cell assembly. When the battery cell assembly is in the first fast charging mode, if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, the first circulation pipeline is controlled to close, the first heater is turned off, and the charging power of the inner battery cell of the battery cell assembly is controlled to be 0; if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, and the temperature of the inner battery cell of the battery cell assembly is less than the second preset temperature, the first heater is turned off, the second heater is turned on, both the first circulation pipeline and the second circulation pipeline are opened, and the charging power of the inner battery cell of the battery cell assembly is controlled to be 0; wherein, the first preset temperature is less than the second preset temperature; When the battery cell assembly is in the second fast charging mode, if the temperature of the battery cell assembly is lower than the first preset temperature, the charging power of the battery cell in the inner layer of the battery cell assembly is controlled to be 0, the first heater and the second heater are both turned on for heating, and the first circulation pipeline and the second circulation pipeline are both opened.

[0015] This invention provides a battery and a charging / discharging control method for the battery. The battery includes a cell pack, a thermal management system, and a charging / discharging management system. The cell pack includes at least three different types of cells, arranged in at least three nested layers. From the innermost to the outermost layer of the cell pack, the energy density of each type of cell gradually decreases, while the discharge capacity of each type of cell gradually increases within a preset temperature range. This ensures the performance of the entire battery pack at low temperatures while maintaining the battery's energy density. The thermal management system is located on one side of the cell pack and is used to control the temperature of the cell pack. The charging / discharging management system... Connected to the cell pack and thermal management system, the charge / discharge management system controls the discharge of corresponding types of cells based on the temperature and operating conditions of the cell pack during discharge, and also controls the operation of the thermal management system. During charging, the system controls the charging power of each type of cell based on the temperature and charging mode of the cell pack, and also controls the operation of the thermal management system. This allows the thermal management system to control the battery temperature during charging and discharging, improving charging speed and safety, and preventing excessively low or high battery temperatures. Ultimately, this results in a battery pack with advantages such as good low-temperature performance, high energy density, fast charging speed, and high safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a battery provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the battery cell assembly provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another battery cell assembly provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the thermal management system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of an electromagnetic three-way valve provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the appearance of an electromagnetic three-way valve provided in an embodiment of the present invention; Figure 7 A schematic diagram of the first control logic for an electromagnetic three-way valve provided in an embodiment of the present invention; Figure 8 A schematic diagram of the second control logic for the electromagnetic three-way valve provided in an embodiment of the present invention; Figure 9 A schematic diagram of the third control logic for the electromagnetic three-way valve provided in an embodiment of the present invention; Figure 10 A schematic diagram of the fourth control logic for the electromagnetic three-way valve provided in an embodiment of the present invention; Figure 11 A schematic diagram of the fifth control logic of the electromagnetic three-way valve provided in an embodiment of the present invention; Figure 12 A schematic diagram of the sixth control logic of the electromagnetic three-way valve provided in the embodiment of the present invention; Figure 13 This is a schematic flowchart of a battery charging and discharging control method provided in an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0018] This invention provides a battery. Figure 1 This is a schematic diagram of the structure of a battery provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the battery cell assembly provided in an embodiment of the present invention, as shown below. Figure 1 and Figure 2 As shown, the battery includes a cell pack 110, a thermal management system 120, and a charge / discharge management system 130.

[0019] The cell assembly 110 includes at least three different types of cells 111, and the cells 111 of each type are arranged in at least three nested layers; wherein, from the innermost layer to the outermost layer of the cell assembly 110, the energy density of each type of cell 111 gradually decreases, and the discharge capacity of each type of cell 111 gradually increases within a preset temperature range.

[0020] The thermal management system 120 is located on one side of the cell pack 110 and is used to control the temperature of the cell pack 110.

[0021] The charge / discharge management system 130 is connected to the battery cell assembly 110 and the thermal management system 120 respectively. When the battery cell assembly 110 is discharging, the charge / discharge management system 130 controls the corresponding type of battery cell 111 to discharge according to the temperature and operating conditions of the battery cell assembly 110, and controls the thermal management system 120 to work. When the battery cell assembly 110 is charging, the charge / discharge management system 130 controls the charging power of each type of battery cell 111 according to the temperature and charging mode of the battery cell assembly 110, and controls the thermal management system 120 to work.

[0022] The battery cell assembly 110 includes at least three different types of battery cells 111, for example, Figure 2 The battery cell assembly 110 includes at least three different types of battery cells 111. Each battery cell 111 can be composed of multiple small battery cells. The battery cells 111 of each type are arranged in a nested manner. The outermost battery cell 111 wraps around the inner battery cell 111 of the battery cell assembly 110. The battery cells 111 in the middle of the battery cell assembly 110 can completely or partially wrap around the innermost battery cell 111 of the battery cell assembly 110, so as to take advantage of the high discharge capacity of the outermost battery cell 111 within a preset temperature range and ensure the performance of the entire battery cell assembly 110 within the preset temperature range. The preset temperature range can be a low temperature range. In winter, the temperature of the outermost cell 111 is the lowest and the temperature drops the fastest. The outermost cell 111 has a higher discharge capacity at low temperatures, meaning that its low-temperature charge and discharge capacity and energy retention rate are significantly better than those of the inner cells 111. By utilizing the high discharge capacity of the outermost cell 111 at low temperatures, the performance of the entire cell pack 110 at low temperatures can be guaranteed, giving the battery pack the advantages of both good low-temperature performance and high energy density.

[0023] Specifically, the thermal management system 120 can be composed of liquid cooling pipes and located on one side of the cell assembly 110 to heat or cool the cell assembly 110, control its temperature, and improve its safety. Furthermore, the charge / discharge management system 130 can be connected to both the cell assembly 110 and the thermal management system 120 to control the charging and discharging of each cell in the cell assembly 110 and to control the operation of the thermal management system 120.

[0024] The charge and discharge management system 130 can control the corresponding type of battery cell 111 to discharge according to the temperature and operating conditions of the battery cell group 110 when the battery cell group 110 is discharging. For example, the temperature of the battery cell group 110, the output power of the battery cell group 110 and the remaining charge of each battery cell can be used to control the corresponding battery cell 111 to discharge. The thermal management system 120 can be controlled to work according to the temperature of the battery cell group 110 to cool the battery cell group 110 when it heats up due to discharge. The charge / discharge management system 130 can also control the charging power of various types of cells 111 during the charging of the cell pack 110, based on the temperature and charging mode of the cell pack 110. For example, it can control the charging of the corresponding cells 111 based on the temperature and charging mode of the cell pack 110, the temperature of the cell pack 110, and the remaining capacity of each cell. When the temperature is low, the charging speed of the cells 111 will be reduced. Therefore, when the temperature is low, the charging power can be increased by controlling the operation of the thermal management system 120. This allows the thermal management system 120 to control the temperature of the battery during the charging and discharging process, thereby improving the charging speed and safety of the battery and preventing the battery temperature from being too low or too high. This gives the battery pack the advantages of good low-temperature performance, high energy density, fast charging speed, and high safety.

[0025] This invention provides a battery comprising a cell assembly, a thermal management system, and a charge / discharge management system. The cell assembly includes at least three different types of cells arranged in at least three nested layers. From the innermost to the outermost layer of the cell assembly, the energy density of each type of cell gradually decreases, while the discharge capacity of each type of cell gradually increases within a preset temperature range. This ensures the overall battery pack performance at low temperatures while maintaining the battery's energy density. The thermal management system is located on one side of the cell assembly and is used to control the temperature of the cell assembly. The charge / discharge management system is connected to the cell assembly. The battery pack is connected to the thermal management system. The charge / discharge management system controls the discharge of corresponding types of cells based on the temperature and operating conditions of the battery pack during discharge, and also controls the operation of the thermal management system. During charging, the charge / discharge management system controls the charging power of each type of cell based on the temperature and charging mode of the battery pack, and also controls the operation of the thermal management system. This allows the thermal management system to control the battery temperature during charging and discharging, improving the charging speed and safety of the battery, and preventing the battery temperature from being too low or too high. This gives the battery pack the advantages of good low-temperature performance, high energy density, fast charging speed, and high safety.

[0026] Figure 3 This is a schematic diagram of another battery cell assembly provided in an embodiment of the present invention, as shown below. Figure 3As shown, in some embodiments of the present invention, at least three different types of battery cells 111 include a first battery cell 111a, a second battery cell 111b, and a third battery cell 111c. The first battery cell 111a is nested inside the second battery cell 111b, and both the first battery cell 111a and the second battery cell 111b are nested inside the third battery cell 111c. The first battery cell 111a is located in the innermost layer of the battery cell group 110, and the third battery cell 111c is located in the outermost layer of the battery cell group 110. The energy density of the first cell 111a is greater than the first energy density, the energy density of the second cell 111b is greater than the second energy density, and the energy density of the third cell 111c is greater than the third energy density. The first energy density is greater than the second energy density, and the second energy density is greater than the third energy density. The charge / discharge rate of the first cell 111a within a preset temperature range is greater than the first charge / discharge rate, the charge / discharge rate of the second cell 111b within a preset temperature range is greater than the second charge / discharge rate, and the charge / discharge rate of the third cell 111c within a preset temperature range is greater than the third charge / discharge rate. The first charge / discharge rate is less than the second charge / discharge rate, and the second charge / discharge rate is less than or equal to the third charge / discharge rate.

[0027] The first cell 111a is located in the innermost layer of the cell group 110 and can be an energy-type lithium-ion battery; the second cell 111b is located in the middle layer of the cell group 110 and can be a power-type lithium-ion battery; and the third cell 111c is located in the outermost layer of the cell group 110 and can be a power-type lithium-ion battery.

[0028] The energy density of the first cell 111a is greater than the first energy density, which can be 250 Wh / kg. The energy density of the second cell 111b is greater than the second energy density, which can be 175 Wh / kg. The energy density of the third cell 111c is greater than the third energy density, which can be 150 Wh / kg. The preset temperature range can be the ambient temperature range. The charge / discharge rate of the first cell 111a within the preset temperature range is greater than the first charge / discharge rate, which can be 1C. The charge / discharge rate of the second cell 111b within the preset temperature range is greater than the second charge / discharge rate, which can be 3C. The charge / discharge rate of the third cell 111c within the preset temperature range is greater than the third charge / discharge rate, which can be 3C. The first charge / discharge rate is less than or equal to the second charge / discharge rate, and the second charge / discharge rate is less than the third charge / discharge rate. The higher the first energy density, second energy density, third energy density, first charge / discharge rate, second charge / discharge rate, and third charge / discharge rate, the better. This utilizes the low-temperature characteristics of the first cell 111a, the second cell 111b, and the third cell 111c. In winter, the outermost third cell 111c has the lowest temperature and the fastest temperature drop. The low-temperature charge / discharge capability and energy retention rate of the third cell 111c are significantly better than those of the first cell 111a and the second cell 111b. Therefore, the performance of the entire battery pack at low temperatures can be guaranteed.

[0029] In some embodiments of the present invention, the charge and discharge management system 130 is connected to the first battery cell 111a, the second battery cell 111b and the third battery cell 111c; The charge and discharge management system 130 is used to control the corresponding cell 111 to discharge according to the remaining charge of each cell 111 and the discharge power of the cell group 110 when the cell group 110 is discharging; the charge and discharge management system 130 is also used to control the thermal management system 120 to cool the corresponding cell 111 when the temperature of the cell group 110 is higher than the preset cooling temperature when the cell group 110 is discharging.

[0030] The charge and discharge management system 130 is used to control the corresponding battery cell 111 to discharge according to the remaining charge of each battery cell 111, the discharge power of the battery cell group 110 and the temperature of the battery cell group 110 when the battery cell group 110 is charging, and to control the thermal management system 120 to cool the corresponding battery cell 111.

[0031] Specifically, the charge / discharge management system 130 is connected to the first battery cell 111a, the second battery cell 111b, and the third battery cell 111c to accurately obtain the remaining power of the first battery cell 111a, the second battery cell 111b, and the third battery cell 111c. When the battery cell group 110 discharges, the charge / discharge management system 130 controls the corresponding battery cell 111 to discharge according to the remaining power of each battery cell 111 and the discharge power of the battery cell group 110. For example, when the battery cell group 110 is in a first temperature range and the battery cell group 110 is being controlled to discharge, if the remaining power of the second battery cell 111b and the third battery cell 111c is greater than the first remaining power, the second battery cell 111b and the third battery cell 111c are controlled to discharge first; if the remaining power of the second battery cell 111b and the third battery cell 111c is less than or equal to the first remaining power, the first battery cell 111a, the second battery cell 111b, and the third battery cell 111c are controlled to discharge second. Both cell 111b and the third cell 111c discharge. When cell group 110 discharges within the first temperature range, and the discharge power of cell group 110 is greater than the first discharge power and less than the second discharge power, the second cell 111b and the third cell 111c are controlled to discharge preferentially. When cell group 110 discharges within the first temperature range, and the discharge power of cell group 110 is greater than the second discharge power, the first cell 111a, the second cell 111b, and the third cell 111c are controlled to discharge. When the remaining charge of the second cell 111b is less than the second remaining charge, the second cell 111b is controlled to stop discharging. When the remaining charge of the third cell 111c is less than the third remaining charge, the third cell 111c is controlled to stop discharging. Wherein, the first remaining charge is greater than the second remaining charge, and the second remaining charge is greater than the third remaining charge. The charge / discharge management system 130 can also control the thermal management system 120 to cool the corresponding battery cell 111 if the temperature of the battery cell group 110 is higher than the preset cooling temperature during the discharge process of the battery cell group 110.

[0032] When controlling the charging of the battery cell assembly 110, the charge / discharge management system 130 can control the charging of the corresponding battery cell 111 based on the remaining charge of each battery cell 111, the discharge power of the battery cell assembly 110, and the temperature of the battery cell assembly 110. Simultaneously, it controls the thermal management system 120 to cool the corresponding battery cell 111 to improve charging efficiency. The thermal management system 120 can perform targeted cooling and heating of the first battery cell 111a, the second battery cell 111b, and the third battery cell 111c during the charging and discharging process, thereby improving temperature control efficiency, enhancing safety, precisely controlling the temperature of the battery cell assembly 110, and improving the overall temperature uniformity of the battery cell assembly 110.

[0033] Figure 4 This is a schematic diagram of the structure of the thermal management system provided in an embodiment of the present invention, as shown below. Figure 4As shown, in some embodiments of the present invention, the thermal management system 120 includes a first circulation pipeline 121, a second circulation pipeline 122, a first heater 123, a second heater 124, a circulating water pump 125, a heat exchanger 126, and a solenoid three-way valve 127.

[0034] The outlet of the circulating water pump 125 is connected to the first end of the heat exchanger 126 via a pipe, and the second end of the heat exchanger 126 is connected to the inlet of the solenoid three-way valve 127 via a pipe; the heat exchanger 126 is used to control the temperature of the circulating liquid.

[0035] The heat exchanger 126 can cool the circulating liquid by exchanging heat with external water pipes. The circulating liquid is located in the first circulating pipe 121, the second circulating pipe 122, and various other pipes of the thermal management system 120. The circulating liquid can heat or cool the battery cell assembly 110. The electromagnetic three-way valve 127 can control the conduction of the first circulating pipe 121 and the second circulating pipe 122, that is, control the first circulating pipe 121 to form a circulating water circuit with the circulating water pump 125, or control the second circulating pipe 122 to form a circulating water circuit with the circulating water pump 125.

[0036] The first heater 123 is located at the inlet of the first circulation pipe 121. The first outlet of the electromagnetic three-way valve 127 is connected to the inlet of the first circulation pipe 121. The outlet of the first circulation pipe 121 is connected to the first inlet of the circulating water pump 125. The first circulation pipe 121 is located on one side of the cell assembly 110. The vertical projection of the first circulation pipe 121 on the cell assembly 110 is located within at least one type of cell 111. The first circulation pipe 121 is used to heat or cool the corresponding cell 111 through circulating liquid.

[0037] The second heater 124 is located at the inlet of the second circulation pipe 122. The second outlet of the electromagnetic three-way valve 127 is connected to the inlet of the second circulation pipe 122. The outlet of the second circulation pipe 122 is connected to the second inlet of the circulating water pump 125. The second circulation pipe 122 is located on one side of the cell assembly 110. The vertical projection of the second circulation pipe 122 on the cell assembly 110 is located within at least two types of cells 111. The second circulation pipe 122 is used to heat or cool the corresponding cells through circulating liquid.

[0038] Specifically, the first circulation pipe 121 and the second circulation pipe 122 can be located on the same side of the cell assembly 110. The first circulation pipe 121 is located outside the second circulation pipe 122. The vertical projection of the first circulation pipe 121 on the cell assembly 110 can be located within the third cell 111c, allowing for heating or cooling of the third cell 111c. The heat source for the first circulation pipe 121 is the first heater 123. The vertical projection of the second circulation pipe 122 on the cell assembly 110 is located within the first cell 111a and the second cell 111b, allowing for heating or cooling of the first cell 111a and the second cell 111b. The heat source for the second circulation pipe 122 is the second heater 124.

[0039] In addition, since the battery pack 110 generates heat during charging and discharging, the third battery cell 111c arranged on the periphery can heat the first battery cell 111a and the second battery cell 111b through heat conduction. When the temperature inside the battery pack 110 is too high or has an overheating tendency, the heat exchanger 126 can dissipate heat from the battery pack 110.

[0040] The first circulation pipe 121 and the second circulation pipe 122 can each form two circulating water circuits. The flow direction of the circulating liquid in the first circulation pipe 121 is: outlet of the circulating water pump 125, heat exchanger 126, electromagnetic three-way valve 127, first heater 123, first circulation pipe 121, and first inlet of the circulating water pump 125. The heating of the first battery cell 111a and the second battery cell 111b mainly depends on the third battery cell 111c and the second circulation pipe 122. The flow direction of the circulating liquid in the second circulation pipe 122 is: outlet of the circulating water pump 125, heat exchanger 126, electromagnetic three-way valve 127, second heater 124, second circulation pipe 122, and second inlet of the circulating water pump 125. The flow rate of the circulating water pump 125, the flow rate of the heat exchanger 126, the flow direction and flow rate inside the electromagnetic three-way valve 127, and the heating power of the first heater 123 and the second heater 124 can all be independently controlled by the charge and discharge management system 130.

[0041] In some embodiments of the present invention Figure 5 This is a schematic diagram of the structure of the electromagnetic three-way valve provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the appearance of the electromagnetic three-way valve provided in an embodiment of the present invention, as shown below. Figure 5 and Figure 6 As shown, the electromagnetic three-way valve 127 includes a valve body 1271 and a valve core 1272.

[0042] The inlet N, the first outlet M1, and the second outlet M2 of the electromagnetic three-way valve 127 are all located on the valve body 1271. The inlet N of the electromagnetic three-way valve 127 is located between the first outlet M1 and the second outlet M2. The inlet N and the first outlet M1 and the inlet N and the second outlet M2 are all spaced at a preset distance.

[0043] The valve core 1272 is located at the center of the valve body 1271. The valve core 1272 is used to control the connection between the inlet N and the first outlet M1 or / and the second outlet M2 by rotation, and to control the flow rate between the inlet N and the first outlet M1 or / and the second outlet M2.

[0044] Specifically, the valve body 1272 includes three pipe joints: the inlet N of the electromagnetic three-way valve 127, the first outlet M1, and the second outlet M2. The internal cavity of the valve body 1271 is circular, and the valve core 1272 is located at the center of the internal cavity of the valve body 1271. The circulating liquid flows into the valve body 1271 through the inlet N of the electromagnetic three-way valve 127. The valve core 1272 controls the connection between the inlet N and the first outlet M1 and / or the second outlet M2 by rotation. It can also control the connection between the inlet N and the first outlet M1, or between the inlet N and the second outlet M2, thereby controlling the flow rate between the inlet N and the first outlet M1 and / or the second outlet M2, controlling the flow rate of the circulating liquid to the first circulation pipe 121 or the second circulation pipe 122, and thus achieving precise temperature control of the battery cell assembly 110.

[0045] In some embodiments of the present invention, such as Figure 5 and Figure 6 As shown, the electromagnetic three-way valve 127 also includes a servo motor 1273, which is coaxially connected to the valve core 1272. The servo motor 1273 is connected to the charge and discharge management system 130. The charge and discharge management system 130 is also used to send control signals to the servo motor 1273 according to the temperature of the battery pack 110, and control the servo motor 1273 to rotate. The servo motor 1273 is used to control the rotation angle of the valve core 1272 by rotating it, so as to control the connection or partial connection between the water inlet N and the first water outlet M1, and the connection or partial connection between the water inlet N and the second water outlet M2.

[0046] Specifically, the servo motor 1273 is coaxially connected to the valve core 1272. The relative rotation is restricted by the key and keyway. The servo motor 1273 can rotate, thereby controlling the rotation angle of the valve core 1272 to control the connection or partial connection between the inlet N and the first outlet M1, and between the inlet N and the second outlet M2, thereby controlling the flow rate of the circulating liquid in the first circulation pipe 121 or the second circulation pipe 122, and thus achieving precise control of the temperature of the battery cell assembly 110.

[0047] The liquid chamber of valve body 1271 can be sealed by the valve body cover and valve core 1272, and the position where the motor shaft of servo motor 1273 passes through is sealed by a sealing ring to prevent liquid leakage. Valve core 1272 can control the liquid flow direction, flow rate and flow state at different angles.

[0048] In some embodiments of the present invention, such as Figure 5 and Figure 6 As shown, the valve core 1272 includes a first interval point A, a second interval point B, and a third interval point C. The valve core 1272 can be approximated as a triangle. The first interval point A, the second interval point B, and the third interval point C are located at the three corners of the valve core 1272, respectively, and the distances between the first interval point A, the second interval point B, and the third interval point C are all the same.

[0049] The central angle formed by the inlet N and the first outlet M1 with the center of the valve body 1272 is less than 120°, and the central angle formed by the inlet N and the second outlet M2 with the center of the valve body 1272 is less than 120°.

[0050] Specifically, by controlling the distances between the first interval point A, the second interval point B, and the third interval point C to be the same, that is, the central angles formed by adjacent first interval points A, second interval points B, and third interval points C with the center of the circle are all 120°, while the central angles formed by the inlet N and the first outlet M1 with the center of the valve body 1272 are less than 120°, and the central angles formed by the inlet N and the second outlet M2 with the center of the valve body 1272 are also less than 120°. For example, the distances between the inlet N and the first outlet M1 with the center of the valve body 1272 are... The central angle formed by the centers of the valve body 1272 is 90°. The central angle formed by the inlet N and the second outlet M2 with the center of the valve body 1272 is also 90°. This ensures that the valve core 1272 can connect or partially connect the inlet N with the first outlet M1 and the inlet N with the second outlet M2 when it rotates. This controls the flow rate of the circulating liquid in the first circulation pipe 121 or the second circulation pipe 122, thereby achieving precise temperature control of the battery cell assembly 110.

[0051] The valve core 1272 of the electromagnetic three-way valve 127 is controlled by the servo motor 1273 to rotate, thereby controlling the direction of fluid flow. It mainly includes six control logics, namely the first control logic, the second control logic, the third control logic, the fourth control logic, the fifth control logic, and the sixth control logic.

[0052] Figure 7 This is a schematic diagram of the first control logic for an electromagnetic three-way valve provided in an embodiment of the present invention. Figure 7 The first control logic of the electromagnetic three-way valve 127 is that the inlet N and the first outlet M1 of the electromagnetic three-way valve 127 are fully connected, the inlet N and the second outlet M2 of the electromagnetic three-way valve 127 are blocked by the valve core 1272, the flow of the second circulation pipeline 122 is 0, and the first outlet M1 is completely unobstructed. Therefore, the first control logic can realize the full flow of the first circulation pipeline 121.

[0053] Figure 8 This is a schematic diagram of the second control logic for the electromagnetic three-way valve provided in an embodiment of the present invention. Figure 8 The second control logic of the electromagnetic three-way valve 127 is that the inlet N and the second outlet M2 of the electromagnetic three-way valve 127 are partially connected, and the inlet N and the second outlet M2 of the electromagnetic three-way valve 127 are completely blocked by the valve core 1272. The flow rate of the second circulation pipeline 122 is 0, and the first outlet M1 is partially blocked and not completely flowable. Therefore, the flow control of the first circulation pipeline 121 can be realized under the second control logic.

[0054] Figure 9 This is a schematic diagram of the third control logic for the electromagnetic three-way valve provided in an embodiment of the present invention. Figure 9 The third control logic of the electromagnetic three-way valve 127 is that the inlet N and the second outlet M2 of the electromagnetic three-way valve 127 are fully connected. The inlet N and the first outlet M1 of the electromagnetic three-way valve 127 are blocked by the valve core 1272. The flow rate of the first circulation pipeline 121 is 0. The second outlet M2 is completely unobstructed. Therefore, the second circulation pipeline 122 can achieve full flow under the third control logic.

[0055] Figure 10 This is a schematic diagram of the fourth control logic for the electromagnetic three-way valve provided in an embodiment of the present invention. Figure 10 The fourth control logic of the electromagnetic three-way valve 127 is that the inlet N and the first outlet M1 of the electromagnetic three-way valve 127 are partially connected, and the inlet N and the first outlet M1 of the electromagnetic three-way valve 127 are completely blocked by the valve core 1272. The flow rate of the first circulation pipeline 121 is 0, and the second outlet M2 is partially blocked and not completely flowable. Therefore, the flow control of the second circulation pipeline 122 can be realized under the fourth control logic.

[0056] Figure 11 This is a schematic diagram of the fifth control logic for the electromagnetic three-way valve provided in an embodiment of the present invention. Figure 9 The fifth control logic of the electromagnetic three-way valve 127 is that the inlet N of the electromagnetic three-way valve 127 is blocked from the second outlet M2 and the first outlet M1 by the valve core 1272, and the flow rates of the first circulation pipeline 121 and the second circulation pipeline 122 are both 0.

[0057] Figure 12 This is a schematic diagram of the sixth control logic of the electromagnetic three-way valve provided in the embodiment of the present invention. The sixth control logic of the electromagnetic three-way valve 127 is that the inlet N of the electromagnetic three-way valve 127 is simultaneously connected to the second outlet M2 and the first outlet M1, and all of them are partially blocked by the valve core 1272. The flow rates of the first circulation pipeline 121 and the second circulation pipeline 122 are distributed by the rotation position of the valve core 1272, and the sum of the two flow rates is equal to the flow rate of the inlet N of the electromagnetic three-way valve 127.

[0058] In some embodiments of the present invention, the charging modes of the battery pack 110 include at least a first fast charging mode and a second fast charging mode.

[0059] The charge and discharge management system 130 is also used to control the charging power of the inner cells of the battery pack 110 to 0 when the temperature of the battery pack 110 is lower than the first preset temperature in the first fast charging mode, and to control the first circulation pipeline 121 to be turned on and the first heater 123 to be turned on to heat the outermost cells 111 of the battery pack 110.

[0060] The charge / discharge management system 130 is further configured to, when the battery cell assembly 110 is in the first fast charging mode, if the temperature of the battery cell assembly 110 is greater than a first preset temperature and less than a second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to a preset heating threshold or the temperature of the outermost battery cell 111 of the battery cell assembly 110 is greater than the second preset temperature, control the first circulation pipeline to close, the first heater to turn off heating, and control the charging power of the inner battery cell 111 of the battery cell assembly 110 to be 0; if the temperature of the battery cell assembly 110 is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to a preset heating threshold or the temperature of the outermost battery cell 111 of the battery cell assembly 110 is greater than the second preset temperature, and the temperature of the inner battery cell of the battery cell assembly 110 is less than the second preset temperature, control the first heater to turn off heating, the second heater to turn on heating, control both the first circulation pipeline 121 and the second circulation pipeline 122 to open, and control the charging power of the inner battery cell 111 of the battery cell assembly 110 to be 0; wherein, the first preset temperature is less than the second preset temperature.

[0061] The charge and discharge management system 130 is also used to control the charging power of the inner cells of the battery pack 110 to 0 when the temperature of the battery pack 110 is lower than the first preset temperature in the second fast charging mode, control the first heater 123 and the second heater 124 to turn on heating, and control the first circulation pipe 121 and the second circulation pipe 122 to open.

[0062] Specifically, the charging modes of the battery pack 110 include a first fast charging mode and a second fast charging mode. The first fast charging mode is a normal fast charging mode. The control scheme of the charge and discharge management system 130 in the first fast charging mode specifically includes: 1. When the initial maximum temperature of the entire cell pack 110 is below -20℃, the charging power of the first cell 111a and the second cell 111b is 0W. The first heater 123 is turned on to heat up and the first circulation pipeline 121 enters the first control logic to achieve full flow. The heating power of the first heater 123 is positively correlated with the initial temperature of the cell pack 110. At the same time, the charge and discharge management system 130 determines the charging power of the third cell 111c based on the current minimum temperature of the third cell 111c, the remaining charge (SOC), and the battery health status.

[0063] 2. When the minimum temperature of the third cell 111c in the cell pack 110 rises to -20℃ to -10℃, the heating power of the first heater 123 is negatively correlated with the cumulative heating power consumption. When the cumulative heating of the first heater 123 reaches the threshold or the minimum temperature of the third cell 111c is greater than -10℃, the first heater 123 is turned off. At the same time, the minimum temperature inside the cell pack 110 is detected. When the minimum temperature is still below -10℃, the second heater 124 is turned on to heat, and the electromagnetic three-way valve 127 is controlled to be in the sixth control logic, opening the shunt mode of the circulation pipeline. The first circulation pipeline 121 and the second circulation pipeline 122 are both connected, so that the battery temperature tends to be uniform. The charging power of the first cell 111a and the second cell 111b is still 0W. At the same time, the charging power of the third cell 111c is determined according to the current minimum temperature, SOC, and battery health status of the third cell 111c.

[0064] 3. When the lowest temperature of the entire cell group 110 is higher than -10℃, the second heater 124 is turned off, but the electromagnetic three-way valve 127 is kept in the sixth control logic. The first circulation pipeline 121 and the second circulation pipeline 122 are both open. The charging power of the first cell 111a, the second cell 111b and the third cell 111c is determined by the real-time collected cell minimum temperature, SOC and battery health status.

[0065] The second fast charging mode is the super fast charging mode. The control scheme of the charging and discharging management system 130 in the second fast charging mode includes: 1. When the initial maximum temperature of the entire cell pack 110 is below -20℃, the charging power of the first cell 111a is 0W, the first heater 123 and the second heater 124 are turned on for heating at the same time, the electromagnetic three-way valve 127 is in the sixth control logic, the first circulation pipeline 121 and the second circulation pipeline 122 are both open, the heating power of the first heater 123 is positively correlated with the initial temperature, the power of the second heater 124 is the highest rated power, and the charging power of the third cell 111c is determined according to the current minimum temperature, SOC and battery health status of the third cell 111c. 2. When the minimum temperature of the entire cell pack 110 rises to -20℃ to 0℃, the heating power of the first heater 123 is negatively correlated with the cumulative heating power consumption, and the power of the second heater 124 is positively correlated with the minimum temperature of the cell pack 110. At this time, only the third cell 111c is charged. 3. When the minimum temperature of the cell pack 110 is greater than 0℃, the first heater 123 is turned off, the second heater 124 is kept on, the electromagnetic three-way valve 127 is in the third control logic, the second circulation pipeline 122 is fully open, and the power of the second heater 124 is positively correlated with the minimum temperature of the cell pack 110. At the same time, the charging power is determined based on the minimum temperature, SOC and battery health status of the first cell 111a, the second cell 111b and the third cell 111c.

[0066] 4. When the highest temperature of the cell pack 110 reaches 25℃ or the lowest temperature reaches 18℃, the second heater 124 is turned off, the electromagnetic three-way valve 127 is in the third control logic, and the second circulation pipeline 122 is fully open to ensure the uniformity of the internal temperature of the battery pack. At the same time, the controller determines the charging power based on the current lowest cell temperature, SOC and battery health status of the first cell 111a, the second cell 111b and the third cell 111c.

[0067] 5. When the maximum temperature of the battery cell assembly 110 exceeds 35°C, the battery cell assembly 110 enters the heat dissipation mode, that is, the heat exchanger 126 is used to remove the heat of the battery cell assembly 110 and reduce the charging power of the second battery cell 111b and the third battery cell 111c.

[0068] The charging modes of the battery pack 110 can also include a normal temperature charging mode, which can be set by referring to points 3, 4, and 5 of the second fast charging mode.

[0069] Furthermore, the battery in this embodiment of the invention can be a vehicle battery. During driving, when the vehicle is started at a minimum temperature below -20°C for the cell pack 110, the charge / discharge management system 130 can prioritize using the third cell 111c to provide power to the vehicle. Simultaneously, the second heater 124 is activated, and the second circulation pipe 122 enters full-flow mode. The power for the second heater 124 can be supplied by the third cell 111c, and the heating power of the second heater 124 is positively correlated with the minimum temperature of the cell pack 110. Due to the self-heating of the third cell 111c and the continuous heating of the second heater 124 during vehicle operation, the temperature of the third cell 111c gradually increases. When the minimum cell temperature is above 0°C, the second cell 111b gradually participates in driving the vehicle, and the output power of the second cell 111b is positively correlated with the cell temperature.

[0070] In addition, when a user initiates a scheduled charging, if the minimum temperature of the battery cell pack 110 is below 10°C, the charge and discharge management system 130 can control the second heater 124 to turn on for heating. When the minimum temperature reaches 18°C, the second heater 124 turns off, while maintaining the full flow mode of the second circulation pipeline 122.

[0071] The charge / discharge management system 130 of this embodiment is also used to control the discharge of different battery cells 111 under different operating conditions. The control logic includes a low-temperature short-range discharge scheme, a normal-temperature full-condition discharge scheme, and a low-temperature long-range discharge scheme. The charge and discharge management system 130 is used to control the corresponding battery cell 111 to discharge according to the remaining charge of each battery cell 111, the discharge power of the battery cell group 110 and the temperature of the battery cell group 110 when the battery cell group 110 is charging, and to control the thermal management system 120 to cool the corresponding battery cell 111.

[0072] The low-temperature short-range discharge scheme includes: 1. When the remaining charge of the third cell 111c and the second cell 111b is higher than 50%, the third cell 111c and the second cell 111b are used first to extend the life of the first cell 111a; 2. When the cell group 110 discharges at high power (discharge power exceeds 50% of the maximum power), the third cell 111c and the second cell 111b are used first. When the SOC of the third cell 111c is lower than 5%, discharge stops, and when the SOC of the second cell 111b is lower than 20%, discharge stops; 3. When the SOC of the third cell 111c or the second cell 111b is lower than 50%, ... 4. When the battery pack 110 is discharging at ultra-high power (discharge power exceeds 70% of maximum power), the first battery cell 111a, the third battery cell 111c, and the second battery cell 111b can be used simultaneously. 5. When the user initiates scheduled charging, if the remaining charge of the third battery cell 111c is higher than 5% or the remaining charge of the second battery cell 111b is higher than 20%, the first battery cell 111a needs to be charged through the DC-DC converter while providing power to the vehicle, so that the third battery cell 111c and the second battery cell 111b are in a depleted state, thereby improving the overall charging rate of the battery pack.

[0073] Under dual-power or triple-power discharge conditions, the DC-DC converter ensures that the output voltage of the cell group 110 reaches the same level and controls the current output. The priority of using the cell group 110 mainly utilizes the high lifespan of the third cell 111c. The cycle life of the third cell 111c can reach 8000-10000 cycles, which is better than the second cell 111b and the first cell 111a. Therefore, prioritizing the use of the third cell 111c can ensure that different types of cells in the entire cell group 110 can reach their cycle life almost simultaneously, thereby reducing material waste.

[0074] The normal temperature full-condition and low temperature long-distance discharge schemes include: 1. Prioritize the use of the third cell 111c; 2. For high-power discharge of the 110 cell group (exceeding 50% of the maximum power), use the third cell 111c + the first cell 111a; 3. For ultra-high-power discharge of the 110 cell group (exceeding 70% of the maximum power), use the first cell 111a, the third cell 111c and the second cell 111b.

[0075] This invention provides a battery that ensures the performance of the entire battery pack at low temperatures while maintaining the battery's energy density. During the charging and discharging of the battery cells, the system controls the charging and discharging of the corresponding types of cells according to the temperature and operating conditions of the battery cells, and controls the operation of the thermal management system. This allows the thermal management system to control the battery temperature during the charging and discharging process, thereby improving the charging speed and safety of the battery and preventing the battery temperature from being too low or too high. As a result, the battery pack has the advantages of good low-temperature performance, high energy density, fast charging speed, and high safety.

[0076] This invention also provides a battery charging and discharging control method. This method is used to control the charging and discharging of the battery in any embodiment of this invention and can be executed by the battery's charging and discharging management system. Figure 13 This is a schematic flowchart of a battery charging and discharging control method provided in an embodiment of the present invention, as shown below. Figure 13 As shown, the battery charging and discharging control method includes: S110. When the battery cell group is discharging, control the corresponding type of battery cell to discharge according to the temperature and operating conditions of the battery cell group, and control the thermal management system to work.

[0077] S120. When the battery pack is charging, the charging power of each type of battery cell is controlled according to the temperature and charging mode of the battery pack, and the thermal management system is controlled to work.

[0078] For details, please refer to Figure 1-3When the cell group 110 discharges, the corresponding cell 111 is controlled to discharge according to the remaining charge of each cell 111 and the discharge power of the cell group 110. For example, when the cell group 110 is controlled to discharge within a first temperature range, if the remaining charge of the second cell 111b and the third cell 111c is greater than the first remaining charge, the second cell 111b and the third cell 111c are controlled to discharge first; if the remaining charge of the second cell 111b and the third cell 111c is less than or equal to the first remaining charge, the first cell 111a, the second cell 111b, and the third cell 111c are all controlled to discharge; when the cell group 110 is controlled to discharge within the first temperature range, and the cell group 110 is discharged within the first temperature range, the discharge of the cell group 110 is controlled to discharge within the first temperature range, and the discharge of the cell group 110 is controlled to discharge within the first temperature range, the discharge of the cell group 111 is controlled to discharge within the first temperature range, and the discharge of the cell group 1 ... When the discharge power of cell 10 is greater than the first discharge power but less than the second discharge power, the second cell 111b and the third cell 111c are controlled to discharge preferentially. When cell group 110 is controlled to discharge within the first temperature range, and the discharge power of cell group 110 is greater than the second discharge power, the first cell 111a, the second cell 111b, and the third cell 111c are controlled to discharge. When the remaining charge of the second cell 111b is less than the second remaining charge, the second cell 111b is controlled to stop discharging, and when the remaining charge of the third cell 111c is less than the third remaining charge, the third cell 111c is controlled to stop discharging. Wherein, the first remaining charge is greater than the second remaining charge, and the second remaining charge is greater than the third remaining charge. Alternatively, during the discharge process of cell group 110, if the temperature of cell group 110 is higher than the preset cooling temperature, the thermal management system 120 is controlled to cool the corresponding cell 111. When controlling the charging of the battery cell assembly 110, the charging of the corresponding battery cell 111 can be controlled according to the remaining charge of each battery cell 111, the discharge power of the battery cell assembly 110, and the temperature of the battery cell assembly 110. Simultaneously, the thermal management system 120 is controlled to cool the corresponding battery cell 111 to improve charging efficiency. The thermal management system 120 can perform targeted cooling and heating of the first battery cell 111a, the second battery cell 111b, and the third battery cell 111c during charging and discharging, thereby improving temperature control efficiency, enhancing safety, precisely controlling the temperature of the battery cell assembly 110, and improving the overall temperature uniformity of the battery cell assembly 110.

[0079] In some embodiments of the present invention, such as Figure 3 As shown, the battery cell includes a first battery cell, a second battery cell, and a third battery cell. During battery cell group discharge, the system controls the discharge of corresponding types of cells based on the temperature and operating conditions of the battery cell group, and controls the operation of the thermal management system, including: S210. When controlling the discharge of the battery cell group within the first temperature range, if the remaining charge of the third battery cell and the second battery cell is greater than the first remaining charge, the third battery cell and the second battery cell are controlled to discharge.

[0080] The first temperature range can be a low temperature range, and the first remaining charge can be 50%. In the low temperature range, when the remaining charge of the third cell 111c and the second cell 111b is higher than 50%, the third cell 111c and the second cell 111b are used first to extend the life of the first cell 111a.

[0081] S220. When the remaining power of the third and second cells is less than or equal to the first remaining power, control the first, third, and second cells to discharge.

[0082] When the SOC of the third cell 111c or the second cell 111b is lower than 50%, the first cell 111a begins to participate in the discharge process, and the first cell 111a, the second cell 111b and the third cell 111c all discharge.

[0083] S230. When the battery cell group is controlled to discharge within the first temperature range, and the discharge power of the battery cell group is greater than the first discharge power and less than the second discharge power, the third battery cell and the second battery cell are controlled to discharge. The charge and discharge management system is also used to control the first battery cell, the third battery cell and the second battery cell to discharge when the battery cell group is controlled to discharge within the first temperature range and the discharge power of the battery cell group is greater than the second discharge power.

[0084] The first discharge power can be 50% of the maximum power of cell group 110, and the second discharge power can be 70% of the maximum power of cell group 110. When cell group 110 discharges at high power (discharge power of cell group 110 is greater than 50% of the maximum power), the third cell 111c and the second cell 111b are used first. When the SOC of the third cell 111c is lower than 5%, the discharge stops. When the SOC of the second cell 111b is lower than 20%, the discharge stops. When cell group 110 discharges at ultra-high power (discharge power exceeds 70% of the maximum power), the first cell 111a, the third cell 111c and the second cell 111b can be used simultaneously.

[0085] S240. When the remaining charge of the second battery cell is less than the second remaining charge, control the second battery cell to stop discharging; when the remaining charge of the third battery cell is less than the third remaining charge, control the third battery cell to stop discharging; wherein, the first remaining charge is greater than the second remaining charge, and the second remaining charge is greater than the third remaining charge.

[0086] When the SOC of the third cell 111c or the second cell 111b is below 50%, the first cell 111a begins to participate in the discharge process.

[0087] In some embodiments of the present invention, the charging modes of the battery pack include at least a first fast charging mode and a second fast charging mode. During charging, the charging power of each type of battery cell is controlled according to the temperature of the battery pack and the charging mode of the battery pack, and the thermal management system is controlled to operate, including: S310. When the battery pack is in the first fast charging mode, if the temperature of the battery pack is lower than the first preset temperature, control the charging power of the inner battery cells of the battery pack to 0, control the first circulation pipeline to be turned on, and turn on the first heater to heat the outermost battery cells of the battery pack.

[0088] The first preset temperature is -20℃. The inner cells of the cell pack 110 are the first cell 111a and the second cell 111b. When the initial maximum temperature of the entire cell pack 110 is lower than -20℃, the charging power of the first cell 111a and the second cell 111b is 0W. The first heater 123 is turned on to heat and the first circulation pipeline 121 enters the first control logic to achieve full flow. The heating power of the first heater 123 is positively correlated with the initial temperature of the cell pack 110. At the same time, the charge and discharge management system 130 determines the charging power of the third cell 111c based on the current minimum temperature of the third cell 111c, the remaining charge (SOC), and the battery health status.

[0089] S320. When the battery pack is in the first fast charging mode, if the temperature of the battery pack is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipe is equal to the preset heating threshold or the temperature of the outermost battery cell of the battery pack is greater than the second preset temperature, control the first circulation pipe to close, the first heater to turn off heating, and control the charging power of the inner battery cell of the battery pack to be 0; if the temperature of the battery pack is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipe is equal to the preset heating threshold or the temperature of the outermost battery cell of the battery pack is greater than the second preset temperature, and the temperature of the inner battery cell of the battery pack is less than the second preset temperature, the first heater to turn off heating, the second heater to turn on heating, control both the first circulation pipe and the second circulation pipe to open, and control the charging power of the inner battery cell of the battery pack to be 0; wherein, the first preset temperature is less than the second preset temperature.

[0090] The second preset temperature can be -10℃. When the lowest temperature of the third cell 111c in the cell pack 110 rises to -20℃ to -10℃, the heating power of the first heater 123 is negatively correlated with the cumulative heating power consumption. When the cumulative heating of the first heater 123 reaches the threshold or the lowest temperature of the third cell 111c is greater than -10℃, the first heater 123 is turned off. At the same time, the lowest internal temperature of the cell pack 110 is detected. When the lowest temperature is still lower than -10℃, the second heater 124 is turned on to heat, and the electromagnetic three-way valve 127 is controlled to be in the sixth control logic, opening the shunt mode of the circulation pipeline. The first circulation pipeline 121 and the second circulation pipeline 122 are both connected, so that the battery temperature tends to be uniform. The charging power of the first cell 111a and the second cell 111b is still 0W. At the same time, the charging power of the third cell 111c is determined according to the current lowest temperature, SOC, and battery health status of the third cell 111c.

[0091] S330. When the battery pack is in the second fast charging mode, if the temperature of the battery pack is lower than the first preset temperature, control the charging power of the inner layer of the battery pack to 0, control the first heater and the second heater to turn on for heating, and control the first circulation pipe and the second circulation pipe to open.

[0092] When the initial maximum temperature of the entire cell pack 110 is below -20℃, the charging power of the first cell 111a is 0W, the first heater 123 and the second heater 124 are turned on for heating at the same time, the electromagnetic three-way valve 127 is in the sixth control logic, the first circulation pipe 121 and the second circulation pipe 122 are both open, the heating power of the first heater 123 is positively correlated with the initial temperature, the power of the second heater 124 is the highest rated power, and the charging power of the third cell 111c is determined according to the current minimum temperature, SOC and battery health status of the third cell 111c.

[0093] Battery packs typically use a single type of cell. For example, ternary lithium batteries have a higher energy density, but no advantage in cost or safety. Lithium iron phosphate batteries have a lower cost, but poorer energy density and low-temperature performance. Sodium-ion batteries have a lower cost and higher low-temperature performance, but lower energy density. If any of these three types of cells are used individually, they all have obvious defects and shortcomings.

[0094] This invention provides a battery charging and discharging control method that mixes three types of cells to fully utilize the unique advantages of each cell and control the battery temperature during charging and discharging, thereby improving the charging speed and safety of the battery and preventing the battery temperature from being too low or too high. This allows the battery pack to have the advantages of good low-temperature performance, high energy density, fast charging speed, and high safety.

[0095] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A battery, characterized in that, The battery includes a cell pack, a thermal management system, and a charge / discharge management system; The battery cell assembly includes at least three different types of battery cells, and the battery cells of each type are arranged in at least three nested layers; wherein, from the innermost layer to the outermost layer of the battery cell assembly, the energy density of each type of battery cell gradually decreases, and the discharge capability of each type of battery cell gradually increases within a preset temperature range. The thermal management system is located on one side of the battery cell assembly, and the thermal management system is used to control the temperature of the battery cell assembly. The charge / discharge management system is connected to the battery cell assembly and the thermal management system respectively. When the battery cell assembly is discharging, the charge / discharge management system controls the corresponding type of battery cell to discharge according to the temperature and operating conditions of the battery cell assembly, and controls the thermal management system to work. When the battery cell assembly is charging, the charge / discharge management system controls the charging power of each type of battery cell according to the temperature and charging mode of the battery cell assembly, and controls the thermal management system to work.

2. The battery according to claim 1, characterized in that, The battery cells include at least three different types of cells, including a first cell, a second cell, and a third cell, wherein the first cell is nested within the second cell, and both the first cell and the second cell are nested within the third cell, the first cell being located in the innermost layer of the cell group, and the third cell being located in the outermost layer of the cell group; The energy density of the first battery cell is greater than the first energy density, the energy density of the second battery cell is greater than the second energy density, and the energy density of the third battery cell is greater than the third energy density. The first energy density is greater than the second energy density, and the second energy density is greater than the third energy density. The charge / discharge rate of the first battery cell within the preset temperature range is greater than the first charge / discharge rate, the charge / discharge rate of the second battery cell within the preset temperature range is greater than the second charge / discharge rate, and the discharge / charge / discharge rate of the third battery cell within the preset temperature range is greater than the third charge / discharge rate. The first charge / discharge rate is less than the second charge / discharge rate, and the second charge / discharge rate is less than or equal to the third charge / discharge rate.

3. The battery according to claim 2, characterized in that, The charge and discharge management system is connected to the first battery cell, the second battery cell, and the third battery cell; The charge-discharge management system is used to control the corresponding cells to discharge according to the remaining charge of each cell and the discharge power of the cell group when the cell group is discharging; the charge-discharge management system is also used to control the thermal management system to cool the corresponding cells if the temperature of the cell group is higher than the preset cooling temperature when the cell group is discharging. The charge and discharge management system is used to control the charging of the corresponding cells according to the remaining power of each cell, the discharge power of the cell group and the temperature of the cell group when the cell group is being charged, and to control the thermal management system to cool the corresponding cells.

4. The battery according to claim 1, characterized in that, The thermal management system includes a first circulation pipeline, a second circulation pipeline, a first heater, a second heater, a circulating water pump, a heat exchanger, and a solenoid three-way valve; The outlet of the circulating water pump is connected to the first end of the heat exchanger via a pipe, and the second end of the heat exchanger is connected to the inlet of the electromagnetic three-way valve via a pipe. The heat exchanger is used to control the temperature of the circulating liquid; The first heater is located at the inlet end of the first circulation pipeline, the first outlet of the electromagnetic three-way valve is connected to the inlet end of the first circulation pipeline, the outlet end of the first circulation pipeline is connected to the first inlet end of the circulating water pump, the first circulation pipeline is located on one side of the battery cell assembly, and the vertical projection of the first circulation pipeline on the battery cell assembly is located within at least one type of battery cell; the first circulation pipeline is used to heat or cool the corresponding battery cell through the circulating liquid. The second heater is located at the inlet end of the second circulation pipeline, the second outlet of the electromagnetic three-way valve is connected to the inlet end of the second circulation pipeline, the outlet end of the second circulation pipeline is connected to the second inlet end of the circulation pump, the second circulation pipeline is located on one side of the battery cell assembly, and the vertical projection of the second circulation pipeline on the battery cell assembly is located within at least two types of battery cells; the second circulation pipeline is used to heat or cool the corresponding battery cell through the circulating liquid.

5. The battery according to claim 4, characterized in that, The electromagnetic three-way valve includes a valve body and a valve core; The inlet, the first outlet, and the second outlet are all located on the valve body, and the inlet is located between the first outlet and the second outlet. The inlet and the first outlet and the inlet and the second outlet are all spaced at a preset distance. The valve core is located at the center of the valve body. The valve core is used to control the connection between the water inlet and the first water outlet and / or the second water outlet by rotation, and to control the flow rate between the water inlet and the first water outlet and / or the second water outlet.

6. The battery according to claim 5, characterized in that, The electromagnetic three-way valve also includes a servo motor, which is coaxially connected to the valve core. The servo motor is connected to the charging and discharging management system, and the charging and discharging management system is also used to send a control signal to the servo motor according to the temperature of the battery pack, so as to control the servo motor to rotate. The servo motor is used to control the rotation angle of the valve core by rotation, so as to control the connection or partial connection between the water inlet and the first water outlet, and the connection or partial connection between the water inlet and the second water outlet.

7. The battery according to claim 5, characterized in that, The valve core includes a first interval point, a second interval point, and a third interval point, and the distances between the first interval point, the second interval point, and the third interval point are all the same; The central angle formed by the inlet and the first outlet with the center of the valve body is less than 120°, and the central angle formed by the inlet and the second outlet with the center of the valve body is less than 120°.

8. The battery according to claim 4, characterized in that, The charging modes of the battery pack include at least a first fast charging mode and a second fast charging mode. The charging and discharging management system is also used to control the charging power of the inner layer of the battery cell to 0 when the temperature of the battery cell group is lower than the first preset temperature when the battery cell group is in the first fast charging mode, and to control the first circulation pipeline to be turned on and the first heater to be turned on to heat the outermost layer of the battery cell group. The charging and discharging management system is further configured to, when the battery cell assembly is in the first fast charging mode, control the first circulation pipeline to close, the first heater to turn off heating, and control the charging power of the inner battery cell to be 0 if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature; if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, and the temperature of the inner battery cell of the battery cell assembly is less than the second preset temperature, control the first heater to turn off heating, the second heater to turn on heating, control both the first circulation pipeline and the second circulation pipeline to open, and control the charging power of the inner battery cell of the battery cell assembly to be 0; wherein, the first preset temperature is less than the second preset temperature; The charging and discharging management system is also used to control the charging power of the inner layer of the battery cell to 0 when the temperature of the battery cell group is lower than the first preset temperature when the battery cell group is in the second fast charging mode, and to control both the first heater and the second heater to turn on for heating, and both the first circulation pipeline and the second circulation pipeline to open.

9. A method for controlling the charging and discharging of a battery, characterized in that, The battery charging and discharging control method is used to control the charging and discharging of the battery according to any one of claims 1-8, and the battery charging and discharging control method includes: When the battery cell assembly is discharging, the corresponding type of battery cell is controlled to discharge according to the temperature and operating conditions of the battery cell assembly, and the thermal management system is controlled to work. During the charging of the battery cell assembly, the charging power of each type of battery cell is controlled according to the temperature and charging mode of the battery cell assembly, and the thermal management system is also controlled to operate.

10. The battery charging and discharging control method according to claim 9, characterized in that, The battery cell includes a first battery cell, a second battery cell, and a third battery cell. During battery cell group discharge, the system controls the discharge of the corresponding type of battery cell based on the temperature and operating conditions of the battery cell group, and controls the operation of the thermal management system, including: When discharging the battery pack within a first temperature range, if the remaining charge of the third battery cell and the second battery cell is greater than the first remaining charge, the third battery cell and the second battery cell are controlled to discharge. When the remaining power of the third battery cell and the second battery cell is less than or equal to the first remaining power, the first battery cell, the third battery cell, and the second battery cell are all controlled to discharge. When the battery cell group is controlled to discharge within the first temperature range, and the discharge power of the battery cell group is greater than the first discharge power and less than the second discharge power, the third battery cell and the second battery cell are controlled to discharge; the charge and discharge management system is further configured to control the first battery cell, the third battery cell and the second battery cell to discharge when the battery cell group is controlled to discharge within the first temperature range and the discharge power of the battery cell group is greater than the second discharge power. When the remaining charge of the second battery cell is less than the second remaining charge, the second battery cell is controlled to stop discharging; when the remaining charge of the third battery cell is less than the third remaining charge, the third battery cell is controlled to stop discharging; wherein, the first remaining charge is greater than the second remaining charge, and the second remaining charge is greater than the third remaining charge; The charging modes of the battery cell assembly include at least a first fast charging mode and a second fast charging mode. During charging, the charging power of each type of battery cell is controlled according to the temperature of the battery cell assembly and the charging mode, and the thermal management system is controlled to operate, including: When the battery cell assembly is in the first fast charging mode, if the temperature of the battery cell assembly is lower than the first preset temperature, the charging power of the inner layer of the battery cell assembly is controlled to be 0, and the first circulation pipeline is controlled to be turned on, and the first heater is turned on to heat the outermost layer of the battery cell assembly. When the battery cell assembly is in the first fast charging mode, if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, the first circulation pipeline is controlled to close, the first heater is turned off, and the charging power of the inner battery cell of the battery cell assembly is controlled to be 0; if the temperature of the battery cell assembly is greater than the first preset temperature and less than the second preset temperature, and the cumulative heating amount of the first circulation pipeline is equal to the preset heating threshold, or the temperature of the outermost battery cell of the battery cell assembly is greater than the second preset temperature, and the temperature of the inner battery cell of the battery cell assembly is less than the second preset temperature, the first heater is turned off, the second heater is turned on, both the first circulation pipeline and the second circulation pipeline are opened, and the charging power of the inner battery cell of the battery cell assembly is controlled to be 0; wherein, the first preset temperature is less than the second preset temperature; When the battery cell assembly is in the second fast charging mode, if the temperature of the battery cell assembly is lower than the first preset temperature, the charging power of the battery cell in the inner layer of the battery cell assembly is controlled to be 0, the first heater and the second heater are both turned on for heating, and the first circulation pipeline and the second circulation pipeline are both opened.

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