Chemical component circuits, equipment and systems

Abstract

The embodiment of the present application provides a chemical fractionation circuit, device and system, which includes a power supply circuit and multiple charge and discharge circuits, and the multiple charge and discharge circuits are connected in series with the power supply circuit. Among them, the charge and discharge circuit includes a first inductor, a first switch tube, a second switch tube, a first capacitor, a first battery cell access component and a second battery cell access component. Based on this, when the first switch tube is turned on and the second switch tube is turned off, the charge and discharge circuit is used for constant current charging or discharging of the battery cell; when the first switch tube and the second switch tube are periodically turned on and off alternately, the charge and discharge circuit is used for constant voltage charging of the battery cell; when the first switch tube is turned off and the second switch tube is turned on, the charge and discharge circuit is used to disconnect the connection between the battery cell and the power supply circuit. It can be seen that constant current and constant voltage charging can be used for charging the battery cell, thereby improving the quality of the battery cell, that is, compared with the related art, the embodiment of the present application improves the reliability of the chemical fractionation system.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a capacitance-splitting circuit, a capacitance-splitting device, and a capacitance-splitting system. Background Art

[0002] Lithium-ion batteries have a wide range of applications due to their high energy density, long service life, high rated voltage, low self-discharge rate, and environmental friendliness. They are used in new energy vehicles, grid energy storage, digital products, and more.

[0003] In the manufacturing process of lithium-ion batteries, formation and capacity separation are two very important processes, both of which affect the quality of the battery. Among them, formation refers to the activation of the positive and negative electrode materials inside the battery (also known as the battery cell) through a certain charging and discharging method, and the formation of a solid electrolyte interface film (Solid ElectrolVteInterface, SEI film) on the surface of the positive and negative electrode materials of the battery; capacity separation refers to the cyclic charging and discharging of the formed batteries to eliminate problematic batteries and group the batteries according to capacity and internal resistance. It can be seen that the basic principles of formation and capacity separation are common. Therefore, in related technologies, both formation and capacity separation can be completed through a formation and capacity separation system, that is, formation and capacity separation can be completed through a set of equipment.

[0004] In related technologies, some battery cells are connected in series during formation or capacity splitting, which reduces the use of cables. However, these battery cells are not very reliable. Specifically, during the formation or capacity splitting process, the cells are charged using only constant current, which results in poor battery quality. Summary of the Invention

[0005] Based on this, the present application provides a chemical fractionation capacitance circuit, a chemical fractionation capacitance device and a chemical fractionation capacitance system to improve the reliability of the chemical fractionation capacitance system.

[0006] In a first aspect, the present application provides a capacitance-combination circuit, comprising:

[0007] Power circuit for connecting power supply equipment; and

[0008] Multiple charging and discharging circuits, which are connected in series in sequence and then connected to the power supply circuit; the charging and discharging circuit includes a first inductor, a first switching tube, a second switching tube, a first capacitor, a first battery cell access component and a second battery cell access component; the first battery cell access component is used to connect the positive electrode of the battery cell, and the second battery cell access component is used to connect the negative electrode of the battery cell; the first switching tube is connected between the first end of the first inductor and the first battery cell access component; the second switching tube is connected between the first end of the first inductor and the second battery cell access component; the first capacitor is connected in parallel with the first switching tube and the second switching tube; the second end of the first inductor serves as the positive end of the charging and discharging circuit, and the connection between the second switching tube and the second battery cell access component serves as the negative end of the charging and discharging circuit;

[0009] When the first switch tube is turned on and the second switch tube is turned off, the charge and discharge circuit is used for constant current charging or discharging of the battery cell; when the first switch tube and the second switch tube are periodically alternately turned on and off, the charge and discharge circuit is used for constant voltage charging of the battery cell; when the first switch tube is turned off and the second switch tube is turned on, the charge and discharge circuit is used to disconnect the battery cell from the power circuit.

[0010] Optionally, a third switching tube is further connected between the negative terminal of the charge and discharge circuit and the second switching tube.

[0011] Optionally, a second inductor is further connected between the first switching tube and the first battery cell access component.

[0012] Optionally, a fuse element is further connected between the first switching tube and the first battery cell access component.

[0013] Optionally, the charge and discharge circuit further includes a first sampling resistor and a second sampling resistor;

[0014] One end of the first sampling resistor is connected to the second end of the first inductor, and the other end serves as the positive terminal of the charge and discharge circuit;

[0015] The second sampling resistor is connected between the first switch tube and the first battery cell access component.

[0016] Optionally, the charge and discharge circuit further includes a second capacitor, which is connected in parallel with the first inductor and the second switch tube.

[0017] Optionally, the charge and discharge circuit further includes a fourth switch tube and a pre-charge circuit;

[0018] The fourth switch tube is connected between the first switch tube and the first battery cell access component;

[0019] One end of the pre-charging circuit is connected to the first battery cell access component, and the other end is connected to the capacitor in the charging and discharging circuit.

[0020] Optionally, the pre-charging circuit includes a switching element and a current-limiting resistor;

[0021] The switch element and the current-limiting resistor are connected in series between the first cell connection component and the capacitor in the charge-discharge circuit.

[0022] In a second aspect, the present application provides a capacitance-combining device, comprising the capacitance-combining circuit as described in the first aspect.

[0023] In a third aspect, the present application provides a chemical component capacity system, comprising a power supply device and the chemical component capacity device as described in the second aspect.

[0024] The present application provides a kind of capacity-splitting circuit, equipment and system, the circuit includes a power supply circuit and a plurality of charge and discharge circuits, and the plurality of charge and discharge circuits are connected in series with the power supply circuit. Wherein, the charge and discharge circuit includes a first inductor, a first switch tube, a second switch tube, a first capacitor, a first cell access component and a second cell access component. Based on this, when the first switch tube is turned on and the second switch tube is turned off, the charge and discharge circuit is used for constant current charging or discharging of the cell; when the first switch tube and the second switch tube are periodically turned on and off alternately, the charge and discharge circuit is used for constant voltage charging of the cell; when the first switch tube is turned off and the second switch tube is turned on, the charge and discharge circuit is used to disconnect the connection between the cell and the power supply circuit. It can be seen that in the process of formation or capacity splitting, constant current and constant voltage charging can be used for charging the cell, which makes the cell "more fully charged", thereby improving the quality of the cell, that is, compared with the related art, the embodiment of the present application improves the reliability of the capacity-splitting system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic diagram of a circuit structure of a chemical composition and capacity system in related technology;

[0027] Figure 2 It is another circuit structure diagram of the chemical composition and capacity system in the related art;

[0028] Figure 3 A schematic structural diagram of a chemical fractionation and capacity system provided in an embodiment of the present application;

[0029] Figure 4 This is an exemplary structural diagram of a chemical component storage system according to an embodiment of the present application;

[0030] Figure 5 A schematic structural diagram of a chemical fractionation and content-splitting device provided in an embodiment of the present application;

[0031] Figure 6 Schematic diagram of the circuit structure between the power supply circuit and the charge-discharge circuit in the capacitance-splitting circuit of an embodiment of the present application;

[0032] Figure 7 A schematic diagram of a circuit structure of a capacitance-combining circuit provided in an embodiment of the present application;

[0033] Figure 8 This is a schematic diagram of an equivalent circuit structure of a capacitance-based circuit according to an embodiment of the present application;

[0034] Figure 9 This is another schematic diagram of an equivalent circuit structure of a capacitance-based circuit according to an embodiment of the present application;

[0035] Figure 10 This is another schematic diagram of an equivalent circuit structure of a capacitance-based circuit according to an embodiment of the present application;

[0036] Figure 11 This is a schematic diagram of a circuit structure when the capacitance-based circuit includes a third switch tube in an embodiment of the present application;

[0037] Figure 12 This is a schematic diagram of a circuit structure when the component capacitance circuit includes a second inductor in an embodiment of the present application;

[0038] Figure 13 This is a schematic diagram of a circuit structure when the capacitance circuit includes a fuse element in an embodiment of the present application;

[0039] Figure 14 This is a schematic diagram of a circuit structure when the capacitance-based circuit includes two sampling resistors in an embodiment of the present application;

[0040] Figure 15 This is a schematic diagram of a circuit structure when the capacitance-based circuit includes a second capacitor in an embodiment of the present application;

[0041] Figure 16 This is a schematic diagram of a circuit structure in which the capacitance-forming circuit according to an embodiment of the present application includes a fourth switch tube and a pre-charging circuit;

[0042] Figure 17 A schematic diagram of a circuit structure of a pre-charging circuit in an embodiment of the present application;

[0043] Figure 18This is a schematic diagram of an exemplary circuit structure of a capacitance-combining circuit in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0046] It should also be understood that the terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims or above-mentioned drawings of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. In addition, the term "connection" (if any) in the specification, claims or above-mentioned drawings of this application should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection, and "connection" can be a direct connection or an indirect connection through an intermediate medium. In addition, the term "and / or" (if any) used in the specification, claims or above-mentioned drawings of this application refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0047] In addition, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0048] In the related art, when the partial formation and capacity division system is being formed or divided, the battery cells are connected in series. Figure 1 In the shown formation and capacity division system, when all relays are in the off state, the cells are connected in series. In this case, the system can simultaneously form or divide the cells. Figure 2In the formation and capacity separation system shown, when all the multi-way switches are turned to "down", the battery cells are also connected in series. In this case, the system can also perform formation or capacity separation for each battery cell at the same time.

[0049] Based on this, the inventors of this application discovered that the aforementioned formation and capacity splitting system has a low reliability problem. Specifically, during the formation or capacity splitting process, the battery cells need to be charged and discharged according to a preset strategy. However, because the battery cells are connected in series, they are usually only charged with a constant current, which affects the quality of the battery cells.

[0050] More specifically, the power supply device usually outputs a certain current value of electrical energy (i.e., constant current output). Since the battery cells are connected in series, the current value flowing through each battery cell is the same, so the system can use constant current charging. However, due to the different internal resistance of the battery cells, the voltage value across each battery cell is not the same. In addition, the battery cell should be disconnected from the power supply device when constant voltage charging is completed (for example, Figure 1 When a certain battery cell completes constant voltage charging, the corresponding relay must be closed, or Figure 2 (The system requires the corresponding multi-way switch to be turned "up" when a cell completes constant voltage charging.) Understandably, when a cell is disconnected from the power supply, the voltage across the other cells will change, making the system unable to meet the requirements of constant voltage charging. Therefore, such capacity-fractionated systems typically only use constant current charging for charging cells. However, constant current charging alone cannot fully charge the cell, resulting in poor cell quality.

[0051] To this end, embodiments of the present application provide a chemical fractionation and capacitance circuit, a chemical fractionation and capacitance device, and a chemical fractionation and capacitance system.

[0052] The chemical composition and storage system provided in the embodiment of the present application is as follows: Figure 3 As shown, the cell formation and capacity division system may include a power supply device 10 and a cell formation and capacity division device 20. The power supply device 10 may be connected to at least one input power source (such as a power grid, wind power, photovoltaic power, etc.), and the cell formation and capacity division device 20 may be connected to a plurality of battery cells. In one embodiment, the power supply device 10 and / or the cell formation and capacity division device 20 may realize mutual conversion between AC and DC, voltage rise and fall, etc., that is, at least one of the two devices realizes the processing of electric energy to meet the requirements of cell formation or capacity division. It should be noted that, compared with the related art, the cell formation and capacity division system in the embodiment of the present application has higher reliability.

[0053] For example, Figure 4As shown, the power supply device 10 may include an AC / DC circuit, and the formation and capacity division device 20 may include a DC / DC circuit. For specific connection relationships, please refer to the accompanying drawings. In this example, the processing of electrical energy is jointly implemented by the two devices. For example, during the charging stage of formation or capacity division, the AC / DC circuit can convert the AC power input from the power grid and / or photovoltaic power into DC power, and the DC / DC circuit can perform voltage conversion (e.g., boost) on the electrical energy output by the AC / DC circuit to provide suitable electrical energy for charging the battery cell; conversely, during the discharge stage of formation or capacity division, the DC / DC circuit can perform voltage conversion (e.g., step-down) on the electrical energy output by the battery cell, and the AC / DC circuit can convert the DC power output by the DC / DC circuit into AC power to feed back to the power grid or supply the load, etc.

[0054] The chemical composition and content-splitting device 20 provided in the embodiment of the present application is as follows: Figure 5 As shown, a cell formation or capacity division circuit 210 may be included. It should be noted that, through the cell formation or capacity division circuit 210 in the embodiment of the present application, constant current and constant voltage charging can be used for charging the battery cell during the formation or capacity division process, which allows the battery cell to be "charged more fully" and thus improves the quality of the battery cell. That is, compared with the related art, the embodiment of the present application improves the reliability of the cell formation or capacity division system.

[0055] The embodiment of the present application provides a capacitance-combining circuit 210, such as Figure 6 As shown, it may include a power circuit 2110 and multiple charging and discharging circuits 2120. Among them, multiple charging and discharging circuits 2120 are connected in series with the power circuit 2110, that is, multiple charging and discharging circuits 2120 are connected in series between the positive and negative poles of the power circuit 2110. In this embodiment, the power circuit 2110 is used to connect to the power supply device 10. For example, the power circuit 2110 may include the DC / DC circuit mentioned above, which is used to connect to the AC / DC circuit in the power supply device 10. In addition, as Figure 7 As shown, the charge and discharge circuit 2120 may include a first inductor L1 , a first switch tube Q1 , a second switch tube Q2 , a first capacitor C1 , a first cell connection component 2121 , and a second cell connection component 2122 .

[0056] The first cell access member 2121 is used to connect to the positive electrode of the cell, and the second cell access member 2122 is used to connect to the negative electrode of the cell. That is, the cells are connected via a pair of cell access members. In one embodiment, the chemical separation device 20 has a needle bed including multiple probe assemblies, so both the first cell access member 2121 and the second cell access member 2122 can include probe assemblies.

[0057] The first switching transistor Q1 is connected between the first end of the first inductor L1 and the first cell access component 2121, the second switching transistor Q2 is connected between the first end of the first inductor L1 and the second cell access component 2122, and the first capacitor C1 is connected in parallel with the first switching transistor Q1 and the second switching transistor Q2. In one embodiment, the first switching transistor Q1 and the second switching transistor Q2 can both comprise MOS transistors, etc.; furthermore, the capacitance component device 20 can include a controller, and the control terminals of the switching transistors in each charging and discharging circuit 2120 can be connected to the controller to be turned on or off under the control of the controller.

[0058] In addition, the second end of the first inductor L1 serves as the positive terminal of the charge and discharge circuit 2120, and the connection between the second switch tube Q2 and the second battery cell access component 2122 serves as the negative terminal of the charge and discharge circuit 2120. That is, the second end of the first inductor L1 is connected to the positive electrode of the power supply circuit 2110 or the negative terminal of the "previous" charge and discharge circuit, and the connection between the second switch tube Q2 and the second battery cell access component 2122 is connected to the negative electrode of the power supply circuit 2110 or the positive terminal of the "next" charge and discharge circuit.

[0059] Based on this, when the first switch tube Q1 is turned on and the second switch tube Q2 is turned off, the charge and discharge circuit 2120 is used for constant current charging or discharging of the battery cell; when the first switch tube Q1 and the second switch tube Q2 are periodically alternately turned on and off, the charge and discharge circuit 2120 is used for constant voltage charging of the battery cell; when the first switch tube Q1 is turned off and the second switch tube Q2 is turned on, the charge and discharge circuit 2120 is used to disconnect the battery cell from the power circuit 2110 (i.e., bypass the battery cell).

[0060] The following combination Figure 8-10 Detailed introduction to the working principle of the charge and discharge circuit 2120:

[0061] (1) During the formation or capacity division charging stage, the battery cell should be charged with a constant current first to achieve rapid charging of the battery cell. The first switch tube Q1 can be controlled to be turned on and the second switch tube Q2 can be turned off. The circuit equivalent diagram at this time can be found in Figure 8 It is understood that, at this time, the multiple battery cells are connected in series, and the current flowing through each battery cell is the same, so each battery cell can be charged with a constant current. In one embodiment, the current value of the power output by the power circuit 2110 can be dynamically adjusted according to the number of battery cells being charged.

[0062] (2) After constant current charging is completed, constant voltage charging should be performed to charge the battery cell more fully. The first switch tube Q1 and the second switch tube Q2 can be controlled to alternately turn on and off periodically. The circuit equivalent diagram at this time can be referred to Figure 9It can be understood that at this time, the first inductor L1, the first switch tube Q1, the second switch tube Q2 and the first capacitor C1 form a boost circuit. Therefore, it is only necessary to reasonably control the duty cycle of the two switches to keep the voltage across the battery cell constant, that is, each battery cell can be charged at a constant voltage. In one embodiment, the duty cycle of the two switches can be dynamically adjusted according to the input voltage and output voltage of the boost circuit, that is, it can be dynamically adjusted according to the voltage value across the charge and discharge circuit 2120.

[0063] (3) After constant voltage charging is completed, since each battery cell is different, the time when constant voltage charging is completed for each battery cell is different. Therefore, after constant voltage charging is completed, the battery cell should be disconnected from the power circuit 2110 to stop charging. Then the first switch tube Q1 can be controlled to be turned off and the second switch tube Q2 can be turned on. The circuit equivalent diagram at this time can be referred to Figure 10 It is understood that at this time, the battery cell is bypassed and disconnected from the power circuit 2110. In one embodiment, whether the battery cell has completed constant voltage charging can be determined based on the voltage value and current value at both ends of the battery cell.

[0064] (4) After the battery is charged, it should be discharged (i.e., the formation or capacity separation discharge stage). The first switch tube Q1 can be controlled to be turned on and the second switch tube Q2 can be turned off. The circuit equivalent diagram at this time can be referred to Figure 8 It is understandable that multiple cells are connected in series and then discharged to the power circuit 2110. Similarly, the time when each cell completes discharge is also different. Therefore, when the cell is discharged, it should also be disconnected from the power circuit 2110. Then, the first switch tube Q1 can be controlled to be disconnected and the second switch tube Q2 can be turned on. Figure 10 In one embodiment, whether the battery cell has completed discharge can be determined based on the voltage value and current value at both ends of the battery cell. In addition, it should be noted that after the battery cell has completed discharge, it can be determined whether the next round of charge and discharge is needed based on actual conditions.

[0065] As can be seen from the above, through the embodiments of the present application, during the formation or capacity division process, constant current and constant voltage charging can be used for charging the battery cells, which allows the battery cells to be "charged more fully", thereby improving the quality of the battery cells. In other words, compared with the related art, the embodiments of the present application improve the reliability of the formation and capacity division system. It is also worth mentioning that the charge and discharge circuit 2120 in the embodiments of the present application can realize the charging and discharging of the battery cells through only two switching tubes, which greatly saves the use of switching elements. For example, there is no need to use multi-way switches, relays, etc., which reduces costs and further improves the reliability of the formation and capacity division system.

[0066] In one embodiment, if Figure 11As shown, a third switch tube Q3 is also connected between the negative terminal of the charge and discharge circuit 2120 and the second switch tube Q2. Specifically, when the battery cell is connected to the charge and discharge circuit 2120, a reverse connection may occur (for example, caused by manual operation errors). If the battery cell is charged and discharged at this time, it may cause damage to the battery cell, components, etc. Based on this, before the battery cell is connected, the third switch tube Q3 can be controlled to be disconnected. In this way, when the battery cell is connected, if the battery cell is reversely connected at this time, since the third switch tube Q3 is in a disconnected state, a loop cannot be formed between the positive and negative poles of the battery cell, thereby avoiding the damage problem caused by the reverse connection of the battery cell; if the battery cell is not reversed when connected, the third switch tube can be directly controlled to be turned on. In one embodiment, the controller described above can determine whether the battery cell is reversely connected, and thereby control the conduction or disconnection of the third switch tube Q3.

[0067] It is worth mentioning that the embodiment of the present application sets the third switch tube Q3 between the negative terminal of the charge and discharge circuit 2120 and the second switch tube Q2, which can greatly save energy consumption and further improve the reliability of the formation and capacity division system. Specifically, on the one hand, during the formation and capacity division charging process, the constant current charging time is much longer than the constant voltage charging time, so combined with Figure 8 As can be understood from the equivalent circuit diagram shown, since the third switch tube Q3 is set between the negative terminal of the charge and discharge circuit 2120 and the second switch tube Q2, the electric energy does not pass through the third switch tube Q3. Therefore, in this stage, no additional energy consumption is caused by the third switch tube Q3. On the other hand, during the formation and capacitance-dividing discharge process, the equivalent circuit diagram of the charge and discharge circuit 2120 is as shown in FIG. Figure 8 As shown, similarly, the electric energy output by the battery cell does not pass through the third switch tube Q3, so no additional energy consumption is caused by the third switch tube Q3 in this stage.

[0068] In one embodiment, if Figure 12 As shown, a second inductor L2 is further connected between the first switch Q1 and the first cell connector 2121. Specifically, the power output by the power circuit 2110 may contain AC components, so the second inductor L2 can act as a ripple to improve the quality of the power input to the cell.

[0069] In one embodiment, if Figure 13 As shown, a fuse element FU is also connected between the first switching tube Q1 and the first cell connector 2121. Specifically, when a circuit fault or abnormality occurs, a large current is generated, which may damage components, cells, etc. in the circuit. Therefore, the fuse element FU can be melted when the circuit current flows large, preventing damage to components, cells, etc. In one embodiment, the fuse element includes a fuse.

[0070] In one embodiment, if Figure 14 As shown, the charge and discharge circuit 2120 also includes a first sampling resistor R1 and a second sampling resistor R2. Among them, one end of the first sampling resistor R1 is connected to the second end of the first inductor L1, and the other end serves as the positive terminal of the charge and discharge circuit 2120; the second sampling resistor R2 is connected between the first switch tube Q1 and the first battery cell access component 2121. Specifically, the voltage value at both ends of the charge and discharge circuit 2120 can be known through the two sampling resistors. In this way, in the constant voltage charging stage of formation or capacity division, the duty cycle of the two switching tubes can be controlled according to the voltage value at both ends, so that the voltage at both ends of the battery cell remains constant. In addition, the voltage value obtained by the second sampling resistor and the current value flowing through the second sampling resistor can be regarded as the voltage value at both ends of the battery cell and the current value flowing through the battery cell, respectively. Therefore, it is possible to determine whether the battery cell has completed constant current charging, constant voltage charging, charging completion, etc. based on this voltage value and / or current value. In one embodiment, both the first sampling resistor R1 and the second sampling resistor R2 can include high-precision sampling resistors.

[0071] In one embodiment, if Figure 15 As shown, the charge-discharge circuit 2120 further includes a second capacitor C2, which is connected in parallel with the first inductor L1 and the second switch Q2. Specifically, during the formation or capacitance-dividing discharge phase, the second capacitor C2 can improve the quality of the power output by the battery cell.

[0072] In one embodiment, if Figure 16 As shown, the charge and discharge circuit 2120 also includes a fourth switch tube Q4 and a pre-charge circuit 2123. Among them, the fourth switch tube Q4 is connected between the first switch tube Q1 and the first battery cell access component 2121; one end of the pre-charge circuit 2123 is connected to the first battery cell access component 2121, and the other end is connected to the capacitor in the charge and discharge circuit 2120 (for example, connected to the first capacitor C1 and / or the second capacitor C2). Specifically, when the battery cell is connected to the circuit, if the battery cell has energy storage, an inrush current may be generated (that is, the battery cell may generate an inrush current when connected when it is powered), causing damage to components and the like. Based on this, before the battery cell is connected to the circuit, the fourth switch tube Q4 can be controlled to be disconnected. In this way, when the battery cell is connected, the damage to the components caused by the inrush current can be avoided by disconnecting the fourth switch tube Q4. At the same time, the pre-charging circuit 2123 can use the inrush current to charge the capacitor in the circuit, so that the inrush current can be consumed, and the power supply circuit 2110 can save the electric energy consumed by charging the capacitor, thereby reducing the energy consumption of the component system and further improving the reliability of the system. In addition, it can be understood that after the capacitor is charged, the fourth switch tube Q4 can be controlled to be turned on, and the connection between the pre-charging circuit 2123 and the capacitor and the battery cell can be disconnected to prevent current backflow and the like.

[0073] In one embodiment, if Figure 17As shown, the pre-charge circuit 2123 may include a switching element K and a current-limiting resistor R3, and the switching element K and the current-limiting resistor R3 are connected in series between the first battery access component 2121 and the capacitor (e.g., the first capacitor C1 and / or the second capacitor C2) in the charge and discharge circuit 2120. Specifically, before the battery cell is accessed, the switching element K can be controlled to close, so that when the battery cell is accessed, the inrush current can charge the capacitor through the current-limiting resistor R. It is understandable that the current-limiting resistor R3 can limit the charging current of the capacitor and play a role in protecting the capacitor. In addition, after the capacitor is charged, the switching element K can be controlled to disconnect to disconnect the pre-charge circuit 2123 from the capacitor and the battery cell. In one embodiment, the switching element K may include a relay or the like.

[0074] In summary, the capacitance-combining circuit in the embodiment of the present application can be exemplarily as follows: Figure 18 As shown, please refer to the previous discussion for the specific connection relationship and no further details will be given here. Based on this, before the battery cell is connected to the circuit, the third switch tube can be controlled to be disconnected, the fourth switch tube can be controlled to be disconnected, and the switch element K can be closed. When the battery cell is connected, if the battery cell is not reversely connected, the third switch tube Q3 is controlled to be turned on. At this time, the impact current connected to the battery cell charges the first capacitor C1 and the second capacitor C2 through the current limiting resistor R3; if the battery cell is reversely connected, the third switch tube Q3 is kept disconnected to achieve the purpose of preventing reverse connection. After the capacitor is charged, the switch element K can be controlled to be disconnected, and the fourth switch tube Q4 can also be controlled to be turned on. In this way, during the formation or capacity division charging stage, the first switch tube Q1 can be controlled to be turned on and the second switch tube Q2 can be turned off to perform constant current charging; after the constant current charging is completed, the first switch tube Q1 and the second switch tube Q2 can be controlled to be periodically turned on and off alternately to perform constant voltage charging. In addition, when the battery cell completes constant voltage charging, the first switch tube Q1 can be controlled to be turned off and the second switch tube Q2 can be controlled to be turned on to disconnect the battery cell from the power circuit 2110 (i.e., bypass the battery cell). During the formation or capacity division discharge stage, the first switch tube Q1 can be controlled to be turned on and the second switch tube Q2 can be turned off to discharge the battery cell to the power circuit 2110. In addition, when the battery cell is discharged, the first switch tube Q1 can also be controlled to be turned off and the second switch tube Q2 can be controlled to be turned on to disconnect the battery cell from the power circuit 2110. It can be seen that through the formation or capacity division circuit 210 in the embodiment of the present application, during the formation or capacity division process, constant current and constant voltage charging can be used for charging the battery cell, which allows the battery cell to be "charged more fully", thereby improving the quality of the battery cell. That is, compared with the related art, the embodiment of the present application improves the reliability of the capacity division system.

[0075] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A capacitance-combination circuit, characterized in that: include: Power circuit, used to connect power supply equipment; and Multiple charging and discharging circuits, wherein the multiple charging and discharging circuits are sequentially connected in series and then connected to the power circuit; the charging and discharging circuits include a first inductor, a first switching tube, a second switching tube, a first capacitor, a first battery cell access component, and a second battery cell access component; the first battery cell access component is used to connect to the positive electrode of the battery cell, and the second battery cell access component is used to connect to the negative electrode of the battery cell; The first switching tube is connected between the first end of the first inductor and the first cell access component; the second switching tube is connected between the first end of the first inductor and the second cell access component; the first capacitor is connected in parallel with the first switching tube and the second switching tube; the second end of the first inductor serves as the positive terminal of the charge-discharge circuit, and the connection between the second switching tube and the second cell access component serves as the negative terminal of the charge-discharge circuit; a third switching tube is further connected between the negative terminal of the charge-discharge circuit and the second switching tube, and a second inductor is further connected between the first switching tube and the first cell access component; When the first switch tube is turned on and the second switch tube is turned off, the charge and discharge circuit is used for constant current charging or discharging of the battery cell; when the first switch tube and the second switch tube are periodically alternately turned on and off, the charge and discharge circuit is used for constant voltage charging of the battery cell; when the first switch tube is turned off and the second switch tube is turned on, the charge and discharge circuit is used to disconnect the battery cell from the power circuit.

2. The circuit according to claim 1, wherein: A fuse element is further connected between the first switch tube and the first battery cell connector.

3. The circuit according to claim 1, wherein: The charge and discharge circuit further includes a first sampling resistor and a second sampling resistor; One end of the first sampling resistor is connected to the second end of the first inductor, and the other end serves as the positive terminal of the charge and discharge circuit; The second sampling resistor is connected between the first switch tube and the first battery cell access component.

4. The circuit according to claim 1, wherein: The charge and discharge circuit further includes a second capacitor, which is connected in parallel with the first inductor and the second switch tube.

5. The circuit according to any one of claims 1 to 4, characterized in that: The charge and discharge circuit further includes a fourth switch tube and a pre-charge circuit; The fourth switch tube is connected between the first switch tube and the first battery cell access component; One end of the pre-charging circuit is connected to the first battery cell access component, and the other end is connected to the capacitor in the charging and discharging circuit.

6. The circuit according to claim 5, characterized in that The pre-charging circuit includes a switching element and a current-limiting resistor; The switch element and the current-limiting resistor are connected in series between the first cell connector and the capacitor in the charge-discharge circuit.

7. A chemical fractionation device, characterized in that: The method comprises the capacitance-combining circuit as described in any one of claims 1 to 6.

8. A chemical fractionation system, characterized in that: It comprises a power supply device and the chemical component capacity device as claimed in claim 7.

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