CN113682199A

CN113682199A - Formation and capacitance circuit, equipment and system

Info

Publication number: CN113682199A
Application number: CN202110964897.XA
Authority: CN
Inventors: 毛广甫; 王杰; 康小伟
Original assignee: Repower Technology Co ltd
Current assignee: Repower Technology Co ltd
Priority date: 2021-06-25
Filing date: 2021-08-20
Publication date: 2021-11-23
Also published as: CN113306450A; CN216659649U

Abstract

The circuit comprises a power supply circuit and a plurality of charging and discharging circuits, wherein the plurality of charging and discharging circuits are sequentially connected in series and then are connected with the power supply circuit. The charging and discharging circuit comprises a first inductor, a first switch tube, a second switch tube, a first capacitor, a first battery cell access piece and a second battery cell access piece. Based on this, when the first switch tube is switched on and the second switch tube is switched off, the charge and discharge circuit is used for constant current charging or discharging of the battery cell; when the first switching tube and the second switching tube are periodically and alternately switched on and off, the charge-discharge circuit is used for constant-voltage charging of the battery cell; when the first switch tube is disconnected and the second switch tube is switched on, the charging and discharging circuit is used for disconnecting the connection between the battery cell and the power circuit. It can be seen that the charging of the battery cell can adopt constant-current constant-voltage charging, so that the quality of the battery cell is improved, that is, compared with the related art, the embodiment of the application improves the reliability of the chemical composition capacity system.

Description

Formation and capacitance circuit, equipment and system

Technical Field

The application relates to the technical field of lithium batteries, in particular to a formation and grading circuit, formation and grading equipment and a formation and grading system.

Background

The lithium ion battery has the advantages of high energy density, long service life, high rated voltage, low self-discharge rate, environmental protection and the like, so the lithium ion battery is quite widely applied to new energy automobiles, power grid energy storage, digital products and the like.

In the manufacturing process of lithium ion batteries, formation and capacity grading are two very important processes, and both of them affect the quality of the batteries. The formation refers to activating positive and negative electrode materials inside a battery (also called as a battery cell) in a certain charging and discharging manner, and forming a Solid Electrolyte Interface (SEI) film on the surfaces of the positive and negative electrode materials of the battery; capacity grading refers to the cyclic charge and discharge of the formed batteries so as to eliminate the problematic batteries and group the batteries according to capacity and internal resistance. Therefore, the basic principles of formation and capacity division are common, and therefore, in the related art, formation and capacity division can be completed through one formation and capacity division system, that is, formation and capacity division can be completed through one set of equipment.

In the related art, when the partial formation and capacity grading system performs formation or capacity grading, the battery cells are connected in series in sequence, so that the use of cables can be saved. However, the reliability of such chemical composition and capacitance system is not high, and specifically, only constant current charging is adopted for charging the battery cell during the chemical composition or capacitance separation process, which may result in insufficient quality of the battery cell.

Disclosure of Invention

Based on this, the application provides a chemical composition capacitance circuit, chemical composition capacitance equipment and chemical composition capacitance system to improve the reliability of chemical composition capacitance system.

In a first aspect, the present application provides a chemical composition capacitance circuit, comprising:

the power supply circuit is used for connecting power supply equipment; and

the charging and discharging circuits are sequentially connected in series and then connected with the power supply circuit; the charging and discharging circuit comprises a first inductor, a first switch tube, a second switch tube, a first capacitor, a first battery cell access piece and a second battery cell access piece; the first battery cell access piece is used for connecting the positive electrode of the battery cell, and the second battery cell access piece is used for connecting the negative electrode of the battery cell; the first switch tube is connected between the first end of the first inductor and the first battery cell access piece; the second switch tube is connected between the first end of the first inductor and the second battery cell access piece; the first capacitor is connected with the first switch tube and the second switch tube in parallel; the second end of the first inductor is used as the positive end of the charge and discharge circuit, and the joint of the second switch tube and the second battery cell access piece is used as the negative end of the charge and discharge circuit;

when the first switch tube is switched on and the second switch tube is switched off, the charge and discharge circuit is used for constant-current charging or discharging of the battery cell; when the first switching tube and the second switching tube are periodically and alternately switched on and off, the charge-discharge circuit is used for constant-voltage charging of the battery cell; when the first switch tube is disconnected and the second switch tube is switched on, the charging and discharging circuit is used for disconnecting the connection between the battery cell and the power circuit.

Optionally, a third switching tube is further connected between the negative end of the charge and discharge circuit and the second switching tube.

Optionally, a second inductor is further connected between the first switching tube and the first cell access member.

Optionally, a fusing element is further connected between the first switching tube and the first battery cell access member.

Optionally, 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 with the second end of the first inductor, and the other end of the first sampling resistor is used as the positive electrode end of the charge-discharge circuit;

the second sampling resistor is connected between the first switching tube and the first battery core access piece.

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

Optionally, the charge and discharge circuit further includes a fourth switching tube and a precharge circuit;

the fourth switching tube is connected between the first switching tube and the first battery cell access piece;

one end of the pre-charging circuit is connected with the first battery cell access piece, and the other end of the pre-charging circuit is connected with the capacitor in the charging and discharging circuit.

Optionally, the pre-charge circuit includes a switching element and a current-limiting resistor;

the switching element and the current-limiting resistor are connected in series between the first battery cell access piece and a capacitor in the charging and discharging circuit. .

In a second aspect, the present application provides a component capacitance apparatus comprising the component capacitance circuit according to the first aspect.

In a third aspect, the present application provides a component-capacitive system comprising a power supply device and a component-capacitive device as described in the second aspect.

The application provides a become partial volume circuit, equipment and system, this circuit includes a power supply circuit and a plurality of charge-discharge circuit, and a plurality of charge-discharge circuit are connected with power supply circuit after establishing ties in proper order. The charging and discharging circuit comprises a first inductor, a first switch tube, a second switch tube, a first capacitor, a first battery cell access piece and a second battery cell access piece. Based on this, when the first switch tube is switched on and the second switch tube is switched off, the charge and discharge circuit is used for constant current charging or discharging of the battery cell; when the first switching tube and the second switching tube are periodically and alternately switched on and off, the charge-discharge circuit is used for constant-voltage charging of the battery cell; when the first switch tube is disconnected and the second switch tube is switched on, the charging and discharging circuit is used for disconnecting the connection between the battery cell and the power circuit. It can be seen that, in the formation or capacity grading process, the battery cell can be charged by constant current and constant voltage, so that the battery cell can be charged more fully, the quality of the battery cell is improved, and the reliability of the formation and capacity grading system is improved compared with the related art.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic circuit diagram of a chemical composition and capacity system in the related art;

FIG. 2 is a schematic diagram of another circuit structure of a chemical composition and capacitance system in the related art;

FIG. 3 is a schematic structural diagram of a chemical component volumetric system according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of an exemplary configuration of a chemical component volumetric system in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a chemical component container apparatus according to an embodiment of the present disclosure;

fig. 6 is a schematic circuit structure diagram between a power circuit and a charging/discharging circuit in the chemical composition capacitance circuit according to the embodiment of the present application;

fig. 7 is a schematic circuit structure diagram of a chemical composition capacitance circuit according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of an equivalent circuit structure of a varactor circuit according to an embodiment of the present application;

FIG. 9 is a schematic diagram of another equivalent circuit structure of the composite capacitive circuit according to the embodiment of the present application;

FIG. 10 is a schematic diagram of another equivalent circuit structure of the composite capacitive circuit according to the embodiment of the present application;

FIG. 11 is a schematic diagram of a circuit structure of the composite capacitive circuit including a third switch transistor according to an embodiment of the present application;

fig. 12 is a schematic diagram of a circuit structure when the composite capacitive circuit includes the second inductor according to an embodiment of the present application;

FIG. 13 is a schematic diagram of a circuit configuration in an embodiment of the present application in which the composite capacitive circuit includes a fuse element;

FIG. 14 is a schematic diagram of a circuit structure of the composite capacitive circuit including two sampling resistors according to the embodiment of the present application;

FIG. 15 is a schematic diagram of a circuit structure of the composite capacitive circuit including a second capacitor according to an embodiment of the present application;

FIG. 16 is a schematic diagram of a circuit structure of the composite capacitive circuit including the fourth switch tube and the precharge circuit according to the embodiment of the present application;

FIG. 17 is a schematic circuit diagram of a pre-charge circuit according to an embodiment of the present application;

fig. 18 is a schematic diagram of an exemplary circuit structure of the chemical capacitive circuit in the embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is to be understood that the terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should also be understood that the terms "first," "second," "third," "fourth," and the like in the description, in the claims, or in the above-described drawings (if any) are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order, and may be construed to indicate or imply relative importance or implicitly to the features indicated. In addition, the term "connected" (if any) in the specification, claims or drawings of the present application is to be interpreted broadly, for example, the term "connected" may be a fixed connection, a detachable connection, an integrated connection, an electrical connection, or a signal connection, and the term "connected" may be a direct connection or an indirect connection via an intermediate medium. Furthermore, the term "and/or" (if present) as used in the specification, claims, or drawings of the present application refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

Moreover, in the subject application, any embodiment or design described herein as "exemplary" or "e.g.," is not to be construed as preferred or advantageous over other embodiments or designs, and rather, use of the term "exemplary" or "e.g.," is intended to present relevant concepts in a concrete fashion.

In the related art, when the partial formation and capacity separation system performs formation or capacity separation, the battery cells are connected in series in sequence. For example, in the formation and capacity division system shown in fig. 1, when all relays are in the off state, the cells are connected in series in sequence, in which case the system can simultaneously perform formation or capacity division for each cell. For another example, in the component-capacitance system shown in fig. 2, when the switches of all the multi-way switches are turned "down", the cells are also connected in series in sequence, and in this case, the system may also perform component-capacitance or capacitance-capacitance for each cell at the same time.

Based on this, the inventors of the present application found that: the formation and capacity system has the problem of low reliability. Specifically, in the formation or capacity grading process, the battery cells need to be charged and discharged according to a preset strategy, but because the battery cells are connected in series in sequence, the battery cells are usually charged only by a constant current, which affects the quality of the battery cells.

More specifically, the power supply device usually outputs electric energy with a certain current value (i.e., constant current output), and since the cells are connected in series in sequence, the current value flowing through each cell is the same, so the system can adopt a constant current charging mode. However, due to reasons such as different internal resistances of the battery cells, the voltage values at the two ends of each battery cell are different, and the battery cells should be disconnected from the power supply device when the constant voltage charging is completed (for example, the system in fig. 1 needs to close the corresponding relay when a certain battery cell completes the constant voltage charging, or the system in fig. 2 needs to turn the corresponding multi-way switch "on" when a certain battery cell completes the constant voltage charging), it can be understood that when a battery cell is disconnected from the power supply device, the voltage values at the two ends of other battery cells will change, and thus the system cannot meet the constant voltage charging mode. Therefore, the battery cell is usually charged by the chemical composition and capacitance system only by using a constant current, but the battery cell cannot be fully charged only by using the constant current, which may result in insufficient quality of the battery cell.

Therefore, the embodiment of the application provides a chemical composition capacitance circuit, a chemical composition capacitance device and a chemical composition capacitance system.

As shown in fig. 3, the chemical component capacitance system according to the embodiment of the present application may include a power supply device 10 and a chemical component capacitance device 20. The power supply device 10 may be connected to at least one input power source (e.g., a power grid, wind power, photovoltaic, etc.), and the chemical component capacitance device 20 may be connected to a plurality of electrical cores. In an embodiment, the power supply device 10 and/or the chemical composition and capacity separation device 20 may implement ac/dc conversion, voltage increase/decrease, and the like, that is, at least one of the two devices implements processing of electric energy to meet the requirement of electrical chemical composition or capacity separation. It should be noted that, compared with the related art, the composition and capacity system in the embodiment of the present application has higher reliability.

Illustratively, as shown in fig. 4, the power supply device 10 may include an AC/DC circuit, and the chemical component capacitance device 20 may include a DC/DC circuit, with reference to the drawings. In the present example, the processing of the electrical energy is implemented by two devices, for example, in a charging phase of formation or grading, the AC/DC circuit may convert the alternating current of the grid and/or the photovoltaic input into direct current, and the DC/DC circuit may 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 cells; conversely, during the formation or capacity-grading discharge phase, the DC/DC circuit may perform voltage conversion (e.g., step down) on the electrical energy output by the cell, and the AC/DC circuit may convert the direct current output by the DC/DC circuit into an alternating current for feeding back to the grid or supplying to a load, etc.

The chemical composition capacitance device 20 provided in the embodiment of the present application, as shown in fig. 5, may include a chemical composition capacitance circuit 210. It should be noted that, with the formation and capacitance dividing circuit 210 in the embodiment of the present application, in the formation or capacitance dividing process, the battery cell may be charged with a constant current and a constant voltage, so that the battery cell may be "fully charged", 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 formation and capacitance dividing system.

The composition capacitive circuit 210 according to the embodiment of the present disclosure, as shown in fig. 6, may include a power circuit 2110 and a plurality of charging and discharging circuits 2120. The plurality of charge/discharge circuits 2120 are connected in series to the power supply circuit 2110, that is, the plurality of charge/discharge circuits 2120 are connected in series to the power supply circuit 2110 between the positive and negative electrodes thereof. In the present embodiment, the power circuit 2110 is used for connecting the power device 10, and for example, the power circuit 2110 may include the aforementioned DC/DC circuit for connecting the AC/DC circuit in the power device 10. In addition, as shown in fig. 7, the charging and discharging circuit 2120 may include a first inductor L1, a first switch Q1, a second switch Q2, a first capacitor C1, a first cell access piece 2121, and a second cell access piece 2122.

The first cell access member 2121 is configured to connect to an anode of a cell, and the second cell access member 2122 is configured to connect to a cathode of the cell, that is, the cell is connected through a pair of cell access members. In one embodiment, the chemical component volumetric apparatus 20 has a needle bed comprising a plurality of probe assemblies, and thus each of the first cell access 2121 and the second cell access 2122 may comprise a probe assembly.

The first switch tube Q1 is connected between the first end of the first inductor L1 and the first cell access part 2121, the second switch tube Q2 is connected between the first end of the first inductor L1 and the second cell access part 2122, and the first capacitor C1 is connected in parallel with the first switch tube Q1 and the second switch tube Q2. In one embodiment, the first switching transistor Q1 and the second switching transistor Q2 may each include MOS transistors or the like; in addition, the chemical composition capacitive device 20 may have a controller therein, and the control terminal of each switching tube in each charging and discharging circuit 2120 may be connected to the controller to be turned on or off under the control of the controller.

In addition, the second end of the first inductor L1 serves as the positive terminal of the charge and discharge circuit 2120, the connection point of the second switch tube Q2 and the second cell access piece 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 terminal of the power circuit 2110 or the negative terminal of the "previous" charge and discharge circuit, and the connection point of the second switch tube Q2 and the second cell access piece 2122 is connected to the negative terminal of the power circuit 2110 or the positive terminal of the "next" charge and discharge circuit.

Based on this, when the first switch Q1 is turned on and the second switch 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 switching tube Q1 and the second switching tube Q2 are periodically and alternately switched on and off, the charging and discharging circuit 2120 is used for constant-voltage charging of the battery cell; when the first switch Q1 is turned off and the second switch 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).

The operation of the charge/discharge circuit 2120 is described in detail below with reference to fig. 8-10:

(1) in the charging stage of formation or capacity grading, the battery cell is charged at a constant current to realize rapid charging of the battery cell. The first switch Q1 can be controlled to be turned on and the second switch Q2 can be controlled to be turned off, and the equivalent circuit diagram can be seen in fig. 8. It can be understood that, at this time, the plurality of battery cells are connected in series in sequence, and then the currents flowing through each battery cell are the same, so that each battery cell can be subjected to constant current charging. In one embodiment, the current value of the power output by the power circuit 2110 may be dynamically adjusted according to the number of cells being charged.

(2) After the constant-current charging is finished, constant-voltage charging is required to be carried out so that the battery cell is full. The first switch Q1 and the second switch Q2 can be controlled to be turned on and off alternately periodically, and the equivalent circuit diagram can be seen in fig. 9. At this time, it can be understood that the first inductor L1, the first switch tube Q1, the second switch tube Q2, and the first capacitor C1 form a boost circuit, so that the voltages at the two ends of the battery cell can be kept constant by only reasonably controlling the duty ratios of the two switch tubes, that is, each battery cell can be charged at a constant voltage. In an embodiment, the duty ratio of the two switching tubes may be dynamically adjusted according to the input voltage and the output voltage of the boost circuit, that is, according to the voltage value at two ends of the charging and discharging circuit 2120.

(3) After the constant voltage charging is completed, since each battery cell is different, the time when each battery cell completes the constant voltage charging is different, and therefore, the battery cell should be disconnected from the power supply circuit 2110 after the constant voltage charging is completed, and the charging is stopped. The first switch Q1 can be controlled to be turned off and the second switch Q2 can be controlled to be turned on, and the equivalent circuit diagram can be seen in fig. 10. It will be appreciated that the cell is now bypassed and the connection to the power circuit 2110 is broken. In one embodiment, whether the battery cell has completed the constant voltage charging may be determined according to a voltage value, a current value, and the like across the battery cell.

(4) After the battery cell is charged, the battery cell should be discharged (i.e., during a discharging phase of formation or capacity division), and then the first switch Q1 may be controlled to be turned on, and the second switch Q2 may be controlled to be turned off, at this time, the equivalent circuit diagram may refer to fig. 8. It can be understood that a plurality of battery cells are sequentially connected in series and then discharged to the power circuit 2110. Similarly, the discharge time of each cell is different, so that when the cell is disconnected from the power circuit 2110 after the discharge is completed, the first switch tube Q1 can be controlled to be disconnected, and the second switch tube Q2 can be controlled to be switched on, as shown in fig. 10. In one embodiment, whether the cell has completed discharging may be determined according to a voltage value, a current value, and the like of the two ends of the cell. In addition, after the battery cell is discharged, whether the next round of charging and discharging is required or not can be determined according to actual conditions.

Therefore, according to the embodiment of the application, in the formation or capacity grading process, the battery cell can be charged by adopting constant current and constant voltage, so that the battery cell can be charged more fully, the quality of the battery cell is improved, and the reliability of the formation and capacity grading system is improved compared with the related art. In addition, it is worth mentioning that the charging and discharging circuit 2120 in the embodiment of the present application can realize charging and discharging of the battery cell only through two switching tubes, so that the use of the switching element is greatly saved, for example, a multi-way switch, a relay, and the like are not needed, the cost is reduced, and the reliability of the chemical composition capacitance system is further improved.

In one embodiment, as shown in fig. 11, a third switch Q3 is further connected between the negative terminal of the charge and discharge circuit 2120 and the second switch Q2. Specifically, when the battery cell is connected to the charge and discharge circuit 2120, a reverse connection condition (for example, caused by manual operation error) may occur, and if the battery cell is charged and discharged at this time, the battery cell, the component, and the like may be damaged. Therefore, before the battery cell is connected, the third switching tube Q3 can be controlled to be disconnected, so that when the battery cell is connected, if the battery cell is reversely connected, a loop cannot be formed between the positive electrode and the negative electrode of the battery cell due to the fact that the third switching tube Q3 is in a disconnected state, and the problem of damage caused by reverse connection of the battery cell can be solved; if the electric core is not reversely connected during connection, the third switch tube is directly controlled to be conducted. In an embodiment, the controller described above may determine whether the cell is reversely connected, and accordingly, the third switching tube Q3 is turned on or off.

It should be noted that in the embodiment of the present application, the third switching tube Q3 is disposed between the negative terminal of the charge and discharge circuit 2120 and the second switching tube Q2, so that energy consumption can be greatly saved, and reliability of the chemical capacitive system can be further improved. Specifically, on the one hand, in the formation and capacitance-grading charging process, the duration of the constant-current charging is much longer than that of the constant-voltage charging, and it can be understood from the equivalent circuit diagram shown in fig. 8 that, since the third switching tube Q3 is disposed between the negative terminal of the charging and discharging circuit 2120 and the second switching tube Q2, the electric energy does not pass through the third switching tube Q3, and therefore, no additional energy consumption is caused by the third switching tube Q3 at this stage; on the other hand, in the formation and capacity-grading discharging process, the equivalent circuit diagram of the charging and discharging circuit 2120 is as shown in fig. 8, and similarly, the electric energy output by the battery cell does not pass through the third switching tube Q3, so that no extra energy consumption is caused by the third switching tube Q3 at this stage.

In an embodiment, as shown in fig. 12, a second inductor L2 is further connected between the first switch tube Q1 and the first cell access member 2121. Specifically, the power output by the power circuit 2110 may contain an ac component, so that the second inductor L2 may function as a ripple, so as to make the power input to the battery cell better.

In one embodiment, as shown in fig. 13, a fuse element FU is further connected between the first switch Q1 and the first cell access 2121. Specifically, can produce great electric current when the circuit breaks down or unusual, so can damage components and parts, electric core etc. in the circuit, consequently fuse element FU can fuse when great electric current appears in the circuit, avoids components and parts, electric core etc. to take place to damage. In one embodiment, the fuse element comprises a fuse.

In an embodiment, as shown in fig. 14, the charging and discharging circuit 2120 further includes a first sampling resistor R1 and a second sampling resistor R2. One end of the first sampling resistor R1 is connected to the second end of the first inductor L1, and the other end is used as the positive terminal of the charge and discharge circuit 2120; the second sampling resistor R2 is connected between the first switch Q1 and the first cell access 2121. Specifically, the voltage values at the two ends of the charge and discharge circuit 2120 can be obtained through the two sampling resistors, so that in the formation or capacity-grading constant-voltage charging stage, the duty ratios of the two switching tubes can be controlled according to the voltage values at the two ends, and the voltages at the two ends of the battery cell are kept constant. In addition, the voltage value obtained through the second sampling resistor and the current value flowing through the second sampling resistor can be regarded as the voltage value at the two ends of the battery cell and the current value flowing through the battery cell, respectively, so that whether the battery cell completes constant current charging, constant voltage charging, charging completion and the like can be determined according to the voltage value and/or the current value. In one embodiment, each of the first sampling resistor R1 and the second sampling resistor R2 may include a high-precision sampling resistor.

In an embodiment, as shown in fig. 15, the charging and discharging circuit 2120 further includes a second capacitor C2, and the second capacitor C2 is connected in parallel with the first inductor L1 and the second switch Q2. Specifically, in the discharge stage of formation or capacity division, the second capacitor C2 may enable the electric energy output by the battery cell to be better.

In one embodiment, as shown in fig. 16, the charging and discharging circuit 2120 further includes a fourth switch tube Q4 and a pre-charging circuit 2123. The fourth switching tube Q4 is connected between the first switching tube Q1 and the first cell access piece 2121; the precharge circuit 2123 has one end connected to the first cell access device 2121 and the other end connected to a capacitor in the charge/discharge circuit 2120 (e.g., 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 stored energy, an impact current may be generated (that is, the battery cell is connected to the circuit under the condition of electricity, the impact current may be generated), so that the components are damaged, and the like. Based on this, before the battery core is connected to the circuit, the fourth switching tube Q4 can be controlled to be disconnected, so that when the battery core is connected, the damage of the impact current to the components can be avoided through the disconnected fourth switching tube Q4; meanwhile, the pre-charging circuit 2123 can charge the capacitor in the circuit by using the impact current, so that the impact current can be consumed, and the electric energy consumed by the power circuit 2110 for charging the capacitor can be saved, thereby reducing the energy consumption of the component capacitance system and further improving the reliability of the system. In addition, it can be understood that after the charging of the capacitor is finished, the fourth switching tube Q4 may be controlled to be turned on, and the connection between the precharge circuit 2123 and the capacitor or the battery cell may also be disconnected, so as to prevent the occurrence of a current backflow.

In an embodiment, as shown in fig. 17, the pre-charging 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 cell access 2121 and a capacitor (e.g., the first capacitor C1 and/or the second capacitor C2) in the charging and discharging circuit 2120. Specifically, before electric core inserts, can control switch element K closed, so when electric core inserts, impulse current can charge for the electric capacity through current limiting resistor R, and it can be understood that current limiting resistor R3 can restrict the charging current size of electric capacity, plays the effect of protection electric capacity. In addition, after the capacitor is charged, the switching element K may be controlled to be turned off to disconnect the precharge circuit 2123 from the capacitor and the battery cell. In an embodiment, the switching element K may include a relay or the like.

As described above, the formation-capacitance circuit in the embodiment of the present application can be exemplarily shown in fig. 18, and please refer to the foregoing discussion for details of the connection relationship and the like, which is not described herein again. Based on this, before the electric core is connected into the circuit, the third switching tube can be controlled to be disconnected, the fourth switching tube can be controlled to be disconnected, and the switching element K can be controlled to be closed. When the battery cell is connected, if the battery cell is not reversely connected, the third switching tube Q3 is controlled to be switched on, and at the moment, 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 core is reversely connected, the third switching tube Q3 is kept disconnected, so that the purpose of preventing reverse connection is achieved. After the capacitor is charged, the switching element K may be controlled to be turned off, and the fourth switching tube Q4 may be controlled to be turned on. In this way, in the charging stage of formation or capacity grading, the first switch tube Q1 can be controlled to be on, and the second switch tube Q2 can be controlled to be off, so as to perform constant-current charging; after the constant-current charging is completed, the first switching tube Q1 and the second switching tube Q2 may be controlled to be periodically turned on and off alternately to perform constant-voltage charging, and in addition, when the battery cell completes the constant-voltage charging, the first switching tube Q1 may be controlled to be turned off, the second switching tube Q2 may be controlled to be turned on, and the connection between the battery cell and the power circuit 2110 is disconnected (i.e., the battery cell is bypassed). In the discharge stage of formation or capacity division, the first switch tube Q1 may be controlled to be turned on, and the second switch tube Q2 may be controlled to be turned off, so as to discharge the battery cell to the power circuit 2110, and in addition, after the discharge of the battery cell is completed, the first switch tube Q1 may also be controlled to be turned off, and the second switch tube Q2 may also be controlled to be turned on, so as to disconnect the battery cell from the power circuit 2110. It can be seen that, with the formation and capacitance sharing circuit 210 in the embodiment of the present application, in the formation or capacitance sharing process, the battery cell may be charged by a constant current and a constant voltage, so that the battery cell may be "fully charged", 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 formation and capacitance sharing system.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A capacitive grading circuit, comprising:

the power supply circuit is used for connecting power supply equipment; and

2. The circuit of claim 1, wherein a third switching tube is further connected between the negative terminal of the charge and discharge circuit and the second switching tube.

3. The circuit of claim 1, wherein a second inductor is further connected between the first switching tube and the first cell access member.

4. The circuit of claim 1, wherein a fuse element is further connected between the first switching tube and the first cell access member.

5. The circuit of claim 1, wherein the charge and discharge circuit further comprises a first sampling resistor and a second sampling resistor;

6. The circuit of claim 1, wherein the charging and discharging circuit further comprises a second capacitor connected in parallel with the first inductor and the second switching tube.

7. The circuit according to any one of claims 1-6, wherein the charging and discharging circuit further comprises a fourth switch tube and a pre-charging circuit;

8. The circuit of claim 7, wherein the pre-charge circuit comprises a switching element and a current limiting resistor;

the switching element and the current-limiting resistor are connected in series between the first battery cell access piece and a capacitor in the charging and discharging circuit.

9. A chemical composition capacitance device comprising the chemical composition capacitance circuit according to any one of claims 1 to 8.

10. A chemical composition and capacitance system comprising a power supply apparatus and the chemical composition and capacitance apparatus according to claim 9.