Sodium ion battery charging device

Abstract

The utility model belongs to the technical field of battery charging, and provides a sodium ion battery charging device, which comprises an auxiliary charging circuit with one end connected with a charger and the other end connected with a battery pack; the auxiliary charging circuit comprises a cut-in circuit which is configured to conduct a charging loop of the battery pack to charge the battery pack when the charger is connected; the input end of the cut-out circuit is connected with the battery management system, the output end of the cut-out circuit is connected with the cut-in circuit, and the cut-out circuit is configured to turn off the cut-in circuit when the battery management system is powered on, so that the auxiliary charging circuit exits working. The device has the advantages that under the condition that the sodium battery is discharged to 0V, the battery pack can be normally charged after a charger is connected, and the condition that a battery system cannot work is avoided; and when the electrified voltage of the battery pack is increased, and the BMS can work normally, the auxiliary charging circuit can be automatically switched out without interfering the normal operation of the charging of the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of battery charging, in particular to a sodium ion battery charging device. Background Art

[0002] With the rapid growth of global battery demand and the uneven spatial distribution of lithium resources, China's battery industry chain is beginning to face the problem of lithium resource constraints. In contrast, sodium resources are abundant, widely distributed, and simple to refine. After large-scale commercial use, there will be a greater cost advantage, so sodium-ion batteries can be used as a substitute for lithium iron phosphate batteries.

[0003] Compared with lithium-ion batteries, sodium-ion batteries have the following advantages: (1) cheaper materials; (2) better high and low temperature performance; (3) better safety performance; (4) can be discharged to 0 V. As lithium-ion batteries frequently catch fire during transportation, the ability of sodium-ion batteries to discharge to 0 V can solve transportation safety issues. However, once the battery is discharged to 0 V, its BMS protection system will no longer work, making it impossible to turn on the charging switch and resulting in a situation where charging cannot be performed. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a sodium ion battery charging device, which is used to solve the problem that the sodium battery can be normally charged when connected to a charger when the battery is discharged to 0V.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A sodium ion battery charging device comprises an auxiliary charging circuit, one end of which is connected to a charger and the other end of which is connected to a battery pack; the auxiliary charging circuit is configured to connect to the charger after the battery pack is discharged to 0V so that the battery pack is charged normally, and automatically cut out when a battery management system in the battery pack is powered on.

[0007] Furthermore, the auxiliary charging circuit includes:

[0008] a cut-in circuit, configured to conduct a charging circuit of the battery pack to charge the battery pack when the charger is connected;

[0009] The cut-out circuit has an input end connected to the battery management system and an output end connected to the cut-in circuit, and is configured to turn off the cut-in circuit when the battery management system is powered on, so that the auxiliary charging circuit stops working.

[0010] Further, the cut-in circuit includes:

[0011] A first-stage step-down circuit, whose input end is connected to the charger and whose output end outputs a first voltage signal;

[0012] The second-stage step-down circuit has an input terminal receiving the first voltage signal and an output terminal outputting a second voltage signal, wherein the second voltage signal is used to conduct the charging circuit of the battery pack.

[0013] Further, the first-stage step-down circuit includes: a resistor R31, a resistor R35, a resistor R37, a capacitor C67, a diode D2, a voltage-stabilizing diode Z2, a transistor Q5, and a transistor Q6;

[0014] Among them, the cathode of the diode D2 is electrically connected to the anode of the charger, and the anode of the diode D2 is connected to one end of the resistor R31. The other end of the resistor R31 is respectively connected to one end of the resistor R35, one end of the resistor R37, and the collector of the transistor Q5. The other end of the resistor R35 is connected to the collector of the transistor Q6, and the other end of the resistor R37 is connected to the base of the transistor Q6. The emitter of the transistor Q6 is connected to the base of the transistor Q5, and the emitter of the transistor Q5 is used to output the first voltage signal. The cathode of the voltage stabilizing diode Z2 is connected to the base of the transistor Q6, and the anode of the diode Z2 is connected to the anode of the charger. A capacitor C67 is arranged between the emitter of the transistor Q5 and the anode of the charger.

[0015] Furthermore, the second-stage step-down circuit includes: a resistor R33, a resistor R38, a resistor R41, a resistor R50, a MOS transistor Q4 and a MOS transistor Q7;

[0016] The source of the MOS tube Q4 inputs the first voltage signal, a resistor R33 is connected in series between the gate and the source of the MOS tube Q4, the gate of the MOS tube Q4 is connected to the drain of the MOS tube Q7 through the resistor R38, and the drain of the MOS tube Q4 outputs the second voltage signal; the first switch signal is input to the gate of the MOS tube Q7 through the resistor R41, the gate of the MOS tube Q7 is connected to the negative electrode of the charger through the resistor R50, and the source of the MOS tube Q7 is connected to the negative electrode of the charger;

[0017] When the first switch signal is input to the MOS transistor Q7, the second-stage buck circuit outputs a second voltage signal due to the conduction of the MOS transistor Q7 and the MOS transistor.

[0018] Furthermore, an optocoupler U11 is provided in the cut-out circuit, a first input port of the optocoupler U11 is connected to the battery management system to obtain a first control signal sent by the battery management system, and a second input port of the optocoupler U11 is connected to the first buck circuit and the second buck circuit;

[0019] When the first input port of the optical coupler U11 receives the first control signal, the optical coupler U11 forms a second switch signal when inputting the first voltage signal output by the first step-down circuit into the second input port.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The device can discharge the sodium battery to 0V, and then charge the battery pack normally after connecting to the charger without causing the battery system to fail to work; and when the voltage of the battery pack rises, so that the BMS therein can work normally, the auxiliary charging circuit will automatically cut out without interfering with the normal operation of the battery pack charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a framework diagram of the charging device in the embodiment provided by the utility model;

[0023] Figure 2 It is a circuit diagram of the cut-in circuit in the embodiment provided by the utility model;

[0024] Figure 3 It is a circuit diagram of a charging switch in an embodiment provided by the utility model;

[0025] Figure 4 It is a circuit diagram of a cut-out circuit in the embodiment provided by the utility model. DETAILED DESCRIPTION

[0026] It should be noted that in the present invention, the descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The following are specific embodiments of the present invention, and the technical solution of the present invention is further described in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments.

[0029] In this embodiment, if Figure 1As shown, a sodium ion battery charging device is provided, including an auxiliary charging circuit, one end of which is connected to the charger and the other end of which is connected to the battery pack.

[0030] The auxiliary charging circuit is configured to connect to the charger after the battery pack is discharged to 0V so that the battery pack is charged normally, and automatically switch out when the battery management system in the battery pack is powered on.

[0031] Wherein, the auxiliary charging circuit includes:

[0032] a cut-in circuit, configured to conduct a charging circuit of the battery pack to charge the battery pack when the charger is connected;

[0033] The cut-out circuit has an input end connected to the battery management system and an output end connected to the cut-in circuit, and is configured to shut down the cut-in circuit when the battery management system is powered on, so that the auxiliary charging circuit stops working.

[0034] In the cut-in circuit, the cut-in circuit includes: a first-stage buck circuit and a second-stage buck circuit. The input end of the first-stage buck circuit is connected to the charger, and the output end outputs a first voltage signal; the input end of the second-stage buck circuit receives the first voltage signal, and the output end outputs a second voltage signal, and the second voltage signal is used to conduct the charging circuit of the battery pack.

[0035] like Figures 2 to 4 As shown, the first-stage step-down circuit includes: a resistor R31, a resistor R35, a resistor R37, a capacitor C67, a diode D2, a voltage-stabilizing diode Z2, a transistor Q5, and a transistor Q6.

[0036] Among them, the cathode of diode D2 is electrically connected to the anode of the charger, and its anode is connected to one end of resistor R31, the other end of resistor R31 is respectively connected to one end of resistor R35, one end of resistor R37, and the collector of transistor Q5, the other end of resistor R35 is connected to the collector of transistor Q6, and the other end of resistor R37 is connected to the base of transistor Q6. The emitter of transistor Q6 is connected to the base of transistor Q5, and the emitter of transistor Q5 is used to output the first voltage signal. The cathode of voltage stabilizing diode Z2 is connected to the base of transistor Q6, and its anode is connected to the cathode of the charger, and capacitor C67 is arranged between the emitter of transistor Q5 and the cathode of the charger.

[0037] The second-stage step-down circuit includes: a resistor R33, a resistor R38, a resistor R41, a resistor R50, a MOS transistor Q4 and a MOS transistor Q7.

[0038] The source of the MOS tube Q4 inputs the first voltage signal, a resistor R33 is connected in series between the gate and the source of the MOS tube Q4, the gate of the MOS tube Q4 is connected to the drain of the MOS tube Q7 through the resistor R38, and the drain of the MOS tube Q4 outputs the second voltage signal. The first switch signal is input to the gate of the MOS tube Q7 through the resistor R41, the gate of the MOS tube Q7 is connected to the negative electrode of the charger through the resistor R50, and the source of the MOS tube Q7 is connected to the negative electrode of the charger.

[0039] When the first switch signal is input to the MOS transistor Q7, the second-stage buck circuit outputs a second voltage signal due to the conduction of the MOS transistor Q7 and the MOS transistor Q4.

[0040] A charge-discharge switch is provided in the charge-discharge loop, which includes: a MOS tube Q21, a resistor R82, a diode D9, a transistor Q8, a resistor R51, a resistor R57 and a fuse F2.

[0041] The emitter of the transistor Q8 is input with the second voltage signal, the base of the transistor Q8 is connected to the emitter of the transistor Q8 through the resistor R52, and the base of the transistor Q8 is also connected to the negative electrode of the charger through the resistor R57. The collector of the transistor Q8 is connected to the positive electrode of the diode D9, the negative electrode of the diode D9 is connected to the gate of the MOS transistor Q21, the source of the MOS transistor Q21 is connected to the negative electrode of the charger, the drain of the MOS transistor Q21 is connected to the negative electrode of the battery pack through the fuse, and the resistor R82 is connected in series between the source and the gate of the MOS transistor Q21.

[0042] The cut-out circuit includes: a resistor R32, a resistor R34, a voltage stabilizing diode ZD2, a capacitor C68, an optical coupler U11, a diode D8, a resistor R36 and a resistor R40.

[0043] The first input port of the optocoupler U11 is connected to the cathode of the diode D8, the anode of the diode D8 is connected to the battery management system through the resistor R36, and the first input port of the optocoupler U11 is connected to the battery management system to obtain the first control signal sent by the battery management system. The first output interface of the optocoupler U11 is grounded through the resistor R40.

[0044] The second input port of the optocoupler U11 is connected to the emitter of the transistor Q5 in the first-stage step-down circuit through the resistor R32, and the second input port of the optocoupler U11 is connected to the resistor R41 in the second step-down circuit through the resistor R34. A capacitor C68 is connected in series between the second input port of the optocoupler U11 and the second output port of the optocoupler U11, and the second output port of the optocoupler U11 is also connected to the negative electrode of the charger, and the positive electrode of the zener diode ZD2 is connected to the negative electrode of the charger, and its negative electrode is connected to the second input port of the optocoupler U11 through the resistor R34.

[0045] When the first input port of the optocoupler U11 receives the first control signal, the optocoupler U11 converts the first voltage signal output by the first step-down circuit into a second switch signal when inputting the first voltage signal into the second input port.

[0046] After connecting to the charger, the first voltage signal (VDC) is first obtained through the first-stage step-down circuit. Since the battery management system cannot get power at this time, the optocoupler U11 cannot be turned on. Therefore, the first voltage signal forms a high-level first switch signal on the second input port of the optocoupler U11, which is input into the second-stage step-down circuit after passing through the port COM_ON to turn on the MOS tube Q7. Then, when the MOS tube Q7 is turned on, the MOS tube Q4 is also turned on, thereby obtaining the second voltage signal.

[0047] The second voltage signal output by the second-stage step-down circuit is output to the charge-discharge switch through the V11 port, and the MOS tube Q21 is turned on by the transistor Q8, thereby forming a path between the charger and the battery pack, and the battery pack can be powered.

[0048] When the battery pack is powered, the battery management system in the battery pack can also be powered, so that the first control signal can be output through the battery management system. When the first control signal is input to the cut-out circuit via the SYS port, the optocoupler U11 is turned on, so a low level is formed at the second input port of the optocoupler U11. The second switch signal formed by the low level signal is input into the second-stage buck circuit via the port COM_ON to turn off the MOS tube Q7. When the MOS tube Q7 is turned off, the MOS tube Q4 is also turned off, and the second voltage signal cannot be output, so the auxiliary charging circuit will stop working.

[0049] Since no microprocessor is used, the overall power consumption is low, and after completing the 0V charging start, the charging process can be quickly cut out without interfering with the normal operation of the battery pack charging.

[0050] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A sodium ion battery charging device, characterized in that: It includes an auxiliary charging circuit, one end of which is connected to the charger and the other end of which is connected to the battery pack; the auxiliary charging circuit is configured to connect to the charger after the battery pack is discharged to 0V so that the battery pack is charged normally, and automatically cut out when the battery management system in the battery pack is powered on.

2. A sodium ion battery charging device according to claim 1, characterized in that: The auxiliary charging circuit comprises: a cut-in circuit, configured to conduct a charging circuit of the battery pack to charge the battery pack when the charger is connected; The cut-out circuit has an input end connected to the battery management system and an output end connected to the cut-in circuit, and is configured to turn off the cut-in circuit when the battery management system is powered on, so that the auxiliary charging circuit stops working.

3. A sodium ion battery charging device according to claim 2, characterized in that: The cut-in circuit comprises: A first-stage step-down circuit, whose input end is connected to the charger and whose output end outputs a first voltage signal; The second-stage step-down circuit has an input terminal receiving the first voltage signal and an output terminal outputting a second voltage signal, wherein the second voltage signal is used to conduct the charging circuit of the battery pack.

4. A sodium ion battery charging device according to claim 3, characterized in that: The first-stage step-down circuit includes: a resistor R31, a resistor R35, a resistor R37, a capacitor C67, a diode D2, a voltage-stabilizing diode Z2, a transistor Q5, and a transistor Q6; Among them, the cathode of the diode D2 is electrically connected to the anode of the charger, and the anode of the diode D2 is connected to one end of the resistor R31. The other end of the resistor R31 is respectively connected to one end of the resistor R35, one end of the resistor R37, and the collector of the transistor Q5. The other end of the resistor R35 is connected to the collector of the transistor Q6, and the other end of the resistor R37 is connected to the base of the transistor Q6. The emitter of the transistor Q6 is connected to the base of the transistor Q5, and the emitter of the transistor Q5 is used to output the first voltage signal. The cathode of the voltage stabilizing diode Z2 is connected to the base of the transistor Q6, and the anode of the diode Z2 is connected to the anode of the charger. A capacitor C67 is arranged between the emitter of the transistor Q5 and the anode of the charger.

5. A sodium ion battery charging device according to claim 4, characterized in that: The second-stage step-down circuit includes: a resistor R33, a resistor R38, a resistor R41, a resistor R50, a MOS transistor Q4 and a MOS transistor Q7; The source of the MOS tube Q4 inputs the first voltage signal, a resistor R33 is connected in series between the gate and the source of the MOS tube Q4, the gate of the MOS tube Q4 is connected to the drain of the MOS tube Q7 through the resistor R38, and the drain of the MOS tube Q4 outputs the second voltage signal; the first switch signal is input to the gate of the MOS tube Q7 through the resistor R41, the gate of the MOS tube Q7 is connected to the negative electrode of the charger through the resistor R50, and the source of the MOS tube Q7 is connected to the negative electrode of the charger; When the first switch signal is input to the MOS transistor Q7, the second-stage buck circuit outputs a second voltage signal due to the conduction of the MOS transistor Q7 and the MOS transistor.

6. A sodium ion battery charging device according to claim 5, characterized in that: The cut-out circuit is provided with an optical coupler U11, a first input port of the optical coupler U11 is connected to a battery management system to obtain a first control signal sent by the battery management system, and a second input port of the optical coupler U11 is connected to a first buck circuit and a second buck circuit; When the first input port of the optical coupler U11 receives the first control signal, the optical coupler U11 forms a second switch signal when inputting the first voltage signal output by the first buck circuit into the second input port.

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