Battery cell protection circuit, battery protection board and battery

Abstract

The invention provides a battery cell protection circuit, a battery protection board and a battery, and relates to the technical field of battery cell protection, the battery cell protection circuit comprises a battery cell protection chip and a switch module, the battery cell protection chip controls the switch module to be in a first state when the voltage of a battery cell is abnormal, and the switch module is in a second state when the voltage of the battery cell is abnormal. The battery cell in the battery is disconnected from the charging and discharging port through the switch module under the condition that the switch module is in the first state so as to protect the battery, and the battery cell is connected with the charging and discharging port through the switch module under the condition that the voltage of the battery cell is recovered to be normal, so that the battery is recovered to be normal; compared with the prior art that the battery is scrapped due to protective fusing of the fuse in the battery, the rejection rate of the battery is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of battery cell protection, and specifically relates to a battery cell protection circuit, a battery protection board, and a battery. Background Art

[0002] Batteries usually use fuses as secondary protection devices. For example, batteries in 3C electronic products are equipped with fuses. When the voltage of the battery cell is abnormal, the fuse in the battery blows, disconnecting the battery cell from the charging and discharging port to reduce the risk of battery burning.

[0003] However, the fuse is a one-time device and cannot be restored after protective melting. The protective melting of the fuse in the battery causes the battery to be scrapped. For example, in the production test of the battery, the protective melting of the fuse in the battery is often mistakenly triggered, resulting in the battery being scrapped. Summary of the invention

[0004] The present application aims to provide a protection circuit for a battery cell, a protection board for a battery, and a battery, which at least solve the problem in the prior art that the battery is scrapped due to protective fusing of the fuse in the battery.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a battery cell protection circuit, including: a battery cell protection chip, a switch module;

[0007] The battery cell protection chip is electrically connected to the switch module, and the battery cell protection chip is used to be electrically connected to the battery cell, and when the voltage of the battery cell is abnormal, the switch module is controlled to be in the first state;

[0008] The switch module is used to be arranged between the battery cell and the charging and discharging port of the battery cell. When the switch module is in a first state, the battery cell is disconnected from the charging and discharging port. When the voltage of the battery cell returns to normal, the switch module switches to a second state, so that the battery cell is connected to the charging and discharging port.

[0009] Optionally, the switch module includes a first switch sub-module and a second switch sub-module; the first state is that the first switch sub-module is turned on and the second switch sub-module is turned off, and the second state is that the first switch sub-module is turned off and the second switch sub-module is turned on; the battery cell protection chip is electrically connected to the first switch sub-module, and the first switch sub-module is electrically connected to the second switch sub-module; the second switch sub-module is used to be arranged between the battery cell and the charging and discharging port.

[0010] Optionally, the first switch submodule includes a first diode, a first resistor, and a first switch device; the positive electrode of the first diode is electrically connected to the control end of the battery cell protection chip, and the negative electrode of the first diode is electrically connected to the first end of the first resistor; the second end of the first resistor is grounded; the control end of the first switch device is electrically connected to the negative electrode of the first diode, the first end of the first switch device is electrically connected to the control end of the second switch submodule, and the second end of the first switch device is grounded.

[0011] Optionally, the second switch submodule includes a second switch device and a second diode; the first end of the second switch device is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device is used to be electrically connected to the charge and discharge port, the control end of the second switch device is electrically connected to the positive electrode of the second diode, and the control end of the second switch device is used to be electrically connected to the first control end of the fuel meter chip; the negative electrode of the second diode is electrically connected to the control end of the first switch submodule; wherein, the battery cell group includes at least one of the battery cells; the fuel meter chip is used to control the second switch device to conduct when the voltage of the battery cell is normal.

[0012] Optionally, the second switch submodule includes a second switch device, a fourth switch device, a second diode, and a third diode; the first end of the second switch device is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device is electrically connected to the first end of the fourth switch device, the control end of the second switch device is electrically connected to the positive electrode of the second diode, and the control end of the second switch device is used to be electrically connected to the first control end of the fuel meter chip; the negative electrode of the second diode is electrically connected to the control end of the first switch submodule; the second end of the fourth switch device is used to be electrically connected to the charging and discharging port, the control end of the fourth switch device is electrically connected to the positive electrode of the third diode, and the control end of the fourth switch device is used to be electrically connected to the second control end of the fuel meter chip; the negative electrode of the third diode is electrically connected to the control end of the first switch submodule; wherein the battery cell group includes at least one of the battery cells; the fuel meter chip is used to control the second switch device and the fourth switch device to be turned on when the voltage of the battery cell is normal.

[0013] Optionally, the switch module also includes a third switch submodule; the first switch submodule is electrically connected to the third switch submodule, and is used to control the second switch submodule to be turned off and the third switch submodule to be turned on when the first switch submodule is turned on; and to control the second switch submodule to be turned on and the third switch submodule to be turned off when the first switch submodule is turned off; the third switch submodule is used to be electrically connected to the first electrode of the battery cell group, and when the third switch submodule is turned on and the voltage of the battery cell group is greater than a voltage threshold, the first switch submodule remains turned on; when the third switch submodule is turned on and the voltage of the battery cell group is less than a voltage threshold, the first switch submodule is turned off; wherein the battery cell group includes at least one of the battery cells.

[0014] Optionally, the third switch submodule includes a third switch device, a second resistor, a third resistor, and a fourth resistor; the first end of the second resistor is used to be electrically connected to the first electrode of the battery cell group, and the second end of the second resistor is electrically connected to the first end of the third switch device; the second end of the third switch device is grounded through the first switch submodule, and the control end of the third switch device is electrically connected to the first end of the fourth resistor; the first end of the third resistor is used to be electrically connected to the first electrode of the battery cell group, and the second end of the third resistor is electrically connected to the first end of the fourth resistor; the second end of the fourth resistor is electrically connected to the control end of the first switch submodule.

[0015] Optionally, the switch module is also used to be electrically connected to a fuel meter chip; wherein the fuel meter chip is used to control the switch module to be in a first state when the battery cell group is abnormal, and to control the switch module to be in a second state when the battery cell group is normal; the battery cell group includes at least one of the battery cells.

[0016] In a second aspect, an embodiment of the present application provides a battery protection board, comprising a battery cell protection circuit as described in the first aspect.

[0017] In a third aspect, an embodiment of the present application provides a battery, comprising at least one battery cell, and a protective plate of the battery as described in the second aspect.

[0018] In the embodiment of the present application, when the voltage of the battery cell is abnormal, the battery cell protection chip controls the switch module to be in the first state, and then the switch module disconnects the battery cell from the charge and discharge port when the switch module is in the first state to protect the battery, and when the voltage of the battery cell returns to normal, the switch module switches to the second state to connect the battery cell to the charge and discharge port to restore the battery to normal, which reduces the battery scrap rate compared with the prior art in which the fuse in the battery is protectively blown, resulting in the battery being scrapped. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below.

[0020] Figure 1 It is a structural schematic diagram of a protection circuit of a battery cell provided in an embodiment of the present application;

[0021] Figure 2 This is a specific structural schematic diagram of a protection circuit for a battery cell provided in an embodiment of the present application;

[0022] Figure 3 is another specific structural schematic diagram of the protection circuit of the battery cell provided in an embodiment of the present application;

[0023] Figure 4 This is another specific structural schematic diagram of the protection circuit of the battery cell provided in the embodiment of the present application;

[0024] Figure 5 This is yet another specific structural diagram of the protection circuit of the battery cell provided in the embodiment of the present application.

[0025] Reference numerals:

[0026] 10 - switch module; 11 - first switch submodule; 12 - second switch submodule; 13 - third switch submodule; 20 - battery cell protection chip; 30 - battery cell; 40 - charge and discharge port. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0029] Reference Figure 1 The embodiment of the present application provides a battery cell protection circuit, including: a battery cell protection chip 20 and a switch module 10; the battery cell protection chip 20 is electrically connected to the switch module 10, and the battery cell protection chip 20 is used to be electrically connected to the battery cell 30, and when the voltage of the battery cell 30 is abnormal, the switch module 10 is controlled to be in a first state; the switch module 10 is used to be arranged between the battery cell 30 and the charge and discharge port 40 of the battery cell 30, and when the switch module 10 is in the first state, the battery cell 30 is disconnected from the charge and discharge port 40, and when the voltage of the battery cell 30 returns to normal, the switch module 10 switches to the second state, so that the battery cell 30 is connected to the charge and discharge port 40.

[0030] It should be noted that the voltage abnormality of the battery cell 30 includes the voltage of the battery cell 30 being too high, the voltage of the battery cell 30 being too low, etc. Specifically, the voltage of the battery cell 30 being too high means that the voltage of the battery cell 30 is higher than the maximum voltage value in the standard voltage range of the battery cell 30, and the voltage of the battery cell 30 being too low means that the voltage of the battery cell 30 is lower than the minimum voltage value in the standard voltage range of the battery cell 30.

[0031] After the switch module 10 is in the first state, the switch module 10 can adjust the state of the switch module 10 according to the voltage of the battery cell 30. Specifically, when the voltage of the battery cell 30 returns to normal, the switch module 10 switches to the second state so that the battery cell 30 is connected to the charging and discharging port 40.

[0032] In some embodiments, the cell protection chip 20 is further used to control the switch module 10 to be in the second state when the voltage of the cell 30 is normal.

[0033] In some embodiments, the battery cell group in the battery includes at least one battery cell 30, and the charge and discharge port 40 is used to charge the battery cell group in the battery, or to discharge the battery to the outside, that is, to charge the battery cell 30 in the battery, or to discharge the battery cell 30 in the battery to the outside;

[0034] The battery cell protection chip 20 is used to be electrically connected to each battery cell 30 of the battery cell group. When the voltage of at least one battery cell 30 is abnormal, the switch module 10 is controlled to be in the first state, so that the battery cell group is disconnected from the charge and discharge port 40. After the switch module 10 is in the first state, the switch module 10 can adjust the state of the switch module 10 according to the voltage of the battery cell group (the total voltage of all battery cells 30 in the battery cell group). Specifically, when the voltage of the battery cell group returns to normal, the switch module 10 switches to the second state, so that the battery cell group is connected to the charge and discharge port 40. It should be noted that when the voltage of each battery cell 30 in the battery cell group is normal, the voltage of the battery cell group is normal, and when the voltage of at least one battery cell 30 in the battery cell group is abnormal, the voltage of the battery cell group is abnormal. The battery cell protection chip 20 is also used to control the switch module 10 to be in the second state when the voltage of the battery cell group is normal.

[0035] In the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the battery cell protection chip 20 controls the switch module 10 to be in the first state, and then the switch module 10 disconnects the battery cell 30 in the battery from the charge and discharge port 40 when the switch module 10 is in the first state to protect the battery, and when the voltage of the battery cell 30 returns to normal, the switch module 10 switches to the second state to connect the battery cell 30 with the charge and discharge port 40 to restore the battery to normal, which reduces the battery scrap rate compared with the prior art in which the fuse in the battery is protectively blown, resulting in the battery being scrapped.

[0036] Optionally, refer to Figure 2 The switch module 10 includes a first switch submodule 11 and a second switch submodule 12; the first state is that the first switch submodule 11 is turned on and the second switch submodule 12 is turned off, and the second state is that the first switch submodule 11 is turned off and the second switch submodule 12 is turned on; the battery cell protection chip 20 is electrically connected to the first switch submodule 11, and the first switch submodule 11 is electrically connected to the second switch submodule 12; the second switch submodule 12 is used to be arranged between the battery cell 30 and the charge and discharge port 40.

[0037] In the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the switch module 10 is controlled to be in the first state through the battery cell protection chip 20, that is, the first switch submodule 11 is turned on and the second switch submodule 12 is turned off. Specifically, when the voltage of the battery cell 30 is abnormal, the first switch submodule 11 is controlled to be turned on through the battery cell protection chip 20, and then when the first switch submodule 11 is turned on, the second switch submodule 12 is controlled to be turned off, and then when the second switch submodule 12 is turned off, the battery cell 30 in the battery is disconnected from the charge and discharge port 40, so as to protect the battery.

[0038] Optionally, the first switch submodule 11 includes a first diode D1, a first resistor R1, and a first switch device Q1; the positive electrode of the first diode D1 is electrically connected to the control terminal CO of the battery cell protection chip 20, and the negative electrode of the first diode D1 is electrically connected to the first end of the first resistor R1; the second end of the first resistor R1 is grounded; the control end of the first switch device Q1 is electrically connected to the negative electrode of the first diode D1, the first end of the first switch device Q1 is electrically connected to the control end of the second switch submodule 12, and the second end of the first switch device Q1 is grounded.

[0039] Specifically, in some embodiments, the first switching device Q1 is an NMOS tube, which is a negative channel Metal Oxide Semiconductor tube (Negative channel Metal Oxide Semiconductor); in other embodiments, the first switching device Q1 is an NPN transistor, which is composed of three semiconductors, including two N (Negative Electricity) type semiconductors (electronic semiconductors) and one P (Positive Electricity) type semiconductor (hole semiconductor), with the P-type semiconductor in the middle and two N-type semiconductors on both sides.

[0040] In the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the battery cell protection chip 20 controls the first switch device Q1 to be turned on, and then the first switch device Q1 controls the second switch submodule 12 to be turned off when the first switch device Q1 is turned on, and then the second switch submodule 12 controls the battery cell 30 in the battery to be disconnected from the charge and discharge port 40 when the second switch submodule 12 is turned off, so as to protect the battery.

[0041] Optionally, the second switch submodule 12 includes a second switch device Q2 and a second diode D2; the first end of the second switch device Q2 is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device Q2 is used to be electrically connected to the charge and discharge port 40, the control end of the second switch device Q2 is electrically connected to the positive electrode of the second diode D2, and the control end of the second switch device Q2 is used to be electrically connected to the first control end CHG of the fuel meter chip U1; the cathode of the second diode D2 is electrically connected to the control end of the first switch submodule 11; wherein, the battery cell group includes at least one of the battery cells 30; the fuel meter chip U1 is used to control the second switch device Q2 to be turned on when the voltage of the battery cell 30 is normal.

[0042] It should be noted that the control end of the first switch submodule 11 is the first end of the first switch device Q1 , and the control end of the second switch submodule 12 is the cathode of the second diode D2 .

[0043] In some embodiments, the first electrode of the battery cell group is the positive electrode of the battery cell group, the second electrode of the battery cell group is the negative electrode of the battery cell group, and the second electrode of the battery cell group is grounded.

[0044] Specifically, the first switch device Q1 is an NMOS tube, the second switch device Q2 is an NMOS tube, the gate of the first switch device Q1 is electrically connected to the cathode of the first diode D1, the drain of the first switch device Q1 is electrically connected to the cathode of the second diode D2, the source of the first switch device Q1 is grounded, the source of the second switch device Q2 is electrically connected to the first electrode of the battery cell group, the drain of the second switch device Q2 is electrically connected to the charge and discharge port 40, the gate of the second switch device Q2 is electrically connected to the anode of the second diode D2, and the gate of the second switch device Q2 is also electrically connected to the first control terminal CHG of the power meter chip U1; in other embodiments, the first switch device Q1 and the second switch device Q2 are both NPN transistors.

[0045] In some embodiments, reference Figure 2The protection circuit of the battery cell also includes an electric meter chip U1, a fifth resistor R5, a sixth resistor R6, a fourth diode D4, a fifth switch device Q5, and a sixth switch device Q6. The first control terminal CHG of the electric meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the control end of the fifth switch device Q5, the first end of the fifth switch device Q5 is electrically connected to the second end of the second switch device Q2, and the second end of the fifth switch device Q5 is electrically connected to the first end of the sixth switch device Q6; the second control terminal DSG of the electric meter chip U1 is electrically connected to the first end of the sixth resistor R6 The second end of the sixth resistor R6 is electrically connected to the control end of the sixth switch device Q6, and the second end of the sixth switch device Q6 is electrically connected to the charge and discharge port 40; the third control end FUSE of the fuel meter chip U1 is electrically connected to the anode of the fourth diode D4, and the cathode of the fourth diode D4 is electrically connected to the control end of the first switch device Q1, and the third control end FUSE of the fuel meter chip U1 is used to control the on and off of the first switch device Q1; when the battery is charging and discharging normally, the first control end CHG of the fuel meter chip U1 and the second control end DSG of the fuel meter chip U1 both output a high level.

[0046] Specifically, the fifth switch device Q5 and the sixth switch device Q6 can both be NMOS tubes, the first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the gate of the fifth switch device Q5, the source of the fifth switch device Q5 is electrically connected to the drain of the second switch device Q2, and the drain of the fifth switch device Q5 is electrically connected to the drain of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the gate of the sixth switch device Q6, and the source of the sixth switch device Q6 is electrically connected to the charge and discharge port 40; the third control terminal FUSE of the fuel meter chip U1 is electrically connected to the gate of the first switch device Q1.

[0047] In other embodiments, reference Figure 3 The first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the control end of the fifth switch device Q5, the first end of the fifth switch device Q5 is electrically connected to the first electrode of the battery cell group, and the second end of the fifth switch device Q5 is electrically connected to the first end of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the control end of the sixth switch device Q6, the second end of the sixth switch device Q6 is electrically connected to the first end of the second switch device Q2, and the second end of the second switch device Q2 is electrically connected to the charge and discharge port 40.

[0048] Specifically, the fifth switch device Q5 and the sixth switch device Q6 can both be NMOS tubes, the first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the gate of the fifth switch device Q5, the source of the fifth switch device Q5 is electrically connected to the first electrode of the battery cell group, and the drain of the fifth switch device Q5 is electrically connected to the drain of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the gate of the sixth switch device Q6, the source of the sixth switch device Q6 is electrically connected to the source of the second switch device Q2, and the drain of the second switch device Q2 is electrically connected to the charge and discharge port 40.

[0049] In the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the battery cell protection chip 20 controls the first switch device Q1 to be turned on, and then controls the second switch device Q2 to be turned off when the first switch device Q1 is turned on, and then controls the battery cell 30 in the battery to be disconnected from the charge and discharge port 40 when the second switch device Q2 is turned off, so as to protect the battery.

[0050] Optionally, refer to Figure 4 The second switch submodule 12 includes a second switch device Q2, a fourth switch device Q4, a second diode D2, and a third diode D3; the first end of the second switch device Q2 is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device Q2 is electrically connected to the first end of the fourth switch device Q4, the control end of the second switch device Q2 is electrically connected to the positive electrode of the second diode D2, and the control end of the second switch device Q2 is used to be electrically connected to the first control end CHG of the electricity meter chip U1; the cathode of the second diode D2 is electrically connected to the control end of the first switch submodule 11 The second end of the fourth switch device Q4 is used to be electrically connected to the charge and discharge port 40, the control end of the fourth switch device Q4 is electrically connected to the anode of the third diode D3, and the control end of the fourth switch device Q4 is used to be electrically connected to the second control end DSG of the fuel gauge chip U1; the cathode of the third diode D3 is electrically connected to the control end of the first switch submodule 11; wherein, the battery cell group includes at least one battery cell 30; the fuel gauge chip U1 is used to control the second switch device Q2 and the fourth switch device Q4 to be turned on when the voltage of the battery cell 30 is normal.

[0051] It should be noted that the control end of the first switch submodule 11 is the first end of the first switch device Q1 , and the control end of the second switch submodule 12 includes the cathode of the second diode D2 and the cathode of the third diode D3 .

[0052] Specifically, the first switch device Q1 is an NMOS tube, the second switch device Q2 is an NMOS tube, and the fourth switch device Q4 is an NMOS tube. The gate of the first switch device Q1 is electrically connected to the cathode of the first diode D1, the drain of the first switch device Q1 is electrically connected to the cathode of the second diode D2, the source of the first switch device Q1 is grounded, the source of the second switch device Q2 is electrically connected to the first electrode of the battery cell group, the drain of the second switch device Q2 is electrically connected to the drain of the fourth switch device Q4, the gate of the second switch device Q2 is electrically connected to the anode of the second diode D2, and the gate of the second switch device Q2 is also electrically connected to the first control terminal CHG of the fuel gauge chip U1; the source of the fourth switch device Q4 is electrically connected to the charge and discharge port 40, the gate of the fourth switch device Q4 is electrically connected to the anode of the third diode D3, and the gate of the fourth switch device Q4 is also electrically connected to the second control terminal DSG of the fuel gauge chip U1; in other embodiments, the first switch device Q1, the second switch device Q2, and the fourth switch device Q4 are all NPN transistors.

[0053] In some embodiments, reference Figure 4 The first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the control end of the fifth switch device Q5, the first end of the fifth switch device Q5 is electrically connected to the second end of the fourth switch device Q4, and the second end of the fifth switch device Q5 is electrically connected to the first end of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the control end of the sixth switch device Q6, and the second end of the sixth switch device Q6 is electrically connected to the charge and discharge port 40.

[0054] Specifically, the fifth switch device Q5 and the sixth switch device Q6 can both be NMOS tubes, the first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the gate of the fifth switch device Q5, the source of the fifth switch device Q5 is electrically connected to the source of the fourth switch device Q4, and the drain of the fifth switch device Q5 is electrically connected to the drain of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the gate of the sixth switch device Q6, and the source of the sixth switch device Q6 is electrically connected to the charge and discharge port 40; the third control terminal FUSE of the fuel meter chip U1 is electrically connected to the gate of the first switch device Q1.

[0055] In other embodiments, reference Figure 5The first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the control end of the fifth switch device Q5, the first end of the fifth switch device Q5 is electrically connected to the first electrode of the battery cell group, and the second end of the fifth switch device Q5 is electrically connected to the first end of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the control end of the sixth switch device Q6, the second end of the sixth switch device Q6 is electrically connected to the first end of the second switch device Q2, and the second end of the fourth switch device Q4 is electrically connected to the charge and discharge port 40.

[0056] Specifically, the fifth switch device Q5 and the sixth switch device Q6 can both be NMOS tubes, the first control terminal CHG of the fuel meter chip U1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the gate of the fifth switch device Q5, the source of the fifth switch device Q5 is electrically connected to the first electrode of the battery cell group, and the drain of the fifth switch device Q5 is electrically connected to the drain of the sixth switch device Q6; the second control terminal DSG of the fuel meter chip U1 is electrically connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is electrically connected to the gate of the sixth switch device Q6, the source of the sixth switch device Q6 is electrically connected to the source of the second switch device Q2, and the source of the fourth switch device Q4 is electrically connected to the charge and discharge port 40.

[0057] In the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the battery cell protection chip 20 controls the first switch device Q1 to be turned on, and then controls the second switch device Q2 and the fourth switch device Q4 to be turned off when the first switch device Q1 is turned on, and then controls the battery cell 30 in the battery to be disconnected from the charge and discharge port 40 when the second switch device Q2 and the fourth switch device Q4 are turned off, so as to protect the battery.

[0058] Optionally, the switch module 10 also includes a third switch submodule 13; the first switch submodule 11 is electrically connected to the third switch submodule 13, and is used to control the second switch submodule 12 to be turned off and the third switch submodule 13 to be turned on when the first switch submodule 11 is turned on; and to control the second switch submodule 12 to be turned on and the third switch submodule 13 to be turned off when the first switch submodule 11 is turned off; the third switch submodule 13 is used to be electrically connected to the first electrode of the battery cell group, and when the third switch submodule 13 is turned on and the voltage of the battery cell group is greater than a voltage threshold, the first switch submodule 11 remains turned on; when the third switch submodule 13 is turned on and the voltage of the battery cell group is less than a voltage threshold, the first switch submodule 11 is turned off; wherein the battery cell group includes at least one of the battery cells 30.

[0059] In the embodiment of the present application, when the first switch submodule 11 is turned on, the second switch submodule 12 is controlled to be turned off, and the third switch submodule 13 is controlled to be turned on. Then, when the third switch submodule 13 is turned on and the voltage of the battery cell group is greater than the voltage threshold, it is determined that there are battery cells 30 with abnormal voltage in the battery cell group, and the first switch submodule 11 is controlled to remain turned on, so that the battery cells 30 in the battery are disconnected from the charge and discharge ports 40; when the third switch submodule 13 is turned on and the voltage of the battery cell group is greater than the voltage threshold, it is determined that there are battery cells 30 with abnormal voltage in the battery cell group, and the first switch submodule 11 is controlled to remain turned on, so that the battery cells 30 in the battery are disconnected from the charge and discharge ports 40; When the three switch submodules 13 are turned on and the voltage of the battery cell group is less than the voltage threshold, it is determined that the voltage of each battery cell 30 in the battery cell group has returned to normal, so that the first switch submodule 11 is turned off, and then the second switch submodule 12 is turned on to restore the connection between the battery cell 30 and the charge and discharge port 40; when the first switch submodule 11 is turned off, the second switch submodule 12 is controlled to be turned on, and the third switch submodule 13 is controlled to be turned off, so that the battery cell 30 in the battery is connected to the charge and discharge port 40.

[0060] Optionally, the third switch submodule 13 includes a third switch device Q3, a second resistor R2, a third resistor R3, and a fourth resistor R4; the first end of the second resistor R2 is used to be electrically connected to the first electrode of the battery cell group, and the second end of the second resistor R2 is electrically connected to the first end of the third switch device Q3; the second end of the third switch device Q3 is grounded through the first switch submodule 11, and the control end of the third switch device Q3 is electrically connected to the first end of the fourth resistor R4; the first end of the third resistor R3 is used to be electrically connected to the first electrode of the battery cell group, and the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4; the second end of the fourth resistor R4 is electrically connected to the control end of the first switch submodule 11.

[0061] Specifically, in some embodiments, the first switch device Q1 is an NMOS tube, the second switch device Q2 is an NMOS tube, and the third switch device Q3 is a PMOS tube, and the PMOS tube is a positive channel Metal Oxide Semiconductor tube.

[0062] The first end of the second resistor R2 is electrically connected to the first electrode of the battery cell group, the second end of the second resistor R2 is electrically connected to the source of the third switching device Q3, the drain of the third switching device Q3 is electrically connected to the first end of the first resistor R1, the gate of the third switching device Q3 is electrically connected to the first end of the fourth resistor R4, the first end of the third resistor R3 is electrically connected to the first electrode of the battery cell group, the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is electrically connected to the drain of the first switching device Q1.

[0063] In other embodiments, in some embodiments, the first switching device Q1 is an NPN transistor, the second switching device Q2 is an NPN transistor, and the third switching device Q3 is a PNP transistor. The PNP transistor is composed of three semiconductors, including an N-type semiconductor (electron semiconductor) and two P-type semiconductors (hole semiconductors), with the N-type semiconductor in the middle and the two P-type semiconductors on both sides.

[0064] Optionally, in some embodiments, the gate voltage value of the first switching device Q1 is expressed as:

[0065]

[0066] Among them, V g is the gate voltage value of the first switching device Q1, V B is the voltage value of the battery pack, V d is the on-state voltage drop value of the third switch device Q3, r1 is the resistance value of the first resistor R1, and r2 is the resistance value of the second resistor R2.

[0067] When the gate voltage value of the first switching device Q1 is greater than the on-voltage threshold value of the first switching device Q1, the first switching device Q1 is turned on; when the gate voltage value of the first switching device Q1 is less than the on-voltage threshold value of the first switching device Q1, the first switching device Q1 is turned off.

[0068] By adjusting the resistance values ​​of the first resistor R1 and the second resistor R2 , the voltage value of the cell group that turns off the first switch device Q1 can be adjusted, that is, the voltage value of the cell group that restores conduction between the cell 30 and the charge and discharge port 40 .

[0069] In the embodiment of the present application, when the first switch submodule 11 is turned on, the second switch submodule 12 is controlled to be turned off, and the third switch device Q3 is controlled to be turned on. Then, when the third switch device Q3 is turned on and the voltage of the cell group is greater than the voltage threshold, it is determined that there are cells 30 with abnormal voltage in the cell group, and the first switch submodule 11 is controlled to remain turned on, so that the cell 30 in the battery is kept disconnected from the charge and discharge port 40; when the third switch device Q3 is turned on and the voltage of the cell group is less than the voltage threshold, it is determined that the voltage of each cell 30 in the cell group is restored to normal, so that the first switch submodule 11 is turned off, and then the second switch submodule 12 is turned on, so that the cell 30 in the battery is restored to conduction with the charge and discharge port 40; when the first switch submodule 11 is turned off, the second switch submodule 12 is controlled to be turned on, and the third switch device Q3 is controlled to be turned off, so that the cell 30 in the battery is connected to the charge and discharge port 40.

[0070] Optionally, the switch module 10 is also used to be electrically connected to the fuel meter chip U1; wherein, the fuel meter chip U1 is used to control the switch module 10 to be in a first state when the battery cell group is abnormal, and to control the switch module 10 to be in a second state when the battery cell group is normal; the battery cell group includes at least one of the battery cells 30.

[0071] In an embodiment of the present application, when the battery cell group is abnormal (for example, the battery cell group is charging and discharging abnormally), the fuel meter chip U1 controls the switch module 10 to be in a first state, so that the battery cell 30 in the battery is disconnected from the charge and discharge port 40 to protect the battery; when the battery cell group is normal (for example, the battery cell group is charging and discharging normally), the fuel meter chip U1 controls the switch module 10 to be in a second state, so that the battery cell 30 is connected to the charge and discharge port 40 to restore the battery to normal.

[0072] An embodiment of the present application provides a battery protection board, including the battery cell protection circuit as described above.

[0073] The specific implementation process of the protection circuit of the battery cell in the protection board of the battery is similar to the implementation process of the protection circuit of the battery cell mentioned above, and will not be repeated here.

[0074] An embodiment of the present application provides a battery, including at least one battery cell 30, and a protective plate of the battery as described above.

[0075] The specific implementation process of the protection circuit of the battery cell is similar to the implementation process of the protection circuit of the battery cell mentioned above, and will not be repeated here.

[0076] Through the embodiment of the present application, it can be achieved that the switch module 10 is used to replace the fuse, which not only has the protection function of the fuse, but also can be restored after protection, and the recovery voltage can be adjusted, which greatly reduces the waste of batteries.

[0077] To sum up, in the embodiment of the present application, when the voltage of the battery cell 30 is abnormal, the switch module 10 is controlled to be in the first state through the battery cell protection chip 20, and then the battery cell 30 in the battery is disconnected from the charge and discharge port 40 through the switch module 10 when the switch module 10 is in the first state, so as to protect the battery, and when the voltage of the battery cell 30 returns to normal, the switch module 10 switches to the second state, so that the battery cell 30 is connected to the charge and discharge port 40 to restore the battery to normal, which reduces the battery scrap rate compared with the prior art in which the fuse in the battery is protectively blown, resulting in the battery being scrapped.

[0078] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0079] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A protection circuit for a battery cell, characterized in that: include: A battery cell protection chip (20) and a switch module (10); The battery cell protection chip (20) is electrically connected to the switch module (10), and the battery cell protection chip (20) is used to be electrically connected to the battery cell (30), and when the voltage of the battery cell (30) is abnormal, the switch module (10) is controlled to be in a first state; The switch module (10) is used to be arranged between the battery cell (30) and the charge and discharge port (40) of the battery cell (30); when the switch module (10) is in a first state, the battery cell (30) is disconnected from the charge and discharge port (40); and when the voltage of the battery cell (30) returns to normal, the switch module (10) is switched to a second state, so that the battery cell (30) is connected to the charge and discharge port (40).

2. The protection circuit of the battery cell according to claim 1, characterized in that: The switch module (10) comprises a first switch submodule (11) and a second switch submodule (12); the first state is that the first switch submodule (11) is turned on and the second switch submodule (12) is turned off, and the second state is that the first switch submodule (11) is turned off and the second switch submodule (12) is turned on; The battery cell protection chip (20) is electrically connected to the first switch submodule (11); The first switch submodule (11) is electrically connected to the second switch submodule (12); The second switch submodule (12) is used to be arranged between the battery cell (30) and the charge and discharge port (40).

3. The protection circuit of the battery cell according to claim 2, characterized in that: The first switch submodule (11) comprises a first diode (D1), a first resistor (R1), and a first switch device (Q1); The positive electrode of the first diode (D1) is electrically connected to the control terminal CO of the battery cell protection chip (20), and the negative electrode of the first diode (D1) is electrically connected to the first end of the first resistor (R1); The second end of the first resistor (R1) is grounded; The control end of the first switch device (Q1) is electrically connected to the cathode of the first diode (D1), the first end of the first switch device (Q1) is electrically connected to the control end of the second switch submodule (12), and the second end of the first switch device (Q1) is grounded.

4. The protection circuit of the battery cell according to claim 2, characterized in that: The second switch submodule (12) comprises a second switch device (Q2) and a second diode (D2); The first end of the second switch device (Q2) is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device (Q2) is used to be electrically connected to the charge and discharge port (40), the control end of the second switch device (Q2) is electrically connected to the positive electrode of the second diode (D2), and the control end of the second switch device (Q2) is used to be electrically connected to the first control end (CHG) of the electricity meter chip (U1); The cathode of the second diode (D2) is electrically connected to the control end of the first switch submodule (11); The battery cell group comprises at least one battery cell (30); the electricity meter chip (U1) is used to control the second switch device (Q2) to be turned on when the voltage of the battery cell (30) is normal.

5. The protection circuit of the battery cell according to claim 2, characterized in that: The second switch submodule (12) comprises a second switch device (Q2), a fourth switch device (Q4), a second diode (D2), and a third diode (D3); The first end of the second switch device (Q2) is used to be electrically connected to the first electrode of the battery cell group, the second end of the second switch device (Q2) is electrically connected to the first end of the fourth switch device (Q4), the control end of the second switch device (Q2) is electrically connected to the positive electrode of the second diode (D2), and the control end of the second switch device (Q2) is used to be electrically connected to the first control end (CHG) of the electricity meter chip (U1); The cathode of the second diode (D2) is electrically connected to the control end of the first switch submodule (11); The second end of the fourth switch device (Q4) is used to be electrically connected to the charge and discharge port (40), the control end of the fourth switch device (Q4) is electrically connected to the positive electrode of the third diode (D3), and the control end of the fourth switch device (Q4) is used to be electrically connected to the second control end DSG of the electricity meter chip (U1); The cathode of the third diode (D3) is electrically connected to the control end of the first switch submodule (11); The battery cell group comprises at least one battery cell (30); the electricity meter chip (U1) is used to control the second switch device (Q2) and the fourth switch device (Q4) to be turned on when the voltage of the battery cell (30) is normal.

6. The protection circuit of the battery cell according to claim 2, characterized in that: The switch module (10) further comprises a third switch submodule (13); The first switch submodule (11) is electrically connected to the third switch submodule (13), and is used for controlling the second switch submodule (12) to be turned off and the third switch submodule (13) to be turned on when the first switch submodule (11) is turned on; and controlling the second switch submodule (12) to be turned on and the third switch submodule (13) to be turned off when the first switch submodule (11) is turned off; The third switch submodule (13) is used to be electrically connected to the first electrode of the battery cell group, and when the third switch submodule (13) is turned on and the voltage of the battery cell group is greater than a voltage threshold, the first switch submodule (11) remains turned on; when the third switch submodule (13) is turned on and the voltage of the battery cell group is less than the voltage threshold, the first switch submodule (11) is turned off; Wherein, the battery cell group includes at least one battery cell (30).

7. The protection circuit of the battery cell according to claim 6, characterized in that: The third switch submodule (13) comprises a third switch device (Q3), a second resistor (R2), a third resistor (R3), and a fourth resistor (R4); The first end of the second resistor (R2) is used to be electrically connected to the first electrode of the battery cell group, and the second end of the second resistor (R2) is electrically connected to the first end of the third switch device (Q3); The second end of the third switch device (Q3) is grounded through the first switch submodule (11), and the control end of the third switch device (Q3) is electrically connected to the first end of the fourth resistor (R4); The first end of the third resistor (R3) is used to be electrically connected to the first electrode of the battery cell group, and the second end of the third resistor (R3) is electrically connected to the first end of the fourth resistor (R4); The second end of the fourth resistor (R4) is electrically connected to the control end of the first switch submodule (11).

8. The protection circuit of the battery cell according to claim 1, characterized in that: The switch module (10) is also used to be electrically connected to the electricity meter chip (U1); The power meter chip (U1) is used to control the switch module (10) to be in a first state when the battery cell group is abnormal, and to control the switch module (10) to be in a second state when the battery cell group is normal; the battery cell group includes at least one battery cell (30).

9. A battery protection plate, characterized in that: A protection circuit comprising a battery cell as claimed in any one of claims 1 to 8.

10. A battery, characterized in that: The invention comprises at least one battery cell and a protection plate for the battery as claimed in claim 9.

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