Overcurrent protection device for high current battery and high current battery

Abstract

The utility model relates to a kind of overcurrent protection device and large current battery of large current battery, the large current battery includes battery pack and the overcurrent protection device, the overcurrent protection device includes: detection circuit, first end is connected with the battery pack, for detecting the output current of the battery pack;Control circuit, first end is connected with the third end of the detection circuit, for when the output current of the battery pack is detected by the detection circuit greater than or equal to preset threshold, output off signal;Protection circuit, first end is connected with the second end of the detection circuit, second end is connected with the second end of the control circuit, third end is connected with the third end of the control circuit, fourth end is connected with negative pole port, for after receiving the off signal, the current between the battery pack and the negative pole port is turned off.The utility model can protect large battery current, improve the safety performance of large battery current.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to an overcurrent protection device for a high-current battery and a high-current battery. Background Technology

[0002] With the development of electrical equipment, the demand for high-current batteries is increasing. High-current batteries can provide a large current, but the large current can also easily damage the battery itself, leading to safety issues such as spontaneous combustion.

[0003] Currently, there are two common overcurrent protection methods for high-current batteries. One is to configure a discharge protection circuit on the battery management system circuit board, which can protect against high current damage to a certain extent. However, this method does not protect the high-current battery itself, and the discharge protection can easily cause the battery to spontaneously combust.

[0004] Another approach is to use MOSFETs to improve the ability to handle high currents. However, this second approach also has drawbacks. In high-current scenarios, multiple MOSFETs may need to be connected in parallel to ensure that the battery management system's overcurrent capacity exceeds the maximum current of the high-current battery. However, connecting multiple MOSFETs in parallel increases the overall size of the protection circuit, which is mainly composed of MOSFETs. In this application scenario, the different pin lengths between the MOSFETs and the driver circuit cause the driver circuit to switch the MOSFETs at different speeds. This results in an inability to balance the current when a high current flows, potentially damaging the MOSFETs.

[0005] It is evident that existing overcurrent protection solutions for high-current batteries are still inadequate. Utility Model Content

[0006] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this utility model provides an overcurrent protection device for a high-current battery and a high-current battery.

[0007] In a first aspect, this utility model provides an overcurrent protection device for a high-current battery, the high-current battery comprising a battery pack and the overcurrent protection device, the overcurrent protection device comprising:

[0008] The detection circuit has its first terminal connected to the battery pack and is used to detect the output current of the battery pack.

[0009] The control circuit, with its first terminal connected to the third terminal of the detection circuit, is used to output a shutdown signal when the detection circuit detects that the output current of the battery pack is greater than or equal to a preset threshold.

[0010] The protection circuit has a first terminal connected to the second terminal of the detection circuit, a second terminal connected to the second terminal of the control circuit, a third terminal connected to the third terminal of the control circuit, and a fourth terminal connected to the negative terminal port. It is used to cut off the current between the battery pack and the negative terminal port after receiving the shutdown signal.

[0011] Optionally, the control circuit is further configured to output an enable signal when the detection circuit detects that the output current of the battery pack is less than a preset threshold.

[0012] The protection circuit is also used to, upon receiving the activation signal, cause the output current of the battery pack to enter the protection circuit from the first terminal of the protection circuit and then output it from the fourth terminal of the protection circuit to the negative terminal.

[0013] Optionally, the protection circuit includes:

[0014] 2N shunt units, of which And it is an integer.

[0015] The 2N shunt units are used to shunt the output current of the battery pack when the output current of the battery pack enters from the first terminal of the protection circuit after receiving the turn-on signal, and then output it from the fourth terminal of the protection circuit to the negative terminal.

[0016] Optionally, the 2N shunt units in the protection circuit are stacked.

[0017] Optionally, the protection circuit includes:

[0018] At least one type I shunt unit and at least one type II shunt unit,

[0019] The first end of the first type of shunt unit is connected to the second end of the protection circuit through a corresponding first shunt resistor, the second end is connected to the middle end, and the third end is connected to the first end of the protection circuit.

[0020] The first end of the second type of shunt unit is connected to the third end of the protection circuit through the corresponding second shunt resistor, the second end is connected to the middle end, and the third end is connected to the fourth end of the protection circuit.

[0021] The number of the first type of diversion unit and the second type of diversion unit are equal.

[0022] Optionally, the protection circuit includes:

[0023] At least one discharge MOSFET and at least one charge MOSFET,

[0024] The gate of the discharge MOS transistor is connected to the second terminal of the protection circuit through a corresponding first shunt resistor, the drain is connected to the middle terminal, and the source is connected to the first terminal of the protection circuit.

[0025] The gate of the charging MOS transistor is connected to the third terminal of the protection circuit through the corresponding second shunt resistor, the drain is connected to the middle terminal, and the source is connected to the fourth terminal of the protection circuit.

[0026] The number of discharge MOS transistors and charging MOS transistors are equal.

[0027] Optionally, the protection circuit further includes:

[0028] Conductive metal substrate, used for electrical conductivity and heat dissipation;

[0029] The conductive metal carrier plate includes a first region, a second region, and a third region. The first surface of the first region is connected to the first end of the first type of shunt unit, the first surface of the second region is connected to the third end of the second type of shunt unit, and the first surface of the third region is connected to the intermediate end.

[0030] Optionally, the protection circuit further includes:

[0031] A ceramic substrate, connected to the second surface of the first region, the second surface of the second region, and the third surface of the third region, is used for thermal insulation and electrical insulation.

[0032] Wherein, the second surface of the first region is disposed opposite to the first surface of the first region, the second surface of the second region is disposed opposite to the first surface of the second region, and the second surface of the third region is disposed opposite to the first surface of the third region.

[0033] Optionally, the conductive metal substrate is a copper substrate.

[0034] In a second aspect, a high-current battery is provided, the high-current battery including a battery pack and an overcurrent protection device as described in any of the preceding claims.

[0035] This invention provides an overcurrent protection device for a high-current battery and a high-current battery. The high-current battery includes a battery pack and the overcurrent protection device. The overcurrent protection device includes: a detection circuit, with its first terminal connected to the battery pack, for detecting the output current of the battery pack; a control circuit, with its first terminal connected to the third terminal of the detection circuit, for outputting a shutdown signal when the detection circuit detects that the output current of the battery pack is greater than or equal to a preset threshold; and a protection circuit, with its first terminal connected to the second terminal of the detection circuit, its second terminal connected to the second terminal of the control circuit, its third terminal connected to the third terminal of the control circuit, and its fourth terminal connected to the negative terminal, for cutting off the current between the battery pack and the negative terminal after receiving the shutdown signal. In this embodiment, when the output current of the battery pack is greater than or equal to the preset threshold, the protection circuit is turned off, and the battery pack no longer outputs current. That is, when the high-current battery may experience overcurrent, the overcurrent protection device can cut off the current, thereby protecting the high-current battery and improving its safety performance. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 The diagram shown is a schematic diagram of a high-current battery according to an embodiment of this utility model.

[0039] Figure 2 The diagram shown is a schematic diagram of the protection circuit according to an embodiment of the present invention;

[0040] Figure 3 The diagram shown is a schematic diagram of the protection circuit according to an embodiment of the present invention;

[0041] Figure 4 The diagram shown is a schematic diagram of the protection circuit of an embodiment of this utility model. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0043] Figure 1 The diagram shown is a schematic representation of a high-current battery according to an embodiment of this utility model. (Refer to...) Figure 1 As shown, this utility model embodiment provides an overcurrent protection device for a high-current battery.

[0044] The high-current battery includes a battery pack 100 and the overcurrent protection device, the overcurrent protection device comprising:

[0045] The detection circuit 110 has its first terminal connected to the battery pack 100 and is used to detect the output current of the battery pack 100.

[0046] The control circuit 120 has its first terminal connected to the third terminal of the detection circuit 110, and is used to output a shutdown signal when the detection circuit 110 detects that the output current of the battery pack 100 is greater than or equal to a preset threshold.

[0047] The protection circuit 130 has a first terminal connected to the second terminal of the detection circuit 110, a second terminal connected to the second terminal of the control circuit 120, a third terminal connected to the third terminal of the control circuit 120, and a fourth terminal connected to the negative terminal port 140. It is used to cut off the current between the battery pack 100 and the negative terminal port 140 after receiving the shutdown signal.

[0048] In this embodiment of the present invention, when the output current of the battery pack 100 is greater than or equal to a preset threshold, the protection circuit 130 is turned off, and the battery pack 100 no longer outputs current. That is, when a high-current battery may experience overcurrent, the overcurrent protection device can cut off the current, thereby protecting the high-current battery and improving the safety performance of the high-current battery.

[0049] In this embodiment of the present invention, the control circuit 120 is further configured to output an activation signal when the detection circuit 110 detects that the output current of the battery pack 100 is less than a preset threshold.

[0050] The protection circuit 130 is also used to, upon receiving the activation signal, cause the output current of the battery pack 100 to enter the protection circuit 130 from the first terminal of the protection circuit 130 and then output it from the fourth terminal of the protection circuit 130 to the negative terminal 140.

[0051] In this embodiment of the present invention, when the output current of the battery pack 100 is less than a preset threshold, the output current is output through the protection circuit 130 to supply power to the outside.

[0052] Figure 1 The positive port 150 is the positive terminal of the high-current battery.

[0053] In this embodiment of the invention, the protection circuit includes:

[0054] 2N shunt units, of which And it is an integer.

[0055] The 2N shunt units are used to shunt the output current of the battery pack when the output current of the battery pack enters from the first terminal of the protection circuit after receiving the start signal, and then output it from the fourth terminal of the protection circuit to the negative terminal 140.

[0056] In this embodiment of the invention, the negative terminal is the negative terminal 140 of the high-current battery for external power supply. The high-current battery also includes a positive terminal 150 for external power supply, see reference. Figure 1 As shown, the positive terminal 150 is connected to the positive terminal of the battery pack.

[0057] In this embodiment of the invention, the 2N shunt units in the protection circuit are stacked.

[0058] In this embodiment of the invention, the 2N shunt units are stacked, which can reduce the size of the protection circuit, shorten the signal transmission path, reduce the delay between the turn-off signals received by different shunt units and / or the delay between the start signals, avoid the inconsistency between the start and / or turn-off times caused by the delay of the shunt unit start and / or turn-off times, reduce the reduction of current shunt capacity caused by inconsistency, increase the current carrying capacity of the protection circuit, avoid the protection current burnout, and help the high-current battery output a larger current.

[0059] In this embodiment of the invention, the protection circuit includes:

[0060] At least one type I shunt unit and at least one type II shunt unit,

[0061] The first end of the first type of shunt unit is connected to the second end of the protection circuit through a corresponding first shunt resistor, the second end is connected to the middle end, and the third end is connected to the first end of the protection circuit.

[0062] The first end of the second type of shunt unit is connected to the third end of the protection circuit through the corresponding second shunt resistor, the second end is connected to the middle end, and the third end is connected to the fourth end of the protection circuit.

[0063] The number of the first type of diversion unit and the second type of diversion unit are equal.

[0064] In this embodiment of the invention, the protection circuit includes 2N shunt units, wherein N shunt units are first-type shunt units and N shunt units are second-type shunt units.

[0065] In this embodiment of the invention, the protection circuit includes:

[0066] At least one discharge MOSFET and at least one charge MOSFET,

[0067] The gate of the discharge MOS transistor is connected to the second terminal of the protection circuit through a corresponding first shunt resistor, the drain is connected to the middle terminal, and the source is connected to the first terminal of the protection circuit.

[0068] The gate of the charging MOS transistor is connected to the third terminal of the protection circuit through the corresponding second shunt resistor, the drain is connected to the middle terminal, and the source is connected to the fourth terminal of the protection circuit.

[0069] The number of discharge MOS transistors and charging MOS transistors are equal.

[0070] Figure 2 The diagram shown is a schematic of the protection circuit according to an embodiment of the present invention. Figure 2 As shown, 210 is a discharge MOSFET and 220 is a charge MOSFET. Figure 2 The diagram shows two discharge MOSFETs and two charge MOSFETs. Figure 2 The first and second shunt resistors are not shown in the diagram.

[0071] Figure 3 The diagram shown is a schematic diagram of the protection circuit according to an embodiment of this utility model. Figure 3 As shown, the discharge MOSFET is a MOSFET wafer / chip, and the charging MOSFET is also a MOSFET wafer / chip.

[0072] In a MOS transistor wafer, the first pin is the gate ( Figure 3 The G terminal (G) is connected to the control circuit; the source terminal has multiple pins ( Figure 3 The source of the charging MOSFET is connected to the detection circuit, and the source of the discharging MOSFET is connected to the negative terminal; the drain also has multiple pins. Figure 3 The drain is connected to the middle terminal. Figure 3In the embodiment shown, each MOS transistor wafer may have multiple source (S) pins and multiple drain (D) pins during connection. Multiple source pins and multiple drain pins need to be connected in parallel during connection.

[0073] Figure 3 In the circuit, the first shunt resistor is such as R27, R31, etc., and the second shunt resistor is such as R25, R32, etc. (Refer to...) Figure 3 As shown, it will not be elaborated further here.

[0074] In this embodiment of the invention, the protection circuit further includes:

[0075] Conductive metal substrate, used for electrical conductivity and heat dissipation;

[0076] The conductive metal carrier plate includes a first region, a second region, and a third region. The first surface of the first region is connected to the first end of the first type of shunt unit, the first surface of the second region is connected to the third end of the second type of shunt unit, and the first surface of the third region is connected to the intermediate end.

[0077] In this embodiment of the invention, the protection circuit further includes:

[0078] A ceramic substrate, connected to the second surface of the first region, the second surface of the second region, and the third surface of the third region, is used for thermal insulation and electrical insulation.

[0079] Wherein, the second surface of the first region is disposed opposite to the first surface of the first region, the second surface of the second region is disposed opposite to the first surface of the second region, and the second surface of the third region is disposed opposite to the first surface of the third region.

[0080] In this embodiment of the present invention, the conductive metal carrier plate is a copper carrier plate; in other embodiments of the present invention, the conductive metal carrier plate may also be a silver carrier plate or a silver-plated carrier plate.

[0081] In this embodiment of the invention, a conductive metal carrier plate is used, which is directly connected to the pins of the shunt unit, effectively replacing the traditional wires with the metal carrier plate. By directly connecting the conductive metal pins to the conductive metal carrier plate instead of traditional wire connections, the signal transmission path is shortened, the current carrying capacity of the protection circuit is improved, and it is beneficial for high-current batteries to output larger currents.

[0082] Figure 4 The diagram shown is a schematic of the protection circuit according to an embodiment of the present invention. Figure 4As shown, the first region 410 of the conductive metal carrier plate is the first terminal of the protection circuit and is connected to the battery pack; the second region 440 of the conductive metal carrier plate is the fourth terminal of the protection circuit and is connected to the negative terminal port, serving as the negative terminal of the high-current battery; the third region of the conductive metal carrier plate is not shown.

[0083] refer to Figure 4 As shown, the protection circuit of this utility model embodiment also includes a second terminal 420 and a third terminal 430, which are respectively connected to the control circuit and used to receive a shutdown signal and an on signal.

[0084] The protection circuit of this utility model embodiment also includes a fifth terminal 450 and a sixth terminal 460. These two ports are reserved ports and can be used for testing, detection, etc.

[0085] In this embodiment of the invention, the die bonding process, a chip packaging technology, can be used. This process boasts extremely high precision, typically reaching 10µm. In this embodiment, the die bonding process directly encapsulates multiple MOS wafers onto a conductive metal substrate, directly connecting the conductive metal substrate to the pins of the shunt unit. This effectively replaces traditional wires with a metal substrate. Direct metal-to-metal connections, replacing traditional wire connections, achieve micron- or even nanometer-level connection spacing. This allows for ultra-fine pitch stacking and packaging within a very small space, eliminating the need for long metal wires, shortening the signal transmission path, and saving on traditional processes such as MOS transistor encapsulation, significantly reducing the final product size. Furthermore, the high-precision bonding process reduces the length of the MOS control pins, internally connecting them together, with separate pins for charging and discharging MOS. For rapid heat dissipation, the copper substrate thickness can be increased to 0.3mm, further enhancing heat dissipation. On the other hand, considering heat transfer, a ceramic substrate is added to the other side of the conductive metal substrate for insulation, reducing heat transfer to other PCBs. The ceramic substrate also serves as an insulator.

[0086] This utility model embodiment also provides a high-current battery, which includes a battery pack and an overcurrent protection device as described above.

[0087] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0088] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An overcurrent protection device for a high current battery, characterized by, The high-current battery includes a battery pack and the overcurrent protection device, the overcurrent protection device comprising: The detection circuit has its first terminal connected to the battery pack and is used to detect the output current of the battery pack. The control circuit, with its first terminal connected to the third terminal of the detection circuit, is used to output a shutdown signal when the detection circuit detects that the output current of the battery pack is greater than or equal to a preset threshold. The protection circuit has a first terminal connected to the second terminal of the detection circuit, a second terminal connected to the second terminal of the control circuit, a third terminal connected to the third terminal of the control circuit, and a fourth terminal connected to the negative terminal port. It is used to cut off the current between the battery pack and the negative terminal port after receiving the shutdown signal.

2. The overcurrent protection device of claim 1, wherein The control circuit is also used to output an enable signal when the detection circuit detects that the output current of the battery pack is less than a preset threshold. The protection circuit is also used to, upon receiving the activation signal, cause the output current of the battery pack to enter the protection circuit from the first terminal of the protection circuit and then output it from the fourth terminal of the protection circuit to the negative terminal.

3. The overcurrent protection device of claim 2, wherein The protection circuit includes: 2N shunt units, wherein , and is an integer, The 2N shunt units are used to shunt the output current of the battery pack when the output current of the battery pack enters from the first terminal of the protection circuit after receiving the turn-on signal, and then output it from the fourth terminal of the protection circuit to the negative terminal.

4. The overcurrent protection device of claim 3, wherein The 2N shunt units in the protection circuit are stacked.

5. The overcurrent protection device of claim 2, wherein The protection circuit includes: At least one type I shunt unit and at least one type II shunt unit, The first end of the first type of shunt unit is connected to the second end of the protection circuit through a corresponding first shunt resistor, the second end is connected to the middle end, and the third end is connected to the first end of the protection circuit. The first end of the second type of shunt unit is connected to the third end of the protection circuit through the corresponding second shunt resistor, the second end is connected to the middle end, and the third end is connected to the fourth end of the protection circuit. The number of the first type of diversion unit and the second type of diversion unit are equal.

6. The overcurrent protection device of claim 2, wherein The protection circuit includes: At least one discharge MOSFET and at least one charge MOSFET, The gate of the discharge MOS transistor is connected to the second terminal of the protection circuit through a corresponding first shunt resistor, the drain is connected to the middle terminal, and the source is connected to the first terminal of the protection circuit. The gate of the charging MOS transistor is connected to the third terminal of the protection circuit through the corresponding second shunt resistor, the drain is connected to the middle terminal, and the source is connected to the fourth terminal of the protection circuit. The number of discharge MOS transistors and charging MOS transistors are equal.

7. The overcurrent protection device of claim 5, wherein The protection circuit also includes: Conductive metal substrate, used for conductivity and heat dissipation; The conductive metal carrier plate includes a first region, a second region, and a third region. The first surface of the first region is connected to the first end of the first type of shunt unit, the first surface of the second region is connected to the third end of the second type of shunt unit, and the first surface of the third region is connected to the intermediate end.

8. The overcurrent protection device of claim 7, wherein, The protection circuit also includes: A ceramic substrate, connected to the second surface of the first region, the second surface of the second region, and the third surface of the third region, is used for thermal insulation and electrical insulation. Wherein, the second surface of the first region is disposed opposite to the first surface of the first region, the second surface of the second region is disposed opposite to the first surface of the second region, and the second surface of the third region is disposed opposite to the first surface of the third region.

9. The overcurrent protection device of claim 7, wherein, The conductive metal carrier plate is a copper carrier plate.

10. A high current battery characterized by, The high-current battery includes a battery pack and an overcurrent protection device as described in any one of claims 1 to 9.

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