Active disengagement device and method for an abnormal battery cell

Abstract

This invention provides an active disconnection device and method for faulty battery cells. Through the mechanical movement of a conductive needle, the faulty cell is completely physically separated from the main circuit of the battery pack, thoroughly cutting off the power supply path from adjacent cells to the faulty cell. This fundamentally blocks the triggering and propagation of internal short circuit deterioration and thermal runaway, significantly improving the inherent safety of the battery pack. Simultaneously with the disconnection of the faulty cell, a bypass circuit is established through the upper conductive layer of the double-layer circuit board, allowing the remaining normal battery cells to continue operating in series. This avoids the problem of the entire battery pack shutting down after triggering traditional relay protection schemes, achieving safe degraded operation of the equipment. The single-cell, single-module design allows for flexible cascading via module connection devices, adapting to battery modules with different series counts, resulting in high integration. After a fault, only the corresponding faulty cell and module need to be replaced, eliminating the need for replacing the entire pack, significantly reducing maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of battery pack safety control technology, and in particular to an active disconnection device and method for abnormal battery cells. Background Technology

[0002] With the rapid development of the new energy industry, lithium-ion battery packs are widely used in electric vehicles, energy storage power stations, unattended equipment, and other scenarios with extremely high requirements for power supply safety and continuity. Existing battery packs generally adopt a grouping architecture with multiple battery cells connected in series. When a single battery cell experiences abnormal faults such as internal short circuits, overheating, overcharging, or over-discharging, it is very easy to trigger thermal runaway and spread to adjacent cells, causing serious safety accidents. At the same time, conventional fault protection actions often lead to the interruption of power supply to the entire battery pack, which cannot meet the usage requirements of high reliability scenarios.

[0003] Existing battery pack fault protection technologies mainly suffer from the following core defects: Traditional main circuit relay protection schemes have inherent safety and functional shortcomings: existing conventional protection methods rely on the battery management system (BMS) to disconnect the main positive or main negative relay of the battery pack when a fault is detected. On the one hand, after the fault is triggered, the entire battery pack will stop working completely, and safe degraded operation cannot be achieved, which cannot meet the core requirements such as electric vehicle limp-out and emergency power supply of energy storage power stations. On the other hand, it can only cut off the external main circuit of the battery pack. If the abnormal cell is physically damaged or internally short-circuited, the adjacent cells can still continue to feed energy to the faulty cell through the internal physical connection of the battery pack, which cannot fundamentally prevent the triggering and propagation of thermal runaway.

[0004] Existing single-cell bypass solutions cannot achieve complete physical isolation: Current mainstream power electronic bypass solutions such as fuses, thyristors, and MOSFETs can only achieve circuit switching at the electrical level. The faulty cell is still physically connected to the main circuit of the battery pack, and the energy feed path of the faulty cell cannot be completely cut off. Under internal short circuit and high temperature scenarios, device failure is very likely to occur, and the risk of thermal runaway cannot be eliminated.

[0005] Limited applicability and insufficient versatility: Existing mechanical cell release devices can only be adapted to battery arrangements where the positive and negative tabs are on the same side. For pouch batteries, some prismatic batteries, and cylindrical batteries, which commonly use tabs arranged on opposite sides, there is a lack of an effective integrated solution for active cell release and bypass, which cannot simultaneously achieve physical disconnection of faulty cells and continuous maintenance of the series circuit.

[0006] Insufficient reliability of operation and potential safety hazards: Existing solutions mostly adopt a step-by-step operation logic of "disconnect first, then bypass". There is a time difference between disconnection and bypass, which can easily cause arcing, device burning and even secondary failures under high current conditions. At the same time, there is a lack of safety verification mechanism before operation, which cannot guarantee the safety of the operation process. Summary of the Invention

[0007] To address the technical problems existing in the prior art, this invention provides a device for use in power batteries or energy storage battery packs that can automatically physically disconnect and bypass a single cell from the electrical circuit when an abnormality such as an internal short circuit or overheating occurs. The device utilizes a mechanical structure to achieve rapid physical disconnection and a double-layer circuit board design to achieve automatic bypassing, thereby blocking fault current and preventing the spread of thermal runaway.

[0008] On the one hand, an active removal device for abnormal battery cells is provided, which is applied to a battery pack containing at least one battery cell, including upper and lower double-layer circuit boards, conductive needles and a drive mechanism. The upper and lower double-layer circuit board includes an upper conductive layer 11, a lower conductive layer 12, an insulating layer 14, and a module connection device 15. The upper conductive layer 11 is a bypass conductive layer, the lower conductive layer 12 is a working circuit conductive layer, and the insulating layer 14 is sandwiched between the upper conductive layer 11 and the lower conductive layer 12 to achieve electrical isolation between them. The insulating layer 14 has through-holes for the installation position of the conductive needle. The module connection device 15 is fixed to the end of the double-layer circuit board and is used for electrical series connection between adjacent conductive circuit modules. The conductive needle includes a positive conductive needle 21 and a negative conductive needle 22. Both the positive conductive needle 21 and the negative conductive needle 22 are perpendicularly inserted into the through-hole, and can move synchronously back and forth between the first state and the second state along their own axis. In the first state, the lower end of the positive electrode conductive needle 21 is connected to the positive electrode tab and the lower conductive layer 12 of the corresponding battery cell, the lower end of the negative electrode conductive needle 22 is connected to the negative electrode tab and the lower conductive layer 12 of the corresponding battery cell, and the upper ends of the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are separated from the upper conductive layer 11, so that the corresponding battery cell is connected to the working circuit of the battery pack. In the second state, the positive electrode needle driving mechanism 31 and the negative electrode needle driving mechanism 32 respectively drive the positive electrode conductive needle 21 and the negative electrode conductive needle 22 to act, causing their lower ends to separate from the tabs of the battery cell, cutting off the current, and the faulty battery pack to be disconnected from the main circuit; at the same time, the upper ends of the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are in contact with the bypass conductive layer of the upper conductive layer 11 to form a bypass circuit, and electrons flow to the next module through the upper conductive layer 11; The driving mechanism includes a positive electrode driving mechanism 31 connected to the positive electrode conductive needle 21 and a negative electrode driving mechanism 32 connected to the negative electrode conductive needle 22. The driving mechanism is used to receive control signals and drive the corresponding conductive needle to switch between a first state and a second state.

[0009] Preferably, one end of the positive electrode needle driving mechanism 31 and the negative electrode needle driving mechanism 32 is a fixed end, which is fixedly installed on the support structure of the double-layer circuit board or battery module, and the other end is an actuating end, which is fixedly connected to the end of the corresponding conductive needle.

[0010] Preferably, the driving mechanism is any one of a bidirectional latching linear motor, a bidirectional latching electromagnet, a cylinder, or a latching spring mechanism. The driving mechanism can drive the corresponding conductive needle to complete axial movement and can latch and maintain the current position after power is cut off.

[0011] Preferably, the conductive needle has a three-section structure, including an upper contact portion, a middle insulating section and a lower contact portion. The middle insulating section is covered with a high-temperature resistant insulating material to isolate the upper conductive layer 11 and the lower conductive layer 12 in a non-conductive state.

[0012] Preferably, the module connection device 15 is any one of wire or nickel-plated copper plate, used to realize the cascading expansion of multiple sets of conductive circuit modules.

[0013] Preferably, the insulating layer 14 is an FR-4 epoxy board or a PI polyimide film, and the upper conductive layer 11 and the lower conductive layer 12 are both copper foil conductive layers.

[0014] Preferably, for battery cells with tabs located on the same side, the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are independently set for each individual battery cell, so as to realize the independent disconnection and bypass of a single faulty battery cell.

[0015] Preferably, for battery cells with tabs located on opposite sides, the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are arranged in pairs for two adjacent battery cells, which are used to simultaneously control the on / off state of the working circuit between the two adjacent battery cells and the battery pack.

[0016] Preferably, it also includes a battery management system (BMS), which is electrically connected to the sampling unit of each battery cell to collect the voltage, temperature, internal resistance, and charging / discharging current operating parameters of the battery cell in real time. At the same time, it is communicatively connected to all drive mechanisms to issue control commands to the drive mechanisms.

[0017] On the other hand, a method for actively removing abnormal battery cells is provided, based on the aforementioned active removal device for abnormal battery cells, and applied to a battery pack containing at least one battery cell, comprising the following steps: S1. System initialization and real-time status monitoring: The system completes initialization upon power-up, and all conductive pins are reset to the first state. The battery management system (BMS) collects the operating parameters of each battery cell in the battery pack in real time and uploads the collected data to the central control system via the CAN bus. S2. Faulty Cell Identification and Judgment: The central control system performs real-time analysis and threshold judgment on the uploaded battery operating parameters. When the parameters of a battery cell meet the preset fault conditions, the battery cell is identified as a faulty battery. The preset fault conditions include at least one of the following: battery cell voltage exceeds the normal operating range, voltage difference with other batteries in the same group exceeds a preset threshold, surface temperature exceeds the safety upper limit, and internal resistance change rate exceeds a preset threshold. S3 Safety Pre-verification and Command Issuance: The central control system triggers a fault alarm, prioritizes cutting off non-essential electrical equipment, and after completing the safety pre-verification, it synchronously issues a disconnection control command to the positive electrode needle drive mechanism 31 and negative electrode needle drive mechanism 32 of the conductive circuit module corresponding to the faulty battery via the CAN bus; the safety pre-verification includes confirming that the battery pack charging and discharging current is within the preset low current safety threshold and confirming that the load is in a safe and stable state. S4. Active disconnection of faulty cell and synchronous switching of bypass: After receiving the disconnection control command, the positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 act synchronously, driving the corresponding positive electrode conductive needle 21 and negative electrode conductive needle 22 to switch from the first state to the second state, so that the faulty battery cell is completely physically disconnected from the working circuit of the battery pack. At the same time, a bypass circuit is established through the upper conductive layer 11, and the remaining normal battery cells of the battery pack continue to work in series. S5. Fault Resolution and System Reset: After the faulty battery has been repaired or replaced, the main control system issues a reset command, and the corresponding drive mechanism drives the positive conductive needle 21 and the negative conductive needle 22 to reset from the second state to the first state, and the battery pack resumes normal operation mode with the entire series.

[0018] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: 1. Achieve complete physical isolation of faulty cells, eliminating the spread of thermal runaway from the root: Unlike traditional electrical bypass solutions that can only disconnect the circuit, this invention achieves complete physical separation of the faulty cell from the main circuit of the battery pack through the mechanical movement of conductive needles. This completely cuts off the energy supply path from adjacent cells to the faulty cell, fundamentally blocking the deterioration of internal short circuits and the triggering and spread of thermal runaway, and significantly improving the inherent safety of the battery pack.

[0019] 2. Ensure continuous power supply to the battery pack and achieve safe degraded operation: While disconnecting the faulty cell, the present invention simultaneously establishes a bypass circuit through the upper conductive layer of the double-layer circuit board, allowing the remaining normal battery cells to continue operating in series. This avoids the problem of the entire battery pack shutting down after the traditional relay protection scheme is triggered, and can meet the needs of scenarios with high requirements for power supply continuity, such as electric vehicles, energy storage power stations, and unmanned equipment, to achieve safe degraded operation of the equipment.

[0020] 3. Compatible with dual-row arrangement and applicable to a wide range of scenarios: This invention can be adapted to two mainstream battery arrangement methods, namely, same-side tab and opposite-side tab, through the flexible configuration of conductive needles. It covers the packing schemes of most battery types, such as square, soft-pack, and cylindrical, without the need for major modifications to the existing battery pack structure. It has a wide range of applications and strong versatility.

[0021] 4. High synchronization of action and strong safety protection: The present invention drives the positive and negative conductive needles to move synchronously through the drive mechanism, and completes the physical disconnection and bypass conduction at the same time. There is no time difference in action, which avoids the arcing and burning problems that are easy to be caused by the "disconnect first and then connect" scheme. At the same time, a pre-safety verification mechanism is set up to perform the disconnection action only under the conditions of low current and safe load, which further improves the reliability and safety of the device.

[0022] 5. Modular design, easy to expand and maintain: The present invention adopts a single battery and single module design, which can be flexibly cascaded through module connection device to adapt to battery modules with different number of strings, with high integration; after failure, only the corresponding faulty cell and module need to be replaced, without replacing the whole group, which greatly reduces the operation and maintenance cost. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a battery pack on the same side as the tab in normal flow state according to the present invention. Figure 2 This is a schematic diagram of a battery pack with a faulty battery disconnected on the same side as the tab according to the present invention. Figure 3 This is a schematic diagram of a battery pack with the tab on the opposite side in normal flow state according to the present invention. Figure 4 This is a schematic diagram of a battery pack in a faulty, disconnected state on the opposite side of the electrode according to the present invention. In the attached diagram: 11-upper conductive layer; 12-lower conductive layer; 14-insulating layer; 15-module connection device; 21-positive conductive needle; 22-negative conductive needle; 31-positive needle driving mechanism; 32-negative needle driving mechanism. Detailed Implementation

[0025] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0026] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0027] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0028] In this embodiment of the invention, sometimes a subscript such as W1 may be mistakenly written as a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0029] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0030] This invention is applicable to scenarios with high requirements for power supply continuity, such as electric vehicles, energy storage power stations, and unmanned equipment. In these scenarios, when a single cell in the battery pack malfunctions, this invention can physically isolate the faulty cell, ensuring safe degraded operation of the equipment.

[0031] The present invention provides an active disconnection device for abnormal battery cells, which uses a mechanical structure to achieve rapid physical disconnection and a double-layer circuit board design to achieve automatic bypass, thereby blocking fault current and preventing thermal runaway propagation.

[0032] I. The active separation device for abnormal battery cells specifically includes: 1. Double-layer circuit board: comprising an upper conductive layer and a lower conductive layer. The upper conductive layer is a bypass conductive layer, and the lower conductive layer is a working circuit conductive layer. The two conductive layers are isolated by an insulating layer.

[0033] 2. Conductive needle: Vertically inserted between the upper and lower double-layer circuit boards. The conductive needle can switch between a first normal state and a second detached state.

[0034] 3. Driving mechanism: connected to the conductive needle, used to drive the conductive needle to move in response to a control signal.

[0035] Specifically: The device is applied to battery packs containing at least one battery cell. Each battery cell corresponds to an independent conductive circuit module. The core components include upper and lower double-layer circuit boards, conductive needles, and a drive mechanism. The specific structure and connection relationship of each component are as follows: 1. Double-layer circuit board The double-layer circuit board includes an upper conductive layer 11, a lower conductive layer 12, an insulating layer 14, and a module connection device 15. The upper conductive layer 11 is a bypass conductive layer, and the lower conductive layer 12 is a working circuit conductive layer. The insulating layer 14 is fixedly disposed between the upper conductive layer 11 and the lower conductive layer 12, achieving complete electrical isolation between the two conductive layers, with through-holes provided only at the installation positions of the corresponding conductive pins. The module connection device 15 is disposed at the ends of the double-layer circuit board and includes, but is not limited to, high-current conductive structures such as wires and connecting copper plates, for connecting individual modules, realizing electrical series connection and current flow between adjacent conductive circuit modules.

[0036] 2. Conductive needle The conductive needles include a positive conductive needle 21 and a negative conductive needle 22. Both the positive conductive needle 21 and the negative conductive needle 22 penetrate vertically through the corresponding insulating vias of the upper and lower double-layer circuit boards and can be switched synchronously between a first state (normal state) and a second state (detached state) along their own axial direction.

[0037] First state (normal state): The lower end of the positive conductive needle 21 is connected to the positive electrode tab and the lower conductive layer 12 of the corresponding single cell, and the lower end of the negative conductive needle 22 is connected to the negative electrode tab and the lower conductive layer 12 of the corresponding single cell; the upper ends of both the positive conductive needle 21 and the negative conductive needle 22 are completely separated from the upper conductive layer 11, the upper conductive layer 11 is in the disconnected state, and the corresponding single cell forms a normal working circuit with the battery pack through the lower conductive layer 12.

[0038] Second state (disengagement state): In the second state, the positive electrode needle driving mechanism 31 and the negative electrode needle driving mechanism 32 respectively drive the positive electrode conductive needle 21 and the negative electrode conductive needle 22 to act, so that their lower ends separate from the tabs of the battery cell, cut off the current, and the faulty battery pack is disconnected from the main circuit; at the same time, the upper ends of the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are in contact with the bypass conductive layer of the upper conductive layer 11 to form a bypass circuit, and electrons flow to the next module through the upper conductive layer 11.

[0039] 3. Drive mechanism The driving mechanism includes a positive electrode needle driving mechanism 31 and a negative electrode needle driving mechanism 32. The positive electrode needle driving mechanism 31 is connected to the positive electrode conductive needle 21, and the negative electrode needle driving mechanism 32 is connected to the negative electrode conductive needle 22. It is used to respond to the control signals of the BMS and the main control system and drive the corresponding conductive needle to move and switch between the first state and the second state.

[0040] Among them, one end of the positive electrode needle driving mechanism 31 and the negative electrode needle driving mechanism 32 is a fixed end, which is fixedly installed on the support structure of the double-layer circuit board or battery module, and the other end is an actuating end, which is fixedly connected to the corresponding conductive needle; the driving mechanism includes, but is not limited to, a linear motor that can realize forward and reverse driving, an electromagnet that can switch between power on and off states, a cylinder that can be charged and discharged, a locking spring mechanism, etc., which can drive the corresponding needle to complete the up and down movement and can lock and maintain the current state.

[0041] Adaptive design for different battery layouts: For scenarios where the tabs of a single battery cell are located on the same side, the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are independently set for each single battery cell, which can realize the independent disconnection and bypass of a single faulty battery cell.

[0042] For scenarios where the tabs of a battery cell are located on opposite sides, the positive electrode conductive needle 21 and the negative electrode conductive needle 22 are set for two adjacent battery cells, which can simultaneously control the connection and disconnection of the two battery cells with the main circuit, so as to realize the synchronous disconnection and bypass of the battery pack where the faulty cell is located.

[0043] II. The active escape method includes the following steps; This is applied to a battery pack with at least one battery cell. Each battery cell corresponds to a corresponding conductive circuit module. The conductive circuit module is composed of an upper conductive layer 11, a lower conductive layer 12, an insulating layer 14, a positive electrode needle driving mechanism 31, a negative electrode needle driving mechanism 32, and a module connection part 15. The insulating layer 14 isolates the upper conductive layer 11 and the lower conductive layer 12. The module connection part 15 is used to connect each battery cell module. The BMS detects the real-time status of each battery cell. Each individual cell has a positive electrode conductive needle 21 and a negative electrode conductive needle 22 that are simultaneously in either the first state or the second state. In the first state, after the positive electrode conductive needle 21 is connected to the positive electrode of the corresponding single cell and the negative electrode conductive needle 22 is connected to the negative electrode of the corresponding single cell, it is connected to the lower conductive layer 12, so that the current flows through the lower conductive layer 12 of the corresponding single cell, so that the corresponding single cell and the battery pack form a normal working circuit. In the second state, after the positive electrode conductive needle 21 is disconnected from the positive electrode of the corresponding single cell and the negative electrode conductive needle 22 is disconnected from the negative electrode of the corresponding single cell, it connects to the upper conductive layer 11, so that the current flows through the corresponding single cell to form a bypass circuit, and physically disconnects the connection with the corresponding battery cell. The positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 are connected to the positive electrode conductive needle 21 and the negative electrode conductive needle 22 of the corresponding single cell, and are controlled by the BMS to switch the corresponding needle between the first state and the second state.

[0044] The specific steps are as follows: (a) System initialization and real-time status monitoring This system is applied to battery packs with at least one battery cell. Each battery cell corresponds to an independent conductive circuit module. The conductive circuit module consists of an upper conductive layer 11, a lower conductive layer 12, an insulating layer 14, a positive electrode needle driving mechanism 31, a negative electrode needle driving mechanism 32, and a module connection device 15. After the system is powered on and initialized, all conductive needles are reset to the first state (normal state). The BMS collects the operating parameters of each battery cell in real time (including cell voltage, surface temperature, internal resistance, battery pack charging and discharging current, etc.) and uploads them to the central control system via the CAN bus.

[0045] (II) Faulty Entity Identification and Status Determination The central control system performs real-time analysis and threshold determination on the uploaded battery operating parameters. When the parameters of a single battery cell meet the preset fault conditions, the cell is identified as a faulty battery. The positive electrode conductive needle 21 and the negative electrode conductive needle 22 corresponding to each single battery cell are always synchronously in the first or second state, with no timing difference in action.

[0046] The preset fault conditions include, but are not limited to: battery cell voltage exceeding the normal operating range, voltage difference with other batteries in the same group exceeding a threshold, surface temperature exceeding the safety upper limit, and internal resistance mutation rate exceeding a threshold. For example, the normal operating voltage of a lithium iron phosphate battery is 2.5V-3.65V, and the normal operating temperature is no higher than 60℃. When a battery cell is detected to be outside the above range, it is identified as a faulty battery.

[0047] (III) Normal working mode (first state) In the first state, the positive conductive needle 21 is connected to the positive terminal of the corresponding single cell, and the negative conductive needle 22 is connected to the negative terminal of the corresponding single cell. Both are connected to the lower conductive layer 12, so that the current flows through the lower conductive layer 12 of the corresponding single cell. The corresponding single cell and the battery pack form a normal operating circuit, and the battery pack operates normally for charging and discharging.

[0048] (iv) Fault isolation and bypass switching (second state) Once the central control system identifies a faulty battery, it first issues an alarm, prioritizes cutting off non-essential electrical equipment, and then confirms the safe and stable status based on the application environment (e.g., vehicle stops moving, unmanned equipment stops working, energy storage battery stops charging and discharging, etc.). Simultaneously, after confirming that the battery pack current is within the required low current range, the central control system sends control commands to the corresponding drive mechanism via the CAN bus. The positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 operate synchronously, driving the corresponding positive electrode conductive needle 21 and negative electrode conductive needle 22 to switch to the second state: the positive electrode conductive needle 21 disconnects from the positive electrode of the corresponding single battery cell, and the negative electrode conductive needle 22 disconnects from the negative electrode of the corresponding single battery cell. Both are connected to the upper conductive layer 11, allowing the current to pass through the upper conductive layer 11 to form a bypass loop, while physically disconnecting from the corresponding battery cell, thus achieving the active disconnection of the faulty single cell.

[0049] (v) Troubleshooting and System Reset After the faulty battery is repaired or replaced, the main control system issues a reset command, which drives the positive conductive needle 21 and the negative conductive needle 22 from the second state to the first state, restoring the conduction between the battery cell and the lower conductive layer 12, and the battery pack returns to normal operation mode.

[0050] The technical application of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] Example 1: Active disconnection device for abnormal battery cells (applied to battery modules on the same side as the tabs) The corresponding instruction manual for this embodiment is attached. Figure 1 Appendix Figure 2 This technology is applied to lithium iron phosphate power battery modules with multiple battery cells arranged in parallel and both positive and negative tabs located on the same side. The specific structure is as follows: This device is applied to a power battery pack containing N series-connected battery cells. Each battery cell corresponds to an independent conductive circuit module, and all modules are connected in series through the module connection device 15.

[0052] 1. Double-layer circuit board: The entire board covers the tabs of all battery cells. From top to bottom, it consists of an upper conductive layer 11, an insulating layer 14, and a lower conductive layer 12. The upper conductive layer 11 is a bypass conductive layer, with an independent conductive area for each conductive circuit module. The lower conductive layer 12 is a working circuit conductive layer, with conductive pads for the positive and negative tabs of each battery cell. The insulating layer 14 is made of FR-4 high-temperature resistant insulating medium, completely isolating the upper conductive layer 11 and the lower conductive layer 12, with through-insulation vias reserved only at the installation positions of the corresponding conductive pins. The module connection device 15 uses nickel-plated copper plates, fixed to both ends of the double-layer circuit board, to achieve electrical series connection between adjacent modules.

[0053] 2. Conductive needles: Each conductive circuit module is equipped with one positive conductive needle 21 and one negative conductive needle 22. Both of them penetrate vertically through the reserved through holes of the double-layer circuit board and can move up and down along the axis. The installation position of the positive conductive needle 21 corresponds one-to-one with the positive electrode tab of the battery cell, and the installation position of the negative conductive needle 22 corresponds one-to-one with the negative electrode tab of the battery cell.

[0054] 3. Driving Mechanism: Each conductive circuit module is equipped with one set of positive electrode electric needle driving mechanism 31 and one set of negative electrode electric needle driving mechanism 32. The driving mechanism adopts a bidirectional latching electromagnet. The fixed end of the positive electrode electric needle driving mechanism 31 is installed on the aluminum alloy support frame of the double-layer circuit board, and the actuating end is fixedly connected to the top end of the positive conductive electric needle 21. The fixed end of the negative electrode electric needle driving mechanism 32 is installed on the support frame, and the actuating end is fixedly connected to the top end of the negative conductive electric needle 22. The driving mechanism can receive pulse control signals, drive the corresponding electric needle to complete the up and down movement, and latch and maintain the current position state after power failure.

[0055] 4. Control Unit: Includes BMS and central control system. The BMS is electrically connected to the voltage and NTC temperature sampling unit of each battery cell, and collects battery operating parameters in real time at a frequency of 10Hz. It also communicates with the central control system and all drive mechanisms via CAN bus.

[0056] The working process of the device in this embodiment is as follows: Normal state (first state, corresponding to the appendix) Figure 1 Both the positive conductive needle 21 and the negative conductive needle 22 are in the depressed position. Their lower ends are in close contact with the positive electrode tab, negative electrode tab, and lower conductive layer 12 of the corresponding battery cell, respectively, and are conducting electricity. Their upper ends are completely separated from the upper conductive layer 11. The current flow path is: electrons flow in → lower conductive layer 12 → positive conductive needle 21 → battery positive electrode → flow through battery cell → battery negative electrode → negative conductive needle 22 → lower conductive layer 12 → module connection device 15 → next module, finally forming a complete series working circuit, and the battery pack is charged and discharged normally.

[0057] Escape state (second state, corresponding to the attached state) Figure 2When the BMS detects a fault such as abnormal voltage or temperature exceeding 60°C in a battery cell, after the main control system completes the safety verification, it issues a disconnect command to the positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 of the corresponding module. The drive mechanism actuates, lifting the positive electrode conductive needle 21 and the negative electrode conductive needle 22 upwards. The lower ends of the two needles are completely physically separated from the tab and lower conductive layer 12 of the faulty battery cell, while the upper ends are in contact with the upper conductive layer 11 for conduction. The current flow path is switched to: electrons flow in from the left module connection device 15 → lower conductive layer 12 → positive electrode conductive needle 21 → upper conductive layer 11 → negative electrode conductive needle 22 → lower conductive layer 12 → module connection device 15 → next module. Electrons no longer flow into the faulty battery cell and are bypassed through the upper conductive layer 11. The faulty battery cell is completely physically disconnected from the main circuit, while the remaining normal battery cells remain connected in series.

[0058] The disengagement action based on this mechanical structure is only permitted under low current conditions; a large current can flow while the probe is stationary. Therefore, the main control system must only execute the disengagement action when the detected current is appropriate.

[0059] In this embodiment: when an abnormality is detected in a single battery cell, such as voltage being outside the normal range or temperature exceeding a threshold, the cell is identified as a faulty battery. For example, the normal operating voltage of a lithium iron phosphate battery is 2.5–3.65V, and the normal operating temperature is no higher than 60°C. If a cell is detected to be outside the normal operating voltage range, or has an excessively large voltage difference with other cells, or has a temperature rise exceeding 60°C, or other potential danger signals, the battery is identified as faulty.

[0060] The specific process is as follows: The BMS detects battery parameters and uploads them to the central control system in real time via the CAN bus. The central control system performs data analysis, and when an abnormality is detected, it issues an alarm and prioritizes cutting off non-essential electrical equipment. Then, depending on the application environment (e.g., the vehicle stops moving, unmanned equipment stops working, energy storage batteries stop charging and discharging), once the state is confirmed to be safe and stable, the central control system sends corresponding control commands to the corresponding drive mechanism via the CAN bus. After receiving the release command, the drive mechanism controls the corresponding electrode to move upward, completing the release of a single battery cell.

[0061] Example 2: Active method for removing abnormal battery cells (application to battery modules on the opposite side of the tab) The corresponding instruction manual for this embodiment is attached. Figure 3 Appendix Figure 4 Based on the active release device described in Example 1, it is applied to an energy storage battery pack with battery cells arranged sequentially, positive and negative tabs located at opposite ends of the battery, and adjacent cells connected in series via an adapter plate. The specific steps are as follows: Step 1: System Initialization and Real-time Monitoring The battery pack consists of multiple lithium iron phosphate battery cells connected in series. Each pair of adjacent battery cells corresponds to a set of conductive circuit modules. The upper and lower double-layer circuit boards are laid on one side of the battery pack adapter plate. When the system is powered on and initialized, all positive conductive pins 21 and negative conductive pins 22 are reset to the first state (pressed down). The BMS collects the voltage, temperature, internal resistance parameters of each battery cell and the total charging and discharging current of the battery pack in real time at a frequency of 10Hz, and uploads all collected data to the central control system in real time via the CAN bus.

[0062] Step 2: Normal working mode operation In the first state, the positive conductive needle 21 and the negative conductive needle 22 are in a depressed state. Their lower ends are in close contact with the adapter plate and the lower conductive layer 12 of the corresponding two battery cells, respectively, and their upper ends are separated from the upper conductive layer 11. The current flow path is as follows: electrons flow in → lower conductive layer 12 → positive conductive needle 21 → battery tab → flow through the first battery cell in this group → battery tab → the second battery cell in this group → flow through the second battery cell in this group → battery tab → negative conductive needle 22 → lower conductive layer 12 → module connection device 15 → the next module, forming a complete series working circuit, and the battery pack operates normally for charging and discharging.

[0063] Step 3: Faulty Component Identification and Judgment The central control system analyzes the uploaded battery parameters in real time. When it detects abnormal conditions such as the voltage of a battery cell exceeding the normal operating range of 2.5V-3.65V, the cell temperature exceeding 60℃, or the voltage difference with other cells exceeding 200mV, and the abnormal conditions last for more than 3 seconds of anti-shake time, the cell is identified as a faulty battery, and the conductive circuit module where the faulty battery is located is locked.

[0064] Step 4: Security Pre-verification and Action Command Issuance The central control system triggers a fault alarm, prioritizes cutting off non-essential electrical equipment, and performs two safety checks simultaneously: first, confirming that the charging and discharging current of the battery pack has dropped to within the preset low current safety threshold; second, confirming that the energy storage battery has stopped charging and discharging and that the load is in a safe state. After the checks are passed, the central control system sends a disconnection control command to the positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 of the module where the faulty battery is located via the CAN bus.

[0065] Step 5: Active disconnection and bypass switching of fault group Upon receiving the command, the positive electrode needle drive mechanism 31 and the negative electrode needle drive mechanism 32 operate synchronously, driving the positive electrode conductive needle 21 and the negative electrode conductive needle 22 to lift upwards and switch to the second state: the lower end of the needle is completely physically separated from the terminals and adapters of the two battery cells in this group, and the faulty battery pack composed of the two batteries is completely disconnected from the main circuit and no longer participates in charging and discharging; at the same time, the upper end of the needle makes contact with the upper conductive layer 11 to establish a bypass circuit, and the current flow path is switched to: electrons flow in → lower conductive layer 12 → positive electrode conductive needle 21 → upper conductive layer 11 → negative electrode conductive needle 22 → lower conductive layer 12 → module connection device 15 → next module. The current no longer flows through the faulty battery pack, and bypass is completed through the upper conductive layer 11. The remaining normal battery cells remain connected in series to achieve safe degraded operation of the battery pack.

[0066] Step 6: Troubleshooting and System Reset After maintenance personnel complete the repair or replacement of the faulty battery, they issue a reset command through the central control system. The corresponding drive mechanism drives the positive conductive needle 21 and the negative conductive needle 22 to reset downwards to the first state. The lower end of the needle is reconnected to the adapter piece and the lower conductive layer 12, and the upper end is separated from the upper conductive layer 11. The battery pack resumes the normal charging and discharging mode of the entire series.

[0067] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An active disconnection device for abnormal battery cells, applied to a battery pack containing at least one battery cell, characterized in that, It includes upper and lower double-layer circuit boards, conductive needles, and a drive mechanism; The upper and lower double-layer circuit board includes an upper conductive layer (11), a lower conductive layer (12), an insulating layer (14), and a module connection device (15); the upper conductive layer (11) is a bypass conductive layer, the lower conductive layer (12) is a working circuit conductive layer, the insulating layer (14) is sandwiched between the upper conductive layer (11) and the lower conductive layer (12) to achieve electrical isolation between the two, and the insulating layer (14) has a through-hole insulating via corresponding to the installation position of the conductive needle; the module connection device (15) is fixed to the end of the double-layer circuit board and is used for electrical series connection between adjacent conductive circuit modules; The conductive needle includes a positive conductive needle (21) and a negative conductive needle (22). Both the positive conductive needle (21) and the negative conductive needle (22) are perpendicularly inserted into the through-hole and can move synchronously back and forth between the first state and the second state along their own axis. In the first state, the lower end of the positive electrode conductive needle (21) is connected to the positive electrode tab and the lower conductive layer (12) of the corresponding battery cell, the lower end of the negative electrode conductive needle (22) is connected to the negative electrode tab and the lower conductive layer (12) of the corresponding battery cell, and the upper ends of the positive electrode conductive needle (21) and the negative electrode conductive needle (22) are separated from the upper conductive layer (11), so that the corresponding battery cell is connected to the working circuit of the battery pack; In the second state, the lower end of the positive electrode conductive needle (21) is completely physically separated from the positive electrode tab and the lower conductive layer (12) of the corresponding battery cell, and the lower end of the negative electrode conductive needle (22) is completely physically separated from the negative electrode tab and the lower conductive layer (12) of the corresponding battery cell. The upper ends of the positive electrode conductive needle (21) and the negative electrode conductive needle (22) are both connected to the upper conductive layer (11), so that the corresponding battery cell is physically disconnected from the working circuit of the battery pack and a bypass circuit is formed. In the second state, the positive electrode needle driving mechanism (31) and the negative electrode needle driving mechanism (32) respectively drive the positive electrode conductive needle (21) and the negative electrode conductive needle (22) to separate their lower ends from the tabs of the battery cell, cut off the current, and disconnect the faulty battery pack from the main circuit; at the same time, the upper ends of the positive electrode conductive needle (21) and the negative electrode conductive needle (22) are in contact with the bypass conductive layer of the upper conductive layer (11) to form a bypass circuit, and electrons flow to the next module through the upper conductive layer (11); The driving mechanism includes a positive electrode driving mechanism (31) connected to the positive electrode conductive needle (21) and a negative electrode driving mechanism (32) connected to the negative electrode conductive needle (22). The driving mechanism is used to receive control signals and drive the corresponding conductive needle to switch between a first state and a second state.

2. The active removal device for abnormal battery cells according to claim 1, characterized in that, One end of the positive electrode needle driving mechanism (31) and the negative electrode needle driving mechanism (32) is a fixed end, which is fixedly installed on the support structure of the double-layer circuit board or battery module, and the other end is an actuating end, which is fixedly connected to the end of the corresponding conductive needle.

3. The active removal device for abnormal battery cells according to claim 2, characterized in that, The driving mechanism is any one of a bidirectional latching linear motor, a bidirectional latching electromagnet, a cylinder, or a latching spring mechanism. The driving mechanism can drive the corresponding conductive needle to complete axial movement and can latch and maintain the current position after power is cut off.

4. The active removal device for abnormal battery cells according to claim 1, characterized in that, The conductive needle has a three-section structure, including an upper contact part, a middle insulating section and a lower contact part. The middle insulating section is covered with a high-temperature resistant insulating material, which is used to isolate the upper conductive layer (11) and the lower conductive layer (12) in a non-conductive state.

5. The active disconnection device for abnormal battery cells according to claim 1, characterized in that, The module connection device (15) is any one of wire or nickel-plated copper plate, used to realize the cascading expansion of multiple sets of conductive circuit modules.

6. The active removal device for abnormal battery cells according to claim 1, characterized in that, The insulating layer (14) is an FR-4 epoxy board or a PI polyimide film, and the upper conductive layer (11) and the lower conductive layer (12) are both copper foil conductive layers.

7. The active disconnection device for abnormal battery cells according to claim 1, characterized in that, For battery cells with tabs on the same side, the positive electrode conductive needle (21) and the negative electrode conductive needle (22) are independently set for each battery cell to realize the independent disconnection and bypass of a single faulty battery cell.

8. The active disconnection device for abnormal battery cells according to claim 1, characterized in that, For battery cells with tabs on opposite sides, the positive electrode conductive needle (21) and the negative electrode conductive needle (22) are paired up for two adjacent battery cells to simultaneously control the on / off state of the working circuit of the two adjacent battery cells and the battery pack.

9. The active disconnection device for abnormal battery cells according to claim 1, characterized in that, It also includes a battery management system (BMS), which is electrically connected to the sampling unit of each battery cell to collect the voltage, temperature, internal resistance, and charging / discharging current operating parameters of the battery cell in real time. At the same time, it is communicatively connected to all drive mechanisms to issue control commands to the drive mechanisms.

10. A method for actively removing abnormal battery cells, implemented based on the active removal device for abnormal battery cells according to any one of claims 1 to 9, applied to a battery pack containing at least one battery cell, characterized in that, Includes the following steps: S1. System initialization and real-time status monitoring: The system completes initialization upon power-up, and all conductive pins are reset to the first state. The battery management system (BMS) collects the operating parameters of each battery cell in the battery pack in real time and uploads the collected data to the central control system via the CAN bus. S2. Faulty cell identification and judgment: The central control system performs real-time analysis and threshold judgment on the uploaded battery operating parameters. When the parameters of a battery cell meet the preset fault conditions, the battery cell is identified as a faulty battery. The preset fault conditions include at least one of the following: the battery cell voltage exceeds the normal operating range, the voltage difference with other batteries in the same group exceeds a preset threshold, the surface temperature exceeds the safety upper limit, and the internal resistance change rate exceeds a preset threshold. S3 Safety Pre-verification and Command Issuance: The central control system triggers a fault alarm, prioritizes cutting off non-essential electrical equipment, and after completing the safety pre-verification, it synchronously issues a disconnection control command to the positive electrode needle drive mechanism (31) and negative electrode needle drive mechanism (32) of the conductive circuit module corresponding to the faulty battery via the CAN bus; the safety pre-verification includes confirming that the battery pack charging and discharging current is within the preset low current safety threshold and confirming that the load is in a safe and stable state; S4. Active disconnection of faulty cell and synchronous switching of bypass: After receiving the disconnection control command, the positive electrode needle drive mechanism (31) and the negative electrode needle drive mechanism (32) act synchronously, driving the corresponding positive electrode conductive needle (21) and negative electrode conductive needle (22) to switch from the first state to the second state, so that the faulty battery cell is completely physically disconnected from the working circuit of the battery pack. At the same time, a bypass circuit is established through the upper conductive layer (11), and the remaining normal battery cells of the battery pack continue to work in series. S5. Fault resolution and system reset: After the faulty battery is repaired or replaced, the main control system issues a reset command, and the corresponding drive mechanism drives the positive electrode conductive needle (21) and the negative electrode conductive needle (22) to reset from the second state to the first state, and the battery pack resumes normal operation mode of the whole string.

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