Lithium ion battery safety early warning system and method

Abstract

The invention discloses a safety early warning system and method for a lithium ion battery, and the system comprises a pressure overturning sheet disposed in the battery, and the pressure overturning sheet is provided with a contact part protruding towards one side of a positive pole of the battery; when the internal pressure of the battery reaches a certain threshold value, the pressure overturning piece deforms under the action of the pressure to drive the contact part to be in contact with the positive pole of the battery, and the voltage between the battery cover plate of the battery and the positive pole of the battery is triggered to change; the early warning system further comprises a voltage signal receiver used for receiving a voltage signal between the battery cover plate and the battery positive pole. And the voltage signal receiver sends an early warning signal to the terminal after receiving the pressure signal. According to the early warning system and method, the voltage change between the battery cover plate and the positive pole does not affect the normal discharging and charging process of the battery, so that the normal use of an energy storage system of the whole vehicle is not affected, time is won for maintenance and replacement, and meanwhile, safety accidents are also avoided.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a lithium-ion battery safety early warning system and method. Background Art

[0002] With the vigorous promotion of electric vehicles and new power systems, the safety of lithium-ion batteries has received more and more attention. The safety of lithium-ion batteries includes three parts: intrinsic safety, passive safety and active safety.

[0003] Intrinsic safety means that the thermal stability of the positive and negative electrode materials and the electrolyte is improved so that the battery body does not experience thermal runaway. For example, the technology disclosed in patent WO202 / 026621A1 improves the thermal stability of lithium-rich manganese-based materials by anion and cation doping and fast ion conductor coating;

[0004] Passive safety includes the heat insulation, heat dissipation, safety protection design of the battery and fire prevention measures after thermal runaway, such as the technology disclosed in patent authorization announcement number CN221861861U, which sets temperature, smoke, gas and other sensors and fire prevention devices in a single sub-battery compartment; secondly, for example, the technology disclosed in patent publication / announcement number CN18431693A and CN204760445U, which designs a pneumatic deformable part on the end cover to prevent battery overcharging;

[0005] In terms of active safety, the battery is used below the thermal runaway safety boundary through technologies such as battery thermal management, status assessment, and safety warning. For example, the technology disclosed in CN118330495A and CN118457351A uses information such as battery pack temperature, heat generation, and EIS impedance, and uses threshold setting, cluster analysis, and other methods to analyze the safety status of the battery pack in real time, and actively alarm when the battery is abnormal.

[0006] Among many technologies in the prior art, passive safety technology often causes permanent damage to the battery, making it impossible to continue using the battery. In addition, passive safety technology and active safety technology are not closely combined to form an effective linkage. In the above CN204760445U, when the battery expands inside, the bendable and deformable circuit-breaking conductive part deforms and triggers the cover plate device, causing the positive and negative electrodes to short-circuit, the fuse to blow, and the battery cannot continue to charge or discharge.

[0007] Therefore, based on the above technical problems, technicians in this field urgently need to develop a lithium-ion battery safety early warning system and method. Summary of the invention

[0008] The purpose of the present invention is to provide a lithium-ion battery safety warning system and method, which combines active and passive safety together, triggers voltage signal changes through the internal pressure of the battery, and sends out a warning signal to remind users to repair and replace the battery in time to prevent safety accidents.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A lithium-ion battery safety early warning system of the present invention comprises:

[0011] A pressure reversal sheet disposed inside the battery, the pressure reversal sheet having a contact portion protruding toward one side of the positive electrode column of the battery;

[0012] When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet is deformed under the pressure to drive the contact portion to contact the positive electrode of the battery, and trigger the voltage between the battery cover and the positive electrode of the battery to change;

[0013] The early warning system also includes:

[0014] A voltage signal receiver for receiving a voltage signal between the battery cover and the positive electrode of the battery;

[0015] The voltage signal receiver sends an early warning signal to the terminal after receiving the voltage signal.

[0016] Furthermore, the battery comprises:

[0017] The battery positive electrode column and the battery cover plate;

[0018] The battery positive electrode column comprises a positive electrode riveted column and a positive electrode column terminal;

[0019] The pressure flip sheet is placed inside the battery, and the edge of the pressure flip sheet is connected to the battery cover;

[0020] When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet is deformed under the action of the pressure to drive the contact portion to contact the positive electrode terminal of the battery.

[0021] Furthermore, an upper insulating member is installed between the battery cover and the positive electrode terminal;

[0022] A lower insulating member is disposed at the lower portion of the battery cover plate, and an edge of the pressure flip sheet is fixed between the battery cover plate and the lower insulating member.

[0023] Furthermore, when the pressure flip plate is in a normal state, the positive electrode terminal and the battery cover are insulated by the upper insulating member, and the resistance between the battery cover and the positive electrode terminal is not less than 1 MΩ;

[0024] After the pressure reversal sheet is reversed, the positive electrode terminal and the battery cover are in electrical contact through the contact portion of the pressure reversal sheet, and the resistance between the battery cover and the positive electrode terminal is not greater than 100Ω.

[0025] Furthermore, the battery cover plate is insulated from the negative electrode of the battery, and the resistance between the battery cover plate and the negative electrode of the battery is not less than 1 MΩ.

[0026] Furthermore, the pressure reversal sheet includes a middle portion of an integrated structure and an extension portion formed in a circumferential direction of the middle portion;

[0027] The thickness of the extension portion is smaller than the thickness of the middle portion;

[0028] The end of the extension portion contacts the battery cover plate, and the area of ​​the extension portion close to the middle portion is a pressure deformation area;

[0029] The middle portion protrudes toward the positive electrode terminal side to form the contact portion.

[0030] Furthermore, the pressure threshold of the pressure reversal plate is less than the valve opening pressure of the battery safety valve.

[0031] Furthermore, the pressure threshold of the pressure reversal sheet is less than 0.1MPa-0.2MPa.

[0032] The present invention also discloses a lithium-ion battery safety early warning method, which is based on the early warning system as described above;

[0033] The safety early warning method mainly comprises the following steps:

[0034] S101, when the internal pressure of the battery reaches a certain threshold, the pressure flip sheet on the battery cover is triggered to flip and deform;

[0035] S102, the pressure flip sheet contacts the positive electrode of the battery, triggering a change in the voltage between the battery cover and the positive electrode;

[0036] S103, after receiving the voltage signal, the voltage signal receiver issues a warning signal;

[0037] S104: A warning signal is sent to the terminal, and a safety failure warning message is issued to the user.

[0038] Furthermore, the warning signal is an audible and visual warning signal.

[0039] In the above technical solution, the present invention provides a lithium-ion battery safety early warning system and method, which has the following beneficial effects:

[0040] The safety warning system and method provided by the present invention adopts a pressure flip plate that can be deformed by the change of internal pressure of the battery between the battery cover and the positive electrode column. When the internal pressure of the battery changes and reaches a certain threshold, the pressure flip plate is deformed and flipped to drive the contact part to contact the positive electrode terminal, so as to realize timely detection of faults and send safety fault warning information to the user.

[0041] The voltage change between the battery cover and the positive pole of the early warning system and method of the present invention will not affect the normal discharge and charging process of the battery, and therefore will not affect the normal use of the energy storage system of the entire vehicle, thereby gaining time for maintenance and replacement and avoiding the occurrence of safety accidents.

[0042] The system structure of the present invention does not require changing the existing assembly process, and only needs to be combined with the early warning method of the present invention to achieve battery safety early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0044] Figure 1 A block diagram of a lithium-ion battery safety early warning method disclosed in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of the structure of a battery cover of a lithium-ion battery safety warning system disclosed in an embodiment of the present application;

[0046] Figure 3 A schematic structural diagram of a positive electrode column of a battery cover before a pressure flip plate flips over a lithium-ion battery safety early warning system disclosed in an embodiment of the present application;

[0047] Figure 4 A schematic structural diagram of a positive electrode column of a battery cover after a pressure flip plate of a lithium-ion battery safety early warning system disclosed in an embodiment of the present application is flipped;

[0048] Figure 5 A schematic diagram of voltage monitoring between a battery cover and a positive electrode column in a parallel battery pack of a lithium-ion battery safety early warning system disclosed in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of voltage monitoring between a battery cover and a positive electrode in a series battery pack of a lithium-ion battery safety warning system disclosed in an embodiment of the present application.

[0050] Description of reference numerals:

[0051] 201, positive pole; 202, battery safety valve; 203, battery cover; 204, negative pole;

[0052] 20101, positive pole terminal; 20102, positive pole riveting pole;

[0053] 301, upper insulating member; 302, lower insulating member;

[0054] 4. Pressure flip sheet;

[0055] 401, contact portion; 402, extension portion; 403, pressure deformation region;

[0056] 501, total positive; 502, total negative; 503, voltage signal receiver. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0058] See also Figures 2 to 6 As shown;

[0059] This embodiment discloses a lithium-ion battery safety early warning system, which includes:

[0060] A pressure reversal sheet 4 is disposed inside the battery, and the pressure reversal sheet 4 has a contact portion 401 protruding toward one side of the positive electrode column of the battery;

[0061] When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet 4 is deformed under the pressure to drive the contact portion 401 to contact the battery positive electrode 201, and trigger the voltage between the battery cover 203 and the battery positive electrode 201 to change;

[0062] The early warning system also includes:

[0063] A voltage signal receiver 503 for receiving a voltage signal between the battery cover 203 and the battery positive pole 201;

[0064] After receiving the voltage signal, the voltage signal receiver 503 sends a warning signal to the terminal.

[0065] Specifically, this embodiment discloses a lithium-ion battery safety warning system, which mainly arranges a pressure flip sheet 4 on one side of the positive pole 201 of the battery, and drives the pressure flip sheet 4 to deform and flip through the change of the internal pressure of the battery, so as to realize the system of realizing the electrical contact between the battery cover 203 and the positive pole 201 of the battery by using the pressure flip sheet 4. When the internal pressure of the battery changes and reaches a certain threshold, the pressure flip sheet 4 deforms under the action of pressure to drive the contact part 401 to contact the positive pole 201 of the battery, and triggers the voltage between the battery cover 203 and the positive pole 201 of the battery to change, and then receives the voltage signal through the voltage signal receiver 503, and sends a warning signal to the terminal.

[0066] First, the structure of the battery is further introduced, especially the structure of one end of the battery positive electrode column 201, specifically: the battery of this embodiment includes a battery positive electrode column 201 and a battery cover plate 203;

[0067] The positive electrode column 201 of the battery includes a positive riveted column 20102 and a positive column terminal 20101; according to conventional connection methods, the connection between the battery cover 203, the positive electrode column 201 and the voltage detection device can be soldered or mechanically fastened. The pressure flip sheet 4 of this embodiment is placed inside the battery, and the edge of the pressure flip sheet 4 is connected to the battery cover 203;

[0068] When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet 4 is deformed under the pressure to drive the contact portion 401 to contact the positive electrode terminal 20101 of the battery.

[0069] Preferably, an upper insulating member 301 is installed between the battery cover 203 and the positive electrode terminal 20101 of this embodiment;

[0070] A lower insulating member 302 is disposed at the lower portion of the battery cover plate 203 , and the edge of the pressure flip sheet 4 is fixed between the battery cover plate 203 and the lower insulating member 302 .

[0071] Among them, in the normal state of the pressure reversal sheet 4 of this embodiment, the positive electrode terminal 20101 and the battery cover 203 are insulated by the upper insulating member 301, and the resistance between the battery cover 203 and the positive electrode terminal 20101 is not less than 1MΩ;

[0072] After the pressure flip sheet 4 is flipped, the positive electrode terminal 20101 and the battery cover 203 are electrically contacted through the contact portion 401 of the pressure flip sheet 4, and the resistance between the battery cover 203 and the positive electrode terminal 20101 is not greater than 100Ω.

[0073] Secondly, the pressure flip plate 4 of this embodiment is only arranged on one side of the positive electrode column 201 of the battery, and there is no pressure flip plate 4 on the negative electrode column 204 side, so the battery cover 203 of this embodiment and the negative electrode column 204 of the battery are insulated, and the resistance between the battery cover 203 and the negative electrode column 204 of the battery is not less than 1MΩ.

[0074] Based on the above principle, the pressure reversal sheet 4 of this embodiment includes a middle portion of an integrated structure and an extension portion 402 formed in the circumferential direction of the middle portion;

[0075] The thickness of the extension portion 402 is smaller than the thickness of the middle portion;

[0076] The end of the extension portion 402 contacts the battery cover plate 203, and the area near the middle portion of the extension portion 402 is a pressure deformation area 403;

[0077] The middle portion protrudes toward the positive electrode terminal 20101 to form a contact portion 401.

[0078] Preferably, the pressure threshold of the pressure reversal plate 4 of this embodiment is less than the valve opening pressure of the battery safety valve.

[0079] Specifically, the pressure threshold of the pressure reversal sheet 4 is less than 0.1 MPa-0.2 MPa.

[0080] The present invention also discloses a lithium-ion battery safety early warning method, which is based on the early warning system as described above;

[0081] See also Figure 1 As shown, the safety warning method mainly includes the following steps:

[0082] S101, when the internal pressure of the battery reaches a certain threshold, the pressure flip sheet 4 on the battery cover 203 is triggered to flip and deform;

[0083] S102, the pressure flip sheet 4 contacts the battery positive electrode 201, triggering a change in the voltage between the battery cover 203 and the positive electrode 201;

[0084] S103, after receiving the voltage signal, the voltage signal receiver 503 issues a warning signal;

[0085] S104: A warning signal is sent to the terminal, and a safety failure warning message is issued to the user.

[0086] Among them, the warning signal of this embodiment is an audible and visual warning signal.

[0087] Embodiment 1:

[0088] See also Figure 5As shown, for ternary material lithium-ion batteries, the opening pressure of the battery safety valve 202 is 0.9±0.1MPa, and the flip pressure of the pressure flip plate 4 is 0.7±0.1MPa. The connection method of the battery pack is shown in Figure 5 , connected in parallel, when the internal pressure of a battery reaches 0.7MPa, the pressure reversal piece 4 is activated, Figure 3 Change to Figure 4 , the voltage detection device detects the change of the voltage signal, and then the control system sends a warning signal to the terminal, prompting the terminal user to replace or repair the battery in time.

[0089] Embodiment 2:

[0090] See also Figure 6 As shown, for lithium iron phosphate lithium-ion batteries, the opening pressure of the battery safety valve 202 is 0.8±0.1MPa, and the flip pressure of the pressure flip plate 4 is 0.6±0.1MPa. The connection method of the battery pack is shown in Figure 6 , are connected in series. When the internal pressure of a battery reaches 0.6MPa, the pressure reversal sheet 4 is activated. Figure 3 becomes Figure 4 The voltage detection device detects the change of the voltage signal, and then the control system sends a warning signal to the terminal, prompting the terminal user to replace or repair the battery in time.

[0091] Similarly, for sodium ion batteries, the parameters in the second embodiment are used, and after the pressure reversal sheet 4 is actuated, Figure 3 Changes to Figure 4 , the voltage detection device detects the voltage signal change, and then the control system sends a warning signal to the terminal, prompting the terminal user to replace or repair the battery in time.

[0092] The warning signal of this embodiment can adopt an audible and visual warning signal, and the signal can be sent remotely to the monitoring platform at the same time, which can activate the system self-protection function, cut off the power supply, and prevent battery damage or thermal runaway risks.

[0093] The battery and battery pack involved in this embodiment can be used in electric vehicles and energy storage systems to provide reliable safety warnings for electric vehicles and energy storage systems, improve the safety and stability of electric vehicles and energy storage systems, and prevent the occurrence of safety accidents.

[0094] In the above technical solution, the present invention provides a lithium-ion battery safety early warning system and method, which has the following beneficial effects:

[0095] The safety warning system and method provided by the present invention adopts a method of setting a pressure flip sheet 4 that can be deformed by the change of internal pressure of the battery between the battery cover 203 and the positive electrode column 201. When the internal pressure of the battery changes and reaches a certain threshold, the pressure flip sheet 4 is deformed and flipped to drive the contact part 401 to contact the positive electrode terminal 20101, so as to realize timely detection of faults and send safety fault warning information to the user.

[0096] The voltage change between the battery cover 203 and the positive electrode 201 of the early warning system and method of the present invention will not affect the normal discharge and charging process of the battery, and therefore will not affect the normal use of the energy storage system of the entire vehicle, thereby gaining time for maintenance and replacement and avoiding the occurrence of safety accidents.

[0097] The system structure of the present invention does not require changing the existing assembly process, and only needs to be combined with the early warning method of the present invention to achieve battery safety early warning.

[0098] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A lithium-ion battery safety early warning system, characterized in that: The early warning system includes: A pressure reversal sheet (4) disposed inside the battery, the pressure reversal sheet (4) having a contact portion (401) protruding toward one side of the battery positive electrode column (201); When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet (4) deforms under the action of the pressure to drive the contact portion (401) to contact the battery positive electrode column (201), and triggers a change in the voltage between the battery cover plate (203) and the battery positive electrode column (201); The early warning system also includes: A voltage signal receiver (503) for receiving a voltage signal between the battery cover (203) and the battery positive pole (201); The voltage signal receiver (503) sends a warning signal to the terminal after receiving the voltage signal.

2. A lithium-ion battery safety early warning system according to claim 1, characterized in that: The battery comprises: The battery positive electrode column (201) and the battery cover plate (203); The battery positive electrode column (201) comprises a positive electrode riveted column (20102) and a positive electrode column terminal (20101); The pressure flip sheet (4) is placed inside the battery, and the edge of the pressure flip sheet (4) is connected to the battery cover plate (203); When the internal pressure of the battery reaches a certain threshold, the pressure flip sheet (4) is deformed under the action of the pressure to drive the contact portion (401) to contact the positive pole terminal (20101) of the battery.

3. A lithium-ion battery safety warning system according to claim 2, characterized in that: An upper insulating member (301) is installed between the battery cover plate (203) and the positive electrode terminal (20101); A lower insulating member (302) is provided at the lower part of the battery cover plate (203), and an edge of the pressure flip sheet (4) is fixed between the battery cover plate (203) and the lower insulating member (302).

4. A lithium-ion battery safety early warning system according to claim 3, characterized in that: When the pressure flip plate (4) is in a normal state, the positive electrode terminal (20101) and the battery cover plate (203) are insulated by the upper insulating member (301), and the resistance between the battery cover plate (203) and the positive electrode terminal (20101) is not less than 1 MΩ; After the pressure flip sheet (4) is flipped, the positive pole terminal (20101) and the battery cover (203) are electrically contacted through the contact portion (401) of the pressure flip sheet (4), and the resistance between the battery cover (203) and the positive pole terminal (20101) is not greater than 100Ω.

5. A lithium-ion battery safety early warning system according to claim 4, characterized in that: The battery cover plate (203) and the negative electrode column (204) of the battery are in an insulating state, and the resistance between the battery cover plate (203) and the negative electrode column (204) of the battery is not less than 1 MΩ.

6. A lithium-ion battery safety warning system according to claim 2, characterized in that: The pressure reversal sheet (4) comprises a middle portion of an integrated structure and an extension portion (402) formed in the circumferential direction of the middle portion; The thickness of the extension portion (402) is smaller than the thickness of the middle portion; The end of the extension portion (402) contacts the battery cover plate (203), and the area of ​​the extension portion (402) close to the middle portion is a pressure deformation area (403); The middle portion protrudes toward one side of the positive electrode terminal (20101) to form the contact portion (401).

7. A lithium-ion battery safety warning system according to claim 1, characterized in that: The pressure threshold of the pressure reversal plate (4) is less than the valve opening pressure of the battery safety valve (202).

8. A lithium-ion battery safety warning system according to claim 7, characterized in that: The pressure threshold of the pressure reversal sheet (4) is less than 0.1 MPa-0.2 MPa.

9. A lithium-ion battery safety early warning method, characterized in that: The safety warning method is based on the warning system as described in any one of claims 1 to 8; The safety early warning method mainly comprises the following steps: S101, when the internal pressure of the battery reaches a certain threshold, the pressure flip sheet (4) on the battery cover (203) is triggered to flip and deform; S102, the pressure reversal sheet (4) contacts the positive electrode column (201) of the battery, triggering a change in the voltage between the battery cover plate (203) and the positive electrode column (201); S103, after receiving the voltage signal, the voltage signal receiver (503) issues a warning signal; S104: A warning signal is sent to the terminal, and a safety failure warning message is issued to the user.

10. A lithium-ion battery safety early warning method according to claim 9, characterized in that: The warning signal is an audible and visual warning signal.

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