A lithium ion battery pressure relief valve, battery cover plate, battery monomer, electric device

Abstract

The utility model relates to battery safety technical field, especially a kind of lithium ion battery pressure relief valve, battery cover plate. Pressure relief valve includes metal sheet, piezoelectric element, insulating layer and signal acquisition unit;The edge of metal sheet is fixedly connected on battery housing and is covered on pressure release port;Metal sheet is used to generate corresponding deformation according to the pressure of metal sheet inside;Piezoelectric element is arranged on the inside surface of metal sheet, and piezoelectric element is used to form corresponding voltage according to the pressure generated inside battery;Insulating layer is covered on the surface of piezoelectric element;The input end of signal acquisition unit is connected with the output end of piezoelectric element, and signal acquisition unit is used to monitor the pressure of metal sheet inside according to the voltage generated by piezoelectric element. The utility model provides by setting piezoelectric element on the inside surface of metal sheet, realizes the real-time monitoring of the pressure change inside battery and can convert tiny pressure change into clear measurable electric signal.

Description

Technical Field

[0001] This utility model relates to the field of battery safety technology, and in particular to a lithium-ion battery pressure relief valve, battery cover, battery cell, and electrical device. Background Technology

[0002] With the widespread use of electronic devices and the development of portable devices, lithium-ion batteries have become one of the most mainstream battery types due to their advantages such as high energy density, long cycle life, and low self-discharge rate. However, during use, lithium-ion batteries may experience a sharp increase in internal pressure due to abnormal conditions such as overcharging, over-discharging, short circuits, or high temperatures, leading to safety accidents. Therefore, the safety of lithium-ion batteries has always been a focus of industry attention.

[0003] Currently, lithium-ion batteries typically employ a pressure relief valve structure to handle abnormally high internal pressure. Traditional pressure relief valves primarily work by creating a pressure relief hole in the battery casing or top cover, and sealing this hole with a pressure relief plate. When the internal pressure of the battery reaches a certain threshold, the pressure relief plate ruptures, releasing internal gas and preventing the battery from exploding. Utility Model Content

[0004] To address the lack of monitoring functionality in the existing pressure relief valves, this invention provides a lithium-ion battery pressure relief valve, a battery cover, a battery cell, and an electrical device.

[0005] In a first aspect, this utility model provides a lithium-ion battery pressure relief valve, which includes a metal sheet, a piezoelectric element, an insulating layer, and a signal acquisition unit;

[0006] The edge of the metal sheet is fixedly connected to the battery casing and covers the pressure relief port; the metal sheet is used to generate corresponding deformation according to the pressure inside the metal sheet;

[0007] The piezoelectric element is disposed on the inner surface of the metal sheet, and the piezoelectric element is used to generate a corresponding voltage according to the pressure generated inside the battery;

[0008] The insulating layer is applied to the surface of the piezoelectric element;

[0009] The input terminal of the signal acquisition unit is connected to the output terminal of the piezoelectric element, and the signal acquisition unit is used to monitor the pressure inside the metal sheet based on the voltage generated by the piezoelectric element.

[0010] In one embodiment of the present invention, the inner surface of the metal sheet is provided with grooves, which break under a preset pressure.

[0011] In one embodiment of the present invention, the inner surface of the metal sheet is divided into several concentric ring regions along the radial direction;

[0012] The plurality of concentric ring regions are adjacent to each other and do not overlap, including:

[0013] A first concentric ring region, on which a first engraving is provided;

[0014] The second concentric ring region is provided with a piezoelectric element.

[0015] The third concentric ring region has a second groove.

[0016] In one embodiment of this utility model, the first scratch breaks under a first preset pressure, and the second scratch breaks under a second preset pressure; the first preset pressure is less than the second preset pressure.

[0017] In one embodiment of this utility model, the depth of the first groove is greater than the depth of the second groove.

[0018] In one embodiment of this utility model, with the normal direction of the horizontal plane where the metal sheet is located as the top view direction, the area of ​​the second concentric ring region is larger than the area of ​​the first concentric ring region when viewed from the top view direction.

[0019] In one embodiment of this utility model, with the normal direction of the horizontal plane where the metal sheet is located as the top view direction, the area of ​​the third concentric ring region is larger than the area of ​​the second concentric ring region when viewed from the top view direction.

[0020] Secondly, this utility model provides a battery cover plate, which includes the lithium-ion battery pressure relief valve as described above.

[0021] Thirdly, this utility model provides a battery cell, which includes the battery cover plate as described above.

[0022] Fourthly, this utility model provides an electrical device, which includes a battery cell as described above.

[0023] Based on the above, compared with the prior art, the lithium-ion battery pressure relief valve provided by this utility model has at least one of the following beneficial technical effects:

[0024] Firstly, by placing the piezoelectric element on the inner surface of the metal sheet, real-time monitoring of internal pressure changes in the battery is achieved; the piezoelectric ceramic film has high sensitivity and good linear response characteristics, which can convert minute pressure changes into clear and measurable electrical signals.

[0025] Secondly, the insulating layer effectively prevents the electrolyte from corroding the piezoelectric ceramic film, ensuring stable transmission of electrical signals;

[0026] Thirdly, the metal sheet can deform rapidly when the pressure exceeds the limit, opening the pressure relief channel and releasing the excess pressure inside the battery, thereby protecting the battery from damage.

[0027] Other features and beneficial effects of this invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other beneficial effects of this invention can be realized and obtained through the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0028] 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, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0029] Figure 1 The diagram shown is a structural schematic of the pressure relief valve provided in the first embodiment of this utility model;

[0030] Figure 2 The figures shown are a cross-sectional view (top) and a bottom view (bottom) of the pressure relief valve provided in the second embodiment of this utility model.

[0031] Figure 3 The figures shown are a cross-sectional view (top) and a bottom view (bottom) of the metal sheet provided in the second embodiment of this utility model.

[0032] Figure 4 The diagram shown is a structural schematic of the battery cover provided in the fourth embodiment of this utility model.

[0033] Figure label:

[0034] 10. Metal sheet; 11. First concentric ring region; 111. First notch; 12. Second concentric ring region; 13. Third concentric ring region; 131. Second notch; 20. Piezoelectric element; 30. Insulating layer; 40. Battery casing; 100. Battery cover; 110. Positive electrode post; 120. Negative electrode post; 130. Lithium-ion battery pressure relief valve. Detailed Implementation

[0035] In the description of this utility model, it should be noted that all terms used in this utility model (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model pertains, and should not be construed as limiting this utility model; it should be further understood that the terms used in this utility model should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this utility model.

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0037] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] Please see Figure 1The first embodiment of this utility model provides a lithium-ion battery pressure relief valve, which includes a metal sheet 10, a piezoelectric element 20, an insulating layer 30, and a signal acquisition unit (not shown in the figure).

[0041] When the internal pressure of the lithium-ion battery changes, the piezoelectric element 20 generates electrical signals of varying intensities in response to the pressure change. The signal acquisition unit converts these electrical signals into digital signals and transmits them to the control system. This process enables real-time monitoring of changes in the internal pressure of the battery. If the pressure exceeds a preset safety threshold, it triggers the deformation of the metal sheet 10, opening the pressure relief channel and releasing excess pressure inside the battery, thereby protecting the battery from damage.

[0042] In this embodiment, the metal sheet 10 may be made of high-strength stainless steel or aluminum alloy, with a thickness of approximately 0.3 mm, and is circular or square in shape, matching the shape of the battery cover 100, and is used to generate corresponding deformation according to the pressure on the inner side of the metal sheet 10. In a preferred embodiment of this utility model, the middle part of the metal sheet 10 is designed as a deformable region, and the thickness of this region is slightly thinner than other regions, so that it can quickly undergo elastic or plastic deformation when the pressure exceeds the limit.

[0043] In this embodiment, the edge of the metal sheet 10 is fixedly connected to the battery casing 40 and covers the pressure relief port; for example, the metal sheet 10 can be tightly bonded to the battery cover plate 100 by laser welding technology to form a sealed pressure relief valve. When the internal pressure of the battery exceeds the pressure relief threshold of the pressure relief valve, the deformable area of ​​the metal sheet 10 deforms under pressure, opening the pressure relief valve and allowing excess gas inside the battery to be discharged through the pressure relief valve, rapidly reducing the internal pressure and temperature of the battery.

[0044] In this embodiment, the piezoelectric element 20 is disposed on the inner surface of the metal sheet 10. The piezoelectric element 20 is used to generate a corresponding voltage according to the pressure generated inside the battery. Specifically, the piezoelectric element 20 can be a piezoelectric ceramic film made of lead zirconate titanate (PZT) based material with a thickness of approximately 0.5 mm. PZT material has high sensitivity and good linear response characteristics, which can convert minute pressure changes into clear and measurable electrical signals, and is also easy to process. The piezoelectric ceramic film is circular or square, and its edges are tightly bonded to the metal sheet 10 with conductive silver paste to ensure effective transmission of electrical signals. Its working principle is based on the piezoelectric effect. When the internal pressure of the battery acts on the piezoelectric ceramic film, the crystal lattice deforms, and the two poles generate a charge signal proportional to the pressure, realizing real-time pressure monitoring. Under the condition of repeated internal pressure of the battery, the safety of the PZT piezoelectric ceramic film depends critically on its excellent fatigue resistance and the durability of the material itself. Given that the internal pressure of a battery typically remains at a low level of 0-100 kPa during normal operation, the opening pressure of the pressure relief valve is set at 0.9-1 MPa, while the actual working pressure range of the PZT membrane as a pressure sensor is controlled within 1 MPa. This reasonable working pressure range ensures that the PZT membrane remains in a safe state far below its fatigue limit (79.1 MPa) during long-term use, thereby guaranteeing its stable and reliable operation inside the battery and providing strong support for battery safety monitoring.

[0045] In this embodiment, the insulating layer 30 is deposited on the surface of the piezoelectric element 20. Specifically, the insulating layer 30 is made of polyimide (PI) material, with a thickness of approximately 50 to 100 micrometers, and uniformly covers the outer surface of the piezoelectric element 20. PI material has excellent high-temperature resistance, chemical corrosion resistance, and high electrical insulation properties, enabling it to operate stably for a long time in the harsh electrolyte environment inside the battery. This effectively prevents the electrolyte from corroding the piezoelectric element 20, while ensuring stable transmission of electrical signals and avoiding signal leakage or interference.

[0046] In this embodiment, the input terminal of the signal acquisition unit is connected to the output terminal of the piezoelectric element 20. The signal acquisition unit is used to monitor the pressure inside the metal sheet 10 based on the voltage generated by the piezoelectric element 20. Specifically, the signal acquisition unit includes a high-precision analog front-end (AFE) circuit and an analog-to-digital converter (ADC). The AFE circuit amplifies and filters the weak electrical signal generated by the piezoelectric ceramic film to improve the signal-to-noise ratio. The ADC converts the processed analog signal into a digital signal for subsequent digital signal processing. The signal acquisition unit is powered by the power management circuit inside the battery to ensure that it can continuously and stably acquire pressure signals during battery operation.

[0047] In a preferred embodiment of this invention, the integration of the lithium-ion battery pressure relief valve and the battery cover 100 employs precision laser welding technology. Furthermore, the junction between the metal sheet 10 and the battery cover 100 is designed with a special sealing structure, such as an O-ring or gasket, further enhancing the sealing performance of the pressure relief valve. This design not only improves the structural stability of the pressure relief valve but also ensures that it will not fail due to leakage during long-term use. The shape and size of the metal sheet 10 are optimized according to the internal pressure relief requirements of the battery to ensure that it can deform rapidly and reliably when the preset pressure is reached, achieving the pressure relief function and ensuring that the pressure relief valve can quickly and effectively release internal pressure in emergency situations.

[0048] Furthermore, the various parts are electrically connected and mechanically fixed through methods such as conductive silver paste, laser welding, or threaded connections. Preferably, the piezoelectric element 20 and the metal sheet 10 are coated with an adhesive for bonding and fixing, such as conductive silver paste, to achieve electrical connection and ensure effective transmission of electrical signals. The metal sheet 10 and the battery cover 100 are mechanically fixed and sealed through laser welding technology. The signal acquisition unit is connected to the piezoelectric ceramic membrane through wires to acquire electrical signals and transmit them to the control system. This linkage method ensures that the piezoelectric ceramic membrane can monitor changes in the internal pressure of the battery in real time, and achieve pressure relief through the deformation of the metal sheet 10 when the pressure exceeds the limit, while transmitting the pressure signal to the control system for analysis and processing.

[0049] Please see Figures 1 to 2 In the second embodiment of this utility model, a lithium-ion battery pressure relief valve is provided, the pressure relief valve including a metal sheet 10, a piezoelectric element 20, an insulating layer 30 and a signal acquisition unit;

[0050] In this embodiment, the inner surface of the metal sheet 10 is provided with grooves, which break under a preset pressure. Specifically, the inner surface of the metal sheet 10 is divided into several concentric ring regions along the radial direction; the several concentric ring regions are adjacent to each other and do not overlap, and the common center of the multiple concentric ring regions is located at the center of the metal sheet 10. Please refer to [reference needed] for details. Figure 2 The region, after being divided into areas, includes: a first concentric ring region 11, a second concentric ring region 12, a third concentric ring region 13, and a fourth concentric ring region; wherein, the first concentric ring region 11 is provided with a first groove 111; the second concentric ring region 12 is provided with a piezoelectric element 20; the third concentric ring region 13 is provided with a second groove 131; and the fourth concentric ring region is used for fixed connection with the battery casing 40.

[0051] Currently, the mainstream method uses a single concentrated area of ​​grooves. If this area has manufacturing defects (such as uneven groove depth or material impurities), abnormal local stress (such as minor deformation during installation), or media corrosion, it may rupture before reaching the preset pressure, or fail to rupture when the pressure reaches the standard ("stuck"), directly causing the pressure relief function to fail.

[0052] In the second embodiment, two or more regions of the first concentric ring region 11 and the third concentric ring region 13 are marked (inner side + outer side) to form a redundant design. With this design, even if one region fails due to the above-mentioned problem, the other region can still rupture normally under the preset pressure, ensuring that the pressure relief function is not interrupted. In addition, the two regions are subjected to force independently, and the impact of local abnormalities on the whole is dispersed, reducing the probability of functional failure caused by accidental factors.

[0053] Meanwhile, under pressure, the grooved areas of the metal sheet 10 become weak points where stress concentrates. A groove in a single concentrated area will concentrate all stress in a ring-shaped region, potentially causing premature breakage (i.e., "premature breakage") because the local stress peak exceeds the design threshold (even if the overall system pressure does not meet the standard). Multiple grooved areas, however, disperse stress. When pressure is applied to the metal sheet 10, stress is simultaneously transmitted to both the inner and outer grooved areas, preventing excessive stress concentration in a single area. The formation of multiple weak points through multiple ring-shaped grooved areas results in a more uniform stress distribution, and the breakage timing is closer to the preset pressure (rather than premature action due to abnormal local stress), improving the accuracy of pressure control.

[0054] Preferably, the first notch 111 breaks under a first preset pressure, and the second notch 131 breaks under a second preset pressure; the first preset pressure is less than the second preset pressure. For details, please refer to... Figure 3 The depth of the first notch 111 is greater than the depth of the second notch 131. By setting the first notch 111 and the second notch 131 of different depths on the metal sheet 10, the gradient pressure relief area control of the internal gas pressure of the battery is achieved. When the internal gas pressure of the battery is greater than the first preset pressure, the first notch 111 breaks and begins to relieve pressure, and the gas begins to relieve pressure through the pressure relief port formed by the breakage of the first notch 111. When the internal gas pressure of the housing is greater than the second preset pressure, the second notch 131 breaks and begins to relieve pressure. At this time, the gas can be relieved through the pressure relief ports formed by the first notch 111 and the second notch 131 respectively.

[0055] It should be noted that the shape of the grooves on the outer surface of the metal film in the above embodiments can be ring-shaped, straight, arc-shaped, or other different shapes. The grooves can cover the entire concentric ring area or only partially cover the concentric ring area.

[0056] In the third embodiment of this utility model, a lithium-ion battery pressure relief valve is provided, the pressure relief valve including a metal sheet 10, a piezoelectric element 20, an insulating layer 30 and a signal acquisition unit;

[0057] Compared to the second embodiment, in this embodiment, with the normal direction of the horizontal plane where the metal sheet 10 is located as the top view direction, the area of ​​the second concentric ring region 12 is larger than the area of ​​the first concentric ring region 11; with the normal direction of the horizontal plane where the metal sheet 10 is located as the top view direction, the area of ​​the third concentric ring region 13 is larger than the area of ​​the second concentric ring region 12.

[0058] It is worth noting that, firstly, the first concentric ring region 11 ruptures preferentially under low pressure (first preset pressure), preventing a rapid pressure rise through localized pressure relief. Since it is necessary to ensure that a certain amount of pressure is released after rupture (e.g., at least enough to control the system pressure within a safe range between the first and second preset pressures) to avoid insufficient pressure relief leading to a continuous pressure increase and forcing the outer ring to rupture prematurely (thus negating the purpose of staged pressure relief), and also to avoid a sudden increase in the pressure relief channel after rupture, causing a sharp drop in system pressure (exceeding the necessary range) and affecting normal equipment operation; therefore, the first concentric ring region 11 should be smaller than the second concentric ring region 12 and the third concentric ring region 13.

[0059] Secondly, the core function of the second concentric ring region 12 is to stably and accurately sense the system pressure through piezoelectric ceramics. Therefore, its area design must serve the purpose of measurement accuracy, and the pressure measurement of the piezoelectric element 20 depends on the uniform transmission of force on the internal surface of the battery. If the area of ​​the middle ring is too small, the contact area inside the ceramic battery will be insufficient, which may lead to increased measurement error due to local stress concentration (e.g., stress abrupt change at the edge after the inner ring breaks), and may even fail to reflect the true system pressure; while if it is too large, it will result in the metal pressure relief area being too small, making it difficult to fully relieve pressure.

[0060] Regarding the third concentric ring region 13, which is the outermost region, it has the advantage of having the largest usable area because it is located at the outermost edge of the metal sheet 10. That is, in the concentric ring structure, the area of ​​the outer ring = the area of ​​the outer circle - the area of ​​the middle ring. By increasing the radial width, the area can be significantly expanded, making it suitable for playing the role of efficient pressure relief. More importantly, the larger area of ​​the third concentric ring region 13 can reduce the pressure fluctuation of "secondary rupture": if the area of ​​the outer ring is too small, the pressure relief after rupture will be insufficient, which may cause the pressure to oscillate around the second preset pressure (repeatedly approaching the threshold), increasing the risk; while a large area can release enough medium at once, quickly reducing the pressure to a safe range.

[0061] Please see Figure 4The fourth embodiment of this utility model provides a battery cover 100, which is provided with conventionally arranged structures such as a positive terminal post 110, a negative terminal post 120, and a lithium-ion battery pressure relief valve 130. The lithium-ion battery pressure relief valve 130 is located in the middle of the battery cover 100.

[0062] like Figure 4 The schematic diagram of the lithium-ion battery cover shown depicts positive and negative terminals 110 and 120 located on opposite sides of the cover, connected to the internal electrodes of the battery, providing interfaces for power output and input to external circuits. A power management circuit connects to both terminals, drawing power from the battery to supply power to the main control circuit. The main control circuit, as the core control unit on the battery cover, is connected to the power management circuit, receives power from it, and monitors several key internal battery status indicators, including but not limited to pressure. The main control circuit is connected via signal lines to a pressure relief valve 130 located in the center of the battery cover and other sensors around it, receiving signals from the sensors and performing preliminary processing. Other structures within the battery cover described above are conventional techniques in this field, and those skilled in the art can adapt them according to existing technology; further details are omitted here.

[0063] In this embodiment, a high-safety, high-capacity LFP energy storage battery is selected, with a normal internal pressure range between 0-100 kPa. The piezoelectric paste uses a piezoelectric ceramic film made of lead zirconate titanate (PZT)-based material, with a precise thickness of 0.5 mm. The operating range of this piezoelectric element 20 can cover the entire process of the battery from normal state to abnormal pressure rise. It can generate an electrical signal proportional to the pressure within a pressure range of 0-300 kPa, and its sensitivity is as high as 0.1 V / kPa. It can convert pressure changes as small as 0.1 kPa into clear and measurable electrical signals, ensuring accurate monitoring of changes in the battery's internal pressure.

[0064] The pressure threshold set on the notch is a specific design parameter that needs to be determined based on the actual application scenario and safety requirements of the battery. The notch shape is usually V-shaped, U-shaped, or rectangular, with a depth generally between 1 / 3 and 1 / 2 of the piezoelectric ceramic film thickness, a length typically between a few millimeters and tens of millimeters, and a width of about 0.1mm to 0.5mm. In this embodiment, both the first notch 111 and the second notch 131 are X-shaped, and the surface depths covering their respective areas are 1 / 3 and 1 / 2 of the piezoelectric ceramic film thickness, respectively.

[0065] The metal sheet 10 is made of high-strength stainless steel, with a uniform thickness of 0.3 mm, and is circular with a diameter of 12 mm, matching the shape of the battery cover 100. The middle part of the metal sheet 10 is designed as a deformable area, and its thickness is reduced to 0.15 mm through machining to allow for rapid plastic deformation when the internal pressure of the battery exceeds 200 kPa. The metal sheet 10 and the battery cover 100 are joined using precision laser welding technology, with the welding depth precisely controlled at 0.1 mm and the welding width at 0.5 mm, forming a sealed and secure connection. Simultaneously, an O-ring is installed at the joint. The O-ring is made of fluororubber, which has excellent high-temperature resistance and chemical corrosion resistance, maintaining its sealing performance over a long period in the complex environment inside the battery and effectively preventing electrolyte leakage.

[0066] The analog front-end (AFE) circuit in the signal acquisition unit employs a high-precision operational amplifier to amplify the weak electrical signal generated by the piezoelectric ceramic film. The amplification factor is adjustable from 100 to 1000 times. Simultaneously, an active filter removes noise signals with frequencies higher than 1kHz. The analog-to-digital converter (ADC) has a 16-bit resolution and a sampling frequency of 10kHz, accurately converting the processed analog signal into a digital signal to ensure the control system's real-time and accurate judgment of the battery status.

[0067] The following describes the battery cell of an embodiment of this utility model.

[0068] A battery cell according to an embodiment of the present invention includes: a casing, an electrode core, and a battery cover.

[0069] The outer casing forms an open receiving cavity, within which the electrode core is housed. This allows the electrode core to be placed inside the outer casing, facilitating its protection, extending its service life, and enhancing its safety during use.

[0070] The battery cover is the aforementioned battery cover, and its specific structure will not be described in detail here. In summary, the battery cell of this embodiment of the present invention, by adopting the aforementioned battery cover, can, to a certain extent, ensure the working performance of the battery cell, enable the battery cell to operate for a long time, and ensure the safety of the battery cell in use.

[0071] It should be noted that the outer shell can be formed by stamping or welding, and the material of the outer shell can be aluminum or steel, etc.

[0072] The following describes the electrical device according to an embodiment of the present invention.

[0073] An electrical device according to an embodiment of the present invention includes: a plurality of battery cells.

[0074] Among them, the battery cell is the aforementioned battery cell, and the specific structure of the battery cell will not be described in detail here.

[0075] As can be seen from the above structure, the electrical device of this utility model, by adopting the aforementioned battery cell, is beneficial to improving the working performance of the electrical device and ensuring the safety of the electrical device in use.

[0076] It should be noted that the electrical devices mentioned here can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc.

[0077] Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; spacecraft can include airplanes, rockets, space shuttles, and spacecraft; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0078] In specific examples, the electrical device is formed into a vehicle such as an electric vehicle or an electric car, which can be powered by the aforementioned battery pack.

[0079] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of this utility model can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0080] Although this document frequently uses terms such as metal sheet, first concentric ring region, first notch, second concentric ring region, third concentric ring region, second notch, piezoelectric element, insulating layer, battery casing, battery cover, positive electrode post, negative electrode post, and lithium-ion battery pressure relief valve, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model. The terms "first," "second," etc. (if present) in the specification, claims, and accompanying drawings of the embodiments of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A pressure relief valve for a lithium-ion battery, characterized in that, The pressure relief valve includes a metal sheet, a piezoelectric element, an insulating layer, and a signal acquisition unit; The edge of the metal sheet is fixedly connected to the battery casing and covers the pressure relief port; the metal sheet is used to generate corresponding deformation according to the pressure inside the metal sheet; The piezoelectric element is disposed on the inner surface of the metal sheet, and the piezoelectric element is used to generate a corresponding voltage according to the pressure generated inside the battery; The insulating layer is applied to the surface of the piezoelectric element; The input terminal of the signal acquisition unit is connected to the output terminal of the piezoelectric element, and the signal acquisition unit is used to monitor the pressure inside the metal sheet based on the voltage generated by the piezoelectric element.

2. The lithium-ion battery pressure relief valve according to claim 1, characterized in that, The inner surface of the metal sheet is provided with grooves, which break under a preset pressure.

3. The lithium-ion battery pressure relief valve according to claim 2, characterized in that, The inner surface of the metal sheet is divided into several concentric ring regions along the radial direction; The plurality of concentric ring regions are adjacent to each other and do not overlap, including: A first concentric ring region, on which a first engraving is provided; The second concentric ring region is provided with a piezoelectric element. The third concentric ring region has a second groove.

4. The lithium-ion battery pressure relief valve according to claim 3, characterized in that, The first scratch breaks under a first preset pressure, and the second scratch breaks under a second preset pressure; the first preset pressure is less than the second preset pressure.

5. The lithium-ion battery pressure relief valve according to claim 4, characterized in that, The depth of the first notch is greater than the depth of the second notch.

6. The lithium-ion battery pressure relief valve according to claim 3, characterized in that, Viewed from above, with the normal direction of the horizontal plane where the metal sheet is located as the top view direction, the area of ​​the second concentric ring region is larger than the area of ​​the first concentric ring region.

7. The lithium-ion battery pressure relief valve according to claim 6, characterized in that, Viewed from above, with the normal direction of the horizontal plane where the metal sheet is located as the top view direction, the area of ​​the third concentric ring region is larger than the area of ​​the second concentric ring region.

8. A battery cover, characterized in that, The battery cover includes a lithium-ion battery pressure relief valve as described in any one of claims 1-7.

9. A single battery cell, characterized in that, The battery cell includes the battery cover as described in claim 8.

10. An electrical device, characterized in that, The electrical device includes the battery cell as described in claim 9.

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