A single cell and a battery device

Abstract

The application discloses a single battery and a battery device, which comprise a battery shell and a battery core. The battery shell has a battery cavity for accommodating the battery core. One end surface of the battery shell is provided with a pressure relief part. The pressure relief part comprises a pressure relief area. When the battery cavity reaches a pressure relief pressure, the pressure relief area opens the pressure relief. The battery core comprises a battery core body and a tab part extending from at least one end of the battery core body. The battery core body comprises a pole piece. In a first direction, the total thickness of the battery core body is d mm. In a second direction, the minimum distance between one end of the pole piece facing the pressure relief area and the pressure relief area is h mm. The range of h / d is 0.02-0.25. The application can ensure that the single battery can timely release pressure and smoothly exhaust when thermal runaway occurs, avoid excessive gas production and unsmooth exhaust, prevent the pressure relief port from being blown open, and affect the safety of adjacent single batteries. Meanwhile, the energy density of the single battery can be ensured, and the endurance of the battery can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a single cell battery and a battery device. Background Technology

[0002] As new energy batteries continue to pursue higher energy density and faster charging speeds, safety risks are becoming increasingly prominent. Specifically, if a single battery cell experiences pressure leakage, its high energy density can trigger rapid thermal runaway. The high-temperature, high-pressure gas generated by this rapid thermal runaway cannot be depressurized in time, ultimately leading to a greater risk of thermal runaway.

[0003] Therefore, how to effectively depressurize, prevent greater heat spread, and improve the safety of battery systems is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a single cell battery that can release pressure in a timely manner to avoid a greater risk of thermal runaway;

[0005] Another object of this application is to provide a battery device having the above-mentioned single cell.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] The first aspect of this application provides a single battery cell, including a battery casing and a battery cell. The battery casing has a battery cavity for accommodating the battery cell. One end face of the battery casing is provided with a pressure relief portion, which includes a pressure relief area. The pressure relief area is configured to open and release pressure when the battery cavity reaches a pressure relief pressure.

[0008] The battery cell includes a battery cell body and an electrode tab extending from at least one end of the battery cell body. The battery cell body includes an electrode sheet. Along a first direction, the total thickness of the battery cell body is d mm. Along a second direction, the minimum distance between the end of the electrode sheet facing the pressure relief area of ​​the pressure relief section and the pressure relief area is h mm. The range of h / d is 0.02~0.25.

[0009] The first direction is perpendicular to the large surface of the battery cell, and the second direction is the arrangement direction of the battery cell and the pressure relief part.

[0010] The single-cell battery provided by the above technical solution selects an h / d value within the range of 0.02 to 0.25. This avoids the problem of poor venting caused by an excessively small h / d value, and also avoids the problem of low energy density caused by an excessively large h / d value. The single-cell battery provided in this application, by controlling the relationship between the distance between the electrode and the pressure relief area and the thickness of the cell, ensures timely pressure relief and smooth venting during thermal runaway. This prevents excessive gas production and poor venting, which could lead to the pressure relief port bursting and affecting the safety of adjacent single-cell batteries, thus avoiding a greater risk of thermal runaway. Simultaneously, it also ensures the energy density of the single-cell battery and improves battery life.

[0011] A second aspect of this application provides a battery device including a base plate and a single cell disposed on the base plate, the single cell being a single cell as described in any of the preceding claims.

[0012] The battery device provided in this application has the aforementioned single cell, and therefore also has the aforementioned single cell, which will not be described again in this application. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the end face of a battery cell with a pressure relief portion disclosed in the embodiments of this application;

[0015] Figure 2 for Figure 1 Sectional view along line AA;

[0016] Figure 3 for Figure 2 A magnified view of part A in the image;

[0017] Figure 4 for Figure 1 Sectional view along line BB;

[0018] Figure 5 for Figure 4 A magnified view of part B in the image;

[0019] Figure 6 This is a schematic diagram of the pressure relief section disclosed in the embodiments of this application;

[0020] Figure 7 This is a diagram showing the positional relationship between the battery cell and the pressure relief section as disclosed in the embodiments of this application;

[0021] Figure 8 This is a diagram showing the positional relationship between the battery cell and the pressure relief section, as disclosed in another embodiment of this application.

[0022] Figure 9 This is an exploded view of the battery cell and insulating board disclosed in the embodiments of this application;

[0023] The meanings of the various reference numerals in the figure are as follows:

[0024] 100-Battery casing;

[0025] 200 - Pressure relief section; 201 - Pressure relief area; 2011 - Reinforcement section; 202 - Score;

[0026] 300 - Cell; 301 - Electrode; 302 - Separator; 303 - Tab;

[0027] 400 - Insulation board; 401 - Insulation bump; 402 - Exhaust area. Detailed Implementation

[0028] This application discloses a single-cell battery that can release pressure in a timely manner to avoid a greater risk of thermal runaway.

[0029] This application also discloses a battery device having the above-described single cell.

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] The battery casing of a single battery cell is equipped with a pressure relief section, and the battery cell is located inside the battery cavity of the casing. Due to abnormal conditions such as overcharging, overheating, or short circuit of the battery cell, a large amount of gas will be generated inside the battery cavity. When the pressure inside the battery cavity rises to a set threshold, the gas pressure will cause the pressure relief section to open, allowing the high-pressure gas inside the battery cavity to be released, thereby preventing the battery from exploding or rupturing due to excessive pressure.

[0032] In thermal runaway scenarios, the activation of the pressure relief section can effectively release the high pressure inside the battery cavity, preventing individual cells from exploding. However, for high-energy-density batteries, excessive internal pressure during thermal runaway may cause excessive damage to the pressure relief port and its surrounding casing during pressure relief, resulting in high-temperature ejected materials being sprayed towards other parts of the battery pack or other individual cells.

[0033] Research indicates that a key reason for rapid thermal runaway and violent flame eruptions in individual cells lies in inadequate pressure relief and insufficient structural strength around the pressure relief port. If the battery casing cannot withstand the pressure after the pressure relief port opens, the burst area will be too large, spraying high-temperature materials to other parts of the individual cell and other cells in the battery pack, endangering the safety of adjacent cells.

[0034] Based on this, embodiments of this application disclose a single-cell battery to reduce the impact on the safety of adjacent single-cell batteries in the event of thermal runaway.

[0035] like Figures 1-5 As shown, the single battery disclosed in this application embodiment includes a battery case 100 and a battery cell 300. The battery case 100 has a battery cavity, and the battery cell 300 is disposed in the battery cavity of the battery case 100.

[0036] The battery casing 100 is an external protective structure for the battery cell 300, used to house the battery cell 300 and isolate it from the external environment. The battery casing 100 is mainly made of metals such as aluminum, iron, and steel. Typically, the battery casing 100 includes a battery casing body and a battery cover plate encapsulated at the open end of the battery casing body. One end of the battery casing body is an open end to facilitate the installation of the battery cell 300 inside the battery casing 100 through this opening. To seal the opening of the battery casing body, the battery casing 100 also includes a battery cover plate disposed on the opening of the battery casing body. That is, the battery cover plate is a component that covers the opening of the battery casing body to isolate the housing space of the battery cell 300 from the external environment. The shape of the battery cover plate can be adapted to the shape of the battery casing body to fit the battery casing. The cover plate can be made of a material with a certain hardness and strength (such as aluminum alloy). The pressure relief part 200 can be disposed on the battery cover plate or on the battery casing body.

[0037] The battery casing 100 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. The shape of the battery casing 100 can be determined according to the specific shape and size of the battery cell 300. The battery casing 100 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0038] A pressure relief section 200 is provided on one end face of the battery casing 100. It should be noted that the pressure relief section 200 can be formed directly on one end face of the battery casing 100, or it can be connected to the corresponding end face of the battery casing 100. If the pressure relief section 200 is connected to one end face of the battery casing 100, a pressure relief port needs to be provided on the corresponding end face of the battery casing 100, and the pressure relief section 200 is connected to the pressure relief port to seal it. The connection method can be welding or other connection methods.

[0039] The pressure relief section 200 may include a pressure relief area 201, which is configured to open and release pressure when the internal pressure of the battery case 100 is reached. A notch 202 may be provided on the pressure relief area 201. When the internal pressure of the battery case 100 is reached, the notch 202 breaks, causing the pressure relief area 201 to open and release pressure. When a large amount of gas is generated inside a single battery cell due to abnormal conditions such as overcharging, overheating, or short circuit, causing the internal pressure to rise to a certain level, the pressure generated by the gas will cause the notch 202 to break, causing the pressure relief area 201 to detach from or bend on the battery case 100, thus forming a pressure relief port on the battery case 100 to release the pressure inside the battery case 100.

[0040] It should be noted that the notch 202 may be omitted, and the pressure relief area 201 may be thinned to make the pressure relief area 201 thinner, so that when the pressure relief pressure is reached inside the battery case 100, the pressure relief area 201 can burst open.

[0041] The battery cell 300 includes a battery cell body and an electrode tab 303 extending from at least one end of the battery cell body. The battery cell body includes an electrode 301, which includes a current collector and an active material coated on at least one surface thereon.

[0042] The electrode 301 of the battery cell generally includes a positive electrode and a negative electrode, with a separator between them. The battery cell is composed of the positive electrode, the negative electrode, and the separator 302 (e.g., Figure 7 and Figure 8 (As shown) is formed by winding or stacking. The positive electrode sheet includes a positive current collector and a positive active material. The positive current collector can be made of metal materials such as aluminum foil, nickel foil, and stainless steel, or a composite foil formed by combining metals and insulating materials. The positive active material includes the positive active material, conductive agent, binder, etc. The positive active material includes one or more of lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0043] Similarly, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector can be made of metal materials such as copper foil, aluminum foil, and stainless steel, or it can be a composite foil material formed by combining metals and insulating materials. The negative electrode active material includes the negative electrode active material, conductive agent, binder, etc. The negative electrode active material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0044] The separator 302 is an insulating membrane disposed between the positive electrode and the negative electrode to prevent electrons from passing through while allowing ions to pass through. The material of the separator 302 includes at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, etc.

[0045] Along the first direction, the total thickness of the cell body is dmm. When there is one cell 300 in the battery cavity, the total thickness is the thickness of one cell 300; when there are multiple cells 300 in the battery cavity, the total thickness is the sum of the thicknesses of the multiple cells 300.

[0046] The first direction is perpendicular to the large surface of the cell. That is, the single cell is a prismatic cell, and the cell is folded into a rectangular structure inside the cell casing 100. Along the first direction, the greater the thickness of the cell, the greater the energy density of the single cell.

[0047] like Figure 7 As shown, along the second direction, the minimum distance between the end of the electrode 301 facing the pressure relief region 201 and the pressure relief region 201 is hmm. The second direction is the arrangement direction of the cell body and the pressure relief section 200. The electrode 301 typically includes a positive electrode and a negative electrode. The minimum distance between the electrode 301 and the pressure relief region 201 refers to the distance between the positive electrode and the pressure relief region 201 and the electrode closest to it. The minimum distance hmm between the end of the electrode 301 facing the pressure relief region 201 and the pressure relief region 201 reflects the smoothness of venting during thermal runaway. The larger hmm is, the greater the height of the venting channel, the smoother the venting, and the less likely the pressure relief port of the pressure relief section 200 is to burst. The smaller hmm is, the smaller the height of the venting channel, the larger the volume of the cell 300, the higher the energy density of the single cell, and the longer the battery life.

[0048] Furthermore, when the pressure relief area 201 is provided with a notch 202, the distance between the end of the electrode 301 facing the pressure relief area 201 and the pressure relief area 201 should be the distance between the electrode 301 and the thinnest part of the pressure relief area 201 (i.e., the position of the notch 202).

[0049] The single-cell battery disclosed in this application selects the h / d ratio within the range of 0.02 to 0.25. This avoids both the problem of poor venting caused by an excessively small h / d value and the problem of low energy density caused by an excessively large h / d value. The single-cell battery provided in this application, by controlling the relationship between the distance between the electrode 301 and the pressure relief region 201 and the thickness of the cell, ensures timely pressure relief and smooth venting during thermal runaway. This prevents excessive gas production and poor venting, which could lead to the pressure relief port bursting and affecting the safety of adjacent single-cell batteries, thus avoiding a greater risk of thermal runaway. Simultaneously, it also ensures the energy density of the single-cell battery and improves battery life.

[0050] For example, h / d can be 0.02, 0.05, 0.07, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of h / d within the range of 0.02 to 0.25 according to their needs.

[0051] In a specific embodiment of this application, the value of dmm can range from 20mm to 100mm. For example, dmm can be 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose a specific value of dmm within the range of 20mm to 100mm according to their needs.

[0052] In a specific embodiment of this application, the value of hmm can range from 1.5mm to 5mm. For example, hmm can be 1.5mm, 1.7mm, 1.9mm, 2.2mm, 2.4mm, 2.8mm, 3.1mm, 3.3mm, 3.5mm, 3.7mm, 4mm, 4.3mm, 4.6mm, 4.8mm, 5mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of hmm within the range of 1.5mm to 5mm according to their needs.

[0053] In one specific embodiment of this application, along the first direction, the ratio of the thickness of the tab 303 to the thickness of the battery cell can be 0.08 to 0.4. That is, in this embodiment, the width of the tab 303 reflects its current-carrying capacity. Specifically, the wider the tab 303, the stronger its current-carrying capacity. The ratio of the width of the tab 303 to the thickness of the battery cell is selected within the range of 0.08 to 0.4, meaning the width of the tab 303 is directly proportional to the thickness of the battery cell. A thicker battery cell indicates a higher energy density per cell, thus requiring a wider tab 303 to ensure sufficient current-carrying capacity.

[0054] For example, the ratio of the thickness of the tab 303 to the thickness of the battery cell can be 0.08, 0.1, 0.13, 0.16, 0.18, 0.2, 0.24, 0.28, 0.3, 0.33, 0.36, 0.4, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above thickness ratio within the range of 0.08 to 0.4 according to their needs.

[0055] When the battery cell is a wound cell, the area ratio k at the corner of the battery cell satisfies 0.02≤k≤0.08. It should be noted that the above area ratio refers to the ratio of the cross-sectional area of ​​the battery cell, or the ratio of the projected area of ​​the battery cell on the end face of the battery casing 100.

[0056] The cross-section of a wound battery cell includes straight segments and curved segments connecting two straight segments (i.e., corners). The area ratio k at the corners refers to the ratio of the sum of the areas at the corners at both ends of the battery cell to the total cross-sectional area of ​​the battery cell.

[0057] Stress concentration occurs at the corners of the wound cell, resulting in significant gas production. If k is too large, the internal gas production will be too high, preventing timely venting. In this embodiment, k is in the range of 0.02 to 0.08, which avoids the problem of insufficient venting due to excessive gas production and prevents excessive internal pressure in the battery. It also avoids the problem of short circuits caused by insufficient k at the corners of the wound cell, leading to contact between the positive and negative electrodes.

[0058] For example, k can be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can choose any specific value of k in the range of 0.02 to 0.08 according to their needs.

[0059] When the cell body is a laminated cell, the electrode 301 of the laminated cell includes a positive electrode and a negative electrode. The positive electrode includes at least two discontinuous sub-positive electrodes, and the negative electrode includes at least two discontinuous sub-negative electrodes. The tab portion 303 includes a positive tab electrically connected to the positive electrode and a negative tab electrically connected to the negative electrode.

[0060] like Figure 8 As shown, along the third direction, the ratio of the width of the positive electrode tab to the width of the positive electrode plate is 0.3 to 1. For example, the ratio of the width of the positive electrode tab to the width of the positive electrode plate can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the ratio within the range of 0.3 to 1 according to their needs.

[0061] Correspondingly, along the third direction upwards, the ratio of the width of the negative electrode tab to the width of the negative electrode sheet is 0.3 to 1. For example, the ratio of the width of the negative electrode tab to the width of the negative electrode sheet can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. It should be noted that the above values ​​are merely specific examples, and those skilled in the art can arbitrarily choose the specific value of the ratio within the range of 0.3 to 1 according to their needs.

[0062] The third direction is perpendicular to both the first and second directions. In this embodiment, the ratio of the width of the positive tab to the width of the positive electrode plate, and the ratio of the width of the negative tab to the width of the negative electrode plate, are designed to be 0.3 to 1, ensuring that the positive and negative tabs have appropriate widths to guarantee overcurrent capacity. As the parts connecting the battery cell to the external circuitry, wider positive and negative tabs mean a larger heat dissipation area. Heat generated inside the battery cell can be transferred to the outside of the battery cell more quickly through the larger surface area of ​​the positive and negative tabs, and then dissipated.

[0063] like Figure 9 As shown, an insulating bump 401 is provided between the end face of the battery casing 100 with the pressure relief section 200 and the battery cell, and at least one end face of the insulating bump 401 abuts against the battery cell. It should be noted that during thermal runaway of a single battery cell, a large amount of high-temperature, high-pressure gas is generated. This high-temperature, high-pressure gas needs to be discharged through the pressure relief section 200. The insulating bump 401 can guide the flow of these gases, causing the high-temperature, high-pressure thermal runaway gas to be discharged in a predetermined, safe direction, away from the battery casing or other critical components that may cause a short circuit.

[0064] The insulating bumps 401 create gaps between the end face of the battery casing 100 with the pressure relief portion 200 and the battery cell 300. These gaps serve as channels for the rapid discharge of thermal runaway gases. Compared to a design without insulating bumps 401, the inclusion of insulating bumps 401 increases the space and smoothness of gas flow, allowing thermal runaway gases to escape from the battery more quickly. Faster venting speed helps reduce excessive pressure inside the battery caused by the accumulation of thermal runaway gases, reducing the likelihood of extreme events such as battery explosions.

[0065] The greater the height of the insulating bump 401, the smoother the venting; the smaller the height of the insulating bump 401, the less space it occupies in the battery. In this embodiment, along the first direction, the ratio of the width of the insulating bump 401 to the thickness of the battery cell is 0.016 to 0.8.

[0066] For example, the ratio of the width of the insulating bump 401 to the thickness of the battery cell can be 0.016, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above ratio within the range of 0.016 to 0.8 according to their needs.

[0067] In this embodiment, the ratio is selected within the range of 0.016 to 0.8. This avoids the problem of excessive venting caused by the insulating bump 401 occupying too much venting space due to an excessively large ratio, and also avoids the problem of insufficient support strength of the insulating bump 401 due to an excessively small ratio.

[0068] To prevent the insulating bump 401 from melting and blocking gas exhaust after thermal runaway, in this embodiment, the melting point of the insulating bump 401 is 500℃~1000℃. This ensures that after battery thermal runaway, the insulating bump 401 does not melt or its melting rate is slowed down, allowing the thermal runaway gas to escape from the battery more quickly.

[0069] The insulating bump 401 can be made of one or more of the following materials: phenolic resin, stainless steel, aluminum alloy, nickel-based alloy, titanium alloy, etc.

[0070] Those skilled in the art can select materials with appropriate melting points to fabricate the insulating bump 401 according to their needs. For example, materials with melting points of 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, and 1000℃ can be selected to fabricate the insulating bump 401.

[0071] Furthermore, the distance between the insulating bump 401 and the edge of the battery cell is 0.5mm to 10mm. That is, the insulating bump 401 is not supported on either side of the edge of the battery cell, allowing an exhaust channel to be formed on either side of the insulating bump 401, resulting in better exhaust performance. In this embodiment, selecting a distance of 0.5mm to 10mm between the insulating bump 401 and the edge of the battery cell avoids both the problem of poor exhaust performance due to an excessively small distance and the problem of poor support for the battery cell due to an excessively large distance.

[0072] For example, the distance between the insulating bump 401 and the edge of the battery cell can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the distance between the insulating bump 401 and the edge of the battery cell within the range of 0.5mm to 10mm according to their needs.

[0073] Furthermore, the distance between the insulating bump 401 and the pressure relief area 201 should not be too close, as this would obstruct the flow of thermal runaway gas towards the pressure relief area 201. In this embodiment, the minimum distance between the insulating bump 401 and the pressure relief area 201 along the third direction is 30mm to 100mm; the third direction is perpendicular to the first and second directions respectively. When the single cell is a prismatic battery, the third direction is the length direction of the end face of the battery casing 100. The minimum distance between the insulating bump 401 and the pressure relief area 201 refers to the distance between the edge of the insulating bump 401 facing the pressure relief area 201 and the edge of the pressure relief area 201 facing the insulating bump 401 along the third direction. This setting can reduce the obstruction of thermal runaway gas by the insulating bump 401 while ensuring that the exhaust channel height in the area where the pressure relief area 201 is located is sufficient.

[0074] For example, the minimum distance between the insulating bump 401 and the pressure relief area 201 can be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the minimum distance between the insulating bump 401 and the pressure relief area 201 within the range of 30mm to 100mm according to their needs.

[0075] In one specific embodiment of this application, the ratio of the length of the insulating bump 401 to the length of the battery cell is 0.14 to 0.94 along the third direction. The larger the dimension of the insulating bump 401 in the third direction, the more stable the height of the exhaust channel supported by the insulating bump 401, but it will also occupy the space between the end face of the battery casing 100 and the battery cell. In this embodiment, selecting a ratio of the length of the insulating bump 401 to the length of the battery cell within the range of 0.14 to 0.94 along the third direction can reduce the occupation of exhaust space while ensuring the stability of the exhaust channel height. This avoids the problem of excessive occupation of the exhaust channel due to an excessively large ratio, which would affect the smoothness of exhaust; and also avoids the problem of a small supporting area and a low exhaust channel height in non-supported areas due to an excessively small ratio.

[0076] For example, the ratio of the length of the insulating bump 401 to the length of the battery cell can be 0.14, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.94, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above ratio within the range of 0.14 to 0.94 according to their needs.

[0077] Along the third direction upwards, the length of the insulating bump 401 can range from 20mm to 330mm. For example, the length of the insulating bump 401 can be 20mm, 30mm, 40mm, 50mm, 60mm, 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 200mm, 220mm, 240mm, 260mm, 280mm, 300mm, 330mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the length of the insulating bump 401 within the range of 20mm to 330mm according to their needs.

[0078] Along the third direction upwards, the length of the battery cell can range from 140mm to 350mm. For example, the length of the battery cell can be 140mm, 50mm, 160mm, 180mm, 200mm, 220mm, 240mm, 260mm, 280mm, 300mm, 320mm, 340mm, 350mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the battery cell length within the range of 140mm to 350mm according to their needs.

[0079] Cell 300 is the core component for generating and storing electrical energy, operating at high voltage. The battery casing 100 is typically made of metal and serves to protect the cell 300 and provide structural support. Under certain circumstances, such as when a single cell is subjected to vibration or pressure, cell 300 may come into contact with the battery casing 100, causing a short circuit. A short circuit can instantly generate a large current, potentially leading to serious safety incidents such as battery overheating, fire, or even explosion.

[0080] Based on this, such as Figure 5 and Figure 9 As shown in a specific embodiment of this application, an insulating plate 400 is provided between the end face of the battery casing 100 with the pressure relief portion 200 and the battery cell body. The insulating plate 400 can effectively block the conductive path between the battery cell 300 and the end face of the battery casing 100, avoiding such a dangerous situation. The insulating plate 400 can also typically act as a buffer, reducing the direct impact on the battery cell when the battery is subjected to external impact or vibration. When a single battery cell is impacted, the insulating plate 400 can absorb part of the impact force, reducing the risk of damage to the battery cell 300 due to vibration and impact, and extending the service life of the battery cell 300.

[0081] An insulating protrusion 401 is disposed on an insulating plate 400. The insulating protrusion 401 can be integral with the insulating plate 400, or it can be fixed to the insulating plate 400 by a fixing method. The fixing method is not limited to adhesive bonding, fastener connection, etc.

[0082] The insulating plate 400 can be made of PP (Polypropylene), PET (Polyethylene terephthalate), PPS (Polyphenylene sulfide), PI (Polyimide), etc.; the insulating bump 401 can be made of one or more of the following materials: stainless steel, aluminum alloy, nickel-based alloy, titanium alloy, etc., so that after the battery thermal runaway, the insulating bump 401 does not melt or slows down the melting rate, allowing the thermal runaway gas to escape from the battery more quickly.

[0083] Since the insulating plate 400 has a large dimension in the third direction, the positions of the insulating bumps 401 can be symmetrical about the center position of the pressure relief area 201 along the third direction to ensure more stable support for the battery cell. Only one insulating bump 401 may be provided, or multiple insulating bumps 401 may be provided; the number of insulating bumps 401 is not limited in this embodiment.

[0084] An exhaust zone 402 is provided in the area corresponding to the pressure relief zone 201 of the insulating plate 400. The thermal runaway gas between the insulating plate 400 and the cell 300 will pass through the exhaust zone 402, pass through the insulating plate 400, and be discharged into the pressure relief zone 201 on the battery case 100. Finally, the battery will be discharged through the area where the pressure relief zone 201 is located.

[0085] The exhaust zone 402 may include several through holes, that is, the exhaust zone 402 may include only one larger through hole (e.g., Figure 9 (As shown in the illustration), multiple small through holes arranged at intervals can also be opened in this area. This embodiment does not limit the way the exhaust zone 402 is opened, as long as thermal runaway gas can pass through.

[0086] Furthermore, the number of insulating bumps 401 is at least two, and at least two insulating bumps 401 are arranged along the third direction on both sides of the pressure relief region 201. In this embodiment, insulating bumps 401 are provided on both sides of the pressure relief region 201, which provides better support for the battery cell 300, so that thermal runaway gas on either side of the pressure relief region 201 can flow quickly to the pressure relief region 201 and be discharged through the pressure relief port of the pressure relief region 201.

[0087] like Figure 6As shown in a specific embodiment of this application, a reinforcing portion 2011 is provided on the inner periphery of the pressure relief region 201. That is, a reinforcing portion 2011 is provided within the boundary of the pressure relief region 201. The reinforcing portion 2011 protrudes from at least one surface of the pressure relief region 201 and can be formed in the pressure relief region 201 by stamping. The reinforcing portion 2011 can effectively enhance the mechanical strength of the pressure relief region 201, enabling it to withstand higher internal pressures. During the use of a single battery cell, especially under abnormal conditions (such as overcharging, over-discharging, short circuits, etc.), a large amount of gas is generated inside the battery, causing a sharp increase in pressure. The presence of the reinforcing portion 2011 prevents the pressure relief region 201 from deforming or rupturing when subjected to these high pressures, ensuring the sealing and stability of the pressure relief portion 200 under normal operating pressure. During the production, transportation, and daily use of the battery, it may be subjected to various external impacts or vibrations. The reinforcement section 2011 can also improve the ability of the pressure relief zone 201 to resist these external forces, reduce the risk of premature rupture of the pressure relief zone 201 due to accidental impact, and ensure that the pressure relief section 200 is only opened when it is really needed.

[0088] The reinforcing part 2011 can be obtained by bending through the pressure relief area 201. The reinforcing part 2011 can be a structure that protrudes towards the side of the battery cell or a structure that is recessed towards the side of the battery cell. Of course, the side of the pressure relief area 201 facing the battery cell can simultaneously include both the reinforcing part 2011 with a protruding structure and the reinforcing part 2011 with a recessed structure.

[0089] The design of the reinforcing section 2011 also allows for more precise control over the opening pressure of the pressure relief zone 201. By rationally designing the shape, size, and layout of the reinforcing section 201, the deformation mode and rupture timing of the pressure relief zone 201 under specific pressure can be adjusted. This ensures that when the internal pressure of the battery reaches a preset safety limit, the pressure relief zone 201 can accurately rupture and open, releasing internal gas and preventing serious damage to the battery or even safety accidents caused by excessive pressure.

[0090] In one specific embodiment of this application, the area of ​​the pressure relief zone 201 is 10 mm². 2 ~300mm 2 For example, the area of ​​the pressure relief zone 201 can be 10 mm². 2 30mm 2 50mm 2 70mm 2 90mm 2 100mm 2 120mm 2 140mm 2 160mm 2 180mm 2 200mm 2220mm 2 240mm 2 260mm 2 280mm 2 300mm 2 It should be noted that the above values ​​are merely specific examples, and those skilled in the art can adjust the values ​​according to their needs within 10mm. 2 ~300mm 2 The specific value of the area of ​​any pressure relief zone 201 within the range.

[0091] The ratio of the area of ​​the pressure relief region 201 to the total thickness of the battery cell is 0.2 to 12, in mm. For example, the ratio of the area of ​​the pressure relief region 201 to the total thickness of the battery cell can be 0.2 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above ratio within the range of 0.2 mm to 12 mm according to their needs.

[0092] In this embodiment, the ratio is selected within the range of 0.2mm to 12mm. This avoids the problem that the pressure relief port area is too large due to the ratio being too large, resulting in insufficient strength of the battery casing 100; and it also avoids the problem that the pressure relief port area is too small due to the ratio being too small, resulting in inability to release pressure in a timely manner.

[0093] In one specific embodiment of this application, the battery casing 100 includes a bottom surface, and a pressure relief portion 200 is disposed on the bottom surface of the battery casing 100. That is, the individual battery cell has a structure with the pressure relief portion protruding from the bottom, and pressure is relieved from the bottom of the battery. Since the individual battery cell is relieved from the bottom, the minimum distance between the electrode 301 and the notch 202 should be set to be larger. Those skilled in the art can appropriately increase the value of hmm based on the requirements, which can ensure that the exhaust channel has a greater height and reduce the impact of gravity on the height of the exhaust channel of the cell 300.

[0094] This application also discloses a battery device, which includes a base plate and a single battery cell disposed on the base plate. The single battery cell is the same as the one disclosed in the above embodiments. Since it has the aforementioned single battery cell, it possesses all the technical effects of the aforementioned single battery cell, which will not be repeated here. Furthermore, the end face of the battery casing 100 with the pressure relief portion 200 faces the base plate.

[0095] As illustrated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0096] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0097] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0098] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A single-cell battery, characterized in that, The battery includes a battery case (100) and a battery cell (300). The battery case (100) has a battery cavity for accommodating the battery cell (300). One end face of the battery case (100) is provided with a pressure relief section (200). The pressure relief section (200) includes a pressure relief area (201). The pressure relief area (201) is configured to open and release pressure when the battery cavity reaches the pressure relief pressure. The battery cell (300) includes a battery cell body and an electrode tab (303) extending from at least one end of the battery cell body. The battery cell body includes an electrode (301). Along a first direction, the total thickness of the battery cell body is d mm. Along a second direction, the end of the electrode (301) facing the pressure relief region (201) has a minimum distance of h mm from the pressure relief region (201). The range of h / d is 0.02 to 0.

25. The first direction is perpendicular to the large surface of the battery cell, and the second direction is the arrangement direction of the battery cell and the pressure relief part (200).

2. The single-cell battery as described in claim 1, characterized in that, dmm is 20mm~100mm; And / or, hmm is 1.5mm~5mm.

3. The single-cell battery as described in claim 2, characterized in that, Along the first direction, the ratio of the thickness of the tab (303) to the thickness of the battery cell is 0.08 to 0.

4.

4. The single-cell battery as described in claim 1, characterized in that, The battery cell is a wound battery cell, and the area ratio k at the corner of the battery cell satisfies 0.02≤k≤0.

08.

5. The single-cell battery as described in claim 1, characterized in that, The battery cell is a laminated battery cell, and the electrode (301) of the laminated battery cell includes a positive electrode and a negative electrode. The positive electrode includes at least two discontinuous sub-positive electrodes, and the negative electrode includes at least two discontinuous sub-negative electrodes.

6. The single-cell battery as described in claim 5, characterized in that, The tab portion (303) includes a positive tab electrically connected to the positive electrode plate and a negative tab electrically connected to the negative electrode plate; Along the third direction, the ratio of the width of the positive electrode tab to the width of the positive electrode plate is 0.3~1; Along the third direction, the ratio of the width of the negative electrode tab to the width of the negative electrode sheet is 0.3 to 1, and the third direction is perpendicular to the first direction and the second direction, respectively.

7. The single-cell battery as described in claim 1, characterized in that, An insulating protrusion (401) is provided between the end face of the battery case (100) with the pressure relief part (200) and the battery cell body, and at least one end face of the insulating protrusion (401) abuts against the battery cell body. Along the first direction, the ratio of the width of the insulating bump (401) to the thickness of the battery cell is 0.016 to 0.

8.

8. The single-cell battery as described in claim 7, characterized in that, The distance between the insulating bump (401) and the edge of the battery cell is 0.5mm to 10mm.

9. The single-cell battery as described in claim 7, characterized in that, Along the third direction upward, the minimum distance between the insulating bump (401) and the pressure relief area (201) is 30mm~100mm; The third direction is perpendicular to the first direction and the second direction, respectively.

10. The single-cell battery as described in claim 7, characterized in that, Along the third direction upward, the ratio of the length of the insulating bump (401) to the length of the battery cell is 0.14 to 0.94; The third direction is perpendicular to the first direction and the second direction, respectively.

11. The single-cell battery as described in claim 7, characterized in that, The melting point of the insulating bump (401) is 500℃~1000℃.

12. The single-cell battery as described in claim 7, characterized in that, An insulating plate (400) is provided between the end face of the battery case (100) with the pressure relief part (200) and the battery cell body, and the insulating protrusion (401) is provided on the insulating plate (400); Along the third direction, the position of the insulating bump (401) is symmetrical about the center position of the pressure relief area (201), and the third direction is perpendicular to the first direction and the second direction respectively.

13. The single-cell battery as described in claim 12, characterized in that, The number of insulating bumps (401) is at least two, and at least two insulating bumps (401) are arranged on both sides of the pressure relief area (201) in a third direction.

14. The single-cell battery according to any one of claims 1-13, characterized in that, The inner periphery of the pressure relief area (201) is provided with a reinforcing part (2011), which protrudes from at least one surface of the pressure relief area (201).

15. The single-cell battery as described in claim 1, characterized in that, The area of ​​the pressure relief zone (201) is 10 mm². 2 ~300mm 2 The ratio of the area of ​​the pressure relief zone (201) to the total thickness of the battery cell is 0.2 to 12, in mm.

16. The single-cell battery as described in claim 1, characterized in that, The battery casing (100) includes a bottom surface, and the pressure relief part (200) is disposed on the bottom surface of the battery casing (100).

17. A battery device, characterized in that, It includes a base plate and a plurality of individual cells disposed on the base plate, wherein the individual cells are the individual cells as described in any one of claims 1-16.

18. The battery device as claimed in claim 17, characterized in that, The end face of the battery casing (100) with the pressure relief part (200) faces the bottom plate.

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