Battery monomer, battery and electric device

Abstract

The utility model is applicable to the technical field of batteries, and provides a battery monomer, a battery and a power utilization device, the power utilization device comprises the battery, the battery comprises the battery monomer, and the battery monomer comprises a shell assembly, an electrode assembly and a central needle. The shell assembly is cylindrical. And the electrode assembly is arranged in the shell assembly. And the central needle is arranged at the center of the electrode assembly. The center needle is provided with a center hole which extends in the length direction of the center needle. The outer diameter of the shell assembly is 40 mm to 60 mm. And the length of the battery monomer is 200 to 400 mm. And the capacity of the battery monomer is 38Ah to 65Ah. And the aperture of the central hole is 4-8 mm. By arranging the center needle with the center hole, gas generated by the electrode assembly is exhausted through the center hole of the center needle, the exhaust effect of the electrode assembly is enhanced, and the risk that the gas generated by the electrode assembly is accumulated in the electrode assembly is reduced. And the safety performance of the battery monomer is enhanced while the energy density of the battery monomer is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery cell, a battery and an electrical device. Background Art

[0002] With the development of new energy, more and more fields are using new energy as power. Power batteries are widely used in new energy vehicles, consumer electronics, energy storage systems and other fields.

[0003] As the size of battery cells increases, the capacity of battery cells also increases, and the gas production volume and gas production rate during thermal runaway of the electrode assembly will also increase at the same time. The gas generated by the electrode assembly has the risk of accumulating inside the electrode assembly, affecting the exhaust effect of the electrode assembly and further affecting the safety performance of the battery cells. Utility Model Content

[0004] In view of this, the embodiments of the present application hope to provide a battery cell, a battery, and an electrical device, aiming to improve the energy density of the battery cell and enhance the exhaust effect of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, including:

[0006] A housing assembly, which is cylindrical;

[0007] An electrode assembly, disposed in the housing assembly;

[0008] A center needle is disposed at the center of the electrode assembly, the center needle has a center hole, and the center hole extends along the length direction of the center needle;

[0009] The outer diameter of the housing component is 40 mm to 60 mm; the length of the battery cell is 200 mm to 400 mm; the capacity of the battery cell is 38 Ah to 65 Ah, and the diameter of the center hole is 4 mm to 8 mm.

[0010] The battery cell provided in the embodiment of the present application has a large energy density. The center needle can enhance the structural strength of the electrode assembly and enhance the exhaust effect of the electrode assembly, thereby reducing the risk of gas generated by the electrode assembly accumulating in the electrode assembly, thereby improving the exhaust effect of the battery cell, and taking into account the safety performance of the battery while increasing the battery energy density.

[0011] In some embodiments, the side wall of the center needle is provided with one or more through holes, and the through holes connect the center hole and the outer periphery of the center needle.

[0012] By setting one or more through holes connecting the center hole and the periphery of the center needle on the side wall of the center needle, the gas generated by the electrode assembly can be introduced into the center hole of the center needle through the through holes, reducing the risk of gas generated by the electrode assembly accumulating in the electrode assembly, thereby improving the exhaust effect of the battery cell.

[0013] In some embodiments, the difference between the outer diameter of the central needle and the diameter of the central hole is 0.5 mm to 2 mm.

[0014] Such an arrangement can increase the strength of the center needle and improve the gas conductivity of the center needle, thereby improving the safety of the battery cell.

[0015] In some embodiments, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, wherein the coating density of the active material of the positive electrode sheet is 0.16 mg / mm 2 ~0.3mg / mm 2 .

[0016] In this way, the capacity and energy density of the battery cell can be increased.

[0017] In some embodiments, the shell assembly includes a shell body, a first end cover, and a second end cover, the two ends of the shell body are open, the first end cover and the second end cover are respectively arranged at the two ends of the shell body, the battery cell includes a positive electrode column, a first explosion-proof valve and a first current collecting disk, the positive electrode column and the first explosion-proof valve are both arranged on the first end cover, the first current collecting disk is located on the side of the electrode assembly facing the first end cover, and the distance from the surface of the first current collecting disk facing the side where the first end cover is located to the inner surface of the first end cover is 3.5mm to 8mm.

[0018] In this embodiment, since the distance D3 from the surface of the first collecting disk facing the first end cover to the inner surface of the first end cover is 3.5 mm to 8 mm, the straight-line distance from the electrode assembly to the first explosion-proof valve is increased, and the risk of thermal runaway spray from the battery cell clogging the first explosion-proof valve is reduced, that is, the risk of blockage of the first explosion-proof valve is reduced, thereby improving the safety of the battery cell.

[0019] In some embodiments, the ratio of the total area of ​​the first explosion-proof valve to the capacity of the battery cell is 3.5 mm 2 / Ah~4.0mm 2 In this embodiment, the ratio range of the total area of ​​the first explosion-proof valve to the capacity of the battery cell can further improve the safety performance of the battery cell.

[0020] In some embodiments, the shell assembly includes a shell body, a first end cover, and a second end cover, the two ends of the shell body are open, the first end cover and the second end cover are respectively arranged at the two ends of the shell body, the battery cell includes a second explosion-proof valve, a negative electrode column and a second current collecting disk, the second explosion-proof valve and the negative electrode column are both arranged on the second end cover, the second current collecting disk is located on the side of the electrode assembly facing the second end cover, and the distance from the surface of the second current collecting disk facing the side where the second end cover is located to the inner surface of the second end cover is 3.5mm to 8mm.

[0021] In this embodiment, since the distance D4 from the surface of the second current collecting disk on the side facing the second end cover to the inner surface of the second end cover is 3.5 mm to 8 mm, the straight-line distance from the electrode assembly to the second explosion-proof valve is increased, and the risk of thermal runaway spray from the battery cell clogging the second explosion-proof valve is reduced, that is, the risk of blockage of the second explosion-proof valve is reduced, thereby improving the safety of the battery cell.

[0022] In some embodiments, the ratio of the total area of ​​the second explosion-proof valve to the capacity of the battery cell is 3.5 mm 2 / Ah~4.0mm 2 In this embodiment, the ratio range of the total area of ​​the second explosion-proof valve to the capacity of the battery cell can further improve the safety performance of the battery cell.

[0023] In a second aspect, an embodiment of the present application provides a battery, comprising the battery cell described in any embodiment of the present application.

[0024] The battery provided in the embodiment of the present application can improve the energy density of the battery cell and enhance the exhaust effect of the battery cell by adopting the battery cell involved above, thereby improving the energy density of the battery and enhancing the exhaust effect of the battery.

[0025] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery cell described in any embodiment of the present application or the battery described in any embodiment of the present application.

[0026] The electrical device provided in the embodiment of the present application can improve the energy density of the battery cell and enhance the exhaust effect of the battery cell by adopting the battery cell or battery involved above, thereby improving the energy density of the battery and enhancing the exhaust effect of the battery, so that the electrical device has higher reliability performance.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0029] Figure 2 A top view of a battery cell provided for some embodiments of the present application;

[0030] Figure 3 for Figure 2 Section view along AA;

[0031] Figure 4 for Figure 2 Sectional view along BB;

[0032] Figure 5 A top view of a center needle provided for some embodiments of the present application;

[0033] Figure 6 for Figure 5 Section view along CC.

[0034] Description of reference numerals:

[0035] 1. Shell assembly; 2. Electrode assembly; 3. Shell body; 4. Center needle; 5. Center hole; 6. First end cover; 7. Second end cover; 8. Positive pole; 9. Negative pole; 10. First explosion-proof valve; 11. Second explosion-proof valve; 12. First current collecting disk; 13. Second current collecting disk; 14. Through hole; H. Length of battery cell; D. Outer diameter of shell assembly; V. Total area of ​​explosion-proof valve; D1. Outer diameter of center needle; D2. Diameter of center hole; D3. Distance from the surface of first current collecting disk facing the first end cover to the inner surface of first end cover; D4. Distance from the surface of second current collecting disk facing the second end cover to the inner surface of second end cover. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0037] The various specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction, for example, different embodiments and technical solutions can be formed by combining different specific technical features. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features in the utility model will not be described separately.

[0038] In the following description, the terms "first\second\..." are only used to distinguish different objects, and do not mean that the objects have the same or related points. It should be understood that the directions "above", "below", "outside" and "inside" are all directions in normal use, and the directions "left" and "right" refer to the left and right directions shown in the specific corresponding schematic diagrams, which may be the left and right directions in normal use or not.

[0039] It should be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element. "Multiple" means greater than or equal to two.

[0040] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0041] In related technologies, in order to increase the energy density of batteries, the capacity of battery cells can be increased by increasing the length of battery cells, reducing the space occupied by mechanical parts to increase the space utilization of active materials, etc. However, as the size of battery cells increases, the capacity of battery cells increases accordingly, and the gas production and gas production rate of electrode assemblies during thermal runaway will also increase at the same time. The gas generated by the electrode assembly has the risk of accumulating in the electrode assembly, which affects the exhaust effect of the electrode assembly and further affects the safety performance of the entire battery cell.

[0042] In view of the above problems, an embodiment of the present application provides a battery cell, including a housing assembly, an electrode assembly and a center pin.

[0043] The outer shell assembly is cylindrical. The electrode assembly is arranged in the outer shell assembly. The center needle is arranged at the center of the electrode assembly. The center needle has a center hole, and the center hole extends along the length direction of the center needle. Among them, the outer diameter D of the outer shell assembly is 40mm~60mm (millimeter). The length H of the battery cell is 200mm~400mm. The capacity of the battery cell is 38Ah~65Ah (ampere-hour). The aperture D2 of the center hole is 4mm~8mm. In this way, the battery cell has a larger energy density, and the center needle can enhance the structural strength of the electrode assembly, enhance the exhaust effect of the electrode assembly, reduce the risk of gas generated by the electrode assembly accumulating in the electrode assembly, and then improve the exhaust effect of the battery cell, while improving the energy density of the battery and taking into account the safety performance of the battery.

[0044] The present application provides a battery, which includes a battery cell. A battery is a single physical module that includes one or more battery cells to provide a higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in mixed connection through a busbar. Mixed connection means that multiple battery cells are connected in series and in parallel.

[0045] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. As an example, the multiple battery cells may be fixed by cable ties or the like to form a battery module. As an example, the multiple battery cells may also be fixed by end plates, side plates, or the like to form a battery module.

[0046] In other embodiments, the battery may be a battery pack, which may include a box and a battery cell. As an example, the battery cell may be directly accommodated in the box. As an example, the battery cell may also be formed into a battery module first and then accommodated in the box.

[0047] The battery cell involved in the embodiments of the present application refers to the smallest unit for storing and outputting electric energy, wherein the battery cell can be a secondary battery or a primary battery.

[0048] The embodiment of the present application provides an electric device, including the above-mentioned battery cell or battery. The battery cell or battery can provide electric energy for the electric device. The electric device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0049] In the following embodiments, for the convenience of description, an electric vehicle according to an embodiment of the present application is taken as an example for description.

[0050] The vehicle may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. A battery is provided inside the vehicle. The battery may be provided at the bottom, head or tail of the vehicle. The battery may be used to power the vehicle. For example, the battery may be used as an operating power source for the vehicle. The vehicle may also include a controller and a motor. The controller is used to control the battery to power the motor, for example, for starting, navigating and operating power requirements of the vehicle during driving.

[0051] In some embodiments of the present application, the battery can be used not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0052] The present application embodiment provides a battery cell. Figure 1 The battery cell includes a housing component 1, an electrode component 2, and a center pin 4. The housing component 1 is cylindrical. The electrode component 2 is disposed in the housing component 1. The center pin 4 is disposed at the center of the electrode component 2. Figure 3 , Figure 4 , Figure 5 , Figure 6 The center needle 4 has a center hole 5, and the center hole 5 extends along the length direction of the center needle 4. The outer diameter D of the housing assembly 1 is 40 mm to 60 mm. The length H of the battery cell is 200 mm to 400 mm. The capacity of the battery cell is 38 Ah to 65 Ah. The diameter D2 of the center hole is 4 mm to 8 mm.

[0053] The housing assembly 1 is the appearance structural part of the battery cell, and the electrode assembly 2 and other structures are accommodated in the housing assembly 1. The housing assembly 1 may include a housing body 3 with two hollow ends and end caps disposed at opposite ends of the housing body 3. The end caps close the opening of the housing body 3.

[0054] The cylindrical shape of the housing assembly 1 means that the cross-sectional shape of the housing body 3 is approximately circular. In this embodiment, the battery cell can also be referred to as a cylindrical battery cell.

[0055] The electrode assembly 2 is a component in the battery cell where electrochemical reactions occur. One or more electrode assemblies 2 may be included in the housing assembly 1. The electrode assembly 2 is mainly formed by winding pole sheets (positive pole sheets and negative pole sheets), and a separator is usually provided between the positive pole sheet and the negative pole sheet. The portion of the pole sheet (positive pole sheet and negative pole sheet) having active materials constitutes the main body of the electrode assembly 2, and the main body is connected to the pole ears. The positive pole ear and the negative pole ear may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the pole ears connect the poles to form a current loop.

[0056] In a battery cell, the number of electrode assemblies 2 can be one or more.

[0057] In some cases, the electrode assembly 2 may also be referred to as a bare cell, a wound body, etc.

[0058] The outer diameter D of the housing assembly may be 40 mm, 43 mm, 45 mm, 48 mm, 50 mm, 54 mm, 58 mm, 60 mm, etc.

[0059] The outer diameter D of the housing component can be measured by clamping the housing component 1 with a vernier caliper.

[0060] The length H of the battery cell may be 200 mm, 220 mm, 250 mm, 280 mm, 300 mm, 340 mm, 360 mm, 380 mm, 400 mm, etc.

[0061] The length H of a battery cell refers to the maximum dimension of the battery cell along its length direction. When measuring, the battery cell can be placed on a flat surface and the distance from the highest part of the battery cell to the flat surface can be measured with a ruler.

[0062] The capacity of the battery cells is 38Ah, 40Ah, 45Ah, 50Ah, 56Ah, 58Ah, 60Ah, 63Ah, 65Ah, etc.

[0063] The capacity of a battery cell can be tested using a capacity tester. Specifically, the battery cell to be tested is placed in the capacity tester, and the test is performed according to the instructions of the capacity tester to obtain the actual capacity of the battery cell.

[0064] The capacity of a battery cell can be the actual discharge capacity within the nominal voltage window of the battery cell at 25°C / 0.33C current density, where C refers to the total capacity of the battery cell.

[0065] The diameter D2 of the center hole can be 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, etc.

[0066] The aperture D2 of the center hole can also be measured using tools such as a vernier caliper.

[0067] The battery cell of the embodiment of the present application has a relatively large energy density. Since the center needle 4 is arranged in the electrode assembly 2, the center needle 4 can enhance the structural strength of the electrode assembly 2. The center hole 5 helps to enhance the exhaust effect of the electrode assembly 2 and reduce the risk of gas generated by the electrode assembly 2 accumulating in the electrode assembly 2, thereby improving the exhaust effect of the battery cell, and taking into account the safety performance of the battery while improving the battery energy density.

[0068] In some embodiments, the electrode assembly 2 includes a positive electrode sheet and a negative electrode sheet, wherein the coating density of the active material of the positive electrode sheet is 0.16 mg / mm 2 ~0.3mg / mm 2 (milligrams per square millimeter). For example, 0.16 mg / mm 2 、0.18mg / mm 2 , 0.20mg / mm 2 , 0.22mg / mm 2 , 0.23mg / mm 2 , 0.25mg / mm 2 , 0.27mg / mm 2 , 0.28mg / mm 2 , 0.29mg / mm 2 , 0.3mg / mm 2 Etc. This helps to improve the capacity and energy density of the battery cells.

[0069] The cross-sectional shape of the center needle 4 is not limited, for example, it can be circular, polygonal, elliptical, etc., which is not limited here.

[0070] In the exemplary description of the present application, the cross-sectional shape of the center needle 4 is taken as an example to be described as a circle.

[0071] Exemplarily, the center needle 4 is located at the winding center of the electrode assembly 2 , for example, the positive electrode sheet and the negative electrode sheet are wound around the center needle 4 as the winding center.

[0072] In some embodiments, see Figure 6 The side wall of the center needle 4 is provided with one or more through holes 14, and the through holes 14 are connected to the center hole 5 and the periphery of the center needle 4. In this way, the gas generated by the electrode assembly 2 can be introduced into the center hole 5 of the center needle 4 through the through holes 14, reducing the risk of gas generated by the electrode assembly 2 accumulating in the electrode assembly 2, thereby improving the exhaust effect of the battery assembly.

[0073] The shape of the through hole 14 is not limited, for example, it can be circular, polygonal, etc., which is not limited here.

[0074] For example, on the basis of ensuring the structural strength of the center needle 4 , the number of through holes 14 can be as large as possible to maximize the exhaust effect of the electrode assembly 2 .

[0075] In some embodiments, the difference between the outer diameter D1 of the center needle 4 and the diameter D2 of the center hole is 0.5 mm to 2 mm, that is, D1-D2=0.5 mm to 2 mm, for example, 0.5 mm, 0.65 mm, 0.8 mm, 0.95 mm, 1.1 mm, 1.25 mm, 1.4 mm, 1.55 mm, 1.7 mm, 1.85 mm, 2 mm, etc.

[0076] The difference between the outer diameter D1 of the center needle 4 and the diameter D2 of the center hole can also be understood as the wall thickness of the center needle 4 .

[0077] In this embodiment, it is helpful to ensure the structural strength of the center needle 4. In addition, on the basis of ensuring the structural strength of the center needle 4 and the exhaust effect of the center hole 5, the overall size of the center needle 4 is relatively compact to reduce the space occupied by the center needle 4 on the electrode assembly 2.

[0078] In some embodiments, see Figure 1 The housing assembly 1 includes a housing body 3, a first end cap 6, and a second end cap 7. Both ends of the housing body 3 are open, and the first end cap 6 and the second end cap 7 are respectively arranged at both ends of the housing body 3. The battery cell includes a positive electrode column 8, a first explosion-proof valve 10, and a first current collecting plate 12. The positive electrode column 8 and the first explosion-proof valve 10 are both arranged on the first end cap 6. The first current collecting plate 12 is located on the side of the electrode assembly 2 facing the first end cap 6. Please refer to Figure 3 The distance D3 from the surface of the first collecting plate 12 facing the first end cover 6 to the inner surface of the first end cover 6 is 3.5 mm to 8 mm, for example, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, etc.

[0079] The first end cap 6, the second end cap 7, and the shell body 3 are arranged to form an internal space of the battery cell, wherein the formed internal space can be used to accommodate the electrode assembly 2 and other components. The material of the shell body 3 is not limited, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0080] The first end cover 6 (or the second end cover 7) refers to a component that covers the opening of the shell body 3 to isolate the internal environment of the battery cell from the external environment. The shape of the first end cover 6 (or the second end cover 7) can be adapted to the shape of the opening of the shell body 3. The first end cover 6 (or the second end cover 7) can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cover is not easily deformed when squeezed and collided, so that the battery cell can have a higher structural strength and the safety performance can also be improved.

[0081] The material of the first end cap 6 (or the second end cap 7) can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the present application embodiment does not impose any special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the first end cap 6 (or the second end cap 7), and the insulating member can be used to isolate the electrical connection components in the shell body 3 from the first end cap 6 (or the second end cap 7) to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0082] It should be noted that the description of the first end cover 6 (or the second end cover 7 ) means that the description of the first end cover 6 can also be replaced by the second end cover 7 .

[0083] The pole is a component with conductive properties. The pole is used as the current transmission end of the battery cell to transmit current. The pole and the pole ear of the electrode assembly 2 can be conductively connected through an adapter, a collector plate, etc. The positive pole 8 establishes a conductive path with the positive pole ear of the electrode assembly 2, and the negative pole 9 establishes a conductive path with the negative pole ear of the electrode assembly 2.

[0084] The current collecting plate is conductively connected to the electrode assembly 2, specifically, the current collecting plate is conductively connected to the pole tab of the electrode assembly 2. In this way, the current can be efficiently concentrated and directed to the pole, ensuring efficient operation of the battery cell.

[0085] The first explosion-proof valve 10 is used to prevent and deal with overpressure or overheating problems of battery cells under certain circumstances, so as to avoid the occurrence of battery elevator explosion accidents.

[0086] In this embodiment, since the distance D3 from the surface of the first collecting plate 12 on the side facing the first end cover 6 to the inner surface of the first end cover 6 is 3.5 mm to 8 mm, the straight-line distance from the electrode assembly 2 to the first explosion-proof valve 10 is increased, and the risk of thermal runaway spray from the battery cell clogging the first explosion-proof valve 10 is reduced, that is, the risk of blockage of the first explosion-proof valve 10 is reduced, thereby improving the safety of the battery cell.

[0087] For example, the ratio of the total area of ​​the first explosion-proof valve 10 to the capacity of the battery cell is 3.5 mm 2 / Ah~4.0mm 2 / Ah. For example, 3.5mm 2 / Ah, 3.6mm 2 / Ah, 3.7mm 2 / Ah, 3.8mm 2 / Ah, 3.9mm 2 / Ah, 4.0mm 2 / Ah, etc.

[0088] The total area of ​​the first explosion-proof valve 10 may be measured by measuring the outer contour of the first explosion-proof valve 10 and calculating the actual area.

[0089] In this embodiment, the ratio range of the total area of ​​the first explosion-proof valve 10 to the capacity of the battery cell can further improve the safety performance of the battery cell.

[0090] See also Figure 1 The outer shell assembly 1 includes a shell body 3, a first end cover 6, and a second end cover 7. Both ends of the shell body 3 are open, and the first end cover 6 and the second end cover 7 are respectively arranged at both ends of the shell body 3. The battery cell includes a second explosion-proof valve 11, a negative electrode column 9, and a second current collecting disc 13. The second explosion-proof valve 11 and the negative electrode column 9 are both arranged on the second end cover 7. The second current collecting disc 13 is located on the side of the electrode assembly 2 facing the second end cover 7. The distance D from the surface of the second current collecting disc 13 facing the second end cover 7 to the inner surface of the second end cover 7 is 43.5mm~8mm.

[0091] The second explosion-proof valve 11 is used to prevent and deal with overpressure or overheating problems of the battery monomer under certain circumstances, so as to avoid the occurrence of battery elevator explosion accidents.

[0092] In this embodiment, since the distance D4 from the surface of the second collecting plate 13 on the side facing the second end cover 7 to the inner surface of the second end cover 7 is 3.5 mm to 8 mm, the straight-line distance from the electrode assembly 2 to the second explosion-proof valve 11 is increased, and the risk of thermal runaway spray from the battery cell clogging the second explosion-proof valve 11 is reduced, that is, the risk of blockage of the second explosion-proof valve 11 is reduced, thereby improving the safety of the battery cell.

[0093] It should be noted that in some embodiments, only one explosion-proof valve may be provided, that is, only the first explosion-proof valve 10 or only the second explosion-proof valve 11 may be provided. In other embodiments, both the first explosion-proof valve 10 and the second explosion-proof valve 11 may be provided.

[0094] For example, the ratio of the total area of ​​the second explosion-proof valve 11 to the capacity of the battery cell is 3.5 mm 2 / Ah~4.0mm 2 / Ah. For example, 3.5mm 2 / Ah, 3.6mm 2 / Ah, 3.7mm 2 / Ah, 3.8mm 2 / Ah, 3.9mm 2 / Ah, 4.0mm 2 / Ah, etc.

[0095] The total area of ​​the second explosion-proof valve 11 may be measured by measuring the outer contour of the second explosion-proof valve 11 and calculating the actual area.

[0096] In this embodiment, the ratio range of the total area of ​​the second explosion-proof valve 11 to the capacity of the battery cell can further improve the safety performance of the battery cell.

[0097] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0098] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing assembly, which is cylindrical; An electrode assembly, disposed in the housing assembly; A center needle is disposed at the center of the electrode assembly, the center needle has a center hole, and the center hole extends along the length direction of the center needle; The outer diameter of the housing component is 40 mm to 60 mm; the length of the battery cell is 200 mm to 400 mm; the capacity of the battery cell is 38 Ah to 65 Ah, and the diameter of the center hole is 4 mm to 8 mm.

2. The battery cell according to claim 1, characterized in that: The side wall of the center needle is provided with one or more through holes, and the through holes communicate with the center hole and the outer periphery of the center needle.

3. The battery cell according to claim 1, characterized in that: The difference between the outer diameter of the center needle and the diameter of the center hole is 0.5 mm to 2 mm.

4. The battery cell according to claim 1, characterized in that: The electrode assembly includes a positive electrode sheet and a negative electrode sheet, wherein the coating density of the active material of the positive electrode sheet is 0.16 mg / mm 2 ~0.3mg / mm 2 .

5. The battery cell according to claim 1, characterized in that: The shell assembly includes a shell body, a first end cover, and a second end cover, the two ends of the shell body are open, the first end cover and the second end cover are respectively arranged at the two ends of the shell body, the battery cell includes a positive electrode column, a first explosion-proof valve and a first current collecting disk, the positive electrode column and the first explosion-proof valve are both arranged on the first end cover, the first current collecting disk is located on the side of the electrode assembly facing the first end cover, and the distance from the surface of the first current collecting disk on the side facing the first end cover to the inner surface of the first end cover is 3.5mm to 8mm.

6. The battery cell according to claim 5, characterized in that: The ratio of the total area of ​​the first explosion-proof valve to the capacity of the battery cell is 3.5mm 2 / Ah~4.0mm 2 / Ah.

7. The battery cell according to claim 1, characterized in that: The shell assembly includes a shell body, a first end cover, and a second end cover, the two ends of the shell body are open, the first end cover and the second end cover are respectively arranged at the two ends of the shell body, the battery cell includes a second explosion-proof valve, a negative electrode column, and a second current collecting disk, the second explosion-proof valve and the negative electrode column are both arranged on the second end cover, the second current collecting disk is located on the side of the electrode assembly facing the second end cover, and the distance from the surface of the second current collecting disk on the side facing the second end cover to the inner surface of the second end cover is 3.5mm to 8mm.

8. The battery cell according to claim 7, characterized in that: The ratio of the total area of ​​the second explosion-proof valve to the capacity of the battery cell is 3.5mm 2 / Ah~4.0mm 2 / Ah.

9. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 8 or the battery according to claim 9.

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