Cylindrical battery and electric device

Abstract

The present application relates to the technical field of battery, in particular to a cylindrical battery and an electric device. The cylindrical battery comprises a shell, an electric core and an electrolyte arranged in the shell, and the electric core comprises a positive plate, a diaphragm and a negative plate. At least one end of the shell is provided with an open end in the direction perpendicular to the radial direction of the shell, and the open end is connected with a cover plate assembly. The cylindrical battery satisfies 0.95≤Kg≤2.80, Kg=V void / G, G≠0; wherein G is the volume of gas generated by the cylindrical battery at 85 DEG C after 168h storage, which is converted into the volume of gas at 25 DEG C and 101kPa, and the unit is mL; V void is the space volume inside the cylindrical battery after the electric core is formed by formation and is divided, which is in addition to the electric core and the electrolyte, and the unit is cm 3 The battery of the present application can reduce the swelling range of the shell, inhibit the increase of internal resistance, prevent the false action of the safety valve, and improve the safety and reliability of the battery in the limited shell space.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a cylindrical battery and an electrical device. Background Technology

[0002] In recent years, cylindrical lithium-ion batteries, used in high-capacity, high-power, and compact applications, typically require achieving high energy density within a limited casing while maintaining safety and reliability during high-temperature storage and cycling. For cylindrical cells employing a full-tab structure, this results in improved rate performance and a more compact internal space layout. Current technologies either limit the cell's external dimensions to reserve internal cavities, optimize material systems and electrolyte formulations to reduce gas production, or indirectly evaluate safety performance using outcome indicators such as post-storage internal resistance growth and casing bulging. However, because short-height cylindrical cells maintain 5Ah-level capacity while further compressing their axial space, simply limiting the external dimensions cannot characterize whether the actual internal space available for gas buffering is sufficient.

[0003] Therefore, in the design of short-high full-tab cylindrical cells, how to obtain a battery replacement aid that can match the gas production with the buffer space while ensuring high capacity, so as to avoid casing bulging, abnormal increase in internal resistance and safety valve activation caused by excessive internal pressure accumulation, has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention aims to at least partially solve one of the technical problems in the related art. To this end, the present invention provides a cylindrical battery and an electrical device that can… To solve the above-mentioned technical problems, the present invention is implemented as follows: According to one aspect of the present invention, a cylindrical battery is provided, comprising: a housing, and a cell and an electrolyte disposed in the housing, the cell comprising a positive electrode, a separator and a negative electrode; and at least one end of the housing is provided with an opening in a direction perpendicular to the radial direction of the housing, the opening end being connected to a cover plate assembly. The cylindrical battery satisfies: 0.95 ≤ Kg ≤ 2.80, Kg = V void / G, G≠0; Where G is the gas volume generated by the cylindrical battery after storage at 85°C for 168 hours, converted to the gas volume under conditions of 25°C and 101 kPa, in mL; V void The internal volume of the cylindrical battery, excluding the battery cell and the electrolyte, after the cell has undergone formation and capacity testing. Unit: cm. 3 .

[0005] In some of these implementations, 1.20 ≤ Kg ≤ 2.30.

[0006] In some of these implementations, 0.50cm 3 ≤V void ≤0.85cm 3 .

[0007] In some of these implementations, 0.25 mL ≤ G ≤ 0.78 mL.

[0008] In some of these implementations, 0.58cm 3 ≤V void ≤0.76cm 3 .

[0009] In some of these implementations, 0.30 mL ≤ G ≤ 0.62 mL.

[0010] In some embodiments, the cylindrical battery also satisfies: 0.095 ≤ V void / C 0.2 ≤0.170.

[0011] In some of these implementations, 0.050 ≤ G / C 0.2 ≤0.155; where C 0.2 The discharge capacity of the cylindrical battery at 25°C and 0.2C is expressed in Ah; and C... 0.2 ≠0.

[0012] In some of these implementations, 0.110 ≤ V void / C 0.2 ≤0.155.

[0013] In some of these implementations, 0.060 ≤ G / C 0.2 ≤0.125.

[0014] In some of these implementations, 4.9Ah≤C 0.2 ≤5.2Ah.

[0015] In some of these embodiments, the shell is a hollow cylinder; In a direction perpendicular to the radial direction of the housing, the housing has a radially spaced groove near the open end; the total height of the housing is H1, in mm; the height of the battery cell is HJ, in mm; the maximum radial dimension of the housing is D, in mm; the dimension from the end of the housing away from the open end to the end of the groove away from the open end is H5, in mm. Wherein, 2.6mm≤H2-HJ≤5.0mm; and / or, 0.6mm≤H5-HJ≤2.4mm; and / or, 3.06≤H1 / D≤3.14.

[0016] In some of these embodiments, the value of H1 ranges from 63.5 mm to 66.5 mm.

[0017] In some of these embodiments, the value of D ranges from 20.6 mm to 21.5 mm.

[0018] In some of these embodiments, the groove has a size of H4 in the direction perpendicular to the radial direction of the housing, where 0.15mm ≤ H4 ≤ 0.45mm.

[0019] In some embodiments, the depth of the groove in the radial direction of the housing is 1.3 mm to 1.9 mm.

[0020] In some embodiments, the positive electrode sheet includes a positive current collector and a positive electrode coating disposed on at least one surface of the positive current collector in the thickness direction, the positive electrode coating including a positive electrode active material; The positive electrode also satisfies at least one of features (1) to (3): (1) The positive electrode active material comprises a layered high-nickel lithium transition metal oxide with a nickel molar content of 88 mol% to 93 mol%; (2) The areal density of the positive electrode coating on one side of the positive electrode sheet is 12.3 mg / cm³. 2 ~14.0 mg / cm 2 (3) The compaction density of the positive electrode sheet is 3.45 g / cm³. 3 ~3.65g / cm 3 .

[0021] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode coating disposed on at least one surface of the negative electrode current collector in the thickness direction, the negative electrode coating including a negative electrode active material; The negative electrode also satisfies at least one of features (1) to (3): (1) The negative electrode active material includes at least one of graphite and silicon-carbon materials; (2) The areal density of the negative electrode coating on one side of the negative electrode sheet is 5.3 mg / cm³. 2 ~6.2mg / cm 2 (3) The compaction density of the negative electrode sheet is 1.50 g / cm³. 3 ~1.65g / cm 3 .

[0022] In some embodiments, the electrolyte comprises a lithium salt and an additive, wherein the lithium salt comprises at least one of LiPF6, LiFSI, and LiDFOB, and the additive comprises at least one of vinylene carbonate, fluoroethylene carbonate, 1,3-propane sulpholactone, and ethylene sulfate.

[0023] In some of these embodiments, the cylindrical battery, after being stored at 85°C for 168 hours, exhibits a DCR growth rate of less than or equal to 18% at 25°C and 50% SOC.

[0024] In some embodiments, after the cylindrical battery is stored at 85°C for 168 hours, the radial bulge of the casing is less than or equal to 0.12 mm. In some embodiments, the cylindrical battery has a DCR growth rate of less than or equal to 22% after 300 cycles of 8A charging / 40A discharging at 25°C, and the radial bulge of the casing is less than or equal to 0.16 mm.

[0025] According to another aspect of the present invention, an electrical device is provided, comprising: a cylindrical battery as described in any of the above embodiments.

[0026] Implementing the technical solution of the present invention has at least the following beneficial effects: The cylindrical battery in this invention uses a gas buffer coefficient Kg=V. void / G, and limited to 0.95≤Kg≤2.80, the bufferable space volume V void The forced correlation between the storage gas production volume G and the reserved space creates a clear matching window for the gas production volume. When the Kg is within this range, the internal reserved space is sufficient to stably absorb the high-temperature storage gas, avoiding excessive internal pressure accumulation. This effectively reduces the casing expansion, suppresses DCR growth, and prevents safety valve malfunction, significantly improving the safety and reliability of cylindrical batteries within a limited casing space.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0029] Figure 1 The diagram shown is a schematic diagram of the shell structure provided by the present invention.

[0030] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0031] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0032] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0033] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0034] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0035] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0036] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0037] Currently, when the height of the cylindrical battery casing is shortened from a high platform to a short-height structure of 21650, if a capacity of 4.9Ah to 5.2Ah is still to be maintained, the space available for absorbing high-temperature storage or circulating gas after accommodating the core is compressed. Some methods only limit the external dimensions of the cell, some only require reducing the amount of gas generated, and some only focus on the increase in DC internal resistance or the amount of casing bulging after storage. None of them forcibly correlate the volume of bufferable space with the volume of gas generated during high-temperature storage. As a result, under the short-height geometry, once the amount of gas generated exceeds the limit that the internal space can buffer, problems such as significant casing bulging, a large increase in DC internal resistance, and even the activation of the safety valve can easily occur. On the other hand, simply increasing the cavity may sacrifice the effective core loading capacity and capacity.

[0038] The inventors of this invention have discovered that the internal buffer space volume V void The gas production rate G during high-temperature storage is one of two mutually restrictive quantities, V void This refers to the internal volume of the battery cell after it has undergone chemical composition and capacity testing, excluding the solid phase of the battery cell and the electrolyte. It mainly includes the axial cavities between the core end and the cap assembly, between the core end and the bottom of the casing, and the radial clearance cavity between the outer periphery of the core and the inner wall of the casing. G refers to the gas volume generated after the battery cell is stored at 85℃ for 168 hours, converted to conditions of 25℃ and 101 kPa. When V... void When the pressure is insufficient or the gas output is too high, the gas cannot be reliably buffered. The increased internal pressure will compress the electrode interface, causing an increase in DC internal resistance and deformation of the casing. When either of these two factors is controlled alone, there may still be a situation where insufficient cavity and excessive gas production coexist, which reduces safety.

[0039] In view of the technical problems existing in the prior art, the present invention provides a cylindrical battery and an electrical device, proposing to define the gas buffer coefficient Kg as Kg=V void / G, and limits the range of Kg values, ensuring 0.95≤Kg≤2.80, G≠0. Limitations are also made on Vvoid, G, their normalized ratios to discharge capacity, end margin, casing geometry, electrode parameters, material system, and performance indicators after storage and cycling. This ensures the certainty of gas buffering capacity while maintaining high capacity, allowing the product to be reverse-verified through dimensional measurement, capacity testing, CT or disassembly volume determination, storage gas absorption testing, and electrical performance retesting. The total casing height H1 and outer diameter D determine the overall shape of the battery; the cell height HJ is the axial height of the core after flattening; the difference between the casing shoulder height H2, lower end height H5, and HJ reflects the end buffer gap on the cap side and bottom side of the casing. Capacity C0.2 is the discharge capacity under 25℃ and 0.2C discharge conditions. According to Kg=V void The gas buffer coefficient obtained by / G, with its lower and upper limits set, allows the reserved space to absorb high-temperature storage gas without excessively sacrificing the loading capacity.

[0040] The specific technical solution of the present invention is as follows: Cylindrical battery A cylindrical battery is provided, comprising: a casing, and a cell and an electrolyte disposed in the casing, the cell including a positive electrode, a separator and a negative electrode; at least one end of the casing is provided with an opening in a direction perpendicular to the radial direction of the casing, the open end being connected to a cover plate assembly.

[0041] Cylindrical batteries satisfy the following conditions: 0.95 ≤ Kg ≤ 2.80, Kg = V void / G, G≠0; where G is the gas volume produced by the cylindrical battery after storage at 85℃ for 168h, converted to the gas volume under conditions of 25℃ and 101kPa, unit: mL; V void The internal volume of a cylindrical battery, excluding the battery cell and electrolyte, after the cell has undergone formation and capacity testing. Unit: cm. 3 .

[0042] As an example, the casing can be made of metals such as aluminum, copper, or aluminum alloy, and has a housing space containing the battery cell and electrolyte. The electrolyte includes a solvent and a lithium salt. The solvent can be ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), etc., and the lithium salt can include lithium tetrafluoroborate (LiBF4), lithium dioxalate borate (LiBOB), lithium difluorooxalate borate (LiDFOB), lithium difluorophosphate (LiPO2F / LiPO2F2), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), etc. The cover assembly can include caps and terminals made of metal, as well as insulating seals and plastic parts, etc., without specific limitations. The casing is a hollow cylinder, with at least one end having an opening. The cover assembly is connected to the open end of the casing to form a sealed space. The diaphragm can be made of polymer materials such as polyethylene, without specific limitations.

[0043] The cavity volume V inside the shell void The gas buffering capacity (G) after the battery is stored at 85°C for 168 hours is calculated so that its ratio (Kg) falls within the range of 0.95 to 2.80. Specifically, Kg can be any value between 0.95, 0.96, 0.98, 1.0, 1.05, 1.1, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.40, 2.50, 2.60, 2.70, or 2.80. This allows for the quantification of gas buffering capacity from the design stage. voidG represents the actual space within the casing capable of accommodating gas generated during high-temperature storage or circulation, while Kg represents the total gas production. Kg indicates the degree of matching between the buffer space and the gas production volume. When Kg is less than 0.95, the buffer space is insufficient relative to the gas production volume. After high-temperature storage, the gas cannot be effectively contained, easily leading to a rapid increase in internal pressure, increased casing bulging, and an excessive increase in DC internal resistance, potentially even triggering the safety valve. When Kg is greater than 2.80, although the buffering capacity is sufficient, the effective core loading is sacrificed to create excessive cavity space, resulting in a decrease in battery capacity or failure to achieve the expected energy density. Therefore, limiting Kg to the range of 0.95 to 2.80 achieves a manufacturable and verifiable balance between safety and capacity. Understandably, the measurement of G could involve charging a cylindrical battery to 100% charge after separation and testing, storing it in an 85°C oven for 168 hours, cooling the battery to 25°C after storage, puncturing or opening the casing in a sealed gas collection device, collecting the released gas volume, and then converting this gas volume to the conditions of 25°C and 101 kPa. If a pressure method is used, the initial pressure, final pressure, container volume, and temperature of the sealed container are recorded, and the volume is converted to the gas volume at 25°C and 101 kPa using the ideal gas law. V void The method for obtaining V is as follows: The battery cell is non-destructively scanned using industrial CT, with a voxel size not exceeding 20 μm. Three-dimensional segmentation software is used to identify the shell, cap assembly, core solid phase, end cavities, radial gap cavities, and liquid phase region. The first end cavity between the positive end face of the core and the cap assembly, the second end cavity between the negative end face of the core and the bottom of the shell, and the radial gap cavity between the outer periphery of the core and the inner wall of the shell are added together. The volume of the liquid phase occupied by the free electrolyte is subtracted to obtain V. void If necessary, the battery cell can be disassembled in an inert atmosphere, and the CT results can be verified by calculating the difference between the net volume of the casing, the volume of the core after draining, the volume of the structural components, and the volume of the free liquid.

[0044] In some embodiments, 1.20 ≤ Kg ≤ 2.30. Exemplarily, Kg can be any value between any one or any two of 1.2, 1.3, 1.4, 1.5, 1.8, 1.9, 2.0, 2.1, 2.2, or 2.3. By limiting Kg to this range, the matching risk caused by design deviations or process fluctuations can be reduced, ensuring more reliable buffering of gas generation during storage, resulting in more consistent safety performance and lower bulging risk in mass production of the battery.

[0045] In some embodiments, 0.50cm 3 ≤V void ≤0.85cm 3 For example, V void It can be 0.50cm 3 0.53cm3 0.55cm 3 0.58cm 3 0.60cm 3 0.63cm 3 0.65cm 3 0.68cm 3 0.70cm 3 0.73cm 3 0.76cm 3 0.78cm 3 0.80cm 3 0.83cm 3 Or 0.85cm 3 The value can be any one of the above values ​​or any point between any two. If it is less than the above range, even if the gas production is at a low level, the reserved buffer space may not be sufficient to smooth out internal pressure fluctuations at a capacity of 5Ah and the corresponding high-temperature gas production, leading to an increased risk of swelling and DC internal resistance growth. If it is greater than the above range, for cylindrical batteries with limited total casing height and outer diameter, the effective loading volume of the core will have to be compressed, making it difficult to maintain a discharge capacity of 4.9Ah or higher.

[0046] In some embodiments, 0.25 mL ≤ G ≤ 0.78 mL. Exemplarily, G can be any one of 0.25 mL, 0.28 mL, 0.30 mL, 0.33 mL, 0.35 mL, 0.38 mL, 0.40 mL, 0.43 mL, 0.45 mL, 0.48 mL, 0.50 mL, 0.53 mL, 0.55 mL, 0.58 mL, 0.60 mL, 0.63 mL, 0.65 mL, 0.68 mL, 0.70 mL, 0.73 mL, 0.75 mL, or 0.78 mL, or any point value between any two. If it is less than the above range, it indicates that the gas production is extremely low, possibly due to the use of special materials and processes, but this may be accompanied by a significant increase in cost or sacrifice of other performance characteristics such as rate of increase or low temperature. If the pressure exceeds the above range, even with sufficient buffer space, the weight may easily fall below the lower limit of 0.95, leading to excessive accumulation of internal pressure, and the growth rate of shell bulging and DC internal resistance exceeding the safety boundary.

[0047] In some embodiments, 0.58cm 3 ≤V void ≤0.76cm 3 For example, V void It can be 0.58cm 3 0.60cm 3 0.62cm 3 0.64cm 3 0.66cm 3 0.68cm3 0.70cm 3 0.72cm 3 0.74cm 3 Or 0.76cm 3 Any point value in either or between any two of them.

[0048] In some embodiments, 0.30 mL ≤ G ≤ 0.62 mL. Exemplarily, G can be any one or any point value between any two of 0.30 mL, 0.33 mL, 0.35 mL, 0.38 mL, 0.40 mL, 0.43 mL, 0.45 mL, 0.48 mL, 0.50 mL, 0.53 mL, 0.55 mL, 0.58 mL, 0.60 mL, or 0.62 mL.

[0049] In some embodiments, the cylindrical battery also satisfies: 0.095 ≤ V void / C 0.2 ≤0.170.

[0050] For example, V void / C 0.2 The value can be any one of 0.095, 0.100, 0.105, 0.110, 0.115, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, 0.150, 0.155, 0.160, 0.165, or 0.170, or any point value between any two. Limiting the buffer space and gas production within the above ranges eliminates the influence of different capacity designs on buffer evaluation, allowing cylindrical batteries of various capacities to be quickly determined to have sufficient gas buffering capacity through dimensionless parameters. V void / C 0.2 This can be referred to as the unit capacity buffer space. If it is smaller than the above range, the gas buffer space allocated per unit capacity is too small, and once the gas production at high temperature approaches the upper limit, the internal pressure will rise rapidly. If it is larger than the above range, it often means sacrificing too much effective electrode loading space, which is not conducive to achieving high energy density. It can be understood that V void / C 0.2 The derived unit is cm. 3 / Ah.

[0051] In some embodiments, 0.050 ≤ G / C 0.2 ≤0.155; where C 0.2 The value represents the discharge capacity of a cylindrical battery at 25°C and 0.2C, expressed in Ah. 0.2 ≠0.

[0052] For example, G / C 0.2The value can be any one of 0.050, 0.058, 0.065, 0.072, 0.080, 0.088, 0.095, 0.102, 0.110, 0.118, 0.125, 0.132, 0.140, 0.148, or 0.155, or any point between any two. If it is less than the above range, it indicates that the gas production of the material system is excessively suppressed, which may rely on expensive additives or special formation processes. If it is greater than the above range, the gas production load per unit capacity is too high, the buffering difficulty increases significantly, and it is easy to lead to the breach of the safety boundary. This can be understood as G / C... 0.2 The derived unit is mL / Ah.

[0053] In some embodiments, 0.110 ≤ V void / C 0.2 ≤0.155. For example, V void / C 0.2 It can be any point value between any one of 0.110, 0.115, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, 0.150, or 0.155.

[0054] In some embodiments, 0.060 ≤ G / C 0.2 ≤0.125. For example, G / C 0.2 It can be any point value between any one of 0.060, 0.065, 0.072, 0.080, 0.088, 0.095, 0.102, 0.110, 0.118 or 0.125.

[0055] In some embodiments, 4.9Ah≤C 0.2 ≤5.2Ah. For example, C 0.2 It can be any point value between any one of 4.9Ah, 4.93Ah, 4.96Ah, 4.99Ah, 5.02Ah, 5.05Ah, 5.08Ah, 5.11Ah, 5.14Ah, 5.17Ah or 5.2Ah.

[0056] In some embodiments, the housing is a hollow cylinder; a radial groove is provided near the open end of the housing in a direction perpendicular to the radial direction of the housing; the total height of the housing is H1, in mm; the height of the battery cell is HJ, in mm; the maximum radial dimension of the housing is D, in mm; and the dimension from the end of the housing away from the open end to the end of the groove away from the open end is H5, in mm.

[0057] For example, refer to Figure 1The shell can be made of metal in a cylindrical shape and is hollow. At least one end of the shell has an opening. The electrolyte and the battery cell are disposed in the shell. At the end of the shell near the opening, there is a groove extending radially into the shell.

[0058] Preferably, 2.6mm≤H2-HJ≤5.0mm; and / or, 0.6mm≤H5-HJ≤2.4mm; and / or, 3.06≤H1 / D≤3.14. For example, H2-HJ can be any point value between any two of 2.6mm, 2.84mm, 3.08mm, 3.32mm, 3.56mm, 3.8mm, 4.04mm, 4.28mm, 4.52mm, 4.76mm or 5.0mm; H5-HJ can be any point value between any two of 0.6mm, 0.78mm, 0.96mm, 1.14mm, 1.32mm, 1.5mm, 1.68mm, 1.86mm, 2.04mm, 2.22mm or 2.4mm; H1 / D can be any point value between any two of 3.06, 3.07, 3.08, 3.09, 3.10, 3.11, 3.12, 3.13 or 3.14.

[0059] In some embodiments, the value of H1 ranges from 63.5mm to 66.5mm. Exemplarily, it can be any point value between any one or any two of 63.5mm, 63.8mm, 64.1mm, 64.4mm, 64.7mm, 65.0mm, 65.3mm, 65.6mm, 65.9mm, 66.2mm, or 66.5mm.

[0060] In some embodiments, the value of D ranges from 20.6 mm to 21.5 mm. Exemplarily, it can be any point value between any one or any two of 20.6 mm, 20.7 mm, 20.8 mm, 20.9 mm, 21.0 mm, 21.1 mm, 21.2 mm, 21.3 mm, 21.4 mm, or 21.5 mm.

[0061] In some embodiments, the groove dimension is H4 in the direction perpendicular to the radial direction of the housing, where 0.15mm ≤ H4 ≤ 0.45mm. Exemplarily, H4 can be any value between any one or any two of the following: 0.15mm, 0.18mm, 0.20mm, 0.23mm, 0.25mm, 0.28mm, and for the housing, 0.30mm, 0.33mm, 0.35mm, 0.38mm, 0.40mm, 0.43mm, or 0.45mm.

[0062] In some embodiments, the depth of the groove in the radial direction of the housing is 1.3 mm to 1.9 mm. Exemplarily, the depth of the groove can be any one of 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm or 1.9 mm, or any value between any two of them.

[0063] In some embodiments, the positive electrode sheet includes a positive current collector and a positive electrode coating disposed on at least one side surface of the positive current collector in the thickness direction, the positive electrode coating including a positive electrode active material.

[0064] For example, the positive electrode coating can be disposed on one surface or both surfaces of the positive electrode current collector in the thickness direction; the positive electrode coating includes a positive electrode active material, such as lithium-ion positive electrode material, sodium-ion positive electrode material, etc. The lithium-ion positive electrode material includes, but is not limited to, lithium iron phosphate, ternary materials, etc., and the sodium-ion positive electrode material includes, but is not limited to, layered transition metal oxides, such as Na x MO2, M=Mn, Fe, Ni, Co, Cu, etc.

[0065] Optionally, the positive electrode active material includes layered high-nickel lithium transition metal oxides with a nickel molar content of 88 mol% to 93 mol%.

[0066] For example, the molar content of nickel in the positive electrode active material can be any one of 88 mol%, 89 mol%, 90 mol%, 91 mol%, 92 mol%, 92.5 mol%, or 93 mol%, or any point value between any two. While providing high specific capacity, the surface side reactions and lattice oxygen release of high nickel positive electrode materials under high temperature storage conditions are one of the main sources of gas production. Limiting the nickel content to the above range can balance capacity utilization and gas production level.

[0067] Optionally, the areal density of the positive electrode coating on one side of the positive electrode sheet is 12.3 mg / cm³. 2 ~14.0 mg / cm 2 For example, the areal density of the positive electrode coating on one side of the positive electrode sheet can be 12.3 mg / cm³. 2 12.5 mg / cm 2 12.8 mg / cm 2 13mg / cm 2 13.5 mg / cm 2 13.6 mg / cm 2 13.7 mg / cm 2 13.8 mg / cm 2 13.9 mg / cm 2 Or 14.0 mg / cm 2 Any point value in either or between any two of them.

[0068] Optionally, the compaction density of the positive electrode is 3.45 g / cm³. 3 ~3.65g / cm 3 For example, the compaction density of the positive electrode can be 3.45 g / cm³. 3 3.5g / cm 3 3.55g / cm 3 3.6g / cm 3 Or 3.65g / cm 3 Any point value in either or between any two of them.

[0069] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode coating disposed on at least one side surface of the negative electrode current collector in the thickness direction, the negative electrode coating including a negative electrode active material.

[0070] Optionally, the negative electrode active material includes, but is not limited to, one or more of graphite and silicon carbide materials.

[0071] Optionally, the areal density of the negative electrode coating on one side of the negative electrode sheet is 5.3 mg / cm³. 2 ~6.2mg / cm 2 For example, the areal density of the negative electrode coating on one side of the negative electrode sheet is 5.3 mg / cm³. 2 5.5 mg / cm 2 5.8 mg / cm 2 6mg / cm 2 Or 6.2 mg / cm 2 Any point value in either or between any two of them.

[0072] Optionally, the compaction density of the negative electrode is 1.50 g / cm³. 3 ~1.65g / cm 3 For example, the compaction density of the negative electrode is 1.50 g / cm³. 3 1.50g / cm 3 1.55g / cm 3 1.60g / cm 3 Or 1.65g / cm 3 Any point value in either or between any two of them.

[0073] In some embodiments, the electrolyte includes a lithium salt and additives. The lithium salt includes, but is not limited to, one or more of LiPF6, LiFSI (lithium bisfluorosulfonylimide) and LiDFOB (lithium difluorooxalate borate). The additives include, but are not limited to, one or more of vinylene carbonate (VC), fluoroethylene carbonate (FEC), DTD (ethylene sulfate), propylene sulfonate lactone (PS), 1,3-propane sulfonate lactone and ethylene sulfate.

[0074] In some embodiments, after the cylindrical battery is stored at 85°C for 168 hours, the DCR growth rate at 25°C and 50% SOC is less than or equal to 18%.

[0075] In some embodiments, after the cylindrical battery is stored at 85°C for 168 hours, the radial bulge of the casing is less than or equal to 0.12 mm.

[0076] In some embodiments, after 300 cycles of charging at 8A and discharging at 25°C, the DCR growth rate of the cylindrical battery is less than or equal to 22%, and the radial bulge of the casing is less than or equal to 0.16 mm.

[0077] [Electrical appliances] In some embodiments of the present invention, an electrical device is provided, comprising: the cylindrical battery in any of the above embodiments.

[0078] Optionally, the electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, energy storage devices, amusement equipment, elevators and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; 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, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc. The aforementioned vehicles can be fuel-powered vehicles, natural gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery is installed inside the vehicle, which can be located at the bottom, front, or rear of the vehicle. The battery can be used to power the vehicle; for example, the battery can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller controls the battery's power supply to the motor, for example, to meet the vehicle's power needs during starting, navigation, and driving. The battery can serve not only as the vehicle's operating power source but also as its driving power source, replacing or partially replacing fuel or natural gas to provide propulsion.

[0079] The diaphragm used in this embodiment is a diaphragm used in the art and is not particularly limited herein. All solvents and substances in this invention are commercially available.

[0080] Since the battery provided in this embodiment of the invention adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0081] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. However, the implementation and protection of the present invention are not limited thereto. The following embodiments are only some embodiments of the present invention and are not intended to limit the present invention.

[0082] Example 1 A 21650 all-tab cylindrical lithium-ion cell.

[0083] The positive electrode active material is a layered high-nickel lithium transition metal oxide with a nickel content of approximately 90 mol%. The mass ratio of the positive electrode active material, conductive carbon black, carbon nanotubes, and PVDF binder in the positive electrode slurry is 97.2:1.3:0.2:1.3. The above materials are dispersed in NMP and stirred to prepare the positive electrode slurry. The positive electrode slurry is coated onto both sides of a 12 μm thick aluminum foil current collector, and after drying, rolling, and slitting, the positive electrode sheet is obtained. The areal density of the positive electrode on one side is 13.2 mg / cm³. 2 The positive electrode compaction density is 3.54 g / cm³. 3 The width of the positive electrode material area is 55.0 mm, and the width of the positive electrode empty foil area is 4.0 mm.

[0084] The negative electrode active material is made of artificial graphite and silicon carbon. The mass ratio of artificial graphite, silicon carbon, conductive agent, CMC (carboxymethyl cellulose), and SBR (styrene-butadiene rubber) in the negative electrode slurry is 78.0:18.0:1.0:1.2:1.8. The above materials are dispersed in deionized water and stirred to prepare the negative electrode slurry. The negative electrode slurry is coated on both sides of a 6μm thick copper foil current collector, and after drying, rolling, and slitting, the negative electrode sheet is obtained. The areal density of the negative electrode on one side is 5.75 mg / cm³. 2 The negative electrode compaction density is 1.58 g / cm³. 3 The width of the negative electrode material area is 56.0 mm, and the width of the negative electrode empty foil area is 3.5 mm.

[0085] The positive electrode, separator, and negative electrode are wound to form a core. After winding, the ends of the positive and negative electrode sheets are flattened to form full-tab end faces. The height HJ of the flattened core is 61.0 mm. The core is then installed into a cylindrical shell, and the current collector is welded, the cap is welded, electrolyte is injected, the electrolyte is allowed to stand, formation is performed, and capacity testing is completed. The electrolyte includes carbonate solvent, LiPF6 lithium salt, LiFSI lithium salt, and VC, FEC, and DTD film-forming additives. The total height H1 of the cylindrical shell is 65.0 mm, the outer diameter D is 21.0 mm, the shoulder height H2 is 64.8 mm, and the lower end height H5 is 62.3 mm. The distance from H2 to HJ is 3.8 mm, and the distance from H5 to HJ is 1.3 mm.

[0086] In this embodiment, Vcell = π × (D / 2) 2 Calculate the external volume of the shell by ×H1 / 1000, where H1 and D are in mm, and Vcell is in cm. 3The calculated value of Vcell is approximately 22.5 cm. 3 The volume V of the internal bufferable cavity was measured using CT 3D segmentation. void It is 0.66cm 3 Discharge capacity C at 25℃ and 0.2C 0.2 The gas production is 5.02 Ah. After storage at 85℃ for 168 hours, the gas production G, calculated at 25℃ and 101 kPa, is 0.42 mL. Therefore, V... void / C 0.2 It is 0.131cm 3 / Ah, GC is 0.084mL / Ah, Kg is 1.57.

[0087] Example 2 The difference between Example 2 and Example 1 is that by adjusting the height of the core after flattening to 61.6 mm and adjusting the thickness of the negative end pad to 0.10 mm, the internal buffer cavity volume V is increased. void From 0.66cm 3 It became 0.54cm 3 V void / C 0.2 From 0.131cm 3 / Ah becomes 0.108cm 3 / Ah, Kg changed from 1.57 to 1.26.

[0088] Example 3 The difference between Example 3 and Example 1 is that by adjusting the height of the core after flattening to 60.3mm and adjusting the height of the end insulation to 0.35mm, the internal buffer cavity volume V is increased. void From 0.66cm 3 It becomes 0.78 cm3, V void / C 0.2 From 0.131cm 3 / Ah becomes 0.157cm 3 / Ah, Kg changed from 1.57 to 1.86.

[0089] Example 4 The difference between Example 4 and Example 1 is that by adjusting the total mass fraction of film-forming additives to 2.2% and adjusting the formation cutoff current to 0.03C, the gas production G after 168h storage at 85℃ changed from 0.42mL to 0.30mL, GC changed from 0.084mL / Ah to 0.060mL / Ah, and Kg changed from 1.57 to 2.20.

[0090] Example 5 The difference between Example 5 and Example 1 is that by adjusting the formation temperature to 45°C and the high-temperature aging time to 36h, the gas production G after 168h storage at 85°C changed from 0.42mL to 0.70mL, GC changed from 0.084mL / Ah to 0.140mL / Ah, and Kg changed from 1.57 to 0.94.

[0091] Example 6 The difference between Example 6 and Example 1 is that: by adjusting the height of the core after flattening to 61.5mm and adjusting the formation and aging conditions to reduce the gas production G to 0.61mL, V void From 0.66cm 3 It became 0.55cm 3 The GC concentration decreased from 0.084 mL / Ah to 0.122 mL / Ah, and the Kg concentration decreased from 1.57 to 0.90.

[0092] Example 7 The difference between Example 7 and Example 1 is that the height of the core after flattening was adjusted to 60.0 mm, and the surface density of the positive electrode was adjusted to 12.7 mg / cm³. 2 And adjust the total mass fraction of film-forming additives to 2.5%, so that V void From 0.66cm 3 It became 0.82cm 3 G changed from 0.42 mL to 0.32 mL, and Kg changed from 1.57 to 2.56.

[0093] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that by adjusting the height of the core after flattening to 62.0 mm and adjusting the thickness of the end insulation to 0.05 mm, the internal buffer cavity volume V is increased. void From 0.66cm 3 It became 0.35cm 3 V void / C 0.2 From 0.131cm 3 / Ah becomes 0.070cm 3 / Ah, Kg changed from 1.57 to 0.80.

[0094] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that by adjusting the high-temperature aging time to 12h and adjusting the total mass fraction of film-forming additives to 0.3%, the gas production G after 168h storage at 85℃ changed from 0.42mL to 0.95mL, GC changed from 0.084mL / Ah to 0.190mL / Ah, and Kg changed from 1.57 to 0.69.

[0095] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that by adjusting the injection volume to 18.6g and the standing time to 10h, the free liquid ratio changed from 4.5% to 12.0%, thus increasing the buffer cavity volume V. void From 0.66cm 3 It became 0.55cm 3 The weight decreased from 1.57 kg to 0.92 kg.

[0096] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that by adjusting the height of the core after flattening to 62.0 mm and adjusting the thickness of the lower end pad to 0.03 mm, H2-HJ changes from 3.8 mm to 2.1 mm and H5-HJ changes from 1.3 mm to 0.3 mm.

[0097] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the height of the core after flattening was adjusted to 61.9 mm, the high-temperature aging time was adjusted to 12 h, and the total mass fraction of the film-forming additive was adjusted to 0.2%, thus achieving V void From 0.66cm 3 It became 0.38cm 3 G changed from 0.42 mL to 0.85 mL, and Kg changed from 1.57 to 0.45.

[0098] Performance testing 1. Capacity test at 25℃ and 0.2C After capacity testing, the battery cell was left to stand at 25°C for 12 hours, then charged at a constant current of 0.2C to 4.2V, followed by constant voltage charging to a cutoff current of 0.05C. After standing for 30 minutes, it was discharged at a constant current of 0.2C to 2.5V, and the discharge capacity C was recorded. 0.2 At least three cells were tested in each embodiment or comparative example, and the average value was taken as C. 0.2 .

[0099] 2. Internal bufferable cavity volume Vvoid test Industrial CT was used for non-destructive scanning of the battery cell, with a voxel size no larger than 20 μm. Three-dimensional segmentation software was used to identify the shell, cap assembly, core solid phase, end cavities, radial gap cavities, and liquid phase region. The volume of the first end cavity between the positive end face of the core and the cap assembly, the second end cavity between the negative end face of the core and the bottom of the shell, and the radial gap cavity between the outer periphery of the core and the inner wall of the shell were added together, and the volume of the liquid phase occupied by the free electrolyte was subtracted to obtain V. void If necessary, the battery cell is disassembled in an inert atmosphere, and the CT results are verified by calculating the difference between the net volume of the casing, the volume of the core after draining, the volume of the structural components, and the volume of the free liquid.

[0100] 3. Gas production test during 85℃ high-temperature storage The battery cell was charged to 100% SOC and stored in an 85°C hot chamber for 168 hours. After storage, the cell was cooled to 25°C, and the casing was punctured or opened in a sealed gas collection device to collect the released gas volume. The gas volume was converted to G at 25°C and 101 kPa. If a pressure method was used for testing, the initial pressure, final pressure, container volume, and temperature of the sealed container were recorded, and converted to the gas volume at 25°C and 101 kPa using the ideal gas law. The formula GC = G / C was then calculated. 0.2 and Kg=V void / G.

[0101] 4. DCR test before and after storage The battery cell was adjusted to 50% SOC and left to stand at 25℃ for 2 hours. The discharge rate (DCR) before storage was tested using a 10-second discharge pulse method. After storage at 85℃ for 168 hours and then returning to 25℃, the DCR was retested under the same SOC and pulse conditions. The DCR growth rate was calculated using the following formula: DCR growth rate = (DCR) after -DCR before ) / DCR before ×100%.

[0102] 5. Casing bulge test The maximum outer diameter and total height of the battery cell before and after storage are measured using a laser diameter gauge or a 2D projector. The maximum radial bulge of the casing, ΔD, is the difference between the maximum outer diameter after storage and the maximum outer diameter before storage. If necessary, the diameter is measured along the axial direction of the battery cell in the adjacent areas of the positive and negative ends, and the maximum change value is taken as ΔD.

[0103] 6. Re-measurement of gas production, bulging, and internal resistance after circulation. At 25°C, the sample was cycled 300 times with an 8A charge and a 40A discharge, with the discharge cutoff voltage at 2.5V or the temperature safety cutoff condition. After cycling, C0.2, DCR, shell dimensions, and safety valve status were remeasured; if necessary, the post-cycle sample was CT scanned or disassembled to determine residual V. void The ratio of free liquid and the state of gas production after circulation.

[0104] 7. Determining the safety valve or pressure relief margin After high-temperature storage and cycling, observe the safety valve for signs of operation, including cap deformation, open pressure relief port, abnormal weight loss, abnormal voltage drop, or visible liquid spray marks. For samples that do not operate, the adequacy of the pressure relief margin can be determined by considering the shell bulge, DCR growth rate, and gas production.

[0105] The test results are shown in Table 1.

[0106] Table 1 As shown in Table 1, comparing Example 2, Example 3 and Comparative Example 1, the unit capacity buffer cavity volume V void / C 0.2 It is a crucial structural parameter that determines the internal pressure distribution after gas generation in a short-capacity 5Ah battery cell. Example 2 uses V... void / C 0.2 Controlled within 0.108cm 3 / Ah, Example 3 controlled at 0.157cm 3 Both [Ah] and [other components] maintained low DCR growth and minimal shell bulging after storage at 85°C. Comparative Example 1, although still in the 5Ah range and with no significant increase in gas production per unit capacity, [had a higher V]. void / C 0.2 Reduced to 0.070cm 3 / Ah, the lack of compressible and dispersible end / radial space for the gas leads to localized internal pressure concentration, increasing the bulge to 0.18 mm and raising the DCR growth rate to 25.0%. This illustrates that the V defined in this invention... void / C 0.2 The range is not simply about sacrificing core load to achieve a cavity, but rather about establishing a measurable balance between short-height geometry, capacity, and safety margin. Within this range, the cell can still maintain a capacity of 4.9Ah to 5.2Ah, while gas from high-temperature storage can be buffered by end and radial gaps.

[0107] Comparing Examples 4 and 5 with Comparative Example 2, it can be seen that the gas production rate (GC) per unit capacity reflects the gas production load of the high-nickel cathode, silicon-carbon anode, and electrolyte system at a capacity of 5 Ah. In Example 4, by adjusting the film-forming additives and formation conditions, the GC was reduced to 0.060 mL / Ah, resulting in low DCR growth and bulging. In Example 5, the GC was increased to 0.140 mL / Ah, which, although close to the upper limit, was still within the acceptable range. void Even when the end margin is still within the acceptable range, the cell's safety valve has not activated. In Comparative Example 2, the GC level rose to 0.190 mL / Ah, exceeding the scope of this invention, even if V... void Maintain at 0.66cm 3 The Kg still decreased to 0.69, indicating that the gas production had exceeded the stable buffering capacity of the short-height shell. This comparison shows that simply retaining the cavity cannot solve the problem of excessive gas production load; GC and V must be combined. void Only through joint constraints can we prevent the internal pressure from rising, the interface from deteriorating, and the safety valve from activating after high-temperature storage.

[0108] Comparing Examples 6 and 7 with Comparative Example 5, it can be seen that the gas buffer coefficient Kg can simultaneously reflect the matching degree of gas production and buffer space. In Example 6, Kg is 0.90, near the lower boundary, indicating that DCR growth and expansion are close to the acceptable upper limit. In Example 7, Kg is 2.56, indicating that the buffer space is sufficient relative to the gas production, and the DCR growth after storage is low, but the capacity is close to the lower limit, suggesting that excessively high Kg may also be accompanied by a reduction in effective loading space. Comparative Example 5 simultaneously reduces V... void Increasing G to reduce Kg to 0.45 resulted in a maximum bulge of 0.28 mm, a DCR increase of 38.0%, and safety valve activation. This demonstrates that Kg is not arbitrarily high; it should fall within the matching window defined by this invention. This window can eliminate deviations from the combination of "insufficient cavity + excessive gas production" and also avoids sacrificing capacity to obtain excessive buffer space.

[0109] Comparing Example 1 and Comparative Example 4, it can be seen that the end allowances H2-HJ and H5-HJ are used to ensure V void It has a practically bufferable position and shape. Comparative Example 4's V void It is 0.65cm 3 It is close to 0.66 cm in Example 1. 3 GC and Kg did not deviate significantly, but H2-HJ decreased to 2.1 mm and H5-HJ decreased to 0.3 mm, indicating that the buffer space is more of a local non-uniform gap, rather than an axial cavity that can participate in buffering on both the cap side and the bottom side of the shell. After high-temperature storage, the radial bulge and DCR growth of Comparative Example 4 were significantly higher than those of Example 1, indicating that gas is prone to local pressure concentration near the flattened end of the full-tab, which in turn affects end flow collection and interface contact. This invention uses the end margin as a structural auxiliary limitation, which can prevent the use of only total V void This addresses the issue of insufficient end space, ensuring a true connection between gas generation buffering capacity and the short-high all-hole tab structure.

[0110] Comparing Example 1 and Comparative Example 3, it is clear that simply increasing the injection volume or free liquid does not equate to improving gas production buffering capacity. Comparative Example 3 increased the injection volume to raise the free liquid ratio to 12.0%, which superficially benefits wetting, but the free liquid occupies space that could otherwise be used for gas buffering, thus reducing V... void Reduced to 0.55cm 3 The weight decreased to 0.92 kg. After high-temperature storage, the DCR growth rate and bulging amount of Comparative Example 3 were both higher than those of Example 1, indicating that excess free liquid in the short-height shell can compress the gas phase buffer margin and may promote side reactions or uneven gas-liquid migration at high temperatures. Example 1 used V voidBy limiting the volume occupied by the liquid phase and using GC and Kg measurements together, this design distinguishes itself from a simple liquid injection approach. This design allows the 5Ah short-height cell to retain the necessary wetting without sacrificing gas buffer space.

[0111] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0112] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0113] It should be noted that the terms "and / or" or " / " used herein are merely descriptions of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The singular forms "a," "described," and "the" used in the embodiments of the invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0114] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cylindrical battery, characterized in that, It includes: a housing, and a battery cell and an electrolyte disposed in the housing, the battery cell including a positive electrode, a separator and a negative electrode; at least one end of the housing is provided with an opening in a direction perpendicular to the radial direction of the housing, the open end being connected to a cover plate assembly; The cylindrical battery satisfies: 0.95 ≤ Kg ≤ 2.80, Kg = V void / G, G≠0; Where G is the gas volume generated by the cylindrical battery after storage at 85°C for 168 hours, converted to the gas volume under conditions of 25°C and 101 kPa, in mL; V void The internal volume of the cylindrical battery after the cell has undergone formation and capacity testing, excluding the cell and the electrolyte, is expressed in cm³. 3 .

2. The cylindrical battery according to claim 1, characterized in that, Satisfying at least one of features (1) to (3): (1)1.20≤Kg≤2.30;(2)0.50cm 3 ≤V void ≤0.85cm 3 ;(3)0.25mL≤G≤0.78mL。 3. The cylindrical battery according to claim 1 or 2, characterized in that, 0.58cm 3 ≤V void ≤0.76cm 3 ; And / or, 0.30mL≤G≤0.62mL.

4. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery also satisfies: 0.095 ≤ V void / C 0.2 ≤0.170; And / or, 0.050≤G / C 0.2 ≤0.155; where C 0.2 The discharge capacity of the cylindrical battery at 25°C and 0.2C is expressed in Ah; and C... 0.2 ≠0.

5. The cylindrical battery according to claim 4, characterized in that, Satisfying at least one of features (1) to (3): (1)0.110≤V void / C 0.2 ≤0.155; (2)0.060≤G / C 0.2 ≤0.125; (3) 4.9Ah≤C 0.2 ≤5.2Ah.

6. The cylindrical battery according to claim 1, characterized in that, The shell is a hollow cylindrical shape; In a direction perpendicular to the radial direction of the housing, the housing has a radially spaced groove near the open end; the total height of the housing is H1, in mm; the height of the battery cell is HJ, in mm; the maximum radial dimension of the housing is D, in mm; the dimension from the end of the housing away from the open end to the end of the groove away from the open end is H5, in mm. Wherein, 2.6mm≤H2-HJ≤5.0mm; and / or, 0.6mm≤H5-HJ≤2.4mm; and / or, 3.06≤H1 / D≤3.

14.

7. The cylindrical battery according to claim 6, characterized in that, Satisfying at least one of features (1) to (4): (1) The value range of H1 is 63.5mm~66.5mm; (2) The value of D ranges from 20.6 mm to 21.5 mm; (3) In the direction perpendicular to the radial direction of the housing, the size of the groove is H4, 0.15mm≤H4≤0.45mm; (4) In the radial direction of the housing, the depth of the groove is 1.3mm~1.9mm.

8. The cylindrical battery according to claim 1, characterized in that, The positive electrode sheet includes a positive current collector and a positive electrode coating disposed on at least one surface of the positive current collector in the thickness direction, the positive electrode coating including a positive electrode active material; The positive electrode also satisfies at least one of features (1) to (3): (1) The positive electrode active material comprises a layered high-nickel lithium transition metal oxide with a nickel molar content of 88 mol% to 93 mol%; (2) The areal density of the positive electrode coating on one side of the positive electrode sheet is 12.3 mg / cm³. 2 ~14.0 mg / cm 2 (3) The compaction density of the positive electrode sheet is 3.45 g / cm³. 3 ~3.65g / cm 3 ; And / or, the negative electrode sheet includes a negative electrode current collector and a negative electrode coating disposed on at least one side surface of the negative electrode current collector in the thickness direction, the negative electrode coating including a negative electrode active material; The negative electrode also satisfies at least one of features (1) to (3): (1) The negative electrode active material includes at least one of graphite and silicon-carbon materials; (2) The areal density of the negative electrode coating on one side of the negative electrode sheet is 5.3 mg / cm³. 2 ~6.2mg / cm 2 (3) The compaction density of the negative electrode sheet is 1.50 g / cm³. 3 ~1.65g / cm 3 ; And / or, the electrolyte comprises a lithium salt and an additive, wherein the lithium salt comprises at least one of LiPF6, LiFSI and LiDFOB, and the additive comprises at least one of vinylene carbonate, fluorovinyl carbonate, 1,3-propane sulpholactone and ethylene sulfate.

9. The cylindrical battery according to claim 1, characterized in that, Satisfying at least one of features (1) to (3): (1) After the cylindrical battery is stored at 85°C for 168 hours, the DCR growth rate at 25°C and 50% SOC is less than or equal to 18%; (2) After the cylindrical battery is stored at 85°C for 168 hours, the radial expansion of the casing is less than or equal to 0.12 mm; (3) After the cylindrical battery is charged at 25°C and discharged at 8A for 300 cycles, the DCR growth rate is less than or equal to 22%, and the radial expansion of the casing is less than or equal to 0.16 mm.

10. An electrical appliance, characterized in that, include: The cylindrical battery according to any one of claims 1 to 9.

Images