Battery and power-consuming device

Abstract

Battery, including: several battery cells arranged along the thickness direction of the battery cells, the battery cell comprising a housing and an electrode arrangement received in the housing; and a box body for receiving the multiple battery cells, wherein the box body comprises at least two boundary beams, wherein two adjacent boundary beams are arranged on one of the two sides of the multiple battery cells along the thickness direction, wherein the expansion pressure of the battery cell in the thickness direction is 0.5 MPa to 2.4 MPa, and the boundary beam comprises a first side surface facing the multiple battery cells, wherein the first side surface is designed such that the maximum displacement of the first side surface in the thickness direction at a pressure of 1.7 MPa is less than or equal to 8 mm.

Description

Technical field

[0001] The present application relates to the technical field of batteries, in particular a battery and a power-consuming device. State of the art

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools, etc.

[0003] In the development of battery technology, improving the reliability of batteries represents a research direction in battery technology. Disclosure of the invention

[0004] The present application provides a battery and a power-consuming device, which can increase the reliability of the battery.

[0005] In a first aspect, the embodiments of the present application provide a battery comprising multiple battery cells and a housing. The multiple battery cells are arranged along the thickness direction of the battery cells, each battery cell comprising a housing and an electrode assembly received in the housing. The housing serves to receive the multiple battery cells and comprises at least two limiting beams, with two adjacent limiting beams each being arranged on one of the two sides of the multiple battery cells along the thickness direction. The expansion pressure of the battery cell in the thickness direction is 0.5 MPa to 2.4 MPa. The limiting beam comprises a first side surface facing the multiple battery cells, the first side surface being configured such that the maximum displacement of the first side surface in the thickness direction at a pressure of 1.7 MPa is less than or equal to 8 mm.

[0006] The expansion pressure of the battery cell is related to the density of the electrode arrangement. According to the embodiments of this application, the limiting beam has a higher strength, allowing the battery cell to exhibit an expansion pressure greater than or equal to 0.5 MPa in the thickness direction, thereby increasing the density of the electrode arrangement and improving the energy density of the battery cell. The expansion pressure of the battery cell in the thickness direction is less than or equal to 2.4 MPa, and the limiting beam exhibits higher resistance to deformation.Therefore, the battery cell's boundary beam can provide effective constraints in the thickness direction to reduce deformation of the electrode assembly during the cycling process, decrease the risk of wrinkling of the electrode assembly's separator, reduce the risk of local gap expansion between the positive and negative electrode sheets, reduce polarization, and improve the battery cell's cycle performance. According to the present application, by regulating the expansion pressure of the battery cell within a reasonable range and appropriately designing the boundary beam, the deformation of the battery cell and the boundary beam can be reduced, the risk of the box body cracking decreased, and the battery cell's cycle performance improved.

[0007] In some embodiments, the expansion pressure of the battery cell in the thickness direction is 1.5 MPa to 2.0 MPa, which reduces the deformation of the limiting beam, decreases the risk of cracking of the box body, and improves the cycle performance of the battery cell. By limiting the expansion pressure of the battery cell to 1.5 MPa to 2.0 MPa, the required strength of the limiting beam can be reduced, thus lowering costs.

[0008] In some embodiments, the electrode arrangement comprises two first surfaces and two second surfaces, wherein the two first surfaces are arranged opposite each other along the thickness direction, and the two second surfaces are arranged opposite each other along a direction perpendicular to the thickness direction, with the second surface connecting the two first surfaces. The area of ​​the first surface is larger than the area of ​​the second surface. By arranging the first surface with a larger area relative to the first side surface along the thickness direction, the load-bearing area of ​​the boundary beam can be increased and the deformation of the boundary beam reduced when the battery arrangement expands.

[0009] In some embodiments, the first surface runs parallel to the first side surface, which reduces the stress concentration during the expansion of the electrode arrangement, reduces the local deformation of the limiting beam, improves the uniformity of the load distribution on the electrode arrangement, and can increase the cycle performance of the battery cell.

[0010] In some embodiments, the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material.

[0011] In some embodiments, the one-sided coating weight of the negative electrode film layer is 90 mg / 1540.25 mm². 2 up to 170 mg / 1540.25 mm 2, optional 110 mg / 1540.25 mm 2 up to 150 mg / 1540.25 mm 2 The one-sided coating weight of the negative electrode film layer is related to the expansion of the negative electrode film layer. By limiting the one-sided coating weight of the negative electrode film layer to the area mentioned above, both the energy density and the expansion pressure of the battery cell can be ensured to a certain extent simultaneously, thereby reducing the deformation of the battery cell and the limiting bar.

[0012] In some embodiments, the compaction density of the negative electrode film layer at 100% SOC of the battery cell is 1.15 g / cm³. 3 up to 1.36 g / cm³ 3 , optional 1.25 g / cm² 3 up to 1.36 g / cm³ 3The density of the negative electrode film layer is related to the expansion of the battery cell at 100% charge. By limiting the density of the negative electrode film layer to the range mentioned above, both the energy density and the expansion pressure of the battery cell can be ensured to a certain extent simultaneously, thereby reducing the deformation of the battery cell and the limiting bar.

[0013] In some embodiments, the porosity of the negative electrode sheet is between 27% and 40%. A negative electrode sheet porosity greater than or equal to 27% can provide space for impurities generated by side reactions of the negative electrode sheet, slow the expansion of the negative electrode sheet, reduce the expansion pressure of the battery cell, minimize deformation of the battery cell and the boundary bar, and improve the cycle performance of the battery cell. A negative electrode sheet porosity of less than or equal to 40% can simultaneously ensure the energy density of the battery cell.

[0014] In some embodiments, the negative electrode active material comprises at least one synthetic graphite and one natural graphite. Both synthetic and natural graphite exhibit excellent conductivity, which reduces heat generation in the negative electrode sheet and improves the fast-charging performance of the battery cell.

[0015] In some embodiments, the negative electrode active material comprises a silicon-based material, wherein the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 0.3% to 10%, optionally 1% to 6%. Introducing the silicon-based material into the negative electrode sheet increases both the capacity and the energy density of the battery cell, but also increases the size of the negative electrode sheet. Therefore, by limiting the mass fraction of the element silicon in the negative electrode active material to 0.3% to 10%, both the energy density and the size of the battery cell can be maintained to a certain extent simultaneously, thereby reducing the deformation of the battery cell and the boundary beam and improving the cycle performance of the battery cell.

[0016] In some embodiments, the silicon-based material comprises at least one silicon oxide compound and a silicon-carbon composite.

[0017] In some embodiments, the negative electrode film layer comprises a first negative electrode film layer and a second negative electrode film layer, the second negative electrode film layer being arranged between the first negative electrode film layer and the negative electrode current collector. The negative electrode active material comprises a first negative electrode active material arranged in the first negative electrode film layer and a second negative electrode active material arranged in the second negative electrode film layer, the first negative electrode active material comprising synthetic graphite and the second negative electrode active material comprising one or more synthetic graphite, natural graphite, and silicon-based materials.The first negative electrode film layer and the second negative electrode film layer can be designed differently, thereby ensuring both the extent and the capacity of the negative electrode film layer to a certain extent simultaneously; the double-layer coating makes it possible to build up the pore difference of the negative electrode film layer, reduce the tortuosity of ion transport, reduce side reactions and improve the fast charging performance of the battery cell.

[0018] In some embodiments, the ratio of the thickness of the first negative electrode film layer to the thickness of the second negative electrode film layer is 3:7 to 7:3, optionally 4:6 to 6:4. By adjusting the ratio of the thickness of the first negative electrode film layer to the thickness of the second negative electrode film layer, the gradient pore difference between the upper and lower layers can be further increased, the tortuosity of lithium ion transport reduced, and the fast-charging capability of the battery cell improved.

[0019] In some embodiments, the thickness of the first negative electrode film layer is less than or equal to the thickness of the second negative electrode film layer, which can further improve the fast charging capability of the battery cell.

[0020] In some embodiments, the volume-averaged particle size Dv50 of the first negative electrode active material is less than or equal to the volume-averaged particle size Dv50 of the second negative electrode active material.

[0021] The particle size of the first and second negative electrode active materials differs, which can improve the fast-charging performance of the battery cell. During fast charging, the overpotential of the first negative electrode film layer is typically higher, and the bottleneck during fast charging is mainly located in this layer. In the embodiments of the present application, the particle size of the first negative electrode active material is relatively small, which can shorten the solid-phase transport path of the ions, improve fast-charging performance, and reduce the problem of ion deposition on the surface of the negative electrode sheet. The larger particle size of the second negative electrode active material allows for the formation of larger pores in the second negative electrode film layer.During charging, the pores can absorb the expansion, reducing the amount of expansion of the negative electrode film layer and reducing the deformation of the battery cell and the limiting bar.

[0022] In some embodiments, the volume-averaged particle size Dv50 of the first negative electrode active material is 7.8 µm to 14.3 µm, optionally 7.8 µm to 11.3 µm. The volume-averaged particle size Dv50 of the second negative electrode active material is 9.5 µm to 18.5 µm, optionally 9.5 µm to 14.6 µm.

[0023] By setting the volume-averaged particle size Dv50 of the first negative electrode active material to the above range, the solid-phase transport path of lithium ions can be shortened and the fast-charging performance improved; on the other hand, the material does not agglomerate as easily during the manufacturing process, which can improve the material's stability; furthermore, the first negative electrode active material in the above volume-averaged particle size range can interact with the second negative electrode active material, which is advantageous for establishing a gradient pore difference between the first negative electrode film layer and the second negative electrode film layer, reducing the tortuosity of lithium ion transport and improving the fast-charging performance of the battery cell.If the volume-averaged particle size Dv50 of the second negative electrode active material is 9.5 µm to 18.5 µm, the pores of the second negative electrode film layer can be made richer, which has a positive effect on improving the fast charging capability of the battery cell and reduces the expansion of the negative electrode film layer during the charging process.

[0024] In some embodiments, the specific surface area of ​​the negative electrode active material is 0.5 m². 2 / g up to 3 m 2 / g, optional 0.6 m 2 / g up to 1.2 m 2 / g. By limiting the specific surface area of ​​the negative electrode active material to greater than or equal to 0.5 m² 2 The fast-charging capability of the battery cell can be increased by limiting the specific surface area of ​​the negative electrode active material to less than or equal to 3 m². 2 / g can reduce side reactions of the battery cell during storage and decrease the expansion pressure.

[0025] In some embodiments, the electrode arrangement comprises a positive electrode sheet, wherein the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material, the positive electrode active material being a lithium-containing phosphate. The lithium-containing phosphate exhibits high cycle stability. The use of the lithium-containing phosphate as the positive electrode active material can reduce the cycle degradation of the battery cell caused by the excessive temperature rise during fast charging.

[0026] In some embodiments, the one-sided coating weight of the positive electrode film layer is 200 mg / 1540.25 mm². 2 up to 370 mg / 1540.25 mm 2 , optional 240 mg / 1540.25 mm 2 up to 330 mg / 1540.25 mm 2 . If the one-sided coating weight of the positive electrode film layer is set in the above range, the amount of heat generated per unit area of ​​the positive electrode sheet can be limited, thus ensuring the increase in energy density and charging rate performance of the battery cell simultaneously.

[0027] In some embodiments, the compaction density of the positive electrode film layer at 100% SOC of the battery cell is 2.50 g / cm³. 3 up to 2.80 g / cm³ 3 , optional 2.55 g / cm² 3 up to 2.70 g / cm³ 3If the density of the positive electrode film layer is within the above range, this is advantageous for increasing the energy density of the battery cell; and because the positive electrode active material in the positive electrode film layer is relatively densely packed, and the contact resistance between the particles is low, the resistance of the positive electrode sheet can be further reduced, thereby decreasing heat generation during fast charging.

[0028] In some embodiments, the porosity of the positive electrode sheet is between 25% and 32%. A porosity of 25% or higher can provide space for impurities generated by side reactions within the positive electrode sheet, reduce the expansion pressure of the battery cell, minimize deformation of the battery cell and the boundary bar, and improve the battery cell's cycle life. A porosity of 32% or lower can simultaneously ensure the battery cell's energy density.

[0029] In some embodiments, the thickness of the positive electrode sheet is 0.13 mm to 0.2 mm. By using a thinner positive electrode sheet, the migration path of ions can be shortened, the migration rate of ions increased, the heat generation of the battery cell reduced, and the fast-charging performance of the battery cell improved.

[0030] In some embodiments, the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer is 0.05 to 0.3. By limiting the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer to greater than or equal to 0.05, the current-carrying capacity of the positive electrode current collector can be increased, the temperature rise of the positive electrode sheet reduced, and the fast-charging performance of the battery cell improved; by limiting the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer to less than or equal to 0.3, the capacity loss of the positive electrode sheet can be reduced.In the embodiments of the present application, the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer is limited to 0.05 to 0.3, which ensures both the fast charging capability and the energy density of the battery cell to a certain extent simultaneously.

[0031] In some embodiments, the volume-averaged particle size of the positive electrode active material meets the conditions 1 µm ≤ Dv50 ≤ 2 µm and 0.4 µm ≤ Dv10 ≤ 0.7 µm. The particle size of the positive electrode active material is relatively small, resulting in a short deintercalation and intercalation path of lithium ions within the positive electrode active material and a low amount of heat generation. Furthermore, the particle size of the above positive electrode active material is not too small, thus reducing agglomeration during the processing and manufacturing process, and ensuring stable performance of the positive electrode active material.

[0032] In some embodiments, the battery cell comprises an electrolyte solution contained within the housing.

[0033] In some embodiments, the conductivity of the electrolyte solution at room temperature is 15 mS / cm to 20 mS / cm. If the conductivity of the electrolyte solution is within the above range, the migration rate of ions in the electrolyte solution is relatively high, which can further reduce the internal resistance of the battery cell, thereby reducing heat generation and thus improving the fast-charging performance of the battery cell.

[0034] In some embodiments, the electrolyte solution comprises an organic solvent, wherein the organic solvent includes one or more carbonate solvents and carboxylic acid ester solvents. The combination of organic solvents can improve the conductivity of the electrolyte solution and reduce its viscosity, thereby increasing the fast-charging performance of the battery.

[0035] In some embodiments, the carbonate solvent comprises one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

[0036] In some embodiments, the carboxylic acid ester comprises R1-COO-R2, wherein R1 and R2 each independently comprise an alkyl group with 1 to 5 carbon atoms or a halogenated alkyl group with 1 to 5 carbon atoms. The chain-like carboxylic acid ester solvent exhibits high electrical conductivity, which has a positive effect on improving the fast-charging capability of the battery cell.

[0037] In some embodiments, the electrolyte solution comprises a lithium salt, wherein the lithium salt comprises lithium bis(fluorosulfonyl)imide LiFSI and lithium hexafluorophosphate LiPF6, wherein the molar concentration of the lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L to 0.5 mol / L and the molar concentration of the lithium hexafluorophosphate LiPF6 is 0.5 mol / L to 1.0 mol / L.

[0038] In some embodiments, the density ρ of the electrolyte solution at room temperature satisfies the condition 1.05 g / mL ≤ ρ ≤ 1.35 g / mL. If the density ρ of the electrolyte solution is within the above range, the migration rate of lithium ions in the electrolyte solution is relatively high, which can further reduce the internal resistance of the battery cell, thereby reducing heat generation and thus improving the fast-charging performance of the battery cell.

[0039] In some embodiments, the electrode arrangement comprises a negative electrode sheet; the dimension of the electrode arrangement along the thickness direction is denoted by T, the thickness of the negative electrode sheet by T1, and the number of layers of the negative electrode sheet stacked in the thickness direction by N. T, T1, and N satisfy the condition 0.3 ≤ (N × T1) / T ≤ 0.5. During the battery cell's cycle process, the thickness of the negative electrode sheet increases due to irreversible side reactions, leading to expansion of the battery cell; by limiting (N × T1) / T to between 0.3 and 0.5, the expansion of the battery cell and the deformation of the limiting beam can be reduced.

[0040] In some embodiments, the distance between two adjacent boundary beams in the thickness direction is designated D1. Several battery cell rows are arranged between adjacent boundary beams, the multiple battery cell rows being arranged along a direction perpendicular to the thickness direction, and each battery cell row comprising at least two battery cells arranged along the thickness direction. The overall dimension of the electrode arrangements of the battery cells in the battery cell row in the thickness direction is designated D2; where 85% ≤ D2 / D1 ≤ 92%.

[0041] D2 / D1 is related to the expansion pressure exerted by the battery cell on the limiting beam. Limiting D2 / D1 to less than or equal to 92% reduces the expansion pressure of the battery cell, decreases the deformation of the limiting beam and the battery cell, and reduces the risk of the box cracking. Limiting D2 / D1 to greater than or equal to 85% improves space utilization in the thickness direction and increases the battery's energy density. Limiting D2 / D1 to between 85% and 92% allows for a degree of simultaneous consideration of both the expansion pressure of the battery cell and the battery's energy density.

[0042] In some embodiments, the boundary beam comprises a second side surface, wherein the second side surface is arranged on the side of the boundary beam facing away from the multiple battery cells and is inclined towards the first side surface.

[0043] When the battery cell expands during the cycling process and exerts a force on the boundary beam, the inclination of the second side face can dissipate this force, thereby increasing the deformation resistance of the boundary beam and reducing deformation or displacement of the first side face. The first side face can thus provide stronger restraint for the battery cell, reducing expansion deformation and improving the battery cell's cycle performance. Compared to a solution where the boundary beam's deformation resistance is increased by simply increasing its size, this solution, which uses the inclined second side face to increase deformation resistance, can reduce the boundary beam's weight and increase the battery's energy density.

[0044] In some embodiments, the angle α between the first and second face is between 1° and 25°. Setting the angle α to 1° or greater ensures that the boundary beam has high structural strength and stiffness, thereby increasing its resistance to deformation. Setting the angle α to 25° or less limits the maximum thickness dimension of the boundary beam, saving space and optimizing its use in that direction.

[0045] In some embodiments, the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L, and the angle α between the first and second sides is 5° to 20°. The expansion of the battery cell is related to its volume energy density. The present application specifies the angle α according to the volume energy density of the battery cell in order to ensure, to a certain extent, that the battery's requirements for expansion pressure and energy density are met simultaneously.

[0046] In some embodiments, the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L, and the angle α between the first and second side faces is 8° to 25°. The battery cell exhibits a higher energy density, and its expansion pressure is also greater; increasing the angle α allows the battery cell's limiting bar to provide more confining force, thereby improving the battery cell's cycle performance.

[0047] In some embodiments, the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material comprising at least one silicon oxide compound and one silicon-carbon composite. The angle α between the first side surface and the second side surface is 8° to 25°.

[0048] The introduction of silicon oxide or silicon-carbon composite materials can increase the capacity of the negative electrode sheet and thus the energy density of the battery cell. However, these materials also lead to increased expansion of the negative electrode sheet during the cycling process. By setting the angle α to between 8° and 25°, the deformation resistance of the limiting beam can be increased, thereby limiting the expansion of the battery cell and reducing the risk of cycle degradation that can result from the introduction of silicon oxide or silicon-carbon composite materials.

[0049] In some embodiments, the boundary beam comprises a third side surface, wherein the third side surface is located on the side of the boundary beam facing away from the battery cell and is parallel to the first side surface, and the third side surface is connected to the second side surface. The third side surface allows the maximum dimension of the boundary beam to be limited in the thickness direction and increases the space utilization. By combining the third and second side surfaces, the boundary beam can form an approximately trapezoidal cross-section, thereby increasing the structural strength and stiffness of the boundary beam and reducing its deformation.

[0050] In some embodiments, the box body comprises a frame body and a support beam, the frame body defining a receiving space in which the boundary beams and the multiple battery cells are arranged. The support beam is arranged on the side of the boundary beam facing away from the multiple battery cells and connects the frame body and the boundary beam.

[0051] During the battery's cycling process, the limiting bar serves to counteract the expansion forces of the battery cells. The frame body can support the limiting bar with its support beams, thus providing effective support and reducing its deformation. This, in turn, restricts the expansion of the battery cells and increases their cycle life.

[0052] In some embodiments, the limiting beam extends along a direction perpendicular to its thickness. The box body includes several support beams spaced apart along the extension direction of the limiting beam. These multiple support beams can increase the confining force acting on the limiting beam, improve the uniformity of the load distribution in different areas of the limiting beam, reduce the deformation of the limiting beam during the battery cell's cycle process, and improve the battery's cycle performance.

[0053] In some embodiments, the boundary beam also comprises a second side surface and a third side surface, the third side surface being located on the side of the boundary beam facing away from the battery cell and running parallel to the first side surface, and the second side surface being connected to one end of the third side surface and inclined towards the first side surface. The support beam is connected to the third side surface. The third side surface runs perpendicular to the thickness direction. By connecting the support beam to the third side surface, the support beam can effectively brace the boundary beam in the thickness direction, thereby reducing the deformation of the boundary beam.

[0054] In some embodiments, the boundary beam comprises an outer wall and several stiffening ribs, the outer wall enclosing a receiving chamber, with the stiffening ribs arranged within the receiving chamber and connected to the outer wall. The outer wall comprises the first side face. The receiving chamber can provide the boundary beam with a deformation space for energy absorption and reduce the overall weight of the boundary beam, thus increasing the energy density of the battery. The stiffening ribs increase the structural strength and stiffness of the boundary beam and improve its resistance to deformation.

[0055] In some embodiments, the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material being a silicon-based material. The mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1% to 6%; the thickness of the outer wall is 2 mm to 7 mm, and the thickness of the stiffening ribs is 2 mm to 7 mm.

[0056] The introduction of silicon-based material increases the capacity of the negative electrode sheet and the energy density of the battery cell. This material also increases the expansion of the negative electrode sheet during the cycling process. By carefully controlling the thickness of the outer wall and the stiffening ribs, in combination with the silicon content, the risk of deformation of the boundary beam due to the use of silicon-based material can be reduced, thus improving the battery's cycle performance.

[0057] In some embodiments, the outer wall comprises a first side wall and a second side wall spaced apart in the thickness direction, the second side wall being located on the side of the first side wall facing away from the battery cell, and the first side wall comprising a first side surface. The multiple stiffening ribs include first stiffening ribs connected to the first side wall. The expansion deformation of the battery cell during the cycle process exerts a force on the boundary beam, the force acting first on the first side wall. The first stiffening ribs are connected to the first side wall and can transfer the force to other parts of the outer wall as well as support the first side wall, thereby improving the deformation resistance of the first side wall.

[0058] In some embodiments, at least one of the first stiffening ribs is inclined relative to the thickness direction. The expansion deformation of the battery cell during the cycle process exerts a force on the first side wall, with the force component in the thickness direction being relatively large; the first stiffening ribs, which are inclined relative to the thickness direction, can distribute the force and thus reduce the risk of crush failure of the first stiffening ribs.

[0059] In some embodiments, the boundary beam extends along a direction perpendicular to the thickness direction. At least two of the first stiffening ribs are spaced apart along a direction perpendicular to both the extension direction of the boundary beam and the thickness direction, and are inclined in opposite directions relative to the thickness direction. By inclined the at least two first stiffening ribs in opposite directions, the structural strength and stiffness of the boundary beam can be further increased. When the first side wall is subjected to a force in the thickness direction, opposite torque directions act on the two first stiffening ribs, thereby reducing the risk of rotational deformation of the two first stiffening ribs.

[0060] In some embodiments, the angle between the first stiffening ribs and the thickness direction is 30° to 80°. By setting the angle β to 30° to 80°, the pressure and moment acting on the first stiffening ribs can be ensured to a certain extent simultaneously. This reduces the risk of crush failure or rotational deformation of the first stiffening ribs, increases the structural strength and stiffness of the boundary beam, and provides effective restraint for the battery cell.

[0061] In some embodiments, the first side wall comprises a central region and two edge regions, wherein the two edge regions extend from both ends of the central region in a direction parallel to the first side surface and perpendicular to the direction of extension of the boundary beam, and the central region and the edge regions have the same dimensions. At least one of the first stiffening ribs is connected to the central region.

[0062] During the battery cell's cycle process, the center of the cell expands more significantly along its vertical axis. Since the central region of the first sidewall faces the center of the battery cell, the force acting on the central region is generally greater than the force acting on the outer region. By connecting the at least one first stiffening rib to the central region, support can be provided to suppress the expansion deformation of the battery cell during the cycle process.

[0063] In some embodiments, the outer wall comprises a first side wall and a second side wall spaced apart along the thickness direction, the second side wall being located on the side of the first side wall facing away from the multiple battery cells, and the first side wall comprising the first side surface. The second side wall comprises a first section and a second section, the first section being parallel to the first side wall, and the second section extending from an end of the first section and inclined towards the first side wall. At least one of the stiffening ribs is connected to the junction between the first section and the second section.

[0064] During the battery cell's cycle process, the cell expands and exerts a force on the first sidewall. Part of this force can be transferred via the stiffening ribs to the junction between the first and second sections, thus distributing the stress. Both the first and second sections can support the first sidewall via the stiffening ribs, reducing its deformation.

[0065] In some embodiments, the outer wall comprises a first side wall, a second side wall, and a top wall, wherein the second side wall is arranged on the side of the first side wall facing away from the multiple battery cells, the top wall connects the first side wall and the second side wall, and the first side wall comprises the first side surface. The boundary beam also includes a partition connected to the top wall, the partition being arranged in the thickness direction between the first side wall and the second side wall. At least one of the stiffening ribs connects the first side wall and the partition, and at least one of the stiffening ribs connects the second side wall and the partition.

[0066] The arrangement of the partition and stiffening ribs creates a multi-chamber structure within the confining beam, increasing its overall rigidity. During the battery cell's cycle, it expands and exerts a force on the first side wall. The partition can transfer and distribute this force, reducing deformation of the first side wall and effectively confining the battery cell.

[0067] In some embodiments, the boundary beam is designed as a single-piece structure. This reduces weak connection points of the boundary beam, which contributes to increasing its structural strength and stiffness.

[0068] In some embodiments, the battery further comprises an insulating element arranged between the limiting bar and the housing. The insulating element can isolate and separate the limiting bar from the housing, increase the creepage distance between the battery cell and the limiting bar, reduce the risk of short circuits, and increase reliability.

[0069] In some embodiments, the battery further comprises a confining element that connects adjacent limiting beams. During the battery cell's cycling process, the battery cell expands and exerts a force on the limiting beam. The confining element can exert a limiting force on the limiting beam, thereby reducing deformation of the limiting beam, limiting the amount of expansion of the battery cell, improving the cycle performance of the battery cell, and reducing the risk of the battery box cracking.

[0070] In some embodiments, the confining element is connected to the battery cell, thereby increasing the connection strength between the battery cell and the housing. In the event of an impact, the vibration of the battery cell relative to the housing is reduced, thus improving the reliability and stability of the battery.

[0071] In some embodiments, the confining element is glued to the battery cell. Gluing allows for a quick and stable connection between the battery cell and the confining element, thereby increasing the confining force exerted by the element on the battery cell.

[0072] In some embodiments, the restraint element is detachably connected to the limiting beam. This detachable connection facilitates subsequent maintenance or replacement of the restraint element.

[0073] In some embodiments, the battery further comprises a fastening element that connects the restraint element and the limiting beam. At least part of the fastening element is embedded in and secured to the limiting beam. Embedding the fastening element in the limiting beam increases the connection strength between the fastening element and the limiting beam and reduces the risk of connection failure between the fastening element and the limiting beam. The restraint element can be connected to the limiting beam via the fastening element, with the connection of the fastening element to the restraint element being independent of the limiting beam.This allows for a needs-based and flexible choice of connection type between the fastening element and the restraint element and improves the connection strength between the fastening element and the restraint element.

[0074] In some embodiments, the limiting beam has an internal receiving chamber in which the fastener is held. By providing this receiving chamber, the fastener can be completely embedded in the limiting beam, thereby increasing the bond strength between the fastener and the limiting beam.

[0075] In some embodiments, the limiting beam extends along a direction perpendicular to its thickness. Multiple limiting elements are provided, spaced apart along the extension direction of the limiting beam. These multiple limiting elements can increase the limiting force acting on the limiting beam, improve the uniformity of the load distribution in different areas of the limiting beam, reduce the deformation of the limiting beam during the battery cell's cycle process, and improve the battery's cycle performance.

[0076] In some embodiments, the battery comprises several bus components, wherein the several bus components electrically connect the several battery cells to one another. The several bus components comprise at least one first bus component, wherein the first bus component comprises a first bus layer and a second bus layer, which are stacked on top of each other and connected to one another, the first bus layer connecting at least two of the battery cells, which are arranged in the thickness direction.

[0077] The first bus component has a structure with at least two layers, where both the first and second bus layers are capable of conducting current. This results in a large current-carrying area for the first bus component, which reduces heat generation and increases the battery's fast-charging capability. Provided the current-carrying area meets the requirements, the thickness of the first bus layer can be reduced by designing the first bus component as a double-layer structure. The battery cell expands during the charging cycle, thus stretching the first bus layer. The first bus layer then has a reduced thickness.It is easily deformable to adapt to the deformation of the battery cell, thereby reducing the risk of tearing at the connection point between the battery cell and the first bus layer and increasing the reliability of the battery.

[0078] In some embodiments, the battery cell includes an electrode terminal arranged on the housing, the electrode terminal being electrically connected to the electrode assembly. The portion of the first bus layer that does not overlap with the second bus layer is connected to the electrode terminal. The second bus layer can bypass the connection point between the first bus layer and the electrode terminal, thereby reducing the impact of the second bus layer on this connection point as the battery cell expands. This reduces the risk of the connection point between the electrode terminal and the first bus layer breaking and increases the reliability of the battery.

[0079] In some embodiments, the first bus component comprises at least one bent section, wherein the bent section connects the first bus layer and the second bus layer. The bent section can connect the first bus layer and the second bus layer and transmit current between the first bus layer and the second bus layer, thereby improving the current-carrying capability of the first bus component.

[0080] In some embodiments, the first bus layer comprises a first bus section, a second bus section, and a first buffer section for connecting the first and second bus sections, wherein the first bus section and the second bus section are arranged along the thickness direction and connected to different battery cells. The bending section is arranged to bypass the first buffer section.

[0081] During the battery cell's cycle process, the cell expands and exerts a tensile force on the first bus layer. The first buffer section can relieve stresses through deformation, thereby reducing the load at the connection point between the first bus section and the battery cell, as well as the load at the connection point between the second bus section and the battery cell. This reduces the risk of a connection failure between the first bus layer and the battery cell. The bending section is not directly connected to the first buffer section, thus reducing its influence on the deformation of the first buffer section and facilitating its deformation.

[0082] In some embodiments, the second bus layer comprises a first stacking section, a second stacking section, and a second buffer section, wherein the first stacking section is stacked with the first bus layer and connected by at least one of the bending sections, and the second stacking section is stacked with the second bus layer and connected by at least one of the bending sections. The second buffer section connects the first stacking section and the second stacking section. In the stacking direction of the first bus layer and the second bus layer, the second buffer section overlaps at least partially with the first buffer section.

[0083] During the battery cell's cycle process, the cell expands and exerts a tensile force on the first bus layer. Both the first and second buffer sections can relieve stresses through deformation, thereby reducing the risk of a connection failure between the first bus layer and the battery cell. The at least partial overlap of the second buffer section with the first buffer section brings their deformation zones closer together. This reduces the risk of the first and second buffer sections being damaged by other components during deformation.

[0084] In some embodiments, the second buffer section and the first buffer section are arranged next to each other to save space.

[0085] In some embodiments, the multiple bus components also include at least one second bus component, wherein the thickness of the second bus component is greater than the thickness of the first bus layer, and the thickness of the second bus component is greater than the thickness of the second bus layer.

[0086] Within the battery, the expansion rates of the battery cells can vary at different points. For the battery cell with a lower expansion rate, a second bus component with a single-layer structure can be used; compared to the first bus component, the second bus component has a simpler structure, is easier to manufacture, and can save costs. The thickness of the second bus component is greater than that of both the first and second bus layers, and its current-carrying capacity can meet the requirements.

[0087] In some embodiments, the sum of the thickness of the first bus layer and the thickness of the second bus layer equals the thickness of the second bus component. This reduces the difference in current-carrying capacity between the first and second bus components and improves current consistency.

[0088] In some embodiments, the battery cell adjacent to the boundary bar is connected to the first bus component. During charging, the expansion of several battery cells in the thickness direction can overlap, leading to significant displacement of the battery cell adjacent to the boundary bar. By using the first bus component with a double-layer structure to connect the battery cell closest to the boundary bar, the risk of a connection failure between the first bus component and the battery cell can be reduced.

[0089] In some embodiments, the thickness of the first bus layer is 1 mm to 2.5 mm, optionally 1.2 mm to 1.8 mm. The thickness of the first bus layer is selected according to the expansion pressure of the battery cell, thus ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first bus layer simultaneously, in order to improve the fast-charging capability and reliability of the battery.

[0090] In some embodiments, the thickness of the second bus layer is 1 mm to 2.5 mm.

[0091] In some embodiments, the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L and the thickness of the first bus layer is less than or equal to 2.5 mm; or the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L and the thickness of the first bus layer is less than or equal to 2.2 mm.

[0092] The dimensions of the battery cell are related to its volume energy density. The present application specifies the thickness of the first bus layer according to the volume energy density of the battery cell, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first bus layer simultaneously, in order to improve the fast-charging capability and reliability of the battery.

[0093] In some embodiments, the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material being a silicon-based material. The mass fraction of elemental silicon in the silicon-based material in the negative electrode active material is 1% to 6%; the thickness of the first bus layer is 1.2 mm to 2.2 mm and the thickness of the second bus layer is 1.2 mm to 2.2 mm.

[0094] The introduction of silicon-based material increases the capacity of the negative electrode layer and thus the energy density of the battery cell. This material also increases the expansion of the negative electrode layer during the cycling process. By precisely defining the thickness of the first bus layer and the second bus layer in combination with the silicon content, the risk of connection failure between the first bus layer and the battery cell can be reduced. Furthermore, the current-carrying capacity requirements of the first bus layer can be met.

[0095] In some embodiments, the first bus layer comprises a first bus section, a second bus section, and a first buffer section for connecting the first and second bus sections. The first and second bus sections are arranged along the thickness direction and connected to different parts of the battery cells. In the stacking direction of the first and second bus layers, the first buffer section projects beyond the first and second bus sections. A recess is provided at the position of the first buffer section in the first bus layer corresponding to this position. Providing this recess reduces the rigidity of the first buffer section, thus facilitating its deformation during battery cell expansion.

[0096] In some embodiments, the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L and the depth of the depression is 1.2 mm to 2.5 mm; or the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L and the depth of the depression is 1 mm to 2.2 mm.

[0097] The dimensions of the battery cell are related to its volume energy density. The present application specifies the depth of the recess according to the volume energy density of the battery cell, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first buffer section simultaneously, in order to improve the fast-charging capability and reliability of the battery.

[0098] In some embodiments, the charging time of the battery cell from 10% SOC to 80% SOC is 5 to 10.5 minutes. The battery cell has a fast-charging capability, which can save charging time.

[0099] In a second aspect, the embodiments of the present application provide a power-consuming device comprising a battery according to one of the embodiments of the first aspect, wherein the battery serves to provide power. Brief description of the drawings

[0100] To better illustrate the technical solutions in the embodiments of the present application, a brief description of the drawings required in these embodiments is given below. Of course, the drawings described below represent only some embodiments of the present application, and other drawings can be created by a person skilled in the art based on these drawings without any creative effort. Fig. Figure 1 is a schematic representation of the structure of a vehicle according to some embodiments of the present application; Fig. Figure 2 is a schematic representation of a battery according to some embodiments of the present application; Fig. Figure 3 is a schematic exploded view of the battery cell according to some embodiments of the present application; Fig.Figure 4 is a schematic representation of a battery according to some embodiments of the present application; Fig. 5 is a schematic sectional view along the direction AA of Fig. 4; Fig. 6 is an enlarged schematic view of the in Fig. 5 framed area; Fig. Figure 7 is a schematic representation of an electrode arrangement of Fig. 3; Fig. Figure 8 is a schematic sectional view of the electrode arrangement of Fig. 7; Fig. Figure 9 is a schematic sectional view of a negative electrode sheet of a battery cell according to some embodiments of the present application; Fig. Figure 10 is a schematic sectional view of a negative electrode sheet of a battery cell according to further embodiments of the present application; Fig.Figure 11 is a schematic sectional view of a positive electrode sheet of a battery cell according to some embodiments of the present application; Fig. Figure 12 is a schematic partial sectional view of a battery according to further embodiments of the present application; Fig. Figure 13 is a schematic partial sectional view of a battery according to further embodiments of the present application; Fig. Figure 14 is a schematic representation of the structure of a battery according to further embodiments of the present application; Fig. 15 is a schematic partial sectional view of the in Fig. 14 shown battery; Fig. Figure 16 is an enlarged schematic view of the in Fig. 4 circled areas; Fig. Figure 17 is a schematic representation of the structure of a first bus component of Fig. 16; Fig.Figure 18 is a schematic representation of the connection of a battery cell with a first bus component according to some embodiments of the present application; Fig. 19 is a schematic top view of a battery according to further embodiments of the present application; Fig. 20 is an enlarged schematic view of the in Fig. 19 framed area, and Fig. Figure 21 is a schematic representation of the structure of a second bus component from Fig. 20. Reference symbol list

[0101] 1. Vehicle; 2. Battery; 3. Control unit; 4. Motor; 10, battery cell; 100, battery cell array; 10a, large surface area; 10b, narrow surface area; 11, Electrode array; 111, Positive electrode sheet; 1111, Positive electrode current collector; 1112, Positive electrode film layer; 112, Negative electrode sheet; 1121, Negative electrode current collector; 1122, Negative electrode film layer; 11221, First negative electrode film layer; 11222, Second negative electrode film layer; 112a, Straight layer; 113, Separator; 11a, Main body section; 11b, Positive electrode tab; 11c, Negative electrode tab; 11d, First surface; 11e, Second surface; 11f, Third surface; 12, Housing; 121, Housing body; 122, End cover; 13, Electrode connection; 20, Box body; 21, Boundary beam; 211, Outer wall; 2111, First side wall; 21111, Central section; 21112, Edge section; 2112, Second side wall; 21121, First section; 21122, Second section; 2113, Top wall; 2114, Bottom wall; 212, Stiffening rib; 212a, First stiffening rib; 212b, Second stiffening rib; 213, Receiving chamber; 214, Partition wall; 2141, Third section; 2142, Fourth section; 21a, First side surface; 21b, Second side surface; 21c, Third side surface; 22, frame body; 23, support beam; 24, support plate; 30, insulating element; 40, restricting element; 50, adhesive layer; 60, fastening element; 70, bus component; 70a, first bus component; 70b, second bus component; 70c, third bus component; 71, first bus layer; 711, first bus section; 712, second bus section; 713, first buffer section; 714, recess; 72, second bus layer; 721, first stacking section; 722, second stacking section; 723, second buffer section; 73, bending section; 80, Fasteners; X, thickness direction; Y, extent direction; Z, height direction. Detailed descriptions

[0102] To clarify the objectives, technical solutions, and advantages of the embodiments of the present application, the technical solutions in these embodiments are clearly described below in conjunction with the drawings. Obviously, the described embodiments represent only a subset of the embodiments of the present application, but not all of them. All other embodiments that a person skilled in the art could have derived without creative effort based on the embodiments of the present application fall within the scope of protection of the present application.

[0103] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as they are generally understood by engineers in the technical field to which this application relates. The terms used in the description of this application serve solely to describe specific embodiments and are not intended to limit the scope of this application. The terms "comprise" and "include," and all variations thereof, as used in the description and claims of this application and in the brief description of the drawings, are intended to convey non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or the above drawings of this application serve to distinguish between different objects and not to describe any particular order or priority relationship.

[0104] A reference to "embodiment" in the present application means that certain features, structures, or properties described in connection with an embodiment may be included in at least one embodiment of the present application. The appearance of the foregoing phrase in different places in the description does not necessarily mean that it refers to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0105] In the description of this application, it should be noted that the terms "assemble," "connect," "couple," and "attach" should be interpreted broadly unless expressly stated and defined otherwise. They may, for example, refer to permanent connections, detachable connections, or integral connections; they may mean direct connections or indirect connections via an intermediate medium; and they may encompass internal communication between two components. A person skilled in the art will be able to understand the specific meaning of the above terms in this application within the relevant context.

[0106] The term “and / or” in the present application serves only to describe an associative relationship between the associated objects, indicating that three types of relationships are possible, such as A and / or B, which can represent the following three scenarios: A alone, both A and B, and B alone. Furthermore, the symbol “ / ” in the present application generally represents an “or” relationship between the front and back associated objects.

[0107] In the embodiments of the present application, the same reference numerals denote the same parts, and for the sake of brevity, detailed descriptions of the same parts in the various embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of various parts in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are only examples and are not intended to limit the present application.

[0108] The “range” disclosed in the present application is defined in terms of a lower bound and an upper bound. A given range is defined by selecting a lower bound and an upper bound. The selected lower bound and upper bound define the limits of the specific range. The ranges thus defined may or may not include the end values ​​and may be specified in any combination; that is, any lower bound can be combined with any upper bound to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, then ranges of 60 to 110 and 80 to 120 are also conceivable. Furthermore, if minimum range values ​​of 1 and 2 and maximum range values ​​of 3, 4, and 5 are listed, then all of the following ranges are conceivable: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5.In the present application, unless otherwise specified, a range of numbers "a to b" represents an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the range "0 to 5" means that all real numbers between "0 to 5" are listed therein, and "0 to 5" is simply an abbreviation for these number combinations. Furthermore, if a particular parameter is specified as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0109] The term ‘several’ used in the present application refers to two or more (including two).

[0110] The term "parallel" encompasses not only the case of absolute parallelism, but also the case of approximate parallelism, which is commonly understood in engineering. The term "perpendicular" encompasses not only the case of absolute perpendicularity, but also the case of approximate perpendicularity, which is commonly understood in engineering.

[0111] Current market trends clearly show that the use of batteries is becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydroelectric, thermal, wind, and solar power plants, but also extensively in electric vehicles such as e-bikes, e-motorcycles, and electric cars, as well as in many sectors such as aerospace. With the continuous expansion of battery applications, market demand is also rising steadily.

[0112] The battery refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. The battery cell is the smallest unit that makes up a battery. During the battery cell's cycle process, electrochemical reactions occur inside, causing it to expand. This continuous expansion of the battery cell negatively impacts the overall performance of the battery.

[0113] In light of this, the battery is typically equipped with a limiting bar to restrict the expansion of the battery cell and to support and confine it. The restriction of the battery cell by the limiting bar affects the battery cell's cycle life.

[0114] Against this background, the embodiments of the present application provide a battery which, through the rational design of the battery cell and the limiting bar, effectively limits the expansion of the battery cell and improves the cycle performance of the battery cell.

[0115] The battery described in the embodiments of the present application is suitable for a power-consuming device that uses a battery. The power-consuming device can be a device that uses a battery as a power source or various energy storage systems in which the battery serves as an energy storage element. The power-consuming device can be, for example, a mobile phone, a tablet, a laptop, an electric toy, a power tool, an electric bicycle, an electric vehicle, a ship, a spacecraft, etc., but is not limited to these. The electric toy can include stationary or mobile electric toys such as a game console, an electric toy car, an electric toy ship, and an electric toy airplane, etc., and the spacecraft can include an airplane, a rocket, a space transporter, and a spacecraft, etc.

[0116] For the sake of clarity, the following examples of implementation are illustrated using a vehicle as an example of a power-consuming device.

[0117] Fig. Figure 1 is a schematic representation of the structure of a vehicle according to some embodiments of the present application.

[0118] As in Fig. As shown in Figure 1, a battery 2 is located in vehicle 1. The battery 2 can be positioned at the bottom, front, or rear of vehicle 1. The battery 2 can be used to supply power to vehicle 1. For example, the battery 2 can be used as the operating power source for vehicle 1.

[0119] The vehicle 1 may further comprise a control unit 3 and a motor 4, wherein the control unit 3 is used to control the battery 2 to supply power to the motor 4, for example to meet the work power requirements of the vehicle 1 when starting, navigating and driving.

[0120] In some embodiments of the present application, the battery 2 can serve not only as an operating current source for the vehicle 1, but also as a propulsion current source for the vehicle 1, replacing fuel or natural gas wholly or partially to provide the propulsion of the vehicle 1.

[0121] Fig. Figure 2 is a schematic representation of a battery according to some embodiments of the present application.

[0122] With reference to Fig. 2 In some embodiments, the battery 2 comprises a box body 20 and several battery cells 10 which are contained in the box body 20.

[0123] Battery cell 10 can be a secondary battery, where the secondary battery is a battery cell that can continue to be used by activating the active material through charging after the battery cell has been discharged.

[0124] For example, battery cell 10 can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, or a lead-acid battery cell, etc.

[0125] For example, battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, wherein the prismatic battery cell includes a square battery cell, a leaf-shaped battery cell, and a polygonal battery, wherein the polygonal battery is, for example, a hexagonal battery.

[0126] The multiple battery cells 10 can be connected in series, parallel, or in a mixed circuit, where a mixed circuit means that both series and parallel connections exist between the multiple battery cells 10. The multiple battery cells 10 can be connected directly in series, parallel, or in a mixed circuit, and the assembly formed from the multiple battery cells 10 can be housed in the box 20; of course, the multiple battery cells 10 can also first be connected in series, parallel, or in a mixed circuit to form a battery module, and several battery modules can then be further connected in series, parallel, or in a mixed circuit to form a whole and housed in the box 20.

[0127] In some embodiments, the box body 20 can be designed as part of a vehicle chassis. For example, part of the box body 20 can become at least part of the vehicle floor, or part of the box body 20 can become at least part of a cross member and a longitudinal member of the vehicle.

[0128] Fig. Figure 3 is a schematic exploded view of the battery cell according to some embodiments of the present application.

[0129] With reference to Fig. 3 In some embodiments, the battery cell 10 comprises a housing 12 and the electrode arrangement 11, which is received in the housing 12,

[0130] The housing 12 has a hollow structure, inside which a receiving chamber is formed for receiving the electrode assembly 11 and the electrolyte. The shape of the housing 12 can be determined according to the specific shape of the electrode assembly 11. If the electrode assembly 11 has a cuboid structure, a cuboid housing can be selected.

[0131] As an example, the housing 12 comprises a housing body 121 and an end cover 122, wherein the housing body 121 has an opening and the end cover 122 serves to cover the opening.

[0132] The housing body 121 is a component that serves to cooperate with the end cover 122 to form the inner cavity of the battery cell 10, the inner cavity formed being able to accommodate the electrode arrangement 11, the electrolyte and other components.

[0133] The housing body 121 and the end cap 122 can be separate components. For example, the housing body 121 can be provided with an opening, and the end cap 122 can cover the opening to form the inner cavity of the battery cell 10.

[0134] The housing body 121 can have various shapes and dimensions, for example, cuboid, cylindrical, hexagonal prismatic, and others. In particular, the shape of the housing body 121 can be determined according to the specific shape and size of the electrode arrangement 11. The housing body 121 can be made of various materials, for example, copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application are not specifically limited in this respect.

[0135] The shape of the end cap 122 can be adapted to the shape of the housing body 121 to fit onto it. The material of the end cap 122 and the material of the housing body 121 can be the same or different. Optionally, the end cap 122 can be made of a material with a specific hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). This prevents the end cap 122 from deforming easily under crushing or impact, thus enabling the battery cell 10 to have higher structural strength and improving reliability.

[0136] The end cover 122 is connected to the housing body 121 by welding, gluing, snapping or in some other way.

[0137] The housing body 121 can be open at one end or at both ends. In some examples, the housing body 121 can have a structure open at one end, with an end cap 122 provided and placed on the housing body 121. In other examples, the housing body 121 can have a structure open at both ends, with two end caps 122 provided, each of which is placed on one of the two openings of the housing body 121.

[0138] The electrode assembly 11 is a component in which electrochemical reactions take place in the battery cell 10. One or more electrode assemblies 11 can be contained in the housing body 121.

[0139] In some embodiments, the electrode arrangement 11 comprises a positive electrode sheet and a negative electrode sheet. During the charging and discharging process of the battery cell 10, the active ions (e.g., lithium ions) intercalate and deintercalate between the positive electrode sheet and the negative electrode sheet.

[0140] For example, the sections of the positive electrode sheet and the negative electrode sheet containing active substance form a main body section 11a of the electrode assembly 11, and the section of the positive electrode sheet without active substance forms a positive electrode tab 11b, and the section of the negative electrode sheet without active substance forms a negative electrode tab 11c. The positive electrode tab 11b and the negative electrode tab 11c can be located together at one end of the main body section 11a or each at one of the two ends of the main body section 11a.

[0141] In some embodiments, the electrode arrangement 11 also includes a separator that is arranged between the positive electrode sheet and the negative electrode sheet and serves mainly to prevent a short circuit between the positive and the negative electrode, while at the same time allowing the passage of the active ions.

[0142] In some embodiments, the electrode arrangement 11 has a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a coiled structure.

[0143] In some embodiments, the electrode arrangement 11 has a stacked structure.

[0144] For example, several positive electrode sheets and several negative electrode sheets can be provided, with the several positive electrode sheets and the several negative electrode sheets being stacked alternately.

[0145] For example, several positive electrode sheets can be provided while a negative electrode sheet is folded to form several stacked folded sections, with a positive electrode sheet sandwiched between adjacent folded sections.

[0146] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form several stacked folded sections.

[0147] For example, several separators can be provided, each arranged between any adjacent positive or negative electrode sheets.

[0148] For example, a separator can be continuously arranged by folding or winding it between any adjacent positive or negative electrode sheets.

[0149] In some embodiments, the battery cell 10 also includes an electrode terminal 13 arranged on the housing 12; the electrode terminal 13 can be electrically connected to the electrode arrangement 11 to supply or dissipate electrical energy.

[0150] In some embodiments, the electrode connection 13 is electrically connected to the electrode tab. For example, two electrode connections 13 are provided, wherein the two electrode connections 13 are electrically connected to the positive electrode tab 11b and the negative electrode tab 11c, respectively.

[0151] Fig. Figure 4 is a schematic representation of a battery according to some embodiments of the present application; Fig.5 is a schematic sectional view along the direction AA of Fig. 4; Fig. 6 is an enlarged schematic representation of the in Fig. 5. framed area; Fig. Figure 7 is a schematic representation of an electrode arrangement of Fig. 3; Fig. Figure 8 is a schematic sectional view of the electrode arrangement of Fig. 7.

[0152] With reference to Fig.Figures 4 to 8 describe embodiments of the present application providing a battery 2 comprising multiple battery cells 10 and a housing 20. The multiple battery cells 10 are arranged along the thickness direction X of the battery cell 10. The battery cell 10 comprises a housing 12 and an electrode arrangement 11 received in the housing 12. The housing 20 serves to receive the multiple battery cells 10. The housing 20 comprises at least two limiting beams 21, with two adjacent limiting beams 21 being arranged on each of the two sides of the multiple battery cells 10 along the thickness direction X. The expansion pressure of the battery cell 10 in the thickness direction X is 0.5 MPa to 2.4 MPa.The boundary beam 21 comprises a first side surface 21a facing the multiple battery cells 10, wherein the first side surface 21a is designed such that the maximum displacement of the first side surface 21a in the thickness direction X at a pressure of 1.7 MPa is less than or equal to 8 mm.

[0153] The battery cells 10 between two adjacent boundary beams 21 can be arranged in a single row or in multiple rows. For example, a row of battery cells 10 can form a battery cell row 100, wherein the battery cell row 100 comprises at least two battery cells 10 arranged along the thickness direction X.

[0154] The battery cell 10 can comprise one or more electrode assemblies 11. Optionally, the electrode assemblies 11 are arranged along the thickness direction X.

[0155] Optionally, the expansion pressure of the battery cell 10 in the thickness direction X is 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, 1.1 MPa, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, 2.0 MPa, 2.1 MPa, 2.2 MPa, 2.3 MPa or 2.4 MPa.

[0156] For example, the expansion pressure of battery cell 10 can be measured as follows:

[0157] At an ambient temperature of 45 °C, battery cell 10 is discharged to 2.0 V at a constant discharge rate of 1 C;

[0158] The battery cell 10 is clamped between two clamping plates, the two clamping plates being located on one side of the battery cell 10 along the thickness direction X and covering the large surface 10a (the large surface 10a is the surface of the battery cell 10 on one side in the thickness direction X);

[0159] At an ambient temperature of 45 °C, the battery cell is charged to 3.8 V at a constant charging rate of 0.8 C, and the pressure exerted by the battery cell on the terminal plates is detected and recorded;

[0160] According to the above charging and discharging strategy, the battery cell is cyclically charged and discharged until the battery cell reaches 70% SOH (i.e., the capacity retention rate of the battery cell = discharge capacity of the battery cell / nominal capacity of the battery cell = 70%), and the maximum pressure exerted by the battery cell on the terminal plates is recorded;

[0161] The expansion pressure Q of the battery cell in the thickness direction is calculated as: maximum pressure / area of ​​the large surface.

[0162] Two or more boundary bars 21 can be provided. As an example, at least one battery cell row 100 is arranged between any two adjacent boundary bars 21.

[0163] The limiting beam 21 can be used to limit the expansion deformation of the battery cell 10 in the thickness direction X. The limiting beam 21 can be in direct contact with the battery cell 10 in the thickness direction X; alternatively, other components can be arranged between the limiting beam 21 and the battery cell 10, i.e., the limiting beam 21 limits the expansion of the battery cell 10 via this component.

[0164] For example, the first side surface 21a of the boundary beam 21 can be a vertical plane opposite the large surface of the battery cell 10.

[0165] For example, the maximum displacement E of the first side surface 21a of the boundary beam 21 along the thickness direction under a pressure of 1.7 MPa can be measured as follows: (1) The battery cells 10 of battery 2 are removed and the box body 20 of battery 2 is attached to a clamping device; (11) a printhead of a pressure testing device is placed against the first side surface 21a of the boundary bar 21, the printing area of ​​the printhead placed against the first side surface 21a being aligned with the large surface 10a of the battery cell 10; (III) A constant force F is applied to the printhead, causing it to move along the thickness direction X of the battery cell 10, and the maximum displacement E of the printhead is recorded. For example, the area of ​​the print surface is denoted as S, where F / S is 1.7 MPa.

[0166] For example, the maximum displacement of the first side surface 21a in the thickness direction X is less than or equal to 8 mm when the print head presses against the central area of ​​the first side surface 21a along the extension direction Y of the boundary bar 21.

[0167] The expansion pressure of the battery cell 10 is related to the density of the electrode arrangement 11. According to the embodiments of this application, the limiting beam has a higher strength, allowing the battery cell 10 to exhibit an expansion pressure greater than or equal to 0.5 MPa in the thickness direction X, thereby increasing the density of the electrode arrangement 11 and improving the energy density of the battery cell 10. In other embodiments, the expansion pressure of the battery cell 10 in the thickness direction X is less than or equal to 2.4 MPa, and the limiting beam 21 exhibits higher resistance to deformation.Therefore, the limiting bar 21 of the battery cell 10 can provide effective restraint in the thickness direction X to reduce the deformation of the electrode assembly 11 during the cycling process, reduce the risk of wrinkling deformation of the separator of the electrode assembly 11, reduce the risk of local increase in the distance between the positive and negative electrode sheets, reduce polarization, and improve the cycle performance of the battery cell 10. According to the present application, by regulating the expansion pressure of the battery cell within a reasonable range and appropriately designing the limiting bar 21, the deformation of the battery cells 10 and the limiting bar can be reduced, the risk of cracking of the box body 20 can be decreased, and the cycle performance of the battery cell 10 can be improved.

[0168] In some embodiments, the electrode arrangement 11 comprises two first surfaces 11d and two second surfaces 11e, wherein the two first surfaces 11d are arranged opposite each other along the thickness direction X, and the two second surfaces 11e are arranged opposite each other along a direction perpendicular to the thickness direction X, and the second surface 11e connects the two first surfaces 11d. The area of ​​the first surface 11d is larger than the area of ​​the second surface 11e.

[0169] By arranging the first surface 11d with a larger area compared to the first side surface 21a along the thickness direction X, the load-bearing area of ​​the boundary beam 21 can be increased and the deformation of the boundary beam 21 reduced when the electrode arrangement 11 is extended.

[0170] In some embodiments, the first surface 11d runs parallel to the first side surface 21a, which reduces the stress concentration during the expansion of the electrode arrangement 11, reduces the local deformation of the limiting beam 21, improves the uniformity of the load distribution on the electrode arrangement 11 and increases the cycle performance of the battery cell 10.

[0171] In the embodiments of the present application, the term "parallel" encompasses not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering. In the battery, due to manufacturing tolerances, displacements, and deformations of the battery cell during the cycling process, etc., the first surface 11d and the first side surface 21a may exhibit variations. For example, if the angle between the first surface 11d and the first side surface 21a is between 0° and 5°, the first surface 11d and the first side surface 21a can be considered parallel.

[0172] In some embodiments, the two second surfaces 11e are arranged opposite each other along the extension direction Y of the boundary beam 21. The extension direction Y of the boundary beam 21 can be perpendicular to the thickness direction X. By way of example, the extension direction Y of the boundary beam 21 is the length direction of the boundary beam 21.

[0173] In some embodiments, the main body section 11a comprises two first surfaces 11d, two second surfaces 11e and two third surfaces 11f; the two third surfaces 11f are arranged at both ends of the battery cell 10 along the vertical direction Z, and the third surfaces 11f are connected to the two first surfaces 11d and the two second surfaces 11e.

[0174] The positive electrode tab 11b and the negative electrode tab 11c extend from the same third surface 11f, or the positive electrode tab 11b and the negative electrode tab 11c each extend from one of the two third surfaces 11f.

[0175] In some embodiments, at least part of the second surface 11e is arc-shaped. Optionally, the electrode arrangement 11 has a wound structure, and the second surface 11e is an arc-shaped surface.

[0176] In some embodiments, the outer surface of the battery cell 10 comprises two large surfaces 10a and two narrow surfaces 10b. The two large surfaces 10a are arranged opposite each other along the thickness direction X, and the two narrow surfaces 10b are arranged opposite each other along the extent direction Y. The two ends of the large surface 10a along the extent direction Y are connected to the two narrow surfaces 10b. The area of ​​the large surface 10a is larger than the area of ​​the narrow surface 10b.

[0177] In some embodiments, the large surface 10a, the first side surface 21a and the first surface 11d run parallel to each other.

[0178] In some embodiments, the battery cell 10 is a square battery cell. Optionally, the narrow surface 10b runs perpendicular to the large surface 10a.

[0179] In some embodiments, the expansion pressure of the battery cell 10 in the thickness direction X is 1.5 MPa to 2.0 MPa.

[0180] In the embodiments of the present application, limiting the expansion pressure of the battery cell 10 in the thickness direction X to 1.5 MPa to 2.0 MPa reduces the deformation of the limiting beam 21, decreases the risk of cracking of the box body 20 and improves the cycle performance of the battery cell 10.

[0181] By limiting the expansion pressure of the battery cell 10 to 1.5 MPa to 2.0 MPa, the requirement for the strength of the limiting beam 21 can be reduced and the costs lowered.

[0182] Fig. Figure 9 is a schematic sectional view of a negative electrode sheet of a battery cell according to some embodiments of the present application.

[0183] With reference to Fig. 8 and Fig.In some embodiments, the electrode arrangement 11 comprises a negative electrode sheet 112, wherein the negative electrode sheet 112 comprises a negative electrode current collector 1121 and a negative electrode film layer 1122 arranged on at least one side of the negative electrode current collector 1121, wherein the negative electrode film layer 1122 comprises a negative electrode active material.

[0184] In the embodiments of the present application, the negative electrode film layer 1122 can be arranged only on one side of the negative electrode current collector 1121, or negative electrode film layers 1122 can be arranged on both sides of the negative electrode current collector 1121.

[0185] Optionally, the two surfaces of the negative electrode current collector 1121, which are arranged opposite each other along its thickness direction, are each provided with a negative electrode film layer 1122. The negative electrode film layers 1122 on the two surfaces of the negative electrode current collector 1121 can consist of the same negative electrode active material or of different negative electrode active materials; the thickness of the negative electrode film layers 1122 on the two surfaces of the negative electrode current collector 1121 can be the same or different.

[0186] In some embodiments, part of the negative electrode current collector 1121 is not covered by the negative electrode film layer 1122; the part of the negative electrode current collector 1121 not covered by the negative electrode film layer 1122 can be used to form a negative electrode tab 11c.

[0187] In some embodiments, the negative electrode current collector 1121 can be a metal foil or a composite current collector. For example, the metal foil can include at least one foil made of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. The composite current collector can comprise a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. For example, the metal material in the metal material layer can include at least one of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. For example, the polymer material base layer can include at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0188] In some embodiments, the thickness of the negative electrode current collector 1121 is 4 µm to 6 µm. For example, the thickness of the negative electrode current collector 1121 is 4 µm, 4.5 µm, 5 µm, 5.5 µm or 6 µm, or lies in a range consisting of any two of the above values.

[0189] In some embodiments, the compaction density of the negative electrode film layer 1122 at 100% SOC of the battery cell is 1.15 g / cm³. 3 up to 1.36 g / cm³ 3 For example, the compaction density of the negative electrode film layer 1122 in battery cell 10 at a 100% charge level is 1.15 g / cm³. 3 , 1.18 g / cm³ 3 , 1.20 g / cm³ 3 ,· 1.22 g / cm³ 3 , 1.25 g / cm³ 3 , 1.28 g / cm³ 3 , 1.3 g / cm³ 3 , 1.32 g / cm³ 3 , 1.35 g / cm³ 3 or 1.36 g / cm³ 3 , or lies within a range consisting of any two of the above values.

[0190] For example, 100% SOC (state of charge) and 0% SOC are defined as follows:

[0191] The battery cell is charged at a constant rate of 0.33C up to the upper charging limit voltage and then further charged at a constant voltage down to 0.05C, corresponding to a 100% state of charge (SOC). The battery cell is then discharged at a constant rate of 0.33C down to the final discharge voltage, corresponding to a 0% SOC. For example, the upper charging limit voltage of the battery could be 3.8V; the discharge cut-off voltage could be 2.0V.

[0192] For example, the density of the negative electrode film layer in a battery cell at 100% state of charge (SOC) has a well-known significance in engineering. The negative electrode sheet is removed from the battery cell at 100% state of charge (SOC), and the density of the negative electrode film layer is measured. For instance, a single-sided coated negative electrode sheet (in the case of a double-sided coated electrode sheet, the negative electrode film layer can be wiped off one side first) is taken, then punched into small discs with an area S1, weighed, and its weight recorded as M1. Its thickness H1 is then measured. Next, the negative electrode film layer of the previously weighed negative electrode sheet is wiped off, the resulting negative electrode current collector is weighed, its weight recorded as M0, and its thickness H0 is measured.The one-sided coating weight of the negative electrode film layer = (the weight of the negative electrode sheet M1 - the weight of the negative electrode current collector M0) / S1, the thickness of the negative electrode film layer - the thickness of the negative electrode sheet H1 - the thickness of the negative electrode current collector H0, the compaction density of the negative electrode film layer = the one-sided coating weight of the negative electrode film layer / the thickness of the negative electrode film layer.

[0193] The density of the negative electrode film layer 1122 is related to the expansion of the battery cell 10 at 100% charge. This is achieved by limiting the density of the negative electrode film layer 1122 to 1.15 g / cm³. 3 up to 1.36 g / cm³ 3To a certain extent, both the energy density and the expansion pressure of the battery cell 10 can be ensured simultaneously, thereby reducing the deformation of the battery cell 10 and the limiting bar 21.

[0194] If the compaction density of the negative electrode film layer 1122 is within the above range, this is advantageous for increasing the energy density of the battery cell 10; and because the negative electrode active material in the negative electrode film layer 1122 is relatively densely packed and the contact resistance between the particles is low, the resistance of the negative electrode sheet 112 can be further reduced and the heat generation thereby decreased.

[0195] If the density of the negative electrode film layer 1122 is within the range above, the fast-charging capability of the battery cell 10 can be improved. A low density of the negative electrode film layer 1122 can increase the porosity of the negative electrode sheet 112, slow down the expansion of the negative electrode sheet, and reduce the expansion pressure of the battery cell 10.

[0196] In some embodiments, the compaction density of the negative electrode film layer 1122 at 100% SOC of the battery cell is 1.25 g / cm³. 3 up to 1.36 g / cm³ 3 , which can improve the energy density of battery cell 10.

[0197] In some embodiments, the one-sided coating weight of the negative electrode film layer is 1122 90 mg / 1540.25 mm². 2 up to 170 mg / 1540.25 mm 2For example, the one-sided coating weight of the negative electrode film layer is 1122 90 mg / 1540.25 mm². 2 , 92 mg / 1540.25 mm2, 95 mg / 1540.25 mm 2 , 96 mg / 1540.25 mm 2 , 100 mg / 1540.25 mm 2 , 102 mg / 1540.25 mm 2 , 104 mg / 1540.25 mm 2 , 105 mg / 1540.25 mm 2 , 108 mg / 1540.25 mm 2 , 110 mg / 1540.25 mm 2 , 112 mg / 1540.25 mm 2 , 114 mg / 1540.25 mm 2 115 mg / 1540.25 mm 2 , 116 mg / 1540.25 mm 2 , 118 mg / 1540.25 mm 2 , 120 mg / 1540.25 mm 2 , 122 mg / 1540.25 mm 2 , 125 mg / 1540.25 mm 2 , 128 mg / 1540.25 mm 2 , 130 mg / 1540.25 mm 2 , 132 mg / 1540.25 mm 2 , 135 mg / 1540.25 mm 2 , ; 137 mg / 1540.25 mm 2 , 140 mg / 1540.25 mm 2 , 142 mg / 1540.25 mm 2 , 145 mg / 1540.25 mm 2 , 148 mg / 1540.25 mm 2 , 150 mg / 1540.25 mm 2 , 152 mg / 1540.25 mm2 , 155 mg / 1540.25 mm 2 , 160 mg / 1540.25 mm 2 , 165 mg / 1540.25 mm 2 , 167 mg / 1540.25 mm 2 or 170 mg / 1540.25 mm 2 , or lies within a range consisting of any two of the above values.

[0198] The one-sided coating weight of the negative electrode film layer 1122 is related to the extent of the negative electrode film layer. This is achieved by limiting the one-sided coating weight of the negative electrode film layer 1122 to 90 mg / 1540.25 mm². 2 up to 170 mg / 1540.25 mm 2 To a certain extent, both the energy density and the expansion pressure of the battery cell 10 can be ensured simultaneously, thereby reducing the deformation of the battery cell 10 and the limiting bar 21.

[0199] Furthermore, by limiting the one-sided coating weight of the negative electrode film layer 1122 to 90 mg / 1540.25 mm2 up to 170 mg / 1540.25 mm 2 the amount of heat generated by the negative electrode sheet 112 per unit area is limited and the temperature rise of the battery cell 10 is reduced, especially during fast charging.

[0200] In some embodiments, the one-sided coating weight of the negative electrode film layer is 1122,110 mg / 1540.25 mm². 2 up to 150 mg / 1540.25 mm 2 , in order to continue to simultaneously ensure the energy density and expansion pressure of battery cell 10.

[0201] In some embodiments, the porosity of the negative electrode sheet 112 is 27% to 40%. For example, the porosity of the negative electrode sheet 112 can be 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%.

[0202] The porosity of the negative electrode sheet can be defined as the percentage of the pore volume within the negative electrode sheet relative to the total volume of the negative electrode sheet. As an example, a double-sided coated negative electrode sheet is used for a battery cell at 0% charge; the porosity of the negative electrode sheet is measured with an AccuPyc 11 1340 density analyzer according to the national standard GB / T 24586-2009.

[0203] In the embodiments of the present application, a porosity of the negative electrode sheet 112 greater than or equal to 27% can provide space for impurities formed by side reactions of the negative electrode sheet 112, slow down the expansion of the negative electrode sheet 112, reduce the expansion pressure of the battery cell 10, reduce the deformation of the battery cell 10 and the limiting bar 21, and improve the cycle performance of the battery cell 10. A porosity of the negative electrode sheet 112 less than or equal to 40% can simultaneously ensure the energy density of the battery cell 10.

[0204] In some embodiments, the negative electrode active material comprises a carbon-based material. Optionally, the carbon-based material comprises graphite particles, wherein the degree of graphitization of the graphite particles is 92.0% to 94.5%. By way of example, the degree of graphitization of the graphite particles is 92.0%, 92.5%, 93%, 93.5%, 94%, or 94.5%, or lies within a range consisting of any two of the above values.

[0205] If the graphitization degree of the graphite particles is within the above range, the graphite particles exhibit excellent conductivity, which reduces the heat generation of the negative electrode sheet 112 and the battery cell 10; in addition, the fast charging performance of the battery cell 10 can be improved.

[0206] In some embodiments, the negative electrode active material comprises at least one synthetic graphite and one natural graphite. The synthetic graphite and the natural graphite exhibit excellent conductivity, which reduces the heat generation of the negative electrode sheet 112 and improves the fast-charging performance of the battery cell 10.

[0207] In some embodiments, the negative electrode active material comprises a silicon-based material. The introduction of the silicon-based material can increase the capacity of the negative electrode active material and the energy density of the battery cell 10.

[0208] In some embodiments, the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 0.3% to 10%. For example, the mass fraction of the element silicon in the negative electrode active material is 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.2%, 8.5%, 8.8%, 9%, 9.2%, 9.5%, 9.8%, or 10%, or lies within a range consisting of any two of the above values.

[0209] By introducing the silicon-based material into the negative electrode sheet 112, both the capacity and the size of the negative electrode sheet 112 can be increased. Therefore, by limiting the mass fraction of the element silicon in the negative electrode active material to between 0.3% and 10%, both the energy density and the size of the battery cell 10 can be ensured to a certain extent simultaneously, thereby reducing the deformation of the battery cell 10 and the limiting bar 21 and improving the cycle performance of the battery cell 10.

[0210] In some embodiments, the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1% to 6%.

[0211] The qualitative and quantitative determination of the individual substances or elements in the present application can be carried out using suitable equipment and methods known to those skilled in the art. The relevant methods of determination may refer to national and international testing standards as well as national and international company standards. Those skilled in the art may also adjust certain test steps / equipment parameters with regard to test accuracy in order to obtain more precise test results. A single method may be used for the qualitative or quantitative determination, or a combination of several methods may be used.

[0212] For example, the silicon-based material can be subjected to X-ray powder diffraction testing and qualitative analysis according to the general rule JIS / K0131-1996 for X-ray diffraction analysis on the negative electrode sheet or the negative electrode active material.

[0213] In some embodiments, the silicon-based material may comprise at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy material.

[0214] In some embodiments, the silicon-based material comprises at least one silicon oxide compound and a silicon-carbon composite.

[0215] In some embodiments, the negative electrode active material can comprise, in addition to the carbon-based material and optionally the silicon-based material, at least one tin-based material and lithium titanate. The tin-based material can comprise at least one elemental tin, tin oxide, and tin alloy.

[0216] In some embodiments of the present application, the negative electrode film layer 1122 comprises at least one film layer. In other words, the negative electrode film layer 1122 can use a single film layer or at least two film layers. Optionally, the negative electrode film layer 1122 comprises at least two film layers.

[0217] In the case where the negative electrode film layer 1122 comprises a single film layer, the negative electrode active material in the negative electrode film layer 1122 comprises a carbon-based material and optionally also a silicon-based material. In the case where a single film layer is present, the volume-averaged particle size Dv50 of the negative electrode active material is 8.2 µm to 13.5 µm. For example, the volume-averaged particle size Dv50 of the negative electrode active material is 8.2 µm, 8.5 µm, 8.8 µm, 9 µm, 9.2 µm, 9.5 µm, 9.8 µm, 10 µm, 10.2 µm, 10.5 µm, 10.8 µm, 11 µm, 11.2 µm, 11.5 µm, 11.8 µm, 12 µm, 12.2 µm, 12.5 µm, 12.8 µm, 13 µm, 13.2 µm or 13.5 µm, or lies in a range consisting of any two of the above values.

[0218] In the case where the negative electrode film layer 1122 comprises at least two film layers, the negative electrode active material in the negative electrode film layer 1122 comprises a carbon-based material and optionally also a silicon-based material. The silicon-based material can be located in one or at least two of the at least two film layers. The negative electrode film layer 1122 can comprise two film layers, three film layers, four film layers, or even more film layers.

[0219] Fig. Figure 10 is a schematic sectional view of a negative electrode sheet of a battery cell according to further embodiments of the present application.

[0220] With reference to Fig.In some embodiments, the negative electrode film layer 1122 comprises a first negative electrode film layer 11221 and a second negative electrode film layer 11222, wherein the second negative electrode film layer 11222 is arranged between the first negative electrode film layer 11221 and the negative electrode current collector 1121. The negative electrode active material comprises a first negative electrode active material arranged in the first negative electrode film layer 11221 and a second negative electrode active material arranged in the second negative electrode film layer 11222, wherein the first negative electrode active material comprises synthetic graphite and the second negative electrode active material comprises one or more synthetic graphite, natural graphite, and silicon-based materials.

[0221] The interface between the first negative electrode film layer 11221 and the second negative electrode film layer 11222 is regular or irregular, optionally irregular.

[0222] The first negative electrode film layer 11221 and the second negative electrode film layer 11222 can be configured differently, thereby ensuring to some extent that both the extent and the capacity of the negative electrode film layer 1122 are simultaneously achieved; the double-layer coating makes it possible to build up the pore difference of the negative electrode film layer 1122, reduce the tortuosity of the ion transport, reduce the side reactions and improve the fast charging performance of the battery cell 10.

[0223] The artificial graphite can have a smaller volume-averaged particle size Dv50, which on the one hand shortens the solid-phase transport path of lithium ions and improves fast charging performance; on the other hand, the material does not agglomerate as easily during the manufacturing process, which can improve the stability of the material.

[0224] In some embodiments, the ratio of the thickness of the first negative electrode film layer 11221 to the thickness of the second negative electrode film layer 11222 is 3:7 to 7:3. Optionally, the ratio of the thickness of the first negative electrode film layer 11221 to the thickness of the second negative electrode film layer 11222 is 3:7, 4:6, 5:5, 6:4, or 7:3. Optionally, the ratio of the thickness of the first negative electrode film layer 11221 to the thickness of the second negative electrode film layer 11222 is 4:6 to 6:4.

[0225] By adjusting the ratio of the thickness of the first negative electrode film layer 11221 to the thickness of the second negative electrode film layer 11222, the gradient pore difference between the upper and lower layers can be further increased, the tortuosity of lithium ion transport reduced, and the fast-charging capability of the battery cell 10 improved.

[0226] In some embodiments, the thickness of the first negative electrode film layer 11221 is less than or equal to the thickness of the second negative electrode film layer 11222, which can further improve the fast charging capability of the battery cell 10.

[0227] In some embodiments, the first negative electrode active material is in granular form, and the second negative electrode active material is in granular form.

[0228] In some embodiments, the volume-averaged particle size Dv50 of the first negative electrode active material is less than or equal to the volume-averaged particle size Dv50 of the second negative electrode active material. Optionally, the volume-averaged particle size Dv50 of the first negative electrode active material is smaller than the volume-averaged particle size Dv50 of the second negative electrode active material.

[0229] The particle size of the first and second negative electrode active materials differs, which can improve the fast-charging performance of the battery cell 10; during fast charging, the overpotential of the first negative electrode film layer 11221 is typically higher, and the bottleneck during fast charging is mainly in the first negative electrode film layer 11221. In the embodiments of the present application, the particle size of the first negative electrode active material is relatively small, which can shorten the solid-phase transport path of the ions, improve the fast-charging performance, and reduce the problem of ion deposition on the surface of the negative electrode sheet 112. The larger particle size of the second negative electrode active material allows for the formation of larger pores in the second negative electrode film layer 11222.During charging, the pores can absorb the expansion, reducing the amount of expansion of the negative electrode film layer 1122 and reducing the deformation of the battery cell 10 and the limiting bar 21.

[0230] In some embodiments, the volume-averaged particle size Dv50 of the first negative electrode active material is 7.8 µm to 14.3 µm, optionally 7.8 µm to 11.3 µm. For example, the volume-averaged particle size Dv50 of the first negative electrode active material is 7.8 µm, 8.0 µm, 8.2 µm, 8.5 µm, 8.8 µm, 9 µm, 9.2 µm, 9.5 µm, 9.8 µm, 10 µm, 10.2 µm, 10.5 µm, 10.8 µm, 11 µm, 11.3 µm, 11.2 µm, 11.5 µm, 11.8 µm, 12 µm, 12.2 µm, 12.5 µm, 12.8 µm, 13 µm, 13.2 µm. 13.5 µm, 13.8 µm, 14 µm, 14.1 µm or 14.3 µm, or lies within a range consisting of any two of the above values.

[0231] If the volume-averaged particle size Dv50 of the first negative electrode active material is set to 7.8 µm to 14.3 µm, the solid-phase transport path of lithium ions can be shortened and the fast-charging performance improved; on the other hand, the material does not agglomerate as easily during the manufacturing process, which can improve the stability of the material; furthermore, the first negative electrode active material in the above volume-averaged particle size range can interact with the second negative electrode active material, which is advantageous for establishing a gradient pore difference between the first negative electrode film layer 11221 and the second negative electrode film layer 11222, reducing the tortuosity of lithium ion transport and improving the fast-charging performance of the battery cell 10.

[0232] The volume-averaged particle size Dv50 of the material refers to the particle size corresponding to 50% of the volume distribution, and the volume-averaged particle size Dv10 to the particle size corresponding to 10% of the volume distribution. The particle sizes can be determined using devices and methods known in the art. For example, the negative electrode active material is used as a sample, and the Dv50 and Dv10 of the particles are measured using a Mastersizer 2000E laser particle size analyzer in accordance with test standard GB / T 19077-2016.

[0233] In some embodiments, the volume-averaged particle size Dv50 of the second negative electrode active material is 9.5 µm to 18.5 µm, optionally 9.5 µm to 14.6 µm.

[0234] For example, the volume-averaged particle size Dv50 of the negative electrode active material is 9.5 µm, 10 µm, 10.5 µm, 11 µm, 11.5 µm, 12 µm, 12.5 µm, 13 µm, 13.5 µm, 14 µm, 14.5 µm, 14.6 µm, 15 µm, 15.5 µm, 16 µm, 16.5 µm, 17 µm, 17.5 µm, 18 µm or 18.5 µm, or lies in a range consisting of any two of the above values.

[0235] If the volume-averaged particle size Dv50 of the second negative electrode active material is 9.5 µm to 18.5 µm, the pores of the second negative electrode film layer 11222 can become richer, which is advantageous for improving the fast-charging capability of the battery cell 10 and reduces the expansion of the negative electrode film layer 1122 during the charging process.

[0236] In some embodiments, the first negative electrode active material comprises graphite particles, and the volume-averaged particle size Dv50 of the graphite particles in the first negative electrode film layer 11221 is 7.8 µm to 14.3 µm, optionally 7.8 µm to 11.3 µm. Optionally, the first negative electrode active material comprises synthetic graphite.

[0237] The second negative electrode active material comprises graphite particles, and the volume-averaged particle size Dv50 of the graphite particles is 9.5 µm to 18.5 µm, optionally 9.5 µm to 14.6 µm. Optionally, the second negative electrode active material comprises natural graphite.

[0238] In some embodiments, the specific surface area of ​​the negative electrode active material is 0.5 m². 2 / g up to 3 m 2 / g, optional 0.6 m 2 / g up to 1.2 m 2 / g. For example, the specific surface area of ​​the negative electrode active material is 0.5 m².2 / g, 0.6 m 2 / g, 0.7 m 2 / g, 0.8 m 2 / g, 0.9 m 2 / g, 1.0 m 2 / g, 1.1 m 2 / g, 1.2 m 2 / g, 1.3 m 2 / g, 1.4 m 2 / g, 1.5 m 2 / g, 1.6 m 2 / g, 1.7 m 2 / g, 1.8 m 2 / g, 1.9 m 2 / g, 2.0 m 2 / g, 2.1 m 2 / g, 2.2 m 2 / g, 2.3 m 2 / g, 2.4 m 2 / g, 2.5 m 2 / g, 2.6 m 2 / g, 2.7 m 2 / g, 2.8 m 2 / g, 2.9 m 2 / g or 3.0 m 2 / g, or lies within a range consisting of any two of the above values.

[0239] The specific surface area of ​​the material has a well-known meaning in engineering and can be determined using devices and methods known in engineering, for example according to the test standard GB / T 19587-2017. In this process, the negative electrode active material is used as the sample and the specific surface area is measured using a specific surface and pore size analyzer (model: Tri-Star 3020) from the American manufacturer Micromeritics.

[0240] In the embodiments of the present application, the specific surface area of ​​the negative electrode active material can be limited to greater than or equal to 0.5 m². 2 / g the fast charging capability of the battery cell 10 is increased; by limiting the specific surface area of ​​the negative electrode active material to less than or equal to 3 m² 2 / g can reduce side reactions of the battery cell 10 during storage, slow down the expansion of the negative electrode sheet and reduce the expansion pressure.

[0241] Fig. Figure 11 is a schematic sectional view of a positive electrode sheet of a battery cell according to some embodiments of the present application.

[0242] With reference to Fig. 8 and Fig. 11 The electrode arrangement 11 comprises a positive electrode sheet 111, wherein the positive electrode sheet 111 comprises a positive electrode current collector 1111 and a positive electrode film layer 1112 arranged on at least one side of the positive electrode current collector 1111.

[0243] For example, the positive electrode current collector 1111 has two surfaces that are opposite each other in its thickness direction, and the positive electrode film layer 1112 is arranged on one or both of the two opposite surfaces of the positive electrode current collector 1111.

[0244] In some embodiments, the positive electrode film layer 1112 comprises a positive electrode active material, wherein the positive electrode active material is a lithium-containing phosphate. The lithium-containing phosphate exhibits high cycle stability. The use of the lithium-containing phosphate as the positive electrode active material can reduce the cycle degradation of the battery cell 10 caused by the excessive temperature rise during the fast charging process.

[0245] In some embodiments, the compaction density of the positive electrode film layer 1112 at 100% SOC of the battery cell is 2.50 g / cm³. 3 up to 2.80 g / cm³ 3 , optional 2.55 g / cm² 3 up to 2.70 g / cm³ 3 . When battery cell 10 is at a state of charge (SOC) of 100%, the density of the positive electrode film layer 1112 is, for example, 2.50 g / cm³. 3 , 2.52 g / cm³ 3 , 2.55 g / cm³ 3 , 2.56 g / cm³ 3 , 2.57 g / cm³ 3 , 2.58 g / cm³ 3 , 2.60 g / cm³ 3 , 2.62 g / cm³ 3 , 2.65 g / cm³ 3 , 2.68 g / cm³ 3 , 2.70 g / cm³ 3 , 2.72 g / cm³ 3 , 2.75 g / cm³ 3 , 2.78 g / cm³ 3 or 2.80 g / cm² 3 , or lies within a range consisting of any two of the above values.

[0246] If the compaction density of the positive electrode film layer 1112 is within the above range, this is advantageous to increase the energy density of the battery cell 10; and because the positive electrode active material in the positive electrode film layer 1112 is relatively densely packed, and the contact resistance between the particles is low, the resistance of the positive electrode sheet 111 can be further reduced, thereby reducing heat generation during fast charging.

[0247] In the embodiments of the present application, the density of the positive electrode film layer 1112 at a state of charge (SOC) of 100% of the battery cell has the meaning known in the art. Here, the positive electrode sheet 111 is removed from the battery cell 10 at a state of charge (SOC) of 100%, and the density of the positive electrode film layer 1112 is measured. By way of example, the test method for the density of the positive electrode film layer 1112 can be the same as the test method for the density of the negative electrode film layer 1122.

[0248] In some embodiments, the one-sided coating weight of the positive electrode film layer is 1112 200 mg / 1540.25 mm². 2 up to 370 mg / 1540.25 mm 2 , optional 240 mg / 1540.25 mm 2 up to 330 mg / 1540.25 mm 2For example, the one-sided coating weight of the positive electrode film layer is 1112,200 mg / 1540.25 mm². 2 , 210 mg / 1540.25 mm 2 , 220 mg / 1540.25 mm 2 , 230 mg / 1540.25 mm 2 , 240 mg / 1540.25 mm 2 , 250 mg / 1540.25 mm 2 , 260 mg / 1540.25 mm 2 , 270 mg / 1540.25 mm 2 , 280 mg / 1540.25 mm 2 , 290 mg / 1540.25 mm 2 , 300 mg / 1540.25 mm 2 , 310 mg / 1540.25 mm 2 , 320 mg / 1540.25 mm 2 , 330 mg / 1540.25 mm 2 , 340 mg / 1540.25 mm 2 , 350 mg / 1540.25 mm 2 , 360 mg / 1540.25 mm 2 or 370 mg / 1540.25 mm 2 , or lies within a range consisting of any two of the above values.

[0249] In the embodiments of the present application, the one-sided coating weight of the positive electrode film layer 1112 has the meaning known in the art and can be determined using devices and methods known in the art, and the detection method is the same as the above test method for the one-sided coating weight of the negative electrode film layer 1122.

[0250] If the one-sided coating weight of the positive electrode film layer is 1112 to 200 mg / 1540.25 mm 2 up to 370 mg / 1540.25 mm 2 By determining the amount of heat generated per unit area of ​​the positive electrode sheet 111, it can be limited so that the increase in energy density and charging rate performance of the battery cell 10 can be ensured simultaneously.

[0251] In some embodiments, the porosity of the positive electrode sheet 111 is 25% to 32%. For example, the porosity of the positive electrode sheet 111 is 25%, 26%, 27%, 28%, 29%, 30%, 31%, or 32%, or lies in a range consisting of any two of the above values.

[0252] In the embodiments of the present application, the porosity of the positive electrode sheet 111 has the meaning known in the art and can be determined using devices and methods known in the art, and the detection method is the same as the above test method for the porosity of the negative electrode sheet 112.

[0253] A porosity of 25% or greater than or equal to the positive electrode sheet 111 can provide space for impurities generated by side reactions of the positive electrode sheet 111, reduce the expansion pressure of the battery cell, reduce the deformation of the battery cell 10 and the limiting bar 21, and improve the cycle performance of the battery cell 10. A porosity of 32% or less than or equal to the positive electrode sheet 111 can simultaneously ensure the energy density of the battery cell 10.

[0254] In some embodiments, the thickness of the positive electrode sheet 111 is 0.13 mm to 0.2 mm. For example, the thickness of the positive electrode sheet 111 is 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm or 0.2 mm, or lies in a range consisting of any two of the above values.

[0255] In the embodiments of the present application, the thickness of the positive electrode sheet 111 has a known meaning in the art and can be determined using devices and methods known in the art. For example, the thickness of the positive electrode sheet 111 is measured with a high-precision micrometer.

[0256] By using the positive electrode sheet 111 with a lower thickness, the migration path of ions can be shortened, the migration rate of ions increased, the heat generation of the battery cell 10 reduced and the fast charging performance of the battery cell 10 improved.

[0257] In some embodiments, the ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 is 0.05 to 0.3. By way of example, in the embodiments of the present application, the thickness of the positive electrode film layer 1112 corresponds to the thickness of the positive electrode film layer 1112 located on one side of the positive electrode current collector 1111.

[0258] For example, the ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28 or 0.3, or lies in a range consisting of any two of the above values.

[0259] By limiting the ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 to greater than or equal to 0.05, the current-carrying capacity of the positive electrode current collector 1111 can be increased, the temperature rise of the positive electrode sheet 111 reduced, and the fast-charging performance of the battery cell 10 improved; by limiting the ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 to less than or equal to 0.3, the capacity loss of the positive electrode sheet 111 can be reduced. In the embodiments of the present application, the ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 is limited to 0.05 to 0.3, thereby ensuring, to a certain extent, both the fast-charging capability and the energy density of the battery cell 10 simultaneously.

[0260] The thicknesses of the positive electrode film layer and the positive electrode current collector have meanings known in the art and can be determined using devices and methods known in the art. For example, the thickness of the positive electrode sheet is measured with a high-precision micrometer, the film layer is removed from the surface of the positive electrode current collector, and the thickness of the positive electrode current collector is measured with a high-precision micrometer. If the positive electrode film layer is coated on one side, its thickness is equal to the thickness of the positive electrode sheet minus the thickness of the positive electrode current collector. If the positive electrode film layer is coated on both sides, its thickness is equal to (thickness of the positive electrode sheet minus thickness of the positive electrode current collector) divided by 2.

[0261] In some embodiments, the thickness of the positive electrode current collector 1111 is 10 µm to 15 µm, optionally 12 µm to 15 µm. For example, the thickness of the positive electrode current collector 1111 is 10 µm, 10.5 µm, 11 µm, 11.5 µm, 12 µm, 12.5 µm, 13 µm, 13.5 µm, 14 µm, 14.5 µm, or 15 µm, or lies within a range consisting of any two of the above values. When the thickness of the positive electrode current collector 1111 is within the above range, the positive electrode current collector 1111 exhibits excellent current conductivity and enables a higher energy density of the battery cell 10.

[0262] In some embodiments, part of the positive electrode current collector 1111 is not covered by the positive electrode film layer 1112; the part of the positive electrode current collector 1111 not covered by the positive electrode film layer 1112 can be used to form a positive electrode tab 11b.

[0263] In some embodiments, the positive electrode active material comprises a lithium-containing phosphate with an olivine structure or its modified material.

[0264] The lithium-containing phosphate with an olivine structure, or its modified material, can be a lithium-containing phosphate with an olivine structure or a material obtained by coating modification. For example, the lithium-containing phosphate with an olivine structure comprises phosphate particles and an ion-conducting layer, wherein the phosphate particles are coated with the ion-conducting layer, and the ion-conducting layer comprises one or more of C, Fe, Ti, Zr, Hf, Ge, and Sn.

[0265] In some embodiments, the mass fraction of the lithium-containing phosphate with an olivine structure or its modified material in the positive electrode active material can be greater than or equal to 80% and less than or equal to 100%. The positive electrode active material in the present application can be considered a system of the lithium-containing phosphate with an olivine structure or its modified material system. If the mass fraction of the lithium-containing phosphate with an olivine structure or its modified material is less than 100%, the positive electrode active material can also comprise, but is not limited to, a commonly used positive electrode active material, for example, at least one of lithium-containing transition metal oxides.Examples of lithium-containing transition metal oxides may include, but are not limited to, at least one of the following: lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their respective modified compounds.

[0266] Optionally, the mass fraction of the lithium-containing phosphate with olivine structure or its modified material in the positive electrode active material is 100%.

[0267] In some embodiments, the volume-averaged particle size of the positive electrode active material meets the conditions 1 µm ≤ Dv50 ≤ 2 µm and 0.4 µm ≤ Dv10 ≤ 0.7 µm.

[0268] For example, the Dv50 value of the positive electrode active material can be 1 µm, 1.1 µm, 1.15 µm, 1.2 µm, 1.25 µm, 1.3 µm, 1.35 µm, 1.4 µm, 1.45 µm, 1.5 µm, 1.55 µm, 1.6 µm, 1.65 µm, 1.7 µm, 1.75 µm, 1.8 µm, 1.85 µm, 1.9 µm, 1.95 µm or 2 µm, or be in a range consisting of any two of the above values.

[0269] For example, the Dv10 value of the positive electrode active material can be 0.4 µm, 0.45 µm, 0.5 µm, 0.55 µm, 0.6 µm, 0.65 µm or 0.7 µm, or be in a range consisting of any two of the above values.

[0270] The particle size of the positive electrode active material is relatively small, which means that the deintercalation and intercalation path of lithium ions in the positive electrode active material is short and the amount of heat generated is low; furthermore, the particle size of the above positive electrode active material is not too small, which reduces agglomeration during the processing and manufacturing process, so that the performance of the positive electrode active material remains stable.

[0271] The volume-averaged particle size Dv50 of the material refers to the particle size corresponding to 50% of the volume distribution, and the volume-averaged particle size Dv10 to the particle size corresponding to 10% of the volume distribution. The particle sizes can be determined using devices and methods known in the art. For example, the positive electrode active material is used as a sample, and the Dv50 and Dv10 of the particles are measured using a Mastersizer 2000E laser particle size analyzer in accordance with test standard GB / T 19077-2016.

[0272] In some embodiments, the battery cell 10 comprises an electrolyte solution contained in the housing 12. During the charging and discharging process of the battery cell 10, the active ions migrate between the positive electrode sheet 111 and the negative electrode sheet 112 for intercalation and deintercalation, the electrolyte solution having the function of conducting the active ions between the positive electrode sheet 111 and the negative electrode sheet 112.

[0273] In some embodiments, the conductivity of the electrolyte solution at room temperature is 13 mS / cm to 20 mS / cm, optionally 15 mS / cm to 20 mS / cm. For example, the conductivity of the electrolyte solution at room temperature is 13 mS / cm, 13.5 mS / cm, 14 mS / cm, 14.5 mS / cm, 15 mS / cm, 15.5 mS / cm, 16 mS / cm, 16.5 mS / cm, 17 mS / cm, 17.5 mS / cm, 18 mS / cm, 18.5 mS / cm, 19 mS / cm, 19.5 mS / cm, or 20 mS / cm, or lies within a range consisting of any two of the above values.

[0274] For example, the room temperature could be 25 °C.

[0275] If the conductivity of the electrolyte solution is within the above range, the migration rate of ions in the electrolyte solution is relatively high, which can further reduce the internal resistance of battery cell 10, thereby reducing heat generation and thus improving the fast charging performance of battery cell 10.

[0276] The conductivity of the electrolyte solution refers to the ionic conductivity and can be determined using devices and methods known in the art, e.g. the test is carried out according to the industry standard HG-T 4067-2015.

[0277] In some embodiments, the density ρ of the electrolyte solution at room temperature satisfies the condition 1.05 g / mL ≤ ρ ≤ 1.35 g / mL.

[0278] For example, the density ρ of the electrolyte solution is 1.05 g / mL, 1.10 g / mL, 1.15 g / mL, 1.2 g / mL, 1.25 g / mL, 1.3 g / mL, or 1.35 g / mL, or lies in a range consisting of any two of the above values.

[0279] If the density ρ of the electrolyte solution is within the above range, the migration rate of lithium ions in the electrolyte solution is relatively high, which can further reduce the internal resistance of battery cell 10, thereby reducing heat generation and thus improving the fast charging performance of battery cell 10.

[0280] In the embodiments of the present application, the density of the electrolyte solution has a meaning known in the art and can be determined using devices and methods known in the art, for example by reference to GB / T 2013-2010 for testing.

[0281] In some embodiments, the electrolyte solution comprises an organic solvent, wherein the organic solvent comprises one or more carbonate solvents and carboxylic acid ester solvents.

[0282] In some embodiments, the carboxylic ester solvent comprises a chain-like carboxylic ester solvent, wherein the mass fraction of the chain-like carboxylic ester solvent in the organic solvent is 5% to 75%. The mass fraction of the chain-like carboxylic ester solvent is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%, or lies within any two of the above values. When the mass fraction of the chain-like carboxylic ester solvent is within the above range, the viscosity of the electrolyte solution system is relatively low, which has a positive effect on the migration of lithium ions.

[0283] In some embodiments, the mass fraction of the chain-like carboxylic acid ester solvent in the organic solvent is 30% to 70%.

[0284] In some embodiments, the carboxylic acid ester comprises R1-COO-R2, wherein R1 and R2 each independently comprise an alkyl group with 1 to 5 carbon atoms or a halogenated alkyl group with 1 to 5 carbon atoms. The above-mentioned chain-like carboxylic acid ester solvent exhibits high electrical conductivity, which has a positive effect on improving the fast-charging capability of the battery cell 10.

[0285] In some explanatory examples, the carbonate solvent comprises one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.

[0286] Optionally, the carbonate solvent may also include one or more of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate.

[0287] The aforementioned carbonate solvent and chain-like carboxylic acid ester solvents are used together to improve the conductivity of the electrolyte solution, which has a positive effect on the migration of lithium ions.

[0288] Optionally, the mass fraction of the carbonate solvent in the organic solvent can be 5% to 95%, 25% to 60%, or 30% to 45%. For example, the mass fraction of the carbonate solvent in the organic solvent could be 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 40%, 45%, 48%, 50%, 55%, or 60%, or any combination of these values. The carbonate solvent with the mass fraction specified above can further improve the conductivity of the electrolyte solution, which has a positive effect on the migration of lithium ions.

[0289] For example, the carbonate solvent comprises one or more of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, wherein the mass fraction of the carbonate solvent is 25% to 60%.

[0290] By combining the organic solvents, the conductivity of the electrolyte solution can be improved and the viscosity reduced, thereby increasing the fast charging performance of battery 2.

[0291] In some embodiments, the electrolyte solution comprises a lithium salt. The lithium salt comprises one or more fluorinated sulfonylimide salts and lithium hexafluorophosphate (LiPF6). The aforementioned lithium salt is readily dissociated, which promotes the rapid migration of lithium ions; furthermore, the electrolyte solution system is relatively stable and does not decompose easily, which can improve the cycle life of battery cell 10.

[0292] Optionally, the fluorine-containing sulfonylimide salt comprises one or more of lithium bis(fluorosulfonyl)imide; LiFSI and lithium bis(trifluoromethanesulfonyl)imide LiTFSI.

[0293] In some embodiments, the lithium salt comprises lithium bis(fluorosulfonyl)imide LiFSI and lithium hexafluorophosphate LiPF6, wherein the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L to 0.5 mol / L and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5 mol / L to 1.0 mol / L. For example, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.4 mol / L to 0.5 mol / L and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.7 mol / L. For example, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.5 mol / L and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.5 mol / L. For example, the molar concentration of lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L and the molar concentration of lithium hexafluorophosphate LiPF6 is 0.8 mol / L.

[0294] Optionally, the ratio of the molar concentration of lithium bis(fluorosulfonyl)imide to the molar concentration of lithium hexafluorophosphate LiPF6 is (2 to 5):10. For example, the ratio of the molar concentration of lithium bis(fluorosulfonyl)imide to the molar concentration of lithium hexafluorophosphate LiPF6 is 2:10, 2.5:10, 3:10, 3.5:10, 4:10, 4.5:10 or 5:10, or lies in a range consisting of any two of the above values.

[0295] With renewed reference to Fig. 4 to Fig. In some embodiments, the electrode arrangement 11 comprises a negative electrode sheet 112; the dimension of the electrode arrangement 11 along the thickness direction X is denoted by T, the thickness of the negative electrode sheet 112 by T1, and the number of layers of the negative electrode sheet 112 stacked in the thickness direction by N. T, T1, and N satisfy the condition 0.3 ≤ (N × T1) / T ≤ 0.5.

[0296] The negative electrode sheet 112 comprises at least one) straight layer 112a extending perpendicular to the thickness direction X, wherein straight layers 112a are provided in the electrode arrangement 11 N.

[0297] As an example, battery cell 10 is disassembled at a charge level of 0% and the electrode arrangement 11 is removed; T and T1 are measured using a high-precision micrometer.

[0298] For example, the electrode arrangement 11 has a wound structure, and the negative electrode sheet 112 comprises N straight layers 112a; alternatively, the electrode arrangement 11 has a stacked structure, and the electrode arrangement 11 comprises N negative electrode sheets 112, wherein the negative electrode sheets 112 each comprise a straight layer 112a.

[0299] During the cycle process of battery cell 10, the thickness of the negative electrode sheet 112 increases due to irreversible side reactions, leading to an expansion of battery cell 10; by limiting (N × Tl) / T to 0.3 to 0.5, the expansion of battery cell 10 can be reduced and the deformation of the limiting bar 21 reduced.

[0300] In some embodiments, the distance between two adjacent boundary beams 21 in the thickness direction X is designated D1. Several battery cell rows 100 are arranged between adjacent boundary beams 21, the multiple battery cell rows 100 being arranged along a direction perpendicular to the thickness direction X, and each battery cell row 100 comprising at least two battery cells 10 arranged along the thickness direction X. The overall dimension of the electrode arrangements 11 of the battery cells 10 of the battery cell row 100 in the thickness direction is designated D2; where 85% ≤ D2 / D1 ≤ 92%.

[0301] The first side surfaces 21a of two adjacent boundary beams 21 are arranged opposite each other, and D1 is the minimum distance between the first side surfaces 21a of the two boundary beams 21 along the thickness direction X. The first side surface 21a runs perpendicular to the thickness direction X.

[0302] As an example, D1 is measured at the point where the limiting bar 21 overlaps with the battery cell 10 along the thickness direction.

[0303] As an example, several battery cell rows 100 are arranged along the extension direction Y of the boundary bar 21.

[0304] For example, the battery cell series comprises 100 K1 battery cells 10. Each battery cell 10 includes K2 electrode arrays 11 stacked along the thickness direction X. For battery cell 10 at 0% SOC, the dimension of the electrode array 11 along the thickness direction X is denoted by T, where D2 = K1 × K2 × T. K1 is a positive integer greater than 1. K2 is a positive integer.

[0305] D2 / D1 is related to the expansion pressure exerted by the battery cell 10 on the limiting beam 21. In the embodiments of the present application, limiting D2 / D1 to less than or equal to 92% reduces the expansion pressure of the battery cell 10, the deformation of the limiting beam 21 and the battery cell 10, and the risk of cracking of the box body 20. Limiting D2 / D1 to greater than or equal to 85% improves the space utilization in the thickness direction X and increases the energy density of the battery 2. By limiting D2 / D1 to 85% to 92%, the expansion pressure of the battery cell 10 and the energy density of the battery 2 can be ensured to a certain extent simultaneously.

[0306] In some embodiments, the boundary beam 21 comprises a second side surface 21b, wherein the second side surface 21b is arranged on the side of the boundary beam 21 facing away from the multiple battery cells 10 and is inclined towards the first side surface 21a.

[0307] When the battery cell 10 expands during the cycling process and exerts a force on the limiting bar 21, the inclination of the second side surface 21b can distribute the force, thereby increasing the deformation resistance of the limiting bar 21 and reducing the deformation or displacement of the first side surface 21a. The first side surface 21a can provide stronger restraint for the battery cell 10, reducing its expansion deformation and improving its cycle performance. Compared to a solution where the deformation resistance of the limiting bar 21 is increased by simply increasing its size, the solution where the deformation resistance is increased by means of the inclined second side surface 21b can reduce the weight of the limiting bar 21 and increase the energy density of the battery 2.

[0308] In some embodiments, the angle α between the first side surface 21a and the second side surface 21b is 1° to 25°. For example, α can be 1°, 2°, 3°, 5°, 6°, 8°, 10°, 12°, 15°, 18°, 20°, 21°, 23° or 25°, but is not limited to these.

[0309] By setting the angle α to greater than or equal to 1°, it can be ensured that the boundary beam 21 has high structural strength and stiffness, thereby increasing its resistance to deformation. By setting the angle α to less than or equal to 25°, the maximum dimension of the boundary beam 21 in the thickness direction X can be limited to save space and optimize its use in that direction.

[0310] In some embodiments, the volume energy density of the battery cell is 10,390 Wh / L to 450 Wh / L and the angle α between the first side surface 21a and the second side surface 21b is 5° to 20°.

[0311] In the embodiments of the present application, the volume energy density of the battery cell 10 has a meaning known in the art and can be determined using devices and methods known in the art.

[0312] The expansion of battery cell 10 is related to its volume energy density. The present application defines the angle α according to the volume energy density of battery cell 10 in order to simultaneously meet, to a certain extent, the requirements of battery 2 regarding expansion pressure and energy density.

[0313] In some embodiments, the volume energy density of the battery cell is 10 450 Wh / L to 480 Wh / L and the angle α between the first side surface 21a and the second side surface 21b is 8° to 25°.

[0314] The expansion of battery cell 10 is related to its volume energy density. The present application defines the angle α according to the volume energy density of battery cell 10 in order to simultaneously meet, to a certain extent, the requirements of battery 2 regarding expansion pressure and energy density.

[0315] According to the embodiments of the present application, the battery cell 10 has a higher energy density, and the expansion pressure of the battery cell 10 is also greater; an increase in the angle α allows the limiting bar 21 of the battery cell 10 to provide more confining force, thereby improving the cycle performance of the battery cell 10.

[0316] In some embodiments, the electrode arrangement 11 comprises a negative electrode sheet 112, wherein the negative electrode sheet 112 comprises a negative electrode current collector 1121 and a negative electrode film layer 1122 arranged on at least one side of the negative electrode current collector 1121, wherein the negative electrode film layer 1122 comprises a negative electrode active material, the negative electrode active material comprising at least one silicon oxide compound and a silicon-carbon composite. The angle α between the first side surface 21a and the second side surface 21b is 8° to 25°.

[0317] By introducing the silicon oxide compound or the silicon-carbon composite, the capacity of the negative electrode sheet 112 can be increased, thus enhancing the energy density of the battery cell 10. However, the introduction of the silicon oxide compound and the silicon-carbon composite also leads to increased expansion of the negative electrode sheet 112 during the cycling process. By setting the angle α to between 8° and 25°, the deformation resistance of the limiting beam 21 can be increased, thereby providing a constraint on the expansion of the battery cell 10 and reducing the risk of cycle degradation of the battery cell 10 that can be caused by the introduction of the silicon oxide compound and the silicon-carbon composite.

[0318] In some embodiments, the limiting beam 21 is designed as a single-piece structure. This reduces weak connection points of the limiting beam 21, which contributes to increasing its structural strength and stiffness. Alternatively, the limiting beam 21 can also be assembled from several components; for example, it can be welded together from several sheet metal parts.

[0319] In some embodiments, the limiting beam 21 is a profile beam.

[0320] The boundary beam 21 can have a hollow beam structure, formed in one piece from a plate or rod by processes such as stamping / extrusion or metal casting. The wall thickness of the boundary beam 21 can range from 1 mm to 8 mm, depending on the actual requirements, with 3 mm to 5 mm being typical. At this wall thickness, the boundary beam 21 offers good value for money, as it can exhibit both low weight and good structural strength, thereby effectively suppressing the expansion deformation that occurs during the cycle process of the battery cell 10.

[0321] The limiting beam 21 can be made of materials such as steel, iron, aluminum and aluminum alloys, but is not limited to these.

[0322] In some embodiments, the box body 20 comprises a frame body 22 and a support beam 23, wherein the frame body 22 defines a receiving space in which the boundary beams 21 and the multiple battery cells 10 are arranged. The support beam 23 is arranged on the side of the boundary beam 21 facing away from the multiple battery cells 10 and connects the frame body 22 and the boundary beam 21 to each other.

[0323] Optionally, the frame body 22 can be a rectangular frame body.

[0324] One or more support beams 23 may be provided.

[0325] Of two adjacent boundary beams 21, one boundary beam 21 can be connected to the support beam 23, or the two boundary beams 21 can each be connected to a support beam 23.

[0326] During the battery 2 cycle process, the limiting bar 21 serves to counteract the expansion force of the battery cells 10 during the cycle. The frame body 22 can support the limiting bar 21 by means of the support beams 23, thereby providing effective support for the limiting bar 21 and reducing its deformation. This, in turn, restricts the expansion of the battery cell 10 and increases its cycle life.

[0327] By providing the support force between the frame body 22 and the limiting beam 21, the overall structural strength and stiffness of the box body 20 can be improved and the risk of cracking of the box body 20 can be reduced.

[0328] In some embodiments, the frame body 22 comprises several side beams which are arranged and connected one after the other to form an annular frame body 22.

[0329] In some embodiments, the support beam 23 extends along the thickness direction X. Optionally, the cross-section of the support beam 23 can be rectangular, trapezoidal, elliptical, circular, L-shaped, or another form perpendicular to the thickness direction X.

[0330] In some embodiments, the support beam 2, 3 is designed as a plate or as a hollow beam structure. The support beam 23 can be made of steel, aluminum, or aluminum alloys.

[0331] In some embodiments, the support beam 23 and the frame body 22 can be firmly connected to each other by welding, bolting or snapping.

[0332] In some embodiments, the limiting beam 21 extends along a direction perpendicular to the thickness direction X. The box body 20 comprises several support beams 23, which are spaced apart along the extension direction Y of the limiting beam 21. The multiple support beams 23 can increase the confining force acting on the limiting beam 21, improve the uniformity of the load distribution in different areas of the limiting beam 21, reduce the deformation of the limiting beam 21 during the cycle process of the battery cell 10, and improve the cycle performance of the battery 2.

[0333] In some embodiments, the battery 2 further comprises an insulating element 30, which is arranged between the limiting bar 21 and the housing 12. The insulating element 30 can isolate and separate the limiting bar 21 from the housing 12, increase the creepage distance between the battery cell 10 and the limiting bar 21, reduce the risk of short circuits and increase reliability.

[0334] In some embodiments, the insulating element 30 is glued to at least one of the housing 12 and the limiting bar 21.

[0335] Fig. Figure 12 is a schematic partial sectional view of a battery according to further embodiments of the present application.

[0336] With reference to Fig.12 In some embodiments, the boundary bar 21 comprises a third side surface 21c, wherein the third side surface 21c is arranged on the side of the boundary bar 21 facing away from the battery cell 10 and runs parallel to the first side surface 21a, wherein the third side surface 21c is connected to the second side surface 21b.

[0337] The third side surface 21c allows the maximum dimension of the boundary beam 21 in the thickness direction X to be limited, thus increasing space utilization. By combining the third side surface 21c and the second side surface 21b, the boundary beam 21 can form an approximately trapezoidal cross-section, thereby increasing the structural strength and stiffness of the boundary beam 21 and reducing its deformation.

[0338] For example, the second side surface 21b is connected to one end of the third side surface 21c and inclined towards the first side surface 21a.

[0339] In some embodiments, the box body 20 also includes a support plate 24, wherein the multiple battery cells 10 and the limiting bars 21 are arranged on the same side of the support plate 24 and attached to the support plate 24. By way of example, the support plate 24 and the multiple battery cells 10 are arranged along the vertical direction Z of the battery cell 10.

[0340] In some embodiments, the box body 20 also includes a cover plate (not shown), wherein the cover plate and the support plate 24 are arranged opposite each other along the vertical direction Z and are attached to the frame body 22. The battery cell and the limiting bar are arranged between the cover plate and the support plate.

[0341] In some examples, the carrier plate 24 is located above the battery cell, with the battery cell arranged in reverse; alternatively, in other examples, the carrier plate 24 is located below the battery cell, with the battery cell arranged upright.

[0342] In some embodiments, both the third side surface 21c and the first side surface 21a are vertical planes.

[0343] In some embodiments, the second side surface 21b extends from the end of the third side surface 21c, which is facing away from the support plate 24, and is inclined towards the first side surface 21a.

[0344] In some embodiments, the support beam 23 is connected to the third side surface 21c. The third side surface 21c runs perpendicular to the thickness direction X. By connecting the support beam 23 to the third side surface 21c, the support beam 23 can effectively support the boundary beam 21 in the thickness direction X, thereby reducing the deformation of the boundary beam 21.

[0345] Furthermore, by forming the third side surface 21c as a vertical plane, the connection of the boundary beam 21 with the support beam 23 can be facilitated and the construction of the support beam 23 can be simplified.

[0346] In some embodiments, the boundary beam 21 comprises an outer wall 211 and several stiffening ribs 212, wherein the outer wall 211 encloses a receiving chamber 213, and the several stiffening ribs 212 are arranged in the receiving chamber 213 and connected to the outer wall 211. The outer wall 211 comprises the first side surface 21a.

[0347] For example, the outer wall 211 also includes a second side surface 21b. Optionally, the outer wall 211 also includes a third side surface 21c.

[0348] For example, both the stiffening ribs 212 and the outer wall 211 extend along the extension direction Y of the boundary beam 21.

[0349] The receiving chamber 213 can provide the boundary beam 21 with a deformation space for energy absorption and reduce the overall weight of the boundary beam 21, thus contributing to an increase in the energy density of the battery 2. The stiffening ribs 212 increase the structural strength and stiffness of the boundary beam 21 and improve its deformation resistance.

[0350] In some embodiments, the electrode arrangement 11 comprises a negative electrode sheet 112, wherein the negative electrode sheet 112 comprises a negative electrode current collector 1121 and a negative electrode film layer 1122 arranged on at least one side of the negative electrode current collector 1121, wherein the negative electrode film layer 1122 comprises a negative electrode active material, the negative electrode active material being a silicon-based material; the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1% to 6%; the thickness of the outer wall 211 is 2 mm to 7 mm and the thickness of the stiffening ribs 212 is 2 mm to 7 mm.

[0351] For example, the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1%, 2%, 3%, 4%, 5%, or 6%. For example, the thickness of the outer wall 211 is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, or 7 mm.

[0352] The introduction of the silicon-based material increases the capacity of the negative electrode sheet 112 and the energy density of the battery cell 10. The introduction of the silicon-based material also increases the expansion of the negative electrode sheet 112 during the cycling process. By determining the thickness of the outer wall 211 and the thickness of the stiffening ribs 212 in combination with the silicon content, the risk of deformation of the limiting beam 21 due to the introduction of the silicon-based material can be reduced, and the cycle performance of the battery 2 can be improved.

[0353] In some embodiments, the outer wall 211 comprises a first side wall 2111 and a second side wall 2112, which are spaced apart from each other in the thickness direction X, wherein the second side wall 2112 is arranged on the side of the first side wall 2111 facing away from the battery cell 10, and the first side wall 2111 comprises the first side surface 21a. The multiple stiffening ribs 212 comprise first stiffening ribs 212a, which are connected to the first side wall 2111.

[0354] By way of example, among the several stiffening ribs 212 of the boundary beam 21, the stiffening ribs 212 directly connected to the first side wall 2111 are designated as the first stiffening rib 212a. In the boundary beam 21, all stiffening ribs 212 can be the first stiffening ribs 212a, or only some stiffening ribs 212 can be the first stiffening ribs 212a.

[0355] For example, the stiffening ribs 212 and the outer wall 211 can be formed as a single piece. Alternatively, the stiffening ribs 212 and the outer wall 211 can be formed independently of each other. The stiffening ribs 212 can be inserted into the outer wall 211 and attached to it by welding, bolting, or other means.

[0356] The expansion deformation of the battery cell 10 during the cycle process exerts a force on the limiting beam 21, with the force initially acting on the first side wall 2111. The first stiffening ribs 212a are connected to the first side wall 2111 and can transfer the force to other parts of the outer wall 211 as well as support the first side wall 2111, thereby improving the deformation resistance of the first side wall 2111.

[0357] In some embodiments, the number of stiffening ribs ranges from 212 to 8.

[0358] In some embodiments, the two ends of each of the stiffening ribs 212 are connected to the first side wall 2111 and the second side wall 2112, respectively.

[0359] In some embodiments, the second side wall 2112 includes a second side surface 21b.

[0360] In some embodiments, at least one of the first stiffening ribs 212a is inclined relative to the thickness direction X.

[0361] The expansion deformation of the battery cell 10 during the cycle process exerts a force on the first side wall 2111, with the force component in the thickness direction X being relatively large; the first stiffening ribs 212a, which are inclined relative to the thickness direction X, can dissipate the force and thus reduce the risk of crush failure of the first stiffening ribs 212a.

[0362] In some embodiments, the boundary beam 21 extends along a direction perpendicular to the thickness direction X. At least two of the first stiffening ribs 212a are spaced apart along a direction perpendicular to both the extension direction Y of the boundary beam 21 and the thickness direction X, and are inclined in an opposite direction relative to the thickness direction X.

[0363] For example, at least two of the first stiffening ribs 212a are arranged along the vertical direction Z of the battery cell 10.

[0364] By inclining the at least two first stiffening ribs 212a in opposite directions, the structural strength and stiffness of the boundary beam 21 can be further increased. If the first side wall 2111 is subjected to a force X in the thickness direction, opposite torque directions act on the two first stiffening ribs 212a, thereby reducing the risk of rotational deformation of the two first stiffening ribs 212a.

[0365] In some embodiments, the angle β between the first stiffening rib 212a and the thickness direction X is 30° to 80°.

[0366] By setting the angle β to between 30° and 80°, the pressure and moment acting on the first stiffening ribs 212a can be ensured to a certain extent simultaneously. This reduces the risk of crushing failure or rotational deformation of the first stiffening ribs 212a, increases the structural strength and stiffness of the limiting beam 21, and provides effective restraint for the battery cell 10.

[0367] In some embodiments, the first side wall 2111 comprises a central region 21111 and two edge regions 21112, wherein the two edge regions 21112 extend from both ends of the central region 21111 in a direction parallel to the first side surface 21a and perpendicular to the extension direction Y of the boundary beam 21, and the central region 21111 and the edge regions 21112 have the same dimensions. At least one of the first stiffening ribs 212a is connected to the central region 21111.

[0368] During the cycle process of battery cell 10, the center of the battery cell 10 expands more strongly along its own vertical direction Z. Since the central region 21111 of the first side wall 2111 is opposite the center of the battery cell 10, the force acting on the central region 21111 is generally greater than the force acting on the edge region 21112. By connecting the at least one first stiffening rib 212a to the central region 21111, support can be provided to the central region 21111 to suppress the expansion deformation of the battery cell 10 during the cycle process.

[0369] In some embodiments, at least two of the first stiffening ribs 212a are directly connected to the central area 21111.

[0370] In some embodiments, the number of first stiffening ribs 212a that are directly connected to the central region 21111 is greater than the number of first stiffening ribs 212a that are directly connected to the edge region.

[0371] In some embodiments, all of the first stiffening ribs 212a are directly connected to the central area 21111.

[0372] In some embodiments, the outer wall 211 comprises a first side wall 2111 and a second side wall 2112, which are spaced apart along the thickness direction X, wherein the second side wall 2112 is located on the side of the first side wall 2111 facing away from the multiple battery cells 10, and the first side wall 2111 comprises the first side surface 21a. The second side wall 2112 comprises a first section 21121 and a second section 21122, wherein the first section 21121 extends parallel to the first side wall 2111, and the second section 21122 extends from an end of the first section 21121 and is inclined towards the first side wall 2111. At least one of the stiffening ribs 212 is connected to the junction between the first section 21121 and the second section 21122.

[0373] In the embodiments of the present application, it is not necessary for the first section 21121 and the first side wall 2111 to be absolutely parallel. They can also be approximately parallel in an engineering sense.

[0374] For example, the first section 21121 includes a third side surface 21c, and the second section 21122 includes a second side surface 21b.

[0375] During the cycle process of battery cell 10, the battery cell 10 expands and exerts a force on the first side wall 2111. Part of this force can be transferred via the stiffening ribs 212 to the junction between the first section 21121 and the second section 21122, thereby distributing the stress. Both the first section 21121 and the second section 21122 can support the first side wall 2111 via the stiffening ribs 212 to reduce the deformation of the first side wall 2111.

[0376] In some embodiments, the first stiffening ribs 212a are connected to the junction between the first section 21121 and the second section 21122.

[0377] Fig. Figure 13 is a schematic partial sectional view of a battery according to further embodiments of the present application.

[0378] In some embodiments, the outer wall 211 comprises a first side wall 2111, a second side wall 2112 and a cover wall 2113, wherein the second side wall 2112 is arranged on the side of the first side wall 2111 facing away from the multiple battery cells 10, the cover wall 2113 connects the first side wall 2111 and the second side wall 2112, and the first side wall 2111 comprises the first side surface 21a.

[0379] As an example, the cover wall 2113 is arranged on one side of the receiving chamber 213 along the vertical direction Z.

[0380] In some embodiments, the cover wall 2113 comprises a cover surface, wherein the cover surface connects the first side surface 21a and the second side surface 21b.

[0381] In some embodiments, the boundary beam 21 also includes a partition wall 214 connected to the cover wall 2113, wherein the partition wall 214 is arranged in the thickness direction X between the first side wall 2111 and the second side wall 2112. At least one of the stiffening ribs 212 connects the first side wall 2111 and the partition wall 214, and at least one of the stiffening ribs 212 connects the second side wall 2112 and the partition wall 214.

[0382] The arrangement of the partition 214 and stiffening ribs 212 creates a multi-chamber structure inside the boundary beam 21, which contributes to increasing the overall stiffness of the boundary beam 21. During the cycle process of the battery cell 10, the battery cell 10 expands and exerts a force on the first side wall 2111. The partition 214 can transfer and distribute this force to reduce the deformation of the first side wall 2111 and thereby confine the battery cell 10.

[0383] In some embodiments, the partition wall 214 can be formed in one piece with the outer wall 211 or attached to the outer wall 211 by welding.

[0384] In some embodiments, the partition 214 comprises a third section 2141 and a fourth section 2142, wherein the fourth section 2142 extends from the upper end of the third section 2141 along the vertical direction Z and is inclined relative to the third section 2141.

[0385] In some embodiments, the first section 21121 runs parallel to the third section 2141, and the second section 21122 runs parallel to the fourth section 2142.

[0386] In some embodiments, one end of a stiffening rib 212 is connected to the junction between the first section 21121 and the second section 21122, and the other end is connected to the junction between the third section 2141 and the fourth section 2142.

[0387] In some embodiments, the stiffening rib 212, which connects the second side wall 2112 and the partition wall 214, can be a second stiffening rib 212b.

[0388] In some embodiments, at least one of the first stiffening ribs 212a is connected at the junction between the third section 2141 and the fourth section 2142.

[0389] In some embodiments, the outer wall 211 also includes a bottom wall 2114, wherein the bottom wall 2114 and the top wall 2113 are arranged along the vertical direction Z of the battery cell 10.

[0390] In some embodiments, the bottom wall 2114 is attached to the support plate 24.

[0391] Fig. Figure 14 is a schematic representation of the structure of a battery according to further embodiments of the present application. Fig. 15 is a schematic partial sectional view of the in Fig. 14 shown battery.

[0392] With reference to Fig. 14 and Fig. 15 In some embodiments, the battery 2 further comprises a limiting element 40, wherein the limiting element 40 connects adjacent limiting beams 21 to each other.

[0393] One or more restriction elements 40 may be provided.

[0394] The restricting element 40 can be connected to the limiting beam 21 by welding, snapping, fastening connection or in any other way.

[0395] The constraint element 40 has a ribbon-like structure, a linear structure, a support structure, or another structure. For example, the constraint element 40 extends along the thickness direction X of the battery cell 10.

[0396] During the cycle process of battery cell 10, the battery cell 10 expands and exerts a force on the limiting beam 21. The limiting element 40 can exert a limiting force on the limiting beam 21, thereby reducing the deformation of the limiting beam 21, limiting the expansion of battery cell 10, improving the cycle performance of battery cell 10, and reducing the risk of cracking of the box body 20.

[0397] In some embodiments, the restricting element 40 can exert a preload force on the adjacent limiting beam 21.

[0398] In some embodiments, the confining element 40 has a ribbon-shaped structure. The ribbon-shaped structure is inexpensive and space-saving; by using the confining element 40 with a ribbon-shaped structure, the space utilization inside the battery 2 can be improved and the energy density of the battery 2 increased.

[0399] In some embodiments, the restricting element 40 comprises a metal band. By way of example, the restricting element 40 comprises a steel band.

[0400] In some embodiments, the limiting element 40 is arranged on one side of the battery cell 10 along the vertical direction Z. The limiting element 40 can limit the battery cell 10 in the vertical direction Z.

[0401] In some embodiments, the restraint element 40 is connected to the battery cell 10, thereby increasing the connection strength between the battery cell 10 and the housing 20. In the event of an impact on the battery 2, the vibration of the battery cell 10 relative to the housing 20 is reduced, thus improving the reliability and stability of the battery 2.

[0402] In some embodiments, a confining element 40 is connected to the battery cells 10 of at least one battery cell row 100. Optionally, a confining element 40 is connected to the battery cells 10 of two adjacent battery cell rows 100.

[0403] In some embodiments, the confining element 40 is glued to the battery cell 10. Gluing allows for a quick and stable connection between the battery cell 10 and the confining element 40, thereby increasing the confining force exerted by the confining element 40 on the battery cell 10.

[0404] In some embodiments, an adhesive layer 50 is provided between the restricting element 40 and the battery cell 10. For example, the adhesive layer 50 comprises a structural element or a double-sided adhesive tape.

[0405] In some embodiments, the restricting element 40 is detachably connected to the limiting beam 21. This detachable connection facilitates subsequent maintenance or replacement of the restricting element 40.

[0406] A screw connection, a snap connection or another type of detachable connection can be used between the restricting element 40 and the limiting beam 21, but is not limited to this.

[0407] In some embodiments, the battery 2 further comprises a fastening element 60, wherein the fastening element 60 connects the limiting element 40 and the limiting beam 21. At least a portion of the fastening element 60 is embedded in and fastened to the limiting beam 21.

[0408] The fastening element 60 can be fully embedded in the boundary beam 21 or only partially embedded in the boundary beam 21. The fastening element 60 is attached to the boundary beam 21.

[0409] One or more fastening elements 60 may be provided.

[0410] The fastening element 60 can be attached to the limiting beam 21 by welding, snapping, riveting, screwing, gluing or in any other way.

[0411] By embedding the fastener 60 in the limiting beam 21, the connection strength between the fastener 60 and the limiting beam 21 is increased, and the risk of connection failure between the fastener 60 and the limiting beam 21 is reduced. The limiting element 40 can be connected to the limiting beam 21 via the fastener 60, with the connection between the fastener 60 and the limiting element 40 being independent of the limiting beam 21. This allows for a flexible and needs-based choice of connection type between the fastener 60 and the limiting element 40 and improves the connection strength between the fastener 60 and the limiting element 40.

[0412] In some embodiments, the limiting beam 21 has an internal receiving chamber 213, in which the fastening element 60 is received. By providing the receiving chamber 213, the fastening element 60 can be completely embedded in the limiting beam 21, thereby increasing the connection strength between the fastening element 60 and the limiting beam 21.

[0413] Optionally, the limiting beam 21 is assembled from several sheet metal parts, and the fastening element 60 can be attached to the sheet metal parts during assembly.

[0414] In some alternative embodiments, the limiting beam 21 has an upper recess extending from the top wall 2113, wherein the fastening element 60 can be inserted into the upper recess and attached to the limiting beam 21.

[0415] In some embodiments, the restricting element 40 is attached to the fastening element 60 by means of a fastening means 80.

[0416] In some embodiments, the limiting beam 21 extends along a direction perpendicular to the thickness direction X. Several limiting elements 40 are provided, wherein the several limiting elements 40 are arranged at intervals along the extension direction Y of the limiting beam 21.

[0417] The multiple constraint elements 40 can increase the constraint force acting on the limiting beam 21, improve the uniformity of the load distribution in different areas of the limiting beam 21, reduce the deformation of the limiting beam 21 during the cycle process of the battery cell 10 and improve the cycle performance of the battery 2.

[0418] Fig. Figure 16 is an enlarged schematic view of the in Fig.4 circled areas; Fig. Figure 17 is a schematic representation of the structure of a first Btis component of Fig. 16; Fig. Figure 18 is a schematic representation of the connection of a battery cell with a first bus component according to some embodiments of the present application.

[0419] With reference to Fig. 4 as well Fig. 16 to Fig. 18 In some embodiments, the battery 2 further comprises several bus components 70, wherein the several bus components 70 electrically connect the several battery cells 10 to each other.

[0420] The multiple bus components 70 can connect the multiple battery cells 10 in series, parallel or mixed configurations.

[0421] The multiple bus components 70 can have the same structure or different structures.

[0422] In some embodiments, the multiple bus components 70 comprise at least one first bus component 70a, wherein the first bus component 70a comprises a first bus layer 71 and a second bus layer 72, which are stacked on top of each other and connected to each other, wherein the first bus layer 71 connects at least two of the battery cells 10, which are arranged in the thickness direction X.

[0423] The multiple bus components 70 can all be first bus components 70a or some can be first bus components 70a.

[0424] The first bus layer 71 and the second bus layer 72 can be formed as a single-piece structure. Alternatively, the first bus layer 71 and the second bus layer 72 can also be formed separately and joined by welding or other means.

[0425] The first bus component 70a has a structure with at least two layers, whereby both the first bus layer 71 and the second bus layer 72 of the first bus component 70a can conduct current. This results in the first bus component 70a having a large current-conducting area, which reduces the heat generation of the first bus component 70a and increases the fast-charging capability of the battery 2.

[0426] Provided that the current-carrying area meets the requirements, the thickness of the first bus layer 71 can be reduced by designing the first bus component 70a as a double-layer structure. The battery cell 10 expands during the cycling process, thereby stretching the first bus layer 71. The first bus layer 71 has a relatively small thickness. It is easily deformable to adapt to the deformation of the battery cell 10, thus reducing the risk of the connection between the battery cell 10 and the first bus layer 71 breaking and increasing the reliability of the battery 2.

[0427] In some embodiments, the battery cell 10 comprises an electrode terminal 13 arranged on the housing 12, wherein the electrode terminal 13 is electrically connected to the electrode arrangement 11. The first bus layer 71 is connected to the electrode terminal 13 of the battery cell 10.

[0428] Optionally, the first bus layer 71 is welded to the electrode connection 13.

[0429] In some embodiments, the part of the first bus layer 71 that does not overlap with the second bus layer 72 is connected to the electrode terminal 13.

[0430] The second bus layer 72 can bypass the connection point between the first bus layer 71 and the electrode terminal 13, thereby reducing the impact of the second bus layer 72 on the connection point between the first bus layer 71 and the electrode terminal 13 during battery cell expansion. This reduces the risk of the connection point between the electrode terminal 13 and the first bus layer 71 breaking and increases the reliability of the battery 2. Furthermore, when assembling the battery cell 10 and the first bus component 70a, the area of ​​the first bus layer 71 used for connection with the electrode terminal 13 is not covered by the second bus layer 72, thus reducing assembly difficulty.

[0431] In some embodiments, the first bus layer 71 is welded to the electrode connection 13 and forms a weld trace, and the second bus layer 72 does not cover the weld trace.

[0432] In some embodiments, the second bus layer 72 partially overlaps with the electrode terminal 13 in the stacking direction of the first bus layer 71 and the second bus layer 72, which shortens the conductor path between the second bus layer 72 and the electrode terminal 13, thereby reducing the resistance and heat generation.

[0433] In some embodiments, the first bus layer 71 and the second bus layer 72 are stacked along the vertical direction Z of the battery cell 10. In other words, the stacking direction of the first bus layer 71 and the second bus layer 72 runs parallel to the vertical direction Z.

[0434] In some embodiments, the second bus layer 72 can be arranged on the side of the first bus layer 71 facing the battery cell 10 or on the side of the first bus layer 71 facing away from the battery cell 10.

[0435] In some embodiments, the first bus component 70a comprises at least one bending section 73, wherein the bending section 73 connects the first bus layer 71 and the second bus layer 72.

[0436] One or more bending sections 73 may be provided.

[0437] The bending section 73 can connect the first bus layer 71 and the second bus layer 72 and transfer current between the first bus layer 71 and the second bus layer 72, thereby improving the current-carrying capability of the first bus component 70a.

[0438] In some embodiments, the first bus layer 71 comprises a first bus section 711, a second bus section 712 and a first buffer section 713 for connecting the first bus section 711 and the second bus section 712 together, wherein the first bus section 711 and the second bus section 712 are arranged along the thickness direction X and are connected to different battery cells 10.

[0439] In some embodiments, the bending section 73 is arranged such that it bypasses the first buffer section 713. The bending section 73 is not directly connected to the first buffer section 713.

[0440] For example, the bending section 73 extends from one end of the first bus layer 71 along the direction of extension Y and is bent towards the side facing away from the battery cell. The bending section 73 does not cover the side surface of the first buffer section 713 along the direction of extension Y.

[0441] The first bus section 711 can be connected to the electrode terminal 13 of one battery cell 10 or simultaneously to the electrode terminals 13 of at least two battery cells 10. The second bus section 712 can be connected to the electrode terminal 13 of one battery cell 10 or simultaneously to the electrode terminals 13 of at least two battery cells 10.

[0442] During the cycle process of battery cell 10, the battery cell 10 expands and exerts a tensile force on the first bus layer 71; the first buffer section 713 can relieve stresses by deformation, thereby reducing the load at the connection point between the first bus section 711 and the battery cell 10, as well as the load at the connection point between the second bus section 712 and the battery cell 10, and thus reducing the risk of a connection failure between the first bus layer 71 and the battery cell 10. The bending section 73 is not directly connected to the first buffer section 713, thereby reducing the influence of the bending section 73 on the deformation of the first buffer section 713 and facilitating the deformation of the first buffer section 713.

[0443] In some embodiments, the first bus section 711 is arranged above the electrode terminal 13 of the battery cell 10, and the second bus section 712 is arranged above the electrode terminal 13 of the battery cell 10.

[0444] In some embodiments, the first buffer section 713 comprises an arc-shaped structure.

[0445] In some embodiments, the first bus section 711 is connected to the second bus layer 72 by at least one of the bending sections 73, and the second bus section 712 is connected to the second bus layer 72 by at least one of the bending sections 73.

[0446] In some embodiments, the second bus layer 72 comprises a first stacking section 721, a second stacking section 722, and a second buffer section 723, wherein the first stacking section 721 is stacked with the first bus section 711 and connected by at least one of the bending sections 73, and the second stacking section 722 is stacked with the second bus section 712 and connected by at least one of the bending sections 73. The second buffer section 723 connects the first stacking section 721 and the second stacking section 722. In the stacking direction of the first bus layer 71 and the second bus layer 72, the second buffer section 723 overlaps at least partially with the first buffer section 713.

[0447] During the cycle process of battery cell 10, the battery cell 10 expands and exerts a tensile force on the first bus layer 71; both the first buffer section 713 and the second buffer section 723 can relieve stresses through deformation, thereby reducing the risk of a connection failure between the first bus layer 71 and the battery cell 10. The at least partial overlap of the second buffer section 723 with the first buffer section 713 results in the deformation areas of the first buffer section 713 and the second buffer section 723 being closer together. This reduces the risk of the first buffer section 713 and the second buffer section 723 being damaged by other parts during deformation.

[0448] In some embodiments, the second buffer section 723 and the first buffer section 713 are arranged adjacent to each other. The embodiments of the present application can save space.

[0449] In some embodiments, the thickness of the first bus layer 71 is 1 mm to 2.5 mm. Optionally, the thickness of the first bus layer 71 is 1.2 mm to 1.8 mm. For example, the thickness of the first bus layer 71 is 1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm.

[0450] In the embodiments of the present application, the thickness of the first bus layer 71 is selected according to the expansion pressure of the battery cell 10, whereby the current-carrying capacity of the first bus layer 71 and the deformation capacity of the first bus layer 71 can be ensured to a certain extent simultaneously in order to improve the fast-charging capability and reliability of the battery 2.

[0451] In some embodiments, the thickness of the second bus layer 72 is 1 mm to 2.5 mm. Optionally, the thickness of the second bus layer 72 is 1.2 mm to 1.8 mm. For example, the thickness of the second bus layer 72 is 1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm.

[0452] The thickness of the second bus layer 72 can be selected based on the thickness of the first bus layer 71 and the current-carrying capacity of the first bus component required for the battery. For example, the second bus layer 72 can have a greater thickness than the first bus layer 71 if the thickness of the first bus layer 71 is small, in order to increase the current-carrying capacity of the first bus component.

[0453] In some embodiments, the volume energy density of the battery cell is 10 390 Wh / L to 450 Wh / L and the thickness of the first bus layer 71 is less than or equal to 2.5 mm.

[0454] The dimensions of the battery cell 10 are related to its volume energy density. The present application specifies the thickness of the first bus layer 71 according to the volume energy density of the battery cell 10, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first bus layer 71 simultaneously, in order to improve the fast-charging capability and reliability of the battery 2.

[0455] In some embodiments, the volume energy density of the battery cell is 10 450 Wh / L to 480 Wh / L and the thickness of the first bus layer 71 is less than or equal to 2.2 mm.

[0456] The dimensions of the battery cell 10 are related to its volume energy density. In a battery 2 that uses battery cells 10 with high volume energy density, the thickness of the first bus layer 71 must be reduced. In the embodiments of the present application, the thickness of the first bus layer 71 is selected according to the volume energy density of the battery cell 10, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first bus layer 71 simultaneously, in order to improve the fast-charging capability and reliability of the battery 2.

[0457] In some embodiments, the electrode arrangement 11 comprises a negative electrode sheet 112, wherein the negative electrode sheet 112 comprises a negative electrode current collector 1121 and a negative electrode film layer 1122 arranged on at least one side of the negative electrode current collector 1121, wherein the negative electrode film layer 1122 comprises a negative electrode active material, the negative electrode active material being a silicon-based material. The mass fraction of elemental silicon in the silicon-based material in the negative electrode active material is 1% to 6%; the thickness of the first bus layer 71 is 1.2 mm to 2.2 mm and the thickness of the second bus layer 72 is 1.2 mm to 2.2 mm.

[0458] For example, the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1%, 2%, 3%, 4%, 5%, or 6%. For example, the thickness of the first bus layer 71 is 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, or 2.2 mm. For example, the thickness of the second bus layer 72 is 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, or 2.2 mm.

[0459] The introduction of the silicon-based material increases the capacity of the negative electrode sheet 112 and the energy density of the battery cell 10. The introduction of the silicon-based material also increases the expansion of the negative electrode sheet 112 during the cycling process. By specifying the thickness of the first bus layer 71 and the thickness of the second bus layer 72 in combination with the silicon content, the risk of a connection failure between the first bus layer 71 and the battery cell 10 due to the introduction of the silicon-based material can be reduced. Furthermore, the current-carrying capacity requirements of the first bus component 70a can be met.

[0460] In some embodiments, the first bus layer 71 comprises a first bus section 711, a second bus section 712, and a first buffer section 713 for connecting the first bus section 711 and the second bus section 712, wherein the first bus section 711 and the second bus section 712 are arranged along the thickness direction X and connected to different battery cells 10. In the stacking direction of the first bus layer 71 and the second bus layer 72, the first buffer section 713 projects beyond the first bus section 711 and the second bus section 712. A recess 714 is provided at the position of the first bus layer 71 corresponding to the first buffer section 713.

[0461] By providing the recess 714, the strength of the first buffer section 713 can be reduced, which facilitates the deformation of the first buffer section 713 when the battery cell 10 expands.

[0462] In some embodiments, the volume energy density of the battery cell is 10,390 Wh / L to 450 Wh / L and the depth H2 of the recess 714 is 1.2 mm to 2.5 mm.

[0463] The dimensions of the battery cell 10 are related to its volume energy density. The present application specifies the depth of the recess 714 according to the volume energy density of the battery cell 10, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first buffer section 713 simultaneously, in order to improve the fast-charging capability and reliability of the battery 2.

[0464] In some embodiments, the volume energy density of the battery cell is 10 450 Wh / L to 480 Wh / L and the depth of the recess 714 is 1 mm to 2.2 mm.

[0465] The dimensions of the battery cell 10 are related to its volume energy density. In a battery 2 that uses battery cells 10 with high volume energy density, the difficulty of deformation of the first buffer section 713 must be reduced. In the embodiments of the present application, the depth of the recess 714 is determined according to the volume energy density of the battery cell 10, thereby ensuring, to a certain extent, both the current-carrying capacity and the deformation capacity of the first buffer section 713 simultaneously, in order to improve the fast-charging capability and reliability of the battery 2.

[0466] Fig. 19 is a schematic top view of a battery according to further embodiments of the present application; Fig. 20 is an enlarged schematic view of the in Fig. 19 framed area; Fig.Figure 21 is a schematic representation of the structure of a second bus component from Fig. 20.

[0467] With further reference to Fig. 17 to Fig. 21 In some embodiments, the multiple bus components 70 also include at least one second bus component 70b, wherein the thickness of the second bus component 70b is greater than the thickness of the first bus layer 71, and the thickness of the second bus component 70b is greater than the thickness of the second bus layer 72.

[0468] For example, the second bus component 70b has a single-layer structure, and the first bus component 70a has a multi-layer structure.

[0469] In battery 2, the expansion of the battery cells 10 can vary at different locations. For battery cells 10 with lower expansion, a second bus component 70b with a single-layer structure can be used; compared to the first bus component 70a, the second bus component 70b has a simpler structure, is easier to manufacture, and can save costs. The thickness of the second bus component 70b is greater than the thickness of the first bus layer 71 and the thickness of the second bus layer 72, and its current-carrying capacity can meet the requirements.

[0470] In some embodiments, the sum of the thickness of the first bus layer 71 and the thickness of the second bus layer 72 is equal to the thickness of the second bus component 70b. In some embodiments of the present application, the difference in current-carrying capacity between the first bus component 70a and the second bus component 70b can be reduced and the current consistency improved.

[0471] In some embodiments, the battery cell 10 adjacent to the boundary bar 21 is connected to the first bus component 70a. During charging, the expansion of several battery cells 10 in the thickness direction X can overlap, leading to a significant displacement of the battery cell 10 adjacent to the boundary bar 21. By using the first bus component 70a with a double-layer structure to connect the battery cell 10 closest to the boundary bar 21, the risk of a connection failure between the first bus component 70a and the battery cell 10 can be reduced.

[0472] In some embodiments, the multiple bus components 70 also include a third bus component 70c, wherein the third bus component 70c can connect two of the battery cells 10 that are adjacent along the extension direction.

[0473] In some embodiments, the charging time of battery cell 10 from 10% SOC to 80% SOC is between 5 and 10.5 minutes. For example, the charging time of battery cell 10 from 10% state of charge to 80% state of charge is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, or 5 min, or lies within a range consisting of any two of the above values.

[0474] In the embodiments of the present application, the battery cell 10 has a fast-charging capability, which saves charging time.

[0475] In some embodiments, the charging steps of battery 2 or of any battery cell 10 of which battery 2 consists, from 10% to 80% can be carried out as follows: With a constant current of 5.0 C, charging from 10% SOC to 15% SOC is achieved; With a constant current of 5.0 C, charging from 15% SOC to 20% SOC is achieved; With a constant current of 5.0 C, charging from 20% SOC to 25% SOC is achieved; With a constant current of 5.0 C, charging from 25% SOC to 30% SOC is achieved; With a constant current of 5.0 C, charging from 30% SOC to 35% SOC is achieved; With a constant current of 5.0 C, charging from 35% SOC to 40% SOC is achieved; With a constant current of 4.6 C, it charges from 40% SOC to 45% SOC; With a constant current of 4.3 C, it charges from 45% SOC to 50% SOC; Charging with a constant current of 4.0 C from 50% SOC to 55% SOC; With a constant current of 3.7 C, it charges from 55% SOC to 60% SOC; With a constant current of 3.4 C, it charges from 60% SOC to 65% SOC; With a constant current of 3.1 C, it charges from 65% SOC to 70% SOC; With a constant current of 2.9 C, it charges from 70% SOC to 75% SOC; With a constant current of 2.7 C, the battery is charged from 75% SOC to 80% SOC.

[0476] As an example, the above charging strategy is carried out in an environment of 30 °C.

[0477] In some embodiments, the charging step of battery cell 10 from 0% SOC to 10% SOC can be carried out as follows: Charging from 0% SOC to 10% SOC is performed with a constant current of 5.0 C.

[0478] In some embodiments, the charging steps of battery cell 10 from 80% SOC to 98% SOC can be performed as follows: With a constant current of 1.8 C, charging from 80% SOC to 85% SOC is achieved; With a constant current of 1.3 C, it charges from 85% SOC to 90% SOC; With a constant current of 0.7 C, it charges from 90% SOC to 95% SOC; With a constant current of 0.33 C, charging from 95% SOC to 98% SOC is achieved.

[0479] In some embodiments, the charging step of battery cell 10 from 98% SOC to 100% SOC can be performed as follows: Charging from 98% SOC to 100% SOC is carried out with a constant current of 0.01 C, 0.05 C, 0.1 C, or 0.3 C. Alternatively, the charging step of battery cell 10 from 98% SOC to 100% SOC can be performed as follows: Charging from 98% SOC to 100% SOC is carried out with a constant current of 0.01 C, 0.05 C, or 0.1 C.

[0480] In some embodiments, the charging current during the charging process of battery cell 10 from 10% SOC to 80% SOC can be 2C to 6C, optionally 2.7C to 5C. During the charging process of battery cell 10, the charging current can change according to the SOC of battery cell 10.

[0481] In some embodiments, the battery cell 10 can be a lithium-ion battery cell. After the battery cell 10 has undergone 20 cycles according to the charging and discharging strategies, the negative electrode sheet of the battery cell 10 is disassembled, and the lithium plating area of ​​the negative electrode sheet is observed and measured. The ratio of the area of ​​the lithium plating area to the total area of ​​the negative electrode sheet is less than 2%.

[0482] As an example, the discharge strategy is carried out by discharging with a constant current of 0.33 C to 2.0 V.

[0483] For example, the charging strategy could be as follows: A constant current of 5.0 C charges the battery from 0% SOC to 5% SOC; With a constant current of 5.0 C, charging from 5% SOC to 10% SOC is achieved; With a constant current of 5.0 C, charging from 10% SOC to 15% SOC is achieved; With a constant current of 5.0 C, charging from 15% SOC to 20% SOC is achieved; With a constant current of 5.0 C, charging from 20% SOC to 25% SOC is achieved; With a constant current of 5.0 C, charging from 25% SOC to 30% SOC is achieved; With a constant current of 5.0 C, charging from 30% SOC to 35% SOC is achieved; With a constant current of 5.0 C, charging from 35% SOC to 40% SOC is achieved; With a constant current of 4.6 C, it charges from 40% SOC to 45% SOC; With a constant current of 4.3 C, it charges from 45% SOC to 50% SOC; Charging with a constant current of 4.0 C from 50% SOC to 55% SOC; With a constant current of 3.7 C, it charges from 55% SOC to 60% SOC; With a constant current of 3.4 C, it charges from 60% SOC to 65% SOC; With a constant current of 3.1 C, it charges from 65% SOC to 70% SOC; With a constant current of 2.9 C, it charges from 70% SOC to 75% SOC; With a constant current of 2.7 C, it charges from 75% SOC to 80% SOC; With a constant current of 1.8 C, it charges from 80% SOC to 85% SOC; With a constant current of 1.3 C, it charges from 85% SOC to 90% SOC; With a constant current of 0.7 C, it charges from 90% SOC to 95% SOC; With a constant current of 0.33 C, it charges from 95% SOC to 98% SOC; With a constant current of 0.1 C, it charges from 98% SOC to 100% SOC.

[0484] The battery cell 10 according to the embodiments of the present application can be charged from 10% SOC to 80% SOC in 10.5 minutes without lithium plating or with only minimal lithium plating, and exhibits good fast-charging capability. For example, a ratio of the area of ​​the lithium plating area to the total area of ​​the negative electrode sheet of less than 0.05% can be considered no lithium plating, and a ratio of the area of ​​the lithium plating area to the total area of ​​the negative electrode sheet of less than 2% and greater than or equal to 0.05% can be considered minimal lithium plating.

[0485] According to some embodiments of the present application, the present application further provides a power-consuming device comprising a battery 2 according to one of the above embodiments, wherein the battery 2 serves to supply power to the power-consuming device. The power-consuming device may be one of the aforementioned devices or systems that uses the battery 2.

[0486] With reference to Fig. Figures 2 to 18 describe embodiments of the present application providing a battery 2 comprising several battery cells 10, a box body 20, a limiting element 40, and several bus components 70. Several battery cells 10 are accommodated in the box body 20.

[0487] The battery cell 10 comprises a housing 12 and an electrode arrangement 11 contained in the housing 12. The expansion pressure of the battery cell in the thickness direction X is 0.5 MPa to 2.4 MPa.

[0488] The electrode arrangement 11 comprises a positive electrode sheet 111, a negative electrode sheet 112, and a separator 113, wherein the separator 113 separates the positive electrode sheet 111 and the negative electrode sheet 112. Optionally, the positive electrode sheet 111, the negative electrode sheet 112, and the separator 113 are arranged in a coiled configuration.

[0489] The negative electrode sheet 112 comprises a negative electrode current collector 1121 and a negative electrode film layer 1122 arranged on at least one side of the negative electrode current collector 1121, wherein the negative electrode film layer 1122 comprises a negative electrode active material. The porosity of the negative electrode sheet 112 is 27% to 40%. The compaction density of the negative electrode film layer 1122 at 100% state of charge (SOC) of the battery cell is 1.15 g / cm³. 3 up to 1.36 g / cm³ 3 .

[0490] The negative electrode film layer 1122 comprises a first negative electrode film layer 11221 and a second negative electrode film layer 11222, wherein the second negative electrode film layer 11222 is arranged between the first negative electrode film layer 11221 and the negative electrode current collector 1121. The negative electrode active material comprises a first negative electrode active material arranged in the first negative electrode film layer 11221 and a second negative electrode active material arranged in the second negative electrode film layer 11222, wherein the first negative electrode active material comprises synthetic graphite and the second negative electrode active material comprises one or more synthetic graphite, natural graphite and silicon-based material.The volume-averaged particle size Dv50 of the first negative electrode active material is less than or equal to the volume-averaged particle size Dv50 of the second negative electrode active material.

[0491] The positive electrode sheet 111 comprises a positive electrode current collector 1111 and a positive electrode film layer 1112 arranged on at least one side of the positive electrode current collector 1111. The density of the positive electrode film layer 1112 at 100% state of charge (SOC) of the battery cell is 2.50 g / cm³. 3 up to 2.80 g / cm³ 3The porosity of the positive electrode sheet 111 is 25% to 32%. The ratio of the thickness of the positive electrode current collector 1111 to the thickness of the positive electrode film layer 1112 is 0.05 to 0.3. The positive electrode active material comprises a lithium-containing phosphate with an olivine structure or a modified version thereof. The volume-averaged particle size of the positive electrode active material meets the conditions 1 µm ≤ Dv50 ≤ 2 µm and 0.4 µm ≤ Dv10 ≤ 0.7 µm.

[0492] The box body 20 comprises two boundary beams 21, the two boundary beams 21 being spaced apart along the thickness direction X of the battery cell 10. The multiple battery cells 10 are arranged in an array and form multiple battery cell rows 100. The multiple battery cell rows 100 are arranged along the extension direction Y of the boundary beams 21. Each battery cell row 100 comprises at least two of the battery cells 10, which are arranged along the thickness direction X of the battery cell 10. Multiple battery cells 10 are arranged between the two boundary beams 21.

[0493] The boundary beam 21 comprises a first side surface 21a facing the multiple battery cells 10, wherein the first side surface 21a is designed such that the maximum displacement of the first side surface 21a in the thickness direction X at a pressure of 1.7 MPa is less than or equal to 8 mm.

[0494] The box body 20 comprises a frame body 22 and a support beam 23, wherein the frame body 22 defines a receiving space in which the boundary beams 21 and the multiple battery cells 10 are arranged. The support beam 23 is arranged on the side of the boundary beam 21 facing away from the multiple battery cells 10 and connects the frame body 22 and the boundary beam 21 to each other. The confining element 40 connects adjacent boundary beams 21 to each other and is bonded to the battery cell 10.

[0495] The multiple bus components 70 electrically connect the multiple battery cells 10 to one another. The multiple bus components 70 comprise at least one first bus component 70a, wherein the first bus component 70a comprises a first bus layer 71 and a second bus layer 72, which are stacked on top of each other and connected to one another, wherein the first bus layer 71 connects at least two of the battery cells 10, which are arranged in the thickness direction X. Example of implementation

[0496] The following exemplary embodiments describe in more detail the content disclosed in the embodiments of the present application. These exemplary embodiments serve only as an illustration, since various modifications and changes within the scope of the content disclosed in the embodiments of the present application are obvious to the person skilled in the art. Unless otherwise stated, all proportions, percentages, and ratios given in the following exemplary embodiments refer to mass. All reagents used in the exemplary embodiments are commercially available or are synthesized by conventional methods and can be used directly without further treatment. The instruments used in the exemplary embodiments are commercially available. Example 11. Production of the positive electrode sheet

[0497] The positive electrode sheet comprised a positive electrode current collector and positive electrode film layers arranged on both sides of the positive electrode current collector, the positive electrode current collector being an aluminum foil with a thickness of 15 µm.

[0498] The positive electrode film layer comprised a film layer formed by uniform application of the positive electrode paste (solvent: N-methyl-2-pyrrolidone NMP) to the surface of the conductive layer of the positive electrode, drying and cold pressing. The positive electrode film layer comprised a positive electrode active material, a binder polyvinylidene fluoride (PVDF) and a conductive agent acetylene carbon black in a weight ratio of 97:2:1.

[0499] The positive electrode active material comprised lithium iron phosphate and an ion-conducting layer, wherein the surface of the lithium iron phosphate was coated with the ion-conducting layer, which comprised lithium iron titanium phosphate (Li₂FeTi(PO₄)₃) and amorphous carbon. The Dv₅₀ value of the positive electrode active material was 1.6 µm and the Dv₁₀ value was 0.64 µm.

[0500] The one-sided coating weight of the positive electrode film layer was 0.21 g / 1540.25 mm². 2 The compaction density of the positive electrode film layer after cold pressing was 2.6 g / cm³. 3 . 2. Production of the negative electrode sheet

[0501] The negative electrode sheet comprised a negative electrode current collector and negative electrode film layers arranged on both sides of the negative electrode current collector, the negative electrode current collector being a copper foil with a thickness of 6 µm.

[0502] The negative electrode film layer comprised a film layer formed by uniformly applying the negative electrode paste (solvent: deionized water) to the surface of the conductive layer of the negative electrode, followed by drying and cold pressing.

[0503] The one-sided coating weight of the negative electrode film layer is 0.096 g / 1540.25 mm². 2 The compaction density of the negative electrode film layer after cold pressing is 1.6 g / cm³. 3 .

[0504] The negative electrode film layer comprised a first negative electrode film layer and a second negative electrode film layer, with the second negative electrode film layer being located between the first negative electrode film layer and the negative electrode current collector.

[0505] The first negative electrode film layer comprised graphite particles, a conductive agent acetylene carbon black, a first lithium-containing binder (a copolymer of lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate, wherein the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer and hydroxyethyl acrylate monomer was 35%:30%:15%:20%), a negative electrode binder styrene-butadiene rubber and a thickening agent sodium carboxymethylcellulose with a mass ratio of 97.5:0.5:0.5:0.5:1. The mass fraction of the element lithium in the first lithium-containing binder was 4.8%, the Dv50 value of the graphite particles was 11.3 µm, the graphite particles each comprised an artificial graphite and a carbon coating layer, the surface of the artificial graphite was coated with the carbon coating layer, and the mass fraction of the carbon coating layer was 3.5%.

[0506] The second negative electrode film layer comprised graphite particles, a conductive agent acetylene carbon black, a second lithium-containing binder (a copolymer of lithium acrylate-acrylonitrile-acrylamide-hydroxyethyl acrylate, wherein the molar ratio of lithium acrylate monomer, acrylonitrile monomer, acrylamide monomer and hydroxyethyl acrylate monomer was 35%:30%:15%:20%), a negative electrode binder styrene-butadiene rubber and a thickening agent sodium carboxymethylcellulose with a mass ratio of 96.5:0.5:0.5:1.5:1. The mass fraction of the element lithium in the second lithium-containing binder was 4.8%, the Dv50 value of the graphite particles was 11.3 µm, the graphite particles each comprised an artificial graphite and a carbon coating layer, the surface of the artificial graphite was coated with the carbon coating layer, and the mass fraction of the carbon coating layer was 3.5%. 3. Separator

[0507] The separator comprised a base film, the base film being a 7 µm thick polyethylene film layer with a porosity of 42%. 4. Preparation of the electrolyte solution

[0508] The electrolyte solution comprised an organic solvent, a lithium salt, and an additive.

[0509] The organic solvent comprised a chain-like carboxylic acid ester solvent (ethyl acetate) with a mass fraction of 60% and a carbonate solvent with a mass fraction of 40% (30% ethylene carbonate EC, the remainder dimethyl carbonate), whereby the mass fractions of the individual components in the organic solvent were calculated based on the mass of the organic solvent.

[0510] Based on the mass of the electrolyte solution, the mass fraction of the additive was 6.5%, comprising vinylene carbonate VC, fluoroethylene carbonate FEC, ethylene sulfite ES and lithium difluoro(oxalato)borate LiDFOB in a mass ratio of 5:0.5:0.5:0.5.

[0511] The lithium salt comprised 1 mol / L lithium hexafluorophosphate LiPF6.

[0512] The conductivity of the electrolyte solution at room temperature was 16.4 mS / cm. 5. Manufacturing the battery cell

[0513] The above positive electrode sheet, separator, and negative electrode sheet were stacked sequentially. The separator was positioned between the positive and negative electrode sheets to provide insulation. This arrangement was placed in the casing, and after drying, the electrolyte solution was injected. A battery cell was then obtained through vacuum sealing, setting, formation, and shaping, etc. (6) Battery production

[0514] Several of the manufactured battery cells were installed in the box body and positioned between two limit beams. The bus components were then welded together, and the high- and low-voltage cable harnesses were installed to create the battery.

[0515] The limiting beam was made of an aluminum alloy and could form a structure similar to that in Fig. Figure 12 shows the two boundary beams located on both sides of the multiple battery cells along the thickness direction. The thickness of the outer wall of the boundary beam was 2 mm, the thickness of the two stiffening ribs of the boundary beam was 2 mm, and the angle α between the first and second sides of the boundary beam was 5°. Example 2

[0516] The battery cell and the battery were manufactured using a similar process to that described in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing were adjusted. Example 3

[0517] The battery cell and the battery were manufactured using a similar process to that described in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing were adjusted. Example 4

[0518] The battery cell and the battery were manufactured using a similar process to that described in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing were adjusted. Example 5

[0519] The battery cell and the battery were manufactured using a similar method to that in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, the compaction density of the negative electrode film layer after cold pressing, the angle α between the first side surface and the second side surface of the boundary beam, and the wall thickness of the outer wall of the boundary beam were adjusted. Example 6

[0520] The battery cell and the battery were manufactured using a similar method to that in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, the compaction density of the negative electrode film layer after cold pressing, the angle α between the first side surface and the second side surface of the boundary beam, and the wall thickness of the outer wall of the boundary beam were adjusted. Comparative example 1

[0521] The battery cell and the battery were processed using a similar method to that described in embodiment 1. The difference from embodiment 1 was that the coating weight of the positive electrode film layer on one side, the coating weight of the negative electrode film layer on one side, and the compaction density of the negative electrode film layer were adjusted after cold pressing. Comparative example 2

[0522] The battery cell and the battery were manufactured using a similar process to that described in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing were adjusted. Comparative example 3

[0523] The battery cell and the battery were manufactured using a similar method to that in embodiment 1. The difference from embodiment 1 was that the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, the compaction density of the negative electrode film layer after cold pressing, the angle α between the first side surface and the second side surface of the boundary beam, and the wall thickness of the outer wall of the boundary beam were adjusted. Performance tests: 1. Test of the expansion pressure of the battery cell:

[0524] At an ambient temperature of 45 °C, a battery cell manufactured above was discharged to 2.0 V at a constant discharge rate of 1 C;

[0525] The battery cell was clamped between two clamping plates, with each clamping plate located on one of the two sides of the battery cell along the thickness direction and covering the main surface; At an ambient temperature of 45 °C, the battery cell was charged to 3.8 V at a constant charging rate of 0.8 C, and the pressure exerted by the battery cell on the terminal plates was detected and recorded; According to the above charging and discharging strategy, the battery cell was cyclically charged and discharged until it degraded to 70% SOH (i.e., the discharge capacity of the battery cell was degraded to 70% of its nominal capacity), and the maximum pressure exerted by the battery cell on the terminal plates was recorded. The expansion pressure Q of the battery cell in the thickness direction was calculated as: maximum pressure / area of ​​the large surface. 2. Test of the maximum displacement E of the first side face of the boundary beam along the thickness direction under a pressure of 1.7 MPa.

[0526] The box body was attached to a device; A printhead of a pressure testing device was placed against the first side surface 21a of the boundary beam, with the printing area of ​​the printhead placed against the first side surface 21a coinciding with the large surface area of ​​the battery cell; A constant force F was applied to the printhead, causing it to move along the thickness direction X of battery cell 10, and the maximum displacement E of the printhead was recorded. For example, the area of ​​the print surface was denoted as S, where F / S was 1.7 MPa.

[0527] It should be explained here that the box body used to record the maximum displacement E was identical to the box body used to hold the battery cell. 3. Test of volume energy density:

[0528] The discharge energy of the first cycle was tested according to the following steps: At 25 °C, the battery cell manufactured above was charged to 3.8 V with a constant current of 0.33 C and then discharged to 2.0 V with a constant current of 0.33 C. The discharge energy A0 at this time was recorded in Wh.

[0529] Battery cell volume: The length, width, and height of the battery cell were measured using calipers (generally based on the battery cell casing size, excluding the height of the electrode terminals and the insulating film outside the casing). The battery cell volume V0 was calculated in units of L.

[0530] The volume energy density of the battery cell VED = A0 / V0 in the unit Wh / L. 4. Cycle performance test 1:

[0531] At an ambient temperature of 45 °C, the above-constructed battery was discharged, with the battery cell being discharged to 2.0 V at a constant discharge rate of 1 C; The above-mentioned battery was charged at an ambient temperature of 45 °C, with the battery cell being charged to 3.8V at a constant charging rate of 0.8 C; According to the above charging and discharging strategy, the battery cell was cyclically charged and discharged until a cycle drop occurred or the battery was degraded to 70% SOH (discharge capacity of the battery cell / nominal capacity of the battery cell = 70%). 5. Cycle performance test II:

[0532] At an ambient temperature of 30 °C, the above-constructed battery was discharged, with the battery cell being discharged to 2.0 V at a constant discharge rate of 0.33 C; The following charging strategy was used at an ambient temperature of 30 °C: A constant current of 5.0 C charges the battery from 0% SOC to 5% SOC; With a constant current of 5.0 C, charging from 5% SOC to 10% SOC is achieved; With a constant current of 5.0 C, charging from 10% SOC to 15% SOC is achieved; With a constant current of 5.0 C, charging from 15% SOC to 20% SOC is achieved; With a constant current of 5.0 C, charging from 20% SOC to 25% SOC is achieved; With a constant current of 5.0 C, charging from 25% SOC to 30% SOC is achieved; With a constant current of 5.0 C, charging from 30% SOC to 35% SOC is achieved; With a constant current of 5.0 C, charging from 35% SOC to 40% SOC is achieved; With a constant current of 4.6 C, it charges from 40% SOC to 45% SOC; With a constant current of 4.3 C, it charges from 45% SOC to 50% SOC; Charging with a constant current of 4.0 C from 50% SOC to 55% SOC; With a constant current of 3.7 C, it charges from 55% SOC to 60% SOC; With a constant current of 3.4 C, it charges from 60% SOC to 65% SOC; With a constant current of 3.1 C, it charges from 65% SOC to 70% SOC; With a constant current of 2.9 C, it charges from 70% SOC to 75% SOC; With a constant current of 2.7 C, it charges from 75% SOC to 80% SOC; With a constant current of 1.8 C, it charges from 80% SOC to 85% SOC; With a constant current of 1.3 C, it charges from 85% SOC to 90% SOC; With a constant current of 0.7 C, it charges from 90% SOC to 95% SOC; With a constant current of 0.33 C, it charges from 95% SOC to 98% SOC; With a constant current of 0.1 C, it charges from 98% SOC to 100% SOC.

[0533] According to the above charging and discharging strategy, the battery cell was cyclically charged and discharged until a cycle drop occurred or the battery was degraded to 70% SOH.

[0534] It should be explained here that cycle performance test I and cycle performance test II were each carried out with one of two batteries manufactured using the same reconditioning method.

[0535] The test results for embodiments 1 to 5 and comparison examples 1 to 3 are listed in Table 1. Table 1 One-sided coating weight of the positive electrode film layer (g / 1540.25 mm²) 2 ) One-sided coating weight of the negative electrode film layer (g / 1540.25 mm²) 2 ) Compaction density of the positive electrode film layer after cold pressing (g / cm²) 3 ) Compaction density of the negative electrode film layer after cold pressing (g / cm³) 3 ) Expansion pressure Q(MPa) angle α Wall thickness of the outer wall of the boundary beam (mm) Maximum displacement E (mm) Volume energy densityVED (Wh / L) Cycle drop (Cycle performance test I) Cycle drop (Cycle performance test II) Example 1 0,21 0,096 2,6 1,6 0,5 5° 2 8 390 No No Example 2 0,29 0,131 2,63 1,63 1,5 5° 2 8 405 No No Example 3 0,34 0,155 2,65 1,63 2,4 5° 2 8 415 No No Example 4 0,29 0,131 2,63 1,63 1,5 8° 3 6 405 No No Example 5 0,29 0,131 2,63 1,63 1,5 10° 4 4 405 No No Comparative example 1 0,18 0,08 2,6 1,58 0,3 5° 2 8 380 No No Comparative example 2 0,31 0,14 2,7 1,65 2,7 5° 2 8 430 Yes Yes Comparative example 3 0,34 0,155 2,65 1,63 2,4 0° 1,5 9 415 Yes Yes

[0536] As shown in Table 1, the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing were relatively low in comparison example 1. Although the battery cell exhibited low expansion pressure and did not readily experience cycle degradation during the cycling process, the volume energy density of the battery cell was relatively low.

[0537] Referring to embodiments 1 to 5 and comparative example 1, the volume energy density of the battery cell in the embodiments of the present application could be increased to or greater than 390 Wh / L by increasing the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing. Although the expansion pressure of the battery cell was not less than 0.5 MPa, the expansion of the battery cell could be effectively limited in combination with a limiting bar with higher deformation resistance, in order to improve the cycle performance of the battery and the battery cell and to reduce the risk of battery cycle degradation.

[0538] Referring to embodiments 1 to 5 and comparative example 2, in the embodiments of the present application, by adjusting parameters such as the one-sided coating weight of the positive electrode film layer, the compaction density of the positive electrode film layer after cold pressing, the one-sided coating weight of the negative electrode film layer, and the compaction density of the negative electrode film layer after cold pressing, the expansion pressure of the battery cell could be limited to no more than 2.4 MPa and the volume energy density of the battery cell could be achieved at 415 Wh / L. The limiting bar with higher deformation resistance could effectively limit the expansion of the battery cell in order to improve the cycle performance of the battery and the battery cell and to reduce the risk of battery cycle degradation.

[0539] Referring to implementation examples 1 to 5 and comparative example 3, the deformation resistance of the boundary beam could be adjusted by modifying the angle and the wall thickness of the outer wall of the boundary beam. By increasing the deformation resistance of the boundary beam, the angle α, the wall thickness of the outer wall of the boundary beam, or other parameters (e.g., the material of the boundary beam), the expansion of the battery cell at a battery cell expansion pressure of 2.4 MPa could be effectively restricted and limited, thereby improving the cycle performance of the battery and the battery cell and reducing the risk of battery cycle degradation.

[0540] Referring to Table 1, the embodiments of the present application enable the deformation of the battery cell to be limited, the risk of battery cycle degradation to be reduced, and the cycle performance of the battery and the battery cell to be improved during the fast charging process. The battery cell of the present application has a fast-charging capability, and the charging time of the battery cell from 10% SOC to 80% SOC is 5 to 10.5 minutes.

[0541] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other, provided there is no conflict.

[0542] Finally, it should be noted that the foregoing embodiments serve only to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, it should be obvious to a person skilled in the art that he may further modify the technical solutions described in the aforementioned embodiments or replace some of their technical features with equivalent features; and such modifications or replacements, however, do not result in the essence of the corresponding technical solutions diverging from the spirit and scope of the technical solutions of the embodiments of the present application. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited non-patent literature

[0000] Rule JIS / K0131-1996

[0212] Test standard GB / T 19077-2016 [0232, 0271] Test standard GB / T 19587-2017

[0239] GB / T 2013-2010

[0280]

Claims

[1] Battery, comprising: several battery cells arranged along the thickness direction of the battery cells, the battery cell comprising a housing and an electrode arrangement received in the housing; and a box body for receiving the multiple battery cells, wherein the box body comprises at least two boundary beams, wherein two adjacent boundary beams are arranged on one of the two sides of the multiple battery cells along the thickness direction, wherein the expansion pressure of the battery cell in the thickness direction is 0.5 MPa to 2.4 MPa, and the boundary beam comprises a first side surface facing the multiple battery cells, wherein the first side surface is designed such that the maximum displacement of the first side surface in the thickness direction at a pressure of 1.7 MPa is less than or equal to 8 mm. [2] Battery according to claim 1, wherein the expansion pressure of the battery cell in the thickness direction is 1.5 MPa to 2.0 MPa. [3] Battery according to claim 1 or 2, wherein the electrode arrangement comprises two first surfaces and two second surfaces, wherein the two first surfaces are arranged opposite each other along the thickness direction and the two second surfaces are arranged opposite each other along a direction perpendicular to the thickness direction, and the second surface connects the first surfaces together; wherein the area of ​​the first surface is larger than the area of ​​the second surface. [4] Battery according to claim 3, wherein the first surface is parallel to the first side surface. [5] Battery according to one of claims 1 to 4, wherein the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material. [6] Battery according to claim 5, wherein the one-sided coating weight of the negative electrode film layer is 90 mg / 1540.25 mm² 2 up to 170 mg / 1540.25 mm 2 is, optionally 110 mg / 1540.25 mm 2 up to 150 mg / 1540.25 mm 2 . [7] Battery according to claim 5 or 6, wherein the density of the negative electrode film layer at 100% SOC of the battery cell is 1.15 g / cm³ 3 up to 1.36 g / cm³ 3 is, optionally 1.25 g / cm² 3 up to 1.36 g / cm³ 3 . [8] Battery according to any one of claims 5 to 7, wherein the porosity of the negative electrode sheet is 27% to 40%. [9] Battery according to any one of claims 5 to 8, wherein the negative electrode active material comprises at least one of artificial graphite and natural graphite. [10] Battery according to any one of claims 5 to 9, wherein the negative electrode active material comprises a silicon-based material, wherein the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 0.3% to 10%, optionally 1% to 6%. [11] Battery according to claim 10, wherein the silicon-based material comprises at least one silicon oxide compound and silicon-carbon composite. [12] Battery according to any one of claims 5 to 11, wherein the negative electrode film layer comprises a first negative electrode film layer and a second negative electrode film layer, wherein the second negative electrode film layer is arranged between the first negative electrode film layer and the negative electrode current collector; wherein the negative electrode active material comprises a first negative electrode active material arranged in the first negative electrode film layer and a second negative electrode active material arranged in the second negative electrode film layer, wherein the first negative electrode active material comprises an artificial graphite and the second negative electrode active material comprises one or more of artificial graphite, natural graphite and silicon-based material. [13] Battery according to claim 12, wherein the ratio of the thickness of the first negative electrode film layer to the thickness of the second negative electrode film layer is 3:7 to 7:3, optionally 4:6 to 6:

4. [14] Battery according to claim 12 or 13, wherein the thickness of the first negative electrode film layer is less than or equal to the thickness of the second negative electrode film layer. [15] Battery according to any one of claims 12 to 14, wherein the volume-averaged particle size Dv50 of the first negative electrode active material is less than or equal to the volume-averaged particle size Dv50 of the second negative electrode active material. [16] Battery according to any one of claims 12 to 15, wherein the volume-averaged particle size Dv50 of the first negative electrode active material is 7.8 µm to 14.3 µm, optionally 7.8 µm to 11.3 µm; wherein the volume-averaged particle size Dv50 of the second negative electrode active material is 9.5 µm to 18.5 µm, optionally 9.5 µm to 14.6 µm. [17] Battery according to any one of claims 5 to 16, wherein the specific surface area of ​​the negative electrode active material is 0.5 m² 2 / g up to 3 m 2 / g is, optionally 0.6 m 2 / g up to 1.2 m 2 / G. [18] Battery according to any one of claims 1 to 17, wherein the electrode arrangement comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material, wherein the positive electrode active material is a lithium-containing phosphate. [19] Battery according to claim 18, wherein the one-sided coating weight of the positive electrode film layer is 200 mg / 1540.25 mm² 2 up to 370 mg / 1540.25 mm 2 is, optionally 240 mg / 1540.25 mm 2 up to 330 mg / 1540.25 mm 2 . [20] Battery according to claim 18 or 19, wherein the density of the positive electrode film layer at 100% SOC of the battery cell is 2.50 g / cm³ 3 up to 2.80 g / cm³ 3 is, optionally 2.55 g / cm² 3 up to 2.70 g / cm³ 3 . [21] Battery according to any one of claims 18 to 20, wherein the porosity of the positive electrode sheet is 25% to 32%. [22] Battery according to any one of claims 18 to 21, wherein the thickness of the positive electrode sheet is 0.13 mm to 0.2 mm. [23] Battery according to one of claims 18 to 22, wherein the ratio of the thickness of the positive electrode current collector to the thickness of the positive electrode film layer is 0.05 to 0.

3. [24] Battery according to any one of claims 18 to 23, wherein the volume-averaged particle size of the positive electrode active material satisfies the conditions 1 µm ≤ Dv50 ≤ 2 µm and 0.4 µm ≤ Dv10 ≤ 0.7 µm. [25] Battery according to any one of claims 1 to 24, wherein the battery cell comprises an electrolyte solution contained in the housing. [26] Battery according to claim 25, wherein the conductivity of the electrolyte solution at room temperature is 15 mS / cm to 20 mS / cm. [27] Battery according to claim 25 or 26, wherein the electrolyte solution comprises an organic solvent, the organic solvent comprising one or more carbonate solvents and carboxylic acid ester solvents. [28] Battery according to claim 27, wherein the carbonate solvent comprises one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. [29] Battery according to claim 27 or 28, wherein the carboxylic acid ester comprises R1-COO-R2, wherein R1 and R2 each independently comprise an alkyl group with 1 to 5 carbon atoms or a halogenated alkyl group with 1 to 5 carbon atoms. [30] Battery according to any one of claims 25 to 29, wherein the electrolyte solution comprises a lithium salt, wherein the lithium salt comprises lithium bis(fluorosulfonyl)imide LiFSI and lithium hexafluorophosphate LiPF6, wherein the molar concentration of the lithium bis(fluorosulfonyl)imide LiFSI is 0.2 mol / L to 0.5 mol / L and the molar concentration of the lithium hexafluorophosphate LiPF6 is 0.5 mol / L to 1.0 mol / L. [31] Battery according to any one of claims 25 to 30, wherein the density ρ of the electrolyte solution at room temperature satisfies the condition 1.05 g / mL ≤ ρ ≤ 1.35 g / mL. [32] Battery according to any one of claims 1 to 31, wherein the electrode arrangement comprises a negative electrode sheet; wherein the dimension of the electrode arrangement along the thickness direction is designated by T, the thickness of the negative electrode sheet is designated by T1 and the number of layers of the negative electrode sheet stacked in the thickness direction is designated by N; wherein T, T1 and N satisfy the condition 0.3 ≤ (N×T1) / T ≤ 0.

5. [33] Battery according to any one of claims 1 to 32, wherein the distance between two adjacent boundary beams in the thickness direction is designated by D1; wherein several battery cell rows are arranged between the adjacent boundary beams, the several battery cell rows being arranged along a direction perpendicular to the thickness direction, and the battery cell rows each comprising at least two battery cells arranged along the thickness direction; wherein the overall dimension of the electrode arrangements of the battery cells of the battery cell row in the thickness direction is designated by D2; wherein 85% ≤ D2 / D1 ≤ 92%. [34] Battery according to any one of claims 1 to 33, wherein the limiting bar comprises a second side surface, the second side surface being arranged on the side of the limiting bar facing away from the multiple battery cells and inclined towards the first side surface. [35] Battery according to claim 34, wherein the angle α between the first side surface and the second side surface is 1° to 25°. [36] Battery according to claim 34 or 35, wherein the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L and the angle α between the first side surface and the second side surface is 5° to 20°. [37] Battery according to claim 34 or 35, wherein the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L and the angle α between the first side surface and the second side surface is 8° to 25°. [38] Battery according to any one of claims 34 to 37, wherein the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises at least one of silicon oxide compound and silicon-carbon composite; wherein the angle α between the first side surface and the second side surface is 8° to 25°. [39] Battery according to one of claims 34 to 38, wherein the boundary bar comprises a third side surface, the third side surface being arranged on the side of the boundary bar facing away from the battery cell and running parallel to the first side surface, and the third side surface being connected to the second side surface. [40] Battery according to any one of claims 1 to 39, wherein the box body comprises a frame body and a support beam, wherein the frame body defines a receiving space in which the boundary beams and the multiple battery cells are arranged; wherein the support beam is arranged on the side of the boundary beam facing away from the multiple battery cells and connects the frame body and the boundary beam. [41] Battery according to claim 40, wherein the limiting beam extends along a direction perpendicular to the thickness direction; wherein the box body comprises several support beams spaced apart along the extension direction of the limiting beam. [42] Battery according to claim 40 or 41, wherein the boundary beam also comprises a second side surface and a third side surface, the third side surface being arranged on the side of the boundary beam facing away from the battery cell and being parallel to the first side surface, and the second side surface being connected to an end of the third side surface and being inclined towards the first side surface; wherein the support beam is connected to the third side surface. [43] Battery according to any one of claims 1 to 42, wherein the boundary beam comprises an outer wall and several stiffening ribs, wherein the outer wall encloses a receiving chamber, and the several stiffening ribs are arranged in the receiving chamber and connected to the outer wall; wherein the outer wall comprises the first side surface. [44] Battery according to claim 43, wherein the electrode arrangement comprises a negative electrode sheet, the negative electrode sheet comprising a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, the negative electrode film layer comprising a negative electrode active material, the negative electrode active material comprising a silicon-based material; wherein the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1% to 6%; wherein the thickness of the outer wall is 2 mm to 7 mm and the thickness of the stiffening ribs is 2 mm to 7 mm. [45] Battery according to claim 43 or 44, wherein the outer wall comprises a first side wall and a second side wall spaced apart along the thickness direction, the second side wall being arranged on the side of the first side wall facing away from the battery cell and the first side wall comprising the first side surface; wherein the multiple stiffening ribs comprise first stiffening ribs connected to the first side wall. [46] Battery according to claim 45, wherein at least one of the first stiffening ribs is inclined relative to the thickness direction. [47] Battery according to claim 46, wherein the limiting beam extends along a direction perpendicular to the thickness direction; wherein at least two of the first stiffening ribs are spaced apart along a direction perpendicular to both the extension direction of the limiting beam and the thickness direction and are inclined in an opposite direction relative to the thickness direction. [48] ​​Battery according to claim 46 or 47, wherein the angle between the first stiffening ribs and the thickness direction is 30° to 80°. [49] Battery according to any one of claims 45 to 48, wherein the first side wall comprises a central region and two edge regions, wherein the two edge regions extend from both ends of the central region in a direction parallel to the first side surface and perpendicular to the extension direction of the boundary beam, and the central region and the edge region have the same dimensions; wherein at least one of the first stiffening ribs is connected to the central region. [50] Battery according to any one of claims 45 to 49, wherein the outer wall comprises a first side wall and a second side wall spaced apart along the thickness direction, the second side wall being arranged on the side of the first side wall facing away from the multiple battery cells, and the first side wall comprising the first side surface; wherein the second side wall comprises a first section and a second section, wherein the first section runs parallel to the first side wall, and the second section extends from one end of the first section and is inclined towards the first side wall; wherein at least one of the stiffening ribs is connected to the junction between the first section and the second section. [51] Battery according to any one of claims 43 to 50, wherein the outer wall comprises a first side wall, a second side wall and a cover wall, wherein the second side wall is arranged on the side of the first side wall facing away from the multiple battery cells, the cover wall connects the first side wall and the second side wall together, and the first side wall comprises the first side surface; wherein the boundary beam also includes a partition wall connected to the top wall, the partition wall being arranged in the thickness direction between the first side wall and the second side wall; wherein at least one stiffening rib connects the first side wall and the partition, and at least one stiffening rib connects the second side wall and the partition. [52] Battery according to any one of claims 43 to 51, wherein the limiting bar is formed as a one-piece structure. [53] Battery according to any one of claims 1 to 52, further comprising an insulating element arranged between the limiting bar and the housing. [54] Battery according to any one of claims 1 to 53, further comprising a limiting element connecting adjacent limiting bars together. [55] Battery according to claim 54, wherein the limiting element is connected to the battery cell. [56] Battery according to claim 55, wherein the limiting element is glued to the battery cell. [57] Battery according to one of claims 54 to 56, wherein the limiting element is detachably connected to the limiting bar. [58] Battery according to one of claims 54 to 57, further comprising a fastening element, wherein the fastening element connects the limiting element and the limiting bar, wherein at least a part of the fastening element is embedded in the limiting bar and fastened to the limiting bar. [59] Battery according to claim 58, wherein the limiting bar has an internal receiving chamber, wherein the fastening element is received in the receiving chamber. [60] Battery according to any one of claims 54 to 59, wherein the limiting bar extends along a direction perpendicular to the thickness direction; wherein several restriction elements are provided, wherein the several restriction elements are spaced apart along the extension direction of the boundary beam. [61] Battery according to any one of claims 1 to 60, further comprising several bus components, wherein the bus components electrically connect the several battery cells to each other; wherein the multiple bus components comprise at least one first bus component, wherein the first bus component comprises a first bus layer and a second bus layer stacked on top of each other and connected to each other, wherein the first bus layer is connected to at least two of the battery cells arranged along the thickness direction. [62] Battery according to claim 61, wherein the battery cell comprises an electrode terminal arranged on the housing, wherein the electrode terminal is electrically connected to the electrode arrangement; where the part of the first bus layer that does not overlap with the second bus layer is connected to the electrode terminal. [63] Battery according to claim 61 or 62, wherein the first bus component comprises at least one bending section, the bending section connecting the first bus layer and the second bus layer. [64] Battery according to claim 63, wherein the first bus layer comprises a first bus section, a second bus section and a first buffer section for connecting the first and second bus sections together, wherein the first bus section and the second bus section are arranged along the thickness direction and are connected to different battery cells; wherein the bending section is arranged in such a way that it bypasses the first buffer section. [65] Battery according to claim 64, wherein the second bus layer comprises a first stacking section, a second stacking section and a second buffer section, wherein the first stacking section is stacked with the first bus section and connected by at least one of the bending sections; and the second stacking section is stacked with the second bus section and connected by at least one of the bending sections, wherein the second buffer section connects the first stacking section and the second stacking section; wherein the second buffer section overlaps at least partially with the first buffer section in the stacking direction of the first bus layer and the second bus layer. [66] Battery according to claim 65, wherein the second buffer section is arranged adjacent to the first buffer section. [67] Battery according to one of claims 61 to 66, wherein the multiple bus components also include at least one second bus component, wherein the thickness of the second bus component is greater than the thickness of the first bus layer and the thickness of the second bus component is greater than the thickness of the second bus layer. [68] Battery according to claim 67, wherein the sum of the thickness of the first bus layer and the thickness of the second bus layer is equal to the thickness of the second bus component. [69] Battery according to one of claims 61 to 68, wherein the battery cell adjacent to the limiting bar is connected to the first bus component. [70] Battery according to any one of claims 61 to 69, wherein the thickness of the first bus layer is 1 mm to 2.5 mm, and / or the thickness of the second bus layer is 1 mm to 2.5 mm. [71] Battery according to any one of claims 61 to 70, wherein the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L and the thickness of the first bus layer is less than or equal to 2.5 mm; or where the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L and the thickness of the first bus layer is less than or equal to 2.2 mm. [72] Battery according to one of claims 61 to 71, wherein the electrode arrangement comprises a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises a silicon-based material; wherein the mass fraction of the element silicon in the silicon-based material in the negative electrode active material is 1% to 6%, wherein the thickness of the first bus layer is 1.2 mrn to 2.2 mm and the thickness of the second bus layer is 1.2 mm to 2.2 mm. [73] Battery according to any one of claims 61 to 72, wherein the first bus layer comprises a first bus section, a second bus section and a first buffer section for connecting the first and second bus sections together, wherein the first bus section and the second bus section are arranged along the thickness direction and are connected to different battery cells; wherein the first buffer section extends beyond the first bus section and the second bus section in the stacking direction of the first bus layer and the second bus layer; a recess is provided at the position of the first bus layer corresponding to the first buffer section. [74] Battery according to claim 73, wherein the volume energy density of the battery cell is 390 Wh / L to 450 Wh / L and the depth of the recess is 1.2 mm to 2.5 mm; or where the volume energy density of the battery cell is 450 Wh / L to 480 Wh / L and the depth of the depression is 1 mm to 2.2 mm. [75] Battery according to any one of claims 1 to 74, wherein the charging time of the battery cell from 10% SOC to 80% SOC is 5 minutes to 10.5 minutes. [76] Power-consuming device, characterized by that it comprises a battery according to any one of claims 1 to 75 for providing electrical energy.

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