Battery cell, battery device, power-consuming device

Abstract

Battery cell comprising: an electrode arrangement, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode main body section and at least one positive electrode tab section, wherein the positive electrode main body section is connected to the positive electrode tab section and the total width of the positive electrode tab section along the width direction of the positive electrode main body section is 50% to 100% of the total width of the positive electrode main body section. wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the negative electrode current collector comprises a negative electrode main body section and at least one negative electrode tab section, wherein the negative electrode main body section is connected to the negative electrode tab section and the total width of the negative electrode tab section along the width direction of the negative electrode main body section is 50% to 100% of the total width of the negative electrode main body section, wherein the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm² 2 up to 0.145 g / 1540.25 mm 2 amounts, an electrolyte, wherein the electrolyte comprises an organic solvent, wherein the organic solvent comprises a first solvent, wherein the first solvent comprises at least one of dimethyl carbonate and a linear carboxylic ester, wherein the structural formula of the linear carboxylic ester satisfies R1-COO-R2, wherein R1 and R2 are each independently selected from an alkyl group or a halogenated alkyl group from C1 to C5; wherein the mass fraction of the first solvent is 4% to 72% based on the total mass of the electrolyte.

Description

Technical field

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

[0002] Lithium-ion battery cells are widely used in energy storage systems for hydroelectric, coal-fired, wind, and solar power plants, as well as in many other applications such as power tools, e-bikes, e-motorcycles, and electric vehicles. With the increasing use of battery cells, the market is also placing higher demands on battery performance. However, current batteries still exhibit many shortcomings in their application, and fast-charging performance needs further improvement.

[0003] It should be noted that the above explanations are intended only to provide technical background information relating to the present application and do not necessarily represent the state of the art. Registration content

[0004] In a first aspect of the present application, the present application proposes a battery cell comprising: an electrode arrangement, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode main body section and at least one positive electrode tab section,wherein the positive electrode main body section is connected to the positive electrode tab section and the total width of the positive electrode tab section along the width direction of the positive electrode main body section is 50% to 100% of the total width of the positive electrode main body section, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the negative electrode current collector comprises a negative electrode main body section and at least one negative electrode tab section,wherein the negative electrode main body section is connected to the negative electrode tab section and the total width of the negative electrode tab section along the width direction of the negative electrode main body section is 50% to 100% of the total width of the negative electrode main body section, wherein the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm, 2 up to 0.145 g / 1540.25 mm 2an electrolyte comprising an organic solvent, the organic solvent comprising a first solvent comprising at least one of dimethyl carbonate and a linear carboxylic ester, the structural formula of the linear carboxylic ester being R1-COO-R2, wherein R1 and R2 are each independently selected from an alkyl group or a halogenated alkyl group from C1 to C5; wherein the mass fraction of the first solvent, based on the total mass of the electrolyte, is 4% to 72%. In this way, the fast-charging performance of the battery cell can be effectively improved and the performance of the battery cell under fast-charging conditions can be increased.

[0005] In some embodiments, the total width of the positive electrode blade section is 40 mm to 160 mm and / or the total width of the negative electrode blade section is 40 mm to 160 mm and / or the width of the positive electrode blade section is 40 mm to 160 mm and / or the width of the negative electrode blade section is 40 mm to 160 mm. Therefore, the current-passing area of ​​the positive electrode blade section and the negative electrode blade section is relatively large, and the heat dissipation capacity is relatively good.

[0006] In some embodiments, the positive electrode tab section and the negative electrode tab section are located on the same side of the positive electrode body section, or the positive electrode tab section and the negative electrode tab section are located on two opposite sides of the positive electrode body section. This can simplify the connection of the external circuit and the assembly process.

[0007] In some embodiments, the positive electrode current collector comprises the positive electrode body section and several of the positive electrode tab sections, wherein at least two of the positive electrode tab sections are located on two opposite sides of the positive electrode body section, and / or the negative electrode current collector comprises the negative electrode body section and several of the negative electrode tab sections, wherein at least two of the negative electrode tab sections are located on two opposite sides of the negative electrode body section. This allows for a more uniform heat distribution and reduces electrode tab deformation caused by excessive one-sided force.

[0008] In some embodiments, the positive electrode current collector comprises the positive electrode main body section and several of the spaced-apart positive electrode tab sections, and / or the negative electrode current collector comprises the negative electrode main body section and several of the spaced-apart negative electrode tab sections. This allows the electron transfer path to be shortened and the heat generation of the battery to be reduced.

[0009] In some embodiments, the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm². 2 up to 0.135 g / 1540.25 mm 2 This results in the battery cell having a relatively high volume energy density.

[0010] In some embodiments, the charging time from 10% SOC to 80% SOC is 7 to 15 minutes. This gives the battery cell relatively good fast-charging performance.

[0011] In some embodiments, the single-layer coating weight of the negative electrode active material layer is 0.136 g / 1540.25 mm². 2 up to 0.145 g / 1540.25 mm 2 This results in the battery cell having a relatively high volume energy density.

[0012] In some embodiments, the charging time from 10% SOC to 80% SOC is 20 to 30 minutes. This gives the battery cell relatively good fast-charging performance.

[0013] In some embodiments, the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located at least on one side of the negative electrode current collector, wherein the density of the negative electrode active material layer is 1.2 g / cm³. 3 up to 1.5 g / cm³ 3This contributes to increasing the fast charging performance of the battery cell.

[0014] In some embodiments, the negative electrode active material layer comprises a negative electrode active material, wherein the negative electrode active material comprises a silicon-containing material and the mass fraction of silicon in the negative electrode active material is 0.1% to 7%. This allows the mass energy density of the battery cell to be increased.

[0015] In some embodiments, the mass fraction of silicon in the negative electrode active material is 1% to 5%. This allows the mass energy density of the battery cell to be further increased.

[0016] In some embodiments, the negative electrode active material layer comprises a first negative electrode active material layer and a second negative electrode active material layer stacked on top of each other, with the first negative electrode active material layer located on one side near the negative electrode current collector, wherein the Dv50 value of the first negative electrode active material in the first negative electrode active material layer is 9.2 µm to 18.5 µm and the Dv50 value of the second negative electrode active material in the second negative electrode active material layer is 7.2 µm to 15.5 µm. This allows for a significant improvement in the fast-charging performance and energy density of the battery cell.

[0017] In some embodiments, the conductivity of the electrolyte is between 10 mS / cm and 20 mS / cm. This helps to increase the fast charging performance of the battery cell.

[0018] In some embodiments, the mass fraction of the first solvent, relative to the total mass of the electrolyte, is 16% to 72%. This can increase the fast-charging performance of the battery cell.

[0019] In some embodiments, the mass fraction of the linear carboxylic acid ester, based on the total mass of the electrolyte, ranges from 32% to 68%. This effectively reduces the viscosity of the electrolyte and improves the fast-charging performance of the battery.

[0020] In some embodiments, the electrolyte further comprises a first lithium salt additive, wherein the first lithium salt additive comprises at least one of fluorinated borate and fluorinated phosphate, the mass fraction of the first lithium salt additive being 0.05% to 0.5% based on the total mass of the electrolyte. This effectively reduces the internal resistance of the battery cell.

[0021] In some embodiments, the first lithium salt additive comprises at least one of lithium difluorophosphate, lithium difluoro(oxalato)phosphate, lithium difluoro(oxalato)borate, and lithium tetrafluoroborate. This contributes to the formation of a low-resistance solid electrolyte film on the surface of the negative electrode active material.

[0022] In some embodiments, the mass fraction of the first lithium salt additive, based on the total mass of the electrolyte, is 0.1% to 0.3%. This contributes to reducing the cost of the battery cell.

[0023] In some embodiments, the organic solvent further comprises a second solvent, wherein the second solvent comprises at least one of ethylene dicarbonate, ethylene carbonate, propylene dicarbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, and butylene carbonate. This contributes to improving the cycle life of the battery cell.

[0024] In some embodiments, the second solvent comprises diethyl carbonate, wherein the content of diethyl carbonate is not less than 12% based on the total mass of the electrolyte.

[0025] In some embodiments, the electrolyte further comprises a non-lithium salt additive, wherein the non-lithium salt additive comprises at least one of vinylene carbonate, fluoroethylene carbonate, and ethyl vinylene carbonate. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0026] In some embodiments, the carbonate additive comprises at least one of vinylene carbonate (VC), fluoroethylene carbonate (FEC), and ethyl vinylene carbonate. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0027] In some embodiments, the mass fraction of vinylene carbonate is 0.5% to 2.5% and / or the mass fraction of fluoroethylene carbonate is 0.05% to 2% based on the total mass of the electrolyte. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0028] In some embodiments, the sulfate additive comprises at least one of 4,4-ethylene sulfate, bis(ethylene sulfate), vinylcyclotrisulfate and 1,3-propanesultone.

[0029] In some embodiments, the mass fraction of the non-lithium salt additive, based on the total mass of the electrolyte, is 0.05% to 3%. This contributes to reducing the cost of the battery cell.

[0030] In some embodiments, the electrolyte further comprises a second lithium salt additive, wherein the second lithium salt additive comprises at least one of lithium bis(oxalato)borate, lithium difluorobisoxalatophosphate, lithium tetrafluoro(oxalato)phosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethylsulfonyl)imide, lithium trifluoromethanesulfonate, and lithium perchlorate. This contributes to the formation of a solid electrolyte film with relatively high ionic conductivity on the surface of the negative electrode active material.

[0031] In some embodiments, the electrolyte further comprises an electrolyte lithium salt, wherein the electrolyte lithium salt comprises at least one of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass fraction of the electrolyte lithium salt, based on the total mass of the electrolyte, is greater than or equal to 13%. This contributes to increasing the conductivity of the electrolyte.

[0032] In some embodiments, the electrolyte lithium salt comprises lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide in the electrolyte is (1,2-2) : 1. This helps to further increase the conductivity of the electrolyte.

[0033] In some embodiments, the compaction density of the positive electrode active material layer is 2.2 g / cm³. 3 up to 2.6 g / cm³ 3 This helps to increase the fast charging performance and the energy density of the battery cell.

[0034] In some embodiments, the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises: a core section, the core section comprising a lithium-containing phosphate with an olivine structure, and a coating layer, wherein the coating layer coats the surface of the lithium-containing phosphate with an olivine structure and the coating layer contains one or more of C, Fe, Ti, Zr, Hf, Ge, and Sn. This contributes to increasing the structural stability and ionic conductivity of the positive electrode active material.

[0035] In some embodiments, the lithium-containing phosphate with olivine structure comprises a compound with the general formula of Li x1 A y1 Me a M1 b P 1-c X c Y z, where 0.5 ≤ x1 ≤ 1.3, 0 ≤ y1 ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5, where A comprises one or more of Na, K, and Mg; Me comprises one or more of Mn, Fe, Co, and Ni; M1 comprises one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; X comprises one or more of S, Si, Cl, B, C, and N; and Y comprises one or more of O and F. This contributes to increasing the ionic conductivity and electronic conductivity of the core section.

[0036] In some embodiments, the coating layer comprises a carbon layer, wherein the degree of graphitization of the carbon layer is 0.15 to 0.32. This contributes to improving the electronic conductivity of the positive electrode active material.

[0037] In some embodiments, the positive electrode active material in a cross-section of the positive electrode active material layer comprises a lithium-containing phosphate with an olivine structure having a longest diameter of 1 µm to 3 µm and a lithium-containing phosphate with an olivine structure having a shortest diameter of 0.1 µm to 0.3 µm. This contributes to increasing the energy density of the battery cell.

[0038] In some embodiments, the positive electrode active material fulfills at least one of the following conditions: the particle size Dv50 of the positive electrode active material is 1 µm to 5 µm, the particle size Dv10 of the positive electrode active material is 0.4 µm to 0.7 µm, and the positive electrode active material is a primary particle or a single-crystal-like particle. This results in a relatively large particle size of the positive electrode active material, which has a positive effect on increasing the energy density of the battery cell.

[0039] In some embodiments, the positive electrode active material layer further comprises a lithium-rich material, wherein the lithium-rich material includes at least one of lithium ferrite, lithium nickelate, lithium nickel copperate, lithium phosphate, dilithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, and lithium nickel cobalt manganese oxide. This contributes to increasing the cycle life of the battery cell.

[0040] In some embodiments, the length of the battery cell is L, and the width of the battery cell is H, where the value of L is 4 to 10 times the value of H. In this way, the volume utilization of the battery can be effectively improved and the overall energy density of the battery increased.

[0041] In some embodiments, the value of L is 4 to 7 times the value of H. This gives the battery cell both a relatively high energy density and a relatively low internal resistance.

[0042] In some embodiments, L is 400 mm to 1,000 mm and / or H is 80 mm to 160 mm.

[0043] In some embodiments, the battery cell further comprises a housing body, wherein the electrode arrangement is located in the housing body, and the housing body comprises two first housing walls arranged opposite each other, and a surrounding wall connecting the two first housing walls, wherein the surrounding wall comprises: two second housing walls arranged opposite each other along the longitudinal direction of the first housing wall, two third housing walls arranged opposite each other along the transverse direction of the first housing wall, wherein the second housing wall is provided with an electrode terminal, wherein the positive electrode tab section and the negative electrode tab section are each electrically connected to the electrode terminals on the two second housing walls, wherein between the second housing wall, which is electrically connected to the positive electrode tab section,and a pull-in structure is provided on the positive electrode main body section, wherein the pull-in structure is configured to pull in several of the positive electrode tab sections. This facilitates the attachment of the positive electrode tab and the welding between the positive electrode sheet and the electrode column.

[0044] In some embodiments, a chamfer is provided on the edge of the positive electrode blade in the longitudinal direction of the first housing wall. This facilitates quick assembly of the electrode arrangement.

[0045] In some embodiments, the second housing wall, which is connected to the negative electrode tab section, is provided with a liquid injection hole. This facilitates the injection of the electrolyte.

[0046] In some embodiments, the liquid injection port and a pressure relief section of the housing body are located on different secondary housing walls, with the pressure relief section being configured to release pressure within the housing body. This reduces corrosion of the pressure relief section by the electrolyte during the injection process.

[0047] In some embodiments, at least one mounting hole is provided at the electrode connection, with an electrode column being guided through the mounting hole and riveted to the electrode tab section. This helps to reduce the volume and weight of the battery cell and increase its energy density.

[0048] In some embodiments, at least two mounting holes are provided at the electrode connection, with each electrode column being guided through the mounting hole and riveted to the electrode tab section. This helps to increase the current-carrying capacity of the electrode column.

[0049] In some embodiments, the diameter of the electrode column is 3 mm to 8 mm. This gives the electrode column both a relatively high current-carrying capacity and a relatively small footprint.

[0050] In some embodiments, the electrode column riveted to the positive electrode tab section and the electrode column riveted to the negative electrode tab are arranged offset along the length of the first housing wall; optionally, the electrode column riveted to the positive electrode tab and the electrode column riveted to the negative electrode tab are arranged diagonally along the length of the first housing wall. This contributes to increasing the volume energy density of the assembled battery module or battery pack.

[0051] In some embodiments, the electrode column and the electrode lug are electrically connected via a transfer plate. This significantly improves weld quality and connection reliability between the electrode column and the electrode lug.

[0052] In some embodiments, the electrode column and the electrode tab are directly electrically connected. This helps to reduce the structural complexity within the battery cell, reduce the volume of the battery cell, and increase the energy density.

[0053] In some embodiments, the distance between the two first housing walls is D, where D is less than or equal to 30 mm. This benefits the rapid heat dissipation of the battery cell.

[0054] In some embodiments, D is 10 mm to 25 mm. This gives the battery cell relatively high mechanical strength and relatively good heat dissipation.

[0055] In some embodiments, the thickness of the first housing wall and the third housing wall is each independently less than or equal to 0.5 mm. This allows the volume energy density of the battery cell to be increased.

[0056] In some embodiments, the first and third housing walls comprise at least one aluminum and steel housing, respectively. This increases the mechanical strength of the battery cell.

[0057] In some embodiments, the first and third housing walls are made of steel, with a wall thickness of 0.1 mm to 0.5 mm. This effectively mitigates the volume expansion of the battery cell during charging and discharging.

[0058] In some embodiments, the first and third housing walls are made of aluminum, with a wall thickness of 0.3 mm to 0.4 mm. This effectively increases the mass energy density of the battery cell.

[0059] In some embodiments, the first and third housing walls are obtained by bending and welding aluminum plates, with the weld seam located at the junction between the first and third housing walls. This reduces electrolyte leakage.

[0060] In some embodiments, a lateral retaining plate is provided between the electrode assembly and the first housing wall. This helps to increase the structural stability of the battery cell.

[0061] In some embodiments, at least one of the second housing walls is provided with a pressure relief section, the pressure relief section being configured to release pressure within the housing body, and the area of ​​a positive projection of the pressure relief section onto the second housing wall comprising 7% to 15% of the area of ​​the second housing wall. This helps to quickly release the internal overpressure gas through the pressure relief section when the internal pressure of the battery cell is too high.

[0062] In some embodiments, the battery capacity is Q, where the ratio of the area of ​​the positive projection of the pressure relief section on the second casing wall to Q is greater than or equal to 1.1, where the unit of Q is Ah and the unit of the area is mm². 2 This helps to quickly release the excess pressure gas inside the battery cell.

[0063] In a second aspect of the present application, a battery device is provided which includes the aforementioned battery cell, wherein the battery device comprises at least one battery module, one battery pack, and one energy storage device. Therefore, the battery device has all the features and advantages of the aforementioned battery cell, which are not described in detail here.

[0064] In a third aspect of the present application, the present application proposes a power-consuming device comprising the aforementioned battery cell. The power-consuming device thus possesses all the features and advantages of the aforementioned battery cell, which are not described in detail here. Brief description of the drawings

[0065] The above and / or additional aspects and advantages of the present application will become apparent and easily understandable from the description of the exemplary embodiments in conjunction with the following accompanying drawings. In this regard: Fig. Figure 1 is a schematic representation of the structure of an electrode arrangement produced by a stacking process according to an embodiment of the present application; Fig. Figure 2 is a schematic representation of the structure of a positive electrode current collector according to an embodiment of the present application; Fig. Figure 3 is a schematic representation of the structure of a positive electrode current collector according to a further embodiment of the present application; Fig. Figure 4 is a schematic representation of the structure of the positive electrode current collector according to a further embodiment of the present application; Fig. Figure 5 is a schematic representation of the structure of the positive electrode current collector according to a further embodiment of the present application; Fig. Figure 6 is a schematic representation of the structure of an electrode arrangement produced by a winding process according to an embodiment of the present application; Fig. Figure 7 is a schematic representation of the structure of a battery cell according to an embodiment of the present application; Fig. Figure 8 is a schematic representation of the partial structure of a housing body according to an embodiment of the present application; Fig. Figure 9 is a schematic representation of the partial structure of a housing body according to a further embodiment of the present application; Fig.Figure 10 is a schematic representation of the partial structure of the housing body according to a further embodiment of the present application; Fig. Figure 11 is a schematic representation of the partial structure of the housing body according to a further embodiment of the present application; Fig. Figure 12 is a schematic representation of the partial structure of the housing body according to a further embodiment of the present application; Fig. Figure 13 is a schematic representation of the partial structure of the housing body according to a further embodiment of the present application; Fig. Figure 14 is a schematic representation of the partial structure of the housing body according to a further embodiment of the present application; Fig. Figure 15 is a schematic representation of the structure of a power-consuming device according to an embodiment of the present application. Reference symbol list:

[0066] 11. Positive electrode body section; 12. Positive electrode tab section; 21. Negative electrode body section; 22. Negative electrode tab section; 101. First housing wall; 102. Second housing wall; 103. Third housing wall; 104. Pressure relief section; 105. Electrode column; 106. Retraction structure; 107. Injection hole; 108. Transfer plate. Detailed descriptions

[0067] The embodiments of the present application are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. However, an unnecessarily detailed description can be omitted. For example, a detailed description of known facts and a repeated description of essentially the same structure can be avoided. This is to prevent the following description from becoming unnecessarily lengthy, thus facilitating understanding by those skilled in the art. Furthermore, the drawings and the following description serve to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0068] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those normally understood by technicians in the technical field to which this application relates; the terms used in this application serve only to describe specific embodiments and are not intended to limit the present application; the numerical values ​​of the parameters mentioned in this application may be measured using various measurement methods commonly used in the field, unless otherwise specified (for example, they may be tested according to the methods specified in the embodiments of this application).

[0069] The terms “comprise” and “consist” in the description and claims of the present application and all variations thereof are open expressions, that is to say, they include the content specified in the present application but do not exclude other content.

[0070] In the description of this application, all figures given herein are approximate values, regardless of whether the words "about" or "approximately" are used. The value of each figure may deviate by less than 10% or by a difference that a person skilled in the art considers reasonable, for example 1%, 2%, 3%, 4%, or 5%.

[0071] 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.

[0072] In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the terms "length", "width", "thickness", "top", "bottom", "front", "back", "left", "right", etc. are based on the orientation or positional relationship shown in the drawings and serve only to facilitate the description of the present application and to simplify the description, without indicating or implying that the designated devices or elements have a particular orientation or must be designed and operated in a particular orientation, and therefore should not be understood as a limitation of the present application.

[0073] In the description of this application, the terms "first", "second", etc., serve only for descriptive purposes and are not to be understood as indicating or implying their relative significance or as an implicit indication of the number of technical features specified. "First feature" or "second feature" may comprise one or more of these features.

[0074] In the description of this application, “several” means two or more.

[0075] In the description of the present application, “A and / or B” may include a case of A alone, the case of B alone, or each of the cases of A and B, where A and B are used only as examples and may be any technical feature connected by “and / or” in the present application.

[0076] Unless otherwise stated, all embodiments and optional embodiments of the present application may be combined to form a new technical solution.

[0077] Unless otherwise specified, all technical features and optional technical features of the present application can be combined to form a new technical solution.

[0078] Improving the battery's fast-charging capability allows users to quickly provide their devices with a significant amount of power, reducing charging wait times and enhancing the overall user experience. However, fast charging accelerates the chemical reaction rate within the battery cell, causing the battery to generate more heat. Sustained high temperatures accelerate the aging of battery materials, particularly electrolyte degradation and the breakdown of the positive electrode active material, thus shortening the battery's cycle life. Simultaneously, the current flowing through the electrode tab during fast charging is also relatively high, placing relatively high demands on the maximum current the electrode tab can handle.

[0079] If the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm² 2up to 0.145 g / 1540.25 mm 2The single-layer coating weight of the negative electrode active material layer is relatively high, while the thickness of the negative electrode active material layer on the surface of the negative electrode current collector is moderate, and the uniformity is relatively high. This results in a relatively short lithium-ion transfer path within the negative electrode active material layer, enabling rapid intercalation and deintercalation of the negative electrode active material during charging and discharging. Simultaneously, the battery cell exhibits a relatively high energy density, making it suitable for battery cells with relatively high demands on fast-charging performance.Furthermore, by using an electrode tab section in the positive and negative electrode current collector, whose total width is 50% to 100% of the total width of the corresponding main body section, the number of current conduction paths at the electrode tab can be effectively increased, which means that during fast charging and discharging of the battery, the current flowing through the electrode tab section is relatively high and the requirements for the current carrying capacity of the electrode tab section under fast charging conditions can be met.The relatively large cross-section of the electrode tab section can simultaneously reduce its resistance and thus the heat generation at the root of the electrode tab section. Therefore, the electrode tab section, which meets the aforementioned requirements, reduces heat generation and accumulation within the battery cell under higher current loads and offers a larger surface area for heat dissipation. This enhances the heat dissipation of the electrode tab section, helping to keep the system temperature of the battery cell relatively low during fast charging. Furthermore, the first solvent, due to its relatively low viscosity, exhibits relatively high conductivity, which can effectively reduce the internal resistance of the battery cell, while also having a relatively low boiling point.If the aforementioned battery cell can maintain a relatively low system temperature under fast charging conditions, the heat loss of the first solvent caused by the relatively high temperature rise of the battery cell can be effectively reduced, allowing the first solvent to stably and fully exploit its advantage of relatively high conductivity, thereby reducing the heat generation of the battery cell during the fast charging process, increasing the output power under fast charging conditions, and further improving the fast charging performance of the battery cell.

[0080] The present application can improve the energy density of the battery cell and its performance under fast-charging conditions by using a suitable coating weight of the negative electrode active material layer and a suitable amount of the first solvent. However, a large amount of heat is easily generated during fast charging and accumulates within the battery cell, causing the first solvent, which has a relatively low boiling point, to produce gases and release acid, thus impairing the fast-charging performance of the battery.By combining an electrode tab structure with a relatively large current passage area, the temperature rise of the battery cell during the fast charging process can be effectively slowed down and the occurrence of the aforementioned disadvantages of the highly conductive, low-boiling first solvent during fast charging can be reduced, resulting in a relatively low internal resistance of the battery cell, reduced heat generation of the battery cell under fast charging conditions, improved output power and relatively good performance under fast charging conditions.

[0081] Referring to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig.6. In a first aspect of the present application, the present application proposes a battery cell comprising: an electrode arrangement, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode main body section 11 and at least one positive electrode tab section 12.wherein the positive electrode main body section 11 is connected to the positive electrode tab section 12 and the total width W1 of the positive electrode tab section 12 along the width direction of the positive electrode main body section 11 is 50% to 100% of the total width V1 of the positive electrode main body section 11, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the negative electrode current collector comprises a negative electrode main body section 21 and at least one negative electrode tab section 22,wherein the negative electrode main body section 21 is connected to the negative electrode tab section 22 and the total width W2 of the negative electrode tab section 22 along the width direction of the negative electrode main body section 21 is 50% to 100% of the total width V2 of the negative electrode main body section 21, wherein the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm, 2 up to 0.145 g / 1540.25 mm 2is; an electrolyte, wherein the electrolyte comprises an organic solvent, wherein the organic solvent comprises a first solvent, the first solvent comprising at least one of dimethyl carbonate and a linear carboxylic acid ester, the structural formula of the linear carboxylic acid ester being R1-COO-R2, wherein R1 and R2 are each independently selected from an alkyl group or a halogenated alkyl group from C1 to C5; wherein the mass fraction of the first solvent, based on the total mass of the electrolyte, is 4% to 72%. By using the appropriate coating weight of the negative electrode active material layer, the energy density of the battery cell and its performance under fast-charging conditions can be improved.Furthermore, by using the electrode tab structure with a relatively large electrode tab section, the current conductivity of the electrode tab section can be effectively improved and the temperature rise of the battery cell during fast charging can be mitigated, which in turn allows the internal resistance of the battery cell to be further reduced by using the first solvent with high conductivity and low boiling point, thus reducing the heat generation of the battery cell under fast charging conditions, increasing the output power, improving the fast charging performance of the battery cell and increasing the performance of the battery cell under fast charging conditions.

[0082] It is understood that the positive electrode active material layer is located on at least one side of the positive electrode main body section of the positive electrode current collector and that the negative electrode active material layer is located on at least one side of the negative electrode main body section of the negative electrode current collector.

[0083] For example, the widths of the positive electrode tab section and the negative electrode tab section can be equal. If the widths of the positive electrode current collector and the negative electrode current collector are also equal, the ratio of the total width of the positive electrode tab section 12 to the total width of the positive electrode main body section 11 along the width direction of the positive electrode main body section 11 is the same as the ratio of the total width of the negative electrode tab section 22 to the total width of the negative electrode main body section 21 along the width direction of the negative electrode main body section 21.

[0084] It should be noted that if the electrode assembly is manufactured by the stacking process, the electrode assembly may comprise a multi-layered, continuously arranged structure of positive electrode sheet / separator / negative electrode sheet / separator.The ratio of the total width W1 of the aforementioned positive electrode tab section 12 to the total width V1 of the positive electrode main body section 11 corresponds to the ratio of the width of the electrode tab section to the width of the main body section in each positive electrode sheet, while the ratio of the total width W2 of the aforementioned negative electrode tab section 22 to the total width V2 of the negative electrode main body section 21 similarly corresponds to the ratio of the width of the electrode tab section to the width of the main body section in each negative electrode sheet; when the electrode assembly is produced by the winding process, the electrode assembly comprises only one layer of the positive electrode sheet, one layer of the separator, and one layer of the negative electrode sheet, the positive electrode sheet having multiple positive electrode tab sections 12.At this point, the ratio of the total width of the aforementioned positive electrode tab section 12 to the total width of the positive electrode main body section 11 corresponds to the ratio of the sum of the widths of all positive electrode tab sections to the width of the positive electrode tab section, while the ratio of the total width of the aforementioned negative electrode tab section 22 to the total width of the negative electrode main body section 21 similarly corresponds to the ratio of the sum of the widths of all negative electrode tab sections to the width of the negative electrode tab section.

[0085] For example, the total width W1 of the positive electrode tab section 12 along the width direction of the positive electrode main body section 11 can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% of the total width V1 of the positive electrode main body section 11.

[0086] For example, the total width W2 of the negative electrode tab section 22 along the width direction of the negative electrode main body section 21 can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% of the total width V2 of the negative electrode main body section 21.

[0087] When a battery cell is charged and discharged at a high rate, the current and voltage within the cell increase accordingly, and the current flowing through the electrode tab also increases. A relatively large electrode tab area means relatively low resistance. On the one hand, according to Ohm's law, at the same voltage, an electrode tab with a relatively large area can carry a higher current, thus having a greater current-carrying capacity. On the other hand, if the resistance of the electrode tab is relatively low, the heat generated by resistance loss after the current has flowed through the electrode tab can be reduced, thereby decreasing the heat generation of the battery at high currents and indirectly improving the battery's heat dissipation efficiency.The relatively low boiling point of the first solvent significantly reduces the negative effects on the performance of the battery cell, and the first solvent can fully exploit its advantages in terms of increasing the conductivity of the electrolyte and improving the fast-charging capability of the battery cell.

[0088] In some embodiments, the width of the positive electrode body section 11 can be larger than its length, or its width can be equal to its length, or its width can be smaller than its length. That is, the positive electrode tab section 12 can be located on the long side or the short side of the positive electrode body section 11. Similarly, the negative electrode tab section 22 can be located on the long side or the short side of the negative electrode body section 21.

[0089] In some embodiments, the total width W1 of the positive electrode tab section can range from 40 mm to 160 mm.

[0090] For example, W1 can be 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm or 160 mm.

[0091] Likewise, in some embodiments, the total width W2 of the negative electrode tab section 22 can also be 40 mm to 160 mm.

[0092] For example, W2 can be 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm or 160 mm.

[0093] If the total widths of the positive electrode tab section and the negative electrode tab section are each within the aforementioned ranges, the current-carrying area of ​​the electrode tab section is relatively large, which can effectively improve the current-carrying capability of the electrode tab section and mitigate the temperature rise of the battery cell during fast charging. This, in turn, allows the internal resistance of the battery cell to be further reduced by using the first solvent with high conductivity and low boiling point, thus reducing the heat generation of the battery cell under fast-charging conditions, improving the fast-charging performance of the battery cell, and increasing the performance of the battery cell under fast-charging conditions.

[0094] In some embodiments, the width W3 of the positive electrode tab section can be 12 40 mm to 160 mm.

[0095] For example, W1 can be 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm or 160 mm.

[0096] Likewise, in some embodiments, the width W4 of the negative electrode tab section 22 can be 40 mm to 160 mm.

[0097] For example, W2 can be 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm or 160 mm.

[0098] With reference to Fig.4 corresponds to the total width W1 of the positive electrode tab section 12 in the manufacture of the electrode arrangement by the stacking process as an example of the total width of several stacked positive electrode tab sections 12 after stacking the positive electrode sheet and the negative electrode sheet and the separator, while the total width W2 of the negative electrode tab section 22 similarly corresponds to the total width of several stacked negative electrode tab sections 22 after stacking the positive electrode sheet and the negative electrode sheet and the separator.

[0099] With reference to Fig.6 corresponds to the total width W1 of the above-mentioned positive electrode tab section 12 in the manufacture of the electrode arrangement by the winding process, as an example, to the total width of the several stacked positive electrode tab sections 12 after winding the positive electrode sheet and the negative electrode sheet and the separator, while the total width W2 of the above-mentioned negative electrode tab section 22 similarly corresponds to the total width of the several stacked negative electrode tab sections 22 after winding the positive electrode sheet and the negative electrode sheet and the separator.

[0100] In some embodiments, the positive electrode tab section 12 and the negative electrode tab section 22 are located on the same side of the positive electrode body section 11. In electrode arrangements obtained by the stacking or winding process, the positive electrode body sections 11 are all arranged parallel to the negative electrode body sections 21, so that the positive electrode tab section 12 and the negative electrode tab section 22 are also located on the same side of the negative electrode body section 21. This can simplify the connection of the external circuit and the assembly process.

[0101] In some embodiments, the positive electrode tab section 12 and the negative electrode tab section 22 are located on two opposite sides of the positive electrode body section 11. In electrode arrangements obtained by the stacking or winding process, the positive electrode body sections 11 are all arranged parallel to the negative electrode body sections 21, so that the positive electrode tab section 12 and the negative electrode tab section 22 are also located on opposite sides of the negative electrode body section 21. This allows for a more uniform heat distribution and reduces deformation of the electrode tab due to excessive one-sided force.

[0102] With reference to Fig.In some embodiments, the positive electrode current collector comprises the positive electrode main body section 11 and several of the positive electrode tab sections 12, wherein at least two of the positive electrode tab sections 12 are located on two opposite sides of the positive electrode main body section 11. Similarly, the negative electrode current collector can comprise the negative electrode main body section and several of the negative electrode tab sections, wherein at least two of the negative electrode tab sections are located on two opposite sides of the negative electrode main body section. This allows for a more uniform heat distribution and reduces deformation of the electrode tab due to excessive one-sided force.

[0103] With reference to Fig.In some embodiments, the positive electrode current collector comprises the positive electrode main body section 11 and several positive electrode tab sections 12 spaced apart along the longitudinal direction of the positive electrode current collector. Similarly, the negative electrode current collector can also comprise the negative electrode main body section 21 and several negative electrode tab sections 22 spaced apart along the longitudinal direction of the negative electrode current collector.

[0104] If the positive electrode current collector includes several positive electrode tab sections 12 and the negative electrode current collector includes several negative electrode tab sections 22, the electron transfer path between the positive electrode tab section and the negative electrode tab section is relatively short, which can reduce the heat generation of the battery and improve fast charging performance.

[0105] The specific examples of implementation are described below based on the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 described:

[0106] With reference to Fig.In some specific embodiments, the stacking process for manufacturing the electrode assembly is taken as an example, which uses a rectangular positive electrode sheet. A positive electrode tab section 12 is located on one of the two short sides of the positive electrode current collector, extending along the longitudinal direction of the positive electrode current collector, where the width of the positive electrode tab section is W3 and the total width V1 of the positive electrode main body section is the width of the positive electrode current collector. Similarly, the corresponding negative electrode current collector can also have a similar structure.There is a negative electrode tab section on one of the two short sides of the negative electrode current collector, which extends along the longitudinal direction of the negative electrode current collector, wherein the width of the negative electrode tab section is W4 and the total width V2 of the negative electrode main body section is the width of the negative electrode current collector.

[0107] With reference to Fig.2 In some specific embodiments, the stacking process for manufacturing the electrode assembly is taken as an example, which uses a rectangular positive electrode sheet. In this process, a positive electrode tab section 12 is located on each of the short sides of the positive electrode current collector, extending along the longitudinal direction of the positive electrode current collector. The extension directions of the two positive electrode tab sections 12 are opposite, with the widths W3 of the multiple positive electrode tab sections 12 being equal or different, and the total width V1 of the positive electrode main body section being the width of the positive electrode current collector. Similarly, the corresponding negative electrode current collector can also have a similar structure.The widths W4 of the several negative electrode tab sections can be the same or different, and the total width V2 of the negative electrode main body section is the width of the negative electrode current collector.

[0108] With reference to Fig.In some specific embodiments, the stacking process for manufacturing the electrode arrangement is taken as an example, which uses a rectangular positive electrode sheet. Several positive electrode tab sections 12 are located on one of the two long sides of the positive electrode current collector, extending along the width direction of the positive electrode current collector. The several positive electrode tab sections 12 are spaced apart along the length direction of the positive electrode current collector, and the width of each positive electrode tab section can be the same or different. Using the example of three positive electrode tab sections, the widths of the three positive electrode tab sections 12 are L1, L2, and L3, where L1, L2, and L3 can all be the same, all be different, or any two of them can be the same.The total width W1 of the positive electrode tab section is the sum of the widths of the multiple positive electrode tab sections, i.e., W1 = L1 + L2 + L3, while the total width V1 of the positive electrode main body section is the length of the positive electrode current collector. Similarly, the corresponding negative electrode current collector can also have a similar structure. In this case, the total width W2 of the negative electrode tab section is the sum of the widths of the multiple negative electrode tab sections, and the width of the negative electrode main body section is the length of the negative electrode current collector.

[0109] With reference to Fig.4 In some specific embodiments, the multiple positive electrode tab sections 12 are arranged offset in the electrode arrangement produced by the stacking process (adjacent positive electrode tab sections overlap at least partially). The total width W1 of the positive electrode tab section 12 corresponds to the total width of the multiple stacked positive electrode tab sections 12 after stacking the positive electrode sheet, the negative electrode sheet, and the separator. Similarly, the multiple negative electrode tab sections 22 are arranged offset (adjacent negative electrode tab sections overlap at least partially). The total width W2 of the negative electrode tab section 22 corresponds to the total width of the multiple stacked negative electrode tab sections 22 after stacking the positive electrode sheet, the negative electrode sheet, and the separator.

[0110] With reference to Fig. In some specific embodiments, the winding process for manufacturing the electrode arrangement is taken as an example. The corresponding positive electrode current collector can have several positive electrode tab sections 12 extending horizontally along a direction perpendicular to the long side of the positive electrode main body section 11, the width W3 of each positive electrode tab section being equal or different. Similarly, the corresponding negative electrode current collector can also have a similar structure, the width W4 of each negative electrode tab section being equal or different.

[0111] Referring to Fig.6 In some specific embodiments, the positive electrode current collector and the negative electrode current collector in the electrode arrangement produced by the winding process exhibit the following characteristics: Fig.The structure shown in Figure 5 is shown. The total width W1 of the above-mentioned positive electrode tab section 12 corresponds to the total width of the several stacked positive electrode tab sections 12 after winding the positive electrode sheet and the negative electrode sheet as well as the separator (adjacent positive electrode tab sections overlap at least partially), while the total width W2 of the above-mentioned negative electrode tab section 22 similarly corresponds to the total width of the several stacked negative electrode tab sections 22 after winding the positive electrode sheet and the negative electrode sheet as well as the separator (adjacent negative electrode tab sections overlap at least partially).

[0112] For example, the single-layer coating weight of the negative electrode active material layer can be 0.1 g / 1540.25 mm². 2 , 0.105 g / 1540.25 mm 2 , 0.115 g / 1540.25 mm2 , 0.12 g / 1540.25 mm 2 , 0.125 g / 1540.25 mm 2 , 0.13 g / 1540.25 mm 2 , 0.135 g / 1540.25 mm 2 , 0.14 g / 1540.25 mm 2 , 0.145 g / 1540.25 mm 2 be.

[0113] As an example, the single-layer coating weight of the negative electrode active material layer can be tested using the following method: the coating weight can be determined by wiping the negative electrode active material layer onto the negative electrode sheet and calculating the mass difference before and after wiping.

[0114] In some embodiments, the organic solvent comprises a first solvent, wherein the first solvent comprises at least one of dimethyl carbonate (DMC) and a linear carboxylic acid ester, the structural formula of which satisfies R1-COO-R2, wherein R1 and R2 are each independently selected from an alkyl group or a halogenated alkyl group from C1 to C5. This allows the viscosity of the electrolyte to be effectively reduced.

[0115] The aforementioned first solvent has a relatively low viscosity, resulting in a relatively low overall viscosity of the electrolyte, which consists primarily of the organic solvent. Intermolecular interactions within the low-viscosity electrolyte are relatively weak, and intermolecular movement is more unrestricted. This accelerates the diffusion and migration of lithium ions within the electrolyte. During rapid charging and discharging of the battery cell, concentration polarization continues to occur within the battery. A relatively high ion migration rate of the electrolyte can reduce this concentration polarization. The aforementioned low-viscosity electrolyte can effectively reduce concentration polarization by increasing the ion migration rate and thus improve the battery's fast-charging performance.

[0116] As an example, the viscosity of the electrolyte can be tested using the following method: the viscosity is tested with a viscometer. The Chinese national standard GB / T10247-2008 "Method for measuring viscosity" is referenced: when the rotor rotates continuously at a constant speed within the sample at a specific temperature, the shear force to which it is subjected causes the spring to generate a torque proportional to the viscosity, thus determining the viscosity value.

[0117] In some embodiments, the linear carboxylic acid ester comprises at least one of ethyl formate, isopropyl formate, ethyl acetate (EA), methyl acetate, propyl acetate, and methyl propionate. This allows the viscosity of the electrolyte to be further reduced.

[0118] The linear carboxylic acid ester exhibits relatively good lithium salt solubility, which can improve electrolyte conductivity, accelerate lithium ion migration within the battery, and enhance battery charging and discharging efficiency. Furthermore, the linear carboxylic acid ester displays relatively good thermal and oxidation stability at high temperatures, contributing to improved battery stability under fast-charging conditions and reducing the risk of thermal runaway.

[0119] In some embodiments, the mass fraction of the first solvent, relative to the total mass of the electrolyte, is 16% to 72%. This can increase the fast-charging performance of the battery cell.

[0120] For example, the mass fraction of the first solvent relative to the total mass of the electrolyte can be 4%, 8%, 12%, 16%, 20%, 24%, 28%, 32%, 36%, 40%, 44%, 48%, 52%, 56%, 60%, 64%, 68% or 72%.

[0121] As the mass fraction of the first solvent increases, the viscosity of the electrolyte gradually decreases and the fast charging performance of the battery is further improved.

[0122] As an example, the quantitative test of the first solvent can be carried out using the following method: the organic components in the electrolyte can be quantitatively analyzed by gas chromatography in accordance with the standard GB / T9722-2006.

[0123] In some embodiments, the mass fraction of the linear carboxylic acid ester is 32% to 68% based on the total mass of the electrolyte.

[0124] For example, the mass fraction of the linear carboxylic acid ester relative to the total mass of the electrolyte can be 32%, 36%, 40%, 44%, 48%, 52%, 56%, 60%, 64% or 68%.

[0125] The linear carboxylic acid ester has a relatively low viscosity, which can further reduce the liquid phase transfer resistance of lithium ions and improve the fast charging and cycle performance of the battery cell if the mass fraction of the linear carboxylic acid ester relative to the total mass of the electrolyte is within the range mentioned above.

[0126] As an example, the quantitative analysis of the linear carboxylic acid ester can be tested using the following method: the organic components in the electrolyte can be quantitatively analyzed by gas chromatography in accordance with the standard GB / T9722-2006.

[0127] It is understood that the electrolyte generally comprises an organic solvent and a lithium salt (including electrolyte lithium salt and lithium salt additive), wherein the mass fraction of the organic solvent is approximately 80% relative to the total mass of the electrolyte, and the remainder may be lithium salt and / or additive.

[0128] In some embodiments, the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm². 2 up to 0.135 g / 1540.25 mm 2 This results in the battery cell having a relatively high volume energy density.

[0129] If the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm² 2 up to 0.135 g / 1540.25 mm 2With this coating, the thickness of the negative electrode active material layer is relatively small, and the distance lithium ions need to diffuse through the negative electrode active material layer is relatively short. This accelerates lithium ion transfer and facilitates improved fast-charging performance of the battery. For example, the charging time for a battery cell using the negative electrode sheet with the aforementioned coating weight is 7 to 15 minutes from 10% SOC to 80% SOC. This results in relatively good fast-charging performance for the battery cell.

[0130] Using a vehicle as an example of a power-consuming device, the state of charge (SOC) of a vehicle battery in real-world use is typically between 10% and 80%, which reduces the user waiting time for charging and significantly improves the user experience when the battery charging time is relatively short in this SOC range.

[0131] In some embodiments, the single-layer coating weight of the negative electrode active material layer is 0.136 g / 1540.25 mm². 2 up to 0.145 g / 1540.25 mm 2 This results in the battery cell having a relatively high volume energy density.

[0132] In some embodiments, the single-layer coating weight of the negative electrode active material layer is 0.136 g / 1540.25 mm². 2 up to 0.145 g / 1540.25 mm 2The volume energy density of the battery cell can range from 410 Wh / L to 430 Wh / L, achieved by assembling the aforementioned positive electrode sheets. This results in a relatively high volume energy density for the battery cell.

[0133] If the single-layer coating weight of the negative electrode active material layer is 0.136 g / 1540.25 mm 2 up to 0.145 g / 1540.25 mm 2 The thickness of the negative electrode active material layer is relatively large, and the negative electrode active material can provide more sites for deintercalation and intercalation of lithium ions, which contributes to improving the energy density of the battery.

[0134] In some embodiments, the charging time for the battery cell from 10% SOC to 80% SOC is 20 to 30 minutes. This gives the battery cell relatively good fast-charging performance.

[0135] In some embodiments, the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located at least on one side of the negative electrode current collector, wherein the density of the negative electrode active material layer is 1.2 g / cm³. 3 up to 1.5 g / cm³ 3 This contributes to increasing the fast charging performance of the battery cell.

[0136] For example, the compaction density of the negative electrode active material layer can be 1.2 g / cm³. 3 , 1.3 g / cm³ 3 , 1.4 g / cm³ 3 or 1.5 g / cm² 3 be.

[0137] If the density of the negative electrode active material layer is within the range mentioned above, the density of the negative electrode active material layer is relatively moderate, with a relatively high rate of deintercalation and intercalation of lithium ions of the negative electrode sheet, which has a positive effect on the fast charging performance of the battery.

[0138] As an example, the test method for the compaction density of the negative electrode active material layer can be the same as the test method for the compaction density of the positive electrode active material layer and is not described in detail here.

[0139] In some embodiments, the negative electrode sheet can be manufactured as follows: the aforementioned components for manufacturing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder, and any other components, are dispersed in a solvent (such as deionized water) to form a negative electrode paste; the negative electrode current collector is coated with this negative electrode paste. After drying, rolling (such as a cold pressing process), and other processes, the negative electrode active material layer can be formed, and the negative electrode sheet obtained. The aforementioned density of the negative electrode active material layer refers to the density of the negative electrode active material layer after rolling.Specifically, the density of the negative electrode active material layer after rolling and forming treatment, the density of the negative electrode active material layer when the battery cell is in a fully charged or fully discharged state, and the density of the negative electrode active material layer after the battery cell has been left to rest for a long time, all lie within the range mentioned above.

[0140] In some embodiments, the negative electrode current collector can be a metal foil or a composite current collector. For example, copper foil can be used as the metal foil. The composite current collector can comprise a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on the polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0141] In some embodiments, the negative electrode active material can be a negative electrode active material known in the art for a battery. For example, the negative electrode active material can comprise at least one synthetic graphite, one natural graphite, one soft carbon, one hard carbon, one silicon-based material, one tin-based material, one lithium titanate, and the like. The silicon-based material can be selected from at least one elemental silicon, one silicon oxide compound, one silicon-carbon composite, one silicon-nitrogen composite, and one silicon alloy. The tin-based material can be selected from at least one elemental tin, one tin oxide compound, and one tin alloy.However, the present application is not limited to these materials, and other conventional materials that can be used as negative electrode active material for a battery may also be used. This negative electrode active material can be used alone or in combination with two or more.

[0142] In some embodiments, the negative electrode active material layer may optionally further comprise a binder. The binder may be selected from at least one of the following: styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0143] In some embodiments, the negative electrode active material layer can optionally further comprise a conductive material. The conductive material can be selected from at least one of superconducting carbon, carbon black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0144] In some embodiments, the negative electrode active material layer may optionally also include other excipients, such as a thickening agent (such as sodium carboxymethylcellulose (CMC-Na)).

[0145] In some embodiments, the negative electrode active material layer comprises a negative electrode active material, wherein the negative electrode active material comprises a silicon-containing material and the mass fraction of silicon in the negative electrode active material is 0.1% to 7%. This allows the mass energy density of the battery cell to be increased.

[0146] The theoretical specific capacity of silicon is up to 4,200 mAh / g, which is significantly higher than that of graphite. Adding silicon-containing material to the negative electrode active material effectively improves the battery's mass energy density. Furthermore, the SEI (solid electrolyte film) breaks down and reorganizes, as pure silicon materials undergo enormous volume expansion (up to over 300%) after the intercalation of lithium ions. This consumes the electrolyte and active lithium ions, ultimately reducing the battery's cycle life.By controlling the mass fraction of silicon in the silicon-containing material to between 0.1% and 7%, it is not only possible to utilize the extremely high theoretical specific capacity of silicon to improve the mass energy density of the battery, but also to help reduce the volume expansion and contraction of the silicon-containing material during the charging and discharging process.

[0147] For example, the mass fraction of silicon in the silicon-containing material is 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5% or 7%.

[0148] For example, the silicon-containing material could be a silicon-carbon material.

[0149] In some embodiments, the mass fraction of silicon in the silicon-containing material is 1% to 5%. This allows the mass energy density of the battery cell to be further increased.

[0150] As an example, the mass fraction of silicon in silicon-containing material can be tested using the following method: Standards YS / T1006.2-2014, GB / T23367.2-2009, or YS / T1028.5-2015 can be referenced. Specifically, an inductively coupled plasma emission spectrometer (ICP) can be used for the measurement, following the manufacturer's instructions.

[0151] In some embodiments, the negative electrode active material layer comprises a first negative electrode active material layer and a second negative electrode active material layer stacked on top of each other, with the first negative electrode active material layer located on one side near the negative electrode current collector, wherein the Dv50 value of the first negative electrode active material in the first negative electrode active material layer is 9.2 µm to 18.5 µm and the Dv50 value of the second negative electrode active material in the second negative electrode active material layer is 7.2 µm to 15.5 µm. This allows for a significant improvement in the fast-charging performance and energy density of the battery cell.

[0152] If the particle size Dv50 of the first and second negative electrode active materials is within the range mentioned above, the particle size of the second negative electrode active material will be smaller than that of the first. The particle size in the first negative electrode active material layer is larger, thus providing more lithium deintercalation sites and increasing battery capacity, while the particle size in the second negative electrode active material layer is smaller, resulting in a faster lithium deintercalation rate and contributing to improved battery fast-charging performance.

[0153] In some embodiments, the conductivity of the electrolyte is between 10 mS / cm and 20 mS / cm. This helps to increase the fast charging performance of the battery cell.

[0154] For example, the conductivity of the electrolyte can be 10 ms / cm, 11 ms / cm, 12 ms / cm, 13 ms / cm, 14 ms / cm, 15 ms / cm, 16 ms / cm, 17 ms / cm, 18 ms / cm, 19 ms / cm or 20 ms / cm.

[0155] If the conductivity of the electrolyte is within the specified range, the electrolyte can conduct lithium ions more effectively, thereby effectively reducing the internal resistance of the battery. This helps to improve the fast charging performance of the battery and reduce the temperature increase of the battery caused by the resistance heating effect during the charging and discharging process, thus reducing the thermal stress within the battery cell and thereby improving battery performance at high power.

[0156] For example, the conductivity of the electrolyte can be directly determined using a conductivity meter according to a method known in engineering.

[0157] In some embodiments, the electrolyte further comprises a first lithium salt additive, wherein the first lithium salt additive comprises at least one of fluorinated borate and fluorinated phosphate, the mass fraction of the first lithium salt additive being 0.05% to 0.5% based on the total mass of the electrolyte. This effectively reduces the internal resistance of the battery cell.

[0158] For example, the mass fraction of the first lithium salt additive, relative to the total mass of the electrolyte, can be 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45% or 0.5%.

[0159] Adding a lithium salt additive consisting of at least one of the fluorinated borates and fluorinated phosphates to the battery cell electrolyte facilitates the formation of a low-resistance SEI film with boron and phosphorus atoms on the surface of the negative electrode active material. This effectively reduces the internal resistance of the battery cell, resulting in both high energy density and fast charging performance. If the mass fraction of the first lithium salt additive is within the range mentioned above, it contributes to the formation of the low-resistance SEI film on the surface of the negative electrode active material. At the same time, only a relatively small amount is used, which helps to reduce the cost of the electrolyte.

[0160] As an example, the mass fraction of the first lithium salt additive relative to the total mass of the electrolyte can be tested using the following method: The free electrolyte is extracted from the finished battery, and the concentration of the first lithium salt additive is tested using an ion chromatographic method. The concentration of the first lithium salt additive in the electrolyte can be quantitatively analyzed using an ion chromatography analysis method according to standard JY / T020-1996.

[0161] In some embodiments, the first lithium salt additive comprises at least one of lithium difluorophosphate, lithium difluoro(oxalato)phosphate, lithium difluoro(oxalato)borate, and lithium tetrafluoroborate. This contributes to the formation of a low-resistance solid electrolyte film on the surface of the negative electrode active material.

[0162] The first lithium salt additive itself exhibits a relatively high ionic conductivity, which can increase the migration rate of lithium ions in the electrolyte; furthermore, during the first charging, the first lithium salt additive can form a stable and dense SEI film with low resistance on the surface of the negative electrode active material, thereby not only reducing the side reactions between the negative electrode active material and the electrolyte, but also reducing the internal resistance of the battery.

[0163] In some embodiments, the mass fraction of the first lithium salt additive, based on the total mass of the electrolyte, is 0.1% to 0.3%. This contributes to reducing the cost of the battery cell.

[0164] The amount of the first lithium salt additive in the electrolyte depends on the migration distance of the lithium ions between the positive and negative electrodes. If the migration distance is long, the amount of the first lithium salt additive in the electrolyte must be increased accordingly to reduce the battery's internal resistance and mitigate the increase in internal resistance caused by the long migration distance. If the mass fraction of the first lithium salt additive in the electrolyte is within the range mentioned above, the battery cell can exhibit both relatively low internal resistance and low manufacturing costs.

[0165] In some embodiments, the organic solvent further comprises a second solvent, wherein the second solvent comprises at least one of ethylene dicarbonate, ethylene carbonate (EC), propylene dicarbonate, ethyl methyl carbonate (EMC), diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, and fluoroethylene carbonate. This contributes to improving the cycle life of the battery cell.

[0166] The previously mentioned second solvent has a wide electrochemical stability window and can even remain stable in a high-voltage environment, thereby reducing its own decomposition in the electrochemical reaction and increasing the cycle life of the battery cell.

[0167] In some embodiments, the second solvent comprises diethyl carbonate, wherein the mass fraction of the diethyl carbonate, based on the total mass of the electrolyte, is greater than or equal to 12%. This contributes to further improving the cycle life of the battery cell.

[0168] Diethyl carbonate has a suitable viscosity and boiling point, which allows the physical properties of the electrolyte to be adapted so that the electrolyte has a suitable viscosity and relatively good performance at low temperatures.

[0169] In some embodiments, the electrolyte further comprises a non-lithium salt additive, wherein the non-lithium salt additive includes a sulfate additive and a carbonate additive. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0170] The carbonate non-lithium salt additive with double bonds contributes to the formation of a flexible SEI film on the surface of the negative electrode active material, thereby slowing down the destruction of the interfacial film by the cyclic volume expansion of the negative electrode active material during the cyclic charging and discharging process, improving the cycle stability of the battery cell and increasing the cycle life.

[0171] In some embodiments, the carbonate additive comprises at least one of vinylene carbonate, fluoroethylene carbonate, and ethyl vinylene carbonate. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0172] In some embodiments, the mass fraction of vinylene carbonate is 0.5% to 2.5% and / or the mass fraction of fluoroethylene carbonate is 0.05% to 2% based on the total mass of the electrolyte. This contributes to the formation of a dense and stable solid electrolyte film on the surface of the negative electrode active material.

[0173] For example, the mass fraction of vinylene carbonate relative to the total mass of the electrolyte is 0.5%, 1%, 1.5%, 2.0% or 2.5%.

[0174] For example, the mass fraction of fluoroethylene carbonate relative to the total mass of the electrolyte is 0.05%, 0.1%, 0.5%, 1%, 1.5% or 2.0%.

[0175] It is understood that, since the carbonate non-lithium salt additive with double bonds participates in the formation of the SEI film on the surface of the negative electrode active material during the formation process and is thus partially consumed, the actual amount of the aforementioned substances found in the battery cell is somewhat less than the amount added. For example, if the amount of vinylene carbonate added is 2.0%, the amount actually found in the battery cell, based on the total mass of the electrolyte, is approximately 0.87%; if the amount of fluoroethylene carbonate added is 1.3%, the amount actually found in the battery cell, based on the total mass of the electrolyte, is approximately 0.05%.

[0176] In some embodiments, the sulfate additive comprises at least one of 4,4-ethylene sulfate, bis(ethylene sulfate), vinylcyclotrisulfate and 1,3-propanesultone.

[0177] In some embodiments, the mass fraction of the non-lithium salt additive, based on the total mass of the electrolyte, is 0.05% to 3%. This contributes to reducing the cost of the battery cell.

[0178] In some embodiments, the electrolyte further comprises a second lithium salt additive, wherein the second lithium salt additive comprises at least one of lithium bis(oxalato)borate, lithium difluorobisoxalatophosphate, lithium tetrafluoro(oxalato)phosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethylsulfonyl)imide, lithium trifluoromethanesulfonate, and lithium perchlorate. This contributes to the formation of a solid electrolyte film with relatively high ionic conductivity on the surface of the negative electrode active material.

[0179] The second lithium salt additive can form a dense and stable interfacial film on the surface of the negative electrode active material, prior to the organic solvent. This inhibits the oxidative decomposition of the organic solvent at the negative electrode and reduces the consumption of active lithium due to the side reaction between the negative electrode active material and the electrolyte. Direct contact between the organic solvent and the negative electrode active material is effectively prevented, and the presence of the interfacial film also helps to reduce the dissolution of transition metals from the negative electrode active material.

[0180] In some embodiments, the electrolyte further comprises an electrolyte lithium salt, wherein the electrolyte lithium salt comprises at least one of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass fraction of the electrolyte lithium salt, based on the total mass of the electrolyte, is greater than or equal to 13%. This contributes to increasing the conductivity of the electrolyte.

[0181] For example, the mass fraction of the lithium salt in the electrolyte, relative to the total mass of the electrolyte, is 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 21%, 23%, 24% or 25%.

[0182] If the mass fraction of the electrolyte lithium salt, relative to the total mass of the electrolyte, is within the range mentioned above, the electrolyte exhibits both relatively high ionic conductivity and low viscosity. Upon dissolving the electrolyte lithium salt in an organic solvent, lithium ions can be released and form a solvation structure with the electrolyte, which improves the electrolyte's conductivity and promotes rapid lithium ion migration within the electrolyte.

[0183] In some embodiments, the electrolyte lithium salt comprises lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide in the electrolyte is (1,2-2) : 1. This helps to further increase the conductivity of the electrolyte.

[0184] Compared to lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide exhibits better conductivity, thermal stability, hydrolysis resistance, and other properties. However, lithium bis(fluorosulfonyl)imide has the disadvantage of being difficult to completely dissociate. Lithium hexafluorophosphate offers advantages in terms of commercial production and application maturity, and has relatively low production costs. If the electrolyte lithium salt contains both lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate can promote the dissociation of lithium bis(fluorosulfonyl)imide, improving the electrolyte performance and thus enhancing the battery's cycle life and fast-charging performance.

[0185] As an example, the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide in the electrolyte can be tested using the following method: the concentration of the inorganic components in the electrolyte can be quantitatively analyzed using the ion chromatography analysis method according to standard JY / T020-1996.

[0186] For example, the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide in the electrolyte can be 1.2 : 1, 1.3 : 1, 1.4 : 1, 1.5 : 1, 1.6 : 1, 1.7 : 1, 1.8 : 1, 1.9 : 1 or 2 : 1.

[0187] In some embodiments, the compaction density of the positive electrode active material layer is 2.2 g / cm³. 3 up to 2.6 g / cm³ 3 This helps to increase the fast charging performance and the energy density of the battery cell.

[0188] For example, the compaction density of the positive electrode active material layer can be 2.2 g / cm³. 3, 2.3 g / cm³ 3 , 2.4 g / cm³ 3 , 2.5 g / cm³ 3 or 2.6 g / cm³ 3 be.

[0189] If the density of the positive electrode active material layer is within the range mentioned above, the density of the positive electrode active material layer is relatively moderate and the positive electrode sheet has a relatively high energy density.

[0190] As an example, the compaction density of the positive electrode active material layer can be tested using the following method: it is obtained by measuring the mass and thickness of the positive electrode active material layer and then dividing these values. The mass and thickness of the positive electrode active material layer can be determined by wiping the positive electrode active material layer onto the positive electrode sheet and calculating the mass and thickness differences before and after wiping.

[0191] In some embodiments, the positive electrode sheet can be produced as follows: the positive electrode active material, the conductive agent, the binder, and any other components are dispersed in a solvent (such as N-methyl-2-pyrrolidone) to form a positive electrode paste; the positive electrode current collector is coated with this paste. After drying, rolling (such as a cold pressing process), and other processes, the positive electrode active material layer can be formed, and the positive electrode sheet obtained.

[0192] The aforementioned density of the positive electrode active material layer refers to the density of the positive electrode active material layer after rolling. Specifically, the density of the positive electrode active material layer after rolling and forming treatment, the density of the positive electrode active material layer when the battery cell is in a fully charged or fully discharged state, and the density of the positive electrode active material layer after the battery cell has been left undisturbed for a long time, all fall within the aforementioned range.

[0193] In some embodiments, the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises: a core section, the core section comprising a lithium-containing phosphate with an olivine structure, and a coating layer, wherein the coating layer coats the surface of the lithium-containing phosphate with an olivine structure and the coating layer contains one or more of C, Fe, Ti, Zr, Hf, Ge, and Sn. This contributes to increasing the structural stability and ionic conductivity of the positive electrode active material.

[0194] The lithium-containing phosphate with an olivine structure is cost-effective and possesses a high theoretical specific capacity, contributing to improved battery cell energy density. Furthermore, the olivine structure maintains crystal integrity during charging and discharging, reduces structural stress, and extends the battery's cycle life. The coating layer effectively mitigates the poor electronic and ionic conductivity of the lithium-containing phosphate with an olivine structure, improving the capacity per gram of positive electrode active material as well as the powder compaction density.

[0195] In some embodiments, the lithium-containing phosphate with olivine structure comprises a compound with the general formula of Li x1 A y1 Me a M1 b P 1-c X c Y z, where 0.5 ≤ x1 ≤ 1.3, 0 ≤ y1 ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5, where A comprises one or more of Na, K, and Mg; Me comprises one or more of Mn, Fe, Co, and Ni; M1 comprises one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; X comprises one or more of S, Si, Cl, B, C, and N; and Y comprises one or more of O and F. This contributes to increasing the ionic conductivity and electronic conductivity of the core section.

[0196] If the lithium-containing phosphate with olivine structure meets the above-mentioned general formula, its advantages over ternary materials are fully exploited to improve the high-temperature resistance and structural stability of the battery cell produced from it, thereby reducing the manufacturing costs of the battery cell.

[0197] During the charging and discharging process of a battery, deintercalation and intercalation, as well as the consumption of lithium, occur, and the molar content of lithium varies depending on the battery's state of discharge. In the enumeration of positive electrode active materials in the present application, the molar content of lithium refers to the initial state of the material, i.e., the state before it is added. The positive electrode active material is used in the battery system. After the charge-discharge cycle, the molar content of lithium may change.

[0198] In the list of positive electrode active materials for lithium-ion batteries in the present application, the molar content of O is only a theoretical value. The release of oxygen from the lattice leads to a change in the molar content of O, which is why the molar content of O varies in practice.

[0199] In some embodiments, the coating layer comprises a carbon layer, wherein the degree of graphitization of the carbon layer is 0.15 to 0.32. This contributes to improving the electronic conductivity of the positive electrode active material.

[0200] By providing the carbon layer, the electronic conductivity of the lithium-containing phosphate with olivine structure can be significantly improved, the lack of poor electronic conductivity of the lithium-containing phosphate with olivine structure can be compensated for, and the capacity of the battery cell can be improved.

[0201] For example, the degree of graphitization of the carbon layer can be 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.27, 0.29, 0.31 or 0.32.

[0202] If the graphitization degree of the carbon layer is within the range mentioned above, the arrangement of carbon atoms in the carbon layer is relatively disordered, there are a relatively large number of lattice defects, a complete graphite lattice is not formed, and the electronic conductivity is somewhat lower than that of carbon materials with a higher degree of graphitization. The carbon layer with a relatively disordered arrangement of carbon atoms typically exhibits a relatively high specific surface area, which helps to ensure complete contact between the core section and the electrolyte, thus improving the efficiency of lithium ion transfer at the interface between the two phases.

[0203] As an example, the degree of graphitization of the carbon layer can be tested using the following method: the degree of graphitization can be determined by the lattice parameters of the carbon crystals using the XRD diffraction method in accordance with standards JB / T4220-2011 and JISK0131-1996.

[0204] In some embodiments, the positive electrode active material in a cross-section of the positive electrode active material layer comprises a lithium-containing phosphate with an olivine structure having a longest diameter of 1 µm to 3 µm and a lithium-containing phosphate with an olivine structure having a shortest diameter of 0.1 µm to 0.3 µm. This contributes to increasing the energy density of the battery cell.

[0205] As an example, the positive electrode active material in a cross-section of the positive electrode active material layer along the thickness direction comprises a lithium-containing phosphate with an olivine structure with a longest diameter of 1 µm, 1.5 µm, 2 µm, 2.5 µm or 3 µm.

[0206] As an example, the positive electrode active material in a cross-section of the positive electrode active material layer along the thickness direction comprises a lithium-containing phosphate with an olivine structure with a shortest diameter of 0.1 µm, 0.15 µm, 0.2 µm, 0.25 µm or 0.3 µm.

[0207] In some embodiments, the particle size Dv50 of the positive electrode active material is 1 µm to 5 µm.

[0208] For example, the particle size Dv50 of the positive electrode active material can be 1 µm, 1.5 µm, 2 µm, 2.5 µm, 3 µm, 3.5 µm, 4 µm, 4.5 µm or 5 µm.

[0209] In some embodiments, the particle size Dv10 of the positive electrode active material is 0.4 µm to 0.7 µm.

[0210] For example, the particle size Dv10 of the positive electrode active material can be 0.4 µm, 0.5 µm, 0.6 µm or 0.7 µm.

[0211] If the particle sizes Dv50 and Dv10 of the positive electrode active material are within the range mentioned above, the overall particle size distribution of the positive electrode active material is relatively reasonable, which has a positive effect on improving the powder compaction density of the positive electrode active material and then contributes to improving the compaction density of the positive electrode sheet and finally to improving the volume energy density of the battery cell.

[0212] The particle size Dv50 mentioned above refers to the particle size that corresponds to the value when the cumulative volume distribution percentage of particles reaches 50%.

[0213] The particle size Dv10 mentioned above refers to the particle size that corresponds to the value when the cumulative volume distribution percentage of particles reaches 10%.

[0214] As an example, the particle size of the positive electrode active material can be determined using particle size analysis via laser diffraction. Specifically, the particle size of the positive electrode active material can be determined according to standard GB / T19077-2016 using a laser particle size analyzer (e.g., Malvern Master Size 3000).

[0215] In some embodiments, the positive electrode active material consists of primary particles or single-crystal-like particles. This results in a relatively large particle size of the positive electrode active material, which has a positive effect on increasing the energy density of the battery cell.

[0216] If the positive electrode active material consists of primary particles or single-crystal-like particles, its particle size is relatively large, which contributes to improving the powder compaction density. Furthermore, assuming a similar particle size distribution, the larger the primary particle size of the positive electrode active material, the higher its powder compaction density, which positively impacts the volume energy density of the battery cell.

[0217] In some embodiments, the positive electrode active material is a mixture of primary and secondary particles, where primary particles can increase the powder compaction density of the positive electrode active material and secondary particles can improve the ionic conductivity of the positive electrode active material. The combined use of primary and secondary particles improves the volume energy density and the fast-charging capability of the battery.

[0218] In some embodiments, the positive electrode active material layer further comprises a lithium-rich material, wherein the lithium-rich material includes at least one of lithium ferrite, lithium nickelate, lithium nickel copperate, lithium phosphate, dilithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, and lithium nickel cobalt manganese oxide. This contributes to increasing the cycle life of the battery cell.

[0219] During the initial charging of the battery, a SEI film forms on the surface of the negative electrode active material. Breakage and recombination of this SEI film during the charge-discharge cycle each result in irreversible lithium ion consumption, leading to reduced efficiency in the first cycle and a loss of battery capacity. By adding a lithium-rich material, the lost lithium can be replenished prior to battery preparation, thereby reducing or preventing the capacity reduction caused by lithium loss and extending the battery's cycle life.

[0220] In some embodiments, the lithium-rich material comprises at least one of lithium ferrite, lithium nickelate, and lithium oxalate. After the lithium-rich material has released lithium ions through the formation process, the residual products can improve and reduce the internal resistance of the positive electrode active material, improve the DC impedance of the battery, and increase the battery's charging and discharging performance.

[0221] In some embodiments, the positive electrode current collector can be a metal foil or a composite current collector. For example, aluminum foil can be used as the metal foil. The composite current collector can comprise a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on the polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0222] In some embodiments, the positive electrode active material layer can optionally also comprise a binder. For example, the binder can be at least one of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylic resin.

[0223] In some embodiments, the positive electrode active material layer can optionally further comprise a conductive material. For example, the conductive material can comprise at least one of superconducting carbon, carbon black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0224] In some embodiments, the separator material can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film without any particular restriction. If the separator is a multi-layer composite film, the materials of each layer can be the same or different without any particular restriction.

[0225] In some embodiments, the positive electrode sheet, the negative electrode sheet and the separator can be formed into an electrode arrangement by a winding or stacking process.

[0226] In some embodiments, the length of the battery cell is L, and the width of the battery cell is H, where the value of L is 4 to 10 times the value of H. In this way, the volume utilization of the battery can be effectively improved and the overall energy density of the battery increased.

[0227] By flattening and lengthening the battery cell, a thin and elongated shape is created. This elongated battery cell is directly arranged and combined to form a battery pack, eliminating the need for a central module structure. This effectively improves the volume utilization of the battery pack and can increase the overall energy density of the battery cell.

[0228] For example, the value of L can be 4 times, 4.5 times, 5 times, 5.5 times, 6 times, 6.5 times, 7 times, 7.5 times, 8 times, 8.5 times, 9 times, 9.5 times or 10 times the value of H.

[0229] If the ratio between the values ​​of L and H is within the aforementioned range, this helps to improve the volume utilization of the battery pack formed by the assembly of the battery cells. Furthermore, in the event of a collision or external impact, the force acting on the battery cell is more uniform and distributed, thus effectively reducing the risk of a short circuit.

[0230] In some embodiments, the value of L is 4 to 7 times the value of H. This gives the battery cell both a relatively high energy density and a relatively low internal resistance.

[0231] In some embodiments, L is 400 mm to 1,000 mm and / or H is 80 mm to 160 mm.

[0232] For example, L can be 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, 800 mm, 850 mm, 900 mm, 950 mm or 1,000 mm.

[0233] For example, H can be 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm or 160 mm.

[0234] If L and H are within the aforementioned range, the battery cell size is moderate, which facilitates transport and rapid assembly. The lithium-ion transfer path within the battery cell is relatively short, and the internal resistance of the battery cell is relatively low.

[0235] In some exemplary embodiments, referring to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig.8, the battery cell further comprises a housing body, wherein the electrode arrangement is located in the housing body and the housing body comprises two first housing walls 101, which are arranged opposite each other, and a surrounding wall which connects the two first housing walls 101, wherein the surrounding wall comprises: two second housing walls 102, which are arranged opposite each other along the longitudinal direction of the first housing wall 101, two third housing walls 103, which are arranged opposite each other along the transverse direction of the first housing wall 101, wherein the second housing wall 102 is provided with an electrode terminal, wherein the positive electrode tab section 12 and the negative electrode tab section 22 are each electrically connected to the electrode terminals on the two second housing walls 102, wherein between the second housing wall 102,which is electrically connected to the positive electrode tab section 12, and a retraction structure 106 is provided to the positive electrode main body section 11, wherein the retraction structure 106 is configured to retract several of the positive electrode tab sections 12. This facilitates the attachment of the positive electrode tab and the welding between the positive electrode sheet and the electrode column 105.

[0236] Referring to the Fig. 4 and Fig.5. The positive electrode tab section 12 and the negative electrode tab section 22 of the battery cell are each brought out of the two second housing walls of the housing body, i.e., the electrode tabs are brought out from opposite sides, which helps to arrange the battery cells more efficiently in a limited space, making it easier for several battery cells within the battery pack to form an efficient series and parallel structure, while at the same time reducing the space occupied by the connecting elements between the battery cells and improving the volume energy density of the battery pack.To improve the volume energy density, the stacking process can be used to form the electrode arrangement, wherein each positive electrode sheet has a corresponding positive electrode tab section and each negative electrode sheet has a corresponding negative electrode tab section, wherein all positive electrode tab sections 12 and negative electrode tab sections 22 must be collected separately and then electrically connected to the corresponding electrode terminals to achieve current convergence.

[0237] Normally, the positive electrode current collector is made of aluminum foil and the negative electrode current collector of copper foil. Since the copper foil is soft and brittle, the negative electrode tab section must first be welded to the second housing wall with the corresponding electrode column and then installed in the surrounding wall structure formed by the first and third housing walls. Finally, the positive electrode tab section is welded to the second housing wall with the corresponding electrode column.To reduce the possibility that the electrode tab is inserted inside out during welding of the positive electrode tab section to the corresponding second housing wall, thereby causing an internal short circuit in the battery cell, several positive electrode tab sections can be fixed by a pull-in structure to reduce the possibility of inserting an inside-out electrode tab and to facilitate welding of the positive electrode tab section to the lower base of the electrode column.

[0238] In some embodiments, a chamfer is provided on the edge of the positive electrode blade in the longitudinal direction of the first housing wall 101. This facilitates quick assembly of the electrode arrangement and reduces the risk of the electrode arrangement penetrating the separator when entering the housing body.

[0239] In some embodiments, the second housing wall 102, which is connected to the negative electrode tab section 22, is provided with a liquid injection hole. This facilitates the injection of the electrolyte.

[0240] Since a pull-in structure is provided for pulling the positive electrode tab section into the second housing wall connected to the positive electrode tab section, the liquid injection hole is provided on the second housing wall 102 connected to the negative electrode tab section 22 in order to give the second housing wall a relatively high mechanical strength.

[0241] In some exemplary embodiments, referring to the Fig. 9 and Fig.In Figure 10, the liquid injection port 107 and a pressure relief section 104 of the housing body are located on different second housing walls 102, the pressure relief section 104 being configured to release pressure within the housing body. This reduces corrosion of the pressure relief section 104 by the electrolyte during the injection process.

[0242] Since the electrolyte corrodes the pressure relief section when the electrolyte is injected into the battery cell through the liquid injection hole, the liquid injection hole and the pressure relief section of the housing body should be located on different second side walls.

[0243] In some exemplary embodiments, referring to Fig.11, at least one mounting hole is provided at the electrode connection, wherein the electrode column 105 is guided through the mounting hole and riveted to the electrode tab section. This contributes to reducing the volume of the battery cell, decreasing the weight of the battery cell and increasing the energy density of the battery cell.

[0244] By creating an electrical connection via a single electrode column, the number of connection points can be reduced, the production and assembly process simplified, fewer materials and processing steps are required, and costs can be lowered.

[0245] In some exemplary embodiments, referring to the Fig. 9 and Fig.10. At least two mounting holes are provided at the electrode connection, with each electrode column 105 being guided through the mounting hole and riveted to the electrode tab section. This contributes to increasing the current-carrying capacity of the electrode column 105.

[0246] An electrical connection via a double electrode column can distribute the current, reduce local overheating, and improve the fast charging performance of the battery.

[0247] In some embodiments, the diameter of the electrode column 105 is 3 mm to 8 mm. This gives the electrode column 105 both a relatively high current-carrying capacity and a relatively small footprint.

[0248] For example, the diameter of the electrode column can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm or 8 mm.

[0249] If the diameter of the electrode column is within the range mentioned above, the electrode column has a relatively high current-carrying capacity and a relatively low internal resistance, which can reduce heat generation.

[0250] In some exemplary embodiments, referring to Fig. In the first housing wall 101, the electrode column 105 riveted to the positive electrode tab section 12 and the electrode column 105 riveted to the negative electrode tab are arranged offset along the longitudinal direction of the first housing wall 101. Optionally, the electrode column 105 riveted to the positive electrode tab and the electrode column 105 riveted to the negative electrode tab are arranged diagonally along the longitudinal direction of the first housing wall 101. This helps to arrange the battery cells more efficiently in a limited space and to improve the volume energy density of the assembled battery module or battery pack.

[0251] In some exemplary embodiments, referring to Fig. In section 13, the electrode column 105 and the electrode lug are electrically connected via a transfer plate 108. This significantly improves the weld quality and connection reliability between the electrode column 105 and the electrode lug.

[0252] If the electrical connection between the electrode column and the electrode tab is made via the transfer plate, the shape and size of the transfer plate can be adapted to different distances and positions as needed; furthermore, the welding process of the transfer plate has relatively few defects, which can contribute to a more uniform current distribution, a reduction in local overheating and potential differences, and a longer battery lifespan.

[0253] In some exemplary embodiments, referring to Fig.In section 14, the electrode column 105 and the electrode tab are directly electrically connected. This helps to reduce the structural complexity within the battery cell, reduce the volume of the battery cell, and increase the energy density.

[0254] If the electrode column and the electrode tab are directly electrically connected, the connecting element is eliminated, which simplifies the internal structure of the battery cell, reduces the assembly steps and lowers the overall manufacturing costs.

[0255] In some embodiments, the battery cells described above can also be directly assembled into a battery pack, thus eliminating the battery module structure and improving the battery's energy density. The number of battery cells contained in the battery pack can be one or more, and the specific number can be selected by a person skilled in the art depending on the application and capacity of the battery pack.

[0256] In some embodiments, the distance between the two first housing walls is 101 D, where D is less than or equal to 30 mm. This benefits the rapid heat dissipation of the battery cell.

[0257] Since the charging current and voltage flowing through the battery cell increase accordingly under fast-charging conditions, the heat generated also increases significantly, according to Joule's law. In the case of a long-strip battery cell, the first casing wall is the surface with the largest area of ​​the battery cell; therefore, the heat dissipation effect of the battery cell is relatively good near the first casing wall. However, in the thickness direction of the battery cell, i.e., in the width direction of the third casing wall, the heat diffuses slowly within the battery cell. If the distance D between the two first casing walls is within the range mentioned above, the heat dissipation effect of the battery cell in the thickness direction is relatively good, which contributes to achieving good heat dissipation during fast charging and improves the fast-charging performance of the battery cell.

[0258] In some embodiments, D is 10 mm to 25 mm. This gives the battery cell relatively high mechanical strength and relatively good heat dissipation.

[0259] For example, D can be 5 mm, 10 mm, 15 mm, 20 mm, 25 mm or 30 mm.

[0260] In some embodiments, the thickness of the first housing wall 101 and the third housing wall 103 is each independently less than or equal to 0.5 mm. This allows the volume energy density of the battery cell to be increased.

[0261] If the thickness of the first casing wall 101 and the third casing wall 103 is within the range mentioned above, the casing wall is relatively thin and the weight of the casing body is relatively low, which has a positive effect on improving the mass energy density and volume energy density of the battery cell.

[0262] For example, the thickness of the first housing wall 101 and the third housing wall 103 can be the same.

[0263] In some embodiments, the first housing wall 101 and the third housing wall 103 comprise at least one aluminum housing and one steel housing. This increases the mechanical strength of the battery cell.

[0264] For the same thickness, the mechanical strength of the aluminum housing is greater than that of the steel housing, which allows the electrode arrangement to be held better and reduces the expansion of the battery cell during the charging and discharging process.

[0265] For the same thickness, the density of the aluminum casing is lower than that of the steel casing, which further reduces the weight of the casing body and further improves the mass energy density of the battery cell.

[0266] In some embodiments, the first housing wall 101 and the third housing wall 103 are steel housings, with the wall thickness of the steel housing being 0.1 mm to 0.5 mm. This effectively mitigates the volume expansion of the battery cell during the charging and discharging process.

[0267] In some embodiments, the first housing wall 101 and the third housing wall 103 are aluminum housings, with the wall thickness of the aluminum housing being 0.3 mm to 0.4 mm. This effectively increases the mass energy density of the battery cell.

[0268] In some embodiments, the first housing wall 101 and the third housing wall 103 are obtained by bending and welding aluminum plates, with the weld seam being located at the connection between the first housing wall 101 and the third housing wall 103. This reduces electrolyte leakage.

[0269] The aluminum housing obtained by bending and laser welding the aluminum plate has an excellent sealing effect, which can effectively prevent electrolyte leakage, increase the stability of the internal environment of the battery cell and improve the cycle life of the battery cell.

[0270] In some embodiments, the electrolyte as a whole also exhibits a relatively low viscosity, particularly if the organic solvent in the electrolyte is predominantly a low-viscosity solvent. Low-viscosity electrolytes tend to decompose and gasse at high charge and discharge rates, leading to expansion of the battery cell. The weld is a mechanical weak point and can crack under extreme conditions. To prevent rapid deterioration due to electrolyte leakage after weld failure, the weld at the junction between the third and first casing walls can be positioned away from the bottom. This prevents the electrolyte from easily escaping the battery cell even after the weld fails, effectively suppressing rapid battery deterioration.

[0271] In some embodiments, a lateral retaining plate is provided between the electrode arrangement and the first housing wall 101. This helps to increase the structural stability of the battery cell.

[0272] The lateral retaining plate can block direct contact between the electrode blade and the housing body, thus reducing damage to the electrode blade caused by the rounding at the edge of the inner wall of the housing body.

[0273] In some embodiments, at least one of the second housing walls 102 is provided with a pressure relief section 104, wherein the pressure relief section 104 is configured to release pressure within the housing body, and the area of ​​the positive projection of the pressure relief section 104 on the second housing wall 102 comprises 7% to 15% of the area of ​​the second housing wall 102. This helps to quickly release the internal overpressure gas through the pressure relief section 104 when the internal pressure of the battery cell is too high.

[0274] For example, the area of ​​the pressure relief section can be 155 mm² 2 the area of ​​the second housing wall can be 1920 mm 2 be.

[0275] If the area of ​​the positive projection of the pressure relief section 104 on the second housing wall 102 lies within the above-mentioned range, the pressure relief section can react quickly when the internal pressure of the battery cell suddenly increases and break to release the internal pressure, taking up relatively little space on the second housing wall, so that other structural elements can be conveniently arranged on the second housing wall.

[0276] In some embodiments, the capacity of the battery cell is Q, where the area of ​​the positive projection of the pressure relief section 104 on the second housing wall 102 is P, wherein the ratio of P to Q is greater than or equal to 1.1, where the unit of Q is Ah and the unit of P is mm 2 This helps to quickly release the excess pressure gas inside the battery cell.

[0277] If the battery cell capacity is relatively large, the concentration of low-viscosity electrolyte in the battery is correspondingly high, and the amount of gas generated per unit time during high-rate charging and discharging is substantial. Furthermore, lithium bis(fluorosulfonyl)imide continues to undergo gas-generating side reactions with the negative electrode active material layer when fully charged. Therefore, a pressure relief section with a larger area is required to provide more venting space, allowing for a rapid response and release of internal pressure through rupture in the initial stages of a sudden pressure increase within the battery cell. If the pressure-to-pressure-volume (P / Q) ratio is within the aforementioned range, the area of ​​the pressure relief section is adapted to the battery capacity and can meet the pressure relief requirements of a battery cell of the corresponding capacity.

[0278] In some embodiments, each of the two second housing walls can be provided with a pressure relief section. The proportional relationship between the area of ​​the pressure relief section and the area of ​​the second housing wall can be found in the above description.

[0279] A second aspect of the present application provides a battery device comprising the aforementioned battery cell, wherein the battery device can be a battery module, a battery pack, and an energy storage device. Therefore, the battery device possesses all the features and advantages of the aforementioned battery cell, which are not described in detail here.

[0280] In a third aspect of the present application, the present application proposes a power-consuming device comprising the aforementioned battery cell. The power-consuming device thus possesses all the features and advantages of the aforementioned battery cell, which are not described in detail here.

[0281] The aforementioned battery cell or battery pack can be used as a power source for the power-consuming device and can also be used as an energy storage unit for the power-consuming device. Power-consuming devices can include, but are not limited to, mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0282] The power-consuming device can be selected as either a battery cell or a battery pack, depending on its usage requirements.

[0283] Fig. Figure 15 is an example of a power-consuming device. This power-consuming device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the power-consuming device's requirements for high power and high battery energy density, the battery pack can be used.

[0284] The solutions in the present application are described below with reference to specific embodiments. It should be noted that the following embodiments serve only to illustrate the present application and are not to be considered as limiting its scope. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the technical literature or product instructions must be followed. The reagents and instruments used, without manufacturer information, are all commercially available products. Example 11) Production of the positive electrode sheet

[0285] The positive electrode sheet comprised an aluminum foil for the positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer comprised a film formed by uniformly applying the positive electrode paste (the solvent being N-methyl-2-pyrrolidone) to the surface of the aluminum foil for the positive electrode current collector, drying, and cold pressing. The positive electrode active material layer comprised the positive electrode active material, the conductive agent (carbon black), and the binder (polyvinylidene fluoride (PVDF)) in a weight ratio of 97.5:1.4:1.1. The positive electrode active material was lithium iron phosphate containing phosphorus and comprising aluminum, titanium, and vanadium, with the mass fractions of aluminum, titanium, and vanadium being 0.012%, 0.025%, and 0.025%, respectively.In cross-section of the positive electrode active material layer along the thickness direction, the positive electrode active material comprised a lithium-containing phosphate with an olivine structure with a longest diameter of 2.5 µm and a lithium-containing phosphate with an olivine structure with a shortest diameter of 0.2 µm, wherein the total width of the positive electrode tab section was 50% of the total width of the positive electrode main body section and the single-layer coating weight of the positive electrode active material layer was 0.283 g / 1540.25 mm. 2 The density of the positive electrode active material layer was 2.45 g / cm³. 3 fraud. 2) Production of the negative electrode sheet

[0286] The negative electrode sheet comprised a copper foil for the negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer was a film formed by uniformly applying the negative electrode paste (the solvent being deionized water) to the surface of the aluminum foil for the negative electrode current collector, drying, and cold pressing. This layer consisted of the negative electrode active material itself, a styrene-butadiene rubber (SBR) binder, a sodium carboxymethylcellulose (CMC-Na) thickener, and carbon black (Super P) conductive material in a weight ratio of 96.2:1.8:1.2:0.8. The negative electrode active material was single-layer graphite.The particle size Dv50 of the negative electrode active material was 10.5 µm, with the total width of the negative electrode tab section being 50% of the total width of the negative electrode main body section, and the single-layer coating weight of the negative electrode active material layer being 0.127 g / 1540.25 mm. 2 was, with the compaction density of the negative electrode active material layer being 1.45 g / cm³ 3 fraud. 3) Separator

[0287] The separator was a porous polypropylene (PP) film. 4) Production of the electrolyte

[0288] The organic solvent substances in the electrolyte had a ratio of EA / DMC / EC = 10 / 55 / 35 and the electrolyte lithium salt in the electrolyte is lithium hexafluorophosphate with a mass fraction of 12.5%. 5) Battery production

[0289] The lithium-ion battery comprised a casing, an electrode assembly, and an electrolyte, wherein the electrode assembly and the electrolyte were arranged within the casing. The electrode assembly comprised a positive electrode sheet and a negative electrode sheet, as well as a separator. The electrode assembly was a wound electrode assembly, and the separator was positioned between the positive and negative electrode sheets. The length L of the battery cell was 510 mm, the width H of the battery cell was 120 mm, and the thickness D of the battery cell was 16 mm.

[0290] The differences between the other embodiments and embodiment 1 were shown in Tables 1 to 5. Table 1 number Ratio of the total width of the positive electrode tab section to the total width of the positive electrode main body section (in %) Ratio of the total width of the negative electrode tab section to the total width of the negative electrode main body section (in %) Example 1 50 50 Example 2 70 70 Example 3 100 100 Table 2 number Organic solvent in the electrolyte Mass ratio of the individual components in the organic solvent Example 1 EA / DMC / EC 10 / 55 / 35 Example 4 EA / DMC / EC 5 / 60 / 35 Example 5 EA / EC 70 / 30 Example 6 EA / EC 90 / 10 Table 3 number Single-layer coating weight of the negative electrode active material layer (g / 1540.25 mm²) 2 ) Example 1 0,127 Example 7 0,12 Example 8 0,145 Table 4 number Electrolyte lithium salt Example 1 LiPF6 Example 9 LiPF6 / LiFSI, mass ratio of 2 : 1 Example 10 LiPF6 / LiFSI, mass ratio of 1.2 : 1 Table 5 number Non-lithium salt additive Mass fraction of the non-lithium salt additive relative to the total mass of the electrolyte (in %) Example 1 / / Example 11 FEC, VC 1,3, 2 Example 12 FEC, VC 1,5, 1,5 Example 13 FEC, VC 0,5, 0,05 Comparative example 1

[0291] Comparative example 1 was identical to embodiment 1, except that the total width of the positive electrode tab section was 30% of the total width of the positive electrode main body section, the total width of the negative electrode tab section was 30% of the total width of the negative electrode main body section, and the single-layer coating weight of the positive electrode active material layer was 0.25 g / 1540.25 mm². 2 The single-layer coating weight of the negative electrode active material layer was 0.1 g / 1540.25 mm². 2 was and the organic solvent substances in the electrolyte and their ratio EA / EC = 90 / 10 were. Comparative example 2

[0292] Comparative example 2 was identical to embodiment 1, except that the single-layer coating weight of the positive electrode active material layer was 0.3 g / 1540.25 mm². 2 The single-layer coating weight of the negative electrode active material layer was 0.145 g / 1540.25 mm². 2 was, and the organic solvent substances in the electrolyte and their ratio DMC / EC = 60 / 40 were. Comparative example 3

[0293] Comparative example 3 was identical to embodiment 1, except that the total width of the positive electrode tab section was 100% of the total width of the positive electrode main body section, the total width of the negative electrode tab section was 100% of the total width of the negative electrode main body section, and the single-layer coating weight of the positive electrode active material layer was 0.31 g / 1540.25 mm². 2The single-layer coating weight of the negative electrode active material layer was 0.16 g / 1540.25 mm². 2 was, and the organic solvent substances in the electrolyte and their ratio EA / EC = 90 / 10 were.

[0294] The fast-charging performance of the batteries in embodiments 1 to 10 and in comparison examples 1 to 3 was tested. The test method is as follows, and the test results are listed in Table 1-1.

[0295] Charging Time Test: ① Voltage Calibration: 1) A stacked three-electrode battery is constructed from the positive electrode sheet, the negative electrode sheet, the separator, and the electrolyte in the exemplary embodiments or comparative examples and left at rest for 30 minutes at 25 °C; 2) The battery cell is charged at 0.33 C at 25 °C to the final charging voltage of 3.65 V and further charged at the final charging voltage at constant voltage until the current reaches 0.05 C and charging is terminated (where C represents the nominal capacity of the battery cell); 3) The battery cell is left at rest for 1 hour at 25 °C; 4) The battery cell is discharged at 0.33 C at 25 °C to the final discharge voltage of 2.5 V, and the total discharge capacity C0 from the battery cell is recorded;5) The battery cell is left at rest for 1 hour at 25 °C. ② Charging test at room temperature: 1) A stacked three-electrode battery is constructed from the positive electrode sheet, the negative electrode sheet, the separator, and the electrolyte in the exemplary embodiments or comparative examples and left at rest for 30 minutes; 2) The battery is discharged with a direct current of 0.33 C0 to the discharge cut-off voltage of 2.5 V, which corresponds to 0% SOC; 3) The battery is left at rest for 5 minutes; 4) The battery is charged with a constant current of 5 C0 until the negative electrode potential is 0 V, the capacity C1 at this time is read, which corresponds to C1 / C0 SOC; 5) The battery is left at rest for 5 minutes;6) The battery is charged with a constant current of 4.5 C0 until the negative electrode potential reaches 0 V. The capacity C2 at this point is read, which corresponds to C2 / C0 SOC; 7) The battery is left at rest for 5 minutes; 8) The battery is charged with a constant current of 4 C0 until the negative electrode potential reaches 0 V. The capacity C3 at this point is read, which corresponds to C3 / C0 SOC; 9) The battery is left at rest for 5 minutes; 10) The battery is charged with a constant current of 3 C0 until the negative electrode potential reaches 0 V. The capacity C4 at this point is read, which corresponds to C4 / C0 SOC; 11) The battery is left at rest for 5 minutes; 12) The battery is charged with a constant current of 2 C0 until the negative electrode potential is 0 V, the capacity C5 at this time is read out, which corresponds to C5 / C0 SOC;13) The battery is left at rest for 5 minutes; 14) The battery is charged with a constant current of 1 C0 until the negative electrode potential is 0 V, the capacity C6 at this time is read, which corresponds to C6 / C0 SOC; 15) The battery is left at rest for 5 minutes; 16) The battery is charged with a constant current of 0.8 C0 until the negative electrode potential is 0 V, the capacity C7 at this time is read, which corresponds to C7 / C0 SOC; 17) The battery is left at rest for 5 minutes; 18) The battery is charged with a constant current of 0.5 C0 until the negative electrode potential is 0 V, the capacity C8 at this time is read, which corresponds to C8 / C0 SOC; 19) The battery is left at rest for 5 minutes;20) The battery is charged with a constant current of 0.33 C0 until the negative electrode potential reaches 0 V. The capacity C9 at this point (also known as C0) is read, which corresponds to 100% SOC. The required charging time is calculated by adding the total charging times from 10% SOC to 80% SOC.

[0296] Temperature rise test: a temperature sensor lead is placed at any point on the top cover of the battery cell to monitor the temperature of the top cover, and the following charging operations are then carried out on the battery cell: 1) In the exemplary embodiments or comparative examples, the battery cell is discharged with a direct current of 0.33 C to the discharge cut-off voltage of 2.5 V, which corresponds to 0% SOC; 2) it is left to rest for 5 minutes and charged with a constant current of 5 C to C1 / CSOC (the value of C1 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C represents the nominal capacity of the battery cell); 3) it is left to rest for 5 minutes and charged with a constant current of 4.5 C to C2 / CSOC (the value of C2 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C is the nominal capacity of the battery cell); 4) it is left to rest for 5 minutes and charged with a constant current of 4 C to C3 / CSOC (the value of C3 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C is the nominal capacity of the battery cell); 5) it is left to rest for 5 minutes and charged with a constant current of 3 C to C4 / CSOC (the value of C4 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C represents the nominal capacity of the battery cell); 6) it is left to rest for 5 minutes and charged with a constant current of 2 C to C5 / CSOC (the value of C5 is the capacity that the stacked three-electrode battery corresponds to in the negative electrode lithium plating window test, where C represents the nominal capacity of the battery cell); 7) it is left to rest for 5 minutes and charged with a constant current of 1 C to C6 / CSOC (the value of C6 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C is the nominal capacity of the battery cell); 8) it is left to rest for 5 minutes and charged with a constant current of 0.8 C to C7 / CSOC (the value of C7 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C represents the nominal capacity of the battery cell); 9) it is left to rest for 5 minutes and charged with a constant current of 0.5 C to C8 / CSOC (the value of C8 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C represents the nominal capacity of the battery cell); 10) It is left at rest for 5 minutes and charged with a constant current of 0.33 C to C9 / CSOC (the value of C9 is the capacity that the stacked three-electrode battery corresponds to when testing the negative electrode lithium plating window, where C represents the nominal capacity of the battery cell), whereby the battery cell reaches a full state of charge, i.e. 100% SOC; The temperature increase of the battery cell during charging from 10% SOC to 80% SOC is monitored and recorded.

[0297] The cycle performance of the battery cell in embodiment 1, in embodiments 11 to 13, was tested using the following test method and the test results are listed in Table 1-2.

[0298] Cycle life: The battery cell is charged to a final voltage of 3.65 V at a constant current of 1 C at 45 °C, then charged to 0.05 C at a constant voltage, and after a 10-minute rest period, the battery cell is discharged to 2.5 V at a constant current of 1 C. This step is repeated until the capacity retention rate drops to 80%, and the number of cycles at that point is recorded. Table 1-1 number Temperature increase (in °C) Time (in minutes) Example 1 20 15 Example 2 18 15 Example 3 15 15 Example 4 20 10,5 Example 5 22 13 Example 6 23 12 Example 7 20 14,5 Example 8 17 17 Example 9 20,8 14,2 Example 10 24,5 12,8 Comparative example 1 40 11 Comparative example 2 20 20 Comparative example 3 18 22 Table 1-2 number Number of cycles (in cycles) Example 1 1250 Example 11 1580 Example 12 1475 Example 13 1340

[0299] It should be noted that the present application is not limited to the embodiments mentioned above. The above embodiments are merely examples, and all embodiments that have essentially the same structure and effect as the technical idea within the technical solution of the present application are all included within the technical scope of the present application. Furthermore, other possibilities in which various modifications conceivable to a person skilled in the art are added to the embodiments, and some components of the embodiments are combined to form other embodiments, are also included within the scope of the present application without departing from the core 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 patent literature

[0000] GB 10247-2008

[0116] Cited non-patent literature

[0000] Standard GB / T9722-2006 [0122, 0126] Standards YS / T1006.2-2014, GB / T23367.2-2009 or YS / T1028.5-2015

[0150] Standard GB / T19077-2016

[0214]

Claims

[1] Battery cell comprising: an electrode arrangement, the electrode arrangement comprising a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode main body section and at least one positive electrode tab section, wherein the positive electrode main body section is connected to the positive electrode tab section and the total width of the positive electrode tab section along the width direction of the positive electrode main body section is 50% to 100% of the total width of the positive electrode main body section. wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector, wherein the negative electrode current collector comprises a negative electrode main body section and at least one negative electrode tab section, wherein the negative electrode main body section is connected to the negative electrode tab section and the total width of the negative electrode tab section along the width direction of the negative electrode main body section is 50% to 100% of the total width of the negative electrode main body section, wherein the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm² 2 up to 0.145 g / 1540.25 mm 2 amounts, an electrolyte, wherein the electrolyte comprises an organic solvent, wherein the organic solvent comprises a first solvent, the first solvent comprising at least one of dimethyl carbonate and a linear carboxylic ester, the structural formula of the linear carboxylic ester being R1-COO-R2, wherein R1 and R2 are each independently selected from an alkyl group or a halogenated alkyl group from C1 to C5; wherein the mass fraction of the first solvent is 4% to 72% based on the total mass of the electrolyte. [2] Battery cell according to claim 1, wherein the total width of the positive electrode sheet section is 40 mm to 160 mm and / or the total width of the negative electrode sheet section is 40 mm to 160 mm and / or the width of the positive electrode sheet section is 40 mm to 160 mm and / or the width of the negative electrode sheet section is 40 mm to 160 mm. [3] Battery cell according to claim 1 or 2, wherein the positive electrode tab section and the negative electrode tab section are located on the same side of the positive electrode main body section or the positive electrode tab section and the negative electrode tab section are located on two opposite sides of the positive electrode main body section. [4] Battery cell according to one of claims 1 to 3, wherein the positive electrode current collector comprises the positive electrode main body section and several of the positive electrode tab sections, wherein at least two of the positive electrode tab sections are located on two opposite sides of the positive electrode main body section, and / or wherein the negative electrode current collector comprises the negative electrode main body section and several of the negative electrode tab sections, wherein at least two of the negative electrode tab sections are located on two opposite sides of the negative electrode main body section. [5] Battery cell according to one of claims 1 to 4, wherein the positive electrode current collector comprises the positive electrode main body section and several of the spaced-apart positive electrode tab sections, and / or wherein the negative electrode current collector comprises the negative electrode main body section and several of the spaced-apart negative electrode tab sections. [6] Battery cell according to any one of claims 1 to 5, wherein the single-layer coating weight of the negative electrode active material layer is 0.1 g / 1540.25 mm² 2 up to 0.135 g / 1540.25 mm 2 amounts. [7] Battery cell according to claim 6, wherein the charging time of the battery from 10% SOC to 80% SOC is 7 to 15 minutes. [8] Battery cell according to any one of claims 1 to 5, wherein the single-layer coating weight of the negative electrode active material layer is 0.136 g / 1540.25 mm² 2 up to 0.145 g / 1540.25 mm 2 amounts. [9] Battery cell according to claim 8, wherein the charging time of the battery from 10% SOC to 80% SOC is 20 to 30 minutes. [10] Battery cell according to any one of claims 1 to 9, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer located at least on one side of the negative electrode current collector, wherein the density of the negative electrode active material layer is 1.2 g / cm³ 3 up to 1.5 g / cm³ 3 amounts. [11] Battery cell according to claim 10, wherein the negative electrode active material layer comprises a negative electrode active material, wherein the negative electrode active material comprises a silicon-containing material and the mass fraction of silicon in the negative electrode active material is 0.1% to 7%. [12] Battery cell according to claim 11, wherein the mass fraction of silicon in the negative electrode active material is 1% to 5%. [13] Battery cell according to claim 10, wherein the negative electrode active material layer comprises a first negative electrode active material layer and a second negative electrode active material layer stacked on top of each other, wherein the first negative electrode active material layer is located on one side near the negative electrode current collector, wherein the Dv50 value of the first negative electrode active material in the first negative electrode active material layer is 9.2 µm to 18.5 µm and the Dv50 value of the second negative electrode active material in the second negative electrode active material layer is 7.2 µm to 15.5 µm. [14] Battery cell according to any one of claims 1 to 13, wherein the conductivity of the electrolyte is 10 ms / cm to 20 ms / cm. [15] Battery cell according to any one of claims 1 to 14, wherein the mass fraction of the first solvent is 16% to 72% based on the total mass of the electrolyte. [16] Battery cell according to any one of claims 1 to 15, wherein the mass fraction of the linear carboxylic acid ester is 32% to 68% based on the total mass of the electrolyte. [17] Battery cell according to one of claims 1 to 16, wherein the electrolyte further comprises a first lithium salt additive, wherein the first lithium salt additive comprises at least one of fluorine-containing borate and fluorine-containing phosphate, wherein the mass fraction of the first lithium salt additive is 0.05% to 0.5% based on the total mass of the electrolyte. [18] Battery cell according to claim 17, wherein the first lithium salt additive comprises at least one of lithium difluorophosphate, lithium difluoro(oxalato)phosphate, lithium difluoro(oxalato)borate and lithium tetrafluoroborate. [19] Battery cell according to claim 17, wherein the mass fraction of the first lithium salt additive is 0.1% to 0.3% based on the total mass of the electrolyte. [20] Battery cell according to one of claims 1 to 19, wherein the organic solvent further comprises a second solvent, the second solvent comprising at least one of ethylene dicarbonate, propylene dicarbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate and butylene carbonate. [21] Battery cell according to claim 20, wherein the second solvent comprises diethyl carbonate, wherein the mass fraction of the diethyl carbonate is greater than or equal to 12% based on the total mass of the electrolyte. [22] Battery cell according to one of claims 1 to 21, wherein the electrolyte further comprises a non-lithium salt additive, the non-lithium salt additive comprising a sulfate additive and a carbonate additive. [23] Battery cell according to claim 22, wherein the carbonate additive comprises at least one of vinylene carbonate, fluoroethylene carbonate and ethyl vinylene carbonate. [24] Battery cell according to claim 23, wherein the mass fraction of vinylene carbonate is 0.5% to 2.5% and / or the mass fraction of fluoroethylene carbonate is 0.05% to 2% based on the total mass of the electrolyte. [25] Battery cell according to claim 22, wherein the sulfate additive comprises at least one of 4,4-ethylene sulfate, bis(ethylene sulfate), vinylcyclotrisulfate and 1,3-propanesultone. [26] Battery cell according to one of claims 22 to 25, wherein the mass fraction of the non-lithium salt additive is 0.05% to 3% based on the total mass of the electrolyte. [27] Battery cell according to one of claims 1 to 26, wherein the electrolyte further comprises a second lithium salt additive, the second lithium salt additive comprising at least one of lithium bis(oxalato)borate, lithium difluorobisoxalatophosphate, lithium tetrafluoro(oxalato)phosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethylsulfonyl)imide, lithium trifluoromethanesulfonate and lithium perchlorate. [28] Battery cell according to any one of claims 1 to 27, wherein the electrolyte further comprises an electrolyte lithium salt, wherein the electrolyte lithium salt comprises at least one of lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass fraction of the electrolyte lithium salt is greater than or equal to 13% in relation to the total mass of the electrolyte. [29] Battery cell according to claim 28, wherein the electrolyte lithium salt comprises lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, wherein the mass ratio of lithium hexafluorophosphate to lithium bis(fluorosulfonyl)imide in the electrolyte is (1,2-2) :

1. [30] Battery cell according to one of claims 1 to 29, wherein the density of the positive electrode active material layer is 2.2 g / cm³ 3 up to 2.6 g / cm³ 3 amounts. [31] Battery cell according to any one of claims 1 to 30, wherein the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises: a core section, wherein the core section comprises a lithium-containing phosphate with an olivine structure, and a coating layer, wherein the coating layer coats the surface of the lithium-containing phosphate with an olivine structure and the coating layer contains one or more of C, Fe, Ti, Zr, Hf, Ge and Sn. [32] Battery cell according to claim 31, wherein the lithium-containing phosphate with olivine structure is a compound with the general formula of Li x1 A y1 Me a M1 b P 1-c X c Y z includes, where 0.5 ≤ x1 ≤ 1.3, 0 ≤ y1 ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5, where A comprises one or more of Na, K and Mg, Me comprises one or more of Mn, Fe, Co and Ni, M1 comprises one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La and Ce, X comprises one or more of S, Si, Cl, B, C and N, and Y comprises one or more of O and F. [33] Battery cell according to claim 31 or 32, wherein the coating layer comprises a carbon layer, wherein the degree of graphitization of the carbon layer is 0.15 to 0.

32. [34] Battery cell according to one of claims 31 to 33, wherein the positive electrode active material in a cross-section of the positive electrode active material layer along the thickness direction comprises a lithium-containing phosphate with olivine structure having a longest diameter of 1 µm to 3 µm and a lithium-containing phosphate with olivine structure having a shortest diameter of 0.1 µm to 0.3 µm. [35] Battery cell according to any one of claims 31 to 34, wherein the positive electrode active material meets at least one of the following conditions, that the particle size Dv50 of the positive electrode active material is 1 µm to 5 µm; that the particle size Dv10 of the positive electrode active material is 0.4 µm to 0.7 µm; that the positive electrode active material is primary particles or single-crystal-like particles. [36] Battery cell according to one of claims 31 to 35, wherein the positive electrode active material layer further comprises a lithium-rich material, wherein the lithium-rich material comprises at least one of lithium ferrite, lithium nickelate, lithium nickel copperate, lithium phosphate, dilithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate and lithium nickel cobalt manganese oxide. [37] Battery cell according to any one of claims 1 to 36, wherein the length of the battery cell is L and the width of the battery cell is H, wherein the value of L is 4 to 10 times the value of H. [38] Battery cell according to claim 37, wherein the value of L is 4 to 7 times the value of H. [39] Battery cell according to claim 37 or 38, wherein L is 400 mm to 1,000 mm and / or H is 80 mm to 160 mm. [40] Battery cell according to any one of claims 1 to 39, further comprising a housing body, wherein the electrode arrangement is located in the housing body and the housing body comprises two first housing walls arranged opposite each other and a surrounding wall connecting the two first housing walls, wherein the surrounding wall comprises: two second housing walls arranged opposite each other along the longitudinal direction of the first housing wall, two third housing walls arranged opposite each other along the transverse direction of the first housing wall, wherein the second housing wall is provided with an electrode terminal, wherein the positive electrode tab section and the negative electrode tab section are each electrically connected to the electrode terminals on the two second housing walls, wherein between the second housing wall,which is electrically connected to the positive electrode tab section, and a retraction structure is provided to the positive electrode main body section, wherein the retraction structure is configured to retract several of the positive electrode tab sections. [41] Battery cell according to claim 40, wherein a chamfer is provided on the edge of the positive electrode sheet in the longitudinal direction of the first housing wall. [42] Battery cell according to claim 40 or 41, wherein the second housing wall, which is connected to the negative electrode tab section, is provided with a liquid injection hole. [43] Battery cell according to claim 42, wherein the liquid injection hole and a pressure relief section of the housing body are located on different second housing walls, the pressure relief section being configured to be able to release the pressure inside the housing body. [44] Battery cell according to one of claims 40 to 43, wherein at least one mounting hole is provided at the electrode connection, wherein an electrode column is guided through the mounting hole and riveted to the electrode tab section. [45] Battery cell according to one of claims 40 to 43, wherein at least two mounting holes are provided at the electrode connection, wherein each electrode column is guided through the mounting hole and riveted to the electrode tab section. [46] Battery cell according to claim 44 or 45, wherein the diameter of the electrode column is 3 mm to 8 mm. [47] Battery cell according to claim 44 or 45, wherein the electrode column riveted to the positive electrode tab section and the electrode column riveted to the negative electrode tab are arranged offset in the longitudinal direction of the first housing wall, optionally the electrode column riveted to the positive electrode tab and the electrode column riveted to the negative electrode tab are arranged diagonally in the longitudinal direction of the first housing wall. [48] ​​Battery cell according to claim 44 or 45, wherein the electrode column and the electrode tab are electrically connected via a transfer plate. [49] Battery cell according to claim 44 or 45, wherein the electrode column and the electrode tab are directly electrically connected. [50] Battery cell according to claim 40, wherein the distance between the two first housing walls is D, where D is less than or equal to 30 mm. [51] Battery cell according to claim 50, wherein D is 10 mm to 25 mm. [52] Battery cell according to claim 40, wherein the thickness of the first housing wall and the third housing wall is each independently less than or equal to 0.5 mm. [53] Battery cell according to claim 52, wherein the first housing wall and the third housing wall comprise at least one of aluminum housing and steel housing. [54] Battery cell according to claim 53, wherein the first housing wall and the third housing wall are steel housings, wherein the wall thickness of the steel housing is 0.1 mm to 0.5 mm. [55] Battery cell according to claim 53, wherein the first housing wall and the third housing wall are aluminum housings, wherein the wall thickness of the aluminum housing is 0.3 mm to 0.4 mm. [56] Battery cell according to claim 55, wherein the first housing wall and the third housing wall are obtained by bending and welding aluminium plates, the weld being located at the connection between the first housing wall and the third housing wall. [57] Battery cell according to claim 40, wherein a lateral retaining plate is provided between the electrode arrangement and the first housing wall. [58] Battery cell according to claim 40, wherein at least one of the second housing walls is provided with a pressure relief section, wherein the pressure relief section is configured to be able to release the pressure inside the housing body, and the area of ​​a positive projection of the pressure relief section on the second housing wall is 7% to 15% of the area of ​​the second housing wall. [59] Battery cell according to claim 58, wherein the capacity of the battery is Q, wherein the ratio of the area of ​​the positive projection of the pressure relief section on the second housing wall to Q is greater than or equal to 1.1, wherein the unit of Q is Ah and the unit of the area is mm 2 is. [60] Battery device, comprising a battery cell according to any one of claims 1 to 59, wherein the battery device comprises at least one of a battery module, a battery pack and an energy storage device. [61] Power-consuming device comprising a battery cell according to any one of claims 1 to 59.

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